... appropriate software on each machine together with a public telephone line. This method is fairly cheap to set up with no need for much extra equipment, but data transfer is slow and the phone bills can be high. As it is a public telephone line it is not very secure and so vulnerable to hackers. Renting a dedicated leased line from a telecommunications service provider, of which you are sole user, is much more secure but more expensive. Examples of Wide Area Networks: Broadcast services These are services that use radio links. The commonest example is teletext where images from computers are sent as part of the television signal. Broadcast services also include networks with terminals or workstations linked by radio or infrared signals. This could be useful in many situations such as in supermarkets where checking stock can be done using a wireless hand-held terminal that transfers the data directly from the ...

See this essay or coursework document in full right now