Mike, Frank, thread - Holy Legacy Infrastructure!
I was searching last night for information on a subject we were discussing a while back, Frank: the actual effect of inter-user interference in crowded spectrum: this with a view to the present and future efficacy of spreading and hopping techniques in avoiding such interference.
I had come across a tangential reference to the MIT thesis of Paul Shepherd. The inference was that the actual probability of such interference was minimal.
I would appreciate any references, links that anyone can offer on this subject.
However, I got into a lateral drift (again!) and came upon this post, which I pass on (slightly truncated) FWIW; a requiem for permanence.
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Since that time, I've gotten some interest in Microwave towers. It's a transient interest. It's always been there, but never been too strong ... but the reason it's surfaced right now is the divestiture of AT&T Microwave network.
Many of you know that AT&T has been replacing the old Microwave shots with fiberoptic. Now, they've sold the remaining towers to American Tower, which will be remodeling a lot of them into PCS and Cell sites. This brings a colorful chapter of the Bell System to a close. These sites were built to withstand anything, and they withstood everything but the increasing demand for bandwidth. My brother-in-law tells of working on a crew that installed the power for several sites outside of Las Vegas, Nevada. He was an electrician, but this job found him using a jackhammer, drilling into the solid rock in order to put in massive pure copper grounds. The foot-thick concrete walls were filled with copper, to protect against the EMP that a nuclear blast would provide. Manned towers sometimes included a shower to wash off fallout. An Autovon building near Delta, Utah, even included a sprinkler system to wash fallout off the whole building. Many towers included antennas to communicate with Air Force One.
A few months ago, an AT&T radio tech who will remain nameless gave me a tour of one of the remaining towers. "It's not like it used to be," he said. "In its heyday, this was something." One massive Caterpiller generator remained where three had been. Dials from the generators stopped at 3000 amps. Frames had been torn out, and the circuits remaining were all solid state. A map on the wall showed where the paths had gone. One by one, the towers had been decommissioned and removed from the path map, although the towers themselves remain. An engraved sign on the wall proudly welcomed all comers to the tower; a large sign extolled the virtues of communication, and Long Lines' part in it. I suspect that tower will soon be totally gutted, if it hasn't been already. The fact that it sits on a fiber route might keep it functioning as a fiber regeneration station. I gather from reading American Tower's SEC filings that not all of the site buildings are being sold along with the towers.
I guess it's true that if you get rid of something, some person will become nostalgic about "the good old days." I wouldn't give up my fiber for anything, but I thought TD readers might like to briefly remember the Long Lines Microwave days, before they are gone for good. The few sites I have photographed are reached via the URL:
stillyoung.com
In many cases, these towers were impressive pieces of engineering, more than just a communications tower. In any case, these towers were built to stitch together the telephone patchwork of a nation, and they served us well. They have done so for 40 years.
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