Network Coding for Satellite Systems
RFC 8975
Internet Research Task Force (IRTF) N. Kuhn, Ed.
Request for Comments: 8975 CNES
Category: Informational E. Lochin, Ed.
ISSN: 2070-1721 ENAC
January 2021
Network Coding for Satellite Systems
Abstract
This document is a product of the Coding for Efficient Network
Communications Research Group (NWCRG). It conforms to the directions
found in the NWCRG taxonomy (RFC 8406).
The objective is to contribute to a larger deployment of Network
Coding techniques in and above the network layer in satellite
communication systems. This document also identifies open research
issues related to the deployment of Network Coding in satellite
communication systems.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Research Task Force
(IRTF). The IRTF publishes the results of Internet-related research
and development activities. These results might not be suitable for
deployment. This RFC represents the consensus of the Coding for
Efficient Network Communications Research Group of the Internet
Research Task Force (IRTF). Documents approved for publication by
the IRSG are not a candidate for any level of Internet Standard; see
Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8975.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
Table of Contents
1. Introduction
2. A Note on the Topology of Satellite Networks
3. Use Cases for Improving SATCOM System Performance Using Network
Coding
3.1. Two-Way Relay Channel Mode
3.2. Reliable Multicast
3.3. Hybrid Access
3.4. LAN Packet Losses
3.5. Varying Channel Conditions
3.6. Improving Gateway Handover
4. Research Challenges
4.1. Joint Use of Network Coding and Congestion Control in
SATCOM Systems
4.2. Efficient Use of Satellite Resources
4.3. Interaction with Virtualized Satellite Gateways and
Terminals
4.4. Delay/Disruption-Tolerant Networking (DTN)
5. Conclusion
6. Glossary
7. IANA Considerations
8. Security Considerations
9. Informative References
Acknowledgements
Authors' Addresses
1. Introduction
This document is a product of and represents the collaborative work
and consensus of the Coding for Efficient Network Communications
Research Group (NWCRG); while it is not an IETF product and not a
standard, it is intended to inform the SATellite COMmunication
(SATCOM) and Internet research communities about recent developments
in Network Coding. A glossary is included in Section 6 to clarify
the terminology used throughout the document.
As will be shown in this document, the implementation of Network
Coding techniques above the network layer, at application or
transport layers (as described in [RFC1122]), offers an opportunity
for improving the end-to-end performance of SATCOM systems.
Physical- and link-layer coding error protection is usually enough to
provide quasi-error-free transmission, thus minimizing packet loss.
However, when residual errors at those layers cause packet losses,
retransmissions add significant delays (in particular, in
geostationary systems with over 0.7 second round-trip delays).
Hence, the use of Network Coding at the upper layers can improve the
quality of service in SATCOM subnetworks and eventually favorably
impact the experience of end users.
While there is an active research community working on Network Coding
techniques above the network layer in general and in SATCOM in
particular, not much of this work has been deployed in commercial
systems. In this context, this document identifies opportunities for
further usage of Network Coding in commercial SATCOM networks.
The notation used in this document is based on the NWCRG taxonomy
[RFC8406]:
* Channel and link error-correcting codes are considered part of the
error protection for the PHYsical (PHY) layer and are out of the
scope of this document.
* Forward Erasure Correction (FEC) (also called "Application-Level
FEC") operates above the link layer and targets packet-loss
Show full document text