Method and device for discovering relay user equipment UE and storage medium

Abstract

The invention relates to a discovery method and device of relay user equipment UE and a storage medium, and belongs to the technical field of communication. The method is applied to first relay UE, and the method comprises the following steps: receiving a discovery message; if the relay forwarding identifier represents that the end UE set allows the relay UE to forward, adding a user information identifier of the first relay UE in the first relay UE set; forwarding the discovery message added with the user information identifier of the first relay UE; wherein the discovery message at least carries one or more of the following parameters: an end UE set, and the end UE set comprises a user information identifier of the source end UE and a user information identifier of the destination end UE; a first relay UE set, wherein the first relay UE set comprises user information identifiers of relay UEs passing by from the source UE to the first relay UE in the relay UE discovery process; and the relay forwarding identifier is used for representing whether the end UE set allows the relay UE to forward or not. According to the invention, discovery of the multi-hop relay UE can be supported.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a method, apparatus, and storage medium for discovering a relay user equipment (UE). Background Art

[0002] Currently, the R18 standard in the 3GPP (3rd Generation Partnership Project) protocol has studied and standardized the ProSe (Proximity Services) scenario in the 5G (5th Generation Mobile Communication Technology) system.

[0003] In the ProSe scenario, when two UEs (User Equipment) cannot communicate directly due to reasons such as long distance or poor signal quality, another UE can be used as a relay for communication. These two UEs are called End UEs, and the UE that acts as a relay is called a UE-to-UE Relay. The End UE communicates with the UE-to-UE Relay through the PC5 (Proximity Communication) interface. Before communicating with another End UE through the UE-to-UE Relay, the End UE needs to first discover a suitable UE-to-UE Relay and then establish a connection through this UE-to-UE Relay.

[0004] However, the R18 standard only supports End UEs to discover UE-to-UE Relays that support single hop, and does not support End UEs to discover UE-to-UE Relays that support multi-hop. Summary of the Invention

[0005] Based on this, it is necessary to provide a method, apparatus, and storage medium for discovering a relay user equipment (UE) to solve the above technical problems.

[0006] In a first aspect, a method for discovering a relay user equipment (UE) is provided. The method is applied to a first relay UE and includes:

[0007] Receiving a discovery message;

[0008] If the relay forwarding identifier indicates that the set of End UEs allows the relay UE to perform forwarding, adding the user information identifier of the first relay UE to the first relay UE set;

[0009] Forward the discovery message after adding the user information identifier of the first relay UE;

[0010] Wherein, the discovery message carries at least one or more of the following parameters:

[0011] The set of end UEs, which includes the user information identifiers of the source end UE and the destination end UE;

[0012] The set of first relay UEs, which includes the user information identifiers of the relay UEs passed by from the source end UE to the first relay UE during the relay UE discovery process;

[0013] The relay forwarding identifier, which is used to indicate whether the relay UE is allowed to forward for the set of end UEs.

[0014] As an alternative implementation, the receiving the discovery message includes:

[0015] Receiving a discovery announcement message sent by other relay UEs;

[0016] Or, receiving a discovery request message sent by the source end UE or other relay UEs.

[0017] As an alternative implementation, the discovery message also carries at least a hop count identifier, which is used to indicate the number of times the relay UE is allowed to forward for the set of end UEs.

[0018] As an alternative implementation, before adding the user information identifier of the first relay UE to the set of first relay UEs, the method further includes:

[0019] If the hop count identifier is not 0, subtract 1 from the hop count identifier and add the user information identifier of the first relay UE to the set of first relay UEs;

[0020] If the hop count identifier is 0, discard the discovery message.

[0021] As an alternative implementation, the discovery message also carries at least an end UE set identifier, which is used to uniquely identify the set of end UEs.

[0022] As an alternative implementation, before adding the user information identifier of the first relay UE to the set of first relay UEs, the method further includes:

[0023] If the first relay UE has not forwarded the end UE set identifier, store the end UE set identifier locally and add the user information identifier of the first relay UE to the first relay UE set;

[0024] If the first relay UE has forwarded the end UE set identifier, discard the discovery message.

[0025] As an optional implementation manner, the method further includes:

[0026] Receive a discovery response message sent by the destination end UE or the second relay UE;

[0027] Send the discovery response message to the source end UE or the third relay UE;

[0028] Wherein, the discovery response message carries at least one or more of the following parameters:

[0029] The end UE set;

[0030] The second relay UE set, the second relay UE set includes the user information identifier of the relay UE passed by from the source end UE to the destination end UE during the relay UE discovery process and the layer 2 identifier of the relay UE, the layer 2 identifier is used for the subsequent connection establishment process, the second relay UE is the relay UE after the first relay UE in the second relay UE set, and the third relay UE is the relay UE before the first relay UE in the relay UE set.

[0031] As an optional implementation manner, the method further includes:

[0032] Send a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters:

[0033] The end UE set, the end UE set is the end UE set obtained by the first relay UE during the relay UE discovery process and / or the UE communication process;

[0034] The third relay UE set, the third relay UE set at least includes the user information identifier of the relay UE passed by from the source end UE in the end UE set to the first relay UE;

[0035] The relay forwarding identifier, the relay forwarding identifier is used to indicate whether the end UE set allows the relay UE to forward.

[0036] As an alternative implementation, the discovery announcement message further carries at least a hop count identifier, which is used to represent the number of times the relay UE is allowed to forward by the end UE set. The hop count identifier is determined according to the initial hop count identifier and the hop count corresponding to the source end UE in the end UE set reaching the first relay UE. The initial hop count identifier is determined by the first relay UE or the policy control function PPCF network element.

[0037] As an alternative implementation, the discovery announcement message further carries at least an end UE set identifier, which is used to uniquely identify the end UE set. The end UE set identifier is generated by the first relay UE or the CF network element according to the end UE set.

[0038] As an alternative implementation, the method further includes:

[0039] Sending a registration request message to the access and mobility management function AMF network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to represent that the first relay UE supports the discovery function of the multi-hop relay UE;

[0040] Receiving a non-access stratum NAS message sent by the PCF network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes the user information identifier of the first relay UE, the end UE set identifier, and / or the hop count identifier.

[0041] In a second aspect, a method for discovering a relay user equipment UE is provided. The method is applied to an end UE, and the method includes:

[0042] Sending a first discovery request message; wherein, the first discovery request message carries at least one or more of the following parameters:

[0043] A first end UE set, which includes the user information identifier of the source end UE and the user information identifier of the destination end UE; the end UE is the source end UE in the first end UE set;

[0044] A first relay UE set;

[0045] A relay forwarding identifier, which is used to represent whether the first end UE set allows the relay UE to forward.

[0046] As an alternative implementation, the method further includes:

[0047] Receiving a second discovery request message sent by the relay UE;

[0048] If the destination UE in the second set of UE ends contains the said UE end, send a discovery response message to the said relay UE;

[0049] Wherein, the second discovery request message carries at least one or more of the following parameters:

[0050] The second set of UE ends, the second set of UE ends includes the user information identifier of the source UE end and the user information identifier of the destination UE end, and the UE end is the destination UE end in the second set of UE ends;

[0051] The second set of relay UEs, the second set of relay UEs includes at least the user information identifier of the relay UE passed by from the source UE end to the destination UE end in the second set of UE ends;

[0052] The discovery response message carries at least one or more of the following parameters;

[0053] The second set of UE ends;

[0054] The second set of relay UEs.

[0055] As an optional implementation manner, the first discovery request message further carries at least a hop count identifier, the hop count identifier is used to represent the number of times that the first set of UE ends allows the relay UE to forward, and the hop count identifier is determined by the UE end or the Policy Control Function (PCF) network element.

[0056] As an optional implementation manner, the first discovery request message further carries at least an identifier of the set of UE ends, the identifier of the set of UE ends is used to uniquely identify the first set of UE ends, and the identifier of the set of UE ends is generated by the UE end or the PCF network element according to the first set of UE ends.

[0057] As an optional implementation manner, the method further includes:

[0058] Send a registration request message to the Access and Mobility Management Function (AMF) network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the first set of UE ends and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to represent that the UE end supports the discovery function of the multi-hop relay UE;

[0059] Receive a non-access stratum (NAS) message sent by the PCF network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter at least includes the user information identifier of the UE end, the identifier of the set of UE ends and / or the hop count identifier.

[0060] In a third aspect, a method for discovering a relay user equipment (UE) is provided. The method is applied to an access and mobility management function (AMF) network element, and the method includes:

[0061] Receiving a registration request message sent by the UE;

[0062] Sending a first non-access stratum (NAS) message to a policy control function (PCF) network element;

[0063] Receiving a second NAS message sent by the PCF network element;

[0064] Sending a third NAS message to the UE;

[0065] Wherein, at least a proximity service capability parameter is carried in the registration request message, and the proximity service capability parameter includes an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to represent that the UE supports the discovery function of a multi-hop relay UE;

[0066] At least the proximity service capability parameter is carried in the first NAS message;

[0067] At least a proximity service policy parameter is carried in the second NAS message, and the proximity service policy parameter includes a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier;

[0068] The proximity service policy parameter is carried in the third NAS message.

[0069] In a fourth aspect, a method for discovering a relay user equipment (UE) is provided. The method is applied to a policy control function (PCF) network element, and the method includes:

[0070] Receiving a first non-access stratum (NAS) message sent by an access and mobility management function (AMF) network element;

[0071] Sending a second NAS message to the AMF network element;

[0072] Wherein, at least a proximity service capability parameter is carried in the first NAS message, and the proximity service capability parameter includes an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to represent that the UE supports the discovery function of a multi-hop relay UE;

[0073] At least a proximity service policy parameter is carried in the second NAS message, and the proximity service policy parameter includes a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier, and the end UE set identifier is generated based on the end UE set.

[0074] Fifth aspect, a relay user equipment (UE) is provided, including a memory, a transceiver, and a processor, where the memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0075] Receive a discovery message;

[0076] If the relay forwarding identifier indicates that the set of end UEs allows the relay UE to forward, add the user information identifier of the first relay UE to the first relay UE set;

[0077] Forward the discovery message after adding the user information identifier of the first relay UE;

[0078] Wherein, the discovery message carries at least one or more of the following parameters:

[0079] The set of end UEs, which includes the user information identifiers of the source end UE and the destination end UE;

[0080] The first relay UE set, which includes the user information identifiers of the relay UEs passed by from the source end UE to the first relay UE during the relay UE discovery process;

[0081] The relay forwarding identifier, which is used to indicate whether the set of end UEs allows the relay UE to forward.

[0082] As an optional implementation manner, the receiving the discovery message includes:

[0083] Receive a discovery announcement message sent by another relay UE;

[0084] Or, receive a discovery request message sent by the source end UE or another relay UE.

[0085] As an optional implementation manner, the discovery message further carries at least a hop count identifier, which is used to indicate the number of times the set of end UEs allows the relay UE to forward.

[0086] As an optional implementation manner, before adding the user information identifier of the first relay UE to the first relay UE set, the processor is further used to perform the following operations:

[0087] If the hop count identifier is not 0, subtract 1 from the hop count identifier and add the user information identifier of the first relay UE to the first relay UE set;

[0088] If the hop count identifier is 0, discard the discovery message.

[0089] As an alternative implementation, the discovery message further carries at least a set identifier of the end UEs, and the set identifier of the end UEs is used to uniquely identify the set of end UEs.

[0090] As an alternative implementation, before adding the user information identifier of the first relay UE to the first relay UE set, the processor is further configured to perform the following operations:

[0091] If the first relay UE has not forwarded the set identifier of the end UEs, store the set identifier of the end UEs locally and add the user information identifier of the first relay UE to the first relay UE set;

[0092] If the first relay UE has forwarded the set identifier of the end UEs, discard the discovery message.

[0093] As an alternative implementation, the processor is further configured to perform the following operations:

[0094] Receive a discovery response message sent by the destination end UE or the second relay UE;

[0095] Send the discovery response message to the source end UE or the third relay UE;

[0096] Wherein, the discovery response message carries at least one or more of the following parameters:

[0097] The set of end UEs;

[0098] The second relay UE set, which includes the user information identifier of the relay UEs passed by from the source end UE to the destination end UE during the relay UE discovery process and the layer 2 identifier of the relay UEs. The layer 2 identifier is used for subsequent connection establishment processes. The second relay UE is the next relay UE of the first relay UE in the second relay UE set, and the third relay UE is the previous relay UE of the first relay UE in the relay UE set.

[0099] As an alternative implementation, the processor is further configured to perform the following operations:

[0100] Send a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters:

[0101] The set of end UEs, which is the set of end UEs obtained by the first relay UE during the relay UE discovery process and / or the UE communication process;

[0102] A third relay UE set, where the third relay UE set at least includes user information identifiers of relay UEs through which a source UE in the end UE set reaches the first relay UE;

[0103] A relay forwarding identifier, which is used to indicate whether the end UE set allows a relay UE to perform forwarding.

[0104] As an optional implementation manner, the discovery announcement message further at least carries a hop count identifier, where the hop count identifier is used to indicate the number of times the end UE set allows a relay UE to forward, and the hop count identifier is determined according to an initial hop count identifier and the hop count corresponding to the source UE in the end UE set reaching the first relay UE, and the initial hop count identifier is determined by the first relay UE or a policy control function (PCF) network element.

