Terminal device, method, and integrated circuit

Abstract

To enhance service continuity in UE-to-Network relay (U2N Relay), in which a terminal device communicates with a base station device via a relay terminal device.SOLUTION: A terminal device 122 communicates via at least one relay terminal device that communicates with a base station device. The terminal device has an RRC entity, and the RRC entity has a function of receiving an instruction to release a PC5 unicast link from a layer higher than an RRC layer. If a link to which the terminal device is connected is a PC5 unicast link with a relay terminal device communicating with the base station device, the terminal device releases the PC5 unicast link and initiates a procedure for re-establishing an RRC connection with the base station device.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a terminal device, a method, and an integrated circuit. [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-Patent Document 1] 3GPP TS 38.331 v17.3.0," NR; Radio Resource Control (RRC) protocol specification" pp70-116,pp218-223,pp316-1107 [Non-Patent Document 2] 3GPP TS 38.321 v17.1.0, "NR; Medium Access Control (MAC) protocol specification" pp17-104 [Non-Patent Document 3] 3GPP TS 38.213 v17.1.0, "NR; Physical layer procedures for control" pp14-20 [Non-Patent Document 4] 3GPP TS 38.351 v17.1.0, "NR; Sidelink Relay Adaptation Protocol (SRAP) Specification" [Non-Patent Document 5] 3GPP TS 38.322 v17.1.0, "NR; Radio Link Control (RLC) protocol specification" pp13-30 [Non-Patent Document 6] 3GPP TS 38.323 v17.1.0, "NR; Packet Data Convergence Protocol (PDCP) specification" pp13-20,pp33-39 [Non-Patent Document 7] 3GPP TS 38.300 v17.2.0, "NR; NR and NG-RAN Overall Description" pp43-44,pp166-175 Summary of the Invention [Problem to be solved by the invention]

[0006] In 3GPP, as an extension technology of NR, a technology called sidelink (SL) is being considered, in which terminal devices communicate directly with each other without going through the core network. In addition, studies have begun on a technology called UE-to-Network Relay (U2N Relay), in which a relay terminal device provides communication via sidelink, allowing a terminal device to communicate with a base station device via the relay terminal device, as well as on enhancing service continuity in U2N Relay. [Means for solving the problem]

[0007] In order to achieve the above object, one aspect of the present invention provides the following: A first aspect of the present invention provides a method for communicating with a base station device via at least one relay terminal device. A terminal device for performing a PC5 unicast link with a relay terminal device communicating with a base station device, the terminal device having an RRC entity, the RRC entity having a function of receiving an instruction to release a PC5 link from a layer higher than an RRC layer, and If it is a PC5 unicast link, release the PC5 unicast link and re-establish communication with the base station. The function is to initiate a procedure to

[0008] In addition, one aspect of the present invention is a method for communicating with a base station device via at least one relay terminal device. The terminal device has an RRC entity, and the RRC entity has a function of receiving an instruction to release a PC5 link from a layer higher than an RRC layer, and the link to which the terminal device is connected is a PC5 unicast link with a relay terminal device communicating with a base station device. If the PC5 unicast link is a unicast link, the PC5 unicast link is released and communication with the base station is restarted. The method includes at least the step of initiating a procedure for establishing the network.

[0009] In addition, one aspect of the present invention is a method for communicating with a base station device via at least one relay terminal device. an integrated circuit implemented in a terminal device for receiving an RRC message from the base station device, Based on the function and the determination that one or both of the two conditions are not met, a function for setting up a special cell according to the dedicated setting of the special cell included in the RRC message; and a dedicated setting for the special cell is a setting for a special cell and a setting dedicated to the terminal device, the two conditions being that (a) the terminal device plays the role of a remote terminal device, and (b) no direct path is established after applying the RRC message. Effect of the Invention

[0010] One aspect of the present invention has been made in consideration of the above-mentioned circumstances, and has as its object to provide a terminal device, a base station device, a method, and an integrated circuit that can efficiently perform communication control. According to one aspect of the present invention, it is possible to provide a terminal device, a method, and an integrated circuit that realize efficient communication control processing. [Brief description of the drawings]

[0011] [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. 13 is a diagram showing an example of a protocol configuration in a discovery procedure according to the embodiment; [Diagram 5] FIG. 2 is a block diagram showing the configuration of a terminal device according to the embodiment. [Figure 6] FIG. 2 is a block diagram showing the configuration of a base station device according to the embodiment. [Figure 7] FIG. 1 is a diagram showing an example of a protocol configuration in NR according to this embodiment. [Figure 8]FIG. 2 is a diagram showing an example of a protocol configuration of a control plane of an L2 U2N relay according to the embodiment. [Figure 9] FIG. 2 is a diagram illustrating an example of a protocol configuration of a user plane of an L2 U2N relay according to the embodiment. [Figure 10] 4 is an example of processing according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the present embodiment will be described in detail with reference to the drawings.

[0013] In this embodiment, the names of the nodes and entities and the processes in the nodes and entities will be described when the radio access technology is NR, but this embodiment may be applied to other radio access technologies. The name may be a different name.

[0014] 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.

[0015] 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 the E-UTRA protocol described later. The E-UTRA protocol consists of the E-UTRA User Plane (UP) protocol, which will be described later, and and an E-UTRA control plane (CP) protocol described later. The ng-eNB 100 may terminate the E-UTRA user plane protocol and the E-UTRA control plane protocol for the UE 122. A radio access network configured by eNBs may be referred to as E-UTRAN.

[0016] 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 a Uu interface. The gNB (g Node B) 102 may be a base station device of the NR. The gNB 102 may have the NR protocol described below. The NR protocol includes the NR User Plane (UP) protocol described below and the NR Control Plane (CP) protocol described below. The gNB 102 may be configured to transmit an NR user plane protocol to the UE 122. and may terminate NR control plane protocols.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] There are three transmission modes for NR SL communication, and SL communication is performed 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 ID and Destination Layer-2 ID are respectively called Source L2 ID. The three transmission modes are "Unicast transmission", "Groupcast transmission", and "Broadcast transmission". The transmission mode is "cast type, broadcast transmission". Unicast transmission in direct communication is supported on PC5. A PC5 unicast link between two UEs may be established for direct communication. Unicast links may be added, modified, or released according to application layer requests or communication requirements.

[0022] 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.

[0023] Groupcast transmission is also performed between UEs that belong to a sidelink group. (1) Support for sidelink HARQ feedback. do.

[0024] In addition, broadcast transmission is performed for (1) sending and receiving user traffic between UEs on the sidelink It is characterized by faith.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The AS (Access Stratum) layer may be a layer including some or all of the PHY 200, the MAC 202, the RLC 204, the PDCP 206, the SRAP 800, the SDAP 310, and the RRC 208. The Discovery 400 may be a layer higher than the AS layer.

[0029] 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.

[0030] 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, sidelink 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 are sometimes referred to as NR PHY, NR MAC, NR RLC, NR PDCP, and NR RRC, respectively.

