[aprssig] How The FCC Plans To Destroy GPS - A Simple Explanation

[clayj at nwlink.com]

Yeah, this is definitely BPL "dejavu all over again".

But, as someone on Time-Nuts (where this originated) pointed out - the
first time the LightSquared (?) folks mess up either a military or
aviation GPS; the FCC will pull this authorization (and, as Steve says,
then the attorneys and consultants will get rich(er)).

In the meantime, there IS something we can do - I wrote all 3 of my
congresscritters (which is easy these days, just fill out some contact
information and cut/paste the text) and asked that they look into this. 
So far,only Patty Murray (Sen D WA) has responded; but her response was a
"legislative inquiry" to the FCC, asking them to respond to me.

Imagine how annoyed the FCC would get if they got 2 or 3 of these from
EVERY representative and senator; or even 50% of them!   If they get
annoyed enough, they MIGHT take a second look.

Clay
N7QNM


> Reposted from the Yahoo TinyTrack group:
>
> "Seen this in the VX-8R and TH-D7 groups here on Yahoo. Since I haven't
> seen it posted in here... I figured I would (as it would have a serious
> effect on APRS tracking).
>
> <http://freegeographytools.com/2011/how-the-fcc-plans-to-destroy-gps-a-simple-explanation>
>
>
> Mike - N1EVH"
>
>
> Quick summary of the story:   The FCC has apparently fast-track
> authorized, through a questionable procedure, a "4G" high-speed wireless
> internet service to operate on frequencies directly adjacent the the 1575
> MHz GPS channel.
>
> This system, ostensibly a satellite-based service, would be augmented by
> thousands of terrestrial "fill-in" transmitters that could desensitize or
> block GPS receivers for a radius of several miles around each site.
>
>
>
> I have already observed this phenomenon from 1.9 GHz PCS cellular base
> stations.  Some GPS systems with remotely-mounted active antennas
> containing 15-20 dB gain preamps (to offset the coax loss) will
> desensitize and go out of lock when they get within a half-block or so of
> a PCS cell site.  (All-in-one GPS devices, such as hockey-puck or
> mouse-type units or car navigators, where a non-amplified passive antenna
> is connected directly to the receiver front end, don't seem to be prone to
> this problem.)
>
> In the case of PCS, the offending transmitters are 400 MHz or so away from
> the GPS channel.  This new threat is DIRECTLY ADJACENT to the the GPS
> channel, and most likely will be a far far worse problem.
>
>
>
> Is this the BPL fiasco redux??
>
> Or more directly comparable, the mess on 800 MHz where thousands of Nextel
> transmitters were licensed on frequencies interleaved with 800 MHz public
> safety channels.  The problem was that the public safety systems use
> relatively few base stations, often on mountains or tall towers many miles
> away from the users' handhelds; i.e. delivering a relatively low signal
> strength to users on the ground.  The Nextel systems were placing
> transmitters on low towers every few blocks in town, yielding signals on
> the ground hundreds or thousands of times greater. These were massively
> overloading the front ends of PS receivers on adjacent channels,
> desensitizing them without creating audible interference.
>
> Hundreds of millions of dollars have been spent in a 800-MHz rebanding
> process (where Nextel is supposed to pay for new radio gear for the PS
> users on a different block of frequencies) that has dragged on for years
> now. So far, the rebanding effort has mainly benefited communications
> attorneys and radio design consultants hired by both sides.
>
>
> -------------------------------------------------------------------------------
>
> --
>
> Stephen H. Smith    wa8lmf (at) aol.com
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> Skype:        WA8LMF
> Home Page:          http://wa8lmf.net
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