JP4841630B2 - Mobile communication system and mobile terminal - Google Patents

Description

  In the present invention, the base station can control the transmission rate, transmission power (transmission permission power, transmission permission maximum power), transmission timing, use frequency, and the like of a plurality of mobile terminals. The present invention relates to a mobile communication system that performs wireless communication and a mobile terminal that constitutes the mobile communication system.

In recent mobile communication systems, the main data communication system is changing from a circuit switching system to a packet communication system.
The packet communication method is generally based on a constant connection, but a mobile terminal of a mobile communication system has a limited battery capacity that can be carried.
Therefore, in the mobile communication system, when adopting the packet communication method (always connected), it is necessary to realize low power consumption of the mobile terminal.

There are 3GPP (3 ^rd Generation Partnership Project) as the standardization organization for mobile communication systems.
Currently, in 3GPP, discussions on the next version of the mobile communication system, UTRAN system (Release 7) and Evolved RAN system (E-UTRAN, LTE: Long Term Evolution), are underway. Discussions are underway to reduce power consumption in the system.
In the discussion, in a mobile terminal using a packet communication method, there is a possibility that no transmission / reception data exists even when a wireless section is connected. It has been decided to establish a new supported operation.

In the LTE system, the state 1 “Idle” inactive at the RRC level and the state 2 “Active (broadly defined)” in the active state are defined. As shown in FIG. 13, a new state 2-A “Active” and a state 2-B “DRX / DTX operation period during Active” are introduced in “Active”. It is disclosed.
Also, in the following Non-Patent Document 2, a DRX / DTX period (DRX / DTX period) is provided in RRC_Connected (corresponding to state 2 in FIG. 13) in order to realize low power consumption of the mobile terminal. It is stated that it is possible.

State 1 in FIG. 13 is called “Idle”, “LTE_Idle”, “RRC_Idle”, “NAS_Idle”, etc., and the mobile terminal in State 1 in FIG. 13 is set by NAS (Non-Access Stratum). The reception operation is performed in a DRX cycle (a cycle different from the DRX cycle in the DRX / DTX operation period (state 2-B in FIG. 13) during Active). That is, the paging operation is performed.
State 2 in FIG. 13 is referred to as “Active”, “LTE_Active”, “RRC_Active”, “RRC_Connected”, “Connected”, “NAS_Active”, and the like.

In addition, the state 2-A in FIG. 13 is referred to as “Active”, “MAC_Active”, or the like.
State 2-B in FIG. 13 includes “Dormant”, “MAC_Dormant”, “DRX / DTX period (DRX / DTX period)”, “DRX / DTX period during Active”, “DRX / DTX period during Connected”, etc. An operation for realizing low power consumption in an active mobile terminal is performed (for example, data (user data and control data) is temporarily stopped to be transmitted or received).

Non-Patent Document 3 below describes the period during which the DRX operation is performed and the period during which the DTX operation is performed in the active DRX / DTX operation period (state 2-B in FIG. 13). A technique signaled by Medium Access Control) is disclosed.
In Patent Document 1 below, although different from the DTX cycle in the DRX / DTX operation period during Active (state 2-B in FIG. 13), the cycle of CQI (Channel Quality Indicator) transmitted from the mobile terminal to the base station is described. A technique for switching between high speed and low speed depending on the presence or absence of downlink data transmission is disclosed. Thereby, the effective utilization of the uplink radio resource is achieved.

Non-Patent Document 4 below discloses a technique in which a mobile terminal confirms whether there is data addressed to itself in a DRX cycle in Active (state 2 in FIG. 13) using a downlink scheduling channel.
Non-Patent Document 6 below describes a DRX period notification method.
The DRX period notification method will be described with reference to FIG.
The control data (for example, L1 / L2 control signal etc.) accompanying the initial transmission data (user data) from the base station includes a DRX period.
If the mobile terminal fails to receive the initial transmission data transmitted from the base station, it transmits a HARQ Nack signal (negative acknowledgment signal) to the base station.
When receiving the Nack signal transmitted from the mobile terminal, the base station performs retransmission. The DRX period is not included in the control data accompanying this retransmission.
When the mobile terminal succeeds in receiving retransmission data transmitted from the base station, it transmits an HARQ Ack signal (acknowledgment signal) to the base station and starts a timer A.
When receiving the Ack signal transmitted from the mobile terminal, the base station starts timer A.
After the timer A expires, the mobile terminal and base station start DRX operation.

Non-Patent Document 8 below discloses a DRX operation when two DRX cycles are set.
The following Non-Patent Document 5 is different from the Non-Patent Documents 1 to 4 and Patent Document 1 described above, but is the operation of low power consumption performed by the mobile terminal capability information (UE Capabilities) indicating the capability of the mobile terminal? Techniques for determining whether or not are disclosed.

In addition, the control signal used to enable communication between the mobile terminal and the base station via the wireless link includes an upper layer signal such as an “L3 control signal” (Layer3 control signaling, L3 message), and There is a signal called “L1 / L2 control signal” (Layer1 / Layer2 control signaling).
The L3 control signal is a control signal that is mainly notified from an upper layer such as the RRC layer at the time of initial transmission including the time of call connection (RRC Connect) occurrence, and the uplink, downlink, and downlink via the downlink. Configure link channels and assign radio resources.
On the other hand, the L1 / L2 control signal is a control signal that is frequently exchanged between the mobile terminal and the base station in both uplink and downlink, and the mobile terminal allocates radio resources to the base station in the uplink. The L1 / L2 control signal is also used when the radio resource is changed irregularly according to the data size change or the communication channel quality requirement, including the uplink scheduling request signal for requesting or when the call connection is generated or continued. use.
In the L1 / L2 control signal, when the base station or mobile terminal receives data on the uplink or downlink, an Ack signal / Nack signal that responds to the other party as to whether or not the data has been received, and the received data Quality information CQI (Channel Quality Indicator) indicating quality or channel quality is also included.

The following Non-Patent Document 7, an uplink reference signal (Reference Signal) is demodulated (stands for demodulation) and synchronous detection (Detection) reference signal used for the reference signal used for quality measurement of uplink channel (Sounding Reference Signal) It is shown that there are two types of signals.
Here, the sounding reference signal (Sounding RS) is a signal transmitted from the mobile terminal (UE) to the base station (eNB) in order for the base station to measure uplink communication quality.

Non-Patent Document 9 below describes time division multiplexing (TDM) as a method of data transmission other than E-MBMS (Evolved Multimedia Broadcast Service) and non-E-MBMS (non-MBMS, non-EMBMS). ) Only is used. The unit of time division is a subframe unit.
E-MBMS is a multicast / broadcast multimedia service. Mass broadcast contents such as news, weather forecasts, and mobile broadcasts are transmitted to a plurality of mobile terminals.

The base station maps E-MBMS data to DL-SCH (Downlink Shared Channel) or MCH (Multicast Channel) and transmits the data to the mobile terminal.
Further, LTE provides not only broadcast communication services (other than E-MBMS (non-MBMS)) but also communication services for individual mobile terminals among a plurality of mobile terminals. A communication service for an individual mobile terminal is referred to as a Unicast service.
Non-Patent Document 10 below discloses that only the first one symbol or only the first two symbols in a subframe allocated to E-MBMS by time division multiplexing is used in the Unicast service.

However, Non-Patent Documents 1 to 3 and Patent Document 1 disclose specific examples for effectively realizing the low power consumption of the mobile terminal in the DRX / DTX operation period during Active (state 2-B in FIG. 13). The method is not disclosed.
That is, Non-Patent Documents 1 and 2 disclose that a new state (state 2-B in FIG. 13) for supporting low power consumption of the mobile terminal is disclosed, but DRX in the newly installed Active is disclosed. In the / DTX operation period (state 2-B in FIG. 13), a method for efficiently realizing the low power consumption of the mobile terminal is not disclosed.

In Non-Patent Document 3, as described above, in the DRX / DTX operation period during Active (state 2-B in FIG. 13), the period in which the DRX operation is performed and the period in which the DTX operation is performed are as follows: Although a technique signaled by the MAC of the base station is disclosed, a DRX / DTX cycle setting method for efficiently realizing low power consumption of the mobile terminal is not disclosed.
Also, the DRX period notification method of Non-Patent Document 6 is different from the DRX period notification method disclosed in the present invention.
Further, in the method of Non-Patent Document 6, every time the base station receives a Nack signal from a mobile terminal (“time (i)”, “time (ii)”, “time (iii)” shown in FIG. 14), the DRX operation is performed. There is a problem that scheduling for determining the start timing (DRX period end timing) must be performed, which increases the scheduling load. Therefore, it does not solve the problem of notifying the DRX period while reducing the scheduling load of the base station in the present invention, and there is no suggestion about this problem.

Further, in the DRX operation in which two DRX cycles disclosed in Non-Patent Document 8 are set, no consideration is given to the case where HARQ is applied.
Therefore, when the DRX cycle information is notified by the L1 / L2 control signal together with the initial transmission data, or is notified at the time of radio bearer setup as in the conventional method, retransmission by HARQ is performed in the DRX cycle. When the value exceeds the value, there is a problem that it is impossible to shift to the DRX operation.

Non-Patent Documents 9 and 10 describe nothing about DRX operation (DRX operation during Active).
It is not disclosed what information is notified in symbols usable for the Unicast service in the subframe allocated to E-MBMS.

  Patent Document 1 discloses a technique for switching a high speed / low speed depending on whether or not downlink data transmission is performed for a CQI cycle transmitted from a mobile terminal to a base station. There is no disclosure of signaling between stations. Note that the technique disclosed in Patent Document 1 is a technique before introducing a low power consumption operation in a mobile terminal in Active (state 2 in FIG. 13).

Next, as described above, Non-Patent Document 4 describes a technique in which a mobile terminal confirms whether or not data addressed to itself exists in a DRX cycle in Active (state 2 in FIG. 13) using a downlink scheduling channel. Is disclosed. In other words, there is a period in which the mobile terminal in the active DRX / DTX operation period (state 2-B in FIG. 13) cannot receive downlink data from the base station.
Therefore, even if the base station desires to transmit downlink data to the mobile terminal in the active DRX / DTX operation period (state 2-B in FIG. 13), the data is transmitted if it is not after a preset period. You can't do that.
For this reason, the throughput of the corresponding mobile terminal is lowered, and if it is desired to prioritize throughput over low power consumption, it cannot be realized.

The following Non-Patent Document 5 is a technique for determining whether or not to execute an operation with low power consumption based on mobile terminal capability information (UE Capabilities) so that it can be applied even when priority is given to throughput. Is disclosed.
However, in the current technology, the mobile terminal capability information (UE Capabilities) is a unique value for each mobile terminal.
Also, mobile terminal capability information (UE Capabilities) is notified from the mobile terminal to the network side at the time of RRC (Radio Resource Control) connection (at attach, at the time of transmission, at the time of location registration, etc.).
Therefore, in the current technology, a parameter indicating whether to prioritize the realization of low power consumption or the improvement of throughput is specific to each mobile terminal, and the timing that can be notified is limited. It is difficult to effectively realize low power consumption during the DRX / DTX operation period (state 2-B in FIG. 13).

3GPP standard document TR25.913 V7.2.0 3GPP standard document TR25.813 V0.9.0 3GPP contribution R2-060888 3GPP contribution R2-060591 3GPP contribution R2-060846 3GPP contribution R2-070279 3GPP standard document TR25.814 V7.0.0 3GPP contribution R2-070265 3GPP contribution R1-071245 3GPP contribution R2-070701 JP 2003-204298 A

  Since the conventional mobile communication system is configured as described above, state 2-B “active DRX / DTX operation period” in state 2 “Active (broadly defined)” active at the RRC level. Can be introduced. However, the method for efficiently realizing the low power consumption of the mobile terminal and the method for setting the DRX / DTX cycle are not stipulated, and there is a problem that the low power consumption of the mobile terminal cannot always be efficiently realized. there were.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a mobile communication system and a mobile terminal that can efficiently realize low power consumption of the mobile terminal.

In the mobile communication system according to the present invention, when the mobile terminal and the base station perform wireless communication, the mobile terminal measures the quality of the downlink communication path, and transmits the quality measurement result to the base station. In a mobile communication system that performs downlink scheduling according to a quality measurement result, the mobile terminal transmits a quality measurement result to the base station, and a timing to transmit an acknowledgment signal or a negative response signal to the base station. Are overlapped, an acknowledgment signal or a negative acknowledgment signal is transmitted without transmitting the quality measurement result .

  As a result, there is an effect that the power consumption of the mobile terminal can be efficiently realized.

1 is a configuration diagram showing a mobile communication system according to Embodiment 1 of the present invention. It is a block diagram which shows the mobile terminal of the mobile communication system by Embodiment 1 of this invention. It is a block diagram which shows the base station of the mobile communication system by Embodiment 1 of this invention. It is a sequence diagram which shows the processing content of the mobile communication system by Embodiment 1 of this invention. It is a flowchart which shows the processing content of step ST5 in the protocol process part 33. FIG. It is a sequence diagram which shows the processing content of the mobile communication system by Embodiment 2 of this invention. It is explanatory drawing which shows the example of determination of a DRX period and a DTX period. It is a sequence diagram which shows the processing content of the mobile communication system by Embodiment 3 of this invention. It is explanatory drawing which shows the example of mapping of a physical channel. It is a sequence diagram which shows the processing content of the mobile communication system by Embodiment 5 of this invention. It is a sequence diagram which shows the processing content of the mobile communication system by Embodiment 5 of this invention. It is explanatory drawing which shows an example of an indicator. It is explanatory drawing which shows the state transition of a mobile communication system. It is explanatory drawing of the method with which the base station shown by the nonpatent literature 6 notifies a DRX period to a mobile terminal. It is explanatory drawing of the term used by this invention. It is a sequence diagram which shows the processing content of the mobile communication system by Embodiment 1 of this invention. It is explanatory drawing which shows the example of determination of a DRX period and a DTX period. It is a sequence diagram which shows the processing content of the mobile communication system by Embodiment 2 of this invention. It is explanatory drawing which shows an example of the method of notifying a DRX period from a base station to a mobile terminal. It is a sequence diagram which shows an example of the processing content of a mobile terminal and a base station. It is explanatory drawing which shows an example of the method of notifying a DRX period from a base station to a mobile terminal when a DTX period and a DRX period are set equal. It is explanatory drawing which shows the example of a timing in case the DRX period corresponding to several radio bearers is set in parallel in the downlink. It is explanatory drawing which shows an example of the method of notifying a DTX period from a base station to a mobile terminal in case there exists uplink data. It is explanatory drawing which shows an example in the case of setting it as a sounding signal as an upstream transmission signal when there is no upstream data. It is explanatory drawing which shows the parameter of the time from the reception timing of a received signal to the transmission timing after DTX operation | movement. It is explanatory drawing which shows an example of the method of notifying a DRX period and a DTX period from a base station to a mobile terminal about the case where there exists data transmission in a downlink and an uplink, respectively, and a DRX period and a DTX period are made the same. It is a sequence diagram which shows the flow of DRX control of the mobile communication system by Embodiment 8 of this invention. It is a sequence diagram which shows the flow of DTX control of the mobile communication system by Embodiment 8 of this invention. It is a flowchart figure which shows the processing flow of the DRX / DTX period setting method in DTX control of a mobile communication system by Embodiment 8 of this invention, and DRX control. It is explanatory drawing which shows the actual operation example of DRX control in the downlink data transmission at the time of the HARQ mode by Embodiment 8 of this invention. It is explanatory drawing which shows the actual operation example of DTX control in the uplink data transmission at the time of the HARQ mode by Embodiment 8 of this invention. It is explanatory drawing which shows the actual operation example of DTX control when two types of data and control signals from which a DTX period differs are generated in the uplink data transmission at the HARQ mode by Embodiment 8 of this invention. In downlink data transmission in the HARQ mode according to the eighth embodiment of the present invention, it is an explanatory diagram showing an actual operation example of DRX control when data having a different DRX cycle is newly generated during sleep in the DRX period. It is explanatory drawing which shows the case where two DRX periods shown by the nonpatent literature 8 are set. When two DRX cycles are set, the method disclosed in the seventh embodiment is applied to the setting of the DRX cycle [2], and the setting of the DRX cycle [1] is disclosed in the eighth embodiment. It is explanatory drawing which applies a method. FIG. 10 is a sequence diagram of a mobile terminal and a base station in a method combining the method disclosed in Embodiment 7 and a conventional method according to the magnitude relationship between the required time according to the maximum number of HARQ (MAX) retransmissions and the DRX cycle. It is explanatory drawing which shows an example when the timing which transmits an upstream Ack signal / Nack signal, and CQI transmission timing overlap. It is explanatory drawing which shows an example when the timing which transmits an upstream Ack signal / Nack signal, and CQI transmission timing overlap. It is explanatory drawing which shows an example of the DRX operation | movement method in the mobile communication system by Embodiment 12 of this invention. It is a sequence diagram which shows an example of the processing content of the mobile terminal and base station by Embodiment 12 of this invention. It is explanatory drawing which shows an example of the DRX operation | movement method in the mobile communication system by the modification 1 of Embodiment 12 of this invention. It is a sequence diagram which shows an example of the processing content of the mobile terminal and base station by the modification 1 of Embodiment 12 of this invention. It is explanatory drawing which shows an example of the DRX operation | movement method in the mobile communication system by the modification 2 of Embodiment 12 of this invention. It is a sequence diagram which shows an example of the processing content of the mobile terminal and base station by the modification 2 of Embodiment 12 of this invention. It is explanatory drawing which shows an example of the DRX operation | movement method in the mobile communication system by the modification 3 of Embodiment 12 of this invention. It is explanatory drawing which shows an example of the relationship between QoS of a service, and an initial DRX cycle. It is explanatory drawing which shows the example of allocation of radio | wireless resources other than E-MBMS and E-MBMS. It is explanatory drawing which shows the example of allocation of the radio | wireless resource in the sub-frame allocated to E-MBMS. It is explanatory drawing which shows an example of the DRX operation | movement method in the mobile communication system for demonstrating the subject of Embodiment 13 of this invention. It is explanatory drawing which shows an example of the operation | movement of E-MBMS and the DRX operation | movement method in the mobile communication system by Embodiment 13 of this invention. It is a sequence diagram which shows an example of the processing content of the mobile terminal and base station by Embodiment 13 of this invention. It is a sequence diagram which shows an example of the processing content of the mobile terminal by the modification 1 of Embodiment 13 of this invention, and a base station. It is explanatory drawing which shows an example of the DRX operation | movement method in the mobile communication system for demonstrating the subject of Embodiment 14 of this invention. It is explanatory drawing which shows an example of the DRX operation | movement method in the mobile communication system by Embodiment 14 of this invention. It is a sequence diagram which shows an example of the processing content of the mobile terminal and base station by Embodiment 14 of this invention.

Hereinafter, in order to describe the present invention in more detail, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.
Hereinafter, the LTE system will be described. However, the mobile communication system in which the uplink and downlink schedulers control and indicate the transmission rate, transmission power (transmission permission power, transmission permission maximum power), transmission timing, use frequency, use frequency width, etc. to each mobile terminal (for example, In the UTRAN system, the present invention is applicable.
Embodiment 1 FIG.
1 is a block diagram showing a mobile communication system according to Embodiment 1 of the present invention.
The mobile communication system in FIG. 1 is an LTE system, in which an uplink scheduler and a downlink scheduler of a base station have transmission rates, transmission powers (transmission permission power, transmission permission maximum power), transmission timings, use frequencies, It controls the width of the frequency used.
Further, in the mobile communication system of FIG. 1, transport channels (Transport Channels) for communication between a mobile terminal and a base station will be described. However, since the transport channel is under discussion, the name and definition may be changed in the future, but it goes without saying that the present invention is applicable even when the name and definition are changed.

In the present invention, state 2-B in FIG. 13 is referred to as “active DRX / DTX operation period”, but the period in which both the active DRX operation period and the active DTX operation period overlap is in the active state. This will be described as a DRX / DTX operation period (state 2-B in FIG. 13).
The DRX operation period during Active is described as a period in which a reception operation for a certain period of time and an operation that does not perform reception for a certain period of time are repeated in the DRX cycle during Active (see FIG. 15). There is also an active DRX operation period in which the number of repetitions of the DRX cycle is one.
A period during which the DRX operation period is active and no reception is performed will be described as a DRX period (DRX period) and a DRX interval (DRX interval) (see FIG. 15).
In addition, the portion excluding the DRX period during the DRX operation period will be described as Active during the DRX operation period (see FIG. 15).
As an example of the reception operation performed by the mobile terminal 3 in the DRX operation period during the DRX cycle, the following reception operations (1) to (8) are conceivable.
(1) Data receiving operation for confirming whether there is data destined for the mobile terminal 3 using the downlink scheduling channel (2) Monitoring operation for downlink L1 / L2 control signal (3) Measurement operation (peripheral cell measurement, Measurement of own cell etc.)
(4) User data (Traffic data) reception operation (5) Uplink timing information (Timing information, Timing Advance (TA)) reception operation (6) Downlink reference signal reception operation (7) HARQ-compatible Ack for upstream data Signal / Nack Signal Reception Operation (8) Combined Operation of (1) to (7) However, the combined operation of (1) to (7) in (8) may be continuous in time or discontinuous.

Hereinafter, HARQ (Hybrid Automatic Repeat Request) will be described.
A case where HARQ is applied to transmission data from a base station to a mobile terminal will be described.
When the mobile terminal receives data from the base station, the mobile terminal performs error detection processing on the data. As a response signal to the base station, the mobile terminal transmits an Ack signal when no error is detected by the error detection process, and transmits a Nack signal when an error is detected by the error detection process.
When receiving the Ack signal from the mobile terminal, the base station transmits new data to the mobile terminal. When receiving the Nack signal from the mobile terminal, the base station retransmits the same data to the mobile terminal.
HARQ can also be applied to transmission data from a mobile terminal to a base station, as described above.

The active DTX operation period is described as a period in which a transmission operation for a certain period of time and an operation in which transmission for a certain period of time is not performed are repeated in the DTX cycle during the active period (see FIG. 15). There is also an active DTX operation period in which the number of repetitions of the DTX cycle is one. A period in which the transmission is not performed during Active during the DTX operation period will be described as a DTX period (DTX Period) and a DTX interval (DTX Interval) (see FIG. 15).
Further, a portion during the DTX operation period and excluding the DTX period will be described as Active during the DTX operation period (see FIG. 15).

As an example of the transmission operation performed by the mobile terminal 3 during the DTX operation period in the DTX cycle, the following transmission operations (1) to (9) are conceivable.
(1) transmit operation (2) demodulating (stands for demodulation) and the synchronous detection operation of transmitting a reference signal used in (Detection) (3) reference signal quality measurement object of up channel information used for downlink scheduling (e.g. CQI) (Sounding (Reference Signal) transmission operation (4) Uplink scheduling request transmission operation (5) User data (Traffic data) transmission operation (6) Transmission operation for measuring uplink timing by base station (for example, Sounding Reference Signal, CQI) , RACH transmission, etc. can be considered.)
(7) HARQ-compatible Ack / Nack signal transmission operation for downlink data (8) L1 / L2 control signal transmission operation (9) Combination operation of (1) to (8) (1) in (9) ) To (8) may be continuous or discontinuous in time.

The present invention is applicable even when the definition of the words described above is changed.
For example, as a transmission operation performed by the mobile terminal 3 in the DTX cycle, (3) a reference signal (Sounding Reference Signal) for the purpose of measuring the quality of the uplink channel is transmitted, or (6) by the base station As a transmission operation for performing uplink timing measurement, when a Sounding Reference Signal is transmitted, the DTX cycle may be called a Sounding Reference Signal transmission cycle. Even in that case, the present invention is applicable.
Further, for example, as a transmission operation performed by the mobile terminal 3 in the DTX cycle, (1) when information used for downlink scheduling (for example, CQI) is transmitted, or (6) uplink timing by the base station As a transmission operation for performing measurement, when CQI is transmitted, it is conceivable that the DTX cycle is called a CQI transmission cycle. Even in that case, the present invention is applicable.

Further, the period during which the DRX operation period during Active, the DTX operation period during Active, or the DRX operation period during Active or the DTX operation period is performed is also applicable as State 2-B in FIG. is there.
In the future discussion, the number of states and the definition of each state may be changed, but it goes without saying that the present invention is applicable even when the number of states and the definition of each state are changed. Yes.

In FIG. 1, a base station control apparatus 1 has a plurality of base stations 2 under its control, and transmits / receives control data and user data to / from a plurality of base stations 2 under its control. The base station control device 1 is referred to as aGW or RNC.
The base station 2 has a plurality of mobile terminals 3 under its umbrella and performs wireless communication with the mobile terminals 3 under its control. That is, the base station 2 has uplink and downlink schedulers, which enable data transmission / reception between the base station 2 and the mobile terminal 3 to improve throughput of the individual mobile terminals 3 and the entire mobile communication system. Scheduling for that. Scheduling means that the uplink and downlink schedulers control and instruct each mobile terminal on the transmission rate, transmission power (transmission permission power, transmission permission maximum power), transmission timing, usage frequency, usage frequency width, and the like.
Also, retransmission control of data (control data, user data) using HARQ (Hybrid Automatic Repeat Request) is performed. Note that the base station 2 is referred to as a NodeB, an E-UTRAN NodeB (E-NodeB, eNB), or the like.
The mobile terminal 3 performs wireless communication with the base station 2. The mobile terminal 3 is referred to as a mobile station, UE (User Equipment), MS (Mobile Station), or the like.

Here, a transport channel in which the base station 2 and the mobile terminal 3 communicate will be described.
BCH (Broadcast Channel) is a channel through which the base station 2 transmits broadcast information to the mobile terminal 3 being served by the base station 2.
DL-SCH (Downlink Shared Channel) is a shared channel (Shared Channel) through which the base station 2 transmits control data and user data to the mobile terminal 3 being served by the base station 2.

The PCH (Paging Channel) is a movement by the DRX cycle of the mobile terminal 3 set by the network by the base station 2 (a cycle different from the DRX cycle in the active DRX / DTX operation period (state 2-B in FIG. 13)). This channel supports discontinuous reception (intermittent reception) of the terminal 3.
UL-SCH (Uplink Shared Channel) is a shared channel through which the mobile terminal 3 transmits control data and user data to the base station 2.
RACH (Random Access Channel) is a channel that is randomly transmitted from the mobile terminal 3 to the base station 2.
It is considered that a plurality of base stations 2 communicate data with each other.

FIG. 2 is a block diagram showing a mobile terminal of the mobile communication system according to Embodiment 1 of the present invention.
The protocol processing unit 11 outputs control data addressed to the base station 2 or the base station control device 1 to the transmission data buffer unit 13, collects control data transmitted from the base station 2, and performs protocol processing using the control data And so on.
The application unit 12 outputs user data to the transmission data buffer unit 13, collects user data transmitted from the base station 2, and performs processing for converting the user data into a form used by the user.

The transmission data buffer unit 13 temporarily stores the control data output from the protocol processing unit 11 and the user data output from the application unit 12, and uses the sleep request signal generated by the sleep request signal generation unit 20 as control data. As a temporary storage.
The encoder unit 14 performs encoding processing such as error correction processing on the control data and user data stored in the transmission data buffer unit 13.
The encoder unit 14 may output the control data and user data to the modulation unit 15 without performing the encoding process on the control data and user data stored in the transmission data buffer unit 13.

The modulation unit 15 modulates the control data and user data output from the encoder unit 14 and performs a process of outputting the modulated control data and user data to the antenna 16.
The antenna 16 transmits the data modulated by the modulator 15 to the base station 2 as a radio signal, receives the radio signal transmitted from the base station 2, and outputs the radio signal to the demodulator 17.

The demodulator 17 performs a demodulation process on the radio signal output from the antenna 16, and performs a process of outputting the demodulated control data and user data to the decoder unit 18.
The decoder unit 18 performs decoding processing such as error correction on the demodulated control data and user data by the demodulating unit 17, and transmits the decoded control data to the protocol processing unit 11, the DTX cycle storage unit 21, and the DRX cycle storage unit 22. And the decoded user data is output to the application unit 12.

That is, the decoder unit 18 determines whether or not it is possible to shift to the active DRX operation period, which is a temporary data reception stop period, of the decoded control data. Is output to the protocol processing unit 11, DTX cycle information (supply stop cycle information) indicating the DTX cycle set by the base station 2 is output to the DTX cycle storage unit 21, and indicates the DRX cycle set by the base station 2 The DRX cycle information (supply stop cycle information) is output to the DRX cycle storage unit 22.
However, the decoder unit 18 may output the control data and user data to the protocol processing unit 11 and the application unit 12 without performing the decoding process on the control data and user data after demodulation by the demodulation unit 17. .
Note that the antenna 16, the demodulator 17, the decoder 18, and the protocol processor 11 constitute a determination result receiving unit by the base station 2.

For example, the DTX determination unit 19 checks whether or not the data to be transmitted to the base station 2 is stored in the transmission data buffer unit 13. If the data to be transmitted to the base station 2 is not stored, the DTX determination unit 19 temporarily transmits the data. It is determined that it is possible to shift to the active DTX operation period which is the stop period. The DTX determination unit 19 constitutes a shift determination unit.
When the determination result of the DTX determination unit 19 indicates that the sleep request signal generation unit 20 can shift to the active DTX operation period, the sleep request signal generation unit 20 generates a sleep request signal under the instruction of the protocol processing unit 11, A process of outputting the sleep request signal to the transmission data buffer unit 13 as control data is performed.

The DTX cycle storage unit 21 is a memory that stores DTX cycle information (supply stop cycle information) indicating the DTX cycle set by the base station 2 among the control data decoded by the decoder unit 18.
The DRX cycle storage unit 22 is a memory that stores DRX cycle information (supply stop cycle information) indicating the DRX cycle set by the base station 2 among the control data decoded by the decoder unit 18.
The DTX determination unit 19 may be included in the transmission data buffer unit 13. Further, the DTX determination unit 19, the sleep request signal generation unit 20, the DTX cycle storage unit 21, and the DRX cycle storage unit 22 may each be included in the protocol processing unit 11.

The control unit 23 controls all the processing units constituting the mobile terminal 3. For example, the control unit 23 indicates that the determination result of the DTX determination unit 19 can shift to the active DTX operation period, and the protocol processing unit 11 can shift to the active DRX operation period. When the determination result of the base station 2 indicating that it is possible is acquired, the data transmission processing unit according to the DTX cycle information stored in the DTX cycle storage unit 21 and the DRX cycle information stored in the DRX cycle storage unit 22 (For example, the encoder unit 14 and the modulation unit 15) and a process of temporarily stopping the supply of power to the reception processing unit (for example, the demodulation unit 17 and the decoder unit 18) are performed.
The DTX cycle storage unit 21, the DRX cycle storage unit 22, and the control unit 23 constitute a power supply stop unit.

Although the control unit 23 temporarily stops supplying power to the transmission processing unit and the reception processing unit, the protocol processing unit 11 temporarily supplies power to the transmission processing unit and the reception processing unit. You may make it stop.
In the first embodiment, a description will be given of a case where the control unit 23 temporarily stops the supply of power to the encoder unit 14, the modulation unit 15, the demodulation unit 17, and the decoder unit 18. For example, power supply to the protocol processing unit 11, the application unit 12, the transmission data buffer unit 13, the DTX determination unit 19, the sleep request signal generation unit 20, the DTX cycle storage unit 21, the DRX cycle storage unit 22, etc. May be temporarily stopped.

