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What is a "cable modem"? How does that work?
Digital Cable access is the other method we use to offer highspeed access to our customers, though the market is limited to areas serviced by Knology, as getting access to CATV pipes is a major struggle, since the cable industry is not regulated as a telecommunications industry, as the telephone industry is, and the FCC has not yet mandated open access and competition between service providers. This will hopefully change soon, but may be much less likely now that AOL has gotten their own access, and is no longer as active in the Open Access Coalition.
Cable works over a hybrid fiber-coax cable that allows for upstream data on the low-frequency channels (channels two noisy for television) and dedicates a higher-frequency channel for downstream data, as if it were another channel on your cable box. (Channels are really just frequency ranges.) the Cable company sends the RF signal to a "cable modem" (which does not actualy modulate or demodulate anything). The cable modem then converts the signal to Ethernet to connect to a standard NIC on your computer, via a crossover cable. On the other end, the Cable company converts the RF signal to ATM cells to connect to our network.
Cable bandwidth is shared from the "headend" (where the fiber terminates at the head of a neighborhood) down. It is divided among each of the cable users in the neighborhood, so the more of your neighbors are connected, the less bandwidth you have to yourself. The maximum cable data transfer rate is 8 Mbps, but more practically, customers will see transer rates of 300 Kbps to 1.5 Mbps.
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