Obtaining cellsite gps location on Blackberry Curv

Details of my phone:

  Model:Blackberry Curve 8520
  Version :5.0.0.1036
  data services :on

When I am installing google maps I am able to see the location ,so there is a chance of obtaining the current location using this phone.

I am trying to develop an application which will show the current location of the phone,by using the cell site locations because this phone model does not have an in-built GPS device.

I am using the following code:

   BlackBerryCriteria bc=new BlackBerryCriteria(GPSInfo. GPS_MODE_CELLSITE );        
   try {
    LocationProvider lp=LocationProvider.getInstance(bc);
           if(lp !=null)
           {
            Location loc=lp.getLocation(-1);
            add (new EditField(loc.getQualifiedCoordinates().getLatitude()+"\n"+loc.getQualifiedCoordinates().getLongitude(),""));
           }
    else
         {
        add(new EditField("unable to find the location provider", ""));
         }
    } catch (LocationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }}

I am installing the alx file on the bb phone using desktop manager.

On starting the application it is giving me an Uncaught exception:

NET.RIM.DEVICE.API.SYSTEM.UNSupportedOperationException.

The device might currently not support GPS_MODE_CELLSITE. Check using

 GPSInfo.isGPSModeAvailable(GPS_MODE_CELLSITE)

and use another mode if neccessary.

It might not support GPS_MODE_CELLSITE because:

There is no valid SIM card in your phone (ok, i assume you have one :)
Check if your device and carrier have available GPS mode you are using (here)
If your carrier is Verizone, check for Verizon GPSSettings signing requirement
Your APN settings are not correct (Options > Device > Advanced Settings > TCP IP)
You don't have a BlackBerry Service Plan (not too sure about that one)