JP2015162745A - Carrier aggregation communication method and terminal used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve smooth communication in carrier aggregation communication, save power of a terminal, and effectively use a component carrier.SOLUTION: In carrier aggregation communication, activation and deactivation controls of a frequency band in which upstream and downstream communication is so performed that the control of a frequency band in which only a downstream communication is performed are related, or connections in all frequency bands concerning a small cell base station are deactivated or cut.

Description

  The present invention relates to a carrier aggregation communication method and a terminal used therefor.

LTE-A, which is a communication standard for mobile phones, presents a communication system that extends a band by combining CCs (component carriers) that are two or more basic frequency blocks. The combination of continuous or discontinuous CCs to increase the bandwidth is called CA (carrier aggregation).
Patent Document 1 describes the following points regarding wireless communication between a terminal and one base station, in particular, CA of an LTE-A system. (1) In order to provide functions such as synchronization, access, system information, and paging, when there are a plurality of CCs serving as a serving cell of a terminal, one serving cell is provided as a primary cell, and (2) the base station Informing the terminal of the setting value of the deactivation timer via a system message (eg SIB2) or RRC message (eg RRC connection reconfiguration message), (3) The terminal turns on the deactivation timer The condition is that the downlink transmission using the CC having the activation / deactivation function is successfully received (for example, the time when the base station transmits ACK), and (4) the deactivation timer is Deactivating CC corresponding to the deactivation timer when turned off is described.
Non-Patent Document 1 discloses that for dual connection (dual connectivity) in which a terminal that performs CA is connected to one macrocell base station and one small cell base station, uplink data or downlink data is transmitted from the small base station or terminal. The small cell needs to be activated when it occurs, the small cell base station can send a deactivation command to the terminal at any time for small cell deactivation, and the macro cell base station also deactivates the small cell It is described that an enable command can be transmitted to a terminal.

Special table 2013-513321 gazette

3GPP TSG-RAN WG2 Meeting # 83bis Ljubljana, Slovenia, October 7-October 11, 2013 R2-133273

  However, Patent Document 1 does not mention the setting of the deactivation timer at the time of dual connection. Moreover, although the nonpatent literature 1 has description about dual connection, only a secondary cell is assumed as a small cell, and about the mode of deactivation, it is a terminal using a deactivation timer. There is nothing to mention, including deactivation of CC. Here, even if the deactivation timer described in Patent Document 1 is extended and applied to dual connection, two or more secondary cells constituting a small cell are associated with deactivation in dual connection. The present inventor has discovered that since all of the secondary cells are inactivated when they exist, the inconvenience of falling into a state where uplink transmission cannot be performed (for example, a state where ACK and NACK cannot be transmitted) occurs. .

One object of embodiments of the invention, the CA LTE-A, in particular, in CA dual connection, deactivation or cleavage of _{S Cell} two or more number of CC of CA is operated, respectively, It is to execute without hindering communication, to save power of the terminal and to effectively use CC. The other subject of embodiment of this invention becomes clear from the following description.

  In the carrier aggregation communication, the activation / deactivation control of the frequency band for performing uplink and downlink communication is associated with the control of the frequency band for performing downlink communication only.

  According to the embodiment of the present invention, smooth execution of carrier aggregation communication, power saving in a terminal, and effective use of a component carrier can be achieved.

It is a block diagram of the communication system which concerns on 1st, 2nd embodiment. It is a figure which shows the frequency relationship of P _Cell and S _Cell . It is a schematic block diagram which shows the structure of the terminal which concerns on 1st Embodiment. It is a schematic block diagram which shows the structure of the macrocell base station which concerns on 1st Embodiment. It is a schematic block diagram which shows the structure of the small cell base station which concerns on 1st Embodiment. It is an operation | movement sequence diagram of the communication system which concerns on 1st Embodiment. It is an operation | movement sequence diagram of the terminal in connection with the deactivation timer setting which concerns on 1st Embodiment. It is a schematic block diagram which shows the structure of the terminal which concerns on 2nd Embodiment. It is a schematic block diagram which shows the structure of the small cell base station which concerns on 2nd Embodiment. It is an operation | movement sequence diagram of the deactivation of the small cell which concerns on 2nd Embodiment.

