KR20150110426A - Apparatus and method for moniotoring d2d transmission in connected status - Google Patents

Abstract

Disclosed are a method and an apparatus for monitoring a D2D transmission in a connected state in a communications system which supports a device to device (D2D) method. The method includes the steps of: performing D2D monitoring by a D2D user equipment (UE) during a D2D resource cycle and a DRX cycle in a RRC state; transmitting to a base station an indicator including a UE function; and resetting a RRC connection from the base station wherein the D2D resource cycle and the DRX cycle are configured not to overlap on the basis of the indicator.

Description

[0001] APPARATUS AND METHOD FOR MONITORING D2D TRANSMISSION IN CONNECTED STATUS [0002]

The present invention relates to an apparatus and method for monitoring D2D (Device to Device) transmission in a connected state.

The D2D discovery process is a process in which a D2D-enabled user equipment (UE) (D2D-enabled UE) is placed in proximity to another D2D- Is present. The discovering D2D-enabled UE determines if another D2D-enabled UE is interested in the searching D2D-enabled UE based on the D2D discovery process. The other D2D-enabled UE may determine that the neighbor of the other D2D-enabled UE needs to be notified by one or more authorized applications in the searching D2D- I am interested in D2D-enabled UEs.

As an example, a social networking application may be enabled to use the D2D search feature. The D2D discovery process enables a D2D-enabled UE of a given user of a social networking application to search for D2D-enabled UEs of friends of a friend of the social networking application, Enabled UEs to be searched by D2D-enabled UEs of a given user's friends. In another example, the D2D discovery process may be performed by a D2D-enabled UE of a given user of a search application, a D2D-enabled UE of a given user of the search application, It may be possible to search for stores / restaurants of the enabled UE.

In a frequency division duplex (FDD) system, D2D communication is performed on the uplink (UL) frequency. One of the methods for allocating the resource (s) to the D2D UE for transmission is the dedicated signaling method between the D2D UE and the base station (BS (base station) or eNB (evolved Node B).) The UE requests a dedicated resource from the eNB, and the eNB allocates dedicated resource (s) for transmission to the D2D UE. The resource request and the resource allocation occur in a connection state in which the UE and the eNB are connected to each other. D2D UEs that are transmitting D2D packets (discovery or data packets) receive D2D packets (such as discovery or data) from other D2D UEs, Packets) at the UE. In a connected state, the UE must continue to monitor the downlink (DL) frequency to receive at least the Packet Data Common Control Channel (PDCCH) transmitted by the eNB. D2D When the UE wants to receive D2D packets on the UL frequency in the connected state, it performs the following operations.

1. The D2D UE shall not only transmit and receive D2D packets on the UL frequency.

a. These are not a problem when the D2D UE is able to receive D2D packets through D2D resources that are not used for D2D transmission.

2. However, the D2D UE shall transmit control data or data packets on the UL frequency to the eNB and receive D2D packets on the UL frequency.

a. They are not a problem if the resources for communication with the D2D and eNB are separate.

b. However, when the D2D resources and the communication resources with the eNB are frequency division multiplexed in the same subframe, the UE monitors the D2D resources when the communication with the eNB is not scheduled.

c. The UE must receive the PDCCH on the DL frequency and receive the D2D packets on the UL frequency. All UEs do not have the capability to simultaneously receive on DL frequency and UL frequency.

It is therefore important that the UE must monitor the DL frequency for the PDCCH even though there is no data scheduled on the UL or DL frequency.

The UE may be in a connection state for communication with the eNB, or may be in a connection state for dedicated resource allocation for D2D. Since the UE has a long discovery transmission periodicity and the discovery transmissions are periodically transmitted, they may be in a connected state for a very long time when entering a connection state for dedicated resource allocation for D2D discovery. At this time, the UE may not be able to monitor the D2D transmissions in the connected state. Therefore, there is a need for an apparatus and method for monitoring D2D transmissions in a connected state.

The present invention provides an apparatus and method for monitoring D2D transmissions in a connected state in a communication system supporting a device to device scheme.

