JP7169400B2 - Terminal and communication method - Google Patents

Description

The present invention relates to a user device that supports D2D and a NW (network) device that communicates with the user device.

LTE (Long Term Evolution) and successor systems of LTE (for example, LTE-A (LTE Advanced), 4G, FRA (Future Radio Access), 5G, etc.), user devices directly without going through a radio base station D2D (Device to Device), which is a communication method, is under consideration (for example, Non-Patent Document 1).

D2D reduces traffic between the user equipment and the base station, and enables communication between the user equipment even when the base station becomes unable to communicate due to a disaster or the like.

D2D is D2D discovery (also called D2D discovery, D2D discovery) for finding other communicable user devices, and D2D communication for direct communication between user devices (D2D direct communication, also called direct communication between terminals). ) and Hereinafter, D2D communication, D2D discovery, etc. are simply referred to as D2D when not particularly distinguished. A signal transmitted and received in D2D is called a D2D signal.

In addition, 3GPP (3rd Generation Partnership Project) is considering realizing V2X by extending the D2D function. Here, V2X is a part of ITS (Intelligent Transport Systems). V2I (Vehicle to Infrastructure), which means a form of communication between a roadside unit (RSU: Road-Side Unit) and V2N (Vehicle to Infrastructure), which means a form of communication between a car and a driver's mobile terminal Nomadic device), and V2P (Vehicle to Pedestrian), which means a form of communication between automobiles and mobile terminals of pedestrians.

"Key drivers for LTE success: Services Evolution", September 2011, 3GPP, Internet URL: http://www.3gpp.org/ftp/Information/presentations/presentations_2011/2011_09_LTE_Asia/2011_LTE-Asia_3GPP_Service_evolution.pdf 3GPP TS36.300 V13.2.0 (2015-12) 3GPP TS36.331 V13.1.0 (2016-03)

Existing D2D specified in 3GPP (for example, Non-Patent Documents 2 and 3) is a technology optimized for multicast communication. Multicast is also assumed in V2X under consideration by 3GPP.

Therefore, transmission power control, link adaptation, MIMO, HARQ/CSI feedback, etc., which are functions for realizing optimized unicast communication, are not supported in existing D2D. On the other hand, in the future, it is conceivable that the number of use cases where it is desirable to use optimized unicast communication, such as low-delay and highly reliable D2D/V2X communication, will increase.

In order to achieve optimized unicast communication between user devices, it is necessary for each user device to establish a D2D connection using appropriate connection parameters commensurate with its own capabilities and the capabilities of the communication partner. is.

The present invention has been made in view of the above points, and it is an object of the present invention to provide technology that enables D2D connection to be established between user devices using appropriate connection parameters.

According to the disclosed technique, a transmitting unit that transmits a connection request including communication parameters to another terminal;
a receiving unit that receives a connection permission from the other terminal,
the communication parameters include information about CSI feedback;
The transmission unit transmits a notification of a connection request including the communication parameters by an RRC connection reconfiguration message for unicast communication between terminals.
A terminal is provided.

According to the disclosed technique, a technique is provided that enables establishment of a D2D connection between user devices using appropriate connection parameters.

It is a figure for demonstrating V2X. It is a figure for demonstrating D2D, and shows "D2D discovery." It is a figure for demonstrating D2D, and shows "D2D communication." FIG. 4 is a diagram for explaining MAC PDUs used for D2D communication; FIG. 4 is a diagram for explaining the format of SL-SCH subheader; FIG. 2 is a diagram for explaining an example of a channel structure used in D2D; FIG. FIG. 4 is a diagram showing a structure example of PSDCH, showing an example of a resource pool; FIG. 2 is a diagram showing an example structure of PSDCH, showing a PUSCH-based structure; FIG. 4 is a diagram showing an example structure of PSCCH and PSSCH, showing an example of a resource pool; FIG. 2 shows an example structure of PSCCH and PSSCH, showing a PUSCH-based structure; FIG. 4 is a diagram showing a resource pool configuration and showing subframes; FIG. 4 is a diagram showing a resource pool configuration, showing resource blocks; 1 is a diagram illustrating a configuration example of a radio communication system according to an embodiment; FIG. FIG. 10 is a diagram showing a processing sequence example 1; FIG. 10 is a diagram showing a processing sequence example 2; FIG. 11 is a diagram showing a processing sequence example 3; FIG. 13 is a diagram showing a processing sequence example 4; FIG. 13 is a diagram showing a processing sequence example 5; FIG. 4 is a diagram for explaining an example of a method of transmitting terminal capabilities, and shows an example of transmitting a large-capacity discovery signal including UE capabilities once every two times; FIG. 4 is a diagram for explaining an example of a method of transmitting terminal capabilities, and shows an example of transmitting UE capabilities in a message separate from the message of the discovery signal; FIG. 12 is a diagram showing a processing sequence example 6; FIG. 10 is a diagram for explaining an example of determination operation of terminal autonomous connection/network-assisted connection, and shows option 1; FIG. 10 is a diagram for explaining an example of determination operation of terminal autonomous connection/network assisted connection, and shows option 2; FIG. 10 is a diagram for explaining an example of determination operation of terminal autonomous connection/network-assisted connection, and shows option 3; It is a figure showing an example of functional composition of a user's unit concerning this embodiment. It is a figure which shows an example of functional structure of the NW apparatus which concerns on this Embodiment. It is a figure which shows an example of the hardware constitutions of the user apparatus and NW apparatus which concern on this Embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments. For example, although the radio communication system according to the present embodiment assumes a system based on LTE, the present invention is not limited to LTE and can be applied to other systems. In the present specification and claims, "LTE" is not only a communication method compatible with 3GPP release 8 or 9, but also 3GPP release 10, 11, 12, 13, or release 14 or later. It is used in a broad sense including the 5th generation communication system.

Also, the technology according to the present embodiment is widely applicable to D2D in general. Also, "D2D" includes V2X as its meaning. In addition, the term "D2D" refers not only to D2D in LTE, but also to inter-terminal communication in general.

Also, “communication” in this specification means general “communication” and does not limitively refer to “D2D communication” as a classification of “D2D” described above. Hereinafter, when referring to "D2D communication" as a classification of "D2D", it is described as "D2D communication".

Also, in the embodiments described below, the D2D connection is a unicast D2D connection, but the application of the present invention is not limited to unicast. For example, the processes such as UE capability acquisition, connection parameter determination, and D2D connection establishment described in the present embodiment may be applied to 1:N (N is an integer equal to or greater than 2) group cast D2D connection. Further, "connection" in the present embodiment means a logical connection between devices, and more specifically, it means that D2D communication using connection parameters can be performed between devices. do.

