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To: Mark Laubach who wrote (567)	6/14/1999 6:19:00 PM
From: Frank A. Coluccio	Respond to of 2347

Mark, I enjoyed reading your reporting on the DOCSIS/IEEE work. I posted the url from your message over in the Last Mile thread, asking for opinions, in case you are interested. While we're at it, I wouldn't mind having you critique my take on the validity of the GTE-AOL open access demo that was performed just recently. If you don't mind, it's posted in the ATHM Thread, at: Message 10111888 Regards, Frank Coluccio

To: Mark Laubach who wrote (567)	6/14/1999 7:38:00 PM
From: pat mudge	Read Replies (1) \| Respond to of 2347

Mark --- Thanks for your great response. Your explanation is amazingly clear and any misunderstanding on my part can be attributed to kinship with Winnie the Pooh. A few questions: 1) Would it be to a company's advantage to implement 1.2 specifications before the standard is set to avoid its 1.0 and 1.1 modems having to be replaced? 2) If so, would these 1.2-ready modems be software upgradable to any standards not yet set? 3) If 1.0 and 1.1 don't include S-CDMA modulations, is it possible for a S-CDMA chip to be certified? 4) If not, how would anyone using that technology pass 1.2 without first passing 1.0 and 1.1? The kicker is that in order to have all cable modems use fragmentation on an upstream channel, the channel must only have DOCSIS 1.1 modems allocated to it, requiring that DOCSIS 1.0 modems be allocated to one or more other upstream channels. . . .If the delay/jitter requirements of the traffic mix require more control than a mixed channel provides, then the cable operator must allocate additional upstream channels and allocate the DOCSIS 1.0 modems out of the way of the DOCSIS 1.1 modems requiring the tighter bandwidth allocation management. I take this to mean time-sensitive traffic, including voice, will be given preferential treatment. If true, then I take it proprietary equipment without voice would operate at slower speeds. From CableLabs document: cablelabs.com "Interoperability testing, including creating test plans and procedures, will begin in April and will run through March of next year," said Rouzbeh Yassini, executive consultant to CableLabs and the head of the cable modem initiative. "We anticipate beginning certification waves for 1.1 in April 2000," Yassini added. He noted that DOCSIS 1.1 headend equipment also will be qualified on a similar schedule. DOCSIS 1.1 headends must support 1.0 and 1.1 modems and DOCSIS 1.1 modems must be able to act as a 1.0 modem when connected to a DOCSIS 1.0 headend. 5) If it's necessary to pass 1.1 before passing 1.2 --- and if 1.1 testing doesn't begin until April 2000 --- doesn't this push 1.2 further into 2000? . The S-CDMA mode of DOCSIS 1.2 requires that an additional 6-MHz upstream channel be allocated. The last I looked at the draft specification, TDMA and S-CDMA will not be mixed in the same upstream channel. If a cable plant has a mixture of "legacy" [<g>] DOCSIS 1.0 or DOCSIS 1.1 modems with DOCSIS 1.2 modems, additional channels will be required for operation of DOCSIS 1.2 features. 6) What are the chances 1.2 will be modified to eliminate the need to designate a separate channel for 1.2 features wherever 1.1 and 1.0 modems are in operation? 7) If a modem is 1.0 and 1.1 certified, is DOCSIS 1.2 certification mandatory to be compliant with a 1.2 head-end? (I understand how they function but wonder about certification process.) The S-CDMA mode of DOCSIS 1.2 requires that an additional 6-MHz upstream channel be allocated. 8) What MHz stream is required for TDMA 1.2? I couldn't find reference to any S-CDMA companies being in DOCSIS testing either in the past or currently. If they're hoping to dominate the market with their proprietary modulation being written into the 1.2 standard, isn't there a fair amount of risk that the ostensible advantage will disappear before it materializes? Admittedly I'm a novice, yet I wonder if DOCSIS 1.0 and 1.1 will evolve into a de facto standard by the time 1.2 becomes reality. Please correct my conclusions wherever needed. Regards, Pat Additional CableLabs' links some may find useful: cablelabs.com CableLabs FAQ on DOCSIS cablelabs.com Paul Baran, CMTO board member and co-founder, gives Winter CableLabs conference keynote: cablelabs.com