Picking a pipeline

Currently, four major companies compete for bundled, cable-TV, telephone, and high-speed Internet service: AT&T, with its new subsidiary MediaOne; AOL/Direct TV; Microsoft's Web TV; and Residential Communications Network (RCN).

Bundled services can theoretically come into people's homes over any of four technology "pipelines."

As a group, these pipelines are called broadband, and they can carry more information, more quickly than traditional telephone lines.

So far, the four providers are using three, each with its own shortcomings.

AT&T/MediaOne and RCN use coaxial television cable - the same wire that delivers cable TV to your home - which can carry lots of data.

The cable is cheap, but adding telephone service requires expensive switching technology, so it has been installed in only a few communities. Experts expect it to be widespread in a few years.

Web TV and AOL TV use regular telephone lines, which have switching capability but are slower than the coaxial TV cable.

Upgrades will make them faster, but it's still not clear whether they can compete with cable.

With Direct TV, AOL TV can go wireless - the third "pipeline" -via satellite. This is the technology used by many cellular-phone companies - fast, switchable, installed, but expensive to use.

The fourth "pipeline," in theory, is the one that gets your toaster going, electric-power wires.

They can't yet carry telephone, Internet, or TV traffic, but electric utilities are working on it.