A method for monitoring D2D transmission in a connected state includes performing D2D monitoring by a D2D terminal during a D2D resource cycle and a discontinuous reception (DRX) cycle in an RRC (Radio Resource Control) state Process; Transmitting an indicator for directing D2D monitoring to the base station; And resetting the RRC connection from the base station, wherein resources of the D2D resource cycle and resources of the DRX cycle are not overlapped based on the indicator.

An apparatus for a D2D terminal for monitoring a D2D transmission in a connected state, the apparatus comprising: a D2D monitoring module for performing D2D monitoring during a D2D resource cycle and a DRX cycle in an RRC state; A transmitter for transmitting an indicator for directing D2D monitoring to the base station; And a controller for re-establishing an RRC connection with the base station, wherein resources of the D2D resource cycle and resources of the DRX cycle are configured not to overlap based on the indicator.

A method according to an embodiment of the present invention is a method for monitoring D2D transmission in a connected state at a base station, the method comprising: during a D2D resource cycle and a D2D monitoring in a DRX cycle, The method comprising the steps of: And configuring resources of the D2D resource cycle and resources of the DRX cycle not to overlap based on the indicator; And re-establishing an RRC connection with the terminal.

An apparatus for monitoring a D2D transmission in a connected state in a base station, the apparatus comprising: a D2D resource monitoring unit for monitoring D2D from a terminal in a RRC state during a D2D resource cycle and a DRX cycle; A receiving unit for receiving an indicator for indicating an indicator; And a controller for configuring resources of the D2D resource cycle and resources of a DRX cycle so as not to overlap with each other based on the indicator and reestablishing an RRC connection with the terminal.

Other aspects, benefits, and key features of the present invention will become apparent to those skilled in the art from the following detailed description, which is set forth in the accompanying drawings and which discloses preferred embodiments of the invention.

It may be effective to define definitions for certain words and phrases used throughout this patent document before processing the specific description portions of the present disclosure below: "include" and " Comprise "and its derivatives mean inclusive inclusion; The term " or "is inclusive and means" and / or "; The terms " associated with "and " associated therewith ", as well as their derivatives, are included within, (A) to (A) to (B) to (C) to (C) to (C) Be communicable with, cooperate with, interleave, juxtapose, be proximate to, possibility to communicate with, possibility to communicate with, It means big or is bound to or with, have a property of, etc .; The term "controller" means any device, system, or portion thereof that controls at least one operation, such devices may be hardware, firmware or software, or some combination of at least two of the hardware, Lt; / RTI > It should be noted that the functionality associated with any particular controller may be centralized or distributed, and may be local or remote. Definitions for particular words and phrases are provided throughout this patent document and those skilled in the art will recognize that such definitions are not only conventional, But also to future uses of the phrases.

Figure 1 illustrates a D2D resource that is periodically configured in accordance with one embodiment of the present invention;
Figure 2 illustrates a connected mode DRX cycle in accordance with one embodiment of the present invention;
Figure 3 is an exemplary diagram of a non-overlapping connected mode DRX cycle and a D2D resource cycle in accordance with an embodiment of the present invention.
4 is a flow diagram illustrating a method for monitoring D2D transmissions in a connected state according to a first sub-embodiment of the first embodiment of the present invention;
5 is a flow diagram illustrating a method for monitoring D2D transmissions in a connected state according to a second sub-embodiment of the first embodiment of the present invention;
Figure 6 is a flow diagram illustrating a method for monitoring D2D transmissions in a connected state according to a third sub-embodiment of the first embodiment of the present invention;
7 is a flow diagram illustrating a method for monitoring D2D transmissions in a connected state according to a fourth sub-embodiment of the first embodiment of the present invention;
8 is a block diagram of a UE according to an embodiment of the present invention;
9 is a flow diagram illustrating a method for monitoring D2D transmission in a connected state in accordance with a second embodiment of the present invention;
10 is a flow diagram illustrating a method for monitoring D2D transmissions in a connected state in accordance with a third embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same components are denoted by the same reference numerals as possible in the accompanying drawings. Further, the detailed description of well-known functions and constructions that may obscure the gist of the present invention will be omitted.

Also, the terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary meanings, and the inventor is not limited to the concept of terms in order to describe his invention in the best way. It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be properly defined.

