Patent ID: 8019356
Filing Date: 2011-09-13
Classification: G01S

Abstract:
1. A method in a mobile station, the method comprising: transitioning from obtaining one or more position fixes using a first position determination method to obtaining one or more position fixes using a second position determination method automatically and in response to detection of a first change in an RF environment based, at least in part, on a history of attempted position fixes; transitioning from obtaining one or more position fixes using said second position determination method to obtaining one or more position fixes using said first position determination method automatically and in response to detection of a second change in said RF environment; waiting a first duration before said transitioning from obtaining one or more position fixes using said second position determination method to obtaining one or more position fixes using said first position determination method; and obtaining one or more position fixes using said second position determination method for a second duration before said transitioning from said second position determination method to said first position determination method, wherein said second duration is longer than said first duration, in response to failure of said first position determination method to obtain one or more position fixes following waiting said first duration.