Communication method, terminal, communication system, and storage medium

Abstract

The present disclosure relates to a communication method, a terminal, a communication system, and a storage medium. The method executed by a relay terminal comprises: receiving first information sent by a first terminal, wherein the first information is used by the first terminal to request to establish a direct communication PC5 link with the relay terminal; and broadcasting second information on the basis of a specified Layer-2 ID, wherein the second information is used by the relay terminal to request to establish a PC5 link with a target second terminal. The solution of the present disclosure improves the performance of the relay terminal, and further improves the network performance.

Description

Communication method, terminal, communication system and storage medium Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular to a communication method, a terminal, a communication system, and a storage medium. Background Art

[0002] Proximity Service (ProSe) is a service provided by the 3rd Generation Partnership Project (3GPP) system for user equipment (UE) that is in close proximity. ProSe technology primarily includes ProSe discovery and ProSe communication. In a ProSe scenario, when a source UE and a target UE cannot communicate directly, the source UE can communicate with the target UE through a UE with relay functionality (UE-to-UE Relay, referred to as a relay UE).

[0003] Summary of the Invention

[0004] The embodiments of the present disclosure provide a communication method, a terminal, a communication system, and a storage medium.

[0005] According to a first aspect of an embodiment of the present disclosure, a communication method is proposed, which is performed by a relay terminal. The method includes: receiving first information sent by a first terminal, the first information being used by the first terminal to request the establishment of a direct communication PC5 link with the relay terminal; and broadcasting second information according to a specified Layer-2 ID, the second information being used by the relay terminal to request the establishment of a PC5 link with a target second terminal.

[0006] According to a second aspect of an embodiment of the present disclosure, a communication method is proposed, which is executed by a second terminal. The method includes: listening to a broadcast based on a specified Layer-2 ID, receiving second information broadcast by a relay terminal after receiving first information sent by a first terminal, the first information being used by the first terminal to request the establishment of a PC5 link with the relay terminal, and the second information being used by the relay terminal to request the establishment of a PC5 link with a target second terminal.

[0007] According to a third aspect of an embodiment of the present disclosure, a relay terminal is proposed, comprising: a transceiver module for receiving first information sent by a first terminal, the first information being used by the first terminal to request the establishment of a direct communication PC5 link with the relay terminal; and broadcasting second information according to a specified layer 2 Layer-2 ID, the second information being used by the relay terminal to request the establishment of a PC5 link with a target second terminal.

[0008] According to a fourth aspect of an embodiment of the present disclosure, a terminal is proposed, including: a transceiver module, used to monitor broadcasts based on a specified Layer-2 ID, and receive second information broadcast by a relay terminal after receiving first information sent by a first terminal, wherein the first information is used by the first terminal to request to establish a PC5 link with the relay terminal, and the second information is used by the relay terminal to request to establish a PC5 link with a target second terminal.

[0009] According to the fifth aspect of an embodiment of the present disclosure, a relay terminal is proposed, comprising: one or more processors; a memory coupled to the processor, wherein the memory stores executable instructions, and when the executable instructions are executed by the processor, the relay terminal executes the communication method described in the first aspect.

[0010] According to the sixth aspect of the embodiment of the present disclosure, a terminal is proposed, comprising: one or more processors; a memory coupled to the processor, wherein the memory stores executable instructions, and when the executable instructions are executed by the processor, the terminal executes the communication method described in the second aspect.

[0011] According to the seventh aspect of an embodiment of the present disclosure, a communication system is proposed, comprising a first terminal, a relay terminal, and a second terminal, wherein the relay terminal is configured to implement the communication method described in the first aspect, and the second terminal is configured to implement the communication method described in the second aspect.

[0012] According to an eighth aspect of an embodiment of the present disclosure, a storage medium is proposed, which stores instructions. When the instructions are executed on a communication device, the communication device executes the communication method described in the first aspect or the second aspect.

[0013] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0014] Upon receiving the first information sent by the first terminal, the relay terminal broadcasts the second information based on the specified Layer-2 ID to request the establishment of a PC5 link with the target second terminal. The disclosed method solves the problem of the relay terminal being unable to select the correct unicast target Layer-2 ID for uniquely identifying the target second terminal to send the second information upon receiving the first information from the first terminal, because the relay terminal broadcasts the second information based on the specified Layer-2 ID. This enables the relay terminal to send the second information to the target second terminal without knowing the unicast target Layer-2 ID for uniquely identifying the target second terminal, thereby improving the performance of the relay terminal and, in turn, the network performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following drawings required for describing the embodiments are introduced. The following drawings are merely some embodiments of the present disclosure and do not impose specific limitations on the protection scope of the present disclosure.

[0016] FIG1A is a schematic diagram showing the architecture of a communication system according to an embodiment of the present disclosure.

[0017] FIG1B is a schematic diagram showing a relay discovery process according to an embodiment of the present disclosure.

[0018] FIG1C is a schematic diagram of a Layer-2 link establishment process according to an embodiment of the present disclosure.

[0019] FIG2 is an interactive schematic diagram illustrating a communication method according to an embodiment of the present disclosure.

[0020] FIG3A is a flow chart illustrating a communication method according to an embodiment of the present disclosure.

[0021] FIG3B is a flow chart illustrating a communication method according to an embodiment of the present disclosure.

[0022] FIG4A is a flow chart showing a communication method according to an embodiment of the present disclosure.

[0023] FIG4B is a flow chart illustrating a communication method according to an embodiment of the present disclosure.

[0024] FIG5 is a flow chart showing a communication method according to an embodiment of the present disclosure.

[0025] FIG6 is a schematic diagram of an interaction flow of a communication method according to an embodiment of the present disclosure.

[0026] FIG7A is a schematic structural diagram of a relay terminal according to an exemplary embodiment of the present disclosure.

[0027] FIG7B is a schematic structural diagram of a second terminal according to an exemplary embodiment of the present disclosure.

[0028] FIG8A is a schematic structural diagram of a communication device proposed in an embodiment of the present disclosure.

[0029] FIG8B is a schematic structural diagram of a chip proposed in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] The embodiments of the present disclosure provide a communication method, a terminal, a communication system, and a storage medium.

[0031] In a first aspect, an embodiment of the present disclosure proposes a communication method, which is executed by a relay terminal. The method includes: receiving first information sent by a first terminal, the first information being used by the first terminal to request to establish a direct communication PC5 link with the relay terminal; and broadcasting second information according to a specified layer 2 Layer-2 ID, the second information being used by the relay terminal to request to establish a PC5 link with a target second terminal.

[0032] In the above embodiment, upon receiving the first information sent by the first terminal, the relay terminal broadcasts the second information based on the specified Layer-2 ID to request establishment of a PC5 link with the target second terminal. The present disclosure solves the problem of the relay terminal being unable to select the correct unicast target Layer-2 ID for uniquely identifying the target second terminal to send the second information upon receiving the first information from the first terminal, because the relay terminal broadcasts the second information based on the specified Layer-2 ID. This enables the relay terminal to send the second information to the target second terminal without knowing the unicast target Layer-2 ID for uniquely identifying the target second terminal, thereby improving the performance of the relay terminal and, in turn, the network performance.

[0033] In combination with some embodiments of the first aspect, in some embodiments, before broadcasting the second information according to the specified Layer-2 ID, it includes: completing a secure establishment process of a PC5 link between the first terminal and the relay terminal.

[0034] In the above embodiment, it is specified that the second information is sent after the security establishment process of the first-hop PC5 link between the first terminal and the relay terminal is completed, thereby avoiding the problem of establishing the second-hop PC5 link between the relay terminal and the target second terminal when the first-hop PC5 link is not established. This can improve the efficiency of establishing the PC5 link from the first terminal to the target second terminal.

[0035] In combination with some embodiments of the first aspect, in some embodiments, the designated Layer-2 ID is indicated by a network device or is pre-configured locally.

[0036] In the above embodiment, two methods for obtaining a specified Layer-2 ID are provided to adapt to different application scenarios, thereby improving the applicability of the solution.

[0037] With reference to some embodiments of the first aspect, in some embodiments, the first information is a direct communication request DCR.

[0038] In the above embodiment, the first terminal may request to establish a first-hop PC5 link with the relay terminal through a direct communication request DCR (Direct Communication Request).

[0039] In conjunction with some embodiments of the first aspect, in some embodiments, the first information includes at least one of the following:

[0040] a user information identifier of the first terminal;

[0041] The user information identifier of the relay terminal;

[0042] The user information identifier of the target second terminal;

[0043] Unicast Layer-2 ID;

[0044] ProSe service information, including information about a ProSe identifier used to request establishment of a Layer-2 link for PC5 communication;

[0045] RSC;

[0046] The first security information includes security information used to establish a PC5 link between the first terminal and the relay terminal.

[0047] In the above embodiment, at least one of the user information identifier of the first terminal, the user information identifier of the relay terminal, the user information identifier of the target second terminal, the unicast Layer-2 ID, the ProSe service information, the RSC, and the first security information can be configured in the first information to securely and efficiently establish the first-hop PC5 link.

[0048] In combination with some embodiments of the first aspect, in some embodiments, the unicast Layer-2 ID is a unicast target Layer-2 ID of the target second terminal determined by the first terminal.

[0049] In the above embodiment, it is specified that the unicast Layer-2 ID may be the unicast target Layer-2 ID of the target second terminal determined by the first terminal to assist in establishing a Layer-2 link for PC5 communication from the first terminal to the target second terminal.

[0050] In combination with some embodiments of the first aspect, in some embodiments, the Layer-2 link of the PC5 communication includes a PC5 link between the first terminal and the relay terminal, and a PC5 link between the relay terminal and the target second terminal.

[0051] In the above embodiment, the Layer-2 link that regulates PC5 communication from the first terminal to the target second terminal includes a first-hop PC5 link and a second-hop PC5 link.

[0052] In combination with some embodiments of the first aspect, in some embodiments, the second information is DCR.

[0053] In the above embodiment, the relay terminal may request to establish a second-hop PC5 link with the target second terminal through a direct communication request DCR.

[0054] In conjunction with some embodiments of the first aspect, in some embodiments, the second information includes at least one of the following:

[0055] a user information identifier of the first terminal;

[0056] The user information identifier of the relay terminal;

[0057] The user information identifier of the target second terminal;

[0058] ProSe service information;

[0059] RSC;

[0060] The second security information includes security information used to establish a PC5 link between the relay terminal and the target second terminal.

[0061] In the above embodiment, at least one of the user information identifier of the first terminal, the user information identifier of the relay terminal, the user information identifier of the target second terminal, ProSe service information, RSC, and the second security information can be configured in the second information to securely and efficiently establish the second-hop PC5 link.

[0062] In combination with some embodiments of the first aspect, in some embodiments, the user information identifier of the target second terminal is encrypted.

[0063] In combination with some embodiments of the first aspect, in some embodiments, the relay terminal is a 5G ProSe Layer-3 UE-to-UE relay terminal; the first terminal is a source 5G ProSe Layer-3 end terminal; and the target second terminal is a target 5G ProSe Layer-3 end terminal.

[0064] In the above embodiments, the technical solution disclosed in the present invention is applicable to 5G ProSe communication scenarios based on 5G ProSe Layer-3 UE-to-UE Relay.

