Currently, DOCSIS 3 uses 5-42 MHz for the upstream.
For example, that means my cable modem is transmitting a signal down the copper at 5 MHz.
The thing about coaxial networks is there's a single copper conductor carrying everything.
So what about my neighbors. They have to transmit on 5 MHz too.
What if me and all my neighbors are uploading something at the same time. How does DOCSIS work without interference?
The reason I post this question only regarding upstream and not downstream is because I can see how downstream would work. The cable headend can send everyone's data to everyone on the node. And only the right person can decrypt it. Everyone else discards what they cant decrypt.
The upstream is different because everyone's modem would act like a signal jammer to everyone else, wouldn't it? Or does everyone on the same node use a different frequency. If that's true, then that makes me wonder what exactly nodes do.