Original URL: https://www.theregister.com/2011/08/12/lightsquared_gps/

LightSquared blasts GPS naysayers in FCC letter

Is GPS too important to be restricted by law?

By Bill Ray

Posted in Networks, 12th August 2011 15:04 GMT

LightSquared, the US operator hoping to camp beside the GPS frequencies, has written to the FCC accusing the GPS industry of failing to comply with the Department of Defence standards.

The letter is in response to the industry complaints that LightSquared is putting lives and property at risk by insisting on setting up a 4G network in the nearby bands. The GPS crowd doesn't deny that it hasn't been playing by the rules, but claims that it would be impossible to prevent interference from the high-powered transmissions and that it is now too big to be allowed to fail.

When LightSquared acquired the bands, from a couple of satellite phone operators, they were considered worthless, as they were encumbered by a restriction requiring their use with satellites. LightSquared successfully lobbied the FCC, while making friends in the White House, and had the rules changed so it can (and looks like it will) deploy a ground-based 4G network in the frequencies.

One of those bands is right beside the GPS bands, while the other is some distance off, and LightSquared has offered to commence deployment at the latter band while the GPS people get their act together. But both bands are too close to the GPS signal for the industry, which claims LightSquared network "pose[s] an immediate and direct threat to ... the United States economy and the safety of life and property".

LightSquared says the GPS kit is at fault for failing to follow the DoD guidelines, which state that GPS receivers must be responsible for ensuring they only receive signals on the right frequency. The GPS industry says that can't be done, as the technology simply doesn't exist: "There has never been, nor will there ever be, a filter that can block out signals in an immediately adjacent frequency band that are so much more powerful, nor has LightSquared put forward any credible, independent expert opinion or other evidence that this is possible," the rep told us.

The situation is analogous to a company, LightSquared, buying a patch of land, only to discover a neighbour's building intrudes upon it. The new owner complains to the authorities who may rule that the building is to be removed. But if that building is the stanchion of a significant bridge, then removing it will have a detrimental effect on the society, so even if that bridge is owned by a private company it still might not be acceptable for the land's new owner to demand the stanchion is removed. An alternative agreement will have to be reached.

Taking that analogy further, the GPS crowd reckon LightSquared should have known of the incursion when buying the land, and as the land is supposed to be agricultural (satellite-linked), no one should be building on it anyway.

The vast majority of GPS kit currently picks up signals that are broadcast in the bands owned by LightSquared, and even the more distant band is picked up by some 200,000 or so receivers. They're not supposed to, but the millions of GPS receivers already deployed do not comply with those guidelines, while the SaveOurGPS campaign says compliance is impossible.

It now looks as if LightSquared's network will get built, thanks to Sprint's involvement, so the American public will have to decide if GPS has been in the band long enough to gain squatters' rights, or if it should be kicked out to let the owner take possession. ®