[0065] In the second aspect, an embodiment of the present disclosure proposes a communication method, which is executed by a second terminal, and the method includes: listening to a broadcast based on a specified Layer-2 ID, and receiving second information broadcast by a relay terminal after receiving first information sent by a first terminal, wherein the first information is used by the first terminal to request to establish a PC5 link with the relay terminal, and the second information is used by the relay terminal to request to establish a PC5 link with the target second terminal.

[0066] In combination with some embodiments of the second aspect, in some embodiments, the method further includes: upon receiving the second information, completing a secure establishment process of a PC5 link between the relay terminal and the target second terminal.

[0067] In combination with some embodiments of the second aspect, in some embodiments, the second information is broadcast by the relay terminal after completing the secure establishment process of the PC5 link between the first terminal and the relay terminal.

[0068] In combination with some embodiments of the second aspect, in some embodiments, the designated Layer-2 ID is indicated by a network device or is pre-configured locally.

[0069] With reference to some embodiments of the second aspect, in some embodiments, the first information is a direct communication request DCR.

[0070] In conjunction with some embodiments of the second aspect, in some embodiments, the first information includes at least one of the following:

[0071] a user information identifier of the first terminal;

[0072] The user information identifier of the relay terminal;

[0073] The user information identifier of the target second terminal;

[0074] Unicast Layer-2 ID;

[0075] Proximity Service (ProSe) service information, including information about a ProSe identifier used to request establishment of a Layer-2 link for PC5 communication;

[0076] Relay service code RSC;

[0077] The first security information includes security information used to establish a PC5 link between the first terminal and the relay terminal.

[0078] In combination with some embodiments of the second aspect, in some embodiments, the unicast Layer-2 ID is a unicast target Layer-2 ID of the target second terminal determined by the first terminal.

[0079] In combination with some embodiments of the second aspect, in some embodiments, the Layer-2 link of the PC5 communication includes a PC5 link between the first terminal and the relay terminal, and a PC5 link between the relay terminal and the target second terminal.

[0080] In combination with some embodiments of the second aspect, in some embodiments, the second information is DCR.

[0081] In conjunction with some embodiments of the second aspect, in some embodiments, the second information includes at least one of the following:

[0082] a user information identifier of the first terminal;

[0083] The user information identifier of the relay terminal;

[0084] The user information identifier of the target second terminal;

[0085] ProSe service information;

[0086] RSC;

[0087] The second security information includes security information used to establish a PC5 link between the relay terminal and the target second terminal.

[0088] In conjunction with some embodiments of the second aspect, in some embodiments, the user information identifier of the target second terminal is encrypted;

[0089] The method further includes: the second terminal parsing the encrypted user information identifier of the target second terminal according to a secret key, and determining the second terminal that successfully parses the user information identifier of the target second terminal as the target second terminal.

[0090] In combination with some embodiments of the second aspect, in some embodiments, the relay terminal is a 5G ProSe Layer-3 UE-to-UE relay terminal; the first terminal is a source 5G ProSe Layer-3 end terminal; and the target second terminal is a target 5G ProSe Layer-3 end terminal.

[0091] In a third aspect, an embodiment of the present disclosure provides a communication method, performed by a first terminal, the method comprising:

[0092] Sending first information to the relay terminal, wherein the first information is used by the first terminal to request to establish a direct communication PC5 link with the relay terminal, and causing the relay terminal to broadcast second information according to the specified layer 2 Layer-2 ID, wherein the second information is used by the relay terminal to request to establish a PC5 link with the target second terminal.

[0093] In a fourth aspect, an embodiment of the present disclosure proposes a relay terminal, which includes at least one of a transceiver module and a processing module; wherein the relay terminal is used to execute the optional implementation method of the first aspect.

[0094] In a fifth aspect, an embodiment of the present disclosure proposes a terminal, which includes at least one of a transceiver module and a processing module; wherein the terminal is used to execute an optional implementation method of the second aspect or the third aspect.

[0095] In a sixth aspect, an embodiment of the present disclosure proposes a relay terminal, which includes: one or more processors; wherein the relay terminal is used to execute the optional implementation method of the first aspect.

[0096] In a seventh aspect, an embodiment of the present disclosure proposes a terminal, comprising: one or more processors; wherein the terminal is used to execute an optional implementation of the second aspect or the third aspect.

[0097] In an eighth aspect, an embodiment of the present disclosure proposes a communication system, which includes: a first terminal, a relay terminal, and a second terminal; wherein the relay terminal is configured to execute the method described in the optional implementation manner of the first aspect, and the second terminal is configured to execute the method described in the optional implementation manner of the second aspect.

[0098] In the ninth aspect, an embodiment of the present disclosure proposes a storage medium, which stores instructions. When the instructions are executed on a communication device, the communication device executes the method described in the optional implementation of the first aspect, the second aspect, or the third aspect.

[0099] In a tenth aspect, an embodiment of the present disclosure proposes a program product. When the program product is executed by a communication device, the communication device executes the method described in the optional implementation of the first aspect, the second aspect, or the third aspect.

[0100] In an eleventh aspect, an embodiment of the present disclosure proposes a computer program, which, when executed on a computer, enables the computer to execute the method described in the optional implementation of the first aspect, the second aspect, or the third aspect.

[0101] In a twelfth aspect, an embodiment of the present disclosure provides a chip or a chip system, wherein the chip or chip system includes a processing circuit configured to execute the method described in the optional implementation of the first aspect, the second aspect, or the third aspect.

[0102] It is understandable that the first terminal, relay terminal, second terminal, network device, communication system, storage medium, program product, computer program, chip, or chip system described above are all used to perform the method proposed in the embodiments of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding methods and will not be repeated here.

[0103] The present disclosure provides a communication method, terminal, communication system, and storage medium. In some embodiments, the terms "communication method" and "information processing method," "method for forwarding U2U relay communication requests," and "method for sending a DCR message via a U2U relay" are interchangeable; the terms "communication device" and "information processing device," and "device for forwarding U2U relay communication requests" are interchangeable; and the terms "communication system" and "information processing system," and "system for forwarding U2U relay communication requests" are interchangeable.

[0104] The embodiments of the present disclosure are not exhaustive and are merely illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined. For example, some or all steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0105] In each embodiment of the present disclosure, unless otherwise specified or provided for by logic, the terms and / or descriptions between the embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form a new embodiment based on their inherent logical relationships.

[0106] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0107] In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular, such as "a", "an", "the", "above", "said", "the", "the", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun following the article may be understood as a singular expression or a plural expression.

[0108] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0109] In some embodiments, the terms "at least one," "one or more," "a plurality of," "multiple," etc. may be used interchangeably.

[0110] In some embodiments, descriptions such as "at least one of A and B," "A and / or B," "A in one case, B in another case," or "in response to one case A, in response to another case B" may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); and in some embodiments, A and B (both A and B are executed). The above is also applicable when there are more branches such as A, B, and C.

[0111] In some embodiments, "A or B" and other descriptions may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). The above is also applicable when there are more branches such as A, B, C, etc.

[0112] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects and do not constitute any restriction on the position, order, priority, quantity or content of the description objects. For the statement of the description object, please refer to the description in the context of the claims or embodiments, and the use of prefixes should not constitute unnecessary restrictions. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields". "First" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number and can be one or more. Taking "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", then the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different. For another example, if the description object is "information", then the "first information" and the "second information" can be the same information or different information, and their contents can be the same or different.

[0113] In some embodiments, “including A,” “comprising A,” “used to indicate A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0114] In some embodiments, terms such as "time / frequency" and "time / frequency domain" refer to the time domain and / or the frequency domain.

[0115] In some embodiments, terms such as "in response to...", "in response to determining...", "in the case of...", "at the time of...", "when...", "if...", "if...", etc. can be used interchangeably.

[0116] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not less than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0117] In some embodiments, devices, etc. can be interpreted as physical or virtual, and their names are not limited to the names recorded in the embodiments. Terms such as "device", "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", and "subject" can be used interchangeably.

[0118] In some embodiments, "network" can be interpreted as devices included in the network (eg, access network equipment, core network equipment, etc.).

[0119] In some embodiments, the terms "access network device (AN device)", "radio access network device (RAN device)", "base station (BS)", "radio base station" "fixed station", "node", "access point", "transmission point (TP)", "reception point (RP)", "transmission / reception point (TRP)" "panel", "antenna panel", "antenna array", "cell", "macro cell", "small cell", "femto cell", "pico cell", "sector", "cell group", "serving cell", "carrier", "component carrier", "bandwidth part (BWP)" and the like may be used interchangeably.

[0120] In some embodiments, the terms "terminal", "terminal device", "user equipment (UE)", "user terminal", "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, etc. can be used interchangeably.

[0121] In some embodiments, the access network device, the core network device, or the network device can be replaced by a terminal. For example, the various embodiments of the present disclosure can also be applied to a structure in which the communication between the access network device, the core network device, or the network device and the terminal is replaced by communication between multiple terminals (for example, device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it is also possible to set the structure in which the terminal has all or part of the functions of the access network device. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. can be replaced by side channels, and uplinks, downlinks, etc. can be replaced by side links.

[0122] In some embodiments, the terminal may be replaced by an access network device, a core network device, or a network device. In this case, the access network device, the core network device, or the network device may have a structure that has all or part of the functions of the terminal.

[0123] In some embodiments, obtaining data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0124] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0125] In addition, each element, each row, or each column in the table of the embodiment of the present disclosure can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0126] Although operations are described in a particular order in the accompanying drawings in the disclosed embodiments, this should not be construed as requiring that the operations be performed in the particular order shown or in a serial order, or that all of the operations shown be performed to obtain the desired result. In certain circumstances, multitasking and parallel processing may be advantageous. Furthermore, sending multiple messages via the same message may also be advantageous.

[0127] FIG1A is a schematic diagram illustrating an architecture of a communication system according to an embodiment of the present disclosure. As shown in FIG1A , the communication system 100 may include a first terminal 101 , a relay terminal 102 , and a second terminal 103 .

[0128] In some embodiments, the first terminal 101, the relay terminal 102, or the second terminal 103 includes, for example, a mobile phone, a wearable device, an Internet of Things device, a car with communication function, a smart car, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, and at least one of a wireless terminal device in a smart home, but is not limited thereto.

[0129] In some embodiments, the communication system 100 may further include a network device, which may include at least one of an access network device and a core network device.

[0130] Optionally, the access network device is, for example, a node or device that accesses the terminal to the wireless network. The access network device may include an evolved NodeB (eNB), a next generation evolved NodeB (ng-eNB), a next generation NodeB (gNB), a node B (NB), a home node B (HNB), a home evolved nodeB (HeNB), a wireless backhaul device, a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a base band unit (BBU), a mobile switching center, a base station in a 6G communication system, an open base station (Open RAN), a cloud base station (Cloud RAN), a base station in other communication systems, and at least one of an access node in a Wi-Fi system, but is not limited thereto.

[0131] In some embodiments, the network device is a base station. Optionally, the base station is, for example, a macro base station, a micro base station (also known as a small station), a relay station, an access point, a 5G base station or a future base station, a satellite, a transmission point (Transmitting and Receiving Point, TRP), a transmission point (Transmitting Point, TP), a mobile switching center, or other devices that perform base station functions in a communication system, etc., which are not specifically limited in the embodiments of the present disclosure. For ease of description, in all embodiments of the present disclosure, devices that provide wireless communication functions for terminal devices are collectively referred to as network devices or base stations.

