METHOD AND ARRANGEMENT FOR D2D DISCOVERY

• US 20150131571A1
• Filed: 10/24/2012
• Published: 05/14/2015
• Est. Priority Date: 06/19/2012
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Fodor, Gabor, Li, Zhe
• Granted Patent: US 9,736,817 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

A method for sending beacon signals is provided. The beacon signals are to be received by a slave device to discover the master device for Device to Device communication. The master device receives information from a network node. The information informs about a set of available peer discovery resources to be used in a peer discovery frame by the master device for sending beacon signals. The beacon signals are detected by the slave device. The master device obtains a beacon transmission probability. At each specific peer discovery frame, the master device determines according to the beacon transmission probability, whether or not a beacon signal shall be transmitted during that specific peer discovery frame. When determining to transmit a beacon signal during that specific peer discovery frame, master device sends the beacon signal by choosing one of the peer discovery resources out of the received set of available peer discovery resources.

Claims

1. A method in a master device for sending beacon signals, which beacon signals are to be received by a slave device to discover the master device for Device to Device, D2D, communication, which master device is comprised in a wireless network, the method comprising:

receiving from a network node information about a set of available peer discovery resources to be used in a peer discovery frame by the master device for sending beacon signals, which beacon signals are to be detected by the slave device,

obtaining a beacon transmission probability, which beacon transmission probability is the probability that the master device transmits a beacon signal in a specific peer discovery frame,

at each specific peer discovery frame determining according to the beacon transmission probability, whether or not a beacon signal shall be transmitted during that specific peer discovery frame, and

when determining to transmit a beacon signal during that specific peer discovery frame, sending the beacon signal by choosing one of the peer discovery resources out of the received set of available peer discovery resources.

2. The method according to claim 1, further comprising

obtaining from the network node, information about the number of registered master devices within a cell or tracking area associated with the network node,

and wherein obtaining the beacon transmission probability comprises determining the beacon transmission probability based on the number of available peer discovery resources in the peer discovery resource set and the number of active master devices.

3. The method according to claim 1, wherein the beacon transmission probability is received from the network node in a transmission.

4. The method according to claim 1, wherein the information about the set of available peer discovery resources further comprises information about which Orthogonal Frequency Multiple Access, OFDM, frame to be used by the master device as the peer discovery frame for sending the beacon signals.

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

registering to the network node by signalling that the master device requests to be detected by a slave device.

6. The method according to claim 1, further comprising

obtaining from the network node, information about the number of slave devices that have registered at the network node and a threshold value T that the master device shall use as a target rate for a discovering rate of the number of registered slave devices with respect to the number of registered slave devices.

7. The method according to claim 6, further comprising

stopping the beacon signal transmission when the threshold T is reached.

8. The method according to claim 6, further comprising

maintaining a list of slave devices that have discovered the master device.

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

when the number of discovering slaves does not change during a number of subsequent peer discovery frames, stopping the sending of the beacon signals.

10. A method in a network node for assisting in Device to Device, D2D, discovery, which network node is comprised in a wireless network, the method comprising:

receiving from respective one or more master devices, a registration that the master device requests to be detected by a slave device;

sending information to the respective one or more master devices, which information comprises the number of registered master devices and a set of available peer discovery resources, which set of available peer discovery resources are to be used in a peer discovery frame by the respective one or more master devices for sending beacon signals, which beacon signals are to be received by slave devices to discover the master device for D2D communication.

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

determining a beacon transmission probability based on the number of available peer discovery resources in the peer discovery resource set and the number of registered master devices, and which beacon transmission probability is the probability that the master device transmits a beacon signal in a specific peer discovery frame,

sending the beacon transmission probability to the respective one or more master devices.

12. The method according to claim 10, further comprising

sending to the respective one or more master devices information about the number of slave devices that have registered at the network device and a threshold value that the respective one or more master device shall use as a target rate for a discovering rate of the number of registered slave devices with respect to the number of registered slave devices.

