DOCSIS 3.0 vs 3.1.... i asked a question another site and this was the longest in depth answer:
“So D3.1 uses OFDM for downstream, which is a single 96MHz or 192MHz carrier that houses MANY subcarriers. Each of those subcarriers acts like a D3.0 carrier, but is much smaller in size (both frequency bandwidth and data transmission capabilities).
The number of channels to choose from doesn't make data transmission any "smoother", it just allows for more overall capacity by bonding smaller pipes together to make a bigger pipe. D3.0 carriers individually have a capacity of 38.8mb/s, thus without multiple connected together you couldn't have 100mb+ speed tiers. All DOCSIS 3.0 and prior channels are 6MHz wide, and do not contain subcarriers.
D3.1 builds on this by adding many subcarriers, and housing them in a single wide carrier that eliminates losses at the edge of each QAM channel. In a 6MHz wide D3.0 channel, there is typically a 1MHz guard band to prevent interference from adjacent channels, this guard band is eliminated and can be used for data transmission with OFDM in D3.1. Also, if you experience any noise/interference on the line feeding your modem, D3.1 allows the modem to turn off individual subcarriers to eliminate the errors you would have otherwise, and continue to use the remainder of the subcarriers bonded together. If that were to occur in D3.0, you would lose an entire 6MHz 38.8mb data pipe, even if the noise only occurs at a very small portion of that bandwidth.
Also...D3.1 modems are backwards compatible with 3.0, and most ISP's will use both simultaneously. If you look at a typical Gig cable service, you will see a single OFDM carrier bonded with 24-32 D3.0 carriers as well. This increases overall capacity, and allows for more customers per node, and less "peak hours" bandwidth reduction.
I could go more in depth if you would like, but I have a feeling I've already been confusing enough LOL”
