Cable Modems

Overview

Cable modems are used to enable broadband Internet access. They are a type of Network Bridge that contains multiple network segments at the data layer. Cable modems provide bidirectional data communication using radio frequency channels on cable television (CATV) infrastructure. Cable modems enable easy, affordable, and quick access to the Internet. Your speed will be much faster than with a dial-up modem.

Some cable modems feature a high quality interface for fast connectivity and a built-in firewall that helps to protect your network from virtual intruders. You can select a variety of cable modems for your household. The cost of the cable modem can range anywhere from $8 to $100. Sometimes, a cable Internet provider will cover the cost of your cable modem.

Benefits

Cable modems offer a variety of benefits to home users, businesses, schools, and institutions. They are generally inexpensive and frequently, cable Internet providers will waive all hardware and set up fees. You can purchase your cable Internet with a variety of options and plans. Typically, cable Internet service costs around $49 per month. You can also purchase comprehensive packages for cable Internet, television, and phone from $79 to $100 per month. If you set up a network, multiple users can access the Internet over the same cable line. With a network, users can also share the same network hardware including printers and the modem itself. Unlike dial-up Internet, cable Internet makes it possible to always be online, without constantly dialing the ISP phone number. You should assess your needs to determine what Internet speeds and packages are best for you.

How It Works

Your cable modem will work with a cable service provider. If you have cable TV, you can receive high speed Internet through the same line and provider. These cable lines are called coaxial cables and carry cable television and Internet signals. Some systems also use fiber optic cables for these connections. Even when the fiber cable is in use, the signals will move through the fiber optic cables for further distribution. Since cable modems position downstream or upstream data, they can be used to enable internet access through cable lines. Upstream and downstream data movement requires two types of equipment: cable modems at the customer end and cable modem termination systems (CMTS) at the service provider's end. All networking, security, and Internet access management is managed by this equipment.

Most of the cable systems have digital cable connection, so you can use a set-top box to connect to the Internet. A set-top box includes a tuner, modulator, demodulator, Media Access Control (MAC), and microprocessor. The tuner contains a splitter that separates Internet data channels from CATV programming. It also contains a diplexer which allows use of frequencies from upstream and downstream data. These signals are passed on to the demodulator. MAC is a device that acts as an interface between the hardware/software portions on the network protocols. A microprocessor is required to pick up the slack on the Mac's part. The Cable Modem Termination System enables many users to connect to the Internet at the same time.

Companies/Brands

Companies including Cable Labs and Motorola manufacture cable modems. You should talk to your cable and phone provider to see whether cable internet access is available in your area.