What is GPS?
Global Positioning System (GPS) is a worldwide radio-navigation system formed from a constellation of about 24 satellites operated by the United States. The GPS receiver on your mobile needs to connect with at least 3 satellites (4 or more if elevation is desired) to obtain a lock and display your current location on the map.
What is A-GPS? How is it different from GPS?
Conventional GPS has difficulty providing reliable positions in poor signal conditions, for example, when surrounded by tall buildings or being indoors.
The difference between A-GPS and conventional GPS is that in such cases where the satellite signals are weak, A-GPS takes the help of ‘Assistance Servers’ to connect to the nearest cellular towers to try and triangulate your position and thereby speeds up the Time To First Fix (TTFF) by telling the GPS receiver roughly where it is so it can acquire an accurate fix with the satellites faster.
What is Google Maps? Is it really GPS?
Google Maps for Mobile is not really GPS. It is a location service which allows non-GPS phones, a GPS like experience by utilizing mere cellular tower triangulation to locate your position. Google Maps does not require your mobile to have a GPS receiver. The software retrieves information to determine the nearest cell site and then looks up the location of the cell site using a database of known cell sites. The “my location” thus derived is not accurate unlike conventional GPS and your location could be inaccurate to the extent of a few hundred metres.
Does GPS require data intensive GPRS plans?
GPS basically is a mobile handset service and not a network service. It uses a GPS chip to connect to GPS satellites and does not require any GPRS connection.
A-GPS & Google Maps on the other hand requires a connection through GPRS and requires data intensive download plans.
Moreover, it is advisable to pre-load the maps on your mobile using a CD or a Wifi connection, as downloading of maps via GPRS can be very expensive if you do not have data intensive or unlimited data plans.
Is GPS free to use? Why do I have to pay for certain features?
The GPS satellites are operated by the government of the United States, and it is a completely free service available to all users on a continuous, worldwide basis. Only voice guided navigation based on GPS whereby the phone directs you using a computer voice when and where to turn is a paid subscription service.
Which mobile phones currently are GPS enabled?
Many GPS enabled mobiles are currently available in the market. The more popular models are:
Nokia 6110 Navigator, Nokia N95, Nokia N82, Nokia N78, Nokia E66, Nokia E71, Nokia E90
Apple iPhone 3G
HTC P3300, HTC Touch Diamond, HTC TyTN II
Sony Ericsson C702, C905, G900
BlackBerry 8820/8830/8310
It is advisable to verify whether the mobile handset supports A-GPS in addition to conventional GPS before making your purchase. And if you do not want to upgrade to a GPS enabled mobile, you can still enjoy a GPS like experience on supported devices using Google Maps My Location service.
