[time-nuts] Lightsquared and a little math

[Charles P. Steinmetz]

Stanley wrote:

>Wonder if the clients of this network reduce power as cell phones do 
>to increase battery life and reduce interference or they will use a 
>dish on the fixed clients, not that would help with interference 
>from the sat. The web site reads like the sat will distribute the 
>internet signal direct to the clients

The issue is not signals from satellites, which are very 
weak.  Satellite operators serving mobile and portable devices (which 
generally cannot employ high-gain, narrow-beamwidth antennas like the 
dish antennas used for stationary ("fixed," in FCC parlance) 
satellite services such as direct-to-home television reception) have 
found that there are significant coverage "holes" and have asked the 
FCC to allow them to use an "ancillary terrestrial component" ("ATC") 
-- i.e., base transcievers on towers, like cellular base stations -- 
to cover the holes.  The ATC rules, as they are currently written, 
require the ATC component to be ancillary to and integrated with a 
robust satellite system that is available to all system users (the 
"integrated service" rule).

Even with ATC, the Mobile Satellite Service ("MSS") has never really 
caught on, so it represents a fair chunk of spectrum getting very 
little use.  Some MSS providers seek to create primarily-terrestrial 
systems with an essentially vestigial satellite component.  The FCC 
(in its National Broadband Plan -- see 
http://www.broadband.gov/plan/) has started to move toward allowing 
terrestrial-only services to operate on a co-primary basis with the 
MSS on MSS spectrum, which has emboldened MSS 
licensees.  Lightsquared, which is an MSS licensee, petitioned for a 
conditional waiver of the "integrated service" rule, which the FCC granted:

http://fjallfoss.fcc.gov/edocs_public/attachmatch/DA-11-133A1.pdf

One of the conditions imposed by the FCC was "the creation of a 
process to address interference concerns regarding GPS and, further, 
that this process must be completed to the Commission's satisfaction 
before LightSquared commences offering commercial service, pursuant 
to the approval of its request, on its L-Band MSS frequencies."  This 
process is expected to be completed within 90 days.  See paragraphs 
39-43 of the FCC order linked above.

So:  The FCC seems determined to allow the expanded use of L-band MSS 
frequencies for terrestrial use to deliver mobile broadband services, 
and Lightsquared is just one company looking to benefit.  The primary 
threat to GPS (GPS L1 is 1575.42 GHz) is from terrestrial base 
stations serving mobile devices and operating up to 1.559 GHz, 
although millions of mobile handsets operating between 1.6265 and 
1.6605 GHz may also be a worry.

The FCC has made way more than its share of boneheaded technical 
decisions over the decades (to name just the most visible tip of the 
iceberg: NTSC, multiplexed FM stereo, NRSC preemphasis of AM signals, 
AM stereo, forcing the switch to digital television, choice of 
ATSC/8VSB as the digital television standard, choice of IBOC as the 
AM/FM digital radio standard, etc., etc. -- and that's just in the 
broadcast area).  This time, it's a mad, desperate dash to find 500 
MHz of spectrum usable for mobile broadband in the next 5 years.

In my view, this technical tone-deafness at the FCC persists because 
there has been no engineering expertise or background at the 
Commission(er) level since ... well, I'm not sure there ever was, but 
perhaps in the 1930s-'40s.  The FCC staff is supposed to provide 
engineering support, but Commissioners often do not listen to the 
staff as carefully as they should and sometimes the staff gets it 
wrong.  IMO, the 5-person Commission should always include at least 
one engineer and one economist so that at least in theory it has 
enough expertise to do a reality check on proposals at the Commission level.

Thus, the truth (at least as I see it) is much more complicated than 
a simplistic conspiracy theory -- but then, it always is.

Best regards,

Charles