The Law of the Telecosm
The Law of the Telecosm
I want to share an important excerpt from Telecosm with you. The working of the law of the telecosm has launched an era of unprecedented advances in telecommunications…
Hovnanian’s campaign into the spectrum began when a cable company announced one day in 1985, under the Cable Act of 1984 and franchise rights granted by local governments, it had the right to wire one of his housing developments then under construction.
Until that day, Hovnanian’s own company could package cable with his homes through what are called satellite master antenna TV systems. In essence, each Hovnanian development had its own cable headend where programs are collected and sent out to subscribers.
When the cable company, now Monmouth CableVision, went to court and its claim was upheld by a judge, Hovnanian sought alternatives. First he flirted with the idea of having the phone company deliver compressed video to his homes. In 1986, in the era before FCC Commissioner Alfred Sikes, that was both illegal and impractical. Then he met Bernard Bossard and decided to attack through the air.
An early pioneer in microchips who had launched a semiconductor firm and eventually sold it to M/A COM, Bossard was familiar with both the soaring power of computers and the murky problems of broadband noise that have long restricted the air to a small number of broadcast AM TV stations.
Attacking Through the Air
Air delivery of cable television programming had long seemed unpromising. Not only was there too little spectrum available to compete with cable, but what spectrum there was, was guarded by the FCC and state public utilities commissions. Nonetheless, in the early 1990s “wireless cable” did become a niche market, led by Microband Wireless Cable and rivals and imitators across the land.
Using fragments of a frequency band between 2.5 and 2.7 gigahertz (billions of cycles per second), Microband, after some financial turmoil, now profitably broadcasts some 16 channels to 35,000 New York City homes in line of sight from the top of the Empire State Building. As long as they are restricted to a possible maximum of 200 megahertz and use AM, however, wireless firms will no longer be able to compete with the cable industry. Cable companies offer an installed base of potential gigahertz connections and near universal coverage.
Having spent much of his life working with microwaves for satellites and the military, Bossard had a better idea. He claimed he could move up the spectrum and pioneer on frontiers of frequency between 27.5 and 29.5 gigahertz, previously used chiefly in outer space. That would mean he could command in the air some half a million times the communications power, or bandwidth, of typical copper telephone links, some ten times the bandwidth of existing wireless cable, some four times the bandwidth of the average cable industry coaxial connection, and twice the bandwidth of the most advanced cable systems.
The conventional wisdom was that these microwaves (above about 12 gigahertz) are useless for anything but point-to-point transmissions and are doubtful even for these. For radio communication, the prevailing folklore preferred frequencies that are cheap to transmit long distances and that can penetrate buildings and tunnels, bounce off the ionosphere or scuttle across continents along the surface of the earth. The higher the frequency, the less it can perform these feats essential to all broadcasting ― and the less it can be sent long distances at all.
Moreover, it was believed, these millimeter-sized microwaves not only would fail to penetrate structures and other obstacles but would reflect off them and off particles in the air in a way that would cause hopeless mazes of multipath. Multipath would be translated into several images, i.e., ghosts, on the screen.
Finally, there was the real show-stopper. Everyone knew that these frequencies are microwaves. The key property of microwaves, as demonstrated in the now ubiquitous ovens, is absorption by water. Microwaves cook by exciting water molecules to a boil. Microwave towers are said to kill birds by irradiating their fluids. Microwave radar systems won’t work in the rain. Mention microwaves as a possible solution to the spectrum shortage, and everyone ― from editors at Forbes to gurus at Microsoft, from cable executives to Bell Labs researchers ― laughs and tells you about the moisture problem.
So it was no surprise that when in 1986 Bossard went to M/A COM and other companies and financiers with his idea of TV broadcasting at 28 gigahertz, he was turned down flat. Amid much talk of potential “violations of the laws of physics,” jokes about broiling pigeons and warnings of likely resistance from the FCC, he was spurned by all. In fairness to his detractors, Bossard had no license, patent, or prototype at the time. But these holes in his plan did not deter Vahak Hovnanian and his son Shant from investing many millions of dollars in the project. It could be the best investment the Hovnanian tycoons ever made.
New Rule of Radio
For 35 years, the wireless communications industry has been inching up the spectrum, shifting slowly from long and strong wavelengths toward wide and weak bands of shorter wavelengths. Mobile phone services have moved from the 1950s radio systems using low FM frequencies near 100 megahertz, to the 1960s spectrum band of 450 megahertz, to the current cellular band of 900 megahertz accommodating more than 10 million cellular subscribers in the US.
During the 1990s, this trend will accelerate sharply. Accommodating hundreds of millions of users around the world, cellular communications will turn digital, leap up the spectrum and even move into video. Shannon’s laws show that this will impel vast increases in the cost-effectiveness of communications.
In general, the new rule of radio is the shorter the transmission path, the better the system. Like transistors on semiconductor chips, transmitters are more efficient the more closely they are packed together. As Peter Huber writes in his masterly new book, The Geodesic Network 2, the new regime favors “geodesic networks,” with radios intimately linked in tiny microcells. As in the law of the microcosm, the less space, the more the room.
This rule turns the conventional wisdom of microwaves upside down. For example, it is true that microwaves don’t travel far in the atmosphere. You don’t want to use them to transmit 50,000 watts of Rush Limbaugh over 10 Midwestern states, but to accommodate 200 million two-way communicators will require small cells; you don’t want the waves to travel far. It is true that microwaves will not penetrate most buildings and other obstacles, but with lots of small cells, you don’t want the waves to penetrate walls to adjacent offices.
Microwaves require high-power systems to transmit, but only if you want to send them long distances. Wattage at the receiver drops off in proportion to the fourth power of the distance from the transmitter. Reducing cell sizes as you move up the spectrum lowers power needs far more than higher frequencies increase them. Just as important, mobile systems must be small and light. The higher the frequency, the smaller the antenna and the lighter the system can be.
All this high-frequency gear once was prohibitively expensive. Any functions over two gigahertz require gallium arsenide chips, which are complex and costly. Yet the cost of gallium arsenide devices is dropping every day as their market expands. Meanwhile, laboratory teams are now tweaking microwaves out of silicon. In the world of electronics ― where prices drop by a third with every doubling of accumulated sales ― any ubiquitous product will soon be cheap.
The law of the telecosm dictates that the higher the frequency, the shorter the wavelength, the wider the bandwidth, the smaller the antenna, the slimmer the cell and ultimately, the cheaper and better communication. The working of this law will render obsolete the entire idea of scarce spectrum and launch an era of advances in telecommunications comparable to the recent gains in computing. Transforming the computer and phone industries, the converging spirits of Maxwell, Shannon, and Shockley even pose a serious challenge to the current revolutionaries in cellular telephony.
Editor, Gilder’s Daily Prophecy