Sending Data from Home Without Using a Phone Line


There is another popular alternative to analog modems and DSL about which you should at least know the basics. Many homes in the United States also have cable TV (CATV) service. Similar in topology to DSL, cable modems provide an always-on Internet access service, using the CATV cable to transmit the data. You can surf the Internet over the cable and make all the phone calls you want over your telephone lineand you can watch TV at the same time.

Cable modems use frequencies that would have otherwise been used for additional TV channels. It's a little like having an "Internet" channel to go along with CNN, TBS, ESPN, The Cartoon Network, and all your other favorite cable channels.

Although the details are much different, the general ideas are just like DSL:

  • The cable can be split and connected to both the cable modem and the TVs in the house.

  • The CATV company splits out the data from the TV signals at its local office.

  • The CATV company gives the data to a router owned by an ISP.

  • If the ISP is different from the cable company, you pay a monthly fee to the ISP for Internet service, and a monthly fee to the cable company for the basic TV service.

  • Cable uses asymmetric speeds, typically maxing out at 40 Mbps toward the home, but the downstream bandwidth is shared among multiple subscribers.




Computer Networking first-step
Computer Networking First-Step
ISBN: 1587201011
EAN: 2147483647
Year: 2004
Pages: 173
Authors: Wendell Odom

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