LightSquared and the GPS Industry Struggle to Coexist

Can LightSquared's ambitious new 4G wireless network play nice with vital location services?

by / September 28, 2011 0
LightSquared's Jeff Carlisle says his company spent $9 million to eliminate GPS interference. Photo by Bob Rives Bob Rives [photoshoot]

Others have tried and failed, but with a go-ahead pending from the FCC, one wireless broadband company is a step away from transforming the wireless industry. Backed by billionaire hedge fund manager Philip Falcone, Virginia-based LightSquared has signed a 15-year contract with Sprint Nextel and is ready to begin a cooperative eight-year network build-out that would provide terrestrial and satellite-based 4G-long term evolution (LTE) Internet service to 260 million Americans by the end of 2015.

But the contender has a powerful opponent. LightSquared operates in a band of radio frequency adjacent to GPS, raising fears that the new 4G service could interfere with GPS-based location systems used for public safety, aircraft navigation and other crucial tasks. Indeed, last year, LightSquared’s initial transmissions interfered with GPS receivers — prompting the company to cut both signal strength and the size of its operable spectrum in order to create a buffer between its 4G service and GPS signals.

Additional testing has not yet been done, but analysts predict the changes may eliminate the interference with standard GPS receivers. However, LightSquared still needs to eliminate interference with high-precision receivers, which improve the accuracy of hurricane and earthquake monitoring, as well as farming, construction and surveying equipment. These high-precision GPS receivers account for roughly .5 percent of GPS receivers used nationally.

The GPS industry is up in arms. It wants the FCC to move LightSquared elsewhere on the frequency spectrum in the name of public safety. LightSquared contends that the problems can be solved without relocating its signal. The Federal Aviation Administration (FAA) sided firmly with the GPS industry, issuing a report in July stating that 794 human fatalities would occur from 2014 to 2023 due to “LightSquared impacts to GPS,” and would cost taxpayers $72 billion in GPS retrofitting costs. LightSquared maintains that the GPS interference problems stem from a lack of foresight by GPS device manufacturers and noted that LightSquared is also concerned about the public safety ramifications. Will GPS and LightSquared find common ground?

Organizing the Band 
Allowing LightSquared to build a full-fledged network in its current spectrum band — known as the Mobile Satellite Service or MSS band — doesn’t make any sense, contends Jim Kirkland, founding member of the Coalition to Save Our GPS. LightSquared’s current chunk of spectrum is a legacy of the company’s initial business plan to create a land-based network to fill gaps in satellite network coverage, Kirkland said, explaining that, “[In] spectrum planning and management, you put similar uses next to each other.”

In early September, the House Committee on Science, Space and Technology heard testimony from Scott Pace, director of the Space Policy Institute at George Washington University. Pace, who has been involved with GPS issues for more than 20 years, proposed that the FCC, Obama administration and Congress deny LightSquared operation in its current state and withdraw its license to operate in the MSS band. 

Allowing LightSquared to operate without searching for alternate solutions, Pace said, violates the traditional organization of wireless spectrum and creates interference issues.

Pace proposed one solution — allowing LightSquared’s satellites to operate in their current spectrum location adjacent to GPS, but moving the company’s terrestrial service elsewhere on the spectrum. Space on the wireless spectrum may be hard to come by, he said, but jeopardizing a utility as important as GPS is not an option. “When it comes to spectrum efficiency, GPS is arguably the most efficient use of spectrum the world has ever seen,” Pace said. “Almost a billion people are currently benefiting from the 20 MHz GPS signal that is available today.”

As with any feud, the story of LightSquared’s open wireless broadband network and GPS changes dramatically depending on who’s telling it. In 2002, LightSquared and GPS industry representatives were on the same page when they drafted an agreement restricting any part of LightSquared’s signal from entering GPS frequencies. In the intervening years, several revisions were made to LightSquared’s plan through the FCC; some industry rules changed and now both parties are living with the reality that being a good neighbor is easier said than done. Determining who is in the wrong and what will happen next is a complex matter that will affect how much of the country connects to the Internet.

To help make sense of things is Alex Wyglinski, an assistant professor at Worcester Polytechnic Institute, who specializes in wireless spectrum and signal processing issues. “It’s kind of scary that they’re trying to do this so close to the GPS band,” he said. “The problem is, there’s not enough spectrum out there.”

Across the United States, 200 million cell phones are stuffed into purses, jammed into pockets and clipped to belts — and more are added every day. LightSquared simply is attempting to meet that connectivity demand, Wyglinski said. “The problem in modern society is that frequency is getting really crowded.”

