KR20080091639A - Method and apparatus for indicating discontinuous reception mode in mobile telecommunication system - Google Patents

Abstract

A method and an apparatus for instructing the DRX(Discontinuous Reception) mode operation in a mobile telecommunication system are provided to reduce the signal load according to the DRX transition and to instruct the transition toward the desired DRX process of a base station efficiently. A process for determining an object DRX process for a terminal is performed. Thereafter, a process for deducting the index of the object DRX process from the index of the present DRX process of the terminal is performed. When the deducted value is larger than 0, a process for producing the DRX instruction information is performed so the transition of the DRX process is performed to the DRX process with the low index as much as the deducted value. When the deducted value is not larger than 0, a process for producing the DRX instruction information is performed so the transition of the DRX process is performed to the DRX process with the low index as much as the sum of the number of plural DRX processes and the deducted value. Thereafter, a process for transmitting the DRX instruction information to the terminal by means of the MAC(Medium Access Control) signal or two-layer or one layer signal.

Description

TECHNICAL AND APPARATUS FOR INDICATING DISCONTINUOUS RECEPTION MODE IN MOBILE TELECOMMUNICATION SYSTEM}

1 is a diagram illustrating an example of a structure of a next generation mobile communication system.

2 is a diagram illustrating a protocol structure of a next generation mobile communication system.

3 illustrates a DRX transition for DRX steps in accordance with a preferred embodiment of the present invention.

4 illustrates a transition between two DRX steps supported in real time and non real time services in accordance with a preferred embodiment of the present invention.

5 and 6 illustrate protocol layer entities for delivering DRX information via L1 / L2 signaling or MAC signaling in accordance with a preferred embodiment of the present invention.

7 is a flowchart illustrating an operation of transmitting a DRX related signaling by a base station according to the first embodiment of the present invention.

8 is a flowchart illustrating an operation of receiving, by a terminal, DRX related signaling according to a first embodiment of the present invention.

9 is a diagram illustrating a case in which a base station explicitly instructs a terminal to move to each DRX step according to the second embodiment of the present invention.

10 is a flowchart illustrating an operation of a base station transmitting DRX related signaling according to a second embodiment of the present invention.

11 is a flowchart illustrating an example of an operation of receiving, by a terminal, DRX related signaling according to a second embodiment of the present invention.

12 is a flowchart illustrating another example of an operation of receiving, by a terminal, DRX related signaling according to a second embodiment of the present invention.

13 is a flowchart illustrating an operation of a base station transmitting DRX related signaling according to a third embodiment of the present invention.

14 is a flowchart illustrating an example of an operation of receiving, by a terminal, DRX related signaling according to a third embodiment of the present invention.

15 is a flowchart illustrating another example of an operation of receiving, by a terminal, DRX related signaling according to a third embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an asynchronous mobile communication system, and more particularly, to a method and apparatus for efficiently instructing various stages of DRX operation in which a plurality of discontinuous reception (DRX) cycles are operated.

UMTS (Universal Mobile Telecommunication Service) system is based on the European mobile system Global System for Mobile Communications (GSM) and General Packet Radio Services (GPRS), and Wideband Code Division Multiple Access: Third generation asynchronous mobile communication system using " CDMA. &Quot;

3GPP (3rd Generation Partnership Project) in charge of UMTS standardization is discussing Long Term Evolution (LTE) as the next generation mobile communication system of UMTS system. LTE is a technology that implements high-speed packet-based communication of about 100 Mbps, aiming for commercialization in 2010. To this end, various schemes are discussed. For example, a scheme of reducing the number of nodes located on a communication path by simplifying a network structure, or approaching wireless protocols as close as possible to a wireless channel are under discussion.

1 illustrates an example of a structure of a next generation (Evolved) UMTS mobile communication system.

Referring to FIG. 1, as illustrated, an Evolved UMTS Radio Access Network (hereinafter referred to as an 'E-UTRAN' or an 'E-RAN') 110 and 112 may be an Evolved Node B (hereinafter referred to as “E-UTRAN”). It is simplified to a two node structure of 120, 122, 124, 126, and 128, and an anchor node 130, 132. The user equipment (hereinafter referred to as 'UE') 101 connects to the Internet Protocol network 114 by the E-UTRAN 110 and 112.

