Abstract: GPS satellites are culled into a minimum, preferred group having a longest dwell time within a cone of space, and communicated to mobile devices or subscribers within a particular region (e.g., serviced by a particular base station). The culling may initially be a list of GPS satellites visible to a particular base station at a particular time. As a preferred culling, only those GPS satellites currently within a cone of space above the relevant base station are selected for communication by a mobile device within the service area of the relevant base station. As an ultimate culling, a minimum set of GPS satellites may be selected based on, e.g., being not only within an arbitrary cone of space normal to the base station, but also projected to remain within that cone of space for the longest period of time, i.e., having the longest dwell time.