ShadowGeek

There has been several experiments showing that Lightsquare’s systems interfere with GPS frequencies.  Lightsquare is now seeking a ruling to put the blame on the GPS manufactures and therefore be permitted to roll out it’s system while forcing the GPS manufactures to fix their systems.  If this goes through it will be a disaster.  First of all, the GPS systems in question are already out in the market, and Lightsquare’s isn’t.  Even if this was the fault of the GPS equipment, there is not economical or technical way to update every GPS device, especially those that are securely embedded inside of systems.

But, this is not the GPS manufacture’s fault as Lightsquare will have you believe.  GPS receivers are just that, receivers.  They only listen for the GPS signal that is broadcasted from the satellites above.  The GPS signal is very weak, and therefore the receivers must be sensitive to pick them up the signal.  If Lightsquare is broadcasting too close to the GPS frequencies, or on the GPS frequencies, of course these sensitive receivers will pick it up.  Welcome to basic radio theory.  GPS receivers have been around for many years, and have evolved.  In the beginning it took a long time to pick up a satellite and only a few could be picked up at a time.  That wasn’t good enough for either military or commercial use (no good if your GPS only starts working after you arrived at your destination), so they pushed up the sensitivity and improved the processing.  Now they have GPS receivers that can find your location quickly, just like we want it.  The outcome of this is that a small buffer is needed around the frequencies to ensure that they aren’t accidentally interfered with.  That is the price we pay to have a GPS system that works, and that is the frequencies that Lightsquare wants to use.

Sorry Lightsquare.  Much of our civil infrastructure, consumer electronics, and military systems rely on GPS.  If your systems are going to interfere with them then you lose.  If your system was already deployed and GPS was new, then the roles would be reversed.  You are the one coming late to the frequency party and therefore get stuck dealing with the outcome of several years of evolution of GPS.

I like what Lightsquare is trying to do, and I do hope that they can find some frequency band that will work for them.  However, the GPS bands must remain off-limits.  It is unfortunate for any company that has a good idea, and believe that they have a right to develop systems that border on the GPS, that their plans get screwed.  The Government did a poor job of laying down a foundation for frequency management.  There was no way to do it well, given that no one had any idea as to how wireless technology would evolve.  The FCC has done its best with what it has, but it is stuck with many legacy decisions and systems that abuse the frequencies they are given.  At some point we’ll have to make the same transition as we did with standard to digital televisions, but this time with military radios, satellite communications, and commercial wireless devices.  It will be a challenge and will likely take several hundred years to complete.  Until then, Lightsquare and others like them are stuck with what we have, no matter how unfair it may seam.

Best of luck Lightsquare, but stay away from my GPS… it is often the only thing that knows where I’m going… and I’d like to get there someday.