[GeoStL] Re: LightSquared Transmission interfers with GPS Signals
- From: Tom Wolpert <tom_wolpert@xxxxxxxxxxx>
- To: geocaching@xxxxxxxxxxxxx
- Date: Wed, 22 Jun 2011 09:54:59 -0700 (PDT)
There's more recent news about this. LightSquared has conceded that their
original proposal will cause problems. They are looking at moving to a more
distant part of the spectrum, as well as cutting the power by about 50%. Don't
know that this will solve all the problems, but it's a step in the right
direction. Also, I don't think the FCC approval was final. LightSquared is
supposed to be working with GPS manufacturers to come up with an acceptable
solution.
Tom
________________________________
From: Bob TheCacher <cachefinder@xxxxxxxxxxx>
To: geocaching@xxxxxxxxxxxxx
Sent: Wed, June 22, 2011 11:46:14 AM
Subject: [GeoStL] LightSquared Transmission interfers with GPS Signals
Some of you may already know that LightSquared is building another cell phone
network using satellites and ground base receivers/transmitters. They want to
use a frequency band so close to the MSS band (GPS signal band) that it
interferes with the signal acquisition. Here is an excerpt of an article that
I
thought was worth reading:
On January 26, 2011, the Federal Communications Commission (FCC) issued an
Order
and Authorization giving LightSquared conditional approval to build out its
ground-based wireless network (referred to as an ancillary terrestrial
component, ATC) by reusing its authorized mobile satellite service (MSS)
spectrum. The approval is subject to further testing and FCC review (see
below).
Why is the GPS community concerned? The base stations of the LightSquared
network will transmit signals in a radio band immediately adjacent to the GPS
frequencies. The GPS community is concerned because testing has shown that
LightSquared's ground-based transmissions overpower the relatively weak GPS
signal from space. Although LightSquared will operate in its own radio band,
that band is so close to the GPS signals that most GPS devices pick up the
stronger LightSquared signal and become overloaded or jammed.
There is also concern that the FCC may approve a technical solution to the
problem that requires millions of existing GPS users to upgrade or replace
their
devices.
I hope our current GPS's still work after they get their network in place.
Bob Pratt
BBD1
Other related posts:
