Here is a list of words relating to radio communications in general and KENWOOD- specific terminologies. It is a good starting point to learn when you may get lost with terminologies or acronyms.

Select the 1st letter



This combines the 10BASE-T and 100BASE-TX Ethernet standards into a single term. 100BASE-TX is a general term referring to a group of fast Ethernet standards used for transmission over twisted-pair cables, etc. 10BASE-T is another Ethernet standard. Both 10BASE-T and 100BASE-TX are used to link equipment in a star-configured LAN via a hub. 10BASE-T can be used to transmit data at up to 10Mbps over a maximum distance of 100 meters, while 100BASE-TX is capable of data transmission at 100Mbps over the same distance. 100BASE-TX equipment is usually compatible with 10BASE-T, so it is possible for them to coexist on a single network.

2-Tone (Two-Tone)

This refers to two-tone squelch. This function employs a sequential transmission of 2 audible tones for user selection, enabling the receiver to hear an alert tone. It can also be used for group calling.

4-Level FSK modulation

Frequency Shift Keying (FSK) is a modulation method by which the instantaneous frequency of a carrier is discretely changed according to a digital code. For example, with 2-level FSK, bit 0 changes the carrier frequency to -Δf, while bit 1 changes the carrier frequency to +Δf. With 4-level FSK, codes 00, 01, 10 and 11 indicate frequency shifts of +Δf, +3Δf, -Δf and -3Δf. Using 4 values instead of 2, 4-level FSK allows for double the data rate; alternatively, it is possible to send the same amount of data using half the bandwidth. Since FSK modulation has a constant envelope, the effects of amplitude shift are reduced and a non-linear Class C amplifier can be used.

5-Tone (Five-Tone)

Originally a European signaling protocol, this is a burst of audio tones (actually as many as 7) used to initiate a radio conversation via selective calling. Several formats are used.



The Advanced Encryption Standard (AES) is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST). For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits.


Abbreviation for Accessory.

Air Interface

Protocol specifying connection and transmission methods between radio units in a digital mobile radio system.


AMBE™ is an abbreviation for Advanced Multi-Band Excitation, an audio compression technology developed by Digital Voice Systems, Inc. (DVSI). This technology maintains audio quality over a narrower transmission bandwidth than linear-predictive encoding systems, and copes well with transmission errors and noise. AMBE+2™ is the latest version of AMBE™.

AMBE+2™ is a trademark of Digital Voice Systems Inc.


Automatic Number Identification. This identifies the transmitting radio and is used in two-way selective calling.


Association of Public-Safety Communications Officials-International (APCO) was founded in 1935. It is the world’s oldest and largest organization of public safety communications professionals and supports the largest U.S. membership base of any public safety association.


Abbreviation for Auxiliary port. A terminal for connecting a peripheral device.


Automatic Vehicle Location. A system or service using a radio terminal and a vehicle-mounted GPS device that enables owners to prevent vehicle theft or locate stolen vehicles. It can also provide trip information for bus and other transport service passengers, and increase operational efficiency for trucking companies.



Bit Error Rate. This measures the error bits in a received bit stream over a given period.


Call interruption

Call Interruption is the function to enable a transceiver other than the transmitting transceiver to terminate voice communications by sending and receiving the Call Interruption request message.

Class-C Power Amplifier

A power amplifier employing Class C electronics. Power amplifier circuits (output stages) are classified as A, B, AB or C. Class A, B, and AB are linear amplifiers, while Class C can be categorized as non-linear. Class C amplifiers conduct less than 50% of the input signal and the distortion at the output is high, yet high efficiencies (up to 90%) are possible. Class C amps thus have advantages in efficiency and cost performance when compared to Class A, B and AB, which are used for digital wireless communications.


To copy user programmable data ? such as frequency, ID, signal and scan information ? from one radio to another.

Conventional Mode

A communications method whereby the user selects the appropriate channel for a call, since a control device to assign a traffic channel is not available. In Direct Mode Operation mobile radios communicate with each other directly, while in Repeater Operation they communicate via a repeater.


Continuous Tone-Coded Squelch System. A circuit that adds continuous tones to the transmitted signal to enable the other party to screen out unwanted signals and receive only the desired station. This is common for business radio systems as it allows multiple transceivers to use the same radio frequency. Equivalent to KENWOOD's proprietary QT (Quiet tone) system.


