Variable parameter telephone system with security features for prison, has extensions for use by detainees and central supervision device controlling access and monitoring facilities

摘要

The telephone system has several extensions (2) for use by inmates, and separate extensions (3) for the use of monitors. All extensions are connected to at least one supervisory unit (1) which can operate in a number of modes according to the institution in which it is installed. The prison administration can access some or all of the system control functions, and is able to record called numbers, monitor and record conversations, compile a log of calls, and restrict access as necessary.