cell location indoors

My question is simple, how in the heavens do I开发者_StackOverflow get the exact location of a cell phone which is indoors, GPS wont work since it requires clear skys. Network Provider of the LocationManager only gives me the location of the closest cell tower of my network provider. Will appreciate the help.

---

Many phones actually don't use GPS, but A-GPS, which also relies on tower signals. You should therefore have a go at tower triangulation, which if you can find enough towers may give you a good approximation of your location.

Keep in mind getting "exact" location is already not happening in true GPS (since even though the US Army gets millimeter precision, they reserve the strategic right to limit you to meter precision, and to fuzz the signal at any time they see fit), and of course, if you expect to get "exact" location information inside a building without GPS, Signal or Wifi, you should call Harry Potter and ask for his Map API...

If your need actually is essential, and you have the budget clearance the equip your locations, you can use special emitters, like Shopkick did. However, I expect you would be better served making less stringent requirements for your locating precision.

---

Actually you can "digg" with this solution : http://www.infrasurvey.ch/?lang=en . It is a UGPS. Always good to know that these kind of techs exist... and it does not use magic.

---

The network provider also uses WiFi access point to determine location, so you might get a better fix than your closest cell tower. However, without a GPS, you only get a coarse location, there is really no way around it.

---

Unfortunately they are the only options you have here. If you have access to some Wifi routers, you can have a look at some positioning method based on Wifi signal strength and the router's MAC Address, for example Skyhook Wireless or you can implement some method on your own.

---

You can check out Tagin! which is an open source, location tagging engine that may be used to create indoor location-based services (LBS) and applications. The project is close to completion and will be up shortly. Here's the Wiki for the same.

Disclaimer: I am a developer on the Tagin! project as a part of Google Summer of Code.

---

By exact location...do you mean cartesian (x,y,z) coordinates (and if so relative to what origin) or do you mean geolocation (latitude, longitude, altitude)? Are you trying to find something from where you are or pinpoint its location on a map?

There are no precise solutions for the latter at this point but there are several solutions coming out which will use directional beaconing technology like is available with Bluetooth 4.0 that can give you a fix on when you are getting close to your phone or headed in the right direction. I took a quick look at the tagin link provided by someone above. I won't go into all of the flaws of using wifi ranging as is done there but suffice to say using wifi fingerprints are hard to setup and sustain and accuracy depends on, among other things, how many people are in the room with you (humans are good conductors of wifi radio and this method uses wifi signal strength to figure out where you are from the object you seek).