Relay discovery method, communication device, communication system, and storage medium

Abstract

A relay discovery method, a communication device, a communication system, and a storage medium. The method comprises: a first-hop relay device sends a first message to a next-hop device, wherein the first message comprises: a first field, indicating the maximum relay hop count; and a second field, indicating a relay hop count corresponding to the first-hop relay device.

Description

Relay discovery method, communication device, communication system and storage medium Technical Field

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

[0002] 5G Proximity-based Services (ProSe) enable user equipment (UE) to communicate with each other through relay UEs. This means that if a source UE (Source UE) cannot communicate directly with a target UE (Target UE), the source UE will attempt to discover a relay device to communicate with the target UE, i.e., user equipment to user equipment (UE to UE, U2U) relay communication.

[0003] Summary of the Invention

[0004] Since U2U relay communication only supports single-hop relay communication, the communication range of U2U relay communication is small and it is difficult to meet communication needs.

[0005] Embodiments of the present disclosure provide a relay discovery method, a communication device, a communication system, and a storage medium.

[0006] According to a first aspect of an embodiment of the present disclosure, a relay discovery method is provided, wherein the method includes:

[0007] The first-hop relay device sends a first message to the next-hop device; the first message includes:

[0008] The first field indicates the maximum number of relay hops;

[0009] The second field indicates the number of relay hops corresponding to the first-hop relay device.

[0010] According to a second aspect of an embodiment of the present disclosure, a relay discovery method is provided, wherein the method includes:

[0011] The n-th hop relay device receives the n-1-th hop first message; the n-1-th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1-th hop relay device; n is a positive integer greater than 1;

[0012] Determining the number of relay hops corresponding to the n-th hop relay device according to the second field of the n-1th hop first message;

[0013] When the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, an n-th hop first message is generated based on the n-1-th hop first message; the first field of the n-th hop first message indicates the maximum number of relay hops; the second field of the n-th hop first message is used to indicate the number of relay hops corresponding to the n-th hop relay device.

[0014] According to a third aspect of an embodiment of the present disclosure, a relay discovery method is provided, wherein the method includes:

[0015] The source terminal receives a first message; the first message includes: a first field indicating a maximum number of relay hops; a second field indicating a number of relay hops corresponding to the relay device;

[0016] A relay path for relay communication is selected according to the first message.

[0017] According to a fourth aspect of an embodiment of the present disclosure, a relay discovery method is provided, wherein the method includes:

[0018] The first-hop relay device sends the first message;

[0019] The n-th hop relay device receives the n-1-th hop first message; the n-1-th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1-th hop relay device; n is a positive integer greater than 1;

[0020] The n-hop relay device determines, according to the second field of the n-1-hop first message, the number of relay hops corresponding to the n-hop relay device; when the number of relay hops corresponding to the n-hop relay device is less than or equal to the maximum number of relay hops, generating an n-hop first message according to the n-1-hop first message; the first field of the n-hop first message indicates the maximum number of relay hops; the second field of the n-hop first message is used to indicate the number of relay hops corresponding to the n-hop relay device;

[0021] The source terminal receives the first message and selects a relay path for relay communication according to the first message.

[0022] According to a fifth aspect of an embodiment of the present disclosure, a first relay device is provided, wherein the first relay device is a first-hop relay device, and the first relay device includes:

[0023] The first sending module is configured to send a first message to a next-hop device, wherein the first message includes:

[0024] The first field indicates the maximum number of relay hops;

[0025] The second field indicates the number of relay hops corresponding to the first-hop relay device.

[0026] According to a sixth aspect of an embodiment of the present disclosure, a second relay device is provided, wherein the second relay device is an n-th hop relay device, and the second relay device includes:

[0027] A first receiving module is configured to receive a first message of the n-1th hop; the first message of the n-1th hop includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1th hop relay device; n is a positive integer greater than 1;

[0028] The first processing module is configured to determine the number of relay hops corresponding to the n-hop relay device based on the second field of the n-1-hop first message; when the number of relay hops corresponding to the n-hop relay device is less than or equal to the maximum number of relay hops, generate the n-hop first message based on the n-1-hop first message; the first field of the n-hop first message indicates the maximum number of relay hops; the second field of the n-hop first message is used to indicate the number of relay hops corresponding to the n-hop relay device.

[0029] According to a seventh aspect of an embodiment of the present disclosure, a source terminal is provided, wherein the source terminal includes:

[0030] A second receiving module is configured to receive a first message; the first message includes: a first field indicating a maximum number of relay hops; a second field indicating a number of relay hops corresponding to the relay device;

[0031] The second processing module is configured to select a relay path for relay communication according to the first message.

[0032] According to the eighth aspect of an embodiment of the present disclosure, a communication system is provided, wherein the communication system includes a source terminal, a first relay device, a second relay device and a target terminal; the first relay device is configured to implement the relay discovery method provided by the first aspect, the second relay device is configured to implement the relay discovery method provided by the second aspect, and the source terminal is configured to implement the relay discovery method provided by the third aspect.

[0033] According to a ninth aspect of an embodiment of the present disclosure, a communication device is provided, wherein the communication device includes:

[0034] one or more processors;

[0035] The processor is used to call instructions to enable the communication device to execute the relay discovery method provided by the first aspect, the second aspect or the third aspect.

[0036] According to the tenth aspect of an embodiment of the present disclosure, a storage medium is provided, wherein the storage medium stores instructions, and when the instructions are executed on a communication device, the communication device executes the relay discovery method provided by the first aspect, the second aspect or the third aspect.

[0037] The technical solution provided by the embodiments of the present disclosure is conducive to realizing a U2U relay communication process that supports multiple hops, and can effectively increase the communication range of the U2U relay communication. By carrying a first field in the first message to limit the maximum number of relay hops of the relay communication and a second field to indicate the number of hops of the current relay, the device that subsequently receives the first message can be used to determine whether to continue to relay and send the first message. In this way, the relay range of the relay communication is improved through multi-hop relay, and the broadcast storm of the first message can be limited.

[0038] It should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and are not restrictive of the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the embodiments of the present invention.

[0040] FIG1 is a schematic diagram showing an architecture of a communication system according to an exemplary embodiment;

[0041] FIG2 is an interactive schematic diagram illustrating a relay discovery method according to an exemplary embodiment;

[0042] FIG3A is a schematic diagram showing a flow chart of a relay discovery method according to an exemplary embodiment;

[0043] FIG3B is a schematic diagram showing a flow chart of a relay discovery method according to an exemplary embodiment;

[0044] FIG3C is a schematic diagram showing a flow chart of a relay discovery method according to an exemplary embodiment;

[0045] FIG3D is a schematic diagram showing a flow chart of a relay discovery method according to an exemplary embodiment;

[0046] FIG4A is a schematic diagram showing a flow chart of a relay discovery method according to an exemplary embodiment;

[0047] FIG4B is a schematic diagram showing a flow chart of a relay discovery method according to an exemplary embodiment;

[0048] FIG5 is an interactive schematic diagram showing a relay discovery method according to an exemplary embodiment;

[0049] FIG6A is a flowchart diagram 1 showing a U2U discovery method in mode A according to an exemplary embodiment;

[0050] FIG6B is a second flow chart illustrating a U2U discovery method in mode A according to an exemplary embodiment;

[0051] FIG7A is a schematic structural diagram of a first relay device according to an exemplary embodiment;

[0052] FIG7B is a schematic structural diagram of a second relay device according to an exemplary embodiment;

[0053] FIG7C is a schematic structural diagram of a source terminal according to an exemplary embodiment;

[0054] FIG8A is a schematic structural diagram of a communication device 8100 according to an exemplary embodiment;

[0055] FIG8B is a schematic structural diagram of a chip 8200 according to an exemplary embodiment. DETAILED DESCRIPTION

[0056] Embodiments of the present disclosure provide a relay discovery method, a communication device, a communication system, and a storage medium.

[0057] In a first aspect, an embodiment of the present disclosure provides a relay discovery method, wherein the method includes:

[0058] The first-hop relay device sends a first message to the next-hop device; the first message includes:

[0059] The first field indicates the maximum number of relay hops;

[0060] The second field indicates the number of relay hops corresponding to the first-hop relay device.

[0061] In the above embodiment, by adding a first field and a second field to the first message, the first field is used to indicate the maximum number of relay hops supported by the destination terminal that the first relay device can relay, and the second field is used to indicate the number of relay hops corresponding to the first-hop relay device; this facilitates the implementation of a multi-hop U2U relay communication process and can effectively increase the communication range of the U2U relay communication. By carrying the first field to limit the maximum number of relay hops for relay communication and the second field to indicate the number of hops for the current relay in the first message, a device that subsequently receives the first message can determine whether to continue relaying the first message. In this way, the relay range of the relay communication is improved through multi-hop relay, and the broadcast storm of the first message can be limited.

[0062] In conjunction with some embodiments of the first aspect, in some embodiments, the first message further includes at least one of the following:

[0063] The third field is used to at least indicate a terminal that can be relayed by the first-hop relay device;

[0064] The fourth field is used to at least indicate the first-hop relay device.

[0065] In the above embodiment, the first message may also include at least a third field for indicating the terminals that the first-hop relay device can relay, and / or at least a fourth field for indicating the first-hop relay device; thereby facilitating the recipient of the first message to determine the sender of the first message and all the terminals that the first-hop relay device can relay, and facilitating the recipient of the first message to determine whether to use the relay service provided by the first-hop relay device to realize relay communication between the source terminal and the target terminal.

[0066] In combination with some embodiments of the first aspect, in some embodiments, the terminal indicated by the third field is determined by the first-hop relay device based on historical relay discovery; and / or, the terminal indicated by the third field is determined based on the configuration information of the first-hop relay device.

[0067] In the above embodiment, the terminal that the first-hop relay device indicated by the third field can relay may be a terminal discovered by the first-hop relay device in a historical relay discovery process, and / or, the terminal that the first-hop relay device indicated by the third field can relay may be a terminal pre-configured for the first-hop relay device, thereby enabling the first-hop relay device to more flexibly determine the terminal that it can relay.

[0068] In conjunction with some embodiments of the first aspect, in some embodiments, the fourth field includes at least one of the following:

[0069] A source layer 2 identifier, used to identify the first-hop relay device;

[0070] Destination layer 2 identifier, used to identify the next hop device that receives the first message.

[0071] In the above embodiment, by carrying the source layer 2 identifier and the destination layer 2 identifier in the fourth field, the subsequent source terminal and / or the n-th hop relay device can establish a layer 2 connection with the 1st hop relay device based on the source layer 2 identifier and the destination layer 2 identifier, so as to utilize the layer 2 connection for relay communication.

