Operation method of relay UE for remote UE

Abstract

A method for operating a relay user equipment (UE) for a remote UE is provided in one disclosure of the present specification. The method may include the following steps: the relay UE receives a radio resource control (RRC) reconfiguration message or an RRC connection reconfiguration message from a base station. The RRC reconfiguration message or the RRC connection reconfiguration message may include identification information of a data radio bearer (DRB) shared with the remote UE and information about a protocol data unit (PDU) session that must be deleted or released in the DRB. The method may include the following steps: based on the received RRC reconfiguration message or the RRC connection reconfiguration message, the access stratum (AS) layer of the relay UE relays information that a user plane (UP) connection of the PDU session is released to the non-access stratum (NAS) layer of the relay UE.

Description

Technical Field

[0001] This specification relates to mobile communications. Background Art

[0002] With the success of Long Term Evolution (LTE) / LTE-Advanced (LTE-A), the 4th generation mobile communications, there has been more interest in the next generation, ie, the 5th generation (also known as 5G), mobile communications and accordingly, extensive research and development is being conducted.

[0003] 5G mobile communications defined in the International Telecommunication Union (ITU) provide data transfer rates of up to 20 Gbps and a perceptible transfer rate of at least 100 Mbps anytime, anywhere. "IMT-2020" is the official name and is intended to be commercialized worldwide in 2020.

[0004] The fifth generation of mobile communications supports multiple parameter sets (and / or multiple subcarrier spacing (SCS)) to support various 5G services. For example, if the SCS is 15kHz, a wide area can be supported in the traditional cellular band, and if the SCS is 30kHz / 60kHz, dense cities, lower latency, and wider carrier bandwidth can be supported. If the SCS is 60kHz or higher, a bandwidth greater than 24.25GHz can be supported to overcome phase noise.

[0005] The NR band is defined as two types of frequency ranges, FR1, FR2. FR1 is 410MHz-7125MHz, and FR2 is 24250MHz-52600MHz, which means millimeter wave (mmW).

[0006] For convenience of explanation, among the frequency ranges used in the NR system, FR1 may mean “a range below 6 GHz”. FR2 may mean “a range above 6 GHz” and may be referred to as millimeter wave (mmW).

[0007] [Table 1]

[0008] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 450MHz-6000MHz 15,30,60kHz FR2 24250MHz-52600MHz 60,120,240kHz

[0009] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a frequency band from 410 MHz to 7125 MHz, as shown in Table 2 below. That is, FR1 may include a frequency band above 6 GHz (or, 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or, 5850, 5900, 5925 MHz, etc.) included in FR1 may include an unlicensed frequency band. The unlicensed frequency band can be used for various purposes, for example, for communication of vehicles (e.g., autonomous driving).

[0010] [Table 2]

[0011] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 450MHz-7125MHz 15,30,60kHz FR2 24250MHz-52600MHz 60,120,240kHz

[0012] The ITU has proposed three usage scenarios such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low-latency communications (URLLC).

[0013] First, URLLC involves usage scenarios that require high reliability and low latency. For example, services such as autonomous driving, factory automation, and augmented reality require high reliability and low latency (e.g., latency less than or equal to 1ms). Currently, the latency statistics for 4G (LTE) are 21-43ms (best 10%) and 33-75ms (median). This is not enough to support services that require latency less than or equal to 1ms.

[0014] Next, eMBB use cases involve use cases that require mobile ultra-wideband.

[0015] The core network designed for existing LTE / LTE-A seems to be difficult to adapt to ultra-wideband high-speed services.

[0016] Therefore, there is an urgent need to redesign the core network of 5G mobile communications.

[0017] Figure 1 It is a structural diagram of the next generation mobile communication network.

[0018] The 5G Core (5GC) can include various components. Figure 1 In the figure, 5GC includes access and mobility management function (AMF) 41, session management function (SMF) 42, policy control function (PCF) 43, user plane function (UPF) 44, application function (AF) 45, unified data management (UDM) 46 and non-3GPP interworking function (N3IWF) 49, which correspond to some of the components therein.

[0019] The UE 10 is connected to a data network through the UPF 44 via a Next Generation Radio Access Network (NG-RAN).

[0020] The UE 10 may be provided with data services over an untrusted non-3GPP access, such as a wireless local area network (WLAN). In order to connect the non-3GPP access to the core network, a N3IWF 59 may be deployed.

[0021] Figure 2 is an example diagram illustrating an expected structure of the next generation mobile communication in terms of nodes.

[0022] Reference Figure 2 , the UE is connected to the data network (DN) through NG-RAN.

[0023] The control plane function (CPF) node shown performs all or part of the functions of the mobility management entity (MME) of 4G mobile communication and all or part of the control plane functions of the serving gateway (S-GW) and PDN gateway (P-GW) of 4G mobile communication. The CPF node includes an access and mobility management function (AMF) and a session management function (SMF).

[0024] The user plane function (UPF) node shown is a gateway through which user data is sent / received. The UPF node can perform all or part of the user plane functions of the S-GW or P-GW of 4G mobile communication.

[0025] The Policy Control Function (PCF) shown is the node that controls the provider's policy.

[0026] The shown Application Function (AF) is a server for providing several services to the UE.

[0027] The Unified Data Management (UDM) shown is a server type that manages subscriber information, such as a Home Subscriber Server (HSS) of 4G mobile communications. The UDM stores subscriber information in a Unified Data Repository (UDR) and manages it.

[0028] The Authentication Server Function (AUSF) shown authenticates and manages the UE.

[0029] The Network Slice Selection Function (NSSF) shown is a node for network slicing as described below.

[0030] exist Figure 2 In , the UE can use multiple protocol data unit (PDU) sessions to access two data networks simultaneously.

[0031] Figure 3 is an example diagram illustrating an architecture for supporting simultaneous access to two data networks.

[0032] Figure 3 This paper illustrates an architecture that allows a UE to access two data networks simultaneously using one PDU session.

[0033] Figure 2 and Figure 3 The reference points shown are as follows.

[0034] N1 is the reference point between UE and AMF.

[0035] N2 is the reference point between (R)AN and AMF.

[0036] N3 is the reference point between (R)AN and UPF.

[0037] N4 is the reference point between SMF and UPF.

[0038] N5 is the reference point between PCF and AF.

[0039] N6 is the reference point between UPF and DN.

[0040] N7 is the reference point between SMF and PCF.

[0041] N8 is the reference point between UDM and AMF.

[0042] N9 is the reference point between UPFs.

[0043] N10 is the reference point between UDM and SMF.

[0044] N11 is the reference point between AMF and SMF.

[0045] N12 is the reference point between AMF and AUSF.

[0046] N13 is the reference point between UDM and AUSF.

[0047] N14 is the reference point between AMFs.

[0048] N15 is the reference point between PCF and AMF.

[0049] N16 is the reference point between SMFs.

[0050] N22 is the reference point between AMF and NSSF.

[0051] Figure 4 is another example diagram showing the structure of the radio interface protocol between UE and gNB.

[0052] The radio interface protocol is based on the 3GPP radio access network standard. The radio interface protocol consists of a physical layer, a data link layer, and a network layer horizontally, and is vertically divided into a user plane for transmitting data information and a control plane for transmitting control signals.

[0053] Based on the lower three layers of the widely known Open Systems Interconnection (OSI) reference model in communication systems, the protocol layer can be divided into L1 (layer 1), L2 (layer 2), and L3 (layer 3).

[0054] Hereinafter, each layer of the radio protocol will be described.

[0055] The first layer, the physical layer, provides information transfer services using physical channels. The physical layer is connected to the upper medium access control layer through a transmission channel, and data between the medium access control layer and the physical layer is transmitted through the transmission channel. In addition, data is transmitted between different physical layers (i.e., between the physical layer on the sending side and the physical layer on the receiving side) through the physical channel.

[0056] The second layer includes a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer.

[0057] The third layer includes a radio resource control (hereinafter referred to as RRC) layer. The RRC layer is defined only in the control plane and is responsible for controlling logical channels, transport channels, and physical channels related to the configuration, reconfiguration, and release of radio bearers. In this case, RB refers to a service provided by the second layer for data transmission between the UE and the E-UTRAN.

[0058] The non-access stratum (NAS) layer performs functions such as connection management (session management) and mobility management.

[0059] The NAS layer is divided into a NAS entity for mobility management (MM) and a NAS entity for session management (SM).

[0060] 1) The NAS entity for MM generally provides the following functions.

[0061] The NAS processes related to AMF include the following.

[0062] -Registration management and access management process. AMF supports the following functions.

[0063] -Secure NAS signaling connection between UE and AMF (integrity protection, encryption)

[0064] 2) The NAS entity for SM performs session management between UE and SMF.

[0065] The NAS-SM layer of the UE and SMF handles (i.e., generates and processes) SM signaling messages. The content of the SM signaling messages is not interpreted by the AMF.

[0066] - In case of SM signaling transmission

[0067] - The NAS entity for MM creates a NAS-MM message which derives how and where to deliver the SM signalling message through a security header indicating the NAS transport of SM signalling and additional information about the received NAS-MM.

[0068] - Upon receiving SM signaling, the NAS entity for SM performs an integrity check of the NAS-MM message, analyzes the additional information, and derives the method and location for deriving the SM signaling message.

[0069] In addition, Figure 4 In the wireless communication network, the RRC layer, RLC layer, MAC layer and PHY layer located below the NAS layer are collectively referred to as the access layer (AS).

[0070] The network system (ie, 5GC) for the next generation mobile communication (ie, 5G) also supports non-3GPP access. An example of non-3GPP access is typically WLAN access. WLAN access can include both trusted WLAN and untrusted WLAN.

[0071] In the system for 5G, AMF performs registration management (RM) and connection management (CM) for 3GPP access as well as non-3GPP access.

[0072] Furthermore, due to an increase in user demands for a social networking service (SNS), communication between UEs in close physical proximity, ie, device-to-device (D2D) communication, is required.

[0073] In addition, for a remote UE in a shadow area, any UE can operate as a relay UE.

[0074] If the relay UE and the remote UE share and use a data radio bearer (DRB), the relay UE must maintain the DRB for the remote UE even when the PDU session of the relay UE is deactivated. In this case, the NAS layer of the relay UE may not recognize whether the PDU session is deactivated.

[0075] As a result, the core network considers the PDU session to be inactive, while the relay UE considers the PDU session to be still active, resulting in a state mismatch of the PDU session. Summary of the invention

[0076] Technical Purpose

[0077] Therefore, one object of this specification is to propose a method for solving the above-mentioned problems.