In the embodiment of the present invention to be described later, a wireless network supporting direct communication between devices will be described as a D2D network. However, the technical structure proposed in the embodiment of the present invention should not be construed as being limited to the D2D network. That is, the technical structure proposed in the embodiment of the present invention can be equally applied to a wireless network or a cellular system supporting direct communication between devices. In particular, in an embodiment of the present invention, a transmitting terminal in the wireless network initiates an operation in response to driving of an application selected based on D2D communication with at least one receiving terminal. The transmitting terminal transmits a discovery signal or discovery information to discover at least one receiving terminal to form a link according to D2D communication. That is, this means a series of processes for informing another terminal located at a close distance of the identity and interest of the transmitting terminal. At this time, the identity and the interest may be an identifier (ID) of the terminal, an application identifier, a service identifier, or the like, and may be variously configured according to the D2D service and the operation scenario.

It is assumed that the hierarchical structure of the D2D terminal is composed of a D2D application layer, a D2D management layer, and a D2D transport layer, though it is not shown in the figure. The D2D application layer refers to a D2D service application program driven by a terminal operating system (OS), and the D2D management layer is responsible for converting the discovery information generated in the D2D application program into a format suitable for the transport layer. (PHY / MAC) layer of long term evolution (LTE) or Wi-Fi wireless communication standard. At this time, inter-terminal discovery may have the following procedure. When the user executes the D2D application program, information for discovery is generated in the application layer and transmitted to the D2D management layer. The D2D management layer converts the discovery information received from the D2D application layer into a management layer message. The management layer message is transmitted through the transport layer of the MS, and the MSs receiving the management layer message perform a reception operation in a reverse order of the transmission process.

Meanwhile, the inter-terminal communication is a communication method for directly transmitting traffic between terminals without going through an infrastructure such as a base station or an access point (AP). At this time, inter-terminal communication can be performed between the terminals without performing the inter-terminal discovery process and then performing communication based on the result (i.e., with the dis- tributed terminals) or without inter-terminal discovery process. The necessity of the inter-terminal discovery process before the inter-terminal communication can be changed according to the D2D service and the operation scenario.

D2D service scenarios can be broadly categorized into commercial services (eg, commercial services or non public safety services) and public safety services. Each service may include a myriad of use cases, but representatively examples are advertisements, social network services (SNS), games, public safety, and public safety services .

1) Advertisement: A network operator who supports D2D can use pre-registered shops, cafes, movie theaters, restaurants, etc. to communicate their identities to D2D users located at close distances using inter-terminal discovery or inter- can do. At this time, interests can be advertisers' promotions, event information, discount coupons, and the like. Among D2D users, those who are interested in discounting and couponing a specific product upload their interests to the D2D server. If the identity received by the D2D users matches the user's interests, the user can visit the store and obtain more information using existing cellular network or inter-terminal communication. In another example, an individual user can discovery a taxi located in the vicinity of the user through the inter-terminal discovery, and exchange data on the destination, charge information, and the like through the existing cellular communication or inter-terminal communication.

2) SNS (social network service): The user can send his / her application and the interest of the application to other users located in the adjacent area. At this time, the identity or the interest used in inter-terminal discovery may be a friend list or an application identifier of the application. After the user performs the inter-terminal discovery, the user can share the contents of his / her photos, videos, etc. with the nearby users through the inter-terminal communication.

3) Game: The user discovers users and game applications through the inter-terminal discovery process in order to enjoy a mobile game with users located in close proximity, and performs communication between the terminals in order to transmit data necessary for the game can do.

4) Public safety and public safety services: Police officers and firefighters may use D2D communication technology for public safety purposes. That is, if cellular networks are partially destroyed due to an emergency such as a fire or landslide, or natural disasters such as earthquakes, volcanic eruptions, or tsunamis, police and firefighters can use D2D communication technology to discover nearby associates The emergency information of each user can be shared among the adjacent users.

The D2D terminal described below may include one of a transmitting terminal and a receiving terminal. In this specification, a cellular terminal and a D2D terminal can be distinguished from each other. The cellular terminal can communicate with a base station or another terminal using a conventional cellular communication network without a direct link between the terminals. The D2D terminal refers to a terminal that performs D2D discovery or D2D direct communication through a direct link between terminals. At this time, the D2D terminal can perform communication with the base station for transmission and reception of various control information. The term " terminal " used in this specification without any particular distinction can be interpreted to refer to a cellular terminal as well as a D2D terminal.

