hmm , yes bit i want to use the GPS function , I dont want to be forced to have internet connection to use GPS
You're not being forced to have an internet connection to use GPS, GPS works perfectly well without an internet connection. What doesn't work is the application you are using to plot your GPS co-ordinates on, as that software requires an internet connection (either 3G or WiFi).
If I buy for example GPS module eg Garmin or whatever do I also need to have a internet connection ?
No, but you will get very basic maps unless you pay a small fortune for good quality ones. These maps will then be stored in the unit, and will be used to plot the GPS co-ordinates on them.
I thought GPS can be used without internet , then why do I need those satellites ?
It can. You are confusing two different things, well three possibly.
1. GPS uses satellites for location co-ordinates. No internet connection needed on the SGS or a standalone Garmin unit.
2. GPS can be assisted to get a quicker location via a network lookup (either WiFi or cellular). Internet connection is needed on the SGS. I don't know if such a feature is available on standalone units.
3. The GPS co-ordinates from the satellites are plotted on the screen. This data is overlayed onto nothing, or onto maps. For Google Maps, the map data is downloaded in realtime - so an internet connection is needed. For the standalone Garmin unit, the maps are stored in the internal memory, so no internet connection is needed.
If, for example, Garmin released some software for the SGS that held its maps on the SD card, then you would not need an internet connection either.
I can use google maps through my WiFi and still find locations
As the GPS in the SGS is pretty rubbish, most people/configs are using network assised GPS. This works by either looking up the cellular ID you are connected to, or any WiFi points you are close to. Once these details are obtained, it connects to the internet to do a reverse lookup and obtain your co-ordinates, then plot you on the map.
This requires a data connection. If you are connected to a WiFi AP, you will have this data connection. If you are not, you will have no way of turning those Cellular IDs or WiFi SSIDs into co-ordinates, hence it can not plot the location.
If you go into Settings, Location and Security and disable "Use wireless networks" it will rely soley on the GPS, but as a result may take longer to get a fix on location, and may also not be as acurate (due to the crappy GPS implementation in the current SGS firmwares).
You will still not get any map data in Google Maps without being connected to the WiFi or with a 3G data plan, however.
Hope that helps clarify things!
thank you dude 