13. The method according to claim 10, wherein the information about the set of available peer discovery resources further comprises which Orthogonal Frequency Multiple Access, OFDM, frame to be used by the master device as the specific peer discovery frame for sending the beacon signals.

14. A master device for sending beacon signals, which beacon signals are to be received by a slave device to discover the master device for Device to Device, D2D, communication, which master device is comprised in a wireless network, the master device comprising:

a receiving circuit configured to receive from a network node information about a set of available peer discovery resources to be used in a peer discovery frame by the master device for sending beacon signals, which beacon signals are to be detected by the slave device,

an obtaining circuit configured to obtain a beacon transmission probability, which beacon transmission probability is the probability that the master device transmits a beacon signal in a specific peer discovery frame,

a sending circuit configured to at each specific peer discovery frame determine according to the beacon transmission probability, whether or not a beacon signal shall be transmitted during that specific peer discovery frame, and

when determining to transmit a beacon signal during that specific peer discovery frame, send the beacon signal by choosing one of the peer discovery resources out of the received set of available peer discovery resources.

15. The master device according to claim 14, wherein the obtaining circuit further is configured to obtain from the network node, information about the number of registered master devices within a cell or tracking area associated with the network node, and wherein the obtaining circuit further is configured to obtain the beacon transmission probability by determine the beacon transmission probability based on the number of available peer discovery resources in the peer discovery resource set and the number of active master devices.

16. The master device according to claim 14, wherein the beacon transmission probability is received from the network node in a transmission.

17. The master device according to claim 14, wherein the information about the set of available peer discovery resources further comprises which Orthogonal Frequency Multiple Access, OFDM, frame to be used by the master device as the specific peer discovery frame for sending the beacon signals.

18. The master device according to claim 14, wherein the sending circuit further is configured to register to the network node by signalling that the master device requests to be detected by a slave device.

19. The master device according to claim 14, wherein the obtaining circuit further is configured to obtain from the network node, information about the number of slave devices that have registered at the network node and a threshold value T that the master device shall use as a target rate for a discovering rate of the number of registered slave devices with respect to the number of registered slave devices.

20. The master device according to claim 19, further comprising a stopping circuit configured to stop the beacon signal transmission when the threshold T is reached.

21. The master device according to claim 19, further comprising a maintaining circuit configured to maintain a list of slave devices that have discovered the master device.

22. The master device according to claim 21, wherein the stopping circuit further is configured to stop the sending of the beacon signals when the number of discovering slaves does not change during a number of subsequent peer discovery frames.

23. A network node for assisting in Device to Device, D2D, discovery, which network node is comprised in a wireless network, the network node comprises

a receiving circuit configured to receive from respective one or more master devices, a registration that the master device requests to be detected by a slave device;

a sending circuit configured to send information to the respective one or more master devices, which information comprises the number of registered master devices and a set of available peer discovery resources, which set of available peer discovery resources are to be used in a peer discovery frame by the respective one or more master devices for sending beacon signals, which beacon signals are to be received by slave devices to discover the master device for D2D communication.

24. The network node according to claim 23, further comprising,

a processor configured to determine a beacon transmission probability based on the number of available peer discovery resources in the peer discovery resource set and the number of registered master devices, which beacon transmission probability is the probability that the master device transmits a beacon signal in a specific peer discovery frame, and wherein the sending circuit further is configured to send the beacon transmission probability to the respective one or more master devices.

25. The network node according to claim 23, wherein the sending circuit further is configured to send to the respective one or more master devices information about the number of slave devices that have registered at the network device and a threshold value that the respective one or more master device shall use as a target rate for a discovering rate of the number of registered slave devices with respect to the number of registered slave devices.

26. The network node according to claim 23, wherein the information about the set of available peer discovery resources further comprises which Orthogonal Frequency Multiple Access, OFDM, frame to be used by the master device as the specific peer discovery frame for sending the beacon signals.