<First Embodiment>
FIG. 1 shows a schematic configuration of a communication system 1 common to the first and second embodiments of the present invention. The communication system 1 includes a base station a ₁ , base stations b _{1 to} b _5, and a terminal a. The base station a ₁ is a base station having a macro cell area (communication range), and the base stations b _{1 to} b ₅ are base stations each having a small cell area. The terminal a is a movable or fixed user terminal. In FIG. 1, for simplicity of explanation, only one terminal a is shown as a terminal. As an example, the terminal a can communicate with the base station a ₁ and the base station b ₁ using CA (carrier aggregation) that simultaneously uses CC (component carrier) that is four LTE carriers. In the CA relationship between the terminal a and the base station a ₁ and the base station b ₁ , one of the four CCs is a PCC (primary CC), and the other three CCs are SCCs (secondary CCs). However, CCs that play a PCC role in the small cell are collectively referred to as SCCs here. In between the terminal a and the base station _{a 1,} it performs a CA with PCC and one SCC. These CC serving cells (cells from which terminal a receives service) are referred to as P _Cell (primary cell) and S _Cell0 (one secondary cell among a plurality of secondary cells). In FIG. 1, P _Cell and S _Cell0 are shown by the same large ellipse C _a1 , but this is exemplary. In between the terminal a and the base station _{b 1,} performs CA with two SCC. The serving of these CC say that _{S Cell1} and _{S Cell2.} In Figure _{1, S Cell1} and _{S Cell2} is shown with a small same ellipse _{C b1,} which are exemplary. P _Cell and _{S Cell0} which will include at _{S Cell1} and _{S Cell2,} the former and the latter may be located terminal a is in the overlapping portion overlapping part. Hereinafter, the corresponding CC may be referred to as the above serving cell. In FIG. 1, a code P _Cell and codes S _Cell0 to S _Cell2 indicate CC links (lines) corresponding to serving _cells . Note that the above is an example, and communication between the terminal a and the base station a ₁ can be performed using two or more S _cells in addition to the P _cell , and the terminal a and the base station a ₁ Communication between the stations b ₁ can be performed using two or more S _Cells in addition to S _{Cell 1} .

In Figure 1, the terminal a is connected pair of the (linked) with the base station _{a 1} in _{P Cell} corresponding to CC of CC and downlink uplink, and corresponds to the CC of the downlink _{S Cell0} in connection with the base station _{a 1.} The terminal a is connected to the base station b _{1 by} S _Cell (uplink / downlink S _Cell ) corresponding to the _paired uplink CC and downlink CC, and is connected to the base station by S _Cell2 corresponding to the downlink CC. b Connect with ₁ . Since the communication system 1 of the first and second embodiments of the present invention is an FDD system (frequency division duplex), the uplink CC and the downlink CC that are paired have different frequencies. However, these embodiments of the present invention can also be applied to TDD systems (time division duplex). SCC is a carrier extended to allocate additional resources in addition to PCC, and is divided into an activated state, an inactivated state, and a disconnected state. Is done. The terminal a can monitor or receive the CC control channel (PDCCH) and data channel (PDSCH) only while in the activated state, thereby reducing the power consumption of the terminal a.

