With the flurry of satellite photos, real-time UAV video, Blue Force tracking, and plain old voice communications, todays warfighters need all the wireless transmission capacity they can get. With nearly 200 countries around the globe having their own unique ideas on how to use radio spectrum, the U.S. military cant just roll in and fire up their gear anymore without the potential for interference with the local cell phone operators or disrupting TV and radio broadcasts.
DARPAs (Defense Advanced Research Projects Agency) neXt Generation (XG) communications program is on a fast track developing tools to be used in combination with the coming generation of software-defined radios. DARPA hopes to increase available bandwidth ten-fold by using portable spectrum analysis tools to look at the full range of RF spectrum, finding available chunks, and organize networks to use available space without stepping on host or adjoining nations communication systems. Disrupting a host nations cell phone service is not good for PR and effective psychological operations campaigns requires the U.S. to have the capability to cleanly broadcast TV and radio signals to an adversaries citizens. Jamming media broadcasts needs to be a planned activity, not inadvertent collateral damage from operations.
Tools DARPA have publicly demonstrated include a lightweight spectrum analyzer weighing in under two pounds and about the size of a larger paperback book that can be connected to a laptop and put into a backpack. Such gear has typically weighed in at 20 lbs or more and taken a couple of shelves of rack space.
DARPA has also released a specialized programming language to define spectrum policy usage for software radios. Using results from the spectrum analyzer and other information such as a countrys wireless broadcasting policies, a set of rules can be coded and loaded into radios to avoid stepping on operating services while using as much open spectrum as possible. DARPA is developing the language as an open standard and hopes commercial manufacturers will help develop it and incorporate it into their civilian products. Free market spectrum advocates have high hopes for software-defined cognitive radios to take advantage of changes in existing Federal Communications Commission policy in the civilian market. - Doug Mohney
