Device-anchor base station selection and detection

1. A method of operation of a wireless device of a cellular communications network, comprising:

transmitting, by the wireless device, a signature assigned to the wireless device on one or more radio resources assigned to the wireless device for detection of candidate device-anchor base stations;

in response to transmitting the signature, receiving, by the wireless device, a response from one or more of a plurality of candidate device-anchor base stations;

selecting, by the wireless device, a device-anchor base station for the wireless device from the plurality of candidate device-anchor base stations based on the responses, the plurality of candidate device-anchor base stations being wireless devices that satisfy one or more predefined criteria for serving as a candidate device-anchor base station; and

establishing, by the wireless device, a connection between the wireless device and the device-anchor base station for the wireless device such that data transmissions between the wireless device and a base station of the cellular communications network are via the device-anchor base station.

2. The method of claim 1 wherein

in response to transmitting the signature, receiving the responses comprises receiving responses from two or more of the plurality of candidate device-anchor base stations; and

selecting the device-anchor base station comprises selecting the device-anchor base station from the two or more of the plurality of candidate device-anchor base stations based on the responses.

3. The method of claim 2 wherein, for each candidate device-anchor base station of the two or more of the plurality of candidate device-anchor base stations, the response from the candidate device-anchor base station includes information that is indicative of a received power at the candidate device-anchor base station for the signature transmitted by the wireless device; and

selecting the device-anchor base station from the two or more of the plurality of candidate device-anchor base stations based on the responses comprises selecting a candidate device-anchor base station having a highest received power among the two or more of the plurality of candidate device-anchor base stations as the device-anchor base station for the wireless device.

4. The method of claim 1 wherein receiving the response from the one or more of the plurality of candidate device-anchor base stations comprises:

after not receiving a response to transmitting the signature within a predefined amount of time, re-transmitting the signature assigned to the wireless device on the one or more radio resources assigned to the wireless device for detection of candidate device-anchor base stations;

in response to re-transmitting the signature, receiving a response from at least one of the plurality of candidate device-anchor base stations; and

selecting the device-anchor base station from at least one of the plurality of candidate device-anchor base stations based on the response from the at least one of the plurality of candidate device-anchor base stations.

5. The method of claim 1 further comprising receiving a data transmission from a serving base station of the wireless device via the device-anchor base station of the wireless device.

6. The method of claim 1 further comprising transmitting data from the wireless device to a serving base station of the wireless device via the device-anchor base station of the wireless device.

7. The method of claim 1 wherein the wireless device is a machine type communication device.

8. The method of claim 7 wherein selecting the device-anchor base station for the wireless device comprises selecting the device-anchor base station for the machine type communication device when the machine type communication device is in a coverage hole.

9. The method of claim 7 wherein selecting the device-anchor base station for the wireless device comprises selecting the device-anchor base station for the machine type communication device when a load on a serving cell of the machine type communication device is greater than a predefined threshold representing a high load condition.

10. The method of claim 1 further comprising:

selecting one or more additional device-anchor base stations for the wireless device from the plurality of candidate device-anchor base stations; and

establishing a connection between the wireless device and each of the one or more additional device-anchor base stations.

11. The method of claim 10 wherein at least some data transmissions between the wireless device and the base station are via the device-anchor base station and the one or more additional device-anchor base stations using a multi-point communication scheme.

12. The method of claim 1 wherein the plurality of candidate device-anchor base stations are a preconfigured group of candidate device-anchor base stations, and the method further comprises:

selecting the preconfigured group of candidate device-anchor base stations from two or more preconfigured groups of candidate device-anchor base stations.

13. The method of claim 1 wherein selecting the device-anchor base station for the wireless device comprises selecting the device-anchor base station based on a stored pairing between the device-anchor base station and the wireless device.

14. A wireless device in a cellular communications network, comprising:

a transceiver; and

a processor associated with the transceiver and configured to:

transmit, via the transceiver, a signature assigned to the wireless device on one or more radio resources assigned to the wireless device for detection of candidate device-anchor base stations;

in response to transmitting the signature, receive, via the transceiver, a response from one or more of a plurality of candidate device-anchor base stations;

select a device-anchor base station for the wireless device from the plurality of candidate device-anchor base stations based on the responses, the plurality of candidate device-anchor base stations being wireless devices that satisfy one or more predefined criteria for serving as a candidate device-anchor base station; and

establish a connection between the wireless device and the device-anchor base station for the wireless device such that data transmissions between the wireless device and a base station of the cellular communications network are via the device-anchor base station.

15. The wireless device of claim 14 wherein the processor is further configured to:

receive, via the transceiver, a data transmission from a serving base station of the wireless device via the device-anchor base station of the wireless device.

16. The wireless device of claim 14 wherein the processor is further configured to:

transmit data, via the transceiver, from the wireless device to a serving base station of the wireless device via the device-anchor base station of the wireless device.

17. The wireless device of claim 14 wherein the wireless device is a machine type communication device.

18. The wireless device of claim 17 wherein, in order to select the device-anchor base station for the wireless device, the processor is further configured to select the device-anchor base station for the machine type communication device when the machine type communication device is in a coverage hole.

19. The wireless device of claim 17 wherein, in order to select the device-anchor base station for the wireless device, the processor is further configured to select the device-anchor base station for the machine type communication device when a load on a serving cell of the machine type communication device is greater than a predefined threshold representing a high load condition.