CN111698753A

CN111698753A - Relay selection method and device, equipment and storage medium

Info

Publication number: CN111698753A
Application number: CN201910186606.1A
Authority: CN
Inventors: 郭春霞
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2019-03-12
Filing date: 2019-03-12
Publication date: 2020-09-22
Anticipated expiration: 2039-03-12
Also published as: CN111698753B

Abstract

The embodiment of the application discloses a relay selection method, a device, equipment and a storage medium, wherein the method comprises the following steps: under a relay selection scene, a source node and a target node respectively initiate a discovery process.

Description

Relay selection method and device, equipment and storage medium

Technical Field

The embodiment of the application relates to but is not limited to the technology of the internet of things, and particularly relates to a relay selection method, a relay selection device, relay selection equipment and a relay selection storage medium.

Background

In the existing relay selection scheme of the internet of things, a source node and candidate relay nodes initiate discovery processes, which means that all candidate relay nodes receiving a source node discovery signal need to initiate discovery processes to find a target node, and thus means that more candidate relay nodes initiate discovery processes, which causes resource waste and energy consumption waste.

Disclosure of Invention

In view of the above, embodiments of the present application provide a relay selection method and apparatus, a device, and a storage medium to solve at least one problem in the related art.

The technical scheme of the embodiment of the application is realized as follows:

the embodiment of the application provides a relay selection method, which comprises the following steps:

under a relay selection scene, a source node and a target node respectively initiate a discovery process.

under a relay selection scene, a first other node receives discovery signals broadcast by a source node and/or a target node;

and responding to the discovery signal, and broadcasting the discovery response signal or feeding back the discovery response signal to the source node and/or the target node when determining that the self is qualified as a candidate relay node according to a first judgment criterion.

An embodiment of the present application provides a relay selection apparatus, including:

a discovery unit, configured to discover a wireless link outage in a relay selection scenario;

and the initiating unit is used for initiating the discovery process.

a second receiving unit, configured to receive a discovery signal broadcast by a source node and/or a target node in a relay selection scenario;

and the first processing unit is used for responding to the discovery signal, and broadcasting the discovery response signal or feeding back the discovery response signal to the source node and/or the target node when determining that the first processing unit is qualified as a candidate relay node according to a first judgment criterion.

An embodiment of the present application provides a relay selection device, which includes a memory and a processor, where the memory stores a computer program that can be run on the processor, and the processor implements the steps in the relay selection method when executing the program.

An embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps in the relay selection method described above.

In the embodiment of the application, under a relay selection scene, a source node and a target node respectively initiate a discovery process; in this way, in the related art, all candidate relay nodes receiving the source node discovery signal need to initiate a discovery process, so that resource waste and energy consumption waste are caused by too many nodes initiating the discovery process; in the embodiment of the application, only the source node and the target node initiate the discovery process, so that the waste of resources and energy consumption is avoided.

Drawings

Fig. 1 is a schematic structural diagram of a network architecture according to an embodiment of the present application;

fig. 2 is a schematic flow chart of an implementation of a relay selection method in an embodiment of the present application;

fig. 3 is a schematic flow chart of an implementation of a relay selection method in an embodiment of the present application;

fig. 4 is a schematic flow chart of an implementation of a relay selection method in an embodiment of the present application;

fig. 5 is a schematic diagram illustrating a relay selection and link establishment process when a single hop exists and a plurality of candidate relays exist according to an embodiment of the present application;

fig. 6 is a schematic diagram of a relay selection and link establishment process when there are multiple hops according to an embodiment of the present application;

FIG. 7 is a diagram illustrating a discovery signal and a discovery response signal according to an embodiment of the present application;

fig. 8 is a schematic diagram illustrating a process of relay selection and link establishment in the presence of multiple candidate relays and multiple hops according to an embodiment of the present application;

fig. 9A is a schematic structural diagram of a relay selection device in an embodiment of the present application;

fig. 9B is a schematic structural diagram of a relay selection device in the embodiment of the present application;

fig. 10 is a schematic diagram of a hardware entity of the relay selection device in the embodiment of the present application.

Detailed Description

The current LTE-V2X technology does not support the relay technology, while the D2D technology supports the relay technology, wherein the relay mechanism in the D2D technology is as follows: firstly, the candidate relay informs the remote terminal of its own relay identity by sending a discovery signal (discovery), and then the remote terminal selects a corresponding relay according to the received discovery RSRP value sent by the candidate relay. The discovery process is initiated by two modes on the core network side, namely a mode A (model A) discovery process and a mode B (model B) discovery process, wherein:

the discovery flow for model A type is similar to the declaration "I am this" externally, and includes: firstly, a terminal sends a discovery request signal to a network; secondly, if the network agrees, the terminal can send a discovery signal at the port of the PC 5; again, all remote terminals that hear the discovery signal simply receive a response to the discovery signal, but do not provide additional information.

The model B type discovery procedure is similar to the external declaration of "I want to find a parking lot," and includes: firstly, a terminal sends a discovery request signal to a network; secondly, if the network agrees, the terminal can send a discovery query signal at a port PC 5; thirdly, all the remote terminals which hear the signal need to feed back corresponding additional information, so that the discovery terminal can find a proper remote terminal conveniently and establish connection. When the terminal is not connected with the network, the discovery process can be directly initiated without obtaining the network authorization.

The existing cellular network supports a relay technology, which is mainly used for providing a data packet forwarding function between a terminal and a network, that is, a source UE initiates a discovery process to a relay, all candidate relays that receive the signal and meet link quality requirements initiate discovery processes, a base station is searched, and if the base station feeds back a discovery response signal, which means that connection can be established with the candidate relays, the candidate relays feed back the discovery response signal to the source UE, thereby establishing a connection relationship between the source UE and the relay-network. And conversely, the same is true for the process of searching the target terminal initiated from the network side.

In the existing relay selection scheme, it is assumed that direct communication cannot be performed between an original receiving node and a transmitting node due to the reasons of distance, path loss, shielding and the like, and data needs to be forwarded from a source node to a target node by means of a third-party relay. In a car networking scene, a one-to-one communication link is supposed to be originally established between two cars (OBUs) or between a car (OBU) and a roadside radio device (RSU), when passing through an intersection, due to the entering of other cars or the blocking of a high-rise at a corner, the communication link is interrupted due to the wearing loss of the cars or the high-rise, at the moment, a source node and a target node both know that the link is interrupted, the link establishment can be completed by taking other OBUs or RSUs on the road as relays, and data transmission between the source node and the target node is realized.

