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The B2 Bomber's radar frequency was recently sold to a Russian entrepeneur on accident. The incident emphasized the military's increasing spectrum woes.  (Source: U.S. Air Force)

The F22 Raptor's AWACS targeting probably won't work outside the U.S. This is just one of the many costly spectrum issues the Air Force and armed forces are having in the U.S. as civilian spectrum use increases.  (Source: Wikimedia)
Costly blunders and redesigns all part of military networking growth pains

The U.S. military originally had a virtual monopoly of certain communications channels.  It was one of the few entities to be using internet, and it used many areas of the spectrum untouched by civilian communications.  However, with the digital revolution and the expansion of civilians onto the internet and increasing using of the digital spectrum, the military is finding adapting to the deprivation of these bands difficult.

Last year during the bandwidth auction, the portion of the spectrum used by the B-2 bomber's Raytheon APQ-181 radar was accidentally sold to an obscure multinational organization according to Military.com.  As a result, U.S. taxpayers will be footing the over $1B USD bill to replace the radar in the 20 remaining jets.

With users demanding video-ready smartphones, high-speed mobile internet, and other emerging applications, the military is finding that the spectrum is quickly disappearing, and it’s having trouble finding areas for its own sensitive technologies.

Other expensive losses abound.  The Joint Tactical Information Distribution System, a costly system used to get AWACS targeting data to F-22 fighter jets has "limited supportability outside the continental U.S."

Another key issue is the steady creep of civilian communications into the spectrum used for flight-test telemetry.  While there are workarounds to gather some additional information, telemetry data remains essential to testing both manned and unmanned aircraft and protecting pilots from failures.

Ultimately, more data takes more bandwidth -- an unalterable fact -- and to achieve higher frequencies more power is required.  This places inherent limitations to the amount of data capable of being communicated over the spectrum.

Military designers are in a sticky situation as they can't compress their data, in many cases, like civilian applications.  "This is not a cell phone,” said Darrell Ernst. "You can't ask the pilot to wait while you redial."

Ernst works for the Mitre Corp., a member of a U.S.-European delegation trying to raise international awareness of bandwidth issues, and estimates that by 2020 the Air Force will need 600 MHz of spectrum for telemetry data.  Currently the only vacant spot suggested to them is the 5091 and 5150 MHz band.  The Air Force is eager to occupy even this meager 59 MHz offer.  States Mr. Ernst, "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."

When it comes to the spectrum issues, there are few good answers, just more fears and doubts.  As a final example of the industry problems, when the Joint Strike Fighter (JSF) test program is flying two missions no other combat aircraft will be able to fly in the Western U.S.  States Mr. Ernst, "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."



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let me clear some things up
By inperfectdarkness on 3/24/2009 8:23:50 AM , Rating: 3
JTIDS (aka link 16) is a TDMA datalink. due to the number of players who can be tranmitting on this link--as well as the fraction of a second allotted to data transmission--as well as the required signal for net-time-reference & encryption; well i would think it's rather obvious why compression isn't much of an option.

you also have to comprehend that what technology is possible in the civillian world was originally pioneereed by military technology. that said; once the militay pays for something--it doesn't get upgraded for free. this is why the AWACS, for instance, is still using the same phased-array radar designed in the 1960's. it's why the USAF still uses bulky-oversized consoles for its C2 platforms--rather than laptops (which could most likely replace all of these at a fraction of the space).

COTS supply has made huge inroads in the last 2 decades--but we're still not where we COULD be...because even "recent" platforms still used antiquated hardware--not to mention some software. JSTARS (where i work--since someone already brought it up) is a mostly COTS supplied weapons-system. however, it is also a 20+ year old design--and even upgrading to hardware/software made in the last 10 years would be a dramatic improvement.

moving on:

the military does NOT have to work around civillian traffic. nor should it have to. we specifically employ airframes such as the compass-call & JSIR tracking to create "pinholes" in an otherwise unusable EM spectrum--within which our platforms can function. in the event of a war, the idea is to control the EM spectrum & keep the enemy from using it to their advantage. playing "tap-dance" with consumer bandwidth (which, if you recall...has to be GRANTED to the private sector) only would defeat the purpose.

it is a damn shame we have to retrofit the entire b2 fleet--and i sincerely hope that the cost of the retrofit will come out of the FCC budget or whomever is responsible for the auction--it DAMNED WELL SHOULDN'T come out of the military budget. and it's not like we can say "oops, my bad! can we have that bandwidth back, please?" we've pretty much broadcast a secret-classified radar operating frequency.




By inperfectdarkness on 3/24/2009 8:34:07 AM , Rating: 2
forgot to mention 1 other thing:

communications systems are more adaptable to changes in transmission bandwidth than radar systems--exponentially so if we're talking about a datanet.

data can be transmitted without signal distortion/corruption & be interpreted correctly by the receiving systems on the other end easily.

radar systems, on the other hand, are tailor-made to fit the intention of the platform. without going into extensive radar theory--the combination of PRF, beamwidth, signal attenuation, etc. all combine to form a rather narrow "optimum frequency band" for a specific radar system.

and even our military doesn't have all the kinks totally worked out; which is why we have JSIRs.


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