Mobile Radio Glossary
Analog -
continuous non-discrete values, in radio: the proportionate modulation of a radio signal by its source
Architecture -
design and organizational structure of the radio system and its subsystems
Area of operation -
area throughout which a radio can effectively operate or is authorized to operate
AVL -
Automatic Vehicle Location, system whereby vehicles are tracked or the location of a vehicle is determined using global positioning technology (GPS)
Backbone -
fiber optic, wire line, or microwave interconnections that link radio infrastructure components
Base station -
radio transmitter/receiver, usually located at a tower site
Bit error rate -
quantity of corrupted information in a digital transmission
Capacity -
quantity of radio users the system can accommodate simultaneously
Channel -
single radio frequency on which a radio transmits or receives
Channel loading -
number of radio users accessing the system over a period of time
Channel reuse -
reuse of the same channel or frequency in another geographic area of a radio system
Clear channel -
radio channel or frequency that is not in use in an adjacent or nearby geographic area
Control hub -
radio network hardware that routes control, voice and radio information and links tower sites to the radio network
Conventional radio -
each radio channel is independent of other channels
Coverage -
area of effective radio operation
Data Network (wireless) -
Network of radio data transmitters for the wireless transfer of information to and from vehicles
Data (non-dedicated) -
transmission of either voice or data over a radio transmitter
Data transmission rate -
quantity of information that can be transferred over a radio channel over a specific period of time
Dedicated data -
radio transmitter configured to transmit and receive only data
Digital -
information encoded in discrete values
Emission -
specifications for the type of modulation and information carried by a radio channel
Encryption -
encoding or scrambling the information in a radio transmission to prevent interception and deciphering of the information by an unauthorized party
Equipment contracts -
contracts with vendor(s) for supplying equipment discounts to agencies and political subdivisions
Fading -
propagation attenuation of a radio transmission when approaching the outer limits of the effective radio coverage area
Fail safe -
the ability of a system to continue functioning at a minimum level when system control components fail
FCC -
Federal Communications Commission
Fiber optic -
high capacity transmission line, used to connect radio network control hubs
Frequency band -
radio channels or frequencies occupying a specific portion of the electromagnetic spectrum
Frequency distribution -
the allocation of radio channels throughout a system
GPS -
Global Positioning System, receivers calculate ground position from satellite based transmissions
Hybrid radio system -
radio system comprised of multiple technologies
In-building coverage -
effective coverage of a radio throughout a building
Infrastructure -
permanent equipment, structures and facilities comprising the radio communications system
Interface -
a communications link between independent systems Interoperability -
ability for independent agencies and departments to establish radio communications when required
Low band -
portion of the radio spectrum occupying frequencies from 30-50MHz
Mapping -
computer based mapping of geographic regions and structures, commonly used to aid in routing and locating emergency vehicles
MDT -
mobile data terminal, in-vehicle computer
MHz -
megahertz, measure of frequency in millions of cycles per second
Microwave -
high frequency wireless communications link
Migration path -
planned transition of public safety radio users onto the statewide radio system
Mobile radio -
radio transmitter/receiver mounted in a vehicle
Modulation -
variations imposed on a radio frequency for the transmission of information
Narrow band -
FCC specifications for reducing the amount of space each radio channel occupies in the radio spectrum for the purpose of creating additional radio channels in the VHF and UHF frequency bands
Noise -
harmful variations or interference in a radio transmission
Portable radio -
handheld transmitter/receiver
Propagation -
transmission of electromagnetic energy through space or other medium
Public safety -
governmental entities that are authorized to protect life, property and safety of the citizenry and render aid in times of emergency or disaster
Redundant -
back-up resources in the event of primary service or equipment failure
Reliability -
measured consistency of radio signal strength
Repeat transmission -
retransmission of data over a radio channel, usually due to an error occurring during the previous transmission
RF engineering -
radio frequency engineering, analysis of radio frequency propagation characteristics under assumed geographic and atmospheric conditions
RFP -
request for proposal
Roaming -
radio operation over several systems or subsystems
Scanner -
radio receiver that scans radio transmissions
Seamless -
continuous radio coverage from one subsystem to another
Spectrum -
range of frequencies
Subscriber equipment -
mobile radios, portable radios, and mobile data terminals accessing the radio infrastructure
Subscriber fee -
fee assessed per subscriber unit for maintenance costs
Talk group -
computer allocated grouping of radio users
Telephone interconnect -
wireless connection of a two-way radio to a public switched telephone network
Trunking -
communications path established by computer to allocate available radio channels as demand is placed by users
UHF -
Ultra High Frequency, portion of the radio spectrum occupying frequencies from 450-512 MHz
VHF -
Very High Frequency, portion of the radio spectrum occupying frequencies from 150-174 MHz
Virtual office -
capability to conduct office functions remotely from a vehicle
Wide area -
radio coverage over a large geographic area
Wireless data -
transfer of digital information over a radio channel
Wire line -
copper telephone line
700 MHz band -
the FCC recently allocated these former television broadcast channels to public safety entities, no specifications have been established for this band
800 MHz band -
portion of the radio spectrum occupying frequencies from 806-869 MHz
For more information please contact:
Evans Associates
210 South Main Street
Thiensville, Wisconsin 53092
(262)242-6000
fax: (262)242-6045
http://www.evansassoc.com
These pages produced and copyrighted by Evans Associates ©, Consultants In Telecommunications Technology, Thiensville, Wisconsin.