[0031] Regarding entities in the AS stratum for E-UTRA, NR and / or sidelink An entity that has some or all of the functions of the physical layer is called a PHY entity. An entity having some or all of the functions 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 referred to as an RLC entity. An entity having some or all of the functions of the PDCP layer may be referred to as a PDCP entity. An entity having some or all of the functions of the SDAP layer may be referred to as an SDAP entity. An entity having some or all of the functions of the RRC layer may be referred to as an RLC entity. The PHY entity, MAC entity, RLC entity, PDCP entity, SDAP entity, and RRC entity may be rephrased as PHY, MAC, RLC, PDCP, SDAP, and RRC, respectively. In addition, each entity in the AS layer corresponds to E-UTRA, NR, and and / or side links may be common entities or may be separate entities. It may be a

[0032] 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.

[0033] Here, the base station device and the terminal device communicate with each other through the higher layer (Uu interface). A base station apparatus and a terminal apparatus exchange (transmit and receive) signals in a higher layer. A higher layer may be referred to as an upper layer, and the two may be interchangeable. For example, a base station apparatus and a terminal apparatus may transmit and receive an RRC message (also referred to as RRC signaling) in a Radio Resource Control (RRC) layer. Also, a base station apparatus and a terminal apparatus may transmit and receive a MAC Control Element (MAC CE) in a Medium Access Control (MAC) layer. Also, the RRC layer of a terminal apparatus acquires system information broadcast from a base station apparatus. 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.

[0034] 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.

[0035] 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. "Submitting a message to a lower layer" means that RRC messages are sent using SRBs (SRB0, SRB1, SRB2, SRB3, etc.), and therefore the PDCP entity corresponding to each SRB is used. 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.

[0036] 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.

[0037] 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.

[0038] PSBCH (Physical Sidelink Broadcast CHannel) PSCCH (Physical Sidelink Control CHannel) PSSCH (Physical Sidelink Shared CHannel) PSFCH (Physical Sidelink Feedback CHannel)

[0039] The PSBCH may be used to broadcast system information required by a terminal device.

[0040] The PSCCH may be used to indicate resources and other transmission parameters for the PSSCH.

[0041] The PSSCH transmits data to other terminal devices and control regarding HARQ / CSI feedback. It may be used to transmit information.

[0042] The PSFCH may be used to carry HARQ feedback to other terminal devices. .

[0043] 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 have the ability to identify Multicast / Broadcast Services (MBS). The MAC is MAC may have the ability to select a packet. The function to perform intermittent transmission (DTX: Discontinuous Transmission), the function to execute the Random Access (RA) procedure, the function to notify the information of the transmittable power, the 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.

[0044] 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).

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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. In addition, both peer UEs may exchange their UE capabilities and sidelink configuration with each other using a separate bidirectional procedure. A UE may not be interested in sidelink transmission for a PC5-RRC connection. When a sidelink radio link failure is detected and the Layer 2 link release procedure is completed, If so, the UE releases the PC5-RRC connection.

[0050] 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 may transmit signals and / or data (messages) or receive sidelink signals. The receiver receives signals and / or data (messages) via a physical channel for the sidelink. In addition, communication using sidelink transmission and 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 transmission. The PSCCH transmission may carry a 1st stage of the SCI associated with the PSSCH transmission, and a 2nd stage of the SCI may be carried within resources of the PSSCH. Note that the PSCCH transmission may include the 1st SCI, and the PSSCH transmission may include the 2nd SCI. Also, 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. In addition, 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. .

[0051] 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.

[0052] 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 a discovery message. Messages with other names used in the discovery procedure may also be called discovery messages. Below is an overview of the procedures for Model A and Model B in ProSe Direct Discovery.

[0053] 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 Announce message may include information such as the type of discovery message, the ProSe Application Code or ProSe Restricted Code, a security protection element, and may additionally include metadata information. The Announce message may include the Destination Layer-2 ID and the Source Layer-2 ID. The Announce message is transmitted using the Destination L2 ID, and the monitoring UE determines a Destination L2 ID for receiving the Announce message. Note that the Destination L2 ID may be a Layer-2 identifier of the destination UE, and the Source L2 ID may be a Layer-2 identifier of the source UE. The destination UE may simply be referred to as the destination.

[0054] 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.

[0055] Discovery may include types other than ProSe Direct Discovery, which discovers other UEs in order to communicate directly with other UEs, 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 terminal devices in order to connect to a network via a relay terminal device. Note that the above-mentioned discovery is called ProSe. In addition to the above-mentioned types, there may be different types of discovery depending on the application or service performing the sidelink communication. Also, depending on the type of discovery, the information included in the discovery protocol message may differ, or additional messages may be sent to transmit additional information.

[0056] 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.

[0057] 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. When a resource pool dedicated for discovery is configured, the UE may use the resource pool dedicated for discovery as a resource pool for transmitting a discovery message, and when a resource pool dedicated for discovery is not configured, the UE may use a resource pool for sidelink communication as a resource pool for transmitting a discovery message. Note that a plurality of resource pools for sidelink communication and a plurality of resource pools dedicated for discovery may be configured at the same time. Each resource pool may be configured by UE-dedicated signaling or may be configured in advance.

[0058] 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.

[0059] Explain Multi-path relay (or Multi-path relaying) Multipath relay may be a technology in which a terminal device communicates with a base station device using two paths, a direct path and an indirect path. The direct path may be a path in which the terminal device communicates directly with the base station device via a Uu interface. The indirect path may be a path in which the terminal device communicates with the base station device via a relay terminal device. The interface between the terminal device and the relay terminal device may be a PC5 interface or a different interface. In addition, The relay terminal device may be a terminal device that plays the role of U2N Relay UE.

[0060] In multi-path relaying, a bearer that is mapped to a direct path may be called a direct bearer, a bearer that is mapped to an indirect path may be called an indirect bearer, and a bearer that is mapped to both direct and indirect paths may be called a multi-path split bearer (MP) or simply a split bearer.

[0061] Here, we will explain UE-to-Network (U2N) relay. U2N relay is a relay that is used by remote terminal equipment. The U2N relay may be a function that provides connectivity to a network for a remote UE. A remote terminal device that connects to a network using a U2N relay may be referred to as a U2N Remote UE. In addition, a terminal device that provides network connectivity to a U2N Remote UE may be referred to as a U2N relay terminal device (Relay UE), or simply as a relay terminal device (Relay UE). The U2N Relay UE may use a Uu interface for communication with a base station device, and may use a Uu interface for communication with a U2N Remote UE. A PC5 interface may be used for transmitting the U2N relay. In addition, there may be types such as a layer 2 (L2) U2N relay and a layer 3 (L3) U2N relay. A remote terminal device in an L2 U2N relay may be particularly referred to as an L2 U2N Remote UE, and a relay terminal device in an L2 U2N relay may be particularly referred to as an L2 U2N Relay UE, and may be particularly referred to as a serving relay terminal device or a serving relay UE. Also, in the L2 U2N relay, a Sidelink Relay Adaptation Protocol (SRAP) layer may exist.

