It's both TDMA and FDM. Your modem can bond multiple channels on the same coax but each channel is shared amongst all the subscribes on the CMTS. Each DOCSIS re

It's both TDMA and FDM. Your modem can bond multiple channels on the same coax but each channel is shared amongst all the subscribes on the CMTS. Each DOCSIS revision ups the spatial efficiency of each channel but also ups the number of channels. On a side note, my ISP incentives users to upgrade their modems by offering more bandwidth for the same money if you buy a modem that can bond more channels. For example I had a 8/3 DOCSIS 3 modem on a 60mb plan, for the same price they gave me 100mbit for upgrading to a modem that could bond 24/8. It allows them to utilize the network more efficiently