GPS signal interference

[Randygh]

I just received an email from Boat U.S. asking members to contact the FCC to oppose allowing, "LightSquared, to begin a nationwide broadband service adjacent to the radio spectrum used for GPS."

The boat US memo says that allowing LightSquared to operate next to GPS frequencies will cause significant interefence in GPS operation.

My question to the guys who know about this, is there a possiblity of significant GPS interference, resulting in inaccurate readings? I haven't responded to the Boat US request, but will do so if there is a possibility of GPS interference.

[SomeSailor]

I believe the interference they're speaking of will be in lessor quality GPS devices. It's really not the LightSquared signal at all, but the inability of receivers working in nearby frequencies that couldn't reject the noise. We'll have to wait and see if the FCC lets them spread out.

[waclark57]

According to LightSquared they have a fix and/or workaround and are claiming to work with manufacturers to ensure no interference.

Of course, that was in an ad in the WSJ where they were likely hunting for more investors so I don't know how accurate their statements are.

[SomeSailor]

The bottom line though is the bandwidth they've been authorized to use is too tight for them to guarantee harmonics won't interfere with nearby spectrum. They're wanting to use a frequency that Inmarsat uses for voice currently up in the L band. It started out as a satellite to earth only system, and their latest application is to open that up to expand their LTE network. Problem is with all the LTE cell phones coming the interference is gonna be a problem. They're just not sure how much yet. It will happen if they're allowed to proceed.

It's a bad idea.

[MartySchwartz]

I seem to recall reading that the transmit power they were talking about using was significantly greater than the power of the GPS signal. That article (really wish I could remember where it was) said that initial tests showed significant interference with current GPS receivers. While the GPS manufacturers could certainly build better signal discrimination into their units that would not really help those millions of units already out there, like OURS.

Marty......................

[fishaman]

If they proceed, and there will be confirmed interference even with the low quaity GPS, they will be sued by insurance companies for all damage from boats running aground in San Juans...

[SomeSailor]

Or from individuals who suddenly cannot use the hardware they were able to use yesterday.

[debbie]

This is kind of a big deal, kinda. Sprint had just inked a deal with these guys and then it was revealed that there is this small matter of interference...it's for real as far as I can tell, so better to err on the "safe" side (for US) and make the call. (to heck with oil, spectrum is where the money is there days).