In this tutorial you are going to learn about Longitudinal Redundancy Check in Computer Networks. You will learn about various types of error detection methods, understand LRC and its performance.
Introduction
Longitudinal Redundancy Check (LRC) is a type of error detection code that is commonly used in computer networks to detect errors in data transmission. It works by adding a redundancy value to the data being transmitted, which can be used to check the integrity of the data once it has been received.
LRC is a simple form of error detection that is based on the concept of parity. In parity error detection, a value called a parity bit is added to the data being transmitted. The parity bit is chosen such that the number of ones in the data and the parity bit is always even (or always odd). When the data is received, the parity of the data is checked to see if it is still valid. If the parity is not valid, then an error has occurred during transmission.
LRC is similar to parity error detection, but it uses a different approach. Instead of adding a single parity bit, LRC uses a set of parity bits that are calculated based on different subsets of the data. This redundancy value is appended at the end of data. These parity bits can be used to detect errors in any one of the subsets of the data.
Example
To understand how LRC works, let's consider a simple example. Let's say we want to transmit the data "1011" using LRC. We can split this data into two subsets: "10" and "11". We then calculate the parity bit for each subset: the parity of "10" is 1 and the parity of "11" is 0. We then append these parity bits to the data, resulting in the transmitted data "101100".
When the data is received, the same process is repeated to calculate the parity bits for the subsets of the received data. If the calculated parity bits match the ones that were appended to the original data, then the data is assumed to be error-free. If the calculated parity bits do not match, then an error has occurred and the data must be retransmitted.
Advantage and Disadvantage
One advantage of LRC is that it can detect errors in any one of the subsets of the data. This makes it more robust than simple parity error detection, where an error in any part of the data will go undetected. Additionally, LRC is simple to implement and does not require a large amount of computational resources.
However, there are also some disadvantages of LRC. One major disadvantage is that it can only detect errors, not correct them. This means that if an error is detected, the data must be retransmitted, which can lead to increased overhead and decreased throughput in the network. Additionally, LRC can only detect errors in one subset of the data, so if an error occurs in multiple subsets, it will not be detected.
Conclusion
Longitudinal Redundancy Check (LRC) is a type of error detection code that is commonly used in computer networks to detect errors in data transmission. It uses a set of parity bits to provide redundancy in the data, which can be used to check the integrity of the data once it has been received. LRC is a simple and efficient technique but it can only detect errors, it is not able to correct them, this could lead to some drawbacks and decreased throughput in the network. Overall LRC is used in many communication systems like Point to Point Protocol and HDLC where it has proven to be a reliable technique for detecting errors.
This tutorial on Longitudinal Redundancy Check in Computer Networks is contributed by Rajnish Kumar. If you like TheCode11, then do follow us on Facebook, Twitter and Instagram.
