

Why LightSquared cannot deploy LTE - 11031a
http://www.extremetech.com/electronics/117127-why-lightsquared-cannot-deploy-lte

======
thechut
It appears that unlike AT&T and Verizon, LightSquared (formerly known as
SkyTerra) did not purchase this spectrum from the FCC. They are only licensed
to use that spectrum for low bandwidth satellite communications. The way I see
the situation, LightSquared is trying to change the licensing on their
spectrum in order to build a wireless network without having to actually pay
for any of the spectrum.

It seems there may even be somewhat of a conspiracy about getting the spectrum
approved.

See this press release from Chuck Grassley (R-IA):
[http://www.grassley.senate.gov/news/Article.cfm?customel_dat...](http://www.grassley.senate.gov/news/Article.cfm?customel_dataPageID_1502=38201)

The details seem very murky, I welcome anyone that has a better understanding
of how wireless networks work to please inform me.

~~~
aidenn0
Basically they are trying to exploit a loophole in the system: If you have a
satellite transmission network, you are allowed to use terrestrial stations to
fill-in the gaps. They are essentially trying to deploy a terrestrial network
by defining it as an extension of a fairly minimal satellite network.

All of that is just regulatory issues though. What really matters is
interference; I don't (and the FCC doesn't seem to) care if a transmission
comes from the ground or a satellite, so long as it doesn't mess with anybody
else's services.

The two points of view are:

1) LightSquared is operating within their spectrum requirements, so while
there are GPS receivers that will go haywire when they deploy, those GPS
receivers are faulty (as they don't properly deal with neighboring
transmissions on frequencies outside their band).

2) GPS should be granted a special exception to the rules about accepting
interference as GPS is very important and the GPS signals are very weak, so
therefore a receiver with little filtering on the front end is far superior to
one more tolerant of high power signals on neighboring frequencies.

Both arguments have their merit, so it should be interesting to see how things
play out. The more you look into how GPS works, it's a wonder that it works at
all which such low powers (and satellites in the middle of a radiation belt,
no less!)

~~~
ImprovedSilence
Valid points. If I recall correctly, the Obama administration is also pushing
for a nationwide wireelss network
([http://www.google.com/webhp?hl=en&tab=nw&q=obama%20w...](http://www.google.com/webhp?hl=en&tab=nw&q=obama%20wants%20wireless%20networks#sclient=psy-
ab&hl=en&site=webhp&source=hp&q=obama+wants+wireless+networks&btnK=Google+Search&oq=&aq=&aqi=&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=a26525a7a7e68331&biw=1280&bih=875))
, and I believe Lightsquared made a pretty good pitch to them to be able to
use the spectrum. I also knew a lawyer who was doing work for the FCC, that
was examining the possibility of buying back some of the lesser used satellite
bands, for both the lightsquared type of work, as well as for mobile carriers.

------
NelsonMinar
The problem is the spectrum LightSquared wants to use is too close to GPS.
They were licensed for one limited application of that spectrum and are now
trying to shift to another much higher power application and they don't give a
damn if nearby communication is harmed.

Here's a couple of technical articles on the results of testing LightSquared
vs. GPS. <http://www.insidegnss.com/node/2630>
<http://www.pcmag.com/article2/0,2817,2389264,00.asp>

"A report prepared by the Federal Aviation Administration's Navigation
Services division essentially attributes 794 deaths and over $72 billion in
additional costs to U.S. taxpayers if the LightSquared LTE system is
implemented."

------
jws
The FCC wants to deny LightSquared the use of their licensed spectrum because
neighboring users (GPS receivers) cheaped out on their receivers and can't
tolerate Lightspeed's transmissions.

I'm willing to accept that not breaking GPS receivers is a good thing, and
that allowing Garmin et.al. to sell cheap receivers by assuming neighboring
bands they do not have licenses to are unused is possibly a good thing.

But, having an independent, nationwide, high speed internet choice is
_definitely_ a good thing.

