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gunner45 · Today, 21:34

I think 'potholes' might be a bit of a misleading analogy here. DOCSIS doesn't have 'data blocks' with gaps in the way that implies; it’s a continuous stream of symbols.

Under DOCSIS 3.1, when noise appears the CMTS adjusts how efficiently each part of the spectrum is used, e.g. dropping modulation on noisy subcarriers from 64‑QAM down to 16‑QAM as the OP said.

The end result is lower upstream throughput, but nothing is being “widened” — the system is just using more conservative settings on the noisy parts of the spectrum.

Today, 21:34	#13
gunner45 Roger_Gooner Join Date: Nov 2008 Location: London Services: TV Maxit TV with 360 box + phone, M500, VM Hub 5 Posts: 97	Re: Upstream Question. I think 'potholes' might be a bit of a misleading analogy here. DOCSIS doesn't have 'data blocks' with gaps in the way that implies; it’s a continuous stream of symbols. Under DOCSIS 3.1, when noise appears the CMTS adjusts how efficiently each part of the spectrum is used, e.g. dropping modulation on noisy subcarriers from 64‑QAM down to 16‑QAM as the OP said. The end result is lower upstream throughput, but nothing is being “widened” — the system is just using more conservative settings on the noisy parts of the spectrum.