Method for determining resource for device-to-device (D2D) communication in wireless communication system and apparatus therefor

1. A method of determining a resource for device-to-device (D2D) communication in a wireless communication system, the method comprising:

receiving, from a base station (BS), configuration information on a resource pool configured for each level;

selecting a resource pool of D2D communication based on the configuration information;

selecting a resource in the resource pool based on a level to be used in the D2D communication determined by using a load of D2D communication,

wherein the resource pool is configured in at least two levels, and

wherein, when the load f D2D communication is equal to or greater than a threshold load for a specific level and is less than a threshold load of a higher level of the specific level, the specific level is determined as the level; and

transmitting a signal to a counterpart user equipment (UE) of the D2D communication using the selected resource.

2. The method according to claim 1 , wherein the level to be used in the D2D communication is further determined based on an importance of a signal of the D2D communication.

3. The method according to claim 1 , wherein, when the level is determined as n+1, the selected resource pool comprises a resource pool for the level (n+1), where n is a positive integer.

4. The method according to claim 3 , wherein the selected resource pool comprises a resource pool for level n.

5. The method according to claim 1 , wherein:

the configuration information indicates a resource for each level; and

a resource for each level is a resource added from a resource for a low level.

6. The method according to claim 1 , wherein the selecting of the resource pool is performed at a predetermined period.

7. The method according to claim 1 , further comprising:

transmitting information on the determined level to a BS by the UE.

8. The method according to claim 7 , further comprising:

receiving scheduling information based on information on the determined level.

9. The method according to claim 8 , wherein a resource corresponding to a remaining resource pool except for a resource pool of a selected level from the resource pool configured for each level is allocated for a signal with the BS.

10. A user equipment (UE) for performing a method determining a resource for device-to-device (D2D) communication in a wireless communication system, the UE comprising:

a transceiver for transmitting and receiving a signal to and from a base station (BS) or a counterpart UE of D2D communication; and

a processor for processing the signal,

wherein the processor is configured to:

receive, from a base station (BS), configuration information on a resource pool configured for each level select a resource pool of D2D communication based on the configuration information, and

select a resource of D2D communication in the resource pool based on a level of to be used in the D2D communication determined by using a load of D2D communication,

wherein the resource pool is configured in at least two levels,

wherein, when the load of D2D communication is equal to or greater than a threshold load for a specific level and is less than a threshold load of a higher level of the specific level, the specific level is determined as the level, and

transmit a signal to a counterpart user equipment (UE) of the D2D communication using the selected resource.