> if your ISP-side modem directly outputs digital audio, the downstream channel capacity is significantly higher
But why is it higher? It's still an analog channel (the last mile from the ISP to your house), right? Doesn't it get filtered? So isn't it still subject to the Shannon-Nyquist limit?
Here's an ASCII drawing of which parts are digital vs analog as I understood your explanation:
Rest of world<--- digital--->Telco<---digital--->ISPmodem<---analog--->HomeModem
Suppose you're saying that the link between the ISPmodem and the HomeModem is a bare unfiltered copper wire. In that case, I have a different question: Couldn't you send data at megabits per seconds over a mile long copper wire without using modems at all (using just UARTs?).
But why is it higher? It's still an analog channel (the last mile from the ISP to your house), right? Doesn't it get filtered? So isn't it still subject to the Shannon-Nyquist limit?
Here's an ASCII drawing of which parts are digital vs analog as I understood your explanation:
Suppose you're saying that the link between the ISPmodem and the HomeModem is a bare unfiltered copper wire. In that case, I have a different question: Couldn't you send data at megabits per seconds over a mile long copper wire without using modems at all (using just UARTs?).I hope you can clear up my confusion.