Method and apparatus for a source-initiated handoff from a source cellular wireless network to a target non-cellular wireless network

• US 20040146021A1
• Filed: 01/23/2003
• Published: 07/29/2004
• Est. Priority Date: 01/23/2003
• Status: Active Grant

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Love, Robert T., Pazhyannur, Rajesh S., Gopikanth, Venkat, Liss, Raymond M., Fors, Chad M.
• Granted Patent: US 6,904,029 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0066 of control information between different types of networks in order to establish a new radio link in the target network
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

To address the need for an apparatus and method for handoff from a cellular wireless network to a non-cellular wireless network (WLAN, e.g.), the present application describes an access gateway (214) and a dual mode mobile station (201) that enable such handoffs. Dual mode MSs can determine when a handoff to a non-cellular network is preferred and request a handin (302) from the non-cellular network. The access gateway provides information to the MS (304) so that it can initiate a handoff through the serving cellular network. Triggering handoffs in this manner, allows cellular networks to handle handoffs to non-cellular networks in much the same way they handle inter-MSC handoffs today, i.e., source initiated.

Claims

1. An access gateway able to facilitate handoff from a cellular wireless network to a non-cellular wireless network, the access gateway comprising:

a network interface; and

a cellular interworking device, communicatively coupled to the network interface,

adapted to receive a handin request from a mobile station (MS) via a non-cellular access point and the network interface,

adapted to send a handin request acknowledgment to the MS via the non-cellular access point and the network interface in response to the handin request,

adapted to receive a handoff indication from a mobile switching center (MSC) associated with the MS,

adapted to receive a handoff complete indication from the MS via the non-cellular access point and the network interface, and

adapted to send an indication to the MSC that the MS is on channel, in response to the handoff complete indication.

2. The access gateway of claim 1, wherein the non-cellular access point comprises a wireless local area network (WLAN) access point.

3. The access gateway of claim 2, wherein the WLAN access point utilizes wireless signaling of at least one type from the group of signaling types consisting of Bluetooth, HiperLAN 2, and IEEE 802.11.

4. The access gateway of claim 1, wherein the network interface is adapted to send and receive messaging using an internet protocol.

5. The access gateway of claim 1, wherein the cellular interworking device is adapted to perform cellular mobility interworking by interfacing with MSCs and home location registers (HLRs).

6. The access gateway of claim 5, wherein the cellular interworking device is adapted to perform cellular interworking for registration, authentication, and handoff.

7. The access gateway of claim 5, wherein the cellular interworking device is adapted to perform PSTN interworking utilizing at least one landline signaling protocol from the group consisting of ISDN User Part (ISUP) and Mutli Frequency R1 (MFR1).

8. The access gateway of claim 5, wherein the cellular interworking device is adapted to perform cellular mobility interworking by interfacing with a circuit gateway.

9. The access gateway of claim 8, wherein the cellular interworking device is adapted to perform cellular mobility interworking by interfacing with a PBX.

10. A method for facilitating handoff of a mobile station (MS) from a cellular wireless network to a non-cellular wireless network comprising:

receiving, by an access gateway, a handin request from the MS via a non-cellular access point;

sending, by the access gateway in response to the handin request, a handin request acknowledgment to the MS via the non-cellular access point;

receiving, by the access gateway, a handoff indication from a mobile switching center (MSC) associated with the MS;

receiving, by the access gateway, a handoff complete indication from the MS via the non-cellular access point; and

sending, by the access gateway in response to the handoff complete indication, an indication that the MS is on channel to the MSC associated with the MS.

11. The method of claim 10, wherein the handin request acknowledgment comprises a handoff-target identifier.

12. The method of claim 11, wherein the handoff-target identifier comprises a cell identifier.

13. The method of claim 11, wherein the handoff-target identifier comprises a value which is predefined to trigger an automatic handoff determination by the cellular wireless network from which the MS is attempting to handoff.

14. The method of claim 10, further comprising:

receiving, by the access gateway, call information for the MS from the MSC; and

routing, by the access gateway, the call information to the MS via the non-cellular access point.

15. The method of claim 14, wherein the call information is received via DS0 signaling.

16. The method of claim 14, wherein the call information is routed to the non-cellular access point via an internet protocol (IP) network.

17. The method of claim 14, wherein the call information comprises information of at least one type from the group consisting of voice and video-telephony.

18. The method of claim 10, wherein receiving the handoff indication comprises receiving, by the access gateway, a mobile application part (MAP) FACDIR2 message from the MSC.

19. The method of claim 10, further comprising sending, by the access gateway, a MAP facdir2 message to the MSC in response to the MAP FACDIR2 message.

20. The method of claim 10, wherein sending the indication that the MS is on channel comprises sending a MAP MSONCH message.

