ISP
Internet Service Provider. An institution that provides access to the Internet. By establishing points-of-presence (PoP) containing remote access servers and additional devices, as well as a suite of user software packages, the ISPs act as a commercial Internet on-ramp.

ITU or ITU-TSS
International Telecommunications Union, a special agency of the United Nations based in Geneva.

IVR
Interactive Voice Response. Where an inbound call is answered by a recording, which asks the customer to press buttons on the keypad in response to a menu of options. The numbers selected may instruct the system to search for specific information, which is then converted into the spoken word.

Ka-band
The frequency range from 18 to 31 GHz.

kbps
1,000 bits per second.

Kilobyte
A thousand bytes. Actually, usually 1024 (210) bytes.

LAN
Local Area Network. A computer network limited to the immediate area, usually the same building or floor of a building.

Last Mile
An expression used for the cabling or other communication medium from the closest fiber optic point or other type of high speed/large throughput service point to the end users equipment. This may be actually 100 feet to the street or telephone pole, or may be a new line back to the local telephone central office, etc.

Late Target Channel Keyup
A condition when the target cell does not receive the execute target order in time for the arriving mobile, caused by link delays between the mobile telephone switching office and target cell site.

L-Band
The frequency range from 0.5 to 1.5 GHz. Also used to refer to the 950 to 1450 MHz used for mobile communications.

Leased Lines
A circuit rented for exclusive use twenty-four hours a day, seven days a week from a telephone company. The connection exists between two predetermined points and cannot be switched to other locations.

LEO
Low Earth Orbit satellite. Satellites that are not stationary from a fixed point on earth and have the lowest orbit of all communication satellites. Must either be tracked or use a frequency band and access methodology that allows access to the satellite with a non-directional antenna. Most handset-to-satellite systems are based on LEO satellites using L-Band.

Link
In the trunking world, this refers to microwave or phone line links that tie one central controller in one location to another.

Little LEO
Relatively small and inexpensive satellites that provide low-cost, low-data rate, two-way digital communications, and location positioning to small handheld terminals.

Local Access and Transport Area
LATA is a geographic area (called an "exchange" or "exchange area" in the MFJ) within each BOC’s franchised area that has been established by a BOC in accordance with the provisions of the MFJ for the purpose of defining the territory within which a BOC may offer its telecommunications services.

Local Exchange Carrier
LEC. Telephone companies responsible for providing local connections and services.

Local Multipoint Distribution Services
Point/multipoint service with two-way capability to transmit voice, data, and other video information. LMDS can offer innovative consumer services such as two-way interactive video, advanced teleconferencing, telemedicine, telecommuting, and high-speed data services.

Local Service Area
The geographic area that telephones may call without incurring roaming or long distance charges.

MAN
Metropolitan Area Network. Typically, they support transmission speeds from 1.5 Mbps to 45 Mbps.

Management Service Provider
On the Internet, a management service provider (MSP) is a company that manages information technology services for other companies.

MCPC
Multiple Channels Per Carrier. Communications architecture that multiplexes channels of information in the time domain on to a single carrier (frequency domain).

Mbps
1,000,000 bits per second.

Megabyte
A million bytes. A thousand kilobytes.

MEO
Medium Earth Orbit satellite. A satellite that is not stationary from a fixed point on earth and whose orbital path is between the LEOs and GEOs. MEOs must either be ‘tracked’ or use a frequency band and access methodology that allows access to the satellite with a non-directional antenna.

Mesh
Network architecture wherein each node has the ability to communicate with every other node.

Messaging
Using various products, services and technologies to transfer messages from one person to another or from one device to another, such as traditional numeric or alphanumeric paging, e-mail or short messages (SMS) delivered to wireless devices.

MHz
Megahertz. Millions of cycles (Hertz) per second. A frequency or frequency range (bandwidth) through which a cabling system is specified.

Microcell
A bound physical space in which a number of wireless devices can communicate. Because it is possible to have overlapping cells as well as isolated cells, the boundaries of the cell are established by some rule or convention.

Microwave Radio
A radio system operating in the 3-30 GHz frequency band. Characterized as line-of-sight transmission and wide bandwidth. Can typically carry 960 voice channels and more. To reach long distances, several repeater stations, spaced about 30 miles apart, are required. HE, VHF and UHF radios are also used as narrowband transmission systems.

Microwave
Line-of sight, point-to-point transmission of signals at high frequency. Many CATV systems receive some television signals from a distant antenna location with the antenna and the system connected by microwave relay. Also used for data, voice and other types of information transmission.

