Method and apparatus for implementing bi-directional soft handovers between wireless networks without carrier control

• US 6,766,171 B2
• Filed: 06/26/2002
• Issued: 07/20/2004
• Est. Priority Date: 06/26/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Pan, Shaowei, Zhang, Jinzhong, Labun, Nicholas, Favila, Angel
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): MILLER, BRANDON J
• Application Number:
  US10/180,844
• Publication Number:
  US 20040002335A1
• Time in Patent Office: 755 Days
• Field of Search: 455/436-438, 455/439, 455/442, 455/445, 455/430, 455/517
• US Class Current: 455/439
• 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 36/18 for allowing seamless reselection, e.g. soft reselection

Abstract

The present invention provides a method and apparatus that enables handover of a mobile station between a cellular network and a wireless network without control intervention from the cellular network and independent of employed air interface technology. The signaling and control of a switch, for example SS7 messaging, is not required to achieve the handovers implemented by the present invention. In particular, a call is connected (508) between a mobile station (202) and a remote station (204) through a media gateway (210). The media gateway is connected to the mobile station via a first connection line and to the remote station via a second connection line. When the mobile station has entered (514, 516) a transition area (302), a third connection line is established (518) between the media gateway and the mobile station. Communication between the media gateway and the mobile station then is handed-over (526, 528) from the first connection line to the third connection line and, thereafter, the first connection line is disconnected (530).

Claims

1. A method for managing a communication network having an area of coverage, the communication network associated with a media gateway that communicates with a plurality of mobile stations, the method comprising the steps of:

connecting a call between a mobile station and a remote station through the media gateway, the media gateway being connected to the mobile station via a first connection line and to the remote station via a second connection line;

determining that the mobile station entered a transition area of the area of coverage;

establishing a third connection line between the media gateway and the mobile station;

handing-over communication between the media gateway and the mobile station from the first connection line to the third connection line, without coordinating control of the call with another network different from the communication network; and

disconnecting communication between the media gateway and the mobile station via the first connection line.

2. The method of claim 1 wherein, during the step of handing-over communication, the first and third connection lines exist concurrently so that the media gateway may handover communication between the media gateway and the mobile station from the first connection line to the third connection line.

3. The method of claim 1, wherein the first connection line operates within one of either a non-carrier network and a carrier network, and the third connection line operates within the other of either the non-carrier network and the carrier network.

4. The method of claim 3, wherein the non-carrier network is an enterprise network that is not managed by a carrier.

5. The method of claim 4, wherein the enterprise network is a wireless local area network.

6. The method of claim 1, wherein the transition area is located at an outer boundary of the area of coverage.

7. The method of claim 1, wherein the step of determining that the mobile station entered the transition area includes at least one of (a) the step of determining that the mobile station is within a particular range for entering the area of coverage, and (b) the step of determining that the mobile station is within a particular range for exiting the area of coverage.

8. The method of claim 1, wherein the step of determining that the mobile station entered the transition area includes the step of determining a position of the mobile station relative to the transition area based on a radio signal strength indication (“

RSSI”

) of the mobile station.

9. The method of claim 1, wherein the step of establishing the third connection line includes the step of receiving a call from the mobile station that is directed to a predetermined number.

10. A wireless communication system comprising:

a mobile station capable of communication with a remote station;

a carrier network for enabling wireless communication between the mobile station and the remote station within a carrier area of coverage;

a non-carrier network for enabling wireless communication between the mobile station and the remote station within a non-carrier area of coverage;

a media gateway associated with the non-carrier network for connecting a call between the mobile station and the remote station, the media gateway being capable of connecting a first connection line with the mobile station via one of either the carrier network and the non-carrier network, establishing a second connection line with the mobile station via the other of either the carrier network and the non-carrier network, and disconnecting the first connection line, without coordinating control of the call with the carrier network.

11. The wireless communication system of claim 10, wherein the media gateway is capable of connecting a third connection line with the remote station via one of either the carrier network and the non-carrier network.

12. The wireless communication system of claim 10, wherein the first and second connection lines exist concurrently so that the media gateway may handover communication between the media gateway and the mobile station from the first connection line to the second connection line.

13. The wireless communication system of claim 10, wherein the non-carrier network is an enterprise network that is not managed by a carrier.

14. The wireless communication system of claim 10, wherein the non-carrier network is a wireless local area network.

15. The wireless communication system of claim 10, wherein the media gateway determines whether the mobile station entered a transition area of the non-carrier area of coverage.

16. The wireless communication system of claim 15, wherein the transition area is located at an outer boundary of the non-carrier area of coverage.

17. The wireless communication system of claim 15, wherein the media gateway determines one of either (a) the mobile station is within a particular range for entering the non-carrier area of coverage, and (b) the mobile station is within a particular range for exiting the non-carrier area of coverage.

18. The wireless communication system of claim 15, wherein the media gateway determines a position of the mobile station relative to the transition area based on a radio signal strength indication (“

RSSI”

) of the mobile station.

19. The wireless communication system of claim 10, wherein the media gateway receives a call from the mobile station that is directed to a predetermined number.

20. A wireless communication system comprising:

a mobile station capable of communication with a remote station;

a carrier network for enabling wireless communication between the mobile station and the remote station within a carrier area of coverage;

a non-carrier network for enabling wireless communication between the mobile station and the remote station within a non-carrier area of coverage;

a media gateway associated with the non-carrier network for connecting a call between the mobile station and the remote station, the media gateway being capable of connecting a first connection line with the mobile station via the carrier network, determining that the mobile station entered the non-carrier area of coverage, establishing a second connection line with the mobile station via the non-carrier network, and disconnecting the first connection line via the carrier network, without coordinating control of the call with the carrier network.

21. The wireless communication system of claim 20, wherein the first and second connection lines exist concurrently so that the media gateway may handover communication between the media gateway and the mobile station from the first connection line to the second connection line.

22. A wireless communication system comprising:

a mobile station capable of communication with a remote station;

a carrier network for enabling wireless communication between the mobile station and the remote station within a carrier area of coverage;

a non-carrier network for enabling wireless communication between the mobile station and the remote station within a non-carrier area of coverage;

a media gateway associated with the non-carrier network for connecting a call between the mobile station and the remote station, the media gateway being capable of connecting a first connection line with the mobile station via the non-carrier network, determining that the mobile station exited the non-carrier area of coverage, establishing a second connection line with the mobile station via the carrier network, and disconnecting the first connection line via the non-carrier network, without coordinating control of the call with the carrier network.