In the above connection, OFDMA (Orthogonal Frequency Division Multiplexing) is adopted for downlink communication, and SC-FDMA (Single Carrier Frequency Division Multiplexing) is adopted for uplink communication. Uplink control signals from terminal a to base stations a ₁ and b ₁ are transmitted using CC PUCCH (physical uplink control channel), and uplink data signals are transmitted using CC PUSCH (physical uplink shared channel). Sent. In the above-described connection, the downlink control signal from the base stations a ₁ and b ₁ to the terminal a is transmitted using the CC PDCCH (physical downlink control channel), and the downlink data signal is transmitted using the CC PDSCH (physical link). It is transmitted using a downlink shared channel). As an example, terminal a is, the base station _{a 1,} CC of _{P Cell} downlink bandwidth of 10MHz in CC and the frequency _{f 2} of the _{P Cell} uplink bandwidth of 10MHz in the frequency _{f 1} and frequency _{f 3,} In this case, communication can be performed using a downlink S _{Cell 0} CC having a bandwidth of 10 MHz. The terminal a is different from the base station b _{1 in} that the CC of the uplink S _{Cell 1} having the frequency f ₄ and the bandwidth of 20 MHz, the CC of the downlink S _{Cell 1 having} the frequency f ₅ and the bandwidth of 20 MHz, and the CC of the downlink S _{Cell 1 having} the frequency f _6. Communication can be performed using a 20 MHz downlink S _Cell2 CC.
2, the above-mentioned _{P Cell,} shows the relationship between the frequency allocation of S _{Cell0, S Cell1} and _{S Cell20.} The horizontal axis is the frequency axis. The frequencies f ₁ , f ₂ , f ₃ are in the 2 GHz band, and the frequencies f ₄ , f ₅ , f ₆ are in the 3.5 GHz band. P _Cell is a generic term for a pair of downlink and uplink CCs. The same applies to S _Cell1 . Further, the frequencies f ₁ to f ₆ may belong to three or more different frequency bands. The base station a ₁ and the base station b ₁ are connected by a backhaul, for example, an X interface. Therefore, direct communication between the base station a ₁ and the base station b ₁ is enabled. Note that scheduling regarding radio resource allocation is performed independently at the base station a ₁ and the base station b ₁ .

FIG. 3 is a schematic block diagram showing the configuration of the terminal a (FIG. 1). The terminal a includes an LTE transmission unit 311, an LTE transmission unit 312, an LTE reception unit 313, an LTE reception unit 314, and a control unit 320. The terminal a has antennas 331 to 334 connected to each transmission / reception unit. The LTE transmission unit 311 and the LTE reception unit 313 are a transmission unit and a reception unit for the frequency band A (for example, 2 GHz band), respectively. The LTE transmission unit 312 and the LTE reception unit 314 are a transmission unit and a reception unit for frequency band B (for example, 3.5 GHz band), respectively. The terminal a may include an LTE transmission unit and an LTE reception unit in frequency bands other than the frequency band A and the frequency band B. In FIG. 3, the LTE transmission unit and the LTE reception unit are illustrated as separate members. However, if they can be shared, they can be shared and configured as a single member. The frequency band A, the frequency band B, and the like can also be configured as a shared band if they can be shared. The same applies to the configuration of the terminal according to the second embodiment and the configurations of the base stations according to the first and second embodiments described below.
The terminal a performs transmission and reception of signals in the LTE transmission unit 311 and the LTE reception unit 313 using the paired uplink CC and downlink CC of the P _Cell , respectively, and the downlink of the S _{Cell 0} The signal is received by the LTE receiving unit 313 using the CC. The terminal a _is using the CC the CC and downlink uplink _{S Cell1,} carried respectively the transmission and reception of signals in the LTE transmission unit 312 and the LTE receiver 314, and the CC of the downlink _{S Cell2} The signal is received by the LTE receiver 314. Therefore, the terminal a is performed CA connection with 2CC of _{P Cell} and _{S Cell1} the uplink and in the downlink _{P Cell,} be performed CA connection using the 4CC of S _{Cell0, S Cell1} and _{S Cell2} it can. In addition, the terminal a has a CA dual connection with both different base stations, a macro cell base station and a small cell base station. Therefore, these CA connections are intersite CA connections. When the frequency band and the frequency band of the _{S Cell0} of P _Cell is different, the terminal a _is using _{P Cell,} receiving a signal on the LTE receiver 313 transmits a signal in LTE transmission unit 311, and the _{S Cell0} The signal is received by an LTE receiver (not shown) for the frequency band. _Also, when different frequency bands of the frequency band and _{S Cell2} of _{S Cell1,} the terminal a _is using the _{S Cell1,} it transmits a signal in LTE transmission unit 312 receives a signal in LTE receiver 314, and S _{Using Cell2} , a signal is received by an LTE receiver (not shown) for the frequency band. The same applies to the configuration of the terminal according to the second embodiment and the configuration of the base station according to the first and second embodiments described below.

