GNSS Position Computation without Ephemeris 'Single Shot MS Based'

摘要

In Assisted GPS (GNSS) there is some information in the form of "assistance" data that is sent to the mobile terminal equipped with a GNSS receiver. Assistance data helps the GNSS receiver acquire satellite signals faster and at lower power levels as well as compute its own position. Assistance data is essential in many GNSS use cases but it is especially relevant in emergency calls from mobile terminals (e911, e112) where a fast response and the best sensitivity are required. GNSS assistance data is standardized by 3GPP and 3GPP2 in two different flavours, broadly known as MS Based and MS Assisted in GSM/EDGE; and UE Based and UE Assisted in WCMDA. MS Based methods compute the geographical location inside the mobile terminal whereas MS Assisted methods compute position in the network from satellite measurements (range, Doppler shift) taken by the mobile terminal.