[0132] In some embodiments, the network device is a core network device. The core network device can be a single device including a first network element, a second network element, etc., or can be multiple devices or a group of devices, each including all or part of the first network element, the second network element, etc. The network element can be virtual or physical. The core network includes, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), and a Next Generation Core (NGC).

[0133] In some embodiments, the technical solution of the present disclosure can be applied to the Open RAN architecture. In this case, the interfaces between or within the access network devices involved in the embodiments of the present disclosure can be transformed into internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces can be implemented through software or programs.

[0134] In some embodiments, the access network device can be composed of a centralized unit (CU) and a distributed unit (DU), where the CU can also be called a control unit. The CU-DU structure can be used to split the protocol layer of the access network device, with the functions of some protocol layers centrally controlled by the CU, and the functions of the remaining part or all of the protocol layers distributed in the DU, which is centrally controlled by the CU, but is not limited to this.

[0135] It can be understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution proposed in the embodiment of the present disclosure. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution proposed in the embodiment of the present disclosure is also applicable to similar technical problems.

[0136] The following embodiments of the present disclosure may be applied to the communication system 100 shown in FIG1A , or a portion thereof, but are not limited thereto. The entities shown in FIG1A are illustrative only. The communication system may include all or part of the entities shown in FIG1A , or may include other entities other than those shown in FIG1A . The number and form of the entities may be arbitrary, and the entities may be physical or virtual. The connection relationships between the entities are illustrative only. The entities may be connected or disconnected, and the connection may be in any manner, including direct or indirect, wired or wireless.

[0137] The embodiments of the present disclosure can be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5G new radio (NR), future radio access (FRA), new radio access technology (RAT), new radio (NR), new radio access (NX), future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), Public Land Mobile Network (PLMN) networks, Device-to-Device (D2D) systems, Machine-to-Machine (M2M) systems, Internet of Things (IoT) systems, Vehicle-to-Everything (V2X), systems utilizing other communication methods, and next-generation systems based on and extending these methods. Furthermore, multiple systems may be combined (for example, a combination of LTE or LTE-A with 5G).

[0138] In some embodiments, in the 5G ProSe UE-to-UE relay discovery process based on model B, the first terminal 101 can correspond to the 5G ProSe End UE (UE-1), that is, the discoverer; the relay terminal 102 can correspond to the 5G ProSe UE-to-UE Relay, the 5G ProSe UE-to-UE Relay is 5G ProSe UE-to-UE Relay-1, 5G ProSe UE-to-UE Relay-2, or 5G ProSe UE-to-UE Relay-3; the second terminal 103 can correspond to the 5G ProSe End UE (UE-2), that is, the discoverer.

[0139] In some embodiments, referring to FIG. 1B , a 5G ProSe UE-to-UE relay discovery process diagram of Model B is shown. As shown in FIG. 1B , the following steps are included:

[0140] (1) The discoverer 5G ProSe End UE (UE-1) can send a 5G ProSe UE-to-UE relay discovery request message, which may include the discovery message type, its own user information identifier (User Info ID), RSC, and the user information identifier (User Info ID) of the discoverer 5G ProSe End UE (UE-2).

[0141] In some embodiments, the 5G ProSe UE-to-UE relay determines a target Layer 2 (Layer-2) identifier for signaling reception.

[0142] (2) The 5G ProSe UE-to-UE relay that matches the RSC sends a 5G ProSe UE-to-UE relay discovery request message, which may include the discovery message type, the user information identifier of the discoverer 5G ProSe End UE (UE-1), the user information identifier of the UE-to-UE relay, the RSC, and the user information identifier of the discoverer 5G ProSe End UE (UE-2). The message is sent based on the source Layer-2 identifier (Layer-2 ID) and the target Layer-2 identifier (Layer-2 ID).

[0143] In some embodiments, the 5G ProSe End UE (UE-2) determines a target Layer-2 identifier for signaling reception.

[0144] (3) The discovered 5G ProSe End UE (UE-2) that matches the RSC and the user information identifier of the discovered 5G ProSe End UE (UE-2) responds to the 5G ProSe UE-to-UE Relay and sends a 5G ProSe UE-to-UE Relay discovery response message. The message contains the type of discovery message, RSC, the user information identifier of the discoverer 5G ProSe End UE (UE-1) and the user information identifier of the discovered 5G ProSe End UE (UE-2), and is transmitted according to the Source Layer-2 ID and the Destination Layer-2 ID. If the discoverer 5G ProSe End UE (UE-2) receives multiple UE-to-UE Relay discovery request messages with the same RSC and user information identifier of the discoverer 5G ProSe End UE (UE-2) from different 5G ProSe UE-to-UE relays, it can choose whether to respond to a certain 5G ProSe UE-to-UE relay (for example, decide whether to respond based on the PC5 signal strength of each message received).

[0145] (4) The 5G ProSe UE-to-UE relay sends a 5G ProSe UE-to-UE relay discovery response message, which may include the discovery message type, the user information identifier of the UE-to-UE relay, the RSC, and the user information identifier of the discovered 5G ProSe End UE (UE-2). The message is sent using the source Layer-2 identifier (Layer-2 ID) and the target Layer-2 identifier (Layer-2 ID).

[0146] In some embodiments, in the Layer-2 link establishment process based on 5G ProSe Layer-3 UE-to-UE Relay, the first terminal 101 can correspond to the source 5G ProSe Layer-3 End UE (i.e., source 5G ProSe Layer-3 End UE); the relay terminal 102 can correspond to the 5G ProSe Layer-3 UE-to-UE relay (i.e., 5G ProSe Layer-3 UE-to-UE Relay); the second terminal 103 can correspond to the target 5G ProSe Layer-3 End UE (i.e., target 5G ProSe Layer-3 End UE).

[0147] In some embodiments, referring to the schematic diagram of the Layer-2 link establishment process based on 5G ProSe Layer-3 UE-to-UE Relay shown in FIG1C , as shown in FIG1C , the process includes the following steps:

[0148] (1) Perform service authorization and provisioning operations on the source 5G ProSe Layer-3 End UE, the target 5G ProSe Layer-3 End UE, and the 5G ProSe Layer-3 UE-to-UE relay.

[0149] (2) The source 5G ProSe Layer-3 End UE performs 5G ProSe Layer-3 UE-to-UE relay discovery. For details, see the embodiment corresponding to FIG. 1B above, which will not be repeated here.

[0150] (3) The source 5G ProSe Layer-3 End UE sends a Direct Communication Request message to initiate the unicast Layer-2 link establishment process with the 5G ProSe Layer-3 UE-to-UE relay.

[0151] In some embodiments, the source Layer-2 identifier of the direct communication request message is allocated by the source 5G ProSe Layer-3 End UE, and the target Layer-2 identifier is set to the source Layer-2 identifier of the discovery message relayed by the 5G ProSe Layer-3 UE-to-UE.

[0152] (4) If the user information identifier of the 5G ProSe Layer-3 UE-to-UE relay in the direct communication request message matches the user information identifier of the 5G ProSe UE-to-UE relay, and the RSC in the request matches one of the RSCs supported by the relay, the 5G ProSe Layer-3 UE-to-UE relay shall respond by establishing a secure connection with the source 5G ProSe Layer-3 End UE. When security protection is enabled, the source 5G ProSe Layer-3 End UE may send parameters to the 5G ProSe Layer-3 UE-to-UE relay.

[0153] In some embodiments, if the MAC address of the source 5G ProSe Layer-3 End UE is already used by another 5G ProSe Layer-3 End UE, the 5G ProSe Layer-3 UE-to-UE relay may send a message to the source 5G ProSe Layer-3 End UE, indicating that there is an Ethernet MAC address conflict.

[0154] In some embodiments, the source Layer-2 identifier used for the security establishment process is allocated by the 5G ProSe Layer-3 UE-to-UE relay, and the target Layer-2 identifier is set to the source Layer-2 identifier of the received direct communication request message.

[0155] In some embodiments, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for PC5 links for different types of traffic, namely IP traffic, Ethernet traffic, and unstructured traffic.

[0156] In some embodiments, if the PC5 link is used to transmit unstructured traffic, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for different source and target 5G ProSe Layer-3 End UE pairs.

[0157] In some embodiments, after receiving the security establishment process message, the source 5G ProSe Layer-3 End UE obtains the Layer-2 identity of the 5G ProSe Layer-3 UE-to-UE relay for future communications, including signaling and data traffic on the unicast link.

[0158] (5) After the security establishment process in step (4) is completed, the 5G ProSe Layer-3 UE-to-UE relay sends a direct communication request message to initiate the unicast Layer-2 link establishment process with the target 5G ProSe Layer-3 End UE.

[0159] In some embodiments, the source Layer-2 identifier of the direct communication request message is allocated by the 5G ProSe Layer-3 UE-to-UE relay, and the target Layer-2 identifier is the unicast Layer-2 identifier of the target 5G ProSe Layer-3 End UE associated with the user information identifier of the target 5G ProSe Layer-3 End UE.

[0160] In some embodiments, based on the target Layer-2 identifier received from the source UE, the 5G ProSe Layer-3 UE-to-UE relay selects the associated source Layer-2 identifier and target Layer-2 identifier to send a DCR message to the target UE.

[0161] In some embodiments, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for PC5 links for different types of traffic, i.e., IP traffic, Ethernet traffic, and unstructured traffic.

[0162] In some embodiments, if the PC5 link is used to transmit unstructured traffic, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for different source and target 5G ProSe Layer-3 End UE pairs.

[0163] (6) If the user information identifier and RSC of the target 5G ProSe Layer-3 End UE included in the direct communication request match the user information identifier and supported RSC of the target UE, the target 5G ProSe Layer-3 End UE responds by establishing a secure connection with the 5G ProSe Layer-3 UE-to-UE relay. When security protection is enabled, the 5G ProSe Layer-3 UE-to-UE relay can send parameters to the target 5G ProSe Layer-3 End UE.

[0164] In some embodiments, the source Layer-2 identifier used for the security establishment process is allocated by the target 5G ProSe Layer-3 End UE itself, and the target Layer-2 identifier is set to the source Layer-2 identifier of the received direct communication request message.

[0165] In some embodiments, after receiving the security establishment procedure message, the 5G ProSe Layer-3 UE-to-UE relay obtains the Layer-2 identity of the target 5G ProSe Layer-3 End UE for future communications, including signaling and data traffic on the unicast link.

[0166] (7) The target 5G ProSe Layer-3 End UE sends a direct communication accept message to the 5G ProSe Layer-3 UE-to-UE relay that successfully establishes a secure connection.

[0167] (8) For IP traffic, allocate an IPv6 prefix or IPv4 address to the target 5G ProSe Layer-3 End UE.

[0168] (9) After receiving the direct communication accept message from the target 5G ProSe Layer-3 End UE, the 5G ProSe Layer-3 UE-to-UE relay sends a direct communication accept message to the source 5G ProSe Layer-3 End UE with which the secure connection is successfully established.

[0169] (10) For IP traffic, an IPv6 prefix or IPv4 address is allocated to the source 5G ProSe Layer-3 End UE.