[0078] Technical Solution

[0079] In order to solve the above problems, the disclosure of this specification provides a method for a relay user equipment (UE) to operate for a remote UE. The method may include: receiving a radio resource control (RRC) reconfiguration message or an RRC connection reconfiguration message from a base station by the relay UE. The RRC reconfiguration message or the RRC connection reconfiguration message may include identification information of a data radio bearer (DRB) shared with the remote UE and information about a protocol data unit (PDU) session to be deleted or released in the DRB. The method may include: based on the received RRC reconfiguration message or RRC connection reconfiguration message, the access stratum (AS) layer of the relay UE delivers information that the user plane (UP) connection of the PDU session is released to the non-access stratum (NAS) layer of the relay UE.

[0080] In order to solve the above problems, the disclosure of this specification provides a chipset installed on a relay user equipment (UE). The chipset may include: at least one processor; and at least one memory for storing instructions and being electrically connected to at least one processor in operation. The instructions may be executed based on being executed by at least one processor and may perform the following operations: a radio resource control (RRC) reconfiguration message or an RRC connection reconfiguration message is received by the relay UE from a base station. The RRC reconfiguration message or the RRC connection reconfiguration message may include identification information of a data radio bearer (DRB) shared with a remote UE and information about a protocol data unit (PDU) session to be deleted or released in the DRB. The operation may include: based on the received RRC reconfiguration message or the RRC connection reconfiguration message, the access stratum (AS) layer of the relay UE delivers information that the user plane (UP) connection of the PDU session is released to the non-access stratum (NAS) layer of the relay UE.

[0081] In order to solve the above problems, the disclosure of this specification provides a relay user equipment (UE). The relay UE may include: a transceiver; at least one processor; and at least one memory for storing instructions and being electrically connected to the at least one processor in operation. The instructions are executed based on being executed by at least one processor to perform the following operations: the relay UE receives a radio resource control (RRC) reconfiguration message or an RRC connection reconfiguration message from a base station. The RRC reconfiguration message or the RRC connection reconfiguration message may include identification information of a data radio bearer (DRB) shared with a remote UE and information about a protocol data unit (PDU) session to be deleted or released in the DRB. The operation may include: based on the received RRC reconfiguration message or RRC connection reconfiguration message, the access stratum (AS) layer of the relay UE delivers information that the user plane (UP) connection of the PDU session is released to the non-access stratum (NAS) layer of the relay UE.

[0082] In order to solve the above problems, the disclosure of the present specification provides a non-volatile computer-readable storage medium having instructions recorded thereon. The instructions, when executed by one or more installed processors, cause the one or more processors to perform operations including: a radio resource control (RRC) reconfiguration message or an RRC connection reconfiguration message is received by a relay UE from a base station. The RRC reconfiguration message or the RRC connection reconfiguration message may include identification information of a data radio bearer (DRB) shared with a remote UE and information about a protocol data unit (PDU) session to be deleted or released in the DRB. The operation may include: based on the received RRC reconfiguration message or RRC connection reconfiguration message, the access stratum (AS) layer of the relay UE delivers information that the user plane (UP) connection of the PDU session is released to the non-access stratum (NAS) layer of the relay UE.

[0083] Technical Effects

[0084] According to the disclosure of this specification, the problems of the related art can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 It is a structural diagram of the next generation mobile communication network.

[0086] Figure 2 is an example diagram illustrating the expected structure of the next generation mobile communication in terms of nodes.

[0087] Figure 3 is an example diagram illustrating an architecture for supporting simultaneous access to two data networks.

[0088] Figure 4 is another example diagram showing the structure of the radio interface protocol between UE and gNB.

[0089] Figure 5a and Figure 5b is a signal flow diagram illustrating an exemplary PDU session establishment process.

[0090] Figure 6a and Figure 6b The modification process of the PDU session is shown.

[0091] Figure 7 The RRC status is shown.

[0092] Figure 8 The concept of device-to-device (D2D) communication is shown.

[0093] Fig. 9 The architecture of UE to network relay is shown.

[0094] Fig.10 The protocol stack of UE to network relay is shown.

[0095] Fig.11 is an exemplary flow chart illustrating a process by which a network selectively deactivates a UP connection for a PDU session.

[0096] Fig.12a and Figure 12b is an exemplary signal flow diagram illustrating a process according to one disclosed content of this specification.

[0097] Fig.13 is an example Fig.12a and Figure 12b An example diagram of the internal operation of UE-1 (relay UE) is shown.

[0098] Fig.14 A block diagram of a processor in which the disclosed contents of this specification are implemented is shown.

[0099] Fig.15 A wireless communication system according to an embodiment is illustrated.

[0100] Fig.16 A block diagram of a network node according to an embodiment is illustrated.

[0101] Fig.17 is a block diagram illustrating a configuration of a UE according to an embodiment.

[0102] Fig.18 A detailed example Fig.15 The first device shown is a transceiver or Fig.17 A detailed block diagram of the transceiver of the device is shown.

[0103] Fig.19 A communication system 1 to which the disclosure of this specification is applied is exemplified. DETAILED DESCRIPTION

[0104] The technical terms used in this article are only used to describe specific embodiments, and should not be understood as limiting the present disclosure. In addition, unless otherwise defined, the technical terms used in this article should be interpreted as having the meaning commonly understood by those skilled in the art, rather than being too broad or too narrow. In addition, the technical terms used in this article that are determined not to accurately express the spirit of the present disclosure should be replaced by some technical terms that can be accurately understood by those skilled in the art or understood according to these technical terms. In addition, the general terms used in this article should be interpreted in the context defined in the dictionary, rather than being interpreted in an overly narrow manner.

[0105] Unless the meaning of the singular is indeed different from the meaning of the plural in the context, the expressions in the singular in the specification also include the meaning of the plural. In the following description, the term "includes" or "has" may indicate the presence of the features, quantities, steps, operations, components, parts or combinations thereof described in the specification, and may not exclude the presence or addition of another feature, another quantity, another step, another operation, another component, another part or combinations thereof.

[0106] The terms "first" and "second" are used for the purpose of describing various components, and the components are not limited to the terms "first" and "second". The terms "first" and "second" are only used to distinguish one component from another component. For example, a first component may be named a second component without departing from the scope of the present disclosure.

[0107] It should be understood that when an element or layer is referred to as being “connected to” or “coupled to” another element or layer, it can be directly connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers.

[0108] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. In describing the present invention, for ease of understanding, the same reference numerals are used in all drawings to represent the same components, and repeated descriptions of the same components will be omitted. Detailed descriptions of known technologies that are determined to make the subject matter of the present disclosure unclear will be omitted. The accompanying drawings are provided only to make the spirit of the present disclosure easy to understand and should not be intended to limit the present disclosure. It should be understood that the spirit of the present disclosure can also be extended to its modifications, replacements or equivalents in addition to what is shown in the accompanying drawings.

[0109] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, "A or B" in the present disclosure may be interpreted as "A and / or B". For example, "A, B, or C" in the present disclosure may mean "only A", "only B", "only C", or "any combination of A, B, and C".

[0110] In the present disclosure, a slash ( / ) or a comma (,) may represent "and / or". For example, "A / B" may represent "A and / or B". Thus, "A / B" may represent "only A", "only B", or "both A and B". For example, "A, B, C" may represent "A, B, or C".

[0111] In the present disclosure, "at least one of A and B" may represent "only A", "only B", or "both A and B". In addition, the expressions "at least one of A or B" or "at least one of A and / or B" in the present disclosure may be interpreted the same as "at least one of A and B".

[0112] In addition, in the present disclosure, "at least one of A, B, and C" may represent "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B, and / or C" may represent "at least one of A, B, and C".

[0113] In addition, the parentheses used in the present disclosure may represent "for example". Specifically, when shown as "control information (PDCCH)", "PDCCH" may be presented as an example of "control information". In other words, "control information" in the present disclosure is not limited to "PDCCH", and "PDDCH" may be presented as an example of "control information". In addition, even when shown as "control information (i.e., PDCCH)", "PDCCH" may also be presented as an example of "control information".

[0114] The technical features described separately in one of the drawings in the present disclosure may be implemented separately or simultaneously.

[0115] In the drawings, a user equipment (UE) is illustrated by way of example, but the illustrated UE may also be referred to in terms of UE 100 (terminal), mobile equipment (ME), etc. Additionally, the UE may be a portable device such as a laptop computer, mobile phone, PDA, smart phone, or multimedia device, or may be a non-portable device such as a PC or in-vehicle device.

[0116] <PDU Session Establishment Procedure>

[0117] For the PDU session establishment procedure, as described below, there may be two different types of PDU session establishment procedures.

[0118] - The PDU session establishment procedure initiated by the UE.

[0119] - The PDU session establishment procedure initiated by the network. To this end, the network may send a device trigger message to the UE's application (or applications).

[0120] Figure 5a and Figure 5b are signal flowcharts illustrating exemplary PDU session establishment procedures.

[0121] Figure 5a and Figure 5bThe process shown assumes that the UE has registered with the AMF according to the registration procedure. Therefore, it is assumed that the AMF has obtained the user subscription data from the UDM.

[0122] 1) The UE sends a NAS message to the AMF. The message may include single network slice selection auxiliary information (S-NSSAI), data network name (DNN), PDU session ID, request type, N1 SM information, etc.

[0123] Specifically, the UE includes an S-NSSAI from the allowed NSSAI for the current access type. If information about the mapped NSSAI has been provided to the UE, the UE may provide both an S-NSSAI based on the allowed NSSAI and a corresponding S-NSSAI based on the information about the mapped NSSAI. Here, the information about the mapped NSSAI is information about mapping each S-NSSAI in the allowed NSSAI to an S-NSSAI in the NSSAI set for the Home Public Land Mobile Network (HPLMN).

[0124] More specifically, the UE may extract and store the allowed NSSAI and the information about the mapped NSSAI included in the registration acceptance message received from the network (ie, AMF) during the registration process. Thus, the UE may send by including an S-NSSAI based on the allowed NSSAI and a corresponding S-NSSAI based on the information about the mapped NSSAI in the PDU session establishment request message.

[0125] To establish a new PDU session, the UE may generate a new PDU session ID.

[0126] The PDU session establishment procedure initiated by the UE may be started by sending a NAS message with a PDU session establishment request message included in the N1 SM information. The PDU session establishment request message may include a request type, an SSC mode, and protocol configuration options.

[0127] In the case where the PDU session establishment is for configuring a new PDU session, the request type indicates "initial access". However, in the case where there is an existing PDU session between the 3GPP access and the non-3GPP access, the request type may indicate "existing PDU session".