(Overview of D2D)
As described above, the application of the present invention is not limited to LTE. An overview of the D2D technology that is being used will be described. A user apparatus UE in the present embodiment can transmit and receive a D2D signal according to the technique.

As already explained, D2D is roughly divided into "D2D discovery" and "D2D communication". For "D2D discovery", as shown in FIG. 2A , a resource pool for Discovery messages is secured for each Discovery period (also called PSDCH (Physical Sidelink Discovery Channel) period), and the user equipment UE is in the resource pool. Send a Discovery message (discovery signal). More specifically, there are Type 1 and Type 2b. In Type 1, the user equipment autonomously selects transmission resources from the resource pool. In Type 2b, semi-static resources are allocated by higher layer signaling (eg, RRC signaling).

For “D2D communication” as well, resource pools for SCI (Sidelink Control Information)/data transmission are periodically secured as shown in FIG. 2B. The user device on the transmitting side notifies the receiving side of data transmission resources and the like by SCI using resources selected from the control resource pool (PSCCH (Physical Sidelink Control Channel) resource pool), and transmits data using the data transmission resources. . There are Mode1 and Mode2 in more detail about "D2D communication." In Mode 1, resources are dynamically allocated by (E)PDCCH ((Enhanced) Physical Downlink Control Channel) sent from the base station to the user equipment. In Mode2, the user apparatus UE autonomously selects transmission resources from the resource pool. The resource pool is notified by SIB (System Information Block) or defined in advance.

In LTE, the channel used for "D2D discovery" is called PSDCH, the channel for transmitting control information such as SCI in "D2D communication" is called PSCCH, and the channel for transmitting data is PSSCH (Physical Sidelink Shared Channel). is called

A MAC (Medium Access Control) PDU (Protocol Data Unit) used for D2D communication is composed of at least a MAC header, a MAC Control element, a MAC SDU (Service Data Unit), and Padding, as shown in FIG. A MAC PDU may also contain other information. The MAC header consists of one SL-SCH (Sidelink Shared Channel) subheader and one or more MAC PDU subheaders.

As shown in FIG. 4, the SL-SCH subheader is composed of MAC PDU format version (V), source information (SRC), destination information (DST), reserved bit (R), and the like. V is assigned to the beginning of the SL-SCH subheader and indicates the MAC PDU format version used by the user equipment. Information about the sender is set in the sender information. An identifier related to the ProSe UE ID may be set in the source information. Information about the destination is set in the destination information. Information about the ProSe Layer-2 Group ID of the destination may be set in the destination information.

An example of a D2D channel structure is shown in FIG. As shown in FIG. 5, a resource pool of PSCCH and a resource pool of PSSCH used for "D2D communication" are allocated. In addition, a PSDCH resource pool used for “D2D discovery” is allocated in a cycle longer than the channel cycle of “D2D communication”.

Moreover, PSSS (Primary Sidelink Synchronization signal) and SSSS (Secondary Sidelink Synchronization signal) are used as a synchronization signal for D2D. Also, for example, a PSBCH (Physical Sidelink Broadcast Channel) that transmits notification information (broadcast information) such as the D2D system band, frame number, and resource configuration information is used for out-of-coverage operations.

FIG. 6A shows an example of a PSDCH resource pool used for “D2D discovery”. Since the resource pool is set by a bitmap of subframes, the resource pool has an image as shown in FIG. 6A. The same is true for resource pools of other channels. In addition, the PSDCH is repeatedly transmitted (repetition) while performing frequency hopping. The number of repetitions can be set from 0 to 3, for example. Also, as shown in FIG. 6B, the PSDCH has a PUSCH-based structure and a structure in which a DM-RS (demodulation reference signal) is inserted.

FIG. 7A shows an example of resource pools of PSCCH and PSSCH used for “D2D communication”. As shown in FIG. 7A, the PSCCH is repeated once while frequency hopping. The PSSCH is repeated three times while frequency hopping. Also, as shown in FIG. 7B, PSCCH and PSSCH have a PUSCH-based structure, and a structure in which DM-RS is inserted.

FIGS. 8A and 8B show examples of resource pool configurations in PSCCH, PSDCH, and PSSCH (Mode 2). In the temporal direction, the resource pool is represented as a subframe bitmap, as shown in FIG. 8A. Also, the bitmaps are num. It is repeated for the number of times of reprtation. Also, an offset indicating the starting position in each cycle is specified.

In the frequency direction, contiguous allocation and non-contiguous allocation are possible. FIG. 8B shows an example of non-contiguous allocation, where a start PRB, an end PRB, and the number of PRBs (numPRB) are specified as shown.

(System configuration)
FIG. 9 is a diagram showing a configuration example of a radio communication system according to this embodiment. As shown in FIG. 9, the radio communication system according to the present embodiment has NW (network) equipment 20, user equipment UE1, and user equipment UE2. In FIG. 9, both the user equipment UE1 and the user equipment UE2 have both a transmission function and a reception function. Hereinafter, the user equipment UE1 and the user equipment UE2 are described as UE1 and UE2, respectively. Moreover, when UE1 and UE2 are not particularly distinguished, they are simply described as “UE”. Also, "UE" may be referred to as "terminal". Also, in the following description, UE1 and UE2 perform different operations, but UE1 and UE2 have the same functionality, UE2 includes the functionality of UE1 and UE1 includes the functionality of UE2.

As described above, the application of the present invention is not limited to LTE, but as an example, UE1 and UE2 shown in FIG. It has a D2D function including Also, UE1 and UE2 have the function of executing the operation described in this embodiment. Note that with regard to the cellular communication function and the existing D2D function, only a part of the function (the range in which the operations described in this embodiment can be executed) may be provided, or all the functions may be provided. may

Also, the UE may be any device having D2D functionality, but for example, the UE may be a vehicle, a terminal held by a pedestrian, an RSU (UE-type RSU having UE functionality), or the like. The UE according to the present embodiment may be a UE capable of transmitting and receiving only on one frequency (one carrier), or a UE capable of transmitting and receiving simultaneously on multiple frequencies (multiple carriers). may be In addition, the UE according to the present embodiment performs transmission power control, Link adaptation, MIMO transmission/reception, HARQ/CSI feedback, etc. performed between the UE and the eNB in LTE, and performs similar processing with other UEs. It has a function to perform between

The NW device 20 of the present embodiment is assumed to be, for example, a base station. good too. Also, the NW device 20 may be a device (system) including a base station and a device on the upper network side.

(Overview of Embodiment)
In the present embodiment, as a method for unicast D2D connection establishment (connection establishment) between UE1 and UE2, a "network assist connection" that uses assistance from the NW device 20, and an autonomous There are two methods of "terminal autonomous connection" for establishing connection. Note that the state in which “connection is established” between UE1 and UE2 means a state in which UE1 and UE2 each hold connection parameters and can perform unicast D2D communication using the connection parameters. means. UE1 and UE2 may each manage (hold information indicating the D2D CONNECTED state) the state in which the unicast D2D connection is established as the D2D CONNECTED state (connection state). The outline of each method is as follows.

