Ridzuan is on the move again. This short, wiry native Malaysian, who studied telecommunications engineering at the University of Missouri, has a terse way of speaking that reflects an ingrained eagerness to get on to the next thing. We step around a corner. The retaining wall that kept us from looking outward is now only at shoulder height. Earlier, viewed from street level, the city seemed a jungle of buildings, overcrowded sidewalks, and traffic-laden roads. Construction cranes loomed everywhere, aggravating the tropical heat and noise. Now the city unveils itself, and we can see its jagged skyline up close.

Kuala Lumpur is nearly 150 years old, yet in many ways it's a completely new city, with all the growing pains of urban adolescence. A kilometer to the north of us are the Petronas Twin Towers, which shimmer like liquid, as if black oil and molten steel were poured down from a cloudless sky. To our west is the KL Tower, a graceful needle whose shaft is decorated in the Muqarnas style, a traditional floral and abstract motif, which is as common in the Islamic world as the Corinthian column is in the West. An ever-increasing number of 30- and 40-story structures populate the spaces around these leviathans.

Yet of all the buildings in this metropolis of about 1.5 million people, the most important right now might be the obscure titan on Kia Peng street on whose roof we're standing. Here, Jaring's new wireless signal radiates silently from two antennas. The new service isn't so very fast—in the world of DSL (digital subscriber line), 1 to 3 Mb/s is considered fairly slow. Like DSL, this signal has a maximum range of some 5000 meters. Unlike DSL, though, it doesn't need any phone lines, and that's important. Before December 2004, when it officially began selling wireless service, Jaring had to lease a circuit from Telekom Malaysia (which sells a DSL service of its own) in order to give a customer a high-speed connection. The awkwardness of that situation is reflected in Jaring's meager 1-in-50 DSL market share.

For Internet providers, in Malaysia and elsewhere, a wireless network is a solution to a problem. For users starved for broadband, though, it can be a salvation. Not everyone can get DSL. Many customers live outside the radius of reliable connectivity. In addition, the central telephone office has to be equipped with an expensive DSLAM (digital subscriber line access multiplexer); many rural central offices are not. In Malaysia's most remote regions, some communities have no phone service at all.

It was back in 2003 that Jaring's CEO, Mohamed Bin Awang Lah, concluded that his company needed a last-mile network of its own. Despite his academic bent—he has a Ph.D. in electrical engineering from King's College, London—Mohamed is a hard-headed businessman, and this was the sort of decision he has had to make repeatedly in his career. He was the first to implement Internet technology in Malaysia in 1983 (with dial-up connections to Korea, Australia, and the United States) while a professor and deputy dean of engineering at the University of Malaya, in Kuala Lumpur. Then in 1986, Dr. Internet, as I heard more than one person here refer to Mohamed, moved to the Malaysian Institute of Microelectronic Systems, a government R&D organization, and began an Internet-access program that would become, in 1992, Jaring. He built the country's first fiber backbone using the Internet Protocol in 1999, its first virtual private network in 2001, and SchoolNet, a satellite-based broadband network for 2000 remote schools, in 2004.

Jaring—the name is a Malay word that means simply "networking"—was finally spun off as a corporation in April 2005, but it is still wholly owned by the government. (Telekom Malaysia, though publicly traded, is similarly controlled, because the government holds most of the stock. The two companies are, however, controlled by different ministries.) Although Jaring had a head start, today Telekom Malaysia serves 60 percent of all households getting Internet access, about twice as many as Jaring serves, a testament to the power of telecom incumbency.

Mohamed's decision to go wireless was aided by a quirk of Malaysian telecommunications—a ready availability of spectrum. Two 16-megahertz-wide slots in the 2.5- and 2.6-gigahertz bands became available. Rather than sell them in a high-priced auction, the government grants free licenses, and charges modest fees for the spectrum only when it's used. So Jaring pays about 6000 Malaysian ringgit per base station per year—less than US $20 000 annually for the 10 base stations it's built so far.

Mohamed opted for Soma's equipment after visiting a demonstration network that this company operates in Toronto. There were, and still are, a number of wireless broadband alternatives. Mohamed's choice was grounded in the short term: how could he build a network that would start paying for itself almost immediately?

The answer, Mohamed soon discovered, hinged on some questions of system design and performance for which there were only rough guesses. The basic network is simple enough. A subscriber gets a small device, which is heavier, but not much bigger, than a cigar box. The industry calls such a unit a CPE, for customer premises equipment. Stick its power adapter into the wall, connect it to your PC with an Ethernet cable, and voilà—you're attached to the Internet, just as if you had plugged your computer into a DSL modem [see sidebar, "Voice Box, Data Box"]. The technology for making this happen is all pretty straightforward.

Yet, if you're trying to figure out how to make money with the service, uncertainty abounds. How many customers can a single base station support? How many simultaneously? At what data rates? Over what distances? How many people live in the coverage area? Which ones can be expected to sign up? At what monthly rate? How expensive is the base station? The CPE? Will a customer buy or lease it?

They're all questions that Mohamed and his colleagues had to face back in 2003, and I heard them asked anew when I visited Jaring this past October. Representatives of a large cellular company in India happened to be viewing the network at the same time. Although much of India still doesn't have access to broadband, for the fraction that does, it's becoming a commodity, I was told. There, the most basic level of DSL is available for just $6 to $8 per month. And Soma's wireless alternative is appealing in India for the same reasons that it is in Malaysia: bad copper and long distances.

Soma's assessments of how its equipment performs are based less on guesswork today than they were in 2003, largely because of Jaring's still-formative experience. Because signals are weakened by distance and by obstacles like tall buildings, Jaring is selling its service in Kuala Lumpur only within a 3-kilometer radius of a base station, 2 km less than the nominal limit. There's one area where more experience is greatly needed. Soma claims that a single base station radio can handle 500 users at once, and a base station can be equipped with as many as six radios, pointed in different directions, but, as of October, the Jaring network had yet to see more than 200 simultaneous connections per radio.