Terminal device and method

Abstract

To provide a terminal device and a method capable of efficiently controlling sidelink communication.SOLUTION: In a cellular mobile communication system, a first terminal device capable of sidelink communication communicates with a third terminal device via a second terminal device, receives data from an upper layer, and transmits the data and first information to the second terminal device. The first information includes an identifier of a PC5 QoS flow to which the data is mapped and an identifier of an SL-DRB to which the PC5 QoS flow is mapped.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a terminal device and a method. [Background technology]

[0002] The 3G Partnership Project, a standardization project for cellular mobile communication systems In the 3rd Generation Partnership Project (3GPP [registered trademark]), Technical studies and standardization of cellular mobile communication systems, including base stations, core networks, and services, are currently underway.

[0003] For example, technical studies and standardization of E-UTRA (Evolved Universal Terrestrial Radio Access) have begun in 3GPP as a radio access technology (Radio Access Technology: RAT) for 3.9G and 4G cellular mobile communication systems. Currently, 3GPP is also conducting technical studies and standardization of E-UTRA extension technologies. E-UTRA is a Long Term It is also called LTE Evolution (registered trademark), and the extended technology is sometimes called LTE-Advanced (LTE-A) and LTE-Advanced Pro (LTE-A Pro).

[0004] In addition, 3GPP has begun technical discussions and standardization of NR (New Radio, or NR Radio access) as a radio access technology (Radio Access Technology: RAT) for cellular mobile communication systems for the 5th Generation (5G). Technical studies and standardization are currently underway. [Prior art documents] [Non-patent literature]

[0005] [Non-licensed document 1] 3GPP TS 38.331 v17.2.0,"Evolved Universal Terrestrial Radio Access (E-UTRA);Radio Resource Control (RRC);Protocol specifications" pp37-1107

Non-licensed Document 2

Non-licensed Document 4

Non-licensed Document 6

Non-licensed Document 7

[0006] In 3GPP, as an extension technology of NR, a technology called sidelink, which allows terminal devices to communicate directly with each other without going through the core network, is being considered. In addition, research has begun on a technology (UE-to-UE relay) that supports communication between terminal devices by adding other terminal devices between terminal devices.

[0007] One aspect of the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a terminal device, a communication method, and an integrated circuit that can efficiently perform communication control. [Means for solving the problem]

[0008] In order to achieve the above object, one aspect of the present invention provides the following means. That is, one aspect of the present invention is a first terminal device capable of sidelink communication, comprising: a processing unit; a communication unit, the first terminal device communicating with a third terminal device via a second terminal device, The processing unit receives data from an upper layer, and the transmission unit transmits the data and first information to a second terminal device, the first information being a PC5 QoS flow to which the data is mapped. and the identifier of the SL-DRB to which the PC5 QoS flow is mapped.

[0009] Another aspect of the present invention is a second terminal device capable of sidelink communication, comprising: a processing unit; A transmission unit and a reception unit for receiving first information and data from a first terminal device, the first information including an identifier of a PC5 QoS flow to which the data is mapped and a The processing unit determines whether the PC5 is a SL-DRB to be mapped based on the first information. A mapping rule is set between the SL-DRB to which the QoS flow is mapped and the RLC channel of the second terminal device, and the data is transmitted to a third terminal device based on the mapping rule.

[0010] Another aspect of the present invention is a method for a first terminal device capable of sidelink communication, comprising: The first terminal device communicates with the third terminal device via the second terminal device, and transmits data to the third terminal device via a higher layer. and transmitting the data and first information to a second terminal device, the first information including an identifier of a PC5 QoS flow to which the data is mapped and an identifier of a SL-DRB to which the PC5 QoS flow is mapped.

[0011] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0012] According to one aspect of the present invention, a terminal device, a method, and an integrated circuit can realize efficient communication control processing. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram of a communication system according to an embodiment of the present invention. [Diagram 2] A diagram showing an example of a protocol configuration for NR sidelink communication in this embodiment. [Diagram 3] A diagram showing an example of a protocol configuration for NR sidelink communication in this embodiment. [Figure 4] FIG. 1 is a diagram illustrating an example of a protocol configuration of a side link according to the present embodiment. [Diagram 5] FIG. 2 is a block diagram showing the configuration of a terminal device according to the embodiment. [Figure 6] FIG. 1 is a diagram illustrating an example of a protocol configuration of a side link according to the present embodiment. [Figure 7] FIG. 1 is a diagram illustrating an example of a protocol configuration of a side link according to the present embodiment. [Figure 8] 3 shows an example of processing in this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the present embodiment will be described in detail with reference to the drawings.

[0015] In this embodiment, the names of the nodes and entities and the processes in the nodes and entities when the radio access technologies are NR and E-UTRA will be described, but this embodiment may be applied to other radio access technologies. The names of the nodes and entities in this embodiment may be different names.

[0016] Fig. 1 is a schematic diagram of a communication system according to this embodiment. Note that the functions of each node, radio access technology, core network, interface, etc. described using Fig. 1 are only some of the functions closely related to this embodiment, and the system may have other functions.

[0017] E-UTRA may be a radio access technology. E-UTRA may also be an air interface between the UE 122 and the ng-eNB 100. The interface 112 may be referred to as a Uu interface. The ng-eNB (ng E-UTRAN Node B) 100 may be a base station device of the E-UTRAN. The ng-eNB 100 may have an E-UTRA protocol, which will be described later. The E-UTRA protocol may be composed of an E-UTRA User Plane (UP) protocol, which will be described later, and an E-UTRA Control Plane (CP) protocol, which will be described later. The ng-eNB 100 The E-UTRA user plane protocol and the E-UTRA control plane protocol are transmitted to the UE 122. The radio access network composed of eNBs may be referred to as E-UTRAN.

[0018] NR may be a radio access technology. NR also provides an air interface between the UE 122 and the gNB 102. The air interface 112 between the UE 122 and the gNB 102 may be referred to as an air interface. The air interface 112 between the UE 122 and the gNB 102 may be referred to as a Uu interface. The gNB (g Node B) 102 may be an NR base station device. The gNB 102 may have the NR protocol described below. The NR protocol may be composed of an NR user plane (User Plane: UP) protocol described below and an NR control plane (Control Plane: CP) protocol described below. The gNB 102 transmits the NR user plane protocol and the NR control plane (Control Plane: CP) protocol to the UE 122. It may terminate the control plane protocols.

[0019] The interface 110 between the ng-eNB 100 and the gNB 102 may be called an Xn interface. The ng-eNB and the gNB may be connected to the 5GC via an interface called an NG interface (not shown). The 5GC may be a core network. One or more base station devices may be connected to the 5GC via the NG interface.

[0020] The state in which a base station can be connected only via the Uu interface may be called Inside NG-RAN Coverage or In-Coverage (IC). The state in which it is not possible to connect to the device is called Outside NG-RAN Coverage or Out-of-Coverage (OoC). The air interface 114 between the UEs 122 may be referred to as a PC5 interface. Communication between the UEs 122 via the PC5 interface may be referred to as a sidelink (SL). In addition, a terminal device capable of performing sidelink communication may be referred to as a sidelink communication-capable terminal device.

[0021] In the following description, the ng-eNB 100 and / or the gNB 102 are also simply referred to as base station devices, and the UE 122 is also simply referred to as terminal devices or UEs. The PC5 interface is also simply referred to as PC5. The Uu interface is also referred to simply as Uu.

[0022] Sidelink is a technology for direct communication between terminal devices via PC5, and sidelink transmission and reception on PC5 is performed inside and outside the NG-RAN coverage.

[0023] There are three transmission modes for NR SL communication. The S is transmitted in one of the transmission modes by a pair of Source Layer-2 (L2) ID and Destination Layer-2 (L2) ID. The source Layer 2 identifier and destination Layer 2 identifier are the source L2ID and destination L2ID, respectively. The three transmission modes are "Unicast transmission", "Groupcast transmission", and "Broadcast transmission". The transmission mode may be referred to as a broadcast type, etc. Unicast transmission for direct communication is supported on PC5, and a PC5 unicast link between two UEs may be established for direct communication. The PC5 unicast link may be maintained, changed, or released according to application layer requests or communication requirements.