[0072] In combination with some embodiments of the first aspect, in some embodiments, the third field carries terminal list information; the terminal list information includes device information of one or more terminals.

[0073] In the above embodiment, by carrying terminal list information in the third field, the terminal list information includes device information of one or more terminals that can be relayed by the first-hop relay device, so that the next-hop relay device can determine all terminals that can be relayed by the first-hop relay device based on the terminal list information carried in the third field. In a second aspect, the embodiment of the present disclosure provides a relay discovery method, wherein the method includes:

[0074] The n-th hop relay device receives the n-1-th hop first message; the n-1-th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1-th hop relay device; n is a positive integer greater than 1;

[0075] Determining the number of relay hops corresponding to the n-th hop relay device according to the second field of the n-1th hop first message;

[0076] When the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, an n-th hop first message is generated based on the n-1-th hop first message; the first field of the n-th hop first message indicates the maximum number of relay hops; the second field of the n-th hop first message is used to indicate the number of relay hops corresponding to the n-th hop relay device.

[0077] In the above embodiment, after receiving the n-1th hop first message, the n-th hop relay device can determine the relay hop count corresponding to the n-th hop relay device based on the relay hop count indicated by the second field in the n-1th hop first message. Based on whether the relay hop count corresponding to the n-th hop relay device is less than or equal to the maximum relay hop count supported by the destination terminal indicated by the first field in the n-1th hop first message, the n-th hop relay device can determine whether it can continue forwarding the device information of the terminal that the n-1th hop relay device can relay. This can limit broadcast storms of the first message. After determining that the n-th hop relay device can continue forwarding the device information of the terminal that the n-1th hop relay device can relay, the n-th hop first message is generated based on the n-1th hop first message. Based on the second field indicating the relay hop count corresponding to the n-th hop relay device and the first field indicating the maximum relay hop count in the n-1th hop first message, a relay device that subsequently receives the n-th hop first message can determine whether to continue relaying the first message, or a terminal that receives the n-th hop first message can select a relay path for relay communication. In this way, a multi-hop U2U relay communication process can be implemented, which can effectively increase the communication range of the U2U relay communication.

[0078] In conjunction with some embodiments of the second aspect, in some embodiments, the n-1th hop first message further includes a third field; the third field indicates a terminal that can be relayed by the first n-1 hop relay device;

[0079] Generating the n-th hop first message according to the n-1-th hop first message further includes:

[0080] The n-hop first message is generated according to the third field of the n-1-hop first message; the third field of the n-hop first message indicates a terminal that can be relayed by the first n-hop relay devices.

[0081] In the above embodiment, the n-1th hop first message may also include a third field for indicating terminals that the first n-1 hop relay device can relay. When the number of relay hops corresponding to the n-1th hop relay device is less than or equal to the maximum number of relay hops, this indicates that the n-1th hop relay device can continue to forward device information for terminals that the first n-1 hop relay device can relay. The n-1th hop first message may be generated based on the third field in the n-1th hop first message. By using the third field of the n-1th hop first message to indicate terminals that the n-1th hop relay device can relay and terminals that the first n hop relay devices can relay, the recipient of the n-1th hop first message can easily learn the terminals that the first n hop relay devices can relay based on the third field of the n-1th hop first message.

[0082] In combination with some embodiments of the second aspect, in some embodiments, the n-th hop first message further includes a fourth field; the fourth field indicates the n-th hop relay device.

[0083] In the above embodiment, the n-hop first message also includes at least a fourth field for indicating the n-hop relay device; thereby facilitating the receiver of the n-hop first message to determine the sender of the n-hop first message, so as to select the relay device to be accessed during the relay communication between the source terminal and the target terminal.

[0084] In conjunction with some embodiments of the second aspect, in some embodiments, the fourth field of the n-th hop first message includes at least one of the following:

[0085] A source layer 2 identifier, used to identify the n-th hop relay device;

[0086] The destination layer 2 identifier is used to identify the next-hop relay device and / or source terminal that receives the n-th hop first message.

[0087] In the above embodiment, the fourth field of the n-th hop first message may include a source layer 2 identifier and a destination layer 2 identifier, by adding the source layer 2 identifier and the destination layer 2 identifier used for relay sending and relay reception of the n-th hop relay device to the fourth field, so that the subsequent source terminal and / or the n+1-th hop relay device can establish a layer 2 connection with the n-th hop relay device based on the source layer 2 identifier and the destination layer 2 identifier, so as to use the layer 2 connection for relay communication.

[0088] In conjunction with some embodiments of the second aspect, in some embodiments, determining the number of relay hops corresponding to the n-th hop relay device according to the second field of the n-1-th hop first message includes:

[0089] The relay hop count corresponding to the n-1th hop relay device is increased by 1 to obtain the relay hop count corresponding to the nth hop relay device.

[0090] In the above embodiment, the n-hop relay device can determine the relay hop count corresponding to the n-1-hop relay device based on the second field in the first message of the n-1-hop relay device, and then add 1 to the relay hop count corresponding to the n-1-hop relay device to obtain the relay hop count corresponding to the n-hop relay device. This allows the relay device to subsequently determine whether the n-hop relay device can continue to forward the device information of the terminal that the previous n-1-hop relay device can relay based on the relay hop count corresponding to the n-hop relay device and the maximum relay hop count.

[0091] In a third aspect, an embodiment of the present disclosure provides a relay discovery method, wherein the method includes:

[0092] The source terminal receives a first message; the first message includes: a first field indicating a maximum number of relay hops; a second field indicating a number of relay hops corresponding to the relay device;

[0093] A relay path for relay communication is selected according to the first message.

[0094] In the above embodiment, by adding a first field and a second field to the first message, the first field indicates the maximum number of relay hops supported by the destination terminal that the first relay device can relay, and the second field indicates the number of relay hops corresponding to the relay device; thus, the first message can be used to implement a multi-hop U2U relay communication process. When a source terminal needs to communicate with a destination terminal, an appropriate relay path for relay communication is selected based on the first message, allowing the source terminal to communicate with the remote destination terminal through the relay device provided by one or more relay devices, effectively increasing the communication range of the U2U relay communication.

[0095] In conjunction with some embodiments of the third aspect, in some embodiments, selecting a relay path for relay communication according to the first message includes:

[0096] selecting, according to the second field in the first message, a relay device corresponding to the second field indicating the least number of relay hops to perform the relay communication;

[0097] According to the signal strength of the received first message, the relay device corresponding to the first message with the largest signal strength is selected to perform the relay communication.

[0098] In the above embodiment, when selecting a relay path, the source terminal may, based on the second field in the first message indicating the number of relay hops corresponding to the relay device, select the relay device corresponding to the second field with the fewest relay hops as the relay device to be connected, thereby reducing the number of relay devices in the relay path, reducing transmission delay, and improving data transmission rate. Furthermore, the source terminal may, based on the signal strength of the received first message, select the relay device corresponding to the first message with the highest signal strength as the relay device to be connected, thereby effectively ensuring the communication quality between the source terminal and the target terminal.

[0099] In a fourth aspect, an embodiment of the present disclosure provides a relay discovery method, wherein the method includes:

[0100] The first-hop relay device sends the first message;

[0101] The n-th hop relay device receives the n-1-th hop first message; the n-1-th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1-th hop relay device; n is a positive integer greater than 1;

[0102] The n-hop relay device determines, according to the second field of the n-1-hop first message, the number of relay hops corresponding to the n-hop relay device; when the number of relay hops corresponding to the n-hop relay device is less than or equal to the maximum number of relay hops, generating an n-hop first message according to the n-1-hop first message; the first field of the n-hop first message indicates the maximum number of relay hops; the second field of the n-hop first message is used to indicate the number of relay hops corresponding to the n-hop relay device;

[0103] The source terminal receives the first message and selects a relay path for relay communication according to the first message.

[0104] In a fifth aspect, an embodiment of the present disclosure provides a first relay device, wherein the first relay device is a first-hop relay device, and the first relay device includes:

[0105] The first sending module is configured to send a first message to a next-hop device, wherein the first message includes:

[0106] The first field indicates the maximum number of relay hops;

[0107] The second field indicates the number of relay hops corresponding to the first-hop relay device.

[0108] In a sixth aspect, an embodiment of the present disclosure provides a second relay device, wherein the second relay device is an n-th hop relay device, and the second relay device includes:

[0109] A first receiving module is configured to receive a first message of the n-1th hop; the first message of the n-1th hop includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1th hop relay device; n is a positive integer greater than 1;

[0110] The first processing module is configured to determine the number of relay hops corresponding to the n-hop relay device based on the second field of the n-1-hop first message; when the number of relay hops corresponding to the n-hop relay device is less than or equal to the maximum number of relay hops, generate the n-hop first message based on the n-1-hop first message; the first field of the n-hop first message indicates the maximum number of relay hops; the second field of the n-hop first message is used to indicate the number of relay hops corresponding to the n-hop relay device.

[0111] In a seventh aspect, an embodiment of the present disclosure provides a source terminal, wherein the source terminal includes:

[0112] A second receiving module is configured to receive a first message; the first message includes: a first field indicating a maximum number of relay hops; a second field indicating a number of relay hops corresponding to the relay device;

[0113] The second processing module is configured to select a relay path for relay communication according to the first message.

[0114] In the eighth aspect, an embodiment of the present disclosure provides a communication system, wherein the communication system includes a source terminal, a first relay device, a second relay device and a target terminal; the first relay device is configured to implement the relay discovery method described in the optional implementation manner of the first aspect, the second relay device is configured to implement the relay discovery method described in the optional implementation manner of the second aspect, and the source terminal is configured to implement the relay discovery method described in the optional implementation manner of the third aspect.

[0115] In a ninth aspect, an embodiment of the present disclosure provides a communication device, the communication device comprising:

[0116] one or more processors;

[0117] The processor is used to call instructions to enable the communication device to execute the relay discovery method described in the optional implementation manner of the first aspect, the second aspect or the third aspect.

[0118] In the tenth aspect, an embodiment of the present disclosure provides a storage medium, wherein the storage medium stores instructions, which, when the instructions are executed on a communication device, enable the communication device to execute the relay discovery method described in the optional implementation of the first aspect, the second aspect or the third aspect.

[0119] In an eleventh aspect, an embodiment of the present disclosure provides a program product, which, when executed by a communication device, enables the communication device to execute the relay discovery method described in the optional implementation of the first aspect, the second aspect, or the third aspect.