A method for monitoring D2D transmission in the connected state according to the first embodiment of the present invention is as follows.

In a first embodiment of the present invention, the D2D UE is in a connected state and does not have the capability to simultaneously receive on the DL and UL frequencies and wants to receive D2D packets (discovery or data packets) transmitted by other D2D UEs The D2D UE and the eNB operate as follows.

1. UE monitors UL frequency only when switching to connected mode DRX sub-state.

2. The eNB configures the DRX ON cycle duration and the D2D resources (e.g., the D2D resource cycle and the D2D resource in the D2D resource cycle) to not overlap with each other.

In the first embodiment of the present invention, the operation may be performed by the D2D UE even in the case of having the function of simultaneously receiving on DL and UL frequencies to reduce power consumption.

Connection state UL frequency monitoring by UE during DRX sub-state:

The UE monitors the UL frequency only when the UE switches to the connected mode DRX sub-state. Connection Mode In the DRX sub-state, the UE periodically monitors the DL frequency for a short duration. When the UE is in the Connected State DRX sub-state, the D2D UE monitors the UL frequency during the DRX OFF period, i.e. when the UE is not monitoring the DL frequency.

1. Connection Mode of the UE When the DRX module stops DL frequency monitoring, it can send an indication to the D2D monitoring module.

a. The D2D monitoring module may be configured with parameters indicating the subframe in which the connection mode DRX module initiates DL frequency monitoring. For example, the parameter may be longDRX-CycleStartOffset sf1280, and the parameter value may be 511, for example. Connection Mode The system frame number (SFN) and subframe number (sub FN) at which the DRX module starts DL frequency monitoring means that it satisfies the following equation. (SFN * 10 + sub FN) mod 1280 = 511. Therefore, after receiving the above instruction from the connected mode DRX module, the D2D monitoring module can know when the connected mode DRX module will resume DL frequency monitoring.

b. Alternatively, the UE's connection mode DRX module may inform the D2D monitoring module about the sub-frame (SFN, sub-FN) where DL frequency monitoring is to resume.

c. Alternatively, the connection mode DRX module of the UE may send an indication to the D2D monitoring module with information about the period of not monitoring the DL frequency (e.g., the beginning of the subframe and the end of the subframe).

2. Connection Mode In the DRX OFF periods indicated by the DRX module, the UE monitors the subframes in which the D2D resources are configured. During D2D monitoring, the UE monitors the subframes that the UE does not need to transmit to the eNB. D2D resources are configured by RRC.

Non-redundant DRX ON cycle duration and D2D resource configuration by eNB

Figure 1 is a diagram illustrating D2D resources that are periodically configured in accordance with one embodiment of the present invention.

Referring to FIG. 1, D2D resources 100 and 110 are periodically configured. As shown in FIG. 1, the D2D resources are periodically configured for a small duration, e.g., D2D resource duration 100, for each D2D resource cycle 120, for example.

2 is a diagram illustrating a connection mode DRX cycle according to an embodiment of the present invention.

Referring to FIG. 2, the DL frequency is periodically monitored every DRX cycle for a small duration, i.e., an ON duration 200, 210. In the first embodiment of the present invention, the D2D resource cycle and the connected mode DRX cycle are configured such that the 'ON duration 200' on the connected mode DRX cycle 220 is not overlapped with the D2D resource duration 100.

As a typical example, the non-overlap of the 'ON duration 200' on the connected mode DRX cycle and the 'D2D resource duration 100' on the D2D resource cycle can be ensured as follows. The DRX cycle 220 may be defined based on parameters such as DRXCycleDuration, DRXCycleOntime, and DRXOffset. Here, the frame number at which the DRX cycle starts can be defined as Equation (1).

&Quot; (1) "

SFN mod DRXCycleDuration = DRXOffset.

The UE monitors the DL from SFN to SFN + DRXCycleOntime. The D2D resource cycle can be defined based on parameters such as D2DCycleDuration, D2DResourceDuration, DRCOffset. Here, the frame number at which the D2D resource cycle starts can be defined by Equation (2).

&Quot; (2) "

SFN mod D2DCycleDuration = DRXOffset.