The ENBs 120 to 128 correspond to existing Node Bs of the UMTS system and are connected to the UE 101 by a radio channel. Unlike the existing Node B, the ENBs 120 to 128 play a more complex role. In LTE, all user traffic, including real-time services such as Voice over IP (VoIP) over the Internet protocol, is serviced through a shared channel, which requires a device that collects and schedules UE information. 120 to 128 are in charge.

Similar to High Speed Downlink Packet Access (HSDPA) or Enhanced Uplink Dedicated Channel (E-DCH), LTE AR (Hybrid ARQ) is performed between ENBs 120 to 128 and UE 101, but HARQ alone provides various quality of service ( Since the requirements of QoS (Quality of Service) cannot be satisfied, an outer ARQ may be performed at a higher layer, and the separate ARQ (hereinafter, referred to as 'outer-ARQ') may also be used as a terminal. 101) and ENBs 120-128.

LTE is expected to use Orthogonal Frequency Division Multiplexing (OFDM) as its radio access technology in the 20 MHz bandwidth to achieve transmission rates up to 100 Mbps. In addition, an adaptive modulation & coding (AMC) scheme that determines a modulation scheme and a channel coding rate according to the channel state of the terminal will be applied.

Many next-generation mobile communication systems, including LTE, use both HARQ and ARQ as error correction techniques.

Here, HARQ is a technique of increasing reception success rate by soft combining with retransmitted data without discarding previously received data. In more detail, the HARQ receiver determines whether there is an error in a received packet, and according to whether the error exists, a HARQ positive acknowledgment signal (hereinafter, referred to as a HARQ ACK) signal or a HARQ negative acknowledgment. Acknowledgement: hereinafter referred to as 'HARQ NACK' signal is transmitted to the transmitting side. Therefore, the transmitter performs retransmission of the HARQ packet or transmission of a new HARQ packet according to the HARQ ACK / NACK signal. And, the HARQ receiving side reduces the probability of error by soft combining the retransmitted packet with the previously received packet.

ARQ, on the other hand, checks the serial number of the received packet and requests retransmission for the unreceived packet, and does not soft combine the previously received packet with the retransmitted packet. In the LTE system, ARQ operation is a protocol layer called Radio Link Control (hereinafter referred to as 'RLC'), and HARQ operation is referred to as Media Access Control (hereinafter referred to as 'MAC') or Physical (PHY). ) In charge of the hierarchy.

2 illustrates a protocol structure of an LTE system. Here, the layers of the transmitter and the receiver are symmetrically illustrated.

Referring to FIG. 2, in a LTE system, one packet data convergence protocol (PDCP) entities 205, 210, 215, 280, 285, and 290, and radio link control (RLC) entities 220, 225, and the like may be used. 230, 265, 270, and 275 are configured. PDCP layer (205 ~ 215, 280 ~ 290) is responsible for the compression / restoration of the IP header, etc., RLC layer (220 ~ 230, 265 ~ 275) PDCP PDU (Packet Data Unit) which is a packet output from the PDCP layer ) Is reconfigured into an appropriate size RLC PDU, and performs an ARQ operation.

The MAC layers 235 and 260 are connected to several RLC entities 220 to 230 and 265 to 275 configured in one terminal, multiplex the input RLC PDUs to the MAC PDU, and demultiplex the RLC PDUs from the input MAC PDU. To perform the operation.

The HARQ layers 240 and 250 transmit and receive MAC PDUs to each other through a predetermined HARQ operation, and the physical layers 245 and 250 channel-code and modulate higher layer data and make OFDM symbols to transmit them on a wireless channel, Demodulation and channel decoding the OFDM symbols received through the radio channel to deliver to the upper layer.

In general, two layers (Layer 2: L2) cover all PDCP, RLC, and MAC layers 205 to 235 and 260 to 290, and one layer (Layer 1: L1) refers to physical layers 245 and 250. . The PDCP, RLC, and MAC entities exist in a pair of a transmitting side and a receiving side. For example, the transmitting side RLC entities 220 to 230 and the receiving side RLC entities 265 to 275 correspond to each other in a one-to-one manner.

