Perseus-300

The system has modular structure. Each module is a self-maintained jammer and is responsible for jamming in its sector.

The jamming signal is formed basing on results of measuring the levels of useful signals from active channels in protected zone.

The output power of jamming will be set for each active channel in correspondence with its measured level. The inside structure of jamming signal is similar to the structure of useful signal (type of modulation, informative beat stream etc.). Jamming signal is formed independently for each standard.

The measurements of active BTS levels and accordingly renovation of jamming signal should take place not less than 1000 times per second.

Sleeping mode and architecture

The system does not emit jamming signal continuously and stays in “sleeping” mode, but when it detects any attempt of a cellular phone or other subscriber terminal to go on the air, the jamming starts automatically and lasts for some period of time. When this period is over, the system checks whether the cellular phone still tries to go on the air or not, if the phone is still trying, then jamming is activated again. And so on till the cellular phone abandons its attempts to set connection.

In such technology the density of electromagnetic emission from antennas should be in conformity with sanitary-hygienic regulations for public places.

All modules will be unified in one local network through cabling or radio channel with interface RS-485. The system will be protected against mismatching by SWR. In case when such mismatching can take place, the power will be switched off automatically.

The full self-diagnostics of each channel will be done each time when the system is switched on.

The system has modular architecture so if there is a need to jam new standards or frequency ranges then new modules can be added.

For control of the jamming system in the prison automated work station consisting of PC, special software and necessary set of interfaces and converters will be established. The complexes of the system will be controlled through the local radio network (without cabling) with interface RS-485.

Special software allows access to any channel of any module and effects the following operations:

• to switch on/off jamming;
• to adjust the parameters of jamming in case of substantial changes in radio environment (serious change of BTSs power, appearance of new active channels etc);
• to receive information about the current condition of the channel:
  — jamming is on or off;
  — level of power of jamming signal, temperature;
  — SWR conditions;
• to receive information about results of self-diagnostics and carry out full diagnostics during system operation.

The location of each module location will be displayed on the prison map and its current status is highlighted by certain colour. In case new modules should be added to existing complexes, the proper alternations will be made to the software without any disturbance to existing system architecture. The construction of HF modules, their external elements and connections should be in conformance to IP 66. The construction of connections, wires and cables should be protected against insects, fungus and mustiness.

Frequencies and standards for jamming