At Least Something Is Compatible:

Northrop Grumman reports that two months of “rigorous tests” have demonstrated that the Milstar communications satellite ground terminals currently operated by the Air Force and the Army work with the new Advanced Extremely High Frequency Satellite communications system. Northrop Space Technology President Alexis Livanos said that the compatibility of the two systems “reduces cost” and “facilitates the military’s integration” of the legacy and new comm systems. The Lockheed Martin-led AEHF team is slated to launch the first AEHF sat in 2008.