Modem
A device that transmits and receives computer data through a communications channel such as radio, telephone lines or cellular phones. Modem comes from MOdulate/DEModulate.

MTBF
Mean Time Between Failures. MTBF is a basic measure of reliability for repairable items. It can be calculated as an inverse of the failure rate for a content failure rate system.

MTTR
Mean Time To Repair. MTTR is the most common measure of maintainability. It is the average time required to perform corrective maintenance on all the removable items in a product or a system.

Multicast
A process of transmitting messages from one source to many destinations.

Multifunctional LCD
An easy-to-read digital display shows the message count and machine status. Some models include a digital clock. Displays on select models also show the dialed number and a full operation menu.

Multimedia
Combining multiple forms of media in the communication of information.

Multimode Fiber
An optical waveguide in which light travels in multiple modes. Typical core/cladding size (measured in micrometers) is 62.5/125 and 50/125.

Multiplexer
A device, which enables several different signals to be sent down the same line. Sometimes referred to as ‘MUX’.

N-AMPS
Narrowband Advanced Mobile Phone Service. Combines the AMPS transmission standard with digital signaling information to effectively triple the capacity of AMPS while adding basic messaging functionality.

Narrowband PCS
Mobile and portable radio (including paging) services such as two-way paging, acknowledgment paging, voice paging and data services. These services are transmitted over a set of frequencies.

Network Attached Storage
Network Attached Storage (NAS) is hard disk storage that is set up with its own network address rather than being attached to the department computer that is serving applications to a network’s workstation users. By removing storage access and its management from the department server, both application programming and files can be served faster because they are not competing for the same processor resources.

Network Computer
Where you put most of the intelligence back into the server, similar to a mainframe system and dumb terminals where you use the desktop PC merely for input, output and presentation with all the applications run only on the server. However, the NC does have its own intelligence. Also called thin clients.

Network Control Center
Also called traffic control center. In a networked call center environment, where people and equipment monitor real-time conditions across sites, change routing thresholds as necessary and coordinate events that will impact base staffing levels.

Network Operating System
NOS is software that controls the execution of network programs and modules. Structurally, networking software comprises multiple modules, most residing in network servers, but some must be installed in each terminal/station that can access network resources.

Network Operations Center
A network operations center (NOC) is a place from which a telecommunications network is supervised, monitored, and maintained. Enterprises with large networks as well as large network service providers have a network operations center, a room containing visualizations of the network or networks that are being monitored, workstations at which the detailed status of the network can be seen, and the necessary software to manage the networks.

NIC
Network Interface Card. Allows a PC to attach to a network.

Node
A device connected to a network. It is an end point of a network connection common to two or more lines in a network. Nodes can be processors, controllers or workstations.

Noise
More technically referred to as electromagnetic interference (EMI) and radio frequency interference (RFI), electrical noise disrupts the smooth sine wave one expects from utility power.

Number Portability
Number portability is the term used to describe capability of individuals, businesses, and organizations to retain their existing telephone number(s) -and the same quality of service - when switching to a new local service provider.

One-armed Router
A one-armed router is a router that routes traffic between virtual local area networks (VLANs).

OSI Interconnection Model
The Open Systems Interconnection model was created by the International Standards Organization to serve as a blueprint for all network communication technologies dividing up all the processes of networking functions into seven distinct layers. The highest layer is the application that a device is running and with which a user may interact. The lowest layer is simply the physical medium of data transfer, such as coaxial cable. Each layer has its own distinct functions and services. There are a total of seven layers.

Packet Division Multiplexing
Different applications are assigned to different packets within the message frame, instead of different time slots, as with TDM.

Packet Filter
Inspects each packet for user-defined content, such as an IP address, but does not track the state of sessions. This is one of the least secure types of firewalls.

Parabolic Antenna
The most frequently found satellite TV antenna. The function of the parabolic shape is to focus the weak microwave signal hitting the surface of the dish into a single focal point in front of the dish.

Passive Optical Network
A passive optical network (PON) is a system that brings optical fiber cabling and signals all or most of the way to the end user. The optical transmission has no power requirements or active electronic parts once the signal is going through the network.

PBX
Private Branch eXchange. A small to medium sized customer premise telephone system that is also a switch (computer) providing communications between onsite telephones and exterior communications networks.