D2D resources exist from SFN to SFN + D2DResourceDuration.

a) D2DCycleDuration = N * DRXCycleDuration (N = 1, 2, 3, ......); Or N * D2DCycleDuration = DRXCycleDuration (N = 1, 2, 3, ...); If DRXOffset = DRCOffset + D2DResourceDuration or DRCOffset = DRXOffset + DRXCycleOntime, non-overlapping of 'ON duration 200' on the connected mode DRX cycle and 'D2D resource duration 100' on the D2D resource cycle can be ensured. The non-overlap of the 'ON duration 200' on the connected mode DRX cycle and the 'D2D resource duration 100' on the D2D resource cycle is shown in FIG.

Figure 3 is an exemplary diagram of a non-overlapping connected mode DRX cycle and a D2D resource cycle in accordance with an embodiment of the invention.

Referring to FIG. 3, the network or eNB establishes a connection mode DRX cycle specific to the UE without consideration of D2D resources (e.g., D2D resource cycles and D2D resources of the D2D resource cycle). The network or eNB may change the connection mode DRX cycle that is already established for the UE, or may be configured to take into account the D2D resources (e.g., D2D resource cycles and D2D resources in the D2D resource cycle) A DRM cycle may be set up so that the duration time 300 does not overlap with the D2D resources 310).

4 is a flowchart illustrating a method for monitoring D2D transmission in a connected state according to a first sub-embodiment of the first embodiment of the present invention.

4, in a first embodiment of the present invention, when a network or an eNB informs a D2D UE that it is monitoring D2D transmissions from other UEs in a connected state, the D2D resources (e.g., the D2D resource cycle and the D2D D2D resources in the resource cycle). ≪ / RTI >

The D2D UE is in the RRC connection state in step 401. [ The D2D UE monitors the D2D transmissions from the other D2D UE (s) in step 403. In step 405, the D2D UE instructs the network or the eNB to monitor the D2D. In step 407, the network or the eNB sets up the connection mode DRX cycle in consideration of the D2D resource setting. In step 409, the network or the eNB reestablishes the RRC connection to the D2D UE.

5 is a flowchart illustrating a method for monitoring D2D transmissions in a connected state according to a second sub-embodiment of the first embodiment of the present invention.

Referring to FIG. 5, the D2D UE is in an RRC connection state in step 501. FIG. The D2D UE monitors the D2D transmissions from the other D2D UE (s) in step 503. The D2D UE informs the D2D UE that it is monitoring D2D transmissions from other UEs in step 505, when the D2D UE is not capable of simultaneously monitoring DL and UL frequencies (step 505). Instructs eNB to monitor D2D. In step 509, the network or the eNB sets up the connection mode DRX cycle in consideration of the D2D resource setting. The network or the eNB resets the RRC connection to the D2D UE in step 511. [

6 is a flowchart illustrating a method for monitoring D2D transmissions in a connected state according to a third sub-embodiment of the first embodiment of the present invention.

Referring to FIG. 6, the D2D UE is in the RRC state in step 601. FIG. The D2D UE monitors the D2D transmissions from the other D2D UE (s) in step 603.

When the D2D UE is not capable of simultaneously monitoring DL and UL frequencies, it informs that it is monitoring D2D transmissions from other UEs and that the currently configured DRX cycle leads to overlap of ON duration time and D2D resources. Step 607)

In step 609, the D2D UE instructs the network or eNB to monitor the D2D. In step 611, the network or the eNB sets up the connection mode DRX cycle in consideration of the D2D resource setting. In step 613, the network or the eNB reestablishes the RRC connection to the D2D UE.

7 is a flowchart illustrating a method for monitoring D2D transmission in a connected state according to a fourth sub-embodiment of the first embodiment of the present invention.

Referring to FIG. 7, in step 701, the D2D UE is in an RRC connection state. The D2D UE monitors the D2D transmissions from the other D2D UE (s) in step 703.

In step 705, the D2D UE instructs the network or the eNB to monitor the D2D. At this time, a function of not simultaneously monitoring or monitoring the DL and UL frequencies may be indicated to the network or the eNB as part of the UE capability.

In step 707, the network or the eNB determines whether DL and UL frequencies can be simultaneously monitored based on the UE function. If the UE can not simultaneously monitor the DL and UL frequencies in step 709, the network or the eNB sets up the connection mode DRX cycle in consideration of the D2D resource setting.