Wireless signals aren’t well defined like cars driving down lanes on a highway, so every wireless signal automatically interferes with every other signal to some degree. But GPS is particularly vulnerable.

“GPS signals are ridiculously weak,” Wyglinski said. “The satellites are something like 20,000 kilometers up in space. When it reaches Earth, it’s an extremely weak signal. The signal from GPS is actually weaker than the thermal agitation of the electrons in the metal of the receiver.”

The only reason GPS works is because there are complex signal processing algorithms that distill the GPS signal from competing noise and interference within its frequency band. If GPS signals whisper, LightSquared signals scream — and that noisy neighbor could interrupt these quiet conversations.

LightSquared mitigated interference with standard GPS receivers by moving slightly away from GPS on the spectrum band and lowering signal strength. But this creates new problems for the company, Wyglinski said. Reduced signal power means weaker, spottier service for LightSquared customers, and creating a buffer zone — known as a guard band — means there is prime spectrum real estate that’s going unused. “It doesn’t make much business sense,” he said. “LightSquared is really stuck between a rock and a hard place.”

Another problem is the interference with high-precision receivers. If LightSquared can solve that issue, the GPS industry might be appeased. Jeff Carlisle, the company’s vice president of regulatory affairs, said LightSquared has been very cooperative, and now it’s the GPS industry’s turn to carry the onus.

Interference with high-precision receivers isn’t the company’s fault, Carlisle contends. “The GPS industry council asked us to limit our out-of-band emissions, so we did. We spent $9 million developing a filter that did that.”

What the GPS industry didn’t tell LightSquared, Carlisle said, was that high-precision receivers only work properly by reading signals outside the GPS band. In late August, the Information Technology & Innovation Foundation, an IT policy think tank, filed comments with the FCC supporting LightSquared’s claim that the commercial GPS industry is responsible for interference problems between GPS devices and LightSquared’s network. The foundation alleged that the manufacturers of high-precision GPS devices ignored government warnings and guidelines when they built their receivers, deliberately building devices that listen into the satellite L-band spectrum, which is where LightSquared wants to operate.

“The GPS people like to pretend this is something that started a couple of months ago, but they’ve known about this for 10 years,” Carlisle said.

LightSquared isn’t alone in its fight against the GPS industry. Many public interest groups and rural community leaders have presented letters to the FCC in support of the company’s plan.

Carlisle also branded the FAA report supporting the GPS industry a dirty political maneuver. “The report itself was completely inaccurate. They didn’t just say it would cause interference, they said we would completely knock out GPS for 10 years. Nobody is talking about knocking out GPS for one second,” Carlisle said. “They absolutely refuse to acknowledge the fact that high-precision GPS receivers are stationary. We know where they are. Many of them are near airports and we have to restrict our signal near airports anyway. There needs to be a certain amount of reality injected here.”

In fear of LightSquared’s broadcasts, hundreds of companies and groups from the GPS industry have united to create the Coalition to Save Our GPS. Jim Kirkland, vice president of Trimble, a maker of GPS products and founding member of the coalition, said the controversy with LightSquared comes down to a matter of intentions.

LightSquared’s original intent, as authorized by the FCC in 2002, was to offer limited-purpose, ancillary satellite fill-in for terrestrial service, Kirkland said. “This sat around in dormancy for eight years, and now they blame us based on a fill-in authorization and zero activity in eight years,” he said. “All the people talking now about what the FCC did weren’t even around in 2002.”

LightSquared’s chunk of spectrum is valued at roughly $12 billion, but because of the way it was acquired, the company paid only a small fraction of that cost to acquire it, Kirkland said. “No one knew that they were going to do this. You’re telling me that AT&T or Verizon wouldn’t have bought them out?”

As for the claims that the GPS industry is being uncooperative, Kirkland said that’s an exaggeration — and it’s beside the point, because GPS was here first.
“The GPS industry has worked with LightSquared all along,” he said. “Trimble, my company, has two to three engineers working full time trying to find a solution to this problem.”

Who Uses High-Precision GPS?
One of the most outspoken opponents of LightSquared is in agriculture. John Deere sells high-precision GPS systems to farmers who want increased efficiency and accuracy from their equipment. Using a tripod base station, tractors, combines and sprayers can stay within 2.5 cm of their routes. But the receivers won’t work with LightSquared’s current broadcast settings.

GPS is also used in public safety to monitor earthquake and hurricane data. Because high-precision GPS can measure within centimeters, rather than meters, it can give researchers a more informative data set. In 2008, a team of researchers at Purdue University used GPS to predict the 2010 Haiti earthquake.

