Keeping pace - modern modems up to 56kbps

One day, everything related to PCs is old, slow and hopelessly out-of-date. The same is true in the world of modems. Modern users laugh at the mere mention of 2400 baud per second rates, not to mention reminders of acoustic couplers, the old PC/audio connector for telephone receivers. Even recent achievements like 14,400 bps and 28,000 bps are being overshadowed by the latest modems capable of reaching speeds of 33,600 bps. It's no surprise that the PC world is eagerly awaiting the arrival of 56 kbps modems.

The jump to 56K-modem technology is different from the modem speed increases of the past. In this latest case, there are a number of limitations inherent in the technology and the communications infrastructure. First and foremost, the technology will only work over high-quality lines; otherwise the modems will drop back to traditional V.34 speeds.

The industry has already seen this phenomenon with the V.34 modems that have problems connecting at the highest speeds over poor quality lines. 56K also will not work over any link that has a second analogue/digital conversion, for instance at a switchboard. It requires complete digital phone systems, which not all European countries currently have. Moreover, problems occur when conflicting digital conversion standards are used internationally.

A question of standards

Finally, the two leading technology versions - being developed by two groups - are headed for a showdown at the standards committees which may delay a unified standard. One group is headed by Lucent and Rockwell, whose current modem technologies are installed in over 70% of the central site/ISP systems. The second group is headed by U.S. Robotics.

Before a common standard is agreed, one thing is very clear. 56K-modem technology is very exciting and holds the promise to improve performance of many data communications applications. But it may not work all the time everywhere. In Europe alone, where there are many different types of telephone jacks and telecom support, mobile PC users may have to be patient. Many notebook manufacturers may hesitate to introduce this technology into diverse marketplaces - where the costs of supporting many different national markets are an obstacle. However, if standards can be agreed, 56K modems may appear in notebooks in 1997.

GSM on the move

There are few technical standards where Europe leads the world but GSM, or the Global System for Mobile Communications is one of them. This standard was part of the drive in the early 1990s to push European telecoms into a digital age (see also DECT and ISDN). GSM established the 900 MHz radio frequency for widespread digital mobile telephony using a cellular structure at a data transfer rate of 9600 bps. It replaces various analogue systems which were developed in the eighties. GSM allows roaming on a European scale.

GSM has been a phenomenal success and is now in use as the standard in over fifty countries around the world. Outside of Europe, it is popular in Asia and Australia. Japanese telecoms companies have also recently announced a change over to GSM which clearly puts the market power of many Japanese telecoms manufacturers behind the system. Only in the USA has GSM so far met major competition, although there too, many companies are promoting GSM.

For PC users, increasing ubiquity is driving the cost of GSM connectivity down fast. As it is already a digital standard, no modem is required to modulate/demodulate data. A digital converter is all that is necessary to put PC bits into the code used in GSM. A range of these in PC Card format match the various phones and connections currently produced. There is so far no GSM standard connector (see separate article on the Mobile Data Initiative) so cards and phones are currently tied to the same manufacturer.

GSM phones can however be used with differing network suppliers. So for notebook PC users, the hardware does not tie them to a specific network. Phones are fitted out with subscriber cards to activate them within a GSM network. GSM connections to popular service providers are also available allowing mobile PC users to connect to the Internet, send e-mail and FTP files at the cheap internal network rates.