VOIP and Telecommunication Glossary

Access Charge
A fee charged subscribers or other telephone companies by a local exchange carrier for the use of its local exchange networks.

ADPCM
Adaptive Digital Pulse Code Modulation is a way to encode sound so that takes up less room than the way it would be coded if the sound were a WAV, AIFF or on a CD.

Analog Signal
A signaling method that uses continuous changes in the amplitude or frequency of a radio transmission to convey information.

Bandwidth
The capacity of a telecom line to carry signals. The necessary bandwidth is the amount of spectrum required to transmit the signal without distortion or loss of information. FCC rules require suppression of the signal outside the band to prevent interference.

Broadband
Broadband is a descriptive term for evolving digital technologies that provide consumers a signal switched facility offering integrated access to voice, high-speed data service, video-demand services, and interactive delivery services.

Calling Party Pays
A billing method in which a wireless phone caller pays only for making calls and not for receiving them. The standard American billing system requires wireless phone customers to pay for all calls made and received on a wireless phone.

Cellular Technology
This term, often used for all wireless phones regardless of the technology they use, derives from cellular base stations that receive and transmit calls. Both cellular and PCS phones use cellular technology.

Common Carrier
In the telecommunications arena, the term used to describe a telephone company.

Community Antenna TV (CATV)
A service through which subscribers pay to have local television stations and additional programs brought into their homes from an antenna via a coaxial cable.

Dial Around
Long distance services that require consumers to dial a long-distance provider’s access code (or "10-10" number) before dialing a long-distance number to bypass or "dial around" the consumer’s chosen long-distance carrier in order to get a better rate.

Digital Television (DTV)
A new technology for transmitting and receiving broadcast television signals. DTV provides clearer resolution and improved sound quality.

Direct Broadcast Satellite (DBS/DISH)
A high-powered satellite that transmits or retransmits signals which are intended for direct reception by the public. The signal is transmitted to a small earth station or dish mounted on homes or other buildings.

Dropouts
Characters lost in data transmission for some reason.

Frequency Modulation (FM)
A signaling method that varies the carrier frequency in proportion to the amplitude of the modulating signal.

High Definition Television (HDTV)
An improved television system which provides approximately twice the vertical and horizontal resolution of existing television standards. It also provides audio quality approaching that of compact discs.

IP Address
Internet Protocol Address is a numeric string that is used to identify a computer (or other device) to the internet. IP addresses have four sets of numbers with values 0-255 in each set, for example: 000.000.00.0. If you're on the internet, you have an IP address.

IRC
Internet Relay Chat (IRC) is a big, global experience where you can meet people and friends in a channel (similar to AOL's Chat Rooms). IRC is all inter-connected by special IRC servers. To get started, you'll need some IRC software and be able to access an IRC server. Many of the ISP's already come with some form of IRC software. If your ISP software doesn't have IRC, try using any of the search engines available using IRC to search.

ISDN
Integrated Services Digital Network specifications lets large quantities of data (wide- bandwidth) flow from computer to computer using the public telephone network. Under ISDN, a phone call can transfer 64 kilobits of digital data per second. If you're interested, contact your local telephone company.

Landline
Traditional wired phone service.

Network
Any connection of two or more computers that enables them to communicate. Networks may include transmission devices, servers, cables, routers and satellites. The phone network is the total infrastructure for transmitting phone messages.

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

Open Video System
An alternative method to provide cable-like video service to subscribers.

Paging System
A one-way mobile radio service where a user carries a small, lightweight miniature radio receiver capable of responding to coded signals. These devices, called "pagers," emit an audible signal, vibrate or do both when activated by an incoming message.

Prescribed Interexchange Charge (PICC)
The charge the local exchange company assesses the long distance company when a consumer picks it as his or her long distance carrier.

Roaming
The use of a wireless phone outside of the "home" service area defined by a service provider. Higher per-minute rates are usually charged for calls made or received while roaming. Long distance rates and a daily access fee may also apply.

Satellites
A radio relay station that orbits the earth. A complete satellite communications system also includes earth stations that communicate with each other via the satellite. The satellite receives a signal transmitted by an originating earth station and retransmits that signal to the destination earth station. Satellites are used to transmit telephone, television and data signals originated by common carriers, broadcasters and distributors of cable TV program material.

Service Plan
The rate plan you select when choosing a wireless phone service. A service plan typically consists of a monthly base rate for access to the system and a fixed amount of minutes per month.

Service Provider
A telecommunications provider that owns circuit switching equipment.

Subscriber Line Charge (SLC)
A monthly fee paid by telephone subscribers that is used to compensate the local telephone company for part of the cost of installation and maintenance of the telephone wire, poles and other facilities that link your home to the telephone network. These wires, poles and other facilities are referred to as the "local loop." The SLC is one component of access charges.

T1
Faster than ISDN (64 kbs per second), T1 lines transfer data/signals at 1.544 mbs per second. The top of the line is a T3 connection, at 44.736 mbs per second.

TCP
Transmission Control Protocol (TCP) is the way computers communicate with each other over the internet.

Tariff
The documents filed by a carrier describing their services and the payments to be charged for such services.

Telephony
The word used to describe the science of transmitting voice over a telecommunications network.

Unbundling
The term used to describe the access provided by local exchange carriers so that other service providers can buy or lease portions of its network elements, such as interconnection loops, to serve subscribers.

URL
Uniform Resource Locator (URL). URL's are the fixed formats that we all use to get the documents or files we want from the internet. URL's are also used for FTP documents or files, WAIS, and several others.

XModem
An asynchronous file-transfer protocol for personal computers that makes the error-free transmission of files through the telephone system easier. Developed by Ward Christiansen for 8-bit computers running Control Program for Microprocessors (CP/M) and placed in the public domain, the XMODEM protocol is included in most personal computer communications programs and commonly is used to download files from bulletin board systems (BBSs).

YModem
A file transfer protocol that is an improved version of XMODEM-1K. YModem transfers data in 1,024-byte blocks and performs a cyclic redundancy check CRC) on each frame. Also, YModem supports sending more than one file in sequence.

ZModem
An asynchronous file transfer protocol for personal computers that makes the error-free transmission of computer files with a modem easier. ZModem is a very fast protocol that lets you use wild-card file names for transfers. It's also well-liked because you can resume the transfer of a file if the first attempt is interrupted before completion. Next to XModem, ZModem is the most popular file transfer protocol and is included in most communications applications.

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