[0128] The NAS message sent by the UE is encapsulated by the AN in an N2 message. The N2 message is sent to the AMF and may include user location information and access technology type information.

[0129] -N1 SM information may include a SM PDU DN request container including information about PDU session authentication performed by an external DN.

[0130] 2) In case the Request Type indicates "Initial Request", and in case the PDU Session ID is not already in use for an existing PDU Session for the UE, the AMF may determine that the message corresponds to a request for a new PDU Session.

[0131] If the NAS message does not include S-NSSAI, the AMF may determine the default S-NSSAI for the requested PDU Session based on the UE subscription. The AMF may correlate the PDU Session ID with the ID of the SMF and may store the PDU Session ID.

[0132] AMF can select SMF.

[0133] 3)AMF can send a Nsmf_PDUSession_CreateSMContext request message or a Nsmf_PDUSession_UpdateSMContext request message to the selected SMF.

[0134] The Nsmf_PDUSession_CreateSMContext request message may include SUPI, DNN, S-NSSAI, PDU session ID, AMF ID, request type, PCF ID, priority access, N1 SM container, user location information, access type, PEI, GPSI, UE presence in LADN service area, subscription for PDU session status notification, DNN selection mode, and tracking requirements. The SM container may include the PDU session establishment request message.

[0135] The Nsmf_PDUSession_UpdateSMContext request message may include SUPI, DNN, S-NSSAI, SM context ID, AMF ID, request type, N1 SM container, user location information, access type, RAT type, and PEI. The N1 SM container may include a PDU session establishment request message.

[0136] The AMF ID is used to identify the AMF serving the UE. The N1 SM information may include a PDU session establishment request message received from the UE.

[0137] 4) SMF sends a subscriber data request message to UDM. The subscriber data request message may include the subscriber permanent ID and DNN. UDM may send a subscription data response message to SMF.

[0138] In the above step 3, when the request type indicates "existing PDU session", the SMF determines that the corresponding request is caused by switching between 3GPP access and non-3GPP access. The SMF can identify the existing PDU session based on the PDU session ID.

[0139] If the SMF has not searched for the SN-related subscription data of the UE associated with the DNN, the SMF can request the subscription data.

[0140] The subscription data may include the authenticated request type, the authenticated SSC mode, and information about the default QoS profile.

[0141] The SMF may verify that the UE request complies with the user subscription and local policy. Alternatively, the SMF may reject the UE request via NAS SM signaling (including the relevant SM rejection cause), which is forwarded (or transmitted) by the AMF, and then the SMF may notify the AMF that this should be considered as the release of the PDU Session ID.

[0142] 5)SMF sends a Nsmf_PDUSession_CreateSMContext response message or a Nsmf_PDUSession_UpdateSMContext response message to AMF.

[0143] The Nsmf_PDUSession_CreateSMContext response message may include a cause, a SM context ID, or an N1 SM container. The N1 SM container may include a PDU session reject.

[0144] In the above step 3, when SMF receives the Nsmf_PDUSession_CreateSMContext request message and SMF can process the PDU session establishment request message, SMF creates an SM context and the SM context ID is delivered to AMF.

[0145] 6) Secondary authentication / authorization is optionally performed.

[0146] 7a) If a dynamic PCC is used for the PDU session, the SMF selects the PCF.

[0147] 7b)SMF performs the SM policy association establishment process to establish the SM policy association with the PCF.

[0148] 8) If the request type in step 3 indicates "initial request", the SMF selects the SSC mode for the PDU session. If step 5 is not performed, the SMF can also select the UPF. In the case of request type IPv4 or IPv6, the SMF can allocate an IP address / prefix for the PDU session.

[0149] 9)SMF provides information about the policy control request triggering conditions by executing the SM policy association modification process.

[0150] 10) If the request type indicates "initial request", the SMF can use the selected UPF to start the N4 session establishment process, otherwise it can use the selected UPF to start the N4 session modification process.

[0151] 10a) SMF sends N4 Session Establishment / Modification Request message to UPF. In addition, SMF can provide packet discovery, enforcement and reporting rules for packets to be installed in UPF for PDU session. In the case where SMF allocates CN tunnel information, CN tunnel information can be provided to UPF.

[0152] 10b) The UPF may respond by sending an N4 Session Establishment / Modification Response message. In the case where the CN tunnel information is allocated by the UPF, the CN tunnel information may be provided to the SMF.

[0153] 11)SMF sends a Namf_Communication_N1N2MessageTransfer message to AMF. The Namf_Communication_N1N2MessageTransfer message may include PDU session ID, N2 SM information and N1 SM container.

[0154] The N2 SM information may include PDU Session ID, QoS Flow ID (QFI), QoS Profile, CN Tunnel Information, S-NSSAI from Allowed NSSAI, Session-AMBR, PDU Session Type, User Plane Security Enhancement Information, UE Integrity Protection Maximum Data Rate.

[0155] The N1 SM container may include a PDU Session Establishment Accept message.

[0156] The PDU Session Establishment Accept message may include allowed QoS rules, SSC mode, S-NSSAI and assigned IPv4 address.

[0157] 12)AMF sends an N2 PDU Session Request message to RAN. The message may include N2 SM information and NAS message. The NAS message may include PDU Session ID and PDU Session Establishment Accept message.

[0158] The AMF may send a NAS message including the PDU Session ID and a PDU Session Establishment Accept message. Additionally, the AMF may include the N2 SM information received from the SMF in the N2 PDU Session Request message, and may then send a message including the N2 SM information to the RAN.

[0159] 13) The RAN may perform specific signaling exchanges with the UE related to the information received from the SMF.

[0160] The RAN also allocates RAN N3 tunnel information for the PDU session.

[0161] The RAN forwards the NAS message provided in step 10. The NAS message may include a PDU session ID and N1 SM information. The N1 SM information may include a PDU session establishment accept message.

[0162] The RAN sends a NAS message to the UE only if the required RAN resources are configured and the allocation of the RAN tunnel information is successful.

[0163] 14) RAN sends an N2 PDU Session Response message to AMF. The message may include PDU Session ID, cause and N2 SM information. N2 SM information may include PDU Session ID, (AN) Tunnel Information and a list of allowed / rejected QoS profiles.

[0164] -RAN tunnel information may correspond to the access network address of the N3 tunnel corresponding to the PDU session.

[0165] 15)AMF may send a Nsmf_PDUSession_UpdateSMContext request message to SMF. The Nsmf_PDUSession_UpdateSMContext request message may include N2 SM information. In this document, AMF may forward the N2 SM information received from RAN to SMF.

[0166] 16a) If the N4 session for the PDU session has not been configured, the SMF may start the N4 session establishment procedure with the UPF. Otherwise, the SMF may start the N4 session modification procedure with the UPF. The SMF may provide the AN tunnel information and the CN tunnel information. The CN tunnel information shall be provided only if the SMF selects the CN tunnel information in step 8.

[0167] 16b) UPF may send an N4 session modification response message to SMF.

[0168] 17)SMF sends a Nsmf_PDUSession_UpdateSMContext response message to AMF.

[0169] After this step, AMF can deliver relevant events to SMF.

[0170] 18)SMF sends Nsmf_PDUSession_SMContextStatusNotify message.

[0171] 19) SMF sends information to UE through UPF. More specifically, in the case of PDU type IPv6, SMF can generate IPv6 router advertisements and can send the generated advertisements to UE through N4 and UPF.

[0172] 20) During this process, if the PDU session establishment is unsuccessful, the SMF notifies this to the AMF.

[0173] Figure 6a and Figure 6b The modification process of the PDU session is shown.

[0174] The MA PDU session may be established / managed based on the PDU session modification procedure.

[0175] The PDU session modification procedure may be initiated by the UE or may be initiated by the network.

[0176] 1a) When initiated by the UE, the UE may initiate a PDU session modification procedure by sending a NAS message. The NAS message may include an N1 SM container. The N1 SM container may include a PDU session modification request message, a PDU session ID, and information about the maximum data rate for integrity protection of the UE. The PDU session modification request message may include a PDU session ID, a packet filter, requested QoS information, 5GSM core network capabilities, and the number of packet filters. The maximum data rate for integrity protection of the UE indicates the maximum data rate that the UE can support for UP integrity protection. The number of packet filters indicates the number of packet filters supported for the QoS rules.

[0177] According to the location information of the UE, a NAS message is sent to the appropriate AMF via the RAN. The AMF then sends a Nsmf_PDUSession_UpdateSMContext message to the SMF. The message may include a session management (SM) context ID and an N1 SM container. The N1SM container may include a PDU session modification request message.

[0178] 1b) When initiated by the PCF in a network node, the PCF may notify the SMF of the policy change by initiating the SM policy association modification procedure.

[0179] 1c) When initiated by the UDM in the network node, the UDM can update the subscription data of the SMF by sending a Nudm_SDM_Notification message. The SMF can update the session management subscriber data and send an ACK message to the UDM.

[0180] 1d) When initiated by the SMF in a network node, the SMF can trigger a QoS update.

[0181] When triggered according to above 1a to 1d, SMF can perform the PDU session modification process.

[0182] 1e) When initiated by an AN among network nodes, the AN may notify the SMF when releasing the AN resources to which the QoS flow is mapped. The AN may send an N2 message to the AMF. The N2 message may include a PDU session ID and N2 SM information. The N2 SM information may include a QoS flow ID (QFI), user location information, and an indication that the QoS flow is released. The AMF may send an Nsmf_PDUSession_UpdateSMContext message. The message may include an SM context ID and N2 SM information.

[0183] 2) SMF can send a report on the subscription event by performing the SM policy association modification procedure. If the PDU session modification procedure is triggered by 1b or 1d, this step can be skipped. If dynamic PCC is not deployed in the network, the SMF can apply internal policies to decide to change the QoS profile.

[0184] When PDU session modification only requires UPF operation, steps 3 to 7 which will be described later may not be performed.

[0185] 3a) When initiated by the UE or AN, the SMF may respond to the AMF by sending a Nsmf_PDUSession_UpdateSMContext message. The message may include N2 SM information and N2 SM container. The N2 SM information may include PDU session ID, QFI, QoS profile and session-AMBR. The N1 SM container may include a PDU session modification command. The PDU session modification command may include PDU session ID, QoS rules, QuS rule operations, QoS flow level QoS parameters and session-AMBR.