FIG. 3 is a block diagram showing a base station of the mobile communication system according to Embodiment 1 of the present invention.
The aGW communication unit 31 performs data transmission / reception with the base station control device 1 and performs processing for outputting user data and control data transmitted from the base station control device 1 to the transmission data buffer unit 34.
The other base station communication unit 32 performs data transmission / reception with the other base station 2 and performs processing for outputting user data and control data transmitted from the other base station 2 to the transmission data buffer unit 34.
The protocol processing unit 33 exchanges information with the aGW communication unit 31 and the other base station communication unit 32, and also outputs control data addressed to the mobile terminal 3 to the transmission data buffer unit 34 and the control transmitted from the mobile terminal 3. Data is collected and protocol processing is performed using the control data.

The transmission data buffer unit 34 is a memory that temporarily stores control data output from the protocol processing unit 33 and user data output from the aGW communication unit 31 and the other base station communication unit 32.
The encoder unit 35 performs encoding processing such as error correction processing on the control data and user data stored in the transmission data buffer unit 34.
The encoder unit 35 may output the control data and user data to the modulation unit 36 without performing the encoding process on the control data and user data stored in the transmission data buffer unit 34.

The modulation unit 36 modulates the control data and user data output from the encoder unit 35, and performs a process of outputting the modulated control data and user data to the antenna 37.
The antenna 37 transmits the data modulated by the modulation unit 36 as a radio signal to the mobile terminal 3, receives the radio signal transmitted from the mobile terminal 3, and outputs the radio signal to the demodulation unit 38.

The demodulator 38 performs a demodulation process on the radio signal output from the antenna 37, and performs a process of outputting the demodulated control data and user data to the decoder unit 39.
The decoder unit 39 performs decoding processing such as error correction on the demodulated control data and user data by the demodulating unit 38, and the decoded control data is transmitted to the aGW communication unit 31, the other base station communication unit 32, and the protocol processing unit 33. The sleep request signal determination unit 40, the downlink scheduler unit 42, and the uplink scheduler unit 43 output the decoded user data to the aGW communication unit 31 and the other base station communication unit 32.
However, the decoder unit 39 does not perform decoding processing on the control data and user data after demodulation by the demodulating unit 38, and outputs the control data and user data to the protocol processing unit 33, the aGW communication unit 31, and the like. Good.

The sleep request signal determination unit 40 determines whether or not the sleep request signal is included in the control data output from the decoder unit 39, and outputs the determination result to the protocol processing unit 33.
When the determination result of the sleep request signal determination unit 40 indicates that the sleep request signal is included, the protocol processing unit 33 stores, for example, data to be transmitted to the mobile terminal 3 in the transmission data buffer unit 34. If the data to be transmitted to the mobile terminal 3 is not stored, the mobile terminal 3 can shift to the active DRX operation period, which is a temporary data reception stop period. Judgment is made.
Here, the protocol processing unit 33 determines whether or not the mobile terminal 3 can shift to the DRX operation period in which the mobile terminal 3 is active, but this determination determines whether or not the base station 2 can shift to the DTX operation period in which the mobile terminal 3 is active. Is equivalent to determining whether or not.
When the protocol processing unit 33 determines that the mobile terminal 3 can shift to the active DRX operation period, the protocol processing unit 33 outputs the determination result to the transmission data buffer unit 34 as control data.

The QoS storage unit 41 is a memory or the like that stores QoS, which is quality information of a service that is being transmitted / received between the base station 2 and the mobile terminal 3 being served by the base station 2.
The downlink scheduler unit 42 performs downlink scheduling for the mobile terminal 3 being served by the base station 2 under the instruction of the protocol processing unit 33.
The uplink scheduler unit 43 performs uplink scheduling for the mobile terminal 3 being served by the base station 2 under the instruction of the protocol processing unit 33.
The control unit 44 controls all the processing units constituting the base station 2.
FIG. 4 is a sequence diagram showing processing contents of the mobile communication system according to Embodiment 1 of the present invention.

Next, the operation will be described.
When the state of the mobile terminal 3 is in the state 2 “Active (broad sense)” in FIG. 13, the DTX determination unit 19 of the mobile terminal 3 determines whether or not it is possible to shift to the active DTX operation period. (Step ST1).
That is, the DTX determination unit 19 determines whether or not the mobile terminal 3 can perform the active DTX operation.

Here, as an example of the DTX operation, information (for example, CQI) used by the mobile terminal 3 for uplink user data and downlink scheduling, and a pilot signal (a signal used for uplink data synchronous detection compensation, uplink data phase compensation, etc.) ) And an operation (DTX: Discontinuous Transmission) that does not transmit a reference signal (Sounding Reference Signal) for the purpose of measuring the quality of the uplink channel.
Alternatively, the DTX operation may be performed during the following periods (1) to (8) and combinations thereof.
(1) Information used for downlink scheduling (CQI, etc.) is not transmitted (2) Pilot signal is not transmitted (3) Reference signal (Sounding Reference Signal) for uplink channel quality measurement is not transmitted (4) Uplink scheduling request (5) Do not transmit uplink user data (6) Do not transmit for performing uplink timing measurement by the base station (7) Do not transmit HARQ-compatible Ack / Nack signals for downlink data (8) L1 / Do not send L2 control signal

The determination of whether or not the DTX determination unit 19 can perform the DTX operation is performed by, for example, confirming the presence or absence of data in the transmission data buffer unit 13.
Specifically, when there is no data in the transmission data buffer unit 13, it is determined that the DTX operation can be performed, and when there is data, it is determined that the DTX operation cannot be performed.
The DTX determination unit 19 outputs a determination result as to whether or not the DTX operation can be performed to the protocol processing unit 11.

  The sleep request signal generation unit 20 of the mobile terminal 3 can shift to the DTX operation period during Active when the determination result of the DTX determination unit 19 indicates that the DTX operation can be performed. In the case of indicating that, a sleep request signal is generated under the instruction of the protocol processing unit 11, and the sleep request signal is output to the transmission data buffer unit 13 as control data.

Here, the sleep request signal is a signal having all of the following meanings (1) to (5), or a signal having any one of the meanings (1) to (5) and a combination thereof.
(1) This means that the mobile terminal 3 starts an active DTX operation period. (2) There is no data to be transmitted in the transmission data buffer unit 13 of the mobile terminal 3, or there is no data to be transmitted immediately. (3) Means that the base station 2 is requested to match the DRX cycle and the DTX cycle in the state 2 “Active (broad definition)” in FIG. 13 (4) During the DRX / DTX operation period during the Active (5) Means requesting transition to state 2-B in FIG. 13 Means requesting start of DRX operation period during Active Note that the sleep request signal is the above (1) to All of the meanings of (5), combinations, or any one of the meanings of (1) to (5) may be notified to the base station 2 and propagated.

When the sleep request signal generation unit 20 stores the control data (Sleep request signal) in the transmission data buffer unit 13, the encoder unit 14 of the mobile terminal 3 controls the control data (Sleep request signal) stored in the transmission data buffer unit 13. Perform the encoding process for.
When the encoder unit 14 performs the encoding process, the modulation unit 15 of the mobile terminal 3 modulates the control data (Sleep request signal) after the encoding process, and outputs the control data after the modulation (Sleep request signal) to the antenna 16. .

The antenna 16 of the mobile terminal 3 transmits control data (Sleep request signal) modulated by the modulation unit 15 to the base station 2 as a radio signal (step ST2).
Here, the mobile terminal 3 transmits control data (Sleep request signal) to the base station 2 as a radio signal. However, as a method of notifying the Sleep request signal, in addition to mapping to a physical channel, MAC signaling There is a method of mapping to a MAC header or the like.

When receiving the radio signal transmitted from the mobile terminal 3, the antenna 37 of the base station 2 outputs the radio signal to the demodulator 38 (step ST3).
When receiving the radio signal from the antenna 37, the demodulator 38 of the base station 2 performs demodulation processing on the radio signal and outputs the demodulated control data (Sleep request signal) to the decoder unit 39.
The decoder unit 39 of the base station 2 performs a decoding process on the control data (Sleep request signal) after being demodulated by the demodulator 38, and the decoded control data (Sleep request signal) is transmitted to the protocol processing unit 33 and the Sleep request signal. Output to the determination unit 40.

When receiving the control data from the decoder unit 39, the sleep request signal determination unit 40 of the base station 2 determines whether or not the sleep request signal is included in the control data, and the determination result is sent to the protocol processing unit 33. Output to.
When receiving the determination result indicating that the sleep request signal is included from the sleep request signal determination unit 40, the protocol processing unit 33 of the base station 2 determines whether or not the mobile terminal 3 is currently performing the DRX operation. If it is determined (step ST4) and the mobile terminal 3 is currently performing the DRX operation, the process proceeds to step ST6. Alternatively, in step ST4, it may be determined whether or not the mobile terminal 3 is currently in the DRX operation period. Note that the processing in step ST4 is optional and not essential.

  When the mobile terminal 3 is not currently performing the DRX operation, the protocol processing unit 33 of the base station 2 determines whether or not the mobile terminal 3 can perform the DRX operation in Active (broad sense). (Step ST5). Here, the protocol processing unit 33 performs the determination process, but the downlink scheduler unit 42 or the uplink scheduler unit 43 may perform the determination process. Or you may determine whether the mobile terminal 3 can transfer to a DRX operation | movement period in step ST5.

The DRX operation in Active (in a broad sense) means that the mobile terminal 3 does not receive control data and user data for a certain period.
More specifically, the designated monitor signal is received at the designated DRX cycle, and if the data addressed to itself exists, the reception operation is continued, and if the data addressed to itself does not exist, the reception is performed. Means to pause.
Alternatively, it may be possible to restore the normal reception operation from the operation during the DRX operation period in the active (broad sense) with a designated timer.
Details of the processing content of step ST5 in the protocol processing unit 33 will be described later with reference to the flowchart of FIG.
When it is determined in this step ST5 that it is impossible to perform the DRX operation, the determination in step ST5 may be repeated at regular intervals using a timer or the like.

When the protocol processing unit 33 of the base station 2 determines that the mobile terminal 3 can perform the DRX operation in the active (broad sense), the state of the base station 2 is changed to the active DRX / DTX operation period (FIG. 13). State 2-B) (step ST6).
When the protocol processing unit 33 determines whether or not the mobile terminal 3 can perform the DRX operation in the active (broad sense) as described above, that is, shifts to the DRX operation period during the active. When it is determined whether or not it is possible, the determination result is output to the transmission data buffer unit 34 as control data.

When the protocol processing unit 33 stores the control data (determination result) in the transmission data buffer unit 34, the encoder unit 35 of the base station 2 performs an encoding process on the control data (determination result) stored in the transmission data buffer unit 34. carry out.
When the encoder unit 35 performs the encoding process, the modulation unit 36 of the base station 2 modulates the control data (determination result) after the encoding process, and outputs the modulated control data (determination result) to the antenna 37.

The antenna 37 of the base station 2 uses the control data (determination result) modulated by the modulation unit 36 as a radio signal (determination result signal (information), transition notification signal (information), transition notification signal (information)). (Step ST7).
Here, the processing performed in step ST7 after performing the processing in step ST6 is shown. However, the processing in step ST7 may be performed simultaneously with the processing in step ST6, or before the processing in step ST6 is performed. May be implemented.

  In addition, here, the base station 2 transmits control data (determination result) to the mobile terminal 3 as a radio signal. However, as a determination result notification method, in addition to mapping to a physical channel, MAC signaling There is a method of mapping to a MAC header or the like.

When a sleep request signal is transmitted using a channel (transport channel, physical channel) in which a response signal (ACK signal / NACK signal) from the base station 2 to the mobile terminal 3 exists in the process of step ST2 That is, when the sleep request signal is transmitted from the mobile terminal 3 to the base station 2 using a channel (transport channel, physical channel) that supports high-speed retransmission control by HARQ, the response signal (ACK signal / NACK) Signal) and control data (determination result) may be transmitted together.
In this case, compared with the case where control data (determination result) is transmitted using another channel (for example, DL-SCH), further downlink scheduling is unnecessary, and with less delay (Delay). This is advantageous in that control data (determination result) can be notified.

When receiving the radio signal transmitted from the base station 2, the antenna 16 of the mobile terminal 3 outputs the radio signal to the demodulator 17 (step ST8).
When receiving a radio signal from the antenna 16, the demodulator 17 of the mobile terminal 3 performs a demodulation process on the radio signal and outputs the demodulated control data (determination result) to the decoder unit 18.
The decoder unit 18 of the mobile terminal 3 performs a decoding process on the control data (determination result) after demodulation by the demodulation unit 17 and outputs the decoded control data (determination result) to the protocol processing unit 11.

The control unit 23 of the mobile terminal 3 determines whether or not to change the state of the mobile terminal 3 to the active DRX / DTX operation period (state 2-B in FIG. 13) (step ST9).
In the process of step ST1, the control unit 23 of the mobile terminal 3 indicates that the determination result of the DTX determination unit 19 can shift to the active DTX operation period, and the protocol processing unit 11 is active. When the control data (determination result) of the base station 2 indicating that it is possible to shift to the DRX operation period of the mobile station 3 is acquired, the state of the mobile terminal 3 is changed to the active DRX / DTX operation period (state 2- of FIG. 13). The mobile terminal 3 is transitioned to the active DRX / DTX operation period (state 2-B in FIG. 13) by performing a determination to transition to B) (step ST10).

When the control unit 23 of the mobile terminal 3 changes the state of the mobile terminal 3 to the active DRX / DTX operation period (state 2-B in FIG. 13), the control unit 23 performs the DRX operation and the DTX operation (step ST11).
That is, the control unit 23 temporarily stops supplying power to the data transmission processing unit (for example, the encoder unit 14 and the modulation unit 15) according to the cycle indicated by the DTX cycle information stored in the DTX cycle storage unit 21. To do.
Further, according to the cycle indicated by the DRX cycle information stored in the DRX cycle storage unit 22, the supply of power to the data reception processing unit (for example, the demodulator 17 and the decoder unit 18) is temporarily stopped.
Alternatively, the supply of power to the transmission processing unit and the reception processing unit is temporarily performed in a period in which a period in which the power supply can be temporarily stopped according to the DTX cycle information overlaps with a period in which the power supply can be temporarily stopped according to the DRX cycle information. You may make it stop.
Here, the control unit 23 shows that the supply of power to the encoder unit 14, the modulation unit 15, the demodulation unit 17, and the decoder unit 18 is temporarily stopped, but the target of stopping the supply of power is only an example. For example, temporarily supplying power to the protocol processing unit 11, the application unit 12, the transmission data buffer unit 13, the DTX determination unit 19, the sleep request signal generation unit 20, the DTX cycle storage unit 21, the DRX cycle storage unit 22, and the like. You may make it stop.

Even if the control unit 23 of the mobile terminal 3 indicates that the determination result of the DTX determination unit 19 can be shifted to the active DTX operation period in the process of step ST1, the protocol processing unit 11 does not have the Active. When the control data (determination result) of the base station 2 indicating that it is impossible to shift to the middle DRX operation period is acquired (or the determination result to shift to the active DRX operation period is not acquired) ), The state of the mobile terminal 3 is not changed to the active DRX / DTX operation period (state 2-B in FIG. 13), and only the DTX operation is performed (step ST12).
That is, the control unit 23 does not stop the power supply to the data reception processing unit (for example, the demodulation unit 17 and the decoder unit 18), and follows the cycle indicated by the DTX cycle information stored in the DTX cycle storage unit 21. The supply of power to the data transmission processing unit (for example, the encoder unit 14 and the modulation unit 15) is temporarily stopped.
Alternatively, since the supply of power to the reception processing unit cannot be temporarily stopped, the process of temporarily stopping the supply of power to the transmission processing unit may not be performed.

Hereinafter, the processing content of step ST5 in the protocol processing unit 33 will be described in detail.
FIG. 5 is a flowchart showing the processing contents of step ST5 in the protocol processing unit 33.
The protocol processing unit 33 of the base station 2 checks whether or not transmission waiting data of the mobile terminal 3 being served is stored in the transmission data buffer unit 34 (step ST21).
Here, the protocol processor 33 confirms the presence / absence of data, but the downlink scheduler 42 or the uplink scheduler 43 may confirm the presence / absence of data through the protocol processor 33 or directly. The presence / absence of data in the transmission data buffer unit 34 may be confirmed.

Further, the protocol processing unit 33 of the base station 2 performs transmission / reception between the mobile terminal 3 and the base station 2 that have transmitted the QoS of the service stored in the QoS storage unit 41, that is, the “Sleep request signal”. The QoS of the service is confirmed (step ST22).
Here, the protocol processing unit 33 has been shown to check the QoS of the service, but the downlink scheduler unit 42 or the uplink scheduler unit 43 may check the QoS of the service through the protocol processing unit 33, or directly The QoS of the service stored in the QoS storage unit 41 may be confirmed.

Further, the protocol processing unit 33 of the base station 2 confirms information (for example, CQI) used for downlink scheduling of the mobile terminal 3 being served, which is grasped by the downlink scheduler unit 42 (step ST23).
Here, the protocol processor 33 confirms information used for downlink scheduling of the mobile terminal 3, but the uplink scheduler 43 may confirm information used for downlink scheduling via the protocol processor 33. Alternatively, the information used for the downlink scheduling that the downlink scheduler unit 42 grasps may be directly confirmed.

Further, the protocol processing unit 33 of the base station 2 confirms the scheduling load in the downlink scheduler unit 42 (step ST24).
Here, the protocol processor 33 confirms the load of the downlink scheduler unit 42. However, the uplink scheduler unit 43 may confirm the load of the downlink scheduler unit 42 through the protocol processor 33, or directly. The load of the downlink scheduler unit 42 may be confirmed.
Note that the processes of steps ST21 to ST24 may be performed simultaneously or in any order. Moreover, it is not necessary to perform the process of all the steps.

Based on the information confirmed in steps ST21 to ST24, the protocol processing unit 33 of the base station 2 determines whether or not the corresponding mobile terminal 3 can perform an active (broad sense) DRX operation (step ST25). .
Hereinafter, a specific example of the determination process in step ST25 in the protocol processing unit 33 will be described.

When the protocol processing unit 33 confirms in step ST21 that the transmission waiting data of the mobile terminal 3 that has transmitted the “Sleep request signal” is stored in the transmission data buffer unit 34, the protocol processing unit 33 is active (broadly defined). ) Is determined to be impossible.
When transmission waiting data of the mobile terminal 3 that has transmitted the “Sleep request signal” is stored in the transmission data buffer unit 34, if it is determined that an active (broad sense) DRX operation is possible, the DRX operation period This is because the corresponding mobile terminal 3 cannot perform the reception operation of the data stored in the transmission data buffer unit 34.

Also, the protocol processing unit 33 performs transmission / reception between the mobile terminal 3 and the base station 2 that have transmitted the QoS of the service stored in the QoS storage unit 41 confirmed in step ST22, that is, the “Sleep request signal”. If the QoS of the service is high, the request for real-time property is high, it is determined that the DRX operation in the active (broad sense) is impossible.
When the QoS of the service is high, a request for real-time property is high during the DRX operation period when it is determined that an active (broad sense) DRX operation is possible when the service QoS is high. This is because even if user data is transmitted, the user data cannot be transmitted to the mobile terminal 3, and the requested QoS cannot be satisfied.

Also, if the information (eg, CQI) used for downlink scheduling of the affiliated mobile terminal 3 confirmed in step ST23 indicates poor quality, the protocol processing unit 33 temporarily corresponds to the transmission data buffer unit 34. Even if there is transmission waiting data for the terminal 3, it is determined that the DRX operation in the active (broad sense) is possible.
If the CQI value indicates poor quality, there is a high possibility that a reception error will occur even if data is transmitted to the corresponding mobile terminal 3 at a high speed. This is because it is possible to increase the throughput of the entire mobile communication system by allocating radio resources to another mobile terminal 3 exhibiting good quality with a CQI value while realizing a low power consumption of 3. .

Further, when the downlink scheduling load confirmed in step ST24 is high, the protocol processing unit 33 is incapable of performing the active (broad sense) DRX operation of the mobile terminal 3 that has transmitted the “Sleep request signal”. to decide.
The realization of the active (in a broad sense) DRX operation for the mobile terminal 3 means that the downlink scheduler unit 42 uses the DRX of the monitor signal for confirming whether the mobile terminal 3 has data addressed to itself. The point that it is necessary to secure resources for each cycle, the point that transmission is not possible to the mobile terminal 3 performing the active (in a broad sense) DRX operation, and the transition to the active (in a broad sense) DRX operation period For example, it is necessary to determine whether or not it is possible to do so, the load becomes higher compared to the normal reception operation. Therefore, there is a case where the DRX operation in the active (broad sense) in the downlink scheduler unit 42 cannot be supported due to the scheduling load.

Here, the protocol processing unit 33 has been described as determining whether or not the DRX operation in the active (broad sense) is possible. Either one of them, or the downlink scheduler unit 42 and the uplink scheduler unit 43 may be determined jointly.
The information used for the determination may be information other than the information confirmed in steps ST21 to ST24, or all of the information confirmed in steps ST21 to ST24 may not be used.

  As is apparent from the above, according to the first embodiment, it is determined whether or not the mobile terminal 3 can shift to the active DTX operation period, and the active terminal shifts to the active DTX operation period. If it is determined that the base station 2 can shift to the active DRX operation period, power supply to the data transmission processing unit and the reception processing unit of the mobile terminal 3 is performed. Since it is configured to temporarily stop, the power consumption of the mobile terminal 3 can be efficiently realized.

That is, when the mobile terminal 3 is not performing the active (broad sense) DTX operation (when the transmission operation is performed), the power of the transmission processing unit (portion used only for wireless communication) of the mobile terminal 3 is Since it is ON, it is not possible to achieve effective low power consumption even if the DRX operation is performed.
However, by notifying the base station 2 of a “Sleep request signal” generated based on information that only the mobile terminal 3 can know (for example, the presence or absence of data in the transmission data buffer unit 13 of the mobile terminal 3). The base station 2 can more actively perform the DRX operation simultaneously with the DTX operation.
Thereby, it becomes possible to realize the power consumption of the mobile terminal 3 more effectively. As a result, the standby time and continuous call time of the mobile terminal 3 can be extended.

In the first embodiment, the mobile terminal 3 transmits a “Sleep request signal” to the base station 2, but when the mobile terminal 3 does not make a Sleep request, the mobile terminal 3 The “signal” may be transmitted to the base station 2.
Hereinafter, an example of operation when the “Sleep non-request signal” is used will be described with reference to FIG.
The parts having the same step numbers as those in FIG. 4 are assumed to perform the same processing as described in FIG.

Consider a case where the mobile terminal and the base station are in the state 2-A “Active (narrow sense)” in FIG. 13 (step ST1601).
The DTX determination unit 19 of the mobile terminal 3 determines whether or not it is possible to shift to the active DTX operation period when the state of the mobile terminal 3 is in the state 2 “Active (narrow sense)” in FIG. 13. (Step ST1602).
That is, the DTX determination unit 19 determines whether or not the mobile terminal 3 can perform the active DTX operation.

Here, as an example of the DTX operation, the mobile terminal 3 uses information (for example, CQI) used for uplink user data and downlink scheduling, and a pilot signal (a signal used for uplink data synchronous detection compensation, uplink data phase compensation, and the like). ) And an operation (DTX: Discontinuous Transmission) that does not transmit a reference signal (Sounding Reference Signal) for the purpose of measuring the quality of an uplink channel.
The determination of whether or not the DTX determination unit 19 can perform the DTX operation is performed by, for example, confirming the presence or absence of data in the transmission data buffer unit 13.
Specifically, when there is no data in the transmission data buffer unit 13, it is determined that the DTX operation can be performed, and when there is data, it is determined that the DTX operation cannot be performed.
The DTX determination unit 19 outputs a determination result as to whether or not the DTX operation can be performed to the protocol processing unit 11.

  The sleep request signal generation unit 20 of the mobile terminal 3 cannot move to the active DTX operation period when the determination result of the DTX determination unit 19 indicates that the DTX operation cannot be performed. In response to the instruction from the protocol processing unit 11, a sleep unrequested signal is generated, and the sleep unrequested signal is output to the transmission data buffer unit 13 as control data.

Here, the sleep non-request signal is, for example, a signal having all the following meanings (1) to (6), or a signal having any one of the meanings (1) to (6) or a combination thereof. It is.
(1) This means that the mobile terminal 3 ends the active DTX operation period. (2) There is data to be transmitted in the transmission data buffer unit 13 of the mobile terminal 3, or there is data to be transmitted immediately. (3) Notifying the amount of data in the transmission data buffer unit (4) Requesting uplink resource allocation (scheduling) (5) Requesting continuation of the Active state (6) During the DRX operation period during Active Note that the sleep non-request signal means all the meanings of (1) to (6) above, or a combination thereof, or any one of the meanings of (1) to (6). 2 may be a signal to be notified and propagated.

When the sleep request signal generation unit 20 stores the control data (Sleep non-request signal) in the transmission data buffer unit 13, the encoder unit 14 of the mobile terminal 3 controls the control data (Sleep non-request) stored in the transmission data buffer unit 13. Signal) is encoded.
When the encoder unit 14 performs the encoding process, the modulation unit 15 of the mobile terminal 3 modulates the control data (Sleep unsolicited signal) after the encoding process, and sends the modulated control data (Sleep unsolicited signal) to the antenna 16. Output.
The antenna 16 of the mobile terminal 3 transmits the control data (Sleep unrequested signal) modulated by the modulation unit 15 to the base station 2 as a radio signal (step ST1603).

  In this example, the mobile terminal 3 transmits control data (Sleep unsolicited signal) to the base station 2 as a radio signal, but the Sleep unsolicited signal notification method includes a method of mapping to a physical channel, As MAC signaling, there is a method of mapping to a MAC header or the like.

When receiving the radio signal transmitted from the mobile terminal 3, the antenna 37 of the base station 2 outputs the radio signal to the demodulator 38.
When receiving the radio signal from the antenna 37, the demodulator 38 of the base station 2 performs demodulation processing on the radio signal and outputs the demodulated control data (Sleep unrequested signal) to the decoder unit 39.
The decoder unit 39 of the base station 2 performs a decoding process on the control data (Sleep unsolicited signal) demodulated by the demodulator 38, and transmits the decoded control data (Sleep unsolicited signal) to the protocol processor 33 and the Sleep. Output to the request signal determination unit 40.

When receiving the control data from the decoder unit 39, the sleep request signal determining unit 40 of the base station 2 determines whether or not the sleep request signal is included in the control data, and the determination result is sent to the protocol processing unit. (Step ST1604).
When the protocol processing unit 33 of the base station 2 receives the determination result indicating that the sleep non-request signal is included from the sleep request signal determination unit 40, the protocol processing unit 33 determines that the DTX operation during the active cannot be started, and the processing of step 1601 Return to.
On the other hand, if the protocol processing unit 33 of the base station 2 does not receive the determination result indicating that the sleep non-request signal is included from the sleep request signal determination unit 40, the mobile terminal 3 is active (in a broad sense). It is determined whether or not the middle DRX operation can be performed (step ST5).

When it is determined in this step ST5 that it is impossible to perform the DRX operation, the determination in steps ST1604 and ST5 may be repeated at regular intervals using a timer or the like.
Step ST1604 and step ST5 may be in any order.
If it is determined in step ST5 that the DRX operation can be performed, the processes of steps ST6 and ST7 are performed.

When receiving a radio signal from the antenna 16, the demodulator 17 of the mobile terminal 3 performs a demodulation process on the radio signal and outputs the demodulated control data (determination result) to the decoder unit 18.
The decoder unit 18 of the mobile terminal 3 performs a decoding process on the control data (determination result) after demodulation by the demodulation unit 17 and outputs the decoded control data (determination result) to the protocol processing unit 11.
The control unit 23 of the mobile terminal 3 determines whether or not a notification of transition to the DRX / DTX operation period during which the state of the mobile terminal 3 is active (state 2-B in FIG. 13) has been received (step ST1605). .
If it is determined in step ST1605 that the notification of transition to the active DRX / DTX operation period has been received, the processing of step ST10 and step ST11 is performed.
On the other hand, if it is not determined in step ST1605 that the notification of transition to the active DRX / DTX operation period has been received, the process of step ST12 is performed.

  In the first embodiment, the base station 2 transmits the determination result indicating whether or not the base station 2 can shift to the active DRX operation period to the mobile terminal 3. If it is determined that it is possible to shift to the active DRX operation period, a transition instruction to the active DRX / DTX operation period (state 2-B in FIG. 13) is transmitted to the mobile terminal 3. The mobile terminal 3 may transition to the active DRX / DTX operation period (state 2-B in FIG. 13) according to the transition instruction of the base station 2.

Embodiment 2. FIG.
FIG. 6 is a sequence diagram showing processing contents of the mobile communication system according to the second embodiment of the present invention. Hereinafter, processing contents of the mobile communication system will be described.
When the protocol processing unit 33 of the base station 2 determines that the mobile terminal 3 can perform the DRX operation in the active (broad sense), as in the first embodiment, the DRX in the active (broad sense) When performing the operation, the DRX cycle used for the active (broad sense) DRX operation and the DTX cycle used for the active (broad sense) DTX operation to reduce the power consumption of the mobile terminal 3 are determined (step ST31). ).

Here, the optimal DRX cycle and the DTX cycle are as long as possible the time period during which the power of the transmission processing unit and the reception processing unit (portion used only for wireless communication) of the mobile terminal 3 can be turned off (optimal). It is a cycle that is long in the range of time.
As a specific example, as the optimum DRX cycle and DTX cycle, when the DRX cycle and the DTX cycle are determined to be equal, or the DRX cycle and the DTX cycle are determined to be a double cycle, the DRX cycle and the DTX cycle are coordinated. It is possible to make it happen. Furthermore, as another example, a case where the DRX period and the DTX period are determined to be the same period, or a case where the DRX period and the DTX period are determined to be a double period and the DRX period and the DTX period are coordinated are considered. .
Hereinafter, the case where the DRX cycle and the DTX cycle are determined to be equal to each other will be described in detail. However, it is also possible to determine the DRX period and the DTX period to be equal to each other by the same method.
Hereinafter, a specific example of a method for lengthening the period during which the power of the part used only for wireless communication of the mobile terminal 3 can be turned off will be described with reference to FIG.

In FIG. 7, a portion where a period during which the transmission operation is not performed overlaps with a period during which the reception operation is not performed is a period during which the power of the portion used only for wireless communication of the mobile terminal 3 can be turned off.
Pattern 1 in FIG. 7 shows an example when the DTX cycle and the DRX cycle are not determined in step ST31 in FIG. 6 (corresponding to the first embodiment).

Pattern 2 in FIG. 7 determines the DTX cycle and the DRX cycle in step ST31 in FIG. 6 in order to make the period in which the power of the part used only for wireless communication of the mobile terminal 3 can be turned off as long as possible. An example is shown.
As the DTX cycle and DRX cycle determined in the pattern 2, the following (1) to (3) are conceivable.
(1) Make the DTX cycle equal to the DRX cycle. (2) Make the DTX cycle a multiple of the DRX cycle (the DRX cycle and the DTX cycle are multiples).
(3) The DTX cycle is a divisor of the DRX cycle (the DRX cycle and the DTX cycle are multiplied by a factor).

Pattern 3 in FIG. 7 determines the DTX cycle and the DRX cycle in step ST31 in FIG. 6 in order to make the period in which the power of the part used only for wireless communication of the mobile terminal 3 can be turned off as long as possible. In addition, an example of simultaneously determining the start point (Starting Point) of the DTX cycle and the DRX cycle is shown. It is considered that adjusting the start period is also included in coordinating the DRX cycle and the DTX cycle.
At this time, the start of the DTX cycle and the start of the DRX cycle are not only completely matched in time, but a certain offset may exist.
The offset may be an uplink timing and a downlink timing offset, and an offset generated when the time required for the Active period during the DRX operation period is different from the time required for the Active period during the DTX operation period. .