Mobile communication systems such as LTE can operate several levels of DRX. In the DRX mode, the UE monitors a channel from the system every predetermined DRX cycle, and stops the communication operation at other times in order to save power consumption. Different levels of DRX use different DRX cycles to satisfy the quality of service (QoS) of each service. As an example, two different DRX cycles are applied to a real time service and a service that is not sensitive to time delay, and a shorter DRX cycle is preferably used for a real time service. Such an attempt may optimize the power consumption of the terminal.

Therefore, when such multiple stages of DRX are used, the base station instructs each terminal of each DRX cycle, and thus requires a specific technique for the terminal to move between the DRX stages.

The present invention provides a method and apparatus for efficiently transmitting a DRX step to a user equipment by a base station in a mobile communication system using multiple levels of DRX.

The present invention provides a method and apparatus for instructing a base station to instruct a UE of a transition of a DRX step in a mobile communication system using multiple levels of DRX.

According to a first aspect of the present invention, there is provided a method for indicating one of a plurality of DRX steps having different discontinuous reception (DRX) periods in a mobile communication system.

Determining a target DRX stage for the terminal and subtracting the index of the target DRX stage from the index of the current DRX stage of the terminal;

Generating DRX indication information indicating to transition to a DRX step having an index lower than the current DRX step by the subtracted value when the subtracted value is greater than 0;

If the subtracted value is not greater than 0, generate DRX indication information indicating to transition to a DRX step having an index that is lower than the sum of the plurality of DRX steps N and the subtracted value than the current DRX step. Process,

And transmitting the DRX indication information to the terminal using medium access control (MAC) signaling or layer 2 or layer 1 (L2 / L1) signaling.

According to a second aspect of the present invention, there is provided a method for indicating one of a plurality of DRX steps having different discontinuous reception (DRX) periods in a mobile communication system.

Receiving DRX indication information indicating a unit value for transition of a current DRX stage of a terminal from a base station through medium access control (MAC) signaling or layer 2 or layer 1 (L2 / L1) signaling;

Adding the unit value to the index of the current DRX step;

Determining to apply a DRX step having an index equal to the remainder obtained by dividing the added value by the number N of the plurality of DRX steps;

Each DRX cycle according to the determined DRX step, characterized in that it comprises the step of monitoring the downlink channel from the base station to check whether there is data received.

According to a third aspect of the present invention, there is provided a device for indicating one of a plurality of DRX steps having different discontinuous reception (DRX) periods in a mobile communication system.

A terminal for monitoring a downlink channel to check whether there is data received at each DRX cycle according to a current DRX stage;

Determine a target DRX stage for the terminal, subtract the index of the target DRX stage from the index of the current DRX stage of the terminal, and if the subtracted value is greater than 0, it is lower by the subtracted value than the current DRX stage; Generate DRX indication information indicating to transition to a DRX step having an index, and if the subtracted value is not greater than 0, the number of the plurality of DRX steps N and the subtracted value is greater than the current DRX step; Generate DRX indication information instructing to transition to a DRX step having a lower index, and transmit the DRX indication information to the terminal using medium access control (MAC) signaling or layer 2 or layer 1 (L2 / L1) signaling; Includes a base station for transmitting,

Here, the terminal,

After receiving the DRX indication information, the unit value is added to the index of the current DRX step, and the DRX step having the remaining indexes obtained by dividing the added value by the number N of the plurality of DRX steps will be applied. It is characterized by determining.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily flow the gist of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The main subject of the present invention to be described later is that the base station efficiently indicates the DRX cycle to be used by the terminal in the mobile communication system using different DRX cycles for each DRX stage through MAC signaling or L1 / L2 signaling.

In the following description, the 3GPP LTE system, which is an OFDM communication system based on UMTS, will be used. However, the signaling of the DRX stage, which is a basic object of the present invention, is applicable to other mobile communication systems using a similar technical background and channel form with a slight modification without departing from the scope of the present invention. In the judgment of those skilled in the art will be possible.