[0186] The N2 SM information may include information to be sent by the AMF to the AN. The N2 SM information may include a QFI and a QoS profile to inform the AN of adding or modifying one or more QoS flows. If a PDU session modification is requested by a UE for which no user plane resources are configured, the N2 SM information to be delivered to the AN may include information about the establishment of user plane resources.

[0187] The N1 SM container may include a PDU session modification command to be delivered by the AMF to the UE. The PDU session modification command may include QoS rules and QoS flow level QoS parameters.

[0188] 3b) When initiated by SMF, SMF may send Namf_Communication_N1N2MessageTransfer message. The message may include N2 SM information and N1 SM container. N2 SM information may include PDU session ID, QFI, QoS profile and session-AMBR. N1 SM container may include PDU session modification command. PDU session modification command may include PDU session ID, QoS rules and QoS flow level QoS parameters.

[0189] If the UE is in the CM-IDLE state and ATC is activated, the AMF updates and stores the UE context based on the Namf_Communication_N1N2MessageTransfer message, and then steps 3 to 7 described later may be skipped. When the UE enters the reachable state (ie, CM-CONNECTED state), the AMF may send an N1 message to synchronize the UE context with the UE.

[0190] 4) AMF may send an N2 PDU Session Request message to AN. The N2 PDU Session Request message may include the N2 SM information and NAS message received from SMF. The NAS message may include the PDU Session ID and N1 SM container. The N1 SM container may include a PDU Session Modification Command.

[0191] 5) The AN performs AN signaling exchanges with the UE related to the information received from the SMF. For example, in the case of NG-RAN, in order to modify the necessary AN resources related to the PDU session, an RRC connection reconfiguration procedure with the UE may be performed.

[0192] 6) The AN sends an N2 PDU Session ACK message in response to the received N2 PDU Session Request. The N2 PDU Session ACK message may include N2 SM information and user location information. The N2 SM information may include a list of accepted / rejected QFIs, AN tunnel information, and PDU Session ID.

[0193] 7)AMF delivers the user location information and N2 SM information received from AN to SMF through Nsmf_PDUSession_UpdateSMContext message. Then, SMF delivers Nsmf_PDUSession_UpdateSMContext message to AMF.

[0194] 8) SMF sends an N4 session modification request message to UPF to update the N4 session of UPF included in the PDU session modification.

[0195] When generating a new QoS flow, the SMF updates the UL packet detection rule of the new QoS flow together with the UPF.

[0196] 9) In response to receiving a PDU session modification command, the UE sends a NAS message. The NAS message may include a PDU session ID and an N1 SM container. The N1 SM container may include a PDU session modification command ACK.

[0197] 10) The AN sends a NAS message to the AMF.

[0198] 11) The AMF delivers the user location information and the N1 SM container received from the AN to the SMF via the Nsmf_PDUSession_UpdateSMContext message. The N1 SM container may include a PDU session modification command ACK. The SMF may deliver an Nsmf_PDUSession_UpdateSMContext response message to the AMF.

[0199] 12) The SMF sends an N4 session modification request message to the UPF to update the N4 session of the UPF included in the PDU session modification. The message may include an N4 session ID.

[0200] 13) When the SMF interacts with the PCF in step 1b or step 2 above, the SMF may notify the PCF whether PCC decision can be performed through the SM policy association modification process.

[0201] The SMF may notify the requesting entity of the user location information related to the change of the PDU session.

[0202] <RRC state>

[0203] Hereinafter, the RRC state will be described.

[0204] Figure 7 The RRC state is shown.

[0205] When an RRC connection is established between the RRC layer of the UE and the RRC layer of the NG-RAN (i.e., gNB), the UE is in the RRC_CONNECTED state, otherwise it is in the RRC_IDLE state. In the case of NR, the RRC_INACTIVE state is additionally defined, and a UE in the RRC_INACTIVE state can release the connection with the base station while maintaining the connection with the core network.

[0206] <Device-to-Device (D2D) communication>

[0207] On the other hand, hereinafter, D2D communication will be described.

[0208] Figure 8The concept of device-to-device (D2D) communication is shown.

[0209] As service demands for social network services (SNS) increase, communication between UEs physically in close proximity, that is, device-to-device (D2D) communication, is required. In addition, in the case of UEs for public safety, D2D communication may be used.

[0210] In order to reflect the above requirements, Figure 8 As shown, between UE#1 100-1, UE#2 100-2, UE#3 100-3 or between UE#4 100-4, UE#5 100-5, UE#6 100-6, a method for directly communicating without the intervention of the base station (gNB) 300 is being discussed. Of course, UE#1 100-1 and UE#4 100-4 can communicate directly with the help of the base station (gNB) 300. In addition, UE#4 100-4 can act as a relay for UE#5 100-5 and UE#6 100-6. Similarly, UE#1 100-1 can act as a repeater for UE#2 100-2 and UE#3 100-3 far away from the cell center.

[0211] On the other hand, D2D communication is also called Proximity Service (ProSe). In addition, a UE that performs Proximity Service is also called a ProSe UE. A link between UEs used for D2D communication is also called a side link.

[0212] The physical channels used for the sidelink include:

[0213] -Physical Sidelink Shared Channel (PSSCH)

[0214] -Physical Sidelink Control Channel (PSCCH)

[0215] -Physical Sidelink Discovery Channel (PSDCH)

[0216] -Physical Sidelink Broadcast Channel (PSBCH)

[0217] In addition, the following physical signals are used in the side link.

[0218] -Demodulation Reference Signal (DMRS)

[0219] - Side Link Synchronization Signal (SLSS)

[0220] The SLSS includes a primary side link synchronization signal (PSLSS) and a secondary side link synchronization signal (SSLSS).

[0221] Fig. 9 The architecture of UE to network relay is shown. Fig.10The protocol stack for UE-to-network relay is shown.

[0222] Reference Fig. 9 , UE to network relay supports network connection of remote UE.

[0223] The PC5 link is the interface between the UE and the UE-to-network relay. The Uu link is the interface between the UE-to-network relay and the base station.

[0224] If the UE has established a PC5 link with the UE-to-network relay, the UE is considered to be a remote UE.

[0225] The communication between the remote UE and the UE-to-network relay is performed as a one-to-one direct communication.

[0226] Furthermore, in the past, UE-to-network relay only supported one hop, but recently, UE-to-network relay needs to be improved to support multiple hops.

[0227] <Method for selectively activating and deactivating UP connection of PDU session>

[0228] Furthermore, in 5GS, a method to activate or deactivate the User Plane (UP) connection for each PDU Session has been defined.

[0229] Specifically, it is as follows.

[0230] This content applies to the case when the UE has established multiple PDU sessions. Activating the UP connection of an existing PDU session includes activating the user plane connection (ie, data bearers and N3 tunnel) between the UE and the core network (CN).

[0231] For UEs in CM-IDLE state in 3GPP access, the service request procedure triggered by the UE or the network can support independent activation of the UP connection of the PDU session. For UEs in CM-IDLE state in non-3GPP access, the service request procedure triggered by the UE allows reactivation of the UP connection of the PDU session and can support independent activation of the UP connection of the PDU session.

[0232] A UE in CM-CONNECTED state may perform a service request procedure to request independent activation of a UP connection for a PDU session.

[0233] The UP connection for reactivation of a PDU session by the network can be handled as follows:

[0234] - If the UE state in the AMF is in CM-CONNECTED state on the access (e.g. 3GPP access or non-3GPP access) associated with the PDU session in the SMF, the network can use the service request procedure to reactivate the UP connection for the PDU session.

[0235] otherwise

[0236] -If the UE is registered in both 3GPP access and non-3GPP access, and the UE state in the AMF is CM-IDLE state in non-3GPP access, the UE can receive paging messages or notification messages through 3GPP access for the PDU session associated with the SMF.

[0237] -If the UE state in the AMF is in CM-IDLE state in 3GPP access, the paging message may include the access type associated with the PDU session in the SMF. Upon receiving the paging message containing information about the access type, the UE may reply to the 5GC via 3GPP access using a NAS service request message containing a list of PDU sessions associated with the received access type whose UP connection can be reactivated via 3GPP access. If the PDU session for which the UE has received the paging message is included in the list of PDU sessions in the NAS service request, and the paging message is received via downlink data, the 5GC may reactivate the PDU session UP connection via 3GPP access. If the paging message is received via downlink signaling, the service request message may succeed without reactivating the PDU session UP connection via 3GPP access, and the downlink signaling may be delivered to the UE via 3GPP access.

[0238] - If the UE state in the AMF is CM-CONNECTED state in 3GPP access, the notification message may include information about the non-3GPP access type. Upon receiving the notification message, the UE may reply to the 5GC with a NAS SERVICE REQUEST message containing a list of allowed PDU Sessions that can be reactivated via 3GPP access, or an empty list of allowed PDU Sessions if no PDU Sessions are allowed to be reactivated via 3GPP access.

[0239] -If the UE is registered in both 3GPP access and non-3GPP access served by the same AMF, and the UE state in the AMF is CM-IDLE in 3GPP access and CM-CONNECTED in non-3GPP access, the UE may receive a notification message over non-3GPP access for a PDU session associated with the SMF. The notification message may include information about the 3GPP access type. Upon receiving the notification message, the UE may reply to the 5GC via the 3GPP access using a NAS Service Request message when 3GPP access is available.

[0240] A PDU Session may be established as an always-on PDU Session.

[0241] Deactivating the UP connection of a PDU session includes deactivating the corresponding data bearer and N3 tunnel. The UP connections of different PDU sessions can be deactivated independently. When the UP of a PDU session is deactivated using an N9 tunnel whose endpoints are controlled by the I-SMF, the N9 tunnel can be retained. If the PDU session is an always-on PDU session, the SMF may not deactivate the UP connection of the PDU session.

[0242] Fig.11 is an exemplary flow chart illustrating a process by which a network selectively deactivates a UP connection for a PDU session.

[0243] The following procedure is used to deactivate the UP connection for a PDU Session of a UE in CM-CONNECTED state. For always-on PDU Sessions, the SMF may not configure the UPF to report inactivity.

[0244] Step 1. The SMF may determine that the UP connection of a PDU Session may be deactivated in the following cases:

[0245] - During the handover procedure, if all QoS flows of the PDU Session are rejected by the target NG-RAN or if the PDU Session indicated by the AMF cannot be established.

[0246] -UPF detects that the PDU session has no data transmission within the specified inactivity period;

[0247] - For a LADN PDU session, the AMF notifies the SMF that the UE has moved out of the LADN service area; or

[0248] -AMF notifies SMF that the UE has moved out of the allowed area.

