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We discussed this issue of length vs. insertion loss during the call. In my mind, one primary issue is the level of detail and decisions taken during the study group. Refining the objectives, of course, spans both phases of the project (task force and study group). It seems to me, premature to have a detailed channel/loss discussion (which really would get us into some specific PHY proposals) during study group, when we are trying to show that there are some technically feasible, economically feasible proposals out there with broad market potential and unique identity. For the market potential part, I think the distance is the important parameter. However, I also recognize that the rubber meets the road on technical feasibility the insertion loss that goes along with that distance is going to matter. But, to fully specify that insertion loss, we have to get into a level of detail (specifying frequencies, for example) that is really task force work, and therein lies the problem. SO, I looked into the history of 802.3bj to get some guidance, and found that when the group was in study group, they kept the objective in terms of distance, and then later changed it to a corresponding insertion loss during task force, when that became clear. See: the last study group report for what became 802.3bj: http://www.ieee802.org/3/100GCU/public/jul11/0711_100GBCU_close_report.pdf And, when they were changed: http://www.ieee802.org/3/bj/public/mar12/index.html and http://www.ieee802.org/3/bj/public/mar12/minutes_01a_0312_unapproved.pdf As a result, I would suggest going with distances that correspond to the market needs during study group. -george From: Marek Hajduczenia [mailto:marek.hajduczenia@xxxxxxxxx] Dear Mehmet, Please see inline Marek From: Mehmet Tazebay [mailto:mtazebay@xxxxxxxxxxxx] Dear Marek, Thank you for your quick comments. Here is my response to some of the points that you’ve made 1. The objective (e) was intended to go with (g) but since we are considering to remove it then, we need to provide a cable reach for automotive environment and industrial environment (as suggested by Brad) 2. The dB requirement in (g) was intended to make it independent of the topology which is not clear at the moment. In principal, I agree that we should provide the distance goal. [mh0626] I’d think that both might be needed to make sure that the TF in the future knows what to measure the proposals against. 3. (h) is a place holder for now. It was in the original text “faster than 1000BASE-T” but the proposed requirement is much faster. I expect to have some clarification after the wake-up requirement presentation in July-2012 plenary. Then, this goal will have proper wording. [mh0626] A number would be very welcome, to provide a clear target to measure the proposal against. Then you could skip discussions on faster or slower, since these are very relative terms. 4. (i) was discussed yesterday. This is also a generic objective as the requirement on energy efficient operation is not clear yet. We need to have a discussion whether 802.3xx protocol will meet the requirement for RTPGE or not. [mh0626] You could make it into an optional objective and study details once the channel model is available and TF understands more on how PHY is going to operate. 5. There are currently different EMC requirements for different OEMS. In my humble opinion, we need to see a unified requirement which, I believe, is being collected to be presented to the study group. Therefore, I’d like to keep this under discussion. Many thanks for your inputs. Regards, -Mehmet From: Marek Hajduczenia [mailto:marek.hajduczenia@xxxxxxxxx] Dear Mehmet and colleagues, Even though I have not been attending the calls (sorry, overlap with other activities), I have some thoughts on the objectives, wording and what is still missing. I attach the file with some embedded comments. Hope that helps Regards Marek From: Mehmet Tazebay [mailto:mtazebay@xxxxxxxxxxxx] Dear Colleagues, Thank you for your participation to yesterday’s Telco. It was very productive with lots of good discussion. Please find the attached RTPGE preliminary objectives with the group’s feedback. I welcome the inputs and further discussions on the reflector. Regards, -Mehmet |