Compared with pattern 2, pattern 3 can extend the period during which the power of the part used only for wireless communication of mobile terminal 3 can be turned off.
Pattern 4 in FIG. 17 is the start of the DTX cycle and the DRX cycle in order to lengthen as long as possible the period during which the power of the part used only for wireless communication of the mobile terminal 3 can be turned off in step ST31 in FIG. An example in the case of matching (Starting Point) is shown. It is considered that adjusting the start period is also included in coordinating the DRX cycle and the DTX cycle.
In the case where the DTX cycle or the DRX cycle is repeated only once, even if the DTX cycle and the DRX cycle are determined, since it is used only once, it is not meaningful.

If the start of the DTX cycle and the DRX cycle are combined using the pattern 4, or if the DTX cycle or the DRX cycle is repeated only once, the power of the portion used only for wireless communication of the mobile terminal 3 is turned off. The possible period can be lengthened.
At this time, the start of the DTX cycle and the start of the DRX cycle are not only completely matched in time, but a certain offset may exist.
The offset may be an uplink timing and a downlink timing offset, and an offset generated when the time required for the Active period during the DRX operation period is different from the time required for the Active period during the DTX operation period. .

When the protocol processing unit 33 of the base station 2 determines the DTX cycle and the DRX cycle, the information “presence / absence of transmission waiting data of the mobile terminal 3 being served” “QoS of service” confirmed in steps ST21 to ST24 in FIG. It may be determined in consideration of “information used by the downlink scheduler”, “load of the downlink scheduler unit”, and the like.
Further, when the protocol processing unit 33 of the base station 2 determines the DTX cycle and the DRX cycle, the DTX cycle used during Active (in a broad sense) may be determined to be infinite.
When the DTX cycle is determined to be infinite, the mobile terminal 3 does not transmit information (CQI or the like) used for downlink scheduling during the active (broad sense) DRX / DTX operation period.

Further, the DTX cycle and DRX cycle determination processing is performed by either the downlink scheduler unit 42 or the uplink scheduler unit 43, or the downlink scheduler unit 42 and the uplink scheduler unit 43 jointly instead of the protocol processing unit 33. It may be.
Here, the process of step ST31 is shown as being performed before the process of step ST6, but the process of step ST31 may be performed simultaneously with the process of step ST6.

When the protocol processing unit 33 of the base station 2 determines the DTX cycle and the DRX cycle, the state of the base station 2 is changed to the active DRX / DTX operation period (state 2-B in FIG. 13) as in the first embodiment. ) (Step ST6).
Next, the protocol processing unit 33 of the base station 2 shifts to the determination result of whether or not the mobile terminal 3 can perform the DRX operation in the active (broad sense), that is, the DRX operation period in the active. The transmission data buffer unit outputs the determination result (DTX cycle information and DRX cycle information) of the DTX cycle and the DRX cycle as control data. 34.
However, the DTX cycle information includes an indicator indicating the DTX cycle. The DRX cycle information includes an indicator indicating the DRX cycle.

When the protocol processing unit 33 stores the control data (determination result and determination result) in the transmission data buffer unit 34, the encoder unit 35 of the base station 2 controls the control data (determination result and determination) stored in the transmission data buffer unit 34. Encoding process for (result) is performed.
When the encoder unit 35 performs the encoding process, the modulation unit 36 of the base station 2 modulates the control data (determination result and determination result) after the encoding process, and transmits the control data (determination result and determination result) after the modulation to the antenna. To 37.

The antenna 37 of the base station 2 transmits the control data (determination result, determination result) after modulation by the modulation unit 36 to the mobile terminal 3 as a radio signal (step ST32).
Here, a case where the base station 2 transmits the control data (determination result, determination result) to the mobile terminal 3 as a radio signal has been shown. However, as a determination result and determination result notification method, a method of mapping to a physical channel is used. In addition, as MAC signaling, there is a method of mapping to a MAC header or the like.
The notification of the DTX cycle and the DRX cycle may be notified only when the cycle is changed, or may be always notified regardless of the change of the cycle.
Further, the start point (Starting Point) of the DTX cycle and the DRX cycle may be notified. The start is notified by a slot number, a frame number, a symbol number, and the like.
The notification of the start of the DTX cycle and the DRX cycle may be notified only when the start is changed, or may be always notified regardless of the change of the start.

As in the first embodiment, in the process of step ST2, a channel (transport channel, physical channel) in which a response signal (ACK signal / NACK signal) from the base station 2 to the mobile terminal 3 exists is used. When the sleep request signal is transmitted, that is, when the sleep request signal is transmitted from the mobile terminal 3 to the base station 2 using a channel (transport channel, physical channel) that supports high-speed retransmission control by HARQ. The response signal (ACK signal / NACK signal) and control data (determination result, determination result) may be transmitted together.
In this case, compared with the case where control data (determination result, determination result) is transmitted using another channel (for example, DL-SCH), further downlink scheduling is unnecessary, and a small delay ( It is advantageous in that the control data (determination result, determination result) can be notified by Delay.

When receiving the radio signal transmitted from the base station 2, the antenna 16 of the mobile terminal 3 outputs the radio signal to the demodulator 17 (step ST33).
When receiving a radio signal from the antenna 16, the demodulator 17 of the mobile terminal 3 performs demodulation processing on the radio signal and outputs control data (determination result and determination result) after demodulation to the decoder unit 18.
The decoder unit 18 of the mobile terminal 3 performs a decoding process on the control data (determination result, determination result) after demodulation by the demodulation unit 17 and outputs the decoded control data (determination result) to the protocol processing unit 11. . The decoded control data (determination result) is output to the DTX cycle storage unit 21 and the DRX cycle storage unit 22.

The control unit 23 of the mobile terminal 3 determines whether or not to change the state of the mobile terminal 3 to the active DRX / DTX operation period (state 2-B in FIG. 13) (step ST9).
In the process of step ST1, the control unit 23 of the mobile terminal 3 indicates that the determination result of the DTX determination unit 19 can shift to the active DTX operation period, and the protocol processing unit 11 is active. When the control data (determination result) of the base station 2 indicating that it is possible to shift to the DRX operation period of the mobile station 3 is acquired, the state of the mobile terminal 3 is changed to the active DRX / DTX operation period (state 2- A determination is made to make a transition to B).

When receiving the decoded control data (DTX cycle information) from the decoder unit 18, that is, when receiving the DTX cycle information transmitted from the base station 2, the DTX cycle storage unit 21 of the mobile terminal 3 converts the DTX cycle information into the DTX cycle information. Save (steps ST34 and ST35).
When the DRX cycle storage unit 22 of the mobile terminal 3 receives the decoded control data (DRX cycle information) from the decoder unit 18, that is, when the DRX cycle information transmitted from the base station 2 is received, the DRX cycle information is received. Save (steps ST34 and ST35).
The DTX cycle storage unit 21 and the DRX cycle storage unit 22 store the DTX cycle information or DRX cycle information output from the decoder unit 18 by overwriting the already stored DTX cycle information or DRX cycle information, or separately. save.
Further, when information indicating the start of the DTX cycle and DRX cycle is received from the decoder unit 18, the start of the information is also stored.

  When the control unit 23 of the mobile terminal 3 determines to change the state of the mobile terminal 3 to the active DRX / DTX operation period (state 2-B in FIG. 13), as in the first embodiment. Then, the state of the mobile terminal 3 is shifted to the active DRX / DTX operation period (state 2-B in FIG. 13) (step ST10).

When the control unit 23 of the mobile terminal 3 changes the state of the mobile terminal 3 to the active DRX / DTX operation period (state 2-B in FIG. 13), the DRX operation is performed in the same manner as in the first embodiment. A DTX operation is performed (step ST11).
That is, the control unit 23 temporarily stops supplying power to the data transmission processing unit (for example, the encoder unit 14 and the modulation unit 15) according to the cycle indicated by the DTX cycle information stored in the DTX cycle storage unit 21. To do.
Further, according to the cycle indicated by the DRX cycle information stored in the DRX cycle storage unit 22, the supply of power to the data reception processing unit (for example, the demodulator 17 and the decoder unit 18) is temporarily stopped.
Alternatively, the supply of power to the transmission processing unit and the reception processing unit is temporarily performed in a period in which a period in which the power supply can be temporarily stopped according to the DTX cycle information overlaps with a period in which the power supply can be temporarily stopped according to the DRX cycle information. You may make it stop.
Here, a description will be given of a case where the control unit 23 temporarily stops the supply of power to the encoder unit 14, the modulation unit 15, the demodulation unit 17, and the decoder unit 18, but the target of stopping the supply of power is only an example. For example, temporarily supplying power to the protocol processing unit 11, the application unit 12, the transmission data buffer unit 13, the DTX determination unit 19, the sleep request signal generation unit 20, the DTX cycle storage unit 21, the DRX cycle storage unit 22, etc. You may make it stop.

Even if the control unit 23 of the mobile terminal 3 indicates that the determination result of the DTX determination unit 19 can be shifted to the active DTX operation period in the process of step ST1, the protocol processing unit 11 does not have the Active. When the control data (determination result) of the base station 2 indicating that it is impossible to shift to the middle DRX operation period is acquired, the state of the mobile terminal 3 is changed to the active DRX / DTX operation period (state of FIG. 13). Only the DTX operation is performed without making a transition to 2-B) (step ST12).
That is, the control unit 23 does not stop the power supply to the data reception processing unit (for example, the demodulating unit 17 and the decoder unit 18), and only during the period indicated by the DTX cycle information stored in the DTX cycle storage unit 21. The supply of power to the data transmission processing unit (for example, the encoder unit 14 and the modulation unit 15) is temporarily stopped.
Alternatively, since the supply of power to the reception processing unit cannot be temporarily stopped, the process of temporarily stopping the supply of power to the transmission processing unit may not be performed.

  As apparent from the above, according to the second embodiment, when the mobile terminal 3 receives the DTX cycle information and the DRX cycle information from the base station 2, the transmission processing unit and the reception are received according to the DTX cycle information and the DRX cycle information. Since the power supply to the processing unit is stopped, the power supply can be stopped only for an optimum period determined in consideration of the situation of the mobile terminal 3 and the situation of the entire mobile communication system. As a result, the power consumption of the mobile terminal 3 can be more efficiently realized.

That is, according to the second embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.
Each time a transition to an active (broad sense) DRX / DTX operation period is determined, the optimum DTX cycle and DRX cycle are determined in consideration of the situation of the mobile terminal 3 at that time and the situation of the entire mobile communication system. This is advantageous in that it can.
In addition, the transmission operation execution and the reception operation execution can be performed simultaneously by matching the start of the DTX cycle and the DRX cycle. Thereby, it is possible to further lengthen the period during which the power of the part used only for the wireless communication of the mobile terminal 3 can be turned off.
As a result, the power consumption of the mobile terminal 3 can be more efficiently realized, and the standby time and continuous call time of the mobile terminal 3 can be extended.

Further, consider a case where the DTX cycle and the DRX cycle are determined to be equal using the pattern 2 in step ST31.
An example of a notification method from the base station of the DRX cycle and DTX cycle to the mobile terminal and an application method in the mobile terminal of the DRX cycle and DTX cycle will be described.
In that case, in step ST32, only the DTX cycle (or DRX cycle) can be notified from the base station to the mobile terminal.
The mobile terminal that has received only the DTX cycle stores the received DTX cycle in the DTX cycle storage unit 21 and the DRX cycle storage unit 22 (step ST35). Alternatively, the mobile terminal that has received only the DRX cycle stores the received DRX cycle in the DTX cycle storage unit 21 and the DRX cycle storage unit 22. Thereafter, the DRX operation and the DTX operation are performed with the stored equal period.
Thereby, the information (cycle) notified from the base station to the mobile terminal can be reduced. This is beneficial in terms of effective utilization of radio resources.
Furthermore, when the DRX cycle and the DTX cycle are equal, the DTX cycle storage unit 21 and the DRX cycle storage unit 22 can be configured as one storage unit. Thereby, the effect of the reduction of the hardware of a mobile terminal can be acquired.

Further, consider a case where the pattern 2 is used and the DTX cycle and the DRX cycle are determined as cooperation (a constant relationship such as a multiple or a divisor, pattern 3, pattern 4, etc.) in step ST31.
An example of a notification method from the base station of the DRX cycle and DTX cycle to the mobile terminal and an application method in the mobile terminal of the DRX cycle and DTX cycle will be described.
In this case, in step ST32, only the relationship between the DTX cycle (or DRX cycle) and the cooperation can be notified from the base station to the mobile terminal.
The mobile terminal that has received only the relationship between the DTX cycle and the cooperation stores the received DTX cycle in the DTX cycle storage unit 21, and stores the result calculated from the relationship between the DTX cycle and the cooperation in the DRX cycle storage unit 22 (step ST35). ). Alternatively, the mobile terminal that has received only the relationship between the DRX cycle and the cooperation stores the result calculated from the received DRX cycle and the cooperation relationship in the DTX cycle storage unit 21 and stores the DRX cycle in the DRX cycle storage unit 22. Thereafter, the DRX operation and the DTX operation are performed according to the stored cycle.
Thereby, the information (cycle) notified from the base station to the mobile terminal can be reduced. This is beneficial in terms of effective utilization of radio resources.

Further, if the cooperative relationship (multiple, divisor, constant relationship) is a value (static: Static) agreed in advance between the mobile terminal and the base station, in step ST32, the cooperative relationship is changed to the base station. There is no need to notify the mobile terminal. Thereby, the information (cooperation relationship) notified from the base station to the mobile terminal can be further reduced. This is beneficial in terms of effective utilization of radio resources.
The reduction of the information can be applied to the pattern 3 and the pattern 4, and similarly, the effect of effective use of radio resources can be obtained.

Hereinafter, Modification 1 will be described.
In the base station, the DRX cycle and DTX cycle determination method may be changed depending on conditions. As an example, (1) Step ST31 is executed only when the condition is satisfied, for example, the DRX cycle and the DTX cycle are made equal or coordinated, and step ST31 is not executed when the condition is not satisfied. .
(2) Step ST31 is executed when the condition is satisfied, for example, the DRX cycle and the DTX cycle are coordinated, and step ST31 is executed also when the condition is not satisfied, for example, the DRX cycle and the DTX cycle are It can be considered to cooperate in a different relationship from the case of satisfying.

Specific examples of conditions are “whether to maintain uplink synchronization”, “whether the DRX cycle (or DTX cycle) is greater than or equal to a threshold value”, and “the elapsed time since the last TA reception is greater than or equal to the threshold Or not ”.
As an example of Modification 1, consider a case where the transmission operation performed by the mobile terminal 3 in the DTX cycle is a transmission operation for performing uplink timing measurement by the base station.

When maintaining uplink synchronization during the DRX / DTX operation period during Active, it is necessary to determine a DTX cycle that satisfies the maintenance of uplink synchronization.
On the other hand, when uplink synchronization is not maintained, it is not necessary to determine a DTX cycle that satisfies maintaining uplink synchronization. Therefore, there is a merit that the DRX cycle and the DTX cycle are determined separately depending on whether or not the condition is satisfied.
Specifically, when uplink synchronization is maintained in the active DRX / DTX operation period, step ST31 is executed, and when not maintained, step ST31 is not executed. Of course, when maintaining, step ST31 may not be performed, and when not maintaining, step ST31 may be performed.
Thus, for example, when uplink synchronization is maintained, the DRX cycle and the DTX cycle and the start period are equal (pattern 3), and when uplink synchronization is not maintained, the DRX cycle and the DTX cycle can be different. It becomes.

Further, consider a case where, for example, only the DRX cycle and the start period are notified from the base station to the mobile terminal in step ST32.
In this case, when maintaining uplink synchronization, the mobile terminal stores the DRX cycle and the start notified in step ST33 in the DTX cycle storage unit 21 and the DRX cycle storage unit 22 and applies them to the DTX operation.
On the other hand, when the uplink synchronization is not maintained, the DRX cycle and the start notified in step ST33 are stored only in the DRX cycle storage unit 22, and are not stored in the DTX cycle storage unit 21, but applied to the DTX operation. do not do. At this time, the DTX operation may follow the contents of the previous DTX cycle storage unit 21.

By doing this, it is possible to realize different DRX cycle and DTX cycle determination methods depending on whether or not the conditions are satisfied while reducing the notification information (cycle) from the base station to the mobile terminal.
Reducing notification information from the base station to the mobile terminal is beneficial in terms of effective utilization of radio resources. Whether to maintain uplink synchronization in this case may be notified from the base station to the mobile terminal separately from the period. Even in this case, since the information amount of the parameter indicating whether or not the uplink synchronization is maintained is smaller than the information amount for notifying the DTX cycle, it is useful in terms of effective use of radio resources.

In Embodiment 2 and Modification 1, the case where the DRX cycle is transmitted from the base station to the mobile terminal has been described. However, the DRX cycle (or DTX cycle) may be determined in advance. Even in that case, the above example is applicable.
As a specific example, when the determination result of whether or not the DRX operation can be performed is notified in step ST32, the mobile terminal stores a predetermined DRX cycle in the DTX cycle storage unit 21 ( Step ST35). Thereafter, the DRX operation and the DTX operation are performed with the stored equal period.
The DRX cycle (or DTX cycle) determined in advance may be a value determined statically as a mobile communication system, or from a base station to a mobile terminal when a radio bearer session is started quasi-statically. You may notify by the L3 message etc. which are transmitted.

In the second embodiment and the first modification, the mobile terminal 3 transmits a “Sleep request signal” to the base station 2, but when the mobile terminal 3 does not make a Sleep request, the mobile terminal 3 A “Sleep unrequested signal” may be transmitted to the base station 2.
FIG. 18 is a sequence diagram showing the processing contents of the mobile communication system when the “Sleep non-request signal” according to the second embodiment of the present invention is used. The detailed description of FIG. 18 is the same as the description of FIG.
In the second embodiment, the base station 2 transmits a determination result indicating whether or not it is possible to shift to the active DRX operation period to the mobile terminal 3, but the base station 2 If it is determined that it is possible to shift to the active DRX operation period, a transition instruction to the active DRX / DTX operation period (state 2-B in FIG. 13) is transmitted to the mobile terminal 3. The mobile terminal 3 may transition to the active DRX / DTX operation period (state 2-B in FIG. 13) according to the transition instruction of the base station 2.

Embodiment 3 FIG.
FIG. 8 is a sequence diagram showing processing contents of the mobile communication system according to Embodiment 3 of the present invention.
In Embodiments 1 and 2 described above, it is determined whether or not the mobile terminal 3 can shift to the active DTX operation period, and when the mobile terminal 3 can shift to the active DTX operation period, Although it has been shown that the base station 2 temporarily stops the power supply to the data transmission processing unit and the reception processing unit if it is determined that it is possible to shift to the active DRX operation period, The protocol processing unit 11 of the mobile terminal 3 determines whether or not to prioritize low power consumption (or may determine whether or not to prioritize throughput), and sets a parameter indicating the determination content to the base station 2 may be transmitted.
In this case, the protocol processing unit 11 constitutes a priority determination unit, and the transmission data buffer unit 13, the encoder unit 14, the modulation unit 15, and the antenna 16 constitute a parameter transmission unit.

That is, in the third embodiment, a parameter indicating whether or not the mobile terminal 3 gives priority to low power consumption is provided in the mobile terminal capability information (UE Capabilities) indicating the capability of the mobile terminal 3. In this third embodiment, description will be given of a case where a parameter indicating whether or not the mobile terminal 3 gives priority to low power consumption is provided. However, a parameter indicating whether or not the mobile terminal 3 gives priority to throughput is provided. Also good.
This parameter is not a value specific to each mobile terminal 3 but can be changed depending on factors such as the state of the mobile terminal 3 and the user's intention.
Alternatively, the entire mobile terminal capability information (UE Capabilities) including a parameter indicating whether or not to prioritize low power consumption may be changeable.

In the third embodiment, the mobile terminal capability information (UE Capabilities) including the above parameters is transmitted from the mobile terminal 3 to the network side even at the time of RRC (Radio Resource Control) connection (at the time of attachment, at the time of transmission, at the time of location registration, etc.) Can be notified.
Specifically, notification is made when mobile terminal capability information (UE Capabilities) indicating the capability of the mobile terminal 3 is changed. Alternatively, even when the mobile terminal capability information (UE Capabilities) is not changed, notification is made at a predetermined cycle.
When notification is made when the mobile terminal capability information (UE Capabilities) is changed, only the changed parameter may be notified, or the entire mobile terminal capability information (UE Capabilities) may be notified. Good.

Hereinafter, the processing content of a mobile communication system is demonstrated concretely.
The protocol processing unit 11 of the mobile terminal 3 includes a parameter that indicates whether or not to prioritize low power consumption when the mobile terminal capability information (UE Capabilities) is changed or for each predetermined period. Terminal capability information (UE Capabilities) is output to the transmission data buffer unit 13 as control data.
The encoder unit 14 of the mobile terminal 3 performs an encoding process on mobile terminal capability information (UE Capabilities) that is control data stored in the transmission data buffer unit 13.

The modulation unit 15 of the mobile terminal 3 modulates mobile terminal capability information (UE Capabilities), which is control data after the encoding process by the encoder unit 14, and the antenna 16 uses the control data after the modulation by the modulation unit 15 as a radio signal. Transmit to the station 2 (step ST41).
Here, the mobile terminal 3 transmits mobile terminal capability information (UE Capabilities) including parameters to the base station 2 as control data. However, only the parameters may be transmitted to the base station 2.

Here, an example of the mobile terminal capability information (UE Capabilities) will be described.
For example, when the mobile terminal 3 is used by being inserted into a card slot of a notebook personal computer, the priority is “low power consumption priority: low” or “throughput priority: high”.
Further, when the mobile terminal 3 is used in the form of a mobile phone, the priority is “low power consumption priority: high” or “throughput priority: low”.
This is because the battery capacity of the notebook personal computer is larger than the battery capacity of the mobile phone in these cases.

  In the third embodiment, the mobile terminal 3 transmits the mobile terminal capability information (UE Capabilities) including the parameters to the base station 2 as control data. However, the mobile terminal capability information (UE Capabilities) is specific. As a notification method, there are a method of mapping to a layer 3 message by a protocol called RRC (Radio Resource Control), a method of mapping to a physical channel, and a method of mapping to a MAC header or the like as MAC signaling.

At this time, if the notification is made at the same time as the “Sleep request signal” shown in the first embodiment, the DRX / DTX operation period during the Active by the “Sleep request signal” (state 2-B in FIG. 13). This is effective because it indicates the request priority of the mobile terminal 3 for the transition to ().
In particular, an effective mapping method in the case where both the “Sleep request signal” and the “low power consumption priority (throughput priority)” are mapped to a physical channel and notified is disclosed.

There is L1 signaling (physical channel mapping signal) called “Happy Bit” that has been mapped to a physical channel from the past (3GPP Release6 standard TS25.309, etc.).
“Happy Bit” indicates whether or not the mobile terminal 3 is satisfied with the current “Serving Grant value” given to the mobile terminal 3 from the uplink scheduler 43 of the base station 2 for uplink data transmission. It is an indicator in the upward direction that is notified to the base station 2.
That is, it is an indicator that has meaning only when uplink data is transmitted. In other words, when there is a request in the “Sleep request signal”, it is determined that the mobile terminal 3 starts the active DTX operation period, so there is no meaning to transmit “Happy Bit”. It is meaningful to transmit “low power consumption priority (throughput priority)”.
On the other hand, when there is no request in the “Sleep request signal”, it is meaningless to transmit “Happy Bit” because the mobile terminal 3 has not decided to start the active DTX operation period. There is no point in transmitting “low power consumption priority (throughput priority)”.

Three bits are required to map “Happy Bit”, “Sleep request signal”, and “low power consumption priority (throughput priority)” to the physical channel as L1 signaling without any ingenuity.
For example, if mapping is performed as shown in FIG. 9, the mobile terminal 3 can notify the base station 2 of the same amount of information in 2 bits, and the mapping to the physical channel can be reduced by 1 bit. . This is effective in terms of effective use of radio resources.
FIG. 9 is an example, and there is no mapping of the “Sleep request signal” request, and mapping that switches the information indicated by the other bit to “Happy Bit” or “low power consumption priority (throughput priority)” when there is a request. Thus, it can be regarded as equivalent to the technology disclosed herein.

When the antenna 37 receives the radio signal transmitted from the mobile terminal 3, the demodulator 38 of the base station 2 demodulates the radio signal (step ST42).
The decoder unit 39 of the base station 2 performs a decoding process on the mobile terminal capability information (UE Capabilities) that is control data after demodulation by the demodulating unit 38, and performs a protocol process on the mobile terminal capability information (UE Capabilities) after the decoding process. The data is stored in the unit 33 (step ST43).

The protocol processing unit 33 of the base station 2 refers to the parameters included in the mobile terminal capability information (UE Capabilities) to determine whether the mobile terminal 3 gives priority to low power consumption (or whether to give priority to throughput). (Whether or not) is confirmed (step ST44).
When the mobile terminal 3 gives priority to low power consumption, the protocol processing unit 33 of the base station 2 performs DRX in Active in order to achieve low power consumption in Active (broad sense) (state 2 in FIG. 13). An operation that enables a transition to the / DTX operation period (state 2-B in FIG. 13) is performed (step ST45).
For example, the sequence in FIG. 4 is validated, and the base station 2 receives the sleep request signal transmitted from the mobile terminal 3 and determines whether or not it is possible to shift to the active DRX operation period. To do.

When the mobile terminal 3 does not prioritize low power consumption (when priority is given to throughput), the protocol processing unit 33 of the base station 2 reduces the low power consumption during active (state 2 in FIG. 13). Without realizing this, an operation is performed in which the transition to the active DRX / DTX operation period (state 2-B in FIG. 13) is impossible (step ST46).
For example, it is not determined whether or not the transition to the DRX operation period during Active is possible.

  As apparent from the above, according to the third embodiment, it is determined whether or not to prioritize low power consumption, and a parameter indicating the determination content is transmitted to the base station 2, so that Active ( In a broad sense), it is possible to achieve further efficient realization of low power consumption in the middle (state 2 in FIG. 13), and there is an effect that it is possible to realize an optimal reduction in power consumption of the mobile terminal 3.

Further, according to the third embodiment, the following effects can be obtained.
When the mobile terminal capability information (UE Capabilities) indicating the capability of the mobile terminal 3 is changed, a parameter is notified, or even when the mobile terminal capability information (UE Capabilities) is not changed, the parameter is notified at a predetermined cycle Thus, even when the mobile terminal 3 is active (state 2 in FIG. 13), the mobile terminal 3 can notify the base station 2 of the mobile terminal capability information (UE Capabilities). This effect becomes more prominent in the packet communication system that is the concept of constant connection. This is because the number of RRC connections is reduced because it is always connected, and there are few timings at which the mobile terminal capability information (UE Capabilities) can be notified with the conventional technology.
As a result, it is possible to notify the base station 2 from the mobile terminal 3 even during active (state 2 in FIG. 13), whether the parameter change that prioritizes the realization of low power consumption or the improvement of the throughput is desired. Thus, the reduction in power consumption of Active (state 2 in FIG. 13) can be realized more effectively. As a result, the power consumption of the mobile terminal 3 can be reduced more optimally.

As modification 1, in step ST44, the base station confirms whether or not the mobile terminal 3 gives priority to low power consumption (or whether or not to give priority to throughput), and determines that priority is given to low power consumption In step ST45, the DRX cycle and the DTX cycle may be set to be equal to or greater than the threshold value X.
On the other hand, if the base station determines in step ST44 that the mobile terminal 3 does not prioritize low power consumption, the base station may set the DRX cycle and the DTX cycle to be shorter than the threshold value X in step ST46.

The lengths of the DRX cycle and the DTX cycle affect the low power consumption of the mobile terminal. If the cycle is long, it is possible to extend the period during which the mobile terminal is turned off, and thus it is easy to realize low power consumption. . Therefore, it is possible to achieve further efficient reduction of power consumption during Active (broad sense) according to the state of the mobile terminal (state 2 in FIG. 13), and to realize the optimal reduction of power consumption of the mobile terminal 3 The effect which can be done is produced.
In the first modification, “whether or not priority is given to low power consumption” and “whether or not priority is given to (permitting) a longer DRX cycle” or “priority (permitted) to be longer a DTX cycle”. It is also possible to notify the base station of the parameter “ka” separately from the mobile terminal.

As modification 2, in step ST44, the base station confirms whether or not the mobile terminal 3 gives priority to throughput (or whether or not to give priority to low power consumption), and determines that priority is not given to throughput. In step ST45, it may be allowed not to maintain uplink synchronization during the DRX / DTX operation period during uplink Active.
On the other hand, if the base station determines in step ST44 that the mobile terminal 3 prioritizes throughput, it may not allow in step ST46 not to maintain uplink synchronization in the active DRX / DTX operation period.

When uplink synchronization is not maintained, when data (control data, user data) is transmitted from the mobile terminal to the base station, a procedure of establishing uplink synchronization is required before data transmission.
On the other hand, when uplink synchronization is maintained, such a procedure becomes unnecessary. Therefore, whether or not uplink synchronization is maintained affects the throughput. Therefore, it is possible to achieve further efficient reduction of power consumption during Active (broad sense) according to the state of the mobile terminal (state 2 in FIG. 13), and to realize the optimal reduction of power consumption of the mobile terminal 3 The effect which can be done is produced.
In the second modification, parameters such as “whether or not priority is given to throughput (whether or not to give priority to low power consumption)” and “whether or not to maintain uplink synchronization” are separately notified from the mobile terminal to the base station. Even if it does, it is realizable.

Embodiment 4 FIG.
In the third embodiment, the mobile terminal 3 includes the parameter indicating the determination result as to whether or not to prioritize low power consumption in the mobile terminal capability information (UE Capabilities), and the mobile terminal capability information (UE Capabilities) is the base. Although what was transmitted to the station 2 is shown, the above parameters are not included in the mobile terminal capability information (UE Capabilities), and the above parameters are transmitted to the base station 2 separately from the mobile terminal capability information (UE Capabilities). It may be.

Note that the mobile terminal 3 transmits the above parameters to the base station 2 at predetermined intervals even when the above parameters are changed or not changed.
According to this Embodiment 4, there exists an effect which can notify said parameter, without changing the function of mobile terminal capability information (UE Capabilities).
Modifications 1 and 2 of the third embodiment are also applicable to the fourth embodiment.

Embodiment 5 FIG.
FIG. 10 is a sequence diagram showing processing contents of the mobile communication system according to the fifth embodiment of the present invention.
In the third embodiment, the protocol processing unit 11 of the mobile terminal 3 determines whether to prioritize low power consumption, includes a parameter indicating the determination content in the mobile terminal capability information (UE Capabilities), and moves the mobile terminal 3 Although it showed about what transmits terminal capability information (UE Capabilities) to base station 2, when deciding whether protocol processing part 11 of mobile terminal 3 gives priority to low power consumption, it is based on the remaining battery level It may be determined.
Specifically, it is as follows.

First, the protocol processing unit 11 (or the control unit 23) of the mobile terminal 3 checks the remaining battery level (step ST51).
The protocol processing unit 11 (or the control unit 23) of the mobile terminal 3 compares the remaining battery level with a predetermined threshold (the lower limit remaining battery level that needs to prioritize low power consumption), and the remaining battery level is predetermined. If it is equal to or less than the threshold value, a decision to prioritize low power consumption (determination to not prioritize throughput) is made. On the other hand, if the remaining battery level exceeds a predetermined threshold value, a decision that priority is given to low power consumption (determination that priority is given to throughput) is made (step ST52).

