Cable Modem Services

Cable Modem Services

The demand for high-speed Internet access in the past few years has seen the rise of cable modem services as a broadband alternative. The technology takes advantage of the wide reach of cable infrastructure used to deliver television service.

Data is transmitted over the network as radio frequency (RF) signals. The cable modem converts these into digital signals. In addition to television and data signals, analog voice signals can be transmitted over the network. These systems can also perform full-duplex communications. The fiber coming from the homes of subscribers is usually aggregated in remote units, and fiber is used to connect these units to headend routers. This kind of hybrid network is also called a Hybrid Fiber-Coaxial (HFC) network.

Different frequency ranges are used to transmit in upstream and downstream directions. The cable modem uses channels in the 5-to-42 MHz range to transmit data in the upstream direction. Similarly, a TV channel in the 50-to-750 MHz range is used for downstream traffic.

Cable can support a significant amount of bandwidthenough bandwidth to allow subscribers to watch television and be on the Internet at the same time. The cable modem uses 10/100 Ethernet or USB to connect to the user's PC.

In addition to bandwidth, cable is also attractive because of the wide range of applications it can support. Data, voice, and video can all be supported by this medium.

Conversely, because cable is a shared medium, performance can be degraded if too many users are on the same segment. This is the most significant drawback of cable. The shared nature of the medium also raises security concerns, because traffic can potentially be captured using a packet sniffer.