The control unit 320 includes a scheduling monitoring unit 321, an activation / deactivation (activation / deactivation) processing unit 322, and an inactivation timer setting unit 323. In addition, the control unit 320 includes a known member (not shown) that performs various controls related to communication of the terminal a, such as processing of received data and transmission data, and carrier frequency control of each transmission / reception unit. . The configuration related to the known members of the control unit 320 is the same in the configuration of the control unit in the base station of the first embodiment and the configuration of the control unit of the terminal and base station in the second embodiment described below. is there. The deactivation timer setting unit includes a timer T ₀₁ , a timer T _11, and a timer T ₁₂ . The scheduling monitoring unit 321 transmits scheduling information (such as the terminal a ID, user data transport format information, activation / deactivation instruction, etc.) from the base station a ₁ or the base station b ₁ to the terminal a. To monitor. For example, the activation / deactivation processing unit 322 receives an instruction from the activation / deactivation instruction unit 422 (FIG. 4) of the base station a ₁ and sends it to the CC in the instructed CA (carrier aggregation). On the other hand, if the instruction is activated, the CC is activated. If deactivated, the CC is deactivated. The deactivation timer setting unit 323 includes a timer T ₀₁ , a timer T _11, and a timer T ₁₂ for each SCC (secondary CC). That is, the timer _{T 01} corresponds to _{S Cell0,} the timer _{T 11} corresponds to _{S Cell1,} and the timer _{T 12} corresponds to _{S Cell2.} The deactivation _timer, when data is scheduled to some or all of the S _{Cell0, S Cell1} and _{S Cell2,} or when receiving the activation instruction from the base station, the network side (for example, a core network) in A predetermined initial value is set. In the first embodiment, fit when setting deactivation timer _{T 12} of _{S Cell2} a small cell using only the downlink, also set the timer _{T 11} with the uplink and downlink _{S Cell.} This point will be described in detail later.

FIG. 4 is a schematic block diagram showing the configuration of the base station a ₁ (FIG. 1). Base station a ₁ is connected to the core network via the S1 interface, for example. The base station a ₁ includes an LTE transmission unit 411, an LTE reception unit 413, and a control unit 420. The base station a ₁ includes antennas 431 and 433 connected to each transmission / reception unit. The LTE transmission unit 411 and the LTE reception unit 413 are a transmission unit and a reception unit for the frequency band A, respectively. The base station a ₁ performs transmission and reception of signals in the LTE transmission unit 411 and the LTE reception unit 413 using the uplink CC and downlink CC of the P _Cell , and performs LTE transmission using the S _Cell0. The unit 411 transmits a signal. The control unit 420 includes a radio resource arrangement unit 421, an activation / deactivation instruction unit 422, and an inactivation timer setting unit 423. The radio resource arrangement unit 421 performs resource arrangement of data signals and control signals to be transmitted. The activation / deactivation instruction unit 422 instructs the terminal a ₁ to activate or deactivate the CC in the CA. As an instruction method, for example, an instruction at the MAC layer level is performed. In addition, an instruction can be issued for each CC as necessary. The deactivation timer setting unit 423 includes a timer T ^* ₀₁ for S _Cell0 . This deactivation timer T ^* ₀₁ sets the initial value of the timer determined on the network side to the CC when scheduling data to S _Cell0 or transmitting an activation instruction to the terminal. Thus, the base station a _1, it is possible to synchronize the terminal a for CC activation / deactivation state. That is, with the timer T ^* ₀₁ of the base station a ₁ can monitor timer T ₀₁ of the terminal a, thus can be scheduled for activation state CC. The same applies to the timer of the base station b _1.

FIG. 5 is a schematic block diagram showing the configuration of the base station b ₁ (FIG. 1). The base station b ₁ includes an LTE transmission unit 512, an LTE reception unit 514, and a control unit 520. The base station b ₁ includes antennas 532 and 534 connected to each transmission / reception unit. The LTE transmission unit 512 and the LTE reception unit 514 are a transmission unit and a reception unit for frequency band B, respectively. The base station b ₁ uses the uplink CC and the downlink CC of the paired S _{Cell 1} to transmit and receive signals in the LTE transmission unit 512 and the LTE reception unit 514, respectively, and the downlink of the S _{Cell 2} The LTE transmission unit 512 transmits a signal using the link. The control unit 520 includes a radio resource arrangement unit 521, an activation / deactivation instruction unit 522, and an inactivation timer setting unit 523. The radio resource arrangement unit 521 performs resource arrangement of data signals and control signals to be transmitted. The activation / deactivation instruction unit 522 instructs the terminal a to activate or deactivate the CC in the CA. As an instruction method, for example, an instruction at the MAC layer level is performed. Further, it is possible to instruct each CC of _{S Cell1} and _{S Cell2} needed. Deactivation timer setting unit 523 each _comprise a timer ^T _{* 11} and the timer ^T _{* 12} to about _{S Cell1} and _{S Cell2.} When the deactivation timer ^T _{* 11} and ^T _{* 12} was scheduled data to _{S Cell1} and _{S Cell2,} or when sending an activation instruction to the terminal, the CC of the initial value of the timer which is determined by the network side Set to. Further, in the present embodiment, to fit when setting deactivation timer S _Cell2 used only downlink, also set timer S _Cell1 to use uplink and downlink. This point will be described in detail later.

