dslreports logo
 story category
First DOCSIS 3.1 Modems to Hit 4-5 Gbps
While new DOCSIS 3.1 modems should ultimately be capable of hitting 10 Gbps downstream, 1 Gbps up (albeit shared across numerous users on a node), the first modems to be released will likely "only" be capable of half of those speeds initially. The first wave of modems will be 3.0/3.1 hybrids, with the DOCSIS 3.1 half combining two channels/blocks orthogonal frequency-division multiplexing (OFDM) at 192MHz-wide each, and two 96MHz-wide channels for the upstream. Considering how rare anything over 150 to 300 Mbps is among cable operators (Comcast does offer a 505 Mbps tier though that's technically hybrid fiber to the home), that certainly shouldn't be a problem initially.

Most recommended from 50 comments


Kommie2 (banned)
join:2003-05-13
united state

2 recommendations

Kommie2 (banned)

Member

FTTH

It would be cheaper for the provider to go Fiber To The Home, than to deploy this. Comcast is already taking the fiber route in Washington, D.C.

motorola870
join:2008-12-07
Arlington, TX

1 edit

2 recommendations

motorola870

Member

pipe dream (wont happen for a long time)

I don't see cable providers really pushing this out in the next few years as it is impossible without major network upgrades. 2 96MHz wide upstream channels got to be joking. I don't think so as this would require the cable company to replace all amplifiers and it isn't worth it right now as cable providers are just now beginning to use 5-42MHz for upstream to its full potential for DOCSIS 3.0. Also every box, modem and anything to do with the cable plant would have to be replaced as they wouldn't be able to keep linear TV and that would require substantial capital meaning things from DTAs, digtial adapters, VOD servers, and even CMTSs would have to be upgraded. Too costly for now maybe in 2020! We may get lucky and cable decides to figure out that don't touch 5-1500MHz and go for 3GHz cable systems and do a second upstream and downstream path from 1500MHz to 3000MHz and put DOCSIS 3.1 there otherwise we won't ever see it.

more realistic approach would have been 12MHz/24MHz wide upstream channels and 48MHz wide downstream channels with OFDM. 96MHz and 192MHz is too greedy! No cable system is going to have 192MHz to set aside just for downstream on DOCSIS 3.1. The real solution for several years is expanding the downstream to 16 QAM carriers and make the upstream 4 QAMs wide 6.4MHz as anything better than that is unrealistic. TWC in my area is finally able to move 3 6.4MHz upstreams with a legacy 3.2MHz upstream so don't look for DOCSIS 3.1 for years.