CellSignalStrengthWcdma problem (-113Dbm,0Asu)

[saad gold]

Greetings,
I would like to report a very strange behavior of the class "CellSignalStrengthWcdma".
The thing is,it always give me -113 Dbm (0 ASU).I thought first it's the Dual SIM phone or an error in my code."CellSignalStrengthLte" & "CellSignalStrengthGsm" works flawlessly.

@Override
            public void onClick(View arg0) {
            	try{
            	//CODE SIGNAL STRENGTH
             TelephonyManager telephonyManager = (TelephonyManager)getApplicationContext().getSystemService(Context.TELEPHONY_SERVICE);
             //for example value of first element
             CellInfoWcdma cellinfoWcdma = (CellInfoWcdma)telephonyManager.getAllCellInfo().get(0);
             CellSignalStrengthWcdma cellSignalStrengthWcdma = cellinfoWcdma.getCellSignalStrength();
             int res=cellSignalStrengthWcdma.getDbm();
             Toast.makeText(getApplicationContext(), "Your signal strength " + res  , Toast.LENGTH_LONG).show(); 
                //END CODE SIGNAL STRENGTH
           //CODE CELL ID
            	}catch (Exception e) 
                 {Toast.makeText(getApplicationContext(), "network type is : unknown" ,Toast.LENGTH_LONG).show();}
           
           
               }
               
            
           });