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Monday, September 26, 2011

LightSquared vs GPS update

Here's an update on the mess between LightSquared and the Department of Defense and everyone else who relies on GPS technology.

If you aren't aware of the controversy, here's what it boils down to. The Global Positioning System satellites (and other satellite navigation systems such as GLONASS and Galileo) transmit their data using L-Band radio waves, specifically centered at 1575.42 MHz (L1), 1227.60 MHz (L2), 1381.05 MHz (L3), 1176.45 MHz (L5).

LightSquared is a telecommunications company which is attempting to set up a new 4G network, with land-based transmitters using identical or nearly identical frequencies.

Yes, the FCC authorized them to use the frequencies. No, the FCC wasn't thinking real hard when they did that.

Radio Theory 101: a strong signal transmitting from near by will override a weak signal of the same or similar frequency which is transmitting from far away. Which is a polite way of saying that if LightSquared were actually deliberately trying to jam the GPS satellites, they probably couldn't manage a better job of it.

So, one simple solution would have been for the FCC to say "oops", and assign different frequencies to LightSquared. Another simple solution would have been for LightSquared to have taken the moral high ground and asked the FCC for different frequency real-estate. Neither of these things happened.

So the military and the FAA became involved, and explained to congress that LightSquared couldn't utilize the frequencies they'd been allotted by the FCC, because the military and commercial airliners actually relied on GPS to navigate safely. Which might have been the end of the whole conversation, but it turns out that in 2011, not only are corporations now people, but they now take precedence over the military and governmental agencies. It turns out that corporate profitability is much more important than the ability of military vessels and aircraft to carry out their missions, or for airliners to be able to safely navigate in dense cloud cover.

So, this issue is still being debated in congress, with LightSquared and the FCC on one side and the military, FAA and the manufacturers of GPS receivers on the other.

Personally, I am a bit conflicted. On the one hand, I recognize that the safety of hundreds of thousands of airline passengers probably outweighs the needs of people who want to be able to play FarmVille on their cellphones a little faster. On the other hand, I make my living teaching celestial navigation. Since the government turned off (and actually blew up, to ensure that they couldn't be turned on again) the Loran-C radio transmitters, GPS is the primary means of navigation on land, air and sea. Take GPS away, and for an ocean crossing (for example) the only means of navigation left to most people are dead reckoning and celestial. So, no Loran plus no GPS means lots of full classrooms for me, and the money just keeps rolling in.

Yeah, no, not having GPS is still bad. Not having GPS because a telecommunications company doesn't seem to able to play well with others, is really bad. The fact that congress even needs to deliberate on this particular no-brainer is really, really bad. But that's where things stand right now.

The following is an email update from the Coalition to Save Our GPS, a lobbying group working on behalf of the Department of Defense and FAA:


Two recent hearings focused on LightSquared and its impact on GPS signals. On Thursday, September 15th, the House Armed Services Subcommittee on Strategic Forces held a hearing where Air Force General William Shelton testified that, “based on the test results and analysis today, the LightSquared network would effectively jam vital GPS receivers. And to our knowledge thus far, there are no mitigation options that would be effective in eliminating interference to essential GPS services in the United States.’ When questioned about costs, the general responded, ‘We have not estimated cost. However, I think it'd be very safe to say that the cost would be in the b's – billions of dollars.”

On Thursday, September 8th, the House Science, Space and Technology Committee held a hearing on the “Impacts of the LightSquared Network,” where lawmakers and expert witnesses called for further testing of the planned network. Tony Russo, director of the National Coordination Office for Space-Based Positioning, Navigation, and Timing, said: "If GPS is a teaspoon of water, LightSquared is Niagara Falls.”…"Technical experts are split as to whether it is even feasible that we could put a filter in that was both strong enough to knock out the LightSquared signal and still allow us to do our mission.”

Earlier this week, the House Science, Space and Technology Committee and the House Oversight and Government Reform Committee announced that they have taken initial steps to investigate the possibility that political influence may have played a role in the FCC’s decision in the LightSquared waiver. Two letters that the House Science Committee sent to the Office of Management and Budget and the Office of Science and technology Policy can be found here.

We are anticipating Congressional action in the near future on two pieces of legislation that address the GPS interference issue. The first bill, HR 1540, directs the FCC not to proceed on the LightSquared matter until interference to Department of Defense GPS systems is resolved. The second bill, HR 2434, directs the FCC not to proceed on the LightSquared matter until interference to commercial GPS users is resolved. We are hopeful that Congress will take final action on these two bills in the next several weeks.

NTIA and FCC call for more testing:

In a letter to the U.S. Defense and Transportation Departments dated September 9, 2011, Lawrence Strickling, who heads the National Telecommunications and Information Administration, called for further testing of the LightSquared network to conclude by November 30. The letter called primarily for testing of cellular and personal/general navigation devices, noting that additional testing will be required for high-precision receivers once filters are developed to mitigate interference. The letter can be viewed here.

On September 13, 2011, the FCC called for further testing as well to ensure that LightSquared won’t cause harmful interference to GPS. The FCC's public notice can be found here.

LightSquared revises its plans…again:

LightSquared’s latest proposal – its third of the year – includes limiting the on-the-ground power levels its ground stations will transmit. While it appears to be a positive step toward reducing, for some devices, the harmful interference to GPS signals confirmed during testing of LightSquared’s earlier incomplete proposals, it still leaves a huge gap because it does not claim to solve interference to high-precision GPS receivers. Even after three tries, there remain substantial gaps in what LightSquared has offered.

LightSquared’s supposed technical fix for high-precision receivers:

On September 21st, LightSquared, in partnership with Javad GNSS, claimed to have found a solution that will prevent its network from interfering with high-precision GPS devices and that the company will test prototypes during additional tests required by the FCC. LightSquared has, as usual, oversimplified and greatly overstated the significance of the claims of a single vendor to have ‘solved’ the interference issue. There have been many vendor claims that have not proven out in rigorous tests and the demanding tests of marketplace acceptance. Moreover, this is not a one-size-fits-all situation and a few prototypes does not a solution make.

The way forward:

As the Coalition stated in a statement on Tuesday, September 20th, “It’s time for LightSquared to stop its glossy ads, irresponsible rhetoric, revisionist history and finger pointing, and provide genuine, fully-tested solutions to the GPS interference problem. LightSquared has always been prohibited from interfering with GPS, and it should have done its homework on this critical issue before spending its investors’ money. It is not the fault of government GPS users or the GPS industry that LightSquared has failed to offer proposals that actually solve the problem. LightSquared must accept the responsibility to provide technical proposals that do resolve the problem, as well as its financial responsibility to address any interference issues that it cannot resolve by technical proposals.”

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