[0024] Unicast transmission is characterized by: (1) support of one PC5-RRC connection between a paired UE; (2) transmission and reception of control information and user traffic between UEs on the sidelink; (3) support for sidelink HARQ feedback; (4) transmit power control on the sidelink; (5) support for RLC AM; and (6) radio link failure detection for the PC5-RRC connection.

[0025] Groupcast transmission is also performed between UEs that belong to a sidelink group. (1) Support for sidelink HARQ feedback. do.

[0026] In addition, broadcast transmission is performed for (1) sending and receiving user traffic between UEs on the sidelink It is characterized by faith.

[0027] 2 and 3 are diagrams showing an example of a protocol architecture in NR sidelink communication according to this embodiment. Note that the functions of each protocol described using FIG. 2 and / or FIG. 3 are some of the functions closely related to this embodiment, and the protocol may have other functions. Note that in this embodiment, a sidelink (SL) is a communication between terminal devices. It may be a link.

[0028] Fig. 2(A) is a diagram of a protocol stack of a control plane (CP) for SCCH using RRC configured on a PC5 interface. As shown in Fig. 2(A), the control plane protocol stack for SCCH using RRC includes PHY (Physical layer) 200 which is a wireless physical layer, MAC (Medium Access Control) 202 which is a medium access control layer, RLC (Radio Link Control) 204 which is a radio link control layer, and a packet data convergence protocol layer. PDCP (Packet Data Convergence Protocol) 206, which is a layer for wireless resource control (RF control) The RRC 208 may be configured as a radio resource control layer (RRC layer). FIG. 2(B) is a diagram of the protocol stack of the control plane for SCCH using PC5-S configured on the PC5 interface. As shown in FIG. 2(B), The control plane protocol stack includes a PHY (Physical layer) 200 which is a wireless physical layer, a MAC (Medium Access Control) 202 which is a medium access control layer, a RLC (Radio Link Control) 204 which is a radio link control layer, and a Packet Data Convergence Protocol (PDCP) 206 which is a packet data convergence protocol layer, and a PC5 signalling layer (PC5 signalling layer) PC5-S (PC5 Signalling) 210.

[0029] FIG. 3(A) is a diagram of the control plane protocol stack for SBCCH configured on the PC5 interface. As shown in FIG. 3(A), the control plane protocol stack for SBCCH is The network may be composed of a PHY (Physical layer) 200, which is a wireless physical layer, a MAC (Medium Access Control) 202, which is a medium access control layer, a RLC (Radio Link Control) 204, which is a radio link control layer, and an RRC (Radio Resource Control) 208, which is a radio resource control layer. FIG. 3B is a diagram of a protocol stack of the user plane (UP) for STCH configured on the PC5 interface. As shown in FIG. 3B, the control plane protocol stack for STCH includes a PHY (Physical layer) 200 which is a wireless physical layer, a MAC (Medium Access Control) 202 which is a medium access control layer, It may be composed of RLC (Radio Link Control) 204, which is a radio link control layer, PDCP (Packet Data Convergence Protocol) 206, which is a packet data convergence protocol layer, and SDAP (Service Data Adaptation Protocol) 310, which is a service data adaptation protocol layer.

[0030] The AS (Access Stratum) layer may be a layer including some or all of the PHY 200, the MAC 202, the RLC 204, the SRAP 600, the PDCP 206, the SDAP 310, and the RRC 208. The Discovery 400 may be a layer higher than the AS layer.

[0031] In this embodiment, the terms PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), SDAP (SDAP layer), RRC (RRC layer), and PC5-S (PC5-S layer) may be used. In this case, PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), SDAP (SDAP layer), RRC (RRC layer), and PC5-S (PC5-S layer) may be PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), SDAP (SDAP layer), RRC (RRC layer), and PC5-S (PC5-S layer) of the NR sidelink protocol, respectively. In addition, when sidelink communication is performed using the E-UTRA technology, the SDAP layer may not be required. In order to clarify that it is a protocol for sidelink, for example, RLC may be expressed as sidelink RLC, SL RLC, PC5 RLC, etc., and for other protocols, the term "sidelink", "SL", or "PC5" may be added to the beginning to indicate that they are protocols for sidelink.

[0032] In addition, in this embodiment, when distinguishing between E-UTRA protocols and NR protocols, PHY, MAC, RLC, PDCP, and RRC may be referred to as PHY for E-UTRA or PHY for LTE, MAC for E-UTRA or MAC for LTE, RLC for E-UTRA or RLC for LTE, PDCP for E-UTRA or PDCP for LTE, and RRC for E-UTRA or RRC for LTE, respectively. Also, PHY, MAC, RLC, PDCP, and RRC are referred to as These are sometimes referred to as E-UTRA PHY or LTE PHY, E-UTRA MAC or LTE MAC, E-UTRA RLC or LTE RLC, E-UTRA PDCP or LTE PDCP, and E-UTRA RRC or LTE RRC, respectively. In addition, when distinguishing between E-UTRA protocols and NR protocols, PHY, MAC, RLC, PDCP, and RRC are sometimes referred to as PHY for NR, MAC for NR, RLC for NR, RLC for NR, and RRC for NR, respectively. In addition, PHY, MAC, RLC, PDCP, and RRC may be referred to as NR PHY, NR MAC, NR RLC, NR PDCP, and NR RRC, respectively.

[0033] This section describes the entities in the AS layer of E-UTRA and / or NR. An entity that has some or all of the functionality of the MAC layer may be referred to as a PHY entity. An entity that has some or all of the functionality of the MAC layer may be referred to as a MAC entity. An entity having some or all of the functions of the RLC layer may be called an RLC entity. An entity having some or all of the functions of the PDCP layer may be called a PDCP entity. An entity having some or all of the functions of the SDAP layer may be called an SDAP entity. An entity having some or all of the functions of the RRC layer may be called an RRC entity. PHY entity, MAC entity, RLC entity, PDCP entity The PHY, MAC, RLC, PDCP, SDAP, and RRC entities are referred to as PHY, MAC, RLC, PDCP, SDAP, and RRC, respectively. You can replace it.

[0034] Note that data provided to lower layers from MAC, RLC, PDCP, and SDAP, and / or MAC, RLC The data provided to MAC, RLC, PDCP, and SDAP from lower layers may be called MAC PDU (Protocol Data Unit), RLC PDU, PDCP PDU, and SDAP PDU, respectively. Also, the data provided to MAC, RLC, PDCP, and SDAP from higher layers and / or the data provided to higher layers by MAC, RLC, PDCP, and SDAP may be called SDAP PDU. The data is called MAC SDU (Service Data Unit), RLC SDU, PDCP SDU, and SDAP SDU, respectively. A segmented RLC SDU may be referred to as an RLC SDU segment.

[0035] Here, the base station device and the terminal device communicate with each other through the higher layer (Uu interface). For example, the base station device and the terminal device exchange (transmit and receive) signals in the Radio Resource Control (RRC) layer. The base station device and the terminal device may transmit and receive a MAC control element (MAC CE) in a medium access control (MAC) layer. The RRC layer of the terminal device may receive system information broadcast from the base station device. Here, RRC messages, system information, and / or MAC control elements are The input is a higher layer signal or a higher layer parameter. The terminal device receives the higher layer parameter. Each of the parameters included in the higher layer signal may be referred to as a higher layer parameter. For example, in the processing of the PHY layer, the higher layer means a higher layer seen from the PHY layer, and may mean one or more of the MAC layer, the RRC layer, the RLC layer, the PDCP layer, the NAS (Non Access Stratum) layer, etc. For example, in the processing of the MAC layer, the higher layer may mean one or more of the RRC layer, the RLC layer, the PDCP layer, the NAS layer, etc.

[0036] Moreover, terminal devices also exchange (transmit and receive) signals at higher layers on the PC5 interface. Terminal devices may transmit and receive RRC messages (also referred to as RRC signaling) at a Radio Resource Control (RRC) layer. Terminal devices may also transmit and receive RRC messages (also referred to as RRC signaling) at a Medium Access Control (MAC) layer. In the Here, RRC messages and / or MAC control elements are Each of the parameters included in the higher layer signal received by the terminal device may be referred to as a higher layer parameter. For example, PHY In the layer processing, the upper layer means a higher layer from the viewpoint of the PHY layer, and may mean one or more of the MAC layer, the RRC layer, the RLC layer, the PDCP layer, the PC5-S layer, the Discovery layer, etc. In the processing of layers, the higher layer may refer to one or more of the RRC layer, the RLC layer, the PDCP layer, the PC5-S layer, the Discovery layer, etc.