In network-assisted connection, a UE transmits a connection request for unicast D2D connection with another UE to the NW device 20 . Then, the NW device 20 determines connection parameters for each of the two UEs that perform the unicast D2D connection based on the held unicast D2D communication capabilities (UE capabilities) of each UE, and sets the connection parameters. Send to each UE. By each UE receiving connection parameters from the NW device 20, it becomes possible to perform unicast D2D communication using the connection parameters. That is, a unicast D2D connection is established between UEs.

Note that the connection parameters for each of the two UEs may be the same or different between the two UEs.

In terminal autonomous connection, UE capabilities are exchanged between UEs, and connection parameters for unicast D2D connection establishment are determined through negotiation between UEs.

<Example of connection parameters>
Connection parameters (which may also be referred to as communication parameters) used for the unicast D2D connection in this embodiment include, for example, the following parameters: transmission power parameter, transmission carrier, reception carrier, transmission resource pool, Reception resource pool, transmission subframe set, reception subframe set, MIMO transmission mode, presence/absence of HARQ feedback, presence/absence of CSI feedback, mode of CSI feedback, inter-UE L1/L2 control information format, security.

The above is an example, and parameters other than the above may be included. Also, only some of the above parameters may be used. For example, if the carrier (1 carrier, or 2 carriers for transmission and reception) used in unicast D2D communication is predetermined (eg, if notified in advance by system information etc.), Carrier information may not be included in the connection parameters notified from the NW device 20 (or negotiated between UEs).

Hereinafter, processing sequence examples 1 to 4 will be described as examples of processing sequences for network-assisted connection in the wireless communication system shown in FIG. 9, and processing sequence examples 5 and 6 will be described as examples of processing sequences for terminal autonomous connection. explain. Also, an example of a determination operation for selecting either the terminal autonomous connection or the network assisted connection will be described.

In the following processing sequence examples 1 to 6, unicast D2D connection is established between UE1 and UE2. Further, in processing sequence examples 1 to 4, it is assumed that UE 2 issues a connection request to NW device 20 . A UE that makes a connection request to the NW device 20 may be called a "requesting terminal", and a UE with which the "requesting terminal" is a unicast D2D communication partner may be called a "requested terminal". In the following example, UE2 will be the requesting terminal and UE1 will be the requested terminal.

(Network assist connection: processing sequence example 1)
First, processing sequence example 1 in network-assisted connection will be described with reference to FIG. In FIG. 10, it is assumed that UE1, which is a requested terminal, is in an RRC CONNECTED state (hereinafter simply referred to as CONNECTED state) with respect to NW device 20. FIG. The user equipment UE2, which is the requesting terminal, is also in the CONNECTED state. Alternatively, if it is in the RRC IDLE state (hereinafter simply referred to as the IDLE state), it will be in the CONNECTED state by connecting to the NW device 20 before step S102.

Also, both UE1 and UE2 have notified their own UE capabilities to the NW device 20, and the NW device 20 holds the UE capabilities for each UE.

In the processing sequence example 1, the UE1 periodically transmits a discovery signal, for example. The discovery signal may be a signal transmitted by the PSDCH described above, a signal transmitted by a D2D channel other than the PSDCH (eg, PSBCH, PSCCH/PSSCH), or an existing D2D It may be a signal transmitted on a channel other than the channel. The discovery signal contains the ID of UE1. This ID may be an ID for D2D (for side link), or an ID serving as both an ID for D2D and an ID for cellular communication. Also, the discovery signal may include both the ID for D2D and the ID for cellular communication. Also, the discovery signal may include an operator ID, which is the ID of the operator to which the UE1 belongs. It should be noted that “cellular communication” in this embodiment means communication between UEs via the NW device 20 .

In step S101, UE2 receives a discovery signal from UE1. The UE2 determines to establish a unicast D2D connection between the UE2 and the UE1 using the network-assisted connection by a determination operation to be described later, and transmits a connection request to the NW device 20 (step S102).

The connection request transmitted in step S102 includes the ID of UE1, which is the communication partner of UE2. This ID may be an ID for D2D, or an ID serving as both an ID for D2D and an ID for cellular communication. Moreover, both the ID for D2D and the ID for cellular communication may be included in the connection request. Also, the connection request may include an operator ID, which is the ID of the operator to which the UE1 belongs. Note that the connection request also includes the ID of the UE2. Let the ID of UE1 be ID1 and the ID of UE2 be ID2.

In addition, the connection request may further include all or part of information (1) to (3) shown below.

(1) Channel quality between UE1 and UE2 measured by UE2, for example, by reception discovery signal (eg, reception level, reception quality, propagation loss);
(2) Desired QoS and/or desired communication type desired by UE2 in unicast D2D communication with UE1 (eg, information indicating whether it is GBR, desired bit rate);
(3) location information and/or communication range of the requesting terminal (UE2) and/or the requested terminal (UE1);

The NW device 20 that has received the connection request in step S102 uses ID1 and ID2 from the UE capabilities of each UE held in a memory or the like to obtain the UE capability (UE capability 1) corresponding to UE1. , UE2 (denoted as UE capability 2). Then, the NW device 20 determines the communication path (unicast D2D or cellular communication) between the UE1 and the UE2 based on the UE capability 1, the UE capability 2, etc., and determines the unicast D2D as the communication path. If so, the connection parameters for each of UE1 and UE2 are determined, and the determined connection parameters are transmitted to UE1 and UE2, respectively (steps S103 and S104).

Regarding the determination of the communication path, for example, when the network device 20 detects that the UE1 does not have the unicast D2D capability based on the UE capability 1 of the requested terminal UE1, the NW device 20 establishes a communication path between the UE1 and the UE2 via cellular communication. communication. In this case, for example, the UE2 is instructed to perform cellular communication without determining/notifying the connection parameter. Communication paths other than unicast D2D may include communication via a relay terminal in addition to cellular communication.

Also, for example, when the NW device 20 detects that the channel quality included in the connection request is lower (worse) than the value required to ensure the desired QoS level (or desired communication type), the NW device 20 performs cellular communication with the UE 1 and UE2.

When unicast D2D is determined as a communication path, the NW device 20 determines connection parameters within a range not exceeding UE capability 1 and UE capability 2, for example. For example, when the NW device 20 recognizes that UE1 has the capability of 2-layer MIMO transmission/reception and that UE2 has the capability of 4-layer MIMO transmission/reception, the NW device 20 instructs each of UE1 and UE2 to perform MIMO transmission/reception. "2 layers" is notified as a spatial multiplexing parameter. In this case, UE1 and UE2 perform unicast D2D connection establishment using "2 layers" as the spatial multiplexing parameter. That is, UE1 and UE2 each set "2 layers" as a spatial multiplexing parameter, and manage (control) to perform unicast D2D communication in the "2 layers".