[0120] In a twelfth aspect, an embodiment of the present disclosure provides a computer program, which, when executed on a computer, enables the computer to execute the relay discovery method described in the optional implementation manner of the first aspect, the second aspect, or the third aspect.

[0121] It is understandable that the first relay device, the second relay device, the source terminal, the communication device, the communication system, the storage medium, the program product, and the computer program are all used to perform the method provided by 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.

[0122] The present disclosure provides a relay discovery method, communication device, communication system, and storage medium. In some embodiments, the terms "relay discovery method," "information processing method," and "information transmission method" are interchangeable; the terms "information indicating device," "information processing device," and "information transmission device" are interchangeable; and the terms "communication system" and "information processing system" are interchangeable.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0128] In some embodiments, the terms "at least one," "one or more," "a plurality of," "multiple," etc. may be used interchangeably.

[0129] In some embodiments, descriptions such as "at least one of A and B," "A and / or B," "in one case A, in another case B," or "in one case A, in 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 same applies when there are more branches such as A, B, and C.

[0130] 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.

[0131] 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 no unnecessary restriction should be constituted due to the use of prefixes. 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.

[0132] 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.

[0133] In some embodiments, terms such as "...", "determine...", "in the case of...", "at the time of...", "when...", "if...", "if...", etc. can be used interchangeably.

[0134] 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.

[0135] 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.

[0136] In some embodiments, "network" can be interpreted as devices included in the network (eg, access network equipment, core network equipment, etc.).

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] In some embodiments, obtaining data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0142] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0143] 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.

[0144] Fig. 1 is a schematic diagram showing the architecture of a communication system according to an exemplary embodiment.

[0145] As shown in FIG1 , a communication system 100 includes a terminal 101 , a relay device 102 and / or a network device 103 .

[0146] In some embodiments, the terminal 101 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.

[0147] In some embodiments, the relay device 102 may be a terminal and / or roadside equipment capable of providing relay services.

[0148] In some embodiments, the terminal 101 may include a source terminal 1011 and a destination terminal 1012; the relay device 102 may include at least a first relay device 1021 and a second relay device 1022. The source terminal 1011 and the destination terminal 1012 cannot communicate directly, but rather communicate through the first relay device 1021 and / or the second relay device 1022. The first relay device 1021 and / or the second relay device 1022 provide relay services for communication between the source terminal 1011 and the destination terminal 1012.

[0149] In some embodiments, the network device 103 may include an access network device and a core network device.

[0150] In some embodiments, the access network device may be, for example, a node or device that accesses a terminal to a 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.

[0151] 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.

[0152] 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.

[0153] In some embodiments, a core network device may be a single device including one or more network elements, or may be multiple devices or a group of devices, each including one or more network elements. A network element may be virtual or physical. The core network may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), or a Next Generation Core (NGC).

[0154] In some embodiments, the network element is, for example, an Access and Mobility Management Function (AMF).

[0155] In some embodiments, the network element is, for example, a Mobility Management Entity (MME).

[0156] In some embodiments, the network element is used for access and mobility management, such as registration management, connection management, and mobility management, etc., but the name is not limited thereto.

[0157] In some embodiments, the network element may be a network element independent of the core network device.

[0158] 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 provided by 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 provided by the embodiment of the present disclosure is also applicable to similar technical problems.

[0159] The following embodiments of the present disclosure may be applied to the communication system 100 shown in Figure 1, or a portion thereof, but are not limited thereto. The entities shown in Figure 1 are illustrative only. The communication system may include all or part of the entities shown in Figure 1, or may include other entities outside of Figure 1. The number and form of the entities may be arbitrary. The connection relationship between the entities is illustrative only. The entities may be connected or disconnected, and the connection may be in any manner, including direct or indirect, wired or wireless.

[0160] 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).

[0161] FIG2 is an interactive diagram of a relay discovery method according to an exemplary embodiment. As shown in FIG2 , the embodiment of the present disclosure relates to a relay discovery method for a communication system 100, the method comprising:

[0162] Step S2101: The first-hop relay device sends a first message.

[0163] In some embodiments, the first-hop relay device may be a terminal and / or roadside device capable of providing relay services.

[0164] In some embodiments, the first-hop relay device may be a terminal with ProSe capability.

[0165] A ProSe-capable terminal can establish direct communication with another ProSe-capable terminal through the PC5 interface.

[0166] It is worth noting that the relay device with ProSe capability can establish direct communication with UE1 with ProSe capability through the PC5 interface, and on the other hand, establish direct communication with UE2 with ProSe capability through the PC5 interface, so that UE1 and UE2 can communicate through the relay device.

[0167] In some embodiments, the first-hop relay device can establish direct communication with the target terminal.

[0168] It is worth noting that the first-hop relay device can establish direct communication with one or more terminals, which can be understood as the first-hop relay device can communicate with one or more terminals through a direct link.

[0169] In some embodiments, the first-hop relay device sends the first message to the next-hop device.

[0170] In some embodiments, the next-hop device may be an n-th-hop relay device and / or a source terminal; wherein n is a positive integer greater than 1.

[0171] It is worth noting that the n-th hop relay device may be the next hop or multiple hops of the 1st hop relay device.

[0172] For example, after receiving the first message sent by the first-hop relay device, the second-hop relay device may generate a second-hop first message and send the second-hop first message to the third-hop relay device. The third-hop relay device then sends the third-hop first message to the source terminal. In this case, the next-hop device of the first-hop relay device is the second-hop relay device, the next-hop device of the second-hop relay device is the third-hop relay device, and the next-hop device of the third-hop relay device is the source terminal.

[0173] As another example, if both the second-hop relay device and the source terminal can receive the first message sent by the first-hop relay device, the next-hop devices of the first-hop relay device may be the second-hop relay device and the source terminal.

[0174] In some embodiments, the n-th hop relay device or the source terminal receives the first message sent by the 1st hop relay device; wherein n is a positive integer greater than 1.

[0175] In some embodiments, the first-hop relay device may send the first message in a broadcasting manner.

[0176] In some embodiments, the first-hop relay device may perform a Model A relay discovery operation.

[0177] It should be noted that Mode A defines two roles for relay communication: the announcing device and the monitoring device. The announcing device broadcasts messages, while the monitoring device listens for messages broadcast by nearby announcing devices. If the monitoring device hears a message broadcast by the announcing device, the two devices have discovered each other.

[0178] In some embodiments, the first-hop relay device performs a mode A relay discovery operation, which may include:

[0179] The first-hop relay device broadcasts the first message.

[0180] It is worth noting that, during the process of performing the relay discovery operation in mode A, the first-hop relay device may serve as a notification device and broadcast a first message so that the listening device can discover the first-hop relay device.

[0181] In some embodiments, the first message may be a U2U Relay Discovery Announcement Massage.

[0182] In some embodiments, the first message includes: a first field indicating a maximum number of relay hops; and a second field indicating a number of relay hops corresponding to the first-hop relay device.

[0183] In some embodiments, the first field indicates a maximum number of relay hops supported by the first message.

[0184] It is worth noting that the maximum number of relay hops can be the maximum number of hops supported for forwarding the first message. The maximum number of hops supported for forwarding the first message can be understood as the maximum number of hops supported for forwarding the information content carried by the first message; or the maximum number of hops supported for forwarding the first message can be understood as the maximum number of hops supported for forwarding the device information of the terminal that can be relayed by the first-hop relay device.

[0185] The number of relay hops corresponding to the first-hop relay device may indicate the number of relay hops required to reach the destination terminal from the first-hop relay device.

[0186] In some embodiments, the first field indicates the maximum number of relay devices supported by the relay path of the corresponding relay communication; the second field indicates the number of relay hops of the first-hop relay device in the relay path.

[0187] For example, if the source terminal can achieve relay communication with the target terminal via a relay device, then the relay device is the first hop in the relay path of the relay communication, and the relay hop count corresponding to the relay device is 1. If the source terminal can achieve relay communication with the target terminal via a first relay device and a second relay device, then the first relay device is the second hop in the relay path of the relay communication, and the second relay device is the first hop in the relay path of the relay communication. The relay hop count corresponding to the first relay device is 2; and the relay hop count corresponding to the second relay device is 1.

[0188] It is worth noting that the first field in the first message can be used to indicate the maximum number of relay hops supported by the multiple destination terminals that the first-hop relay device can relay; the second field in the first message can be used to indicate the number of relay hops of the first-hop relay device in the relay path corresponding to the multiple destination terminals.

[0189] In some embodiments, the first message further includes at least one of the following: a third field, at least used to indicate a terminal that can be relayed by the first-hop relay device; and a fourth field, at least used to indicate the first-hop relay device.

[0190] In some embodiments, the third field may carry device information of a terminal that can be relayed by the first-hop relay device.

[0191] Here, the terminal that can be relayed by the first-hop relay device can be understood as a terminal that can be relayed by the first-hop relay device, that is, the first-hop relay device can provide a relay service for the terminal.

[0192] Exemplarily, if the first-hop relay device can provide relay services for terminal 1, terminal 2 and terminal 3, then terminal 1, terminal 2 and terminal 3 are devices that can be relayed by the first-hop relay device; the first-hop relay device can carry the device information of terminal 1, terminal 2 and terminal 3 in the third field.

[0193] The first-hop relay device communicates with terminal 1, terminal 2, and terminal 3 via direct links.

[0194] In some embodiments, the terminal indicated by the third field is determined by the first-hop relay device based on historical relay discovery; and / or, the terminal indicated by the third field is determined based on configuration information of the first-hop relay device.

[0195] It should be noted that the network device may pre-configure one or more relay-capable terminals for the first-hop relay device, and the first-hop relay device may carry the device information of the pre-configured one or more relay-capable terminals in the third field of the first message.

[0196] The first-hop relay device can also carry the device information of the terminal obtained in the previous relay discovery process or relay communication process in the third field, which can effectively increase the number of terminals that the first-hop relay device can relay and expand the relay range of the first-hop relay device.

[0197] In some embodiments, the third field carries terminal list information; the terminal list information includes device information of one or more terminals.

[0198] It is worth noting that the device information of one or more terminals that the first-hop relay device can relay is carried in the terminal list information in the form of a list. By carrying the terminal list information in the third field of the first message, the next-hop relay device and / or the source terminal that receives the first message can determine the device information of all terminals that the first-hop relay device can relay based on the terminal list information.

[0199] In some embodiments, the device information of the terminal carried by the third field may include at least one of the following: a device identifier; an application layer identifier.

