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1. Top results related to forward error correction tutorial

   • Forward Error Correction in Computer Networks

     1. Using Hamming Distance :

     2. Using XOR :

     3. Chunk Interleaving :

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   • Forward error correction in .NET

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     Answered Sep 17, 2010 · 3 votes

     If you have free C++ libraries why don't you try to build CLI wrapper around them?

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   • When is forward error correction a good idea for packets?

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     Answered Feb 12, 2009 · 5 votes

     I think it's useful for some applications like Voice (VoIP), where you want to avoid errors, and where you never want stop (to retransmit a NAKed packet) and wait (until it's retransmitted).

     So it might be implemented on top of the Real-time Transport Protocol flavour of UDP.

     Wouldn't it be terrible for latency?

     Are you asking whether forward error correction increases end-to-end delay? If so, I think the answer is "no", but it does increase the needed bandwidth.

     I believe you always already need some latency, to avoid jitter; so for example, you might say "let's delay the whole voice channel by 200 msec, so any/every packet can take from 0 to 200 msec to cross the internet, and be reassembled and sent through the D-to-A converter at the other end."

     Given those numbers, then having no forward error correction might mean that, in each 200 msec period, you send 10 packets each containing 20 msec of data ... and if one is lost, then that's a gap (a glitch) at the other end.

     Whereas, having some forward error correction might mean that, in each 200 msec period, you still send 10 packets ... each packet contains 20 msec of data, plus 10 msec of data that's already been transmitted in another packet (or, maybe you send 30 packets instead of 20). Then, if any single packet is lost, the data which it carried was delivered redundently (half in each of two other packets), which avoids any glitch in the decoded output.

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   • Error detection and error correction algorithm

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     Answered Sep 06, 2011 · 1 votes

     Here is an attempt with some ideas pinched from http://en.wikipedia.org/wiki/Frame_Relay.

     Start off each 64-bit chunk with a fixed header of 01110. Where you have more header info (e.g. sequence number or alternating bit flag, checksum...) you can probably arrange that the bit-pattern 01110 never appears. For arbitrary data, replace any occurrence of 0111 with 01111 - meaning that the effective data rate now depends on the underlying data. Have the provider of data to this layer make sure the data is pretty much random, e.g. by applying a http://en.wikipedia.org/wiki/Randomizer. I think your total data loss here is about 6 bits, which fits with the 6 bits necessary to describe a shift of 0..63.

     In the receiver, look for 01110 to mark the true start of the chunk. If you do not see exactly one such pattern, you know that the chunk has been garbled. I think it takes at least a two-bit error to both destroy an existing 01110 and produce a fake one.

     Garbles that cause chunk misalignment don't look like typical bit garbles, so CRC error rate calculations won't apply out of the box. I would include a non-CRC checksum in each chunk - perhaps a check calculated mod 31 or mod 961 so as to avoid the forbidden 5-bit pattern 01110, although depending on what abuts this you may need to be more restrictive. The chance of an error not being detected would then be about 1 in 31 or 1 in 961, with no particular guarantee about all single errors, unlike polynomial CRC.

     I don't think you have enough space to do per-chunk error correction sensibly, but you could include N error correction chunks after every M ordinary chunks, using e.g. SECDED applied down the columns. You might have e.g. 57 data-bearing chunks and then 6 error correction chunks, treating each payload bit position as bearing 57 data bits and then 6 checksum bits. This should work well if errors tend to corrupt all or none of a single chunk e.g. by causing chunk realignment to fail.

     after comment -

     EDIT

     OK, with one continuously transmitting message you have less bandwidth but relatively more cpu. Two things come to mind:

     1) Given any sort of checksum or other constraint on the message you can achieve some limited error correction by e.g. considering all single bit errors, flipping a bit of the received message, and seeing if the checksum now works.

     2) A message can be checked to see if complies with the bit-stuffing scheme suggested above by looking at only a 5-bit window passed over the message. I think this holds true even if you need to tweak it to work properly at the wraparound. This means that a message can be checked by a BDD of tractable size (Knuth 4A section 7.1.4). This means that you can count the number of 64-bit messages that comply with the bit-stuffing scheme and convert efficiently between message number and message (same section). So you can use this scheme without underlying randomisation or worst-case assumptions about the data to be sent, by just regarding it as an encoding of a number in the range 0..N (where N is to be computed via BDDs) and a 64-bit message. In fact, less elegantly, I think you could use dynamic programming with a 5-bit state instead of BDDs.

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   • Error Correction in Computer Networks

     This article covers in-depth details about Errors in Networking, their types, and methods of Error Correction. By the end of this, you will gain a clear understanding of Error Correction in Computer Networking. So, let us dive deep into Error Correction in Networking.