FIG. 6 is a diagram showing an operation sequence of the communication system 1 (FIG. 1). (Step S601) Initially, the terminal a is waiting at the base station a ₁ (standby state, idle state). (Step S602) The base station _{a 1 transmits} a paging message to the terminal a in _{P Cell.} By this paging (wireless call), signal procedure information in the wireless section is transmitted. (Step S603) connection terminal (a) and the base station _{a 1} is established. (Step S604) The base station _{a 1,} on the other hand, the terminal a is make the connection by the base station _{a 1} and CA, on the other hand, determines the dual connection for connecting by the terminal a and the base station _{b 1} and CA. (Step 605) The base station a ₁ notifies the base station b _{1 of} the dual connection determined in step S604. (Step S606) The base station b ₁ returns to the base station a ₁ a dual connection setting response indicating that the dual connection is ready. (Step S607) The base station a ₁ transmits to the terminal a, a dual connection setup request for requesting to set the dual connection to the base station a ₁ and the base station b _1. (Step S608) terminal a returns the CA connection setup response to the base station _{a 1.} (Step S609, Step S610) The dual connection of the connection between the terminal a and the base station a ₁ by the CA and the connection between the terminal a and the base station b ₁ by the CA is established.
By the above procedure, CA connections using 2CC of _{P Cell} and _{S Cell1} the uplink (dual connection), the downlink CA connection using 4CC of _{P Cell, S Cell0,} S _Cell1 and _{S Cell2} (dual connection) Established. Incidentally, in step S605, may simply be only notification of dual connection, as a response in step S606, the connection with the uplink using the CC of _{S Cell1,} the 2CC of _{S Cell1, S Cell2} the downlink A response indicating that the dual connection including the used CA connection may be performed. Further, at the time of step 605 leave determined only by connecting only _{S Cell1,} or the like may be performed to add _{S Cell2} the connection was established in step S610.

FIG. 7 is a diagram illustrating an operation sequence of the terminal a when the terminal a performs dual connection with the base station a ₁ and the base station b ₁ . (Step S701) terminal a from the base station _{a 1} and the base station _{b 1,} periodically monitors for reception of scheduling information about S _{Cell0, S Cell1} and _{S Cell2.} In the _following, referred to as the _{S Cell_n} are collectively referred to as _{S Cell0,} S _Cell1 and _{S Cell2. Therefore,} sometimes referred to as _{S Cell_n} to refer to either S _{Cell0, S Cell1} and _{S Cell2.} (Step S _< b _> 702) The terminal “a” determines whether it is scheduled to S _{Cell_n} . If this scheduling is performed (YES), the process proceeds to step S703. If scheduling has not been performed (NO), the process returns to step S701. (Step S703) when it is _scheduled, and the initial values _{t 0} to the deactivation timer _{T n} of _{S Cell_n,} proceeds to step S704. The initial value t ₀ is the value notified in advance from the network side. (Step S704)
The terminal a determines whether S _{Cell_n} is a CC for downlink only. If S _{Cell_n} is only downlink (YES), the _{process proceeds} to step S705. If it is not only downlink (NO), that is, if it is CC which became an uplink / down pair, it will return to step S701. (Step S705) The terminal a determines whether or not the uplink CC of the base station that is in communication connection with S _{Cell_n} is a P _Cell . If the uplink CC is P _Cell (YES), the process returns to schedule monitoring in step S501. This is because P _Cell does not become inactive. If the uplink CC is not P _Cell (NO), the process proceeds to step S706. (Step _S706) to the deactivation timer of the CC of the uplink _{(S Cell1)} to the base station that has a communication connection with _{S Cell_n,} it sets an initial value _{t 0.}

