Signalstrength.getgsmsignalstrength() Is Giving Values Without Sim-card Also

Hey I tried for signalStrength.getGsmSignalStrength() for GSM and CDMA devices but I noticed that both the devices gives strength even when sim is not inserted in device.I want to

Solution 1:

i believe this may help you to detect Sim card availability:

TelephonyManagerm= (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);
if (m.getSimState() != TelephonyManager.SIM_STATE_ABSENT){
  // SIM card
} else {
  // No SIM card
}

moreover, you may read this

Solution 2:

Your phone connects to the cellular network even when you don't have a SIM inserted, provided airplane mode is off, so that emergency calls can be made. Cell operators are required by law to allow such calls. So they allow phones without SIM to register on their network and your phone goes in Emergency Calls Only mode. That's why you read signal strength values with no SIM.