In the market, the easiest way to intercept the GSM network service is signal shielding. By blocking the GSM network used by our mobile phones, the purpose of prohibiting the use of mobile phones is achieved, which is what we usually call GSM jammers.
The GSM network signal jammer captures the uplink signal of the GSM mobile phone by monitoring all uplink frequencies in the shielded area; the uplink signal transmitted by the mobile phone has at least one uplink time slot period characteristic, and detects whether the uplink signal strength reaches the uplink time slot period. Setting a power level threshold, and determining whether the transmitting mobile phone is located in the shielding area according to the determination; for the mobile phone determined to be located in the shielding area of the GSM scrambler, transmitting the shielding interference signal of the simultaneous gap, so that the intensity of the interference signal is greater than the mobile phone The strength of the transmitted uplink signal to interfere with the reception of the base station, thereby interrupting the communication of the handset.
According to the shielding method of the GSM signal jammers described above, the uplink signal transmitted by the mobile phone and other shielding interference signals in the shielding area need to be discriminated before the shielding interference signal of the same slot is transmitted; The mobile phone signal further detects whether the uplink signal strength reaches a set power level threshold; if it determines that the other interference signal is blocked, the next action is suspended.