[0062] FIG. 8 is a diagram showing an example of a protocol configuration of a control plane (C-plane) of an L2 U2N relay, including an SRAP layer (SRAP800) according to this embodiment. Also, FIG. 9 is a diagram showing an example of a protocol configuration of a user plane (U-plane) of an L2 U2N relay, including an SRAP layer according to this embodiment. As shown in FIG. 8 and FIG. 9, the SRAP layer may be associated between a Remote UE and a Relay UE, and may be associated between a Relay UE and a gNB102. Note that the gNB102 shown in FIG. 8 and FIG. 9 is an ng-eNB100. In addition, the Remote UE or the Relay UE may be the UE 122. In addition, the Relay UE may have the same configuration as the UE 122.

[0063] Here, we will describe the SRAP layer. The SRAP layer may be called the SRAP sublayer, or simply SRAP. The SRAP sublayer handles the control plane and user interfaces of both the PC5 and Uu interfaces. The SRAP sublayer may reside above the RLC sublayer for the user plane. The SRAP sublayer on PC5 may be used for bearer mapping purposes. In an L2 U2N Relay UE, the SRAP sublayer resides on the Uu interface. In the L2 U2N Remote UE, the SRAP sublayer may include one SRAP entity on the PC5 interface and a separate collocated SRAP entity on the PC5 interface. The SRAP entity associated between the Remote UE and the Relay UE via the PC5 interface is specifically referred to as PC5-SRAP. Alternatively, an SRAP entity associated between a Relay UE and a gNB via a Uu may be specifically referred to as a Uu-SRAP. In addition, to clarify the interface name, other entities may also be expressed in the same format as the SRAP, such as (interface name)-(entity name). Each SRAP entity may have a transmitter and a receiver. On the PC5 interface, the transmitter of the SRAP entity of the L2 U2N Remote UE may be associated with the receiver of the SRAP entity of the L2 U2N Relay UE, and the receiver of the SRAP entity of the L2 U2N Remote UE may be associated with the receiver of the SRAP entity of the L2 U2N Relay UE. Relay may be associated with the transmitter of the SRAP entity of the UE. Also, the Uu interface In the above, the transmission unit of the SRAP entity of the L2 U2N Relay UE is connected to the SRAP entity of the gNB102. The L2 U2N Relay UE may be associated with a receiving unit of an SRAP entity, and the receiving unit of the SRAP entity of the L2 U2N Relay UE may be associated with a transmitting unit of an SRAP entity of the gNB102.

[0064] 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. The RLC channel determining unit 102 may have a function of determining an egress RLC channel.

[0065] Also, in Figures 8 and 9, a PC5 Relay RLC channel may be established between the Remote UE and the Relay UE, and a Uu Relay RLC channel may be established between the Relay UE and gNB102.

[0066] Next, a protocol configuration used between a base station device and a terminal device will be described. In communication performed at the Uu interface between a relay terminal device and a base station device, and in communication performed between a remote terminal device and a base station device via a relay terminal device, a protocol used between the base station device and the terminal device may be used. Note that in communication performed between a remote terminal device and a base station device via a relay terminal device, some protocols may not be associated between the remote terminal device and the base station device.

[0067] FIG. 7 is a diagram showing an example of an NR protocol configuration according to this embodiment. The functions of each protocol described with reference to FIG. 7 are some of the functions closely related to this embodiment, and may have other functions. In this embodiment, uplink (UL) refers to a transmission from a terminal device to a base station device. In this embodiment, the downlink (DL) may be a link to the base station. It may be a link from a station device to a terminal device.

[0068] FIG. 7(A) is a diagram of the NR control plane (CP) protocol stack. As shown in FIG. 7(A), the NR CP protocol may be a protocol between the UE 122 and the gNB 102. That is, the NR CP protocol is , and on the network side, it may be a protocol that terminates at the gNB 102. As shown in FIG. 7(A), NR The control plane protocol stack includes a PHY (Physical layer) 700 which is a wireless physical layer, a MAC (Medium Access Control) 702 which is a medium access control layer, an RLC 704 which is a radio link control layer, and a packet data convergence layer. It may be composed of a PDCP (Packet Data Convergence Protocol) 706, which is a protocol layer (packet data convergence protocol layer), and an RRC (Radio Resource Control) 708, which is a radio resource control layer. Also, FIG. 7B shows the NR user plane (UP) plane. As shown in FIG. 7B, the NR UP protocol may be a protocol between the UE 122 and the gNB 102. That is, the NR UP protocol is a protocol between the gNB 102 on the network side. As shown in FIG. 7B, the NR user plane protocol stack includes a radio physical layer PHY 700, a medium access control layer MAC 702, a radio link control layer RLC 704, a packet data convergence protocol layer PDCP 706, and a service data layer PDCP 707. The service data adaptation protocol layer may be a service data adaptation protocol (SDAP) 710.

[0069] The AS (Access Stratum) layer may be a layer that terminates between the UE 122 and the gNB 102. The AS layer includes some or all of PHY 700, MAC 702, RLC 704, PDCP 706, and RRC 708. The gNB 102 may be a ng-eNB 100. However, the E-UTRA protocol may be used. may not exist, and the E-UTRA protocol may have some different functions than the NR protocol.

[0070] An example of the function of the PHY will be described. The PHY of the terminal device receives the downlink from the PHY of the base station device. Receives data transmitted via a Downlink (DL) physical channel. The PHY of the terminal device may have an uplink (UL) object with respect to the PHY of the base station device. The PHY may have a function of transmitting data via a physical channel. The PHY may be connected to a higher MAC via a transport channel. The PHY may pass data to the MAC via the transport channel. The PHY may also pass data from the MAC via the transport channel. In the PHY, a Radio Network Temporary Identifier (RNTI) may be used to identify various control information.

[0071] Here, the physical channels will be described. The physical channels used for wireless communication between a terminal device and a base station device may include the following physical channels.

[0072] PBCH (Physical Broadcast CHannel) PDCCH (Physical Downlink Control CHannel) PDSCH (Physical Downlink Shared CHannel) PUCCH (Physical Uplink Control CHannel) PUSCH (Physical Uplink Shared CHannel) PRACH (Physical Random Access CHannel)

[0073] The PBCH may be used to broadcast system information required by a terminal device.

[0074] In addition, in NR, the PBCH may be used to broadcast a time index (SSB-Index) within a period of a synchronization signal block (SSB).

[0075] The PDCCH is a downlink radio communication channel (radio communication from a base station device to a terminal device). The UE may be used to transmit (or carry) Downlink Control Information (DCI), where one or more DCIs (DCI In other words, a format for the downlink control information may be defined. The fields corresponding to the PDCCH candidates may be defined as DCI and mapped to information bits. The PDCCH may be transmitted in a search space. The terminal device may monitor a set of PDCCH candidates in the serving cell. Monitoring a set of PDCCH candidates may mean attempting to decode the PDCCH according to a certain DCI format. In addition, the terminal device may The PDCCH candidate may be monitored at configured monitoring occasions in one or more configured control resource sets (CORESETs) configured by the service configuration. The DCI format may be used for scheduling the PUSCH in the serving cell. The PUSCH may be used for transmitting user data, transmitting an RRC message (to be described later), and the like.

