Radio terminal, method to operate a radio terminal, and method to operate a radio communications network
A first radio terminal of a radio communications network. In one example, the first radio terminal includes an electronic processor, a communication module, and an antenna. The electronic processor is configured, together with the communication module, and the antenna, to cause the radio terminal to transmit, in a first transmission to a second radio terminal, data via a first subset of a set of SPS radio resources, reserve a second subset of the set of SPS radio resources for a subsequent data transmission, and in response to detecting a triggering event, skip the subsequent data transmission.
1. A first radio terminal (UE 1 ) of a radio communications network, the first radio terminal comprising:
an electronic processor, a communication module, and an antenna, wherein the electronic processor is configured, together with the communication module, and the antenna, to cause the radio terminal to perform a set of operations including:
determining a configuration for the first radio terminal (UE 1 ), wherein the configuration indicates radio resources (rr 1 -rr 4 ) of a shared device-to-device radio channel (CH), wherein the indicated radio resources (rr 1 -rr 4 ) are intended for a transmission by the first radio terminal (UE 1 );
selecting a sensing resource (sr) of the radio resources (rr 1 -rr 4 );
sensing the sensing resource (sr);
determining a contention indicator (CONT) based on the sensing resource (sr); and
transmitting, towards a second radio terminal (UE 2 ), the contention indicator (CONT),
wherein the transmitted contention indicator indicates a contention situation at the sensing resource (sr) and the identity of the sensing resource (sr).
2. The first radio terminal (UE 1 ) according to claim 1 , the set of operations further include:
transmitting, towards the second radio terminal (UE 2 ), a sensing indicator, which indicates an identity of a subsequent radio resource for sensing by the first radio terminal (UE 1 ).
3. The first radio terminal (UE 1 ) according to claim 2 , wherein transmitting the sending indicator causes the second radio terminal (UE 2 ) to refrain from using the subsequent radio resource for transmission.
4. The first radio terminal (UE 1 ) according to claim 2 , wherein the set of operations further include:
transmitting, towards the second radio terminal (UE 2 ), a reservation indicator, which indicates an identity of the subsequent radio resource or a subsequent auxiliary radio resource for transmitting by the first radio terminal (UE 1 ).
5. The first radio terminal (UE 1 ) according to claim 4 , wherein transmitting the reservation indicator causes the second radio terminal (UE 2 ) to refrain from using the subsequent radio resource or subsequent auxiliary radio resource for transmission.
6. The first radio terminal (UE 1 ) according to claim 1 , wherein the set of operations further include:
determining at least one auxiliary radio resource (ar 1 ; ar 2 ), wherein the at least one auxiliary radio resource (ar 1 ; ar 2 ) and the radio resources (rr 1 -rr 4 ) are disjoint; and
transmitting, towards the at least one second radio terminal (UE 2 ), data via the at least one auxiliary radio resource (ar 1 ; ar 2 ).
7. The first radio terminal (UE 1 ) according to claim 6 , wherein the data transmitted via the auxiliary radio resource includes an out-of-sequence indicator, the out-of-sequence indicator indicating that the auxiliary radio resource is an auxiliary radio resource.
8. The first radio terminal (UE 1 ) according to claim 1 , wherein determining the contention indicator (CONT) includes:
determining a received signal strength for the at least one sensing resource (sr);
comparing the received signal strength with a threshold; and
determining the contention indicator (CONT) in dependence on the comparison.
9. The first radio terminal (UE 1 ) of claim 2 , wherein refraining from using the subsequent radio resource for transmission or subsequent auxiliary radio resource for transmission includes one of skipping, sub-slot skipping, delayed skipping, or early skipping.
10. A method to operate a first radio terminal (UE 1 ) of a radio communications network, the method comprising:
determining a configuration for the first radio terminal (UE 1 ), wherein the configuration indicates radio resources (rr 1 -rr 4 ) of a shared device-to-device radio channel (CH), wherein the indicated radio resources (rr 1 -rr 4 ) are intended for a transmission by the first radio terminal (UE 1 );
selecting a sensing resource (sr) of the radio resources (rr 1 -rr 4 );
sensing the sensing resource (sr);
determining a contention indicator (CONT) based on the sensing resource (sr); and
transmitting, towards a second radio terminal (UE 2 ), the contention indicator (CONT),
wherein the transmitted contention indicator indicates a contention situation at the sensing resource (sr) and the identity of the sensing resource (sr).
11. The method according to claim 10 , further comprising:
transmitting, towards the second radio terminal (UE 2 ), a sensing indicator, which indicates an identity of a subsequent radio resource for sensing by the first radio terminal (UE 1 ).
12. The method according to claim 11 , wherein transmitting the sending indicator causes the second radio terminal (UE 2 ) to refrain from using the subsequent radio resource for transmission.
13. The method according to claim 11 , further comprising:
transmitting, towards the second radio terminal (UE 2 ), a reservation indicator, which indicates an identity of the subsequent radio resource or a subsequent auxiliary radio resource for transmitting by the first radio terminal (UE 1 ).
14. The method according to claim 13 , wherein transmitting the reservation indicator causes the second radio terminal (UE 2 ) to refrain from using the subsequent radio resource or subsequent auxiliary radio resource for transmission.
15. The method according to claim 10 , further comprising:
determining at least one auxiliary radio resource (ar 1 ; ar 2 ), wherein the at least one auxiliary radio resource (ar 1 ; ar 2 ) and the radio resources (rr 1 -rr 4 ) are disjoint; and
transmitting, towards the at least one second radio terminal (UE 2 ), data via the at least one auxiliary radio resource (ar 1 ; ar 2 ).
16. The method according to claim 15 , wherein the data transmitted via the auxiliary radio resource includes an out-of-sequence indicator, which indicates that the auxiliary radio resource is an auxiliary radio resource.
17. The method according to claim 10 , wherein the determining the contention indicator (CONT) includes:
determining a received signal strength for the at least one sensing resource (sr);
comparing the received signal strength with a threshold; and
determining the contention indicator (CONT) in dependence on the comparison.
18. The first radio terminal (UE 1 ) of claim 12 , wherein refraining from using the subsequent radio resource for transmission or subsequent auxiliary radio resource for transmission includes one of skipping, sub-slot skipping, delayed skipping, or early skipping.