Methods providing scheduling for sidelink communications and related wireless terminals and network nodes

1. A method of operating a first wireless terminal providing network communication with a radio access network using a network carrier and providing sidelink communications using a sidelink carrier, the method comprising:

receiving a scheduling grant from the radio access network using a network subframe of the network carrier;

obtaining a first time measurement relating to the sidelink carrier, wherein the first time measurement is a time measurement of an initial boundary of the measurement sidelink subframe;

obtaining a second time measurement relating to the network carrier, wherein the second time measurement is a time measurement of an initial boundary of the network subframe including the scheduling grant; and

responsive to the scheduling grant, the first time measurement, and the second time measurement, selecting a communication sidelink subframe of the sidelink carrier to be used for a sidelink communication, wherein selecting the communication sidelink subframe comprises one of selecting the communication sidelink subframe having a first delay after the measurement sidelink subframe responsive to the first time measurement being less than the second time measurement and selecting the communication sidelink subframe having a second delay after the measurement sidelink subframe responsive to the first time measurement being greater than the second time measurement.

2. The method of claim 1 , wherein the first time measurement is a time measurement of a boundary of a measurement sidelink subframe, and wherein the second time measurement is a time measurement of a boundary of the network subframe, including the scheduling grant at the first wireless device.

3. The method of claim 2 further comprising:

comparing the first and second time measurements, wherein selecting comprises selecting the communication sidelink subframe based on comparing the first and second time measurements.

4. The method of claim 1 , wherein the scheduling grant is a first scheduling grant and the communication sidelink subframe is a first communication sidelink subframe, wherein the first scheduling grant is completed during a first reference sidelink subframe, and wherein selecting the first communication sidelink subframe comprises selecting the first communication sidelink subframe having a first delay after the first reference sidelink subframe responsive to the first scheduling grant being completed during a first half of the first reference sidelink subframe, the method further comprising:

receiving a second scheduling grant from the radio access network using a second network subframe of the network carrier, wherein the second scheduling grant is completed during a second reference sidelink subframe;

obtaining a third time measurement relating to the sidelink carrier;

obtaining a fourth time measurement relating to the network carrier;

responsive to the second scheduling grant, the third time measurement, and the fourth time measurement, selecting a second communication sidelink subframe of the sidelink carrier to be used for a sidelink communication, wherein selecting the second communication sidelink subframe comprises selecting the second communication sidelink subframe having a second delay after the second reference sidelink subframe responsive to second scheduling grant being completed during a second half of the second reference sidelink subframe.

5. The method of claim 1 further comprising:

after selecting the sidelink subframe, transmitting the sidelink communication using the sidelink subframe of the sidelink carrier.

6. The method of claim 5 , wherein transmitting comprises transmitting the sidelink communication from the first wireless terminal to a second wireless terminal using the sidelink subframe of the sidelink carrier so that the sidelink communication is directly terminated between the first and second wireless terminals.

7. The method of claim 1 , wherein the network carrier is a Uu carrier.

8. The method of claim 1 , wherein the sidelink carrier is a PC5 carrier.

9. The method of claim 1 , wherein the wireless terminal is a vehicular wireless terminal, and wherein the sidelink communication comprises at least one of a vehicle-to-vehicle (V2V) communication, or a vehicle-to-person (V2P) communication.

10. The method of claim 1 , wherein subframes of the network carrier and subframes of the sidelink carrier have different timing references.

11. A computer program product comprised on a non-transitory computer readable storage medium, the computer program product including instructions which, when executed by at least one processor of a wireless terminal, causes the wireless terminal to operate to:

receive a scheduling grant from the radio access network using a network subframe of the network carrier,

obtain a first time measurement relating to the sidelink carrier, wherein the first time measurement is a time measurement of an initial boundary of the measurement sidelink subframe,

obtain a second time measurement relating to the network carrier, wherein the second time measurement is a time measurement of an initial boundary of the network subframe including the scheduling grant, and

select a communication sidelink subframe of the sidelink carrier to be used for a sidelink communication responsive to the scheduling grant, the first time measurement, and the second time measurement, wherein selecting the communication sidelink subframe comprises one of selecting the communication sidelink subframe having a first delay after the measurement sidelink subframe responsive to the first time measurement being less than the second time measurement and selecting the communication sidelink subframe having a second delay after the measurement sidelink subframe responsive to the first time measurement being greater than the second time measurement.