[0249] The SMF may decide to release the UPF of the N3 termination point. In this case, the SMF proceeds with steps 2 and 3. Otherwise, if the SMF decides to keep the UPF of the N3 termination point, the SMF may proceed with step 4.

[0250] Step 2. The SMF may initiate an N4 session release procedure to release the intermediate UPF of the N3 termination point. If there are multiple intermediate UPFs, this step may be performed for each UPF to be released. The SMF may initiate an N4 session modification procedure to the UPF connected to the released UPF (i.e., the N9 termination point or PDU session anchor).

[0251] Step 3. If the intermediate UPF of the N3 termination point is released in step 2, the SMF initiates the N4 session modification process to the UPF connected to the released UPF, indicating that the AN tunnel information of the N3 tunnel of the corresponding PDU session needs to be removed. In this case, the UPF connected to the released UPF can buffer the DL packets of the PDU session or discard the DL packets of the PDU session or forward the DL packets of the PDU session to the SMF based on the buffering instructions provided by the SMF. When the PDU session corresponds to a LADN, the SMF can notify the UPF connected to the released UPF to discard the downlink data of the PDU session and / or not provide further data notification messages.

[0252] Otherwise, the N4 session modification process may occur towards the N3 termination point.

[0253] Step 4. If the UPF of the N3 termination point is not released in step 2, the SMF can initiate the N4 session modification process, which indicates that the AN tunnel information of the N3 tunnel of the corresponding PDU session needs to be removed.

[0254] In this case, the UPF may buffer the DL packets of the PDU session or discard the DL packets of the PDU session or forward the DL packets of the PDU session to the SMF based on the buffering instructions provided by the SMF. When the PDU session corresponds to a LADN, the SMF may notify the UPF to discard the downlink data of the PDU session and / or not provide further data notification messages.

[0255] Step 5. The SMF may send a Namf_Communication_N1N2MessageTransfer message to release the NG-RAN resources associated with the PDU session. The message may include the PDU session ID and N2 SM information. The N2 SM information may include an N2 resource release request. The N2 resource release request may include the PDU session ID.

[0256] Step 6.AMF may send an N2 PDU Session Resource Release Command including the N2 SM information received from SMF.

[0257] Step 7. The NG-RAN may issue an NG-RAN specific signaling exchange with the UE (e.g., RRC connection reconfiguration) to release the NG-RAN resources associated with the PDU session received from the AMF. When the user plane connection for the PDU session is released, the AS layer in the UE indicates this to the NAS layer.

[0258] If the UE is in RRC Inactive state, this step can be skipped. When the UE changes from RRC Inactive state to RRC Connected state, the NG-RAN and the UE synchronize the released radio resources of the deactivated PDU sessions.

[0259] Step 8. NG-RAN confirms the N2 PDU session resource release command to AMF, which includes the N2 SM resource release Ack message. The N2 SM resource release Ack message may include user location information and secondary RAT usage data.

[0260] Step 9.AMF sends a Nsmf_PDUSession_UpdateSMContext message to confirm the message in step 5. The Nsmf_PDUSession_UpdateSMContext message may include N2 SM information. The N2 SM information may include secondary RAT usage data.

[0261] On the other hand, in the case of layer 2 UE to network relay, the relay UE and the remote UE respectively establish their own PDU sessions with the network. That is, although the remote UE receives network connection services through the relay UE, the remote UE is able to exchange NAS messages with the network, thereby creating or modifying the PDU session, and also perform a service request process for reactivating the UP connection of the PDU session.

[0262] In addition, the relay UE can share and use Uu Data Radio Bearer (DRB) with the remote UE. That is, the DRB used by the relay UE to send and receive its own traffic can also be used for the purpose of relaying the traffic of the remote UE.

[0263] <Problems to be Solved by the Disclosure of This Specification>

[0264] like Fig.11 As described in step 7 of , when the PDU session of the UE is deactivated, the AS layer of the UE sends to the NAS layer that the UP connection is also released according to the deactivation. Therefore, when the UE needs to reuse the PDU session for which the UP connection has been released, it can request an operation for activating the UP connection of the PDU session from the network.

[0265] However, if the relay UE and the remote UE share and use Uu DRB (hereinafter, referred to as DRB), the relay UE needs to maintain the DRB for the remote UE even if the PDU session of the relay UE is deactivated.

[0266] Therefore, the relay UE (specifically, the NAS layer of the relay UE) may fail to recognize whether the PDU session is deactivated. As a result, the core network believes that the PDU session is deactivated, but the relay UE believes that the PDU session is still active, resulting in a state mismatch of the PDU session. Specifically, this may cause problems with the relay UE sending services through the PDU session.

[0267] <Disclosure of this specification>

[0268] In order to solve the above problem, the disclosure of this specification proposes a method for processing UP deactivation of a PDU session of a relay UE.

[0269] Hereinafter, in this specification, user equipment (UE) and terminal may be used interchangeably. In addition, UE-to-network relay, ProSe UE-to-network relay, relay, relay UE, UE-NW relay, eRelay, eRelay UE, eRelay-UE, ProSe relay, and ProSe relay UE may be used interchangeably. In addition, remote UE, eRemote UE, eRemote-UE, ProSe remote UE, and ProSe remote may be used interchangeably.

[0270] In this specification, UP connection deactivation of a PDU session is used interchangeably with PDU session deactivation and UP deactivation of a PDU session. In addition, UP connection activation of a PDU session is used interchangeably with PDU session activation and UP activation of a PDU session.

[0271] The method proposed in this specification is applicable to various services such as eMBB, vehicle-to-everything (V2X), public safety, Internet of Things (IoT), IIoT, etc.

[0272] In this specification, PC5 may refer to NR PC5 only, or may refer to both NR PC5 and LTE PC5.

[0273] In this specification, NG-RAN may refer to only gNB, or may refer to both gNB and ng-eNB.

[0274] The method for processing PDU session deactivation of relay UE proposed in this specification consists of a combination of one or more of the following operations / configurations / steps.

[0275] Fig.12a and Figure 12b is an exemplary signal flow diagram illustrating a process according to one disclosed content of this specification.

[0276] exist Fig.12a and Figure 12bIn the example, since UE-2 requires network connection service, after selecting UE-1 as the UE to network relay, it can be assumed that one-to-one direct communication has been established. That is, it can be assumed that UE-1 (i.e., relay UE) and UE-2 (i.e., remote UE) have established a PC5 unicast link. In the following, PC5 unicast link is used interchangeably with unicast link, second layer link, layer 2 link and L2 link. When UE-1 and UE-2 form a relationship of relay UE and remote UE (or establish a relationship), they can interact with the network (e.g., for authentication / authorization). The service AMF of each UE can obtain information of the other UE (e.g., the ID of the other UE, temporary ID, etc.) and store the obtained information in the context of the service UE. For example, the service AMF (AMF-2) of UE-2, which is a remote UE, can store information of UE-1, which is a relay UE, in the context of UE-2.

[0277] The information of UE-1 includes the serving AMF information and the subscription permanent identifier (SUPI) of UE-1, the 5G globally unique temporary identifier (5G-GUTI), the 5G-S-temporary mobile subscriber identity (5G-S-TMSI), and the 5G-TMSI.

[0278] Step 1. Activate the UP connection of PDU Session #1 created by UE-1.

[0279] The UP connection of the PDU session may be activated according to various procedures including the following.

[0280] -PDU session establishment procedure requested by UE

[0281] -Service request process initiated by UE

[0282] - Network initiated service request procedure

[0283] -Registration process

[0284] Activating the UP connection for the PDU session involves: the NG-RAN (i.e., gNB or ng-eNB) establishing a DRB with the UE. To this end, the NG-RAN (i.e., gNB or ng-eNB) may perform an RRC reconfiguration procedure or an RRC connection reconfiguration procedure with the UE.

[0285] Taking the service request procedure as an example, the NG-RAN (i.e., gNB or ng-eNB) may perform an RRC connection reconfiguration procedure with the UE based on the N2 request message received from the AMF. The NG-RAN (i.e., gNB or ng-eNB) may establish a DRB with the UE to support all QoS flows of PDU Session #1 belonging to UE-1. To this end, in the case of gNB, an RRC reconfiguration message is used, while in the case of ng-eNB, an RRC connection reconfiguration message is used.

[0286] The RRC reconfiguration message contains the radioBearerConfig field to configure the DRB.

[0287] [Table 3]

[0288]

[0289] defaultDRB indicates whether the default DRB is used for the PDU session.

[0290] Since the UP connection needs to be activated for PDU Session #1 of UE-1, DRB-ToAddModList is included above.

[0291] For example, if a QoS flow (QFI=0) is included in PDU Session #1 of UE-1 and a DRB is generated for this purpose, DRB-ToAddMod may be included in the following form. Hereinafter, main information elements (IEs) will be mainly described.

[0292] i) drb-Identity = 1

[0293] ii)sdap-Config

[0294] ii-1) pdu-Session = 0

[0295] ii-2)sdap-HeaderDL="present"

[0296] ii-3)sdap-HeaderUL="present"

[0297] ii-4)defaultDRB="true"

[0298] ii-5)mappedQoS-FlowsToAdd={QFI=0}

[0299] Although the use of DRB-ToAddModList and DRB-ToAddMod has been described above, a new IE may be defined and used for the PDU session of the UE operating as a relay UE, or an existing IE may be modified / extended and used. For example, information notifying that it is for the relay UE itself may be explicitly or implicitly included in DRB-ToAddMod. Alternatively, information notifying that the DRB can be shared between the relay UE and the remote UE may be explicitly or implicitly included.

[0300] UE-1 configures DRB for PDU Session #1 based on the DRB configuration information provided by NG-RAN (i.e., gNB or ng-eNB).

[0301] UE-1 and NG-RAN (i.e., gNB or ng-eNB) store the information / context of the established DRBs.

[0302] Step 2. Activate the UP connection of PDU Session #2 generated by UE-2 (ie, the remote UE).

[0303] Since the data / service of UE-2 (i.e., remote UE) ultimately passes through UE-1 (i.e., relay UE) and NG-RAN (i.e., gNB or ng-eNB), NG-RAN (i.e., gNB or ng-eNB) needs to add / modify / update the DRB for PDU session #2 of UE-2 to the UE.

[0304] It is assumed that the NG-RAN (i.e., gNB or ng-eNB) already knows that UE-2 (i.e., remote UE) is receiving network connection services via UE-1 (i.e., relay UE) through RRC connection establishment with UE-2 (i.e., remote UE).