[0076] PDCCH repetition is achieved by using two search space sets that are explicitly linked by a configuration provided by higher layers (RRC layer). may be operated. Also, two linked search space sets may be associated with a corresponding CORESET. For PDCCH repetition, The two search space sets are configured in the terminal with the same number of PDCCH candidates. Two PDCCH candidates that exist in two linked search space sets may be the same candidate. The PDCCH repetitions may be linked by a complementary index. When a slot is allocated, inter-slot repetition may be allowed, and each repetition may have the same number of Control Channel Elements (CCEs) and coded bits, and the same DCI payload.

[0077] The PUCCH is used in uplink wireless communication (wireless communication from a terminal device to a base station device). The uplink control information may be used to transmit uplink control information (UCI). Here, the uplink control information may include channel state information (CSI) used to indicate the state of a downlink channel. The uplink control information may include a Scheduling Request (SR) used to request an Uplink Shared CHannel (UL-SCH) resource. The link control information includes HARQ-ACK (Hybrid Automatic Repeat reQuest ACKnowledgement). It is okay to be swallowed.

[0078] The PDSCH may be used to transmit downlink data (DL-SCH: Downlink Shared CHannel) from the MAC layer. In addition, the PDSCH may be used to transmit system information (SI: System Information) and random access response (RAR: Random Access Response) in the downlink.

[0079] The PUSCH may be used to transmit uplink data from the MAC layer (UL-SCH: Uplink Shared CHannel) or uplink data together with HARQ-ACK and / or CSI, or may be used to transmit only CSI or only HARQ-ACK and CSI. That is, the PUSCH may be used to transmit only the UCI, and the PDSCH or the PUSCH may be used to transmit an RRC message and a MAC CE, which will be described later. In the PDSCH, an RRC message transmitted from a base station apparatus may be common signaling for a plurality of terminal apparatuses in a cell. Also, an RRC message transmitted from a base station apparatus may be dedicated signaling for a certain terminal apparatus. In other words, the information specific to a terminal apparatus (UE specific information) may be dedicated to a certain terminal apparatus. The PUSCH may be transmitted using the same signaling as the UE's uplink capability. It may also be used to transmit UE Capability.

[0080] The PRACH may be used to transmit a random access preamble. The PRACH is used for initial connection establishment procedures, handover procedures, connection re-establishment procedures, and the above. It may be used for synchronization (timing alignment) for uplink transmissions and to indicate a request for UL-SCH resources.

[0081] Uplink (UL) and / or downlink (DL) used in E-UTRA and / or NR Next, the logical channels for DL ​​(Downlink) will be described.

[0082] The BCCH (Broadcast Control Channel) may be a downlink logical channel for broadcasting control information such as system information (SI).

[0083] A Paging Control Channel (PCCH) may be a downlink logical channel for carrying paging messages.

[0084] A Common Control Channel (CCCH) may be a logical channel for transmitting control information between a terminal device and a base station device. The CCCH is used when the terminal device does not have an RRC connection. In addition, the CCCH may be used between a base station device and multiple terminal devices.

[0085] A DCCH (Dedicated Control Channel) is a logical channel for transmitting dedicated control information in a point-to-point bidirectional manner between a terminal device and a base station device. The dedicated control information may be control information dedicated to each terminal device. The DCCH may be used when the terminal device has an RRC connection.

[0086] A Dedicated Traffic Channel (DTCH) may be a logical channel for transmitting user data point-to-point between a terminal device and a base station device. The DTCH may be a logical channel for transmitting user data. The dedicated user data may be user data dedicated to each terminal device. The DTCH may exist in both the uplink and the downlink.

[0087] Logical channels and transport channels for the uplink in E-UTRA and / or NR This section explains the mapping of the rules.

[0088] CCCH is an uplink transport channel, UL-SCH (Uplink Shared Channel) may be mapped to

[0089] DCCH is an uplink transport channel, UL-SCH (Uplink Shared Channel) may be mapped to

[0090] DTCH is an uplink transport channel, UL-SCH (Uplink Shared Channel) may be mapped to

[0091] Logical channels and transport channels for the downlink in E-UTRA and / or NR This section explains the mapping of the rules.

[0092] BCCH is a downlink transport channel, BCH (Broadcast Channel), and / or Or it may be mapped to a DL-SCH (Downlink Shared Channel).

[0093] The PCCH is mapped to the PCH (Paging Channel), which is a downlink transport channel. That's fine.

[0094] CCCH is a downlink transport channel, DL-SCH (Downlink Shared Channel) may be mapped to

[0095] DCCH is a downlink transport channel, DL-SCH (Downlink Shared Channel) may be mapped to

[0096] DTCH is a downlink transport channel, DL-SCH (Downlink Shared Channel) may be mapped to

[0097] An example of the SDAP function is explained below. SDAP is a service data adaptation protocol layer (SDAP). The SDAP is a service data adaptation protocol layer (SDAP). The SDAP may have a function to map the downlink QoS flow sent from the 5GC to the terminal device via the base station device with a data radio bearer (DRB), and / or map the uplink QoS flow sent from the terminal device to the 5GC via the base station device with a DRB. The SDAP may also have a function to store mapping rule information. The SDAP may also have a function to mark the QoS flow identifier (QoS Flow ID: QFI). The SDAP PDU may include an SDAP PDU for data and an SDAP PDU for control. The SDAP PDU for data is called an SDAP DATA PDU (SDAP Data PDU, SDAP Data PDU). Also, the SDAP PDU for control may be called SDAP CONTROL PDU (SDAP Control PDU). The SDAP entity of the terminal device may be called an SDAP control PDU (SDAP control PDU). One SDAP entity of the terminal device may exist for each PDU session.

[0098] An example of the functions of the RRC will be described. The RRC may have a broadcast function. The RRC may have a paging function from the 5GC. The RRC may have a paging function from the gNB 102 or the ng-eNB 100. The RRC may have an RRC connection management function. The RRC may have a radio bearer control function. The RRC may have a cell group control function. The RRC may have a mobility control function. The RRC may have a terminal device measurement reporting function and a terminal device measurement reporting function. The RRC may have a radio link control function. The RRC may also have a QoS management function. RRC uses RRC messages for broadcasting, paging, RRC connection management, radio bearer control, cell group control, mobility control, terminal device Terminal equipment measurement and reporting and terminal equipment measurement and reporting control, QoS management, radio link loss In addition, RRC messages and packets used in E-UTRA RRC may be used for The parameters may differ from the RRC messages and parameters used in NR RRC.

[0099] RRC messages may be sent using the logical channel BCCH or the logical channel PCCH. RRC messages may be sent using the logical channel CCCH, or may be sent using the logical channel DCCH. In addition, RRC messages sent using the DCCH are referred to as Dedicated RRC signaling, or RRC signaling.

[0100] The RRC messages sent using the BCCH may include, for example, a Master Information Block (MIB), various types of System Information Blocks (SIBs), and other RRC messages. The RRC messages sent using the PCCH may include, for example, paging messages, and other RRC messages.