[0170] (11) For IP communication, the 5G ProSe Layer-3 UE-to-UE relay may store the association between the user information identifier and the IP address of the target 5G ProSe Layer-3 End UE in its Domain Name System (DNS) entry and may act as a DNS server to provide DNS services to other UEs. If the IP address of the target 5G ProSe Layer-3 End UE is not received in step (9), then after step (10), the source 5G ProSe Layer-3 End UE may send a DNS query to the 5G ProSe Layer-3 UE-to-UE relay to request the IP address of the target 5G ProSe Layer-3 End UE, and the 5G ProSe Layer-3 UE-to-UE relay returns the IP address of the target 5G ProSe Layer-3 End UE to the source 5G ProSe Layer-3 End UE.

[0171] In some embodiments, for Ethernet communications, the 5G ProSe Layer-3 UE-to-UE relay maintains an association between the PC5 link and the Ethernet MAC address received from the 5G ProSe Layer-3 End UE.

[0172] In some embodiments, for unstructured traffic communication, for each pair of source 5G ProSe Layer-3 End UE and target 5G ProSe Layer-3 End UE, the 5G ProSe Layer-3 UE-to-UE relay maintains a one-to-one mapping between the PC5 link and the source 5G ProSe Layer-3 End UE and the PC5 link and the target 5G ProSe Layer-3 End UE.

[0173] (12) The source 5G ProSe Layer-3 End UE communicates with the target 5G ProSe Layer-3 End UE through a 5G ProSe Layer-3 UE-to-UE relay.

[0174] In some embodiments, when a source 5G ProSe Layer-3 End UE communicates with multiple target 5G ProSe Layer-3 End UEs, the PC5 link between the source 5G ProSe Layer-3 End UE and the 5G ProSe Layer-3 UE-to-UE relay can be shared for multiple target 5G ProSe Layer-3 End UEs in one RSC, while for each RSC, the PC5 link between the 5G ProSe Layer-3 UE-to-UE Relay and the target 5G ProSe Layer-3 End UE can be established separately. For the shared PC5 link, the Layer-2 link modification procedure should be used.

[0175] In some embodiments, when multiple source 5G ProSe Layer-3 End UEs communicate with one target 5G ProSe Layer-3 End UE, the PC5 link between the 5G ProSe Layer-3 UE-to-UE relay and the target 5G ProSe Layer-3 End UE can be shared in one RSC, while for each RSC, the PC5 link between the source 5G ProSe Layer-3 End UE and the 5G ProSe Layer-3 UE-to-UE relay can be established separately. For the shared PC5 link, the Layer-2 link modification procedure should be used.

[0176] In some embodiments, in step (5), the relay sends the DCR using the target Layer-2 ID, which is the unicast Layer-2 ID of the target 5G ProSe Layer-3 End UE. The unicast Layer-2 ID is associated with the user information ID of the target 5G ProSe Layer-3 End UE. The relay can uniquely determine a target terminal based on the user information ID of the target 5G ProSe Layer-3 End UE, and the relay sends the DCR to the target terminal. However, the user information ID of the target 5G ProSe Layer-3 End UE (obtained during the discovery process) is encrypted in the relay, which means that the relay cannot identify the unique target End UE based on the user information ID of the target End UE. Therefore, when the relay receives a DCR from the source End UE, the relay does not know which target End UE's unicast L2 ID will be selected for sending the DCR message.

[0177] In some embodiments, to solve the problem that the relay cannot select the correct unicast target L2 ID of the target UE to send the DCR message received from the source UE, the embodiments of the present disclosure provide a communication method, a terminal, a communication system, and a storage medium to configure the U2U relay to use the default broadcast target L2 ID to broadcast the DCR message.

[0178] FIG2 is an interactive diagram of a communication method according to an embodiment of the present disclosure. The method can be executed by the above-mentioned communication system. As shown in FIG2 , the method may include the following steps:

[0179] Step S201 : The first terminal 101 sends first information to the relay terminal 102 .

[0180] In some embodiments, the relay terminal 102 receives the first information.

[0181] In some embodiments, the first information is used by the first terminal to request to establish a direct communication PC5 link with the relay terminal.

[0182] In some embodiments, the first information is used by the first terminal to request to establish a first-hop PC5 link with the relay terminal.

[0183] In some embodiments, the name of the first information is not limited, and it can be, for example, a direct communication request message, a specific message, etc.

[0184] In some embodiments, taking the Layer-2 link establishment process based on the 5G ProSe Layer-3 UE-to-UE Relay shown in FIG1C as an example, the relay terminal 102 may be a 5G ProSe Layer-3 UE-to-UE relay terminal; the first terminal 101 may be a source 5G ProSe Layer-3 End terminal; and the second terminal 103 may be a target 5G ProSe Layer-3 End terminal. The first information may be a DCR sent by the source 5G ProSe Layer-3 End UE (i.e., the first terminal 101).

[0185] In some embodiments, the first information includes at least one of the following:

[0186] user information identifier of the first terminal;

[0187] User information identification of the relay terminal;

[0188] User information identifier of the target second terminal;

[0189] Unicast Layer-2 ID;

[0190] Proximity service ProSe service information, including information about a ProSe identifier used to request establishment of a Layer-2 link for PC5 communication;

[0191] Relay service code RSC;

[0192] The first security information includes security information used to establish a PC5 link between the first terminal and the relay terminal.

[0193] For example, the user information identifier of the first terminal is, for example, the User Info ID of the first terminal or another identifier used to uniquely identify a terminal device.

[0194] For example, the user information identifier of the relay terminal is, for example, the User Info ID of the relay terminal or other identifier used to uniquely identify the terminal device. The relay terminal may refer to a 5G ProSe Layer-3 UE-to-UE relay.

[0195] For example, the user information identifier of the target second terminal is, for example, the User Info ID of the target second terminal or another identifier used to uniquely identify the terminal device. The user information identifier of the target second terminal is an encrypted user information identifier, and the relay UE cannot parse and identify the encrypted user information identifier. Therefore, the relay terminal cannot identify the target second terminal based on the encrypted user information identifier.

[0196] In some embodiments, the unicast Layer-2 ID is a unicast target Layer-2 ID of a target second terminal determined by the first terminal.

[0197] In some embodiments, the ProSe service information is information about a ProSe identifier for requesting to establish a Layer-2 link. In some embodiments, the ProSe service information is information about a ProSe identifier.

[0198] In some embodiments, the first security information is security information used to establish a first-hop PC5 link.

[0199] In some embodiments, the Layer-2 link for PC5 communication between the first terminal and the target second terminal includes a first-hop PC5 link between the first terminal and the relay terminal, and a second-hop PC5 link between the relay terminal and the target second terminal.

[0200] In step S202 , the relay terminal 102 responds by establishing a secure connection with the first terminal 101 .

[0201] In some embodiments, if the user information identifier of the 5G ProSe Layer-3 UE-to-UE relay in the first message matches the user information identifier of the relay terminal 102, and the RSC in the first message matches one of the RSCs supported by the relay terminal 102, the relay terminal 102 will respond by establishing a secure connection with the first terminal 101. When security protection is enabled, the first terminal 101 can send parameters to the relay terminal 102.

[0202] In some embodiments, if the MAC address of the first terminal 101 is already used by another 5G ProSe Layer-3 End UE, the relay terminal 102 may send a message to the first terminal 101 indicating that there is an Ethernet MAC address conflict.

[0203] In some embodiments, the source Layer-2 identifier used for the security establishment process is allocated by the relay terminal 102, and the target Layer-2 identifier is set to the source Layer-2 identifier of the received first information. The source Layer-2 identifier of the first information is allocated by the first terminal 101.

[0204] In some embodiments, the relay terminal 102 may select different source Layer-2 identifiers for PC5 links for different types of traffic, ie, IP traffic, Ethernet traffic, and unstructured traffic.

[0205] In some embodiments, if the PC5 link is used to transmit unstructured traffic, the relay terminal 102 may select different source Layer-2 identifiers for different pairs of the first terminal and the second terminal.

[0206] In some embodiments, after receiving the security establishment process message, the first terminal 101 obtains the Layer-2 identifier of the relay terminal 102 for future communications, including signaling and data traffic on the unicast link.

[0207] In some embodiments, after the secure establishment process of the PC5 link between the first terminal 101 and the relay terminal 102 is completed, step S203 is executed.

[0208] In step S203, the relay terminal 102 broadcasts the second information according to the designated Layer-2 ID.

[0209] In some embodiments, the second terminal receives the second information. Optionally, the relay terminal 102 monitors the broadcast based on the specified Layer-2 ID and receives the second information broadcasted by the relay terminal 102 based on the specified Layer-2 ID after receiving the first information sent by the first terminal 101.

[0210] In some embodiments, a designated Layer-2 ID is used for broadcasting the second information, that is, the designated Layer-2 ID serves as the destination L2 ID of the broadcasted second information.

[0211] In some embodiments, the name of the designated Layer-2 ID is not limited, and may be, for example, a default Layer-2 ID, a pre-configured Layer-2 ID, or the like.

[0212] In some embodiments, the designated Layer-2 ID is indicated by the network device or locally preconfigured. For example, the relay terminal receives a third message sent by the network device and determines the designated Layer-2 ID based on the third message. For example, the relay terminal determines the Layer-2 ID based on protocol specifications. For example, the relay terminal obtains a preconfigured designated Layer-2 ID locally.

[0213] In some embodiments, the second information is used by the relay terminal to request to establish a PC5 link with the target second terminal.

[0214] In some embodiments, the second information is used by the relay terminal to request to establish a second-hop PC5 link with the target second terminal.

[0215] In some embodiments, the name of the second information is not limited, and it can be, for example, a direct communication request message, a specific message, etc.

[0216] In some embodiments, in the scenario of the Layer-2 link establishment process based on 5G ProSe Layer-3 UE-to-UE Relay, the second information may be the DCR broadcast by the relay terminal 102.

[0217] In some embodiments, the second information includes at least one of the following:

[0218] user information identifier of the first terminal;

[0219] User information identification of the relay terminal;

[0220] User information identifier of the target second terminal;

[0221] ProSe service information;

[0222] RSC;

[0223] The second security information includes security information used to establish a PC5 link between the relay terminal and the target second terminal.

[0224] For example, the user information identifier of the first terminal is, for example, the User Info ID of the first terminal or another identifier used to uniquely identify a terminal device.

[0225] For example, the user information identifier of the relay terminal is, for example, the User Info ID of the relay terminal or other identifier used to uniquely identify the terminal device. The relay terminal may refer to a 5G ProSe Layer-3 UE-to-UE relay.

[0226] For example, the user information identifier of the target second terminal is, for example, the User Info ID of the target second terminal or another identifier used to uniquely identify the terminal device. The user information identifier of the target second terminal is encrypted, and the target second terminal may refer to the target 5G ProSe Layer-3 End UE. There are multiple second terminals that receive the second information broadcast above, but only the target second terminal stores a key that can parse the user information identifier of the target second terminal, that is, the second terminal that can parse and determine the user information identifier is the target second terminal that establishes a PC5 link with the relay terminal.

[0227] In some embodiments, the ProSe service information is information about a ProSe identifier for requesting to establish a Layer-2 link. In some embodiments, the ProSe service information is information about a ProSe identifier.

[0228] In some embodiments, the second security information is security information used to establish a second-hop PC5 link.

[0229] In some embodiments, the Layer-2 link for PC5 communication between the first terminal and the target second terminal includes a first-hop PC5 link between the first terminal and the relay terminal, and a second-hop PC5 link between the relay terminal and the target second terminal.

[0230] In some embodiments, the source Layer-2 identifier of the second information is allocated by the relay terminal 102 itself, and the target Layer-2 identifier is a specified Layer-2 ID.