[0105] As an optional implementation manner, the discovery announcement message further at least carries an end UE set identifier, which is used to uniquely identify the end UE set, and the end UE set identifier is generated by the first relay UE or the PCF network element according to the end UE set.

[0106] As an optional implementation manner, the processor is further configured to perform the following operations:

[0107] Send a registration request message to an access and mobility management function (AMF) network element; where, the registration request message at least carries a proximity service capability parameter, and the proximity service capability parameter includes the end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the first relay UE supports the discovery function of multi-hop relay UEs;

[0108] Receive a non-access stratum (NAS) message sent by a PCF network element through the AMF network element; where, the NAS message at least carries a proximity service policy parameter, and the proximity service policy parameter includes the user information identifier of the first relay UE, the end UE set identifier, and / or the hop count identifier.

[0109] In a sixth aspect, an end user equipment (UE) is provided, including a memory, a transceiver, and a processor, where, the memory is used to store a computer program; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0110] Send a first discovery request message; where, the first discovery request message at least carries one or more of the following parameters:

[0111] The first set of UE, the first set of UE includes the user information identifier of the source UE and the user information identifier of the destination UE, and the UE is the source UE in the first set of UE;

[0112] The first set of relay UE;

[0113] The relay forwarding identifier, which is used to indicate whether the first set of UE allows the relay UE to forward.

[0114] As an optional implementation manner, the processor is further configured to perform the following operations:

[0115] Receive a second discovery request message sent by the relay UE;

[0116] If the destination UE in the second set of UE includes the UE, send a discovery response message to the relay UE;

[0117] Wherein, the second discovery request message carries at least one or more of the following parameters:

[0118] The second set of UE, the second set of UE includes the user information identifier of the source UE and the user information identifier of the destination UE, and the UE is the destination UE in the second set of UE;

[0119] The second set of relay UE, the second set of relay UE includes at least the user information identifier of the relay UE passed by from the source UE to the destination UE in the second set of UE;

[0120] The discovery response message carries at least one or more of the following parameters;

[0121] The second set of UE;

[0122] The second set of relay UE.

[0123] As an optional implementation manner, the first discovery request message further carries at least a hop count identifier, and the hop count identifier is used to indicate the number of times the first set of UE allows the relay UE to forward; the hop count identifier is determined by the UE or the Policy Control Function (PCF) network element.

[0124] As an optional implementation manner, the first discovery request message further carries at least a UE set identifier, and the UE set identifier is used to uniquely identify the first set of UE; the UE set identifier is generated by the UE or the PCF network element according to the first set of UE.

[0125] As an optional implementation manner, the processor is further configured to perform the following operations:

[0126] Send a registration request message to an access and mobility management function (AMF) network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the first set of UE and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to represent that the UE supports the discovery function of a multi-hop relay UE;

[0127] Receive a non-access stratum (NAS) message sent by a policy control function (PCF) network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter at least includes a user information identifier of the UE, a set identifier of the UE, and / or a hop count identifier.

[0128] In a seventh aspect, an access and mobility management function (AMF) network element is provided, including a memory, a transceiver, and a processor, wherein, the memory is used to store a computer program; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0129] Receive a registration request message sent by a UE;

[0130] Send a first NAS message to a policy control function (PCF) network element;

[0131] Receive a second NAS message sent by the PCF network element;

[0132] Send a third NAS message to the UE;

[0133] Wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes a set of UE and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to represent that the UE supports the discovery function of a multi-hop relay UE;

[0134] The first NAS message carries at least the proximity service capability parameter;

[0135] The second NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the UE, a set identifier of the UE, and / or a hop count identifier;

[0136] The third NAS message carries the proximity service policy parameter.

[0137] In an eighth aspect, a Policy Control Function (PCF) network element is provided, including a memory, a transceiver, and a processor. The memory is configured to store computer programs; the transceiver is configured to transmit and receive data under the control of the processor; and the processor is configured to read the computer programs in the memory and perform the following operations:

[0138] Receive a first Non-Access Stratum (NAS) message sent by an Access and Mobility Management Function (AMF) network element;

[0139] Send a second NAS message to the AMF network element;

[0140] Wherein, at least a Proximity Service Capability parameter is carried in the first NAS message, and the Proximity Service Capability parameter includes a set of terminal User Equipments (UEs) and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to represent that the UE supports the discovery function of multi-hop relay UEs;

[0141] At least a Proximity Service Policy parameter is carried in the second NAS message, and the Proximity Service Policy parameter includes a user information identifier of the UE, a set identifier of the terminal UE set, and / or a hop count identifier, and the set identifier of the terminal UE set is generated based on the set of terminal UEs.

[0142] In a ninth aspect, a discovery device for a relay User Equipment (UE) is provided. The device is applied to a first relay UE and includes:

[0143] A first receiving unit, configured to receive a discovery message;

[0144] An adding unit, configured to add the user information identifier of the first relay UE to the first relay UE set if the relay forwarding identifier indicates that the relay UE is allowed to forward for the set of terminal UEs;

[0145] A first sending unit, configured to forward the discovery message after adding the user information identifier of the first relay UE;

[0146] Wherein, at least one or more of the following parameters are carried in the discovery message:

[0147] The set of terminal UEs, which includes the user information identifiers of the source terminal UE and the destination terminal UE;

[0148] The first relay UE set, which includes the user information identifiers of the relay UEs passed by from the source terminal UE to the first relay UE during the relay UE discovery process;

[0149] The relay forwarding identifier, which is used to represent whether the relay UE is allowed to forward for the set of terminal UEs.

[0150] As an alternative implementation, the first receiving unit is specifically configured to:

[0151] Receive a discovery announcement message sent by another relay UE;

[0152] Or receive a discovery request message sent by the source UE or another relay UE.

[0153] As an alternative implementation, the discovery message further carries at least a hop count identifier, and the hop count identifier is used to represent the number of times that the relay UE is allowed to forward by the end UE set.

[0154] As an alternative implementation, the apparatus further includes:

[0155] A first determination unit, configured to, if the hop count identifier is not 0, decrement the hop count identifier by 1, and add the user information identifier of the first relay UE to the first relay UE set;

[0156] A first discard unit, configured to discard the discovery message if the hop count identifier is 0.

[0157] As an alternative implementation, the discovery message further carries at least an end UE set identifier, and the end UE set identifier is used to uniquely identify the end UE set.

[0158] As an alternative implementation, the apparatus further includes:

[0159] A second determination unit, configured to, if the first relay UE has not forwarded the end UE set identifier, store the end UE set identifier locally, and add the user information identifier of the first relay UE to the first relay UE set;

[0160] A second discard unit, configured to discard the discovery message if the first relay UE has already forwarded the end UE set identifier.

[0161] As an alternative implementation, the apparatus further includes:

[0162] A second receiving unit, configured to receive a discovery response message sent by the destination end UE or a second relay UE;

[0163] A second sending unit, configured to send the discovery response message to the source UE or a third relay UE;

[0164] Wherein, the discovery response message carries at least one or more of the following parameters:

[0165] The end UE set;

[0166] The second relay UE set, where the second relay UE set includes the user information identifier of the relay UE passed by from the source UE to the destination UE during the relay UE discovery process and the layer 2 identifier of the relay UE, and the layer 2 identifier is used for subsequent connection establishment processes. The second relay UE is the relay UE following the first relay UE in the second relay UE set, and the third relay UE is the relay UE preceding the first relay UE in the relay UE set.

[0167] As an optional implementation manner, the device further includes:

[0168] A third sending unit, configured to send a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters:

[0169] The set of end UEs, where the set of end UEs is the set of end UEs obtained by the first relay UE during the relay UE discovery process and / or the UE communication process;

[0170] The third relay UE set, where the third relay UE set at least includes the user information identifier of the relay UE passed by from the source UE in the set of end UEs to the first relay UE;

[0171] A relay forwarding identifier, which is used to indicate whether the set of end UEs allows the relay UE to perform forwarding.

[0172] As an optional implementation manner, the discovery announcement message further carries at least a hop count identifier, where the hop count identifier is used to indicate the number of times the set of end UEs allows the relay UE to forward, and the hop count identifier is determined according to the initial hop count identifier and the hop count corresponding to the source UE in the set of end UEs reaching the first relay UE, and the initial hop count identifier is determined by the first relay UE or the policy control function PCF network element.

[0173] As an optional implementation manner, the discovery announcement message further carries at least an end UE set identifier, where the end UE set identifier is used to uniquely identify the set of end UEs, and the end UE set identifier is generated by the first relay UE or the PCF network element according to the set of end UEs.

[0174] As an optional implementation manner, the device further includes:

[0175] A fourth sending unit that sends a registration request message to an access and mobility management function (AMF) network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the set of end UEs and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the first relay UE supports the discovery function of multi-hop relay UEs.

[0176] A third receiving unit that receives a non-access stratum (NAS) message sent by a policy control function (PCF) network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the first relay UE, a set identifier of end UEs, and / or a hop count identifier.

[0177] In a tenth aspect, a discovery device for a relay user equipment (UE) is provided. The device is applied to an end UE and includes:

[0178] A first sending unit that sends a first discovery request message; wherein, the first discovery request message carries at least one or more of the following parameters:

[0179] A first set of end UEs, which includes a user information identifier of a source end UE and a user information identifier of a destination end UE, and the end UE is the source end UE in the first set of end UEs;

[0180] A first set of relay UEs;

[0181] A relay forwarding identifier, which is used to indicate whether the first set of end UEs allows a relay UE to perform forwarding.

[0182] As an optional implementation, the device further includes:

[0183] A first receiving unit that receives a second discovery request message sent by a relay UE;

[0184] A second sending unit that sends a discovery response message to the relay UE if the destination end UE in the second set of end UEs includes the end UE;

[0185] Wherein, the second discovery request message carries at least one or more of the following parameters:

[0186] A second set of end UEs, which includes a user information identifier of a source end UE and a user information identifier of a destination end UE, and the end UE is the destination end UE in the second set of end UEs;

[0187] The second relay UE set, where the second relay UE set at least includes the user information identifiers of the relay UEs through which the source UE in the second - end UE set reaches the destination UE;

[0188] The discovery response message carries at least one or more of the following parameters;

[0189] The second - end UE set;

[0190] The second relay UE set.

[0191] As an alternative implementation, the first discovery request message also carries at least a hop - count identifier, where the hop - count identifier is used to represent the number of times the first - end UE set allows the relay UE to forward, and the hop - count identifier is determined by the end UE or the policy control function (PCF) network element.

[0192] As an alternative implementation, the first discovery request message also carries at least an end - UE set identifier, where the end - UE set identifier is used to uniquely identify the first - end UE set, and the end - UE set identifier is generated by the end UE or the PCF network element according to the first - end UE set.

[0193] As an alternative implementation, the device further includes:

[0194] A third sending unit, configured to send a registration request message to an access and mobility management function (AMF) network element; where the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the first - end UE set and / or a multi - hop relay identifier, and the multi - hop relay identifier is used to represent that the end UE supports the discovery function of the multi - hop relay UE;

[0195] A second receiving unit, configured to receive a non - access stratum (NAS) message sent by a PCF network element through the AMF network element; where the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter at least includes the user information identifier of the end UE, the end - UE set identifier, and / or the hop - count identifier.

[0196] In an eleventh aspect, a discovery device for a relay user equipment (UE) is provided. The device is applied to an access and mobility management function (AMF) network element, and the device includes:

[0197] A first receiving unit, configured to receive a registration request message sent by a UE;

[0198] A first sending unit, configured to send a first non - access stratum (NAS) message to a policy control function (PCF) network element;

[0199] A second receiving unit, configured to receive a second NAS message sent by the PCF network element;

[0200] A second sending unit, configured to send a third NAS message to the UE;

[0201] Wherein, the registration request message carries at least proximity service capability parameters, and the proximity service capability parameters include an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the UE supports the discovery function of multi-hop relay UEs;

[0202] The first NAS message carries at least the proximity service capability parameters;

[0203] The second NAS message carries at least proximity service policy parameters, and the proximity service policy parameters include a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier;

[0204] The third NAS message carries the proximity service policy parameters.

[0205] In a twelfth aspect, a discovery device for a relay user equipment (UE) is provided. The device is applied to a policy control function (PCF) network element, and the device includes:

[0206] A receiving unit, configured to receive a first non-access stratum (NAS) message sent by an access and mobility management function (AMF) network element;

[0207] A sending unit, configured to send a second NAS message to the AMF network element;

[0208] Wherein, the first NAS message carries at least proximity service capability parameters, and the proximity service capability parameters include an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the UE supports the discovery function of multi-hop relay UEs;

[0209] The second NAS message carries at least proximity service policy parameters, and the proximity service policy parameters include a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier, and the end UE set identifier is generated based on the end UE set.

[0210] In a thirteenth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the first aspect or the second aspect or the third aspect or the fourth aspect are implemented.

[0211] In a fourteenth aspect, a communication system is provided. The communication system includes a relay user equipment (UE), an end UE, a mobility management function (AMF) network element, and a policy control function (PCF) network element. The relay UE executes the steps of the method described in the first aspect, the end UE executes the steps of the method described in the second aspect, the AMF network element executes the steps of the method described in the third aspect, and the PCF network element executes the steps of the method described in the fourth aspect.

[0212] This application provides a method, apparatus, and storage medium for discovering a relay user equipment (UE). The technical solutions provided by the embodiments of this application at least bring the following beneficial effects: The embodiments of this application can implement a multi-hop relay UE discovery process in Model B mode initiated by the end UE and a multi-hop relay UE discovery process in Model A mode initiated by the relay UE.