The present invention relates to a DRX transition when applying a plurality of DRX steps, that is, a plurality of DRX cycles.

3 illustrates a case in which the base station explicitly instructs the UE to move to each DRX cycle according to an exemplary embodiment of the present invention, and is less sensitive to a short DRX step and a time delay using a short DRX cycle for real-time service. A long DRX step is shown using a long DRX cycle for service. In addition, a no DRX step with a DRX cycle of zero, that is, a substantially continuous mode is used. In step 301, the UE is instructed to transition to the non-DRX stage from the base station and moves to the non-DRX stage. In step 302, the UE is instructed to transition to the long DRX step from the base station to move to the long DRX step.

As such, when two DRX steps are used, two bits of signaling information are required to indicate movement to a desired DRX cycle. The signaling information may indicate a transition to one of two DRX steps and a non-DRX step.

FIG. 4 illustrates DRX steps supported by real-time and non-real-time services according to a preferred embodiment of the present invention, and illustrates two DRX cycles optimized for real-time and non-real-time services. Referring to FIG. 4, in step 401, signaling indicating a transition to a short DRX step is transmitted, and in step 402, signaling indicating a transition to a long DRX step is transmitted.

As described above, when the optimized DRX cycle is selected and operated in consideration of the characteristics of each service, in order to inform the UE exactly which DRX to apply to the UE, Radio Resource Control (hereinafter referred to as 'RRC') Configuration and MAC signaling or L1 / 2 signaling may be used. The dual RRC configuration is inefficient when considering the time required for the indication to be applied. Therefore, in the present invention, the DRX transition is indicated by MAC signaling or L1 / L2 signaling. To reduce signaling overhead.

5 and 6 illustrate protocol layer entities for delivering DRX information through L1 / L2 signaling or MAC signaling according to a preferred embodiment of the present invention. In this case, when L1 / L2 signaling is used, information on whether DRX related signaling is present may be delivered to a higher layer through a specific field such as a type field.

Referring to FIG. 5, the transmitting MAC entity 501 located in the base station generates signaling information including DRX indication information for indicating the DRX mode of the terminal, and the transmitting physical layer entity 502 generates the signaling information. Is transmitted to a UE on the receiving side through a Packet Data Control Channel (PDCCH) which is a common control channel. The receiving physical layer entity 503 checks the Cyclic Redundancy Check (CRC) code for the control information received through the PDCCH, confirms that there is no error, and then transfers it to the receiving MAC entity 504. The receiving MAC entity 504 extracts DRX indication information, which is DRX related signaling included in the received control information, and checks the DRX mode to be indicated by the base station from the DRX indication information.

Referring to FIG. 6, the transmitting MAC entity 601 located in the base station generates a control PDU including DRX indication information for indicating a DRX mode of the UE and multiplexes the control PDU with a data PDU including user data. The transmitting side physical layer entity 602 transmits the multiplexed data to a terminal on the receiving side through a Packet Data Shared Channel (PDSCH), which is a shared data channel. The receiving physical layer entity 603 checks the CRC code for the data received through the PDSCH, confirms that there is no error, and transfers the received MAC layer 604 to the receiving MAC entity 604. The receiving MAC entity 604 demultiplexes the received data, extracts a control PDU including DRX indication information, which is DRX related signaling, and identifies a DRX mode to be indicated by the base station from the DRX indication information.

<< first embodiment >>

The first embodiment of the present invention relates to a DRX transition when applying a plurality of DRX steps, that is, a plurality of DRX cycles. When the UE operates two DRX steps except for non-DRX as shown in FIG. 3 in the DRX mode, two bits are required as shown in Table 1 below to indicate each step.

This is because a transition from a long DRX stage to a non-DRX stage should also be possible. As an extension of Table 1, Table 2 below illustrates the case of using two bits for DRX related signaling according to a preferred embodiment of the present invention.

When using the bit mapping of Table 2, even if two or more DRX steps are used, except for non-DRX, only two bits may be used to explicitly indicate the desired DRX step. Can be.

7 is a flowchart illustrating an operation of transmitting a DRX related signaling by a base station according to the first embodiment of the present invention.

