Glossary
This will be updated on a regular basis - if there is anything you are unclear about that is not answered below, please feel free to contact us
ADSL (Asymetrical Digital Subscriber Line)
A method to increase transmission speed in a copper cable. ADSL facilitates the division of capacity into a channel with higher speed to the subscriber, and a channel with significantly lower speed in the other direction. The reduced speed in the other direction makes ADSL services less suitable for customers who need to send out large amounts of data, or who want to use VoIP.
Bandwidth
The information-carrying capacity of a communications channel. Usually expressed in Hertz (cycles per second) for analog circuits and in bits per second (bps) for digital circuits.
Base station
The central radio transmitter/receiver that maintains communications with a mobile radiotelephone with a given range.
Bps
bits per second - meaning data transmission speed, the number of pieces of information transmitted per second.
Broadband
This term has a number of meanings. It was coined originally to describe a channel with more bandwidth than a standard voice grade channel which is usually a 48KHz link.
Extranet
The extension of a company's intranet out onto the Internet, e.g. to allow selected customers, suppliers and mobile workers to access the company's private data and applications via the World Wide Web. Generally an extranet implies real-time access through a firewall of some kind.
ISDN (Integrated Service Digital Network)
A technology which offers high speed transmission of voice, data and video through existing fixed line infrastructure.
LAN (Local Area Network)
A small data network covering a limited area, such as within a building or group of buildings.
Modem
Abbreviation of modular/demodulator, the modem converts digital computer signals into analog form for transmission over analog telephone systems.
Radio Link
Makes it possible to wireless connect a base station to telephone switches and other units in an infrastructure.
Repeater
Receives radio signals from the base station. They are then amplified and re-transmitted to areas where radio shadow occurs. Repeats also work in the opposite direction, i.e. receiving radio signals from mobile telephones, then amplifying and re-transmitting them to the base station.
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 so-called packets which are then sent to their destinations.
SDSL (Symetric Digital Subscriber Line)
The data carrying capacity of the circuit is the same in both directions. All West Somerset Internet's broadband services are Symetric.
SIM card (Subscriber Identity Module card)
A small printed circuit board that must be inserted in any GSM-based mobile phone when signing on as a subscriber. It contains subscriber details, security information and memory for a personal directory of numbers.