The FCC should take a frequency allocated to government use and swap it to
Lightspeed so they have bandwidth they can use. The existing users will pitch
a fit about the expense of moving, but a new nationwide cellular internet
player will likely save billions of dollars for consumers.

~~~
ChrisOstler
That's only telling part of the story, as far as I understand. Lightspeed
wants the FCC to _change_ their license for (lower powered) satellite
communication to allow them to use the spectrum for (higher powered)
terrestrial use.

Users of adjacent spectrum designed their products properly for being adjacent
to lower powered satellite signals. They weren't designed to filter out the
much higher power terrestrial signals that Lightspeed is vying for.

The FCC is not denying Lightspeed the use of their licensed spectrum; they are
not letting Lightspeed redefine their license to be something different than
it is.

~~~
jws
I believe their license includes the right to use terrestrial stations to fill
in. They are under a conditional waiver not use a satellite at all. They are
certainly using spectrum in a way not foreseen, but that is different from
forbidden.

The bottom line is that the US has suspiciously high wireless data costs and a
duopoly controlling the market. It's either make more players, effectively
regulate the existing players, or allow the overpriced drag on consumers to
persist.

There are only a quarter million airplanes in the US. Retrofit all of their
navigation aids systems and free up a couple hundred MHz of bandwidth and
you'd still pay for it with one year's savings from the mobile internet
consumers. (And probably have better navigation in the planes.)

~~~
rprasad
_I believe their license includes the right to use terrestrial stations to
fill in. They are under a conditional waiver not use a satellite at all. They
are certainly using spectrum in a way not foreseen, but that is different from
forbidden._

That's wrong. Only specific bands of wireless are unregulated; the bands at
issue here are heavily regulated and are restricted to low-power satellite
transmissions. Lightsquared had a conditional use permit to use the spectrum
it purchased for alternative purpose _but only if it could show that it would
not interfere with the use of other low powered satellite transmission
spectrums_. Light-squared failed to do so.

An example that has been brought up before: its as if Lightsquared bought a
house in a residential neighborhood, zoned for residential, and then tried to
demand the right to use it as a venue for holding large-scale commercial
concerts.

------
ImprovedSilence
I've known about LightSquared (and their spectrum issue) for awhile now. The
impression I get is that there is little technical evidence that using their
spectrum will infringe upon and overpower the neighboring GPS and other
signals. LTE has VERY tight technical specifications, just to get valid data
through, as the throughput is so high, and is unlikely to be a noisy signal
out of band, enough so to cause interference with it's neighbors. If you'll
notice, the linked article carries very little (or none) technical detail, it
almost sounds like some fear mongering politician wrote it. This ain't the
1940's here people, we aren't just sending random analog radio waves out using
oscillators with a 10% tolerance ratio. The spec is tight, the technology is
bleeding edge, and modern receivers (of GPS and the like) have pretty good
front end filters, out of band noise shouldn't be a huge problem for them.

~~~
rprasad
LTE vs GPS is like the difference between a Tsunami and a dripping faucet.

The problem isn't the noise, it's the volume. The volume alone would overwhelm
the GPS filters' ability to filter out the out-of-band noise.

~~~
aidenn0
To expand on the analogy, it's more like GPS receivers have a very wide funnel
so that they catch every drop. This funnel extends into the range that
lightsquared has. If it weren't GPS, the FCC would just say "fix your damn
receivers, they are within the parameters of your license" but GPS is clearly
Sui Generis because of the combination of the weakness of the signals and the
importance to our infrastructure.

------
jpastika
Interference Studies: <http://saveourgps.org/interference-studies.aspx>

I am by no means an expert on the technical reasons for the interference with
GPS, however, I work in the heavy highway construction industry and
LightSquared's use of the spectrum is of real concern. The level of accuracy
of current GPS guidance systems for construction equipment is astounding and
enables significant improvements in job productivity over conventional
practices.

I hope the truth and or a solution is discovered, as I do like the idea behind
LightSquared and would use the service if available.

------
chc
This doesn't make much sense at all. Why on earth would they license these
frequencies to LightSquared if they didn't want anybody using them?

~~~
RockyMcNuts
They licensed the spectrum for satellite comms, and LightSquared is trying to
use a loophole to use it as (much more valuable) cellular LTE.

------
bradleyland
I'm not sure why anyone is surprised. You can't listen to your iPod during
take-off on a commercial airliner, despite the fact that there is no proof
that they can cause any meaningful interference. How on earth did anyone
expect the licensing bodies would accept that LightSquared's technology could
be trusted not to interfere with such a critical infrastructure component as
GPS?

