current location without using gps - iphone

Question

hai
Can we know current location without using gps? Is it possible?

Answer 1

The iPhone SDK has a framework that automatically utilizes the proper mechanism for determining location based on how accurate the result needs to be. Apple has a good article discussing these different methods of locating a device.
Also, here is a good starting point for learning about programming with Location Services.
Furthermore, you can dive right into the CoreLocation framework documentation and learn about everything you can do using Location Services on iOS.

Answer 2

Yes, CoreLocation can triangulate your position via nearby cell phone towers, but the position won't be as accurate as with GPS. Also, it can get your location via nearby WLANs, but this is even less reliable.

Answer 3

Core Location does what you want (by using Wi-Fi triangulation). Check out the documentation of CLLocationManager

Answer 4

Try this
map.showsUserLocation = YES;
map is my MKMapView Object.

Answer 5

Well thats kind of a very broad and very general question. If you are talking cell phones you can use three tower triangulation which is good when you are hitting three towers all at once, but if you are only hitting one the error can be up to a few kilometers.
Now if you are talking internet accessing devices (ie something with an IP address) again things get dicey. If you are using a stationary access point you will get a close approximation using nearest known Hubs with the IP range the device is in. Mobile devices with IPs are really hard to pinpoint.

Answer 6

More links
http://mithin.in/2009/06/22/using-iphone-sdk-mapkit-framework-a-tutorial
http://www.icodeblog.com/2009/12/22/introduction-to-mapkit-in-iphone-os-3-0-part-2/
and step by step guide.
http://gigaom.com/apple/iphone-dev-sessions-finding-your-way-with-mapkit/

Answer 7

To add to #Jenifer's answer
showsUserLocation
Discussion
This property does not indicate
whether the user’s position is
actually visible on the map, only
whether the map view is allowed to
display it. To determine whether the
user’s position is visible, use the
userLocationVisible property. The
default value of this property is NO.
Setting this property to YES causes
the map view to use the Core Location
framework to find the current
location. As long as this property is
YES, the map view continues to track
the user’s location and update it
periodically.
Core Location Framework
The Core Location framework lets you
determine the current location or
heading associated with a device. The
framework uses the available hardware
to determine the user’s position and
heading. You use the classes and
protocols in this framework to
configure and schedule the delivery of
location and heading events. You can
also use it to define geographic
regions and monitor when the user
crosses the boundaries of those
regions.
If you want to know How does the Core Location do this
It actually uses several mechanisms.
GPS
Cell Tower Triangulation
Wifi Hotspot cataloging
Randomly assuming you are in Cupertino
There are tradeoffs based on speed, precision, and available hardware. A first Gen iPad will only have the 3 option available while the iPhone simulator makes use of the last mechanism.
You can observe the difference in these systems in the map application where it initially guesses based on the cell tower, then refines the guess via GPS.
Only options #3 requires a data connection.
And for the humor impaired including #4 was not totally serious although it is functionally correct. (I think they simulate the GPS reporting that location rather than just hard coding it, but I haven't checked.)
From How does CoreLocation locate the device?

Answer 8

The iPod Touch does something like this. It doesn't have a GPS chip, but instead uses the available WiFi networks in the area to get a rough idea of where you're located.