[0305] The NG-RAN (i.e., gNB or ng-eNB) may determine that it can support the data traffic of UE-2 using the DRB established / configured in step 1 (i.e., DRB with drb-Identity=1). This determination may be based on the QoS characteristics of UE-1's PDU Session #1 (or the QoS flow belonging thereto) and UE-2's PDU Session #2 (or the QoS flow belonging thereto) (e.g., when the QoS characteristics are the same / similar to share the DRB).

[0306] For example, two QoS flows (QFI=0 and QFI=1) may be included in PDU Session #2 of UE-2, and it may be determined that they are supported by the DRB with drb-Identity=1 established / configured in step 1. In this case, the NG-RAN (i.e., gNB or ng-eNB) needs to configure UE-1 (i.e., relay UE) to modify / update the DRB. This can be interpreted as an operation of adding two QoS flows to the DRB.

[0307] To this end, the RRC configuration message may be extended and used, or a new RRC message may be defined and used. When a new RRC message is defined, it may be used to configure DRB / signaling radio bearer (SRB) / RRC for UE-2 (i.e., remote UE) to UE-1 (i.e., relay UE). This may be used when UE-1 (i.e., relay UE) and UE-2 (i.e., remote UE) share and use a radio bearer (RB) and / or use them individually without sharing the RB.

[0308] In the following description, it is assumed that the RRC configuration message is extended and used.

[0309] To reflect the UP connection activation of the PDU session of UE-2 (i.e., the remote UE), DRB-ToAddModList can be modified / extended and used in the RRC configuration message, or a new IE can be defined and used. Regardless of the method used, the DRB configuration information provided to the relay UE can explicitly or implicitly include information indicating that it is for the remote UE.

[0310] In the above method, if a new IE (e.g., DRB-ToAddModList-forRemoteUE) is defined and used as an example, when the NG-RAN (i.e., gNB or ng-eNB) performs an RRC connection reconfiguration procedure with UE-1 (i.e., relay UE), the following information may be provided for DRB modification / update. The main information is mainly introduced below.

[0311] i) drb-Identity = 1

[0312] ii) One or more of the following

[0313] ii-1) Information notifying that it is for the remote UE (ie, UE-2): information notifying that the DRB configuration information provided to the relay UE (ie, UE-1) is for the remote UE (ie, UE-2) is explicitly or implicitly included.

[0314] ii-2) ID information of the remote UE (i.e., UE-2): This includes various types of ID information, such as C-RNTI, SUPI, 5G-GUTI, 5G-S-TMSI, 5G-TMSI, Layer-2 ID, etc.

[0315] ii-3) Notification of information on sharing the DRB between the relay UE (ie, UE-1) and the remote UE (ie, UE-2).

[0316] iii)sdap-Config

[0317] iii-1) pdu-Session = 1

[0318] iii-2)sdap-HeaderDL="present"

[0319] iii-3)sdap-HeaderUL="present"

[0320] iii-4)defaultDRB="true"

[0321] iii-5)mappedQoS-FlowsToAdd={QFI=0,QFI=1}

[0322] UE-1 (i.e., relay UE) modifies / updates the existing DRB (DRB with drb-Identity=1) based on the DRB configuration information provided by NG-RAN (i.e., gNB or ng-eNB). According to the above example, the DRB supports one QoS flow of PDU session #1 of UE-1 (i.e., relay UE) and two QoS flows of PDU session #2 of UE-2 (i.e., remote UE).

[0323] Whether by modifying / extending the DRB-ToAddModList in the RRC configuration message or defining or using a new IE to reflect the UP connection activation of the PDU session of the remote UE (i.e., UE-2), ultimately, the purpose is to inform the relay UE (i.e., UE-1) which DRB to modify / update. Therefore, this can be understood as appropriately providing the necessary information so that the relay UE (i.e., UE-1) can perform DRB configuration based on this.

[0324] UE-1 (i.e., relay UE) and NG-RAN (i.e., gNB or ng-eNB) store the information / context of the established DRB.

[0325] Although not described in detail separately, the NG-RAN (i.e., gNB or ng-eNB) may also perform an RRC connection reconfiguration procedure with UE-2 (i.e., UE-2) for PDU session #2 of UE-2 through UE-1.

[0326] Step 3. SMF determines that the UP connection of PDU Session #1 of UE-1 (i.e., relay UE) can be deactivated. For details of step 3, refer to Fig.11 Step 1.

[0327] Steps 4-8. This will refer to Fig.11 Follow steps 2 to 6.

[0328] Step 9. To reflect the deletion of PDU Session #1 of UE-1 from the DRB (i.e., DRB with drb-Identity=1) shared and used by the relay UE (i.e., UE-1) and the remote UE (i.e., UE-2), the NG-RAN (i.e., gNB or ng-eNB) performs an RRC reconfiguration procedure or an RRC connection reconfiguration procedure with UE-1 (i.e., the relay UE).

[0329] Specifically, in order for UE-1 (i.e., relay UE) to delete information about PDU session #1 of UE-1 (i.e., relay UE) configured in the DRB in step 1, the NG-RAN (i.e., gNB or ng-eNB) sends an RRC reconfiguration message or an RRC connection reconfiguration message.

[0330] For example, NG-RAN (i.e., gNB or ng-eNB) can provide DRB-ToAddMod including the following main information in DRB-ToAddModList of RRC Reconfiguration message or RRC Connection Reconfiguration message.

[0331] i) drb-Identity = 1

[0332] ii)sdap-Config

[0333] ii-1) pdu-Session = 0

[0334] ii-2)sdap-HeaderDL="present"

[0335] ii-3)sdap-HeaderUL="present"

[0336] ii-4)defaultDRB="true"

[0337] ii-5)mappedQoS-FlowsToRelease={QFI=0}

[0338] As another example, the NG-RAN (i.e., gNB or ng-eNB) may provide DRB-ToReleaseList={1} in an RRC reconfiguration message or an RRC connection reconfiguration message.

[0339] The DRB configuration information of the NG-RAN (i.e., gNB or ng-eNB) as described above may implicitly or explicitly include information notifying that the DRB is shared between the relay UE (i.e., UE-1) and the remote UE (i.e., UE-2).

[0340] Due to the DRB configuration (or DRB modification / update configuration, or RRC reconfiguration) of the NG-RAN (i.e., gNB or ng-eNB), UE-1 (i.e., relay UE) can determine that its own PDU session PDU Session #1 has been deleted / removed in the DRB with drb-Identity = 1. This can be interpreted as UE-1 can determine that the DRB with drb-Identity = 1 still exists for the remote UE (i.e., UE-2).

[0341] Although the DRB of drb-Identity=1 itself is not released / removed, UE-1 (i.e., relay UE) can determine that the DRB has been released / removed for itself. As a result, the AS layer of UE-1 (i.e., relay UE) notifies the NAS layer that the UP connection of PDU Session #1 (i.e., its own PDU Session #1) is notified (or provides information notifying this). For this reason, when UE-1 (i.e., relay UE) needs to use PDU Session #1 in the future, it can perform a request to the network for activating the UP connection of PDU Session #1.

[0342] Although the use of DRB-ToAddModList and DRB-ToAddMod or the existing DRB-ToReleaseList has been described, for the PDU session of UE-1 operating as a relay UE, a new IE may be defined and used, or an existing IE may be modified / extended and used. For example, information notifying that it is for a relay UE may be explicitly or implicitly included in DRB-ToAddMod. Alternatively, information notifying that it is for a relay UE may be explicitly or implicitly included in DRB-ToReleaseList.

[0343] UE-1 (i.e., relay UE) and NG-RAN (i.e., gNB or ng-eNB) store the information / context of the modified / updated DRB.

[0344] Step 10. UE-1 (i.e., relay UE) sends an RRC reconfiguration complete message in response to the RRC reconfiguration message of the NG-RAN (i.e., gNB or ng-eNB).

[0345] Steps 11-12. This will refer to Fig.11 Steps 8 to 9.

[0346] Fig.12a and Figure 12b It is shown that the SMF and UPF of PDU Session #1 of UE-1 are the same as the SMF and UPF of PDU Session #2 of UE-2, but different SMFs may be used and different UPFs may be used.

[0347] Fig.13 is an example Fig.12a and Figure 12b An example diagram of the internal operation of UE-1 (relay UE) is shown.

[0348] according to Fig.12a and Figure 12b In steps 3 to 9, when the UP connection of the PDU session #1 of UE-1 (ie, the relay UE) is deactivated and thus the RRC connection reconfiguration process is performed, the PDU session #1 of UE-1 may be deleted from the DRB.

[0349] Then, the AS layer of UE-1 (ie, relay UE) may inform the NAS layer that the UP connection of its PDU Session #1 has been released.

[0350] For this reason, when UE-1 (ie, relay UE) needs to use PDU Session #1 in the future, a request for activating a UP connection of PDU Session #1 may be performed to the network.

[0351] The effects according to the disclosure of this specification are as follows.

[0352] When the relay UE and the remote UE share and use DRBs, the DRBs need to be maintained for the remote UE even if the PDU session of the relay UE is deactivated. Therefore, a phenomenon may occur in which the relay UE (specifically, the NAS layer of the relay UE) does not recognize whether the PDU session is deactivated. As a result, the core network believes that the PDU session is deactivated, but the relay UE believes that the PDU session is still active, which may cause a PDU session state mismatch. The disclosure of this specification ensures that such a mismatch state does not exist. That is, the disclosure of this specification enables the NAS layer of the relay UE to recognize that the PDU session is deactivated.

[0353] Hereinafter, devices to which the above disclosed contents of the present specification can be applied will be described.

[0354] Fig.14 A block diagram of a processor in which the disclosed contents of this specification are implemented is shown.

[0355] As reference Fig.14 As can be seen, the processor 1020 in which the disclosure of this specification is implemented may include multiple circuits for implementing the proposed functions, processes and / or methods described herein. For example, the processor 1020 may include a first circuit 1020-1, a second circuit 1020-2, and a third circuit 1020-3. In addition, although not shown, the processor 1020 may include more circuits. Each circuit may include multiple transistors.

[0356] The processor 1020 may be referred to as an application specific integrated circuit (ASIC) or an application processor (AP), and include at least one of a digital signal processor (DSP), a central processing unit (CPU), and a graphic processing unit (GPU).

[0357] The processor may be a relay UE or a remote UE.

[0358] First, a case where a processor is included in a relay UE will be described.

[0359] The first circuit 1020 - 1 of the processor may receive a radio resource control (RRC) reconfiguration message or an RRC connection reconfiguration message from a base station.

