SI positioning mode: a user initiates a location request, assisted GPS positioning module quickly. Time between 6 seconds to 15 seconds.
This approach can effectively solve common GPS time to get the fastest 30 seconds of satellite ephemeris Star Search slow, if you use AGPS satellite ephemeris will get by moving servers, time can be shortened to 6 seconds -15 seconds.
Corresponds to the process: Start AGPS UI Manager -> start obtaining base station information, IMSI information -> start dialing -> for SUPL protocol with the mobile server communications obtain satellite ephemeris -> configure the GPS module positioning -> Close Communication Network -> navigation software quick access to precision, latitude.
NI positioning modes: server-initiated location request, the mobile server sends an AGPS WAP PUSH messages over Upon receipt of this WAP PUSH, start Assisted GPS module to quickly locate, acquire precision, the latitude, using the SUPL protocol loopback Mobile server. The user does not belong to initiate positioning.
Process corresponding to: "AT command management" found a report message -> into the "SMS, MMS, WAP PUSH AGPS separation layer" -> AGPS is separated WAP PUSH -> AGPS start Applications -> send WAP PUSH content to AGPS applications -> start AGPS UI Administration -> start obtaining base station information, IMSI information -> start dialing -> conduct SUPL server communication protocol with China mobile to obtain satellite ephemeris -> configure GPS module for positioning - > Close communication networks -> quick access to precision navigation software, latitude.
Reproduced in: https: //www.cnblogs.com/wangzehuaw/p/3756790.html