Codan Radio Transportable Radio Systems User Guide - Manual (Page 26)

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5. Appendix – References
5.1 Glossary
• Antenna — An elevated device for radiating and receiving radio waves. It changes electrical currents into electro-
magnetic radio waves and vice versa.
• Antenna Gain — The increase in power radiated by and / or received by an antenna in a given direction compared to
the power radiated in the same direction by a standard omni- directional antenna.
• Antenna Polarization — The orientation of the radiated electric fi eld in relation to the surface of the earth.
• Bandwidth — The amount or portion of the frequency spectrum required to transmit the desired information.
• Beam Antenna — An antenna array that concentrates radio transmission into a narrow directional path or receives
radio signals only from a narrow sector of the total horizon.
• Channel — A narrow band of frequencies including the assigned carrier frequency, within which a radio system
must operate in order to prevent interference with stations on adjacent channels.
• Decibel (dB) — A unit of relative voltage or power. Roughly the smallest change that the human ear can detect. The
decibel is also used to compare relative differences of signal voltages, or power.
• Fade Margin — The difference between the level of the received signal and the receiver threshold. Usually ex-
pressed in decibels.
• Frequency Band — A continuous range of frequencies extending between two limiting frequencies. Common fre-
quency bands in two-way radio are 29-50 MHz (low band), 136-174 MHz (VHF or High Band), 406-512 MHz, 806-824
MHz, 851-869 MHz , 869-901 MHz and 935-940 MHz (UHF Bands).
• Frequency Range — A frequency band including the frequencies at which a system is able to transmit, receive or
amplify power.
• Fresnel Zone — A measurement of path clearance in terms of the effect at the frequency in question. The First
Fresnel Zone is the surface containing every point for which the sum of the distances from that point to the two
ends is one-half wavelength longer than the direct end-to-end path.
• Front-To-Back Ratio (F/B) — The ratio between the power radiated in the forward direction from an antenna to that
radiated to the rear.
• Insolation — The total solar radiation-direct, diffuse and refl ected-received on a surface over a period of time. Usu-
ally expressed in kilowatt-hours per square meter .
• Interference — The effects that occur when undesired signals interfere with the reception of a desired signal.
• Line-Of-Sight Distance (L/S) — The straight-line distance from station to station or horizon. This represents the ap-
proximate normal transmitting range of stations in the VHF and UHF bands.
• Mobile — Equipment designed for vehicular or portable operation.
• Noise — Interference caused by either internal or external sources.
• Path Loss — The reduction or attenuation of signal strength that occurs between the transmitter and receiver.
• Portable Radio — A completely self-contained two-way radio.
• Propagation — The radiation of electromagnetic waves.
• Radio Receiver — A device which amplifi es radio frequency signals, separates the intelligence signal from the RF car-
rier, amplifi es it, and converts it back to the original sound waves.
• Radio Interference — Interference caused by the radio waves of a station or stations other than that from which
reception is desired.
• Repeater — A radio station that automatically rebroadcasts radio signals that are received on a specifi c frequency.
• Transceiver — A combination of transmitting and receiving equipment that uses some or all of the components
jointly in both transmitting and receiving.
• Transmission Loss — A term used to denote the loss in power during the transmission of energy from one point to
another.
• Transmitter — The term applied to the equipment that is used to generate and amplify an RF carrier signal, modu-
lating this carrier signal with intelligence, and then provide output for an antenna to radiate the modulated signal
into space.
• Trunk, Trunking — A computer controlled radio system in which many users can share multiple switched repeater
equipment while retaining privacy.
• Ultra High Frequency (UHF) — The portion of the radio spectrum extending from 300–3000 MHz. (Commonly
thought of as 300 - 1000 MHz).
• Very High Frequency (VHF) — The portion of the radio spectrum extending from 30–300 MHz.
• Yagi — A directional antenna which usually consists of a radiator, a refl ector and one or more director elements.
This antenna exhibits high gain and moderate front-to-back ratio.
5.2 Reference Documents
The following documents provide additional information on repeaters and radio system planning:
• TG-002-1-0-0 Codan Land Mobile Radio Systems
• TG-001-2-0-0 Codan P25 Radio Systems
• LIT-052-1-0-0 Codan Trunked Radio Product Information
• BC Ministry of Forests http://www.for.gov.bc.ca/his/radio/Overview/overview.htm
• Wikipedia http://en.wikipedia.org/wiki/Radio_repeater
• DAN-MKT-103 ET-5 Tactical Repeater — ATF Content — limited distribution
• National Institute of Justice http://www.ncjrs.gov/pdffi les1/nij/191160.pdf
• SafeCom www.safecomprogram.gov