If the existing method of initiating discovery flows by a source node and candidate relay nodes is adopted, it means that all the candidate relay nodes receiving a source node discovery signal need to initiate discovery flows so as to find a target node, which means that more candidate relay nodes initiate discovery flows, thereby causing resource waste and energy consumption waste. And in this scenario, due to the existence of penetration loss, candidate relays cannot be selected by selecting the maximum or minimum RSRP alone.

In addition, in the internet of vehicles scenario, the vehicles are moving at high speed, and the channel environment changes greatly. In order to ensure that the relay link is stable and reliable, parameters such as the speed, the movement direction and the like of the source node, the relay node and the target node need to be considered comprehensively.

The technical solution of the present application is further elaborated below with reference to the drawings and the embodiments.

The present embodiment first provides a network architecture, as shown in fig. 1, the network architecture includes two or more terminals 11 to 1N and a base station 31, wherein the terminals 11 to 1N and the base station 31 interact with each other through a network 21.

The present embodiment proposes a relay selection method, which is applied to a relay selection device (e.g. a node), and the functions implemented by the method may be implemented by a processor in the node calling a program code, although the program code may be stored in a computer storage medium, and it is understood that the node at least includes a processor and a storage medium.

The embodiment of the application provides a relay selection method, which comprises the following steps: under a relay selection scene, a source node and a target node respectively initiate a discovery process.

Fig. 2 is a schematic flow chart of an implementation process of a relay selection method in an embodiment of the present application, and as shown in fig. 2, the method includes:

step S201, in a relay selection scene, a source node and a target node find that a wireless link is interrupted;

step S202, if the source node and the target node find that the wireless link is interrupted, the source node and the target node respectively initiate a discovery process.

In other embodiments, the initiating discovery procedure comprises broadcasting a discovery signal, wherein: the discovery signal includes at least one set of information of:

self node ID, source node ID/target node ID;

source node ID/target node ID, current identity;

self node ID, source node ID/target node ID, current identity.

The node ID comprises a layer 2 identifier and an application identifier; the current identity comprises a source node, a temporary source node, a target node and a temporary target node.

In some embodiments, the discovery signal further includes a moving speed, a moving direction, and/or a size of a data block to be transmitted, and/or a coding adjustment manner, and/or a remaining transmission time.

In other embodiments, the method further comprises:

broadcasting a discovery signal by a temporary source node and/or a temporary target node, wherein:

the signal strength of the temporary source node as the source node meets a first requirement; the signal strength of the temporary target node as the target node meets a first requirement.

Here, the determining of the temporary source node may further include screening Signal Quality of the source node, and the temporary target node may further include screening Signal Quality of the target node, and in the implementation, the Signal Quality may be represented by Reference Signal Receiving Quality (RSRQ), and the Signal strength may be represented by Reference Signal Receiving Power (RSRP).

step S11, under the relay selection scene, the source node and the target node find the interruption of the wireless link;

step S12, the source node and the target node respectively initiate a discovery process;

step S13, after initiating the discovery procedure, the source node and/or the target node receives a discovery response signal sent by a candidate relay node;

here, in a relay selection scenario, a first other node receives a discovery signal broadcast by a source node and/or a target node; and responding to the discovery signal, and broadcasting the discovery response signal or feeding back the discovery response signal to the source node and/or the target node when determining that the self is qualified as a candidate relay node according to a first judgment criterion. The first other node is other than the source node and the target node, and the discovery response signal includes a self node ID, a source node ID, a target node ID, and/or a moving speed, a moving direction, and/or a source and target node ID whose link quality meets a second requirement, or a temporary source and target node ID whose link quality meets a second requirement.

Step S14, the source node and/or the target node establishes links among the source node, the relay node and the target node according to the discovery response signal;

wherein: the candidate relay nodes simultaneously receive discovery signals sent by the source node and the target node, and the signal strength of the source node and the signal strength of the target node both meet a first requirement.

The discovery response signal comprises the self node ID, the source node ID, the target node ID, and/or the source node ID, the target node ID, the temporary target node ID and the temporary source node ID, wherein the moving speed, the moving direction and/or the link quality meet the second requirement.

In some embodiments, when the source node or the target node receives discovery response signals sent by a plurality of candidate relay nodes, the source node and/or the target node establishes links between the source node, the relay nodes and the target node according to the discovery response signals, including one of:

the source node and the target node determine a relay node from the candidate relay nodes according to the same consistency criterion and discovery response signals of the candidate relay nodes, and establish links among the source node, the relay node and the target node;

the source node or the target node determines a relay node from the candidate relay nodes and establishes a link between the source node, the relay node and the target node, for example, the source node or the target node determines a relay node from the candidate relay nodes and establishes a link between the source node, the relay node and the target node according to a certain criterion and discovery response signals of the candidate relay nodes, respectively. That is, the source node or the target node selects the final relay node according to the own criteria, and establishes the connection between the source node (target node) and the relay node;

in some embodiments, the conformance criteria are configured or preconfigured by the base station and comprise one of:

i) the moving direction of the relay node is the same as the moving direction of the source node and the moving direction of the target node;

ii) the moving direction of the relay node is the same as the moving direction of the source node and the target node, and the moving speed of the relay node is closest to the moving speed of the source node and the target node;

iii) the direction of movement of the relay node is the same as the direction of movement of the source node or the target node;

iv) the moving direction of the relay node is the same as that of the source node or the target node, and the moving rate of the relay node is closest to that of the source node or the target node.

As can be seen from the above, the consistency criterion may be that the mean of the moving rates of the relay node and the mean of the moving rates of the source node and the temporary node are closest to each other.

In other embodiments, when the source node or the target node receives discovery response signals sent by a plurality of candidate relay nodes, the source node and/or the target node establishing links between the source node, the relay nodes and the target node according to the discovery response signals includes:

the source node or the target node sends a request message to a base station, wherein the request message carries node information of all or part of candidate relay nodes, and the node information comprises a discovery response signal;

and the source node or the target node determines a relay node according to the response message issued by the base station and establishes links among the source node, the relay node and the target node.