[0200] It should be noted that the device identifier can be used to indicate the first-hop relay device. The application layer identifier can be used to indicate the user identifier of the application; for example, the application layer identifier can be an application layer user information identifier (User Info ID). Relay communication is typically initiated based on application layer services. By carrying the application layer identifier in the third field, it indicates the user identifier of the terminal that the first-hop relay device can relay to initiate the relay communication.

[0201] In some embodiments, the fourth field includes at least one of the following: a source layer 2 identifier, used to identify the first-hop relay device; a destination layer 2 identifier, used to identify the relay reception of the first-hop relay device, which is the next-hop device receiving the first message.

[0202] It should be noted that the source layer 2 identifier can indicate the sender of the first message, that is, the first-hop relay device; the destination layer 2 identifier can indicate the receiver of the first message, that is, the next-hop device that receives the first message. Here, the first-hop relay device uses its own layer 2 identifier as the source layer 2 identifier and the layer 2 identifier of the next-hop relay device and / or the source terminal as the target layer 2 identifier, so as to send the first-hop first message to the next-hop relay device and / or the source terminal. In addition, the subsequent source terminal and / or the n-th hop relay device can establish a layer 2 connection with the first-hop relay device based on the source layer 2 identifier and the destination layer 2 identifier, so as to use the layer 2 connection for relay communication.

[0203] In some embodiments, the source layer 2 identifier and the target layer 2 identifier carried in the first message may be configured by the network device for the first-hop relay device; or, may be determined by the first-hop relay device based on historical relay discovery.

[0204] In some embodiments, the fourth field further includes at least one of the following: a source layer 3 identifier, used to identify the first-hop relay device; a destination layer 3 identifier, used to identify the next-hop device that receives the first message.

[0205] It should be noted that the source layer 3 identifier can indicate the sender of the first message, that is, the first-hop relay device; the destination layer 3 identifier can indicate the receiver of the first message, that is, the next-hop device that receives the first message. Here, the first-hop relay device uses its own layer 3 identifier as the source layer 3 identifier and the layer 3 identifier of the next-hop relay device and / or source terminal as the target layer 3 identifier, so as to send the first-hop first message to the next-hop relay device and / or source terminal. In addition, the subsequent source terminal and / or n-th hop relay device can establish a layer 3 connection with the first-hop relay device based on the source layer 3 identifier and the destination layer 3 identifier, so as to utilize the layer 3 connection for relay communication.

[0206] In some embodiments, the source layer 3 identifier and the target layer 3 identifier carried in the first message may be configured by the network device for the first-hop relay device; or, may be determined by the first-hop relay device based on historical relay discovery.

[0207] In some embodiments, the first hop first message further includes at least one of the following: a fifth field indicating the message type of the first hop first message; and a sixth field indicating the relay service code (RSC) of the first hop first message.

[0208] In some embodiments, the message type of the first hop first message may include but is not limited to: a direct discovery type or a relay discovery type.

[0209] In some embodiments, the RSC may be used to indicate the relay communication service that the first-hop relay device can provide.

[0210] It should be noted that before conducting relay communication, both communicating parties need to perform a relay discovery operation. Either communicating party will discover whether there is a relay device that can provide the corresponding relay communication service based on its own relay communication service. If there is a relay device that can provide the corresponding relay communication service, relay communication can be achieved through the relay device.

[0211] The network device may pre-configure a mapping relationship between relay communication services and RSCs for the first-hop relay device, and each relay communication service corresponds to an RSC.

[0212] The first-hop relay device can determine the RSC corresponding to the relay communication service based on the relay communication service it supports, and carry the RSC in the first message, so that the n-th-hop relay device and / or the source terminal that receives the first message can determine the relay communication service supported by the first-hop relay device.

[0213] Step S2102: The n-th hop relay device generates an n-th hop first message.

[0214] In some embodiments, the n-th hop relay device may be a terminal and / or roadside device capable of providing relay services.

[0215] In some embodiments, the n-th hop relay device may be a terminal with ProSe capability.

[0216] In some embodiments, the n-th hop relay device receives the n-1-th hop first message sent by the n-1-th hop relay device, and generates the n-th hop first message according to the n-1-th hop first message.

[0217] It is worth noting that the generated n-th hop first message may include part or all of the information carried in the (n-1)-th hop first message.

[0218] Exemplarily, the second-hop relay device may receive the first-hop first message sent by the first-hop relay device, and generate the second-hop first message according to the first-hop first message.

[0219] In some embodiments, the (n-1)th hop relay device may be a previous hop relay device of the (n)th hop relay device.

[0220] In some embodiments, the n-th hop relay device may receive an n-1-th hop first message sent by one or more n-1-th hop relay devices; and generate an n-th hop first message according to the multiple n-1-th hop first messages.

[0221] For example, taking a communication system including a source terminal, two target terminals and four relay devices as an example, relay device 1 can communicate directly with target terminal 1, and relay device 2 can relay communication with target terminal 1 through relay device 1; relay device 3 can relay communication with target terminal 1 through relay device 2 and relay device 1; relay device 4 can communicate directly with target terminal 2, and relay device 3 can relay communication with target terminal 2 through relay device 4.

[0222] Relay device 3 can receive the first message sent by relay device 2 and the first message sent by relay device 4, and generate the first message of relay device 3 based on the first message of relay device 2 and the first message sent by relay device 4; the generated first message can indicate the relay path for relay communication with the target terminal 1, and the relay path for relay communication with the target terminal 2.

[0223] In some embodiments, the n-th hop relay device receives a first message sent by the previous n-1 hop relay device; and generates the n-th hop first message according to the first message sent by the previous n-1 hop relay device.

[0224] Exemplarily, the third-hop relay device may receive the first-hop first message sent by the first-hop relay device and the second-hop relay device sent by the second-hop relay device, and generate the third-hop first message according to the first-hop first message and the second-hop first message.

[0225] In some embodiments, the first n-1 hop relay device may be a previous hop or multi-hop relay device of the n-th hop relay device.

[0226] In some embodiments, the n-th hop relay device may perform a Model A relay discovery operation.

[0227] In some embodiments, the n-th hop relay device performs a mode A relay discovery operation, which may include:

[0228] Listen for a first message broadcast by one or more relay devices.

[0229] It is worth noting that during the relay discovery process in Mode A, the n-th hop relay device can act as a listening device, listening for the first message broadcast by surrounding relay devices. When the n-th hop relay device listens to the first message broadcast by a relay device, it is considered that the mutual discovery between the n-th hop relay device and the relay device is complete. The discovered relay device can be considered the previous hop relay device of the n-th hop relay device, that is, the n-1-th hop relay device.

[0230] In some embodiments, the n-1th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1th hop relay device.

[0231] It is worth noting that the maximum number of relay hops indicated by the first field of the (n-1)th hop first message may be the maximum number of hops supported for forwarding by the (n-1)th hop first message.

[0232] The maximum number of hops supported for forwarding of the first message of the n-1th hop can be understood as the maximum number of hops supported for forwarding of the information content carried by the first message of the n-1th hop; or, the maximum number of hops supported for forwarding of the first message of the n-1th hop can be understood as the maximum number of hops supported for forwarding of the device information of the terminal that can be relayed by the n-1th hop relay device.

[0233] In some embodiments, the n-th hop relay device determines the number of relay hops corresponding to the n-th hop relay device according to the second field of the (n-1)-th hop first message.

[0234] In some embodiments, the n-th hop relay device may add 1 to the relay hop count corresponding to the n-1-th hop relay device indicated by the second field of the n-1-th hop first message to obtain the relay hop count corresponding to the n-th hop relay device.

[0235] It is worth noting that the relay hop count corresponding to the n-th hop relay device may indicate the number of relay hops required to reach the destination terminal from the n-th hop relay device.

[0236] In some embodiments, the number of relay hops corresponding to the n-th-hop relay device may indicate the number of relay hops of the n-th-hop relay device in the relay path.

[0237] In some embodiments, generating the n-th hop first message according to the n-1-th hop first message includes:

[0238] When the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, an n-th hop first message is generated according to the n-1-th hop first message.

[0239] It is worth noting that if the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, the n-th hop first message can be generated based on the n-1-th hop first message; if the number of relay hops corresponding to the n-th hop relay device is greater than the maximum number of relay hops, it means that the n-th hop relay device cannot provide relay service for the destination terminal.

[0240] In some embodiments, the generated n-th hop first message includes: a first field and a second field; the first field indicates the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-th hop relay device.

[0241] It is worth noting that the maximum number of relay hops indicated by the first field of the n-th-hop first message may be the maximum number of hops supported for forwarding of the n-th-hop first message.

[0242] The maximum number of hops supported for forwarding of the n-hop first message can be understood as the maximum number of hops supported for forwarding of the information content carried by the n-hop first message; or, the maximum number of hops supported for forwarding of the n-hop first message can be understood as the maximum number of hops supported for forwarding of the device information of the terminal that can be relayed by the n-hop relay device.

[0243] In some embodiments, generating the n-th hop first message according to the first message sent by the first n-1 hop relay device includes:

[0244] Determine, according to the second fields in the plurality of first messages sent by the first n-1 hop relay devices, the first message corresponding to the second field indicating the least number of relay hops as the n-1 hop first message;

[0245] Generate an n-th hop first message according to the n-1-th hop first message.

[0246] It is worth noting that if the n-th hop relay device can receive the first message sent by the previous hop or multi-hop relay device, it can determine the first message indicating the least number of relay hops based on the second fields of multiple first messages, and use the first message indicating the least number of relay hops as the n-1-th hop first message, and generate the n-th hop first message based on the n-1-th hop first message.

[0247] For example, taking the communication system including a source terminal, a target terminal and three relay devices as an example, relay device 1 can communicate directly with the target terminal, and relay device 2 can relay communication with the target terminal through relay device 1; relay device 3 can relay communication with the target terminal through relay device 2 and relay device 1, and the source terminal can communicate directly with relay device 3.

[0248] Relay device 3 can receive the first message sent by relay device 1 and relay device 2; it indicates that the relay path of the relay communication between the source terminal and the target terminal includes: the first path: source terminal-relay device 3-relay device 2-relay device 1-target terminal; the second path: source terminal-relay device 3-relay device 1-target terminal.

[0249] Relay device 3 can generate a first message for relay device 3 based on the first message indicating the minimum number of relay hops (i.e., the first message sent by relay device 1). In this way, the relay path of the relay communication between the source terminal and the target terminal can be source terminal-relay device 3-relay device 1-target terminal.

