Passive GSM Monitoring System for A5.1, A 5.2 (A5.0) Encryption

PKI 1540Print

The PKI 1540 is not limited to A5.2 decryption, but can also decrypt the much more elaborated A5.1 encryption system. The A5.1 encryption is mainly used in Europe and the USA. A localization of the monitoring devices is impossible, as this system works on a passive basis and does not emit any signals. The decryption unit is the main piece of the PKI 1540 in order to decrypt A5.1 encoded conversations. Because such a professional high-capacity processor of course has its price, it is advisable to use only one decryption unit for several monitoring systems. Internet, VPN or LAN can provide the necessary data connections, which, as a further advantage, allows mobile use of this system. This provides a maximum flexibility for numerous monitoring operations.

On request we can also supply a device for stationary use, which also includes the decryption unit. The PKI 1540 is equipped with a receiver unit with a maximum of 32 duplex- channels, a laptop, antenna, power supply and a key decryption unit.

Monitoring of GSM telephone conversations in the near surrounding is possible with both, the handheld device as well as the base station. As all conversations and text messages are recorded on the hard disk of the laptop, an evaluation of the data is possible at any time. PKI 1540 creates a log file listing all telephone numbers of incoming and outgoing calls. The identification of the telephone number of the monitored person can be done with our active systems PKI 1560 or PKI 1580.

With the PKI 1540 it is not possible to find and hold specific mobile phones, because a passive system does not have any influence on the monitored telephones. For this purpose, however, we offer our active systems PKI 1560 and PKI 1580.

The PKI 1540 works in the dual-band range GSM900/1800 or in the single-band range GSM 850 or GSM 1900 and can be equipped with up to 4-32 duplex-channels according to your needs, i.e. it is possible to record a maximum of

32 duplex-channels (both conversation partners). Each receiver unit is equipped with up to 8 duplex-channels.



  • Receiver unit, Laptop computer with software, Decyption unit, antenna.
  • Frequency ranges: 900/1800 or 850 or 1900 MHz
  • Power supply: 12 V DC, 110V – 230V power supply
  • Connectors: LAN, antenna, power supply

Receiver unit:

  • Dimensions: 320 x 300 x 80 mm
  • Weight: 3,8 kg

Decryption unit:

  • Dimensions: 320 x 300 x 510 mm
  • Weight: 19,8 kg