[0037] Hereinafter, the meaning of "A is given (provided) by the upper layer" or "A is given (provided) by the upper layer" may mean that the upper layer (mainly the RRC layer, the MAC layer, etc.) of the terminal device receives A from the base station device or another terminal device, and the received A is given (provided) to the physical layer of the terminal device from the upper layer of the terminal device. For example, in a terminal device, "being provided with upper layer parameters" may mean receiving an upper layer signal from a base station device or another terminal device, and providing the upper layer parameters included in the received upper layer signal to the physical layer of the terminal device from the upper layer of the terminal device. Setting an upper layer parameter in a terminal device may mean that the upper layer parameter is given (provided) to the terminal device. For example, setting an upper layer parameter in a terminal device may mean that the terminal device receives an upper layer signal from a base station device or another terminal device, and sets the received upper layer parameter in the upper layer. However, setting an upper layer parameter in a terminal device may include setting a default parameter that is given in advance to the upper layer of the terminal device. When describing the transmission of an RRC message from a terminal device to a base station device or another terminal device, the expression "submitting a message from the RRC entity of the terminal device to a lower layer" may be used. may mean submitting a message to the PDCP layer. Here, "submitting a message to a lower layer" may mean submitting the message to a PDCP entity corresponding to each SRB since the RRC message is transmitted using an SRB (SRB0, SRB1, SRB2, SRB3, etc.) When the RRC entity of the terminal device receives an indication from a lower layer, the lower layer may mean one or more of a PHY layer, a MAC layer, an RLC layer, a PDCP layer, etc.

[0038] An example of the PHY function will be described. The PHY of the terminal device can communicate with the PHY of other terminal devices via a side link. Transmits and receives data transmitted via the sidelink (SL) physical channel The PHY may have a function to transfer data to the MAC via the transport channel. The PHY may also receive data from the MAC via a transport channel. In this case, a Radio Network Temporary Identifier (RNTI) may be used to identify various pieces of control information.

[0039] Here, the physical channels will be described. The physical channels used for wireless communication between a terminal device and another terminal device may include the following physical channels.

[0040] PSBCH (Physical Sidelink Broadcast CHannel) PSCCH (Physical Sidelink Control CHannel) PSSCH (Physical Sidelink Shared CHannel) PSFCH (Physical Sidelink Feedback CHannel)

[0041] The PSBCH may be used to broadcast system information required by a terminal device.

[0042] The PSCCH may be used to indicate resources and other transmission parameters for the PSSCH.

[0043] The PSSCH transmits data to other terminal devices and control regarding HARQ / CSI feedback. It may be used to transmit information.

[0044] The PSFCH may be used to carry HARQ feedback to other terminal devices. .

[0045] An example of the functions of the MAC will be described. The MAC may be called a MAC sublayer. The MAC may have a function of mapping various logical channels to corresponding transport channels. The logical channels may be identified by a logical channel identity (or logical channel ID). The MAC may be connected to the higher RLC via a logical channel. Depending on the type of information to be transmitted, the logical channels may be divided into a control channel that transmits control information and a traffic channel that transmits user information. The MAC may be configured to transmit one or more different logical channels. The MAC may have a function of multiplexing MAC SDUs belonging to a logical channel and providing them to the PHY. The MAC may also have a function of demultiplexing MAC PDUs provided from the PHY and providing them to a higher layer via the logical channel to which each MAC SDU belongs. The MAC may also have a function of performing error correction through HARQ (Hybrid Automatic Repeat reQuest). The MAC may also have a function of reporting scheduling information. MAC has a function to perform priority processing among terminal devices using dynamic scheduling. MAC should also have a function for performing priority processing between logical channels within one terminal device. MAC has the function of prioritizing overlapping resources within one terminal device. E-UTRA MAC has the function of identifying Multimedia Broadcast Multicast Services (MBMS). The NR MAC may also support multicast / broadcast services. The MAC may have the ability to identify the transport format (MBS). The MAC may have the functionality to select a base station. The MAC may have the functionality to perform discontinuous reception (DRX) and / or discontinuous transmission (DTX), to execute the Random Access (RA) procedure, to notify the available transmission power, and to provide a power header. Power Headroom Report (PHR) function, which notifies the amount of data in the transmission buffer The NR MAC may have a bandwidth adaptation (BA) function. The MAC PDU format used in the NR MAC may be different from the MAC PDU format used in the NR MAC. The MAC PDU also includes a MAC control element (MAC control element), which is an element for controlling the MAC. The MAC address may include a rule element: MAC CE.

[0046] In addition, the MAC sublayer may provide additional services and functions on the PC5 interface, such as radio resource selection for selecting radio resources for sidelink transmission, filtering of packets received in sidelink communication, priority processing between uplink and sidelink, and reporting of sidelink channel state information (Sidelink CSI).

[0047] This section describes the sidelink (SL) logical channels used in E-UTRA and / or NR, and the mapping between the sidelink logical channels and transport channels.

[0048] SBCCH (Sidelink Broadcast Control Channel) transmits sidelink system information in one The SBCCH may be a sidelink logical channel for broadcasting from a terminal device to one or more terminal devices. The SBCCH may be mapped to the SL-BCH, which is a sidelink transport channel. It may be pinged.

[0049] The SCCH (Sidelink Control Channel) may be a logical channel for sidelink for transmitting control information such as a PC5-RRC message or a PC5-S message from one terminal device to one or more terminal devices. The SCCH may be mapped to the SL-SCH, which is a sidelink transport channel.

[0050] The STCH (Sidelink Traffic Control Channel) may be a sidelink logical channel for transmitting user information from one terminal device to one or more terminal devices. The STCH may be mapped to the SL-SCH, which is a sidelink transport channel.

[0051] An example of the function of the RLC will be described. The RLC may be called an RLC sublayer. The E-UTRA RLC may have a function of segmenting and / or concatenating data provided from the PDCP of the upper layer and providing it to a lower layer. The E-UTRA RLC may perform reassembly and reordering of data provided from the lower layer. The NR RLC may have the function of re-ordering and providing it to higher layers. The NR RLC may have a function to add a sequence number to data provided by the PDCP of the layer that is independent of the sequence number added by the PDCP. The NR RLC may also have a function to segment data provided by the PDCP and provide it to a lower layer. The NR RLC may also have a function to reassemble data provided by the lower layer and provide it to a higher layer. The RLC may also have a function to retransmit data and / or a function to request retransmission (Automatic The RLC may have a Repeat reQuest (ARQ) function. The RLC may also have a function for performing error correction by ARQ. The control information sent from the receiving side of the RLC to the transmitting side to indicate the data that needs to be retransmitted in order to perform ARQ may be called a status report. The status report transmission instruction sent by the RLC is called a poll. RLC may have a function to detect data duplication. RLC may also have a function to discard data. RLC has Transparent Mode (TM), Unacknowledged Mode (UM), There may be three modes: TM (Transmit Mode), AM (Acknowledged Mode), and AM (Acknowledged Mode). In TM, data received from the upper layer is not divided, and no RLC header is added. TM RLC entity The TM RLC element is a uni-directional entity. The UM may be configured as a receiving TM RLC entity or as a receiving TM RLC entity. In UM, it is responsible for splitting and / or combining data received from higher layers, adding RLC headers, etc. In the AM, retransmission control of data is not required. The UM RLC entity may be a unidirectional entity or a bi-directional entity. If the UM RLC entity is a unidirectional entity, it may be configured as a transmitting UM RLC entity or a receiving UM RLC entity. If the UM RLC entity is a bi-directional entity, it may be configured as a UM RLC entity consisting of a transmitting side and a receiving side. In the AM The AM RLC entity may perform division and / or concatenation of data received from a higher layer, addition of an RLC header, data retransmission control, etc. The AM RLC entity is a bidirectional entity and may be configured as an AM RLC consisting of a transmitting side and a receiving side. In addition, the data provided to the lower layer by TM and / or the data provided by the lower layer The data provided to and / or from a lower layer in UM may be called a UMD PDU. The data provided to and / or from a lower layer in AM may be called a UMD PDU. The data provided by the RLC or a lower layer may be called AMD PDU. The RLC PDU format used in NR RLC may be different from the RLC PDU format used in NR RLC. In addition, there may be an RLC PDU for data and an RLC PDU for control. The RLC PDU for data may be called an RLC DATA PDU (RLC Data PDU). In addition, the RLC PDU for control may be called an RLC CONTROL PDU (RLC Control PDU). The control RLC PDU used to transmit the status report is called the status PDU (STATUS PDU). good.