PC/PBX
Personal Computer Based Private Branch Exchange. Much more flexible than traditional private branch exchanges because of the modular design of personal computers.

PCMCIA/PC Card
Personal Computer Memory Card International Association. PC Cards are removable, credit-card sized devices that may be plugged into slots in PCs and wireless communication devices to provide fax or modem functions or network cards.

PCS
Personal Communications Service (or System). PCS services include next-generation wireless phone and communication services, wireless local loop, low-powered handsets, in-building wireless LAN service for businesses, enhanced paging service, etc. A personal communications system refers to the hardware and software that provide communications services.

Peak Hours
Typically, when the demand for access to wireless networks is high during the business day. Service providers typically charge full-service per-minute rates during peak hours.

Personal Area Network
A personal area network is a technology that could enable wearable computer devices to communicate with other nearby computers and exchange digital information using the electrical conductivity of the human body as a data network.

PCS
Personal Communications Services. PCS is a wireless phone service somewhat similar to cellular telephone service but emphasizing personal service and extended mobility. It is sometimes referred to as digital cellular (although cellular systems can also be digital).

Peer-to-Peer Communications
A model in which each party has the same capabilities and can initiate a communication session. In recent usage, peer-to-peer has come to describe applications in which users can use the Internet to exchange files with each other directly or through a mediating server.

Personal Identification Number
In the context of wireless devices, the personal identification number (PIN) is a code used in conjunction with a SIM card to complete a call or data transmission.

PKI
Public Key Infrastructure. Enables users of a basically non-secure public network such as the Internet to securely and privately exchange data through the use of a public and a private cryptographic key pair that is obtained and shared through a trusted authority. PKI provides digital certificates that identify individuals or organizations.

PMR
Private Mobile Radio. Generally for use within a defined user group such as the emergency services or by the employees of a mining project.

Port
First and most generally, a place where information goes into or out of a computer or both. On the Internet, port often refers to a number that is a part of the URL, appearing after a colon (:) right after the domain name.

PRI
Primary Rate Interface. A type of ISDN service designed for large organizations. Includes many B-channels (Bearer channels) and one D-channel (Data channel).

Private Network
A network made up of circuits for the exclusive use of an organization or group of affiliated organizations. Can be regional, national or international in scope. Common in large organizations.

Propagation Delay
The amount of time it takes a signal to travel through a cable or system.

Protocol
Agreed-upon methods of communications used by computers. A specification that describes the rules and procedures that products should follow to perform activities on a network, such as transmitting data.

Proxy
A firewall mechanism that replaces the IP address of a host on the internal (protected) network with its own IP address for all traffic passing through it.

PSTN
Public Switched Telephone Network. The complete public telephone system comprising telephone exchanges, local and trunk lines and telephone sets.

PTN
Public Telephone Network. Usually a common carrier such as a telephone company regulated by the FFC.

PTT
Historically, the Ministry of Post, Telecommunications and Telegraph. Now, a term to describe the incumbent, dominant operator in a country, many of which are being or have been privatized.

Public Switched Network
The public telephone network, which provides the capability of interconnecting any home or office with any other.

Queue
Holds callers until an agent becomes available. Queue can also refer to a line or list of items in a system waiting to be processed (for example, e-mail messages).

Radio Link
Makes it possible to wirelessly connect a base station to telephone switches and other units in an infrastructure.

Rate-adaptive DSL
This high-speed form of data transmission is derived from ADSL technologies and is geared toward the residential market, with a few added features. RADSL automatically adjusts line speed based on the condition of the line.

Receiver
An electronic device which enables a particular satellite signal to be separated from all others being received by an earth station and converts the signal format into a format for video, voice or data.

Repeater
Receives radio signals from the base station. They are then amplified and re-transmitted to areas where radio shadow occurs. Repeaters also work in the opposite direction, i.e. receiving radio signals from mobile telephones, then amplifying and re-transmitting them to the base station.

RF
Radio Frequency. For trunking systems, this is usually in the 800 MHz or 900 MHz band. The signals are carried through the air over these ‘RF carrier frequencies’.

Roaming
Within your home network, this means that your mobile phone automatically sets up communication procedures with different radio base stations when on the move. International roaming means that you can use networks other than your own, when traveling abroad.

Router
A data switch that handles connections between different networks. A router identifies the addresses on data passing through the switch, determines which route the transmission should take and collects data in the so-called packets, which are then sent to their destinations.

Routing
The forwarding of data packets in packet-switched networks to the intended address.