Also, for example, based on channel quality information, when the quality is poor, the NW device 20 determines a larger transmission power than when the quality is good (transmission power that does not exceed the UE capability) as a parameter, and sends the UE1 and the UE2 Notice.

A connection is established between UE1 and UE2 that have received the connection parameters in steps S103 and S104, and unicast D2D communication is started (step S105). After UE1 and UE2 receive the connection parameters from the NW device 20, UE2 transmits a connection request requesting connection permission to UE1 (or UE1 to UE2), and UE1 to UE2 (or UE2 to UE1). The connection may be established after the connection grant has been sent. In this case, for example, when UE2 receives the connection permission from UE1, the state of the D2D connection is set to the connected state (connection establishment state), and when UE1 transmits the connection permission to UE2, the state of the D2D connection is set to A connected state (connection established state) is established, and unicast D2D communication starts thereafter.

When the unicast D2D communication is started, each UE, when transmission data is generated, transmits the transmission data using resources, transmission methods, etc. according to its own connection parameters related to connection establishment, It monitors received signals (performs demodulation and decoding operations) using resources, reception methods, etc., according to its own connection parameters.

(Network assist connection: processing sequence example 2)
Next, with reference to FIG. 11, a processing sequence example 2 in network assist connection will be described. In FIG. 11, as in FIG. 10, it is assumed that UE1, which is the requested terminal, is in the CONNECTED state with respect to the NW device 20. In FIG. The requesting terminal, UE2, is also in the CONNECTED state. Alternatively, if it is in the IDLE state, it will be connected to the NW device 20 before step S201 and will be in the CONNECTED state.

Also, both UE1 and UE2 have notified their own UE capabilities to the NW device 20, and the NW device 20 holds the UE capabilities for each UE.

In processing sequence example 2, UE1 does not transmit a discovery signal. Alternatively, UE1 transmits a discovery signal, but UE2 does not (cannot) receive the discovery signal. It is also assumed that UE2 has not measured (cannot measure) the reception level of the signal from UE1. However, UE2 knows the ID of UE1 and wishes to establish a unicast D2D connection with UE1.

In step S<b>201 , UE<b>2 wishes to establish a unicast D2D connection with UE<b>1 and transmits a connection request to the NW device 20 . The information included in the connection request is as described above. However, in this example, the connection request does not contain channel quality information. Note that the UE2 may include information indicating that it has not received the discovery signal from the UE1 in the connection request.

When the NW device 20 that has received the connection request in step S201 detects that the connection request does not contain channel quality information (or contains information indicating that the discovery signal has not been received from the UE1) is detected), a discovery signal transmission instruction is transmitted to UE1 (step S202), and a discovery signal reception instruction is transmitted to UE2 (step S203). For example, the discovery signal transmission instruction includes information on resources (e.g., one or more of carriers, frequency resources, and time resources) used for transmission of the discovery signal, and the discovery signal reception instruction also includes information on the resource. Contains information. Thereby, UE2 can efficiently receive the discovery signal transmitted from UE1.

In the example of FIG. 11, the NW device 20 transmits a discovery signal transmission instruction to UE1 and transmits a discovery signal reception instruction to UE2. A discovery signal transmission instruction may be transmitted, and a discovery signal reception instruction may be transmitted to UE1. In this case, channel quality information, which will be described later, is transmitted from UE 1 to NW device 20 . Also, the NE device 20 may transmit only the discovery signal transmission instruction, or may transmit only the discovery signal reception instruction.

In step S204, a discovery signal is transmitted from UE1 according to the instruction, UE2 receives the discovery signal, and performs channel quality measurement between UE1 and UE2.

In step S<b>205 , the UE 2 transmits the channel quality information to the NW device 20 . Note that UE2 may measure and report the channel quality between UE1 and UE2 only when a measurement instruction is included in the discovery signal reception instruction received from NW device 20 .

The NW device 20 that has received the channel quality information determines the communication path between the UE1 and the UE2 (unicast D2D or cellular communication), and when unicast D2D is determined as a communication path, connection parameters for each of UE1 and UE2 are determined, and the determined connection parameters are transmitted to UE1 and UE2, respectively (steps S206 and S207). ). Then, a connection is established between UE1 and UE2, and unicast D2D communication is started (step S208).

In addition, in the processing sequence examples 1 and 2 described above, the communication path determination and the connection parameter determination in the NW device 20 use the inter-UE channel quality information reported from the UE. is not essential, and the communication path determination and connection parameter determination may be performed, for example, only from the UE capabilities without using channel quality information.

(Network assist connection: processing sequence example 3)
Next, with reference to FIG. 12, a process sequence example 3 in network assist connection will be described. In the case of FIG. 12, it is assumed that UE1, which is the requested terminal, is in the IDLE state with respect to the NW device 20. In the case of FIG. The requesting terminal UE2 is in the CONNECTED state. Also, both UE1 and UE2 have notified their own UE capabilities to the NW device 20, and the NW device 20 holds the UE capabilities for each UE. Also, the NW device 20 holds state information for each UE (information on whether it is in a CONNECTED state or an IDLE state).

In step S<b>301 , UE<b>2 wishes to establish a unicast D2D connection with UE<b>1 and transmits a connection request to the NW device 20 . This connection request is, for example, a connection request similar to the connection request in step S102 shown in FIG. 10, and the information included in the connection request is as described above.

The NW device 20 that has received the connection request determines the communication path between the UE1 and the UE2 (whether unicast D2D or cellular communication) based on the UE capability 1, the UE capability 2, etc., in the same manner as in the processing sequence example 1. ) is determined, and when unicast D2D is determined as the communication path, connection parameters for each of UE1 and UE2 are determined.

However, in this example, the UE1 is in the IDLE state (waiting state), so the connection parameters cannot be transmitted to the UE1 as in the processing sequence examples 1 and 2. FIG. Therefore, in this example, the NW device 20 transmits a special paging message to the UE1 (step S302). Note that the NW device 20 (in this case, assumed to be a device on the core side) utilizes the location information of the requested terminal (UE1) included in the connection request, etc., to transmit a special paging message. may be selected.

In normal LTE processing, a UE in IDLE state that has received a normal paging message goes through a random access procedure, performs RRC connection establishment processing, and becomes CONNECTED state. On the other hand, the paging message transmitted in step S302 of this example causes the UE1 to receive information on a specific resource without causing the UE1 to transition to the CONNECTED state. This makes it possible to reduce the signaling overhead associated with the transition to the CONNECTED state, such as the random access procedure and RRC connection establishment process.