The network or the eNB resets the RRC connection to the D2D UE in step 711.

That is, the fourth sub-embodiment of the first embodiment of the present invention may be directed to the eNB as a function of the UE function that does not simultaneously monitor DL and UL frequencies. Upon receiving the information that monitors the discovery messages from the UE and the UE function that does not simultaneously monitor or monitor the discovery transmissions from the DL and D2D UEs, the network or eNB may configure the DRX cycles as described above.

As a possible embodiment, the network or eNB may always configure the connected mode DRX cycle taking into account the D2D resources set for the RRC-connected D2D UEs (e.g., the D2D resource cycle and the D2D resources in the D2D resource cycle). The network or the eNB may determine that the UE is not based on the S1 context of the UE received from the MME (mobility management entity) during the connection establishment or the D2D.

As a possible embodiment, the network or eNB may configure the connected mode DRX cycle taking into account the D2D resources set for the RRC connected UEs (e.g., D2D resource cycles and D2D resources in the D2D resource cycle).

Alternatively, if the network is assigned dedicated discovery resources to the D2D UEs, the connection mode DRX cycle is considered taking into account the D2D resources (e.g., D2D resource cycles and D2D resources in the D2D resource cycle) set for the RRC-connected D2D UEs It can also be set.

8 is a block diagram of a UE according to an embodiment of the present invention.

Referring to FIG. 8, the UE includes a connection mode DRX module 820, an RRC 810, and a D2D monitoring module 830.

The RRC 810 sets the UE to the RRC state and transmits the DRX configuration to the connected mode DRX module 820 in the RRC state.

The connected mode DRX module 820 performs DRX during the D2D resource cycle and the DRX cycle.

The D2D monitoring module 830 includes a D2D transmitter / receiver (TX / RX) controller 831, a D2D transmitter 833, and a D2D receiver 835.

The D2D TX / RX control unit 831 monitors transmissions from other D2D UEs in the RRC connection mode. The D2D TX / RX control unit 831 may be configured with a parameter indicating a subframe in which the connection mode DRX module 820 starts DL frequency monitoring.

The D2D TX / RX control unit 831 can know the point in time at which the connection mode DRX module 820 starts the DL frequency monitoring again after receiving the instruction from the connection mode DRX module 820. [

When stopping the DL frequency monitoring, the D2D TX / RX controller 831 transmits an indicator requesting the D2D monitoring module 830 to stop the monitoring.

When the D2D transmitter 833 requests frequency monitoring, the D2D transmitter 833 transmits an indicator for requesting monitoring to the RRC 810.

The D2D receiving unit 835 receives the DRX indicator from the connected mode DRX mode 820. [ The D2D receiving unit 835 also receives the D2D resource configuration (D2Dresource_Config) from the RRC 810. [

The connection mode DRX mode 820 may be configured in a terminal that does not support D2D. However, the D2D monitoring module 830 may be configured in the D2D terminal.

It is needless to say that the block diagram of the terminal of FIG. 8 is applicable to the block diagram of the base station according to the embodiment of the present invention.

9 is a flowchart illustrating a method for monitoring D2D transmission in a connected state according to a second embodiment of the present invention.

Referring to FIG. 9, the D2D UE may monitor transmissions from other D2D UEs in the RRC connection mode as follows (901, 903)

The D2D UE sends a monitoring request to the eNB (step 905). Upon receiving the monitoring request, the eNB will not transmit in the DL subframes corresponding to UL subframes with D2D resources, (Step 907) UL subframes with D2D resources are previously informed to the UE using the broadcast information transmitted by the eNB. In DL subframes corresponding to UL subframes with D2D resources, the eNB will not send anything to the UE so that it does not need to monitor the DL frequency while the UE monitors the D2D resources. The eNB may not schedule anything in UL subframes with D2D resources. In a second embodiment of the present invention, the response may indicate specific subframes (having serving D2D resources in the serving cell and / or neighboring cells) that the UE can monitor for D2D. The eNB may also send a response rejecting the request. the eNB may refuse to prioritize communication with the eNB. Upon receiving a response that accepts the D2D UE request, the D2D UE performs the following operations.

