Network Coding Research Group

Document Charter Coding for efficient NetWork Communications Research Group RG (nwcrg)
Title Network Coding Research Group
Last updated 2014-11-13
State Approved
RG State Active
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The objective of the Network Coding Research Group (NWCRG) is to research
Network Coding principles and methods that can benefit Internet communication.
One goal of the NWCRG is to gather the research results and posit the open
questions related to Network Coding in order to develop practical applications
of Network Coding that improve Internet communication. Another goal is to
gather information on the existing practical implementations of Network Coding,
distill common functionalities and propose a path to standardization of Network
Coding-enabled communication.


Network Coding is a technique that can be used to improve a network’s
throughput, efficiency, latency, and scalability, as well as resilience to
partition, attacks, and eavesdropping, as compared to traditional methods. In
Network Coding, these benefits are achieved by exploiting computing and storage
at endpoints and intermediate nodes. It has been shown that Network Coding is
necessary to achieve maximum information flow in a network, based on principles
of Information Theory.

The field of Network Coding has enabled advances in communication areas
including wireless networks, content distribution and peer-to-peer design.

Interest Areas

The following sections outline some of the interest areas of the NWCRG.

Network Coding Research

The NWCRG work in this area will consider the existing theoretical and
experimental results and will identify the areas in Internet communication that
can benefit from Network Coding. Examples of such results are quantitative
analytical bounds and experimental performance gains. The outcome of this work
will be recommendations on promising Network Coding methods and their
associated context. The NWCRG will work in collaboration with other IRTF groups
on common research topics such as congestion control, DTN, SDN.

The following are topics of interest in Network Coding research:

* Performance and efficiency. Determine expected performance gains, including
multi-layer composition; computational complexity of coding; NWC network
resource allocation; signaling overhead; tradeoffs between techniques such as
block and sliding window coding.

* Application layer. Interactions between Network Coding and
application-specific coding (such as video layers encoding); Joint source and
network coding; combining network coding with content/information-centric

* Implications to data link layer. Interaction between Network Coding and data
link protocols, including satellite links (regenerative coding), challenged
wireless links (high loss, intermittent), optical links (replacing
circuit-based redundancy with Network Coding).

* Security, privacy, robustness to attacks. Security implications and benefits;
interaction of network coding and encryption, overhead; fundamental security
properties; anonymity and robustness to blocking.

* Network Coding implications on pricing and economics. How to price services:
on network usage or information rate; incentives to code across flows.

Practical Applications of Network Coding

The NWCRG work in this area will consider the known practical implementations,
analyze their architecture and identify best/common approaches for the
promising Network Coding methods researched above. The NWCRG will then propose
a framework for Network Coding-enabled communication and a path to Network
Coding standard protocols. The NWCRG will identify the relevant IETF areas and
propose draft contributions to specific IETF Working Groups. In case no IETF WG
is found appropriate for a specific Network Coding protocol, the NWCRG will
propose the formation of a new IETF WG.

The following are topics of interest in Network Coding practical application:

* Architectural considerations. control plane, routing/forwarding plane and
transport. Architectural requirements in large-scale, heterogeneous networks;
relationships between data transport, control, forwarding planes and data layer.

* End-to-end vs. hop-by-hop. Stateful operation of Network Coding intermediate
systems; richer interface requirements between routing and transport layers.

* Intra-flow and inter-flow Network Coding. Tradeoffs between performance gains
and complexity of operation.

* Service paradigms (best effort, time-bounded utility). Service reliability
levels using Network Coding’s proactive and reactive reliability mechanisms.

* Common encoding algorithms, service descriptions, and packet formats. While
Network Coding will be applied in different aspects of network operation, there
may be utility in common encoding (and decoding) algorithms, service
descriptions, and packet formats.

IPR Statement

A lot of intellectual property exists in the general area of coding, and
specifically, Network Coding. Research results that are covered by intellectual
property rights can of course be brought to and discussed in the NWCRG.
However, the IRTF requires participants to disclose the existence of IPR in a
timely manner when they bring such contributions to the NWCRG; please see for details.

One desired outcome of the NWCRG is to transition research results in Network
Coding into widely used Internet protocols and technologies. Experience has
shown that this transition is much easier when research results under IPR are
available without the need to obtain licenses or pay fees. This is why RFC 5743
prefers “that the most liberal terms possible be made available for
specifications published as IRTF Stream documents. Terms that do not require
fees or licensing are preferable. Non-discriminatory terms are strongly
preferred over those which discriminate among users.” When publishing its
results in RFC form, the NWCRG therefore strives to make recommendations that
follow this principle.