[0052] In addition, in the sidelink, TM may be used for SBCCH, and group cast In the sidelink, only UM is used in groupcast and broadcast transmission, and UM and AM are available in unicast transmission. In the sidelink, UM in groupcast and broadcast transmission supports only one-way transmission.

[0053] An example of the function of PDCP will be described. PDCP may be called a PDCP sublayer. PDCP may have a function for maintaining sequence numbers. PDCP also provides a mechanism for efficiently transmitting user data such as IP packets and Ethernet frames over wireless sections. The protocol used for IP packet header compression and decompression may be called ROHC (Robust Header Compression) protocol. The protocol used for Ethernet frame header compression and decompression is EHC (Ethernet (registered trademark) PDCP may be called the Header Compression Protocol (PDCP). PDCP may also have a function for encrypting and decrypting data. PDCP may also have a function for protecting and verifying the integrity of data. PDCP may also have a function for re-ordering. PDCP may also have a function for retransmitting PDCP SDUs. PDCP may also have a function for discarding data using a discard timer. PDCP may also have a duplication function. PDCP may also have a function to discard duplicated received data. The PDCP entity is a bidirectional entity and may consist of a transmitting PDCP entity and a receiving PDCP entity. The PDCP PDU format used in E-UTRA PDCP may differ from the PDCP PDU format used in NR PDCP. PDCP PDUs include There may be a PDCP PDU for data and a PDCP PDU for control. The PDCP PDU for data may be called a PDCP DATA PDU (PDCP Data PDU). The PDCP PDU for control may be called a PDCP CONTROL PDU (PDCP Control PDU).

[0054] In addition, Sidelink has the following restrictions on PDCP functions and services: . (1) Out-of-order delivery is supported only for unicast transmission. That's fine. (2) Duplication on the PC5 interface is not supported.

[0055] An example of the SDAP function is explained below. SDAP is a service data adaptation protocol layer (SDAP). In the sidelink, the SDAP is a data adaption protocol layer (DAPA). The sidelink QoS flow (PC5 QoS flow) and sidelink data sent from the The SDAP may have a function of mapping the QoS flow ID (QoS Flow ID: QFI) and the PC5 QoS flow ID (PC5 QoS Flow ID: PQFI or PFI). The SDAP PDU may have a function for controlling the data. The SDAP PDU may be a data SDAP PDU and a control SDAP PDU. The data SDAP PDU is called an SDAP DATA PDU (SDAP Data PDU). Also, the SDAP PDU for control may be called SDAP CONTROL PDU (SDAP Control PDU). In the side link, the SDAP entity of the terminal device is called the SDAP control PDU. The property is the unicast transmission, groupcast transmission, and There may be one per destination for either forwarding, forwarding, or broadcast transmissions. Also, reflective QoS is not supported on PC5 interfaces.

[0056] An example of the RRC function is described below. The RRC is a function for communicating between peer UEs on the PC5 interface. The PC5-RRC protocol may support services and functions such as forwarding PC5-RRC messages for the UE, maintenance and release of PC5-RRC connection between two UEs, detection of sidelink radio link failure for PC5-RRC connection. A PC5-RRC connection is a logical connection between two UEs corresponding to a pair of source L2ID and destination L2ID, and is considered to be established after the corresponding PC5 unicast link is established. There is a one-to-one correspondence between PC5-RRC connection and PC5 unicast link. A UE may have multiple PC5-RRC connections to one or multiple UEs for different pairs of source L2ID and destination L2ID. Separate PC5-RRC procedures and messages may be used by the UE to forward UE capabilities and sidelink configuration to a peer UE. Both peer UEs may also exchange their UE capabilities and sidelink configuration with each other using a separate bidirectional procedure. If they are not interested in sidelink transmissions, they may not use sidelink for PC5-RRC connections. When a link radio link failure is detected and the Layer 2 link release procedure is completed, If so, the UE releases the PC5-RRC connection.

[0057] A UE performing sidelink transmission may transmit a PSCCH and a PSSCH in association with each other. Note that sidelink transmission is performed via a physical channel for sidelink (PSBCH, PSSCH, PSCCH, etc.). The sidelink transmission may be a transmission of a signal and / or data (message), and the sidelink reception may be a reception of a signal and / or data (message) via a physical channel for the sidelink. In addition, communication using the sidelink transmission and the sidelink reception may be referred to as sidelink communication. The UE may recognize the data (message) based on the signal. Each PSSCH transmission may be associated with a PSCCH (a PSCCH) transmission. The PSCCH transmission may carry a 1st stage of the SCI (SCI) associated with the PSSCH transmission, and a 2nd stage of the SCI (SCI) may be carried within resources of the PSSCH (the PSSCH). In addition, the PSCCH transmission may include the 1st SCI, and the PSSCH transmission may include the 2nd SCI. In addition, the PSS ... In addition, PSCCH transmission and PSSCH transmission may be referred to as sidelink transmission, and SCI is a sidelink The first SCI may be sidelink control information (Sidelink Control Information). The first SCI may include information in a format called SCI format 1-A, and may be used for scheduling the PSSCH and the second SCI on the PSSCH. The SCI format 1-A may include information such as data priority, frequency and time resources on which the PSSCH is transmitted, a resource reservation period, a DMRS allocation pattern, a second SCI format, an indication value of a beta offset, the number of DMRS ports, a modulation scheme, and the like. and coding scheme, and other information may be included. Also, the SCI carried on the PSSCH may be a second SCI, and the second SCI may include sidelink scheduling information and / or inter-UE coordination related information. The second SCI may be SCI format 2-A, SCI format 2-B, or SCI format 2-A, SCI format 2-B, and SCI format 2-C may include information such as HARQ process related information, information indicating whether the data is new, a redundancy version, a source ID for identifying a source UE, a destination ID for identifying a destination UE, and information indicating whether HARQ feedback is possible. SCI format 2-A may additionally include information indicating a cast type and information indicating whether channel state information (CSI) is requested. Format 2-B may additionally include a zone identifier and required information regarding communication range. Furthermore, SCI format 2-C may additionally include information indicating whether to request channel state information, and information indicating whether to provide or request inter-UE coordination information. When SCI format 2-C includes information providing inter-UE coordination information, SCI format 2-C may additionally include information such as information indicating a resource combination, information indicating a first resource position, position information of a reference slot, information indicating a type of resource set, and a lowest subchannel index. When SCI format 2-C includes information requesting inter-UE coordination information, SCI format 2-C may additionally include information such as priority, number of subchannels, resource reservation interval, position of a resource selection window, and information indicating a type of resource set. Each SCI format may include information other than the above information. .

[0058] Next, the procedure of the UE receiving the PSSCH will be described. When the UE detects SCI format 1-A on the PSCCH, it can decode the PSSCH according to the detected SCI format 2-A or SCI format 2-B and the associated PSSCH resource configuration configured by the higher layer. Note that the UE may decode more than one PSCCH in each PSCCH resource candidate. In addition, if the UE does not support the modulation and coding scheme indicated in SCI Format 1-A, the UE does not need to decode the corresponding SCI Format 2-A and SCI Format 2-B, and the PSSCH associated with SCI Format 1-A.

[0059] In addition, if the UE is configured in the parameter indicating whether the DMRS used for L1 RSRP measurement during the sensing operation is the DMRS of the PSCCH or the DMRS of the PSSCH at the higher (RRC) layer, Measure the PSSCH RSRP from the DMRS resource element for the PSSCH associated with the received SCI format 1-A, and if the PSCCH is configured, The PSCCH RSRP may be measured from the DMRS resource elements for the .

