A telephone network is a telecommunications network that connects

telephone A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...

s, which allows telephone calls between two or more parties, as well as newer features such as fax and

internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, p ...

. The idea was revolutionized in the 1920s, as more and more people purchased telephones and used them to communicate news, ideas, and personal information. During the 1990s, it was further revolutionized by the advent of computers and other sophisticated communication devices, and with the use of

dial-up internet Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional tele ...

. There are a number of different types of telephone network: * A

landline A landline (land line, land-line, main line, home phone, fixed-line, and wireline) is a telephone connection that uses metal wires or optical fiber telephone line for transmission, as distinguished from a mobile cellular network, which us ...

network where the telephones must be directly wired into a single telephone exchange. This is known as the public switched telephone network or PSTN. * A wireless network where the telephones are mobile and can move around anywhere within the coverage area. * A private network where a closed group of telephones are connected primarily to each other and use a gateway to reach the outside world. This is usually used inside companies and

call centre A call centre ( Commonwealth spelling) or call center (American spelling; see spelling differences) is a managed capability that can be centralised or remote that is used for receiving or transmitting a large volume of enquiries by telephone ...

s and is called a private branch exchange (PBX). * Integrated Services Digital Network (ISDN) Public telephone operators (PTOs) own and build networks of the first two types and provide services to the public under license from the national government. Virtual Network Operators (VNOs) lease capacity wholesale from the PTOs and sell on telephony service to the public directly

References

Telecommunications infrastructure {{telecomm-stub

See also

References