[0250] In some embodiments, the n-1th hop first message further includes a third field, wherein the third field indicates a terminal that can be relayed by the first n-1 hop relay device;

[0251] The generating the n-th hop first message according to the n-1-th hop first message includes:

[0252] When the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, an n-th hop first message is generated according to the third field of the n-1-th hop first message; the third field in the n-th hop first message indicates the terminal that can be relayed by the previous n-hop relay devices.

[0253] In some embodiments, the third field in the n-hop first message may carry device information of a terminal that can be relayed by the first n-hop relay devices.

[0254] Here, the terminals that can be relayed by the first n-hop relay devices may include terminals that can be relayed by the n-th hop relay device and terminals that can be relayed by the first n-1-hop relay device.

[0255] The terminals that the n-hop relay device can relay can be understood as the terminals that the n-hop relay device supports direct communication. It should be noted that if the number of relay hops corresponding to the n-hop relay device is less than or equal to the maximum number of relay hops, it means that the n-hop relay device can continue to forward the device information of the terminals that the n-1-hop relay device can relay; therefore, the device information of the terminals that the first n-1-hop relay device can relay, carried in the third field of the n-1-hop first message, can be added to the third field of the n-1-hop first message.

[0256] In some embodiments, the terminal that the n-hop relay device can relay may be a terminal pre-configured by the network device for the n-hop relay device, and / or, the terminal that the n-hop relay device can relay may be a terminal determined by the n-hop relay device based on historical relay discovery.

[0257] In some embodiments, generating the n-th hop first message according to the third field of the n-1-th hop first message includes:

[0258] If there is at least one terminal whose device information can be relayed by the first n-1 hop relay device and is not carried by the third field of the n-th hop first message, the device information of at least one terminal that can be relayed by the first n-1 hop relay device is added to the third field of the n-th hop first message.

[0259] For example, if the third field of the first message of the n-1th hop carries the device information of terminal 1, terminal 2 and terminal 3, and the third field of the first message of the nth hop carries the device information of terminal 2, terminal 3 and terminal 4, the nth hop relay device can add the device information of terminal 1 to the third field of the first message of the nth hop to generate the first message of the nth hop.

[0260] In some embodiments, the method further comprises:

[0261] When the number of relay hops corresponding to the n-th hop relay device is greater than the maximum number of relay hops, an n-th hop first message is generated according to the terminals that the n-th hop relay device can relay; the third field in the n-th hop first message indicates the terminals that the n-th hop relay device can relay.

[0262] In some embodiments, the third field of the n-hop first message may carry only the device information of terminals that the n-hop relay device can relay. It is worth noting that when the number of relay hops corresponding to the n-hop relay device exceeds the maximum number of relay hops, it indicates that the n-hop relay device cannot continue to forward the device information of terminals that the previous n-1-hop relay device can relay. The n-hop first message may be generated based on the terminals that the n-hop relay device can relay. The third field within the n-hop first message carries only the device information of terminals that the n-hop relay device can relay.

[0263] In some embodiments, the device information of the terminal carried by the third field may include at least one of the following: a device identifier; an application layer identifier.

[0264] It should be noted that the device identifier can be used to indicate the first n-hop relay device. The application layer identifier can be used to indicate the user identifier of the application; for example, the application layer identifier can be the application layer user information identifier (User Info ID). Relay communication is typically initiated based on application layer services. By carrying the application layer identifier in the third field, it can indicate the user identifier of the terminal that the first n-hop relay device can relay and initiate the relay communication.

[0265] In some embodiments, the n-th hop first message further includes a fourth field, and the fourth field indicates the n-th hop relay device.

[0266] In some embodiments, the fourth field may carry device information of the n-th hop relay device.

[0267] In some embodiments, the fourth field also indicates the n-1 th hop relay device.

[0268] In some embodiments, the fourth field may also carry device information of the (n-1)th hop relay device.

[0269] It can be understood that by carrying the device information of the n-th hop relay device and the device information of the n-1-th hop relay device in the fourth field of the n-th hop first message, after the subsequent source terminal receives the n-th hop first message, it can determine the relay devices included in the relay path of the relay communication according to the fourth field of the n-th hop first message.

[0270] In some embodiments, the fourth field of the n-th hop first message includes at least one of the following:

[0271] The source layer 2 identifier is used to identify the n-th hop relay device; the destination layer 2 identifier is used to identify the next hop device that receives the n-th hop first message.

[0272] It should be noted that the source layer 2 identifier can indicate the sender of the n-hop first message, that is, the n-hop relay device; the destination layer 2 identifier can indicate the receiver of the n-hop first message, that is, the next-hop device that receives the n-hop first message. Here, the n-hop relay device uses its own layer 2 identifier as the source layer 2 identifier and the layer 2 identifier of the next-hop relay device and / or the source terminal as the target layer 2 identifier, so as to send the n-hop first message to the next-hop relay device and / or the source terminal. And the subsequent source terminal and / or the (n+1)-hop relay device can establish a layer 2 connection with the n-hop relay device based on the source layer 2 identifier and the destination layer 2 identifier, so as to use the layer 2 connection for relay communication.

[0273] In some embodiments, the source layer 2 identifier and the target layer 2 identifier carried in the n-hop first message may be configured by the network device for the n-hop relay device; or, may be determined by the n-hop relay device based on historical relay discovery.

[0274] In some embodiments, the fourth field further includes at least one of the following: a source layer 3 identifier, used to identify the n-th hop relay device; a destination layer 3 identifier, used to identify the next hop device that receives the n-th hop first message.

[0275] It should be noted that the source layer 3 identifier can indicate the sender of the n-hop first message, that is, the n-hop relay device; the destination layer 3 identifier can indicate the receiver of the n-hop first message, that is, the next-hop device that receives the n-hop first message. Here, the n-hop relay device uses its own layer 3 identifier as the source layer 3 identifier and the layer 3 identifier of the next-hop relay device and / or the source terminal as the target layer 3 identifier, so as to send the n-hop first message to the next-hop relay device and / or the source terminal. In addition, the subsequent source terminal and / or the (n+1)-hop relay device can establish a layer 3 connection with the n-hop relay device based on the source layer 3 identifier and the destination layer 3 identifier, so as to use the layer 3 connection for relay communication.

[0276] In some embodiments, the source layer 3 identifier and the target layer 3 identifier carried in the n-hop first message may be configured by the network device for the n-hop relay device; or, may be determined by the n-hop relay device based on historical relay discovery.

[0277] In some embodiments, the n-hop first message further includes at least one of the following: a fifth field indicating the message type of the n-hop first message; and a sixth field indicating the relay service code (RSC) of the n-hop first message.

[0278] In some embodiments, the message type of the n-th hop first message may include, but is not limited to: a direct discovery type or a relay discovery type.

[0279] In some embodiments, the RSC may be used to indicate the relay communication service that the n-th hop relay device can provide.

[0280] It should be noted that before conducting relay communication, both communicating parties need to perform a relay discovery operation. Either communicating party will discover whether there is a relay device that can provide the corresponding relay communication service based on its own relay communication service. If there is a relay device that can provide the corresponding relay communication service, relay communication can be achieved through the relay device.

[0281] The network device may pre-configure a mapping relationship between relay communication services and RSCs for the n-th hop relay device, and each relay communication service corresponds to an RSC.

[0282] The n-hop relay device can determine the RSC corresponding to the relay communication service based on the relay communication service supported by itself, and carry the RSC in the n-hop first message, so that the n+1-hop relay device and / or the source terminal that receives the n-hop first message can determine the relay communication service supported by the n-hop relay device.

[0283] Step S2103: the n-th hop relay device sends the n-th hop first message.

[0284] In some embodiments, the n-th hop relay device sends the n-th hop first message to the source terminal and / or the (n+1)-th hop relay device.

[0285] In some embodiments, the source terminal and / or the (n+1)th hop relay device receives the (n)th hop first message sent by the (n)th hop relay device.

[0286] In some embodiments, the n-th hop relay device sends the n-th hop first message in a broadcast manner.

[0287] In some embodiments, the n-th hop relay device may perform a Model A relay discovery operation.

[0288] In some embodiments, the n-th hop relay device performs a mode A relay discovery operation, which may include:

[0289] The n-th hop relay device broadcasts the n-th hop first message.

[0290] During the process of performing the relay discovery operation in mode A, the n-th hop relay device may serve as a notification device and broadcast an n-th hop first message so that a listening device may discover the n-th hop relay device.

[0291] It is worth noting that in the embodiment of the present disclosure, the n-th hop relay device can serve as a listening device in the relay discovery process of mode A to listen to the n-1th hop first message broadcast by the n-1th hop relay device; it can also serve as a notification device in the relay discovery process of mode A to broadcast the n-th hop first message so that the listening device (source terminal or n+1th hop relay device) can discover the n-th hop relay device, thereby realizing multi-hop U2U relay discovery supporting mode A.

[0292] Step S2104: The source terminal selects a relay path for relay communication.

[0293] In some embodiments, the source terminal may be a terminal capable of using a relay service.

[0294] In some embodiments, the source terminal may be a ProSe-capable terminal.

[0295] In some embodiments, the source terminal may perform a relay discovery operation to discover one or more relay devices.

[0296] It is understood that the source terminal discovers one or more relay devices by performing a relay discovery operation, thereby forwarding the data packets sent by the source terminal to the target terminal through the relay devices. It is worth noting that the source terminal can directly communicate with the discovered one or more relay devices.

[0297] In some embodiments, if the source terminal discovers multiple relay devices after performing a relay discovery operation, it selects one relay device from the multiple relay devices and uses the relay device as the relay device that relays and forwards for the source device.

[0298] In some embodiments, the source terminal may perform a Model A relay discovery operation.

[0299] In some embodiments, the source terminal performs a mode A relay discovery operation, which may include:

[0300] The source terminal monitors the first message broadcast by the relay device.

[0301] It is worth noting that, in the process of executing the relay discovery operation in mode A, the source terminal can act as a listening device to listen to the first message broadcast by the relay device; when the source terminal listens to the first message sent by one or more relay devices, it can be considered that the mutual discovery between the source terminal and the relay device is completed.

[0302] In some embodiments, the source terminal may monitor the first message broadcast by the relay device within a preset time window.

[0303] In some embodiments, the source terminal selects a relay path for relay communication according to the first message.

[0304] In some embodiments, the source terminal may select a relay path for relay communication with the target terminal based on the first message.

[0305] In some embodiments, the source terminal receives one or more first messages; and selects a relay path for relay communication with the target terminal according to the first messages.

[0306] In some embodiments, if the source terminal receives a first message, it determines whether to use the relay device as a relay device for relay communication with the target terminal based on the first message.