[0060] A terminal device capable of sidelink communication may perform discovery. Discovery may include Model A and Model B. The protocol for the discovery procedure is shown in Figure 4. The stack is described below. Mode A may use a single discovery protocol message, and Model B may use two discovery protocol messages. A discovery protocol message in Model B may be an announcement message, and a discovery protocol message in Model B may be a solicitation message. The announcement message, invitation message, and response message may be collectively called discovery messages, and other messages used in the discovery procedure may be called discovery messages. The following is an outline of the procedures of Model A and Model B in ProSe Direct Discovery.

[0061] In Model A, a UE that transmits an announcement message may be called an announcing UE, and a UE that monitors the announcement message may be called a monitoring UE. The announcement message may include the type of discovery message, ProSe Ap The Announce message may include information such as the Destination Layer-2 ID (L2ID) or the ProSe Restricted Code, security protection element, and may additionally include metadata information. The Announce message is sent using a Destination Layer-2 ID and a Source Layer-2 ID, and the monitored UE determines the Destination Layer-2 ID to receive the Announce message. Note that the destination L2ID may be a Layer-2 identifier of the destination UE, and the source L2ID may be a Layer-2 identifier of the source UE. The destination UE may simply be referred to as the destination.

[0062] In Model B, a UE that sends an invitation message may be called a discoverer UE. Instead, a UE that receives an invitation message and / or a UE that sends a response message to a discoverer UE may be referred to as a discoveree UE. The invitation message may include information such as a type of discovery message, a ProSe Query Code, and a security protection element. The invitation message is sent using a destination L2ID and a source L2ID, and the discoveree UE determines a destination L2ID to receive the invitation message. The discoveree UE that responds to the invitation message sends a response message. The response message may include information such as a type of discovery message, a ProSe Response Code, and a security protection element, and may additionally include metadata information. The response message is sent using a source L2ID, and the destination L2ID is set to the source L2ID of the received invitation message.

[0063] Discovery may include types other than ProSe Direct Discovery, which discovers other UEs in order to communicate directly with them, such as Group member Discovery, which discovers one or more UEs in order to communicate within a group using a sidelink, and 5G ProSe UE-to-Network Relay Discovery, which discovers candidate relay UEs in order to connect to the network via a relay UE. The above-mentioned discovery is implemented by an application called ProSe. In addition to the above-mentioned types, there may be different types of discovery depending on the application or service that performs sidelink communication. Also, depending on the type of discovery, the information included in the discovery protocol message may be different, or additional messages may be sent to transmit additional information.

[0064] FIG. 4 is a diagram showing an example of a protocol configuration including a discovery protocol according to this embodiment. As shown in Figure 4, the discovery plane, including the discovery protocol, The protocol stack includes a PHY (Physical layer) 200 which is a wireless physical layer, a MAC (Medium Access Control) 202 which is a medium access control layer, The RLC 204 may be a radio link control layer, a packet data convergence protocol layer, and a discovery protocol layer, Discovery 400. Discovery 400 is a discovery protocol layer. The interface between UEs performing discovery may be referred to as PC5-D.

[0065] A plurality of resource pools for transmitting messages (discovery messages) used in discovery procedures may be set. One or more resource pools may be configured exclusively for discovery. If a resource pool dedicated to discovery is configured, the UE may use the resource pool dedicated to discovery as the resource pool for transmitting discovery messages, and if a resource pool dedicated to discovery is not configured, the UE may use the resource pool for sidelink communication as the resource pool for transmitting discovery messages. Note that multiple resource pools for sidelink communication and multiple resource pools dedicated to discovery may be configured at the same time. Each resource pool may be configured by UE-dedicated signaling, It may be set in advance.

[0066] It also explains the Direct Communication Request (DCR) message. The direct communication request message may be a message used to establish a unicast link. The DCR message may include at least an identifier of the source UE and may include a target UE identifier. If the target UE's identifier is provided by the application layer, it may contain the target UE's identifier, and may also contain other information, such as security information and application information. The DCR message also uses the source L2 ID and destination L2 ID to identify the unique The discovery message and the DCR message may be transmitted via a sidelink or a broadcast.

[0067] For each unicast PC5-RRC connection, a sidelink signaling radio bearer (SRB) may be configured. The sidelink SRB used to transmit PC5-S messages before PC5-S security is established may be referred to as SL-SRB0. A sidelink SRB used to transmit a PC5-S message for establishing PC5-S security may be referred to as SL-SRB1. A sidelink SRB used to transmit a protected PC5-S message after PC5-S security is established may be referred to as SL-SRB2. A sidelink SRB used to transmit a protected PC5-RRC signaling after PC5-S security is established may be referred to as SL-SRB3. A sidelink SRB used to transmit and / or receive discovery messages in NR may be referred to as SL-SRB4. The PC5-RRC signaling may be RRC signaling between UEs transmitted and received on PC5. The PC5-RRC signaling may be a PC5-RRC message. It may also be called sage.

[0068] UE-to-UE relay is a method in which a source UE communicates with a destination UE via sidelink communication with a relay UE. A relay UE may be a technology for communicating via a source UE. A relay UE may have a function and / or role of forwarding (or relaying) data for a destination UE received from a source UE to the destination UE. The source UE, destination UE, and relay UE may be called by different names. For example, the source UE and destination UE may be called remote UE or U2U Remote UE, and the relay UE may be called U2U relay UE. The term UE-to-UE relay may be called U2U relay. The term remote UE may be replaced with the term End UE. It may be said.

[0069] Figures 6 and 7 show examples of protocol stacks for the control plane (CP) and user plane (UP) in a Layer 2 (L2) UE-to-UE (U2U) relay. 7, an SRAP 600 may be present. The SRAP 600 may be called a SRAP layer (Sidelink Relay Adaptation Protocol layer), SRAP layer, etc. As shown in Fig. 6 and Fig. 7, PHY200, MAC202, RLC204, and SRAP600 may be associated between a remote UE and an L2 U2U relay UE, and between an L2 U2U relay UE and other remote UE, respectively, and PDCP206, RRC208, and SDAP310 may be associated between a remote UE and other remote UE. As shown in Fig. 2, a PC5-S210 (not shown) may be used instead of RRC208 to control the PC5 connection between the remote UE and other remote UE. In the protocol stack for Layer 3 (L3) UE-to-UE relay, PHY200, MAC202, RLC204, PDCP206, RRC208, and SDAP210 may be associated between a remote UE and an U2U relay UE, and between an L2 U2U relay UE and other remote UE, respectively. The SRAP 600 may not be configured ( (not shown). In the L3 U2U relay, the layers above SDAP receive data on the Uu link. on the PC5 link. The SRAP layer may be included in the AS layer.

[0070] Here, we will explain the SRAP layer. The SRAP layer is also called the SRAP sublayer or simply SRAP. The SRAP sublayer provides control and user plane support for the PC5 interface. It may reside above the RLC sublayer for the control plane and below the PDCP sublayer for the user plane of the PC5 interface. The SRAP sublayer on PC5 is used for bearer mapping purposes. In the L2 U2U Relay UE, the SRAP sublayer includes one SRAP entity on the PC5 interface between the source UE and the relay UE, and one SRAP entity on the PC5 interface between the relay UE and the destination UE. This includes separate collocated SRAP entities on the interface. In an L2 U2U Remote UE, the SRAP sublayer may include only one SRAP entity on one PC5 interface. The associated SRAP entity may be specifically referred to as PC5-SRAP. Each SRAP entity may have a transmitter and a receiver. On the PC5 interface, the SRAP entity of the L2 U2U Remote UE The transmitter of the SRAP entity is associated with the receiver of the SRAP entity of the L2 U2U Relay UE. Usually, the receiver of the SRAP entity of the L2 U2U Remote UE receives the SRAP entity of the L2 U2U Relay UE. The cellular network may be associated with a transmitting portion of the cellular network.

[0071] The SRAP entity also has a function of forwarding data, a function of determining the UE ID field and the bearer ID field of the SRAP header to be added to the data packet, and a function of determining an exit link. It may have other functions in addition to the above. It may be possible.