12. A first wireless terminal, UE, adapted to provide network communication with a radio access network using a network carrier and to provide sidelink communication using a sidelink carrier, the first wireless terminal comprising:

a transceiver configured to provide wireless network communication with a radio access network using a network carrier and to provide wireless sidelink communication with a sidelink carrier; and

a processor coupled with the transceiver, wherein the processor is configured to provide wireless network communication and wireless sidelink communication through the transceiver, and wherein the processor is configured to,

receive a scheduling grant from the radio access network using a network subframe of the network carrier,

obtain a first time measurement relating to the sidelink carrier, wherein the first time measurement is a time measurement of an initial boundary of the measurement sidelink subframe,

obtain a second time measurement relating to the network carrier, wherein the second time measurement is a time measurement of an initial boundary of the network subframe including the scheduling grant, and

select a communication sidelink subframe of the sidelink carrier to be used for a sidelink communication responsive to the scheduling grant, the first time measurement, and the second time measurement, wherein selecting the communication sidelink subframe comprises one of selecting the communication sidelink subframe having a first delay after the measurement sidelink subframe responsive to the first time measurement being less than the second time measurement and selecting the communication sidelink subframe having a second delay after the measurement sidelink subframe responsive to the first time measurement being greater than the second time measurement.

13. The first wireless terminal of claim 12 wherein the first time measurement is a time measurement of a boundary of a measurement sidelink subframe, and wherein the second time measurement is a time measurement of a boundary of the network subframe, including the scheduling grant at the first wireless device.

14. The first wireless terminal of claim 13 , wherein the processor is configured to,

compare the first and second time measurements, wherein selecting comprises selecting the communication sidelink subframe based on comparing the first and second time measurements.

15. The first wireless terminal of claim 12 , wherein the scheduling grant is a first scheduling grant and the communication sidelink subframe is a first communication sidelink subframe, wherein the first scheduling grant is completed during a first reference sidelink subframe, and wherein selecting the first communication sidelink subframe comprises selecting the first communication sidelink subframe having a first delay after the first reference sidelink subframe responsive to the first scheduling grant being completed during a first half of the first reference sidelink subframe, wherein the processor is further configured to,

receive a second scheduling grant from the radio access network using a second network subframe of the network carrier, wherein the second scheduling grant is completed during a second reference sidelink subframe,

obtain a third time measurement relating to the sidelink carrier,

obtain a fourth time measurement relating to the network carrier, and

select a second communication sidelink subframe of the sidelink carrier to be used for a sidelink communication responsive to the second scheduling grant, the third time measurement, and the fourth time measurement, wherein selecting the second communication sidelink subframe comprises selecting the second communication sidelink subframe having a second delay after the second reference sidelink subframe responsive to second scheduling grant being completed during a second half of the second reference sidelink subframe.

16. The first wireless terminal of claim 12 , wherein the processor is configured to transmit the sidelink communication using the sidelink subframe of the sidelink carrier after selecting the sidelink subframe.

17. The first wireless terminal of claim 16 , wherein transmitting comprises transmitting the sidelink communication from the first wireless terminal to a second wireless terminal using the sidelink subframe of the sidelink carrier so that the sidelink communication is directly terminated between the first and second wireless terminals.

18. The first wireless terminal of claim 12 , wherein the network carrier is a Uu carrier.

19. The first wireless terminal of claim 12 , wherein the sidelink carrier is a PC5 carrier.

20. The first wireless terminal of claim 12 , wherein the wireless terminal is a vehicular wireless terminal, and wherein the sidelink communication comprises at least one of a vehicle-to-vehicle (V2V) communication, or a vehicle-to-person (V2P) communication.

21. The first wireless terminal of claim 12 , wherein subframes of the network carrier and subframes of the sidelink carrier have different timing references.