In this embodiment, the source node or the target node reports all or part of the candidate relay node information to the base station, the base station assists in completing relay node selection, and then establishes connections among the source node, the relay node, and the target node.

step S21, under the relay selection scene, the source node and the target node find the interruption of the wireless link;

step S22, the source node and the target node respectively initiate a discovery process;

step S23, after initiating the discovery procedure, the source node and/or the target node receives a discovery response signal sent by a candidate relay node;

step S24, the source node and/or the target node establishes links among the source node, the relay node and the target node according to the discovery response signal;

Step S25, if the link establishment between the source node and the target node has been completed by the assistance of the relay node, the source node and the target node send a discovery release signal to inform other nodes that the link establishment has been completed, wherein the discovery release signal includes a source node ID and a target node ID.

An embodiment of the present application provides a relay selection method, fig. 3 is a schematic diagram illustrating an implementation flow of the relay selection method in the embodiment of the present application, and as shown in fig. 3, the method includes:

step S301, in a relay selection scene, a source node and a target node find that a wireless link is interrupted;

step S302, a source node and a target node broadcast discovery signals respectively;

in some embodiments, the source node and the target node broadcast discovery signals separately when they discover a wireless link outage.

Step S303, in a relay selection scene, a first other node receives a discovery signal broadcast by a source node and/or a target node;

wherein the discovery signal comprises at least one set of information of:

self node ID, source node ID/target node ID;

source node ID/target node ID, current identity;

self node ID, source node ID/target node ID, current identity.

Step S304, in response to the discovery signal, when determining that the relay node itself is qualified as a candidate relay node according to a first judgment criterion, broadcasting the discovery response signal or feeding back the discovery response signal to the source node and/or the target node.

Wherein, the discovery response signal comprises the self node ID, the source node ID, the target node ID, and/or the moving speed, the moving direction, and/or the source and target node IDs that the link quality meets the second requirement, or the temporary source and target node IDs that the link quality meets the second requirement.

The embodiment actually provides a scheme that the first other node determines that itself is the candidate relay node in the case of a single hop, in other words, the first judgment criterion is a criterion for judging that itself is the candidate relay qualification in the case of a single hop.

Wherein the first judgment criterion includes a first sub-judgment criterion and a second sub-judgment criterion, wherein the first sub-judgment criterion is a necessary criterion, and the second sub-judgment criterion is an optional criterion, wherein:

the first sub-judgment criterion is that discovery signals of a source node and a target node are received simultaneously; or, the first sub-judgment criterion is that discovery signals of a source node and a target node are received simultaneously, and the signal strength of the source node and the signal strength of the target node meet a first requirement;

the second sub-judgment criterion is whether the moving direction of the second sub-judgment criterion is consistent with the moving direction of the source node and/or the target node, and/or whether the residual data size of the source node can be transmitted to the target node can be ensured according to the moving rates of the source node, the target node and the self node.

In an implementation, the first other node is a node other than the source node and the target node, and the first requirement may be that the signal strength is greater than a preset strength threshold.

In this embodiment of the present application, the moving direction of the source node may be the same as or different from the moving direction of the destination node, and therefore, the first determination criterion may be that, as long as the moving direction of the first other node is the same as the moving direction of the source node, or the moving direction of the first other node is the same as the moving direction of the destination node. Whether the data transmission between the source node and the target node can be completed through the current link can be judged according to the residual transmission time in the discovery signal and the relative speed between the discovery signal and the source node and between the discovery signal and the target node.

An embodiment of the present application provides a relay selection method, fig. 4 is a schematic diagram illustrating an implementation flow of the relay selection method in the embodiment of the present application, and as shown in fig. 4, the method includes:

step S401, in a relay selection scene, a source node and a target node find that a wireless link is interrupted;

step S402, the source node and the target node broadcast discovery signals respectively;

step S403, in a relay selection scene, a first other node receives a discovery signal broadcast by a source node and/or a target node;

in some embodiments, in step S402, if the source node and the target node find that the wireless link is broken, the source node and the target node broadcast discovery signals respectively, and correspondingly, in step S403, in the relay selection scenario, the first other node receives the discovery signals broadcast by the source node and/or the target node when the wireless link is broken.

Wherein the discovery signal comprises at least one set of information of:

self node ID, source node ID/target node ID;

source node ID/target node ID, current identity;

self node ID, source node ID/target node ID, current identity.

Step S404, in response to the discovery signal, when the first other node determines that the first other node qualifies as a candidate relay node according to a first judgment criterion, broadcasting the discovery response signal or feeding back the discovery response signal to the source node and/or the target node;

step S405, when the first other node determines that the first other node does not meet the first sub-judgment criterion and determines that the first other node has the qualification of becoming the temporary source node or the qualification of the temporary target node according to the second judgment criterion, the first other node broadcasts the discovery signal.

Here, the first sub-judgment criterion is not satisfied, that is, the signals of the source node and the target node which satisfy the requirement are not received at the same time.

Here, the second judgment criterion includes: the signal strength of the temporary source node as the source node meets a first requirement; the signal strength of the temporary target node as the target node meets a first requirement. The determining of the temporary source node may further include screening signal quality of the source node, and the temporary target node may further include screening signal quality of the target node, and in the implementation process, the signal quality may be represented by RSRQ, and the signal strength may be RSRP.

Step S406, a second other node receives the discovery signal broadcast by the temporary source node or the temporary target node;

step S407, in response to the discovery signal, when the second other node determines that the second other node is qualified as a candidate relay according to a third determination criterion, broadcasting the discovery response signal, or feeding back the discovery response signal to the temporary source node and/or the temporary target node.

Wherein the third judgment criterion simultaneously comprises the following conditions:

receiving discovery signals of the temporary source node and the temporary target node simultaneously,

The signal strength of the temporary source node and the signal strength of the temporary target node meet a first requirement,

The relay selection time is lower than a time threshold, and

and the multi-hop frequency is less than a frequency threshold value, wherein the multi-hop frequency is the number of the intermediate nodes when the path between the source node and the target node passes through the second other nodes.

