Device-to-device (D2D) subframe with cell identifier

• US 9,992,782 B2
• Filed: 12/18/2014
• Issued: 06/05/2018
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Kalhan, Amit, Chang, Henry
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): George, Ayanah
• Application Number:
  US15/105,523
• Publication Number:
  US 20160323868A1
• Time in Patent Office: 1,265 Days
• Field of Search: None
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 36/0022 for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/0061 of neighbour cell information
• CPC Class Codes: H04W 36/305 Handover due to radio link failure control signalling for hand-off failure H04W36/0079
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 48/14 using user query or user detection
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Device-to-device (D2D) user equipment (UE) devices transmit D2D subframes that include a cell identifier of the base station providing wireless service to the D2D UE device. A D2D UE device requesting D2D communication resources for D2D communication with other D2D UE device(s) indicates the cell identifiers of the cells serving the other D2D device(s) to the base station serving the requesting D2D UE device.

Claims

1. A method comprising:

serving, by a first base station, a first device-to-device (D2D) user equipment (UE) device and a second D2D UE device;

initiating a handover of the second D2D UE device to a second base station;

refraining from performing D2D communication between the first D2D UE device and the second D2D UE device during the handover;

receiving, at the first D2D UE device, a D2D subframe from the second D2D UE device, the first D2D UE device within a first cell provided by the first base station and the second D2D UE device within a second cell provided by the second base station, the D2D subframe conveying a cell identifier identifying the second cell, the D2D subframe indicating that the handover is complete and that the first D2D UE device is permitted to attempt to resume D2D communication with the second D2D UE device; and

sending, to the first base station, a request for D2D communication resources for D2D communication between the first UE device and the second D2D UE device, the request conveying the cell identifier identifying the second cell to the first base station.

2. The method of claim 1, wherein the D2D subframe includes a D2D message comprising the cell identifier.

3. The method of claim 1, wherein a scrambling sequence for scrambling a reference signal of the D2D subframe is a function of the cell identifier.

4. The method of claim 3, wherein the scrambling sequence is a function of a device identifier of the second D2D UE device.

5. The method of claim 3, wherein the scrambling sequence is a function of a D2D group identifier of a D2D group comprising the first D2D EU device and the second D2D UE device.

6. The method of claim 1, further comprising determining whether the second D2D UE device is an intended receiver of D2D transmissions from the first D2D UE device and wherein the request conveys the cell identifier to the first base station when the second D2D UE device is the intended receiver.

7. The method of claim 1, wherein the handover is triggered based on a measurement event triggered within the D2D UE device.

8. The method of claim 1, wherein the D2D subframe is a D2D discovery subframe.

9. A method performed at a first base station, the method comprising:

serving a first device-to-device (D2D) user equipment (UE) device and a second D2D UE device;

handing over the second D2D UE device to a second base station;

receiving, from the first D2D UE device within a first cell provided by the first base station, a request for device-to-device (D2D) communication resources for D2D communication between the first D2D UE device and at least the second D2D UE device, the second D2D UE device within a second cell provided by a second base station, the request comprising a cell identifier of the second cell, the request sent in response to the first D2D UE device receiving a D2D subframe indicating that the handing over of the second D2D UE device is complete and that the first D2D UE device is permitted to attempt to resume D2D communication with the second D2D UE device, which was ceased during the handing over; and

communicating with the second base station to identify common D2D communication resources for the D2D communication; and

assigning the common D2D communication resources to the first D2D UE device for the D2D communication.

10. The method of claim 9, wherein the cell identifier is determined by the first D2D UE device from a D2D subframe transmitted by the second D2D UE device.

11. The method of claim 10, wherein the D2D subframe includes a D2D message comprising the cell identifier.

12. The method of claim 10, wherein a scrambling sequence for scrambling a reference signal of the D2D subframe is a function of the cell identifier.

13. The method of claim 12, wherein the scrambling sequence is a function of a device identifier of the second D2D UE device.

14. The method of claim 12, wherein the scrambling sequence is a function of a D2D group identifier of a D2D group comprising the first D2D UE device and the second D2D UE device.

15. The method of claim 9, wherein the D2D subframe is a D2D discovery subframe.

16. A method comprising:

handing over a first device-to-device (D2D) user equipment (UE) device from a first base station to a second base station;

refraining from performing D2D communication between the first D2D UE device and a second D2D UE device during the handing over;

generating, at the first D2D UE device within a first cell provided by the second base station, a D2D subframe; and

transmitting the D2D subframe from the first D2D UE device to the second D2D UE device within a second cell provided by the first base station, the D2D subframe conveying a cell identifier identifying the first cell to the second D2D UE device, the D2D subframe indicating that the handing over is complete and that the second D2D UE device is permitted to attempt to resume D2D communication with the first D2D UE device.

17. The method of claim 16, wherein the D2D subframe includes a D2D message comprising the cell identifier.

18. The method of claim 16, wherein a scrambling sequence of a reference signal of the D2D subframe is a function of the cell identifier.

19. The method of claim 18, wherein the scrambling sequence is a function of a device identifier of the first D2D UE device.

20. The method of claim 19, wherein the scrambling sequence is a function of a D2D group identifier of a D2D group comprising the first D2D UE device and the second D2D UE device.

21. The method of claim 16, wherein the D2D subframe is a D2D discovery subframe.

22. A device-to-device (D2D) user equipment (UE) device comprising:

a receiver configured to;

receive an indication to refrain from performing D2D communication between the D2D UE device and another D2D UE device during handover of the another D2D UE device to a neighbor cell different from a serving cell of the D2D UE device, and

receive a D2D subframe from the another D2D UE device located in the neighbor cell, the D2D subframe conveying a cell identifier identifying the neighbor cell, the D2D subframe indicating that the handover is complete and that the D2D UE device is permitted to attempt to resume D2D communication with the another D2D UE device; and

a transmitter configured to transmit to a serving base station providing the serving cell, a request for D2D communication resources for D2D communication between the D2D UE device and the another D2D UE device, the request conveying the cell identifier to the serving base station.

23. The D2D UE device of claim 22, wherein the D2D subframe includes a D2D message comprising the cell identifier.

24. The D2D UE device of claim 22, wherein a scrambling sequence for scrambling a reference signal of the D2D subframe is a function of the cell identifier.

25. The D2D UE device of claim 24, wherein the scrambling sequence is a function of a device identifier of the second UE device.

26. The D2D UE device of claim 22 further comprising:

a controller configured to determine whether the another D2D UE device is an intended receiver of D2D transmissions from D2D UE device and wherein the request conveys the cell identifier to the serving base station when the another UE device is the intended receiver.

27. The D2D UE device of claim 22, wherein the D2D subframe is a D2D discovery subframe.