Cyberspace Into Outer Space--Daunting, Yes, but Probably Only a Matter of Time
For cable TV executives, the destruction-from-above scenario of “Independence Day” must seem all too familiar. During the last two years, while struggling to upgrade and extend their aging networks, cable companies have watched as direct-broadcast satellite television captured more than 2.7 million customers. Thanks to its ability to beam 175 digital channels into every home in the country without digging trenches or stringing cable, DBS threatens to render the cable industry all but obsolete.
Spurred by this victory, a handful of companies are now hungrily eyeing the earthbound telecommunications industry. Companies such as Hughes Communications, Motorola and Loral have made highly publicized plans to launch satellite networks that will provide worldwide phone service.
But how these schemes will recoup their multibillion-dollar development costs has always been unclear. Visions of mountain climbers whipping out their personal satellite phone and African villages finally getting wired only beg the question. After all, the first anecdote represents an awfully small market and the second an awfully impoverished one. Add them up, says wireless consultant Bill Frezza, and you still don’t have a viable business.
Instead, Frezza argues, satellite phone systems will succeed only if they offer the high-bandwidth connections that Internet users are demanding and that phone companies are struggling to provide. Basic phone service is too ubiquitous to challenge, but high-speed Internet service is rare and expensive, even in wealthy California. And as costly as the satellite launching business is, it’s still cheaper than the massive job of deploying fiber-optic cable.
Frezza may be correct. But as two representative projects clearly illustrate, providing Internet service by satellite poses some extremely tough technical challenges. On the low end, there is DirectPC, an Internet service from Hughes that is available today. However, it’s beset by crushing limitations that make it impractical for most users. On the high end, there’s Teledesic, a company backed by wireless pioneer Craig McCaw and Microsoft Chairman Bill Gates. Their scheme solves the limitations that face DirectPC, but many critics say it is impossibly ambitious.
DirectPC is a companion service to DirectTV, the Hughes-owned DBS service, and attempts to overlay Internet service on a TV broadcast model. This means it can provide a huge amount of bandwidth down to the customer, but none in the opposite direction. Instead, a normal telephone line is used for “uplink” communications.
When a DirectPC user clicks to download a Web graphic, for example, the request is sent over the phone to Hughes’ operation center. The operation center then fetches the graphic using a high-speed Internet link and beams it up to the DirectPC satellite. The satellite simply acts as a “bent pipe” and shoots the graphic back down to Earth. Because the signal can be received all over the country, it is addressed with an ID number so it’s displayed only on the appropriate screen.
The result? For $14.95 a month and $1,495 worth of satellite equipment, your Internet downloads will run at about 20 times the speed of a standard 14.4 modem. This is a boon for some Web surfers, but such an asymmetric scheme definitely won’t work for those who want to do desktop video conferencing, say, or run their own Web site.
The bandwidth offered by DirectPC comes with one other caveat: It’s a fat pipe, but a very long one. Every time you click on a hyperlink, you have to wait as your signal travels to Hughes’ satellite center, retrieves the new page and then travels 22,000 miles up to the geosynchronous satellite and back down. Even those who only need downward bandwidth may find the system’s lag time, or latency, annoying.
The last problem with DirectPC is its limited capacity. Because the satellite’s signal covers the entire country, every user must share the same frequency band. Unless additional satellites are launched so as to divide the country into “cells,” the system probably can’t support much more than 1 million users.
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All three of these limitations are significant and make satellite service look like a distant contender to fiber optics and cable modems. But the proposed Teledesic scheme shows that the problems are not intrinsic to satellite Internet service.
Led by McCaw, a cellular industry titan until he sold his company to AT&T; for $11.5 billion in 1994, Teledesic is pushing the technological envelope in every direction. Its plan is to launch an astonishing 840 low-Earth-orbit satellites, beginning in 2000 and finishing two years later. Start-up costs are estimated at $9 billion. The best description of the scheme I’ve heard is that “it’s the sort of thing James Bond is called in to stop.”
But what makes Teledesic’s scheme credible are the people involved--besides Gates and McCaw, they’ve hired old Internet hands such as former National Science Foundation official Hans-Werner Braun--and the technology’s elegant design. First off, it’s designed with the Internet, rather than television, in mind. That means it will provide bidirectional, symmetric bandwidth.
Second, signal latency is sharply reduced by using LEO satellites that orbit at an altitude of only 500 miles instead of the 22,000 miles of DirectPC’s geosynchronous satellites. Finally, by using 840 satellites, the globe can be divided into small enough cells to allow for hundreds of millions of simultaneous users.
Nonetheless, Teledesic faces huge questions as to the viability of its scheme. Just launching so many satellites over two years is absolutely unprecedented.
Steve G. Steinberg (steve@wired.com) is an editor at Wired magazine.
