Data handoff method between wireless local area network and wireless wide area network

• US 7,356,015 B2
• Filed: 04/30/2004
• Issued: 04/08/2008
• Est. Priority Date: 05/02/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Steven Blumenthal
• Inventors: Blumenthal, Steven, Ibe, Oliver C.
• Primary Examiner(s): Feild; Joseph
• Assistant Examiner(s): Doan; Kiet
• Application Number:
  US10/836,057
• Publication Number:
  US 20040218575A1
• Time in Patent Office: 1,439 Days
• Field of Search: 455/445, 455/426.1, 455/435, 455/411
• US Class Current: 370/338
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 80/045 involving different protocol versions, e.g. MIPv4 and MIPv6
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A method and associated system enables seamless data roaming and handoff between the wireless local area network (WLAN) and the wireless wide-area network (WWAN). This method enables a mobile device to originate a data connection in the WLAN and have this data connection be automatically handed off to the WWAN without losing the connection when the user goes outside the range of the WLAN. Similarly, it enables a mobile device to originate a data connection in the WWAN and have this data connection be automatically handed off to the WLAN without losing the connection when the user loses the signal of the WWAN. This solution assumes that the user has subscribed to data services from a cellular carrier that will authenticate the user before permitting the handoff.

Claims

1. A method for communicating with a mobile terminal comprising:

establishing a first data communication path passing from a wide area wireless network through a fixed radio terminal over a local wireless network to the mobile terminal by emulating the mobile terminal on a the wide area wireless network using a the fixed radio terminal; and

establishing a second data communication path passing from the wide area wireless network directly to the mobile terminal without passing through the fixed radio terminal; and

switching an active communication session between the first communication path and the second communication path by establishing a third communication path to a controller on the local wireless network, which buffers data to the mobile device during a handoff between the first data communication path and the second data communications path, wherein handing off the active communication session includes successively switching said session between the third communication path and the first communication path and then switching said session between the first communication path and the second communication path.

2. The method of claim 1 wherein the active communication session includes a voice communication session.

3. The method of claim 2 wherein the voice communication session is passed over the local wireless network on the first communication path using a data session.

4. The method of claim 2 wherein the voice communication session is passed over the local network on the first communication path using voice over Internet Protocol.

5. The method of claim 1 wherein switching the active communication session includes switching said session from the first communication path to the second communication path.

6. The method of claim 1 wherein switching the active communication session includes switching said active communication session from the second communication path to the first communication path.

7. The method of claim 1 wherein handing off the active communication session includes successively switching said session between the third communication path and the first communication path and then switching said session between the first communication path and the second communication path.

8. The method of claim 1 further comprising:

using the fixed radio terminal to emulate each of a plurality of mobile terminals each on a respective different one of a plurality of wide area wireless networks.

9. The method of claim 8 further comprising:

for each of the plurality of mobile terminals, switching an active communication session between a communication path passing from the respective one of the wide area networks through the fixed radio terminal over the local network to said mobile terminals and a communication path passing from said wide area wireless network directly to said mobile terminal without passing through the fixed radio terminal.

10. A method for handling handing off a communication session with a mobile terminal between a local wireless network and a wide area wireless network comprising:

switching the communication session between a first communication path extending over the wide area wireless network through a fixed radio terminal and over the local wireless network to the mobile terminal and a temporary communication path passing extending from a controller on the local network to the mobile terminal not passing through fixed radio terminal; and

switching the communication session between the first communication path and a second communication path extending from the wide area wireless network directly to the mobile terminal without passing through the fixed radio terminal;

wherein switching the communication session includes successively switching said session between the temporary communication path and the first communication path and then switching said session between the first communication path and the second communication path;

sending buffered data via the temporary communication path, which was buffered during the switch between the first communications path and the second communication path.

11. A method for handing off a communication session with a mobile terminal between a local wireless network and a wide area wireless network comprising:

a mobile device sending a registration request to a controller system on a local wireless network;

the controller system maintaining a wide area wireless network profile for the mobile device;

the controller system then emulating the mobile device on the wide area wireless network via a fixed radio terminal;

the controller system monitoring the wide area wireless network for data addressed to the mobile device via the fixed radio terminal and forwarding the data addressed to the mobile device to the mobile device via the local wireless network;

the mobile device monitoring a signal strength of the local wireless network;

in response to mobile device determining that the signal strength of the local wireless network is weak, the mobile device sending an initiate handoff signal to the controller system;

the controller system passing connection parameters for a wide area cellular network to the mobile device over the local wireless network;

the mobile device then switching over to a communication session on the wide area cellular network which does not pass through the fixed radio terminal using the connection parameters; and

the controller system buffering data until the mobile device signals the ability to receive data over the wide area cellular network, then sending data via the wide area cellular network.

12. A handoff method for a mobile device on a wide area cellular network moving to a local wireless network, the method comprising:

the mobile device monitoring a signal strength of the wide area cellular network;

in response to mobile device determining that the signal strength of the wide area cellular network is weak, the mobile device then sending an initiate handoff signal to a controller system including parameters of the data communications session on the wide area cellular network;

the cellular controller adopting the data communications session on the wide area cellular network for the mobile device by emulating the mobile device on the wide area cellular network and the mobile device registering on the local wireless network; and

the controller system buffering data received via the data communications session on the wide area cellular network until the mobile device is registered on the local wireless network and the controller system then sending the buffered data to the mobile device over the local wireless network.