Registration of a wlan as a umts routing area for wlan-umts interworking

• US 20050239461A1
• Filed: 06/20/2003
• Published: 10/27/2005
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Wang, Charles Chuanming, Verma, Shaily
• Granted Patent: US 7,764,660 B2
• Time in Patent Office: Days
• US Class Current: 455/435.100
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/1446 wherein at least one of the networks is unlicensed
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 60/04 using triggered events
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 76/19 Connection re-establishment
• CPC Class Codes: H04W 76/22 Manipulation of transport tunnels
• CPC Class Codes: H04W 76/25 Maintenance of established connections
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• 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
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

A system for employing a wireless local area network (WLAN) as a cellular network routing area includes a cellular network, which is capable of determining a location where a service request is made. The cellular network includes a packet-based support node B, which determines if the request can be serviced through a WLAN, which is identified in the cellular network as a routing area. Packet data protocol context is maintained while servicing the request using the WLAN to provide smooth interworking between the WLAN and the cellular network.

Claims

1. A method for registering a Wireless Local Area Network (WLAN) as a cellular network routing area, comprising the steps of:

determining a location of a service request from a user within a cellular network;

determining whether the location is in or near a WLAN access point;

if at or near the WLAN access point, maintaining packet data protocol (PDP) context while servicing the request using the WLAN such that interworking between the WLAN and the cellular network is provided.

2. The method as recited in claim 1, wherein the step of maintaining packet data protocol (PDP) context while servicing the request using the WLAN includes restricting radio signaling between a user and the cellular network while using the WLAN.

3. The method as recited in claim 1, further comprising the step of receiving a request for service for a routing area in a cellular network.

4. The method as recited in claim 3, wherein the WLAN is recognized as a routing area of the cellular network.

5. The method as recited in claim 3, further comprising the step of setting a periodic routing area update timer value while in a WLAN coverage area to reduce signaling while a user is in the WLAN area.

6. The method as recited in claim 1, further comprising the step of establishing packet switched signaling connection through the PDP context when existing the WLAN.

7. The method as recited in claim 1, further comprising the step of controlling the loading of cellular cells by shifting user traffic service to WLANs.

8. The method as recited in claim 1, wherein the interworking between the cellular network and the WLAN is provided by:

uniquely identifying the WLAN as a routing area of the cellular network; and

once identified, setting a routing area update timer to reduce a number of routing area updates to the cellular network.

9. The method as recited in claim 1, wherein the step of maintaining the PDP context includes maintaining the PDP context to reduce handoff delay while re-entering the UMTS network.

10. The method as recited in claim 1, further comprising the step of enabling cellular service providers to control the loading of cells by shifting users to WLANs by changing routing area identifiers of the users to that of a WLAN coverage area.

11. A system for employing a Wireless Local Area Network (WLAN) as a cellular network routing area, comprising:

a cellular network, which is capable of determining a location where a service request is made;

the cellular network comprising a packet-based support node, which determines if the request can be serviced through a WLAN, which is identified in the cellular network as a routing area;

means for maintaining packet data protocol (PDP) context while servicing the request using the WLAN to provide smooth handoff between the WLAN and the cellular network.

12. The system as recited in claim 11, wherein the means of maintaining packet data protocol (PDP) context includes a preservation function provided in a mobile station.

13. The system as recited in claim 11, further comprising a unique routing area identifier, which identifies the WLAN in the cellular network.

14. The system as recited in claim 11, further comprising a periodic routing area update timer wherein a timer value is employed while in a WLAN coverage area to reduce signaling while a user is in the WLAN area.

15. The system as recited in claim 11, further comprising an interworking function for establishing and maintaining user services between the WLAN and the cellular network.

16. The system as recited in claim 11, wherein the cellular network includes a Universal Mobile Telecommunications System (UMTS).

17. The system as recited in claim 11, wherein the means for maintaining packet data protocol (PDP) context further comprises a Radio Access Bearer (RAB) setup procedure for establishing interworking between the cellular network and the WLAN.

18. The system as recited in claim 11, wherein the cellular network learns if a user is in a WLAN coverage area via a routing area identifier (RAI) update message.