[0213] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0214] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0215] Figure 1 An architecture diagram of an existing one-hop ProSe scenario provided for an embodiment of this application;

[0216] Figure 2 A signaling diagram of an existing relay UE discovery process provided for an embodiment of this application;

[0217] Figure 3 Another signaling diagram of an existing relay UE discovery process provided for an embodiment of this application;

[0218] Figure 4 An architecture diagram of a multi-hop ProSe scenario provided for an embodiment of this application;

[0219] Figure 5 A flowchart of a method for discovering a relay UE provided for an embodiment of this application;

[0220] Figure 6 An architecture diagram of a multi-hop ProSe scenario provided for an embodiment of this application;

[0221] Figure 7 A flowchart of a method for discovering a relay UE provided for an embodiment of this application;

[0222] Figure 8 Flow chart of a method for discovering a relay UE provided by an embodiment of the present application;

[0223] Figure 9 Flow chart of a method for discovering a relay UE provided by an embodiment of the present application;

[0224] Figure 10 Flow chart of a method for discovering a relay UE provided by an embodiment of the present application;

[0225] Figure 11 Flow chart of the first example of a method for discovering a relay UE provided by an embodiment of the present application;

[0226] Figure 12 Flow chart of the second example of a method for discovering a relay UE provided by an embodiment of the present application;

[0227] Figure 13 Flow chart of a method for discovering a relay UE provided by an embodiment of the present application;

[0228] Figure 14 Flow chart of a method for discovering a relay UE provided by an embodiment of the present application;

[0229] Figure 15 Flow chart of a method for discovering a relay UE provided by an embodiment of the present application;

[0230] Figure 16 Flow chart of a method for discovering a relay UE provided by an embodiment of the present application;

[0231] Figure 17 Flow chart of the third example of a method for discovering a relay UE provided by an embodiment of the present application;

[0232] Figure 18 Schematic structural diagram of a relay UE provided by an embodiment of the present application;

[0233] Figure 19 Schematic structural diagram of an end UE provided by an embodiment of the present application;

[0234] Figure 20 Schematic structural diagram of an AMF network element provided by an embodiment of the present application;

[0235] Figure 21 Schematic structural diagram of a PCF network element provided by an embodiment of the present application;

[0236] Figure 22 Schematic structural diagram of a discovery device for a relay UE provided by an embodiment of the present application;

[0237] Figure 23 Structural schematic diagram of a discovery device for a relay UE provided by an embodiment of the present application;

[0238] Figure 24 Structural schematic diagram of a discovery device for a relay UE provided by an embodiment of the present application;

[0239] Figure 25 Structural schematic diagram of a discovery device for a relay UE provided by an embodiment of the present application. Detailed implementation manners

[0240] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0241] In the embodiments of the present application, the term "and / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. In the embodiments of the present application, the term "plurality" refers to two or more, and other quantifiers are similar thereto.

[0242] Figure 1 An architecture diagram of an existing one-hop ProSe scenario provided by an embodiment of the present application. As Figure 1 shown, in the existing ProSe scenario, it includes end UE1, relay UE, and end UE2. In the existing ProSe scenario, only communication between end UE1 and end UE2 through a one-hop relay UE is supported.

[0243] The relay UE discovery process defined in the R18 standard in the existing 3GPP protocol supports two modes, specifically as follows.

[0244] (1) Mode A, as Figure 2 shown, the specific steps are as follows.

[0245] Step 201, during the relay UE discovery process and / or the UE communication process, the relay UE obtains the set of end UEs {User Info ID (user information identifier) of end UE1, User Info ID of end UE2}. Among them, this set of end UEs is an encrypted set, and only end UE1 and end UE2 can parse it, and the relay UE cannot parse it.

[0246] Step 202, the relay UE sends a Discovered Announcement message. The Discovered Announcement message contains parameters such as the set of end UEs {User Info ID of end UE1, User Info ID of end UE2}, the User Info ID of the relay UE, and the RSC (Relay Service Code). The RSC is used to characterize the services supported by the relay UE.

[0247] (2) Mode B, as Figure 3 shown, the specific steps are as follows.

[0248] Step 301, end UE1 sends a Discovered Solicitation message. The Discovered Solicitation message contains parameters such as the set of end UEs {User Info ID of end UE1, User Info ID of end UE2} and the RSC.

[0249] Step 302, if the RSC stored locally in the relay UE matches the RSC carried in the Discovered Solicitation message, the relay UE forwards the Discovered Solicitation message. The Discovered Solicitation message contains parameters such as the set of end UEs {User Info ID of end UE1, User Info ID of end UE2}, the User Info ID of the relay UE, and the RSC.

[0250] Step 302, if the RSC stored locally in end UE2 matches the RSC carried in the Discovered Solicitation message and the User Info ID of end UE2 matches the User Info ID of end UE2 in the set of end UEs carried in the Discovered Solicitation message, end UE2 sends a Discovered Response message to the relay UE. The Discovered Response message contains parameters such as the set of end UEs {User Info ID of end UE1, User Info ID of end UE2} and the RSC.

[0251] Step 303, if the RSC stored locally in the relay UE matches the RSC carried in the Discovered Response message, the relay UE sends a Discovered Response message to end UE1. The Discovered Response message contains parameters such as the set of end UEs {User Info ID of end UE1, User Info ID of end UE2}, the User Info ID of the relay UE, and the RSC.

[0252] In the existing ProSe scenario, the source UE (i.e., UE1 in the set of UE) can communicate with the destination UE (i.e., UE2 in the set of UE) through the relay UE, which can extend the communication range and save the UE power. It is an important communication form in public safety and commercial applications. In some scenarios, such as in the basement or forest, the source UE often cannot communicate with the destination UE through a one-hop relay UE. At this time, the source UE often needs to communicate with the destination UE through a multi-hop relay UE. The R18 standard has studied and standardized the discovery process of the UE through a one-hop relay UE, but how the UE discovers through a multi-hop relay UE is an unsolved problem in the R18 standard.

[0253] Figure 4 The architecture diagram of a multi-hop ProSe scenario provided by the embodiment of the present application is as Figure 4 shown. For Mode B of the existing ProSe scenario, in the ProSe scenario of the present application, it includes UE1, relay UE1, relay UE2, relay UE3, and UE2. In the ProSe scenario of the present application, UE1 and UE2 communicate through a multi-hop relay UE. The embodiment of the present application takes the 2-hop relay UE discovery process as an example for illustration, but the embodiment of the present application is applicable to the n (n>=2)-hop relay UE discovery process.

[0254] For Mode B of the existing ProSe scenario, the embodiment of the present application provides a method for discovering a relay UE. The method for discovering the relay UE is executed by the UE, and the UE can be Figure 4 UE1 and UE2 in Figure 5 shown. The specific steps are as follows:

[0255] Step 501, send a first discovery request message. Among them, the first discovery request message carries at least one or more of the following parameters: the first set of UEs, the first set of UEs includes the user information identifier of the source UE and the user information identifier of the destination UE, and the UE is the source UE in the first set of UEs; the first set of relay UEs; the relay forwarding identifier, and the relay forwarding identifier is used to indicate whether the first set of UEs allows the relay UE to forward.

[0256] In implementation, in combination with Figure 4 , when the UE is the source UE (i.e., Figure 4In the case of the terminal UE1), the terminal UE sends a first discovery request message in a broadcast manner. The first discovery request message carries at least one or more of a first set of terminal UEs, a first set of relay UEs, and a relay forwarding indication. Among them, the first set of terminal UEs includes the user information identifier of the source terminal UE and the user information identifier of the destination terminal UE, such as {User Info ID of terminal UE1, User Info ID of terminal UE2}; since the terminal UE is the source terminal UE, the first set of relay UEs is empty at this time; the relay forwarding indication is used to indicate whether the relay UE is allowed to forward the first set of terminal UEs, that is, to indicate whether the first set of terminal UEs supports the multi-hop relay UE discovery function. Optionally, the first discovery request message also carries at least an RSC.

[0257] As an optional implementation manner, in order to limit the scope of relay UE discovery, the first discovery request message also carries at least a hop indication. Among them, the hop indication is used to indicate the number of times the relay UE is allowed to forward the first set of terminal UEs, and the hop indication is determined by the terminal UE or a PCF (Policy Control Function) network element.

[0258] In implementation, in order to limit the scope of relay UE discovery, the first discovery request message also carries at least a hop indication (hop indication). The hop indication is used to indicate the number of times the relay UE is allowed to forward the first set of terminal UEs. The hop indication is determined by the terminal UE or the PCF network element. Each time the first discovery request message is forwarded, the relay UE subtracts 1 from the hop indication until the hop indication is reduced to 0, and then stops forwarding the first discovery request message. Among them, the process of the relay UE restricting the scope of relay UE discovery based on the hop indication carried in the discovery request message will be introduced in detail later, and will not be elaborated here.

[0259] As an optional implementation manner, in order to solve the problem of discovery request message flooding, the first discovery request message also carries at least a terminal UE set identifier. Among them, the terminal UE set identifier is used to uniquely identify the first set of terminal UEs, and the terminal UE set identifier is generated by the terminal UE or the PCF network element according to the first set of terminal UEs.

[0260] In implementation, during the multi-hop relay discovery process, since the relay UE can forward the first discovery request message in a broadcast manner, there is a flooding problem with the first discovery request message. To solve the flooding problem of the discovery request message, the first discovery request message further carries at least a set indication of the terminal UE. The set indication of the terminal UE is used to uniquely identify the first set of terminal UEs. To uniquely identify the first set of terminal UEs, the set indication of the terminal UE is generated by the terminal UE or the PCF network element according to the first set of terminal UEs. In this way, the set indications of the terminal UEs carried in different discovery request messages are different, thus while solving the flooding problem of the discovery request message, preventing the discovery request message from being discarded incorrectly. Among them, the processing procedure for the relay UE to solve the flooding problem of the discovery request message based on the set indication of the terminal UE carried in the discovery request message will be introduced in detail later and will not be elaborated here.

[0261] It should be noted that the relay forwarding identifier and the hop count identifier can be implemented through a relay indication. When the first discovery request message carries a relay indication, it means that the first discovery request message allows the relay UE to forward. At the same time, each time the first discovery request message is forwarded, the relay UE decrements the value of the relay indication by 1 until the value of the relay indication is decremented to 0 and no longer forwards the first discovery request message. Among them, the relay indication is determined by the terminal UE or the PCF network element.

[0262] Figure 6 The architecture diagram of a multi-hop ProSe scenario provided for the embodiments of this application is as Figure 6 shown. For the existing Mode A of the ProSe scenario, in the ProSe scenario of this application, it includes relay UE1, relay UE2, relay UE3, relay UE4, relay UE5, terminal UE1, and terminal UE2. The embodiments of this application take the 4-hop relay UE discovery process as an example for illustration, but the embodiments of this application are applicable to the n (n >= 2)-hop relay UE discovery process.

[0263] For the existing Mode A of the ProSe scenario, the embodiments of this application provide a method for discovering a relay UE. The method for discovering the relay UE is executed by a first relay UE, and the first relay UE can be Figure 6 the relay UE1, relay UE2, relay UE3, relay UE4, and relay UE5 among them. As Figure 7 shown, the specific steps are as follows:

[0264] Step 701, send a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters: an end UE set, which is the end UE set obtained by the first relay UE during the relay UE discovery process and / or the UE communication process; a third relay UE set, which at least includes the user information identifiers of the relay UEs through which the source end UE in the end UE set reaches the first relay UE; a relay forwarding identifier, which is used to indicate whether the end UE set allows the relay UE to perform forwarding.

[0265] In implementation, as shown in Figure 6 when the first relay UE is the relay UE1 in Figure 6 , the first relay UE can send the discovery announcement message by broadcasting. The discovery announcement message carries the end UE set, the third relay UE set, and the relay forwarding identifier. Among them, the end UE set is the end UE set obtained by the first relay UE during the relay UE discovery process and / or the UE communication process, such as {User Info ID of end UE1, User Info ID of end UE2}; the third relay UE set at least includes the user info IDs of the relay UEs through which the source end UE in the end UE set reaches the first relay UE, such as the third relay UE set is {User Info ID of relay UE5, User Info ID of relay UE1}; the relay forwarding identifier is used to indicate whether the end UE set allows the relay UE to perform forwarding. Optionally, the discovery announcement message also carries at least the RSC.

[0266] As an optional implementation manner, in order to limit the scope of relay UE discovery, the discovery announcement message also carries at least a hop count identifier, which is used to indicate the number of times the end UE set allows the relay UE to forward. The hop count identifier is determined according to the initial hop count identifier and the hop count corresponding to the source end UE in the end UE set reaching the first relay UE, and the initial hop count identifier is determined by the first relay UE or the PCF network element.

[0267] In implementation, in order to limit the scope of relay UE discovery, the discovery announcement message also carries at least a hop count identifier. The hop count identifier is used to indicate the number of times the end UE set allows the relay UE to forward. The hop count identifier is obtained by subtracting the hop count corresponding to the source end UE in the end UE set reaching the first relay UE from the initial hop count, and the initial hop count is determined by the first relay UE or the PCF network element. For example, as shown in Figure 6, the initial hop count is 4. The relay UE1 reaches the destination UE1 via the relay UE5, and the hop count is 1, so the hop count identifier is 3. It is found that each time the discovery announcement message is forwarded, the relay UE decreases the hop count identifier by 1 until the hop count identifier is decreased to 0 and the discovery announcement message is no longer forwarded. Among them, the process of the relay UE restricting the discovery scope based on the hop count identifier carried in the discovery announcement message will be introduced in detail later and will not be elaborated here.

