Method and apparatus for updating neighboring base station relations

1. A method, in a serving radio base station of a first radio access network, serving a wireless radio device; the method comprising the serving radio base station:

receiving a measurement report that is based on a reference signal received by the wireless radio device from a radio base station in a further radio access network, and comprises a non-unique identity of the radio base station in the further radio access network, the non-unique identity comprising a physical cell identity (PCI);

sending an identification request, referring to the radio base station in the further radio access network, to at least one neighbor radio base station of the serving radio base station, wherein the at least one neighbor radio base station reports the same non-unique identity as indicated in the received measurement report;

receiving, from the at least one neighbor radio base station of the serving radio base station, non-unique identities of radio base stations associated to the at least one neighbor radio base station and information about the identification of the radio base station in the further radio access network;

establishing a neighbor relation using the information about the identification of the radio base station in the further radio access network, based on received identification information.

2. The method of claim 1 , wherein the information about the identification of the radio base station in the further radio access network is a Transport Network Layer address.

3. The method of claim 1 , wherein a radio access technology of the first radio access network is different from a radio access technology of the further radio access network.

4. The method of claim 1 , further comprising the serving radio base station sending a request for updating a neighbor relation information to the radio base station in the further radio access network.

5. The method of claim 1 , wherein the wireless radio device is further served by a second radio base station of a second radio access network.

6. The method of claim 5 :

wherein the second radio base station serves the wireless radio device with user data; and

wherein the serving radio base station serves the wireless radio device with control data only.

7. The method of claim 5 , wherein the measurement report is received from the second radio base station.

8. The method of claim 5 , wherein a radio access technology of the first radio access network is different from a radio access technology of the second radio access network.

9. The method of claim 5 , further comprising the serving radio base station sending a request for updating the neighbor relation information to the second radio base station.

10. The method of claim 1 , wherein the connection between the serving radio base station and the wireless radio device is a Radio Resource Control (RRC) connection.

11. The method of claim 1 , wherein the serving radio base station receives a negative acknowledgement from the at least one neighbor radio base station, if the radio base station in the further radio access network is not known by the at least one neighbor radio base station.

12. The method of claim 1 , wherein the receiving non-unique identities from the at least one neighbor radio base station is triggered by the serving radio base station via a request message.

13. The method of claim 1 , wherein the serving radio base station receives non-unique identities of radio base stations associated to the at least one neighbor radio base station periodically.

14. A serving radio base station of a first radio access network, serving a wireless radio device, the serving radio base station comprising:

processing circuitry;

memory containing instructions executable by the processing circuitry whereby the serving radio base station is operative to:

receive a measurement report that is based on a reference signal received by the wireless radio device from a radio base station in a further radio access network, and comprises a non-unique identity of the radio base station in the further radio access network, the non-unique identity comprising a physical cell identity (PCI);

send an identification request, referring to the radio base station in the further radio access network, to at least one neighbor radio base station of the serving radio base station, wherein the at least one neighbor radio base station reports the same non-unique identity as indicated in the received measurement report;

receive, from the at least one neighbor radio base station of the serving radio base station, non-unique identities of radio base stations associated to the at least one neighbor radio base station and information about the identification of the radio base station in the further radio access network; and

establish a neighbor relation using the information about the identification of the radio base station in the further radio access network, based on received identification information.

15. The serving radio base station of claim 14 , wherein a radio access technology of the first radio access network is different from a radio access technology of the further radio access network.

16. The serving radio base station of claim 14 , wherein the wireless radio device is further served by a second radio base station of a second radio access network.

17. The serving radio base station of claim 16 :

wherein the second radio base station serves the wireless radio device with user data; and

wherein the serving radio base station serves the wireless radio device with control data only.

18. The serving radio base station of claim 16 , wherein the instructions are such that the serving radio base station is operative to send a request for updating the neighbor relation information to the second radio base station.

19. A non-transitory computer readable recording medium storing a computer program product for controlling a serving radio base station of a first radio access network, serving a wireless radio device, the computer program product comprising program instructions which, when run on processing circuitry of the serving radio base station, causes the serving radio base station to:

receive a measurement report that is based on a reference signal received by the wireless radio device from a radio base station in a further radio access network and comprises a non-unique identity of the radio base station in the further radio access network, the non-unique identity comprising a physical cell identity (PCI);

send an identification request, referring to the radio base station in the further radio access network, to at least one neighbor radio base station of the serving radio base station, wherein the at least one neighbor radio base station reports the same non-unique identity as indicated in the received measurement report;

receive, from the at least one neighbor radio base station of the serving radio base station, non-unique identities of radio base stations associated to the at least one neighbor radio base station and information about the identification of the radio base station in the further radio access network; and

establish a neighbor relation using the information about the identification of the radio base station in the further radio access network, based on received identification information.