[0307] The first message includes a third field that indicates the terminals that the relay device can relay. Based on the third field in the first message, it can be determined whether the target terminal is a terminal for which the relay device can provide relay services. If the target terminal is a terminal for which the relay device can provide relay services, the relay device can be selected as the relay device to be connected.

[0308] In some embodiments, the source terminal may receive multiple first messages and select a relay path for relay communication with the target terminal based on the multiple first messages.

[0309] The source terminal may determine, based on the third field in the first message, a relay device from a plurality of relay devices that can provide relay services for communication between the source terminal and the target terminal, and select a relay path for relay communication with the target terminal.

[0310] In some embodiments, if only one relay device is determined to be able to provide relay service for communication between the source terminal and the target terminal based on the third fields of the received multiple first messages, the relay device is selected as the relay device to be accessed.

[0311] In some embodiments, if it is determined based on the third fields of the multiple received first messages that multiple relay devices can provide relay services for communication between the source terminal and the target terminal, a relay path for relay communication may be selected in at least one of the following ways:

[0312] The source terminal can select the relay device corresponding to the second field indicating the least number of relay hops for the relay communication based on the second field in the first message; the source terminal can select the relay device corresponding to the first message with the largest signal strength as the relay device to be accessed based on the signal strength of the received first message.

[0313] It should be noted that, based on the third fields of multiple first messages, there may be multiple relay devices determined to be able to perform relay communication with the target terminal; in this case, it is necessary to select the relay device to be accessed from the multiple relay devices.

[0314] During relay path selection, the source terminal may select based on the principle of minimum number of hops; that is, the source terminal may select the relay device corresponding to the second field indicating the minimum number of relay hops as the relay device to be accessed based on the second fields in multiple first messages.

[0315] It is worth noting that the source terminal can select the relay device corresponding to the second field indicating the least number of relay hops as the relay device to be accessed, thereby minimizing the number of relay devices in the relay path while realizing communication between the source terminal and the target terminal, thereby reducing transmission delay and improving data transmission rate.

[0316] Alternatively, the source terminal may select based on the principle of the strongest signal; that is, the source terminal may select the relay device corresponding to the first message with the largest signal strength as the relay device to be accessed based on the signal strength of multiple received first messages.

[0317] It is worth noting that if the signal strength of a received first message is weak, it indicates that the communication quality between the source terminal and the relay device corresponding to the first message is poor, which may affect communication between the source terminal and the target terminal. Therefore, by selecting the relay device corresponding to the first message with the strongest signal strength as the relay device to be connected, the communication quality between the source terminal and the target terminal can be effectively guaranteed.

[0318] Alternatively, the source terminal may select a relay device to be accessed based on the signal strengths of the multiple received first messages and the second fields in the multiple first messages.

[0319] It is worth noting that the source terminal may comprehensively consider the signal strength and the number of hops experienced when selecting a relay device to access.

[0320] For example, when multiple relay devices corresponding to the second field with the least relay hops are determined based on the second field, the relay device with the largest signal strength can be selected as the relay device to be accessed based on the signal strength of the first message corresponding to the multiple relay devices.

[0321] For example, when determining the relay devices corresponding to multiple first messages with the largest signal strength based on the signal strength of the received first message, the relay device with the least relay hops can be selected as the relay device to be accessed based on the second field in the multiple first messages with the largest signal strength.

[0322] In some embodiments, the term "information" can be interchangeable with terms such as "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "field", and "data".

[0323] In some embodiments, the term "send" can be interchanged with terms such as "transmit", "report", and "transmit".

[0324] The relay discovery method involved in the embodiments of the present disclosure may include at least one of steps S2101 to S2104. For example, step S2101 may be implemented as an independent embodiment, steps S2102 to S2104 may be implemented as independent embodiments, and steps S2101 and S2104 may be implemented as independent embodiments, but are not limited thereto.

[0325] In some embodiments, steps S2102, S2103, and S2104 are optional, and one or more of these steps may be omitted or replaced in different embodiments. It is understood that if the relay communication service supported by the first-hop relay device is different from the relay communication service required by the n-hop relay device and / or the source terminal, the n-hop relay device and / or the source terminal will not discover the first-hop relay device.

[0326] In some embodiments, step S2101 is optional, and one or more of these steps may be omitted or replaced in different embodiments. It is understood that if the n-hop relay device does not find the n-1-hop relay device, the n-hop relay device may generate an n-hop first message based on the terminals that the n-hop relay device can relay, and send the n-hop first message.

[0327] In some embodiments, steps S2102 and S2103 are optional, and one or more of these steps may be omitted or replaced in different embodiments. It is understood that in a single-hop relay communication system, the source terminal may receive the first message from the first-hop relay device to determine the relay path of the relay communication.

[0328] FIG3A is a flow chart of a relay discovery method according to an exemplary embodiment. As shown in FIG3A , the embodiment of the present disclosure relates to a relay discovery method, which is executed by a first relay device 1021 and includes:

[0329] Step S3101: Send the first message of the first hop.

[0330] In some embodiments, the first relay device may be a 1-hop relay device.

[0331] In some embodiments, the optional implementation of step S3101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

[0332] FIG3B is a flow chart of a relay discovery method according to an exemplary embodiment. As shown in FIG3B , the embodiment of the present disclosure relates to a relay discovery method, which is executed by the first relay device 1021 and includes:

[0333] Step S3201: Send a first message; the first message includes:

[0334] The first field indicates the maximum number of relay hops;

[0335] The second field indicates the number of relay hops corresponding to the first-hop relay device.

[0336] In some embodiments, the first message further includes at least one of the following:

[0337] The third field is used to at least indicate a terminal that can be relayed by the first-hop relay device;

[0338] The fourth field is used to at least indicate the first-hop relay device.

[0339] In some embodiments, the terminal indicated by the third field is determined by the first-hop relay device based on historical relay discovery; and / or, the terminal indicated by the third field is determined based on configuration information of the first-hop relay device.

[0340] In some embodiments, the fourth field includes at least one of the following:

[0341] A source layer 2 identifier, used to identify the first-hop relay device;

[0342] Destination layer 2 identifier, used to identify the next hop device that receives the first message.

[0343] In some embodiments, the third field carries terminal list information; the terminal list information includes device information of one or more terminals.

[0344] FIG3C is a flow chart of a relay discovery method according to an exemplary embodiment. As shown in FIG3C , the embodiment of the present disclosure relates to a relay discovery method, which is performed by the second relay device 1022 and includes:

[0345] Step S3301: Receive the first message.

[0346] In some embodiments, the second relay device may be an n-th hop relay device, where n is a positive integer greater than 1.

[0347] In some embodiments, the nth hop relay device receives the first hop first message sent by the first hop relay device. In some embodiments, the optional implementation of step S3301 can refer to the optional implementation of step S2101 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0348] In some embodiments, the n-th hop relay device receives the n-1-th hop first message sent by the n-1-th hop relay device.

[0349] In some embodiments, the optional implementation of step S3301 can refer to the optional implementation of step S2103 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

[0350] Step S3302: Generate the n-th hop first message.

[0351] In some embodiments, the optional implementation of step S3302 can refer to the optional implementation of step S2102 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

[0352] Step S3303: Send the first message of the nth hop.

[0353] In some embodiments, the optional implementation of step S3303 can refer to the optional implementation of step S2103 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

[0354] The relay discovery method involved in the embodiment of the present disclosure may include at least one of steps S3301 to S3303. For example, step S3302 combined with step S3303 may be implemented as an independent embodiment, but is not limited thereto.

[0355] In some embodiments, step S3301 is optional, and one or more of these steps may be omitted or replaced in different embodiments. It is understood that if the relay service provided by the n-1th hop relay device is different from the relay service required by the n-1th hop relay device, the n-1th hop relay device will not discover the n-1th hop relay device, that is, the n-1th hop relay device will not receive the n-1th hop first message.

[0356] FIG3D is a flow chart of a relay discovery method according to an exemplary embodiment. As shown in FIG3D , the embodiment of the present disclosure relates to a relay discovery method, which is performed by the second relay device 1022 and includes:

[0357] Step S3401: Receive the first message of the (n-1)th hop.

[0358] In some embodiments, the n-1th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1th hop relay device; and n is a positive integer greater than 1.

[0359] Step S3402: Determine the number of relay hops corresponding to the n-th hop relay device according to the second field of the n-1th hop first message.

[0360] Step S3403: When the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, generate an n-th hop first message according to the (n-1)-th hop first message.

[0361] In some embodiments, the n-th hop first message includes a first field and a second field, the first field of the n-th hop first message indicates the maximum number of relay hops; the second field of the n-th hop first message is used to indicate the number of relay hops corresponding to the n-th hop relay device.

[0362] In some embodiments, the n-1th hop first message further includes a third field; the third field indicates a terminal that can be relayed by the first n-1 hop relay device;

[0363] Generating the n-th hop first message according to the n-1-th hop first message further includes:

[0364] The n-hop first message is generated according to the third field of the n-1-hop first message; the third field of the n-hop first message indicates a terminal that can be relayed by the first n-hop relay devices.

[0365] In some embodiments, the n-th hop first message further includes a fourth field; the fourth field indicates the n-th hop relay device.

[0366] In some embodiments, the fourth field of the n-th hop first message includes at least one of the following:

[0367] A source layer 2 identifier, used to identify the n-th hop relay device;

[0368] Destination layer 2 identifier, used to identify the next-hop device that receives the first message of the nth hop.

[0369] In some embodiments, determining the number of relay hops corresponding to the n-th hop relay device according to the second field of the n-1-th hop first message includes:

[0370] The relay hop count corresponding to the n-1th hop relay device is increased by 1 to obtain the relay hop count corresponding to the nth hop relay device.

[0371] In some embodiments, the method further comprises:

[0372] The n-th hop relay device sends the n-th hop first message.

[0373] FIG4A is a flow chart of a relay discovery method according to an exemplary embodiment. As shown in FIG4A , the embodiment of the present disclosure relates to a relay discovery method, which is executed by the source terminal 1011 and includes:

[0374] Step S4101: The source terminal receives the first message.

[0375] In some embodiments, the source terminal receives a 1st-hop first message.

[0376] In some embodiments, the optional implementation of step S4101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

[0377] In some embodiments, the source terminal receives the n-th hop first message.

[0378] In some embodiments, the optional implementation of step S4101 can refer to the optional implementation of step S2103 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

[0379] Step S4102: The source terminal selects a relay path for relay communication.

