INDUSTRY TERMS GLOSSARY

Acura Embedded Systems wishes to provide you, our customers, with the most up-to-date terminology the mobile data and telecommunications industries use.

C5ISR

ACR: Command, Control, Communications, Computers, Combat systems, Intelligence, Surveillance, and Reconnaissance

CAD

ACR: Computer Aided Dispatch

CAI

ACR: Common Air Interface.

A radio to radio signal path defined in terms of Access Method, Modulation Scheme, Vocoding Method, Channel Data Rate and Channel Data Format.

Cellular

A type of mobile radio system in which the area covered is broken into smaller areas called “cells”, each with its own transmitter linked to a central processor.

Channel

Term used in various ways in the telecommunications industry. In this context, refers to a pair of radio frequencies working together to transmit and receive radio signals.

Combiner

A device used to combine the output signals from a number of transmitters into one antenna.

Conventional Radio

Non-trunked. Everyone with access to a channel hears all audio transmitted over that channel. Users must listen to the open channel to determine availability. Similar to a telephone party line.

Coverage

The geographic area of a radio system within which users can access the system.

CSSI

ACR: Console SubSystem Interface to the P25 infrastructure

- D -

DAQ

ACR: Digital Audio Quality

dB

ACR: Decibel.

A unit for measuring the power of an electromagnetic signal; equal to the logarithm of the ratio of the measured signal to that of an arbitrary standard.

DCS

ACR: Department of Correctional Services

DHHS

ACR: Department of Health and Human Services

Digital

Information that is in the form of two discrete states, 0 and 1. Sounds and images are not naturally digital, so in order to be used, they must be encoded or translated into a digital format.

DOT

ACR: Department of Transport

Duplex

The ability to transmit and receive simultaneously.

Duplexer

A device that allows a radio transmitter and receiver to share the same radio antenna without interference to each other.

- E -

EIA

ACR: Electronic Industries Alliance

EMI

ACR: Electromagnetic interference

ERP

ACR: Effective Radiated Power

Radio power levels are expressed by this term, usually in watts or decibels.

EXPRESS CARD

An interface to allow peripheral devices to be connected to a computer. This system has given way to USB devices.

- F -

FCC

ACR: Federal Communications Commission

The federal government agency that regulates commercial and non-federal public safety use of the radio spectrum.

FDMA

ACR: Frequency Division Multiple Access

A method of channel access in which conversations are split apart and transmitted over separate frequencies. Used in narrowband systems.

Fleet Mapping

Fleet mapping involves assigning radio talkgroups to departments, giving or denying access to other department's radio groups. (see Talk Groups.)

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Gain

An increase in signal power that results from a boost in the signal by an electronic device, expressed in decibels (dB).

GHz

ACR: GigaHertz. 1 billion cycles per second

GPS

ACR: Global Positioning System

Reads location information based on input from a system of low-orbit satellites.

- H -

Half Duplex

A communications pathway capable of transmitting in either direction, but not at the same time.

Hz

ACR: Hertz

A measure of frequency in cycles per second, used to express the bandwidth of an analog communications pathway. One Hertz is one cycle per second.

High Band

Commonly refers to VHF public safety radio segments in the ranges from 138-144 MHz and 148-174 MHz.

- I -

Infrastructure

The RF/IT system core that provisions the Provincial or State.

Interference

The disruption of the radio signal reception caused by any undesired source that generates waves at the frequency and along the same path as the desired wave.

Internet

A global system of interconnected computer networks that use the standard Internet Protocol Suite(TCP/IP).

Interoperability

The ability for different public safety agencies to communicate with each other.

Vertical interoperability allows for federal, state and local agencies to communicate.

Horizontal interoperability allows different public safety agencies in the same geographic jurisdiction to communicate.

IP

ACR: Internet Protocol

A data-oriented protocol used for communicating data across a packetswitched internetwork.

IRLP

ACR: Internet Radio Linking Project

A project that links amateur radio stations around the world by using Voice over IP (VoIP). Each gateway consists of a dedicated computer running custom software that is connected to both a radio and the Internet. This arrangement forms what is known as an IRLP Node. Since all end users communicate using a radio as opposed to using a computer directly, IRLP has adopted the motto "Keeping the Radio in Amateur Radio".

ISSI

ACR: Inter-RF Subsystem Interface for different P25 systems to be able to communicate.

IT

ACR: Information Technology

- K -

kbps

ACR: Kilobits per second

Standard measurement of data rate and transmission capacity. One kbps equals 1000 bits per second.

KHz

ACR: KiloHertz

A measure of frequency in cycles per second, used to express the bandwidth of an analog communications pathway. One thousand cycles per second.

