# Switching network

The term **switching network** ( English : *combinational circuit* or *combinatorial circuit* ) is used in technical computer science . It describes a network of elementary logical switching elements ( gates ), which are nowadays technically implemented with transistors (several transistors for each gate ) and can theoretically be investigated with the help of switching algebra .

## General

A switching network represents the circuit-related display medium of a Boolean function . Each Boolean function can be represented by means of a switching network. Conversely, not all properties (e.g. time delay) of a switching network that was built up from electronic components can be represented by a Boolean function.

The switching network links Boolean input variables (summarized in the input vector **x** ), which can assume the values 1 or 0 (true or false), using a Boolean function ( **f** ). The variable values for the switching network are represented by voltage values on the input lines (for example 5 V for 1 and 0 V for 0). The output lines then have values (output vector **y** ) that are dependent on the input values and the Boolean logic function.

The picture shows a switching network that realizes the Boolean function y = f (x).

## properties

If a value **x is present** at the input of the switching network at a point in time , then the value **y** at the output depends on **x** only at this point in time . The time delay is neglected on the logical level, since a switching network does not contain any storage elements ( flip-flops ). In a switching network, internal states from outside cannot be differentiated.

## classification

- A
*switching network*is implemented by a logic circuit . -
Switching chains are
*switching networks*connected in series using transition vectors . - If you add time-delayed feedback to a switching network, you get a switching mechanism (which is no longer called a switching network).
- The generic term for switching mechanism and
*switching network*is switching system - Logical switching elements: non-gates , AND / NAND gates , OR / NOR gates , XOR / XNOR gates .
- A switching circuit is not a
*switching network*, although a*switching network*can be implemented by a switching circuit.

## literature

- Hans Liebig, Stefan Thome:
*Logical design of digital systems.*3rd edition, Springer, Heidelberg 1996, ISBN 3-540-61062-6 - Wolfram Schiffmann, Robert Schmitz:
*Technical computer science 1. Basics of digital electronics.*5th edition, Springer, Berlin 2003, ISBN 3-540-40418-X - Heinz-Dietrich Wuttke, Karsten Henke:
*Switching systems - a machine-oriented introduction.*Pearson Studium, Munich 2003, ISBN 3-8273-7035-3