Switching Techniques

Types: Message, Packet, Pipelining Switching Technique

Circuit Switching

In circuit switching network resources (bandwidth) is divided into pieces and bit delay is constant during a connection. The dedicated path/circuit established between sender and receiver provides a guaranteed data rate. Data can be transmitted without any delays once the circuit is established.
Telephone system network is the one of example of Circuit switching. TDM (Time Division Multiplexing) and FDM (Frequency Division Multiplexing) are two methods of multiplexing multiple signals into a single carrier.

• Frequency Division Multiplexing : Divides into multiple bands
  Frequency Division Multiplexing or FDM is used when multiple data signals are combined for simultaneous transmission via a shared communication medium.It is a technique by which the total bandwidth is divided into a series of non-overlapping frequency sub-bands,where each sub-band carry different signal. Practical use in radio spectrum & optical fiber to share multiple independent signals.
• Time Division Multiplexing : Divides into frames
  Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line. TDM is used for long-distance communication links and bears heavy data traffic loads from end user.
  Time division multiplexing (TDM) is also known as a digital circuit switched.

Formulas in Circuit Switching :

Transmission rate = Link Rate or Bit rate / 
                    no. of slots = R/h bps
Transmission time = size of file / 
                    transmission rate 
                 = x / (R/h) = (x*h)/R second
Total time to send packet to destination =
               Transmission time + circuit setup time 

Question on Circuit switching –
These questions will help you understand circuit switching