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LightSquared struggles to save network after leaked GPS report

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LightSquared is fighting for the life of its proposed LTE network, as government test results emerging later this week question if there’s any possible way its 4G network can coexist with millions of commercial GPS devices. The report, which was leaked to Bloomberg on Friday, found LightSquared’s network would knock out the majority of general location GPS receivers if brought within 100 meters of a cell site. If the report’s findings stand, the Federal Communications Commission will have little choice but to void LightSquared’s plans for terrestrial network rollout, creating huge repercussions for partner Sprint(s S) as well as the 30 or so operators, ISPs and retail brands that have signed up to buy LightSquared 4G capacity.

LightSquared is trying to build a nationwide LTE network using satellite spectrum adjacent to the band GPS satellites use to transmit their location signals. The result has been a political and public maelstrom, pitting LightSquared on one side and GPS device makers, government agencies and any number of industries that depend heavily on satellite system’s location beams on the on the other. At issue is whether LightSquared’s high-powered LTE signals will overpower the much more sensitive GPS receiver embedded in vehicle nav systems, cellphones, airplanes, trucks, farm equipment and countless other devices.

LightSquared is livid about the National Space-Based Positioning, Navigation, and Timing Systems Engineering Forum’s report, which performed tests on 92 different types of GPS receivers, ranging from cheaper GPS handhelds to more sophisticated navigation devices, and found interference problems with 75 percent of them. In a letter dated Dec. 12 sent to the Forum (otherwise known as ExCom), LightSquared said the results of the report were purposely misinterpreted to paint LightSquared in a bad light. Furthermore, the letter stated, the testing didn’t take into account LightSquared’s latest plans to lower the transmission power of many of its towers: measures the would-be mobile operator claims would eliminate almost all of the interference problems ExCom identified.

At a press conference on Monday, LightSquared EVP of Ecosystem Development and Satellite Business Martin Harriman said ExCom tested at power levels 32 times to greater than the power at which the LTE network would operate (LightSquared announced its revised network configuration in September, after ExCom had begun its study). Based on LightSquared’s analysis, only 14 of the 92 different devices would have been affected, and those would see only imperceptible levels of interference, Harriman said. LightSquared and the government are using completely different thresholds to define interference, with the government raising red flags when it measures disruption levels six times lower than the level LightSquared has proposed. Harriman said the 1-decibel change ExCom is measuring is the lowest level at which a GPS receiver could even detect the presence of interference, but it by no means prevents them from functioning.

“It’s kind of like saying an extra foot of water in an 80-foot dam will cause that dam to fail,” Harriman said. He added that LightSquared believes once government testing takes LightSquared’s reduced power levels into account, it expects GPS receivers to skate through the tests with ease. Harriman also pointed out that none of the GPS-enabled mobile phones ExCom saw interference problems, even without taking reduced power levels into account.

But TMF Associates analyst Tim Farrar said he doubts ExCom’s conclusions would have been much different even if measured interference under LightSquared’s revised plan. Farrar pointed out LightSquared isn’t reducing transmission power at all cell sites, just at the low-slung towers in urban areas where devices are more likely to get close to a transmitter. In addition, LightSquared isn’t planning on maintaining those low “power-on-the-ground” levels indefinitely. LightSquared has stated it would gradually increase transmit power at those urban towers over the next five years, bringing them closer to the levels ExCom tested.

Even if LightSquared’s new network plans were to cut down that 75-percent failure rate considerably, any chance of failure would be unacceptable when it comes to the country’s commercial GPS system, Farrar said. Light aircraft use the types of general location receivers that ExCom tested, and even a small amount of interference could have a critical impact, Farrar said. The government is being conservative, Farrar said, but it has every right to be.

“Yes, we’re talking worst-case scenarios,” Farrar said. “If they reduced power levels further, that ‘worst case’ would occur less often, but is that enough when public safety is concerned?”

