Handover mechanism in wireless networks

1. A method comprising:

receiving, by a first base station from a wireless device, at least one measurement report comprising signal quality information of a subset of a plurality of carriers, the wireless device having one connection with the first base station, the connection being configurable to carry a plurality of calls via a radio technology, each call being from a call category in a plurality of call categories; and

initiating a handover of the connection to a second base station of the radio technology based on criteria on the signal quality information, the criteria being employed for handover at least when the connection comprises a plurality of calls of different call types, the criteria comprising a first criterion and a second criterion different from the first criterion, the first criterion being employed if the connection engages in an active call from the first call category, the second criterion being employed if the connection does not engage in an active call from the first call category, wherein:

the first call category is a voice call; and

the first base station is of a different type compared with the second base station.

2. The method of claim 1 , wherein the call is carried over a radio bearer.

3. The method of claim 1 , wherein the at least one measurement report comprises:

at least one channel state information report; and

at least one RRC measurement report.

4. The method of claim 1 , wherein each of the first criterion and the second criterion considers a relative signal quality value.

5. The method of claim 4 , wherein the relative signal quality value considers a first signal quality value of a first carrier of the first base station and a second signal quality value of a second carrier of the second base station.

6. The method of claim 5 , wherein the first criterion is based on comparison of the relative signal quality value with a first threshold value, and the second criterion is based on comparison of the relative signal quality value with a second threshold value.

7. The method of claim 5 , wherein the second signal quality value considers a measured signal quality value and a bias value.

8. The method of claim 1 , wherein a user of the wireless device is billed differently by a service provider for:

calls from the first call category that are carried through the first base station; and

calls from the first call category that are carried through the second base station.

9. The method of claim 1 , wherein:

the first base station is a macro base station; and

the second base station is a femto base station.

10. The method of claim 1 , further comprising

transmitting a first control message to a network node in a wireless network after a handover decision;

receiving a second control message from the network node, the second control message indicating that the second base station accepted a handover request; and

transmitting a handover command to the wireless device.

11. The method of claim 10 , further comprising receiving a proximity indication message from the wireless device before transmitting the first control message, the proximity indication message indicating that the wireless device entered the proximity of the second base station.

12. A first base station comprising:

one or more processors; and

memory storing instructions that, when executed, cause the first base station to:

receive, from a wireless device, at least one measurement report comprising signal quality information of a subset of a plurality of carriers, the wireless device having one connection with the first base station, the connection being configurable to carry a plurality of calls via a radio technology, each call being from a call category in a plurality of call categories; and

initiate a handover of the connection to a second base station of the radio technology based on criteria on the signal quality information, the criteria being employed for handover at least when the connection comprises a plurality of calls of different call types, the criteria comprising a first criterion and a second criterion different from the first criterion, the first criterion being employed if the connection engages in an active call from the first call category, the second criterion being employed if the connection does not engage in an active call from the first call category, wherein:

the first call category is a voice call; and

the first base station is of a different type compared with the second base station.

13. The first base station of claim 12 , wherein the call is carried over a radio bearer.

14. The first base station of claim 12 , wherein the at least one measurement report comprises:

at least one channel state information report; and

at least one RRC measurement report.

15. The first base station of claim 12 , wherein each of the first criterion and the second criterion considers a relative signal quality value.

16. The first base station of claim 15 , wherein the relative signal quality value considers a first signal quality value of a first carrier of the first base station and a second signal quality value of a second carrier of the second base station.

17. The first base station of claim 16 , wherein the first criterion is based on comparison of the relative signal quality value with a first threshold value, and the second criterion is based on comparison of the relative signal quality value with a second threshold value.

18. The first base station of claim 16 , wherein the second signal quality value considers a measured signal quality value and a bias value.

19. The first base station of claim 12 , wherein the user of the wireless device is billed differently by a service provider for:

calls from the first call category that are carried through the first base station; and

calls from the first call category that are carried through the second base station.

20. The first base station of claim 12 , wherein the instructions when executed further cause the base station to receive a proximity indication message from the wireless device before transmitting the first control message, the proximity indication message indicating that the wireless device entered the proximity of the second base station.