The development of GPS on the phone A-GPS status
| the way for action to the user terminal positioning technologies and hybrid positioning technology two. The former action-built GPS receivers terminal position as the main solution. Using this technology from the ground placed in the 20,200 km of 24 simultaneous signals from satellites to space as the base, using radio waves to measure distance and time difference. The basic way of positioning measurement used for the synchronous satellite radio carrier channel to send information the satellite position and time data, GPS receivers since the GPS satellite signal reception after the operation by the receiver unit, be calculated by location, speed and time and other information requested by users. Location of each satellite orbit via satellite ephemeris data obtained through four or more satellites to the receiver of the distance, the receiver can be calculated in the three-dimensional coordinates of the earth. The GPS satellite positioning signals to pass entirely and directly to the location within the GPS receiver is calculated, so the network operators and enterprises need not install any client positioning equipment, we can achieve the accuracy within 10 meters.
Figure I Schematic diagram of GPS positioning technology user terminal
The latter are A-GPS (Assisted-GPS)-based. The same as GPS, A-GPS is the operation of the original in the mobile phone to receive and process location information. However, the biggest difference is that with the GPS A-GPS location in the network side also receive satellite positioning signals installed GPS receiver, to assist mobile terminal positioning. The positioning of this method are: the installation of GPS receivers network terminal to receive the location information, location information will be sent to the phone by the network side, and then calculated by the network side by the mobile phone location information coming from satellite receivers come with signal to obtain accurate location.
Figure II A-GPS |
Last data update: 10.12.2011