Broadband Modems in High-Speed Internet Access and Use

A broadband modem is a type of computer modem used with high-speed internet services. The three common broadband modems are cable, DSL (digital subscriber line), and wireless. Traditional computer modems, in contrast, support low-speed dial-up internet, which is considered nearly obsolete in areas where broadband service is available.

Wired Broadband Modems

A cable modem connects a home computer (or network of home computers) to residential cable lines for internet connectivity. Standard cable modems support a version of the DOCSIS (Data Over Cable Service Interface Specification). In contrast, a DSL modem connects to residential, public telephone service for internet connectivity.

Both cable and DSL modems enable sending digital data over physical lines designed for analog communications (voice or television signals). Fiber internet (for example, Verizon FIOS) does not require a modem because fiber optic cables support all-digital communications.

Wireless Broadband Modems

Wireless modem devices connected to cellular internet services are commonly called mobile hotspots (not to be confused with Wi-Fi hotspots). Technically speaking, you can use a smartphone as a wireless modem to connect it to another local device in tethering mode.

Fixed wireless broadband services sometimes require a modem for connecting the home network to the provider's local radio equipment; this depends on the technology involved.

Using Broadband Modems

Like a television set-top box, both cable and DSL modems typically are supplied by the internet service provider, so it's not a piece of equipment you must shop for on your own (although most providers allow you to buy your own if you choose). Broadband modems are sometimes manufactured together with broadband routers and sold as single units, commonly called home gateways or residential gateways.

When installed separately, a broadband modem connects to the internet on one end and the internal home network on the other. The modem-to-router link uses either an Ethernet or USB cable, depending on which options each device supports. The modem-to-internet connection uses a telephone line (DSL) or a coaxial cable line (for cable modems).

Connectivity Issues

When Microsoft Windows detects a problem with your broadband connection, it displays a message something like this: "Your broadband connection is experiencing connectivity problems." Although the message refers specifically to the modem, this error can indicate other problems such as:

• Setup issues or malfunctions with the broadband router.
• Connection issues between the Windows computer and the router.
• Malfunctions with the modem.

Unlike routers, modems have few settings and troubleshooting options. Typically, administrators must power a modem off and then back on to reset it. For best results, power both the broadband modem and router off and on together.