	US 7,558,852 B2
	Tag location, client location, and coverage hole location in a wireless network
Bretton Lee Douglas, San Jose, Calif. (US); Timothy S. Olson, San Jose, Calif. (US); David E. Halasz, Stow, Ohio (US); John Z. Deng, Canton, Ohio (US); Arnold M. Bilstad, Redwood City, Calif. (US); Sheausong Yang, Saratoga, Calif. (US); Richard D. Rebo, North Royalton, Ohio (US); Jonathan S. Leary, Boston, Mass. (US); and Daryl A. Kaiser, Los Gatos, Calif. (US)
Assigned to Cisco Technology, Inc., San Jose, Calif. (US)
Filed on Aug. 21, 2007, as Appl. No. 11/842,549.
Application 11/842549 is a continuation of application No. 11/286086, filed on Nov. 22, 2005, granted, now 7,293,088.
Application 11/286086 is a continuation in part of application No. 10/629384, filed on Jul. 28, 2003, granted, now 6,990,428.
Claims priority of provisional application 60/649721, filed on Feb. 03, 2005.
Prior Publication US 2007/0281714 A1, Dec. 06, 2007
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 15/173 (2006.01)

U.S. Cl. 709—224 [709/236; 455/404.2; 455/456.1]

23 Claims

1. A method of operating a processing system, comprising:

receiving path loss information from at least one wireless station or radio tag of a wireless network, the path loss information from a wireless station or radio tag being for one or more location frames received at the wireless station or radio tag, each received location frame transmitted by a respective radio tag or a respective client station and having a pre-defined frame structure; and

determining the location of at least one of the wireless client stations or radio tags from the received path loss information using a path-loss based location determining method,

wherein the radio tag or client station uses a common infrastructure for transmitting a location frame, the common intrastrcuture configured for radiolocation by path loss measurement and including a pre-defined protocol common for both radio tags and client stations for transmitting information for reception by the plurality of stations of the wireless network for radiolocation, the pre-defined protocol including using the location frame having the pre-defined frame structure,wherein a location frame conforming to the pre-defined frame structure includes an identifier that provides for a receiving station to recognize the frame as a frame that includes location information, andone or both:wherein the pre-defined protocol includes a pre-assigned multicast address to be used by transmitting radio tags and client stations to transmit location frames,and/orwherein a location frame conforming to the pre-defined frame structure is configured to be receivable by one or more substantially standard wireless stations of a substantially standard IEEE 802.11 wireless local area network, and the predefined protocol includes one or more extensions to the IEEE 802.11 specifications that provide for client stations and radio tags the pre-defined frame structure for location frames.