For example, the paging message sent in step S302 includes a special flag. By detecting the flag in the paging message, UE1 recognizes that this paging message is a special paging message, and performs the following operations without performing an operation for transitioning to the CONNECTED state.

The UE 1 that has received the paging message performs monitoring (demodulation/decoding operation) in resources of a predetermined downlink control CH (channel) search space. In order to reduce battery consumption, the length of time for monitoring may be limited to within a predetermined length of time from the time of receiving the paging message.

The NW device 20 uses resources in the downlink control CH search space to transmit connection parameters addressed to UE1, and UE1 receives the connection parameters (step S303).

Information indicating the downlink control CH search space (eg, time-frequency domain information) is notified to the UE 1 by, for example, system information (eg, specific SIB) broadcast from the NW device 20 . At this time, the ID of UE1 is included in the system information, and UE1 can acquire individual information (information indicating a downlink control CH search space) addressed to UE1. In addition, when the system information is changed, such as including the above information in the system information, the change is notified to the UE by paging or the like, but as described above, when the information addressed to UE1 is added to the system information , it is not necessary to notify the change of system information to anything other than UE1.

Also, the connection parameter notification in step S303 may be performed using system information in the same manner as the notification of the information indicating the downlink control CH search space.

In step S304, the connection parameters for UE2 are notified to UE2, unicast D2D connection is established, and unicast D2D communication is started (step S305).

(Network assist connection: processing sequence example 4)
Next, with reference to FIG. 13, a processing sequence example 4 in network-assisted connection will be described. In the case of FIG. 13 as well, it is assumed that the UE1, which is the requested terminal, is in the IDLE state with respect to the NW device 20. FIG. Differences from the processing sequence example 3 will be mainly described below.

In step S<b>401 , UE<b>2 wishes to establish a unicast D2D connection with UE<b>1 and transmits a connection request to the NW device 20 .

The NW device 20 that has received the connection request determines the communication path between the UE1 and the UE2 (whether unicast D2D or cellular communication) based on the UE capability 1, the UE capability 2, etc., in the same manner as in the processing sequence example 1. ) is determined, and when unicast D2D is determined as the communication path, connection parameters for each of UE1 and UE2 are determined.

Also in this example, the NW device 20 transmits a special paging message (including a special flag) to the UE1 (step S402).

In this example, the paging message causes UE1 to perform terminal autonomous connection without transitioning UE1 to the CONNECTED state.

That is, by detecting the flag in the paging message, the UE1 recognizes that this paging message is a special paging message, and performs terminal autonomous connection without performing an operation for transitioning to the CONNECTED state. Execute (step S404). The details of terminal autonomous connection will be described later.

More specifically, for example, setting information (transmission carrier, reception carrier, transmission resource, reception resource, etc.) for transmitting and receiving a discovery signal for terminal autonomous connection is transmitted from the NW device 20 to UE1 and UE2 according to the system information. ) is notified, and UE1 (and UE2) transmits or receives a discovery signal according to the setting information, and establishes a connection as described later.

Further, as shown in step S403 of FIG. 13, the UE2 may be notified of information instructing terminal autonomous connection. The UE2 that has received this notification can decide to perform terminal autonomous connection. If the notification is not made, for example, the UE 2 decides to perform terminal autonomous connection when no connection parameter is received from the NW device 20 even after a predetermined time has passed since the connection request was transmitted. good too.

In processing sequence examples 3 and 4, the connection request from UE2 to the NW device 20 is used as a trigger, and the NW device 20 is supposed to transmit a special paging message to UE1. , is not limited to the connection request. A special paging message may be sent to the UE even without a connection request, e.g. triggered by the arrival of a certain time. Also, when both UE1 and UE2 are in the IDLE state, the NW device 20 may transmit a special paging message to both UE1 and UE2 when unicast D2D connection is established between UE1 and UE2. good. In this case, both UE1 and UE2 can establish connection, for example, by terminal autonomous connection without transitioning to the CONNECTED state.

(About the effect of network assist connection)
As described above, with the network-assisted connection described above, unicast communication (D2D or cellular) can be performed between UEs for unicast D2D connection even when discovery signals are not transmitted and received between the UEs. This makes it possible to reduce transmission and reception of unnecessary discovery signals, reduce delay associated with UE discovery, and the like.

Also, it becomes possible to select an appropriate communication path (D2D or cellular) corresponding to the UE capability or channel quality. Also, since transmission/reception subframes in the D2D connection can be set as connection parameters, it is possible to avoid simultaneous transmission/reception with the cellular link, for example.

Next, terminal autonomous connection will be described.

(Terminal autonomous connection: processing sequence example 5)
Processing sequence example 5, which is an example of terminal autonomous connection, will be described with reference to FIG. First, as a premise, it is assumed that synchronization between UE1 and UE2 has been established by PSSS/SSSS or the like.

In step S501, UE1 transmits a discovery signal including UE capability 1, which is the UE capability of UE1, UE2 receives the discovery signal, and UE2 includes the UE capability 2, which is the UE capability of UE2. and UE1 receives the discovery signal. Through step S501, UE1 can obtain UE capability 2 of UE2, and UE2 can obtain UE capability 1 of UE1. The discovery signal may be a signal transmitted by PSDCH, a signal transmitted by a D2D channel other than PSDCH (eg, PSBCH, PSCCH/PSSCH), or a signal other than an existing D2D channel. It may be a signal transmitted on a channel of

Here, for example, when UE2 detects that the quality of the discovery signal received from UE1 is better than a predetermined threshold and that UE1 has the unicast D2D capability, terminal autonomous connection is performed with UE1. and sends a connection request to UE1. The connection request may be a signal transmitted by PSDCH, a signal transmitted by a D2D channel other than PSDCH (eg, PSBCH, PSCCH/PSSCH), or an existing D2D channel. It may be a signal transmitted on a channel other than the channel. The connection request includes, for example, the ID of UE2, which is the source of the request, and the ID of UE1, which is the destination of the connection request. The connection request also includes information indicating a desire for unicast D2D connection.

After allowing the unicast D2D connection with UE2, UE1 sends a connection grant to UE2. The connection permission may be a signal transmitted by the PSDCH, a signal transmitted by a D2D channel other than the PSDCH (eg, PSBCH, PSCCH/PSSCH), or a signal other than the existing D2D channel. It may be a signal transmitted on a channel of

In step S504, UE1 sends the connection parameters that UE1 wants to use to UE2, and UE2 sends the connection parameters that UE2 wants to use to UE1. For example, if UE1 determines that the connection parameters received from UE2 match (e.g., are the same) the connection parameters desired by UE1, it sends information to UE2 indicating that it accepts the connection parameters received from UE2. , if UE2 determines that the connection parameters received from UE1 match the connection parameters desired by UE2, it sends information to UE1 indicating that it accepts the connection parameters received from UE1. Thereby, mutual connection parameters are determined, connection is established in step S505 using the connection parameters, and unicast D2D communication is started.