High-precision GPS is essential in surveying and construction, and many of the GPS tools used by surveyors would become useless without wide-band capability.

But LightSquared, he said, is the newcomer. “If someone came up to you and said, ‘Give me all your money,’ does that make you uncooperative if you say ‘No’? We want to make this work,” Kirkland said, “but you’re not going to gamble on E911 calls and hurricane prediction.”

A ground network that reaches 260 million Americans by the end of 2015 is LightSquared’s plan largely because the FCC stipulated that figure — but it’s good news for rural areas that have trouble getting broadband Internet access. Akshay Sharma, mobile infrastructure research director at Gartner, said in some ways LightSquared’s plan could end up doing what Obama’s old high-speed Internet plan was supposed to do.

“That turned out to be more of a jobs act; wireless is probably a better approach for rural America,” he said. “For these wide swaths of land, you can’t reach everywhere with fiber. LightSquared could even turn a lemon into lemonade.”

With Sprint shutting down the Nextel push-to-talk network, LightSquared is in a unique position to provide that functionality with its satellite coverage, Sharma added. And in fact, LightSquared announced in July its intention to provide push-to-talk functionality, emphasizing the benefits to public safety.

Public interest groups are paying attention to LightSquared because the company could help reverse growing vertical integration in the telecommunications industry. LightSquared plans to sell service wholesale to wireless retailers, which analysts say will give any company a chance to compete with the big boys. Deals with Best Buy, Leap Wireless, Cellular South, Net Talk, South Illinois Wireless, Powernet Global and Open Range have been announced.

Michael Calabrese, a senior research fellow at the New American Foundation, is among the public interest group representatives who have presented the FCC with letters supporting LightSquared. “It’s appalling because essentially the GPS industry has decided that they’re just going to take an absolutist position,” he said. “They’re going to take the spectrum for their own use, they’re not going to give it up, and they’re not going to bear any of the responsibility. The GPS people haven’t done anything since 2003, and from a standing start, now it’ll take time and money.”

The FCC has resolved similar issues before, like when Sprint was forced to rearrange the 800 MHz band so as not to interfere with public safety utilities.

“In that case, the FCC’s order sternly stated that certain parties are trying to attribute blame, but no one was to blame. It’s just crowded. These boundary issues are coming up more and more often. There’s only so much beachfront spectrum,” Calabrese said. “I think the FCC’s motivated to try to find a path for the two industries to coexist.”

A likely solution, he said, includes a multipart plan where the most important GPS infrastructure is fixed immediately to eliminate interference issues, and old GPS receivers are phased out over several years. The costs, he added, would likely be divided between GPS and LightSquared.

With the telecom industry trending toward a duopoly dominated by Verizon and AT&T, Calabrese said the FCC should not only allow LightSquared into the market, the agency also should encourage everyone to find technical solutions that allow LightSquared to use its entire spectrum. “The L band is a big chunk of a dwindling supply,” he said, “we can’t really afford to be throwing it away on a guard band.”

LightSquared’s plan also would allow for more innovation in the technology industry, Calabrese said. When Apple released the iPhone, it was forced to partner with a carrier because there are no wireless wholesalers. If LightSquared had been around, Apple or even a much smaller company could have released its device and provided its own service plans, leased through LightSquared.

The deal with Sprint, Calabrese said, was a good move. “That makes us much more hopeful about this. The fact that LightSquared could piggyback on Sprint’s infrastructure means it’s much more likely LightSquared can do this,” he said, adding that it’s also good for Sprint because it makes it likelier that Sprint can survive the impending duopoly. “I think Sprint has in mind becoming an infrastructure co-op. They might invite other carriers to bring spectrum to their towers.”

It’s crunch time for LightSquared. If the company wants to begin testing its network next year, as planned, it will need to find a comprehensive solution to its interference problems. Michael Marcus, a wireless technology expert who worked for the FCC for 25 years, said LightSquared won’t survive if it can’t ace the next round of testing. “The day LightSquared turns on,” he said, “there had better not be interference to most, if not all, GPS units.”

The FCC is unequipped to handle this sort of testing, so the agency has left it to GPS and LightSquared to do the testing and return to the FCC with results, Marcus said. “They all hold hands and cooperate, but when you read the paper, you can see some friction going on.” But it won’t matter who is at fault if the interference problems aren’t fixed, he said, because ultimately, GPS is too important to worry about playing the blame game.

Colin Wood former staff writer

Colin wrote for Government Technology from 2010 through most of 2016.