The magic of 56K

Stand by for improved, ultra-fast modems that promise to revolutionise the speed and ease of surfing the Net. But not just yet. Stephen Pritchard reports

Last month, Internet companies started trials with new, ultra- fast modems. The new hardware is almost twice as fast as the current technology, and it promises an end to the Web browsing that, for many users, was more like swimming through treacle than surfing.

The new modems run at 56,000 bits per second (bps). This is just as well, because the Internet, and in particular the latest Web sites, demand all the capacity they can get.

The "56K" modem should be in the shops within the next few months. Its advocates claim that it will revolutionise the way we use the Internet. According to staff at Internet service providers, using the new modem feels like connecting via a direct line to the Net, a service that can cost pounds 10,000 a year to rent. The 56K modem is based on a technology called pulse code modulation (PCM), which exploits the fact that most of the public telephone network is now digital.

Almost all Internet companies have digital connections to the phone network. Their computers communicate direct with a digital telephone exchange, which in turn uses PCM to squeeze larger amounts of data over the slow copper wires and into people's homes. The process lends itself especially well to surfing the Web because PCM is at its most efficient when downloading information, such as a Web page. In the other direction, uploading, the copper wire puts a brake on speeds.

Unfortunately, there is, as yet, no international blueprint for the way these modems work. Behind the popular face of the Net lies a whole arcana of standards, protocols and committees. The main body that decides how modems talk to one another, the International Telecommunications Union, is unlikely to reach its conclusions before January 1998.

In the meantime, manufacturers are rushing out their own versions of 56K technology, anxious to meet demands for ever-faster access. But different makes may not talk to each other.

Even before any modems were made, manufacturers split into two camps: US Robotics' X2 standard, which the company has said it will license to other firms; and a group, including Hayes and UK manufacturer Pace, using chip-sets from Rockwell. Rockwell, with the most supporters, has set up the Open 56K forum to promote the technology; but US Robotics was the first to go online in the UK.

Industry insiders, such as Derek Oliver at Pace, believe that the Rockwell standard will come to dominate. Manufacturers, Oliver concedes, have been forced to take sides now, so they can have a 56K product in their portfolios. For users, there is the option of waiting until the standard is ratified. The choice for Internet service providers is harder, but their decisions will do much to decide whose modems sell best in the coming year.

PCM modems are really only of use for accessing the Internet because of the way they exploit digital links to the phone company. Two home users exchanging files with 56K modems have ordinary, analogue lines at both ends of the connection, so the modem will work only at V34 (33,600 bps).

Internet companies will have either to opt for just one type of modem, and run the risk of excluding some of their subscribers from high-speed access, or run the two technologies in parallel. "We are vendor-independent," stresses Matthew Townend, at UUNET Pipex. "We run two networks, using Rockwell and US Robotics. As long as bringing out technology towards a standard doesn't exclude existing users, we will support it." Townend admits that this may mean operating two separate dial-up numbers, one for X2 and the other for Open 56K, at least until a single standard emerges.

Even then, not everybody will be able to use the new modems. Parts of the country - for example, those not served by a digital phone exchange - will be left out. And users' experiences with 33,600bps modems show that line quality will be an issue, especially for sending data.

The good news is that the new modems may cost only pounds 30 more than an ordinary V34 model. Also, as long as the modem is upgradable, with software or a new internal chip, anyone who does buy now should still be able to use their equipment when the international standards eventually appear.