Glossary
In the age of the acronym how do you know your Firewall won't clash with your Wi-Fi connection? Here are some definitions and explanations that will help to understand what the world is talking about.
2Mb connection
High speed broadband connection enabling download speeds of 2Mb per second - around 40 times faster than a standard 56k modem.
ADSL
Asymmetric Digital Subscriber Line; a means of providing broadband internet access through existing telephone wires. The signal is fatter coming into the building (512 kbps) than leaving it - hence 'Asymmetric'. The telephone company needs to install special equipment (DSLAM) in the local exchange, and subscribers need to be within 5.5 kms to receive ADSL.
Always-on
One great advantage of most broadband services is the fact that users do not need to log on and off to save telephone bills or to release the line for telephone calls.
ASP
Application Service Provider; an internet server which hosts software and makes it available on demand to subscribers.
Back-end / Back-haul
The processing power which sits behind 'front-end' content. This includes the registration of viewer details, transaction engines to handle payments, content management systems (CMS) which control the flow of programs, customer relationship management applications (CRM) designed to increase understanding of customers, audience tracking devices which monitor user behaviour, resource management (ERP) which aligns production facilities with order delivery, financial, supply chain management (SCM), and more besides.
Bandwidth
The rate in bits per second at which data can be transmitted across a communications network. (These are normally expressed as Kbps - Kilobits per second, Mbps - Megabits per second, Gbps - Gigabits per second, or Tbps - Terabits per second.)
Broadband
A moveable feast, but the bandwidth commonly deemed to qualify as "broadband" is 512 Kbps, the rate at which ADSL reaches the building. However, to achieve true broadband it is necessary for the service to be "Symmetric".
Browser
The software you use to download and display documents on the World Wide Web.
Download
The process of copying files from the internet to your computer.
Encryption
Network security procedure to prevent unsanctioned access. Data are scrambled before transmission and unscrambled by the authorised receiver.
Extranet
Internet service which is protected by user name and password so that it is only available to authorised users. Commonly a means of working on a development project where contributors are geographically separated.
Firewall
Programs which screen data on local area networks to protect access by other internet users.
Fixed wireless
Refers to point-to-point transmission through the air between stationary devices. Compared with mobile radio services transmitted along specific frequencies (which need to be licensed by the Radio Communications Agency, part of the DTI). Point-to-multipoint provides a means of transmitting from a broadband hub (cable, ADSL or satellite) to a large number of subscribers. Point-to-point and mesh radio are means of carrying higher bandwidth services such as video and broadcast services.
Intranet
Office network which uses a web browser and server which is only available to people within an organisation.
ISP
Internet Service Provider. Provides web services to subscribers, hosting websites and providing a range of facilities including billing, security etc.
LAN
Local Area Network. A dedicated data communications system which uses cables to link buildings, usually belonging to one organisation, within a defined location. (See also WAN).
Mobile
The technological advances which are bringing internet access to mobile devices, including cellular phones, Personal Digital Assistants, palmtops etc. The technologies include WML, WAP, GPRS and 3G. Licenses to utilise the radio spectrum through these protocols have been auctioned to telcos for very large sums of money. Transmission requires relay masts and the broader the bandwidth (3G is the broadest) the larger the number of relays needed.
Satellite
Familiar to most people through the spread of satellite-delivered television services. Satellite transmitters have wide geographic footprints - they can reach most parts of the UK, failing only where mountains or other obstacles block the signal. Satellite broadband is particularly relevant to users who operate outside the range of ADSL or cable, offering bandwidth comparable with them. One-way satellite links provide users with a broadband downlink, while the return path is carried on narrower ISDN or telephone wires. Two-way satellite links can provide an always-on service though real time two-way services can suffer delays in transmission. Satellite services are more expensive than DSL delivery.
SDSL
Synchronous DSL. A variant of ADSL which offers a symmetric service.
Video conferencing
Real time video to allow multiple users to broadcast and receive sound and vision simultaneously.
VoIP
Short for Voice over Internet Protocol, enables users to make phone calls across computer networks, providing a low cost and efficient way to complement traditional phone systems.
VPN
Virtual Private Network is a method of using the internet, to give individual users or remote offices secure access to their company's network.
Wi-Fi
Commonly used to signify the 802.11.b standard - a form of wireless networking. Wireless-Fidelty allows the connection of two or more computers without the need for physical cabling between them. The most common forms of Wi-Fi are 802.11.b (capable of up to 11 Mb/Sec) and 802.11.g (capable of up to 54 Mb/Sec).
Wireless
The use of radio signals to connect computers without cables whether it be a computer and a mouse or a network of computers that connect to the internet.
Wireless access point
A device that exchanges data between wireless computers or between wireless computers and wired computers on a network.
Wireless broadband
Technology enabling users within a locality to access the internet via radio frequencies. Offered mainly by specialist service providers, wireless broadband is ideal for subscribers in remote areas as they can be brought into the network without the need for new cabling/wiring across the countryside.