NCJ Number
129955
Journal
Security Management Volume: 35 Issue: 5 Dated: (May 1991) Pages: 31-32,34,40
Date Published
1991
Length
4 pages
Annotation
Security managers need to understand how different burglar alarm systems operate and how the transmission of alarm signals is secured, because alarm systems are crucial to the protection of a company's assets and may also be necessary for insurance.
Abstract
An alarm system consists of sensors, a control unit, and reporting device. The system is most reliable when the alarm signal is transmitted to a remote monitoring system or a central station using a direct wire, transmitter, multiplex, digital, derived-channel, one-way or two-way radio, or a security system combination. All but the radio system use telephone lines to transmit the alarms and are subject to defeat by voltage and resistance substitution techniques. Line security techniques are available for direct-wire and transmitter systems, multiplex systems, and switched networks. A risk analysis should be performed to determine the grade of protection required if alarm protection is required for insurance. 3 references