Vehicle terminal for controlling V2X message transmission between vehicle terminals through V2X service in wireless communication system and communication control method thereof

1. A communication control method of a vehicle user equipment (UE) for controlling vehicle-to-everything (V2X) message transmission between vehicle UEs through a V2X service in a wireless communication system, the communication control method comprising:

receiving a V2X message from a first vehicle UE based on the vehicle UE being located in a coverage area of the first vehicle UE, wherein the first vehicle UE is in a V2X-network exposure function (NEF) active status;

determining whether the V2X message is transmitted to a second vehicle UE located in a coverage area of the vehicle UE, based on relaying information indicating whether the V2X message is relayed; and

transmitting the V2X message to the second vehicle UE, upon determining that the V2X message is transmitted to the second vehicle UE,

wherein the relaying information includes at least one of active status information, relay probability information or residual life information.

2. The communication control method of claim 1 , wherein, when the V2X message is received from the first vehicle UE, the coverage area of the vehicle UE is smaller than a normal coverage area of the vehicle UE.

3. The communication control method of claim 1 ,

wherein the relaying information includes the residual life information, and the residual life information is acquired from the received V2X message,

wherein the determining of whether the V2X message is transmitted further comprises subtracting, by a positive integer of 1, a value of a residual life indicated by the residual life information, and

wherein, when the reduced value of the residual life is greater than 0, the V2X message including the reduced value of the residual life is transmitted to the second vehicle UE.

4. The communication control method of claim 3 , wherein, when the reduced value of the residual life is not greater than 0, the V2X message is not transmitted to the second vehicle UE.

5. The communication control method of claim 1 ,

wherein the relaying information includes the active status information,

wherein the active status information indicates whether the vehicle UE is in the V2X-NEF active status, and

wherein whether the V2X message is transmitted to the second vehicle UE is determined based on whether the vehicle UE is in the V2X-NEF active status.

6. The communication control method of claim 5 ,

wherein the relaying information includes the residual life information,

wherein the residual life information is acquired from the received V2X message,

wherein the determining of whether the V2X message is transmitted further comprises subtracting, by a positive integer of 1, a value of a residual life indicated by the residual life information, and

wherein, when the vehicle UE is in the V2X-NEF active status and the reduced value of the residual life is greater than 0, the V2X message including the reduced value of the residual life is transmitted to the second vehicle UE.

7. The communication control method of claim 1 ,

wherein the relaying information includes the relay probability information,

wherein the relay probability information indicates an event value in a sample space for the V2X message in a predetermined probability distribution defined using [0, 1] as the sample space, and

wherein whether the V2X message is transmitted to the second vehicle UE is determined based on whether the event value is equal to or greater than a predetermined threshold.

8. The communication control method of claim 5 ,

wherein the relaying information includes the relay probability information,

wherein the relay probability information indicates an event value in a sample space for the V2X message in a predetermined probability distribution defined using [0, 1] as the sample space, and

wherein whether the V2X message is transmitted to the second vehicle UE is determined based on whether the event value is equal to or greater than a predetermined threshold.

9. The communication control method of claim 7 , wherein the predetermined probability distribution includes at least one of a uniform distribution, a meta function distribution, an exponential function distribution or a log function distribution.

10. The communication control method of claim 7 ,

wherein the relaying information includes the residual life information,

wherein the residual life information is acquired from the received V2X message,

wherein the determining of whether the V2X message is transmitted further comprises subtracting, by a positive integer of 1, a value of a residual life indicated by the residual life information, and

wherein, when the event value is equal to or greater than the predetermined threshold and the reduced value of the residual life is greater than 0, the V2X message is transmitted to the second vehicle UE.

11. The communication control method of claim 8 , wherein, when the vehicle UE is in the V2X-NEF active status, the event value is equal to or greater than the predetermined threshold, and the reduced value of the residual life is greater than 0, the V2X message is transmitted to the second vehicle UE.

12. The communication control method of claim 1 , wherein the V2X message include a basic safety message (BSM).

13. A vehicle user equipment (UE) for controlling vehicle-to-everything (V2X) message transmission between vehicle UEs through a V2X service in a wireless communication system, the vehicle UE comprising:

a transceiver configured to transmit and receive signals to and from vehicle UEs; and

at least one processor,

wherein the at least one processor:

controls the transceiver to receive a V2X message from a first vehicle UE based on the vehicle UE being located in a coverage area of the first vehicle UE, wherein the first vehicle UE is in a V2X-network exposure function (NEF) active status;

determines whether the V2X message is transmitted to a second vehicle UE located in a coverage area of the vehicle UE, based on relaying information indicating whether the V2X message is relayed; and

controls the transceiver to transmit the V2X message to the second vehicle UE, upon determining that the V2X message is transmitted to the second vehicle UE, and

wherein the relaying information includes at least one of active status information, relay probability information or residual life information.

14. The vehicle UE of claim 13 , wherein the vehicle UE communicates with at least one of a mobile terminal, a network or an autonomous vehicle other than the vehicle UE.

15. The vehicle UE of claim 13 , wherein the vehicle UE implements at least one advanced driver assistance system (ADAS) based on a signal for controlling movement of the vehicle UE.

16. The vehicle UE of claim 13 , wherein the vehicle UE receives user input and switches a driving mode of the vehicle UE from an autonomous driving mode to a manual driving mode or from the manual driving mode to the autonomous driving mode.

17. The vehicle UE of claim 13 , wherein the vehicle UE is autonomously driven based on object information, and the object information includes at least one of information on presence/absence of an object, location information of the object, information on a distance between the vehicle UE and the object or information on a relative velocity between the vehicle UE and the object.

18. A wireless communication system for dynamic relaying control of vehicle-to-everything (V2X) message transmission between vehicle UEs through a V2X service, the wireless communication system comprising:

a first vehicle UE including a first transceiver configured to transmit and receive signals to vehicle UEs, and a first processor configured to control the first transceiver to transmit a V2X message to a second vehicle UE based on the first vehicle UE being located in a coverage area of the second vehicle UE, wherein the second vehicle UE is in a V2X-network exposure function (NEF) active status;

the second vehicle UE including a second transceiver configured to transmit and receive signals to vehicle UEs, and a second processor configured to control the second transceiver to receive the V2X message from the first vehicle UE, to determine whether the V2X message is transmitted to a third vehicle UE located in a coverage area, based on relaying information indicating whether the V2X message is relayed, and to control the second transceiver to transmit the V2X message to the third vehicle UE, upon determining that the V2X message is transmitted to the third vehicle UE; and

the third vehicle UE including a third transceiver configured to transmit and receive signals to vehicle UEs, and a third processor configured to control the third transceiver to receive the V2X message from the second vehicle UE,

wherein the relaying information includes at least one of active status information, relay probability information or residual life information.