Buying Modem Basics

With the advent of broadband access to the internet, you might think that modems have become passe. That's just not the case, as a large majority of users still rely on dial-up service to connect to the internet. However, there are fewer choices in aftermarket modems today simply because virtually all new PCs include an internal modem as standard equipment.

As with all computer and electronics equipment, modems can go bad and may need to be replaced. Modems for use with handheld PCs and PDAs are becoming more widespread. With more Palm and Handspring Visor users wanting access to the internet, e-mail, and other information, these modems are enjoying great popularity.

Modems for desktop PCs come in internal and external models. Most internal models today require a PCI expansion slot. External modems generally require a USB port and operating system support for this feature (Windows 98/Me, Windows 2000/NT, Windows XP, or Mac OS.) Older external models are still available for those who prefer to use a serial port.

All modems these days meet the V.90 standard, which defines operations at 56Kbps. Be aware that this speed is misleading. Because of FCC restrictions on the amount of voltage a modem can put on the line, even a "56K" modem has a speed limit of 53Kbps (with most modems averaging speeds from 40Kbps to 50Kbps). That maximum speed is only in one direction, downloading, and many times, connections are made at a much slower rate. Uploading is performed at 33Kbps at best. A new standard called V.92 has recently been approved, and when implemented by the ISPs (Internet service providers), it will raise the upload speed to as fast as 43Kbps.

Virtually all modems include fax capability. This lets you send and receive faxes using your PC, eliminating the need for a fax machine. Because almost no difference exists in the basic functionality between modems today, manufacturers have started adding special features, such as the ability to send voice messages to other users while communicating online or to automatically differentiate between voice, fax, and data calls.

If you are buying a modem for a laptop, there are two additional features you might want to consider. One is the ability of some laptop PC Card modems to connect to a cellular telephone. Not all modems offer this capability, and even those that do require specific phone models. Another nice feature in PC Card-format modems is built-in jacks that eliminate the need for special connector cables. Wireless modems for laptops or PDAs are also gaining in popularity, although you'll have to stay within a coverage area to maintain your connection.

Broadband internet access methods, such as cable and DSL, require a different type of device. Cable and DSL "modems" do not work the same way as a standard V.90 modem, and most need to be matched to the specific vendor offering the service. You can go into a computer store and purchase a modem for DSL access, but unless it's the one specified by the DSL provider, it might not work.
How to Shop

First, consider whether you want an internal or external modem. External modems require an available port to plug into, but they're easier to install and they offer handy status lights. Internal modems require a free slot inside your PC, and are generally a bit less expensive. Of course, if you use a laptop, you'll want to choose a PC Card modem for maximum portability.

If you're investigating alternative high-speed technologies such as DSL or cable modems, contact your local telephone or cable company before buying equipment. Different localities use different standards, and you'll need to buy equipment that is compatible with your local system.