[0072] In addition, when a remote UE transmits data for a side link to another remote UE, the remote UE may be referred to as a source UE, and the other remote UE may be referred to as a destination UE. Similarly, in the reverse case, when another remote UE transmits data for a side link to a remote UE, the other remote UE may be referred to as a source UE, and the remote UE may be referred to as a destination UE. The source UE may be referred to as a source remote UE, or simply as a remote UE, or may be interchangeable. The destination UE may be referred to as a destination remote UE, or simply as a remote UE, or may be interchangeable. The source UE and the destination UE may be identified by different names, or may be referred to as a U2U source UE, a U2U destination UE, or the like, in order to clarify that they are terminals performing U2U relay. In addition, in order to clarify that communication is performed by L2 U2U relay, For example, they may be referred to as L2 U2U source UE, L2 U2U destination UE, etc., and similarly, when it is made clear that communication is performed via an L3 U2U relay, they may be referred to as, for example, L3 U2U source UE, L3 U2U destination UE, etc. Not only when either a remote UE or another remote UE transmits data for sidelink, but also when forming a certain U2U relay pair (a pair of one remote UE, one relay UE, and another remote UE), a UE that transmits a discovery message first other than the U2U relay UE may be referred to as a source UE, and a UE that is neither a source UE nor a U2U relay UE in the U2U relay may be referred to as a destination UE, or names such as source UE and destination UE may be used simply to distinguish between two remote UEs.

[0073] The UE also uses discovery messages and / or direct communication messages to perform U2U relay. For example, to select a relay UE for U2U relay, The source UE may then send a discovery message or a communication request message directly to the source UE. In this case, the discovery is Model B discovery. A UE (a relay UE candidate) that receives a discovery message or a direct communication request message transmitted from a source UE may transmit a discovery message or a direct communication request message to a destination UE. Also, a UE (a relay UE candidate) may transmit a discovery message and / or a direct communication request message to a source UE. The discovery in this case may be a Model A discovery.

[0074] In the sidelink, the reference signal received power (RSRP) measured by the UE The nal Received Power may be, for example, the following RSRP: (a) PSBCH RSRP (b) PSSCH RSRP (c) PSCCH RSRP

[0075] PSBCH-RSRP (PSBCH RSRP) is a set of multiple demodulation reference signals (DRMs) associated with the PSBCH. The power distribution of resource elements that transmit the Dynamic Multipath Reference Signal (DMRS) is The PSSCH-RSRP (PSSCH RSRP) may be defined as the linear average of the power contributions of the resource elements of the antenna ports transmitting the multiple DMRSs associated with the PSSCH, and in the case of multiple antenna ports, the values ​​of the RSRP for each antenna port may be summed. The PSCCH-RSRP (PSCCH RSRP) may be defined as the linear average of the power contributions of the resource elements of the antenna ports transmitting the multiple DMRSs associated with the PSSCH, and in the case of multiple antenna ports, the values ​​of the RSRP for each antenna port may be summed. The power contribution of the resource elements carrying multiple associated DMRSs may be defined as the linear average of the power contributions of the resource elements carrying multiple associated DMRSs, e.g., for demodulating the PSBCH, PSSCH, and PSCCH signals. In addition, a terminal device that performs sidelink communication with another terminal device may measure the RSRP of the sidelink communication (SL-RSRP) using the PSSCH or PSCCH transmitted from the other terminal device. In addition, the terminal device may use the power contribution of the resource element that transmits the DMRS associated with the PSSCH that carries the discovery message to transmit the discovery message. Alternatively, the RSRP of the message (SD-RSRP) may be measured.

[0076] In addition to the above-mentioned RSRP, the UE 122 also measures the following quantities in the sidelink: may be measured. (a) Sidelink received signal strength indicator (SL RSSI) (b) Sidelink channel occupancy ratio (SL CR) (c) Sidelink channel busy ratio (SL CBR)

[0077] The SL RSSI is the line of power ([W]) observed on the configured subchannels in the OFDM symbols of the slots configured for PSCCH and PSSCH, starting from the second OFDM symbol. The SLCR in slot n may be defined as the shape average. It may be defined as the sum of the number of subchannels used for sidelink transmission from slot [n] to slot [n-1] and the number of subchannels allocated from slot [n] to slot [n+b] divided by the total number of subchannels set from slot [na] to slot [n+b]. In addition, the SL CBR in slot n is determined by determining whether the SL RSSI exceeds a threshold in the resource pool during a period set as a CBR measurement window (from slot [na] to slot [n-1]). The ratio may be defined as the percentage of subchannels that are

[0078] There are two resource allocation modes for NR sidelink communication, Therefore, the mode in which the UE performs sidelink transmission using scheduled resources is called mode 1, and the mode in which the UE automatically selects resources and performs sidelink transmission is called mode 2. In mode 1, the UE must be RRC_CONNECTED, and in mode 2, the UE can perform sidelink transmission regardless of the RRC state or whether it is inside or outside NG-RAN. The UE then automatically selects resources available for sidelink transmission from one or more resource pools configured prior to the sidelink transmission.

[0079] The operation of the transmitting SDAP entity in sidelink communication will be described. When receiving an SDAP SDU for a certain PC5 QoS flow from an upper layer (such as the application layer), if a mapping rule between the PC5 QoS flow and the SL-DRB for the PC5 QoS flow is not stored, the transmitting SDAP entity maps the SDAP SDU to a default SL-DRB, and if a mapping rule between the PC5 QoS flow and the SL-DRB for the PC5 QoS flow is stored, the transmitting SDAP entity maps the SDAP SDU to the SL-DRB according to the mapping rule. In addition, the transmitting SDAP entity ensures that an SDAP header exists in the SL-DRB to which the SDAP SDU is mapped. If configured by RRC to have an SDAP header in the SL-DRB to which the SDAP SDU is mapped, the sending SDAP entity constructs an SL SDAP data PDU with an SDAP header, if configured by RRC to have an SDAP header in the SL-DRB to which the SDAP SDU is mapped, and constructs an SL SDAP data PDU without an SDAP header, if not configured by RRC to have an SDAP header in the SL-DRB to which the SDAP SDU is mapped, and submits the constructed SL SDAP PDU to the lower layer (e.g., the PDCP layer).

[0080] This section describes the operation of the receiving SDAP entity in sidelink communication. When an SDAP data PDU for a certain PC5 QoS flow is received from a lower layer (such as the PDCP layer), the receiving The receiving SDAP entity checks whether the SDAP header exists in the SL-DRB that received the SL SDAP data PDU. If the SL-DRB that received the SL SDAP data PDU is configured by RRC to have an SDAP header, it obtains the SDAP SDU from the SL SDAP data PDU with an SDAP header, and if the SL-DRB that received the SL SDAP data PDU is not configured by RRC to have an SDAP header, it obtains the SDAP SDU from the SL SDAP data PDU without an SDAP header. The receiving SDAP entity then passes the acquired SDAP SDU to a higher layer (such as the application layer).

[0081] Next, the mapping between the PC5 QoS flow and the SL-DRB will be described. When the RRC sets the mapping between the PC5 QoS flow and the SL-DRB for the PC5 QoS flow, the SDAP entity For unicast sidelink communication, (1) an SDAP entity is already established. (2) If the mapping rule of the SL-DRB for the PC5 QoS flow is not stored, and (3) a default SL-DRB is set, an end marker control PDU is sent to the PC5 QoS flow. and generating an end marker control PDU, mapping the end marker control PDU to a default SL-DRB, and In addition, when RRC configures a mapping between PC5 QoS flow and SL-DRB for PC5 QoS flow, the SDAP entity performs the following operations for unicast NR sidelink communication: (1) retrieving the stored mapping between PC5 QoS flow and SL-DRB. The mapping rule for PC5 QoS flow and SL-DRB is different from that for the SL-DRB. If the RRC configures that the SL SDAP header is present in the SL-DRB that conforms to the mapping rule assigned to the SL-DRB, an end marker control PDU is generated for the PC5 QoS flow, and the end marker control PDU is generated for the PC5 QoS flow. The marker control PDU is mapped to the SL-DRB according to the stored mapping rule. The SDAP entity also submits the end marker control PDU to the lower layer (such as the PDCP layer). The RRC stores the mapping rule between the PC5 QoS flow and the SL-DRB set for the PC5 QoS flow. When releasing a group rule, the SDAP entity deletes the mapping rule. Also, when the RRC indicates that a certain SL-DRB is to be released, the SDAP entity Release all mapping rules between the PC5 QoS flows and the SL-DRB associated with the .