[0101] RRC messages sent in the uplink (UL) direction using CCCH include, for example, an RRC setup request message, an RRC resume request message, an RRC reestablishment request message, and an RRC system information request message. The RRC message may include an RRC System Info Request message, etc. Also, for example, an RRC Connection Request message, an RRC Connection Resume Request message, an RRC Connection Reestablishment Request message, etc. Also, other RRC messages may be included.

[0102] RRC messages sent in the downlink (DL) direction using CCCH include, for example, RRC connection rejection. RRC Connection Reject, RRC Connection Setup, RRC Connection Reestablishment, and RRC Connection Reestablishment Reject messages are included. Also, for example, an RRC reject message, an RRC setup message, etc. may be included. Also, other RRC messages may be included.

[0103] RRC signaling sent in the uplink (UL) direction using the DCCH includes, for example, measurement reports. The message may include, for example, a measurement report message, an RRC connection reconfiguration complete message, an RRC connection setup complete message, an RRC connection reestablishment complete message, a security mode complete message, a UE capability information message, etc. RRC Setup Complete, RRC Reestablishment Complete, RRC Resume Complete, Security Mode Complete The RRC signaling may include a Security Mode Complete message, a UE Capability Information message, etc., and may also include other RRC signaling.

[0104] The RRC signaling sent in the downlink (DL) direction using the DCCH may include, for example, an RRC connection reconfiguration message, an RRC connection release message, a security mode command message, a UE capability inquiry message, etc. Also, for example, an RRC reconfiguration message, an RRC resume message, an RRC release message, an RRC reestablishment message, a security mode command message, a UE capability inquiry message, etc. Also, other RRC signaling may be included.

[0105] The above-mentioned functions of PHY, MAC, RLC, PDCP, SDAP, and RRC are merely examples, and some or all of the functions may not be implemented. Also, some or all of the functions of each layer may be included in another layer.

[0106] The radio bearer will now be explained. When a terminal device communicates with a base station device, a radio bearer (RB) is established between the terminal device and the base station device to establish a wireless connection. A radio bearer used for CP may be called a signaling radio bearer (SRB). A radio bearer used for UP may be called a data radio bearer (DRB). A radio bearer identity (ID) may be assigned to each radio bearer. A radio bearer identity for an SRB may be called an SRB identity (SRB ID). A radio bearer identity for a DRB may be called a DRB identity (DRB ID). SRB0 to SRB2 may be defined for the SRB of E-UTRA, or other SRBs may be defined. SRB0 to SRB3 may be defined for the SRB of NR, or other SRBs may be defined. SRB0 may be an SRB for an RRC message that is transmitted and / or received using the CCCH of the logical channel. SRB1 may be an SRB for RRC signaling and for NAS signaling before the establishment of SRB2. The RRC signaling may include piggybacked NAS signaling. All RRC and NAS signaling transmitted and / or received using SRB1 is The logical channel DCCH may be used for NAS signaling and for recording. It may be an SRB for RRC signaling including logged measurement information. All RRC signaling and NAS signaling transmitted and / or received using SRB2. For nulling, the logical channel DCCH may be used. SRB2 may have a lower priority than SRB1. SRB3 is used when EN-DC, NGEN-DC, NR-DC, etc. are set in the terminal device. The logical channel DCCH may be used for all RRC and NAS signaling transmitted and / or received using SRB3. Other SRBs may be provided for other uses. The DRB may be a radio bearer for user data. The RRC signaling transmitted and / or received using the DRB may use the logical channel DTCH.

[0107] The radio bearer in the terminal device is explained. The radio bearer includes the RLC bearer. An RLC bearer may consist of one or two RLC entities and logical channels. If an RLC bearer has two RLC entities, the RLC entity is a TM RLC entity. and / or the transmitting RLC entity and the RLC entity in unidirectional UM mode The SRB0 may be a receiving RLC entity and a receiving RLC entity. The SRB0 may consist of one RLC bearer. The RLC bearer of the SRB0 may consist of the RLC entity of the TM and logical channels. The SRB0 is active in all states of the terminal equipment (RRC idle, RRC connected, RRC inactive, etc.). SRB1 may be established and / or configured in the terminal device by RRC signaling received from the base station device when the terminal device transitions from the RRC idle state to the RRC connected state. SRB1 is a PDCP entity and one or more RLC bearers. The RLC bearer of SRB1 may consist of an RLC entity of the AM and logical channels. The RLC bearer of SRB2 may consist of an RLC entity of the AM and logical channels. An SRB2 may be established and / or configured in the terminal device by RRC signaling received from the station device. The SRB2 consists of one PDCP entity and one or more RLC bearers. The RLC bearer of SRB2 may consist of an AM RLC entity and a logical channel. The PDCP on the base station side of SRB1 and SRB2 may be placed in the master node. SRB3 may be added when a secondary node in EN-DC, NGEN-DC, or NR-DC is added, or When the AS security is activated or the secondary node is changed, One may be established and / or configured in the terminal device by RRC signaling received by the terminal device from the base station device. SRB3 is a direct SRB between the terminal device and a secondary node. The SRB3 consists of one PDCP entity and one or more RLC bearers. The RLC bearer of the SRB3 may consist of an RLC entity of the AM and a logical channel. The PDCP on the base station side of the SRB3 may be placed in the secondary node. The DRB is AS security. One or more DRBs may be established and / or configured in the terminal device by RRC signaling received from the base station device by the terminal device in an RRC connected state with activated security. A DRB may consist of one PDCP entity and one or more RLC bearers. RLC bearers of a DRB may consist of an AM or UM RLC entity, and logical channels.

[0108] For an RLC bearer established and / or configured in a cell group consisting of E-UTRA, the RLC entity established and / or configured may be an E-UTRA RLC. For an RLC bearer established and / or configured in a cell group consisting of NR, the RLC entity established and / or configured may be an E-UTRA RLC. The RLC entity to be established may be an NR RLC. When an EN-DC is configured in the terminal device, the PDCP entity established and / or configured for the Master Node terminated MCG bearer is The PDCP may be either E-UTRA PDCP or NR PDCP. EN-DC is also set in the terminal device. In this case, the PDCP established and / or configured for radio bearers of other bearer types, i.e., master node terminated split bearer, master node terminated SCG bearer, secondary node terminated MCG bearer, secondary node terminated split bearer, and secondary node terminated SCG bearer, may be an NR PDCP. Also, when NGEN-DC, NE-DC, or NR-DC is configured in the terminal device, the PDCP established and / or configured for radio bearers of all bearer types may be an NR PDCP. The PDCP entity may be an NR PDCP.

[0109] In NR, the DRB established and / or configured in the terminal device is one PDU session. In the terminal device, one SDAP entity can be associated with one PDU session. The SDAP entity, the PDCP entity, the RLC entity, and the logical channels may be established and / or configured in the terminal device. It may be established and / or configured by RRC signaling received from a base station device.