Note that the protocol processing unit 11 (or the control unit 23) of the mobile terminal 3 may determine whether or not to prioritize low power consumption in consideration of whether or not the battery is being charged. . This is because if the battery is being charged, it is possible to perform an operation giving priority to throughput without worrying about the remaining battery level.
The predetermined threshold value may be a predetermined value set in advance, or may be a value obtained by notification or calculation by an upper layer.
Since the processing contents of steps ST41 to ST46 are the same as those of the third embodiment, description thereof is omitted.
However, the parameter indicating the content of determination as to whether or not to prioritize low power consumption is not included in the mobile terminal capability information (UE Capabilities), as in the fourth embodiment, You may make it transmit said parameter to the base station 2 separately.

  In the fifth embodiment, the mobile terminal 3 transmits the parameter indicating the determination content as to whether or not to prioritize low power consumption to the base station 2, but the mobile terminal 3 determines the remaining battery level to the base station 2. The base station 2 may determine whether to prioritize low power consumption based on the remaining battery level.

FIG. 11 is a sequence diagram showing processing contents of the mobile communication system according to the fifth embodiment of the present invention.
The protocol processing unit 11 (or control unit 23) of the mobile terminal 3 checks the remaining battery level (step ST51).
Upon confirming the remaining battery level, the protocol processing unit 11 (or control unit 23) of the mobile terminal 3 transmits the remaining battery level to the base station 2 (step ST61).
As a specific method of notifying the remaining battery level, for example, there is a method of notifying the base station 2 with a layer 3 message using a protocol called RRC (Radio Resource Control). There are also a method of mapping to a physical channel and a method of mapping to a MAC header or the like as MAC signaling.

  When the protocol processing unit 11 (or the control unit 23) of the mobile terminal 3 checks the remaining battery level, it checks whether the battery is being charged. If the battery is being charged, the remaining battery level is checked. May be transmitted to the base station 2 assuming that the maximum is (or infinite). Or you may make it transmit the parameter which shows whether it is charging separately to the base station 2 separately from a battery remaining charge. Or you may make it transmit the parameter which shows whether it is charging to the base station 2, without transmitting battery remaining charge.

As information to be transmitted to the base station 2, the following (1) to (3) are conceivable.
(1) Send the absolute value of the battery level (2) Send the ratio of the battery level to the battery capacity (3) Send the indicator When sending the indicator, the absolute value of the battery level or the battery capacity It is possible to reduce the amount of information to be transmitted as compared with the case of transmitting the ratio of the remaining battery level to the. Therefore, it is advantageous in that radio resources can be used effectively. FIG. 12 is an explanatory diagram showing an example of an indicator.

When the protocol processing unit 33 (or the control unit 44) of the base station 2 receives the remaining battery level from the mobile terminal 3 (step ST62), the remaining battery level and a predetermined threshold value (lower limit that needs to prioritize low power consumption) Are compared (step ST63).
If the remaining battery level is equal to or less than a predetermined threshold, the protocol processing unit 33 (or control unit 44) of the base station 2 makes a transition to the active DRX / DTX operation period (state 2-B in FIG. 13). An enabling operation is performed (step ST45).
On the other hand, if the remaining battery level exceeds a predetermined threshold value, an operation is performed in which the transition to the active DRX / DTX operation period (state 2-B in FIG. 13) is impossible (step ST46).

In the case of the fifth embodiment, as in the third and fourth embodiments, when the remaining battery level of the mobile terminal 3 is high, priority is given to the throughput, whereas when the remaining battery level is low, low power consumption is achieved. It is possible to operate with priority, and as a result, it is possible to efficiently realize low power consumption during Active (broad definition) (state 2 in FIG. 13).
Modifications 1 and 2 of the third embodiment are also applicable to the fifth embodiment.

Embodiment 6 FIG.
In the fifth embodiment, the battery remaining level is used as a criterion for determining whether to prioritize low power consumption. However, the user gives his / her will to the mobile terminal 3 (prioritizing low power consumption). The mobile terminal 3 may determine whether or not to prioritize low power consumption based on the user's intention as a criterion.
Alternatively, the mobile terminal 3 may transmit the user's intention to the base station 2, and the base station 2 may determine whether to prioritize low power consumption based on the user's intention as a criterion.

In the case of the sixth embodiment, it becomes possible to operate in accordance with the user's intention whether to prioritize low power consumption (or whether to prioritize throughput), and as a result, during Active (broadly defined) The reduction in power consumption (state 2 in FIG. 13) can be efficiently realized according to the user's intention.
Modifications 1 and 2 of the third embodiment are also applicable to the sixth embodiment.

Embodiment 7 FIG.
Non-Patent Document 6 shows that a DRX cycle is transmitted together with initial transmission data from a base station to a mobile terminal. Usually, the DRX cycle is notified by the L1 / L2 control signal together with the initial transmission data.
On the other hand, in the LTE system, it is considered that HARQ is applied in downlink data transmission and uplink data transmission. When HARQ (Hybrid ARQ) is applied, for example, in the downlink, the base station transmits data to the mobile terminal, and the mobile terminal transmits an Ack signal / Nack signal to the base station according to the reception status of the data. To do. An Ack signal is transmitted when data reception is successful, and a Nack signal is transmitted when data reception is unsuccessful.
When receiving the Ack signal from the mobile terminal, the base station transmits new data, but when receiving the Nack signal, the base station performs retransmission. That is, the base station performs retransmission until it receives an Ack signal indicating successful reception from the mobile terminal.

In Non-Patent Document 6, the DRX cycle is counted from the end of a predetermined timer time after receiving the Ack signal.
However, when HARQ is applied and retransmission occurs, a problem occurs when the base station transmits the DRX cycle together with the initial transmission data.
When the base station notifies the mobile terminal of the DRX cycle, the base station must determine the next time to allocate resources to the mobile terminal. However, if the base station transmits the DRX cycle together with the initial transmission data, when a Nack signal is returned from the mobile terminal and retransmission is necessary, the time for allocating resources with the initial transmission data is reduced by that amount. Will have to be changed. That is, the base station must change the time for allocating resources to the mobile terminal every time it retransmits.
Thus, when retransmission is considered, there arises a problem that the scheduling load of the base station increases.

  In this Embodiment 7, in order to solve the above-described problems, a method in which the base station notifies the mobile terminal of DRX cycle information with a control signal in the downlink is disclosed.

FIG. 19 is an explanatory diagram showing an example of a method of notifying the DRX cycle from the base station to the mobile terminal.
In the figure, in the downlink, white lines represent data, horizontal lines represent L1 / L2 control signals that do not include DRX cycle (DRX interval) information, and diagonal lines represent L1 / L2 control signals that include a DRX cycle. Yes. On the uplink, an Ack signal and a Nack signal are transmitted from the mobile terminal to the base station.

As shown in FIG. 19, the base station does not transmit the DRX cycle information together with the initial transmission data as in the prior art, but the first data that does not accompany the data after receiving the Ack signal transmitted from the mobile terminal in the uplink. Transmit with L1 / L2 control signal.
When the base station receives the Ack signal from the mobile terminal after transmitting the downlink initial transmission data, the base station transmits DRX cycle (A) information at the transmission timing of the next L1 / L2 control signal (( 1)), the operation proceeds to the DRX operation.
After the DRX operation, when there is no downlink data to be transmitted from the base station to the mobile terminal, only the L1 / L2 control signal is transmitted. The L1 / L2 control signal may include DRX cycle information (see (2) in the figure).
When the DRX cycle information is included, the DRX cycle (B) is updated, and the operation shifts to the DRX operation. When DRX cycle information is not included, it may be determined in advance that the immediately preceding DRX cycle is applied.

Next, after the DRX operation, when downlink data transmitted by the base station occurs, the downlink data is transmitted to the mobile terminal. The base station does not transmit the DRX cycle information together with the downlink data.
Similarly, after the DRX operation, the mobile terminal receives downlink data from the base station, and transmits a Nack signal to the base station when the reception result is not successful.
The base station that has received the Nack signal from the mobile terminal transmits downlink retransmission data. The base station does not transmit DRX cycle information together with downlink retransmission data.
Next, the mobile terminal receives downlink data from the base station, and when the reception result is successful, transmits the Ack signal to the base station. The base station that has received the Ack signal from the mobile terminal transmits an L1 / L2 control signal including DRX cycle information (see B in the figure) to the mobile terminal at the timing of transmitting the next L1 / L2 control signal. .

  In FIG. 19, although (2) and the DRX cycle (B) are not changed in (3), the L1 / L2 control signal including the DRX cycle (B) information is transmitted, but the DRX cycle is changed. If there is no such information, the DRX cycle (B) information may not be included, and information (trigger) for notifying the transition to the DRX operation may be used.

The start timing (starting period) of the DRX cycle is the L1 / L2 control signal including the DRX cycle information transmitted to the mobile terminal after receiving the Ack signal from the mobile terminal or the DRX transition information when there is downlink data. Transmission timing may be used.
When there is no downlink data, the transmission timing of the L1 / L2 control signal including the DRX cycle information transmitted to the mobile terminal by the base station or the DRX transition information may be used.

FIG. 20 is a sequence diagram showing an example of processing contents between the mobile terminal and the base station.
The base station determines whether or not downlink data to the mobile terminal has been generated (step ST3201). If downlink data has been generated, the base station moves the L1 / L2 control signal not including the DRX cycle together with the downlink initial transmission data. It transmits to the terminal (step ST3202).
The mobile terminal receives downlink data (step ST3203), and determines the data reception state (step ST3204).

If the reception result is successful, the mobile terminal transmits an Ack signal to the base station (step ST3205). If the reception result is unsuccessful, the mobile terminal transmits a Nack signal to the base station (step ST3206).
The base station receives the reception result (Ack signal / Nack signal) from the mobile terminal (step ST3208), and determines whether it is an Ack signal or a Nack signal (step ST3209).
If the determination result is a Nack signal, downlink retransmission data is transmitted (step ST3210). However, DRX cycle information is not sent together with retransmission data.
When transmitting the Nack signal, the mobile terminal receives downlink retransmission data (step ST3207), determines the reception state of downlink data again, and transmits the Ack signal / Nack signal to the base station according to the determination result. .

The base station repeatedly transmits downlink retransmission data until the reception determination result from the mobile terminal becomes an Ack signal.
The mobile terminal transmits an Ack signal to the base station when the reception status determination result of the downlink retransmission data is successful.
When the reception determination result from the mobile terminal is an Ack signal, the base station transmits an L1 / L2 control signal including a DRX cycle (step ST3211), and then proceeds to a DRX operation (step ST3213).
After receiving the L1 / L2 control signal including the DRX cycle (step ST3212), the mobile terminal moves to the DRX operation (step ST3215).
After the DRX cycle, the base station can perform scheduling for the mobile terminal and shifts to active (step ST3214). Also, the mobile terminal becomes active after the DRX cycle (step ST3216).

When no downlink data is generated in the base station, the base station transmits an L1 / L2 control signal including a DRX cycle (step ST3211), and shifts to a DRX operation.
When receiving the L1 / L2 control signal including the DRX cycle (step ST3212), the mobile terminal shifts to the DRX operation at the DRX cycle included in the L1 / L2 control signal (step ST3215).
Then, after the DRX cycle, the base station can perform scheduling for the mobile terminal and shifts to active (step ST3214). Also, the mobile terminal becomes active after the DRX cycle (step ST3216).

  For example, when there is downlink data, the start timing of the DRX cycle is set as the transmission timing of the L1 / L2 control signal including the DRX cycle information transmitted to the mobile terminal after the base station receives the Ack signal from the mobile terminal. When there is no downlink data, the base station sets the transmission timing of the L1 / L2 control signal including the DRX cycle information transmitted to the mobile terminal. As a result, the timing of becoming active after the DRX operation is the same between the base station and the mobile terminal, and the next data or L1 / L2 control signal can be transmitted and received.

  In the above example, the DRX cycle information has been described as information transmitted from the base station to the mobile terminal. However, DRX transition information may be used when there is no change in the DRX cycle.

As disclosed above, in a system to which HARQ is applied by transmitting DRX cycle information or DRX transition information to a mobile terminal using an L1 / L2 control signal that is not accompanied by data after reception of an Ack signal, by the base station Even when retransmission occurs, it is possible to shift to the DRX operation without any problem.
Furthermore, since it is not necessary to change the time for allocating resources to the mobile terminal each time it is retransmitted, the effect of reducing the scheduling load in the base station can be obtained.

Furthermore, since the base station transmits the DRX cycle information or the DRX transition information to the mobile terminal using the L1 / L2 control signal after receiving the Ack signal, the DRX cycle is longer than the required time corresponding to the maximum number of HARQ retransmissions. Therefore, the DRX cycle can be arbitrarily set without depending on the maximum number of HARQ retransmissions.
Further, even when the mobile terminal cannot receive the DRX cycle or the DRX transition information, the mobile terminal performs the reception operation without entering the DRX operation, and receives at the timing transmitted from the base station after the DRX cycle. Therefore, it is possible to eliminate the occurrence of a reception error after the DRX cycle.
As described above, even when the mobile terminal cannot receive the DRX cycle or the DRX transition information and a state transition error occurs, the effect of eliminating the reception error can be obtained.
Furthermore, even when the base station receives an Ack signal from the mobile terminal in error, neither the base station nor the mobile terminal enters the DRX operation, so that an effect that a state transition error hardly occurs is obtained.
Furthermore, since a state transition error is unlikely to occur, an effect that the timer can be eliminated can be obtained.

In the above embodiment, the transmission timing of the DRX cycle from the base station is the transmission timing of the first L1 / L2 control signal after receiving the Ack signal. It may be the transmission timing of the L1 / L2 control signal after n × TTI (n is greater than 1) after signal reception.
As a result, the scheduler of the base station can adjust the timing for setting the DRX cycle in accordance with the scheduling load after receiving the Ack signal.

The n may be determined in advance or may be notified from the base station to the mobile terminal before the retransmission starts (for example, when a radio bearer session is set up, the base station notifies the mobile terminal. For example, notification by an L3 message to be transmitted or notification by an L1 / L2 control signal transmitted together with initial transmission data may be considered.
Thereby, the mobile terminal does not need to continuously receive the L1 / L2 control signal after transmitting the Ack signal until after nTTI, which leads to low power consumption.

In the above embodiment, the transmission timing of the DRX cycle information or the DRX transition information from the base station is set to the transmission timing of the first L1 / L2 control signal after receiving the Ack signal. Alternatively, the DRX transition information may be transmitted at the subsequent timing, and the DRX operation may be shifted when the DRX transition information is transmitted.
By doing so, the scheduler load of the base station increases between the transmission timing of the DRX cycle information and the transmission timing of the DRX transition information. However, as shown in Non-Patent Document 6, the initial transmission data In addition, an effect is obtained that the scheduler load of the base station can be reduced as compared with the case where DRX cycle information is transmitted.

Furthermore, as disclosed in the second embodiment, it is possible to apply a method in which the DTX cycle and the DRX cycle are equal or coordinated.
FIG. 21 is an explanatory diagram showing an example of a method for notifying the mobile terminal of the DRX cycle when the DTX cycle and the DRX cycle are equal.
In FIG. 21, in the downlink, white represents data, a horizontal line represents an L1 / L2 control signal that does not include DRX cycle (DRX interval) information, and a hatched line represents an L1 / L2 control signal that includes a DRX cycle. ing. In the uplink, an Ack signal, a Nack signal, and a sounding signal used for uplink channel quality evaluation and uplink synchronization are transmitted from the mobile terminal to the base station.

As shown in FIG. 21, the base station does not transmit the DRX cycle information together with the initial transmission data as in the conventional example, but the first L1 / L1 after receiving the Ack signal transmitted from the mobile terminal in the uplink. Transmit with L2 control signal.
When the base station receives the Ack signal from the mobile terminal after transmitting the downlink initial transmission data, the base station transmits DRX cycle (A) information at the transmission timing of the next L1 / L2 control signal ((1 in the figure)). )) And shift to the DRX operation.

When receiving the L1 / L2 control signal including the DRX cycle (A) information, the mobile terminal sets the DTX cycle to the DRX cycle (A).
The mobile terminal transmits a sounding signal to the base station at a timing after the DTX operation in the DTX cycle (A) (see (4) in the figure).
When there is no downlink data to be transmitted to the mobile terminal after the DRX cycle (A), the base station transmits only the L1 / L2 control signal to the mobile terminal. The L1 / L2 control signal may include DRX cycle information (see (2) in the figure).
When the DRX cycle information is included, the DRX cycle (B) is updated, and the operation shifts to the DRX operation. When DRX cycle information is not included, it may be determined in advance that the immediately preceding DRX cycle is applied.

When receiving the L1 / L2 control signal including the DRX cycle (B) information, the mobile terminal sets the DTX cycle to the DRX cycle (B).
The mobile terminal transmits a sounding signal to the base station at a timing after the DTX operation in the DTX cycle (B) (see (5) in the figure).
When downlink data to be transmitted to the mobile terminal occurs after the DRX cycle (B), the base station transmits the downlink data to the mobile terminal. However, the base station does not transmit DRX cycle information together with downlink data.

When the mobile terminal receives downlink data from the base station and the reception result is not successful, the mobile terminal transmits a Nack signal to the base station.
The base station that has received the Nack signal from the mobile terminal transmits downlink retransmission data. However, the base station does not transmit the DRX cycle information together with the downlink retransmission data.
When the mobile terminal receives downlink data from the base station and the reception result is successful, the mobile terminal transmits an Ack signal to the base station.
The base station that has received the Ack signal from the mobile terminal transmits an L1 / L2 control signal including DRX cycle (B) information at the timing of transmitting the next L1 / L2 control signal ((3) in the figure). reference).

When receiving the L1 / L2 control signal including the DRX cycle (B) information, the mobile terminal sets the DTX cycle to the DRX cycle (B).
The mobile terminal transmits a sounding signal to the base station at a timing after the DTX operation in the DTX cycle (B) (see (6) in the figure).

  If the mobile terminal receives the DRX cycle information transmitted from the base station in step ST3212 in the sequence of FIG. 20, the series of operations of the mobile terminal and the base station is to set the DRX cycle information as the DTX cycle. It is sufficient that the mobile terminal shifts to the DTX operation at the DTX cycle.

When there is downlink data, the start timing of the DRX cycle is an L1 / L2 control signal including DRX cycle information or DRX transition information transmitted to the mobile terminal after the base station receives the Ack signal from the mobile terminal. The transmission timing may be used.
When there is no downlink data, the base station may set the transmission timing of the L1 / L2 control signal including DRX cycle information or DRX transition information transmitted to the mobile terminal.

When there is downlink data, the DTX cycle start timing is the Ack signal from the mobile terminal to the base station immediately before the L1 / L2 control signal including DRX cycle information or DRX transition information transmitted from the base station to the mobile terminal. Transmission timing may be used.
When there is no downlink data, the transmission timing of the sounding signal immediately before the L1 / L2 control signal including DRX cycle information or DRX transition information transmitted from the base station to the mobile terminal may be used.

When there is downlink data, the start timing of the DTX cycle may be the reception timing of the L1 / L2 control signal including the DRX cycle information or DRX transition information transmitted from the base station to the mobile terminal.
When there is no downlink data, the reception timing of the L1 / L2 control signal including DRX cycle information or DRX transition information transmitted from the base station to the mobile terminal may be used.

  In the above example, the mobile terminal sets the DTX cycle to the DRX cycle notified from the base station. However, the mobile terminal may set the DRX cycle as shown in the second embodiment. Further, the DTX cycle notification method and application method as shown in the second embodiment may be used.

  As disclosed above, after the base station receives the Ack signal, it transmits the DRX cycle information or the DRX transition information to the mobile terminal using an L1 / L2 control signal not accompanied by data, and the DTX cycle and the DRX cycle are equal. By doing so, in the system to which HARQ is applied, in addition to the effects described in the seventh embodiment, the effects described in the second embodiment can be obtained.

In the seventh embodiment, the case has been described in which the DRX cycle information is transmitted from the base station to the mobile terminal using an L1 / L2 control signal or the like. However, the DRX cycle information is determined in advance, and the base station determines in advance. In some cases, resources are allocated to the mobile terminal at the timing of the designated DRX cycle. The present invention can also be applied to such a case.
The predetermined DRX cycle information is notified by an L3 message or the like transmitted from the base station to the mobile terminal when a radio bearer session is started.
When the DRX cycle notified by the L3 message is, for example, a time interval, the invention disclosed in the seventh embodiment can be applied. However, if the DRX cycle can be changed, the DRX cycle information or the DRX operation transition information may be transmitted by the L1 / L2 control signal transmitted from the base station to the mobile terminal, but the DRX cycle cannot be changed. DRX cycle information cannot be transmitted, and DRX operation transition information may be transmitted.
Both the base station and the mobile terminal may shift to the DRX operation based on the DRX cycle information transmitted by the L1 / L2 control signal or the transition information of the DRX operation.

When the DRX cycle notified by the L3 message is, for example, an absolute time designation, there arises a problem that the time allocated in advance is changed by retransmission.
For example, as absolute time designation, 512 radio frames (10 ms) are numbered (0 to 511) on the time axis, and 10 radio frames are numbered (0 to 9) per TTI, and this is repeated. Can be considered.
The L3 message specifies which time is allocated. For example, the radio frame number n (n = 0, 1, 2,..., 511) is the TTI number 5 or the like.
In this case, the DRX cycle starts at the timing of the TTI number 5 for each radio frame. There arises a problem that the downlink initial transmission data generated at the timing of the TTI number 5 of a certain radio frame is retransmitted by HARQ and exceeds the timing of the TTI number 5 of the next radio frame.

In order to solve the above problem, when the DRX cycle notified by the L3 message is an absolute time designation, for example, an L1 / L2 control signal transmitted from the base station to the mobile terminal is used to change the absolute time of the DRX cycle. Can be notified.
Examples of parameters notified for changing the absolute time include a radio frame number, a TTI number, and a TTI number shift amount. For example, a TTI number 9 is notified, or a TTI number shift amount 6 (TTI number is 1) is notified. Similarly, the radio frame number may be notified.
Both the base station and the mobile terminal may shift to the DRX operation based on the change information of the absolute time of the DRX cycle transmitted by the L1 / L2 control signal.

  By using the method disclosed above, even when a DRX cycle is determined in advance by an L3 message or the like transmitted from a base station to a mobile terminal when a radio bearer session is started, retransmission is performed by HARQ. Occurs, the timing assigned next is exceeded, and it is possible to solve the problem that the downlink data that is generated next in the base station cannot be transmitted.

Next, a case where a DRX cycle corresponding to a plurality of signals and a plurality of radio bearers is set in parallel will be described.
FIG. 22 is an explanatory diagram showing a case where a DRX cycle corresponding to a plurality of radio bearers is set in parallel in the downlink.
In FIG. 22, radio bearers (RB) # 1 and # 3 indicate flexible DRX cycle allocation, and RB # 2 indicates fixed DRX cycle allocation.

Here, flexible allocation is also called dynamic allocation, and the DRX cycle is notified from the base station to the mobile terminal by an L1 / L2 control signal transmitted together with the initial transmission data.
The fixed allocation is a case where the base station allocates resources to the mobile terminal at a timing of a predetermined DRX cycle, and the predetermined DRX cycle information is received from the base station before the radio bearer session is started. Notification is made with an L3 message or the like transmitted to the mobile terminal.

When a plurality of RBs are operating simultaneously, the DRX cycle is determined in the following two ways.
(1) The mobile terminal calculates from the DRX cycle of each RB notified from the base station (2) The base station calculates from the DRX cycle of each RB and notifies the mobile terminal

In the case of (1), the DRX cycle is not notified from the base station to the mobile terminal by the L1 / L2 control signal transmitted together with the initial transmission data, but after the base station receives the Ack signal, the first L1 / L2 control signal is transmitted. It is possible to apply the method disclosed in the seventh embodiment in which DRX cycle information or DRX operation transition information is notified by an L2 control signal. However, regarding the fixed allocation, as described above, since the base station and the mobile terminal share the timing information for entering the DRX operation, it is necessary to notify the transition information of the DRX operation.
In the case of (2), the base station adjusts the DRX cycle and notifies it as one DRX cycle. Therefore, if there is even one flexible allocation, the allocation is flexible. In addition, the fixed allocation only is fixed allocation. Therefore, also in this case, the method disclosed in the seventh embodiment can be applied.

  Thus, when the DRX cycle corresponding to a plurality of radio bearers is set in parallel, the problem caused by HARQ can be solved by using the method disclosed in the seventh embodiment.

Next, Modification 1 will be described.
In the above example, in the downlink, the method of notifying the mobile terminal of the DRX cycle information with an L1 / L2 control signal or the like that is not accompanied by data after the base station receives the Ack signal has been described. The method of notifying the mobile terminal of the DTX cycle information using the L1 / L2 control signal after the base station transmits the Ack signal will be described.

FIG. 23 is an explanatory diagram showing an example of a method of notifying the DTX cycle from the base station to the mobile terminal when there is uplink data.
In FIG. 23, in the downlink, a horizontal line represents an L1 / L2 control signal including uplink resource allocation information, and a hatched line represents an L1 / L2 control signal including DTX cycle (DTX interval) information. In addition, an Ack signal and a Nack signal for uplink data are transmitted from the base station to the mobile terminal. In the uplink, the outline represents data and is transmitted from the mobile terminal to the base station.

As shown in FIG. 23, when the base station succeeds in receiving data transmitted from the mobile terminal in the uplink, the base station transmits DTX cycle (A) information together with the Ack signal to the mobile terminal using the L1 / L2 control signal (FIG. 23). (See middle (1)).
When receiving the DTX cycle (A) information from the base station, the mobile terminal shifts to the DTX operation of the DTX cycle (A) from the transmission timing of the transmission performed immediately before receiving the DTX cycle (A) information.
Next, the mobile terminal transmits initial transmission data to the base station when uplink data exists after the DTX cycle (A).

When the base station fails to receive data transmitted from the mobile terminal on the uplink, the base station transmits an uplink resource allocation for retransmission together with the Nack signal using the L1 / L2 control signal.
The mobile terminal that has received the Nack signal transmits retransmission data to the base station.
When the base station succeeds in receiving the retransmission data transmitted from the mobile terminal in the uplink, the base station transmits DTX cycle (B) information together with the Ack signal using the L1 / L2 control signal (see (2) in the figure).
When receiving the DTX cycle (B) information from the base station, the mobile terminal shifts from the transmission timing of transmission performed immediately before receiving the DTX cycle (B) information to the DTX operation of the DTX cycle (B).

Here, in (2) of FIG. 23, when there is no change in the DTX cycle with (1), the Ack signal transmitted from the base station to the mobile terminal does not accompany uplink resource allocation, and therefore, from the base station to the mobile terminal. The DTX cycle information may not be included together with the Ack signal to be transmitted. In this case, it may be determined in advance that the DTX cycle notified immediately before the DTX cycle is reached again.
Further, although the DTX cycle information is described as information transmitted from the base station to the mobile terminal, the DTX transition information may be used when there is no change in the DTX cycle, as in the case of DRX.

The start timing of the DTX cycle may be a transmission timing of transmission performed immediately before the mobile terminal receives the DTX cycle information from the base station. From this transmission timing, a DTX operation with a DTX cycle is started.
When there is no change in the DTX cycle and no DRX cycle information is sent from the base station to the mobile terminal, the transmission timing of transmission performed immediately before the mobile terminal receives the Ack signal from the base station is set to the DTX cycle. The start timing may be used.

The start timing of the DTX cycle may be a reception timing at which the mobile terminal receives DTX cycle information from the base station. The DTX operation of the DTX cycle is shifted from the reception timing.
If there is no change in the DTX cycle and no DRX cycle information is sent from the base station to the mobile terminal, the reception timing at which the mobile terminal receives the Ack signal from the base station may be the start timing of the DTX cycle. .

FIG. 23 shows a case where uplink data resource allocation is not determined in advance as an example. In this case, the L1 / L2 control signal including the uplink resource allocation information transmitted from the base station is received before the mobile terminal transmits the uplink data. The uplink data may be transmitted at the timing after the DTX operation using the resource based on the uplink resource allocation information.
When uplink data resource allocation is determined in advance, the mobile terminal may not receive uplink resource allocation information transmitted from the base station before transmitting uplink data, and is determined in advance at the timing after the DTX operation. The uplink data may be transmitted using the assigned resource.

Next, a case where there is a case where there is uplink data and a case where there is no uplink data are described.
When there is uplink data, a DTX periodic signal is transmitted together with an Ack signal transmitted from the base station to the mobile terminal. When there is no uplink data, an L1 / L2 control signal transmitted from the base station to the mobile terminal after the uplink transmission signal. A method for transmitting the DTX cycle will be described.

FIG. 24 is an explanatory diagram showing an example of a case where a sounding signal is used as an upstream transmission signal when there is no upstream data.
In FIG. 24, in the downlink, a horizontal line represents an L1 / L2 control signal including uplink resource allocation information, and a hatched line represents an L1 / L2 control signal including DTX cycle (DTX interval) information. In addition, an Ack signal and a Nack signal for uplink data are transmitted from the base station to the mobile terminal. In the uplink, white represents data, black represents a sounding signal, and is transmitted from the mobile terminal to the base station.

As shown in FIG. 24, the mobile terminal transmits uplink data together with the sounding signal to the base station.
When the base station succeeds in receiving the data transmitted from the mobile terminal, the base station transmits the Dck period (A) information together with the Ack signal and the uplink timing adjustment signal (TA) by the L1 / L2 control signal (( See 1)).
When receiving the DTX cycle (A) information from the base station, the mobile terminal shifts to the DTX operation of the DTX cycle (A) from the transmission timing of the transmission performed immediately before receiving the DTX cycle (A) information.

Next, when there is no uplink data after the DTX cycle (A), the mobile terminal transmits a sounding signal to the base station.
Upon receiving the sounding signal, the base station transmits DTX cycle (B) information together with the timing adjustment signal (TA) to the mobile terminal using the L1 / L2 control signal (see (2) in the figure).
When the mobile terminal receives the DTX cycle (B) information from the base station, the DTX operation in the DTX cycle (B) from the transmission timing of the transmission (sounding signal transmission) performed immediately before receiving the DTX cycle (B) information. Migrate to

Next, when uplink data exists after the DTX cycle (B), the mobile terminal transmits initial transmission data together with the sounding signal to the base station.
When the base station fails to receive data transmitted from the mobile terminal in the uplink, the base station transmits the uplink resource allocation for retransmission together with the Nack signal and the timing adjustment signal to the mobile terminal using the L1 / L2 control signal. However, the Nack signal does not include the DTX cycle.
When receiving the Nack signal from the base station, the mobile terminal transmits retransmission data to the base station.
When the base station succeeds in receiving the retransmission data transmitted from the mobile terminal in the uplink, the base station transmits DTX cycle (C) information together with the Ack signal to the mobile terminal using the L1 / L2 control signal ((3) in the figure). reference).
When receiving the DTX cycle (C) information from the base station, the mobile terminal shifts from the transmission timing of transmission performed immediately before receiving the DTX cycle (C) information to the DTX operation of the DTX cycle (C).