Referring to FIG. 7, in step 701, the base station determines whether non-DRX is required in determining the DRX mode of the UE. This determination can be made, for example, by checking the type of services and the QoS configured for the terminal. If the non-DRX is required, the base station proceeds to step 703 and sets the DRX indication information to '00'. On the other hand, if non-DRX is not required, proceed to step 705.

In step 705, the base station determines whether it is necessary to change the current DRX step of the terminal. If it is not necessary, the base station proceeds to step 710 and sets the DRX indication information to '11'. Whether or not it is necessary to change the DRX stage of the terminal can be made by checking whether the terminal can receive data to be transmitted by the base station without a large delay in the DRX cycle according to the current DRX stage of the terminal. If the DRX step of the UE needs to be changed, the process proceeds to step 709 where the BS determines whether it is necessary to shorten the current DRX cycle of the UE. If a shorter DRX cycle is needed, the DRX indication information for the UE in step 707 is set to '01', and if a shorter DRX cycle is not required, a longer DRX cycle is required to indicate that a longer DRX cycle is required in step 708. DRX indication information is set to '10'.

In step 712, the base station transmits the DRX indication information configured in one of the steps 703, 707, 708, and 710 to the terminal through MAC or L2 / L1 signaling, and transmits data to the terminal according to the indicated DRX step.

8 is a flowchart illustrating an operation of receiving, by a terminal, DRX related signaling according to a first embodiment of the present invention.

Referring to FIG. 8, in step 801, the UE receives and detects a control PDU or L2 / L1 signaling signal including DRX indication information. Here, L2 / L1 signaling is detected by a Cell-Radio Network Temporary Identifier (C-RNTI) that uniquely identifies a terminal in a cell. In step 803, the UE determines whether the DRX indication information is '00', and if it is '00', determines that the UE operates in a non-DRX step in step 805.

If it is determined in step 807 that the DRX indication information is '01', in step 809, the UE determines to operate in a lower DRX step using a DRX cycle shorter by one step than the current DRX step. If it is determined in step 811 that the DRX indication information is '10', the UE determines in step 813 to operate at a higher DRX step using a DRX cycle longer by one step than the current DRX step. If it is determined in step 815 that the DRX indication information is '11', the UE determines in step 817 to maintain the current DRX step.

In step 820, the UE monitors the downlink channel according to the DRX mode determined in one of steps 805, 809, 813, and 817 to receive data from the base station. If the determined DRX mode is a non-DRX mode, the downlink channel is continuously monitored.

<< 2nd Example >>

In the second embodiment of the present invention, when two DRX steps are used as shown in FIG. 4, only one bit is used as DRX indication information to indicate a DRX transition, and an example of the meaning mapped to the one bit is described below. It is shown in <Table 3> and <Table 4>.

In the case of MAC signaling or L1 / L2 signaling, if DRX indication information is not delivered to the UE at the present time, the UE determines to maintain the current DRX step. Accordingly, the base station transmits only the DRX indication information for the step transition, not the maintenance as shown in Table 3 or Table 4. That is, if the DRX indication information is mapped as shown in Table 3 or Table 4, the DRX transition indication can be sufficiently transmitted with one bit.

FIG. 9 illustrates a case in which the base station explicitly instructs the UE to move to each DRX stage according to the second embodiment of the present invention. Here, non-DRX stages and two DRX stages are illustrated. The DRX stage is considered to be a DRX stage with a DRX cycle of zero.

Referring to FIG. 9, in step 902, the UE is in a long DRX step and maintains the long DRX step unless it receives DRX indication information from the base station. When receiving the DRX indication information transmitted from the base station, that is, bit '0' in order to command a step longer in step 903, the UE transitions to a non-DRX step in step 901. In this way, if the UE is instructed to move to a step that can no longer proceed, the UE applies the DRX steps repeatedly. In the non-DRX phase, when the terminal receives DRX indication information of '0' or '1' from the base station, the terminal immediately moves to a short DRX phase or a long DRX phase.

10 is a flowchart illustrating an operation of a base station transmitting DRX related signaling according to a second embodiment of the present invention.