Continuous Wave. Morse code is created by switching a continuous wave on and off.



Refers to 25-pin cables and plugs.


Digital Coded Squelch. While CTCSS modulates a carrier with a continuous tone signal, DCS uses a continuous NRZ data stream. Equivalent to KENWOOD's proprietary DQT (Digital Quiet Talk) system.


The Data Encryption Standard (DES) is one of the standard for the encryption of electronic data. That is less secure than AES due to 56-bit smaller key block size

Direct Frequency Assignment (DFA)

This automatically notifies all equipment and subscriber units connected to the network when a new frequency is added to the network.


Digital mobile radio (DMR) is an open digital mobile radio standard defined in the European Telecommunications Standards Institute (ETSI) Standard TS 102 361 parts 1-4, which use two-slot TDMA in a 12.5 kHz. This could double the capacity -- One can obtain 2 talk paths within an Analog 12.5 kHz bandwidth.


Open Application Interface Standard for Voice/data communications protocol developed by members of the DMR Association.


DMR Tier II covers licensed conventional radio systems in LMR/PMR frequency bands.


DMR Tier III covers trunking operation.


Digital Quiet Talk. DQT has 512 codes (from 000 to 777 in octal notation) but 86 code sets are actually used. Since DQT uses FSK modulation with binary data, it is more complex than QT and is incompatible with QT.


Digital Signal Processor. A microprocessor specialized for audio, signaling, error correction and vocoder data. It can relieve the CPU of some of the signal processing load.


Dual Tone Multiple Frequency. Tones are emulated by pressing the 0-9, * and # keys. This is different from CTCSS, since it operates in the audio range and cannot be transmitted simultaneously with voice audio.

Dual-slot Direct Mode

DMR can accept up to two simultaneous subscriber calls can be supported in a 12.5 kHz channel, now that even radio-to-radio, without requiring a base station or repeater.


A communications method for simultaneous transmission and reception using two separate frequencies.



Electronic Industries Alliance.


Electronic Serial Number, a unique number assigned to individual radio units for identification purposes. Automatic ESN acquisition frees the administrator from having to input new subscriber unit information.


A family of frame-based computer networking technologies for LANs, standardized as IEEE 802.3. Originally proposed by Xerox and DEC (now part of Hewlett-Packard).



Frequency Division Multiple Access. A channel access method in which a radio system shares spectrum by assigning different frequencies to multiple users.


Forward Error Correction. A transmitter adds redundancy data to information data prior to transmission so the receiver can detect and correct errors in the received data.

FIPS 140-2

The Federal Information Processing Standard (FIPS) Publication 140-2, (FIPS PUB 140-2), is a U.S. government computer security standard used to accredit cryptographic modules. FIPS 140-2 defines four levels of security, named "Level 1" to "Level 4".


FleetSync is the generic name for KENWOOD's proprietary message communications system that utilizes MSK (Minimum Shift Keying) signaling.
FleetSync allows the user to identify individual transceivers as well as send and receive text messages. FleetSync also supports serial communications, allowing the user to connect a computer or other external device to the transceiver. FleetSync provides diverse messaging functions not possible with conventional voice communications, and it supports a wide variety of operating environments.

FleetSync is a registered trademark of JVCKENWOOD Corporation.


Frequency Modulation, a technique for modulating an analog signal. The information is transmitted by modulating the frequency. FM offers better sound quality with less noise than AM, although FM requires more bandwidth and is therefore not very efficient.


Field Programming Unit, programming software for loading various settings into radio unit.

Fringe Area

Boundary of the coverage area of a transmitter in which signals are weakened and distorted.



Global Positioning System. Developed by the United States military, GPS technology uses signals from about 30 satellites to provide accurate information about one's position on the Earth. The latitude, longitude and altitude of the receiver can be determined with an accuracy ranging from twenty meters or more to just a few centimeters.


ID Map

Displays current User IDs & Group IDs in list format. Makes it easy to check which IDs are available when adding a new ID.




Improved Multi-Band Excitation, an audio compression technology developed by Digital Voice Systems, Inc. (DVSI).

Intrinsically Safe (IS)

Explosion-proof specifications, required for transceivers used in such places as coal mines or oil refineries, where the risk of triggering an explosion is high.

IP (1)

Internet Protocol. The protocol used for data transmission across the Internet. IP forms the foundation of the Internet, and hence plays a major role in Internet activity.