[0360] The RRC reconfiguration message or the RRC connection reconfiguration message may include identification information of a data radio bearer (DRB) shared with a remote UE and information about a protocol data unit (PDU) session to be deleted or released in the DRB.

[0361] The second circuit 1020-2 of the processor can deliver information that the user plane (UP) connection of the PDU session is released from the access stratum (AS) layer of the relay UE to the non-access stratum (NAS) layer of the relay UE based on the received RRC reconfiguration message or RRC connection reconfiguration message.

[0362] The information about the PDU session to be deleted or released in the DRB may be information about the PDU session of the relay UE.

[0363] The data service of the remote UE can be relayed through the DRB.

[0364] The third circuit 1020 - 3 of the processor may send an RRC reconfiguration complete message in response to receiving the RRC reconfiguration message or the RRC connection reconfiguration message.

[0365] A fourth circuit (not shown) of the processor may determine, by the relay UE, to reuse its own PDU session.A fifth circuit (not shown) of the processor may send a service request message.

[0366] A sixth circuit (not shown) of the processor may receive an RRC reconfiguration message or an RRC connection reconfiguration message to activate a UP connection for the PDU session.

[0367] A seventh circuit (not shown) of the processor may enable the relay UE to establish a one-to-one direct communication with the remote UE.

[0368] In the case of determining that the DRB used to send the data service of the relay UE is used to relay the data service of the remote UE, the eighth circuit (not shown) of the processor may receive an RRC reconfiguration message or an RRC connection reconfiguration message from the base station.

[0369] The RRC reconfiguration message or the RRC connection reconfiguration message may include one or more of the following: identification information of the DRB, information notifying that it is for a remote UE, ID information of the remote UE, or information on a PDU session of the remote UE.

[0370] Fig.15 A wireless communication system according to an embodiment is illustrated.

[0371] Reference Fig.15 , a wireless communication system may include a first device 100a and a second device 100b.

[0372] The first device 100a may be a UE described in the disclosure of this specification. Alternatively, the first device 100a may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with a self-driving function, a connected car, a drone (unmanned aerial vehicle (UAV)), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a Fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or a device related to the field of the fourth industrial revolution.

[0373] The second device 100b may be a network node (e.g., AMF or MME) described in the disclosure of this specification. Alternatively, the second device 100b may be a base station, a network node, a transmitting terminal, a receiving terminal, a radio device, a wireless communication device, a vehicle, a vehicle equipped with a self-driving function, a connected car, a drone (unmanned aerial vehicle (UAV)), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a Fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or a device related to the field of the fourth industrial revolution.

[0374] For example, UE may include a cellular phone, a smart phone, a laptop computer, a terminal for digital broadcasting, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation, a plate PC, a tablet PC, an ultrabook, a wearable device (e.g., a watch type terminal (smart watch), a glasses type terminal (smart glasses), a head mounted display (HMD)), etc. For example, the HMD may be a display device in a form worn on the head. For example, the HMD may be used to implement VR, AR, or MR.

[0375] For example, a drone may be a flying vehicle that is flown by a wireless control signal without a person on the flying vehicle. For example, a VR device may include a device that realizes an object or background of a virtual world. For example, an AR device may include a device that realizes an object or background of a virtual world by connecting it to an object or background of a real world. For example, an MR device may include a device that realizes an object or background of a virtual world by merging it with an object or background of a real world. For example, a hologram device may include a device that realizes a 360-degree stereoscopic graphic image by recording and playing back stereoscopic graphic information using the interference phenomenon of light beams generated when two lasers meet, which is called holographic technology. For example, a public safety device may include a video relay device or an imaging device that can be worn on the user's body. For example, an MTC device and an IoT device may be a device that does not require direct human intervention or manipulation. For example, an MTC device and an IoT device may include a smart meter, a vending machine, a thermometer, a smart light bulb, a door lock, or various sensors. For example, a medical device may be a device for the purpose of diagnosing, treating, alleviating, disposing, or preventing a disease. For example, a medical device may be a device for the purpose of diagnosing, treating, alleviating, or correcting an injury or obstacle. For example, a medical device may be a device for the purpose of inspecting, replacing, or modifying a structure or function. For example, a medical device may be a device for the purpose of controlling pregnancy. For example, a medical device may include a device for medical treatment, a device for operation, a device for (external) diagnosis, a hearing aid, or a device for surgery. For example, a safety device may be a device installed to prevent possible dangers and maintain safety. For example, a safety device may be a camera, CCTV, a recorder, or a black box. For example, a Fintech device may be a device capable of providing financial services (such as mobile payments). For example, a Fintech device may include a payment device or a point of sale (POS). For example, a climate / environmental device may include a device for monitoring or predicting the climate / environment.

[0376] The first device 100a may include at least one processor (e.g., processor 1020a), at least one memory (e.g., memory 1010a), and at least one transceiver (e.g., transceiver 1031a). The processor 1020a may perform the above functions, processes, and / or methods. The processor 1020a may execute one or more protocols. For example, the processor 1020a may execute one or more layers of a radio interface protocol. The memory 1010a is connected to the processor 1020a and may store various forms of information and / or instructions. The transceiver 1031a is connected to the processor 1020a and may be controlled to send and receive radio signals.

[0377] The second device 100b may include at least one processor (e.g., processor 1020b), at least one memory device (e.g., memory 1010b), and at least one transceiver (e.g., transceiver 1031b). The processor 1020b may perform the above functions, processes, and / or methods. The processor 1020b may implement one or more protocols. For example, the processor 1020b may implement one or more layers of a radio interface protocol. The memory 1010b is connected to the processor 1020b and may store various forms of information and / or instructions. The transceiver 1031b is connected to the processor 1020b and may be controlled to send and receive radio signals.

[0378] The memory 1010a and / or the memory 1010b may be connected inside or outside the processor 1020a and / or the processor 1020b, respectively, and may be connected to another processor through various techniques such as a wired or wireless connection.

[0379] The first device 100a and / or the second device 100b may have one or more antennas. For example, the antenna 1036a and / or the antenna 1036b may be configured to transmit and receive radio signals.

[0380] Fig.16 A block diagram of a network node according to an embodiment is illustrated.

[0381] In particular, Fig.16 is a diagram illustrating in detail a case where a base station is divided into a central unit (CU) and a distributed unit (DU).

[0382] Reference Fig.16 , base stations W20 and W30 can be connected to the core network W10. Base station W30 can be connected to the adjacent base station W20. For example, the interface between base stations W20 and W30 and the core network W10 can be called NG. The interface between base station W30 and the adjacent base station W20 can be called Xn.

[0383] The base station W30 can be divided into CU W32 and DU W34, W36. That is, the base station W30 can be divided and operated in layers. CU W32 can be connected to one or more DU W34, W36. For example, the interface between CU W32 and DU W34, W36 can be called F1. CU W32 can perform the functions of the high layer of the base station. DU W34, W36 can perform the functions of the low layer of the base station. For example, CU W32 can be a logical node of the radio resource control (RRC), service data adaptation protocol (SDAP) and packet data convergence protocol (PDCP) layers of the host base station (e.g., gNB). DU W34, W36 can be a logical node of the radio link control (RLC), medium access control (MAC) and physical (PHY) layers of the host base station. Alternatively, CU W32 can be a logical node of the RRC and PDCP layers of the host base station (e.g., en-gNB).

[0384] The operation of DU W34, W36 can be partially controlled by CU W32. One DU W34, W36 can support one or more cells. One cell can be supported by only one DU W34, W36. One DU W34, W36 can be connected to one CU W32, and one DU W34, W36 can be connected to multiple CUs through appropriate implementation.

[0385] Fig.17 is a block diagram illustrating a configuration of a UE according to an embodiment.

[0386] Specifically, Fig.17 The UE 100 shown is a more detailed example Fig.15 Figure 1 of the first device.

[0387] The UE includes a memory 1010, a processor 1020, a transceiver 1031, a power management module 1091, a battery 1092, a display 1041, an input unit 1053, a speaker 1042, a microphone 1052, a Subscriber Identity Module (SIM) card, and one or more antennas.

[0388] The processor 1020 may be configured to implement the proposed functions, processes and / or methods described in this specification. The layers of the wireless interface protocol may be implemented in the processor 1020. The processor 1020 may include an application specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The processor 1020 may be an application processor (AP). The processor 1020 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modulator and demodulator (modem). An example of the processor 1020 may be a processor composed of Made by Snapdragon TM Series processors, Manufactured by EXYNOS TM Series processors, A series processors manufactured by Made by HELIO TM Series processors, ATOM manufactured TM series processors or the corresponding next-generation processors.

[0389] The power management module 1091 manages the power of the processor 1020 and / or the transceiver 1031. The battery 1092 supplies power to the power management module 1091. The display 1041 outputs the result processed by the processor 1020. The input unit 1053 receives input to be used by the processor 1020. The input unit 1053 may be displayed on the display 1041. The SIM card is an integrated circuit for securely storing an International Mobile Subscriber Identity (IMSI) and related keys, which is used to identify subscribers in mobile phone devices such as mobile phones and computers. Many types of contact address information can be stored in a SIM card.

[0390] The memory 1010 is connected to the processor 1020 in a manner that operates and stores various types of information to operate the processor 1020. The memory may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. When the embodiment is implemented in software, the technology described in this specification may be implemented in a module (e.g., a process, a function, etc.) for performing the functions described in this specification. The module may be stored in the memory 1010 and executed by the processor 1020. The memory may be implemented inside the processor 1020. Alternatively, the memory 1010 may be implemented outside the processor 1020 and may be communicatively connected to the processor 1020 by various means known in the art.

[0391] The transceiver 1031 is connected to the processor 1020 in a manner of operating and sending and / or receiving radio signals. The transceiver 1031 includes a transmitter and a receiver. The transceiver 1031 may include a baseband circuit for processing radio frequency signals. The transceiver controls one or more antennas to send and / or receive radio signals. In order to initiate communication, the processor 1020 transmits command information to the transceiver 1031 to send a radio signal configuring voice communication data. The antenna is used to send and receive radio signals. When a radio signal is received, the transceiver 1031 can transmit a signal to be processed by the processor 1020 and convert the signal to baseband. The processed signal can be converted into audible or readable information output by the speaker 1042.

[0392] Speaker 1042 outputs sound related results processed by processor 1020. Microphone 1052 receives sound related input to be used by processor 1020.

[0393] The user inputs command information such as a phone number by voice activation using the microphone 1052 or pressing (or touching) a button of the input unit 1053. The processor 1020 processes to perform appropriate functions such as receiving command information, calling a phone number, etc. Operation data on driving may be extracted from the SIM card or the memory 1010. In addition, the processor 1020 may display command information or driving information on the display 1041 so that the user recognizes it or for convenience.