[0231] In some embodiments, the relay terminal 102 may select different source Layer-2 identifiers for PC5 links of different types of traffic, ie, IP traffic, Ethernet traffic, and unstructured traffic.

[0232] In some embodiments, if the PC5 link is used to transmit unstructured traffic, the relay terminal 102 may select different source Layer-2 identifiers for different pairs of the first terminal and the second terminal.

[0233] In step S204 , the second terminal 103 parses the encrypted user information identifier of the target second terminal according to the secret key.

[0234] In some embodiments, the second terminal identified by the encrypted user information of the target second terminal is successfully parsed and determined as the target second terminal.

[0235] Optionally, the target second terminal is a second terminal that can parse the encrypted user information identifier of the target second terminal according to the secret key and matches the parsed user information identifier of the target second terminal.

[0236] In some embodiments, there are multiple second terminals, and the target second terminal is one of the multiple second terminals.

[0237] In some embodiments, the second terminal 103 performing the implementation of step S205 and step S206 is a target second terminal.

[0238] In step S205 , the second terminal 103 responds by establishing a secure connection with the relay terminal 102 .

[0239] If the user information identifier and RSC of the target 5G ProSe Layer-3 End UE included in the second information match the user information identifier and supported RSC of the second terminal 103, the second terminal 103 responds by establishing a secure connection with the relay terminal 102. When security protection is enabled, the relay terminal 102 can send parameters to the second terminal 103.

[0240] In some embodiments, the source Layer-2 identifier used for the security establishment process is allocated by the second terminal 103, and the target Layer-2 identifier is set to the source Layer-2 identifier of the received second information. The source Layer-2 identifier of the second information is allocated by the relay terminal 102.

[0241] In some embodiments, after receiving the security establishment process message, the relay terminal 102 obtains the Layer-2 identifier of the second terminal 103 for future communications, including signaling and data traffic on the unicast link.

[0242] In step S206 , the second terminal 103 sends a direct communication acceptance message to the relay terminal 102 for which the secure connection has been successfully established.

[0243] In some embodiments, the relay terminal 102 receives the direct communication acceptance message sent by the second terminal 103. After the relay terminal receives the direct communication acceptance message from the second terminal, step S207 is executed.

[0244] In some embodiments, for IP traffic, the second terminal is assigned an IPv6 prefix or an IPv4 address.

[0245] In step S207 , the relay terminal 102 sends a direct communication acceptance message to the first terminal 101 with which the secure connection is successfully established.

[0246] In some embodiments, the first terminal 101 receives the direct communication acceptance message sent by the relay terminal 102 .

[0247] In some embodiments, for IP traffic, the first terminal 101 is assigned an IPv6 prefix or an IPv4 address.

[0248] In some embodiments, for IP communication, the relay terminal 102 may store the association between the user information identifier and the IP address of the second terminal 103 in its Domain Name System (DNS) entry, and may serve as a DNS server to provide DNS services to other UEs.

[0249] In some embodiments, if the first terminal 101 does not receive the IP address of the second terminal 103, the first terminal 101 can send a DNS query to the relay terminal 102 to request the IP address of the second terminal 103, and the relay terminal 102 returns the IP address of the second terminal 103 to the first terminal 101.

[0250] In some embodiments, for Ethernet communications, the relay terminal 102 maintains an association between the PC5 link received from the 5G ProSe Layer-3 End UE and the Ethernet MAC address.

[0251] In some embodiments, for unstructured traffic communication, for each pair of the first terminal 101 and the second terminal 103 , the relay terminal 102 maintains a one-to-one mapping between the PC5 link and the first terminal 101 and the PC5 link and the second terminal 103 .

[0252] In some embodiments, the first terminal 101 communicates with the second terminal 103 through the relay terminal 102. That is, the first terminal 101 communicates with the target second terminal through the relay terminal 102.

[0253] In some embodiments, when a first terminal 101 communicates with multiple second terminals 103, the PC5 link between the first terminal 101 and the relay terminal 102 can be shared by the multiple second terminals 103 in one RSC, while a separate PC5 link can be established between the relay terminal 102 and the second terminal 103 for each RSC. For shared PC5 links, a Layer-2 link modification procedure should be used.

[0254] In some embodiments, when multiple first terminals 101 communicate with one second terminal 103, the PC5 link between the relay terminal 102 and the second terminal 103 can be shared by the multiple first terminals 101 in one RSC, while the PC5 link between the first terminal 101 and the relay terminal 102 can be established separately for each RSC. For the shared PC5 link, the Layer-2 link modification procedure should be used.

[0255] In some embodiments, the names of information, etc. are not limited to the names described in the embodiments, and terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "codeword", "codebook", "codeword", "codepoint", "bit", "data", "program", and "chip" can be used interchangeably.

[0256] In some embodiments, "obtain", "get", "get", "receive", "transmit", "bidirectional transmission", "send and / or receive" can be interchangeable, and can be interpreted as receiving from other entities, obtaining from protocols, obtaining from higher layers, obtaining by self-processing, autonomous implementation, etc.

[0257] In some embodiments, terms such as "send", "transmit", "report", "download", "transmit", "bidirectional transmission", "send and / or receive" can be used interchangeably.

[0258] In some embodiments, terms such as "certain", "preset", "preset", "setting", "indicated", "a certain", "any", and "first" can be interchangeable. "Specific A", "preset A", "preset A", "setting A", "indicated A", "a certain A", "any A", and "first A" can be interpreted as A pre-specified in a protocol, etc., or as A obtained through setting, configuration, or indication, etc., or as specific A, a certain A, any A, or first A, etc., but not limited to this.

[0259] The communication method involved in the embodiment of the present disclosure may include at least one of steps S201 to S207. For example, step S203 may be implemented as an independent embodiment, and step S201 and step S203 may be implemented as independent embodiments, but are not limited thereto.

[0260] In some embodiments, step S201, step S202, and step S204 to step S207 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0261] In some embodiments, reference may be made to other optional implementations described before or after the description corresponding to FIG. 2 .

[0262] FIG3A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3A , the present disclosure embodiment relates to a communication method, which is executed by a relay terminal side, and the method includes:

[0263] Step S3101, receiving first information.

[0264] The optional implementation of step S3101 can refer to the optional implementation of step S201 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0265] In some embodiments, the relay terminal 102 receives the first information sent by the first terminal 101, but is not limited thereto and may also receive the first information sent by other entities.

[0266] In some embodiments, the relay terminal 102 obtains first information specified by the protocol.

[0267] In some embodiments, the relay terminal 102 obtains the first information from an upper layer(s).

[0268] In some embodiments, the relay terminal 102 performs processing to obtain the first information.

[0269] In some embodiments, step S3101 is omitted, and the relay terminal 102 autonomously implements the function indicated by the first information, or the above function is default or acquiescent.

[0270] Step S3102: Complete the secure establishment process of the PC5 link between the first terminal and the relay terminal.

[0271] The optional implementation of step S3102 can refer to the optional implementation of step S202 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0272] Step S3103: broadcast the second information according to the specified Layer-2 ID.

[0273] In some embodiments, a designated Layer-2 ID is used for broadcasting the second information, that is, the designated Layer-2 ID serves as the destination L2 ID of the broadcasted second information.

[0274] The optional implementation of step S3103 can refer to the optional implementation of step S203 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0275] Step S3104: Receive a direct communication acceptance message.

[0276] The optional implementation of step S3104 can refer to the optional implementation of step S206 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0277] In some embodiments, the relay terminal 102 receives the direct communication acceptance message sent by the target second terminal, but is not limited thereto and may also receive the direct communication acceptance message sent by other entities.

[0278] In some embodiments, the relay terminal 102 obtains a direct communication acceptance message specified by the protocol.

[0279] In some embodiments, the relay terminal 102 obtains the direct communication acceptance message from the upper layer(s).

[0280] In some embodiments, the relay terminal 102 performs processing to obtain a direct communication acceptance message.

[0281] In some embodiments, step S3104 is omitted, and the relay terminal 102 autonomously implements the function indicated by the direct communication acceptance message, or the above function is default or acquiescent.

[0282] Step S3105: Send a direct communication acceptance message.

[0283] The optional implementation of step S3105 can refer to the optional implementation of step S207 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0284] In some embodiments, the relay terminal 102 sends a direct communication acceptance message to the first terminal 101 , but is not limited thereto and may also send a direct communication acceptance message to other entities.

[0285] The communication method involved in the embodiment of the present disclosure may include at least one of steps S3101 to S3105. For example, step S3103 may be implemented as an independent embodiment, and step S3101 and step S3103 may be implemented as independent embodiments, but are not limited thereto.

[0286] In some embodiments, step S3101, step S3102, step S3104, and step S3105 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0287] FIG3B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3B , the embodiment of the present disclosure relates to a communication method, which is executed by a relay terminal side, and the method includes:

[0288] Step S3201: Receive first information sent by a first terminal, where the first information is used by the first terminal to request to establish a direct communication PC5 link with the relay terminal.

[0289] The optional implementation of step S3201 can refer to the optional implementation of step S201 in Figure 2, step S3101 in Figure 3A, and other related parts in the embodiments involved in Figures 2 and 3A, which will not be repeated here.

[0290] Step S3202: Broadcast second information according to the specified Layer-2 ID, where the second information is used by the relay terminal to request to establish a PC5 link with the target second terminal.

[0291] The optional implementation of step S3202 can refer to the optional implementation of step S203 in Figure 2, step S3103 in Figure 3A, and other related parts in the embodiments involved in Figures 2 and 3A, which will not be repeated here.

[0292] The communication method involved in the embodiment of the present disclosure may include at least one of step S3201 and step S3202. For example, step S3202 may be implemented as an independent embodiment, but is not limited thereto.

[0293] In some embodiments, step S3201 is optional and may be omitted or replaced in different embodiments.

[0294] In an embodiment of the present disclosure, step S3202 may be combined with one or more steps of step S3101, step S3102, step S3104, and step S3105 in FIG. 3A .

[0295] FIG4A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4A , the embodiment of the present disclosure relates to a communication method, which is executed by the second terminal side, and the method includes:

[0296] Step S4101: Receive the second broadcast information.

[0297] The optional implementation of step S4101 can refer to the optional implementation of step S203 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0298] In some embodiments, the second terminal 103 receives the second information broadcast by the relay terminal 102, but is not limited thereto. The second terminal 103 may also receive the second information broadcast by other entities.

[0299] In some embodiments, the second terminal 103 obtains second information specified by the protocol.

[0300] In some embodiments, the second terminal 103 obtains the second information from an upper layer(s).

[0301] In some embodiments, the second terminal 103 performs processing to obtain the second information.

[0302] In some embodiments, step S4101 is omitted, and the second terminal 103 autonomously implements the function indicated by the second information, or the above function is default or by default.

[0303] Step S4102: Parse the encrypted user information identifier of the target second terminal in the second information according to the secret key.

[0304] The optional implementation of step S4102 can refer to the optional implementation of step S204 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0305] In some embodiments, the target second terminal is determined by successfully parsing the second terminal identified by the encrypted user information of the target second terminal.

[0306] Optionally, the target second terminal is a second terminal that can parse the encrypted user information identifier of the target second terminal according to the secret key and matches the parsed user information identifier of the target second terminal.

[0307] In some embodiments, there are multiple second terminals, and the target second terminal is one of the multiple second terminals.