In this embodiment, when the candidate relay node broadcasts the discovery response signal, the method further includes:

and within a timing time, if the first other node does not receive a discovery response signal broadcast by a candidate relay node, determining that the first sub-judgment criterion is not met.

The embodiment actually provides a method that, under the multi-hop condition, when all the first other nodes determine that the first other nodes are not candidate relay nodes, that is, no node receives discovery signals of a source node and a target node at the same time, and the multi-hop is required to pass through the multi-hop. When the node is multi-hop, whether the node can become a temporary source node or a temporary target node is judged according to a second judgment criterion; when the temporary source node or the temporary target node exists, the temporary source node or the temporary target node broadcasts the discovery signal, so that the second other node judges whether the second other node can become the candidate relay node (namely whether the second other node has the candidate relay qualification) according to the third judgment criterion. As can be seen from the above, the second judgment criterion is a criterion for judging whether the relay node itself can become a temporary source node or a temporary destination node in a multi-hop situation, and the third judgment criterion is a criterion for judging whether the relay node itself can become a candidate relay node of the temporary source node and the temporary destination node in the multi-hop situation. The second other node may be a node other than the source node, the target node, the temporary source node, and the temporary target node, in other words, the second other node may be a subset of the first other node, that is, the second other node may be another node of the first other node other than the temporary source node and the temporary target node.

In this embodiment, the source node and the target node respectively initiate a discovery process and select a relay node. The process comprises the following steps:

step S501, if the source node and the target node find that the wireless link is interrupted, respectively initiating a discovery process;

here, the initiating of the discovery procedure by the source node and/or the target node includes: firstly, a source node and/or a target node sends a discovery request signal to a network; second, if the network agrees, the source node and/or the target node may send a discovery signal at port PC 5.

The discovery signal includes its ID, an ID of the source node, an ID of the target node (which may be layer 2 identifier or application identifier), a current identity (temporary source node/temporary target node/source node/target node), and/or a rate size, a moving direction, and/or a size of a data block to be transmitted, and/or a remaining transmission time of the two.

In step S502, other nodes determine whether to qualify as a candidate relay according to the received source node information and/or target node information and according to a first determination criterion.

Here, the other nodes may be nodes other than the source node and the target node; the source node information may be a discovery signal sent by the source node, and the target node information may be a discovery signal sent by the target node;

here, the first judgment criterion includes a mandatory judgment criterion (first sub-judgment criterion) and an optional judgment criterion (second sub-judgment criterion), and the relay node may become a candidate relay node at least until the mandatory judgment criterion is met.

Wherein:

the required judgment criterion is whether the received RSRP thresholds of the source node and the target node or the temporary source node and the target node are both within a certain range;

the optional judgment criterion comprises whether the moving direction of the optional judgment criterion is consistent with the moving directions of the source node and the target node and/or whether the residual data size of the source node can be transmitted to the target node is judged according to the link information and the moving speed.

Step S503, if yes, other nodes (candidate relay nodes) may broadcast the discovery response signal to become relay nodes; or, the candidate relay node feeds back a discovery response signal to the source node (temporary source node); or, the candidate relay node feeds back the discovery response signal to the target node (temporary target node);

the discovery response signal may be a broadcast signal, and the discovery response signal includes a current node ID, a source node ID, a target node ID, a source node or temporary source node whose link quality meets a second requirement, a target node or temporary target node ID, and/or a current moving rate, and/or a moving direction of the target node or temporary target node within a time range in which the remaining data is completely transmitted;

step S504, when no candidate relay exists, all the nodes which meet RSRP requirements and receive source (temporary source) nodes or target (temporary target) nodes become temporary source or target nodes, and a discovery process is initiated to broadcast discovery signals;

if no candidate relay node broadcasts a discovery signal within a certain time, or no candidate relay node establishes connection with a source node or a target node, it is considered that no candidate relay exists at this time, (the scenario may be caused by current link penetration loss or large path loss, and needs multi-hop link auxiliary connection), and all nodes which meet RSRP requirements and receive the source (temporary source) node or the target (temporary target) node become temporary source or target nodes, and a discovery flow is initiated to broadcast the discovery signal.

Repeating the step until a certain node meets the judgment principle to become a candidate relay node, and performing the step S503; if the multi-hop frequency of the relay is higher than a frequency threshold (relay hop number threshold) or the relay selection time exceeds a time threshold (relay selection time threshold), releasing all link connections; wherein, the time threshold of relay selection and the number threshold of relay hops can be related to the service priority.

Step S505, a one-to-one connection between the source node and the target node and the relay node is established between the source node and the target node.

Here, the relay node between the source node and the target node is the final relay node, and three ways of establishing connection are introduced as follows:

mode a): if the multiple candidate relays broadcast the discovery response signal, selecting a final relay from the multiple candidate relays received within a certain time according to a consistency criterion; here, the conformity criterion may be a criterion that the moving rate is closest to the average of the rates of the source node and the temporary node.

And if the temporary source node and/or the temporary target node exist, the temporary source node and the temporary target node select candidate relay nodes according to a consistency principle and establish relay connection. And the temporary source node and the temporary target node after the relay connection is completed become candidate relays, the discovery response signals are broadcasted to the (temporary) source node and the (temporary) target node of the temporary source node and the (temporary) target node again, and the step is repeated until the relay link establishment between the source node and the target node is completed. If the temporary source node or the temporary target node does not meet the judgment criteria of being the temporary source and the temporary target node in the step S504 due to the time change, the whole connection is directly interrupted, and the relay connection is not established for the source and the target node.

Mode b): if a plurality of candidate relays feed back discovery response signals to a source (temporary source) node within a certain time, the source (temporary source) node determines a final relay according to a consistency criterion, establishes link connection with the relay, and then establishes link connection with a target (temporary target) node;

mode c): if a plurality of candidate relays feed back discovery response signals to a target (temporary target) node within a certain time, the target node (temporary target) node determines a final relay according to a consistency criterion, establishes link connection with the relay, and then establishes link connection with a source (temporary source) node;

modes a) and b), c) differ in that:

in the mode a), the candidate relay simultaneously feeds back discovery response signals to the source node and the target node, the source node and the target node simultaneously determine the candidate relay (final relay) according to a consistency criterion, and then link connections between the relay and the source node and the target node are respectively established;

in the modes b) and c), the candidate relay feeds back a response signal to the source node or the target node independently, firstly, unilateral link connection is established, and then, link connection in the other direction is established; if the target node selects one node from the candidate relays as the final relay and establishes the connection, the relay directly establishes the link connection with the source node, and vice versa.