[0082] The header added to the SL SDAP data PDU indicates that the SDAP PDU is an SDAP data PDU. The end marker control PDU may include information indicating the ID of the PC5 QoS flow to which the SL SDAP data PDU belongs (PQFI or PFI: PC5 QoS flow ID). In addition, the end marker control PDU may include information indicating the ID of the PC5 QoS flow to which the SL SDAP data PDU belongs (PQFI or PFI: PC5 QoS flow ID) by the SDAP entity. This is a control PDU used to indicate that the SL-DRB to which the The header added to the end marker control PDU may include information indicating that the SDAP PDU is an SDAP control PDU, and a PQFI.

[0083] In addition, PC5 QoS flow is the finest granularity of QoS forwarding processing in the sidelink. All traffic (data) mapped to the same PC5 QoS flow will be forwarded in the same order (scheduled). Each packet is subject to different PC5 QoS rules (e.g., scheduling policy, queue management policy, rate shaping policy, RLC setting, etc.). Different PC5 QoS flows are required to provide different forwarding treatments. A PC5 QoS flow is associated with a PC5 QoS rule and a PC5 QoS parameter. The PC5 QoS parameters include PQI (PC5 5QI (5G QoS Identifier)), PC5 Flow Bit Rates, PC5 Link Aggregated Bit Rates, Range, Default Value, etc. The PQI is used as a reference for PC5 QoS characteristics, i.e. parameters that control the QoS forwarding treatment of packets via PC5, and the PC5 QoS characteristics are The parameters include resource type, priority level, packet delay budget (PDB), packet error rate (PER), averaging window, and maximum data burst volume. The PDB is a parameter that represents the packet delay between a transmitting UE and a receiving UE on the PC5. In addition, the UE may associate traffic (data) with a QoS flow based on the QoS rule.

[0084] The UE that receives a packet from the application layer matches the packet based on the PC5 QoS rule. If it is determined that a PC5 QoS flow does not exist, it is If requirements are provided by the QoS manager, determine the PC5 QoS parameters according to said requirements, and if said requirements exist, If no PC5 QoS flow satisfies the determined PC5 QoS parameters, the UE determines the PC5 QoS parameters according to the mapping between the service type and the PC5 QoS parameters. If no PC5 QoS flow satisfies the determined PC5 QoS parameters, the UE creates a new PC5 QoS flow that satisfies the determined PC5 QoS parameters, assigns a PFI and a PC5 QoS rule to the new PC5 QoS flow, and if a PC5 QoS flow satisfies the determined PC5 QoS parameters, creates a new PC5 QoS flow that satisfies the determined PC5 QoS parameters. Updates the raw PC5 packet filter set.

[0085] Various embodiments of the present invention will be described based on the above description. Note that the above-described processes may be applied to processes that are omitted in the following description.

[0086] Fig. 5 is a block diagram showing the configuration of a terminal device (UE 122) in this embodiment. In order to avoid a complicated explanation, Fig. 5 shows only main components closely related to this embodiment. Show only.

[0087] The UE 122 shown in FIG. 5 includes a receiver 500 that receives control information (SCI, MAC control element, RRC signaling, etc.), discovery messages, information including user data, and the like from other terminal devices, a processor 502 that performs processing according to parameters included in the received control information, and and other terminal devices, control information (SCI, MAC control elements, RRC signaling, etc.) and discovery A transmission unit 504 for transmitting information including a message and user data. The processing unit 502 may include some or all of the functions of various layers (e.g., a physical layer, a MAC layer, an RLC layer, a PDCP layer, a SRAP layer, a SDAP layer, an RRC layer, a PC5-S layer, a discovery layer, and an application layer). That is, the processing unit 502 includes a physical layer processing unit (PHY processing unit), a MAC layer processing unit (MAC processing unit), an RLC layer Processing section (RLC processing section), PDCP layer processing section (PDCP processing section), SRAP layer processing section (SRAP processing section), SDAP layer processing section Management unit (SDAP processing unit), RRC layer processing unit (RRC processing unit), PC5-S layer processing unit (PC5-S processing unit), Discovery It may include a layer processing unit (discovery processing unit) and some or all of an application layer processing unit. In addition, the ProSe layer, the V2X layer, etc. may be included as part of the application layer, and an application layer that provides services to the ProSe layer, the V2X layer, etc. may exist above the ProSe layer or the V2X layer.

[0088] FIG. 8 shows an example of an embodiment of the present invention.

[0089] In step S800, the UE 122 capable of sidelink communication receives data from an upper layer. In step S802, a determination is made based on the data, and a first terminal device is notified based on the determination. The first information is transmitted.

[0090] In step S800, the data is an SDAP SDU for a certain PC5 QoS flow. In addition, in step S800, the UE 122 may perform some or all of the following determinations: stomach. (Ca) There is a mapping rule between the PC5 QoS flow and the SL-DRB. (Cb) The UE 122 acts as an L2 U2U remote UE.

[0091] If it is determined that both the conditions (Ca) and (Cb) are satisfied, and if the condition (Ca) is not satisfied, If it is determined that the condition (Cb) is satisfied, the first Alternatively, if it is determined that the condition (Ca) is not satisfied and the condition (Cb) is satisfied, the UE 122 may transmit the first information. , which may include, for example, some or all of the following information: (Ia) information identifying the PC5 QoS flow (e.g., PFI or PQFI); (Ib) Mapping rule between the PC5 QoS flow and the SL-DRB set by the UE 122 (Ic) PQI mapped to the PC5 QoS flow (Id) An identifier for identifying the UE 122 (Ie) Mapping rule between the SL-DRB and the RLC channel (PC5 relay RLC channel) of the UE 122

[0092] For example, the first terminal device that has received the first information may The mapping between the SL-DRB and the RLC channel may be performed taking into consideration the mapping rule. The SL-DRB may be an End-to-End (E2E) SL-DRB terminated at a second terminal via a first terminal device from the UE 122, and the RLC channel may be The RLC channel may be an RLC channel used by the first terminal device to transfer the data. The RLC channel may be called a PC5 Relay RLC Channel or may be called by another name. Note that the first terminal device cannot map the SL-DRB and the RLC channel in consideration of the mapping rule between the PC5 QoS flow and the SL-DRB. In this case, that is, when it is determined that transmission satisfying QoS is not possible, information indicating that the mapping between the SL-DRB and the RLC channel cannot be performed may be transmitted to the UE 122, and the mapping between the SL-DRB and the RLC channel may be performed in consideration of the mapping rule between the PC5 QoS flow and the SL-DRB. When the SL-DRB is mapped, that is, when it is determined that the SL-DRB can be transferred while satisfying the QoS, the UE 122 may transmit information indicating that the SL-DRB and the RLC channel have been mapped. The first terminal device that has performed the mapping between the SL-DRB and the RLC channel may transmit information indicating whether or not the mapping between the SL-DRB and the RLC channel has been completed to the UE 122. Note that the first terminal device that has performed the mapping between the SL-DRB and the RLC channel may transmit data including information identifying the SL-DRB to the second terminal device via the RLC channel.

[0093] The first terminal device determines whether or not it is possible to map the SL-DRB and the RLC channel in consideration of the mapping rule between the PC5 QoS flow and the SL-DRB, based on the path quality between the first terminal device and the UE 122, and between the first terminal device and the second terminal device. The path quality may be determined as SL CBR (Sidelink Channel Busy Ratio). It can be RSRP (Reference Signal Received Power) or SL path loss. The determination may be based on the modulation and coding scheme (MCS) used for sidelink transmission, or on other information.

[0094] The UE 122 sets up a mapping between the PC5 QoS flow and the SL-DRB, and in addition, sets up a mapping rule between the SL-DRB and the RLC channel (PC5 Relay RLC channel) of the UE 122. When the mapping rule between the SL-DRB and the RLC channel is set, In this case, a setting regarding a mapping rule between the SL-DRB and the RLC channel may be transmitted to the first terminal device.