Next, when there is no uplink data after the DTX cycle (C), the mobile terminal transmits a sounding signal to the base station.
When receiving the sounding signal, the base station transmits DTX cycle (D) information together with the timing adjustment signal (TA) to the mobile terminal using the L1 / L2 control signal (see (4) in the figure).
When the mobile terminal receives the DTX cycle (D) information from the base station, the DTX operation in the DTX cycle (D) from the transmission timing of the transmission (sounding signal transmission) performed immediately before receiving the DTX cycle (D) information. Migrate to

Next, when there is no uplink data after the DTX cycle (D), the mobile terminal transmits a sounding signal to the base station.
When receiving the sounding signal, the base station transmits DTX cycle (E) information together with the timing adjustment signal (TA) to the mobile terminal using the L1 / L2 control signal (see (5) in the figure).
When the mobile terminal receives the DTX cycle (E) information from the base station, the DTX operation in the DTX cycle (E) from the transmission timing of the transmission (sounding signal transmission) performed immediately before receiving the DTX cycle (E) information. Migrate to

  Also in this case, if there is no change in the DRX cycle, the DRX cycle information may not be included together with the Ack signal transmitted from the base station to the mobile terminal. In this case, it may be determined in advance that, for example, it is the same as the immediately preceding DTX cycle.

The start timing of the DTX cycle may be a transmission timing of transmission performed immediately before the mobile terminal receives the DTX cycle information from the base station. From this transmission timing, a DTX operation with a DTX cycle is started.
If there is no change in the DTX cycle and no DRX cycle information is sent from the base station to the mobile terminal, transmission of transmission performed immediately before the mobile terminal receives an Ack signal or timing adjustment signal from the base station The timing may be the start timing of the DTX cycle.

The start timing of the DTX cycle may be a reception timing at which the mobile terminal receives DTX cycle information from the base station. The DTX operation of the DTX cycle is shifted from the reception timing.
If there is no change in the DTX cycle and no DRX cycle information is sent from the base station to the mobile terminal, the reception timing at which the mobile terminal receives the Ack signal or timing adjustment signal from the base station is set to the DTX cycle. The start timing may be used.

  FIG. 24 shows a case where a sounding signal is used as an uplink transmission signal when there is no uplink data, but it is not limited to a sounding signal. For example, an uplink transmission signal when there is no uplink data such as a CQI signal may be used. That's fine.

In the above example, the case where the DTX cycle information is transmitted from the base station to the mobile terminal using the L1 / L2 control signal has been described. However, the DTX cycle information is determined in advance, and the base station is determined in advance. The present invention disclosed herein can also be applied to the case where resources are allocated to mobile terminals at the timing of the DTX cycle.
The predetermined DTX cycle information is notified by an L3 message or the like transmitted from the base station to the mobile terminal when a radio bearer session is started. For example, even in the case of a time interval or an absolute time designation It can be applied by using the same method as in the downlink.

Furthermore, even when a DTX cycle corresponding to a plurality of signals or a plurality of radio bearers is set in parallel, it can be applied by using a method similar to the method disclosed in the case of the downlink.
Furthermore, as shown in the second embodiment, it is possible to apply a method in which the DRX cycle and the DTX cycle are equal or coordinated.
However, when the mobile terminal needs to receive a signal from any base station related to uplink transmission, the time from the reception timing of the received signal to the transmission timing after the DTX operation may be used as a parameter.

FIG. 25 is an explanatory diagram showing time parameters from the reception timing of the received signal to the transmission timing after the DTX operation.
FIG. 25A shows a case where uplink data is present.
The base station transmits DTX cycle (A) information together with an Ack signal for uplink data to the mobile terminal (see (1) in the figure).
When receiving the DTX cycle (A) information from the base station, the mobile terminal shifts to the DTX operation, makes the DRX cycle equal to the DTX cycle, and shifts to the DRX operation.
However, the mobile terminal receives the uplink resource allocation in preparation for uplink data transmission after the DTX cycle (A), and therefore receives the parameter (tp) earlier than the DTX cycle (A).
Since the base station knows both the DTX cycle (A) transmitted to the mobile terminal and the parameter (tp), it can calculate the timing for transmitting the uplink resource assignment to the mobile terminal.

FIG. 25B shows a case where uplink CQI is transmitted.
After the base station transmits the CQI to the mobile terminal, it transmits DTX cycle (B) information to the mobile terminal (see (2) in the figure).
When receiving the DTX cycle (B) information from the base station, the mobile terminal shifts to the DTX operation, makes the DRX cycle equal to the DTX cycle, and shifts to the DRX operation.
However, since the mobile terminal receives a downlink reference signal in preparation for CQI transmission after the DTX cycle (B), the mobile terminal receives the parameter (tp) earlier than the DTX cycle (B).
Since the base station knows both the DTX cycle (B) transmitted to the mobile terminal and the parameter (tp), it can calculate the timing for transmitting the downlink reference signal to the mobile terminal.

The parameter (tp) may be a positive value (received earlier by tp from the transmission timing) or a negative value (received later by tp from the transmission timing).
The parameter (tp) may be set in advance and shared between the base station and the mobile terminal, or may be notified from the base station to the mobile terminal when a radio bearer session is started. However, the base station may notify the mobile terminal together with the DTX cycle.
By using the method disclosed here, the DRX cycle and the DTX cycle can be formally equalized, and the effects described in the second embodiment can be obtained.

Next, Modification 2 will be described.
Here, a description will be given of a method in which the base station notifies the mobile terminal of DTX cycle information and DRX cycle information when there is data transmission in each of the downlink and the uplink.

When there is data transmission in each of the downlink and uplink, when HARQ is applied, the uplink data ends first, and even if there is only downlink data, the uplink Ack signal / Nack signal for the downlink data Is required.
Further, even if downlink data ends first and only uplink data exists, a downlink Ack signal / Nack signal for the uplink data is required.
Therefore, even if the DRX cycle and the DTX cycle are set to different values, it is not possible to shift to the DRX operation or the DTX operation until both the upstream and downstream data are completed.
Therefore, it is useless to set the DRX cycle and the DTX cycle to different values.

Furthermore, when the base station notifies both the DRX cycle and the DTX cycle to the mobile terminal, and the start timing of the DRX operation and the start timing of the DTX operation are operated individually, the Ack signal / Nack signal in the downlink or uplink However, there is a problem that a reception error occurs in the uplink or downlink because the operation shifts to the DRX operation or the DTX operation.
Therefore, when there is data transmission in each of the downlink and the uplink, it is preferable to make the DRX cycle and the DTX cycle the same.

  In Modification 2, when there is data transmission in each of the downlink and uplink, the DRX cycle and the DTX cycle are made the same, and when the downlink data ends first, the uplink data transmission disclosed in Embodiment 7 above. When the uplink data ends first, the method to which the method for downlink data transmission disclosed in the seventh embodiment is applied is applied.

FIG. 26 is an explanatory diagram showing an example of a method for notifying the DRX cycle and the DTX cycle from the base station to the mobile terminal when there is data transmission in the downlink and the uplink, and the DRX cycle and the DTX cycle are the same. is there.
In this case, it is divided into the following two states.
(1) When downlink data ends first (2) When uplink data ends first

FIG. 26A shows a case where downlink data ends first, and FIG. 26B shows a case where uplink data ends first.
When the downlink data ends first, the base station transmits DTX cycle (A) information to the mobile terminal using the L1 / L2 control signal together with the Ack signal for the uplink final initial transmission data or uplink final retransmission data (in the figure). (See (1)).
When receiving the DTX cycle (A) information from the base station, the mobile terminal makes the DRX cycle equal to the DTX cycle (A).

The start timing of the DRX cycle may be the transmission timing of the L1 / L2 control signal including the DTX cycle that the base station transmits to the mobile terminal.
The start timing of the DTX cycle may be the transmission timing of the last uplink (retransmission) data that the mobile terminal transmits to the base station.

  The method disclosed here applies the above-described Embodiment 7 to downlink data, and after the downlink (retransmission) data ends from the base station to the mobile terminal, compared to the case of applying Modification 1 to the uplink data. There is no need to transmit DRX cycle information. Therefore, there is an effect that the scheduling load of the scheduler of the base station can be reduced.

When the uplink data ends first, the base station receives the Ack signal for the final downlink initial transmission data or the final downlink retransmission data, and then transmits the DRX cycle (B) information by the first L1 / L2 control signal to the mobile terminal. (See (2) in the figure).
When receiving the DTX cycle (B) information from the base station, the mobile terminal makes the DTX cycle equal to the DRX cycle (B).

The start timing of the DRX cycle may be the transmission timing of the L1 / L2 control signal including the DRX cycle transmitted from the base station to the mobile terminal.
The start timing of the DTX cycle may be a transmission timing for transmitting an Ack signal for downlink final (retransmission) data transmitted from the mobile terminal to the base station.

Further, when the mobile terminal needs to receive a signal from any base station prior to uplink transmission, the time from the reception timing to the transmission timing after the DTX operation may be used as a parameter.
Thereby, the mobile terminal can calculate the reception timing of a signal from any base station that the mobile terminal receives prior to uplink transmission.
The parameter may be set in advance and shared between the base station and the mobile terminal, or may be notified from the base station to the mobile terminal when a radio bearer session is started, The base station may notify the mobile terminal together with the DTX cycle.

  In the method disclosed here, the last uplink (retransmission) data is completed from the base station to the mobile terminal, compared with the case where the seventh embodiment is applied to the downlink data and the first modification is applied to the uplink data. There is no need to transmit later DTX cycle information. Therefore, there is an effect that the scheduling load of the scheduler of the base station can be reduced.

  According to the invention disclosed in the modified example 2, when there is data transmission in the downlink and the uplink, respectively, the DRX cycle and the DTX cycle are made the same, and the downlink data ends first, disclosed in the seventh embodiment. When the uplink data transmission method is applied and the uplink data ends first, by applying the downlink data transmission method disclosed in the seventh embodiment, in addition to the effects described in the second embodiment. Thus, the useless setting operation of the DRX cycle or DTX cycle is eliminated, and the upstream or downstream due to the transition to the DRX operation or DTX operation despite the transmission of the Ack signal / Nack signal in the downstream or upstream. The effect of eliminating the occurrence of a reception error is obtained.

Embodiment 8 FIG.
In Embodiment 7 above, in HARQ data transmission during DRX (DTX) operation, data transmission in HARQ mode is successful (in the case of DRX, the Ack signal is transmitted from the mobile terminal, and in the case of DTX, the Ack is transmitted from the base station. The method of notifying the mobile terminal of the DRX (DTX) period until the next data transmission using the L1 / L2 control signal when the signal is transmitted) has been described.
As a result, even if HARQ retransmission continues and the original DRX cycle is exceeded, the DRX (DTX) period is notified from the base station to the mobile terminal after the last transmission is completed. There is no danger of accidentally entering DRX (DTX) operation in the middle, and the effect of reducing the scheduling load in the base station can be obtained. There is a problem that it is necessary to receive the L1 / L2 control signal from the base station once after transmitting the Ack signal.
In addition, since the timing of the next Active during the DRX (DTX) operation period depends on the timing of successful transmission by HARQ, the interval until the start of each initial transmission is different every time, and it is difficult to predict the success of transmission by HARQ. There is no problem.

In this eighth embodiment, in data transmission by HARQ at the time of DRX operation, the DRX (DTX) period is set at the first transmission, and the DRX (DTX) period end timing set first by retransmission in HARQ has been exceeded. Even in such a case, a DRX (DTX) control method in which retransmission is prioritized without entering the DRX (DTX) operation, and the DRX (DTX) period end timing is further extended by the next DRX (DTX) period to be reset. explain.
In addition, in the data transmission using HARQ, even if the initially assumed DRX (DTX) period end timing is exceeded due to repeated retransmission, DRX / DTX control is performed without worrying about the number of retransmissions. And the effect that the scheduling load on the base station side can be reduced can be obtained.

  Further, as in the seventh embodiment, in downlink transmission, there is no need to transmit the L1 / L2 control signal from the base station to the mobile terminal in the middle, and the mobile terminal waits for the L1 / L2 control signal from the base station. Without changing to DRX operation. Similarly to Embodiment 7, the next Active (WakeUp) timing may vary depending on the number of HARQ retransmissions, but the extended period is a fixed rule with respect to the DRX cycle set at the first transmission. Therefore, the interval until the start of each initial transmission can be assumed to some extent. Further, by setting the DTX (DRX) cycle according to a certain rule, it is possible to obtain an effect that it is easy to cope with a sudden change in traffic.

FIG. 27 is a sequence diagram showing a control flow in the DRX operation of the mobile communication system according to the eighth embodiment of the present invention.
Hereinafter, the DRX control flow of the mobile communication system according to the eighth embodiment will be described.
When it is understood that the base station and the mobile terminal are active (in a broad sense), downlink data that needs to be DRX generated is generated.
At this time, the base station shifts to a DRX cycle setting process, and sets a DRX cycle used for an active (broad sense) DRX operation to reduce power consumption of the mobile terminal 3 (step ST5101).

FIG. 29 is a flowchart showing an example of the DRX cycle setting operation in step ST5101.
As shown in FIG. 29, this method can be applied to both DTX cycle setting and DRX cycle setting.
First, the protocol processing unit 33 of the base station 2 confirms whether or not the DRX / DTX operation is in progress and determines that it is not in operation (step ST5301). It is determined whether or not the DRX operation or DTX operation in Active (broad sense) can be performed (step ST5302).

If the DRX / DTX operation can be performed and only the data transmitted from the base station or the control signal periodically generates the idle period, the DRX operation mode is set (step ST5303).
When DRX or DTX operation is required and there are two or more data and control signals having different DRX / DTX periods (step ST5304), the DRX / DTX period end timing closest to the current time in each DRX / DTX period Are calculated and compared (step ST5305).

Then, the DRX / DTX period end timing closest to the data transmission start timing is set to “next DRX / DTX period end timing”. At this time, similarly, the DRX / DTX period end timing closest to the next WakeUp timing (if there is transmission data, the next data transmission start timing) is set as the “next DRX / DTX period end timing” ( Step ST5306).
Further, the timing difference between the next DRX / DTX period end timing and the data transmission start timing is set as a “DRX / DTX cycle”. At this time, similarly, the next DRX / DTX cycle and the subsequent DRX / DTX cycle are also calculated (step ST5307).

When the base station sets the DRX cycle as described above (step ST5101), the base station notifies the mobile terminal of these DRX cycle information (including the next DRX cycle information) using the L1 / L2 control signal together with the data (step ST5101). ST5102). In the base station, if this step is the second or subsequent operation after entering the DRX operation mode, and there is no data to be transmitted when WakeUp after the end of the DRX period (step ST5119), the DRX Only the L1 / L2 control signal including the period information is transmitted to the mobile terminal.
The mobile terminal receives data and an L1 / L2 control signal from the base station (step ST5103).
If the mobile terminal is not in the HARQ mode (step ST5104), based on the DRX cycle notified from the base station, the mobile terminal performs DRX operation (sleep) until the next “DRX period end timing” (steps ST5118 and ST5120).

  If the mobile terminal is in the HARQ mode (step ST5104), the mobile terminal checks the data received in step ST5103, and if there is no problem with the received data, the mobile terminal transmits an Ack signal to the base station (step ST5108). If there is a problem, a Nack signal is transmitted to the base station (step ST5107).

Similarly to the mobile terminal, the base station checks whether or not it is in the HARQ mode (step ST5105), and if not in the HARQ mode, waits until the next “DRX period end timing”.
If it is in the HARQ mode, the Ack signal / Nack signal transmitted from the mobile terminal is received (step ST5109). If the Ack signal is received, the process proceeds to step ST5113 (step ST5110).
On the other hand, if the Ack signal is not received, only the data is retransmitted to the mobile terminal (step ST5111).
The base station repeatedly performs the processes of steps ST5109 to ST5111 until receiving an Ack signal from the mobile terminal. Similarly, the mobile terminal receives the retransmission data (step ST5112) and repeats the processes of steps ST5106 to ST5112 until there is no problem with the received data and the Ack signal is transmitted to the base station (step ST5108).

When receiving the Ack signal from the mobile terminal, the base station checks whether or not the current timing exceeds the DRX period end timing based on the DRX cycle set in step ST5101 (step ST5113).
When the current timing exceeds the DRX period end timing, the base station extends the DRX period end timing by the “next DRX cycle” calculated in step ST 5101, and sets the “next DRX period end timing”. It is updated as “next DRX period end timing” (step ST5115).
Alternatively, in step ST5115, the processing of DRX / DTX cycle setting steps ST5304 to ST5307 shown in FIG. 29 is performed to recalculate the “next DRX cycle” and newly calculate the DRX period end timing “ The timing extended by “DRX cycle” may be updated as “next DRX period end timing”.
Thereafter, the base station returns to the process of step ST5101 when the next DRX period end timing has passed (step ST5119) and sets the next DRX cycle (step ST5101).

The same operation is performed in the mobile terminal.
That is, when the timing at which the mobile terminal proceeds to step ST5114 exceeds the “DRX period end timing” obtained from the DRX cycle information in the L1 / L2 control signal received from the base station in step ST5103, The “next DRX period end timing” obtained by extending “DRX period end timing” by “next DRX cycle” is updated as “next DRX period end timing” (step ST5116).
Thereafter, the mobile terminal sleeps until “next DRX period end timing” (steps ST5118 and ST5120), and after the DRX operation (after WakeUp), returns to the process of ST5103 and waits for reception from the base station.
The “next DRX period end timing” in step ST5116 may be received from the base station in step ST5103. In step ST5103, only the “DRX cycle” and the “next DRX cycle” are received. The “next DRX period end timing” may be calculated and reset.

Alternatively, in step ST5103, each DRX cycle information of the data and control signal generated in the downlink (when there are two or more data, control signals, etc. to be transmitted and the DRX cycle is different, all the DRX cycle information) Is received by the L1 / L2 control signal, and after successful retransmission, when it is determined that the timing when the process proceeds to step ST5114 exceeds the “DRX period end timing”, in step ST5116 on the mobile terminal side, Based on the DRX cycle information, the “next DRX cycle” is recalculated by the method described in steps ST5304 to ST5307 of FIG. 29, and the “DRX cycle end timing” is recalculated. (= Recalculated “Next DRX period end timing”) “Next D May be updated as X period end timing ".
As a result, it is possible to reduce the amount of DRX cycle information notified from the base station using the L1 / L2 control signal in step ST5102, and to obtain an effect that radio resources can be effectively used.

FIG. 30 is a timing chart showing an actual operation according to the DRX operation control sequence described in FIG.
FIG. 30 shows an example of timing when data retransmission occurs in the HARQ mode in downlink communication, and the timing when the retransmission ends exceeds the DRX cycle.

First, an L1 / L2 control signal including initial data and DRX cycle information (DRX cycle (A)) in the downlink is transmitted from the mobile terminal to the mobile station (corresponding to ST5102 in FIG. 27).
Since the mobile terminal is in the HARQ mode, it receives the DRX cycle (A) via the L1 / L2 control signal, calculates the “DRX period end timing” based on this, and is there a problem with the received data? If there is a problem with the received data, a Nack signal is transmitted to the base station in the uplink.
When the base station receives the Nack signal, it retransmits the data to the mobile terminal on the downlink again. At this time, DRX cycle information is not included in the L1 / L2 control signal.

If there is no problem with the second received data, the mobile terminal transmits an Ack signal to the base station on the uplink, and then sleeps until the calculated “DRX period end timing”.
On the other hand, the base station similarly waits until “DRX period end timing”, and then sets the next DRX cycle (B) in step ST5101, and notifies the mobile terminal with an L1 / L2 control signal.
At this time, since no downlink user data is generated, only the L1 / L2 control signal is transmitted.

The mobile terminal wakes up after the “DRX period end timing”, receives the L1 / L2 control signal including the information of the DRX cycle (B), calculates the next “DRX period end timing”, and ends this DRX period Sleep until timing (A + B timing).
After waiting until the timing “A + B”, the base station sets a new DRX cycle (A) in step ST5101, and notifies the mobile terminal with an L1 / L2 control signal.
At this time, downlink user data is generated, and the downlink user data is transmitted to the mobile terminal together with the L1 / L2 control signal.

The mobile terminal that has been sleeping until the timing of “A + B” receives the L1 / L2 control signal including the new DRX cycle (A) and user data after WakeUp.
At this time, transmission by HARQ is not successful due to degradation of radio quality, and reception by the mobile terminal succeeds in the third retransmission (fourth transmission in total), and the mobile terminal transmits an Ack signal in the uplink. Send to.
At this time, since the “DRX period end timing (A + B + A timing in FIG. 30)” calculated by the DRX cycle (A) notified first is already exceeded, the “DRX period end timing” is changed to the DRX cycle (A ) The extended timing is reset to “DRX period end timing (A + B + 2 × A timing)”, and the mobile terminal and the base station sleep until this timing.

As described above, by performing DRX control in consideration of the HARQ mode, it is possible to perform DRX control without any problem even when retransmission due to HARQ is prolonged.
In addition, when the retransmission by HARQ is prolonged, both the base station and the mobile terminal automatically update the next DRX period end timing, thereby reducing the scheduling load on the base station side as compared with the conventional example. be able to.
Further, as in the seventh embodiment, in downlink transmission, there is no need to transmit the L1 / L2 control signal from the base station to the mobile terminal in the middle, and the mobile terminal waits for the L1 / L2 control signal from the base station. Therefore, it is possible to shift to the DRX operation without further reducing the power consumption.

Similarly, the DTX control of the mobile communication system will be described.
FIG. 28 is a sequence diagram showing the flow of DTX control in the mobile communication system.
Hereinafter, the flow of DTX control of the mobile communication system will be described.

First, when transmission data is generated on the mobile terminal side when data communication is not performed on the uplink (step ST5201), the mobile terminal requests a scheduling request (hereinafter, SR for requesting resource allocation and scheduling for uplink transmission). Is transmitted to the base station (step ST5202).
When receiving the SR from the mobile terminal (step ST5203), the base station reserves uplink resources (step ST5205), sets a DTX cycle (step ST5206), and stores these pieces of information in downlink L1 / L2 Notify the mobile terminal via the control signal.
The DTX cycle setting method in step ST5206 has already been described in the explanation section of DRX control, and will be omitted.

When receiving the uplink resource allocation, DTX cycle information, and the like from the base station via the L1 / L2 control signal (step ST5207), the mobile terminal sets the radio resource for transmission and the DTX cycle based on this information. Setting or setting of “DTX period end timing” is performed (step ST5207), and uplink data transmission is started (step ST5208).
When the base station receives uplink data from the mobile terminal (step ST5209) and is not in the HARQ mode (step ST5211), the base station returns to the process of step ST5206 in accordance with the “DTX period end timing” and sets the next DTX cycle. .
If it is in the HARQ mode (step ST5211), the received data is checked (step ST5212). If there is no problem with the received data, an Ack signal is transmitted to the mobile terminal (step ST5214), and if there is a problem with the received data. The Nack signal is transmitted to the mobile terminal (step ST5213).

The mobile terminal receives an Ack signal or a Nack signal from the base station (step ST5216). If the Ack signal is received (step ST5217), the mobile terminal proceeds to the process of step ST5220 and receives a Nack signal (step ST5217). ), The uplink data is retransmitted to the base station (step ST5218).
The processes of steps ST5216 to ST5218 are repeatedly performed until an Ack signal is received from the base station. Similarly, the base station also receives the uplink data retransmitted in step ST5218 (step ST5213), repeats the processes of steps ST5212 to ST5215 until there is no problem with the received data and an Ack signal is transmitted to the mobile terminal. .

  When the mobile terminal succeeds in data transmission, it confirms whether or not the current timing exceeds the “next DTX period end timing” calculated in step ST5207 (step ST5220), and the current timing is the next DTX. If the period end timing is exceeded, the “next DTX period end timing” is extended by “next DTX cycle”, and the “next DTX period end timing” is updated as “next DTX period end timing” ( Step ST5221).

Alternatively, in step ST5204, the mobile terminal does not receive the “DTX cycle information” described so far from the base station, and receives the DTX cycle (if there are multiple cycles, multiple DTX cycle) is received, and when the “next DTX period end timing” is extended in step ST5221, the “next time” recalculated according to the DTX cycle setting method described in steps ST5304 to ST5307 in FIG. The “next DTX period end timing” may be extended by using “the DTX cycle of“.
As a result, in the first step ST5206, it is not necessary to transmit information on the next and subsequent DTX periods using the L1 / L2 control signal, and radio resources can be used effectively.

On the other hand, if the base station succeeds in receiving data from the mobile terminal, it checks whether the current timing exceeds the “next DTX period end timing” as in the mobile terminal (step ST5219). When the timing exceeds the next DTX period end timing, the “next DTX period end timing” is extended by “next DTX period”, and the “next DTX period end timing” is set to “next DTX period end timing”. (Step ST5222), and by this timing, the next DTX cycle is set in step ST5206, and this is transmitted to the mobile terminal via the L1 / L2 control signal.
In step ST5222, the value of “DTX cycle” used when extending the “next DTX period end timing” is changed not at the DTX cycle calculated in step ST5206 but at the time of step ST5222 as in the mobile terminal side. A value obtained by recalculating the “next DTX cycle” by the method described in 29 steps ST5304 to ST5307 may be used.

The mobile terminal waits until “next DTX period end timing” after updating “next DTX period end timing” in step ST5221.
While waiting until the “next DTX period end timing”, the next DTX cycle is received from the base station in step ST5223. During this period (between steps ST5221 to ST5223) and between steps ST5223 to ST5224, it is desirable that the mobile terminal is in DTX operation (sleep) in order to reduce power consumption.
The mobile terminal repeatedly performs Steps ST5207 to ST5223 after completing the DTX operation (WakeUp) at the timing of Step ST5224.

FIG. 31 and FIG. 32 are timing charts showing an actual operation by the DTX operation control sequence described in FIG.
FIG. 31 shows the operation timing when data transmission occurs in the uplink in the HARQ mode, and FIG. 32 shows the case where data and control signals having two types of DTX periods are generated in the uplink in the HARQ mode. The operation timing is shown.

First, the operation timing when data transmission occurs in the uplink in the HARQ mode will be described with reference to FIG.
In FIG. 31, when transmission data (1) is generated, SR is transmitted to the base station on the uplink.
After receiving the SR, the base station notifies the mobile terminal of uplink resource allocation information for data (1) and a DTX cycle (A) for data (1) via a downlink L1 / L2 control signal.
When receiving the uplink resource allocation information and the DTX cycle (A), the mobile terminal transmits (initial transmission) data (1) using the allocated uplink resource.
However, in the example of FIG. 31, the transmission (initial transmission) of the data (1) fails, and the data is retransmitted three times (total four times, the data is transmitted).

After the third retransmission of data (1), reception at the base station is successful, an Ack signal is transmitted from the base station to the mobile terminal, and the mobile terminal receives the Ack signal.
At this time, since the “next DTX period end timing (timing when the time A has passed from the initial transmission)” calculated from the DTX cycle (A) that has already been notified first has been exceeded, the next DTX cycle (A ) The “next DTX period end timing (A + A timing)” that is extended for the next time is reset as the “next DTX end timing”, and the mobile terminal sleeps until this timing.
Meanwhile, in step ST5206, the base station sets a DTX cycle (DTX cycle (B)) and notifies the mobile terminal of the “next DTX cycle (B)” via the downlink L1 / L2 control signal.
The mobile terminal receives the “next DTX cycle (B)”, resets the “next DTX end timing” after WakeUp, transmits data (2), and receives the Ack signal from the base station After that, sleep until “next DTX end timing (= timing after A + A + B from initial transmission of data (1))”.

Next, an operation example when data and control signals having two types of DTX periods are generated in the uplink in the HARQ mode will be described with reference to FIG.
When data (1) is generated in the uplink, an SR is transmitted from the mobile terminal to the base station. In response to this, resource allocation and information on the DTX cycle (DTX cycle (A)) are transmitted from the base station to the downlink L1. The mobile terminal is notified via the / L2 control signal.
The DTX cycle (A) notified at this time is determined by the same method as described for the DRX cycle setting in step ST5101 using FIG. That is, the “DTX period end timing” closest to the current time is selected from the DTX period a of data and the DTX period b of the sounding signal for uplink CQI measurement, and the time from the initial transmission to the “DTX period end timing” Is a value calculated as a DTX cycle.

For example, in FIG. 32, when the DTX cycle a of the data and the DTX cycle b of the sounding signal are compared, since the DTX cycle a of the data is closer, the DTX cycle (A) notified to the mobile terminal is the DTX cycle of the data. It is a.
The mobile terminal having the DTX cycle (A) transmits the data (1) together with the sounding signal by using the allocated resource, but cannot be received well by the base station, and retransmits only the data (1) twice. Yes.
After the second retransmission, the reception at the base station is successful, and the timing at which the Ack signal is returned to the mobile terminal is “DTX period end timing (data ( 1) The timing at which the time A has passed since the initial transmission)) has been exceeded, so that both the base station and the mobile terminal extend the “DTX period end timing” by the next DTX cycle (A) (= data cycle a). Then, the timing when 2 × A time has elapsed from the initial transmission of the data (1) is reset as the “DTX period end timing”.

The mobile terminal sleeps until this timing, and the base station sets the next DTX cycle (B) according to the WakeUp of the mobile terminal, and moves the next DTX cycle (B) via the L1 / L2 control signal. Notify the terminal.
In the calculation of the DTX cycle (B), the next DTX period end timing based on the data cycle a (timing 3 × a from the initial transmission of the data (1)) and the next DTX period end timing based on the sounding signal cycle b (data ( 1) b) from the first transmission of the first transmission), the period end timing of the DTX cycle b closer to the current timing is selected, and the DTX cycle from the WakeUp scheduled timing of the mobile terminal to the period end timing of the next DTX cycle b The procedure of setting as (B) has been passed.

  In this example, it has been described that the calculation of the DTX cycle is performed when the base station side sets the DTX cycle (step ST5206). However, the mobile terminal side receives the DTX cycle of each data, and the DTX cycle is received in step ST5207 or step ST5221. The period may be calculated and set.

  In addition, when the DTX operation is performed during the DRX operation period and the start time of the DTX cycle is set to the start time of the DRX cycle as described in the second embodiment, the Active start timing of the DTX operation period is set to the start time of the current DRX cycle. Alternatively, whether transmission of uplink data or control signals currently occurring is prioritized and whether or not the “next DTX cycle” is adjusted to the start of the DRX cycle may vary depending on the uplink state. This can also be handled by using the DRX / DTX cycle setting and DRX / DTX control method described in the eighth embodiment. In this case, the DTX cycle can be matched with the DRX cycle.

By setting the next DTX cycle in accordance with the WakeUp of the mobile terminal in the manner as described above, even when data and control signals with different DTX cycles are present, the retransmission exceeds the DTX cycle in the HARQ mode. Even if it occurs, it is possible to obtain a DTX control method capable of minimizing the frequency of the L1 / L2 control signal between the base station and the mobile terminal and reducing both processing loads.
In addition, since DRX / DTX cycle setting and DRX / DTX control are performed according to certain rules, even when a sudden change in traffic occurs, the start of the DRX / DTX cycle can be predicted to some extent, so during the DRX operation period, Even when the DTX operation is performed and the start or period of the DTX period is matched with the start or DRX period of the DRX period, the DTX period can be set without difficulty depending on the priority of data and control signals and the uplink state.

Furthermore, as a first modification of the eighth embodiment, as shown in FIG. 33, while the mobile terminal is receiving data (1) in the previous DRX cycle, it has a DRX cycle (B). In some cases, reception data (2) is generated, and this DRX cycle (B) is short enough to enter the DRX period a of data (1) one or more times.
In this case, in the DRX control sequence diagram described with reference to FIG. 27, a new occurrence occurs at the DRX cycle setting in the next step ST5101 when the previous DRX operation is completed (step ST5119 is Yes). It is necessary to set the “current DRX cycle” in consideration of both the DRX cycle (B) of the data (2) and the DRX cycle (A) of the data (1) that has existed so far. In the setting of “current DRX cycle” in step ST5101, it is necessary to reset the DRX cycle by the DRX / DTX cycle setting method as described with reference to FIG.

