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Tuning in to Wireless Alarm Transmission

NCJ Number
Security Volume: 24 Issue: 8 Dated: (August 1987) Pages: 58-60,62,64
K Lyndon
Date Published
5 pages
This article reviews the features of radio alarm transmission and discusses factors to consider in the selection of such an alarm system.
Alarm signaling options have traditionally relied on the telephone system, with attendant line problems, cost, maintenance, and line obstructions that breach protection. Wireless, long-range radio telemetry is an alternative. This alternative has been recently enhanced by improved radio technology and the Federal Communications Commission's opening of more radio bands for security monitoring. The system can be provided from a contract central station or by the business. The telemetry components are transmitters, repeaters, and receivers. The transmitter at a remote site collects data from any number and type of sensors. An activated sensor passes data to the transmitter, which encodes the data and transmits a radio signal. The receiver at the monitoring center collects, decodes, and annunciates the sensor in alarm. When the signal must be transmitted more than 25-30 miles, over hilly terrain, or in congested urban areas, a radio repeater must be used for reliable reception. In selecting a radio system, security managers must first decide on the type of system, whether one-way, two-way, or one-way with a digital dialer backup. Frequency, the radio band on which the signals are transmitted, is another factor, which is influenced by system type, the site to be protected, the distance and terrain, and transmission range. The overall monitoring goal should also be considered. A chart summarizes the features and applications of various brands and models of long-range radio alarm transmission systems.