• The D2D UE may not monitor DL subframes corresponding to UL subframes with D2D resources.

• The D2D UE does not transmit to the eNB over UL subframes with D2D resources. If the UE has to transmit D2D packets on UL subframes with D2D resources, it can send D2D packets. The UE will monitor UL subframes with D2D resources that do not send D2D packets to other UEs.

Or the UE will monitor UL subframes with D2D resources that are not transmitting D2D packets to other UEs or are not transmitting data or control packets to the eNB.

In a second embodiment of the invention, when the network or eNB informs the D2D UE that it is monitoring D2D transmissions from other UEs in the connected state, the UE can monitor through the subframes in which the D2D resources are set And transmits a response. The response may indicate certain subframes (having serving cells and / or discovery resources in neighboring cells) that the UE can monitor for D2D.

10 is a flowchart illustrating a method for monitoring D2D transmission in a connected state according to a third embodiment of the present invention.

10, in the third embodiment of the present invention, the D2D UE can monitor transmissions from other D2D UEs in the RRC connection mode as follows (steps 1001 and 1003)

The D2D UE informs that it is monitoring D2D transmissions from other UEs when it is not capable of simultaneously monitoring DL and UL frequencies (Step 1005) (Step 1007)

In another approach, the ability to simultaneously or not monitor DL and UL frequencies may be directed to the eNB as part of the UE function. Upon receiving the information that it is monitoring the D2D messages from the UE, the eNB may check the UE function monitoring the D2D transmissions and the DL simultaneously from the D2D UEs and transmit the response accordingly (step 1009)

If the UE request is denied, the eNB may set the DRX cycle to allow monitoring of D2D resources when the UE is not monitoring the DL (i.e., during DRX), as in solution 1.

In a third embodiment of the present invention, the UE may send a monitoring indicator to the eNB at the start of D2D monitoring. Upon receiving such a monitoring indicator, the eNB determines whether or not the UE has the capability to simultaneously monitor DL and UL.

If the UE has the capability to simultaneously monitor DL and UL, the eNB may not schedule UL transmissions to the eNB through UL subframes with D2D resources whenever possible, according to the UE's QoS for eNB transmissions . The UE monitors UL subframes with D2D resources whose UL transmission to the eNB is not scheduled.

If the UE does not have the capability to simultaneously monitor the DL and the UL, the eNB performs the following operations.

The eNB informs the UE that it will not send anything to the DL subframes corresponding to UL subframes with D2D resources (either through the transmission of a dedicated message or through a broadcast via system information) Specific DL subframes. In a third embodiment of the present invention, the rule that the eNB will not transmit any of the DL subframes corresponding to UL subframes with D2D resources is predefined. The eNB may not schedule any of the Ul subframes with D2D resources whenever possible, according to the UE ' s QoS for eNB transmissions. The UE may not monitor DL subframes corresponding to UL subframes with D2D resources. In a third embodiment of the invention, the UE may not monitor DL subframes before and after the UL subframe with the discovery resources. The UE will monitor UL subframes with D2D resources that are not transmitting (data or control packets to D2D packets / eNBs to other UEs).

The eNB may set the DRX cycle so that it can monitor the D2D resources when the UE is not monitoring the DL (i.e., during DRX), as in the first embodiment of the invention. For example, this is done when the eNB can not stop the transmission to the DL due to the QoS of the ongoing UE-eNB communication.

When the UE function that simultaneously monitors DL and UL is sent with the monitoring indicator or separately from the UE function, the eNB may understand that the function is part of the UE context from the mobility manager entity (MME). The UE may inform one of the following when D2D monitoring is associated with the discovery:

1. The UE may indicate whether it can receive Discovery (UL) and WAN (DL) in parallel.

2. The UE may indicate whether it can receive Discovery (UL) and WAN (DL) in parallel. In addition, one of the following can be known:

a. Whether Discovery RX uses the DL RX chain

b. Whether Discovery RX uses a dedicated RX chain

c. Whether there is an impact on DL carrier aggregation (DL CA) functionality.