[0380] In some embodiments, the optional implementation of step S4102 can refer to the optional implementation of step S2104 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

[0381] FIG4B is a flow chart of a relay discovery method according to an exemplary embodiment. As shown in FIG4B , the embodiment of the present disclosure relates to a relay discovery method, which is executed by the source terminal 1011 and includes:

[0382] Step S4201: The source terminal receives the first message.

[0383] In some embodiments, the first message includes: a first field indicating a maximum number of relay hops; and a second field indicating a number of relay hops corresponding to the relay device.

[0384] Step S4202: Select a relay path for relay communication according to the first message.

[0385] In some embodiments, selecting a relay path for relaying communication according to the first message includes at least one of the following:

[0386] selecting, according to the second field in the first message, a relay device corresponding to the second field indicating the least number of relay hops to perform the relay communication;

[0387] According to the signal strength of the received first message, the relay device corresponding to the first message with the largest signal strength is selected to perform the relay communication.

[0388] FIG5 is an interactive diagram of a relay discovery method according to an exemplary embodiment. As shown in FIG5 , the embodiment of the present disclosure relates to a relay discovery method for a communication system 100, and the method includes one of the following steps:

[0389] Step S5101: The first-hop relay device sends a first message;

[0390] Step S5102: The n-th hop relay device receives the first message of the (n-1)th hop.

[0391] In some embodiments, the n-1th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1th hop relay device; and n is a positive integer greater than 1.

[0392] Step S5103: The n-th hop relay device generates an n-th hop first message.

[0393] In some embodiments, the n-th hop relay device determines the number of relay hops corresponding to the n-th hop relay device based on the second field of the n-1-th hop first message; when the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, the n-th hop first message is generated based on the n-1-th hop first message.

[0394] In some embodiments, the first field of the n-th hop first message indicates the maximum number of relay hops; the second field of the n-th hop first message is used to indicate the number of relay hops corresponding to the n-th hop relay device;

[0395] Step S5104: The source terminal selects a relay path for relay communication.

[0396] In some embodiments, the source terminal receives a first message sent by one or more relay devices, and selects a relay path for relay communication based on the first message.

[0397] In some embodiments, the above method may include the methods of the above-mentioned communication system side, first relay device side, second relay device side, source terminal side, etc., which will not be repeated here.

[0398] As shown in FIG6A , FIG6A is a flowchart diagram 1 of a U2U discovery method in mode A according to an exemplary embodiment. The U2U discovery method in mode A includes:

[0399] Step 1: The U2U relay detects other UEs nearby.

[0400] The U2U relay can obtain the user information IDs of other nearby UEs based on the RSC.

[0401] Step 2: The U2U relay sends a U2U relay discovery notification message.

[0402] The U2U relay discovery notification message includes: message type, user information ID of the U2U relay, RSC and user information list of the destination terminal.

[0403] In some embodiments, the L2ID of the U2U relay is the source L2ID of the relay discovery notification message.

[0404] It is worth noting that the U2U relay should only notify the user information ID of other nearby UEs that have been assigned a relay indication (relay_indication) when they were previously discovered.

[0405] The destination UE monitors the relay discovery notification message from the U2U relay, and the L2ID of the destination UE is the target L2ID of the relay discovery notification message.

[0406] It is worth noting that the above-mentioned U2U discovery method of Mode A is only applicable to a single hop and does not support multi-hop. There is no method that supports the discovery of multiple U2U relays in Mode A.

[0407] In some embodiments, the multi-hop U2U relay discovery of mode A is supported by adding the maximum allowed number of hops (MaxAllowedHops) and the number of experienced hops (hopsIndex) in the relay discovery notification message.

[0408] The maximum allowed hop count is used to indicate the maximum number of hops that the user information of the destination UE (end UE) can be forwarded; and the experienced hop count is used to indicate the number of relay hops to reach the end UE.

[0409] In some embodiments, each U2U relay supporting Mode A further includes: storing a target list of other destination UEs; the target list includes:

[0410] (1) User information ID of the target End UE;

[0411] (2) Number of hops experienced; for example, if the value of the number of hops experienced is 1, it means that the target End UE can be reached through one hop (i.e., through one U2U relay); if the value of the number of hops experienced is 0 or the number of hops experienced is empty, it means that the target End UE can be reached directly without going through the U2U relay.

[0412] (3) Maximum allowed hop count, indicating the maximum number of hops allowed for forwarding the user information ID of the target End UE.

[0413] (4) Previous hop information.

[0414] As shown in FIG6B , FIG6B is a second flow chart of a U2U discovery method of mode A according to an exemplary embodiment. The method includes:

[0415] Step 0: Configure service authorization or parameters to support multi-hop.

[0416] The source UE, U2U relay 1, U2U relay 2, and U2U relay 3 may be configured with service authorization or parameters from a Policy Control Function (PCF) to support multi-hop U2U relays.

[0417] Step 1: U2U relay 3 sends a U2U relay discovery notification message.

[0418] U2U relay 3 has a target list of other End UEs and sends a U2U relay discovery notification message.

[0419] In some embodiments, the U2U relay 3 may send the U2U relay discovery notification message by broadcasting.

[0420] In some embodiments, the U2U relay discovery notification message includes: the message type, the user information ID of the U2U relay 3, the RSC, and the target list of the End UE.

[0421] Each End UE user information ID in the target list corresponds to the information of the number of hops experienced, the maximum allowed number of hops, and the previous hop U2U relay.

[0422] If the End UE can be reached directly without going through the U2U relay, the previous hop information of the End UE may be empty, or the previous hop information may be 0.

[0423] In some embodiments, the target list of the U2U relay 3 may include one or more End UEs, and for each End UE, includes:

[0424] (1) End UE user information ID;

[0425] (2) Number of hops experienced; for example, if the value of the number of hops experienced is 1, it means that the End UE can be reached through one hop (i.e., through one U2U relay); if the value of the number of hops experienced is 0 or the number of hops experienced is empty, it means that the End UE can be reached directly without going through the U2U relay.

[0426] (3) Maximum allowed hop count, indicating the maximum number of hops allowed for forwarding the user information ID of the End UE. For example, the maximum allowed hop count is 3.

[0427] (4) Previous hop information, indicating the user information ID of the previous hop relay.

[0428] Step 2: The U2U relay 2 updates the target list of the U2U relay 2 based on the target list in the received U2U relay discovery notification message.

[0429] In some embodiments, updating the target list of the U2U relay 2 includes:

[0430] If the number of hops experienced by the End UE in the received target list plus 1 is still less than or equal to the maximum allowed hop number of the End UE, the information of the End UE is added to the target list of U2U relay 2; wherein the added End UE information includes: the user information ID of the End UE, the maximum allowed hop number, the number of hops experienced; and the previous hop information;

[0431] If the number of hops experienced by the End UE in the received target list plus 1 is greater than the maximum allowed hop number of the End UE, the information of the End UE is not added to the target list of the U2U relay 2.

[0432] In some embodiments, if the same End UE is included in multiple received target lists, information of the End UE in the target list with the smaller number of hops can be selected to be added to the target list of the U2U relay 2 .

[0433] For example, the target list for U2U Relay 2 updates includes:

[0434] (1) End UE user information ID.

[0435] (2) The number of hops that have been experienced; for example, if the number of hops that have been experienced plus 1 equals 2, it means that the End UE can be reached through two hops (ie, through a U2U relay 3 and a U2U relay 2).

[0436] (3) Maximum allowed hop count, indicating the maximum number of hops allowed for forwarding the user information ID of the End UE. For example, the maximum allowed hop count is 3.

[0437] (4) Previous hop information, indicating the user information ID of the previous hop relay, that is, the user information ID of U2U relay 3.

[0438] Step 3: U2U relay 2 sends a U2U relay discovery notification message.

[0439] It is worth noting that the U2U relay discovery notification message sent by U2U relay 2 carries the updated target list.

[0440] Step 4: U2U relay 1 updates its target list based on the target list in the received U2U relay discovery notification message.

[0441] For example, the target list updated by U2U relay 1 includes:

[0442] (1) End UE user information ID.

[0443] (2) The number of hops experienced; for example, if the number of hops experienced plus 1 equals 3, it means that the End UE can be reached through three hops (ie, through U2U relay 3, U2U relay 2, and U2U relay 1).

[0444] (3) Maximum allowed hop count, indicating the maximum number of hops allowed for forwarding the user information ID of the End UE. For example, the maximum allowed hop count is 3.

[0445] (4) Previous hop information, indicating the user information ID of the previous hop relay, that is, the user information ID of U2U relay 2.

[0446] Step 5: U2U relay 1 sends a U2U relay discovery notification message.

[0447] It is worth noting that the U2U relay discovery notification message sent by U2U relay 1 carries the updated target list.

[0448] Step 6: The source UE receives multiple U2U relay discovery notification messages and selects the first-hop relay.

[0449] The source UE selects the first-hop relay according to the target list and target End UE in the multiple U2U relay discovery notification messages.

[0450] In some embodiments, the source UE may select the relay corresponding to the target list that has undergone the smallest number of hops as the first-hop relay.

[0451] The embodiments of the present disclosure also provide an apparatus for implementing any of the above methods. For example, an apparatus is provided, comprising a unit or module for implementing each step performed by the source terminal in any of the above methods. For another example, another apparatus is provided, comprising a unit or module for implementing each step performed by a relay device (e.g., a first relay device or a second relay device) in any of the above methods.

[0452] It should be understood that the division of the various units or modules in the above devices 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 devices, 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.

[0453] In the embodiments of the present disclosure, a 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 a 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 to implement 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.

[0454] FIG7A is a schematic diagram of the structure of a first relay device according to an exemplary embodiment. As shown in FIG7A , the first relay device 1021 includes: a first sending module 1021a, configured to send a first message to a next-hop device; the first message includes: a first field indicating the maximum number of relay hops; a second field indicating the number of relay hops corresponding to the first-hop relay device. Optionally, the first sending module 1021a is used to execute the steps related to sending performed by the first relay device in any of the above methods, which are not described in detail here. Optionally, the first relay device 1021 also includes a receiving module, which is used to execute the steps related to receiving performed by the first relay device in any of the above methods, which are not described in detail here.

