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DEFINITION |
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| Analog | The direct representation of a waveform, as opposed to digital which is a coded representation. An analogue signal is one that varies continuously (e.g. Sound waves). Analogue signals vary along two parameters, amplitude (strength) and frequency (tone). The unit of measurement is the Hertz, or cycle per second.
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| Asymmetric Digital Subscriber Line (ADSL) | Utilises a technology that transforms a normal telephone line into a high-speed digital line that enables access to telephony services and the Internet at the same time. ADSL provides always-on access to Internet or TV and Video on-demand services at speeds that are 10 to 40 times faster than a standard 56k modem. An ADSL line has a higher downstream speed (into the end user) than upstream speed (away from the end user).
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| Asymmetric Digital Subscriber Line (ADSL) | Utilises a technology that transforms a normal telephone line into a high-speed digital line that enables access to telephony services and the Internet at the same time. ADSL provides always-on access to Internet or TV and Video on-demand services at speeds that are 10 to 40 times faster than a standard 56k modem. An ADSL line has a higher downstream speed (into the end user) than upstream speed (away from the end user).
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| Bandwidth | The physical characteristic of a telecommunications system that indicates the speed at which information can be transferred. In analogue systems, it is measured in cycles per second (Hertz) and in digital systems in binary bits per second. (Bit/s)
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| Bluetooth | A short-range wireless protocol meant to allow mobile devices to share information and applications.
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| Broadband | A service or connection allowing a considerable amount of information to be conveyed, such as television pictures. Generally defined as a bandwidth > 2Mbit/s
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| Broadband | Integrated Services Digital Network (B-ISDN) The capability to integrate any type of communications signals (voice, data, image or multimedia) and carry them over a single broadband channel of 150-mbps and above, 4k (B-ISDN) regardless of their content.
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| Calling Line Identity (CLI) | A facility that enables identification of the number from which a call is being made.
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| Centrex | A service provided by a PTO which uses the local telephone exchange to provide PABX facilities at the customer premises
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| DDI Direct Dialling | Is a switchboard’s capability to route an incoming call to the extension dialled without the intervention of an operator.
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| Dial-up | Connections made to a data network using the switched network to provide a voiceband or data bearer.
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| Digital | The coded representation of a waveform by, for example, binary digits in the form of pulses of light, as opposed to analogue which is the direct representation of a waveform.
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| Digital European Cordless Telecommunications (DECT) | A system for office cordless networks and suitable for more general cordless use including telepoint type networks.
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| Digital Subscriber Line and VDSL | (Very high data rate Digital Subscriber Line) are all variants of xDSL.
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| Digital Subscriber Line (DSL) | A family of technologies, generically referred to as DSL or xDSL, that are capable of transforming a normal telephone line into a high-speed digital line. These include ADSL (Asymmetric DSL), SDSL (Symmetric DSL), HDSL (High data rate DSL) and VDSL (Very high data rate DSL). DSL enabled lines are capable of supporting services such as fast Internet access and video or TV on-demand.
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| Digital Subscriber Loop | A family of technologies generically referred to as DSL, or xDSL, capable of transforming ordinary phone lines (also known as "twisted copper pairs") into high-speed digital lines, capable of supporting advanced services such as fast Internet access and video-on-demand.
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| Digital technology | This enables information of all types to be transmitted in digital form over networks it is faster than analogue systems.
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| DSL | Technology digital subscriber line technology
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| Ethernet | Is the most widely installed LAN technology. Standardised as IEEE 802.3, an Ethernet LAN uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol (originally developed to manage radio based data communications - hence the name Ethernet) running over a coaxial cable or twisted pair wires. The most commonly installed Ethernet systems are called 10BASE-T and provide transmission speeds up to 10 Mbps. Fast Ethernet, or 100BASE-T10, provides transmission speeds of up to 100 Mbps and is typically used for LAN backbone systems, supporting workstations with 10BASE-T cards. Gigabit Ethernet provides an even higher level of backbone support at 1 Gbps.
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| Firewall | A system designed to prevent unauthorised access to or from a private network
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| GPRS | Packet Switched data radio technology for GSM networks. GPRS connections are always open giving mobile terminal users the same kind of network availability they may be used to from corporate networks. There is no set up and clear down times associated with data calls made via GPRS. Terminals can therefore effectively become a part of the Internet.
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| Integrated Services Digital Network (ISDN) | A network based on the existing digital PSTN that provides digital links to customers and end to end digital connectivity between them. ISDN2 provides a maximum bandwidth of 128kbit/s.
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| Internet | A global network of networks, mainly narrowband, accessed by users with a computer and a modem via a service provider.
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| Internet Service Provider (ISP) | Point of access to the Internet for small business and individual users. The ISP provides its customers with dial-up access to its router which relays traffic to web servers on the Internet.
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| IP - Internet Protocol | Packet data protocol used for routing and carriage of messages across the Internet.
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| IP Telephony | Also known as Internet Telephony or Voice over IP (VoIP). Use of Internet Protocol (IP, see TCP/IP) to carry and route two-way voice communications. IP Telephony can support telephone to telephone links through suitable adapters but also voice communications from telephone to IP terminal (such as a PC with sound card) or from IP terminal to IP terminal. The technique promises drastically reduced costs to carriers and therefore prices to end users – but it still suffers problems with quality.
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| ISDN | See Integrated Services Digital Network
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| Kbps | Kilobits Per Second a measure of the speed of data capable of passing along a line expressed in thousands of bits
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| Local area networks (LANS) | A network allowing the interconnection and intercommunication of a group of computers, primarily for the sharing of resources and exchange of information (e.g. e-mail).
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| Megabits Per Second (Mbps) | A measure of the speed of data capable of passing along a line expressed in millions of bits.
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