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Hey John You make a good point which actually alters my thinking on this topic. Using the word “baseline” might be what needs to be questioned. By technical definition, I take baseline to mean: “information that is used as a starting point by which to compare other information.” So if I was designing a network (not an EPoC channel) for operation, I would design it to support “optimal network performance” for all service in support of an analog, QAM, DOCSIS and an EPoC load at a prescribed level, distortion performance and temperature. That would be the point I would know testing could demonstrate compliance much like is done with FCC testing or network proof of performance. That treats performance in all network configurations the same whether it is a passive network or N+”x” (pick a number) an presents a measurable norm. If the network operates below that level, then performance impact should be expected to the point where operation effectively ceases because of noise and other outside factors. If the network operates above that point, then better performance should be expected with the caveat that there is a point of diminishing returns where composite distortions take a significant toll and can render the network useless. In short, the “bathtub curve.” Moran (Motorola) has demonstrated time and again how many cable networks are not operated properly in the “bathtub curve” for optimal network performance and that is without EPoC in the picture. That can’t be done solely by establishing a baseline of operation of a network for analog, QAM and DOCSIS. It has to be done with EPoC factored into the design equation of the network from the start and not solely as the addition of an EPoC channel. In a deployed fully designed and engineered network, without concern for what the actual top end frequency currently is, where an EPoC channel is added then the expected result should be that all service levels will be lowered to operate under the power constraints of the equipment whether passive or N+”x”. That may, in simple fact, mean the operator has to remove and install lower tap plates to provide a specified level in the customer home who is not involved with EPoC at all. Based on how the network was originally designed and engineered that doesn’t guarantee that FCC yearly performance testing can be met. As the operators know, that has its own implications. So is the purpose of Objectives #3 & 4 to provide a “baseline” channel operation for EPoC or is it to establish an “optimal network performance for all deployed services” when EPoC is in the carriage? Considering the operators (Noll et al) already invoked the “Network Hippocratic” Oath: “First, do no harm to my deployed services…” then Objective 3 directly and Objective 4 because it relies on #3 do not, in my view, meet the premise. So I might agree to wording similar to yours if the objectives stipulate that the addition of an EPoC channel, at the stated data rates and BER performance, can be met when there is no performance impact to other services in an optimal network design which becomes the baseline against which all performance is measured: positive or negative. So making the objective reflect that statement allows for directly developing salient criteria for measuring the success or failure of EPoC in a coax network. How do we state that in the objective? Best regards Tom From: John Ulm [mailto:julm@xxxxxxxxxxxx] Hi Tom, Like Kevin, I'm not sure I agree with your proposed changes. We want EPoC to be able operate in conditions worse than baseline, albeit at lower data rates. So the baseline plant conditions is NOT a minimum for operators. Maybe we can word smith it to say "set the minimum plant conditions for baseline data rate operation". However, I'm in favor of keeping the wording of Objective 3 as it is. Similarly, I don't think the word "ideal" is appropriate. Taking an off the wall example, we could have a passive plant with 3GHz taps in it that gives us a boat load of spectrum. This is enough spectrum to achieve 10Gbps even though plant conditions are far from ideal. I don't think "ideal" adds to Objective 4 so we shouldn't put it in. On Tue, May 8, 2012 at 2:28 PM, Ron Wolfe <rwolfe@xxxxxxxxxx> wrote: Hi Kevin, Sorry I didn’t get a chance to say hello a couple of weeks ago during the Q&A session. Next time … To me, the notion of “ideal” should in fact be attainable, however, it is very unlikely that anything defined as ideal would be sustainable over time. Certainly ideal conditions would not be anticipated outside of a lab environment. Ideal conditions would represent that environment where a system performance could reasonably be expected to perform to its maximum throughput. I think you and Tom are actually saying the same thing when you consider that it is ideal conditions that represent the conditions that permit maximum performance. I think either works, though to me “ideal” was a concept I grasped immediately as representing closely controlled lab conditions, albeit with the understanding that someone else might just as immediately grasp a completely different meaning. Regards, Ron From: Noll, Kevin [mailto:kevin.noll@xxxxxxxxxxx] Thanks for the comments, Tom, especially the reminder about the 1/10Gbps. I'll probably stick with "baseline" for now because it better conveys a multi-dimensional thought (plant conditions are very multi-dimensional). Similarly, "ideal" implies unobtainable. Could you suggest language that leaves room for obtainability? --kan-- -- Kevin A. Noll, CCIE Time Warner Cable From: Tom Staniec <staniecjt@xxxxxxxxx> Kevin I couple of quick comments: slide #5 objective 3 – wording change: Develop a channel model describing a typical real-world coaxial cable plant to set the minimum baseline plant condition for the EPoC specification. Slide #6 objective 4: wording change to sub-bullet 3: a data rate higher than the baseline data rate of 1 Gb/s and up to 10 Gb/s when transmitting in assigned spectrum in ideal channel conditions that permit; Remove red words – add blue words and symbols To me the first statement sets the expectation of the operator of what a “minimum” performing coax plant must do while telling the vendor the EPoC equipment must operate to the desired performance in a minimum plant condition. The second statement indicates in an “ideal” (ie performance that <far> exceeds minimum baseline plant conditions) plant condition the expectation is performance above 1 Gb/s up to 10 Gb/s with measured performance exceeding BER and other standards currently not defined. Regards Tom From: Noll, Kevin [mailto:kevin.noll@xxxxxxxxxxx] I have updated the objectives based on our last conference call and comments received since then. I have attached the deck as a PDF. Please review and comment. --kan-- -- Kevin A. Noll, CCIE Time Warner Cable <="" p=""> |