IP (2)

International Protection. IEC standard IEC60529 (Degrees of protection provided by enclosures) specifies the level of protection from intrusion by body parts, foreign materials or liquids into electrical equipment enclosures. 'IP' is followed by a number indicating the level of protection. The first digit describes the degree of protection from foreign materials, and the second from liquids. For example, in the case of IP54, '5' indicates that the device is dust resistant, though there should be no harmful effects if a small amount of dust enters the enclosure, while '4' indicates that there will be no harmful effects if a small amount of water is splashed on the equipment from any direction. In the case of IP55, the second '5' indicates that water sprayed directly from a nozzle onto the device enclosure from any direction will have no harmful effects.


Internet Protocol Security. IP packet encoding standards for encrypted communications across the internet.



Local Area Network. A network set up within a building which connects devices such as computers and printers, for data transfer via twisted-pair coaxial or optical fiber.


Liquid Crystal Display.


Light Emitting Diode. A type of semiconductor element that emits light when an electrical current passes through it. The three basic colors are red, blue and green, and in combination these can be used to produce a range of other colors including white, making it easy to reproduce full color images. A wide viewing angle is possible.


Logic Trunked Radio. A trunked radio system developed in the late 1970s by the E. F. Johnson Company.



Military Standard. Such standards are defined by the United States Department of Defense for product procurement.


The communications system operates 24/7 that cannot be turned off without impacting operations are referred to as "mission-critical."

Mixed Mode Operation

That allows radios can operate in both digital and FM analog modes, switching automatically as needed. Interoperability with legacy analog radios allows organizations to migrate to full digital at their own pace.


Minimum Shift Keying. A kind of FSK modulation in which the minimum possible carrier frequency shift is set for each data bit.


A system that has multiple sites connected via a network.


Large-scale networks can be created by linking multiple systems using system bridge units. Gen1 bridges are not able to link systems for two-way communications (individual calls/data), but a Gen2 bridge makes this possible, even if the systems codes are different.


Network Manager Server/Client

Software for monitoring system/network status. Featuring centralized log management and analytic functions, it can be used for fault analysis. It is possible to use generic SNMP management applications, but only KENWOOD software is able to acquire and control NEXEDGE-specific information.


NEXEDGE is the trade name for KENWOOD's digital radio systems using the NXDN digital air interface.


Due to the incompatibilities that exist in current trunked radio systems supplied by the various manufacturers, the US FCC allocated five conventional radio channels for the purpose of mutual aid and these are commonly called the NPSPAC (National Public Safety Planning Advisory Committee) mutual aid channels.

NTP Server

A server that distributes the current time using the network time protocol (NTP), which enables clock synchronization between computer systems over data networks with variable latency. A computer’s NTP client accesses the server and adjusts its internal clock based on the response.


Non-Return-to-Zero encoding.


NXDN is the name of the digital air interface protocol and trademark of JVCKENWOOD Corporation and ICOM Inc. It is comprised of a digital radio communications protocol using 4-Level FSK (4LFSK) modulation capable of operating on 12.5 and 6.25 kHz channel bandwidths. NXDN access methodology is classified as FDMA (Frequency Division Multiple Access).



Over-The-Air-Alias; A calling unit’s User ID (UID) alphanumeric alias is sent over the air and displayed on the receiving unit’s LCD, so there is no need to program every fleet alias in every radio.


Oven-Controlled Crystal Oscillator. A highly stable oven-type crystal oscillator in which internal temperature fluctuations are kept to a minimum to ensure precise transmit performance.


With using OTAP Manager Software provides wireless programming for subscriber units in the field. Over-the-air changes to large fleets will result in huge savings by cutting down on extensive travel, labor and fuel costs as well as in lost productivity caused by radio downtime.


The common name for the method of changing or updating encryption keys in a two-way radio system over the radio channel (“over the air”).



Project 25 (P25 or APCO-25) is a suite of standards for digital radio communications for use by federal, state/province and local Public safety organizations in North America to enable them to communicate with other agencies and mutual aid response teams in emergencies.

P25 Phase 1

Phase 1 radio systems operate in 12.5 kHz analog, digital or mixed mode using FDMA access method. Phase 1 radios use Continuous 4 level FM (C4FM) modulation -- a special type of 4FSK modulation. Phase 1 uses the IMBE voice codec.