Referring to FIG. 10, in step 1001, the base station defines a step index for possible DRX steps of the terminal. The non-DRX stage is indexed as 0, the short DRX stage is 1, and the long DRX stage is 2, respectively. In step 1002, the base station determines a DRX stage, that is, a destination stage, to move the terminal according to the types of services and QoS, etc. configured for the terminal, and in step 1003, the base station determines the index of the source stage of the terminal. A is calculated by subtracting the index of the target step.

At step 1005, it is determined whether A is greater than 0, and if it is greater than 0, go to step 1008; In step 1008, the base station sets, as DRX indication information, a bit value indicating to move to a lower DRX step by A using a shorter DRX cycle when the bit mapping of <Table 3> is applied. If a mapping is applied, set a bit value indicating to move to a higher DRX level by (3-A) using a longer DRX period as DRX indication information. Where 3 is the total number of DRX steps including non-DRX steps.

In step 1009, when the bit mapping of <Table 3> is applied, the base station sets a bit value indicating that the UE moves to a lower DRX level by (3 + A) using a shorter DRX cycle, and applies the DRX indication information. 4> uses a longer DRX cycle when bit mapping is applied | Set a bit value indicating to move to a higher DRX step by DRX indication information.

In step 1010, the base station transmits the DRX indication information set in step 1008 or 1009 to the terminal through MAC or L2 / L1 signaling, and transmits data to the terminal according to the indicated DRX step.

FIG. 11 is a flowchart illustrating an operation of receiving, by a terminal, DRX related signaling when Table 3 is applied according to a second embodiment of the present invention.

Referring to FIG. 11, in step 1101, the UE defines the step index for possible DRX steps with the base station. The non-DRX stage is indexed as 0, the short DRX stage is 1, and the long DRX stage is 2, respectively. In step 1102, the UE detects and receives a control PDU or L2 / L1 signaling signal including DRX indication information. Here, the DRX indication information has a bit value of '0' or '1' indicating 1 or 2, which is a step value to be decreased, as shown in Table 3. In step 1103, the UE calculates A by subtracting the unit value indicated by the DRX indication information from the index of the DRX step currently being applied and proceeds to step 1105.

In step 1105, A is determined to be greater than or equal to 0, and if greater than or equal to 0, the process proceeds to step 1106, otherwise proceeds to step 1108. In step 1106, the UE determines to apply the DRX step of index A, and in step 1108, the UE determines to apply the DRX step of index (3 + A). In step 1110, the UE monitors the downlink channel according to the DRX mode determined in step 1106 or 1108 to receive data from the base station. If the determined DRX mode is a non-DRX mode, the downlink channel is continuously monitored.

12 is a flowchart illustrating an operation of receiving, by a terminal, DRX related signaling when <Table 4> is applied according to a second embodiment of the present invention.

Referring to FIG. 12, in step 1201, the UE defines a step index for possible DRX steps with the base station. The non-DRX stage is indexed as 0, the short DRX stage is 1, and the long DRX stage is 2, respectively. In step 1202, the UE detects and receives a control PDU or L2 / L1 signaling signal including DRX indication information. Here, the DRX indication information has a bit value of '0' or '1' indicating 1 or 2, which is a unit value to be increased, as shown in Table 4. In step 1203, the UE calculates A by adding the unit value indicated by the DRX indication information to the index of the currently applied DRX step, and then proceeds to step 1205.

In step 1205, the UE determines to apply the DRX step of the index (A mod 3), and in step 1207, the UE monitors the downlink channel according to the DRX mode determined in step 1205, in order to receive data from the base station. . If the determined DRX mode is a non-DRX mode, the downlink channel is continuously monitored. Where (A mod 3) is the remainder of A divided by 3.

<< third embodiment >>

The third embodiment of the present invention shows a general DRX transition operation for the case where two or more multi stages are used. In general, if the number of DRX steps including non-DRX is N, m bits, which is the smallest integer that satisfies the condition of N <= 2 ^m , are required for DRX related signaling. However, applying bit mapping similar to that in the second embodiment, DRX related signaling is possible with only m bits, which are the smallest integers satisfying N-1 <= 2 ^m . At this time, if N is greater than 1 by an integer multiple of 2, as in the second embodiment, the number of bits required may be reduced by one.

