XCell Pro Stealth Phone is able to detect any changes made by a GSM Interceptor on a GSM network to register or attract the phone to the fake network (GSM Interceptor Proximity Alert). The registration of the phone on a new BTS (the fake BTS generated by a GSM Interceptor) is an automated process and this behaviour is absolutely common in any mobile phone. Any mobile phone will automatically select the strongest GSM signal generated by the GSM Interceptor in case of interception. GSM Interceptors (active and semi-active) force the phone to hand over by suppressing the real network signal with a strong signal and by mimicking the network parameters: MCC, MNC and LAC. However, the ARFCN (communication pair channels) and Cell ID are modified to force the phone to send registration requests to the "new" BTS. The XCell Pro Stealth Phone detects these changes and warns you: a discreet open lock icon is displayed on the home screen. The same open discreet lock icon is displayed during an active call in case of call interception (Call Interception Alert). In addition to the home screen alert, the phone alerts you with a sound/vibration alert.

If the network characteristics change, i.e. if a GSM Interceptor, IMSI Catcher or any other method is used to try to trick the SIM into changing to a breakable A5/2 encryption, the phone will detect this and alert the user with an alarm, vibration or display a message on the screen. No calls or SMS's can then be made. The phone will also randomly change the IMEI on each call, or you can specify an IMEI. A good way of confirming that the phone is changing the IMEI and not just giving the appearance of a different IMEI is to assign a known locked or stolen IMEI to the phone.

The phone will also alert you if it receives an abnormal number of requests to re-register with the GSM network (UnPing function), either from the network itself or from a GSM Interceptor attempting to locate the phone or perform a Kc (Communications Ciphering Key) extraction from your SIM card. The phone can be locked to a specific GSM channel number (ARFCN) to avoid BCCH manipulation procedures performed by GSM Interceptors. The XCell Pro Stealth Phone will display the TMSI value on the home screen, which will remain the same if the phone is intercepted. The phone automatically clears the call log after each outgoing or incoming call and all incoming and outgoing call audio is automatically recorded without any background beeps. All recorded files can be played directly from the phone.