Device to device communications

1. A method for controlling device-to-device communications, comprising:

determining a reference radio bearer which is based on semi-persistent scheduling, wherein the reference radio bearer would provide an adequate service in a cellular access mode,

determining an information of a semi-static resource allocation for the reference radio bearer,

determining a device-to-device communications mode specific offset for a link budget parameter,

signalling a configuration of the reference radio bearer, the information of the semi-static resource allocation for the reference radio bearer and the device-to-device communications mode specific offset for a link budget parameter to the at least one device for use in configuring the at least one device for a device-to-device communications mode, and

configuring the reference radio bearer to become an actual radio bearer in a cellular access mode upon the at least one device switching modes from the device-to-device communications mode to the cellular access mode.

2. The method according to claim 1 , and further comprising:

determining an updated semi-static resource allocation based on updated information on relevant devices.

3. The method according to claim 2 , wherein the updated information on devices comprises:

information on channel conditions and/or connection statuses of devices involved in the device to device communications.

4. The method according to claim 1 , and further comprising signalling information of at least one of a device-to-device service specific indicator, an offset and a threshold to the at least one device for use in configuring the at least one device for device-to-device communications.

5. The method according to claim 1 , wherein the configuring comprises:

configuring the reference radio bearer to become an actual radio bearer in a cellular access mode upon the at least one device switching modes, based on a radio network temporary identity, from the device-to-device communications mode to the cellular access mode.

6. The method according to claim 5 , wherein the information of the semi-static resource allocation comprises at least one of:

the information of the semi-static resource allocation is indicated by at least one of a semi-persistent scheduling cellular radio network temporary identity (C-RNTI) for a device-to-device enabled device, a C-RNTI assigned for a device-to-device link and a C-RNTI assigned for a device-to-device group or cluster, and

the information of the semi-static resource allocation for cellular access mode is indicated by a regular or cellular access mode C-RNTI of a user equipment.

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

configuring at least one device-to-device enabled device for reporting information associated with the reference radio bearer and the semi-static resource allocation thereof.

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

configuring a trigger for reporting and/or switching by a device-to-device enabled device.

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

reporting by the at least one device information associated with a detected performance of a device-to-device link relative to an expected performance of a device-to-device radio bearer configured based on the reference radio bearer or a radio bearer in the cellular access mode.

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

determining link budget parameters for device-to-device communications based on the information of the semi-static resource allocation for the reference radio bearer.

11. The method according to claim 1 , further comprising configuring the at least one device for device-to-device communications, including:

setting, for a device-to-device link, at least one of a maximum allowed transmission power, an offset for a maximum allowed transmission power, a bit rate, an offset for a bit rate, a link delay, a traffic class priority, and a bearer class priority.

12. A method for device-to-device communications, comprising:

obtaining, by a device, a configuration of a reference radio bearer and information of a semi-static resource allocation for the reference radio bearer which is based on semi-persistent scheduling, wherein the reference bearer is determined to provide an adequate service in a cellular access mode,

receiving, by the device, a device-to-device communications mode specific offset for a link budget parameter,

configuring the device for the device-to-device communications mode based on the configuration of the reference radio bearer, the information of semi-static resource allocation and the device-to-device communications mode specific offset for the link budget parameter, and

switching, by the device, a mode from the device-to-device communications mode to the cellular access mode, and applying the reference radio bearer as an actual radio bearer in the cellular access mode.

13. The method according to claim 12 , further comprising:

determining an updated semi-static resource allocation based on updated information on relevant devices.

14. The method according to claim 13 , wherein the updated information on devices comprises information on channel conditions and/or connection statuses of devices involved in the device to device communications.

15. The method according to claim 12 , further comprising:

receiving information of at least one of a device to device service specific indicator, an offset and a threshold to at least one device for use in configuring the device for device-to-device communications.

