Anyone who has ever made a connection GPS from a portable device that is not connected to the mains, knows that the process consumes a lot of battery , especially if used continuously. Of all the functions associated with antennas or sensors that can carry out a smartphone or tablet, the use of GPS is the one that consumes the most battery .
The GPS system , developed by the US Department of Defense (although now has civil uses) consists of 24 satellites located 20 kilometers above our heads , orbiting in a coordinated way to cover the entire surface of the planet. When a GPS device wants to calculate a position, it connects with at least three satellites, which send their ID and clock time. By calculating the time it takes to get the signal to each of the three satellites, by means of triangulation, the exact position of the GPS device is obtained, with a margin of error of a few meters. This margin can be reduced to a few centimeters if a differential GPS is used.
The magazine Forges asked to Robert Love , software engineer at Google , which is why this process consumes more battery than other services that also require using an antenna to connect satellite. Love explains that the communication channel between the GPS device and the satellites runs at a very slow speed , 50 bits per second. During the whole process it is necessary to feed the antenna so that it does not lose the signal. For the same reason, the smartphone or tablet can not enter sleep mode (sleep, or energy saving) so they remain in peak consumption mode all the time.
The greatest battery consumption occurs during the phase in which the connection with the satellites is established . So, instead of cutting a connection to come back later, you may find it more appropriate to keep it activated if you are going to use it soon.
The A- GPS (GPS-assisted) standard improves this process by accelerating it, because it can manage the GPS communication messages through the 3G or WiFi connection of your smartphone, instead of the GPS channel which, 50 bps.
The conclusion of all this theory is that, if you want to keep your smartphone or tablet battery as high as possible, use GPS only when strictly necessary . Nothing to play with him!