lular mess, with different countries going off in different directions (except for those in Scandinavia).
But when it came time to talk digital, the Europeans thrashed out a far-sighted standard: GSM. GSM is optimized for mobile data and is scalable to 64 Kbps. Cable a GSM phone up to a no
tebook PC or personal digital assistant (PDA), and you get great E-mail, faxing, and on-line access to the Internet. You can even hook a Nokia phone to a Hewlett-Packard palmtop.
The U.S. industry came up with D-AMPS (the D stands for digital), but performance was poor. Like GSM, it used time division multiple access (TDMA) technology, but it increased capacity by only a factor of 3. In the early 1990s, Qualcomm came up with code division multiple access (CDMA), which promised much-higher capacities.
Ironically, what CDMA really brought to the table was FUD. And that left the field wide open to GSM. So, while the gripping TDMA-versus-CDMA debate went on inside the U.S. telecommunications industry (and it hasn't stopped yet), the rest of the world was implementing GSM, investing over $50 billion in the infrastructure.
GSM is up and running on 120 live networks in 70 countries. Every month, 750,000 new subscribers sign up. Roaming agreements let you use your phone for voice and data communi
cations in different countries: Calls are charged to your regular account back home.
GSM has reached critical mass. There is no point in trying to trash the technology. GSM will continue to improve; rates will go up, and tariffs will come down. More and more countries are voting with their feet every month, and GSM-ready phones have already become a consumer commodity. Now's the time for fine-tuning and improvements: higher data rates, data compression, bandwidth on demand, packet data, and all kinds of future goodies.
Hope for the U.S. consumer comes from the deployment of the new wireless Personal Communication Services (PCS). PCS networks will come in different flavors. PCS 1900 is the one based on GSM technology. The figure 1900 in the name indicates the frequency in megahertz; the discerning reader may know that GSM operates at 900 MHz. However, this isn't a major issue since it's fairly easy to make a dual-mode phone. So, in principle, anyone who owns a PCS device will be able to use it in
the rest of the world. And vice versa for GSM.
But what is an issue in the U.S. is the fact that there isn't going to be ubiquitous access to digital cellular networks. It's going to be PCS 1900 in some areas, CDMA (eventually) in others, and TDMA (D-AMPS) elsewhere. Thus, the U.S. isn't just going to be out of sync with the rest of the world; it's going to be out of sync with itself.
The only way around this problem is to make dual-mode phones for use within, not outside, the U.S. And the only way to get true ubiquitous coverage is to integrate analog and digital technology, which is a real kludge and pure Kafka. You can always rent a phone when you travel. And in the future you'll probably be able to remove the smart identity card and use it in the rented phone.
GSM does the modulation on the network, not on the PC Card you use for telecommunications with your notebook or PDA. Regular communications software sees a data card as a modem, but the functionality is different. Data stays d
igital until it reaches the network switch. It's modulated if the call is to go over the regular public network, but it stays digital if you ring an ISDN number.
This means that you have an end-to-end digital link. Setup times are a few seconds, versus the current modem-handshaking nonsense that takes 30 to 40 seconds (high overhead if you want to send a few E-mail messages). And now you can use V.42bis data compression over GSM's air interface, so what was 9.6 Kbps shoots up to 30 to 40 Kbps.When multiple-time-slot services come into operation in a couple of years, these transmission rates will be in the hundreds of kilobits per second, so mobile multimedia will be both feasible and affordable.
European technology is looking very cool right now on the digital communications front. Forgive me if I gloat.
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Bob Emmerson writes frequently about telephony issues for BYTE's international edition. He lives in the Netherlands. You can reach him at
73252.1364@compuserve.com
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