With the DRX cycle setting method described so far, the DRX period end timings in two different DRX cycles may be compared, and the time from the start of the current DRX cycle to the close end timing may be reset as the DRX cycle.
However, in this example, since the DRX cycle (B) is included in the DRX cycle, it is necessary to set the DRX cycle so that WakeUp can be performed at the beginning of the new DRX cycle (B). That is, the DRX cycle must be set in the period C from the start of the DRX cycle (A) to the start of the DRX cycle (B).
Thereafter, the DRX cycle may be updated in accordance with the flow described in the flowchart of FIG. The setting of the DRX cycle in this modification can also be applied when a similar situation occurs in DTX control.

  In addition, when data (2) having a new DRX cycle is generated during the DRX operation period of data (1), data (1) is being retransmitted by HARQ, and when retransmission is succeeded thereafter, the previous one 27, in step ST5116 in FIG. 27, the “next DRX period end timing” is extended by the previous DRX period (A) by the method described so far. Alternatively, the DRX cycle (B) of downlink data (2) newly generated from the base station via the L1 / L2 control signal during data retransmission by HARQ is notified to the mobile terminal side, and the steps of FIG. In ST5116, the DRX cycle is recalculated by the method described in steps ST5304 to ST5307 of FIG. 29, and the “next DRX engine end timing” is calculated for the recalculated DRX cycle. It may be long.

As described above, if the DRX / DTX control method and the DRX / DTX cycle setting method described in the eighth embodiment are used, even if retransmission continues in the HARQ mode, the set DRX / DTX cycle is exceeded. Therefore, DRX / DTX control can be performed without worrying about the number of retransmissions in HARQ, and the scheduling load of the base station can be reduced as compared with the prior art.
In addition, compared with the seventh embodiment, since the base station does not need to transmit the L1 / L2 control signal to the mobile terminal during downlink transmission in the HARQ mode, the mobile terminal receives the L1 / L2 control signal. It is possible to shift to the DRX operation without reducing the power consumption of the mobile terminal.

  In addition, since DRX / DTX cycle setting and DRX / DTX control are performed according to certain rules, the DRX / DTX active timing can be predicted to some extent even when a sudden change in traffic occurs. Both can perform DRX / DTX control individually. For example, when the DRX control in the downlink and the DTX control in the uplink are mixed, and the start of the DTX cycle in the DTX control is matched with the start of the DRX cycle in the DRX control. In addition, it is possible to flexibly set the starting point of the DTX cycle and the DTX cycle itself to the DRX cycle according to the uplink data, the priority of the control signal, and the retransmission status in HARQ.

  Furthermore, since DRX / DTX cycle setting and timing control according to certain rules can be performed, such control load can be distributed between the base station and the mobile terminal, and as a result, the scheduling load of the base station can be reduced. In addition, even when data that requires a new DRX operation is generated and the DRX / DTX cycle is short enough to be included in the DRX / DTX cycle of the previous data as in Modification 1, certain rules are followed. The DRX cycle can be changed at different timings, and the DRX / DTX cycle associated with the combination of a plurality of DRX / DTX cycles and the generation of new data can be individually performed by both the base station and the mobile terminal. This is advantageous in that it is possible to obtain a highly flexible DRX / DTX control method that can cope with changes in the frequency. Further, by adjusting the DTX cycle to the DRX cycle, the same effect as in the second embodiment can be obtained.

Embodiment 9 FIG.
Non-Patent Document 8 shows a case where two DRX cycles are set. However, Non-Patent Document 8 does not consider the case of applying HARQ at all. Therefore, if the DRX cycle information is notified by the L1 / L2 control signal together with the initial transmission data, is notified at the time of setting up the radio bearer, or is determined in advance as in the conventional case, the retransmission by HARQ will change the DRX cycle. If it exceeds, there will be a problem that it is not possible to shift to the DRX operation.
Non-Patent Document 8 also shows a method of notifying DRX cycle information but a DRX cycle change signal, but this method also has the above-described problems.
In the ninth embodiment, a method combining the seventh embodiment and the eighth embodiment is disclosed in order to solve the above problems.

FIG. 34 is an explanatory diagram showing a case where two DRX cycles shown in Non-Patent Document 8 are set. In FIG. 34, outlines represent downlink data and L1 / L2 control signals, and hatched lines represent L1 / L2 control signals.
The DRX cycle [1] is set longer than the DRX cycle [2], the DRX cycle [1] is predetermined and shared between the base station and the mobile terminal, and the radio bearer is set up in the DRX cycle [2]. Transmitted from the base station to the mobile terminal.

The mobile terminal that has shifted to the DRX operation in the DRX cycle [1] performs reception processing after the DRX cycle [1], and receives downlink data if there is downlink data ((1 in the figure)). )).
When there is no downlink data, the mobile terminal shifts to the DRX operation at the DRX cycle [2].
The mobile terminal performs a reception process after the DRX cycle [2], and if there is downlink data, receives the downlink data (see (2) in the figure), and receives the next DRX cycle [2]. Continue to receive downlink data until later (see (2) in the figure).

When the mobile terminal receives the L1 / L2 control signal after the next DRX cycle [2] and there is no downlink data, the mobile terminal shifts to the DRX operation of the DRX cycle [2] ((3) in the figure). reference).
Furthermore, the mobile terminal performs reception processing after the DRX cycle [2], and shifts to the DRX operation of the DRX cycle [2] if there is no downlink data (see (4) in the figure).
The mobile terminal performs reception at the earlier timing after the DRX cycle [1] and the timing after the DRX cycle [2]. In FIG. 34, since the timing after the DRX cycle [1] is early, downlink reception is performed at the timing after the DRX cycle [1]. When there is no downlink data, the operation shifts to the DRX operation of the DRX cycle [1] (see (5) in the figure).

In the conventional example shown in Non-Patent Document 8, such a method is used, but the case where HARQ is applied is not considered at all. Therefore, as shown in FIG. 34, when the DRX cycle information is notified by the L1 / L2 control signal together with the last initial transmission data of (1), the HARQ retransmission exceeds the DRX cycle [2]. As a result, there is a problem that the operation cannot be shifted to the DRX operation.
In addition, when retransmission by HARQ occurs immediately before the DRX cycle [1] and exceeds the DRX cycle [1], there is a problem that reception after the DRX cycle [1] cannot be performed.

Non-Patent Document 8 shows a method of notifying DRX cycle information but a DRX cycle change signal, but such a method also causes the above-described problem.
In the ninth embodiment, a method combining the seventh embodiment and the eighth embodiment is disclosed in order to solve the above problems.

FIG. 35 is an explanatory diagram showing an example of a method in which the seventh embodiment and the eighth embodiment are combined in the case where two DRX cycles are set.
The method disclosed in the seventh embodiment is applied for setting the DRX cycle [2], and the method disclosed in the eighth embodiment is applied for setting the DRX cycle [1].
In the downlink, white lines indicate downlink initial transmission data or retransmission data and L1 / L2 control signals, horizontal lines indicate final downlink initial transmission data or retransmission data, and diagonal lines indicate L1 / L2 control signals including DRX transition signals. Represents.
In the uplink, white represents an uplink Ack signal / Nack signal for downlink initial transmission data or retransmission data, and a hatched line represents an Ack signal for final downlink transmission data or retransmission data.

When the base station transmits downlink data to the mobile terminal (see (1) in the figure), transmits the final initial transmission data or retransmission data to the mobile terminal, and then receives the Ack signal from the mobile terminal, the Ack signal After reception, a DRX transition signal is transmitted to the mobile terminal using the first L1 / L2 control signal (see (2) in the figure).
When receiving the DRX transition signal from the base station, the mobile terminal transitions to the DRX operation at the DRX cycle [2].
After the DRX cycle [2], the mobile terminal performs reception of the L1 / L2 control signal, and receives downlink data when there is data addressed to itself (see (3) in the figure).
In addition, after the DRX cycle [2], the L1 / L2 control signal is received, and when there is no data addressed to itself, the DRX cycle [2] shifts again to the DRX operation. These series of operations are repeated by the method described above.

Next, the base station transmits downlink data to the mobile terminal, and transmission of downlink initial transmission data or retransmission data exceeds the timing after DRX cycle [1] due to retransmission or the like ((4) in the figure) Next, the downlink initial transmission data or retransmission data is transmitted.
After receiving the Ack signal from the mobile terminal after transmitting the final initial transmission data or retransmission data to the mobile terminal, the base station transmits the DRX transition signal to the mobile terminal with the first L1 / L2 control signal after receiving the Ack signal. (Refer to (5) in the figure).
When receiving the DRX transition signal, the mobile terminal transitions to the DRX operation in the DRX cycle [2]. However, since the transmission of the downlink initial transmission data or the retransmission data has exceeded the timing after the DRX cycle [1] due to retransmission (see (4) in the figure), the DRX operation in the DRX cycle [1] is performed. Without entering, priority is given to retransmission, etc., and the setting is further extended by the DRX cycle [1].

In this case, it may be determined in advance by the base station and the mobile terminal that the DRX cycle [1] is set again. In addition, information to be reset in the mobile terminal may be notified from the base station.
When the DRX cycle [1] is set again and there is no downlink initial transmission data or retransmission data from the base station to the mobile terminal at the timing after the next DRX cycle [1], the DRX operation of the DRX cycle [1] Migrate to

  By using the method disclosed in the ninth embodiment, even when two DRX cycles are set, it becomes impossible to shift to the DRX operation after the DRX cycle [2] or reception after the DRX cycle [1]. The effect that it becomes possible to eliminate the problem of being unable to perform is obtained.

  In the ninth embodiment, the method disclosed in the seventh embodiment is applied to the DRX cycle [2], and the method disclosed in the eighth embodiment is applied to the DRX cycle [1]. Although shown, the method disclosed in the eighth embodiment may be applied to the DRX cycle [2].

  In the ninth embodiment, two DRX cycles are set. However, when a plurality of DRX cycles are set, the method disclosed in the seventh embodiment and the eighth embodiment are disclosed. You may combine methods.

Embodiment 10 FIG.
In the ninth embodiment, the case where two DRX cycles are set is shown for the combination of the method disclosed in the seventh embodiment and the method disclosed in the eighth embodiment. In the tenth embodiment, a combination of the method disclosed in the seventh embodiment and the conventional method will be described according to the relationship between the required time corresponding to the maximum number of HARQ (MAX) retransmissions and the DRX cycle.

The base station transmits different DRX cycle information to the mobile terminal according to the following conditions.
The required time according to the maximum number of HARQ (MAX) retransmissions is Tmax, and the DRX cycle is TDRX.
(1) When Tmax ≧ TDRX The base station applies the seventh embodiment.
In this case, the base station notifies the mobile terminal of the DRX cycle information with an L1 / L2 control signal or the like after receiving the Ack signal.
In this case, when there is downlink data, the start timing of the DRX cycle is the transmission timing of the L1 / L2 control signal including the DRX cycle information transmitted to the mobile terminal after the base station receives the Ack signal from the mobile terminal. And
When there is no downlink data, the base station uses the transmission timing of the L1 / L2 control signal including the DRX cycle information transmitted to the mobile terminal.
Note that the start timing of the DRX cycle may be a timing at which the base station transmits the L1 / L2 control signal when there is downlink data.

(2) In the case of Tmax <TDRX The base station applies a conventional method.
In this case, the base station notifies the mobile terminal of the DRX cycle information using the L1 / L2 control signal or the in-band signal (mapped to the MAC header as MAC signaling) together with the initial transmission data.
In this case, the start timing of the DRX cycle is set to the transmission timing of the L1 / L2 control signal or the in-band signal in which the base station transmits the DRX cycle information together with the initial transmission data regardless of whether there is downlink data.
However, Tmax may be determined in advance, may be determined semi-statically, or may be determined dynamically.

FIG. 36 shows the sequence of mobile terminals and base stations in a method combining the method disclosed in the seventh embodiment and the conventional method, depending on the relationship between the required time corresponding to the maximum number of HARQ (MAX) retransmissions and the DRX cycle. FIG.
When downlink data is generated (step ST8101), the base station determines whether Tmax <TDRX is satisfied (step ST8102).

When TDRX is larger than Tmax, the base station transmits DRX cycle information together with initial transmission data to the mobile terminal (step ST8103).
When receiving the initial transmission data from the base station (step ST8104), the mobile terminal determines whether or not DRX cycle information is transmitted together with the initial transmission data (step ST8105).
When the DRX cycle has been sent, the mobile terminal uses the DRX cycle start timing as the initial transmission data reception timing (step ST8106), and enters the retransmission state by HARQ (ST8107).

When the mobile terminal successfully receives downlink data, the mobile terminal transmits an Ack signal to the base station and exits the retransmission state.
After transmitting the Ack signal, the mobile terminal transitions to DRX operation (step ST8108).
Base station, after receiving an Ack signal from the mobile terminal, exits the retransmission state, a transition to a DRX operation against the end moving end (step ST8109).
The mobile terminal and the base station shift to the active state after the DRX cycle (steps ST8110 and ST8111).

When TDRX is equal to or less than Tmax, the base station enters a retransmission state by HARQ without transmitting DRX cycle information together with initial transmission data (step ST8112).
The mobile terminal determines whether or not DRX cycle information is transmitted together with the initial transmission data from the base station (step ST8105).
When the DRX cycle information is not transmitted, the mobile terminal enters a retransmission state by HARQ (step ST8112).

When the mobile terminal successfully receives the downlink data, it transmits an Ack signal to the base station and exits the retransmission state.
Further, after transmitting the Ack signal, the mobile terminal shifts to the DRX operation.
After receiving the Ack signal from the mobile terminal, the base station transmits DRX cycle information to the mobile terminal using the first L1 / L2 control signal (step ST8113).
When receiving the DRX periodic signal from the base station (step ST8114), the mobile terminal sets the DRX period start timing as the transmission timing of the Ack signal (step ST8115) and shifts to the DRX operation (step ST8116).
After transmitting the DRX cycle information to the mobile terminal (step ST8113), the base station shifts to the DRX operation for the mobile terminal A (step ST8117).
The mobile terminal and the base station shift to the active state after the DRX cycle (steps ST8118 and ST8119).

As described above, by using a method combining the method disclosed in the seventh embodiment and the conventional method according to the relationship between the required time corresponding to the maximum number of HARQ (MAX) retransmissions and the DRX cycle, Tmax < In the case of TDRX, the DRX cycle can be transmitted with the same L1 / L2 control signal as the initial transmission data, and even if retransmission occurs thereafter, the base station does not need to change the time allocated after the DRX cycle. Therefore, it is possible to reduce the scheduler load.
Further, since it is known that the downlink data to the mobile terminal is generated immediately at the base station, the DRX cycle must be shortened, and the case where Tmax ≧ TDRX is also disclosed in the seventh embodiment. By using this method, it is possible to avoid problems in retransmission.

Embodiment 11 FIG.
When the DTX cycle is a CQI transmission cycle (a cycle for transmitting the downlink channel quality measurement result), the DTX cycle may be determined in advance, or equal to or longer than the DRX cycle.
In such a case, the timing for transmitting the uplink Ack signal / Nack signal for the downlink data may overlap with the CQI transmission timing.
If the Ack signal / Nack signal and the CQI signal are transmitted simultaneously, the PAPR (Peak to Average Power Ratio) increases, which causes problems such as an increase in power consumption, a decrease in transmission power, and an increase in adjacent channel leakage power.

In order to solve such a problem, the eleventh embodiment discloses the following three methods when the timing for transmitting the uplink Ack signal / Nack signal and the CQI transmission timing overlap.
(A) Delay CQI transmission timing (b) Skip CQI transmission (CQI is not transmitted at overlapping timing)
(C) Delay the transmission timing of the Ack signal / Nack signal without changing the CQI transmission timing.

By using these methods, simultaneous transmission of the Ack signal / Nack signal and the CQI signal can be eliminated, and it is possible to shift to the DTX operation. The following two methods are disclosed for the start timing of the DTX cycle.
(A) CQI transmission timing determined in advance (B) Delayed CQI transmission timing

The following method is disclosed as a combination of the CQI transmission timing and the start timing of the DTX cycle.
For the method (a), the method (A) or (B) can be applied. For the method (b), the method (A) can be applied. For the method (c), Method (A) can be applied

FIG. 37 is an explanatory diagram showing an example when the timing for transmitting the uplink Ack signal / Nack signal and the CQI transmission timing overlap.
FIG. 37A shows an example in which the CQI transmission timing is delayed by 1 TTI and the start timing of the DTX cycle is set to a predetermined CQI transmission timing. FIG. 37B shows the start timing of the DTX cycle by skipping CQI transmission. An example in which CQI transmission timing is determined in advance is shown.

When the mobile terminal receives the downlink reference signal from the base station, the mobile terminal calculates the quality CQI of the downlink communication path from the reference signal, and transmits a CQI signal corresponding to the quality CQI to the base station. It is conceivable that the transmission cycle (TCQI) of the CQI signal is determined in advance or is equal to or longer than the DRX cycle.
On the other hand, when downlink data is transmitted from the base station in the downlink, the mobile terminal receives the downlink data and transmits an Ack signal / Nack signal to the base station according to the reception status of the downlink data.

Therefore, when the mobile terminal receives the downlink reference signal together with the downlink data from the base station, the mobile terminal calculates the quality CQI of the downlink communication path from the downlink reference signal, transmits the CQI signal corresponding to the quality CQI to the base station, An Ack signal / Nack signal is transmitted to the base station according to the downlink data reception status.
In this case, the transmission timing of the Ack signal / Nack signal and the transmission timing of the CQI signal overlap.

In such a case, in FIG. 37A, the CQI transmission timing is delayed by 1 TTI. Thereby, the transmission timing of the Ack signal / Nack signal and the transmission timing of the CQI signal are transmitted without overlapping.
In this case, since the start timing of the DTX cycle is a predetermined CQI transmission timing, the mobile terminal that has transmitted the CQI can shift to the DTX operation until the next predetermined CQI transmission timing.

Also, in FIG. 37 (b), CQI transmission is skipped. Accordingly, the Ack signal / Nack signal is transmitted without overlapping the transmission timing of the Ack signal / Nack signal and the transmission timing of the CQI signal.
In this case, since the start timing of the DTX cycle is a predetermined CQI transmission timing, the mobile terminal that has transmitted the Ack signal / Nack signal may shift to the DTX operation until the next predetermined CQI transmission timing. it can.

FIG. 38 is an explanatory diagram showing an example when the timing for transmitting the uplink Ack signal / Nack signal and the CQI transmission timing overlap.
FIG. 38A shows an example in which the CQI transmission timing is delayed by 1 TTI and the CQI transmission timing is delayed as the start timing of the DTX cycle.

When the mobile terminal receives the downlink reference signal from the base station, the mobile terminal calculates the quality CQI of the downlink communication path from the reference signal, and transmits a CQI signal corresponding to the quality CQI to the base station. It is conceivable that the transmission cycle (TCQI) of the CQI signal is determined in advance or is equal to or longer than the DRX cycle.
On the other hand, when downlink data is transmitted from the base station in the downlink, the mobile terminal receives the downlink data and transmits an Ack signal / Nack signal to the base station according to the reception status of the downlink data.

Therefore, when the mobile terminal receives the downlink reference signal together with the downlink data from the base station, the mobile terminal calculates the quality CQI of the downlink communication path from the downlink reference signal, transmits the CQI signal corresponding to the quality CQI to the base station, An Ack signal / Nack signal is transmitted to the base station according to the downlink data reception status.
In this case, the transmission timing of the Ack signal / Nack signal and the transmission timing of the CQI signal overlap.

In such a case, the CQI transmission timing is delayed by 1 TTI. Thereby, the transmission timing of the Ack signal / Nack signal and the transmission timing of the CQI signal are transmitted without overlapping.
In this case, since the start timing of the DTX cycle is the delayed CQI transmission timing, the mobile terminal that has transmitted the CQI can shift to the DTX operation until the CQI transmission timing after the DTX cycle TCQI.

Since the simultaneous transmission of the Ack signal / Nack signal and the CQI signal is eliminated by using the method disclosed in the eleventh embodiment, the PAPR increases, the power consumption increases, the transmission power decreases, and the adjacent channel leakage power. It is possible to avoid the occurrence of problems such as an increase in
Furthermore, by determining the start timing of the DTX cycle by the disclosed method, it is possible to shift to the DTX operation.

Embodiment 12 FIG.
Non-Patent Document 8 shows a case where two DRX cycles are set. However, the DRX operation method disclosed in Non-Patent Document 8 has a problem in terms of low power consumption of the mobile terminal.
The problem of the DRX operation method of Non-Patent Document 8 will be described below with reference to FIG.
However, the DRX operation method of Non-Patent Document 8 has already been described in the ninth embodiment. Therefore, details are omitted.

The problem is that the mobile terminal operating in the DRX cycle [2] set shorter than the DRX cycle [1] passes the DRX cycle [1] even though there is no data to be continuously received. In the meantime, the reception operation of the L1 / L2 control signal must be performed in the DRX cycle [2] (see (4) in FIG. 34).
The above problem is a problem in realizing low power consumption of the mobile terminal.
Further, when the difference between the DRX cycle [1] and the DRX cycle [2] is large, the above problem becomes more prominent.

In the twelfth embodiment, the above problem is solved by the following method.
The mobile terminal receives (monitors) the L1 / L2 control signal after the DRX cycle, and shifts to the DRX operation in the “DRX cycle equal to or less than the current DRX cycle” when there is data addressed to itself.
In addition, after the DRX cycle, the mobile terminal receives (monitors) the L1 / L2 control signal, and when there is no data addressed to itself, the mobile terminal shifts to the DRX operation in the “DRX cycle equal to or greater than the current DRX cycle”. A DRX operation method is disclosed.

Hereinafter, a DRX operation method in the mobile communication system according to the twelfth embodiment will be described.
FIG. 39 is an explanatory diagram showing an example of a DRX operation method in the mobile communication system according to the twelfth embodiment of the present invention. In FIG. 39, white outlines indicate downlink data, and diagonal lines indicate L1 / L2 control signals.
The relationship between the DRX cycle lengths is that the initial DRX cycle is longer than the DRX cycle [2], the DRX cycle [2] is longer than the DRX cycle [3], the DRX cycle [3] is shorter than the DRX cycle [4], Period [4] is shorter than DRX period [5].

The mobile terminal that has shifted to the DRX operation in the initial DRX cycle performs reception processing of the L1 / L2 control signal after the initial DRX cycle, and receives downlink data if there is downlink data addressed to itself (see FIG. 39, see (1)).
The L1 / L2 control signal includes a DRX cycle [2] as “a DRX cycle equal to or less than the current DRX cycle”.

The mobile terminal sets the received DRX cycle [2] as the DRX cycle.
When the reception processing of the L1 / L2 control signal is performed and downlink data is continuously present, the mobile terminal receives downlink data (see (2) in FIG. 39).
After the DRX cycle [2], reception processing of the L1 / L2 control signal is performed, and if there is downlink data addressed to itself, downlink data is received (see (3) in FIG. 39).
The L1 / L2 control signal includes a DRX cycle [3] as a “DRX cycle equal to or less than the current DRX cycle”, which is a shorter DRX cycle.

The mobile terminal sets the received DRX cycle [3] as the DRX cycle.
When the reception processing of the L1 / L2 control signal is performed and there is no continuous downlink data, the mobile terminal performs the DRX operation with the DRX cycle (DRX cycle [3]) ((4 in FIG. 39). )).
In this example, the starting point of the DRX cycle [3] is the head of a subframe including the L1 / L2 control signal for which the DRX cycle [3] is notified (see FIG. 39). As another example, the start point of the DRX cycle [3] may be the head of a subframe including an L1 / L2 control signal for which it has been confirmed that there is no continuous downlink data ((4) in FIG. 39). See).

After the DRX cycle [3], the receiving process of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (5) in FIG. 39).
The L1 / L2 control signal includes a DRX cycle [4] as “a DRX cycle equal to or greater than the current DRX cycle”. The DRX operation of (5) in FIG. 39 is performed using this DRX cycle [4].
After the DRX cycle [4], the reception processing of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (6) in FIG. 39).
The L1 / L2 control signal includes a DRX cycle [5] as a “DRX cycle longer than the current DRX cycle”, which is a longer DRX cycle. The DRX operation of (6) in FIG. 39 is performed using this DRX cycle [5].

FIG. 40 is a sequence diagram showing an example of processing contents of the mobile terminal and the base station according to Embodiment 12 of the present invention.
The base station notifies the mobile terminal of the initial DRX cycle, and sets the initial DRX cycle as the DRX cycle of the mobile terminal (step ST4001).
The mobile terminal receives the initial DRX cycle from the base station, and sets the initial DRX cycle as the DRX cycle (step ST4002).

As an example of the method of notifying the initial DRX cycle from the base station to the mobile terminal, the following method can be considered.
(1) When a radio bearer is set up, the base station notifies the mobile terminal using L3 signaling.
(2) At a dynamic timing, the base station notifies the mobile terminal using an L1 / L2 control signal or in-band signaling (MAC signaling).
(3) Set as a specified value (Static) of the mobile communication system in the base station and the mobile terminal.

  As a specific example of the prescribed value, the maximum value of DRX cycle (for example, 5120 [TTI]) can be considered. When the specified value is used, there is no need to notify the initial DRX cycle from the base station to the mobile terminal, so that an effect of effective use of radio resources can be obtained. In addition, since there is no need to notify the wireless section, no reception error of the mobile terminal occurs. Therefore, it is possible to obtain an effect that a problem that the mobile terminal cannot normally receive downlink data addressed to itself can be obtained by setting different initial DRX cycles between the base station and the mobile terminal due to a reception error of the mobile terminal. .

The base station and the mobile terminal shift to the DRX operation in the above DRX cycle (steps ST4003 and ST4004).
Next, the base station determines whether downlink data has been generated for the mobile terminal (step ST4005).

First, processing contents when downlink data is generated will be described.
When downlink data occurs, the mobile terminal shifts to the process of step ST4006.
The base station notifies that there is downlink data for the mobile terminal using the L1 / L2 control signal after the DRX cycle (step ST4006). In other words, downlink data allocation is performed (see (1) in FIG. 39).
Then, the base station assigns downlink data to the mobile terminal, notifies the “DRX cycle less than or equal to the current DRX cycle”, and notifies the “DRX cycle less than or equal to the current DRX cycle” to the mobile terminal. The DRX cycle is set (step ST4008). However, the processing of step ST4006 and step ST4008 may be simultaneous, and the order is arbitrary.

The mobile terminal performs reception processing of the L1 / L2 control signal after the DRX cycle (step ST4007).
The mobile terminal receives the “DRX cycle equal to or less than the current DRX cycle” by the reception process of the L1 / L2 control signal (step ST4009).
The mobile terminal sets the received “DRX cycle equal to or less than the current DRX cycle” as the DRX cycle (step ST4010). Refer to (1) in FIG.
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4011).
If there is data addressed to the user, the process proceeds to step ST4013. However, the processing from step ST4007 to step ST4011 may be simultaneous, and the order is arbitrary.

The base station transmits downlink data to the mobile terminal using the radio resource allocated in step ST4006 (step ST4012).
The mobile terminal receives downlink data according to the radio resource allocated from the base station in step ST4007 (step ST4013).

The base station determines whether or not the next transmission timing (the timing of the next resource block (RB)) exceeds the DRX cycle (step ST4014).
When the next transmission timing does not exceed the DRX cycle, the process proceeds to step ST4016.
The base station determines whether data is continuously generated for the mobile terminal (step ST4016). If data is generated, the process proceeds to step ST4017.
The base station assigns downlink data to the mobile terminal using continuous L1 / L2 control signals (step ST4017). See (2) in FIG.

The base station assigns downlink data to the mobile terminal using continuous L1 / L2 control signals (step ST4017). See (2) in FIG.
In Step ST4012, the base station transmits downlink data according to the radio resource allocated in Step ST4017.

The mobile terminal determines whether or not the next reception timing (the timing of the next resource block) exceeds the DRX cycle (step ST4015).
When the next reception timing does not exceed the DRX cycle, the process proceeds to step ST4018.
The mobile terminal performs reception processing of the L1 / L2 control signal using the continuous L1 / L2 control signal (step ST4018).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4019). If there is data addressed to the user, the process proceeds to step ST4013.
In Step ST4013, the mobile terminal receives downlink data according to the radio resource allocated from the base station in Step ST4018.

On the other hand, the base station determines whether or not the next transmission timing (timing of the next resource block) exceeds the DRX cycle (step ST4014).
When it is determined that the next transmission timing exceeds the DRX cycle, the process proceeds to step ST4005. See (3) in FIG.
The mobile terminal determines whether or not the next reception timing (the timing of the next resource block) exceeds the DRX cycle (step ST4015).
When the next reception timing exceeds the DRX cycle, the process proceeds to step ST4007.

Further, the base station determines whether or not data for the mobile terminal is continuously generated (step ST4016). If no data is generated, the process proceeds to step ST4003, and the DRX operation is performed in the “DRX cycle” (see (4) in FIG. 39).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4019).
If there is no data addressed to itself, the process proceeds to step ST4004, and the DRX operation is performed in the “DRX cycle”.

Next, a case where no downlink data is generated will be described.
If no downlink data is generated, the base station proceeds to the process of step ST4020.
The base station does not notify the mobile terminal that there is downlink data using the L1 / L2 control signal after the DRX cycle (step ST4020). In other words, downlink data allocation is not performed (see (5) in FIG. 39).
Alternatively, in step ST4020, the base station may notify the mobile terminal that there is no downlink data using an L1 / L2 control signal after the DRX cycle. When notifying that there is no downlink data, the base station notifies clear information from the base station to the mobile terminal when notifying that the downlink data does not exist. An effect of reducing the occurrence of reception errors can be obtained.
Next, the base station notifies the mobile terminal of the “DRX cycle longer than the current DRX cycle” by the L1 / L2 control signal after the DRX cycle, and the notified “DRX cycle longer than the current DRX cycle”. Is set as the DRX cycle of the mobile terminal (step ST4021).
Thereafter, the process proceeds to step ST4003, and the DRX operation is performed in the “DRX cycle”. However, the processing of step ST4020 and step ST4021 may be simultaneous, and the order is arbitrary.

The mobile terminal performs reception processing of the L1 / L2 control signal after the DRX cycle (step ST4007).
The mobile terminal receives the “DRX cycle equal to or longer than the current DRX cycle” by the reception process of the L1 / L2 control signal (step ST4009).
The mobile terminal sets the received “DRX cycle longer than the current DRX cycle” as the DRX cycle (step ST4010). See (5) in FIG.
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4011). Alternatively, it is determined whether a notification that there is no downlink data is received.
When there is no data addressed to itself or when a notification that there is no downlink data is received, the process proceeds to step ST4004, and a DRX operation is performed in the “DRX cycle”. However, the processing from step ST4007 to step ST4011 may be simultaneous, and the order is arbitrary.

In the above description, an example is shown in which “DRX cycle equal to or less than current DRX cycle” and “DRX cycle equal to or greater than current DRX cycle” are notified by the L1 / L2 control signal in steps ST4006 and ST4020. Notification may be made not by the L1 / L2 control signal but by an in-band signal (MAC signaling).
Furthermore, when the radio bearer is set up, the DRX cycle set may be notified from the base station to the mobile terminal using L3 signaling.