[0110] The operations of RRC, PDCP and RLC closely related to this embodiment will be described. First, PDCP data recovery and PDCP re-establishment will be described. The RRC signaling transmitted from the base station to the terminal device includes information related to setting up a radio bearer. An information element (RadioBearerConfig) may be included, and the information element regarding the radio bearer configuration may include a list (DRB-ToAddModList) of settings (DRB-ToAddMod) regarding the addition and / or modification of the DRB, and the settings regarding the addition and / or modification of the DRB may include a DRB identifier (drb-Identity), information indicating that the PDCP is reestablished (reestablishPDCP), and information indicating that the PDCP is to perform data recovery. The RRC of the terminal device may re-establish a PDCP entity of a DRB identified by the DRB identifier based on the information indicating that the PDCP is re-established being set in the RRC signaling, and the RRC of the terminal device may trigger data recovery of a PDCP entity set in a DRB identified by the DRB identifier based on the information indicating that the PDCP performs data recovery being set in the RRC signaling. The information indicating that the DRB is to be re-established and the information indicating that the PDCP is to perform data recovery are combined into one DRB identification. If included in the configuration for adding and / or modifying a DRB identified by the child, the RRC of the terminal device may re-establish a PDCP entity of the DRB identified by the DRB identifier, and the DRB identifier may It may not trigger data recovery of the PDCP entity of the DRB identified by the child.

[0111] The PDCP entity that is requested to recover data by the upper layer (RRC layer) is In the re-established or released AM RLC entity, all PDCP data PDUs for which successful delivery has not been confirmed by the AM RLC entity may be retransmitted in ascending order of the COUNT values ​​associated with the PDUs.

[0112] The PDCP entity that has been requested to re-establish the PDCP entity by the upper layer (RRC layer) shall notify the lower layer of successful delivery of the PDCP data PDU corresponding to the PDCP SDU. It may retransmit or transmit all PDCP SDUs already associated with the PDCP sequence numbers (SN(s)) in ascending order of the COUNT values ​​associated with the PDCP SDUs before the PDCP re-establishment, starting with the first PDCP SDU not yet acknowledged by the COUNT. Note that if the DRB containing the PDCP entity for which re-establishment is requested is suspended, it may consider the PDCP SDU as having been received from the upper layer and may not retransmit the PDCP SDU without restarting the discard timer. may be carried out.

[0113] A PDCP entity may consist of a transmitting PDCP entity and a receiving PDCP entity. Upon receiving a PDCP SDU from an upper layer, the transmitting PDCP entity may start a discard timer associated with the PDCP SDU. When the discard timer for the PDCP SDU expires or successful delivery of the PDCP SDU is notified by a PDCP status report, If so, the transmitting PDCP entity transmits the PDCP SDU together with the corresponding PDCP data PDU. If the PDCP Data PDU has already been submitted to the lower layer, In this case, a discard may be instructed to the lower layer.

[0114] For the AM DRB configured to send PDCP status reports in uplink to higher layers (RRC), The receiving PDCP entity shall notify the higher layer (RRC) of a request to re-establish the PDCP entity. If the higher layer (RRC) requests PDCP data recovery, or When RRC requests a switch of uplink data, the PDCP status report is sent. The RRC of the terminal device may trigger a PDCP status report in the uplink to the configuration of the PDCP entity (pdcp-Config) included in the configuration for the addition and / or modification of the DRB. Based on the information (statusReportRequired) indicating that PDCP switching is enabled in the uplink, The receiving PDCP entity may configure the DRB identified by the DRB identifier to send a PDCP status report. If a PDCP status report is triggered, the receiving PDCP entity may submit the PDCP status report to lower layers as the first PDCP PDU for transmission via the transmitting PDCP entity.

[0115] The control PDCP PDU may be used to transmit a PDCP status report to a peer PDCP. The control PDCP PDU may also be used to transmit control information other than the PDCP status report. The PDCP status report includes information indicating whether the PDCP PDU is for control or data, information indicating which control information is included among the control information that can be included in the control PDCP PDU, reserved bits, and the maximum number of bits missing within a reordering window. The packet may include information indicating the first PDCP PDU (First Missing COUNT: FMC), and bitmap information indicating missing PDCP SDUs and successfully received PDCP SDUs.

[0116] When a PDCP status report is received in the downlink, the transmitting PDCP entity shall The COUNT value and / or the bit that corresponds to the bit that is set to 1 in the bitmap information included in the service report are Alternatively, a PDCP SDU corresponding to a COUNT value smaller than the value indicated by the FMC may be regarded as successfully delivered, and the PDCP SDU regarded as successfully delivered may be discarded.

[0117] The transmitting AM RLC entity is informed of the status by the status PDU from the peer AM RLC entity. A positive ACKnowledgement (ACK) for a certain RLC SDU can be received. When an ACK for a certain RLC SDU associated with a segment number is received, the transmitting AM RLC entity may notify the upper layer of the successful delivery of the RLC SDU. Also, when the upper layer (PDCP) instructs the discard of a specific RLC SDU, the transmitting AM RLC entity may notify the upper layer of the successful delivery of the RLC SDU. If not submitted to the lower layer, the transmitting side of the AM RLC entity shall transmit the indicated RLC SDU. may be discarded.

[0118] Reference signal received power (RSRP) measured in the sidelink may be, for example, the following RSRP. In addition, the following RSRP may be referred to as SL-RSRP. (a) PSBCH RSRP (b) PSSCH RSRP (c) PSCCH RSRP

[0119] 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 measure the RSRP (SD-RSRP) of the discovery message by using, for example, the power contribution of a resource element that transmits a DMRS associated with the discovery message.

[0120] In addition, in measurements on the sidelink, UE 122 may measure the following quantities in addition to SL-RSRP: (a) Sidelink received signal strength indicator (SL RSSI) (b) Sidelink channel occupancy ratio (SL CR) (c) Sidelink channel busy ratio(SL CBR)

[0121] 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

[0122] After discovering candidate L2 U2N Relay UEs and measuring the RSRP of the candidate L2 U2N Relay UEs, the L2 U2N Remote UE may report one or more candidate L2 U2N Relay UEs to the base station device. In addition, the L2 U2N Remote UE reports one or more candidate L2 U2N Relay UEs to the base station device. Before announcing the L2 U2N Relay, the RSRP of the candidate L2 U2N Relay UE is checked to see if it meets the L2 U2N Relay selection criteria. The L2 U2N Remote UE may determine whether or not the candidate L2 U2N Relay UE satisfies the selection criteria and matches the criteria of the higher layer to the base station device. When the L2 U2N Remote UE reports one or more candidate L2 U2N Relay UEs to the base station device, the L2 U2N Remote UE may include identification information of the candidate L2 U2N Relay UE, identification information of the serving cell of the candidate L2 U2N Relay UE, and a measurement result in the report to the base station device. Note that the measurement result may include identification information of the candidate L2 U2N Relay UE. The RSRP (SD-RSRP) of the discovery message transmitted by the Relay UE may be used. Note that the identification information may be an identifier (ID).

