Patent ID: 7412246
Filing Date: 2008-08-12
Classification: H04W

Abstract:
1. A method for locating mobile units within an area using a wireless local area network, comprising: providing reference signal transmitters at selected fixed locations within said area; transmitting reference signals using said reference signal transmitters using a first selected channel of said wireless local area network; providing a computer having a database relating signal strengths of signals transmitted by said reference signal transmitters to location within said area; providing at least one access point coupled to said computer and providing wireless data communications between said computer and at least one mobile unit in said area using one or more channels of said wireless local area network that are different from said first selected channel; receiving a selected plurality of said reference signals at said at least one mobile unit, determining signal strengths of said received reference signals and transmitting data representing said received reference signal strengths to said computer via said at least one access point using said one or more data communications channels; and receiving said data representing reference signal strengths at said computer and determining position of said mobile unit using said database.