Method and system wherein handover information is broadcast in wireless local area networks

• US 6,950,655 B2
• Filed: 06/20/2003
• Issued: 09/27/2005
• Est. Priority Date: 10/01/2002
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Hunkeler, Teresa
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Ewart, James D
• Application Number:
  US10/600,403
• Publication Number:
  US 20040063426A1
• Time in Patent Office: 830 Days
• Field of Search: 455/403, 455/426.1, 455/430, 455/443, 455/525, 455/552.1, 455/554.2, 455/560, 370/329, 370/341
• US Class Current: 455/426.1
• CPC Class Codes: H04W 36/0055 Transmission or use of information for re-establishing the radio link
• CPC Class Codes: H04W 48/10 using broadcasted information
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method and system wherein handover information is broadcast in a wireless local area network. Handover information is broadcast in a beacon frame thereby allowing WTRUs operating in a wireless area network to handover to available alternative systems as desired. WTRUs may read the beacon frame and obtain appropriate information for handing over to alternative systems having coverage areas that overlap that of the wireless local area network. The alternative systems may be any type of wireless system and the wireless local area network may be any type of wireless area network.

Claims

1. A wireless local area network (WLAN), the WLAN having a geographic coverage area which at least partially overlaps coverage areas of alternative wireless communication systems, the WLAN comprising:

an access point comprising;

means for providing a plurality of wireless transmit/receive units (WTRUs) with wireless access to the WLAN; and

means for broadcasting a beacon frame including handover information for handing WTRUs over from the WLAN to one of the available alternative wireless communication systems, the handover information including cell information necessary for establishing a wireless connection to the alternative wireless communication systems;

whereby the WTRU directly establishes a wireless connection to a selected wireless communication system utilizing the cell information without performing additional search for obtaining the cell information from the selected wireless communication system.

2. The wireless local area network of claim 1 wherein the handover information includes information related to network type.

3. The wireless local area network of claim 1 wherein the handover information includes information related to network identity.

4. The wireless local area network of claim 1 wherein the handover information includes cell information for cells surrounding the cell serviced by the access point.

5. The wireless local area network of claim 1 wherein the handover information includes information related to the types of services offered by an available alternative system.

6. The wireless local area network of claim 1 wherein at least one of the available alternative technologies is a PLMN.

7. The wireless local area network of claim 1 wherein at least one of the available alternative technologies is another wireless local area network.

8. The wireless local area network of claim 1 wherein the wireless local area network is an 802.11b network.

9. A method for handing over a wireless transmit/receive (WTRU) from a wireless local area network (WLAN) to an available alternative wireless communication system having a geographic coverage area which at least partially overlaps coverage areas of the WLAN comprising:

broadcasting handover information for handing WTRUs over from the WLAN to the alternative wireless communication system in a beacon frame, the handover information including cell information necessary for establishing a wireless connection to the alternative wireless communication system;

reading the handover information in the beacon frame;

retrieving cell information regarding available alternative wireless communication systems from the handover information in the beacon frame;

selecting an available alternative wireless communication system that is of interest to the user;

performing coverage and quality of service measurements on the selected system; and

handing the user over to the selected available system where the measurements are sufficient and establishing a connection to the selected wireless communication system using the cell information in the beacon frame without performing additional search for obtaining the cell information from the selected wireless communication system.

10. The method of claim 9 wherein the step of selecting an available system that is of interest to the user further includes comparing available systems with systems that are of interest to the user.

11. The method of claim 9 wherein the handover information includes information related to network type.

12. The method of claim 9 wherein the handover information includes information related to network identity.

13. The method of claim 9 wherein the handover information includes cell information for cells surrounding the cell serviced by the access point.

14. The method of claim 9 wherein the handover information includes information related to the types of services offered by an available alternative system.

15. The method of claim 9 wherein at least one of the available alternative technologies is a PLMN.

16. The method of claim 9 wherein at least one of the available alternative technologies is another wireless local area network.

17. The method of claim 9 wherein the wireless local area network is an 802.11b network.

18. A method for handing over a wireless transmit/receive unit (WTRU) from a wireless local area network (WLAN) to an available alternative wireless communication system comprising:

broadcasting handover information for handing WTRUs over from the WLAN to the alternative wireless communication system in a beacon frame, the handover information including cell information necessary for establishing a wireless connection to the alternative wireless communication system;

reading the handover information to determine whether alternative systems are available for handover;

retrieving cell information regarding the available alternative systems that are of interest from the beacon frame;

determining whether the WTRU is capable of supporting the available alternative systems;

selecting an available system that is of interest and the WTRU is capable of supporting;

performing coverage and quality of service measurements on the selected system; and

handing over to the selected available system where the measurements are sufficient and establishing a connection to the selected wireless communication system using the cell information in the beacon frame without performing additional search for obtaining the cell information from the selected wireless communication system.

19. The method of claim 18 wherein the handover information includes information related to network type.

20. The method of claim 18 wherein the handover information includes information related to network identity.

21. The method of claim 18 wherein the handover information includes cell information for cells surrounding the cell serviced by the access point.

22. The method of claim 18 wherein the handover information includes information related to the types of services offered by an available alternative system.

23. The method of claim 18 wherein at least one of the available alternative technologies is a PLMN.

24. The method of claim 18 wherein at least one of the available alternative technologies is another wireless local area network.

25. The method of claim 18 wherein the wireless local area network is an 802.11b network.