Method and apparatus for avoiding signal collision by enhanced distributed coordination access in wireless local access network

1. An operation method of a first communication node for transmitting a message in a vehicle-to-everything (V2X) communication network, comprising:

receiving, by a controller, information regarding a time period including a plurality of transmission slots from a second communication node;

selecting, by the controller, one transmission slot included in the time period based on a first index configured based on the information regarding the time period; and

transmitting, by the controller, a message through the one transmission slot,

wherein the information regarding the time period includes information regarding a number of the plurality of transmission slots included in the time period,

wherein the selecting of the one transmission slot includes detecting a collision between messages in the transmission slot indicated by the first index by performing a carrier sense multiple access/collision avoidance (CSMA/CA) operation in the transmission slot indicated by the first index, and

wherein when the collision is detected as a result of the CSMA/CA operation, reconfiguring a second index except the first index.

2. The operation method according to claim 1 , wherein the number of the plurality of transmission slots included in the time period is configured based on at least one of a number of communication nodes located within a preconfigured distance from the second communication node, a data transmission rate of the message, and a number of messages transmitted during the time period.

3. The operation method according to claim 1 , wherein the receiving of the information regarding the time period includes receiving a wireless access for vehicle environment (WAVE) service advertisement (WSA) including the information regarding the time period through a control channel (CCH).

4. The operation method according to claim 1 , wherein the selecting of the one transmission slot further includes, when a number of performing the reconfiguring of the second index exceeds a preconfigured threshold, changing a channel access mode of the time period.

5. The operation method according to claim 1 , wherein the transmitting of the message further includes, when the transmission of the message is completed in the one transmission slot, maintaining the first index of the one transmission slot after transmitting the message through the one transmission slot.

6. The operation method according to claim 1 , wherein the transmitting of the message further includes, when the one transmission slot is terminated before the transmission of the message is completed, transmitting the message additionally through a transmission slot after the one transmission slot.

7. A second communication node for transmitting a message in a vehicle-to-everything (V2X) communication network, comprising:

a processor;

a memory configured to store at least one instruction executable by the processor; and

at least one antenna configured to perform signal transmission and reception based on an operation of the processor,

wherein when executed by the processor, the at least one instruction is configured to:

generate information regarding transmission slots for granting transmission opportunities to first communication nodes;

generate information regarding a time period including a plurality of transmission slots based on the information regarding the transmission slots; and

transmit a message including the information regarding the time period to the first communication nodes,

wherein the information regarding the time period includes information on a number of the plurality of transmission slots included in the time period, and

wherein the number of the plurality of transmission slots included in the time period is configured based on a number of the first communication nodes located within a preconfigured distance from the second communication node and a number of messages transmitted by the first communication nodes during the time period.

8. The second communication node according to claim 7 , wherein the second communication node is a road side unit (RSU), and the first communication nodes are on board units (OBUs).

9. The second communication node according to claim 7 , wherein the at least one instruction is further configured to transmit a wireless access for vehicle environment (WAVE) service advertisement (WSA) including the information on the time period through a control channel (CCH).

10. A first communication node for transmitting a message in a vehicle-to-everything (V2X) communication network, comprising:

a processor;

a memory configured to store at least one instruction executable by the processor; and

at least one antenna configured to perform signal transmission and reception based on an operation of the processor,

wherein when executed by the processor, the at least one instruction is configured to:

receive information regarding a time period including a plurality of transmission slots from a second communication node;

select one transmission slot included in the time period based on a first index configured based on the information regarding the time period; and

transmit a message through the one transmission slot,

wherein the information regarding the time period includes information regarding a number of the plurality of transmission slots included in the time period,

wherein the at least one instruction is further configured to detect a collision between messages in the transmission slot indicated by the first index by performing a carrier sense multiple access/collision avoidance (CSMA/CA) operation in the transmission slot indicated by the first index, and reconfigure a second index except the first index when the collision is detected as a result of the CSMA/CS operation.

11. The first communication node according to claim 10 , wherein the number of the plurality of transmission slots included in the time period is configured based on at least one of a number of communication nodes located within a preconfigured distance from the second communication node, a data transmission rate of the message, and a number of messages transmitted during the time period.

12. The first communication node according to claim 10 , wherein the at least one instruction is further configured to receive a wireless access for vehicle environment (WAVE) service advertisement (WSA) including the information on the time period through a control channel (CCH).

13. The first communication node according to claim 10 , wherein the at least one instruction is further configured to, when a number of performing the reconfiguring of the second index exceeds a preconfigured threshold, change a channel access mode of the time period.

14. The first communication node according to claim 10 , wherein the at least one instruction is further configured to, when the transmission of the message is completed in the one transmission slot, maintain the first index of the one transmission slot after transmitting the message through the one transmission slot.

15. The first communication node according to claim 10 , wherein the at least one instruction is further configured to, when the one transmission slot is terminated before the transmission of the message is completed, transmit the message additionally through a transmission slot after the one transmission slot.