LightSquared is furious over a news report suggesting that, in various trials, the satellite broadband company's proposed transmission system bumps into GPS devices around 75 percent of the time. A leaked preliminary draft of the government test report quotes the document concluding that LightSquared signals "caused harmful interference to majority of GPS receivers tested" and that "No additional testing is required to confirm harmful interference exists."
The experimentation, which was carried out between October 31 and November 4, showed that 69 of 92 GPS receivers "experienced harmful interference" when within 100 meters of a LightSquared base station, according to the Bloomberg story.
But the disclosure was foul play, LightSquared executives protested in a Monday telephone conference call. And the data is a "distortion of the truth."
"This came from someone in the government process and it is an outrage," declared LightSquared Executive Vice President Martin Harriman.
"We are very disappointed about the leak that occurred on Friday," added the company's general counsel Gordon Lu. "We think it was clearly intended to subvert the fairness of the process. The report presents a completely slanted and selective review of the test results. Clearly the leak was intended to prejudge the issue and prejudice public opinion against LightSquared."
Operational impacts
LightSquared is pressing ahead with its application to build a 4G broadband network, despite widespread opposition from the GPS and aerospace industries. Although the Federal Communications Commission has given the company a green light to move forward, that traffic signal only counts pending tests demonstrating that workrarounds for GPS device interference are feasible.
And it isn't just industry people who are jittery about LightSquared's bid to sell wholesale broadband via licenses that stream close to the Global Positioning System (GPS) bands. Back in April the Pentagon and Department of Transportation sent the FCC a letter expressing their worries and protesting that they hadn't been dealt into the evaluation process.
This led to more government testing, the results of which didn't assuage anyone's fears. A National Telecommunications and Information Agency assessment released four months ago fudged no words about the matter.
"The LightSquared Network initial deployment would cause severe operational impact over significant regions of the United States," the authors of the report warned.
The study, overseen by the National Executive Committee for Space-Based Positioning, Navigation, and Timing (ExCom) suggested that under some circumstances GPS receivers subjected to early phase LightSquared spectrum deployment would be "unusable" for air vehicles flying at 500 feet above the ground.
"LightSquared should not commence commercial services per its planned deployment for terrestrial operations in the 1525-1559 MHz Mobile-Satellite Service (MSS) Band due to harmful interference to GPS operations," ExCom concluded.
Power to the ground
That spectrum region is known as the L-Band. LightSquared argues that the service can leap over these hurdles via a variety of fixes, most notably by transmitting in the lower 10MHz portion of its allotted spectrum at acceptable power levels. This zone "poses no risk to the users of over 99 percent of GPS devices," the company says. The industry would "coordinate and share the cost of underwriting a workable solution for the small number of precision measurement and other devices that may be at risk."
And so the government launched yet another battery of tests, the full results of which are scheduled for release on Wednesday. As for these preliminary result reports, LightSquared pushes back with a letter sent to the Pentagon and Department of Transportation. Central to LightSquared's response is the claim that the reported failure levels must have assumed streams 32 times greater in power than the notches "at which LightSquared will actually operate."
LightSquared wants the government "to analyze the test results based on a measurement of the actual power level of LightSquared's network that will be experienced by GPS devices and not a theoretical model apparently relied upon by the leaked internal analysis," the statement explains. The real levels will be based on LightSquared's "power-on-the-ground" proposal, submitted to the FCC last Wednesday.
LightSquared will transmit at no higher level than -30 dBm until January 1, 2015, the company pledges—then at -27dBm until January 1, 2017, and -24dBm after that, "in order to provide greater certainty to GPS users and manufacturers that GPS receivers designed to look into the L-band will not experience receiver overload."
Open predispositions
The rest of LightSquared's letter more or less insinuates that somebody in the government is prejudiced against the company. Consider these two bullet points from the missive.
- We have raised concerns that some individuals involved in the testing process have displayed open predisposition against LightSquared. In their internal correspondence, for example, they openly discuss LightSquared's financial prospects; that LightSquared may "fold"; and that LightSquared should "warehouse" its spectrum to accommodate "most if not all of the GPS community."
- We have raised concerns about aspects of the testing protocol, including the fact that the GPS manufacturers were permitted to voluntarily submit devices for testing, which has the potential to skew the results.
During the conference call, LightSquared officials were asked whether the company planned to take any formal action based on these complaints. That doesn't appear likely. "The most appropriate thing we can do is raise our concerns," one official told reporters. "Our first step is to raise the issue and we'll see."
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