User Guide: Technical Reference APPENDIX B GLOSSARY OF TERMS
PRELIMINARY
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B-5
Frequency
The number of complete cycles per second existing in a waveform. Measured in
Hertz.
Frequency Hopping (FH)
A type of spreading technique that uses a PN code to change the signal’s
frequency between several pre-assigned values (hopping). Although the signal
itself looks like a narrow band signal at any given point in time, it acts like a spread
signal because of the frequency hopping.
Fresnel Zone
An imaginary ellipse surrounding the direct transmission path formed by all the
points from which a reflected wave would have an increased path length of multiple
of the transmitted signal’s wavelength.
Full Duplex
Independent, simultaneous two-way transmission in both directions.
G
Gain
The increase in signal power caused by a device such as a transmitter or antenna.
H
Hertz (Hz)
A unit of measurement equal to one cycle per second.
Hexadecimal (Hex, or H)
A Base-16 numbering system.
High Density Bipolar Three
(HDB3)
A line interface standard, similar to B8ZS, for E1 that eliminates data streams with
4 or more consecutive zeros. Allows for 64 Kbps clear channel capacity and still
assures a minimum ones density required by E1 lines.
Hop
A term used to describe a single radio path between two points.
Hot-standby
A condition whereby when the primary method of communication goes down, the
secondary method instantly takes over.
I
IF cable
In an
ioLink
system, the coaxial cables which connect the Modem unit to the RF
unit. These cables are terminated with male TNC-type connectors at both ends.
Interface
The signal standard for connecting a microwave system to the connecting
equipment.
Interference
Unwanted signals that cause performance degradation or loss of information.
Intermediate Frequency
(IF)
The frequency to which a microwave signal is converted to permit signal
processing. Typically around 70-200 MHz.
