Patent ID: 7917156

Claim:
A method comprising: at a mobile device, receiving signals from a first more accurate position determination sub-system; generating information indicative of a position of the mobile device based on the signals received from the first more accurate position determination sub-system; at a first time, receiving signals at the mobile device from at least a first transmitter included in a second less accurate position determination sub-system, wherein the first transmitter is located at an associated position; at a different time, receiving signals at the mobile device from the first transmitter in response to selecting a position solution type using the second less accurate position determination sub-system; accessing pseudorange residual information for the first transmitter, wherein the pseudorange residual information for the first transmitter is derived from the information indicative of the position of the mobile device based on the signals received from the first more accurate position determination sub-system, the associated position of the first transmitter, and the signals received at the mobile device from the first transmitter at the first time; and using the signals received at the mobile device from the first transmitter at the different time and the pseudorange residual information for the first transmitter to determine information indicative of the position of the mobile device at the different time.