     Table of Content

     • Introduction
     • Table of Contents
     • What are Errors in Networking?
     • Types of Network Errors
     • Error Identification in Computer Network
     • Error Correction in Computer Networks
     • Conclusion

     Computer Networks play a crucial role in the secured and encrypted transmission of data over the internet. However, the data transfer over a network includes many complex processes that cause some flaws in the data transmission. These flaws are called Errors which can be of different types. Therefore, it is important to correct them for efficient data transmission.

     In this article, we will learn about the different methods of Error Correction in Computer Networks. We will also see the types of errors and methods to identify them. This will resolve all your doubts...

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2. Videos

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     Error Detection and Correction 3: Forward Error Correction

     Jun 7, 2016

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     Tutorial – Why Use Forward Error Correction (FEC)

     Oct 15, 2019

     11.4K Views

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     8:51

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     Forward Error Correction | Computer Networks | Part 2 | FEC error detection in computer networking

     Apr 6, 2020

     18.2K Views

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3. www.youtube.com › watchTutorial – Why Use Forward Error Correction (FEC) - YouTube

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   Oct 15, 2019 · The tutorial video explains why FEC is needed at higher data rates. It sheds light on the implications of FEC for the bit error rates.: Watch the complete we...

   • Video Duration: 3 min
   • Views: 11.4K

   • Author: Keysight Technologies, Inc.

4. www.tutorialspoint.com › forward-error-correction-fecForward Error Correction (FEC) - Online Tutorials Library

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   Jun 27, 2020 · Forward error correction (FEC) is an error correction technique to detect and correct a limited number of errors in transmitted data without the need for retransmission.

5. www.geeksforgeeks.org › forward-error-correctionForward Error Correction in Computer Networks - GeeksforGeeks

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   Jun 4, 2020 · Solving GATE Previous Year's Questions (PYQs) not only clears the concepts but also helps to gain flexibility, speed, accuracy, and understanding of the level of questions generally asked in the GATE exam, and that eventually helps you to gain good marks in the examination.

6. liquidsdr.org › doc › tutorial-fecTutorial: Forward Error Correction - liquidsdr.org

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   This tutorial will demonstrate computation at the byte level (raw message data) by introducing the forward error-correction (FEC) coding module. Please note that liquid only provides some very basic FEC capabilities including some Hamming block codes and repeat codes. While these codes are very fast and enough to get started, they are not very ...

7. www.youtube.com › watchLoRa/LoRaWAN tutorial 14: Forward Error Correction ... - YouTube

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   Oct 4, 2018 · If you like this video and want to support me, go this page for my donation Paypal or crypto addresses:https://www.youtube.com/c/mobilefish/aboutThis is part...

   • Video Duration: 2 min
   • Views: 22.9K

   • Author: Mobilefish.com

8. www.cisco.com › c › enUnderstanding FEC and Its Implementation in Cisco Optics

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   May 13, 2022 · When the optical transceiver is operated in a Cisco host platform, the FEC is enabled by default based on the optical module type that the host software detects (See this downloadable table) 4. In the vast majority of cases, the FEC implementation is dictated by the industry standard that the optic type supports.

9. People also ask

   What is forward error correction (FEC)?

   • Forward error correction (FEC) is an error correction technique to detect and correct a limited number of errors in transmitted data without the need for retransmission. In this method, the sender sends a redundant error-correcting code along with the data frame. The receiver performs necessary checks based upon the additional redundant bits.

   Forward Error Correction (FEC) - Online Tutorials Library

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   What are error correcting codes for forward error corrections?

   • Error correcting codes for forward error corrections can be broadly categorized into two types, namely, block codes and convolution codes. Block codes − The message is divided into fixed-sized blocks of bits to which redundant bits are added for error correction.

   Forward Error Correction (FEC) - Online Tutorials Library

   www.tutorialspoint.com/forward-error-correction-fec

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   How to improve error-correction capability?

   • The error-correction capability of the code is dependent upon many factors, but is usually improved by increasing the amount of redundancy added to the message. The drawback to adding a lot of redundancy is that the communications rate is decreased as the link must be shared among the important data information as well as the redundant bits.

   Tutorial: Forward Error Correction

   liquidsdr.org/doc/tutorial-fec/

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   What are error-correcting codes?

   • Error-correcting codes can be classed as hard-decision or soft-decision codes. Hard-decision FEC is executed by a group of block codes that use fixed codewords and spacings. Soft-decision FEC is performed by convolutional codes that do not use fixed codewords sizes or spacings.

   Understanding FEC and Its Implementation in Cisco Optics

   www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/implementation-optics-wp.html

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10. opg.optica.org › abstractTutorial: Forward Error Correction for Optical Transmission ...

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