Example 1:

this embodiment is used to illustrate how relay selection and link establishment are performed when there is a single hop and there are multiple candidate relays.

TABLE 1

Target vehicle	Vehicle F
		Vehicle A	Vehicle G
Vehicle B	Vehicle H
		Vehicle C	Vehicle I
Vehicle D	Vehicle J
		Vehicle E	Vehicle K
Source vehicle	Vehicle L

Tables 1 and 5 show that there may be some other vehicles between the source vehicle and the target vehicle, such as vehicles A, B, C, D, E, F, G, I, J, K and L. Between vehicles a to L, not all vehicles can receive discovery signals sent by a source vehicle or a target vehicle; for example, assume that none of cars a-E receive the discovery signals transmitted by the source car and the target car, cars F, G and H can receive the discovery signal transmitted by the target car, and cars G, H, I, J, K and L can receive the discovery signal transmitted by the source car.

If the target vehicle and the source vehicle respectively send discovery signals at the moment, wherein: the vehicle F, G, H receives the discovery signal of the target vehicle, and the signal quality meets the second requirement; and the vehicles G-L receive the discovery signal of the source vehicle, and the signal quality meets the second requirement, the vehicles G and H respectively send discovery response signals to the source vehicle and the target vehicle, wherein the discovery response signals comprise a target vehicle ID, the source vehicle ID, the current ID (G \ H), the current speed, the moving direction and the own moving direction within the time range of finishing transmitting the residual data.

The following source vehicle and target vehicle establish a connection in three ways in step 505:

in the mode a), the moving directions of a source vehicle and a target vehicle are found to be the same as the operation directions of the source vehicle and the target vehicle before the link is interrupted, but the speed of the vehicle G is closer to the average speed of the source vehicle and the target vehicle before the link is interrupted, and then the source vehicle and the target vehicle are respectively in relay connection with the vehicle G, so that the vehicle G assists the vehicle networking communication between the source vehicle and the target vehicle.

Mode b), the vehicle G, H feeds back the discovery response signals to the source vehicle respectively, the source vehicle selects the vehicle G as a relay according to the consistency criterion, establishes link connection with the vehicle G, and then establishes link connection with the target vehicle.

Mode c), the vehicle G, H feeds back the discovery response signals to the target vehicle, and the target vehicle selects the vehicle G as a relay according to a certain criterion, establishes link connection with the vehicle G, and then establishes link connection with the source vehicle.

Example 2:

this embodiment is used to illustrate how relay selection and link establishment can be performed in the presence of multihop.

TABLE 2

Target vehicle	Vehicle F (temporary target vehicle)
		Vehicle A	Vehicle G (temporary target vehicle) relay
Vehicle B	Vehicle H
		Vehicle C	Vehicle I
Vehicle D	Vehicle J (temporary Source vehicle) Relay
		Vehicle E	Vehicle K (temporary source vehicle)
Source vehicle	Vehicle L (temporary source vehicle)

Tables 2 and 6 show that there may be some other vehicles between the source and target vehicles, such as vehicles A, B, C, D, E, F, G, I, J, K and L. Between vehicles a to L, not all vehicles can receive discovery signals sent by a source vehicle or a target vehicle; for example, assume that none of cars a-E receive the discovery signals transmitted by the source car and the target car, cars F and G can receive the discovery signal transmitted by the target car, and cars J, K and L can receive the discovery signal transmitted by the source car.

If the target vehicle and the source vehicle respectively send discovery signals at the moment, wherein the vehicle F, G receives the discovery signals of the target vehicle, and the signal quality meets a second requirement; and car J, K, L receives the discovery signal of the source car and the signal quality meets a second requirement. If no terminal broadcasts the corresponding discovery response signal within a certain time, it is determined that no vehicle can become the candidate relay at this time, the vehicle F, G becomes the temporary target vehicle, the vehicles J, K and L become temporary source vehicles, and respectively transmit broadcast signals including the ID of the target vehicle or the source vehicle received by itself, the current ID, the current rate, the moving direction, and the moving direction of itself within the time range in which the transmission of the remaining data is completed.

If the H vehicle receives the broadcast signals of the temporary target vehicle G and the temporary source vehicle J at the same time within a certain time, and the signal quality meets a second requirement, the H vehicle becomes a candidate relay vehicle;

or broadcasting the response signals to the temporary target vehicle G and the temporary source vehicle J simultaneously, and if the vehicle J and the vehicle G find that only the response signals of the vehicle H are received within a certain time, respectively establishing wireless link connection with the vehicle H. If the multi-hop frequency is smaller than the frequency threshold and the relay selection time is smaller than the time threshold, the vehicle G and the vehicle J respectively feed back discovery response signals to the target vehicle and the source vehicle, and a corresponding relay link is established, so that data transmission between the source vehicle and the target vehicle is realized, and the source vehicle, the vehicle J, the vehicle H, the vehicle G and the target vehicle are realized.

Or the vehicle G only feeds back the response signal to the temporary target vehicle G, the vehicle G establishes a wireless link with the vehicle H, and after the link is established, the vehicle H establishes wireless link connection with the temporary source vehicle J. If the multi-hop frequency is smaller than the frequency threshold and the relay selection time is smaller than the time threshold, the vehicle G and the vehicle J respectively feed back discovery response signals to the target vehicle and the source vehicle, and a corresponding relay link is established, so that data transmission between the source vehicle and the target vehicle is realized, and the source vehicle, the vehicle J, the vehicle H, the vehicle G and the target vehicle are realized.

