Interim Meeting Minutes
MIT Media Laboratory - September 19 2017

Attending in Person:
Brandon Williams 		Akamai
William (Bill) Sears		Akamai
Shirley Shi			CodeOn
Cedric Westphal		Huawei					
Steve Blumenthal		Speedy Packets
David Oran			ICNRG Chair
Victor Firoiu			BAE
Marie-Jose Montpetit		NWCRG Co-Chair
Attending Online:
Vincent Roca			NWCRG Chair
Cedric Adjih			INRIA
Michael Welzl			ICCRG Chair
Dave Coombs			Independent Consultant
Josu Bilbao			Ikerlan (and Webex organizer)
Belkacem Teibi 		INRIA
Goiuri Peralta			Universidad del País Vasco
Kyle Schomp			Case Western University
Samah Ghanem		Independant
Stefan Erl 			DLR
Tomaso DeCola		DLR

Minutes as per agenda items

1. Working group status and update of the Charter

The charter update is motivated by the need: (1) to align the charter on directions already taken during the past few years; and (2) to develop strategic orientations so that the group can make quick progress on key aspects. Milestones will be worked on along with the charter update and presented following the discussions.

2. Special Presentation: Network Coding with Satellite Protocols – DLR

(Slides to be uploaded on the wiki)
Essentially COPE over satellite (COPE was over the MIT wifi network) for two-way relay satellite communications. The goal is to improve bandwidth usage: send 3 packets sent instead of 4. There is no erasure correction as the satellite links are implicitly assumed reliable
Underlying work (http://onlinelibrary.wiley.com/doi/10.1002/sat.1223/full) goes into all the technical aspects associated to its operational deployment.

3. Research fundamentals and applied research on Coding

3.1. Research challenges

In general, identifying research challenges is a good way to structure work on the various topics/use-cases considered in NWCRG.

The group identifies two types of challenges:
1.	Adoption challenges: why should we use coding? How different is it from PHY layer coding (we need to answer once and for all if possible to this argument)? How different is it from upper layers (within application, e.g., via robust video coding)? And congestion control which is often presented as an adoption challenge (see below);
2.	Congestion Control. Losses are sometimes appropriate, sometimes not. How to deal with them? Other challenges exist, but this one is perhaps one of the main.

 3.2. Improved or new codes, encoding/decoding optimizations
 
FPGA implementations could be favorable to improve decoding speed (Dave O. 7x). Using GPU could lead to gains but it usually create major delay issues (maybe in delay insensitive applications).
Open question: we usually try to optimize the implementation of an existing code, what about designing codes that are GPU friendly? Does it make sense to take the problem the other way round?

 3.3. Performance evaluation of network codes: how to?

Most Raptor/Fountain codes patents are expiring, opening new opportunities.
Long discussion that also included issues of licensing when comparing codes that have IPR
(MJM note: licensing issues are not just the price, but also the scope/limitations of the license with some razor thin applicability).

Presentation from Vincent (no slides).
We need an agreed methodology to compare codes from various viewpoints is (1) often non trivial and (2) useful. VR agrees to bootstrap the activity but participation from others having experience on the domain is more than welcome.

3.4. Generic API

Presentation from Vincent (Slides to be uploaded on the wiki)
Wide interest for it as a first step to facilitate the experimentation of various codes or codecs.
Comment from Dave O: more a “PI” (protocol interface) than an API (application programming interface).
Vincent comment: designing a code API is “relatively” easy and can be done quickly (several of us have the needed experience), agreeing on protocols, packet formats, etc. is fine but probably a longer term objective.

3.5. Specifying new Network Coding Schemes

Presentation from Vincent (Slides to be uploaded on the wiki)
Presentation on what is expected to write an I-D describing a Network Coding Scheme. The existing RLC FEC Scheme I-D (TSVWG group) can be used as an example for other codes.
Note to all: RLNC draft is still missing, Tetrys draft is not updated.

4. Network Coding Research Use Cases

4.1. NC and satellite

To all interested: Please contribute to the existing Kuhn/Lochin draft.
Need to assess other interest in the community, e.g., any available info on the Intelsat/iDirect project at MIT?

4.2. NC and ICN

Interest was discussed during IETF’99. Cedric W. will take the lead.
Dave O. suggests a joint ICNRG/NWCRG meeting when there is progress.

4.3. Long Delay Networks/DTN

(No input)

4.4. CDN

Short discussion on if Akamai could be interested.

4.5. Storage

No discussion but MJM to contact Prof. Daniel Lucani.

4.6. QUIC

Google is not represented but we assume Ian Swet will continue leading.

4.6. NC and robust communications for the enterprise and in industrial environments

Inputs from Josu (Ikerlan) on NC over powerline. Josu will lead (draft?).

4.7. NC and Congestion Control

Continuation of the morning discussion.
Presentation from Bill (Akamai) on their experience with BBR – notes to follow.
Need for a draft (MJM to lead).
A joint meeting with ICCRG is a possibility.

5. Presentation of ongoing projects related to our RG
Presentation from Dave Combs (Slides to be uploaded on the wiki).
Presents the pitfalls of implementing NC in industry. He supports common “API” and open/common CC approaches as companies/startups spend a lot of time/money on software integration and re-development.

6. Discussions

6.1. Leveraging the group to create new projects

Open Source Project:
Comment from Shirley - CodeOn: should the group become a software developing entity vs. a user of existing software?
IPR remains an issue.
Some agreement talk to the owners of NC software for easy access to software licensing for R&D (not just academia).
Dave O. mentions the H264 example that features an open source software codec of high quality, even if the domain is covered with patents.
Could IETF Hackathon help?

Other projects:
ICN and CC top contenders.

Discussion on interoperability (Victor F.):
Bill (Akamai): Maybe not the time yet.
Who would want multi-vendor solution for a technology implemented at both ends?
A draft on the requirements?

6.2. How to tryout NC in a project?

Simulation under NS3 could be one idea.

7. How do we work better together?

7.1. Use of the wiki for meeting audio recordings, minutes, references, etc.
(Wiki to be updated accordingly)

https://trac.ietf.org/trac/irtf/wiki/nwcrg
Link to IETF materials.

7.2. Use of Google Docs to foster joint document development to meet the proposed milestones

Except for drafts as it is not the most appropriate tool.

7.3. Interim meetings/post IRTF meetings

One interim meeting per year seems reasonable.
Co-locate with a NC Conference?
Maybe too theoretical and may not encourage so much current NWCRG contributors to join. 
Boston is a good location: critical mass of participants

8. IETF’100 meeting preparation (Singapore)

Dave O. (but will be busy) and Cedric W. will be there – others TBD.
Dave O. comments that we do not need to have to a meeting at each IETF.