[0308] In some embodiments, the second terminal that performs the subsequent steps S4103 to S4104 is a target second terminal.

[0309] Step S4103: Complete the secure establishment process of the PC5 link between the relay terminal and the target second terminal.

[0310] The optional implementation of step S4103 can refer to the optional implementation of step S205 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0311] Step S4104: Send a direct communication acceptance message.

[0312] The optional implementation of step S4104 can refer to the optional implementation of step S206 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0313] In some embodiments, the second terminal 103 sends a direct communication acceptance message to the relay terminal 102, but is not limited thereto. The direct communication acceptance message may also be sent to other entities.

[0314] The communication method involved in the embodiment of the present disclosure may include at least one of steps S4101 to S4104. For example, step S4101 may be implemented as an independent embodiment, but is not limited thereto.

[0315] In some embodiments, steps S4102 to S4104 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0316] FIG4B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4B , the embodiment of the present disclosure relates to a communication method, which is executed by the second terminal side, and the method includes:

[0317] Step S4201, listen to the broadcast based on the specified Layer-2 ID, and receive the second information broadcast by the relay terminal after receiving the first information sent by the first terminal, the first information is used by the first terminal to request to establish a PC5 link with the relay terminal, and the second information is used by the relay terminal to request to establish a PC5 link with the target second terminal.

[0318] The optional implementation of step S4201 can refer to step S203 in FIG. 2 , the optional implementation of step S4101 in FIG. 4A , and other related parts in the embodiments involved in FIG. 2 and FIG. 4A , which will not be described in detail here.

[0319] Step S4202: Complete the secure establishment process of the PC5 link between the relay terminal and the target second terminal.

[0320] The optional implementation of step S4202 can refer to the optional implementation of step S205 in Figure 2, step S4103 in Figure 4A, and other related parts in the embodiments involved in Figures 2 and 4A, which will not be repeated here.

[0321] The communication method involved in the embodiment of the present disclosure may include at least one of step S4201 and step S4202. For example, step S4201 may be implemented as an independent embodiment, but is not limited thereto.

[0322] In some embodiments, step S4202 is optional and may be omitted or replaced in different embodiments.

[0323] In an embodiment of the present disclosure, step S4201 may be combined with one or more steps of step S4102, step S4103, and step S4104 in FIG4A .

[0324] Figure 5 is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in Figure 5, the embodiment of the present disclosure relates to a communication method, which is executed by the first terminal side. The method includes:

[0325] Step S501: Send first information.

[0326] The optional implementation of step S501 can refer to the optional implementation of step S201 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0327] In some embodiments, the first terminal 101 sends the first information to the relay terminal 102, but is not limited thereto. The first information may be sent to other entities.

[0328] FIG6A is a schematic diagram of an interaction process of a communication method according to an embodiment of the present disclosure. As shown in FIG6A , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0329] Step S601: The first terminal sends first information to the relay terminal.

[0330] The optional implementation of step S601 can refer to the optional implementation of step S201 in Figure 2, step S3101 in Figure 3A, step S3201 in Figure 3B, and other related parts in the embodiments involved in Figures 2, 3A, and 3B, which will not be repeated here.

[0331] Step S602: The relay terminal completes the secure establishment process of the PC5 link between the first terminal and the relay terminal.

[0332] Optional implementations of step S602 can refer to step S202 in FIG. 2 , optional implementations of step S3102 in FIG. 3A , and other related parts in the embodiments involved in FIG. 2 and FIG. 3A , which will not be described in detail here.

[0333] Step S603: The relay terminal broadcasts the second information according to the specified Layer-2 ID.

[0334] Optional implementations of step S603 may refer to the optional implementations of step S203 in FIG. 2 , step S3103 in FIG. 3A , step S3202 in FIG. 3B , and other related parts in the embodiments involved in FIG. 2 , FIG. 3A , and FIG. 3B , which will not be repeated here.

[0335] Step S604: The second terminal monitors the broadcast based on the specified Layer-2 ID and receives the second information.

[0336] The optional implementation of step S604 can refer to the optional implementation of step S203 in Figure 2, step S4101 in Figure 4A, step S4201 in Figure 4B, and other related parts in the embodiments involved in Figures 2, 4A, and 4B, which will not be repeated here.

[0337] Step S605: The target second terminal completes the secure establishment process of the PC5 link between the relay terminal and the second terminal.

[0338] Optional implementations of step S605 may refer to the optional implementations of step S205 in FIG. 2 , step S4103 in FIG. 4A , step S4202 in FIG. 4B , and other related parts in the embodiments involved in FIG. 2 , FIG. 4A , and FIG. 4B , which will not be described in detail here.

[0339] Step S606: The target second terminal sends a direct communication acceptance message to the relay terminal.

[0340] Optional implementations of step S606 can refer to step S206 in FIG. 2 , optional implementations of step S4104 in FIG. 4A , and other related parts in the embodiments involved in FIG. 2 and FIG. 4A , which will not be described in detail here.

[0341] Step S607: The relay terminal sends a direct communication acceptance message to the first terminal.

[0342] Optional implementations of step S607 may refer to step S207 in FIG. 2 , optional implementations of step S3105 in FIG. 3A , and other related parts of the embodiments involved in FIG. 2 and FIG. 3A , which will not be described in detail here.

[0343] In some embodiments, the above method may include the method described in the above embodiments of the first terminal side, relay terminal side, second terminal side, etc., which will not be repeated here.

[0344] FIG6B is a schematic diagram of an interaction process of a communication method according to an embodiment of the present disclosure. As shown in FIG6B , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0345] (1) Perform service authorization and provisioning operations on the source 5G ProSe Layer-3 End UE, the target 5G ProSe Layer-3 End UE, and the 5G ProSe Layer-3 UE-to-UE relay.

[0346] (2) The source 5G ProSe Layer-3 End UE performs 5G ProSe Layer-3 UE-to-UE relay discovery. For details, see the embodiment corresponding to FIG. 1B above, which will not be repeated here.

[0347] (3) The source 5G ProSe Layer-3 End UE sends a Direct Communication Request message to initiate the unicast Layer-2 link establishment process with the 5G ProSe Layer-3 UE-to-UE relay.

[0348] In some embodiments, the source Layer-2 identifier of the direct communication request message is allocated by the source 5G ProSe Layer-3 End UE, and the target Layer-2 identifier is set to the source Layer-2 identifier of the discovery message relayed by the 5G ProSe Layer-3 UE-to-UE.

[0349] (4) If the user information identifier of the 5G ProSe Layer-3 UE-to-UE relay in the direct communication request message matches the user information identifier of the 5G ProSe UE-to-UE relay, and the RSC in the request matches one of the RSCs supported by the relay, the 5G ProSe Layer-3 UE-to-UE relay shall respond by establishing a secure connection with the source 5G ProSe Layer-3 End UE. When security protection is enabled, the source 5G ProSe Layer-3 End UE may send parameters to the 5G ProSe Layer-3 UE-to-UE relay.

[0350] In some embodiments, if the MAC address of the source 5G ProSe Layer-3 End UE is already used by another 5G ProSe Layer-3 End UE, the 5G ProSe Layer-3 UE-to-UE relay may send a message to the source 5G ProSe Layer-3 End UE, indicating that there is an Ethernet MAC address conflict.

[0351] In some embodiments, the source Layer-2 identifier used for the security establishment process is allocated by the 5G ProSe Layer-3 UE-to-UE relay, and the target Layer-2 identifier is set to the source Layer-2 identifier of the received direct communication request message.

[0352] In some embodiments, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for PC5 links for different types of traffic, namely IP traffic, Ethernet traffic, and unstructured traffic.

[0353] In some embodiments, if the PC5 link is used to transmit unstructured traffic, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for different source and target 5G ProSe Layer-3 End UE pairs.

[0354] In some embodiments, after receiving the security establishment process message, the source 5G ProSe Layer-3 End UE obtains the Layer-2 identity of the 5G ProSe Layer-3 UE-to-UE relay for future communications, including signaling and data traffic on the unicast link.

[0355] (5) After the security establishment process in step (4) is completed, the 5G ProSe Layer-3 UE-to-UE relay sends a direct communication request message to initiate the unicast Layer-2 link establishment process with the target 5G ProSe Layer-3 End UE.

[0356] In some embodiments, the source Layer-2 identifier of the direct communication request message is self-assigned by the 5G ProSe Layer-3 UE-to-UE relay, and the target Layer-2 identifier is a designated Layer-2 ID for broadcast information.

[0357] In some embodiments, based on the target Layer-2 identifier received from the source UE, the 5G ProSe Layer-3 UE-to-UE relay selects the associated source Layer-2 identifier and target Layer-2 identifier to send a DCR message to the target UE.

[0358] In some embodiments, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for PC5 links for different types of traffic, i.e., IP traffic, Ethernet traffic, and unstructured traffic.

[0359] In some embodiments, if the PC5 link is used to transmit unstructured traffic, the 5G ProSe Layer-3 UE-to-UE relay may select different source Layer-2 identifiers for different source and target 5G ProSe Layer-3 End UE pairs.

[0360] (6) If the user information identifier and RSC of the target 5G ProSe Layer-3 End UE included in the direct communication request match the user information identifier and supported RSC of the target UE, the target 5G ProSe Layer-3 End UE responds by establishing a secure connection with the 5G ProSe Layer-3 UE-to-UE relay. When security protection is enabled, the 5G ProSe Layer-3 UE-to-UE relay can send parameters to the target 5G ProSe Layer-3 End UE.

[0361] In some embodiments, the source Layer-2 identifier used for the security establishment process is allocated by the target 5G ProSe Layer-3 End UE itself, and the target Layer-2 identifier is set to the source Layer-2 identifier of the received direct communication request message.

[0362] In some embodiments, after receiving the security establishment procedure message, the 5G ProSe Layer-3 UE-to-UE relay obtains the Layer-2 identity of the target 5G ProSe Layer-3 End UE for future communications, including signaling and data traffic on the unicast link.

[0363] (7) The target 5G ProSe Layer-3 End UE sends a direct communication accept message to the 5G ProSe Layer-3 UE-to-UE relay that successfully establishes a secure connection.

[0364] (8) For IP traffic, allocate an IPv6 prefix or IPv4 address to the target 5G ProSe Layer-3 End UE.

[0365] (9) After receiving the direct communication accept message from the target 5G ProSe Layer-3 End UE, the 5G ProSe Layer-3 UE-to-UE relay sends a direct communication accept message to the source 5G ProSe Layer-3 End UE with which the secure connection is successfully established.

[0366] (10) For IP traffic, an IPv6 prefix or IPv4 address is allocated to the source 5G ProSe Layer-3 End UE.

[0367] (11) For IP communication, the 5G ProSe Layer-3 UE-to-UE relay may store the association between the user information identifier and the IP address of the target 5G ProSe Layer-3 End UE in its Domain Name System (DNS) entry and may act as a DNS server to provide DNS services to other UEs. If the IP address of the target 5G ProSe Layer-3 End UE is not received in step (9), then after step (10), the source 5G ProSe Layer-3 End UE may send a DNS query to the 5G ProSe Layer-3 UE-to-UE relay to request the IP address of the target 5G ProSe Layer-3 End UE, and the 5G ProSe Layer-3 UE-to-UE relay returns the IP address of the target 5G ProSe Layer-3 End UE to the source 5G ProSe Layer-3 End UE.