[0123] In addition, the L2 U2N Remote UE having the serving L2 U2N Relay UE may include the serving L2 U2N Relay UE in the measurement result. The serving L2 U2N Relay UE may use RSRP (SL-RSRP) measured in sidelink communication with the serving L2 U2N Relay UE. If the measurement result does not allow SL-RSRP, SD-RSRP may be used. The serving L2 U2N Relay UE may be an L2 U2N Relay UE that provides connectivity to the base station device to the L2 U2N Remote UE.

[0124] Next, a serving cell will be described. In a terminal device in an RRC connected state in which carrier aggregation (CA) and / or multi-connectivity (MC) are not configured, the serving cell may be configured with one primary cell (PCell). In addition, in a terminal device in an RRC connected state in which CA and / or MC are set, the multiple serving cells are one or more special cells (SpCells) and one or more The SpCell may refer to a set of cells consisting of all secondary cells (SCells) in the PUCCH transmission and contention-based random access memory (PMC). The PCell may support contention-based Random Access (CBRA). The PCell may be a cell used in the RRC connection establishment procedure when a terminal device in the RRC connected state transitions to an RRC connected state. The PCell may also be a cell used in the RRC connection re-establishment procedure in which the terminal device re-establishes the RRC connection. The PCell may be a cell that can be used for random access procedures during handover. The PSCell may be a cell used in the random access procedure when adding a secondary node for MC. The PCell and the PSCell may be SpCells. The SpCell may also be a cell used for purposes other than those mentioned above.

[0125] 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.

[0126] 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.

[0127] 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 receiver 500 receives control information (MAC control elements, RRC signaling, etc.) from the base station device (gNB 102). The processing unit 502 may receive information including control information (MAC control elements, RRC signaling, etc.) and user data from the base station device (gNB102). The transmitting unit 504 may transmit information including control information (MAC control elements, RRC signaling, etc.) and user data to the base station device (gNB102). The processing unit 502 may include some or all of the functions of various layers (e.g., physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, PC5-S layer, Discovery layer, and 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), RLC layer processing unit (RLC processing unit), PDCP layer processing unit (PDCP processing unit), SDAP processing unit (SDAP processing unit), RRC layer processing unit (RRC processing unit), PC5-S layer processing unit (PC5-S processing unit), Discovery layer processing unit (Discovery processing unit), and some or all of the application layer processing unit.

[0128] FIG. 6 is a block diagram showing the configuration of a base station device (gNB102) in this embodiment. In order to avoid complicating the description, FIG. 6 shows only the main components closely related to this embodiment. Only a portion is shown.

[0129] The base station apparatus shown in FIG. 6 includes a transmitter 604 that transmits control information (DCI, MAC CE, RRC signaling, etc.) to the UE 122, a processor 602 that creates control information (DCI, MAC CE, RRC signaling, etc.) and transmits it to the UE 122 to cause the processor 502 of the UE 122 to process it, and a receiver 600 that receives control information (UCI, MAC CE, RRC signaling, etc.) from the UE 122. The processing unit 602 may include some or all of the functions of various layers (e.g., a physical layer, a MAC layer, an RLC layer, a SRAP layer, a PDCP layer, an SDAP layer, an RRC layer, and an NAS layer). That is, the processing unit 602 may include some or all of a physical layer processing unit, a MAC layer processing unit, an RLC layer processing unit, an SRAP layer processing unit, a PDCP layer processing unit, an SDAP processing unit, an RRC layer processing unit, and an NAS layer processing unit.

[0130] FIG. 10 shows an example of an embodiment of the present invention.

[0131] The UE 122 communicating with the base station device performs a determination of information (step S1000), and performs an operation based on the determination (step S1002).

[0132] An RRC layer of a UE that receives the first RRC signaling and the second RRC signaling from a base station device may issue an instruction to a lower layer (PDCP layer) based on the first RRC signaling and the second RRC signaling. The PDCP layer receiving the information from the higher layer (RRC layer) may determine, for example, whether the information includes first information in step S1000. If the PDCP layer of the UE 122 determines that the information includes the first information, it may perform a first operation, for example, in step S1002, and if the PDCP layer determines that the information does not include the first information, it may perform a second operation, for example, in step S1002. The first information is Alternatively, the information may be information indicating that the first operation is to be performed. Also, the first RRC signaling may include an RRC message including a setting for a remote terminal device. The second RRC signaling may be an RRC message including information indicating to perform the first operation, or may be an RRC message including information indicating to perform the first operation. The second RRC signaling may be an RRC message including information indicating to perform PDCP data recovery, or may be an RRC message including information indicating to perform PDCP re-establishment.

[0133] The RRC layer of the UE 122 determines whether to perform a first configuration based on the first RRC signaling. For example, the first configuration may be performed based on the first RRC signaling including a configuration for a remote terminal device, or the first RRC signaling may include The first setting is not performed based on the fact that the setting for the remote terminal device is not included. For example, the first RRC signaling may include information indicating that the first operation is to be performed. The first configuration may be performed based on the first RRC signaling. The RRC layer of the UE 122 may not perform the first configuration based on the fact that the first operation is not included in the packet. For example, the RRC layer of the UE 122 may determine whether to provide the first information to a lower layer based on the first setting. The first RRC signaling may determine to provide the first information to a lower layer based on the fact that the first setting has not been performed, or may determine not to provide the first information to a lower layer based on the fact that the first setting has not been performed. Note that the first RRC signaling and the second RRC signaling may be one RRC signaling. For example, the first RRC signaling may include information indicating that the first operation is to be performed and information indicating that PDCP data recovery is to be performed. For example, the information indicating that the first operation is to be performed and the PDCP re-establishment may be Alternatively, the RRC signaling may include information indicating that the This is also possible.

[0134] Also, the RRC layer of the UE 122 may determine the information based on the second RRC signaling. If the second signaling includes information indicating that PDCP data recovery is to be performed, The second system may determine to instruct a second layer to perform PDCP data recovery. When the signaling includes information indicating that PDCP re-establishment is to be performed, the control unit 10 may determine to instruct a lower layer to perform PDCP re-establishment. Note that instructing a lower layer may be expressed as providing information to a lower layer.

[0135] The first operation is when the information includes information instructing to perform PDCP data recovery. The first operation may be to retransmit all PDCP data PDUs previously submitted to the re-established or released AM RLC entity if the information includes information indicating to perform PDCP re-establishment. The all PDCP data PDUs may be expressed as all PDCP data PDUs that have not been discarded. The first operation may be to retransmit or transmit all PDCP SDUs already associated with the PDCP SN, starting from a first PDCP SDU, in ascending order of COUNT values ​​associated with PDCP SDUs before re-establishment of the PDCP entity, if the information includes information indicating to perform PDCP re-establishment. The all PDCP SDUs may be expressed as all PDCP SDUs that have not been discarded. The second operation may be to If the information includes information instructing to perform PDCP data recovery, the corresponding PDCP data PDUs previously submitted to the re-established or released AM RLC entity are Retransmission of all PDCP data PDUs whose successful transmission has not been confirmed by the lower layer. The second operation may be to instruct the information to perform PDCP re-establishment. If the PDCP SDU contains information that indicates the retransmission of a PDCP SDU, then the PDCP SDUs are retransmitted starting from the first PDCP SDU, in ascending order of the COUNT values ​​associated with the PDCP SDUs before the re-establishment of the PDCP entity, and for which the successful transmission of the corresponding PDCP Data PDU has not been acknowledged by the lower layer, and which are already associated with a PDCP SN. The term "successful delivery" may be interchangeable with the term "successful transmission."

