Method and system for signalling the transfer of voice calls between access points in a wireless local area network

• US 20070189217A1
• Filed: 02/10/2006
• Published: 08/16/2007
• Est. Priority Date: 02/10/2006
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Wang, James, Rawlins, Rudy
• Granted Patent: US 8,700,038 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 65/1083 In-session procedures
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 76/20 Manipulation of established connections
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method for signalling a transfer of a voice call communicated between a wireless device and a second device from a first access point to a second access point in a wireless network, the second device coupled to the first and second access points through a server, the method comprising: receiving at the server from the wireless device a message indicative of a pending transfer between the first and second access points, wherein the wireless device determines whether to send the message by monitoring a characteristic of signals received from each of the first and second access points; and, sending from the server to the second device a message indicative of the pending transfer to thereby prepare the second device for a possible interruption of the voice call.

Claims

1. A method for signalling a transfer of a voice call communicated between a wireless device and a second device from a first access point to a second access point in a wireless network, the second device coupled to the first and second access points through a server, the method comprising:

receiving at the server from the wireless device a message indicative of a pending transfer between the first and second access points, wherein the wireless device determines whether to send the message by monitoring a characteristic of signals received from each of the first and second access points; and

,

sending from the server to the second device a message indicative of the pending transfer to thereby prepare the second device for a possible interruption of the voice call.

2. The method of claim 1 and further comprising, in response to the message from the wireless device, one of the server ending the call, transferring the call to another device, and placing the call on hold.

3. The method of claim 1 wherein the wireless network is a wireless local area network.

4. The method of claim 1 wherein the second device is a second wireless device.

5. The method of claim 1 wherein the second device is any voice-enabled device coupled to the server through a private branch exchange (“

PBX”

).

6. The method of claim 1 wherein the server is a session initiation protocol (“

SIP”

) server and the messages are SIP messages.

7. The method of claim 1 wherein the characteristic is at least one of signal strength, data rate, signal-to-noise ratio, echo level, jitter metric, packet concealment rate, packet loss rate, retransmission rate, and subnet address.

8. The method of claim 1 wherein the wireless device is a dual-mode wireless device operable on both the wireless network and a cellular network.

9. The method of claim 8 and further comprising, in response to the message from the wireless device, the server transferring the call to the cellular network.

10. A system for signalling a transfer of a voice call communicated between a wireless device and a second device from a first access point to a second access point in a wireless network, the second device coupled to the first and second access points through the system, the system comprising:

a processor coupled to the wireless network; and

,

a program executed by the processor, the program including;

a module for receiving from the wireless device a message indicative of a pending transfer between the first and second access points, wherein the wireless device determines whether to send the message by monitoring a characteristic of signals received from each of the first and second access points; and

,

a module for sending to the second device a message indicative of the pending transfer to thereby prepare the second device for a possible interruption of the voice call.

11. The system of claim 10 and further comprising a module for, in response to the message from the wireless device, one of ending the call, transferring the call to another device, and placing the call on hold.

12. The system of claim 10 wherein the wireless network is a wireless local area network.

13. The system of claim 10 wherein the second device is a second wireless device.

14. The system of claim 10 wherein the second device is any voice-enabled device coupled to the system through a private branch exchange (“

PBX”

).

15. The system of claim 10 wherein the system is a session initiation protocol (“

SIP”

) server and the messages are SIP messages.

16. The system of claim 10 wherein the characteristic is at least one of signal strength, data rate, signal-to-noise ratio, echo level, jitter metric, packet concealment rate, packet loss rate, retransmission rate, and subnet address.

17. The system of claim 10 wherein the wireless device is a dual-mode wireless device operable on both the wireless network and a cellular network.

18. The system of claim 17 and further comprising a module for, in response to the message from the wireless device, transferring the call to the cellular network.

19. A computer program product having computer executable code for directing a system to signal a transfer of a voice call communicated between a wireless device and a second device from a first access point to a second access point in a wireless network, the second device coupled to the first and second access points through the system, the code comprising:

code for receiving at the system from the wireless device a message indicative of a pending transfer between the first and second access points, wherein the wireless device determines whether to send the message by monitoring a characteristic of signals received from each of the first and second access points; and

,

code for sending from the server to the second device a message indicative of the pending transfer to thereby prepare the second device for a possible interruption of the voice call.

20. The computer program product of claim 19 and further comprising code for, in response to the message from the wireless device, one of the system ending the call, transferring the call to another device, and placing the call on hold.

21. The computer program product of claim 19 wherein the wireless network is a wireless local area network.

22. The computer program product of claim 19 wherein the second device is a second wireless device.

23. The computer program product of claim 19 wherein the second device is any voice-enabled device coupled to the system through a private branch exchange (“

PBX”

).

24. The computer program product of claim 19 wherein the system is a session initiation protocol (“

SIP”

) server and the messages are SIP messages.

25. The computer program product of claim 19 wherein the characteristic is at least one of signal strength, data rate, signal-to-noise ratio, echo level, jitter metric, packet concealment rate, packet loss rate, retransmission rate, and subnet address.

26. The computer program product of claim 19 wherein the wireless device is a dual-mode wireless device operable on both the wireless network and a cellular network.

27. The computer program product of claim 26 and further comprising code for, in response to the message from the wireless device, the system transferring the call to the cellular network.