Examples of the DRX cycle set include “DRX cycle A, DRX cycle B, DRX cycle C, DRX cycle D”. The relationship of the cycles at this time is “DRX cycle A> DRX cycle B> DRX cycle C> DRX cycle D”.
As a trigger for changing the DRX cycle in this case, an L1 / L2 control signal after the DRX cycle shown in steps ST4006 and ST4020 can be considered.

Specifically, when it is notified by the L1 / L2 control signal that there is downlink data for the mobile terminal (step ST4006), or when a change to a DRX cycle equal to or less than the current DRX cycle is notified. The base station and the mobile terminal set a DRX cycle that is one shorter than the current DRX cycle. Specifically, when the current DRX cycle is the DRX cycle B, the DRX cycle C is set to the DRX cycle.
On the other hand, when the L1 / L2 control signal does not notify that there is downlink data for the mobile terminal (step ST4020), notifies the mobile terminal that there is no downlink data, or DRX longer than the current DRX cycle When the change to the cycle is notified, the base station and the mobile terminal set a DRX cycle that is one longer than the current DRX cycle. Specifically, when the current DRX cycle is the DRX cycle B, the DRX cycle A is set to the DRX cycle. By notifying the DRX cycle set when the radio bearer is set up, it is not necessary to notify the DRX cycle with an L1 / L2 control signal for each DRX cycle, so that the effect of effective use of radio resources can be obtained. .

Furthermore, as a mobile communication system, a DRX cycle set may be set as a prescribed value (Static) in the base station and the mobile terminal. A specific example of the DRX cycle set is the same as that in the case of notification at the time of radio bearer setup.
Moreover, the example of the trigger which changes DRX period is the same as that of the case where it notifies at the time of a radio bearer setup.
When the specified value is used, it is not necessary to notify the mobile station of the DRX cycle from the base station, and thus an effect of effective use of radio resources can be obtained. In addition, since there is no need to notify the wireless section, no reception error of the mobile terminal occurs. Therefore, it is possible to obtain an effect that the mobile terminal cannot set a different DRX cycle between the base station and the mobile terminal due to a reception error of the mobile terminal, and the mobile terminal cannot normally receive downlink data addressed to itself. .
Further, in the above description, an example in which “DRX cycle equal to or less than current DRX cycle” and “DRX cycle equal to or greater than current DRX cycle” is notified by the L1 / L2 control signal in step ST4006 and step ST4020 is shown. However, only the difference ("newly set DRX cycle-current DRX cycle") may be notified. As a result, it is possible to reduce the amount of information (number of bits and number of symbols) when the base station notifies the mobile terminal of the DRX cycle, and the effect of effective use of radio resources can be obtained. In addition, the method using the difference is a notification method from the base station of the DRX cycle to the mobile terminal ("DRX cycle less than current DRX cycle""DRX cycle greater than current DRX cycle" L1 / L2 control signal, in-band Signal, L3 signaling, mobile communication system, etc.).
Further, when there is no need to change the DRX cycle depending on the traffic situation, it is possible not to notify the DRX cycle. Thereby, the effect of the effective utilization of the further radio | wireless resource can be acquired.

The following effects can be obtained by using the DRX operation method described above.
Generally, when there is data destined for the mobile terminal, it indicates that the traffic destined for the mobile terminal becomes high, and it is desirable to shorten the period during which the mobile terminal is not received.
On the contrary, when there is no data addressed to the mobile terminal, it indicates that the traffic is low, and it is considered that the period during which the mobile terminal is not received may be lengthened.
According to the DRX operation method disclosed in the twelfth embodiment, the mobile communication system receives (monitors) the L1 / L2 control signal in the DRX cycle, and as a result, the data addressed to the mobile terminal If there is, the DRX cycle is changed to “DRX cycle less than or equal to the current DRX cycle”, and if there is no data addressed to the mobile terminal, the DRX cycle is changed to “DRX cycle greater than or equal to the current DRX cycle”. It becomes possible.

Therefore, according to the twelfth embodiment, it is possible to obtain a DRX operation method capable of quickly changing the DRX cycle according to the traffic situation.
Thereby, the effect that the mobile terminal can implement | achieve low power consumption according to the condition of traffic can be acquired. As an example of realizing low power consumption of the mobile terminal, a period during which the mobile terminal is considered to be able to turn off the power of the reception system is shown as reception system power supply example 1 and example 2 of the mobile terminal in FIG.
Also, by the DRX operation method shown in the twelfth embodiment, a notification method ("DRX period equal to or less than current DRX period" or "DRX period equal to or greater than current DRX period" from the base station in the DRX period to L1 / L2 This is characterized in that many values can be taken as the DRX cycle regardless of the control signal, the in-band signal, the L3 signaling, the specified value as the mobile communication system, and the like. As a result, it is possible to obtain an effect that can flexibly cope with the traffic situation.

In particular, when compared with the DRX operation method disclosed in Non-Patent Document 8, the following effects can be obtained.
The problem of Non-Patent Document 8 is that the reception operation of the L1 / L2 control signal is performed in the DRX cycle [2] until the DRX cycle [1] elapses even though there is no data to be continuously received. There is a point that must be (see (4) in FIG. 34). In other words, there is a problem that the DRX cycle according to the traffic situation cannot be set quickly. That is, there is a problem that even when there is no data addressed to the mobile terminal, the DRX cycle cannot be changed (lengthened) quickly.

In the DRX operation method disclosed in the twelfth embodiment, the L1 / L2 control signal is received (monitored) in the DRX cycle, and the DRX cycle can be quickly changed in accordance with the traffic situation to the mobile terminal at that time. Since it becomes possible, the subject of the said nonpatent literature 8 can be solved.
Thus, by using the DRX operation method disclosed in the twelfth embodiment, the DRX cycle can be quickly set according to the traffic situation. Therefore, even when the traffic is low, the DRX cycle is changed (lengthened). ), It is not necessary to receive an unnecessary L1 / L2 control signal generated, and the effect of realizing more effective reduction in power consumption of the mobile terminal can be obtained.

A first modification of the twelfth embodiment will be described.
In the twelfth embodiment, an arbitrary value can be set for the “DRX cycle equal to or less than the current DRX cycle” and the “DRX cycle equal to or greater than the current DRX cycle”. Disclosed is a method of making the relationship of DRX cycles newly set according to traffic conditions constant.
A specific example of the relationship between the current DRX cycle and the newly set DRX cycle is shown below.
(A) A method for defining the difference. A specific example of how to obtain a new DRX cycle is as follows.
“DRX cycle equal to or less than current DRX cycle” = “current DRX cycle” + N
“DRX cycle equal to or greater than current DRX cycle” = “current DRX cycle” −N
(B) A method for defining the relationship between divisors and multiples. A specific example of how to obtain a new DRX cycle is as follows.
“DRX cycle equal to or less than current DRX cycle” = “current DRX cycle” × 1 / N
“DRX cycle equal to or greater than current DRX cycle” = “current DRX cycle” × N
In the following description, (a) a case where a relationship between a divisor and a multiple is specified will be described.

FIG. 41 is an explanatory diagram showing an example of a DRX operation method in the mobile communication system according to the first modification. In FIG. 41, outlines represent downlink data, and hatched lines represent L1 / L2 control signals.
The mobile terminal that has shifted to the DRX operation in the initial DRX cycle ("x" in FIG. 41) performs the reception process of the L1 / L2 control signal after the initial DRX cycle, and if there is downlink data addressed to itself, Downlink data is received (see (1) in FIG. 41).

If there is data destined for the mobile terminal, this indicates that the traffic situation will be high. Therefore, in order to shorten the period during which the mobile terminal is not received, “current DRX cycle × 1 / N” is newly set. Set as the DRX cycle. FIG. 41 shows an example of N = 2. Therefore, the value newly set as the DRX cycle is “x / 2”.
When the reception processing of the L1 / L2 control signal is performed and downlink data is continuously present, the mobile terminal receives downlink data (see (2) in FIG. 41).
After the DRX cycle (x / 2), reception processing of the L1 / L2 control signal is performed, and if there is downlink data addressed to itself, downlink data is received (see (3) in FIG. 41).
The mobile terminal sets “current DRX cycle × 1 / N” as a new DRX cycle. FIG. 41 shows an example of N = 2. Therefore, the value newly set as the DRX cycle is “x / 4”.

When the reception processing of the L1 / L2 control signal is performed and there is no continuous downlink data, the mobile terminal performs the DRX operation in the DRX cycle (x / 4) ((4) in FIG. 41). See). In this example, the start point of the DRX cycle is the head of a subframe including the L1 / L2 control signal after the DRX cycle (see FIG. 41).
After the DRX cycle (x / 4), the receiving process of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (5) in FIG. 41).

The DRX cycle used for this DRX operation is set as follows.
When the reception process of the L1 / L2 control signal is performed and there is no downlink data, it indicates that the traffic situation becomes low. In order to lengthen the period during which the mobile terminal is not received, “DRX cycle × N” is set as a new DRX cycle. FIG. 41 shows an example of N = 2. Therefore, the value newly set as the DRX cycle is “x / 2”.
After the DRX cycle (x / 2), the reception processing of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (6) in FIG. 41). The DRX cycle used for this DRX operation is “x / 2 × 2 = x”, which is “x”.

  FIG. 42 is a sequence diagram illustrating an example of processing contents of the mobile terminal and the base station according to the first modification. FIG. 42 is similar to FIG. 40 which is a sequence diagram showing an example of processing contents between the mobile terminal and the base station according to the twelfth embodiment. Since the same step number performs the same process, the description is omitted.

The base station notifies the mobile terminal of “N” indicating the maximum DRX cycle, the minimum DRX cycle, and the relationship between the current DRX cycle and the newly set DRX cycle (step ST4201).
The mobile terminal receives the maximum DRX cycle, the minimum DRX cycle, and “N” from the base station (step ST4202).
The maximum DRX cycle and the minimum DRX cycle notified from the base station to the mobile terminal are parameters that are newly required in the first modification.

In the twelfth embodiment, the base station notifies the mobile terminal of a new DRX cycle every DRX cycle, or the DRX cycle set is notified from the base station to the mobile terminal in advance, or the DRX cycle set Shows an example defined as a mobile communication system.
Compared to this, in the first modification, the base station does not explicitly notify the mobile terminal of the new DRX cycle, and the base station and the mobile terminal each have “current DRX cycle” and “N "A new DRX cycle" is set. By providing the maximum DRX cycle and the minimum DRX cycle as parameters, it is possible to prevent the setting of a long DRX cycle outside the allowable range and a short DRX cycle outside the allowable range.
An example of the maximum DRX cycle is 5120 [TTI]. As an example of the minimum DRX cycle, 1 [TTI] is conceivable.

As an example of the notification method of the maximum DRX cycle, the minimum DRX cycle, and “N” from the base station to the mobile terminal from the base station, the following method can be considered.
(1) When a radio bearer is set up, the base station notifies the mobile terminal using L3 signaling.
(2) As a specified value (Static) of the mobile communication system, it is set in the base station and the mobile terminal.
When the specified value is used, since there is no need to notify the mobile terminal of the maximum DRX cycle, the minimum DRX cycle, and “N” from the base station, the effect of effective use of radio resources can be obtained. In addition, since there is no need to notify the wireless section, no reception error of the mobile terminal occurs. For this reason, the maximum DRX cycle, the minimum DRX cycle, and “N” are set from different base stations between the base station and the mobile terminal due to a reception error of the mobile terminal, and the mobile terminal cannot normally receive downlink data addressed to itself. The effect that no problem occurs can be obtained.
The notification of the maximum DRX cycle, the minimum DRX cycle, and “N” may be simultaneous or different, and the order is arbitrary.
Note that, as a method of notifying the “DRX cycle equal to or less than the current DRX cycle” and “DRX cycle equal to or greater than the current DRX cycle” described in Embodiment 12, when the radio bearer is set up, On the other hand, when the DRX cycle set is notified, or when the DRX cycle set is set as a specified value in the base station and the mobile terminal as the mobile communication system, the parameters of the “maximum DRX cycle” and “minimum DRX cycle” Can be used. As a result, even in the DRX cycle included in the DRX cycle set, the base station can notify the mobile terminal of the DRX cycle that can be set at that time. Accordingly, it is possible to obtain an effect that a more optimal DRX operation method can be realized according to the relationship with other mobile terminals, the sum of mobile terminals in the same cell, the traffic status of the mobile terminal, and the like.
As a notification method, there may be a case where it becomes necessary to be able to change earlier according to a traffic situation or the like. Therefore, a notification method using an L1 / L2 control signal, an in-band signal, etc. in addition to the above can be considered so that the mobile station can be notified more dynamically from the base station.

First, processing contents when downlink data is generated will be described.
When the downlink data is generated, the base station proceeds to the process of step ST4006.
The base station notifies that there is downlink data for the mobile terminal using the L1 / L2 control signal after the DRX cycle (step ST4006). In other words, downlink data allocation is performed (see (1) in FIG. 41).
Next, when setting a new DRX cycle, the base station calculates “DRX cycle” (DRX cycle ′ = DRX cycle × 1 / N) as a provisional DRX cycle (step ST4203).

The base station determines whether the DRX cycle ′ is smaller than the minimum DRX cycle notified to the mobile terminal in step ST4201 (step ST4204).
When the DRX cycle ′ is not smaller than the minimum DRX cycle, the mobile terminal shifts to a process of step ST4205.
The base station sets the DRX cycle ′ as the DRX cycle (step ST4205).
On the other hand, when the DRX cycle ′ is smaller than the minimum DRX cycle, the mobile terminal shifts to the process of step ST4206.
The base station discards the DRX cycle ′ and does not change the DRX cycle (step ST4206). Alternatively, the minimum DRX cycle notified in step ST4201 may be set as the DRX cycle.

The mobile terminal performs reception processing of the L1 / L2 control signal after the DRX cycle (step ST4007).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4011). If there is data addressed to itself, the process proceeds to step ST4211.
In setting a new DRX cycle, the mobile terminal calculates “DRX cycle” (DRX cycle ′ = DRX cycle × 1 / N) as a provisional DRX cycle (step ST4211).

The mobile terminal determines whether the DRX cycle ′ is smaller than the minimum DRX cycle received in step ST4202 (step ST4212).
When the DRX cycle ′ is not smaller than the minimum DRX cycle, the mobile terminal shifts to a process of step ST4213.
The mobile terminal sets the DRX cycle ′ as the DRX cycle (step ST4213).
On the other hand, when the DRX cycle ′ is smaller than the minimum DRX cycle, the mobile terminal shifts to the process of step ST4214.
The mobile terminal discards the DRX cycle ′ and does not change the DRX cycle (step ST4214). Alternatively, the minimum DRX cycle received in step ST4202 may be set as the DRX cycle.

In step ST4006, the base station transmits downlink data using the radio resource allocated to the mobile terminal (step ST4012).
In Step ST4007, the mobile terminal receives downlink data according to the radio resource allocated from the base station (Step ST4013).

Next, a case where no downlink data is generated will be described.
When the downlink data is not generated, the base station moves to the process of step ST4020.
The base station does not notify the mobile terminal that there is downlink data using the L1 / L2 control signal after the DRX cycle (step ST4020). In other words, downlink data allocation (Allocation) is not performed, or notification that there is no downlink data for the mobile terminal is made (see (5) in FIG. 41).
Next, when setting a new DRX cycle, the base station calculates “DRX cycle” (DRX cycle ′ = DRX cycle × N) as a provisional DRX cycle (step ST4207).

The base station determines whether the DRX cycle ′ is greater than the maximum DRX cycle notified to the mobile terminal in step ST4201 (step ST4208).
When the DRX cycle ′ is not longer than the maximum DRX cycle, the mobile terminal shifts to a process of step ST4209.
The base station sets the DRX cycle ′ as the DRX cycle (step ST4209).
On the other hand, when the DRX cycle ′ is larger than the maximum DRX cycle, the processing shifts to step ST4210.
The base station discards the DRX cycle ′ and does not change the DRX cycle (step ST4210). Alternatively, the maximum DRX cycle notified in step ST4201 may be set as the DRX cycle.

The mobile terminal performs reception processing of the L1 / L2 control signal after the DRX cycle (step ST4007).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4011). When there is no data addressed to the user or when a notification that there is no downlink data is received, the mobile terminal shifts to the process of step ST4215.
In setting a new DRX cycle, the mobile terminal calculates “DRX cycle” (DRX cycle ′ = DRX cycle × N) as a provisional DRX cycle (step ST4215).

The mobile terminal determines whether the DRX cycle ′ is greater than the maximum DRX cycle received in step ST4202 (step ST4216).
When the DRX cycle ′ is not longer than the maximum DRX cycle, the mobile terminal shifts to a process of step ST4217.
The mobile terminal sets the DRX cycle ′ as the DRX cycle (step ST4217).
On the other hand, when the DRX cycle ′ is larger than the maximum DRX cycle, the mobile terminal shifts to a process of step ST4218.
The mobile terminal discards the DRX cycle ′ and does not change the DRX cycle (step ST4218). Alternatively, the maximum DRX cycle received in step ST4202 may be set as the DRX cycle.

By using the DRX operation method shown in the first modification, in addition to the effects obtained by using the twelfth embodiment, the following effects can be obtained.
In the twelfth embodiment, with respect to “a DRX cycle equal to or less than the current DRX cycle” and “a DRX cycle equal to or greater than the current DRX cycle”, an arbitrary value is notified from the base station to the mobile terminal. Then, only the relationship “N” between the DRX cycle newly set according to the current DRX cycle and the traffic situation is notified from the base station to the mobile terminal. As a result, the amount of information notified from the base station to the mobile terminal is reduced, so that it is possible to effectively use radio resources.

Furthermore, by using a method for defining the relationship between the divisor and multiple (b) in the relationship between the current DRX cycle and the newly set DRX cycle, the set DRX cycle becomes “N” of the initial DRX cycle. N times "or" 1 / N times n "times. Thereby, it is possible to obtain an effect that a downlink resource to be allocated to the mobile terminal can be predicted at the base station. In addition, when a mismatch in the DRX cycle (state transition error) occurs between the base station and the mobile terminal due to a reception error of the L1 / L2 control signal of the mobile terminal, the base station If the L1 / L2 control signal is notified to the mobile terminal, the mobile terminal can receive the L1 / L2 control signal and can recover from the state transition error.
Regarding the DRX operation method in the case where retransmission occurs due to application of HARQ, two methods are disclosed in this specification.
The method shown in the seventh embodiment and the method shown in the eighth embodiment. In order to obtain the effect that the base station can predict the downlink resource to be allocated to the mobile terminal, the DRX operation method when HARQ is applied and retransmission occurs is the method described in Embodiment 8 above. Use increases the affinity.
In particular, when compared with the DRX operation method disclosed in Non-Patent Document 8, the following effects can be obtained.
By using the method (1) of defining the relationship between the divisor and multiple in the relationship between the current DRX cycle and the newly set DRX cycle shown in the first modification, the method of Non-Patent Document 8 is used. In addition, there is an advantage that the L1 / L2 control signal receiving operation that is desired to avoid in order to reduce the power consumption of the mobile terminal as shown in FIG. Thereby, it is possible to obtain an effect that it is possible to construct a mobile communication system that is advantageous for low power consumption of the mobile terminal as compared with Non-Patent Document 8.

A second modification of the twelfth embodiment will be described.
In Embodiment 12, if the base station does not assign downlink data to the mobile terminal once by the L1 / L2 control signal after the DRX cycle, the mobile station will be notified of “the current DRX cycle or more. DRX cycle ”is set. Also in the mobile terminal, if it is confirmed once by the L1 / L2 control signal after the DRX cycle that no downlink data is allocated, the “DRX cycle longer than the current DRX cycle” notified from the base station is obtained. Set.
In the second modification, if the base station does not continuously assign downlink data to the mobile terminal M times in the L1 / L2 control signal after the DRX cycle, “DRX cycle greater than or equal to DRX cycle” is set. Also in the mobile terminal, if the L1 / L2 control signal after the DRX cycle confirms that the downlink data is not allocated M times continuously, the mobile station notifies the “DRX longer than the current DRX cycle” Set Cycle.

FIG. 43 is an explanatory diagram showing an example of a DRX operation method in the mobile communication system according to the second modification. In FIG. 43, white lines represent downlink data, and hatched lines represent L1 / L2 control signals.
The relationship between the DRX cycle lengths is that the initial DRX cycle is longer than the DRX cycle [2], the DRX cycle [2] is longer than the DRX cycle [3], the DRX cycle [3] is shorter than the DRX cycle [4], Period [4] is shorter than DRX period [5].

The mobile terminal that has shifted to the DRX operation in the initial DRX cycle performs reception processing of the L1 / L2 control signal after the initial DRX cycle, and receives downlink data if there is downlink data addressed to itself (see FIG. 43 (see (1)).
The L1 / L2 control signal includes a DRX cycle [2] as “a DRX cycle equal to or less than the current DRX cycle”. In addition, “M (DRX cycle [2])” corresponding to the DRX cycle [2] is notified from the base station to the mobile terminal. The mobile terminal sets the received DRX cycle [2] as the DRX cycle.

When the reception processing of the L1 / L2 control signal is performed and downlink data is continuously present, the mobile terminal receives downlink data (see (2) in FIG. 43).
After the DRX cycle [2], reception processing of the L1 / L2 control signal is performed, and if there is downlink data addressed to itself, downlink data is received (see (3) in FIG. 43).
The L1 / L2 control signal includes a DRX cycle [3] as “a DRX cycle equal to or less than the current DRX cycle”. In addition, “M (DRX cycle [3])” corresponding to the DRX cycle [3] is notified from the base station to the mobile terminal.
In FIG. 43, description will be made assuming that “M (DRX cycle [3]) = 2”. The mobile terminal sets the received DRX cycle [3] as the DRX cycle.

When the reception process of the L1 / L2 control signal is performed and there is no continuous downlink data, the mobile terminal performs the DRX operation according to the DRX cycle (DRX cycle [3]) ((4 in FIG. 43). )).
In this example, the start point of the DRX cycle [3] is the head of the subframe including the L1 / L2 control signal for which the DRX cycle [3] is notified (see FIG. 43).

After the DRX cycle [3], the receiving process of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (5) in FIG. 43).
The L1 / L2 control signal may include a DRX cycle [4] as “a DRX cycle longer than the current DRX cycle”. However, since it is confirmed only once that the downlink data is not allocated by the L1 / L2 control signal after the DRX cycle [3], and “M (DRX cycle [3]) = 2”. 32 (5), the mobile terminal does not set the DRX cycle [4] as the DRX cycle. Therefore, the DRX cycle remains the DRX cycle [3].
After the DRX cycle [3], the receiving process of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (6) in FIG. 43). Since it has been confirmed M times (M (DRX cycle 3) = 2) that the downlink data is not assigned by the L1 / L2 control signal after the DRX cycle [3], the DRX cycle [4] is changed to DRX. Set as period.

  FIG. 44 is a sequence diagram showing an example of processing contents of the mobile terminal and the base station according to the second modification. FIG. 44 is similar to FIG. 40 which is a sequence diagram showing an example of processing contents of the mobile terminal and the base station according to the twelfth embodiment of the present invention. Since the same step number performs the same process, the description is omitted.

The processing content when downlink data is generated will be described.
When the downlink data is generated, the base station moves to the process of step ST4006.
The base station notifies that there is downlink data for the mobile terminal using the L1 / L2 control signal after the DRX cycle (step ST4006). In other words, downlink data allocation is performed (see (1) in FIG. 43).
The base station assigns downlink data to the mobile terminal, notifies the “DRX cycle less than or equal to the current DRX cycle”, and notifies the “DRX cycle less than or equal to the current DRX cycle” to the DRX of the mobile terminal. The period is set (step ST4008).
The base station notifies the mobile terminal of “M” corresponding to the “DRX cycle equal to or less than the current DRX cycle” notified in step ST4408 (step ST4401). However, the processing of step ST4006, step ST4008, and step ST4401 may be simultaneous, and the order is arbitrary.

The definition of the parameter “M” is as follows.
This parameter adjusts the timing of changing the current DRX cycle to a longer DRX cycle when the traffic situation is low and the frequency of downlink data addressed to the mobile terminal is reduced.
As a specific usage example, if the base station does not continuously generate downlink data allocation for the mobile terminal M times in the L1 / L2 control signal after the DRX cycle, “DRX cycle longer than current DRX cycle” is set. In the mobile terminal, if the L1 / L2 control signal after the DRX cycle confirms that the downlink data is not allocated M times continuously, the mobile station notifies the “DRX longer than the current DRX cycle” Set Cycle.

The mobile terminal performs reception processing of the L1 / L2 control signal after the DRX cycle (step ST4007).
The mobile terminal receives the “DRX cycle equal to or less than the current DRX cycle” by the reception process of the L1 / L2 control signal (step ST4009).
Next, the mobile terminal receives “M” from the base station (step ST4402).
The parameter “M” is a parameter newly provided in the second modification.

As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4011). If there is data addressed to the user, the process proceeds to step ST4403.
The mobile terminal sets the DRX cycle received in step ST4009 as the DRX cycle (step ST4403). Refer to (1) in FIG.

In step ST4006, the base station transmits downlink data using the radio resource allocated to the mobile terminal (step ST4012).
In Step ST4007, the mobile terminal receives downlink data according to the radio resource allocated from the base station (Step ST4013).

Next, a case where no downlink data is generated will be described.
When the downlink data is not generated, the base station moves to the process of step ST4020.
The base station does not notify the mobile terminal that there is downlink data using the L1 / L2 control signal after the DRX cycle (step ST4020). In other words, downlink data allocation is not performed (see (5) in FIG. 43).

The base station notifies the mobile terminal of the “DRX cycle longer than the current DRX cycle” by the L1 / L2 control signal after the DRX cycle (step ST4021).
Based on the L1 / L2 control signal after the DRX cycle, the base station determines whether downlink data allocation to the mobile terminal has occurred M times (“M” corresponding to the current DRX cycle) ( Step ST4404). When the number of times that the allocation to the mobile terminal is not performed is less than M times, the process shifts to the process of step ST4003 without changing the DRX cycle and performs the DRX operation (see (5) in FIG. 43).
On the other hand, when the number of times that the allocation to the mobile terminal is not performed becomes M times, the process proceeds to step ST4405 (see (6) in FIG. 43).
The base station sets the notified “DRX cycle longer than the current DRX cycle” as the DRX cycle of the mobile terminal (step ST4405). Thereafter, the process proceeds to step ST4003, and DRX operation is performed (see (6) in FIG. 43).

The mobile terminal performs reception processing of the L1 / L2 control signal after the DRX cycle (step ST4007).
The mobile terminal receives the “DRX cycle equal to or longer than the current DRX cycle” by the reception process of the L1 / L2 control signal (step ST4009).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST4011). If there is no data addressed to the user, the process proceeds to step ST4406.

The mobile terminal determines whether or not it has been continuously confirmed M times ("M" corresponding to the current DRX cycle) that there is no downlink data allocation to the mobile terminal by the L1 / L2 control signal after the DRX cycle. (Step ST4406). If the number of times of confirming that there is no allocation is less than M, the process proceeds to step ST4004 without changing the DRX cycle, and the DRX operation is performed (see (5) in FIG. 43).
On the other hand, when the number of times of confirming that there is no allocation is M times, the process proceeds to step ST4407 (see (6) in FIG. 43).
The mobile terminal sets the received “DRX cycle equal to or greater than the current DRX cycle” as the DRX cycle (step ST4407). Thereafter, the process proceeds to step ST4004, and DRX operation is performed (see (6) in FIG. 43).

In the above description, “M” is notified by the L1 / L2 control signal in step ST4401, but the in-band signal (MAC signaling) is associated with the corresponding DRX cycle instead of the L1 / L2 control signal. You may make it notify by.
Furthermore, when the radio bearer is set up, the base station may notify the mobile terminal of “M set” in association with the DRX cycle set notified using L3 signaling. Alternatively, “M” corresponding to all DRX cycles may be notified.
When the radio bearer is set up, “M set” is notified in association with the DRX cycle set, thereby “DRX cycle equal to or less than current DRX cycle” is notified by the L1 / L2 control signal for each DRX cycle. In this case, there is no need to notify “M” at this time, so that it is possible to effectively use radio resources.

Further, “M set” may be set in the base station and the mobile terminal as a specified value (Static) in association with the DRX cycle set specified as the mobile communication system. Alternatively, “M” corresponding to all DRX cycles may be set.
When the specified value is used, there is no need to notify the DRX cycle from the base station to the mobile terminal, so that an effect of effectively utilizing radio resources can be obtained.
In addition, since there is no need to notify the wireless section, no reception error of the mobile terminal occurs. Therefore, it is possible to obtain an effect that a problem that the mobile terminal cannot normally receive downlink data addressed to itself can be obtained by setting different DRX cycles between the base station and the mobile terminal due to a reception error of the mobile terminal.

By using the DRX operation method shown in the second modification, in addition to the effects obtained by using the twelfth embodiment, the following effects can be obtained.
In Embodiment 12, if the base station does not assign downlink data to the mobile terminal once by the L1 / L2 control signal after the DRX cycle, the mobile station will be notified of “the current DRX cycle or more. DRX cycle ”is set. Also in the mobile terminal, if it is confirmed once by the L1 / L2 control signal after the DRX cycle that no downlink data is allocated, the “DRX cycle longer than the current DRX cycle” notified from the base station is obtained. Set.

In the second modification, if the base station does not continuously assign downlink data to the mobile terminal M times in the L1 / L2 control signal after the DRX cycle, “DRX cycle greater than or equal to DRX cycle” is set. Also in the mobile terminal, if the L1 / L2 control signal after the DRX cycle confirms that the downlink data is not allocated M times continuously, the mobile station notifies the “DRX longer than the current DRX cycle” Set Cycle.
As a result, when there is no downlink data allocation, it is possible to adjust the period for checking whether or not the traffic situation has actually become low, instead of quickly shifting to the “DRX cycle longer than the current DRX cycle”. It becomes possible. The number of times of confirming that there is no downlink data allocation can be changed.
As a result, it is possible to effectively adjust the downlink throughput and the power consumption reduction of the mobile terminal.

A third modification of the twelfth embodiment will be described.
In the third modification, an example of an optimum method when the first and second modifications are used in combination is shown. Specifically, the parameter “N” in Modification 1 and the parameter “M” in Modification 2 are set to the same value.

FIG. 45 is an explanatory diagram showing an example of a DRX operation method in the mobile communication system according to the third modification. In FIG. 45, white lines indicate downlink data, and hatched lines indicate L1 / L2 control signals.
A mobile terminal that has shifted to a DRX operation in the initial DRX cycle (“x” in FIG. 45) performs reception processing of the L1 / L2 control signal after the initial DRX cycle, and if there is downlink data addressed to itself, Downlink data is received (see (1) in FIG. 45).
If there is data destined for the mobile terminal, this indicates that the traffic situation will be high. Therefore, in order to shorten the period during which the mobile terminal is not received, “current DRX cycle × 1 / N” is newly set. Set as the DRX cycle. FIG. 45 shows an example of N = 2. Therefore, the value newly set as the DRX cycle is “x / 2”.
When the reception processing of the L1 / L2 control signal is performed and downlink data is continuously present, the mobile terminal receives downlink data (see (2) in FIG. 45).

After the DRX cycle (x / 2), reception processing of the L1 / L2 control signal is performed, and if there is downlink data addressed to itself, downlink data is received (see (3) in FIG. 45).
The mobile terminal sets “current DRX cycle × 1 / N” as a new DRX cycle. FIG. 45 shows an example of N = 2. Therefore, the value newly set as the DRX cycle is “x / 4”.
When the reception process of the L1 / L2 control signal is performed and there is no continuous downlink data, the mobile terminal performs the DRX operation with the DRX cycle = x / 4 (see (4) in FIG. 45). reference).
In this example, the start point of the DRX cycle is the head of a subframe including the L1 / L2 control signal after the DRX cycle (see FIG. 45).