[0268] It should be noted that the relay forwarding identifier and the hop count identifier can be implemented through a relay indication. When the discovery announcement message carries a relay indication, it means that the discovery announcement message allows the relay UE to forward. At the same time, each time the discovery announcement message is forwarded, the relay UE decreases the value of the relay indication by 1 until the value of the relay indication is decreased to 0 and the discovery announcement message is no longer forwarded. Among them, the relay indication is determined by the relay UE or the PCF network element.

[0269] As an optional implementation manner, to solve the problem of discovery announcement message flooding, the discovery announcement message also carries at least a destination UE set identifier. Among them, the destination UE set identifier is used to uniquely identify the destination UE set, and the destination UE set identifier is generated by the first relay UE or the PCF network element according to the destination UE set.

[0270] In implementation, during the multi-hop relay discovery process, since the relay UE can forward the discovery announcement message by broadcasting, there is a problem of discovery announcement message flooding. To solve the problem of discovery announcement message flooding, the discovery announcement message also carries at least a destination UE set identifier. The destination UE set identifier is used to uniquely identify the destination UE set. To uniquely identify the destination UE set, the destination UE set identifier is generated by the first relay UE or the PCF network element according to the destination UE set. In this way, the destination UE set identifiers carried in different discovery announcement messages are different, so as to solve the problem of discovery announcement message flooding and prevent the discovery announcement message from being incorrectly discarded. Among them, the process of the relay UE solving the problem of discovery announcement message flooding based on the destination UE set identifier carried in the discovery announcement message will be introduced in detail later and will not be elaborated here.

[0271] For the existing Mode A and Mode B of the ProSe scenario, the embodiments of the present application provide a method for discovering a relay UE. The method for discovering the relay UE is executed by the first relay UE, and the first relay UE can be Figure 4 the relay UE1, relay UE2, and relay UE3 among them, or can be Figure 6 the relay UE2, relay UE3, relay UE4, and relay UE5 among them. As shown in Figure 8 , the specific steps are as follows:

[0272] Step 801: Receive a discovery message. The discovery message carries at least one or more of the following parameters: a set of end UEs, which includes the user information identifiers of the source end UE and the destination end UE; a first set of relay UEs, which includes the user information identifiers of the relay UEs passed by from the source end UE to the first relay UE during the relay UE discovery process; a relay forwarding identifier, which is used to indicate whether the set of end UEs allows the relay UE to perform forwarding.

[0273] In implementation, the first relay UE receives the discovery message. The discovery message carries at least one or more of the following parameters: a set of end UEs, a first set of relay UEs, and a relay forwarding identifier. Among them, the set of end UEs includes the user information identifiers of the source end UE and the destination end UE; the first set of relay UEs includes the user information identifiers of the relay UEs passed by from the source end UE to the first relay UE during the relay UE discovery process; the relay forwarding identifier is used to indicate whether the set of end UEs allows the relay UE to perform forwarding. Optionally, the discovery message also carries at least the RSC.

[0274] As an optional implementation manner, the discovery messages received by the first relay UE are different when the discovery modes (i.e., Mode A and Mode B) in which the first relay UE is located are different. Specifically, it is divided into two cases as follows:

[0275] Case 1: When the first relay UE is in the first discovery mode (Mode A), receive the discovery announcement message sent by other relay UEs.

[0276] In implementation, as shown in Figure 6 When the first relay UE is Relay UE2, Relay UE3, Relay UE4, and Relay UE5 in Figure 6 , the first relay UE can receive the discovery announcement message sent by other relay UEs. Among them, the set of end UEs in the discovery announcement message is {User Info ID of End UE1, User Info ID of End UE2}; when the first relay UE is Relay UE2 in Figure 6 , the first set of relay UEs is {User Info ID of Relay UE5, User InfoID of Relay UE1}. When the first relay UE is Relay UE3 or Relay UE4 in Figure 6 , the first set of relay UEs is {User Info ID of Relay UE5, User Info ID of Relay UE1, User Info ID of Relay UE2}.

[0277] Case 2: When the first relay UE is in the second discovery mode (Mode B), it receives a discovery request message sent by the source UE or other relay UEs.

[0278] In implementation, combined with Figure 4 , the discovery request message received by the first relay UE can be sent by the source UE (for example, the discovery request messages received by relay UE1 and relay UE2 are sent by source UE1). At this time, the source UE set in the discovery request message is {User Info ID of source UE1, User Info ID of source UE2}; the first relay UE set is empty. The discovery request message received by the first relay UE can also be forwarded by a relay UE (for example, the discovery request message received by relay UE3 is forwarded by relay UE1 and relay UE2). The source UE set in the discovery request message is {User Info ID of source UE1, User Info ID of source UE2}; in the discovery request message received by relay UE3 that is forwarded by relay UE1, the first relay UE set is {User Info ID of relay UE1}. Similarly, in the discovery request message received by relay UE3 that is forwarded by relay UE2, the first relay UE set is {User Info ID of relay UE2}.

[0279] Step 802: If the relay forwarding flag indicates that the source UE set allows the relay UE to forward, add the user information identifier of the first relay UE to the first relay UE set.

[0280] In implementation, the first relay UE determines whether the relay forwarding flag indicates that the source UE set allows the relay UE to forward. If the relay forwarding flag indicates that the source UE set allows the relay UE to forward, the first relay UE adds its user info ID to the first relay UE set.

[0281] For example, combined with Figure 4 , when relay UE3 receives the discovery request message forwarded by relay UE1, the first relay UE set after adding the user info ID of the first relay UE is {User Info ID of relay UE1, User Info ID of relay UE3}. Similarly, when relay UE3 receives the discovery request message forwarded by relay UE2, the first relay UE set after adding the user info ID of the first relay UE is {User Info ID of relay UE2, User Info ID of relay UE3}.

[0282] Another example, combined with Figure 6 , when the first relay UE is Figure 6In the case of the relay UE2, the first relay UE set after adding the user info ID of the first relay UE is {User Info ID of relay UE5, User Info ID of relay UE1, User Info ID of relay UE2}. When the first relay UE is Figure 6 In the case of relay UE3 or relay UE4 in it, the first relay UE set after adding the user info ID of the first relay UE is {User Info ID of relay UE5, User Info ID of relay UE1, User Info ID of relay UE2, User Info ID of relay UE3 or User Info ID of relay UE4}.

[0283] If the relay forwarding flag indicates that the end UE set does not allow the relay UE to forward, it means that this discovery message only supports the one-hop relay UE discovery function. The specific processing process is the prior art and will not be elaborated here.

[0284] It should be noted that when the discovery message also carries at least the RSC, the first relay UE can also determine whether the RSC is the same as the RSC configured by the first relay UE. If the RSC is not the same as the RSC configured by the first relay UE, the discovery message is discarded. If the RSC is the same as the RSC configured by the first relay UE, it is further determined whether the relay forwarding flag indicates that the end UE set allows the relay UE to forward.

[0285] Step 803, forward the discovery message after adding the user information identifier of the first relay UE.

[0286] In implementation, after adding the user info ID of the first relay UE to the first relay UE set, the first relay UE can continue to forward the discovery message after adding the user information identifier of the first relay UE by means of broadcasting.

[0287] As an optional implementation manner, in order to limit the scope of relay UE discovery, the discovery message also carries at least a hop count identifier. Among them, the hop count identifier is used to indicate the number of times the end UE set allows the relay UE to forward. Correspondingly, before adding the user information identifier of the first relay UE to the first relay UE set, the first relay UE can also perform the following operations: if the hop count identifier is not 0, subtract 1 from the hop count identifier and perform the step of adding the user information identifier of the first relay UE to the first relay UE set; if the hop count identifier is 0, discard the discovery message.

[0288] In implementation, in order to limit the discovery range of relay UEs, the discovery message also carries at least a hop count identifier. The first relay UE can determine whether the hop count identifier is 0. If the hop count identifier is 0, it indicates that the forwarding of the discovery message has reached the maximum hop count, and the first relay UE discards the discovery message. If the hop count identifier is not 0, the first relay UE decrements the hop count identifier by 1, adds the user info ID of the first relay UE to the first relay UE set, and forwards the discovery message. In this way, by carrying the hop count in the discovery message, the discovery range of relay UEs is limited.

[0289] It should be noted that the relay forwarding identifier and the hop count identifier can also be implemented through a relay identifier. Correspondingly, the first relay UE can determine whether the value of the relay identifier is 0. If the value of the relay identifier is 0, the first relay UE discards the discovery message. If the value of the relay identifier is not 0, the first relay UE decrements the value of the relay identifier by 1, adds the user info ID of the first relay UE to the first relay UE set, and forwards the discovery message.

[0290] As an optional implementation manner, to solve the problem of discovery message flooding, the discovery message also carries at least an end UE set identifier. Among them, the end UE set identifier is used to uniquely identify the end UE set. Correspondingly, before adding the user information identifier of the first relay UE to the first relay UE set, the first relay UE can also perform the following operations: If the first relay UE has not forwarded the end UE set corresponding to the end UE set identifier, store the end UE set identifier locally and perform the step of adding the user information identifier of the first relay UE to the first relay UE set; if the first relay UE has forwarded the end UE set corresponding to the end UE set identifier, discard the discovery message.

[0291] In implementation, during the multi-hop relay discovery process, since the relay UE can forward the discovery message by broadcasting, there is a problem of discovery message flooding. For example, combined with Figure 4 , after receiving the discovery request message, relay UE1, relay UE2, and relay UE3 can continue to forward the discovery request message to each other by broadcasting, and so on, causing serious flooding and duplicate forwarding problems.

[0292] To solve the problem of discovery message flooding, the discovery message also carries at least the set identifier of the end UEs. The first relay UE can determine whether it has forwarded the set of end UEs corresponding to the set identifier of the end UEs. If the first relay UE has forwarded the set of end UEs corresponding to the set identifier of the end UEs, it indicates that the discovery message is a repeatedly forwarded discovery message, and the first relay UE discards the discovery message. If the first relay UE has not forwarded the set of end UEs corresponding to the set identifier of the end UEs, the first relay UE stores the set identifier of the end UEs locally, adds the user info ID of the first relay UE to the first relay UE set, and forwards the discovery message. In this way, by carrying the set identifier of the end UEs in the discovery message, the problem of discovery message flooding is solved.

[0293] In addition, when the discovery message carries both the set identifier of the end UEs and the hop count identifier, if the first relay UE receives multiple discovery messages carrying the same set identifier of the end UEs at the same time, the first relay UE forwards the discovery message with the largest hop count identifier.

[0294] As an optional implementation manner, for the existing Mode B of the ProSe scenario, as Figure 9 shown, the end UE also performs the following steps.

[0295] Step 901: Receive a second discovery request message sent by the relay UE. Among them, the second discovery request message carries at least one or more of the following parameters: the second set of end UEs, the second set of end UEs includes the user information identifier of the source end UE and the user information identifier of the destination end UE, and the end UE is the destination end UE in the second set of end UEs; the second set of relay UEs, the second set of relay UEs includes at least the user information identifiers of the relay UEs passed by from the source end UE to the destination end UE in the second set of end UEs.

[0296] In implementation, combined with Figure 4 In the case where the end UE is the destination end UE (i.e., the end UE2 in Figure 4 ), the end UE can receive the relay UE (i.e., Figure 4The second discovery request message sent by the relay UE3 in []. The second discovery request message carries at least one or more of the following parameters: the second set of end UEs and the second set of relay UEs. Among them, the second set of end UEs includes the user information identifier of the source end UE and the user information identifier of the destination end UE, such as {User Info ID of end UE1, User Info ID of end UE2} (since the end UE is introduced as both end UE1 and end UE2 in the embodiments of the present application, the second set of end UEs is the same as the above first set of end UEs at this time); the second set of relay UEs includes at least the user information identifier of the relay UE passed by from the source end UE to the destination end UE in the second set of end UEs, such as {User Info ID of relay UE1 or User Info ID of relay UE2, User Info ID of relay UE3}. Optionally, the second discovery request message also carries at least the RSC.

[0297] It should be noted that when the set identifier of the end UE is carried in the discovery request message, after the relay UE3 receives the discovery request messages forwarded by the relay UE1 and the relay UE2, it will only forward the discovery request message forwarded by one of the two relay UEs. Therefore, the second set of relay UEs in the discovery request message received by the end UE2 is {User Info ID of relay UE1 or User Info ID of relay UE2, User Info ID of relay UE3}.

[0298] Step 902, if the destination end UE in the second set of end UEs includes the end UE, send a discovery response message to the relay UE. Among them, the discovery response message carries at least the second set of end UEs and the second set of relay UEs.

[0299] In implementation, if the destination end UE in the second set of end UEs includes the end UE, the end UE sends a discovery response message to the relay UE (i.e., Figure 4 the relay UE3 in []) in a unicast manner. Among them, the discovery response message carries at least the second set of end UEs {User Info ID of end UE1, User Info ID of end UE2} and the second set of relay UEs {User Info ID of relay UE1 or User Info ID of relay UE2, User Info ID of relay UE3}. Optionally, the discovery response message also carries at least the RSC.

