Method and apparatus for location-based triggering in an assisted satellite positioning system

A method of location-based triggering in a mobile receiver, comprising:

• designating a triggering region;
• obtaining acquisition assistance data at said mobile receiver from a network, said acquisition assistance data including at least expected pseudoranges;
• measuring pseudoranges from said mobile receiver to a plurality of satellites;
• comparing said measured pseudoranges and said expected pseudoranges using a metric to produce delta values;
• and
• comparing said delta values with a radius restriction value associated with said triggering region.

A mobile receiver, comprising:

• a memory for storing satellite trajectory data;
• a satellite signal receiver for measuring pseudoranges from said mobile receiver to a plurality of satellites;
• and
• a processor for generating expected pseudoranges, computing a delta position with respect to a virtual center of a triggering region using said satellite trajectory data, said measured pseudoranges, and said expected pseudoranges, and for comparing said delta position with a radius restriction value associated with said triggering region.

A mobile receiver, comprising:

• a wireless transceiver for receiving acquisition assistance data from a network, where said acquisition assistance data includes at least expected pseudoranges;
• a satellite signal receiver for measuring pseudoranges from said mobile receiver to a plurality of satellites;
• and
• a processor for comparing said measuring pseudoranges and said expected pseudoranges using a metric to produce delta values, and for comparing said delta values with a radius restriction value of a triggering region having a virtual center.