Radio terminal

1. A radio terminal, comprising:

a controller configured to be capable of relaying traffic between another radio terminal and a network by a proximity service, wherein

the controller performs a control for transmitting first information and second information, in a sidelink,

the first information is used for identifying a location of a radio resource in which the second information is arranged, and

the second information is used to identify a location of a radio resource for requesting the relay by the proximity service.

2. The radio terminal according to claim 1 , wherein

the controller executes a control for receiving, from the another radio terminal, a request for the relay transmitted by using the radio resource.

3. The radio terminal according to claim 2 , wherein

the controller performs a control for transmitting, to a base station, information indicating a desire for the relay, in response to reception of the request for the relay.

4. The radio terminal according to claim 2 , wherein

the radio resource includes a plurality of respectively different small resources,

each of the plurality of small resources is associated with a respectively different temporary identifier,

the request for the relay includes a temporary identifier associated with a small resource used for transmitting the request for the relay,

the controller executes a control for transmitting a response to the request for the relay to the another radio terminal, and

the response includes the temporary identifier included in the request for the relay.

5. The radio terminal according to claim 2 , wherein

the controller executes a control for transmitting a response to the request for the relay to the another radio terminal, and

the response includes information for adjusting a transmission timing to the radio terminal from the another radio terminal.

6. The radio terminal according to claim 1 , wherein

the controller executes, before transmitting the first information, a control for receiving third information in the sidelink from the another radio terminal or a base station, and

the controller starts, in response to receipt of the third information, a control for transmitting the first information.

7. The radio terminal according to claim 1 , wherein

the controller is individually allocated, from a base station, with a dedicated resource used in the sidelink, and

the controller shares the dedicated resource with the another radio terminal.

8. The radio terminal according to claim 1 , wherein

a plurality of control regions used for transmitting control information are arranged in a time direction,

the control information is used for identifying a location of a radio resource in which user data transmitted in a sidelink is arranged,

the controller selects a control region used for transmitting the control information out of the plurality of control regions, according to a sidelink DRX (Discontinuous Reception) operation of the another radio terminal, and

the sidelink DRX operation is an operation for discontinuously monitoring, by the another radio terminal, the plurality of control regions.

9. The radio terminal according to claim 1 , wherein

the controller executes a control for transmitting power control information to the another radio terminal,

the power control information includes parameter information for controlling a transmission power of a sidelink signal to the radio terminal from the another radio terminal, and

the parameter information is decided according to a received power of the sidelink signal from the radio terminal to the another radio terminal.

10. The radio terminal according to claim 1 , wherein

the controller executes a control for transmitting power control information to the another radio terminal,

the power control information includes command information for controlling a transmission power of a sidelink signal to the radio terminal from the another radio terminal, and

the command information is decided according to a received power of the sidelink signal.

11. A radio terminal, comprising:

a controller configured to execute a control for receiving first information and second information, in a sidelink, from another radio terminal configured to be capable of relaying traffic between the radio terminal and a network by a proximity service, wherein

the first information is used to identify a location of a radio resource in which the second information is arranged, and

the second information is used to identify a location of a radio resource for requesting the relay by the proximity service.

12. The radio terminal according to claim 11 , wherein

the controller executes a control for transmitting a request for the relay, to the another radio terminal, by using the radio resource.

13. The radio terminal according to claim 12 , wherein

the radio resource includes a plurality of respectively different small resources,

each of the plurality of small resources is associated with a respectively different temporary identifier, and

the controller includes a temporary identifier associated with a small resource used for transmitting a request for the relay, into the request for the relay.

14. The radio terminal according to claim 13 , wherein

the controller executes a control for receiving a response to the request for the relay from the another radio terminal, and

the response includes the temporary identifier included in the request for the relay.

15. The radio terminal according to claim 12 , wherein

the controller executes a control for receiving a response to the request for the relay from the another radio terminal, and

the response includes information for adjusting a transmission timing to the another radio terminal from the radio terminal.

16. The radio terminal according to claim 11 , wherein

the controller executes, before receiving the first information, a control for transmitting third information in the sidelink, and

the controller receives the first information from the another radio terminal having received the third information.

17. The radio terminal according to claim 11 , wherein

the controller shares a dedicated resource used in the sidelink, with the another radio terminal, and

the dedicated resource is a radio resource allocated individually from a base station to the another radio terminal.

18. The radio terminal according to claim 11 , wherein

a plurality of control regions used for transmitting control information are arranged in a time direction,

the control information is used for identifying a location of a radio resource in which user data transmitted in a sidelink is arranged, and

the controller executes a sidelink DRX (Discontinuous Reception) operation for discontinuously monitoring the plurality of control regions.

19. The radio terminal according to claim 11 , wherein

the controller executes a control for receiving power control information from the another radio terminal,

the power control information includes parameter information for controlling a transmission power of a sidelink signal from the radio terminal to the another radio terminal, and

the parameter information is decided according to a received power of the sidelink signal from the another radio terminal to the radio terminal.

20. The radio terminal according to claim 11 , wherein

the controller executes a control for receiving power control information from the another radio terminal,

the power control information includes command information for controlling a transmission power of a sidelink signal from the radio terminal to the another radio terminal, and

the command information is decided according to a received power of the sidelink signal.