FCC disables B-2 bomber radar - over $1 billion to fix

[David Farber <dave () farber net>]

Begin forwarded message:

From: Simon Higgs <simon () higgs com>
Date: April 14, 2009 10:38:25 PM EDT
To: dave () farber net
Subject: FCC disables B-2 bomber radar - over $1 billion to fix
Reply-To: simon () higgs com

Didn't see this on IP yet:

Bandwidth Demands Crowd Military Needs

Aviation Week's DTI | Bill Sweetman | March 19, 2009

This article first appeared in Defense Technology International.

If a multinational organization that few have heard of, headed by a  
Russian-educated citizen of Mali, managed to disable the radar of a  
major U.S. combat system, you would think someone would make a fuss.  
Apparently not: When the U.S. Federal Communications Commission,  
acting in accordance with the International Telecommunication Union,  
inadvertently sold the operating frequency band of the B-2 bomber's  
Raytheon APQ-181 radar to a commercial user, nobody panicked, even  
though installing new radar arrays on the 20 surviving jets will cost  
well over $1 billion.

While more information is stored electronically and shared, the radio- 
frequency (RF) bandwidth available to share it remains fixed. The  
pressure is increasing, as consumers trade voice telephones for video  
smartphones, computer users everywhere demand broadband and new  
applications emerge. But the concept of network-centric warfare and  
the wider use of unmanned vehicles are making militaries equally  
dependent on the availability of wideband wireless.

The B-2 radar is only one capability that has been lost since the  
information revolution kicked into high gear. The Joint Tactical  
Information Distribution System, the first attempt to create a network- 
centric environment (and currently the only way to get AWACS targeting  
data to an F-22) has "limited supportability outside the continental  
U.S.," according to a U.S. military presentation, because it was  
developed in an occupied band.

Global Hawk's satellite data link operates in a non-government fixed  
satellite service band—i.e., one of the bands used for communications  
between satellites and fixed ground stations—on a limited,  
noninterference basis. The Situational Awareness Data Link and  
Enhanced Position Location Reporting System can't be used in Germany  
or South Korea. Stealth systems present problems, because their  
emitters hop around the widest possible bandwidth to frustrate tracking.

Another, more subtle problem is getting closer at an alarming rate:  
encroachment on the spectrum for flight-test telemetry. Although you  
can fit more memory and processing on the aircraft itself, telemetry  
is more important than ever to flight testing. To test complex systems  
efficiently, you need to have the flight-test engineering team  
monitoring data in real time, so experts on the ground can determine  
if each test point was good and clear the pilot to proceed to the  
next. This calls for higher data rates. Another driver for telemetry  
is testing of increasingly sophisticated unmanned aerial vehicles.

There are two unalterable facts about RF bandwidth. More data takes  
more bandwidth, counted in hertz, and of course there are more hertz  
available at higher frequencies. The second law is that the higher the  
frequency, the harder it is to get range, since it takes more power.

Flight tests can't use a lot of high-technology compression. "This is  
not a cell phone—you can't ask the pilot to wait while you redial,"  
says Darrell Ernst of Mitre Corp., a member of a U.S.-European  
delegation trying to raise international awareness of the bandwidth  
issue at last month's Aero India show in Bangalore. He reckons that  
with manageable compression and modulation techniques, 600 MHz. of  
spectrum will still be needed to fly one test in 2020.

So far, the only space walled off for flight testing is between 5091  
and 5150 MHz. in the microwave band. This segment was reserved for the  
aborted Microwave Landing System project. "If [the flight-test  
community] can get in there and start using it, we can be established  
as the primary user and it will be hard for them to throw us out,"  
according to Ernst.

There are other complications in the testing world. There are  
subcommunities out there—notably Detachment 3 of the U.S. Air Force  
Flight Test Center, located at the Nevada airfield known popularly as  
Area 51—who don't always play well with others when it comes to saying  
what they are doing and what frequency they want cleared.

The high-intensity Joint Strike Fighter (JSF) test program, which is  
going to have to sustain an average of 100 flights a month or more  
once it gets moving, assuming that happens in 2009, claims to have its  
bandwidth issues solved. The snag is that when there are two JSF test  
missions in the air, which will have to happen a lot, nobody else in  
the western U.S. is going to be able to fly. Some engineers are trying  
to persuade JSF to occupy a higher-frequency band, but, as one says:  
"They're the 600-lb. gorilla. They don't see that they have any reason  
to move, and they don't have the radios to do it."

Copyright 2009 Aviation Week's DTI. All opinions expressed in this  
article are the author's and do not necessarily reflect those of  
Military.com.

http://www.military.com/features/0,15240,187202,00.html

--
Best Regards,

Simon Higgs





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