GPS Location without service

Question

I am a new developer and have a simple question that I have searched all over for, but have not found a clear answer yet...

Simply put, I am developing an application that needs to be able to use GPS. The trick is however that I would like to use GPS to get a phone's location even if they have no carrier service.

With that said I have 2 questions.

1. Is is possible to get the GPS location of a phone with no carrier service with a wifi connection?

2. Is is possible to get the GPS location of a phone with no carrier service AND no wifi service?

Thanks in advance

Answer 1

1. Yes, it is on many handsets. The WiFi network may be mapped which will speed up the AGPS chip, or allow offloading of position calculation to the provider.

2. Varies by the GPS chip in question. In some cases, it will simply not work (the GPS processor requires network communication). In most cases the GPS will take up to 10 minutes to fix from a cold start, as it must receive the current satellite almanac in order to compute position.