[0455] FIG7B is a schematic diagram of the structure of a second relay device according to an exemplary embodiment. As shown in FIG7B , the second relay device 1022 includes: a first receiving module 1022a configured to receive an n-1th hop first message; the n-1th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1th hop relay device; n is a positive integer greater than 1; a first processing module 1022b configured to determine the number of relay hops corresponding to the n-1th hop relay device based on the second field of the n-1th hop first message; when the number of relay hops corresponding to the n-1th hop relay device is less than or equal to the maximum number of relay hops, generate an n-th hop first message based on the n-1th hop first message; the first field of the n-1th hop first message indicates the maximum number of relay hops; the second field of the n-1th hop first message indicates the number of relay hops corresponding to the n-1th hop relay device. Optionally, the first receiving module 1022a is used to execute the steps related to information reception performed by the second relay device in any of the above relay discovery methods, which are not described in detail here. Optionally, the first processing module 1022b is used to execute the steps related to information processing performed by the second relay device in any of the above relay discovery methods, which are not described in detail here. Optionally, the first relay device 1021 also includes a sending module, and the above sending module is used to execute the steps related to information sending performed by the second relay device in any of the above relay discovery methods, which are not described in detail here.

[0456] Figure 7C is a schematic diagram of the structure of a source terminal according to an exemplary embodiment. As shown in Figure 7C, the source terminal 1011 includes: a second receiving module 1011a, configured to receive a first message; the first message includes: a first field indicating the maximum number of relay hops; a second field indicating the number of relay hops corresponding to the relay device; a second processing module 1011b, configured to select a relay path for relay communication based on the first message. Optionally, the second receiving module 1011a is used to execute the steps related to information reception performed by the source terminal in any of the above relay discovery methods, which are not repeated here. Optionally, the second processing module 1011b is used to execute the steps related to information processing performed by the source terminal in any of the above relay discovery methods, which are not repeated here.

[0457] Figure 8A is a schematic diagram of the structure of a communication device 8100 according to an exemplary embodiment. The communication device 8100 can be a network device (e.g., an access network device or a core network device), a terminal (e.g., a user device), 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 relay discovery methods. The communication device 8100 can be used to implement the relay discovery method described in the above method embodiment. For details, please refer to the description of the above method embodiment.

[0458] 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. The processor 8101 is used to call instructions to enable the communication device 8100 to perform any of the above relay discovery methods.

[0459] In some embodiments, the communication device 8100 further includes one or more memories 8102 for storing instructions. Optionally, all or part of the memories 8102 may be located outside the communication device 8100.

[0460] In some embodiments, the communication device 8100 further includes one or more transceivers 8103. When the communication device 8100 includes one or more transceivers 8103, the communication steps such as sending and receiving in the above method are performed by the transceiver 8103, and the other steps are performed by the processor 8101.

[0461] In some embodiments, a transceiver may include a receiver and a transmitter, which may be separate or integrated. Optionally, the terms transceiver, transceiver unit, transceiver, and transceiver circuit may be used interchangeably; the terms transmitter, transmitting unit, transmitter, and transmitting circuit may be used interchangeably; and the terms receiver, receiving unit, receiver, and receiving circuit may be used interchangeably.

[0462] Optionally, the communication device 8100 further includes one or more interface circuits 8104, which are connected to the memory 8102. The interface circuits 8104 can be used to receive signals from the memory 8102 or other devices, and can be used to send signals to the memory 8102 or other devices. For example, the interface circuits 8104 can read instructions stored in the memory 8102 and send the instructions to the processor 8101.

[0463] 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.

[0464] FIG8B is a schematic diagram showing the structure of a chip 8200 according to an exemplary embodiment. If the communication device 8100 can be a chip or a chip system, reference can be made to the schematic diagram of the structure of the chip 8200 shown in FIG8B , but the present invention is not limited thereto.

[0465] The chip 8200 includes one or more processors 8201 , and the processor 8201 is used to call instructions to enable the chip 8200 to execute any of the above relay discovery methods.

[0466] In some embodiments, chip 8200 further includes one or more interface circuits 8202, which are connected to memory 8203. Interface circuit 8202 can be used to receive signals from memory 8203 or other devices, and can be used to send signals to memory 8203 or other devices. For example, interface circuit 8202 can read instructions stored in memory 8203 and send the instructions to processor 8201. Optionally, the terms interface circuit, interface, transceiver pin, and transceiver are interchangeable.

[0467] In some embodiments, the chip 8200 further includes one or more memories 8203 for storing instructions. Alternatively, all or part of the memories 8203 may be outside the chip 8200.

[0468] The present disclosure also provides 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 may also be a storage medium readable by other devices. Optionally, the storage medium may be a non-transitory storage medium, but may also be a transient storage medium.

[0469] The present disclosure further provides a program product, which, when executed by the communication device 8100, enables the communication device 8100 to perform any of the above relay discovery methods. Optionally, the program product is a computer program product.

[0470] The present disclosure also provides a computer program, which, when executed on a computer, enables the computer to execute any one of the above relay discovery methods.

[0471] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the invention that follow from the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0472] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A relay discovery method, wherein: The method comprises: The first-hop relay device sends a first message to the next-hop device; the first message includes: The first field indicates the maximum number of relay hops; The second field indicates the number of relay hops corresponding to the first-hop relay device.

2. The method according to claim 1, wherein: The first message also includes at least one of the following: The third field is used at least to indicate a terminal that can be relayed by the first-hop relay device; The fourth field is used to at least indicate the first-hop relay device.

3. The method according to claim 2, wherein: The terminal indicated by the third field is determined by the first-hop relay device based on historical relay discovery; and / or, The terminal indicated by the third field is determined based on the configuration information of the first-hop relay device.

4. The method according to claim 2, wherein: The fourth field includes at least one of the following: A source layer 2 identifier, used to identify the first-hop relay device; The destination layer 2 identifier is used to identify the next hop device that receives the first message.

5. The method according to claim 2 or 3, wherein: The third field carries terminal list information; the terminal list information includes device information of one or more terminals.

6. A relay discovery method, wherein: The method comprises: The n-th hop relay device receives the n-1-th hop first message; the n-1-th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1-th hop relay device; n is a positive integer greater than 1; Determine the number of relay hops corresponding to the n-th hop relay device according to the second field of the n-1th hop first message; When the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, an n-th hop first message is generated according to the n-1-th hop first message; the first field of the n-th hop first message indicates the maximum number of relay hops; the second field of the n-th hop first message is used to indicate the number of relay hops corresponding to the n-th hop relay device.

7. The method according to claim 6, wherein: The n-1th hop first message further includes a third field; the third field indicates a terminal that can be relayed by the first n-1 hop relay device; The generating the n-th hop first message according to the n-1-th hop first message also includes: The n-hop first message is generated according to the third field of the n-1-hop first message; the third field of the n-hop first message indicates a terminal that can be relayed by the previous n-hop relay devices.

8. The method according to claim 6 or 7, wherein: The n-th hop first message further includes a fourth field; the fourth field indicates the n-th hop relay device.

9. The method according to claim 8, wherein: The fourth field of the n-th hop first message includes at least one of the following: A source layer 2 identifier, used to identify the n-th hop relay device; The destination layer 2 identifier is used to identify the next hop device that receives the n-th hop first message.

10. The method according to any one of claims 6 to 9, wherein: The determining, according to the second field of the first message of the n-1th hop, the number of relay hops corresponding to the nth hop relay device includes: The number of relay hops corresponding to the n-1th relay device is increased by 1 to obtain the number of relay hops corresponding to the nth relay device.

11. A relay discovery method, wherein: The method comprises: The source terminal receives a first message; the first message includes: a first field indicating a maximum number of relay hops; a second field indicating a number of relay hops corresponding to the relay device; A relay path for relay communication is selected according to the first message.

12. The method according to claim 11, wherein: The selecting, according to the first message, a relay path for relay communication includes at least one of the following: According to the second field in the first message, selecting a relay device corresponding to the second field indicating the least number of relay hops to perform the relay communication; According to the signal strength of the received first message, a relay device corresponding to the first message with the largest signal strength is selected to perform the relay communication.

13. A relay discovery method, wherein: The method comprises: The first-hop relay device sends a first message; The n-th hop relay device receives the n-1-th hop first message; the n-1-th hop first message includes a first field and a second field; the first field is used to indicate the maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1-th hop relay device ... is a positive integer greater than 1; The n-hop relay device determines the number of relay hops corresponding to the n-hop relay device according to the second field of the n-1-hop first message; when the number of relay hops corresponding to the n-hop relay device is less than or equal to the maximum number of relay hops, generates the n-hop first message according to the n-1-hop first message; the first field of the n-hop first message indicates the maximum number of relay hops; the second field of the n-hop first message is used to indicate the number of relay hops corresponding to the n-hop relay device; The source terminal receives the first message, and selects a relay path for relay communication according to the first message.

14. A first relay device, wherein: The first relay device is a first-hop relay device, and the first relay device includes: The first sending module is configured to send a first message to a next-hop device; the first message includes: The first field indicates the maximum number of relay hops; The second field indicates the number of relay hops corresponding to the first-hop relay device.

15. A second relay device, wherein: The second relay device is an n-th hop relay device, and the second relay device includes: A first receiving module is configured to receive an n-1th hop first message; the n-1th hop first message includes a first field and a second field; the first field is used to indicate a maximum number of relay hops; the second field is used to indicate the number of relay hops corresponding to the n-1th hop relay device; n is a positive integer greater than 1; The first processing module is configured to determine the number of relay hops corresponding to the n-th hop relay device according to the second field of the n-1-th hop first message; when the number of relay hops corresponding to the n-th hop relay device is less than or equal to the maximum number of relay hops, generate the n-th hop first message according to the n-1-th hop first message; the first field of the n-th hop first message indicates the maximum number of relay hops; the second field of the n-th hop first message is used to indicate the number of relay hops corresponding to the n-th hop relay device.

16. A source terminal, wherein: The source terminal comprises: A second receiving module is configured to receive a first message; the first message includes: a first field indicating a maximum number of relay hops; a second field indicating a number of relay hops corresponding to the relay device; The second processing module is configured to select a relay path for relay communication according to the first message.

17. A communication system, wherein: The communication system includes a source terminal, at least two relay devices and a target terminal; one of the relay devices is configured to implement the relay discovery method described in any one of claims 1 to 5, the other relay device is configured to implement the relay discovery method described in any one of claims 6 to 10, and the source terminal is configured to implement the relay discovery method described in any one of claims 11 to 12.

18. A communication device, wherein: The communication device comprises: one or more processors; The processor is used to call instructions to enable the communication device to execute the relay discovery method described in any one of claims 1 to 5, claims 6 to 10, and claims 11 to 12.

19. A storage medium, wherein: The storage medium stores instructions, and when the instructions are executed on a communication device, the communication device executes the relay discovery method according to any one of claims 1 to 5, claims 6 to 10, and claims 11 to 12.

Images