Low Density Parity Check (LDPC) Staircase and Triangle Forward Error Correction (FEC) Schemes
RFC 5170
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RFC - Proposed Standard
(June 2008; No errata)
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Last updated |
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2015-10-14
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IETF
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No shepherd assigned
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IESG state |
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RFC 5170 (Proposed Standard)
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Consensus Boilerplate |
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Unknown
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Responsible AD |
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Magnus Westerlund
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Network Working Group V. Roca
Request for Comments: 5170 INRIA
Category: Standards Track C. Neumann
Thomson
D. Furodet
STMicroelectronics
June 2008
Low Density Parity Check (LDPC) Staircase and Triangle
Forward Error Correction (FEC) Schemes
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract
This document describes two Fully-Specified Forward Error Correction
(FEC) Schemes, Low Density Parity Check (LDPC) Staircase and LDPC
Triangle, and their application to the reliable delivery of data
objects on the packet erasure channel (i.e., a communication path
where packets are either received without any corruption or discarded
during transmission). These systematic FEC codes belong to the well-
known class of "Low Density Parity Check" codes, and are large block
FEC codes in the sense of RFC 3453.
Roca, et al. Standards Track [Page 1]
RFC 5170 LDPC Staircase and Triangle FEC June 2008
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 3
3. Definitions, Notations, and Abbreviations . . . . . . . . . . 3
3.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Notations . . . . . . . . . . . . . . . . . . . . . . . . 4
3.3. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 5
4. Formats and Codes . . . . . . . . . . . . . . . . . . . . . . 6
4.1. FEC Payload IDs . . . . . . . . . . . . . . . . . . . . . 6
4.2. FEC Object Transmission Information . . . . . . . . . . . 6
4.2.1. Mandatory Element . . . . . . . . . . . . . . . . . . 6
4.2.2. Common Elements . . . . . . . . . . . . . . . . . . . 6
4.2.3. Scheme-Specific Elements . . . . . . . . . . . . . . . 7
4.2.4. Encoding Format . . . . . . . . . . . . . . . . . . . 8
5. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2. Determining the Maximum Source Block Length (B) . . . . . 11
5.3. Determining the Encoding Symbol Length (E) and Number
of Encoding Symbols per Group (G) . . . . . . . . . . . . 12
5.4. Determining the Maximum Number of Encoding Symbols
Generated for Any Source Block (max_n) . . . . . . . . . . 13
5.5. Determining the Number of Encoding Symbols of a Block
(n) . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.6. Identifying the G Symbols of an Encoding Symbol Group . . 14
5.7. Pseudo-Random Number Generator . . . . . . . . . . . . . . 17
6. Full Specification of the LDPC-Staircase Scheme . . . . . . . 19
6.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.2. Parity Check Matrix Creation . . . . . . . . . . . . . . . 19
6.3. Encoding . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.4. Decoding . . . . . . . . . . . . . . . . . . . . . . . . . 21
7. Full Specification of the LDPC-Triangle Scheme . . . . . . . . 22
7.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 22
7.2. Parity Check Matrix Creation . . . . . . . . . . . . . . . 22
7.3. Encoding . . . . . . . . . . . . . . . . . . . . . . . . . 23
7.4. Decoding . . . . . . . . . . . . . . . . . . . . . . . . . 23
8. Security Considerations . . . . . . . . . . . . . . . . . . . 24
8.1. Problem Statement . . . . . . . . . . . . . . . . . . . . 24
8.2. Attacks Against the Data Flow . . . . . . . . . . . . . . 24
8.2.1. Access to Confidential Objects . . . . . . . . . . . . 24
8.2.2. Content Corruption . . . . . . . . . . . . . . . . . . 25
8.3. Attacks Against the FEC Parameters . . . . . . . . . . . . 26
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27
11.1. Normative References . . . . . . . . . . . . . . . . . . . 27
11.2. Informative References . . . . . . . . . . . . . . . . . . 27
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