Whide Area Networks: Circuit Switched Networks

An Example: the telephone network

A telephone network is a typical circuit-switched network. For transmitting data (voice) from one point to another, a circuit should be first established.

---

 prev / next
When a telephone A originates a call to a telephone B, the circuit establishes a phisical circuit from the originating phone though the local switching office across trunck lines to remote switching offices an finally to the destination telephone. While a circuit is in place the phone equipment samples the microphone repeatedly, encodes the samples digitally, and transmit it trough the circuit to the receiver.

The quality of the communication is guarateed by the circuit established, which is used only for this communication. The great advantage of this type of networks is of course the guaranteed rate of data transmission. This is absolutly necessary in order to encode and decode the voice into digatal data and from it with a good quality. But the drawback is that this costs much more than, even when there is no data transmission (i.e. none is talking) the price for the connection must be paid.