- L -

LAN

ACR: Local Area Network

LMR

ACR: Land Mobile Radio

LMR systems allow communications between a base and several mobile radios. They can share a single frequency or use multiple frequencies. The LMR industry is regulated by the FCC in part 90.

Low Band

Commonly refers to VHF public safety frequencies in the range of 30-50 MHz.

- M -

Master System Controller

The main switch that controls the radio traffic between tower sites and radio site controllers.

MHz

ACR: MegaHertz

A measure of frequency in cycles per second, used to express the bandwidth of an analog communications pathway. 1 million cycles per second.

MIB

ACR: Management Information Bases

Describes the structure of the management data of a device subsystem.

Mobile Data

Data communications over the air typically from a laptop computer in a public safety vehicle, communicating to a base station.

Modulation

A controlled variation of any property of a carrier wave for the purpose of transferring information.

MDT

ACR: Mobile Data Terminal

Wireless data device with a screen and keyboard, installed in vehicles for limited data applications.

Multicast

The delivery of information to a group of destinations simultaneously using the most efficient strategy to deliver the messages over each link of the network only once, creating copies only when the links to the destinations split. It scales to a larger receiver population by not requiring prior knowledge of whom or how many receivers there are.

Multicast utilizes network infrastructure efficiently by requiring the source to send a packet only once, even if it needs to be delivered to a large number of receivers. The nodes in the network take care of replicating the packet to reach multiple receivers only where necessary.

Multi-Coupler

A device used to connect a multitude of receivers to a single antenna.

Mutual Aid

National or regional frequency that is used only for mutual aid interoperability. There are usually specific policies and procedures governing the use of a mutual aid frequency.

- N -

Narrow Band

In radio, a narrowband (VHF or UHF) channel is 12.5 kHz or less.

NCIC

ACR: National Crime Information Center

The United States' central database for tracking crime-related information.

NEMA

ACR: National Emergency Management Agency

NOC

ACR: Network Operations Center

The NOC will monitor the network traffic, site statuses, alarms and network performance.

Noise

An unwanted signal or disturbance (e.g. static) in a radio communications pathway.

NPSPAC

ACR: National Public Safety Planning Advisory Committee

This committee established a nationwide plan for using frequencies in the 821-824 MHz band and the 866-869 MHz band. Each state has its own plan.

NTIA

ACR: National Telecommunications & Information Administration

The federal government agency that regulates federal government use of the radio spectrum.

- O -

OCIO

ACR: Office of the Chief Information Officer

Ohms

Measure of electric resistance between two points of a conductor.

OTAP

ACR: Over the Air Programming for radios.

OTAR

Over the Air Rekeying for radios.

- P -

Packet-Switching

A method of efficient data transmission whereby the initial message is broken into relatively small digital units that are routed independently and subsequently reassembled.

Paging

System for sending a one-way signal or brief text or voice message over the air. Commercial paging systems can work on a local, regional or national basis, usually requiring only a small pocket device. Paging is done over land mobile radio frequencies. Under some circumstances, this may tend to clutter the channel and create audio fatigue for radio system users who need to hear only tactical information.

Patch

A control function that connects a user on one radio system to a user (or users) on another radio system. The simplest patches are accomplished by a dispatcher.

PIM

ACR: Passive Inter-Modulation

Passive nonlinear interference phenomenon much like the inter-modulation interference generated in active nonlinear components in radio frequency (RF) systems.

PIM harmonics can exist most often and cause problems where at least two high power output RF signals at different frequencies generate inter-modulation products in the sensitive receive frequency bands. Third order products present the highest risk to susceptibility. The initial step to remedy PIM in any system is to require the separation of transmit and receive elements.

PC Card

Originally PCMCIA Card. Typical devices included network cards, modems, and hard disks.

PCMCIA

ACR: Personal Computer Memory Card International Association

PCMCIA Card or CardBus was originally designed for computer storage expansion, but the existence of a usable general standard for notebook peripherals led to many kinds of devices being made available in this form. The PC card port has been superseded by the faster ExpressCard interface and no modern portable computer possesses one.

PSTN

ACR: Public Switched Telephone Network

PFM

ACR: Provincial Fire Marshal’s Office

Public Safety

An agency with responsibility for protection of life, property or natural resources. In this report, includes law enforcement, fire, and medical services.

Public Service

An agency with responsibility for developing and maintaining infrastructures that promote public safety and welfare.

- R -

Radio Spectrum

The subset of the electromagnetic energy spectrum whose wavelengths are between the audible and visible ranges—generally from 500 KHz to 300 GHz.