21. The method of claim 10, wherein sending the indication that the MS is on channel comprises sending the indication to the MSC in response to the handoff complete indication from the MS.

22. The method of claim 10, wherein receiving the handin request comprises receiving the handin request via an internet protocol (IP) packet.

23. A mobile station (MS) able to handoff from a cellular wireless network to a non-cellular wireless network, the MS comprising:

a transmitter;

a receiver; and

a processor, communicatively coupled to the transmitter and receiver,

adapted to send, via the transmitter, a handin request to an access gateway via a non-cellular access point,

adapted to receive, via the receiver, a handin request acknowledgment from the access gateway via the non-cellular access point,

adapted to send, via the transmitter after receiving the handin request acknowledgment, a signal strength message to a serving cellular base site, wherein the signal strength message comprises values intended to trigger a handoff determination,

adapted to receive, via the receiver, a handoff release indication from a serving cellular base site, and

adapted to send, via the transmitter and after receiving the handoff release indication, a handoff complete indication to the access gateway via the non-cellular access point.

24. A method for handing off from a cellular wireless network to a non-cellular wireless network comprising:

sending, by a mobile station (MS), a handin request to an access gateway via a non-cellular access point;

receiving, by the MS, a handin request acknowledgment from the access gateway via the non-cellular access point;

sending, by the MS after receiving the handin request acknowledgment, a signal strength message to a serving cellular base site, wherein the signal strength message comprises values intended to trigger a handoff determination;

receiving, by the MS, a handoff release indication from the serving cellular base site; and

sending, by the MS after receiving the handoff release indication, a handoff complete indication to the access gateway via the non-cellular access point.

25. The method of claim 24, wherein the handin request comprises an indication of from which cellular wireless network the MS is attempting to handoff.

26. The method of claim 25, wherein the handin request comprises a serving cell identifier.

27. The method of claim 26, wherein the serving cell identifier comprises a Base Transceiver Station Identity Code (BSIC).

28. The method of claim 26, wherein the serving cell identifier comprises a PN offset.

29. The method of claim 24, wherein the handin request acknowledgment comprises a handoff-target identifier.

30. The method of claim 29, wherein the handoff-target identifier comprises a cell identifier

31. The method of claim 30, wherein the signal strength message comprises the cell identifier and an artificial signal strength value associated with the cell identifier intended to trigger a handoff of the MS to the non-cellular wireless network identified by the cell identifier.

32. The method of claim 29, wherein the handoff-target identifier comprises a value which is predefined to trigger an automatic handoff determination by the cellular wireless network from which the MS is attempting to handoff.

33. The method of claim 32, wherein the signal strength message comprises the handoff-target identifier in order to trigger a handoff of the MS to the non-cellular wireless network identified by the handoff-target identifier.

34. The method of claim 24, wherein the signal strength message comprises a CDMA Pilot Strength Measurement Message (PSMM).

35. The method of claim 24, wherein the signal strength message comprises a message from the group consisting of MEAS_RES (Measurement Result) and MEAS_REP (Measurement Report).

36. The method of claim 24, further comprising:

receiving, by the MS, call information via the serving cellular base site and a mobile switching center (MSC) associated with the MS; and

receiving, by the MS, call information via the non-cellular access point, the access gateway, and the MSC.

37. The method of claim 36, wherein receiving call information via the non-cellular access point occurs after sending the handoff complete indication.

38. The method of claim 36, wherein receiving call information via the non-cellular access point further comprises receiving call information via a voice-over-IP (VoIP) protocol.

39. The method of claim 38, wherein the VoIP protocol comprises a protocol from the group consisting of a H.323 protocol, a Session Initiation Protocol (SIP), and a Skinny Protocol.

40. The method of claim 24, further comprising obtaining, by the MS, an IP address for the MS.

41. The method of claim 24, further comprising obtaining, by the MS, an IP address for the access gateway.

42. The method of claim 24, further comprising determining, by the MS, that a handoff from the serving cellular base site to the non-cellular access point is preferred.

43. The method of claim 42, wherein determining that a handoff from the serving cellular base site to the non-cellular access point is preferred comprises determining that a handoff is preferred based on at least one handoff factor from the group consisting of relative signal conditions between cellular and non-cellular networks and relative cost of cellular and non-cellular service.

44. The method of claim 24, wherein sending the handin request comprises sending the handin request via an internet protocol (IP) packet.

45. The method of claim 24, wherein sending the handoff complete indication comprises sending the handoff complete indication via an internet protocol (IP) packet.

46. The method of claim 24, wherein the handoff release indication comprises a HND_CMD (handoff command) message from the serving cellular base site.

47. The method of claim 24, wherein the handoff release indication comprises a CDMA Handoff Direction Message from the serving cellular base site.