[0300] It should be noted that when the second discovery request message carries at least the RSC, the terminal UE can also determine whether the RSC is the same as the RSC configured by the terminal UE. If the RSC is different from the RSC configured by the terminal UE, the second discovery request message is discarded. If the RSC is the same as the RSC configured by the terminal UE, it is further determined whether the destination UE in the second terminal UE set includes the terminal UE.

[0301] As an optional implementation manner, for Mode B of the existing ProSe scenario, as Figure 10 shown, the first relay UE further performs the following steps.

[0302] Step 1001: Receive a discovery response message sent by the destination UE or the second relay UE. The discovery response message carries at least one or more of the following parameters: the terminal UE set; the second relay UE set, where the second relay UE set includes the user information identifier of the relay UE and the layer 2 identifier of the relay UE passed by from the source terminal UE to the destination terminal UE during the relay UE discovery process. The layer 2 identifier is used for the subsequent connection establishment process, and the second relay UE is the relay UE after the first relay UE in the second relay UE set.

[0303] In implementation, in combination with Figure 4 , the first relay UE receives the discovery response message. The discovery response message can be sent by the terminal UE or the second relay UE, and the second relay UE is the relay UE after the first relay UE in the second relay UE set. For example, when the first relay UE is relay UE3, the first relay UE receives the discovery response message sent by terminal UE2. When the first relay UE is relay UE1 or relay UE2, the first relay UE receives the discovery response message sent by relay UE3.

[0304] The discovery response message carries at least one or more of the following parameters: the terminal UE set, the second relay UE set, and the layer 2 identifier of the relay UE. The terminal UE set is {User Info ID of terminal UE1, User Info ID of terminal UE2}; the second relay UE set includes the user information identifiers of the relay UEs passed by from the source terminal UE to the destination terminal UE during the relay UE discovery process, and the second relay UE set is {User Info ID of relay UE1 or User Info ID of relay UE2, User Info ID of relay UE3}; the layer 2 identifier is used for the subsequent connection establishment process. Optionally, the discovery response message also carries at least the RSC.

[0305] Step 1002: Send a discovery response message to the source UE or the third relay UE. Here, the third relay UE is the previous relay UE of the first relay UE in the set of relay UEs.

[0306] In implementation, in combination with Figure 4 , the first relay UE sends a discovery response message to the source UE or the third relay UE in a unicast manner. The third relay UE is the previous relay UE of the first relay UE in the second set of relay UEs. For example, when the first relay UE is relay UE3, the first relay UE sends a discovery response message to relay UE1 or relay UE2. When the first relay UE is relay UE1 or relay UE2, the first relay UE sends a discovery response message to source UE1.

[0307] It should be noted that when at least the RSC is also carried in the discovery response message, the first relay UE can also determine whether the RSC is the same as the RSC configured by the first relay UE. If the RSC is not the same as the RSC configured by the first relay UE, the discovery message is discarded. If the RSC is the same as the RSC configured by the first relay UE, the first relay UE further sends a discovery response message to the source UE or the third relay UE.

[0308] Figure 11 This is a flowchart of Example 1 of a discovery method for a relay UE provided by an embodiment of the present application.

[0309] In combination with Figure 4 , as Figure 11 shown, the specific steps are as follows:

[0310] Step 1101: The source UE1 sends a discovery request message in a broadcast manner. The discovery request message carries the source UE set as {User Info ID of source UE1, User Info ID of source UE2}, the relay UE set is empty, RSC, relay forwarding identifier, hop count identifier is 3, and source UE set identifier is 1 - 2.

[0311] Step 1102: The relay UE1 forwards the discovery request message in a broadcast manner. The discovery request message carries the source UE set as {User Info ID of source UE1, User Info ID of source UE2}, the relay UE set as {User Info ID of relay UE1}, RSC, relay forwarding identifier, hop count identifier is 2, and source UE set identifier is 1 - 2.

[0312] Step 1103, Relay UE2 forwards the discovery request message in a broadcast manner. Among them, the discovery request message carries the set of terminal UEs as {User Info ID of terminal UE1, User Info ID of terminal UE2}, the set of relay UEs as {User Info ID of relay UE2}, RSC, relay forwarding identifier, hop count identifier as 2, and terminal UE set identifier as 1-2.

[0313] Step 1104, Relay UE3 forwards the discovery request message sent by Relay UE1 in a broadcast manner. Among them, the discovery request message carries the set of terminal UEs as {User Info ID of terminal UE1, User Info ID of terminal UE2}, the set of relay UEs as {User Info ID of relay UE1, User Info ID of relay UE3}, RSC, relay forwarding identifier, hop count identifier as 1, and terminal UE set identifier as 1-2.

[0314] Step 1105, Terminal UE2 sends a discovery response message to Relay UE3. Among them, the discovery response message carries the set of terminal UEs as {User Info ID of terminal UE1, User Info ID of terminal UE2}, the set of relay UEs as {User Info ID of relay UE1, User Info ID of relay UE3}, and RSC.

[0315] Step 1106, Relay UE3 sends a discovery response message to Relay UE1. Among them, the discovery response message carries the set of terminal UEs as {User Info ID of terminal UE1, User Info ID of terminal UE2}, the set of relay UEs as {User Info ID of relay UE1, User Info ID of relay UE3}, and RSC.

[0316] Step 1107, Relay UE1 sends a discovery response message to Terminal UE1. Among them, the discovery response message carries the set of terminal UEs as {User Info ID of terminal UE1, User Info ID of terminal UE2}, the set of relay UEs as {User Info ID of relay UE1, User Info ID of relay UE3}, and RSC.

[0317] Figure 12 This is the flowchart of Example 2 of a discovery method for a relay UE provided by an embodiment of the present application.

[0318] Combined Figure 6 , as Figure 12 shown, the specific steps are as follows:

[0319] Step 1201, the relay UE1 sends a discovery announcement message in a broadcast manner. Among them, the discovery announcement message carries an end UE set {User Info ID of end UE1, User Info ID of end UE2}, a relay UE set {User Info ID of relay UE5, User Info ID of relay UE1}, RSC, a relay forwarding identifier, a hop count identifier of 3, and an end UE set identifier of 1-2.

[0320] Step 1202, the relay UE2 forwards the discovery announcement message in a broadcast manner. Among them, the discovery announcement message carries an end UE set {User Info ID of end UE1, User Info ID of end UE2}, a relay UE set {User Info ID of relay UE5, User Info ID of relay UE1, User Info ID of relay UE2}, RSC, a relay forwarding identifier, a hop count identifier of 2, and an end UE set identifier of 1-2.

[0321] Step 1203, the relay UE3 and the relay UE4 forward the discovery announcement message in a broadcast manner. Among them, the discovery announcement message carries an end UE set {User Info ID of end UE1, User Info ID of end UE2}, a relay UE set {User Info ID of relay UE5, User Info ID of relay UE1, User Info ID of relay UE2, User Info ID of relay UE3 or relay UE4}, RSC, a relay forwarding identifier, a hop count identifier of 1, and an end UE set identifier of 1-2.

[0322] As an optional implementation manner, for the existing Mode B of the ProSe scenario, as Figure 13 shown, the end UE can also obtain the parameters related to the relay UE discovery process from the PCF network element through the AMF (Access and Mobility Management Function) network element. The specific processing steps are as follows:

[0323] Step 1301, send a registration request message to the AMF network element. Among them, the registration request message carries at least adjacent service capability parameters, and the adjacent service capability parameters include a first end UE set and / or a multi-hop relay identifier; the multi-hop relay identifier is used to represent that the end UE supports the discovery function of multi-hop relay UEs.

[0324] In implementation, the terminal UE may send a Registration Request message to the AMF network element. Among them, the registration request message carries at least a ProSe capability parameter. The ProSe capability parameter includes a first set of terminal UEs and / or a multi-hop relay identifier. The multi-hop relay identifier is used to characterize that the terminal UE supports the discovery function of the multi-hop relay UE (End UE with multi-hop support).

[0325] Step 1302, receive the NAS message sent by the PCF network element through the AMF network element. Among them, the NAS message carries at least a ProSe policy parameter, and the ProSe policy parameter at least includes the user information identifier of the terminal UE, the first RSC, the terminal UE set identifier, and / or the hop count identifier.

[0326] In implementation, the terminal UE receives the NAS (Non-Access Stratum) message sent by the PCF network element through the AMF network element. Among them, the NAS message carries at least a ProSe Policy parameter. The ProSe policy parameter includes the user info ID of the terminal UE, the first RSC, the terminal UE set identifier, and / or the hop count identifier. Optionally, after receiving the ProSe policy parameter sent by the AMF network element, the terminal UE may send a NAS message carrying the ProSe policy transfer result to the AMF network element.

[0327] As an optional implementation manner, for the existing Mode A of the ProSe scenario, such as Figure 14 shown, the first relay UE may also obtain the parameters related to the relay UE discovery process from the PCF network element through the AMF network element. The specific processing steps are as follows:

[0328] Step 1401, send a registration request message to the AMF network element. Among them, the registration request message carries at least a ProSe capability parameter, and the ProSe capability parameter includes a set of terminal UEs and / or a multi-hop relay identifier. The multi-hop relay identifier is used to characterize that the first relay UE supports the discovery function of the multi-hop relay UE.

[0329] In implementation, the first relay UE sends a registration request message to the AMF network element. Among them, the registration request message carries at least a ProSe capability parameter. The ProSe capability parameter includes a set of terminal UEs and / or a multi-hop relay identifier. The multi-hop relay identifier is used to characterize that the first relay UE supports the discovery function of the multi-hop relay UE (UE-to-UE Relay with multi-hop support).

[0330] Step 1402: Receive the NAS message sent by the PCF network element through the AMF network element. Among them, the NAS message carries at least neighboring service policy parameters, and the neighboring service policy parameters include the user information identifier of the first relay UE, the end UE set identifier, and / or the hop count identifier.

[0331] In implementation, the first relay UE receives the NAS message sent by the PCF network element through the AMF network element. Among them, the NAS message carries at least neighboring service policy parameters. The neighboring service policy parameters include the user info ID of the first relay UE, the end UE set identifier, and / or the initial hop count. Optionally, the neighboring service policy parameters also at least include the RSC. Optionally, after receiving the neighboring service policy parameters sent by the AMF network element, the first relay UE may send a NAS message carrying the neighboring service policy transfer result to the AMF network element.

[0332] As an optional implementation manner, for the existing Mode A and Mode B of the ProSe scenario, as Figure 15 shown, the processing procedure of the AMF network element is as follows:

[0333] Step 1501: Receive the registration request message sent by the UE. Among them, the registration request message carries at least neighboring service capability parameters, and the neighboring service capability parameters include the end UE set and / or the multi-hop relay identifier; the multi-hop relay identifier is used to indicate that the UE supports the discovery function of the multi-hop relay UE.

[0334] In implementation, the AMF network element receives the registration request message sent by the UE (including the end UE and the relay UE). Among them, the registration request message carries at least neighboring service capability parameters. The neighboring service capability parameters include the end UE set and / or the multi-hop relay identifier. The multi-hop relay identifier is used to indicate that the UE supports the discovery function of the multi-hop relay UE. Optionally, after receiving the registration request message sent by the UE, the AMF network element may send a Registration Accept message to the UE.

[0335] Step 1502: Send the first NAS message to the PCF network element. Among them, the first NAS message carries at least neighboring service capability parameters.

[0336] In implementation, the AMF network element sends the first NAS message (such as Npcf_UEPolicyControlCreate Request) to the PCF network element. Among them, the first NAS message carries at least neighboring service capability parameters.

[0337] Step 1503: Receive the second NAS message sent by the PCF network element. The second NAS message carries at least proximity service policy parameters, which include the user information identifier of the UE, the end-UE set identifier, and / or the hop count identifier.

[0338] In implementation, the AMF network element receives the second NAS message (such as Namf_Communication_N1N2MessageTransfer) sent by the PCF network element. The second NAS message carries at least proximity service policy parameters. The proximity service policy parameters include the user info ID of the UE, the end-UE set identifier, and / or the hop count. Optionally, the proximity service policy parameters also include at least the RSC.

[0339] Step 1504: Send a third NAS message to the UE. The third NAS message carries proximity service policy parameters.

[0340] In implementation, the AMF network element sends a third NAS message to the UE. The third NAS message carries at least proximity service policy parameters. Optionally, after receiving the proximity service policy parameters sent by the AMF network element, the UE may send a NAS message carrying the proximity service policy transfer result to the AMF network element. Correspondingly, the AMF network element may send a NAS message (such as Namf_N1MessageNotify) carrying the proximity service policy download result to the PCF network element.

[0341] As an optional implementation manner, for the existing Mode A and Mode B of the ProSe scenario, as Figure 16 shown, the processing procedure of the PCF network element is as follows:

[0342] Step 1601: Receive the first NAS message sent by the AMF network element. The first NAS message carries at least proximity service capability parameters. The proximity service capability parameters include the end-UE set and / or the multi-hop relay identifier. The multi-hop relay identifier is used to indicate that the UE supports the discovery function of multi-hop relay UEs.

