I think this brings up four different issues.
- Whether we think we should have objectives for just one or more than one solution for a given speed. I think this should be determined in Study Group as it would affect the CSD’s.
(Robert assumed just one in the suggestions below and I think I agree with that).
- Whether we have objectives for both 200 and 400G. I think this should be determined in Study Group as it would affect the CSD’s. I think we should have a 200G objective (and the
objective should be for a single fiber pair).
- Do we specify the number of fibers for the speed in the objectives. I think this does affect the CSD’s and would prefer to state 4 fiber pairs for the 400G objective.
- Whether we will allow new FEC/Logic. (i.e. PHY versus physical layer). We could leave that to Working Group but I think there will be a much stronger case for “Broad Market Potential”
is we use the existing FEC/Logic so I prefer having “physical layer specifications”.
Beth had an interesting analysis about the study group timing for the 100G per lane group that I think would apply to this group as well. It shows that the study group either has to wrap up its work in March (with the first task force
meeting in May) or wait until July (with a first task force meeting in Nov). My suggestion is that we target July and try to make the hard decisions in Study Group (i.e. have the more specific objectives).
From: Lingle, Robert L (Robert) [mailto:rlingle@xxxxxxxxxxxxx]
Sent: Saturday, December 30, 2017 6:33 AM
Subject: [802.3_NGMMF] what form for our objectives? please discuss
Happy New Year!
Please consider several options for the form of objectives that will be produced by the Study Group for “Next-Gen 200 & 400 Gb/s PHYs over fewer MMF pairs than Existing Ethernet Projects & Standards.” These differences arise from 1) different
forms of objectives in recent projects plus 2) whether we should choose the number of fiber pairs for a speed in Study Group vs. Task Force. (I only included single-pair and even numbers of fiber pairs, since those are the practical choices.) Historically
we have not specified that a specific grade of MMF was required to meet the objective. I show a 400 Gb/s example below, but the options would apply to a 200Gb/s objective as well.
Q. What are the pro’s and con’s of these options? Which do you prefer?
- Define a 400Gb/s PHY for operation over fewer than 16 pairs of MMF with channel lengths up to at least 100 m.
- Define a 400Gb/s PHY for operation over (specify 1 vs. 2 vs. 4 vs. 8) pairs of MMF with channel lengths up to at least 100 m.
- Provide physical layer specifications which support 400Gb/s operation over fewer than 16 pairs of MMF with channel lengths up to at least 100 m.
- Provide physical layer specifications which support 400Gb/s operation over (specify 1 vs. 2 vs. 4 vs. 8) pairs of MMF with channel lengths up to at least 100 m.
Let us have a healthy discussion in advance of the 1/11 telecon, so we can begin to write down draft objectives.
Robert Lingle, Jr., Ph.D.
Acting Chair, IEEE 802.3 NGMMF Study Group
Director, OFS Systems & Technology Strategy
2000 Northeast Expy | Norcross, GA 30071