<Modification 1>
The terminal a sets another initial value t ₁ for the timer of the paired uplink and downlink S _Cell1 . This initial value t ₁ is larger than the initial value t ₀ of the timer for S _{Cell 2} for downlink only. By setting in this way, even if all the downlink S _cells (not shown in FIG. 1) other than the downlink only S _{Cell 2} are inactivated, the paired uplink It is ensured that the link and downlink S _Cell1 are kept activated to the end. After that, when scheduling is not performed for the S _Cell , the paired uplink and downlink S _Cell1 are also finally deactivated. Incidentally, after becoming all CC is inactive base station b _1, when activated again, the base station a ₁ is the base station through the above-mentioned line between the base station a ₁ and the base station b ₁ These CCs can be activated when a control signal is transmitted to b ₁ and the base station a ₁ transmits a control signal to the terminal a via the P _Cell . Alternatively, the base station b ₁ transmits this control signal to the base station a ₁ through the above-described line, and the base station a ₁ issues an activation instruction to the terminal a using the above-described procedure based on this control signal. Can do.
<Modification 2>
For upstream and downstream _{S Cell,} adding a deactivation timer _{T 2} of the exclusive. Set value t ₂ of the deactivation timer T ₂ of the this dedicated, as is the value larger than the initial value t ₀ of the downlink only, additionally under the terms of this setting, the deactivation timer for each S _{Cell_n} to alter the set value of T _2. The deactivation timer T ₂ of the dedicated per the S _{Cell_n,} under conditions of the set values, it is also possible to set the specific setting values in the setting value other than the set of set values of defaults .
(effect)
According to the first embodiment and the first and second modifications of the present invention, when the deactivation timer is turned off by performing the above-described timer setting, the reception of the downlink signal of S _Cell2 corresponding to only the downlink CC is performed. , Avoiding a situation in which uplink transmission (for example, transmission of ACK and NACK) in S _Cell (for example, S _Cell1 ) corresponding to the paired uplink and downlink CCs becomes impossible, and smooth Communication can be executed, power saving of the terminal and effective use of the CC can be achieved.

<Second Embodiment>
FIG. 8 is a schematic block diagram illustrating a configuration of a terminal a ^′ (alternative to the terminal a of the first embodiment) according to the second embodiment. The terminal a ^′ includes an LTE transmission unit 311, an LTE transmission unit 312, an LTE reception unit 313, an LTE reception unit 314, and a control unit 320a. The terminal a has antennas 331 to 334 connected to each transmission / reception unit. LTE transmission unit 311 of the terminal a ^', LTE transmission unit 312, LTE receiver 313 and the LTE receiver 314 is to obtain the same function as the corresponding members of the terminal a of the first embodiment. The control unit 320a includes a scheduling monitoring unit 321, an activation / deactivation processing unit 322a, and an inactivation timer setting unit 323. The configuration of the control unit 320a has the same function as the corresponding member of the terminal a of the first embodiment except for the configuration of the activation / deactivation processing unit 322a. The activation / deactivation processing unit 322a includes a selection unit 811.
Configuration a _^'1 macrocell base station of the second embodiment is the same as the structure base station a ₁ of the first embodiment.
FIG. 9 is a schematic block diagram illustrating a configuration of a base station b ^′ ₁ (alternative to the base station b ₁ of the _first embodiment) according to the second embodiment. Base station b _^'1 is configured to include LTE transmission unit 512, LTE receiver 514 and the control unit 520a. Base station b _^'1 includes an antenna 532 and 534 which are connected to each transceiver. The LTE transmission unit 512 and the LTE reception unit 514 of the base station b ^′ ₁ have the same functions as the corresponding members of the base station b ₁ of the _first embodiment. The control unit 520a includes a radio resource arrangement unit 521, an activation / deactivation instruction unit 522a, and an inactivation timer setting unit 523. Configuration of the control unit 520a, except for the configuration of the activation / deactivation instruction unit 522a, is intended to obtain the same function as the corresponding members of the base station b ₁ of the first embodiment. The activation / deactivation instruction unit 522a includes a selection unit 911. Therefore, in the following solely, explanation of the structure and function of the ^'activation / deactivation processing unit 322a and the base station ^b' ₁ activation / deactivation instruction unit 522a terminal a.