[0343] In implementation, the PCF network element receives a first NAS message (such as Npcf_UEPolicyControlCreate Request) sent by the AMF network element. Among them, the first NAS message carries at least the neighboring service capability parameter, and the neighboring service capability parameter includes the set of end UEs and / or the multi-hop relay identifier. The multi-hop relay identifier is used to indicate that the UE supports the discovery function of multi-hop relay UEs. Optionally, after receiving the first NAS message sent by the AMF network element, the PCF network element may send a NAS message (such as Npcf_UEPolicyControl Create Response) to the AMF network element.

[0344] Step 1602: Send a second NAS message to the AMF network element. Among them, the second NAS message carries at least the neighboring service policy parameter, and the neighboring service policy parameter includes the user information identifier of the UE, the set identifier of the end UEs, and / or the hop count identifier; the set identifier of the end UEs is generated based on the set of end UEs.

[0345] In implementation, the PCF network element may generate the set identifier of the end UEs based on the set of end UEs, determine the user info ID and the hop count identifier of the UE. Then, the PCF network element sends a second NAS message (such as Namf_Communication_N1N2MessageTransfer) to the AMF network element. Among them, the second NAS message carries at least the neighboring service policy parameter, and the neighboring service policy parameter includes at least the user info ID of the UE, the set identifier of the end UEs, and the hop count identifier. This neighboring service policy parameter may be included in the User Equipment Policy Container (UE Policy Container). Optionally, the neighboring service policy parameter also carries at least the RSC.

[0346] Figure 17 This is the flowchart of Example 3 of a method for discovering relay UEs provided by an embodiment of this application.

[0347] As Figure 17 shown, the specific steps are as follows:

[0348] Step 1701: The UE sends a registration request message to the AMF network element. Among them, the registration request message carries at least the neighboring service capability parameter, and the neighboring service capability parameter includes the set of end UEs and / or the multi-hop relay identifier. The multi-hop relay identifier is used to indicate that the UE supports the discovery function of multi-hop relay UEs.

[0349] Step 1702: The AMF network element sends a registration acceptance message to the UE.

[0350] Step 1703: The AMF network element sends an Npcf_UEPolicyControl Create Request to the PCF network element. Among them, the Npcf_UEPolicyControl Create Request carries adjacent service capability parameters.

[0351] Step 1704: The PCF network element sends an Npcf_UEPolicyControl Create Response to the AMF network element.

[0352] Step 1705: The PCF network element sends a Namf_Communication_N1N2Messag eTransfer to the AMF network element. Among them, the Namf_Communication_N1N2MessageTransfer carries at least adjacent service policy parameters, and the adjacent service policy parameters at least include the user information identifier of the UE, the RSC, the set identifier of the end UEs, and the hop count identifier.

[0353] Step 1706: The AMF network element sends a NAS message to the UE. Among them, the NAS message carries adjacent service policy parameters.

[0354] Step 1707: The UE sends a NAS message to the AMF network element. Among them, the NSA message carries the adjacent service policy transfer result.

[0355] Step 1708: The AMF network element sends a Namf_N1MessageNotify to the PCF network element. Among them, the Namf_N1MessageNotify carries the adjacent service policy distribution result.

[0356] The embodiments of the present application provide a method for discovering a relay UE, which can implement a multi-hop relay UE discovery process in Model B mode initiated by an end UE and a multi-hop relay UE discovery process in Model A mode initiated by a relay UE.

[0357] It can be understood that the same / similar parts among the various embodiments of the above methods in this specification can be referred to each other. Each embodiment focuses on the differences from other embodiments. For the related parts, refer to the descriptions of other method embodiments.

[0358] The embodiments of the present application also provide a relay UE, as Figure 18 shown, including a memory 1810, a transceiver 1820, and a processor 1830. Among them, the memory 1810 is used to store computer programs; the transceiver 1820 is used to transmit and receive data under the control of the processor 1830; the processor 1830 is used to read the computer programs in the memory 1810 and perform the following operations:

[0359] Receive a discovery message;

[0360] If the relay forwarding identifier indicates that the set of terminal UEs allows the relay UE to forward, add the user information identifier of the first relay UE to the first relay UE set;

[0361] Forward the discovery message after adding the user information identifier of the first relay UE;

[0362] Among them, the discovery message carries at least one or more of the following parameters:

[0363] The set of terminal UEs, which includes the user information identifier of the source terminal UE and the user information identifier of the destination terminal UE;

[0364] The first relay UE set, which includes the user information identifiers of the relay UEs passed by from the source terminal UE to the first relay UE during the relay UE discovery process;

[0365] The relay forwarding identifier, which is used to indicate whether the set of terminal UEs allows the relay UE to forward.

[0366] As an optional implementation manner, receiving the discovery message includes:

[0367] Receive the discovery announcement message sent by other relay UEs;

[0368] Or, receive the discovery request message sent by the source terminal UE or other relay UEs.

[0369] As an optional implementation manner, the discovery message also carries at least a hop count identifier, which is used to indicate the number of times the set of terminal UEs allows the relay UE to forward.

[0370] As an optional implementation manner, before adding the user information identifier of the first relay UE to the first relay UE set, the processor 1830 is further configured to perform the following operations:

[0371] If the hop count identifier is not 0, subtract 1 from the hop count identifier and add the user information identifier of the first relay UE to the first relay UE set;

[0372] If the hop count identifier is 0, discard the discovery message.

[0373] As an optional implementation manner, the discovery message also carries at least a set of terminal UE identifiers, which are used to uniquely identify the set of terminal UEs.

[0374] As an optional implementation manner, before adding the user information identifier of the first relay UE to the first relay UE set, the processor 1830 is further configured to perform the following operations:

[0375] If the first relay UE has not forwarded the end UE set identifier, store the end UE set identifier locally and add the user information identifier of the first relay UE to the first relay UE set;

[0376] If the first relay UE has already forwarded the end UE set identifier, discard the discovery message.

[0377] As an optional implementation manner, the processor 1830 is further configured to perform the following operations:

[0378] Receive a discovery response message sent by the destination end UE or the second relay UE;

[0379] Send a discovery response message to the source end UE or the third relay UE;

[0380] Wherein, the discovery response message carries at least one or more of the following parameters:

[0381] End UE set;

[0382] Second relay UE set, the second relay UE set includes the user information identifier and the layer 2 identifier of the relay UE passed by from the source end UE to the destination end UE during the relay UE discovery process. The layer 2 identifier is used for the subsequent connection establishment process. The second relay UE is the next relay UE of the first relay UE in the second relay UE set, and the third relay UE is the previous relay UE of the first relay UE in the relay UE set.

[0383] As an optional implementation manner, the processor 1830 is further configured to perform the following operations:

[0384] Send a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters:

[0385] End UE set, the end UE set is the end UE set obtained by the first relay UE during the relay UE discovery process and / or the UE communication process;

[0386] Third relay UE set, the third relay UE set at least includes the user information identifier of the relay UE passed by from the source end UE in the end UE set to the first relay UE;

[0387] Relay forwarding identifier, the relay forwarding identifier is used to characterize whether the end UE set allows the relay UE to forward.

[0388] As an alternative implementation, it is found that the discovery announcement message further carries at least a hop count identifier, where the hop count identifier is used to characterize the number of times the relay UE is allowed to forward by the end UE set. The hop count identifier is determined according to the initial hop count identifier and the hop count corresponding to the source end UE in the end UE set reaching the first relay UE, and the initial hop count identifier is determined by the first relay UE or the Policy Control Function (PCF) network element.

[0389] As an alternative implementation, the discovery announcement message further carries at least an end UE set identifier, where the end UE set identifier is used to uniquely identify the end UE set, and the end UE set identifier is generated by the first relay UE or the PCF network element according to the end UE set.

[0390] As an alternative implementation, the processor 1830 is further configured to perform the following operations:

[0391] Send a registration request message to the Access and Mobility Management Function (AMF) network element; where the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the first relay UE supports the discovery function of the multi-hop relay UE;

[0392] Receive a Non-Access Stratum (NAS) message sent by the PCF network element through the AMF network element; where the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the first relay UE, an RSC, an end UE set identifier, and / or a hop count identifier.

[0393] The embodiment of the present application further provides an end UE, as Figure 19 shown, including a memory 1910, a transceiver 1920, and a processor 1930. Among them, the memory 1910 is used to store a computer program; the transceiver 1920 is used to send and receive data under the control of the processor 1930; the processor 1930 is used to read the computer program in the memory 1910 and perform the following operations:

[0394] Send a first discovery request message; where the first discovery request message carries at least one or more of the following parameters:

[0395] A first end UE set, where the first end UE set includes a user information identifier of the source end UE and a user information identifier of the destination end UE, and the end UE is the source end UE in the first end UE set;

[0396] A first relay UE set;

[0397] A relay forwarding identifier, where the relay forwarding identifier is used to characterize whether the first end UE set allows the relay UE to forward.

[0398] As an alternative implementation, the processor 1930 is further configured to perform the following operations:

[0399] Receive a second discovery request message sent by the relay UE;

[0400] If the destination UE in the second set of UE includes the UE, send a discovery response message to the relay UE;

[0401] Wherein, the second discovery request message carries at least one or more of the following parameters:

[0402] The second set of UE, the second set of UE includes the user information identifier of the source UE and the user information identifier of the destination UE, and the UE is the destination UE in the second set of UE;

[0403] The second set of relay UEs, the second set of relay UEs includes at least the user information identifier of the relay UE passed by from the source UE to the destination UE in the second set of UE;

[0404] The discovery response message carries at least one or more of the following parameters;

[0405] The second set of UE;

[0406] The second set of relay UEs.

[0407] As an alternative implementation, the first discovery request message further carries at least a hop count identifier, and the hop count identifier is used to characterize the number of times that the first set of UE allows the relay UE to forward, and the hop count identifier is determined by the UE or the policy control function PCF network element.

[0408] As an alternative implementation, the first discovery request message further carries at least a UE set identifier, and the UE set identifier is used to uniquely identify the first set of UE, and the UE set identifier is generated by the UE or the PCF network element according to the first set of UE.

[0409] As an alternative implementation, the processor 1930 is further configured to perform the following operations:

[0410] Send a registration request message to the access and mobility management function AMF network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the first set of UE and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of the multi-hop relay UE;

[0411] Receive non-access stratum (NAS) messages sent by a Policy Control Function (PCF) network element through an Access and Mobility Management Function (AMF) network element; wherein, the NAS messages carry at least proximity service policy parameters, and the proximity service policy parameters at least include a user information identifier of the terminal UE, a first Relay Service Code (RSC), a terminal UE set identifier, and / or a hop count identifier.

[0412] An embodiment of this application further provides an AMF network element, as Figure 20 shown, including a memory 2010, a transceiver 2020, and a processor 2030. Among them, the memory 2010 is used to store computer programs; the transceiver 2020 is used to transmit and receive data under the control of the processor 2030; the processor 2030 is used to read the computer programs in the memory 2010 and perform the following operations:

[0413] Receive a registration request message sent by a UE;

[0414] Send a first non-access stratum (NAS) message to a Policy Control Function (PCF) network element;

[0415] Receive a second NAS message sent by the PCF network element;

[0416] Send a third NAS message to the UE;

[0417] Wherein, the registration request message carries at least proximity service capability parameters, and the proximity service capability parameters include a terminal UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the UE supports the discovery function of multi-hop relay UEs;

[0418] The first NAS message carries at least proximity service capability parameters;

[0419] The second NAS message carries at least proximity service policy parameters, and the proximity service policy parameters include a user information identifier of the UE, a Relay Service Code (RSC), a terminal UE set identifier, and / or a hop count identifier;

[0420] The third NAS message carries proximity service policy parameters.

[0421] An embodiment of this application further provides a PCF network element, as Figure 21 shown, including a memory 2110, a transceiver 2120, and a processor 2130. Among them, the memory 2110 is used to store computer programs; the transceiver 2120 is used to transmit and receive data under the control of the processor 2130; the processor 2130 is used to read the computer programs in the memory 2110 and perform the following operations:

[0422] Receive a first non-access stratum (NAS) message sent by an Access and Mobility Management Function (AMF) network element;

[0423] Send a second NAS message to the AMF network element;

[0424] Among them, the first NAS message carries at least a proximity service capability parameter, and the proximity service capability parameter includes an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of the multi-hop relay UE;

[0425] The second NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the UE, a relay service code RSC, an end UE set identifier, and / or a hop count identifier, and the end UE set identifier is generated based on the end UE set.

[0426] The embodiment of the present application further provides a discovery device for a relay UE, as Figure 22 shown. The device is applied to the first relay UE, and the device includes:

[0427] A first receiving unit 2210, configured to receive a discovery message;

[0428] An adding unit 2220, configured to add the user information identifier of the first relay UE to the first relay UE set if the relay forwarding identifier characterizes that the end UE set allows the relay UE to forward;

[0429] A first sending unit 2230, configured to forward the discovery message after adding the user information identifier of the first relay UE;

[0430] Among them, the discovery message carries at least one or more of the following parameters:

[0431] An end UE set, and the end UE set includes the user information identifier of the source end UE and the user information identifier of the destination end UE;

[0432] A first relay UE set, and the first relay UE set includes the user information identifiers of the relay UEs passed by the source end UE to the first relay UE during the relay UE discovery process;

[0433] A relay forwarding identifier, and the relay forwarding identifier is used to characterize whether the end UE set allows the relay UE to forward.

[0434] As an optional implementation manner, the first receiving unit 2210 is specifically configured to:

[0435] Receive a discovery announcement message sent by another relay UE;

[0436] Or, receive a discovery request message sent by the source end UE or another relay UE.