Or the vehicle J only feeds back the response signal to the temporary source vehicle J, the vehicle J establishes a wireless link with the vehicle H, and after the link is established, the vehicle H establishes wireless link connection with the temporary target vehicle G. If the multi-hop frequency is smaller than the frequency threshold and the relay selection time is smaller than the time threshold, the vehicle G and the vehicle J respectively feed back discovery response signals to the target vehicle and the source vehicle, and a corresponding relay link is established, so that data transmission between the source vehicle and the target vehicle is realized, and the source vehicle, the vehicle J, the vehicle H, the vehicle G and the target vehicle are realized.

Example 3:

this embodiment is used to illustrate a discovery signal and discovery response signal example;

referring to fig. 7, the discovery signal includes an own ID, a source node ID, a destination node ID, a current identity, a speed, a moving direction, and the like, wherein the current identity may be a temporary source node, a temporary destination node, a source node, or a destination node.

The discovery response signal includes the self ID, the source node ID, the destination node ID, the source node ID or the temporary source node ID, the destination node ID or the temporary destination node ID, the rate, and the moving direction, where the link quality meets the second requirement.

Example 4:

the embodiment is used to illustrate how to perform relay selection and link establishment when there are multiple candidate relays and there are multiple hops.

Fig. 8 shows a candidate relay selection process, in which E, G candidate relay vehicles become candidate relay vehicles, and a link between the source node a and the target node B can be established by using any one of the following schemes.

Scheme 1) vehicle E broadcasts discovery response signals to E, A, B, C, F, vehicle G broadcasts discovery response signals to G, A, B, C, F, and vehicle C, F receives the discovery response signals and finds itself to be a corresponding temporary source node and a temporary target node. And selecting a candidate relay in E and G as a final relay according to a consistency selection principle. Assuming that G is selected, establishing connection between G and C and F; if the multi-hop frequency is smaller than the frequency threshold and the relay selection time is lower than the time threshold, the vehicle C establishes link connection with the source node and the vehicle F establishes connection with the temporary target node D; if the multi-hop frequency is smaller than the frequency threshold and the relay selection time is smaller than the time threshold, the vehicle D establishes connection with the target node vehicle B, otherwise, all relay connection links are released.

Here, the number of multihops is the number of intermediate nodes in a path between the source node and the destination node passing through the second other node.

Scheme 2) or, the vehicle E and the vehicle G respectively feed back a discovery response signal to the temporary source node C, and the vehicle C selects the vehicle G as a final relay according to a certain criterion and establishes wireless link connection; then vehicle G establishes wireless link connection with temporary target node vehicle F; if the multi-hop frequency is smaller than the frequency threshold and the relay selection time is lower than the time threshold, the vehicle C establishes link connection with the source node A and the vehicle F establishes connection with the temporary target node D; if the multi-hop frequency is smaller than the frequency threshold and the relay selection time is smaller than the time threshold, the vehicle D establishes connection with the target node vehicle B, otherwise, all relay connection links are released.

Scheme 3) or the vehicle E and the vehicle G respectively feed back a discovery response signal to the temporary target node F, and the vehicle F selects the vehicle G as a final relay according to a certain criterion and establishes wireless link connection; then vehicle G establishes wireless link connection with temporary source node vehicle C; if the multi-hop frequency is smaller than the frequency threshold and the relay selection time is lower than the time threshold, the vehicle C establishes link connection with the source node and the vehicle F establishes connection with the temporary target node D; if the multi-hop frequency is smaller than the frequency threshold and the relay selection time is smaller than the time threshold, the vehicle D establishes connection with the target node vehicle B, otherwise, all relay connection links are released.

The embodiment of the application has the following characteristics: 1) if the source node and the target node find that the wireless link is interrupted, respectively initiating a discovery process. 2) The discovery signal includes ID identification of the source and target nodes (which may be layer 2 identification or application identification), and/or rate size, direction of movement, and/or data block size to be transmitted for both. 3) And judging whether the terminal has the qualification of becoming a candidate relay or not by other terminals according to the received source node information and/or target node information and a judgment criterion. If the relay is available, the discovery response signal is broadcasted to the source node and the target node, and the relay becomes a candidate relay. 4) And the source node and the target node select a final relay from a plurality of candidate relays according to a consistency criterion to establish one-to-one connection between the source node, the relay and the target node.

Compared with the prior art, the embodiment of the application has the following technical advantages: 1) the discovery resource waste and the energy consumption waste caused by the discovery process of all the candidate relays are avoided; according to the scheme of the embodiment of the application, only the source node and the target node are needed to perform a discovery process, so that resources and energy consumption are saved; 2) considering that the moving speed of the vehicle in the scene of the internet of vehicles is high, when the candidate relay is selected, the speed, the moving direction and the like of the vehicle need to be considered at the same time so as to ensure that the relay connection is stable, and the residual data transmission between the source node and the target node is completed through one-time relay link establishment.

Based on the foregoing embodiments, embodiments of the present application provide a relay selection apparatus, where units included in the apparatus and modules included in the units may be implemented by a processor in a relay selection device (e.g., a source node, a destination node, other nodes, a temporary source node, a temporary destination node, etc.); of course, it may also be implemented by logic circuitry; in implementation, the processor may be a Central Processing Unit (CPU), a Microprocessor (MPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), or the like.

The relay selection devices in the source node and the target node in the embodiments of the present application are configured to respectively initiate a discovery process in a relay selection scenario.

Fig. 9A is a schematic structural diagram of a relay selection apparatus in an embodiment of the present application, and as shown in fig. 9A, the apparatus 900 includes:

a discovery unit 901, configured to discover a radio link interruption in a relay selection scenario;

an initiating unit 902 is configured to initiate a discovery procedure.

In other embodiments, the initiating unit 902 is further configured to initiate a discovery procedure if the radio link is found to be broken, respectively.

The device judges whether the node where the device is located is a source node or a target node, and if the node where the device is located is found to be the source node or the target node, the device discovers that a wireless link is interrupted in a relay selection scene.

In other embodiments, the initiating unit is configured to broadcast a discovery signal, wherein:

the discovery signal includes at least one set of information of:

self node ID, source node ID/target node ID;

source node ID/target node ID, current identity;

self node ID, source node ID/target node ID, current identity.