Note that, for example, if UE1 wishes to modify any of the connection parameters received from UE2 (e.g., changing 4-layer transmission to 2-layer transmission, etc.), UE1 notifies UE2 of the modified parameter. Negotiations are performed in this manner, and parameters are corrected and determined.

In addition, the connection parameters desired by the UE 2 may be included in the connection request in step S502. Also, connection parameters desired by UE1 may be included in the connection permission in step S503.

<Regarding the transmission method of the UE capability>
As described above, in processing sequence example 5, the UE capability is transmitted in the discovery signal, which may increase the message size and increase overhead. Therefore, in order to reduce overhead, the UE may send the UE capabilities with a longer period than the discovery signal.

For example, as shown in FIG. 15A, the UE transmits a bulk discovery signal containing the UE capabilities every two discovery signal transmissions. It should be noted that once every two times is an example, and in general, once every N times (N is an integer equal to or greater than 2) may be used.

In the example shown in FIG. 15A, the discovery signal formats that can be transmitted may be limited to each TTI or subframe to avoid increasing blind detection for the receiving UE. Also, for example, the discovery signal format may be set in resource pool period units, SFN units, or DFN units by setting in system information or by presetting. Alternatively, a message-based discovery signal composed of control signals/data may be used as the discovery signal.

The UE may also send the UE capabilities in a message separate from the discovery signal message, as shown in FIG. 15B. In the example of FIG. 15B , for example, the discovery signal includes time-frequency resource information for UE capability notification (reception), as shown in “A”, and the UE on the receiving side uses the time-frequency Resources may be used to receive UE capabilities. In this case, the paired discovery signaling message and UE capability message may contain a common identifier.

In the example of FIG. 15B, in order to avoid an increase in blind detection of the receiving side UE when transmitting the discovery signal and UE capabilities on the same channel, the message size is made common by zero padding etc., and the flag in the message indicates both It may be made identifiable. Note that the UE may transmit the discovery signal and the UE capabilities on separate channels.

(Terminal autonomous connection: processing sequence example 6)
Processing sequence example 6, which is another example of terminal autonomous connection, will be described with reference to FIG. Differences from the processing sequence example 5 will be mainly described below.

At step S601, UE1 and UE2 transmit and receive discovery signals respectively. Unlike processing sequence example 5, the discovery signal does not include UE capabilities.

Here, for example, UE2 decides to perform a terminal autonomous connection with UE1, and transmits a connection request and the UE capability of UE2 to UE1 (step S602).

After allowing the unicast D2D connection with UE2, UE1 sends the connection grant and the UE capabilities of UE1 to UE2.

As in the case of processing sequence example 5, connection parameters for UE1 and UE2 are determined (step S604), connection is established in step S605, and unicast D2D communication is started.

In processing sequence example 6, when unicast D2D connection is not performed, transmission of the UE capability is unnecessary, so overhead can be reduced.

In both of process sequence example 5 and process sequence example 6, when the connection request transmitted from UE2 is received by a UE capable of relaying the communication of UE1, the UE capable of relaying responds (permits connection). may be sent to UE2. In this case, even if UE1 cannot make a unicast D2D connection with UE2, unicast communication can be made through the route of “UE2-relayable UE-UE1”.

(Example of determination operation for terminal autonomous connection/network assist connection)
The UE in this embodiment can determine which of the terminal autonomous connection and the network assisted connection to use in establishing the unicast D2D connection, for example, by the method described below. Three examples (options 1-3) are described below. The following description is based on the configuration example shown in FIG.

<Option 1: Judgment based on discovery signal>
In option 1, UE2 decides whether to use terminal autonomous connection or network assisted connection based on the discovery signal received from UE1, as shown in FIG. 17A. Here, it is assumed that the discovery signal includes information necessary for determination (eg, whether UE1 is in RRC connection state, ID of cell to which UE1 is connected, ID of operator to which UE1 belongs).

Based on the discovery signal received from UE1, for example, when UE1 is in the RRC connected state in the same cell as UE2, UE2 determines that network-assisted connection is possible and decides to perform network-assisted connection. Also, for example, UE2 determines not to perform network assisted connection when the operator to which UE1 belongs is different from the operator of UE2.

In Option 1, it is possible to establish a connection according to the state of the UE, which is the communication partner, and to reduce the connection delay and connection failure probability.

<Option 2: Judgment based on instructions from NW device>
In option 2, as shown in FIG. 17B , if the network (specifically, in this example, the NW device 20) is set to use the network assist connection for UE2, UE2 is set , it determines to perform a network assisted connection (that is, to transmit a connection request to the NW device 20).

In option 2, by setting to use network assist connection, the network side can determine whether to allow unicast D2D connection for each connection, enabling efficient path selection for cellular/D2D communication. . For example, it is possible to decide to permit unicast D2D only at the cell edge.

<Option 3: Judgment based on presence/absence of discovery of communication partner UE, presence/absence of capability information>
In option 3, as shown in FIG. 17C, UE2 cannot discover UE1 that it wants to communicate with for unicast D2D (if it does not receive a discovery signal from UE1), or it can discover it, but the channel quality (reception level , reception quality, etc.) is below a predetermined threshold, or if the UE capabilities of UE1 are unknown, attempt to establish a connection with network assisted connection. Option 3 is preferably applicable when the communication partner is not transmitting a discovery signal, when UE2 is not monitoring inter-terminal communication, or when terminal autonomous connection fails.

Options 1 to 3 have been described above, but any two or all of Options 1 to 3 may be applied in combination.

(Device configuration)
A functional configuration example of the UE and the NW device 20 that perform the operations of the embodiment described above will be described.

(user device)
18 is a diagram illustrating an example of a functional configuration of a UE according to an embodiment; FIG. As shown in FIG. 18, the UE has a signal transmission section 101, a signal reception section 102, a determination section 103, and a communication control section 104. It should be noted that FIG. 18 shows only the functional units particularly related to the embodiment of the present invention in the UE, and also has a function (not shown) for performing at least LTE-compliant operations. Also, the functional configuration shown in FIG. 18 is merely an example. As long as the operation according to the present embodiment can be executed, the functional division and the name of the functional unit may be arbitrary.

The signal transmission unit 101 has a D2D signal transmission function and a cellular communication transmission function. The D2D signal transmission function creates a D2D transmission signal and wirelessly transmits the signal. The transmission function of cellular communication creates a transmission signal to be transmitted by UL of cellular communication, and wirelessly transmits the signal.

The signal receiving unit 102 includes a function of wirelessly receiving various signals from other user devices or NW devices 20 and acquiring higher layer signals from the received physical layer signals. In addition, the signal receiving unit 102 has a D2D signal receiving function and a cellular communication receiving function.