[0437] As an optional implementation manner, the discovery message further carries at least a hop count identifier, and the hop count identifier is used to characterize the number of times that the end UE set allows the relay UE to forward.

[0438] As an alternative implementation, the device further includes:

[0439] A first determination unit, configured to, if the hop count identifier is not 0, decrement the hop count identifier by 1, and add the user information identifier of the first relay UE to the first relay UE set;

[0440] A first discard unit, configured to discard the discovery message if the hop count identifier is 0.

[0441] As an alternative implementation, the discovery message further carries at least a terminal UE set identifier, and the terminal UE set identifier is used to uniquely identify the terminal UE set.

[0442] As an alternative implementation, the device further includes:

[0443] A second determination unit, configured to, if the first relay UE has not forwarded the terminal UE set identifier, store the terminal UE set identifier locally, and add the user information identifier of the first relay UE to the first relay UE set;

[0444] A second discard unit, configured to discard the discovery message if the first relay UE has forwarded the terminal UE set identifier.

[0445] As an alternative implementation, the device further includes:

[0446] A second receiving unit, configured to receive a discovery response message sent by a destination terminal UE or a second relay UE;

[0447] A second sending unit, configured to send a discovery response message to a source terminal UE or a third relay UE;

[0448] Wherein, the discovery response message carries at least one or more of the following parameters:

[0449] The terminal UE set;

[0450] The second relay UE set, the second relay UE set includes the user information identifier of the relay UE and the layer 2 identifier of the relay UE passed by from the source terminal UE to the destination terminal UE during the relay UE discovery process, the layer 2 identifier is used for the subsequent connection establishment process, the second relay UE is the next relay UE of the first relay UE in the second relay UE set, and the third relay UE is the previous relay UE of the first relay UE in the relay UE set.

[0451] As an alternative implementation, the device further includes:

[0452] A third sending unit, configured to send a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters:

[0453] The set of terminal UEs, which is the set of terminal UEs obtained by the first relay UE during the relay UE discovery process and / or the UE communication process;

[0454] The third set of relay UEs, where the third set of relay UEs at least includes the user information identifiers of the relay UEs through which the source terminal UE in the set of terminal UEs reaches the first relay UE;

[0455] The relay forwarding identifier, which is used to indicate whether the set of terminal UEs allows the relay UE to perform forwarding.

[0456] As an optional implementation manner, the discovery announcement message further at least carries a hop count identifier, which is used to indicate the number of times the set of terminal UEs allows the relay UE to forward. The hop count identifier is determined according to the initial hop count identifier and the hop count corresponding to the source terminal UE in the set of terminal UEs reaching the first relay UE, and the initial hop count identifier is determined by the first relay UE or the Policy Control Function (PCF) network element.

[0457] As an optional implementation manner, the discovery announcement message further at least carries a set of terminal UE identifiers, which are used to uniquely identify the set of terminal UEs. The set of terminal UE identifiers is generated by the first relay UE or the PCF network element according to the set of terminal UEs.

[0458] As an optional implementation manner, the device further includes:

[0459] The fourth sending unit, which sends a registration request message to the Access and Mobility Management Function (AMF) network element; where the registration request message at least carries a proximity service capability parameter, and the proximity service capability parameter includes the set of terminal UEs and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the first relay UE supports the discovery function of multi-hop relay UEs;

[0460] The third receiving unit, which is used to receive a Non-Access Stratum (NAS) message sent by the PCF network element through the AMF network element; where the NAS message at least carries a proximity service policy parameter, and the proximity service policy parameter includes the user information identifier of the first relay UE, the set of terminal UE identifiers, and / or the hop count identifier.

[0461] The embodiments of the present application further provide a discovery device for a relay UE, as Figure 23 shown. The device is applied to a terminal UE, and the device includes:

[0462] The first sending unit 2310, which is used to send a first discovery request message; where the first discovery request message at least carries one or more of the following parameters:

[0463] The first set of UE at one end, the first set of UE at one end includes the user information identifier of the source UE at one end and the user information identifier of the destination UE at one end, and the UE at one end is the source UE in the first set of UE at one end;

[0464] The first set of relay UEs;

[0465] The relay forwarding identifier, which is used to represent whether the first set of UE at one end allows the relay UE to forward.

[0466] As an optional implementation manner, the device further includes:

[0467] The first receiving unit is configured to receive a second discovery request message sent by the relay UE;

[0468] The second sending unit is configured to send a discovery response message to the relay UE if the destination UE in the second set of UE at one end includes the UE at one end;

[0469] Wherein, the second discovery request message carries at least one or more of the following parameters:

[0470] The second set of UE at one end, the second set of UE at one end includes the user information identifier of the source UE at one end and the user information identifier of the destination UE at one end, and the UE at one end is the destination UE in the second set of UE at one end;

[0471] The second set of relay UEs, the second set of relay UEs includes at least the user information identifier of the relay UE passed by from the source UE to the destination UE in the second set of UE at one end;

[0472] The discovery response message carries at least one or more of the following parameters;

[0473] The second set of UE at one end;

[0474] The second set of relay UEs.

[0475] As an optional implementation manner, the first discovery request message further carries at least a hop count identifier, which is used to represent the number of times that the first set of UE at one end allows the relay UE to forward, and the hop count identifier is determined by the UE at one end or the Policy Control Function (PCF) network element.

[0476] As an optional implementation manner, the first discovery request message further carries at least a UE set identifier at one end, which is used to uniquely identify the first set of UE at one end, and the UE set identifier at one end is generated by the UE at one end or the PCF network element according to the first set of UE at one end.

[0477] As an optional implementation manner, the device further includes:

[0478] A third sending unit, configured to send a registration request message to an Access and Mobility Management Function (AMF) network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes a set of end User Equipments (UEs) and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the end UE supports the discovery function of multi-hop relay UEs.

[0479] A second receiving unit, configured to receive a Non-Access Stratum (NAS) message sent by a Policy Control Function (PCF) network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes at least a user information identifier of the end UE, a set identifier of the end UEs, and / or a hop count identifier.

[0480] An embodiment of the present application further provides a discovery device for relay UEs, as Figure 24 shown. The device is applied to the AMF network element and includes:

[0481] A first receiving unit 2410, configured to receive a registration request message sent by a UE.

[0482] A first sending unit 2420, configured to send a first Non-Access Stratum (NAS) message to a Policy Control Function (PCF) network element.

[0483] A second receiving unit 2430, configured to receive a second NAS message sent by the PCF network element.

[0484] A second sending unit 2440, configured to send a third NAS message to the UE.

[0485] Wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes a set of end UEs and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the UE supports the discovery function of multi-hop relay UEs.

[0486] The first NAS message carries at least a proximity service capability parameter.

[0487] The second NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the UE, a set identifier of the end UEs, and / or a hop count identifier.

[0488] The third NAS message carries a proximity service policy parameter.

[0489] An embodiment of the present application further provides a discovery device for relay UEs, as Figure 25 shown. The device is applied to the PCF network element and includes:

[0490] A receiving unit 2510, configured to receive a first Non-Access Stratum (NAS) message sent by an Access and Mobility Management Function (AMF) network element.

[0491] A sending unit 2520, configured to send a second NAS message to an AMF network element;

[0492] Wherein, the first NAS message carries at least neighboring service capability parameters, and the neighboring service capability parameters include an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of multi-hop relay UEs;

[0493] The second NAS message carries at least neighboring service policy parameters, and the neighboring service policy parameters include a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier, and the end UE set identifier is generated based on the end UE set.

[0494] It should be noted that the division of units in the embodiments of the present application is illustrative, merely a logical function division, and there may be other division methods in actual implementation. In addition, in each embodiment of the present application, each functional unit may be integrated in a processing unit, may exist separately physically for each unit, or two or more units may be integrated in one unit. The above integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0495] If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a processor-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application.

[0496] It should be noted here that the above device provided in the embodiments of the present application can implement all the method steps implemented in the above method embodiments and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiments will not be specifically described in this embodiment.

[0497] The embodiments of the present application provide a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method for discovering relay UEs are implemented.

[0498] An embodiment of the present application provides a communication system, which includes a relay UE, an end UE, an AMF network element, and a PCF network element. The relay UE executes the steps of the method implemented by the above-mentioned first relay UE, the end UE executes the steps of the method implemented by the above-mentioned end UE, the AMF network element executes the steps of the method implemented by the above-mentioned AMF network element, and the PCF network element executes the steps of the method implemented by the above-mentioned PCF network element.

[0499] The processor-readable storage medium can be any available medium or data storage device accessible by the processor, including but not limited to magnetic memories (such as floppy disks, hard disks, magnetic tapes, magneto-optical discs (MO), etc.), optical memories (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor memories (such as ROMs, EPROMs, EEPROMs, non-volatile memories (NANDFLASH), solid-state drives (SSD)).

[0500] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories and optical memories, etc.) containing computer-usable program code.

[0501] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer-executable instructions. These computer-executable instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0502] These processor-executable instructions can also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the processor-readable memory generate a manufactured product including instruction means, and the instruction means implements the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0503] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these modifications and variations.

Claims

1. A method for discovering a relay user equipment (UE), characterized in that, The method is applied to a first relay UE, and the method includes: Receiving a discovery message; If the relay forwarding identifier indicates that the set of end UEs allows the relay UE to perform forwarding, adding the user information identifier of the first relay UE to the first relay UE set; Forwarding the discovery message after adding the user information identifier of the first relay UE; Wherein, the discovery message carries at least one or more of the following parameters: The set of end UEs, which includes the user information identifiers of the source end UE and the destination end UE; The first relay UE set, which includes the user information identifiers of the relay UEs passed by from the source end UE to the first relay UE during the relay UE discovery process; The relay forwarding identifier, which is used to indicate whether the set of end UEs allows the relay UE to perform forwarding.

2. The method according to claim 1, characterized in that, The receiving the discovery message includes: Receiving a discovery announcement message sent by another relay UE; Or, receiving a discovery request message sent by the source end UE or another relay UE.

3. The method according to claim 1 or 2, characterized in that, The discovery message also carries at least a hop count identifier, which is used to indicate the number of times the set of end UEs allows the relay UE to forward.

4. The method according to claim 3, wherein Before adding the user information identifier of the first relay UE to the first relay UE set, the method further includes: If the hop count identifier is not 0, decrementing the hop count identifier by 1 and adding the user information identifier of the first relay UE to the first relay UE set; If the hop count identifier is 0, discarding the discovery message.

5. The method according to claim 1 or 2, characterized in that, The discovery message also carries at least an end UE set identifier, which is used to uniquely identify the set of end UEs.

6. The method according to claim 5, wherein Before adding the user information identifier of the first relay UE to the first relay UE set, the method further includes: If the first relay UE has not forwarded the end UE set identifier, storing the end UE set identifier locally and adding the user information identifier of the first relay UE to the first relay UE set; If the first relay UE has already forwarded the end UE set identifier, discarding the discovery message.

7. The method according to claim 1, wherein The method further includes: Receiving a discovery response message sent by the destination end UE or a second relay UE; Sending the discovery response message to the source end UE or a third relay UE; Wherein, the discovery response message carries at least one or more of the following parameters: The set of end UEs; The second relay UE set, which includes the user information identifiers of the relay UEs passed by from the source end UE to the destination end UE during the relay UE discovery process and the layer 2 identifier of the relay UE, and the layer 2 identifier is used for the subsequent connection establishment process. The second relay UE is the relay UE after the first relay UE in the second relay UE set, and the third relay UE is the relay UE before the first relay UE in the relay UE set.

8. The method according to claim 1, wherein The method further includes: Sending a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters: The set of end UEs, which is the set of end UEs obtained by the first relay UE during the relay UE discovery process and / or the UE communication process; The third relay UE set, which at least includes the user information identifiers of the relay UEs passed by the source end UE in the set of end UEs to reach the first relay UE; The relay forwarding identifier, which is used to indicate whether the relay UE is allowed to forward for the set of end UEs.

9. The method according to claim 8, wherein The discovery announcement message also at least carries a hop count identifier, which is used to indicate the number of times the relay UE is allowed to forward for the set of end UEs. The hop count identifier is determined according to the initial hop count identifier and the hop count corresponding to the source end UE in the set of end UEs reaching the first relay UE. The initial hop count identifier is determined by the first relay UE or the Policy Control Function (PCF) network element.

10. The method according to claim 8, characterized in that, The discovery announcement message also at least carries a set of end UE identifier, which is used to uniquely identify the set of end UEs. The set of end UE identifier is generated by the first relay UE or the PCF network element according to the set of end UEs.

11. The method according to claim 8, wherein The method further includes: Sending a registration request message to the Access and Mobility Management Function (AMF) network element; wherein, the registration request message at least carries a proximity service capability parameter, and the proximity service capability parameter includes the set of end UEs and / or the multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the first relay UE supports the discovery function of multi-hop relay UEs; Receiving a Non-Access Stratum (NAS) message sent by the PCF network element through the AMF network element; wherein, the NAS message at least carries a proximity service policy parameter, and the proximity service policy parameter includes the user information identifier of the first relay UE, the set of end UE identifier, and / or the hop count identifier.