16. The method according to claim 12 , wherein the switching a mode comprises:

switching a mode from the device-to-device communications mode to the cellular access mode based on information on a radio network temporary identity.

17. The method according to claim 12 , wherein the information of the semi-static resource allocation comprises at least one of:

the information of the semi-static resource allocation is indicated by at least one of a semi-persistent scheduling cellular radio network temporary identity (C-RNTI) for a device-to-device enabled device, a C-RNTI assigned for a device-to-device link and a C-RNTI assigned for a device-to-device group or cluster, and

the information of the semi-static resource allocation for cellular access mode is indicated by a regular or cellular access mode C-RNTI of a user equipment.

18. The method according to claim 12 , further comprising:

configuring at least one device-to-device enabled device for reporting information associated with the reference radio bearer and the semi-static resource allocation thereof.

19. The method according to claim 12 , further comprising:

configuring a trigger for reporting and/or switching by a device-to-device enabled device.

20. The method according to claim 12 , further comprising:

reporting by the at least one device information associated with a detected performance of a device-to-device link relative to an expected performance of a device-to-device radio bearer configured based on the reference radio bearer or a radio bearer in the cellular access mode.

21. The method according to claim 12 , further comprising:

determining link budget parameters for device-to-device communications based on the information of the semi-static resource allocation for the reference radio bearer.

22. The method according to claim 12 , wherein configuring the at least one device for device to device communications comprises:

setting, for a device-to-device link, at least one of a maximum allowed transmission power, an offset for a maximum allowed transmission power, a bit rate, an offset for a bit rate, a link delay, a traffic class priority, and a bearer class priority.

23. An apparatus for a network enabling device-to-device communications, the apparatus comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to:

determine a reference radio bearer which is based on semi-persistent scheduling, wherein the reference radio bearer would provide an adequate service in a cellular access mode,

determine an information of a semi-static resource allocation for the reference radio bearer,

determine a device-to-device communications mode specific offset for a link budget parameter,

cause signalling of a configuration of the reference radio bearer, the information of the semi-static resource allocation for the reference radio bearer and the device-to-device communications mode specific offset for a link budget parameter to the at least one device for use in configuring the at least one device for device-to-device communications mode, and

configure the reference radio bearer to become an actual radio bearer in a cellular access mode upon the at least one device switching modes from the device-to-device communications mode to the cellular access mode.

24. The apparatus according to claim 23 , wherein the computer program code is further configured to cause the apparatus to determine or use an updated semi-static resource allocation, the updated semi-static resource allocation being based on updated information on relevant devices.

25. An apparatus for a wireless device, the apparatus comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to:

obtain, by a device, a configuration of a reference radio bearer and information of a semi-static resource allocation for the reference radio bearer which is based on semi-persistent scheduling, wherein the reference radio bearer is determined to provide an adequate service in a cellular access mode

receive, by the device, a device-to-device communications mode specific offset for a link budget parameter,

configure, by the device, the device for a device-to-device communications mode based on the configuration of the reference radio bearer, the information of semi-static resource allocation and the device-to-device communications mode specific offset for a link budget parameter, and

switch, by the device, a mode from the device-to-device communications mode to the cellular access mode, and apply the reference radio bearer as an actual radio bearer in the cellular access mode.

26. The apparatus according to claim 25 , wherein the computer program code is configured to cause the apparatus to configure at least one device-to-device enabled device for reporting information associated with the reference radio bearer and the semi-static resource allocation thereof.

27. The apparatus according to claim 25 , wherein the computer program code is configured to cause the apparatus to determine link budget parameters for device-to-device communications based on the information of the semi-static resource allocation for the reference radio bearer.

28. The apparatus according to claim 25 , wherein the computer program code causing the apparatus to configure comprises causing the apparatus to:

set, for a device-to-device link, at least one of a maximum allowed transmission power, an offset for a maximum allowed transmission power, a bit rate, an offset for a bit rate, a link delay, a traffic class priority, and a bearer class priority.