The determination unit 103 determines whether to perform the unicast D2D connection by the terminal autonomous connection or the unicast D2D connection by the network assisted connection, for example, by the method described with reference to FIGS. 17A to 17C. The determination result is notified to the communication control unit 104 .

The communication control unit 104 controls the signal transmitting unit 101/signal receiving unit 102 so as to cause the signal transmitting unit 101/signal receiving unit 102 to execute the operations of the UE described with reference to processing sequence examples 1 to 6. Further, the communication control unit 104 includes a storage unit that holds connection parameters and setting information received from the NW device 20, and controls the signal transmission unit 101/signal reception unit 102 according to the connection parameters/setting information stored in the storage unit. do. Also, the communication control unit 104 holds state information indicating whether or not a unicast D2D connection has been established. For example, when a unicast D2D connection is established with a certain communication partner UE by using a certain connection parameter, the communication control unit 104 generates the connection parameter, the ID of the communication partner UE, and the unicast D2D connection. It holds state information including information indicating that it is in an established state. Note that "establishing a D2D connection using a connection parameter" means that the UE is in a state capable of performing D2D communication by using (setting) the connection parameter. Accordingly, if there is transmission data, it transmits it and monitors the reception signal.

(NW device 20)
FIG. 19 is a diagram showing an example of the functional configuration of the NW device 20 according to this embodiment. As shown in FIG. 19 , the NW device 20 has a signal transmission section 201 , a signal reception section 202 , a determination section 203 and a communication control section 204 . Note that FIG. 19 shows only the functional units particularly related to the embodiment of the present invention in the NW device 20, and also has a function (not shown) for performing at least LTE-compliant operations. Also, the functional configuration shown in FIG. 19 is merely an example. As long as the operation according to the present embodiment can be executed, the functional division and the name of the functional unit may be arbitrary.

The signal transmission unit 201 has a function of generating a signal to be transmitted to the UE side and transmitting the signal to the UE side. The signal receiving unit 202 includes a function of receiving various signals transmitted from the UE and acquiring, for example, higher layer information from the received signals.

When receiving a connection request from the UE, the determination unit 203 determines a communication path and connection parameters by the method described above.

The communication control unit 204 causes the signal transmission unit 201/signal reception unit 202 to execute the operations of the NW device 20 described with reference to the processing sequence examples 1 to 4, other than the communication path determination operation and the connection parameter determination operation. The signal transmission unit 201/signal reception unit 202 is controlled so that

<Hardware configuration>
The block diagrams (FIGS. 18 and 19) used to describe the above embodiments show blocks in functional units. These functional blocks (components) are implemented by any combination of hardware and/or software. Further, means for realizing each functional block is not particularly limited. That is, each functional block may be realized by one device in which multiple elements are physically and/or logically combined, or may be realized by two or more devices that are physically and/or logically separated. and/or may be indirectly (eg, wired and/or wireless) connected and implemented by these multiple devices.

For example, both the UE and the NW device 20 according to one embodiment of the present invention may function as computers that perform processing according to the present embodiment. FIG. 20 is a diagram showing an example of the hardware configuration of the UE and NW device 20 according to the embodiment. The UE and NW device 20 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

Note that in the following description, the term "apparatus" can be read as a circuit, device, unit, or the like. The hardware configuration of the UE and the NW device 20 may be configured to include one or more of each device indicated by 1001 to 1006 shown in the figure, or may be configured without some devices. good.

Each function in the UE and the NW device 20 is performed by the processor 1001 by loading predetermined software (program) on hardware such as the processor 1001 and the memory 1002, and the communication by the communication device 1004, the memory 1002 and the storage It is realized by controlling reading and/or writing of data in 1003 .

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured with a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, registers, and the like.

The processor 1001 also reads programs (program codes), software modules, or data from the storage 1003 and/or the communication device 1004 to the memory 1002, and executes various processes according to them. As the program, a program that causes a computer to execute at least part of the operations described in the above embodiments is used. For example, the signal transmission unit 101 , the signal reception unit 102 , the determination unit 103 , and the communication control unit 104 of the user equipment UE may be stored in the memory 1002 and implemented by a control program that operates on the processor 1001 . The signal transmission unit 201, the signal reception unit 202, the reception unit 203, the determination unit 204, and the communication control unit 204 of the NW device 20 are stored in the memory 1002 and implemented by a control program that operates on the processor 1001. may Although it has been described that the above-described various processes are executed by one processor 1001, they may be executed by two or more processors 1001 simultaneously or sequentially. Processor 1001 may be implemented with one or more chips. Note that the program may be transmitted from a network via an electric communication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), and RAM (Random Access Memory). may be The memory 1002 may also be called a register, cache, main memory (main storage device), or the like. The memory 1002 can store executable programs (program code), software modules, etc. to perform processing according to one embodiment of the present invention.

The storage 1003 is a computer-readable recording medium, for example, an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disc, a magneto-optical disc (for example, a compact disc, a digital versatile disc, a Blu-ray disk), smart card, flash memory (eg, card, stick, key drive), floppy disk, magnetic strip, and/or the like. Storage 1003 may also be called an auxiliary storage device. The storage medium described above may be, for example, a database, server, or other suitable medium including memory 1002 and/or storage 1003 .

The communication device 1004 is hardware (transmitting/receiving device) for communicating between computers via a wired and/or wireless network, and is also called a network device, network controller, network card, communication module, or the like. For example, the signal transmitter 101 and the signal receiver 102 of the UE may be implemented in the communication device 1004 . Also, the signal transmission unit 201 and the signal reception unit 202 of the NW device 20 may be realized by the communication device 1004 .

The input device 1005 is an input device (for example, keyboard, mouse, microphone, switch, button, sensor, etc.) that receives input from the outside. The output device 1006 is an output device (eg, display, speaker, LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated (for example, a touch panel).

Devices such as the processor 1001 and the memory 1002 are also connected by a bus 1007 for communicating information. The bus 1007 may be composed of a single bus, or may be composed of different buses between devices.

In addition, the UE and NW devices include hardware such as microprocessors, digital signal processors (DSPs), ASICs (Application Specific Integrated Circuits), PLDs (Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays). , and part or all of each functional block may be implemented by the hardware. For example, processor 1001 may be implemented with at least one of these hardware.

(summary)
As described above, according to the present embodiment, a user device that supports D2D transmits a connection request for D2D connection between the user device and another user device to a network device. a receiving unit for receiving connection parameters for the D2D connection from the network device; and a control unit for establishing the D2D connection using the connection parameters. .

With the above configuration, it is possible to establish a D2D connection between user equipments using appropriate connection parameters.