12. A method for discovering a relay user equipment (UE), characterized in that, The method is applied to an end UE, and the method includes: Sending a first discovery request message; wherein, the first discovery request message at least carries one or more of the following parameters: The first set of end UEs, which includes the user information identifier of the source end UE and the user information identifier of the destination end UE, and the end UE is the source end UE in the first set of end UEs; The first relay UE set; The relay forwarding identifier, which is used to indicate whether the relay UE is allowed to forward for the first set of end UEs.

13. The method according to claim 12, characterized in that, The method further includes: Receiving a second discovery request message sent by the relay UE; If the destination end UE in the second set of end UEs includes the end UE, sending a discovery response message to the relay UE; Wherein, the second discovery request message at least carries one or more of the following parameters: The second set of end UEs, which includes the user information identifier of the source end UE and the user information identifier of the destination end UE, and the end UE is the destination end UE in the second set of end UEs; The second relay UE set, which at least includes the user information identifiers of the relay UEs passed by the source end UE to the destination end UE in the second set of end UEs; The discovery response message carries at least one or more of the following parameters; The second UE set; The second relay UE set.

14. The method according to claim 12, wherein The first discovery request message further carries at least a hop count identifier, where the hop count identifier is used to characterize the number of times the first UE set allows the relay UE to forward, and the hop count identifier is determined by the UE or the Policy Control Function (PCF) network element.

15. The method according to claim 12, wherein The first discovery request message further carries at least a UE set identifier, where the UE set identifier is used to uniquely identify the first UE set, and the UE set identifier is generated by the UE or the PCF network element according to the first UE set.

16. The method according to claim 14 or 15, characterized in that, The method further includes: Sending a registration request message to the Access and Mobility Management Function (AMF) network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the first UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of multi-hop relay UEs; Receiving a Non-Access Stratum (NAS) message sent by the PCF network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter at least includes a user information identifier of the UE, a UE set identifier, and / or a hop count identifier.

17. A discovery method for a relay user equipment (UE), characterized in that, The method is applied to the Access and Mobility Management Function (AMF) network element, and the method includes: Receiving a registration request message sent by the UE; Sending a first Non-Access Stratum (NAS) message to the Policy Control Function (PCF) network element; Receiving a second NAS message sent by the PCF network element; Sending a third NAS message to the UE; Wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes a UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of multi-hop relay UEs; The first NAS message carries at least the proximity service capability parameter; The second NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the UE, a UE set identifier, and / or a hop count identifier; The third NAS message carries the proximity service policy parameter.

18. A discovery method for a relay user equipment (UE), characterized in that, The method is applied to the Policy Control Function (PCF) network element, and the method includes: Receiving a first Non-Access Stratum (NAS) message sent by the Access and Mobility Management Function (AMF) network element; Sending a second NAS message to the AMF network element; Wherein, the first NAS message carries at least a proximity service capability parameter, and the proximity service capability parameter includes a UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of multi-hop relay UEs; The second NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the UE, a UE set identifier, and / or a hop count identifier, and the UE set identifier is generated based on the UE set.

19. A relay user equipment (UE), characterized in that, It includes a memory, a transceiver, and a processor. Among them, the memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer programs in the memory and perform the following operations: Receive a discovery message; If the relay forwarding identifier indicates that the set of end UEs allows the relay UE to forward, add the user information identifier of the first relay UE to the first relay UE set; Forward the discovery message after adding the user information identifier of the first relay UE; Among them, the discovery message carries at least one or more of the following parameters: The set of end UEs, which includes the user information identifiers of the source end UE and the destination end UE; The first relay UE set, which includes the user information identifiers of the relay UEs passed by from the source end UE to the first relay UE during the relay UE discovery process; The relay forwarding identifier, which is used to indicate whether the set of end UEs allows the relay UE to forward.

20. The relay UE according to claim 19, wherein The receiving of the discovery message includes: Receive a discovery announcement message sent by other relay UEs; Or, receive a discovery request message sent by the source end UE or other relay UEs.

21. The relay UE according to claim 19 or 20, characterized in that, The discovery message also carries at least a hop count identifier, which is used to indicate the number of times the set of end UEs allows the relay UE to forward.

22. The relay UE according to claim 21, wherein, Before adding the user information identifier of the first relay UE to the first relay UE set, the processor is further used to perform the following operations: If the hop count identifier is not 0, subtract 1 from the hop count identifier and add the user information identifier of the first relay UE to the first relay UE set; If the hop count identifier is 0, discard the discovery message.

23. The relay UE according to claim 19 or 20, characterized in that, The discovery message also carries at least an end UE set identifier, which is used to uniquely identify the set of end UEs.

24. The relay UE according to claim 23, wherein Before adding the user information identifier of the first relay UE to the first relay UE set, the processor is further used to perform the following operations: If the first relay UE has not forwarded the end UE set identifier, store the end UE set identifier locally and add the user information identifier of the first relay UE to the first relay UE set; If the first relay UE has already forwarded the end UE set identifier, discard the discovery message.

25. The relay UE according to claim 19, wherein, The processor is further used to perform the following operations: Receive a discovery response message sent by the destination end UE or the second relay UE; Send the discovery response message to the source end UE or the third relay UE; Among them, the discovery response message carries at least one or more of the following parameters: The set of end UEs; The second relay UE set, where the second relay UE set includes the user information identifier of the relay UE passed by the source UE to the destination UE during the relay UE discovery process and the layer 2 identifier of the relay UE, and the layer 2 identifier is used for the subsequent connection establishment process. The second relay UE is the relay UE after the first relay UE in the second relay UE set, and the third relay UE is the relay UE before the first relay UE in the relay UE set.

26. The relay UE according to claim 19, wherein The processor is further configured to perform the following operations: Send a discovery announcement message; wherein, the discovery announcement message carries at least one or more of the following parameters: The set of end UEs, where the set of end UEs is the set of end UEs obtained by the first relay UE during the relay UE discovery process and / or the UE communication process; The third relay UE set, where the third relay UE set at least includes the user information identifier of the relay UE passed by the source UE in the set of end UEs to the first relay UE; The relay forwarding identifier, which is used to indicate whether the set of end UEs allows the relay UE to perform forwarding.

27. The relay UE according to claim 26, wherein The discovery announcement message also carries at least a hop count identifier, which is used to indicate the number of times the set of end UEs allows the relay UE to forward. The hop count identifier is determined according to the initial hop count identifier and the hop count corresponding to the source UE in the set of end UEs reaching the first relay UE, and the initial hop count identifier is determined by the first relay UE or the policy control function PCF network element.

28. The relay UE according to claim 26, wherein The discovery announcement message also carries at least an end UE set identifier, which is used to uniquely identify the set of end UEs. The end UE set identifier is generated by the first relay UE or the PCF network element according to the set of end UEs.

29. The relay UE according to claim 26, wherein, The processor is further configured to perform the following operations: Send a registration request message to the access and mobility management function AMF network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the set of end UEs and / or the multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the first relay UE supports the discovery function of the multi-hop relay UE; Receive a non-access stratum NAS message sent by the PCF network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes the user information identifier of the first relay UE, the end UE set identifier, and / or the hop count identifier.

30. A user equipment UE, characterized in that, It includes a memory, a transceiver, and a processor. The memory is used to store a computer program. The transceiver is used to transmit and receive data under the control of the processor. The processor is used to read the computer program in the memory and perform the following operations: Send a first discovery request message; wherein, the first discovery request message carries at least one or more of the following parameters: The first set of UE at one end, the first set of UE at one end includes the user information identifier of the source UE and the user information identifier of the destination UE, and the UE at one end is the source UE in the first set of UE at one end; The first set of relay UE; The relay forwarding identifier, which is used to characterize whether the first set of UE at one end allows the relay UE to perform forwarding.

31. The terminal UE according to claim 30, characterized in that, The processor is further configured to perform the following operations: Receive a second discovery request message sent by the relay UE; If the destination UE in the second set of UE at one end includes the UE at one end, send a discovery response message to the relay UE; Wherein, the second discovery request message carries at least one or more of the following parameters: The second set of UE at one end, the second set of UE at one end includes the user information identifier of the source UE and the user information identifier of the destination UE, and the UE at one end is the destination UE in the second set of UE at one end; The second set of relay UE, and the second set of relay UE at least includes the user information identifier of the relay UE passed by from the source UE to the destination UE in the second set of UE at one end; The discovery response message carries at least one or more of the following parameters; The second set of UE at one end; The second set of relay UE.

32. The terminal UE according to claim 30, wherein The first discovery request message also carries at least a hop count identifier, and the hop count identifier is used to characterize the number of times that the first set of UE at one end allows the relay UE to forward, and the hop count identifier is determined by the UE at one end or the Policy Control Function (PCF) network element.

33. The terminal UE according to claim 30, characterized in that, The first discovery request message also carries at least a UE set identifier at one end, and the UE set identifier at one end is used to uniquely identify the first set of UE at one end, and the UE set identifier at one end is generated by the UE at one end or the PCF network element according to the first set of UE at one end.

34. The terminal UE according to claim 32 or 33, characterized in that The processor is further configured to perform the following operations: Send a registration request message to the Access and Mobility Management Function (AMF) network element; wherein, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes the first set of UE at one end and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE at one end supports the discovery function of the multi-hop relay UE; Receive a non-access stratum (NAS) message sent by the PCF network element through the AMF network element; wherein, the NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter at least includes the user information identifier of the UE at one end, the UE set identifier at one end and / or the hop count identifier.

35. An access and mobility management function AMF network element, characterized in that, It includes a memory, a transceiver and a processor. Wherein, the memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer programs in the memory and perform the following operations: Receive a registration request message sent by the UE; Send a first NAS message to the Policy Control Function (PCF) network element; Receive a second NAS message sent by the PCF network element; Send a third NAS message to the UE; Among them, the registration request message carries at least a proximity service capability parameter, and the proximity service capability parameter includes an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the UE supports the discovery function of a multi-hop relay UE; The first NAS message carries at least the proximity service capability parameter; The second NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier; The third NAS message carries the proximity service policy parameter.

36. A Policy Control Function (PCF) network element, characterized in that, It includes a memory, a transceiver, and a processor. Among them, the memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations: Receive a first non-access stratum (NAS) message sent by an access and mobility management function (AMF) network element; Send a second NAS message to the AMF network element; Among them, the first NAS message carries at least a proximity service capability parameter, and the proximity service capability parameter includes an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to indicate that the UE supports the discovery function of a multi-hop relay UE; The second NAS message carries at least a proximity service policy parameter, and the proximity service policy parameter includes a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier, and the end UE set identifier is generated based on the end UE set.

37. A discovery device for a relay user equipment (UE), characterized in that, The device is applied to a first relay UE, and the device includes: A first receiving unit, configured to receive a discovery message; An adding unit, configured to add the user information identifier of the first relay UE to the first relay UE set if the relay forwarding identifier indicates that the end UE set allows the relay UE to perform forwarding; A first sending unit, configured to forward the discovery message after adding the user information identifier of the first relay UE; Among them, the discovery message carries at least one or more of the following parameters: The end UE set, and the end UE set includes the user information identifier of the source end UE and the user information identifier of the destination end UE; The first relay UE set, and the first relay UE set includes the user information identifiers of the relay UEs passed by from the source end UE to the first relay UE during the relay UE discovery process; The relay forwarding identifier, and the relay forwarding identifier is used to indicate whether the end UE set allows the relay UE to perform forwarding.

38. A discovery device for a relay user equipment (UE), characterized in that, The device is applied to an end UE, and the device includes: A first sending unit, configured to send a first discovery request message; among them, the first discovery request message carries at least one or more of the following parameters: A first end UE set, and the first end UE set includes the user information identifier of the source end UE and the user information identifier of the destination end UE, and the end UE is the source end UE in the first end UE set; A first relay UE set; A relay forwarding identifier, and the relay forwarding identifier is used to indicate whether the first end UE set allows the relay UE to perform forwarding.

39. A discovery device for a relay user equipment (UE), characterized in that, The device is applied to an Access and Mobility Management Function (AMF) network element, and the device includes: A first receiving unit, configured to receive a registration request message sent by a UE; A first sending unit, configured to send a first Non-Access Stratum (NAS) message to a Policy Control Function (PCF) network element; A second receiving unit, configured to receive a second NAS message sent by the PCF network element; A second sending unit, configured to send a third NAS message to the UE; Wherein, the registration request message carries at least proximity service capability parameters, and the proximity service capability parameters include an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of multi-hop relay UEs; The first NAS message carries at least the proximity service capability parameters; The second NAS message carries at least proximity service policy parameters, and the proximity service policy parameters include a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier; The third NAS message carries the proximity service policy parameters.

40. A discovery device for a relay user equipment (UE), characterized in that, The device is applied to a Policy Control Function (PCF) network element, and the device includes: A receiving unit, configured to receive a first Non-Access Stratum (NAS) message sent by an Access and Mobility Management Function (AMF) network element; A sending unit, configured to send a second NAS message to the AMF network element; Wherein, the first NAS message carries at least proximity service capability parameters, and the proximity service capability parameters include an end UE set and / or a multi-hop relay identifier, and the multi-hop relay identifier is used to characterize that the UE supports the discovery function of multi-hop relay UEs; Wherein, the second NAS message carries at least proximity service policy parameters, and the proximity service policy parameters include a user information identifier of the UE, an end UE set identifier, and / or a hop count identifier, and the end UE set identifier is generated based on the end UE set.

41. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 11, or 12 to 16, or 17 or 18.

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