[0136] The UE 122 may communicate with the base station device via a relay terminal device. In addition, the UE 122 may be a terminal device that serves as a remote terminal device. Note that the first RRC signaling includes a setting for a remote terminal device, and the second RRC signaling includes a setting for a remote terminal device. The first RRC signaling includes information indicating that PDCP data recovery is to be performed or information indicating that PDCP re-establishment is to be performed, and the first RRC signaling and the second RRC signaling are one RRC signaling. and immediately before receiving the RRC signaling, If the allocation has not been achieved, the first operation does not have to be performed. indicates that PDCP data recovery is performed when not acting as a remote terminal device. In addition, when the second RRC signaling includes information indicating that the remote terminal device is to perform PDCP re-establishment or information indicating that the remote terminal device is to perform PDCP re-establishment, the first operation may not be performed. For example, the setting of the U2N relay used by the remote terminal device may be included in the RRC message. The relevant settings may include the settings of the SRAP layer used for the remote terminal.

[0137] FIG. 10 shows another embodiment of the present invention.

[0138] The UE 122, which communicates with the base station apparatus and the relay terminal apparatus, judges information (step S1000), and performs an operation based on the judgment (step S1002).

[0139] In step S1000, for example, the determination may be made as to whether the RRC entity of the UE 122 is in an upper layer. and receiving first indication information from the UE 122, and the PC5 unicast link to which the UE 122 is connected is It may be to determine whether the first instruction information is the target. Alternatively, the determining may comprise determining that an RRC connection re-establishment procedure is not being performed at the time when the first indication information is received.

[0140] Additionally or alternatively, the determination in step S1000 may be, for example, The first instruction information may be an instruction to release a PC5 unicast link with a serving relay terminal device. In this case, in step S1002, The RRC re-establishment procedure is started based on the determination that the first instruction information is an instruction to release a PC5 unicast link with a serving relay terminal device, and the PC5 unicast link is released based on the determination that the first instruction information is an instruction to release a PC5 unicast link with a serving relay terminal device. Based on determining that the instruction is to release the PC5 unicast link, the PC5 unicast link may be released and an RRC re-establishment procedure may not be initiated.

[0141] Furthermore, in step S1002, a procedure for releasing the PC5 unicast link and re-establishing the RRC connection is performed. The starting operations do not necessarily have to be performed consecutively.

[0142] In FIG. 10, for example, the determination of information in step S1000 is performed when the UE 122 in the RRC connected state The RRC entity may determine whether or not some or all of the following conditions (a) to (c) are met when, or at the time of, releasing a PC5 unicast link notified by a higher layer: (a) The RRC connection re-establishment procedure is not in progress. (b) The PC5 unicast link to be released is for communication with a serving relay terminal equipment. This is a PC5 unicast link configured (c) Multipath is not configured (i.e. it is not a multipath remote terminal device)

[0143] In step S1002, the RRC entity of the UE 122 satisfies any one of the conditions (a) to (c) or Based on the determination that all conditions are met, the RRC connection re-establishment procedure may be initiated. Additionally or alternatively, in step S1002, some or all of the conditions (a) to (c) may be satisfied. RRC connection re-establishment procedures based on determining that any or all of the conditions are not met. You do not need to start the

[0144] In addition, the remote terminal device performs step S1000 based on whether a multipath is set. And / or in step S1002, the remote terminal device may take different actions based on whether multipath is set up. For example, when the RRC entity of the UE 122 receives the first indication information from the higher layer, if the RRC entity of the UE 122 determines in step S1000 that the UE 122 is a remote terminal device in which multipath is set up, in step S1002: The RRC connection re-establishment procedure does not need to be initiated. If it is determined that the remote terminal device is not connected to the RRC connection re-establishment procedure, The multi-path remote terminal device may be a terminal device in which a direct path and a non-direct path are set.

[0145] In each embodiment, the remote terminal device may be an L2 U2N Remote UE, and the relay terminal device may be an L2 U2N Relay UE. In the embodiment, the U2N Relay architecture is illustrated. The device and the remote terminal device may be replaced by other devices.

[0146] A remote terminal device that communicates with a base station device via a relay terminal device, currently PC5 unicast The relay terminal device connected to the relay terminal device via the same link can simultaneously transmit PC5 unicast When a link connection is established, and a path is switched to a handover destination cell or a handover destination relay terminal device, this In this embodiment, the upper layer may initiate an unnecessary RRC connection re-establishment procedure. When a release command for the PC5 unicast link with the serving relay terminal device is received from the layer In this case, the RRC connection re-establishment procedure is started only when the UE is in a standby state, and is not executed when it is not necessary, thereby enabling efficient handover.

[0147] 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" In the above description, the expressions "link", "associate", "link" and the like may be interchangeable.

[0148] 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".

[0149] 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."

[0150] 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.

[0151] 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 the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read and executed by a computer system. The term "computer system" refers to a computer system built into a device, including hardware such as an operating system and peripheral devices. The term "computer-readable recording medium" refers to any of semiconductor recording media, optical recording media, magnetic recording media, etc.

[0152] 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

[0153] 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.

[0154] 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.

[0155] 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]

[0156] 100 ng-eNB 102 gNB 110, 112, 114 Interface 122UE 200, 700 PHY 202, 702 MAC 204, 704 RLC 206, 706 PDCP 208, 708 RRC 210 PC5-S 310, 710 SDAP 400 Discovery 500, 600 receiver 502, 602 Processing section 504, 604 Transmitter 712 NAS 800 SRAP

Claims

1. A terminal device that communicates with a base station device via at least one relay terminal device. So, The terminal device has an RRC entity, The RRC entity has the function of receiving instructions to release the PC5 link from layers higher than the RRC layer. death, If the link to which the terminal device is connected is a PC5 unicast link to a relay terminal device communicating with a base station device, Release the PC5 unicast link and begin the procedure to re-establish communication with the base station. A terminal device having the function.

2. A terminal device that communicates with a base station device via at least one relay terminal device It is a law, The terminal device has an RRC entity, The RRC entity has the function of receiving instructions to release the PC5 link from layers higher than the RRC layer. death, If the link to which the terminal device is connected is a PC5 unicast link to a relay terminal device communicating with a base station device, Release the PC5 unicast link and begin the procedure to re-establish communication with the base station. The method includes at least the steps.

3. A group of terminal devices that communicate with a base station device via at least one relay terminal device. An integrated circuit comprising: The terminal device has an RRC entity, The RRC entity has the function of receiving instructions to release the PC5 link from layers higher than the RRC layer. death, If the link to which the terminal device is connected is a PC5 unicast link to a relay terminal device communicating with a base station device, Release the PC5 unicast link and begin the procedure to re-establish communication with the base station. An integrated circuit that causes the terminal device to perform a function.

Images