network

A wide area network is used to connect remote computers via telephone lines or satellite links. The ISDN (Integrated Services Digital Network) telecommunications network allows high-speed transfer of digital data.

Local area networks can be connected together in a ring circuit or in a star arrangement. In the ring arrangement, signals from a terminal or peripheral circulate around the ring to reach the terminal or peripheral addressed. In the star arrangement, signals travel via a central controller. In a bus network all elements are connected off a single cable that is terminated at each end.

In computing, a method of connecting computers so that they can share data and peripheral devices, such as printers. The main types are classified by the pattern of the connections - star or ring network, for example - or by the degree of geographical spread allowed; for example, local area networks (LANs) for communication within a room or building, and wide area networks (WANs) for more remote systems. The Internet is the linking of computer networks of institutions throughout the world: by 2006, there were about 1 billion users.

JANET (joint academic network) is used in the UK. SuperJANET, launched in 1992, is an extension of this, whose speed was upgraded to 10 gigabits per second (Gbps) in 2002.

One of the most common networking systems is Ethernet, developed in 1973 (released in 1980) at Xerox's Palo Alto Research Center, California, by R M Metcalfe and D R Boggs. Subsequent developments have included 10 gigabit Ethernet, wireless Ethernet, and ATM (asynchronous transmission mode).