The last part of the World Trade Center to hit the ground on the morning of 9/11/2001 was the TV mast on the North tower. That mast contained the transmitting antennas for all of New York's major television stations, plus a number of FM stations. The 300-foot mast was the main distinguishing characteristic of the North tower, and it's the crowning element in all six architectural proposals currently being vetted as replacements for the World Trade Center. None of the proposed buildings in any of the designs are as tall as the old twin towers, but each makes up for the difference with a TV transmitting mast that gives the facility a "1,500-foot-high skyline element."

I would like to suggest an alternative: Drop support for television and instead celebrate the Internet, our new World Wide Commons.

Let's start with the case against television.

Nearly all the lost antennas transmitted analog signals that TV tuners in the New York area found on channels 2, 4, 5, 7, 9, 11, 13 and so on. But back in 1997, the FCC set a 2006 "end date" for analog transmission, mandating replacement of analog signals with new digital signals on an entirely different band. The old VHF and UHF bands would be reallocated for other uses. The move was already underway a year ago at the WTC, where WNET, the PBS affiliate in New York, had spent over $10 million on its digital transmitting plant (we trust insurance will pay for its replacement).

Analog television in the US currently uses most of the spectrum between 52 and 800MHz (Channels 2-6 are 47-88 MHz; Channels 7-13 are 174-233MHz; and Channels 14-66 are 470-790MHz), which is a huge piece of spectral real estate. All of those frequencies rely on line-of-sight propagation, which is more forgiving at the lower frequencies (they carry better through air and refract better around buildings and terrain). That's why the FCC permits stations to broadcast with effective radiated powers (what the antennas radiate toward the horizon) of up to 100kw on channels 2-6, 316kw on channels 7-13 and 5,000kw (5 megawatts) on channels 14-66. The line-of-sight issue requires using the highest mountains, buildings or towers around. The tallest structures on Earth are TV towers (such as the one for KVLY-TV in North Dakota, which is 2,063 feet high), and nearly all the great skyscrapers of the world--Eiffel Tower, Empire State Building, Sears Tower, Hancock Tower--have been festooned with radio and TV masts. So we're talking about huge costs here, not only in physical supports and transmitting equipment, but also in raw electricity.

Yet the horizon at 2,000 feet is just 66 miles. Signals often go much farther than that, but few TV viewers watch signals more than 120 miles away. They have cable for that. Or satellite dishes.

I lived in New Jersey the whole time the World Trade Centers were being built. For awhile I even shared a yard with a British guy named Roy Harvey, who was a foreman on the construction project. (A fun guy who turned me on to Bass Ale). I was also a young radio geek and part-time broadcast engineer who wasted many hours obsessing over transmission issues. I remember visiting the WTC site shortly after the South tower was finished, so I could inspect the special UHF translator antennas that rebroadcast the VHF stations' signals toward the Bronx, where the twin towers cast bad "ghost" reflections. The twin towers also cast a shadow southward toward New Jersey, another reason why there was general agreement about the need to move all the transmitters over from the Empire State Building, where they previously had been for many years.

Except not all engineers shared the same wisdom. See, FCC rules require stations in New York (and other large metropolitan areas) to reduce their output power at elevations of more than 1,000 feet above the average terrain, according to a sliding tradeoff scale: more height, less power. So transmitting from the WTC generally gave stations more reach but less punch. The same was true on FM (with frequencies that start just above TV channel 6), where the sliding scale begins at 500 feet. That's why a minority of New York FMs moved to the WTC; most of them stayed on the Empire State Building. And that's where most of them are likely to stay, no matter what gets built to replace the twin towers.

So there really isn't much reason to move all those TV stations back to the new WTC, other than a marginal advantage in height over the Empire State Building.

Then there is the matter of digital television. Here the frequencies are even higher than most current analog TV. Radiated power is much lower, which is good; but to receive a good digital signal, your receiving antenna needs a clear view of the transmitting antenna. That eliminates a lot of places, regardless of how high you make the signal source.

Cellular telephony found a way around this problem by distributing many low-powered transmitters around a given area. Why not do the same for wireless HDTV? More to our point, why constrain the architecture of the new World Trade Center just to accommodate an old TV transmitting method?

The answer: Don't.

Next question: What should the new WTC support, in the same way it once supported television?

My answer: The Net.

The Internet is conceptually very much in line with the ideas behind the original World Trade Center. It is a marketplace in the deepest sense of that word: a place where people and organizations gather to meet, share culture and do business. The Net was also a boundless source of information and support after the 9/11 attacks--in some ways better than television or radio. Thanks to the Net, companies like Cantor Fitzgerald, which lost nearly 700 people on 9/11, could stay in business.

The Net, like any good marketplace, is something nobody owns, everybody can use and anybody can improve. It is a world-wide phenomenon. In The Future of Ideas (Random House, 2001), Lawrence Lessig calls the Net an "innovation commons". In the same book, he points out that the Net emerges from free protocols and free code. "Free code builds a commons", he writes (p. 56). He cites Linux, Apache, Bind and Sendmail as projects that "together constitute the soul of the Internet":

Together with the public domain protocols that define the Internet (governed by no license at all but free for all to take, referred to collectively as TCP/IP, including the core protocols for the World Wide Web), this free code built the Internet. This is not a single program or a single operating system. The core of the Internet was this collection of code built outside the proprietary model. (P. 56)

That model of the Net is one of the crowning achievements of civilization and is proving to be a very good thing for countless businesses--especially international ones. The only industry that takes exception to this model of the Net is entertainment, specifically the movie and record industries centered in Hollywood.

Wouldn't it be a wonderful move by New York, and by civilization itself, to ignore Hollywood and make the World Trade Center a place where the world wide commons is both manifest and celebrated?

The next question is How?

By saturating its public spaces with high-bandwidth wireless access? That should go without saying (although perhaps some kind of simple paid access could be earmarked to defray the costs of maintaining the service, as well as the physical space). But what else? Outdoor cafés amidst the parkspace? Of course. And what else?

I'm wondering, for example, what kind of public architecture is produced by a culture that doesn't require expression in verticalites. We're not building a cathedral here. Nor a phallic monument to the vanities of this decade's ascendant industry (as other skyscrapers were in the past for banking, insurance, retailing and broadcasting). Instead we are quite literally building a world wide bazaar. What should that look and feel like?

Let's have your suggestions. Seems like a constructive way to spend your 9/11, no?

Doc Searls is senior editor of Linux Journal.