The eNB will interpret that the UE can not perform Discovery (UL) and WAN (DL) reception in parallel in the following situations:

a. When the UE informs that it can not receive Discovery (UL) and WAN (DL) in parallel

b. When the UE is informed that it can receive Discovery (UL) and WAN (DL) in parallel, the DL CA is set up via the maximum DL CA function, and the UE informs one of:

i. Discovery RX uses DL RX chain

Ii. Discovery RX does not use dedicated RX chain

Iii. Impact on DL CA functionality

3. The UE may indicate whether it has a dedicated RX chain to the Discovery RX. If there is no dedicated RX chain, the eNB will interpret that the UE can not perform Discovery (UL) and WAN (DL) reception in parallel.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

Claims (20)

A method for monitoring a device to device (D2D) transmission in a connected state in a communication system,
Performing D2D monitoring by a D2D terminal during a D2D resource cycle and a discontinuous reception (DRX) cycle in a radio resource control (RRC) state;
Transmitting an indicator indicating D2D monitoring to a base station; And
And re-establishing an RRC connection with the base station,
Wherein resources of the D2D resource cycle and resources of the DRX cycle are configured not to overlap based on the indicator. The method according to claim 1,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that the terminal does not include a capability to simultaneously monitor downlink (DL) and uplink (UL) frequencies. The method according to claim 1,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that the terminal includes a function in which a DRX cycle is not set or a configured DRX cycle is set to overlap with D2D resources. The method according to claim 1,
Wherein the terminal has a function of not monitoring DL subframes corresponding to UL subframes with D2D resources. The method according to claim 1,
And a message requesting to monitor the base station based on the indicator is transmitted to the base station. An apparatus of a D2D terminal for monitoring a D2D transmission in a connected state,
A D2D monitoring module that performs D2D monitoring during the D2D resource cycle and the DRX cycle in the RRC state;
A transmitter for transmitting an indicator for directing D2D monitoring to the base station; And
And a controller for re-establishing an RRC connection with the base station,
Wherein resources of the D2D resource cycle and resources of the DRX cycle are configured not to overlap based on the indicator. The method according to claim 6,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that it does not include the capability to simultaneously monitor the downlink (DL) and uplink (UL) frequencies. The method according to claim 6,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that the terminal includes a function in which a DRX cycle is not set or a set DRX cycle is set to overlap with D2D resources. The method according to claim 6,
Wherein the terminal has a function of not monitoring DL subframes corresponding to UL subframes with D2D resources. The method according to claim 6,
And a message requesting to monitor the base station based on the indicator is transmitted to the base station. A method for monitoring a D2D transmission in a connected state at a base station,
Receiving an indicator indicating D2D monitoring from the terminal while the terminal in the RRC state performs D2D monitoring in the D2D resource cycle and the DRX cycle; And
Configuring resources of the D2D resource cycle and resources of the DRX cycle not to overlap with each other based on the indicator; And
And reconfiguring the RRC connection with the MS. 12. The method of claim 11,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that the terminal does not include a capability to simultaneously monitor downlink (DL) and uplink (UL) frequencies. 12. The method of claim 11,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that the terminal includes a function in which a DRX cycle is not set or a configured DRX cycle is set to overlap with D2D resources. 12. The method of claim 11,
Wherein the terminal has a function of not monitoring DL subframes corresponding to UL subframes with D2D resources. 12. The method of claim 11,
And a message requesting to monitor the base station based on the indicator is transmitted to the base station. An apparatus for monitoring a D2D transmission in a connected state at a base station,
A receiving unit for receiving an indicator indicating the D2D monitoring from the terminal while the terminal in the RRC state performs D2D monitoring in the D2D resource cycle and the DRX cycle; And
And a controller for configuring resources of the D2D resource cycle and resources of a DRX cycle so as not to overlap with each other based on the indicator and reestablishing an RRC connection with the terminal. 17. The method of claim 16,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that the terminal does not include a capability to simultaneously monitor downlink (DL) and uplink (UL) frequencies. 17. The method of claim 16,
Wherein the indicator includes information on a function of the terminal,
Wherein the information on the capabilities of the terminal indicates that the terminal includes a function in which a DRX cycle is not set or a set DRX cycle is set to overlap with D2D resources. 17. The method of claim 16,
Wherein the terminal has a function of not monitoring DL subframes corresponding to UL subframes with D2D resources. 17. The method of claim 16,
And a message requesting to monitor the base station based on the indicator is transmitted to the base station.

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