P25 Phase 2

P25 Phase 2 has been developed for trunking systems using a 2-slot TDMA scheme. Phase 2 uses the AMBE+2 voice codec.


Programmable Function Key. Such keys are assigned functions with an FPU.


A generic term for an ANI-like system used in two-way radio systems. It provides identification of the transmitting radio over the air, and is commonly employed in Selective calling/signaling systems, usually in commercial and public safety radio systems.


Abbreviated as PTT. A simplex or half-duplex communications service, where it is only possible to talk while the transmit button is pushed down.



Quiet Talk. KENWOOD's proprietary CTCSS system using EIA tones. This enables the user to call groups or individuals on a single frequency.



Radio Access Number. With NXDN this digital signaling ensures smooth communication among groups using the same channel. Used in the same way as analog signaling with QT/DQT.

Registration Monitor

Checks to see where the specified User ID is currently registered, and with which Group ID it is registered. Enables display of the current call area for the Group ID.


Radio Frequency. Refers to the frequency of the radio waves or electrical signals used as a carrier for wireless communications.


Return on Investment, a figure that expresses the operational profits returned from a particular investment.


Received Signal Strength Indicator. A circuit incorporated into a receiver that indicates the strength of a received signal.



To sequentially receive on specific channels stored in memory, in order to search for a valid transmission.


Communication in one direction at one time. Therefore, simplex communication on the same frequency must alternate between transmission and reception.


Signal to Noise And Distortion. A standardized value used to measure the sensitivity of an FM receiver. Measured in dB (decibels).


A term to describe an aggregate of repeaters in a system.

Site Controller

A site controller allocates calls within a NEXEDGE Gen2 site. It is required for sites with 10 or more repeater channels.


Sub-network Dependent Convergence Protocol (SNDCP) is the protocol which allows the transceiver operated in a P25 Trunking system to establish data communications via an IP network.


Abbreviation for Simple Network Management Protocol, an Internet standard for managing devices and equipment on an IP network. SNMP-compatibility enables use of commercially-available network monitor applications.

System Bridge

A system bridge is required to seamlessly connect a NEXEDGE network with another NEXEDGE trunked network that may use different system codes.

System Configuration Utility

Browser-based application for flexibly applying changes to the system setup, so there is no need to use NEXEDGE Gen2 software.

System Controller

A server-based controller for NEXEDGE Gen2 to centrally control data for device registration, etc. within a trunked system (up to 48 sites per controller).



Time Division Multiple Access. A channel access method whereby a radio system assigns users different time slots on the same frequency. One frequency can thus be shared by multiple stations.

Telephone Interconnect Adapter (KTI-4)

A telephone interconnect adapter connects a NEXEDGE trunked system to an analog telephone patch, providing outbound radio to phone system calls and inbound phone system to radio calls. It also serves as modulator/demodulator between the NEXEDGE digital system and the analog PSTN/PABX system.

Transflective LCD

A transflective liquid crystal display is a liquid crystal display (LCD) that reflects and transmits light for easy visibility both under bright sunlight and dark night.


AA "trunk" is a communications channel between two points, and "Trunked" refers to automatically sharing trunks. A radio system with this capability is a "trunked system," a concept analogous to the way phone lines are switched by an exchange. Traffic channels in a repeater site are thus automatically distributed. Since the controller in a trunked system identifies available repeaters and assigns them to users, a trunked system improves the operation rate of repeaters and offers more spectral efficiency than a conventional system.


A configuration aid rendering complicated initialization settings unnecessary.



Universal Serial Bus. A standard routing system for connecting computers and peripheral equipment.



A type of audio compression technology. Vocoder systems analyze the human voice and can generate an "artificial" voice. This dramatically reduces the amount of information needed to store speech, from a complete audio recording to a series of numbers.


Voice Operated X. With a two-way radio, this is a circuit that automatically activates the transmitter when the user speaks, enabling hands-free switching between transmission and reception. The 'X' indicates the particular device or circuit for voice operation.


Virtual Private Network. A service that creates a discreet virtual network over a public network. This is useful for connecting important bases within a corporation while avoiding the cost of installing a private network. Data encoding and certification systems ensure confidentiality by lowering security risk from leakage, signal interference and interception.



Wide Area Network. A network designed for data communications between computers that are separated geographically, such as those in a company headquarters and its branches.

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