Granted Patent B2

US 8,417,287 · App. 13/308,807 · Granted Apr 9, 2013

Abstract

Claims (39)

1. A virtual gateway for communicating voice and call control data between an IP-based telephone switch connected via a communication link and a dual-mode subscriber device connected via a wireless local area network (WLAN) link, comprising:

a computing device, including

a wireless local area network interface capable of establishing a WLAN link with the dual-mode subscriber device,

a network interface capable of establishing a communication link with the IP-based telephone switch, and

a processor configured to:

relay voice and call control data between the dual-mode subscriber device and the IP-based telephone switch; and

create a message in the first call control signaling format initiating a call from the IP-based telephone switch to the dual-mode subscriber device via a wireless communication system,

wherein:

the call control data transmitted over the communication link are in first call control signaling format and the call control data transmitted over the WLAN link are in second call control signaling format different than the first call control signaling format; and

the message initiating the call is a registration message sent to the IP-based telephone switch.

2. The virtual gateway of claim 1 , wherein the first call control signaling format is one of session initiation protocol (“SIP”) format and H.323 format.

3. The virtual gateway of claim 1 , wherein the processor is further configured to translate the call control data received over the communication link to the second call control signaling format for transmission over the WLAN link, and

wherein the processor is further configured to translate the call control data received over the WLAN link to the first call control signaling format for transmission over the communication link.

4. The method of claim 1 , wherein the message initiating the call is a SIP registration message.

5. The virtual gateway of claim 1 , wherein the processor is further configured to receive from the dual-mode subscriber device a WLAN-based request to hand off the call from the wireless local area network to a wireless communication system.

6. The virtual gateway of claim 1 , wherein the processor is further configured to determine whether a handoff of a call to a wireless communication system is warranted.

7. The virtual gateway of claim 6 , wherein the handoff determination is made through monitoring at least one of an automatic gain control value, receive signal strength indication, packet error rate, signal to noise ratio, maximum allowable data rate, and current data transfer rate.

8. The virtual gateway of claim 1 , wherein the processor is further configured to transmit a WLAN-based switchover instruction to the dual-mode subscriber device.

9. The virtual gateway of claim 1 , wherein the processor is further configured to receive a call confirmation message from the IP-based telephone switch and to relay the call confirmation message to the dual-mode subscriber device.

10. The virtual gateway of claim 9 , wherein the call confirmation message from the IP-base telephone switch is a SIP invite message.

11. A method for communicating voice and call control data between an IP-based telephone switch and a dual-mode subscriber device capable of operation within a wireless communication system, comprising the steps of:

establishing a wireless local area network (WLAN) link with the dual-mode subscriber device;

establishing a communication link with the IP-based telephone switch;

relaying voice and call control data between the dual-mode subscriber device and the IP-based telephone switch; and

creating a message in the first call control signaling format initiating a call from the IP-based telephone switch to the dual-mode subscriber device via a wireless communication system,

wherein:

the call control data transmitted over the communication link are in a first call control signaling format and the call control data transmitted over the WLAN link are in second call control signaling format different than the first call control signaling format; and

the message initiating the call is a registration message sent to the IP-based telephone switch.

12. The method of claim 11 , wherein the first call control signaling format is one of session initiation protocol (“SIP”) format and H.323 format.

13. The method of claim 11 , further comprising the steps of:

translating the call control data received over the communication link to the second call control signaling format for transmission over the WLAN link, and

translating the call control data received over the WLAN link to the first call control signaling format for transmission over the communication link.

14. The method of claim 11 , wherein the message initiating the call is a SIP registration message.

15. The method of claim 14 , further comprising the steps of receiving a call confirmation message from the IP-based telephone switch, and relaying the call confirmation message to the dual-mode subscriber device.

16. The method of claim 15 , wherein the call confirmation message from the IP-base telephone switch is a SIP invite message.

17. The method of claim 11 , further comprising the step of receiving from the dual-mode subscriber device a WLAN-based request to hand off the call from the wireless local area network to a wireless communication system.

18. The method of claim 11 , further comprising the step of determining whether a handoff of a call to a wireless communication system is warranted.

19. The method of claim 11 , wherein the step of determining includes the step of monitoring at least one of an automatic gain control value, receive signal strength indication, packet error rate, signal to noise ratio, maximum allowable data rate, and current data transfer rate.

20. The method of claim 11 , further comprising the step of transmitting a WLAN-based switchover instruction to the dual-mode subscriber device.

Assignments (9)