Tables 5 and 6 below illustrate bit mapping according to the third embodiment of the present invention.

13 is a flowchart illustrating an operation of a base station transmitting DRX related signaling according to a third embodiment of the present invention. Here, non-DRX stages and (N-1) DRX stages are shown, which are considered to be DRX stages with a DRX cycle of zero.

Referring to FIG. 13, in step 1301, the base station defines a step index for possible DRX steps of the terminal. Here, the non-DRX stages are 0, and each DRX stage has 1, 2,... Indexed as (N-1). In step 1302, the base station determines the DRX step, that is, the destination step, to move the terminal according to the types of services and the QoS configured for the terminal, and subtracts the index of the destination step from the index of the original step of the terminal in step 1303. Calculate

In step 1305, it is determined whether A is greater than 0, and if greater than 0, proceed to step 1308, otherwise proceed to step 1309. In step 1308, when the bit mapping of <Table 5> is applied, the base station sets a bit value indicating that the UE moves to a lower DRX level by A using a shorter DRX cycle as DRX indication information. If a mapping is applied, set a bit value indicating DRX indication information to move to a higher DRX level by using a longer DRX cycle (NA).

In step 1309, when the bit mapping of <Table 5> is applied, the base station sets a bit value indicating to move to a lower DRX step by using (N + A) using a shorter DRX cycle as DRX indication information. 6> uses a longer DRX cycle when bit mapping is applied. Set a bit value indicating to move to a higher DRX step by DRX indication information.

In step 1310, the base station transmits the DRX indication information set in step 1308 or 1309 to the terminal through MAC or L2 / L1 signaling, and transmits data to the terminal according to the indicated DRX step.

FIG. 14 is a flowchart illustrating an operation of receiving a DRX related signaling by a terminal when Table 5 is applied according to the third embodiment of the present invention.

Referring to FIG. 14, in step 1401, the UE defines a step index for possible DRX steps with the base station. Here, the non-DRX stages are 0, and each DRX stage has 1, 2,... Indexed as (N-1). In step 1302, the UE detects and receives a control PDU or L2 / L1 signaling signal including DRX indication information. Here, the DRX indication information has a value of m bits indicating one of 0 to (N-1), which is a unit value to be reduced, as shown in Table 5. In step 1403, the UE calculates A by subtracting the unit value indicated by the DRX indication information from the index of the DRX step currently being applied and proceeds to step 1405.

In step 1405, A is determined to be greater than or equal to 0, and if greater than or equal to 0, the process proceeds to step 1407, otherwise proceeds to step 1408. In step 1407, the UE determines to apply the DRX step of index A, and in step 1408, the UE determines to apply the DRX step of index (N + A). In step 1410, the UE monitors the downlink channel according to the DRX mode determined in step 1407 or 1408 to receive data from the base station. If the determined DRX mode is a non-DRX mode, the downlink channel is continuously monitored.

FIG. 15 is a flowchart illustrating an operation of receiving a DRX related signaling by a terminal when <Table 6> is applied according to a third embodiment of the present invention.

Referring to FIG. 15, in step 1501, the UE defines a step index for possible DRX steps with the base station. Here, the non-DRX stages are 0, and each DRX stage has 1, 2,... Indexed as (N-1). In step 1502, the UE detects and receives a control PDU or L2 / L1 signaling signal including DRX indication information. Here, the DRX indication information has a value of m bits indicating one of 0 to (N-1), which is a unit value to be increased, as shown in Table 6. In step 1503, the UE calculates A by adding the unit value indicated by the DRX indication information to the index of the currently applied DRX step, and then proceeds to step 1505.

In step 1505, the UE determines to apply the DRX step of the index (A mod N), and in step 1507, the UE monitors the downlink channel according to the DRX mode determined in step 1505 to receive data from the base station. . If the determined DRX mode is a non-DRX mode, the downlink channel is continuously monitored. Where (A mod N) is the remainder of A divided by N.

<< fourth embodiment >>

The fourth embodiment of the present invention shows a case where cyclic application is performed in both directions of increase and decrease instead of one direction when mapping signaling bits. Table 7 below shows an example of bit mapping when two bits of DRX indication information is used.