LightSquared wants more testing, but this latest setback will increase the already intense political pressure on the company and its principal investor Harbinger Capital Partners. If the FCC decides to deny LightSquared its network, the repercussions will be felt throughout the industry. Sprint has not only contracted with LightSquared to build its LTE network, but Sprint also plans to use half the network’s capacity to augment its own LTE service. A failed LightSquared would drive Sprint even further into the waiting arms of Clearwire(s clwr).

LightSquared has signed up 30 wholesale partners, all which would have to look elsewhere for mobile broadband network. That could benefit Clearwire, which is still clinging to the idea of expanding its wholesale business, and it could benefit Dish Network(s dish), which just picked up some choice satellite spectrum of its own. Unlike LightSquared, though, Dish’s L-band spectrum isn’t sitting smack in the middle of the GPS band.

7 Responses to “LightSquared struggles to save network after leaked GPS report”

  1. Nitin Khanna

    I’m surprised this report is causing any problems. LightSquared’s LTE network deployment has been under fire from the GPS industry since a long time. The LightSquared solution to this problem has been completely ignored by the GPS industry. It’s like the GPS consortium is saying – “We know it’s out fault that our devices will be affected by something that is out of the spectrum we were allowed to use, but anyways, we were here first, so you pay for the changes in tech. Thanks!”

    • Kevin Fitchard

      Hi Nitin, It’s a bit of a mess, isn’t it? While LS is right that GPS receivers listen in on its airwaves, what’s the FCC gonna do? Shut down the nation’s GPS service so Falcone can get an LTE network? I know it’s not as extreme as that. But no matter which way you look at it and who’s fault it is, the outcome is just bad.

      If LS can’t find a solution to mitigate interference, in my opinion the best thing to do is figure out a long-term plan to make he L-band broadband safe. That would require GPS makers to change the design of their devices, but they’d have many years to make those changes, allowing for turnover and retrofits. Otherwise that spectrum will sit their useless.

      • Actually it’s still useful for its original allocation of satellite to mobile terminal services.

        Then, as Lightsquared contends, there have been FCC actions allowing ancillary terrestrial fill-ins. I’m not sure why Lightsquared needs a license modification. Perhaps the license that came with their satellite wasn’t quite adequate to authorize a terrestrial LTE network. LTE networks were still theoretical concepts during the middle of our last decade.

    • Nitin, There are errors in your information and conclusions. 1. GPS receivers work just fine when Lightsquared uses their frequencies as originally (and currently) licensed. The only reason they can’t just build their network is because they are seeking a waiver of the FCC regs that were put in place many years ago to protect the GPS spectrum. 2. Lightsquared’s plan is to take cheap spectrum ($2B worth), twist the FCC’s arm to allow it to be used for terrestrial use (i.e. use it as much more valuable spectrum, worth $10B) and pocket the windfall, while forcing the resulting problem of GPS interference on GPS owners and manufacturers. 3. GPS device filter design is a science of trade-offs, primarily selectivity (avoidance of interference) versus sensitivity (better reception). GPS designers put in adequate filters for transmissions in Lightsquared’s spectrum when they originate from satellites hundred of miles away. To expect them to reduce the performance or increase the cost of GPS receivers when designs were made in light of current FCC protection of power output on neighboring frequencies was in place. And in the end, these companies have to pass their design and manufacturing costs along to us, the consumers, so we just end up paying for it. If you want to see how difficult this is, check out Javed’s presentation (he’s working on a solution to the Lightsquared interference for his high precision GPS devices). He describes Lightsquared’s transmissions to be over 1 trillion times in power than the GPS signals, when measured at the GPS antenna. That is a big deal!

      It is not anywhere near as simple of an issue as Lightsquared makes it out to be in their flurry of deceptive press releases. Please study the history of this spectrum allocation to put Lightsquared’s claims to the test. My opinion is if they want to profit from the re-purposing of their satellite spectrum for terrestrial use, they are the ones who must pay for the GPS solution.