In other embodiments, the apparatus determines whether the node where the apparatus is located is a temporary source node or a temporary target node, and if the node where the apparatus is located is found to be the temporary source node or the temporary target node, the apparatus further includes:

a first broadcasting unit for broadcasting a discovery signal, wherein:

In other embodiments, the node ID includes a layer 2 identification, an application identification; the current identity comprises a source node, a temporary source node, a target node and a temporary target node.

In other embodiments, the discovery signal further includes a moving speed, a moving direction, and/or a size of a data block to be transmitted, and/or a coding adjustment manner, and/or a remaining transmission time.

In other embodiments, the apparatus further comprises:

a first receiving unit, configured to receive a discovery response signal sent by a candidate relay node;

a first establishing unit, configured to establish links among a source node, a relay node, and a target node according to the discovery response signal; wherein:

the candidate relay nodes simultaneously receive discovery signals sent by the source node and the target node, and the signal strength of the source node and the signal strength of the target node both meet a first requirement.

In other embodiments, the discovery response signal includes the self node ID, the source node ID, the target node ID, and/or the source node ID, the target node ID, the temporary target node ID, and the temporary source node ID whose moving speed, moving direction, and/or link quality meet the second requirement.

In another embodiment, when the source node or the target node receives discovery response signals sent by a plurality of candidate relay nodes, the first establishing unit is configured to:

determining a relay node from the candidate relay nodes according to the same consistency criterion and discovery response signals of the candidate relay nodes, and establishing links among a source node, the relay node and a target node; or

And determining a relay node from the candidate relay nodes according to a certain criterion and discovery response signals of the candidate relay nodes, and establishing links among the source node, the relay node and the target node.

In other embodiments, when the source node or the target node receives discovery response signals sent by a plurality of candidate relay nodes, the first establishing unit includes:

a sending module, configured to send a request message to a base station, where the request message carries node information of all or part of candidate relay nodes, and the node information includes a discovery response signal;

a determining module, configured to determine a relay node according to a response message issued by the base station;

the establishing module is used for establishing links among the source node, the relay node and the target node.

In other embodiments, the apparatus further comprises:

a releasing unit, configured to, if link establishment has been completed by assistance of the relay node between the source node and the target node, send a discovery release signal to notify other nodes that link establishment has been completed, where the discovery release signal includes a source node ID and a target node ID.

In other embodiments, the conformance criteria are configured or preconfigured by the base station and comprise one of:

Based on the foregoing embodiments, an embodiment of the present application provides a relay selection apparatus, fig. 9B is a schematic structural diagram of a relay selection apparatus in an embodiment of the present application, and as shown in fig. 9B, the apparatus 910 includes:

a second receiving unit 911, configured to receive a discovery signal broadcast by a source node and/or a target node in a relay selection scenario; in some embodiments, the second receiving unit 911 is configured to receive, in a relay selection scenario, a discovery signal broadcast by the source node and/or the target node when discovering that the wireless link is interrupted.

A first processing unit 912, configured to broadcast a discovery response signal or feed back the discovery response signal to the source node and/or the target node when determining that the relay node is qualified as a candidate relay node according to a first determination criterion in response to the discovery signal.

In other embodiments, the discovery signal includes at least one set of information comprising:

self node ID, source node ID/target node ID;

source node ID/target node ID, current identity;

self node ID, source node ID/target node ID, current identity.

In other embodiments, the discovery response signal includes the self node ID, the source node ID, the target node ID, and/or the moving speed, moving direction, and/or the source and target node IDs whose link quality meets the second requirement, or the temporary source and target node IDs whose link quality meets the second requirement.

In other embodiments, the first determination criterion includes a first sub-determination criterion, where the first sub-determination criterion is that discovery signals of a source node and a target node are received simultaneously, and a signal strength of the source node and a signal strength of the target node meet a first requirement.

In other embodiments, the first determination criterion further includes a second sub-determination criterion, where the second sub-determination criterion is whether a moving direction of the second sub-determination criterion is consistent with a moving direction of the source node and/or the target node, and/or whether it is determined whether it is guaranteed that the remaining data size of the source node is transmitted to the target node according to a moving rate.

In other embodiments, the apparatus further comprises:

and a second broadcasting unit for broadcasting the discovery signal when determining that the first sub-judgment criterion is not satisfied and determining that the second sub-judgment criterion is qualified as the temporary source node or the temporary target node according to the second judgment criterion.

In other embodiments, when the candidate relay node broadcasts the discovery response signal, the apparatus further comprises:

a determining unit, configured to determine that the first sub-judgment criterion is not satisfied if the first other node does not receive the discovery response signal broadcast by the candidate relay node within a timing time.

In other embodiments, the second criterion includes:

In other embodiments, the apparatus further comprises:

a third receiving unit, configured to receive a discovery signal broadcast by the temporary source node or the temporary target node;

and the second processing unit is used for responding to the discovery signal, broadcasting the discovery response signal when determining that the node is qualified as a candidate relay according to a third judgment criterion, or feeding back the discovery response signal to the temporary source node and/or the temporary target node.

In other embodiments, the third determination criterion includes the following conditions:

receiving discovery signals of the temporary source node and the temporary target node at the same time, wherein the signal strength of the temporary source node and the signal strength of the temporary target node meet a first requirement,

The relay selection time is lower than a time threshold, and

The above description of the apparatus embodiments, similar to the above description of the method embodiments, has similar beneficial effects as the method embodiments. For technical details not disclosed in the embodiments of the apparatus of the present application, reference is made to the description of the embodiments of the method of the present application for understanding.

It should be noted that, in the embodiment of the present application, if the relay selection method is implemented in the form of a software functional module and sold or used as a standalone product, the relay selection method may also be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a relay selection apparatus to perform all or part of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read Only Memory (ROM), a magnetic disk, or an optical disk. Thus, embodiments of the present application are not limited to any specific combination of hardware and software.

Correspondingly, an embodiment of the present application provides a relay selection device, including a memory and a processor, where the memory stores a computer program executable on the processor, and the processor implements the steps in the relay selection method described above when executing the program.

Correspondingly, an embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps in the relay selection method described above.

Here, it should be noted that: the above description of the storage medium and device embodiments is similar to the description of the method embodiments above, with similar advantageous effects as the method embodiments. For technical details not disclosed in the embodiments of the storage medium and apparatus of the present application, reference is made to the description of the embodiments of the method of the present application for understanding.

