Methods of connecting.

Users can be connected to the Internet via telephone, via cable, via satellite or via broadcast TV signals.

The goal of telephone companies is to achieve the fastest possible access speed without having to replace the phone wiring in the average home. For the cable TV companies, the

In the U.S. the telcos are promoting ADSL(*), while in Europe the top candidate is XDSL (the "X" has yet to be defined). ISDN(*) technology, however, is available in both the U.S. and other countries. In addition, Sprint is planning a digital telephone network called ION; it is based on a technology called ATM (asynchronous transfer mode), which will carry data, video and voice communications over a standard phone line.

But there are already other forms of high-speed connection for Web users. Recently, Santa Clara, California-based Covad Communications introduced TeleSpeed, a DSL(*) technology that can transmit at speeds up to 50 times faster than those of conventional dial-up modems and up to 10 times faster than the speeds achieved by ISDN (already called a slower cousin of DSL technology). TeleSpeed is available at three download speeds: 144 kilobits per second(*), 1.1 megabits per second and 1.5 megabits per second. In any case, in the next two years all of the U.S. telcos will be able to achieve a downstream rate of between 768 kilobits per second and 1.3 megabits per second.

While everyone waits for the backbone to improve, they can employ RADSL(*) phone technology. RASDL, carried over copper wires, is faster than ADSL technology, which itself has yet to be introduced. Since it is more flexible than ADSL, RADSL can provide longer loops at the ADSL speed of up to 7.1 megabits per second. This should hold everyone until the newest technology on the block, VDSL(*), makes its appearance and offers speeds of between 12 megabits per second and 50 megabits per second, with the highest speed having the shortest loop. In order to compare transmission speeds, one needs to know that regular dial-tone phone lines are capable of delivering speeds of up to 56 kilobits per second (downstream(*)), that satellite dishes can deliver from 12 megabits per second to 100 megabits per second, that ADSL Lite can deliver up to 1.2 megabits per second and that regular cable modems can deliver up to two megabits per second. In practical terms, CD-ROMs require decompressed(*) data streams in the range of 600 kilobits per second to five megabits per second to play full-motion color movies, while broadcast-quality signals need decompressed data rates ranging from six megabits per second to 15 megabits per second.

The new cable modems convert digital data into radio frequencies accepted by home TV sets. Cable TV subscribers will soon have digital set-top boxes with modems that provide the following four services: analog video service; digital video service; phone service; and data service with two-way capability at 40 megabits per second downstream. These modems will have speeds of 39 megabits per second on each six-megahertz channel, and each TV set will be able to carry between 50 and 120 six-megahertz channels. Cable TV systems will tap into the Internet in one of two ways: by using the national backbone provided by the @Home Network or by connecting via Road Runner.

Currently, cable TV passes 97 percent of U.S. homes; some 67 percent of households subscribe to cable's video services, while less than one percent subscribe to cable data services only.

The standard technologies for cable TV seem to be Open Cable (the cable group of the same name is developing an advanced generation of operating systems), Harmony (based on an agreement between the two major hardware suppliers)! and the CMTS(*) standard for cable modems.

While great resources are devoted to high-speed cable in the U.S., the European picture is different. In Europe, cable TV is not as prevalent, so resources are concentrated on telephone and satellite methods of delivery. By 2002, Europeans will have access to the Internet via a digital cellular service called Universal Mobile Telephone Service, which will allow for speeds equal to those of cable TV services.