The first time I started to think that was when they made broadband over power lines, or BPL, legal (sometimes called Power Line Communications, PLC). Assuming you've not read about this, during the Bush administration, under the "leadership" of Micheal Powell (Colin's son), a group of companies petitioned the FCC to allow the distribution of broadband signals over the AC power lines (good summaries here and here). Eventually, they were granted this privilege. What's wrong with that? The broadband signals they want to use are wide bandwidth signals that will cover much of the HF spectrum. The inescapable physics of BPL says the power lines will radiate that broadband energy, interfering with lawful users. You see, the spectrum is allocated to users for specific purposes. Since the HF spectrum is among the first parts of the spectrum ever allocated, the entire HF spectrum is allocated to other users. What the FCC said in allowing this was "you established users are going to be interfered with, so you can take each other to court". This was unprecedented in US law! The US is signatory to treaties that license the HF spectrum to users on a "not to be interfered with" basis. The FCC was obligated to protect those users, but didn't, saying if you don't like the situation and can't resolve it between you, go to court. A key fact is that the rule authorizing BPL mandated keep-away zones around the FCC's installations. This means they knew that interference was unavoidable, and wanted to protect themselves. An "only ones" behavior - from a different agency.
I don't want to spend too much time here. There are many YouTube videos and other sources online that will show you how bad the interference is. Other nations (Japan, for example) studied the situation and refused to allow BPL. The point is that the FCC acted in a way they shouldn't and the technical experts were told to sit down and shut up.
The BPL decision was years ago. Another example is going on today. A company called LightSquared wants to put up broadband services in a different part of the radio spectrum, adjacent to the GPS services. This service will interfere with GPS. While they haven't ruled on the application yet, the FCC is apparently leaning toward allowing it, by asking them to run tests. Now losing the GPS in your car while you're driving around town is inconvenient but probably not fatal ... most of the time. Unfortunately, for airlines relying on GPS navigation, it will cause interference and could cause catastrophe. The aviation advisory group, Radio Technical Commission for Aeronautics, puts it this way:
Given the size of the planned deployment, “GPS-based operations below about 2000 feet will be unavailable over a large radius from the metro deployment center (assuming no other metro deployments are nearby),” the executive summary stated. “Given the situation in the high altitude U.S. East Coast scenario, GPS-based operations will likely be unavailable over a whole region at any normal aircraft altitude.”
I should point out that airlines don't generally use GPS for their primary navigation; GPS is a fairly recent system, while aircraft have been flying with radio navigation since the early days of flight.
And it's not just airplanes or your dashboard GPS that can be wiped out over wide areas. The WSJ said this:
Public safety officials near the testing area reported LightSquared's tower knocked out their GPS systems in some areas, according to Bill Range, New Mexico's E-911 program director, in a letter to federal officials. On Friday, construction giant Deere & Co. also reported to the FCC the risk of "severe interference" on its tractors GPS systemsThe GPS signal is set up to be very weak at the receiver to save power, weight and cost on the satellite transmitters, so strong nearby signals can inadvertently jam it. It's possible that "professional" grade receivers could be modified with the addition of some filtering or other improvements. If the FCC approves LightSquared's system, are they forcing everyone in the US with a GPS receiver to get it modified or replaced?
from as far as 20 miles away from a LightSquared tower and "a complete loss of service" between four miles and 22 miles.
Urgent Communications, a radio trade publication for police and other first responders, puts it this way.
The question then is: Who is going to pay to fix it? This is what the fight is really going to be about.I suspect this is a trick question, unless LightSquared has to provide new GPS receivers for everyone. Otherwise, if local first responders pay for it, the taxpayers buy it, and if the FCC has the Fed.gov pay for it, the taxpayers buy it, too.
Here's the conundrum. This is exactly the role that intelligent regulators should have. The spectrum in question is completely allocated or assigned, and some "bright boys" invent a new system. The FCC should impartially evaluate the technology and either allocate or reject the application; they should work with the licensed users. They have legal requirements to not allow licensed users to be interfered with. Instead of the technical guys evaluating whether or not there's interference, the lawyers set up a confrontational system where they require every license holder to either spend money to change their technology or spend money to fight the interference in court. That's bullcrap. The Commission shouldn't be lawyers; it should be engineers.
GPS is used to shoot approaches at a lot of municipal airports these days...
ReplyDeleteIndeed. The people most likely to be affected are the small pilots, not air transport.
ReplyDeleteI should have pointed that out, so thanks.
Muni airports handle lots or freight runs, which are increasingly used to keep our "just-in-time" manufacturing pipelines filled.
ReplyDeleteThe FBO I worked at during my SmithKline aviation days handled everything from our guys hauling medical and drug test specimens to chartered Twin Beeches picking up custom upholstery and flying it to the auto factory...