Terminal a ^'activation / deactivation processing unit 322a of the base station ^b' receives an instruction from the activation / deactivation instruction unit 522a of the _1, the following (operation 1) or (operation 2) Run selectively. (Operation 1) terminal a ^'selection unit 811 of the activation / deactivation processing unit 322a of the base station ^b' receives an instruction from the activation / deactivation instruction unit 522a of _1, the instruction uplink If it is an instruction to deactivate the downlink S _Cell , all S _Cells (S _{Cell 1} and S _{Cell 2} used in this base station b ^′ ₁ , and if there are other _cells , those S _Cells are also All S _Cells ) are inactivated or disconnected. If the operation by an instruction of the base station b _^'1 1 is selected, the non-activation of the operation 1, if the data signal to be transmitted to the CC to perform the deactivation is not present, immediately and automatically the CC Is inactivated or disconnected, so that power saving of the terminal a and effective use of the CC in other terminals can be achieved. (Operation 2) When the instruction is not an instruction to deactivate the uplink / downlink S _Cell , that is, for example, an instruction of the S _Cell using only the downlink, and if the instruction is activated, the CC's The activation process is performed (and the associated deactivation timer is automatically turned on). If deactivated, the CC deactivation process is immediately and automatically performed. At this time, the deactivation timer has an initial value determined on the network side when data is scheduled in the CC (for example, an arbitrary S _Cell ) or when an activation instruction is received from the base station. The CC timer (terminal and base station timer) is set. Incidentally, the indication of deactivation of the uplink and downlink S _Cell, although the all S _Cell of base stations in communication with the small cell in the non-activated state, its instead, all of the base stations S An instruction for deactivating the _Cell may be separately provided.

FIG. 10 shows an activation / deactivation operation sequence according to the second embodiment.
(Step S1001, the step S1002) dual connection of the connection terminal a ^'and connected and the terminal a according to CA of the base station _{a ^1'} and by CA of the base station _{b 1} is established. The operation sequence at the time of dual connection is the same as that in the first embodiment (steps 601 to 610 in FIG. 6). (Step S1003) The base station b ₁ transmits an activation / deactivation instruction to the terminal a ^′ . (Step S1004) The terminal a ^′ receives this activation / deactivation instruction. (Operation 1) When this instruction is the deactivation instruction of the uplink / downlink S _Cell , the base station to which the small cell belongs _Deactivate or cleave all S _Cells . (Operation 2) If this instruction is deactivation of the S _Cell that uses only the downlink, the S _Cell is deactivated. Further, if this instruction is activation of S _Cell using only the downlink, the small cell is activated. In this case, the S _Cell deactivation timer is automatically turned on accordingly. Then the turn-off of the deactivation timer, the corresponding S _Cell is in a state of all inactive. (Step S1005) In this state, the terminal a ^'still base station ^a' and ₁ remains to establish a connection. (Step S1006) In this state, the S _Cell between the terminal a and the base station b ₁ is inactive, and this state is indicated by a dotted arrow in Step S1006. If this state is a cut state, the dotted arrow disappears. With the activation instruction from the P _Cell , the small cell of the small cell base station b ₁ can return to the activated state again.

<Modification 3>
In Figure 10, but has issued a deactivation instruction at _{S Cell1} the _{S Cell1} and _{S Cell2} base station _{b 1} from the base station itself to be a non-activated state (base station _{b 1),} by using _{P Cell1} This deactivation instruction may be issued from the existing main base station (base station a ₁ ). When activating again, an S _Cell activation instruction is issued from the main base station (base station a ₁ ) using P _Cell .

<Modification 4>
As indicated by the dotted line in step S1006 arrow in FIG 10, the terminal a is the small cell base station b ₁ in the non-activated state, cutting the connection in accordance with an instruction of the non-activated from the base station b ₁ You can also This eliminates the need to separately perform small cell disconnection by the RRC message by performing small cell disconnection (for example, releasing (releasing) the RRC setting of layer 3) in accordance with the S _Cell deactivation instruction. Can do. When the terminal a ^′ connects again to the small cell of the base station b ₁ after this disconnection, the terminal a ^′ is connected again by sending an instruction to add a small cell from the macro base station a ₁ to the terminal a ^′ by an RRC message, for example. That is, the sequence (FIG. 6) from the dual connection notification to the CA connection setting response of the communication system operation sequence described in the first embodiment is performed.

