Backward Compatible
Equipment that can operate with earlier and future versions of software. Backward-compatible products enable innovation without additional equipment upgrade costs.

Band
the frequencies used for a specific class of RF wireless communications system.

Bandwidth
the amount of radio spectrum used by a communications system. Both the transmitter and the receiver have a measurable bandwidth (measured in Hertz). A receiver's bandwidth must be as large or larger than the transmitters bandwidth, so that all of the signal is received.

Biometrics
Usually used as part of an access control system, biometrics identify individuals on the basis of fingerprints, iris patters, or other identifying traits.

Buddy System
an arrangement between two neighboring systems in which a cut phone line in one system activates an alarm via the neighboring system.

Bypass
an instruction to a security system not to arm a specific sensor.