[0368] In some embodiments, for Ethernet communications, the 5G ProSe Layer-3 UE-to-UE relay maintains an association between the PC5 link and the Ethernet MAC address received from the 5G ProSe Layer-3 End UE.

[0369] In some embodiments, for unstructured traffic communication, for each pair of source 5G ProSe Layer-3 End UE and target 5G ProSe Layer-3 End UE, the 5G ProSe Layer-3 UE-to-UE relay maintains a one-to-one mapping between the PC5 link and the source 5G ProSe Layer-3 End UE and the PC5 link and the target 5G ProSe Layer-3 End UE.

[0370] (12) The source 5G ProSe Layer-3 End UE communicates with the target 5G ProSe Layer-3 End UE through a 5G ProSe Layer-3 UE-to-UE relay.

[0371] In some embodiments, when a source 5G ProSe Layer-3 End UE communicates with multiple target 5G ProSe Layer-3 End UEs, the PC5 link between the source 5G ProSe Layer-3 End UE and the 5G ProSe Layer-3 UE-to-UE relay can be shared for multiple target 5G ProSe Layer-3 End UEs in one RSC, while for each RSC, the PC5 link between the 5G ProSe Layer-3 UE-to-UE Relay and the target 5G ProSe Layer-3 End UE can be established separately. For the shared PC5 link, the Layer-2 link modification procedure should be used.

[0372] In some embodiments, when multiple source 5G ProSe Layer-3 End UEs communicate with one target 5G ProSe Layer-3 End UE, the PC5 link between the 5G ProSe Layer-3 UE-to-UE relay and the target 5G ProSe Layer-3 End UE can be shared in one RSC, while for each RSC, the PC5 link between the source 5G ProSe Layer-3 End UE and the 5G ProSe Layer-3 UE-to-UE relay can be established separately. For the shared PC5 link, the Layer-2 link modification procedure should be used.

[0373] In some embodiments, a method for U2U relaying a DCR message includes receiving a first DCR message (ie, first information) from a source End UE (ie, a first terminal), and sending a second DCR message (ie, second information) using a broadcast designated Layer-2 ID.

[0374] In some embodiments, the first DCR message includes:

[0375] The user information ID of the source 5G ProSe End UE (i.e., the first terminal), that is, the identity of the source 5G ProSe End UE requesting the relay operation.

[0376] The user information ID of the 5G ProSe UE-to-UE Relay (i.e., the relay terminal), that is, the identity of the UE-to-UE relay provided to the source 5G ProSe End UE during the 5G ProSe UE-to-UE relay discovery process.

[0377] The user information ID of the target 5G ProSe End UE (i.e., the second terminal), that is, the identity of the target 5G ProSe End UE provided to the source 5G ProSe End UE during the 5G ProSe UE-to-UE relay discovery process.

[0378] Optionally, the first DCR message includes: the target Layer-2 ID of the target 5G ProSe End UE, that is, the unicast target Layer-2 ID of the target 5G ProSe End UE determined by the source 5G ProSe End UE.

[0379] ProSe Service Info: information about a ProSe identifier for requesting establishment of a Layer-2 link.

[0380] RSC: Connection service requested by the source 5G ProSe terminal UE and provided by the 5G ProSe UE-to-UE relay.

[0381] Security Information: security information used to establish the first-hop PC5 link.

[0382] In some embodiments, the second DCR message includes:

[0383] User information identifier (User Info ID) of the source 5G ProSe terminal UE.

[0384] User information identifier (User Info ID) of the target 5G ProSe terminal UE.

[0385] User Info ID for 5G ProSe UE-to-UE relay.

[0386] ProSe service information (ProSe Service Info): information about the ProSe identity.

[0387] Radio Slice Configuration (RSC): a connection service requested by a source 5G ProSe terminal UE and provided by a 5G ProSe UE-to-UE relay.

[0388] Security Information: information used for establishing security for the second-hop PC5 link.

[0389] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0390] The embodiments of the present disclosure further provide an apparatus for implementing any of the above methods. For example, an apparatus is provided, comprising units or modules for implementing each step performed by a terminal in any of the above methods. For another example, another apparatus is provided, comprising units or modules for implementing each step performed by a network device (e.g., an access network device, a core network function node, a core network device, etc.) in any of the above methods.

[0391] It should be understood that the division of the various units or modules in the above device is merely a division of logical functions. In actual implementation, they may be fully or partially integrated into a physical entity, or they may be physically separated. In addition, the units or modules in the device may be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, and the memory stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the various units or modules of the above device, wherein the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory within the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units or modules can be realized by designing the hardware circuits. The above-mentioned hardware circuits can be understood as one or more processors; for example, in one implementation, the above-mentioned hardware circuit is an application-specific integrated circuit (ASIC), which realizes the functions of some or all of the above units or modules by designing the logical relationship of the components in the circuit; for example, in another implementation, the above-mentioned hardware circuit can be realized by a programmable logic device (PLD). Taking a field programmable gate array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by configuring the configuration file, thereby realizing the functions of some or all of the above units or modules. All units or modules of the above devices can be realized in the form of software called by the processor, or in the form of hardware circuits, or in part by the form of software called by the processor, and the rest by hardware circuits.

[0392] In the embodiments of the present disclosure, the processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction reading and execution capabilities, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP). In another implementation, the processor can implement certain functions through the logical relationship of the hardware circuit. The logical relationship of the above-mentioned hardware circuit is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[0393] Figure 7A is a schematic diagram of the structure of a relay terminal proposed according to an exemplary embodiment of the present disclosure. As shown in Figure 7A, the relay terminal 7100 may include at least one of a transceiver module 7101 and a processing module 7102. In some embodiments, the transceiver module is configured to receive first information sent by a first terminal, the first information being used by the first terminal to request the establishment of a direct communication PC5 link with the relay terminal; and to broadcast second information based on a specified Layer-2 ID, the second information being used by the relay terminal to request the establishment of a PC5 link with a target second terminal. Optionally, the transceiver module is configured to execute at least one of the communication steps (e.g., steps S201, S203, S205, and S206, but not limited thereto) performed by the relay terminal 102 in any of the above methods, which are not further described here. Optionally, the processing module is configured to execute at least one of the other steps (e.g., steps S202 and S204, but not limited thereto) performed by the relay terminal 102 in any of the above methods, which are not further described here.

[0394] In some embodiments, the processing module is configured to complete a secure establishment process of a PC5 link between the first terminal and the relay terminal before broadcasting the second information according to the specified Layer-2 ID.

[0395] In some embodiments, the designated Layer-2 ID is indicated by the network device or is pre-configured locally.

[0396] In some embodiments, the first information is a direct communication request DCR.

[0397] In some embodiments, the first information includes at least one of the following:

[0398] a user information identifier of the first terminal;

[0399] The user information identifier of the relay terminal;

[0400] The user information identifier of the target second terminal;

[0401] Unicast Layer-2 ID;

[0402] Proximity service ProSe service information, including information about a ProSe identifier used to request establishment of a Layer-2 link for PC5 communication;

[0403] Relay service code RSC;

[0404] The first security information includes security information used to establish a PC5 link between the first terminal and the relay terminal.

[0405] In some embodiments, the unicast Layer-2 ID is a unicast target Layer-2 ID of the target second terminal determined by the first terminal.

[0406] In some embodiments, the Layer-2 link of the PC5 communication includes a PC5 link between the first terminal and the relay terminal, and a PC5 link between the relay terminal and the target second terminal.

[0407] In some embodiments, the second information is a DCR.

[0408] In some embodiments, the second information includes at least one of the following:

[0409] a user information identifier of the first terminal;

[0410] The user information identifier of the relay terminal;

[0411] The user information identifier of the target second terminal;

[0412] ProSe service information;

[0413] RSC;

[0414] The second security information includes security information used to establish a PC5 link between the relay terminal and the target second terminal.

[0415] In some embodiments, the user information identifier of the target second terminal is encrypted.

[0416] In some embodiments, the relay terminal is a 5G ProSe Layer-3 UE-to-UE relay terminal;

[0417] The first terminal is a source 5G ProSe Layer-3 end terminal;

[0418] The target second terminal is a target 5G ProSe Layer-3 end terminal.

[0419] Figure 7B is a schematic diagram of the structure of a second terminal proposed according to an exemplary embodiment of the present disclosure. As shown in Figure 7B, the second terminal 7200 may include at least one of a transceiver module 7201 and a processing module 7202. In some embodiments, the transceiver module is configured to monitor broadcasts based on a specified Layer-2 ID and receive second information broadcast by a relay terminal after receiving first information sent by a first terminal. The first information is used by the first terminal to request the establishment of a PC5 link with the relay terminal, and the second information is used by the relay terminal to request the establishment of a PC5 link with a target second terminal. Optionally, the transceiver module is configured to execute at least one of the communication steps (e.g., steps S201, S203, S205, and S206, but not limited thereto) performed by the second terminal 103 in any of the above methods, which are not further described here. Optionally, the processing module is configured to execute at least one of the other steps (e.g., steps S202 and S204, but not limited thereto) performed by the second terminal 103 in any of the above methods, which are not further described here.

[0420] In some embodiments, the second information is broadcast by the relay terminal after completing the security establishment process of the PC5 link between the first terminal and the relay terminal; the processing module is used to complete the security establishment process of the PC5 link between the relay terminal and the target second terminal.

[0421] In some embodiments, the designated Layer-2 ID is indicated by the network device or is pre-configured locally.

[0422] In some embodiments, the first information is a direct communication request DCR.

[0423] In some embodiments, the first information includes at least one of the following:

[0424] a user information identifier of the first terminal;

[0425] The user information identifier of the relay terminal;

[0426] The user information identifier of the target second terminal;

[0427] Unicast Layer-2 ID;

[0428] Proximity Service (ProSe) service information, including information about a ProSe identifier used to request establishment of a Layer-2 link for PC5 communication;

[0429] Relay service code RSC;

[0430] The first security information includes security information used to establish a PC5 link between the first terminal and the relay terminal.

[0431] In some embodiments, the unicast Layer-2 ID is a unicast target Layer-2 ID of the target second terminal determined by the first terminal.

[0432] In some embodiments, the Layer-2 link of the PC5 communication includes a PC5 link between the first terminal and the relay terminal, and a PC5 link between the relay terminal and the target second terminal.

[0433] In some embodiments, the second information is a DCR.

[0434] In some embodiments, the second information includes at least one of the following:

[0435] a user information identifier of the first terminal;

[0436] The user information identifier of the relay terminal;

[0437] The user information identifier of the target second terminal;

[0438] ProSe service information;

[0439] RSC;

[0440] The second security information includes security information used to establish a PC5 link between the relay terminal and the target second terminal.

[0441] In some embodiments, the user information identifier of the target second terminal is encrypted;

[0442] The processing module is configured to: the second terminal parse the encrypted user information identifier of the target second terminal according to a secret key, and determine the second terminal that successfully parses the user information identifier of the target second terminal as the target second terminal.

[0443] In some embodiments, the relay terminal is a 5G ProSe Layer-3 UE-to-UE relay terminal;

[0444] The first terminal is a source 5G ProSe Layer-3 end terminal;

[0445] The target second terminal is a target 5G ProSe Layer-3 end terminal.

[0446] In some embodiments, the transceiver module may include a transmitting module and / or a receiving module, and the transmitting module and the receiving module may be separate or integrated. Optionally, the transceiver module may be interchangeable with the transceiver.

