Patent ID: 7397424

Claim:
A system for enabling a wireless computing device to determine its location both when communicating with one or more satellites of a wireless positioning network and when unable to communicate with any satellites of the wireless positioning network, comprising: a wireless computing device; and a wireless positioning system substantially collocated with said wireless computing device, said wireless positioning system having a first positioning mode in which it communicates with the one or more satellites of the wireless positioning network to enable the geographic location of said wireless computing device to be determined upon reception of signals from only the one or more satellites of the wireless positioning network and a second positioning mode in which it enables the geographic location of said wireless computing device to be determined upon reception of signals from at least one non-satellite wireless beacon and analysis of the signals in light of positional information about wireless beacons contained in a database and said wireless positioning system being affanged to switch between said first and second positioning modes to obtain a determination of its geographic location depending on reception of signals from the one or more satellites of the wireless positioning network, when in said first positioning mode and communicating with the one or more satellites of the wireless positioning network, said wireless computing device being arranged to obtain its geographic location based on reception of signals only from the one or more satellites of the wireless positioning network and also obtain identification and signal strength information about non-satellite wireless beacons and also derive positional information about at least one of these wireless beacons, for which identification and signal strength information has been obtained but for which positional information is not present in said database, from both the obtained geographic location of said wireless computing device and the obtained identification and signal strength information about the non-satellite wireless beacons, the derived positional information then being included in said database, and when in said second positioning mode and unable to communicate with the one or more satellites of the wireless positioning network, said wireless computing device being arranged to determine its geographic location based on reception of signals from at least one non-satellite wireless beacon whose positional information is included in said database and analysis of the signals in light of positional information about wireless beacons contained in said database and from which signals have been received.