[0394] Fig.18 A detailed example Fig.15 The first device shown is a transceiver or Fig.17 A detailed block diagram of the transceiver of the device is shown.

[0395] Reference Fig.18 , the transceiver 1031 includes a transmitter 1031-1 and a receiver 1031-2. The transmitter 1031-1 includes: a discrete Fourier transform (DFT) unit 1031-11, a subcarrier mapper 1031-12, an inverse fast Fourier transform (IFFT) unit 1031-13 and a CP insertion unit 1031-14, and a radio transmitter 1031-15. The transmitter 1031-1 may also include a modulator. In addition, for example, a scrambling unit (not shown), a modulation mapper (not shown), a layer mapper (not shown) and a layer permutator (not shown) may be further included, and may be arranged before the DFT unit 1031-11. That is, in order to prevent an increase in the peak-to-average power ratio (PAPR), the transmitter 1031-1 transmits information through the DFT 1011-11 before mapping the signal to the subcarrier. After subcarrier mapping by the subcarrier mapper 1031 - 12 of the signal spread (or precoded in the same sense) by the DFT unit 1031 - 11 , the signal on the time axis is operated by the IFFT unit 1031 - 13 .

[0396] The DFT unit 1031-11 outputs a complex value symbol by performing DFT on the input symbol. For example, when Ntx symbols are input (Ntx is a natural number), the DFT size is Ntx. The DFT unit 1031-11 may be referred to as a transform precoder. The subcarrier mapper 1031-12 maps the complex symbol to each subcarrier in the frequency domain. The complex symbol may be mapped to a resource element corresponding to a resource block allocated for data transmission. The subcarrier mapper 1031-12 may be referred to as a resource element mapper. The IFFT unit 1031-13 outputs a baseband signal for data as a time domain signal by performing IFFT on the input symbol. The CP insertion unit 1031-14 copies a portion of the rear portion of the baseband signal of the data and inserts it into the front portion of the baseband signal of the data. Inter-symbol interference (ISI) and inter-carrier interference (ICI) are prevented by CP insertion, so that orthogonality can be maintained even in a multipath channel.

[0397] On the other hand, the receiver 1031-2 includes a radio receiver 1031-21, a CP remover 1031-22, an FFT unit 1031-23, an equalizer 1031-24, etc. The radio receiver 1031-21, the CP remover 1031-22, and the FFT unit 1031-23 of the receiver 1031-2 perform the reverse functions of the radio transmitter 1031-15, the CP inserter 1031-14, and the IFFT unit 1031-13 of the transmitter 1031-1. The receiver 1031-2 may also include a demodulator.

[0398] <Scenarios in which the Disclosure of This Specification Can Be Applied>

[0399] Although not limited to this, the various descriptions, functions, processes, suggestions, methods and / or operational flowcharts of the disclosed contents of this specification disclosed herein can be applied to various fields requiring wireless communication and / or connection between devices (e.g., 5G).

[0400] Hereinafter, the present disclosure will be described in more detail with reference to the accompanying drawings. Unless otherwise indicated, the same reference numerals in the following drawings and / or descriptions may refer to the same and / or corresponding hardware blocks, software blocks and / or functional blocks.

[0401] Fig.19 A communication system 1 to which the disclosure of this specification is applied is exemplified.

[0402] Reference Fig.19, the communication system 1 applied to the disclosure of this specification includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a radio access technology (e.g., 5G new RAT (NR), long term evolution (LTE)), and may be referred to as a communication / wireless / 5G device. Although not limited to this, the wireless device may include a robot 100a, a vehicle 100b-1, 100b-2, a virtual reality (XR) device 100c, a handheld device 100d and a home appliance 100e, an Internet of Things (IoT) device 100f, and an AI device / server 400. For example, a vehicle may include a vehicle equipped with a wireless communication function, an autonomous driving vehicle, a vehicle capable of performing inter-vehicle communication, and the like. Here, the vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) set in a vehicle, a television, a smart phone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, and the like. Handheld devices may include smart phones, smart tablets, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptop computers), etc. Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device 200a may operate as a base station / network node corresponding to other wireless devices.

[0403] The wireless devices 100a to 100f may be connected to the network 300 via the base station 200. Artificial intelligence (AI) technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a super 5G network. Although the wireless devices 100a to 100f may communicate with each other via the base station 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., side link communication) with each other without passing through the BS 200 / network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0404] Wireless communication / connection 150a, 150b, and 150c may be established between the wireless devices 100a to 100f and the base station 200, and between the base stations 200 / base stations 200. In this document, wireless communication / connection may be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication (or device-to-device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, integrated access and backhaul (IAB)), etc.). The wireless devices 100a to 100f and the base stations 200 / wireless devices 100a to 100f may send / receive radio signals to / from each other through the wireless communication / connection 150a, 150b, and 150c. For example, the wireless communication / connection 150a, 150b, and 150c may send / receive signals through various physical channels. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and at least a portion of a resource allocation process may be performed based on various proposals of the present disclosure.

[0405] In the above, the preferred embodiment has been described exemplarily, but the disclosure of this specification is not limited to such specific embodiment. Therefore, the disclosure of this specification can be modified, changed or improved in various forms within the scope of the claims and within the specification.

[0406] In the above exemplary system, the method is described based on a flowchart as a series of steps or blocks, but is not limited to the order of the steps described, and some steps may occur in a different order or simultaneously with other steps as described above. In addition, those skilled in the art will understand that the steps shown in the flowchart are not exclusive, and other steps may be included or one or more steps of the flowchart may be deleted without affecting the scope of the rights.

[0407] The claims described herein may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. In addition, the technical features of the method claims of this specification and the technical features of the device claims of this specification may be combined to be implemented as a device, and the technical features of the method claims of this specification and the technical features of the device of this specification may be combined and implemented as a method.

Claims

1. A method performed by a first terminal in a wireless communication system, the method comprising the following steps: The first terminal establishes a one-to-one direct communication with the second terminal; A data radio bearer DRB is established by the first terminal, and a protocol data unit PDU session of the first terminal is added to the DRB; Based on the DRB supporting the PDU session of the second terminal, the first terminal modifies the DRB, and the PDU session of the second terminal is added to the DRB, The step of modifying the DRB includes receiving a first radio resource control RRC reconfiguration message from a base station, wherein the first RRC reconfiguration message includes: i) identification ID information for the DRB, ii) an ID message for the second terminal, iii) information notifying that the DRB is shared by the first terminal and the second terminal, and iv) a service data adaptation protocol SDAP configuration for the PDU session of the second terminal; The first terminal receives a second RRC reconfiguration message from the base station, The second RRC reconfiguration message includes: i) the ID information for the DRB and ii) information for the PDU session of the first terminal to be deleted or released in the DRB; and Based on the received second RRC reconfiguration message, the access stratum AS layer of the first terminal delivers information notifying that the user plane connection of the PDU session of the first terminal is released to the non-access stratum NAS layer of the first terminal.

2. The method according to claim 1, wherein: The data service of the second terminal is relayed through the DRB.

3. The method according to claim 1, wherein: The method further comprises the step of sending an RRC reconfiguration complete message in response to receiving the second RRC reconfiguration message.

4. The method according to claim 1, wherein: The method further comprises the following steps: The first terminal determines to reuse the PDU session for itself; and Send a service request message.

5. The method according to claim 4, wherein: The first RRC reconfiguration message is used to activate the user plane connection of the PDU session of the second terminal.

6. A chipset installed on a first terminal in a wireless communication system, the chipset comprising: at least one processor; as well as at least one memory for storing instructions and operatively electrically connected to the at least one processor, The instruction causes the at least one processor to perform an operation based on being executed by the at least one processor, and the operation includes: establishing a one-to-one direct communication with a second terminal; Establishing a data radio bearer DRB, in which a protocol data unit PDU session of the first terminal is added; Based on the DRB supporting the PDU session of the second terminal, modifying the DRB, wherein the PDU session of the second terminal is added to the DRB, Wherein, modifying the DRB includes receiving a first radio resource control RRC reconfiguration message from a base station, wherein the first RRC reconfiguration message includes: i) identification ID information for the DRB, ii) an ID message for the second terminal, iii) information notifying that the DRB is shared by the first terminal and the second terminal, and iv) a service data adaptation protocol SDAP configuration for the PDU session of the second terminal; receiving a second RRC reconfiguration message from the base station, The second RRC reconfiguration message includes: i) the ID information for the DRB and ii) information for the PDU session of the first terminal to be deleted or released in the DRB; and Based on the received second RRC reconfiguration message, the access stratum AS layer delivers information to the non-access stratum NAS layer, notifying that the user plane connection of the PDU session of the first terminal is released.

7. The chipset according to claim 6, wherein: The data service of the second terminal is relayed through the DRB.

8. The chipset according to claim 6, wherein: The operations also include sending an RRC reconfiguration complete message in response to receiving the second RRC reconfiguration message.

9. The chipset according to claim 6, wherein: The operations also include: Determine to reuse the PDU session for oneself; and Send a service request message.

10. A first terminal in a wireless communication system, the first terminal comprising: at least one transceiver; at least one memory; as well as at least one processor, the at least one processor being operatively electrically connected to the at least one transceiver and the at least one memory, The at least one memory stores instructions, and the instructions are executed by the at least one processor to cause the at least one processor to perform operations, and the operations include: establishing a one-to-one direct communication with a second terminal; Establishing a data radio bearer DRB, in which a protocol data unit PDU session of the first terminal is added; Based on the DRB supporting the PDU session of the second terminal, modifying the DRB, wherein the PDU session of the second terminal is added to the DRB, Wherein, modifying the DRB comprises receiving a first radio resource control RRC reconfiguration message from a base station via the at least one transceiver, wherein the first RRC reconfiguration message comprises: i) identification ID information for the DRB, ii) an ID message for the second terminal, iii) information notifying that the DRB is shared by the first terminal and the second terminal, and iv) a service data adaptation protocol SDAP configuration for the PDU session of the second terminal; receiving, via the at least one transceiver, a second RRC reconfiguration message from the base station, The second RRC reconfiguration message includes: i) the ID information for the DRB and ii) information for the PDU session of the first terminal to be deleted or released in the DRB; and Based on the received second RRC reconfiguration message, the access stratum AS layer delivers information to the non-access stratum NAS layer, notifying that the user plane connection of the PDU session of the first terminal is released.

Images