[0447] In some embodiments, the processing module can be a single module or include multiple submodules. Optionally, the multiple submodules each execute all or part of the steps required to be executed by the processing module. Optionally, the processing module and the processor can be interchangeable.

[0448] Figure 8A is a schematic diagram of the structure of a communication device 8100 proposed in an embodiment of the present disclosure. Communication device 8100 can be a network device (e.g., an access network device, a core network device, etc.), a terminal (e.g., a user equipment, etc.), a chip, a chip system, or a processor that supports a network device to implement any of the above methods, or a chip, a chip system, or a processor that supports a terminal to implement any of the above methods. Communication device 8100 can be used to implement the methods described in the above method embodiments. For details, please refer to the description of the above method embodiments.

[0449] As shown in Figure 8A, the communication device 8100 includes one or more processors 8101. The processor 8101 can be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process the communication protocol and communication data, and the central processing unit can be used to control the communication device (such as a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute programs, and process program data. Optionally, the communication device 8100 is used to perform any of the above methods. Optionally, one or more processors 8101 are used to call instructions to enable the communication device 8100 to perform any of the above methods.

[0450] In some embodiments, the communication device 8100 further includes one or more transceivers 8102. When the communication device 8100 includes one or more transceivers 8102, the transceiver 8102 performs at least one of the communication steps such as sending and / or receiving in the above method (e.g., step S201, step S203, step S205, step S206, but not limited thereto), and the processor 8101 performs at least one of the other steps (e.g., step S202, step S204, but not limited thereto). In an optional embodiment, the transceiver may include a receiver and / or a transmitter, and the receiver and transmitter may be separate or integrated. Optionally, the terms transceiver, transceiver unit, transceiver, transceiver circuit, interface circuit, and interface may be interchangeable, the terms transmitter, transmitting unit, transmitter, and transmitting circuit may be interchangeable, and the terms receiver, receiving unit, receiver, and receiving circuit may be interchangeable.

[0451] In some embodiments, the communication device 8100 further includes one or more memories 8103 for storing data. Alternatively, all or part of the memories 8103 may be located outside the communication device 8100. In alternative embodiments, the communication device 8100 may include one or more interface circuits 8104. Optionally, the interface circuits 8104 are connected to the memory 8102 and may be configured to receive data from the memory 8102 or other devices, or to send data to the memory 8102 or other devices. For example, the interface circuits 8104 may read data stored in the memory 8102 and send the data to the processor 8101.

[0452] The communication device 8100 described in the above embodiment may be a network device or a terminal, but the scope of the communication device 8100 described in the present disclosure is not limited thereto, and the structure of the communication device 8100 may not be limited by FIG. 8A. The communication device may be an independent device or may be part of a larger device. For example, the communication device may be: 1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data or programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, an in-vehicle device, a network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[0453] FIG8B is a schematic diagram of the structure of a chip 8200 according to an embodiment of the present disclosure. If the communication device 8100 can be a chip or a chip system, please refer to the schematic diagram of the structure of the chip 8200 shown in FIG8B , but the present disclosure is not limited thereto.

[0454] The chip 8200 includes one or more processors 8201. The chip 8200 is configured to execute any of the above methods.

[0455] In some embodiments, chip 8200 further includes one or more interface circuits 8202. Terms such as interface circuit, interface, and transceiver pins may be used interchangeably. In some embodiments, chip 8200 further includes one or more memories 8203 for storing data. Alternatively, all or part of memory 8203 may be located external to chip 8200. Optionally, interface circuit 8202 is connected to memory 8203 and may be used to receive data from memory 8203 or other devices, or may be used to send data to memory 8203 or other devices. For example, interface circuit 8202 may read data stored in memory 8203 and send the data to processor 8201.

[0456] In some embodiments, the interface circuit 8202 performs at least one of the communication steps (e.g., steps S201, S203, S205, and S206) of the aforementioned method. The interface circuit 8202 performing the communication steps (e.g., steps S201, S203, S205, and S206) of the aforementioned method, for example, means that the interface circuit 8202 performs data exchange between the processor 8201, chip 8200, memory 8203, or a transceiver device. In some embodiments, the processor 8201 performs at least one of the other steps (e.g., steps S202 and S204, but not limited thereto).

[0457] The modules and / or devices described in various embodiments, such as virtual devices, physical devices, and chips, can be arbitrarily combined or separated according to circumstances. Optionally, some or all steps can also be performed collaboratively by multiple modules and / or devices, which is not limited here.

[0458] The present disclosure also proposes a storage medium having instructions stored thereon, which, when executed on the communication device 8100, causes the communication device 8100 to execute any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer-readable storage medium, but is not limited thereto, and may also be a storage medium readable by other devices. Optionally, the storage medium may be a non-transitory storage medium, but is not limited thereto, and may also be a temporary storage medium.

[0459] The present disclosure also provides a program product, which, when executed by the communication device 8100, enables the communication device 8100 to perform any of the above methods. Optionally, the program product is a computer program product.

[0460] The present disclosure also proposes a computer program, which, when executed on a computer, causes the computer to perform any one of the above methods.

Claims

1. A communication method, characterized in that, Performed by a relay terminal, the method includes: Receiving first information sent by a first terminal, where the first information is used for the first terminal to request to establish a direct communication PC5 link with the relay terminal; Broadcasting second information according to a specified Layer-2 ID, where the second information is used for the relay terminal to request to establish a PC5 link with a target second terminal.

2. The method according to claim 1, characterized in that, Before the broadcasting of the second information according to the specified Layer-2 ID, it includes: Completing the security establishment process of the PC5 link between the first terminal and the relay terminal.

3. The method according to claim 1 or 2, characterized in that The specified Layer-2 ID is indicated by a network device or pre-configured locally.

4. The method according to any one of claims 1-3, characterized in that The first information is a Direct Communication Request (DCR).

5. The method according to any one of claims 1-4, characterized in that, The first information includes at least one of the following: The user information identifier of the first terminal; The user information identifier of the relay terminal; The user information identifier of the target second terminal; Unicast Layer-2 ID; Proximity Service (ProSe) service information, including information on the ProSe identifier for requesting to establish a Layer-2 link for PC5 communication; Relay Service Code (RSC); First security information, including security information for establishing the PC5 link between the first terminal and the relay terminal.

6. The method according to claim 5, characterized in that The unicast Layer-2 ID is the unicast target Layer-2 ID of the target second terminal determined by the first terminal.

7. The method according to claim 5 or 6, characterized in that The Layer-2 link for PC5 communication includes the PC5 link between the first terminal and the relay terminal, and the PC5 link between the relay terminal and the target second terminal.

8. The method according to any one of claims 1-7, characterized in that The second information is a DCR.

9. The method according to any one of claims 1-8, characterized in that, The second information includes at least one of the following: The user information identifier of the first terminal; The user information identifier of the relay terminal; The user information identifier of the target second terminal; ProSe service information; RSC; Second security information, including security information for establishing the PC5 link between the relay terminal and the target second terminal.

10. The method according to claim 5 or 9, characterized in that The user information identifier of the target second terminal is encrypted.

11. The method according to any one of claims 1-10, characterized in that The relay terminal is a 5G ProSe Layer-3 UE-to-UE relay terminal; The first terminal is a source 5G ProSe Layer-3 end terminal; The target second terminal is a target 5G ProSe Layer-3 end terminal.

12. A communication method, characterized in that, Performed by a second terminal, the method includes: Monitor broadcasts based on a specified Layer-2 ID, and receive a second message broadcast by a relay terminal after receiving a first message sent by a first terminal, where the first message is used by the first terminal to request to establish a PC5 link with the relay terminal, and the second message is used by the relay terminal to request to establish a PC5 link with a target second terminal.

13. The method according to claim 12, wherein, the second message is broadcast by the relay terminal after completing the security establishment process of the PC5 link between the first terminal and the relay terminal; the method further includes: completing the security establishment process of the PC5 link between the relay terminal and the target second terminal.

14. The method according to claim 12 or 13, wherein, the specified Layer-2 ID is indicated by a network device or pre-configured locally.

15. The method according to any one of claims 12-14, wherein, the first message is a direct communication request DCR.

16. The method according to any one of claims 12-15, characterized in that, The first message includes at least one of the following: a user information identifier of the first terminal; a user information identifier of the relay terminal; a user information identifier of the target second terminal; a unicast Layer-2 ID; ProSe service information of a proximity service, including information on a ProSe identifier for requesting to establish a Layer-2 link for PC5 communication; a relay service code RSC; a first security information, including security information for establishing the PC5 link between the first terminal and the relay terminal.

17. The method according to claim 16, wherein, the unicast Layer-2 ID is a unicast target Layer-2 ID of the target second terminal determined by the first terminal.

18. The method according to claim 16 or 17, wherein, the Layer-2 link for PC5 communication includes the PC5 link between the first terminal and the relay terminal, and the PC5 link between the relay terminal and the target second terminal.

19. The method according to any one of claims 12-18, wherein, the second message is DCR.

20. The method according to any one of claims 12-19, characterized in that, The second message includes at least one of the following: a user information identifier of the first terminal; a user information identifier of the relay terminal; a user information identifier of the target second terminal; ProSe service information; RSC; a second security information, including security information for establishing the PC5 link between the relay terminal and the target second terminal.

21. The method according to claim 16 or 20, wherein, the user information identifier of the target second terminal is encrypted; the method further includes: the second terminal parses the encrypted user information identifier of the target second terminal according to a secret key, and the second terminal that successfully parses the user information identifier of the target second terminal is the target second terminal.

22. The method according to any one of claims 12-21, wherein, The relay terminal is a 5G ProSe Layer-3 UE-to-UE relay terminal; The first terminal is a source 5G ProSe Layer-3 end terminal; The target second terminal is a target 5G ProSe Layer-3 end terminal.

23. A relay terminal, characterized in that, It includes: A transceiver module, configured to receive first information sent by the first terminal, where the first information is used for the first terminal to request to establish a direct communication PC5 link with the relay terminal; broadcast second information according to a specified Layer-2 ID, and the second information is used for the relay terminal to request to establish a PC5 link with the target second terminal.

24. A terminal, characterized in that, It includes: A transceiver module, configured to monitor broadcasts based on a specified Layer-2 ID, and receive second information broadcast by the relay terminal after receiving the first information sent by the first terminal, where the first information is used for the first terminal to request to establish a PC5 link with the relay terminal, and the second information is used for the relay terminal to request to establish a PC5 link with the target second terminal.

25. A relay terminal, characterized in that, It includes: One or more processors; A memory coupled to the processor, where executable instructions are stored on the memory. When the executable instructions are executed by the processor, the relay terminal is caused to execute the communication method described in any one of claims 1-11.

26. A terminal, characterized in that, It includes: One or more processors; A memory coupled to the processor, where executable instructions are stored on the memory. When the executable instructions are executed by the processor, the terminal is caused to execute the communication method described in any one of claims 12-22.

27. A communication system, characterized in that, It includes a first terminal, a relay terminal, and a second terminal. Among them, the relay terminal is configured to implement the communication method described in any one of claims 1-11, and the second terminal is configured to implement the communication method described in any one of claims 12-22.

28. A storage medium, the storage medium stores instructions, characterized in that, When the instruction runs on the communication device, the communication device is caused to execute the communication method described in any one of claims 1-22.

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