Ratherbflyin's Ramblings

It appears that LightSquared is prepared to sue the FCC if the FCC does not issue approval for the company to begin installation and operation of approximately 40,000 towers in the US to provide universal 4G data service across the country. At a glance that may not seem like a big deal, and may even be considered business as usual. However, the issue is a much more complicated one since the network LightSquared is proposing uses a band of frequencies right next to the frequencies that the GPS system uses. During testing, it was demonstrated that there was considerable interference with the operation of some GPS receivers when the receivers were in proximity to the proposed towers.

A number of industries that rely on GPS have been watching this process with considerable unease. The aviation industry in particular is concerned, since the NextGen ATC system that the FAA is working on will rely heavily on GPS. In many industries, interference from LightSquared’s proposed network could cause problems of varying severity, but in aviation any GPS interference could have disastrous consequences.

On the other side of the coin, LightSquared blames the interference on GPS receivers that “hunt” for signals and pick up signals from frequencies that are outside those used by the GPS satellites. They state that the manufacturers of the receivers have ignored standards to prevent receivers from picking up frequencies from outside the GPS band of frequencies. They certainly have a point if, in fact, current receivers do pick up signals that are not coming from the GPS satellites, and those signals are causing interference with the ability of the receiver to calculate an accurate position.

LightSquared actually claims to have a “Simple, Affordable Solution” to the potential problem of interference. However, they make no mention of exactly what “affordable” is. They also seem to imply that existing GPS receivers can be retrofitted with their solution, but given the millions of receivers currently in operation, from cell phones all the way up to airliners and military equipment, will all of the existing receivers be able to be retrofitted? LightSquared claims that the fix will not “increase the selling price” of new receivers to the consumer, but how much will a retrofit of an existing receiver cost?

LightSquared’s simple solution was “developed in a matter of days,” and apparently tests were positive for reducing or eliminating interference. However, I am somewhat skeptical of a one-size-fits-all solution to this problem, especially where aviation is concerned. GPS receivers intended for use in navigation of aircraft are extremely fine-tuned. If the solution created by LightSquared is limited to blocking any frequencies outside of the GPS spectrum, then it may very well work as intended. It will, however, need to be tested in every GPS receiver approved for use in aviation, in every configuration. LightSquared may find their house coming down around their ears if an airliner full of passengers crashes and it is determined that LightSquared’s network was responsible for sending the aircraft off course.