If bit mapping as shown in Table 7 above is applied, it is possible to indicate transition to all specific steps when five DRX steps including non-DRX steps are used, if the determined DRX steps are cycled to be applied. Do.

When the fourth embodiment is applied, an operation of exchanging signaling related to DRX at the base station and the terminal is similar to the above-described flowcharts, and thus detailed description thereof will be omitted.

<< Fifth Embodiment >>

The fifth embodiment of the present invention is to determine the unit value when determining the transition between steps using only two bits of DRX indication information when multiple DRX steps are used. That is, the base station determines whether it is advantageous to apply a long DRX cycle or a short DRX cycle to each terminal according to its decision or an instruction from the network. The unit values to be mapped are determined, and the bit-mapped unit values are transmitted to the terminal through RRC signaling.

That is, before indicating the DRX step of the terminal, the base station notifies the terminal of any one of <Table 1> to <Table 6> indicating bit mapping of the DRX indication information or the bit mapping that is not mentioned through RRC signaling. The DRX mode of the UE is controlled by referring to the transferred bit mapping. At this time, the base station may determine unit values of DRX transition for a specific terminal or a specific group of terminals in consideration of the service type and characteristics of the terminal and the situation of the base station and the network. As an example, a relatively large unit value and a larger number of DRX stages may be used for a terminal that needs to greatly change the DRX stage. For a terminal that is not, relatively small unit values and fewer DRX stages may be used. Can be used.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention provides embodiments in which a base station indicates a transition between DRX steps using minimal signaling bits in a mobile communication system using multiple DRX steps supporting various DRX cycles, thereby reducing signaling load according to DRX transition. Reducing, and the base station can quickly and efficiently indicate the transition to the desired DRX stage.

Claims (3)

A method for indicating one of a plurality of DRX steps having different discontinuous reception (DRX) periods in a mobile communication system, Determining a target DRX stage for the terminal and subtracting the index of the target DRX stage from the index of the current DRX stage of the terminal; Generating DRX indication information indicating to transition to a DRX step having an index lower than the current DRX step by the subtracted value when the subtracted value is greater than 0; If the subtracted value is not greater than 0, generate DRX indication information indicating to transition to a DRX step having an index that is lower than the sum of the plurality of DRX steps N and the subtracted value than the current DRX step. Process, And transmitting the DRX indication information to a terminal using medium access control (MAC) signaling or layer 2 or layer 1 (L2 / L1) signaling. A method for indicating one of a plurality of DRX steps having different discontinuous reception (DRX) periods in a mobile communication system, Receiving DRX indication information indicating a unit value for transition of a current DRX stage of a terminal from a base station through medium access control (MAC) signaling or layer 2 or layer 1 (L2 / L1) signaling; Adding the unit value to the index of the current DRX step; Determining to apply a DRX step having an index equal to the remainder obtained by dividing the added value by the number N of the plurality of DRX steps; And monitoring a downlink channel from the base station every DRX cycle according to the determined DRX step to confirm whether there is data received. An apparatus for indicating one of a plurality of DRX steps having different discontinuous reception (DRX) periods in a mobile communication system, A terminal for monitoring a downlink channel to check whether there is data received at each DRX cycle according to a current DRX stage; Determine a target DRX stage for the terminal, subtract the index of the target DRX stage from the index of the current DRX stage of the terminal, and if the subtracted value is greater than 0, it is lower by the subtracted value than the current DRX stage; Generate DRX indication information indicating to transition to a DRX step having an index, and if the subtracted value is not greater than 0, the number of the plurality of DRX steps N and the subtracted value is greater than the current DRX step; Generate DRX indication information instructing to transition to a DRX step having a lower index, and use the DRX indication information in the terminal using medium access control (MAC) signaling or layer 2 or layer 1 (L2 / L1) signaling; Includes a base station for transmitting to Here, the terminal, After receiving the DRX indication information, add the unit value to the index of the current DRX step, and apply the DRX step having the remaining indexes by dividing the added value by the number N of the plurality of DRX steps. And indicating a DRX operation.

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