It's All about Height
I based my visit to New York City to check out the NYCwireless project and the state of Wi-Fi in NYC [see the September issue of Linux Journal] out of Britt Blaser's apartment, not far below the penthouse level of a high-rise at the corner of 43rd Street and 2nd Avenue in midtown Manhattan.
Britt's apartment has one of the best views in town. To the East, it squarely faces the United Nations building, which looms over the East River like one of those upright slabs from the movie 2001. To the UN's south is Tudor City, an ornate apartment complex built in the 1920s. Remember the Gothic rooftop home of Norman Osborne (played by Willem Dafoe) in Spider-Man? That location is one of four similar "mansions" (each a clever cover for water tanks, elevator pulleys and other rooftop uglies) that sit atop Tudor City's apartment buildings like castles on mountains. Britt's place looks down on all of them, plus the pretty little park in their midst. To the west are two of New York's tallest skyscrapers: the Chrysler Building and the Conde Nast Building, labeled 4 Times Square.
Height has value in New York. That goes for high frequency broadcasting even more than for real estate. All the highest buildings bristle with antennas. Topping the beautiful old Chanin Building nearby on 42nd street are two FM broadcast antennas: an ancient six-bay mast of horizontal clover-leafs that once radiated WQXR, the Classical FM station of the New York Times and a new two-bay antenna that is probably the auxiliary for WQXR or some other station.
The need for auxiliary transmitter sites was brought home when nearly all of New York's TV and a third of its FM stations were destroyed in the 9/11 attack. All of them radiated from one big mast on the North Tower. It was the last piece to hit the ground.
The problem still isn't solved. During my trip, major construction was happening on the top of the Conde Nast building, where workers with cranes were raising the new broadcast tower that will carry the signals of FM stations whose transmitters were lost nearly three years ago. The project is taking a long time because the Empire State Building already is overburdened with TV and FM antennas, including new digital HDTV antennas also lost on 9/11. No engineer wants his station's signal shadowed by higher buildings.
The gargantuan cost and effort required to continue serving brute-force analog radio to increasingly disinterested citizens provided an ironic contrast to the grass-roots Wi-Fi movement carried out by those citizens in the streets and parks below.
As an old broadcast engineer and ham radio guy (from waaay back), I couldn't wait to take advantage of Britt's high-rise to see if we could provide Wi-Fi service to Tudor City's park, half a block away. But the results were disappointing. Yes, we could deliver a barely useful signal to one side of the park, but only when Britt hung his Linksys WAP-11 outside the window.
Thus began my acquaintance with the engineering facts of Wi-Fi life. I had to start by throwing much of what I knew about broadcasting out the window.
Doc Searls is Senior Editor of Linux Journal
- March 2015 Issue of Linux Journal: System Administration
- High-Availability Storage with HA-LVM
- DNSMasq, the Pint-Sized Super Dæmon!
- Localhost DNS Cache
- Real-Time Rogue Wireless Access Point Detection with the Raspberry Pi
- Days Between Dates: the Counting
- You're the Boss with UBOS
- The Usability of GNOME
- Multitenant Sites
- Linux for Astronomers