Home Telephone Network

PSTN stands for public switched telephone network. It is the network of public telephone networks circuit switched around the world, just as the Internet is the network of different IP networks packet switching. Initially, BTI was only an analogy of fixed line telephone network system, however, these days, it is almost entirely digital and includes mobile and land lines.

The technical standards developed by ITU-T are generally govern what the PSTN because it uses E.163/E.164 addresses - that is, ordinary phone numbers - to put his address.

Initially, the phones do not all networks at all, but were in private use, coupled with their wiring. When users wanted to talk to other people, they had many phones that are necessary to communicate. If the person wanted to talk to someone else, they whistled in a transmitter until the other person heard and picked up

Later, a bell was added to indicate an incoming call. Soon, a hook switch has also been added so that the principle of exchange in telegraph systems could be used. each phone user is connected to a local telephone exchange, and each of these telephone conversations were then connected to the trunks. These networks have all been linked with a hierarchical layout until finally neighborhoods, cities, countries, and the world was hooked together. Thus, the RTC was born.

The exchange system changed when automation entered the picture with the pulse dialing. This trade much more sophisticated and requires less human participants to connect the call. Later, numbering at multiple frequencies - which led to the SS7 (signaling protocol) network - has become the standard connection for most of the exchanges by the end of last century.

Although the telephone network has been created using voice connections were analog, and tables used manual, automated telephone exchanges replaced these paintings, and digital switching technology have also been introduced. Today, switches almost always use digital circuits between exchanges, while the son two analog circuits are still used to connect most phones. In the PSTN, the circuit is a basic digital channel 64-kilobits per second.