Patent ID: 7495608

Claim:
A method of determining position of at least one mobile station operating in a wireless communication network, comprising: receiving messages from the at least one mobile station, each message including at least one item of information identifying a portion of a mobile wireless communication network through which the at least one mobile station is receiving wireless communication service; based on identifying information in a first received message, accessing a record in a base station almanac (BSA) database for a base station through which a mobile station is receiving wireless communication service from among a plurality of records in the BSA database, each of the records in the BSA database providing position related information regarding a respective base station; using the position related information from the accessed BSA database record to obtain a mobile station position fix, responsive to the first message; based on identifying information in a second received message, accessing a record in a virtual base station almanac (VBSA) database for a region in which the mobile station is receiving wireless communication service from among a plurality of records in the database, each of the records in the VBSA database providing estimated location information for a region corresponding to combined service areas of defined group of base stations that utilize the same respective identifying information, wherein base stations of the defined group do not have position information indicated in records in the BSA; and using the estimated location information for the region in which the mobile station is receiving wireless communication service, from the accessed VBSA database record, as an estimate of position of a mobile station, responsive to the second message.