Robust radio resource control signaling for HSDPA

• US 20070049278A1
• Filed: 11/23/2005
• Published: 03/01/2007
• Est. Priority Date: 08/30/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lindoff, Bengt, Synnergren, Per, Nilsson, Johan
• Granted Patent: US 8,942,706 B2
• Time in Patent Office: Days
• US Class Current: 455/439
• CPC Class Codes: H04W 36/0055 Transmission or use of information for re-establishing the radio link
• CPC Class Codes: H04W 36/026 Multicasting of data during hand-off

Abstract

A radio network controller is operable in both a unicast signaling mode and a bi-cast signaling mode. In unicast signaling mode, the radio network controller is operable to send radio resource control signals to a mobile station through a serving cell. The radio network controller is operable to go into bi-cast signaling mode during a hard handover. In the bi-cast signaling mode, the radio network controller is operable to send radio resource control messages to the mobile station through both the current serving cell and a target cell. The mobile station is configured to listen to both the current serving cell and the target cell for radio resource control messages. User data, however, is transmitted only from the current serving cell to the mobile station.

Claims

1. A signaling method implemented by a radio network controller for executing a hard handover of a mobile station receiving packet data on a shared downlink traffic channel, said method comprising:

initiating a hard handover of said mobile station from a current serving cell to a target cell responsive to a signaling message from said mobile station;

bi-casting radio resource control messages through both said current serving cell and said target cell during said handover; and

uni-casting user data through the current serving cell during said handover.

2. The signaling method of claim 1 wherein said signaling message comprises a handover request.

3. The signaling method of claim 1 wherein said signaling message comprises a signal strength measurement report.

4. The signaling method of claim 1 wherein bi-casting radio resource control messages comprises bi-casting a handover command to said mobile station through both said current serving cell and said target cell.

5. The signaling method of claim 1 wherein bi-casting radio resource control messages comprises transmitting said radio resource control messages to said mobile station in band over said shared downlink traffic channel from both said current serving cell and said target cell.

6. The signaling method of claim 5 wherein said shared downlink traffic channel comprises a High Speed Downlink Shared Channel, HS-DSCH, in a Wideband Code Division Multiple Access, WCDMA, system.

7. A radio network controller for a radio access network, said radio network controller comprising a radio resource controller operative to:

initiate a hard handover from a current serving cell to a target cell responsive to a signaling message from said mobile station;

bi-cast radio resource control messages to said mobile station through both said current serving cell and said target cell during said handover; and

uni-cast user data through the current serving cell during said handover.

8. The radio network controller of claim 7 wherein said signaling message comprises a handover request from said mobile station.

9. The radio network controller of claim 7 wherein said signaling message comprises a signal strength measurement report from the mobile station.

10. The radio network controller of claim 7 wherein the radio resource messages bi-cast to the mobile station through said current serving cell and said target cell include a handover request.

11. The radio network controller of claim 7 wherein said radio network controller is operative to bi-cast radio resource control messages to said mobile station in band over a shared downlink traffic channel from both said current serving cell and said target cell.

12. The radio network controller of claim 11 wherein said downlink traffic channel comprises a High Speed Downlink Shared Channel ,HS-DSCH, in a Wideband Code Division Multiple Access ,WCDMA, system.

13. A signaling method implemented by a mobile station for executing a handover in a mobile communication network, said method comprising:

sending a signaling message to a radio resource controller to initiate a hard handover from a current serving cell to a target cell; and

listening on a downlink channel in both said current serving cell and said target cell for a response message to said signaling message.

14. The signaling method of claim 13 wherein the signaling message sent by said mobile station to trigger the hard handover comprises a handover request.

15. The signaling method of claim 13 wherein the signaling message sent by said mobile station to initiate the hard handover comprises a signal strength measurement report.

16. The signaling method of claim 13 wherein listening on a downlink channel in both said current serving cell and target cell for a response message comprises listening to a control channel for both said current serving cell and said target cell.

17. The signaling method of claim 16 further comprising listening to said control channel for both said current serving cell and said target cell to detect a scheduled transmission of said response message on a shared downlink traffic channel.

18. The signaling method of claim 17 further comprising receiving said radio response message in band over said shared downlink traffic channel.

19. The signaling method of claim 18 wherein said shared downlink traffic channel comprises a High Speed Downlink Shared Channel, HS-DSCH, in a Wideband Code Division Multiple Access, WCDMA, system.

20. The signaling method of claim 13 further comprising sending a confirmation message to said radio network controller upon receipt of said response message.

21. A mobile station capable of receiving data on a shared downlink traffic channel, said mobile station comprising:

a transceiver to transmit and receive data, including radio resource control messages; and

a control unit to control said transceiver, said transceiver configured to;

send a signaling message to a radio network controller to initiate a hard handover form a current serving cell to a target cell; and

listen for a response message to said signaling message from said radio network controller on a downlink channel in both said current serving cell and said target cell.

22. The mobile station of claim 21 wherein the control unit is configured to send a handover request to the radio network controller to initiate the hard handover.

23. The mobile station of claim 21 wherein the control unit is configured to send a signal strength measurement report to the radio network controller to initiate the hard handover.

24. The mobile station of claim 21 wherein the control unit is configured to listen on a downlink control channel for both said current serving cell and said target cell for said response message.

25. The mobile station of claim 24 wherein the control unit is configured to listen on said downlink control channel for both said current serving cell and said target cell for a scheduled transmission of said response message on a shared downlink traffic channel.

26. The mobile station of claim 25 wherein the mobile station is configured to receive the response message over the shared downlink traffic channel.

27. The mobile station of claim 25 wherein the control unit sends a confirmation message to said radio network controller upon receipt of said response message.

28. A computer readable medium storing code for controlling a mobile station, said code including:

code for causing the mobile station to send a signaling message to a radio resource controller to request a hard handover from a current serving cell to a target cell;

code for causing the mobile station to listen in both said current serving cell and said target sell for a response to said signaling message.

29. The computer readable medium of claim 28 wherein the code for causing the mobile station to listen in both said current serving cell and said target sell for a response to said signaling message causes the mobile station to listen on a control channel in both said current serving cell and said target cell.

30. The computer readable medium of claim 29 wherein the code for causing the mobile station to listen in both said current serving cell and said target sell for a response to said signaling message causes the mobile station to listen to said control channel for a scheduled transmission of said response message on a shared downlink traffic channel.

31. A computer readable medium storing code for controlling a radio network controller, said code including:

code for causing the radio network controller to initiate a hard handover of said mobile station from a current serving cell to a target cell responsive to a signaling message from said mobile station;

code for causing the radio network controller to bi-cast a radio resource control messages through both said current serving cell and said target cell during said handover;

code for causing the radio network controller to uni-cast user data through the current serving cell during said handover.

32. The computer readable medium of claim 31 wherein the code for causing the radio network controller to bi-cast radio resource control messages through both said current serving cell and said target cell during said handover causes the radio network controller to bi-cast radio resource control messages using a shared downlink traffic channels in the current serving cell and the target cell.