It should be noted that fig. 10 is a schematic diagram of a hardware entity of a relay selection apparatus in an embodiment of the present application, and as shown in fig. 10, the hardware entity of the relay selection apparatus 1000 includes: a processor 1001, a communication interface 1002, and a memory 1003, among others

The processor 1001 generally controls the overall operation of the relay selection device 1000.

The communication interface 1002 may enable the relay selection device to communicate with other terminals or base stations, etc. over a network.

The Memory 1003 is configured to store instructions and applications executable by the processor 1001, and may also cache data to be processed or already processed by each module in the processor 1001 and the relay selection device 1000, and may be implemented by a FLASH Memory (FLASH) or a Random Access Memory (RAM).

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units; can be located in one place or distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, the program can be stored in a computer readable storage medium, and the program executes the steps comprising the method embodiments when executed; and the aforementioned storage medium includes: various media that can store program codes, such as a removable Memory device, a Read Only Memory (ROM), a magnetic disk, or an optical disk.

Alternatively, the integrated units described above in the present application may be stored in a computer-readable storage medium if they are implemented in the form of software functional modules and sold or used as independent products. Based on such understanding, the technical solutions of the embodiments of the present application may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a device to perform all or part of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a removable storage device, a ROM, a magnetic or optical disk, or other various media that can store program code.

The above description is only for the embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A relay selection method, the method comprising:

2. The method of claim 1, wherein the initiating the discovery procedure comprises broadcasting a discovery signal, wherein:

the discovery signal includes at least one set of information of:

self node ID, source node ID/target node ID;

source node ID/target node ID, current identity;

self node ID, source node ID/target node ID, current identity.

3. The method of claim 2, further comprising:

4. The method of claim 2, wherein the node ID comprises a layer 2 identification, an application identification; the current identity comprises a source node, a temporary source node, a target node and a temporary target node.

5. The method according to claim 2, wherein the discovery signal further comprises a moving speed, a moving direction, and/or a size of a data block to be transmitted, and/or a coding adjustment manner, and/or a remaining transmission time.

6. The method according to any of claims 1 to 5, wherein after initiating a discovery procedure, the method further comprises:

the source node and/or the target node receive discovery response signals sent by candidate relay nodes;

the source node and/or the target node establish links among the source node, the relay node and the target node according to the discovery response signal; wherein:

7. The method according to claim 6, wherein the discovery response signal comprises the self node ID, the source node ID, the target node ID, and/or the source node ID, the target node ID, the temporary target node ID, and/or the temporary source node ID, wherein the moving speed, the moving direction, and/or the link quality meet the second requirement.

8. The method according to claim 7, wherein when the source node or the target node receives discovery response signals sent by a plurality of candidate relay nodes, the source node and/or the target node establishes links between the source node, the relay nodes and the target node according to the discovery response signals, and the method comprises one of the following steps:

and the source node or the target node determines a relay node from the candidate relay nodes and establishes links among the source node, the relay node and the target node.

9. The method according to claim 7, wherein when the source node or the target node receives discovery response signals sent by a plurality of candidate relay nodes, the source node and/or the target node establishing links between the source node, the relay nodes and the target node according to the discovery response signals comprises:

10. The method of claim 6, further comprising:

if the link establishment between the source node and the target node is completed by the aid of the relay node, the source node and the target node send discovery release signals to inform other nodes that the link establishment is completed, wherein the discovery release signals comprise source node IDs and target node IDs.

11. The method of claim 8, wherein the conformance criteria is configured or preconfigured by the base station and comprises one of:

12. A relay selection method, the method comprising:

13. The method of claim 12, wherein the discovery signal comprises at least one set of information comprising:

self node ID, source node ID/target node ID;

source node ID/target node ID, current identity;

self node ID, source node ID/target node ID, current identity.

14. The method according to claim 12, wherein the discovery response signal comprises the self node ID, the source node ID, the target node ID, and/or the moving speed, the moving direction, and/or the source and target node IDs whose link quality meets the second requirement, or the temporary source and target node IDs whose link quality meets the second requirement.

15. The method of claim 12, wherein the first criterion comprises a first sub-criterion, the first sub-criterion is that discovery signals of a source node and a target node are received simultaneously, and the signal strength of the source node and the signal strength of the target node meet a first requirement.

16. The method according to claim 15, wherein the first criterion further comprises a second sub-criterion, and the second sub-criterion is whether its moving direction is consistent with the moving direction of the source node and/or the target node, and/or whether it is determined whether the remaining data size of the source node can be guaranteed to be transmitted to the target node according to the moving rate.

17. The method of claim 12, further comprising:

and when the first other node determines that the first other node does not meet the first sub-judgment criterion and determines that the first other node is qualified as a temporary source node or a temporary target node according to the second judgment criterion, broadcasting the discovery signal.

18. The method of claim 17, wherein when a candidate relay node broadcasts a discovery response signal, the method further comprises:

and in a timing time, if the first other node does not receive the discovery response signal broadcasted by the candidate relay node, determining that the first sub-judgment criterion is not met.

19. The method of claim 17, wherein the second criterion comprises:

20. The method of claim 19, further comprising:

receiving, by a second other node, a discovery signal broadcast by the temporary source node or the temporary target node;

and responding to the discovery signal, and broadcasting the discovery response signal or feeding back the discovery response signal to the temporary source node and/or the temporary target node when determining that the node is qualified as a candidate relay according to a third judgment criterion.

21. The method according to claim 20, wherein the third determination criterion includes the following conditions:

The relay selection time is lower than a time threshold, and

22. A relay selection apparatus, the apparatus comprising:

and the initiating unit is used for initiating the discovery process.

23. A relay selection apparatus, the apparatus comprising:

24. A relay selection device comprising a memory and a processor, the memory storing a computer program operable on the processor, wherein the processor implements the steps in the relay selection method of any one of claims 1 to 11 when executing the program; alternatively, the processor implements the steps in the relay selection method of any one of claims 12 to 21 when executing the program.

25. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the relay selection method according to any one of claims 1 to 11; alternatively, the computer program when executed by a processor implements the steps in the relay selection method of any of claims 12 to 21.