Integrated Security Systems Design

12 Radio Frequency Systems

BASIC RADIO FREQUENCY THEORY

Radio frequency (RF) systems are never as reliable as wired systems, but they are nonetheless useful when wired alternatives are too costly and total quality of service is not required.

FREQUENCIES AND TRANSMISSION SCHEMES

Frequencies

Analog AM and FM Frequencies

There have been a variety of different types of RF methods used for security systems throughout the years. Common analog communications have included both AM and FM communications at a variety of frequencies from low kilohertz to gigahertz.

Digital Frequencies

Common frequencies include 900 MHz, 2.4 GHz, 4.9 GHz (public safety), and 5 GHz.

Range

Transmitters and receivers are available at 5.0, 5.8, and 5.2 GHz. Other Frequencies ...