The connection request includes, for example, identification information of the other user equipment obtained from the discovery signal received by the receiving unit. With this configuration, the network device can appropriately identify the user device of the communication partner.

The receiving unit may receive connection parameters for D2D connection from the network device by monitoring a predetermined search space when a paging message including a predetermined flag is received from the network device. . With this configuration, for example, even when the user equipment is in the idle state, it is possible to receive connection parameters without transitioning to the connected state.

Further, according to the present embodiment, a network device that communicates with a user device that supports D2D, and receives a connection request for D2D connection between the user device and another user device from the user device. a receiving unit that determines the connection parameters for the D2D connection based on the capability information of the user equipment and the capability information of the other user equipment; and the connection parameters determined by the determination unit A network device is provided, comprising: a transmitting unit that transmits to the user device and transmits the connection parameter determined by the determining unit to the other user device.

With the above configuration, it is possible to establish a D2D connection between user equipments using appropriate connection parameters.

The determination unit determines whether to permit the D2D connection based on the capability information of the user equipment and the capability information of the other user equipment, and if the D2D connection is permitted, the D2D Connection parameters for the connection may be determined. With this configuration, whether or not to permit the D2D connection can be appropriately determined based on the capability information.

<Supplement to the embodiment>
Notification of information is not limited to the aspects/embodiments described herein and may be done in other ways. For example, notification of information includes physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC signaling, MAC signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or a combination thereof. RRC messages may also be referred to as RRC signaling. Also, the RRC message may be, for example, an RRC connection setup message, an RRC connection reconfiguration message, or the like.

Aspects/embodiments described herein support Long Term Evolution (LTE), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, Future Radio Access (FRA), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), It may be applied to systems utilizing Bluetooth®, other suitable systems, and/or advanced next generation systems based thereon.

Input/output information and the like may be stored in a specific location (for example, memory), or may be managed in a management table. Input/output information and the like may be overwritten, updated, or appended. The output information and the like may be deleted. The entered information and the like may be transmitted to another device.

Judgment or judgment may be made by a value represented by one bit (0 or 1), may be made by a true/false value (Boolean: true or false), or may be made by numerical comparison (for example, comparison with a predetermined value).

Information, signals, etc. described herein may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may refer to voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. may be represented by a combination of

The terms explained in this specification and/or terms necessary for understanding this specification may be replaced with terms having the same or similar meanings. For example, channels and/or symbols may be signals. A signal may also be a message.

UE is defined by those skilled in the art as subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal. , a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable term.

The procedures, sequences, etc. of each aspect/embodiment described herein may be permuted so long as there is no inconsistency. For example, the methods described herein present elements of the various steps in a sample order, and are not limited to the specific order presented.

Each aspect/embodiment described herein may be used alone, in combination, or switched between implementations. In addition, the notification of predetermined information (for example, notification of “being X”) is not limited to being performed explicitly, but may be performed implicitly (for example, not notifying the predetermined information). good too.

As used herein, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining", "determining" means, for example, calculating, computing, processing, deriving, investigating, looking up (e.g., in a table, database or other search in data structures), ascertaining as "judgement" or "decision". Also, "judgment" and "determination" are used for receiving (e.g., receiving information), transmitting (e.g., transmitting information), input, output, access (accessing) (for example, accessing data in memory) may include deeming that a "judgment" or "decision" has been made. In addition, "judgment" and "decision" are considered to be "judgment" and "decision" by resolving, selecting, choosing, establishing, comparing, etc. can contain. In other words, "judgment" and "decision" may include considering that some action is "judgment" and "decision".

As used herein, the phrase "based on" does not mean "based only on," unless expressly specified otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

Although the present invention has been described in detail above, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented with modifications and variations without departing from the spirit and scope of the invention defined by the claims. Accordingly, the descriptions herein are for the purpose of illustration and description, and are not intended to have any limiting meaning with respect to the present invention.

(Appendix)
(Section 1)
A user equipment that supports D2D,
a transmission unit configured to transmit a connection request for D2D connection between the user device and another user device to a network device;
a receiving unit that receives connection parameters for the D2D connection from the network device;
and a control unit that establishes the D2D connection using the connection parameter.
(Section 2)
2. The user device according to claim 1, wherein the connection request includes identification information of the other user device obtained from the discovery signal received by the receiver.
(Section 3)
The receiving unit receives connection parameters for D2D connection from the network device by monitoring a predetermined search space when a paging message including a predetermined flag is received from the network device. 3. The user device according to claim 1 or 2.
(Section 4)
A network device that communicates with a user device that supports D2D,
a receiving unit that receives a connection request for D2D connection between the user device and another user device from the user device;
a determination unit that determines connection parameters for the D2D connection based on the capability information of the user equipment and the capability information of the other user equipment;
a transmission unit configured to transmit the connection parameters determined by the determination unit to the user device and to transmit the connection parameters determined by the determination unit to the other user device.
(Section 5)
The determination unit determines whether to permit the D2D connection based on the capability information of the user equipment and the capability information of the other user equipment, and if the D2D connection is permitted, the D2D 5. A network device according to claim 4, characterized in that it determines connection parameters for the connection.

This patent application claims its priority based on Japanese Patent Application No. 2016-109548 filed on May 31, 2016, and the entire contents of Japanese Patent Application No. 2016-109548 are incorporated into this application. do.

UE user equipment eNB base station 101 signal transmission unit 102 signal reception unit 103 determination unit 104 communication control unit 201 signal transmission unit 202 signal reception unit 203 decision unit 204 communication control unit 1001 processor 1002 memory 1003 storage 1004 communication device 1005 input device 1006 output Device

Claims (5)

a transmission unit that transmits a connection request including communication parameters to another terminal;
a receiving unit that receives a connection permission from the other terminal,
the communication parameters include information about CSI feedback;
The transmission unit transmits a notification of a connection request including the communication parameters by an RRC connection reconfiguration message for unicast communication between terminals.
terminal. The terminal according to claim 1, wherein the terminal negotiates the communication parameters with the other terminal. The transmitting unit transmits capability information of the terminal to the other terminal,
The terminal according to claim 1 or 2, wherein the receiving unit receives capability information of the other terminal from the other terminal. a receiving unit that receives a connection request including communication parameters from another terminal;
a transmission unit that transmits a connection permission to the other terminal,
the communication parameters include information about CSI feedback;
The receiving unit receives notification of a connection request including the communication parameters by means of an RRC connection reconfiguration message for unicast communication between terminals.
terminal. a transmission step of transmitting a connection request including communication parameters to another terminal;
receiving a connection permission from the other terminal;
the communication parameters include information about CSI feedback;
In the transmitting step, the connection request notification including the communication parameters is transmitted by an RRC connection reconfiguration message for terminal-to-terminal unicast communication.
The method of communication performed by the terminal.

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