Receiver

The portion of the radio device that converts the radio waves received over the air into a usable audible signal or data stream. It is one of the two main building blocks of a wireless system which is responsible for collecting the RF energy from the antenna and reducing the signal’s frequency down to where it can be accepted by the demodulator. (see Transmitter.)

Repeater

A wireless transceiver that automatically boosts and amplifies a radio signal used to extend the communications capability of subscriber units.

RF

ACR :Radio Frequency

A frequency center point on the radio spectrum.

RF/IT Core

The radio frequency/information technology system core infrastructure.

.

RMS

ACR: Records Management System

Roaming

The ability of a user radio/cell phone to operate on and move throughout the system coverage. The system maintains contact with the user radio/cell phone as it moves from site to site within the system. The user radio/cell phone may also roam onto other systems if the two different systems are networked.

- S -

SATP

ACR: System Acceptance Test Plan

SFM

ACR: State Fire Marshal’s Office

SNMP

ACR: Simple Network Management Protocol

Exposes management data in the form of variables on the managed systems.

SNMP. MIBs: use the notation defined by ASN.1.

Simplex

A communications pathway that operates in only one direction.

SINAD

ACR: Signal-to-Noise plus Distortion ratio

Site Controller

The system controller interface to each tower site to operate radio traffic between the tower and the radio users.

Spectrum

A continuous range of frequencies. See Radio Frequency.

Subscriber User Equipment

Mobile and portable radios used by field personnel; also vehicle repeaters, control stations and interconnect devices.

- T -

Talk-Around

Direct communication between or among subscriber units without the use of a repeater. Generally used in conjunction a repeater system.

Talk Group

Groups of users within a trunked radio system that need to communicate with each other. An individual may belong to more than one talk group. (see Fleet Mapping.)

TCP/IP

ACR: Transmission Control Protocol/Internet Protocol

Common Internet protocol that provides communication across interconnected networks, between computers with different hardware architectures or operating systems.

TDMA

ACR: Time Division Multiple Access

A method of channel access in which conversations are separated into different time slots on a channel.

TIA

ACR: Telecommunications Industry Association

Transmitter

The portion of the radio device that converts an audible signal or data stream into a radio wave and sends it out over the air. It is one of the two main building blocks in a wireless system which is responsible for taking the signal from the modulator, increasing its frequency and power, and then radiating it out the antenna. (see Receiver.)

Trunking

A system in which a number of communications pathways (“trunks” is the term used for telephone lines) are grouped together. A user in a trunked system may be assigned any free trunk. This distributes conversation over all trunks, maximizing usage.

TSB-88

ACR: TIA Telecommunications System Bulletin

Wireless Communications System Performance In Noise And Interference – Limited Situations. Recommended Methods for Technology- Independent Modeling, Simulation, And Verification.

- U -

UHF

ACR: Ultra High Frequency

The part of the radio spectrum between about 300 MHz and 3 GHz. Used in the USA for television, cellular telephone systems, and mobile radio.

UPS

ACR: Uninterruptible Power Supply

USB

Universal Serial Bus

A specification to establish communication between devices and a host controller (usually personal computers), developed and invented by Ajay Bhatt while working for Intel.[2][3] USB is intended to replace many varieties of serial and parallel ports. USB can connect computer peripherals such as mice, keyboards, digital cameras, printers, personal media players, flash drives, and external hard drives.

- V -

Vehicle Repeaters

Devices installed in a vehicle used for the portable radios to communicate through the mobile radios. The mobile radios communicate directly on the radio system. The portables communicate through the repeaters to the radio system. Cross-band repeaters can use different radio frequencies, i.e., an 800 MHz portable can communicate through a cross-band repeater on a VHF mobile radio system.

VHF

ACR: Very High Frequency

The part of the radio spectrum between about 30 MHz and 300 MHz. Used in the USA for radio, television, and mobile radio.

VOCODER

A type of voice coder. Usually consisting of a speech analyzer and a speech synthesizer which converts analog speech into digital signals for transmission and digital signals back into artificial speech sounds for reception.

Voted Receiver

Receive-only sites used to extend radio talk-back coverage. The receiver site is connected to the system and passes the best receive signal from the user radio to the system.

VPN

ACR: Virtual Private Network

A network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or individual users with secure access to their organization's network.

VR

ACR: Vehicle Repeater

VSAT (with VPN encryption)

ACR: Very Small Aperture Terminal

A two-way satellite ground station or a stabilized maritime Vsat antenna with a dish antenna that is smaller than 3 meters.

- W -

WAN

ACR: Wide Area Network

A computer network that covers a broad area.

Wideband

In radio, a radio channel greater than 12.5 kHz.

Wireless

Another term for radio; communications that take place over a pathway that does not use wires.