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Broadband Keywords Glossary
A name, decimal number or bit string used to identify a networked device. ADSL Asymmetric Digital Subscriber Line. Technology that has been developed for enabling high-speed Internet connections using existing telephone networks. Information travels asymmetrically (at lower speed away from the subscriber, and at higher speed towards the subscriber). Typical ADSL rates are 256kbps upstream (towards the network) and 512kbps towards the subscriber. Backbone In the Internet, a backbone is usually referred to as the circuits that interconnect routers. Bandwidth The amount of data that can be transferred over a connection at any one time. Broadband connections range typically from 256kbps to 3Mbps or more. Baud This is a unit of transmission speed. For example, the highest speed modems of 56 kbps transmit at 2400 baud. Broadband An communications link with transmission speeds over a certain minimum. The minimum bandwidth to define broadband varies, and is typically less for wireless connections. A 200kbps for both downstream and upstream transfers is one minimum that has been used. Cable Modem A device installed in the home that allows the subscriber to be connected to a cable internet service provider via the cable network and to have an 'always on' access to the internet. Contention Ratio Contention ratio is the ratio that you share your bandwidth with a number of other users. A contention ratio of 20:1 means that up to 19 other users share your internet connection bandwidth. Data Compression A method of reducing the amount of data to be transmitted. Compression reduces the number of bits needed to represent the data send. Dedicated Access Opposed to shared access, a dedicated access provides your own broadband connection line to the Internet. Dial-up This is a connection using a modem and standard telephone lines to dial-up to an Internet service provider and connect to the Internet. DSL Digital Subscriber Line. A technology that delivers high-speed Internet access over existing telephone wires, while still permitting the use of the telephone service. Ethernet Originally developed by Xerox, this is the most widely used LAN transmission technology. Ethernet LANs operate at 10 Mbps, 100 Mbps (Fast Ethernet) and 1000 Mbps (Gigabit Ethernet). Firewall The general name used for any method to preventing unauthorised access to a service or server, or for stopping certain message types. GPRS General Packet Radio Service. These are high speed Internet connections over GSM network. Theoretical transmission rates up to 115 kbit/s are possible. HDSL High Speed Digital Subscriber Line. This is a DSL technology which could have data rates up to 8Mbps. The range of HDSL is limited to 12,000 feet, but there are technologies to extend that range. High Speed Modem Modems required to receive broadband services. Internet Commonly the name given to the worldwide interconnection of networks using the TCP/IP protocols. IP Address A numerical address for every computer on the Internet. ISP Internet Service Provider. An ISP is a provider for internet connections to private and business customers. Kbps Kilobits per second. Describes the amount of data which is transferred between computers. LAN Local Area Network. A system that links computers (PCs, workstations and servers)into a network. Midband Some ISPs use this term for a slower broadband services of up to 128kbps (but above the dial-up rates of 56kbps). Narrowband A communications channel that transmits at rates less than what broadband systems do. Packet A packet of bits including address, control and data fields that are transmitted together. SDSL Symmetrical Digital Subscriber Line. A DSL connection where the transmission rate is the same in both directions, at rates of up to 2.3 Mbps. Service Provider A company providing services, which may include internet access, web hosting, applications, data storage and many other services, to clients. Shared Access As opposed to dedicated access, a shared broadband access is where a number of users share the same line to connect to the Internet. T1 A term developed by AT&T for a system that transfers digital signals at 1.544 Mbps. TCP Transmission Control Protocol. A sequenced packet switching protocol that provides data transport service for applications on The Internet. UMTS Universal Mobile Transmission System. Also known as 3G (third generation) mobile service, where voice, data and video are transmitted to a cell phone handset or a PC card at rates (at medium-range connection) from 384kbps up to 2Mbps. URL Universal Resource Locator. A hierarchical name string used to identify services available on The Internet. VDSL Very High Speed Digital Subscriber Line. A DSL service with theoretical transfer rates of up to 52 Mbps downstream. Typical operating range of VDSL is up to 4,500 feet. VoIP Voice over IP. A broadband Internet service where voice is digitised, compressed, and placed into packets for transmission over an IP network. WAN Wide Area Network. A network which covers a larger geographical area than a LAN. WLL Wireless Local Loop. A broadband connection system that uses high-frequency radio links to deliver voice and data. WWW World Wide Web. The term and HTML (Hypertext Mark-up Language) were developed by CERN, a Geneva based physics research centre. It is a network of servers providing linked information services on the Internet. xDSL Denotes digital broadband technologies for Digital Subscriber Line, including ADSL, HDSL and VDSL.
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