[0095] Also, for example, the first terminal device that has received the first information may transmit to the UE 122 a mapping rule between an SL-DRB that satisfies QoS and a PC5 QoS flow, that is, a setting of the SDAP layer. In addition, the mapping rule between the SL-DRB and the RLC channel, i.e., the SRAP layer The UE 122 may transmit the SDAP layer configuration to the UE 122. Configure the SDAP layer according to the layer configuration, and map the PC5 QoS flow according to the mapping rule. The PC5 QoS flow may be mapped to an SL-DRB already configured in the UE 122, or a new SL-DRB may be established for the PC5 QoS flow. The PC5 QoS flow may be mapped to the established SL-DRB. The configuration of the SRAP layer and / or the SRAP layer is performed by an RRC message (such as RRCReconfigurationSidelink). The received signal may be transmitted to the UE 122 via the UE 122 .

[0096] In addition, the first terminal device that has received the first information performs a mapping between the PC5 QoS flow and the SL-DRB. Based on the routing rule, the RLC channel or logical channel to which the SL-DRB is mapped is determined. In addition, the remaining PDB may be set based on a PC5 QoS rule or a PC5 QoS parameter associated with the PC5 QoS flow. In addition, the remaining PDB may be set based on the number of relay nodes (U2U relay UEs) existing between the UE 122 and the second terminal device. The device may select resources to be used for sidelink transmission taking into account the remaining PDB. stomach.

[0097] Furthermore, when transmitting the data to the first terminal device, the UE 122 may transmit information on the remaining PDB associated with the data. For example, the information on the remaining PDB may be added to the data as an information element of the SRAP layer, or may be included in a transport block including the data as a MAC CE. The first terminal device that receives the information may determine the remaining PDB to be used for transmitting the data based on the information about the remaining PDB.

[0098] In addition, the UE 122 may notify the UE 122 of the addition of a PC5 QoS flow when establishing or modifying the PC5 unicast link (and Layer-2 link) with a peer terminal device. The information about the PC5 QoS flows may be transmitted to and received from peer terminals. The information may be a PFI of the PC5 QoS flow to be added, PC5 QoS parameters (including at least a PQI) corresponding to the PFI, a service type, etc. It may be determined by negotiation with a peer terminal device.

[0099] In addition, the first terminal device may be an L2 U2U relay UE, and the UE 122 and the second terminal device may be an L2 U2U remote UE. In addition, the UE 122 may communicate with the second terminal device via the first terminal device, and the UE 122 may communicate with the first terminal device and The communication with the second terminal device may be performed via a plurality of other terminal devices. The additional terminal device may have the functionality to perform the same operations as the first terminal device.

[0100] In each embodiment, the first terminal device, the second terminal device, and the other terminal devices are terminal devices capable of sidelink communication, similar to the UE 122, and include a receiving unit, a processing unit, and It may be a terminal device having a configuration including a transmitting unit, or may be called by another name.

[0101] Conventional PC5 QoS processing in NR assumes that data is relayed by the UE. If the data is relayed, it may not be possible to transmit data that satisfies PC5 QoS. By this explanation, we can consider the end-to-end PC5 QoS even when the data is relayed by the UE. This will enable transmission of the message.

[0102] In addition, in the above description, expressions such as "to be notified" and "to be pointed out" may be interchangeable.

[0103] In addition, in the above description, expressions such as "link," "associate," and "link" may be interchangeable.

[0104] In the above description, the terms "included," "included," "included," etc. may be interchangeable.

[0105] In the above description, "the above-mentioned" may be replaced with "the above-mentioned."

[0106] In the above explanation, "confirmed to be...", "set to...", "includes..." Expressions such as the above may be interchangeable.

[0107] Furthermore, in each of the process examples or process flow examples in the above description, some or all of the steps may not be executed. Furthermore, in each of the process examples or process flow examples in the above description, the order of the steps may be different. Furthermore, in each of the process examples or process flow examples in the above description, some or all of the processing within each step may not be executed. Furthermore, in each of the process examples or process flow examples in the above description, the order of the processing within each step may be different. Furthermore, in the above description, "doing B based on A being true" may be rephrased as "doing B". In other words, "doing B" is "being A" may be executed independently.

[0108] In the above explanation, "A may be replaced with B" may mean replacing A with B, as well as replacing B with A. In the above explanation, when it is written that "C may be D" and "C may be E", it may also mean that "D may be E". In the above explanation, when it is written that "F may be G" and "G may be H", it may also mean that "F may be H".

[0109] In the above explanation, if condition "A" and condition "B" are contradictory conditions, condition "B" may be expressed as the "other" condition of condition "A."

[0110] The program that runs on the device according to this embodiment may be a program that controls a Central Processing Unit (CPU) or the like to make a computer function so as to realize the functions of this embodiment. The program or information handled by the program is temporarily loaded into a volatile memory such as a Random Access Memory (RAM) during processing, or is stored in a flash memory. The information is stored in non-volatile memory such as a memory or a hard disk drive (HDD) and is retrieved by the CPU as needed. Reading, modifying and writing are performed by this.

[0111] It should be noted that a part of the device in the above-mentioned embodiment may be realized by a computer. In that case, a program for realizing this control function may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed to realize the control function. The "computer system" here refers to a computer system built into the device, and includes hardware such as an operating system and peripheral devices. The "computer-readable recording medium" may be any of a semiconductor recording medium, an optical recording medium, a magnetic recording medium, and the like.

[0112] Furthermore, the term "computer-readable recording medium" includes those that dynamically hold a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, and those that hold a program for a certain period of time, such as a volatile memory inside a computer system that is a server or client in such a case. The program may be for implementing part of the above-mentioned functions, or may be a program that already has the above-mentioned functions recorded in a computer system. It may be possible to realize this in combination with

[0113] Also, each functional block or feature of the device used in the above-described embodiment may be implemented or executed by an electric circuit, i.e., typically an integrated circuit or a plurality of integrated circuits. The electric circuit designed to execute the functions described herein may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable logic circuit (PLC), or a combination of such circuits. The general purpose processor may include a general purpose gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, controller, microcontroller, or state machine. The general purpose processor, or each of the aforementioned circuits, may be composed of digital circuits or analog circuits. Also, when an integrated circuit technology that replaces current integrated circuits emerges due to advances in semiconductor technology, an integrated circuit based on that technology may be used.

[0114] It should be noted that the present embodiment is not limited to the above-mentioned embodiment. In the embodiment, an example of the device is described, but the present embodiment is not limited to this, and can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as terminal devices or communication devices of AV devices, kitchen devices, cleaning / washing devices, air conditioners, office devices, vending machines, and other household appliances.

[0115] Although this embodiment has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes within the scope of the gist of this embodiment are also included. In addition, this embodiment can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this embodiment. In addition, configurations in which elements described in the above embodiment are replaced with elements that have the same effect are also included. [Explanation of symbols]

[0116] 100 ng-eNB 102 gNB 110, 112, 114 Interface 122UE 200 PHY 202 MAC 204 RLC 206 PDCP 208 RRC 210 PC5-S 310SDAP 400 Discovery 500 Receiver 502 Processing section 504 Transmitter 600 SRAP

Claims

1. A first terminal device capable of sidelink communication, It has a transmitting unit, The first terminal device communicates with the third terminal device via the second terminal device through the side-link communication. The transmitting unit transmits the mapping information between the PC5 QoS flow and the SL-DRB to the second terminal device via the sidelink communication. The SL-DRB is an end-to-end SL-DRB terminated between the first terminal device and the third terminal device. The first terminal device.

2. A second terminal device capable of sidelink communication, Processing unit and The system includes a receiving unit that receives first information from a first terminal device via the aforementioned side-link communication, The second terminal device plays the role of relaying communication between the first terminal device and the third terminal device through the side-link communication. The first piece of information includes mapping information between the PC5 QoS flow and the SL-DRB. Based on the first information, the processing unit performs mapping between the SL-DRB and the RLC channel of the second terminal device. The SL-DRB is an end-to-end SL-DRB terminated between the first terminal device and the third terminal device. The second terminal device.

3. A method for a first terminal device capable of sidelink communication, The first terminal device communicates with the third terminal device via the second terminal device through the side-link communication. The sidelink communication includes the step of transmitting mapping information between the PC5 QoS flow and the SL-DRB to the second terminal device, The SL-DRB is an end-to-end SL-DRB terminated between the first terminal device and the third terminal device. method.

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