Different types of line coding techniques in computer network
Answers
Explanation:
In addition to pulse shaping, there are a number of useful line codes that we can use to help reduce our errors or to have other positive effects on our signal.
Line coding consists of representing the digital signal to be transported, by an amplitude- and time-discrete signal, that is optimally tuned for the specific properties of the physical channel (and of the receiving equipment). The waveform pattern of voltage or current used to represent the 1s and 0s of a digital signal on a transmission link is called line encoding. The common types of line encoding are unipolar, polar, bipolar and Manchester encoding.
Line codes are used commonly in computer communication networks over short distances.
There are numerous ways digital information can be coded onto a transmission medium. Some of the more common include:
Line code table.gif
Each of the various line formats has a particular advantage and disadvantage. It is not possible to select one, which will meet all needs. The format may be selected to meet one or more of the following criteria:
• Minimize transmission hardware
• Facilitate synchronization
• Ease error detection and correction
• Minimize spectral content
• Eliminate a dc component
The Manchester code is quite popular. It is known as a self-clocking code because there is always a transition during the bit interval. Consequently, long strings of zeros or ones do not cause clocking problems.