After the DRX cycle (x / 4), the reception processing of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (5) in FIG. 45). Since the L1 / L2 control signal after the DRX cycle = x / 4 only confirms that the downlink data is not allocated once, and “M = N = 2”, (5 in FIG. ), The mobile terminal does not change the DRX cycle.
After the DRX cycle (x / 4), the receiving process of the L1 / L2 control signal is performed, and if there is no downlink data addressed to itself, the operation shifts to the DRX operation (see (6) in FIG. 45). In the L1 / L2 control signal after DRX cycle = x / 4, it has been confirmed twice ((5) (6) in FIG. 45) that downlink data is not allocated. Then, the mobile terminal changes the DRX cycle. The DRX cycle is “x / 4 × 2 = x / 2”.

The sequence diagram showing an example of the processing contents of the mobile terminal and the base station according to Modification 3 can be used in combination with FIG. 42 which is the sequence of Modification 1 and FIG. 44 which is the sequence diagram of Modification 2. Therefore, the description is omitted.
By using the DRX operation method shown in Modification 3 above, in addition to the effects of using Embodiment 12, Modification 1 and Modification 2, the following effects can be obtained.
By setting the parameter “N” in the first modification and the parameter “M” in the second modification to the same value, the mobile terminal always monitors the L1 / L2 control signal in one “longer DRX cycle”. (See (6) and (7) in FIG. 45).

As a result, when a mismatch in the DRX cycle (state transition error) occurs between the base station and the mobile terminal due to a reception error of the L1 / L2 control signal of the mobile terminal, the base station If the L1 / L2 control signal is notified to the mobile terminal in the “cycle” or initial DRX cycle, the mobile terminal can receive the L1 / L2 control signal and can recover from the state transition error. An effect is obtained.
Regarding the DRX operation method in the case where retransmission occurs due to application of HARQ, two methods are disclosed in this specification.
The method shown in the seventh embodiment and the method shown in the eighth embodiment. In order to obtain the effect of the third modified example, the affinity of the DRX operation method when retransmission is caused by applying HARQ is increased by using the method shown in the eighth embodiment.
In particular, when compared with the DRX operation method disclosed in Non-Patent Document 8, the following effects can be obtained.
In the third modification, since the method of making the relationship between the current DRX cycle and the DRX cycle newly set according to the traffic situation constant is used, as in the method of Non-Patent Document 8, ( There is an advantage that the extra L1 / L2 control signal receiving operation as in 4) does not occur. Thereby, it is possible to obtain an effect that it is possible to construct a mobile communication system that is advantageous for low power consumption of the mobile terminal as compared with Non-Patent Document 8.

A fourth modification of the twelfth embodiment will be described.
In the twelfth embodiment, the method of reporting the “initial DRX cycle” from the base station to the mobile terminal has been described. However, in the fourth modification, a method of setting the initial DRX cycle according to the QoS of the service is disclosed. .

The processing contents of the mobile terminal and the base station are similar to FIG. 40 which is a sequence diagram showing an example of the processing contents of the mobile terminal and the base station according to the twelfth embodiment. Therefore, the following description will focus on the different parts with reference to FIG.
In Step ST4001, the base station does not notify the mobile terminal of the initial DRX cycle.
Instead, when the radio bearer is set up in the base station, the initial DRX cycle is selected according to the QoS of the service notified from the base station to the mobile terminal (for example, according to Example 1 in FIG. 46). , And set as the DRX cycle.
In addition, in step ST4002, instead of receiving the initial DRX cycle, the mobile terminal selects the initial DRX cycle according to the QoS of the service notified from the base station (for example, according to Example 1 in FIG. 46), Set as DRX cycle.

Example 1 in FIG. 46 shows an example of the relationship between the QoS of the service and the initial DRX cycle.
The QoS classification is not limited to Example 1 in FIG. As another example, an initial DRX cycle may be related according to a provided service.
Also, the DRX cycle is not limited to the designation of the TTI unit as shown in Example 1 of FIG. 46, but may be a time unit [ms], a subframe unit, or the like.
Further, the relationship between the QoS of the service and the initial DRX cycle may be defined as a mobile communication system, or may be notified from the base station to the mobile terminal.
In a mobile communication system, when multi-service is realized, an initial DRX cycle corresponding to the highest QoS among services provided by the base station and the mobile terminal is selected and set as the DRX cycle. It may be.
Furthermore, as shown in Example 2 of FIG. 46, the maximum DRX cycle may be set according to the QoS of the service. Alternatively, the minimum DRX cycle may be set according to the QoS of the service.
This modified example 4 can also be applied to modified example 1, modified example 2, and modified example 3.

By using the DRX operation method shown in the fourth modification, in addition to the effects obtained by using the twelfth embodiment, the first modification, the second modification, and the third modification, the following effects can be obtained.
Even when downlink data is generated for the mobile terminal at the base station, if the mobile terminal is in DRX operation, downlink data cannot be transmitted to the mobile terminal.
Therefore, setting a long DRX cycle can reduce the power consumption of the mobile terminal, but also has a disadvantage that the downlink throughput is lowered. That is, when the service QoS is required to be high, by setting the initial DRX cycle or the maximum DRX cycle to be short, it is possible to perform DRX operation as a mobile communication system while satisfying the service QoS. It becomes.

By using the modified example 4, the initial DRX cycle, the maximum DRX cycle, or the optimal initial DRX cycle according to the QoS of the service without notifying the mobile station from the initial DRX cycle and the maximum DRX cycle. Alternatively, it is possible to realize a DRX operation using an optimum maximum DRX cycle.
As a result, it is possible to perform an optimum DRX operation that leads to lower power consumption of the mobile terminal while satisfying the QoS of the service.
In addition, since there is no need to notify the mobile station of the initial DRX cycle, the maximum DRX cycle, or the initial DRX cycle and the maximum DRX cycle, it is also effective in terms of effective use of radio resources. Can do.

Embodiment 13 FIG.
In Non-Patent Document 9, time division multiplexing (TDM) is used as a data transmission method other than E-MBMS (Evolved Multimedia Broadcast Service) and non-E-MBMS (non-MBMS, non-EMBMS). Is disclosed.
FIG. 47 is an explanatory diagram showing an example of assignment of radio resources other than E-MBMS and E-MBMS. As an example, the unit of time division is described in units of subframes.

Non-Patent Document 10 discloses that only the first symbol or only the first two symbols in a subframe allocated to E-MBMS by time division multiplexing (TDM) is used in the Unicast service.
FIG. 48 shows an example of radio resource allocation. Only the first symbol (see (1) in FIG. 48) in the subframe assigned to E-MBMS is used in the Unicast service.
Non-Patent Documents 9 and 10 describe nothing about DRX operation (DRX operation during Active).

When data other than E-MBMS and E-MBMS are time-division multiplexed, and only the first symbol or only a few symbols in the subframe allocated to E-MBMS are available in the Unicast service The following problems arise in relation to DRX operation (DRX operation during Active).
The problem of the thirteenth embodiment will be described with reference to FIG.

The mobile terminal performs the DRX operation in the DRX cycle (x). The mobile terminal receives (monitors) the L1 / L2 control signal for each DRX cycle (see (1) and (2) in FIG. 49). If there is downlink data addressed to itself as a result of the reception process of the L1 / L2 control signal, the downlink data is received by the radio resource allocated by the L1 / L2 control signal.
The radio resource allocated by the L1 / L2 control signal in the dynamic scheduling is within the same subframe as the subframe including the L1 / L2 control signal on the time axis.
On the other hand, if there is no downlink data addressed to itself as a result of the reception process of the L1 / L2 control signal, the DRX operation is performed in the DRX cycle (see (1) in FIG. 49).

The following problems occur at the timing at which the cycle in which E-MBMS is transmitted, in other words, the cycle at which E-MBMS data is time-division multiplexed and the timing at which Active (see FIG. 15) during the DRX operation overlaps. To do.
The symbols that can be used for the Unicast service in the subframe assigned to E-MBMS are only the first one symbol or only the first two symbols, and the L1 / L2 control signal in the subframe not assigned to E-MBMS. Is less than the number of symbols assigned to (first 1 symbol, top 2 symbols, or top 3 symbols).
Therefore, the mobile terminal performing the DRX operation monitors the L1 / L2 control signal at a timing at which the period in which the E-MBMS is transmitted overlaps with the timing of becoming active (see FIG. 15) during the DRX operation period. However, there is a possibility that it cannot be determined whether or not the data addressed to itself exists in the L1 / L2 control signal.

Hereinafter, an operation of E-MBMS as a mobile communication system and a DRX operation method in Embodiment 13 will be described.
FIG. 50 is an explanatory diagram showing an example of an E-MBMS operation and a DRX operation method in the mobile communication system according to the thirteenth embodiment of the present invention.
In FIG. 50, white lines represent Unicast downlink data, right-upward oblique lines represent L1 / L2 control signals, and right-downward oblique lines represent E-MBMS data.

The mobile terminal performs the DRX operation in the DRX cycle (x). The mobile terminal receives (monitors) the L1 / L2 control signal for each DRX cycle (see (1) in FIG. 50).
If there is downlink data addressed to itself as a result of the reception process of the L1 / L2 control signal, the downlink data is received by the radio resource allocated by the L1 / L2 control signal.
The radio resource allocated by the L1 / L2 control signal in the dynamic scheduling is within the same subframe as the subframe including the L1 / L2 control signal on the time axis.
On the other hand, if there is no downlink data addressed to itself as a result of the reception process of the L1 / L2 control signal, the DRX operation is performed in the DRX cycle (see (1) in FIG. 50).

In the mobile terminal, when the cycle in which E-MBMS is transmitted, in other words, the cycle in which E-MBMS data is time-division multiplexed, and the timing at which Active (see FIG. 15) during the DRX operation period overlaps ( In FIG. 50, (see (2)), the reception operation of the L1 / L2 control signal in the DRX operation is not performed (skip).
The mobile terminal in the DRX operation performs the reception operation of the L1 / L2 control signal in the DRX operation in the next subframe of the period in which the E-MBMS is transmitted (see (3) in FIG. 50).

When downlink data transmission is assigned to the mobile terminal with the L1 / L2 control signal in the subframe next to the period in which E-MBMS is transmitted, the downlink data is transmitted according to the assignment in the same subframe. (See (4) in FIG. 50).
In addition, when the period of E-MBMS transmission and the timing of becoming active during the DRX operation period (the reception timing of the L1 / L2 control signal during the DRX operation period) do not overlap, skip is performed in the DRX operation. The reception operation of the L1 / L2 control signal is performed at the same timing as the case where there is no (see (5) in FIG. 50).

FIG. 51 is a sequence diagram showing an example of processing contents of a mobile terminal and a base station according to Embodiment 13 of the present invention.
The base station notifies the mobile terminal of the E-MBMS transmission period and the starting point of the E-MBMS transmission period (Starting Point) (step ST6101). It is considered that the start is notified by a frame number, a subframe number, a slot number, a symbol number, and the like.
Usually, it is sufficient that only the mobile terminal receiving the E-MBMS service receives the notification of the E-MBMS transmission period and the start of the E-MBMS transmission period. However, in the thirteenth embodiment, in Step ST6101, the mobile terminal that receives the E-MBMS service transmission information (E-MBMS transmission period, start of the E-MBMS transmission period) in the E-MBMS service, or It is characterized in that not only a mobile terminal having the ability to receive an E-MBMS service but also all mobile terminals under the base station reception.
This is because even a mobile terminal that receives an E-MBMS service or a mobile terminal other than a mobile terminal that has the ability to receive an E-MBMS service may perform an active DRX operation. For this reason, it is conceivable that BCH (Broadcast Channel) which is a channel for transmitting broadcast information is used for the above notification.

The mobile terminal receives the E-MBMS transmission cycle and the start of the E-MBMS transmission cycle from the base station (step ST6102).
In a mobile communication system in which a mobile terminal that does not perform an active DRX operation or a mobile terminal that does not have an ability to perform an active DRX operation is allowed, all the mobile terminals being served by the base station are E-MBMS. Instead of receiving service transmission information, a mobile terminal that does not perform the DRX operation during Active or a mobile terminal that does not have the capability to perform the DRX operation during Active receives the transmission information of the E-MBMS service. You don't have to.

The base station and the mobile terminal transition to the DRX operation in the DRX cycle (step ST6103, step ST6104).
The base station determines whether downlink data has occurred for the mobile terminal (step ST6105).

First, processing contents when downlink data is generated will be described.
When the downlink data is generated, the base station moves to the process of step ST6106.
The base station determines whether or not the transmission timing of the L1 / L2 control signal during the DRX operation period for the mobile terminal overlaps with the transmission timing of E-MBMS (step ST6106). When the transmission timing of the L1 / L2 control signal overlaps with the transmission timing of E-MBMS, the process proceeds to step ST6111.
The base station does not perform (skip) the transmission operation at the transmission timing of the L1 / L2 control signal in the normal DRX operation (see (2) in FIG. 50) (step ST6111).
In the subframe (see (3) in FIG. 50) next to the transmission timing of the L1 / L2 control signal in the normal DRX operation, the transmission operation of the L1 / L2 control signal in the DRX operation for the mobile terminal is performed.

The mobile terminal determines whether the reception timing of the L1 / L2 control signal during the DRX operation period overlaps with the transmission timing of E-MBMS (step ST6107).
When the reception timing of the L1 / L2 control signal overlaps with the transmission timing of E-MBMS, the mobile terminal shifts to the process of step ST6112.
The mobile terminal does not perform (skip) the reception operation at the reception timing of the L1 / L2 control signal in the normal DRX operation (see (2) in FIG. 50) (step ST6112).
In the subframe (see (3) in FIG. 50) next to the reception timing of the L1 / L2 control signal in the normal DRX operation, the reception operation of the L1 / L2 control signal in the DRX operation is performed.

The base station transmits downlink data using the radio resource allocated to the mobile terminal in Step ST6111 or Step ST6108 (Step ST6113).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST6110). If there is data addressed to itself, the mobile terminal shifts to the process of step ST6114.
The mobile terminal receives downlink data according to the radio resource allocated by the base station in step ST6112 or step ST6109 (step ST6114).

The base station determines whether or not the transmission timing of the L1 / L2 control signal during the DRX operation period for the mobile terminal overlaps with the transmission timing of E-MBMS (step ST6106).
When the transmission timing of the L1 / L2 control signal does not overlap with the transmission timing of E-MBMS, the process proceeds to step ST6108.
The base station performs a transmission operation at the transmission timing of the L1 / L2 control signal in the normal DRX operation (step ST6108). Thereafter, the process proceeds to step ST6113.
The mobile terminal performs a reception operation at the reception timing of the L1 / L2 control signal in the normal DRX operation (step ST5109). Thereafter, the process proceeds to step ST6114.

Next, a case where no downlink data is generated will be described.
If no downlink data is generated, the base station moves to the process of step ST6103 (step ST6105).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST6110). If there is no data addressed to the user, the process proceeds to step ST6104.

According to the thirteenth embodiment, the following effects can be obtained.
It is possible to obtain an effect that the E-MBMS service and the Unicast service can be provided without any provision of information newly transmitted / received between the base station and the mobile terminal.
In solving the problem of the thirteenth embodiment, it is effective in that radio resources can be effectively utilized in that no information is newly transmitted and received between the base station and the mobile terminal. Solution.

A first modification of the thirteenth embodiment will be described.
In the thirteenth embodiment, when the cycle in which the E-MBMS is transmitted overlaps with the timing of becoming active during the DRX operation period, the problem is solved by not performing the transmission / reception operation of the L1 / L2 control signal in the DRX operation. ing.
In the first modification, the mobile terminal overlaps the cycle in which the E-MBMS is transmitted and the timing at which Active (see FIG. 15) during the DRX operation period overlaps (see (2) in FIG. 50). ), The L1 / L2 control signal in the DRX operation is transmitted / received in the DRX cycle using the first symbol or several symbols available in the Unicast service. This causes the following new problem.
The portions other than the symbols that can be used for the Unicast service in the subframe assigned to the E-MBMS are used by the E-MBMS and cannot be used in the Unicast service. Therefore, downlink data transmission to the mobile terminal is performed using the L1 / L2 control signal transmitted from the base station to the mobile terminal using symbols available for the Unicast service in the subframe allocated to E-MBMS. When the allocation is performed, there arises a problem that collision between E-MBMS data and Unicast data occurs (see (3) in FIG. 49).
In the first modification, when the period when the E-MBMS is transmitted overlaps with the timing of becoming active during the DRX operation period, when the downlink data is assigned by the L1 / L2 control signal, The assignment of downlink data is performed by performing the assignment in the next subframe (or after the specified subframe as the mobile communication system or after the subframe notified from the base station to the mobile terminal).

An example of the operation of the E-MBMS as a mobile communication system according to the first modification and the DRX operation method will be described with reference to FIG. In FIG. 50, white lines represent Unicast downlink data, right-upward oblique lines represent L1 / L2 control signals, and right-downward oblique lines represent E-MBMS data.
The mobile terminal performs the DRX operation in the DRX cycle (x). The mobile terminal receives (monitors) the L1 / L2 control signal for each DRX cycle (see (1) in FIG. 50).
If there is downlink data addressed to itself as a result of the reception process of the L1 / L2 control signal, the downlink data is received by the radio resource allocated by the L1 / L2 control signal.
The radio resource allocated by the L1 / L2 control signal in the dynamic scheduling is within the same subframe as the subframe including the L1 / L2 control signal on the time axis.
On the other hand, if there is no downlink data addressed to itself as a result of the reception process of the L1 / L2 control signal, the DRX operation is performed in the DRX cycle (see (1) in FIG. 50).

In the mobile terminal, when the cycle in which E-MBMS is transmitted, in other words, the cycle in which E-MBMS data is time-division multiplexed, and the timing at which Active (see FIG. 15) during the DRX operation period overlaps ( 50 (see (2) in FIG. 50), the L1 / L2 control signal in the DRX operation is transmitted / received in the DRX cycle using the first symbol or several symbols available in the Unicast service.
When downlink data is assigned to the mobile terminal using the L1 / L2 control signal, downlink data is not transmitted / received within the same subframe, and the sub-cycle next to the period in which E-MBMS is transmitted is transmitted. Downlink data is transmitted and received in a frame (see (4) in FIG. 50).
In addition, when the cycle in which E-MBMS is transmitted does not overlap with the timing of becoming active during the DRX operation period (the reception timing of the L1 / L2 control signal during the DRX operation period), the L1 / L2 control signal When downlink data is allocated to a mobile terminal, the radio resource allocated by the L1 / L2 control signal and the time axis are assigned to the downlink data within the same subframe, as in normal dynamic scheduling. Send and receive.

  FIG. 52 is a sequence diagram illustrating an example of processing contents of the mobile terminal and the base station according to the first modification. FIG. 52 is similar to FIG. 51 which is a sequence diagram showing an example of processing contents of the mobile terminal and the base station according to Embodiment 13 of the present invention. Since the same step number performs the same process, the description is omitted.

The processing content when downlink data is generated will be described.
When the downlink data is generated, the base station moves to the process of step ST6201.
The base station notifies that there is downlink data for the mobile terminal using the L1 / L2 control signal after the DRX cycle (step ST6201). In other words, downlink data allocation is performed (see (2) in FIG. 50). Thereafter, the process proceeds to step ST6106.

The mobile terminal performs reception processing of the L1 / L2 control signal after the DRX cycle (step ST6202). Then, the process proceeds to step ST6110.
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST6110). If there is data addressed to the user, the process proceeds to step ST6107.

The base station determines whether or not the transmission timing of the L1 / L2 control signal during the DRX operation period for the mobile terminal overlaps with the transmission timing of E-MBMS (step ST6106). When the transmission timing of the L1 / L2 control signal overlaps with the transmission timing of E-MBMS, the mobile terminal shifts to the process of step ST6203.
The base station skips the transmission timing of the downlink data by one subframe (step ST6203), and transmits the downlink data in the next subframe (see (4) in FIG. 50) in the period in which the E-MBMS is transmitted. Perform (step ST6113).

The mobile terminal determines whether or not the transmission timing of the L1 / L2 control signal during the DRX operation period for the mobile terminal overlaps with the transmission timing of E-MBMS (step ST6107).
When the transmission timing of the L1 / L2 control signal overlaps with the transmission timing of E-MBMS, the mobile terminal shifts to the process of step ST6204.
The mobile terminal skips downlink data reception timing by one subframe (step ST6204), and receives downlink data in the next subframe (see (4) in FIG. 50) of the cycle in which E-MBMS is transmitted. It performs (step ST6114).

The base station determines whether or not the transmission timing of the L1 / L2 control signal during the DRX operation period for the mobile terminal overlaps with the transmission timing of E-MBMS (step ST6106).
When the transmission timing of the L1 / L2 control signal does not overlap with the transmission timing of E-MBMS, the mobile terminal shifts to the process of step ST6113.
In the radio resource allocated to the mobile terminal, downlink data is transmitted in the same subframe as the radio resource and time axis allocated by the L1 / L2 control signal, as in normal dynamic scheduling.

The mobile terminal determines whether the reception timing of the L1 / L2 control signal during the DRX operation period for the mobile terminal overlaps with the transmission timing of E-MBMS (step ST6107).
When the reception timing of the L1 / L2 control signal does not overlap with the transmission timing of E-MBMS, the mobile terminal shifts to the process of step ST6114.
In step ST6202, according to the radio resource allocated by the base station, the radio resource allocated by the L1 / L2 control signal and the time axis are downlink data within the same subframe, as in the normal dynamic scheduling. Receive.

Next, a case where no downlink data is generated will be described.
If no downlink data is generated, the base station moves to the process of step ST6103 (step ST6105).
As a result of receiving (monitoring) the L1 / L2 control signal, the mobile terminal determines whether there is data addressed to itself (step ST6110). If there is no data addressed to the user, the process proceeds to step ST6104.
In the above description, when the transmission timing of the L1 / L2 control signal during the DRX operation period overlaps with the transmission timing of E-MBMS, the reception timing of downlink data is skipped by one subframe, and the period of transmission of E-MBMS An example in which downlink data is transmitted and received in the next subframe is shown. As another example, downlink data may be transmitted / received after a specified subframe as a mobile communication system from a cycle in which E-MBMS is transmitted, or after a subframe notified from a base station to a mobile terminal.
In that case, it is next to the L1 / L2 control signal during the DRX operation period (only the L1 / L2 control signal when the transmission timing of the L1 / L2 control signal during the DRX operation period overlaps with the transmission timing of the E-MBMS may be used). The above operation can be performed by adding a parameter such as For example, “0: shift to DRX operation” “1: monitor L1 / L2 control signal of next subframe” “2: monitor L1 / L2 control signal after n subframes” or “0: shift to DRX operation” “1: Downlink data allocation in the next subframe”, “2: Downlink data allocation after n subframes”, and the like.

By using the DRX operation method shown in the first modification, in addition to the effects obtained by using the thirteenth embodiment, the following effects can be obtained.
Compared to the thirteenth embodiment, in the DRX operation during the Active, the E-MBMS service and the Unicast service are reduced without changing the timing when the mobile terminal becomes Active (see FIG. 15) during the DRX operation period. Service becomes possible.
When the mobile terminal performs an operation other than the operation of confirming (monitoring) whether or not downlink data addressed to itself is assigned at the timing of becoming active during the DRX operation period, the operation timing (cycle) of those operations is The effect that it is not changed can be obtained.
Examples of the operation of the mobile terminal other than the operation of confirming whether or not downlink data addressed to itself are allocated during the DRX operation period include (1) Sounding RS transmission, (2) CQI transmission, and (3) Neighbor cell measurement. And so on.
Only the operation of confirming whether or not downlink data addressed to itself is allocated during the DRX operation period is set as the next subframe of the period in which E-MBMS, which is the method shown in Embodiment 13, is transmitted, and the above (1 ) (2) (3) and the like may be the same subframe as the period in which the E-MBMS is transmitted. However, considering the reduction in power consumption of the mobile terminal, it is effective to match the timing at which the mobile terminal must perform the transmission operation and the reception operation as much as possible. Therefore, the first modification is effective in reducing the power consumption of the mobile terminal.

Embodiment 14 FIG.
In the mobile communication system, the L / L2 signal is controlled by using both of C-RNTI (Cell Radio Network Temporary Identifier) to which the mobile terminal is allocated and G-RNTI (Group RNTI) (GERAN Radio Network Temporary Identifier) 1 / L signal. It is considered to monitor.
C-RNTI is an identifier of a mobile terminal assigned by a control RNC (Controlling Radio Network Controller). C-RNTI is unique in a cell.
In a mobile terminal performing a DRX operation in the DRX cycle, there is a problem that an L1 / L2 control signal corresponding to the G-RNTI is missed at a timing when the DRX cycle and the G-RNTI transmission cycle do not overlap.
In a mobile terminal to which G-RNTI is assigned, when the mobile terminal performs a DRX operation (DRX operation during Active), the following problems occur.
The problem of the fourteenth embodiment will be described with reference to FIG.
In FIG. 53, an oblique line that rises to the right represents an L1 / L2 control signal for C-RNTI, and an oblique line that descends to the right represents an L1 / L2 control signal for G-RNTI.

When the mobile terminal performs the DRX operation in the DRX cycle (X), the mobile terminal receives (monitors) the L1 / L2 control signal every DRX cycle (X) (( 1) (see 2) (4) (5) (6)). Therefore, it is conceivable that the mobile terminal performs a low power consumption operation as exemplified in the reception system power supply example of the mobile terminal shown in FIG.
Consider a case where not only C-RNTI but also G-RNTI is assigned to the mobile terminal by the base station, and it is necessary to monitor the L1 / L2 control signal using G-RNTI. Assume that the notification period or change period of the L1 / L2 control signal corresponding to G-RNTI is “Y”.

In the mobile terminal performing the DRX operation in the DRX cycle (X), the timing at which the cycle X and the cycle Y overlap (L1 / L2 corresponding to G-RNTI in (1) and (5) in FIG. 53) It is possible to receive a control signal.
On the other hand, receiving the L1 / L2 control signal corresponding to G-RNTI at the timing when the cycle X and the cycle Y do not overlap ((3) in FIG. 53) realizes low power consumption by the DRX cycle (X) This is not possible at the mobile terminal you are trying to use.
As described above, a problem arises in realizing low power consumption in a mobile terminal to which G-RNTI is assigned.

Hereinafter, a DRX operation method as the mobile communication system according to the fourteenth embodiment will be described.
FIG. 54 is an explanatory diagram showing an example of the DRX operation method as the mobile communication system according to the fourteenth embodiment of the present invention.
When the mobile terminal performs the DRX operation in the DRX cycle (X), the mobile terminal receives (monitors) the L1 / L2 control signal every DRX cycle (X) (( 1) (see 3) (5) (7) (9)).
Consider a case where not only C-RNTI but also G-RNTI is assigned to the mobile terminal by the base station, and it is necessary to monitor the L1 / L2 control signal using G-RNTI. It is assumed that the notification period (or change period) of the L1 / L2 control signal corresponding to G-RNTI is “Y”.

The base station calculates the DRX cycle again for the mobile terminal to which G-RNTI is assigned. In the recalculation, calculation is performed so that the mobile terminal can receive the L1 / L2 control signal corresponding to G-RNTI at the timing when the period X and the period Y do not overlap (see (3) in FIG. 53). To do.
As a specific example, the greatest common divisor of the cycle X and the cycle Y can be newly set as the DRX cycle. For example, the period “Z” in FIG.

  When the DRX cycle (Z) is notified again from the base station to the mobile terminal, the mobile terminal indicates (1) (2) (3) (4) (5) (6) (7) in FIG. (8) In (9), the L1 / L2 control signal is received, and the mobile terminal transmits the L1 / L2 control signal even at the timing (see (3) in FIG. 53) where the period X and the period Y do not overlap. Will be received.

FIG. 55 is a sequence diagram showing an example of processing contents of the mobile terminal and base station according to Embodiment 14 of the present invention.
The base station notifies the mobile terminal of the DRX cycle, and sets the DRX cycle as the DRX cycle of the mobile terminal (step ST6501).
The mobile terminal receives the DRX cycle from the base station, and sets the DRX cycle as the DRX cycle (step ST6502).

As an example of an initial DRX cycle notification method from the base station to the mobile terminal, the following method can be considered.
(1) When a radio bearer is set up, the base station notifies the mobile terminal using L3 signaling.
(2) The base station notifies the mobile terminal with dynamic timing using an L1 / L2 control signal or in-band signaling (MAC signaling).

The base station and the mobile terminal transition to the DRX operation in the DRX cycle (step ST6503, step ST6504).
The base station notifies the mobile terminal of G-RNTI (step ST6505).
The mobile terminal receives G-RNTI from the base station (step ST6506).

The base station recalculates the DRX cycle for the mobile terminal from the DRX cycle notified to the mobile terminal in step ST6501 and the notification cycle (or change cycle) of the L1 / L2 control signal corresponding to G-RNTI. (Step ST6507).
The base station notifies the mobile terminal of the DRX cycle again, and sets the DRX cycle as the DRX cycle of the mobile terminal (step ST6508).
The mobile terminal re-receives the DRX cycle from the base station, and sets the DRX cycle as the DRX cycle (step ST6509).

The base station shifts to DRX operation in the DRX cycle (step ST6510).
The mobile terminal shifts to the DRX operation in the DRX cycle (step ST6511). At that time, the mobile terminal can perform the DRX operation in the DRX cycle notified from the base station regardless of whether or not the G-RNTI is notified.

  The problem of the fourteenth embodiment is not only when the G-RNTI is assigned to the mobile terminal, but also the mobile terminal needs to receive a plurality of information in the L1 / L2 control signal in different periods. It also occurs in some cases. Even in that case, the problem can be solved by using the fourteenth embodiment.

According to the fourteenth embodiment, the following effects can be obtained.
Even when G-RNTI is assigned to the mobile terminal without providing information to be newly transmitted / received between the base station and the mobile terminal, the mobile communication system can be used to perform DRX operation during Active. An effect that becomes feasible is obtained.
In solving the problem of the fourteenth embodiment, it is an effective solution in terms of effective utilization of radio resources in that no information is newly transmitted / received between the base station and the mobile terminal. is there.
Further, the mobile terminal can perform the DRX operation in the DRX cycle notified from the base station regardless of whether or not the G-RNTI is notified from the base station. Can be simplified.

  As described above, the mobile communication system according to the present invention is suitable for a device that needs to reduce the power consumption of the mobile terminal 3 and increase the standby time or continuous call time of the mobile terminal 3.

Claims (2)

  When the mobile terminal and the base station perform wireless communication, the mobile terminal measures the quality of the downlink communication channel, transmits the quality measurement result to the base station, and the base station determines the quality measurement result. In the mobile communication system that performs downlink scheduling in response, the mobile terminal has a timing for transmitting the quality measurement result to the base station and a timing for transmitting an acknowledgment signal or a negative acknowledgment signal to the base station. In the case of overlapping, the mobile communication system characterized by transmitting the acknowledgment signal or the negative acknowledgment signal without transmitting the quality measurement result.   In a mobile terminal comprising quality measuring means for measuring the quality of a downlink channel and transmitting means for transmitting the measurement result of the quality measuring means to a base station, the transmitting means transmits the measurement result of the quality measuring means to the above-mentioned When the timing to transmit to the base station overlaps with the timing to transmit an acknowledgment signal or a negative response signal to the base station, the acknowledgment signal or the negative response signal is transmitted without transmitting the measurement result of the quality measuring means. A mobile terminal characterized by:

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