By performing the activation / deactivation control method of the embodiment of the present invention, it becomes possible to avoid falling into a state where uplink transmission cannot be performed during downlink signal reception, and in addition, all S _Cells of the small cell base station the possible to deactivation at a time, also, furthermore, produces an effect that it is cut with all S _Cell of small base stations at once as described above.

<Modification 5>
In the first and second embodiments, the macro cell base station a ₁ including P _Cell communication is described as the main base station, and the small cell base station b ₁ is described as the sub base station. However, the base station b ₁ is the main base station. and the base station, the base station a ₁ can be a sub-base station. In this case, the small cell base station b ₁ includes P _Cell communication.

<Modification 6>
In the first and second embodiments, when the main base station a ₁ has a combined uplink and downlink S _Cell (the uplink and downlink S _Cell are not shown in FIG. 1). Since the uplink transmission is possible with P _Cell , it is not necessary to associate an inactivation timer with this uplink / downlink S _Cell . That is, it is possible in the flow chart of FIG. 7, even if there is _{S Cell} uplink and downlink in step _S705, the if there is _{P Cell,} not set deactivation timer in the uplink and downlink _{S Cell.} However, an inactivation timer may be set for all the plurality of uplink / downlink S _Cells of this type.
Similarly, the base station _{b 1,} upstream and downstream _{S If Cell} is component carrier to operate the there 2CC or more, because the any one of the _{S Cell} it is sufficient to activate, the any one of the _{S Cell} A deactivation timer may be set in In this case, the deactivation timer, for example, prioritize the plurality of upstream and downstream S _Cell, it is associated with high priority uplink and downlink S _Cell. Alternatively, it is possible to set the deactivation timer in S _Cell of using up and down associated with the S _Cell downlink only. However, it may be set deactivation timer for all uplink and downlink S _Cell.
<Modification 7>
In FIG. 1, terminal a is located in the communication area of base station a ₁ , base station b _1, and base station b ₂ (base station b ₂ may be another macrocell base station other than base station a ₁ ). In this case, the terminal a can perform carrier aggregation communication with the base station a ₁ , simultaneously perform carrier aggregation communication with the base station b ₁ , and simultaneously perform carrier aggregation communication with the base station b ₂ . This aspect can be applied to the first and second embodiments and modifications thereof.
(effect)
According to the second embodiment and various modifications of the present invention, in addition to the effects of the first embodiment, the terminal can quickly deactivate or disconnect the component carrier of the small cell base station. .

  The embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to the above-described one, and various design changes and the like can be made without departing from the scope of the present invention. Is possible.

  The embodiments of the present invention can be used in the technical field of carrier aggregation dual connection in LTE-A or a technical field similar thereto.

a, a ^′ ... terminals a ₁ , a ^′ _1, ... macro cell base station b ₁ to b ₅ , b ^′ ₁ ... small cell base station

Claims (5)

A carrier aggregation communication method,
Linking activation / deactivation control of a frequency band for uplink and downlink communication with the control of a frequency band for downlink communication only;
Carrier aggregation communication method. A terminal that performs carrier aggregation communication,
Set the deactivation timer to deactivate the frequency band for downlink communication only, and also set the deactivation timer to deactivate the frequency band for uplink and downlink communication A deactivation timer setting unit that also performs,
Terminal. The setting value of the deactivation timer for deactivating the frequency band for performing uplink and downlink communication is the setting value of the deactivation timer for deactivating the frequency band for performing downlink communication only. Exceeding the value,
The terminal according to claim 2. A carrier aggregation communication method,
The terminal deactivates the combined uplink and downlink frequency bands and all other frequency bands used by the base station according to the deactivation instruction of the combined uplink and downlink frequency bands. To
Carrier aggregation communication method. A carrier aggregation communication method,
In response to the deactivation instruction of the frequency band for performing the combined uplink and downlink communication, the terminal disconnects the connection of the combined uplink and downlink frequency bands and all other frequency bands used by the base station. ,
Carrier aggregation communication method.

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