In this tutorial, we are going to learn about error correction in computer networks.
When data goes from the sender to the receiver, error correction codes are there to detect and correct problems.
Methods of Error Correction in Computer Networks:
There are two methods for correcting errors:
Backward error correction: When a backward mistake is identified, the receiver requests that the sender retransmit the entire data unit.
Forward error correction: In this situation, the receiver employs an error-correcting code that corrects the errors automatically.
A single additional bit can identify but not correct the problem.
To rectify faults, one must first determine their specific location. If we want to calculate a single-bit error, for example, the error correcting code will figure out which of the seven bits is incorrect. We’ll need to add some extra unnecessary bits to accomplish this.
Error Correction in Computer Networks Using Hamming Code:
To generate d+r, we add an information of ‘d’ bits to the superfluous bits ‘r’. Each of the (d+r) digits has a decimal value given to it. The ‘r’ bits are there at locations 1,2,…..2k-1. The parity bits are adjusted at the receiving end. We determine the position of an error by the decimal value of the parity bits.
Error Correction in Computer Networks Using XOR :
The exclusive OR approach is very important since it allows re-building the data items. When we apply the XOR property to N data items, we can replicate any of the data items P1 to PN by XORing all of the items and get the replacing the with the result of the preceding operation (R). This technique separates a packet into N chunks. Then we do the exclusive OR of all the chunks, followed by the sending of N+1 chunks. If a chunk is lost or corrupted on the receiver side, it can be rebuilt.
Error Correction Using Chunk Inter-leaving :
Each data packet contains several chunks in this method. The data is there horizontally, chunk by chunk but vertically, the chunks are together to form packets. Because each packet contains a chunk from several original packets. If a packet is lost, only one chunk of each packet is lost, which is normal in multimedia communication. At the receiver, a few small chunks may be missing. Each packet may afford to have one chunk missing since we cannot permit all chunks from the same packet to be missing.