The warnings are dire: The number of available radio frequencies is declining, say U.S. government officials, and with it the Pentagon’s ability to introduce new communications technology...But a seven-year-old firm a stone’s throw from the Capital Beltway says it can harness “white space” in the spectrum to provide interoperable communications. The 30-employee firm, Shared Spectrum, had 2006 revenues of “about $8 million to $9 million” and expects about the same this year...In a test last summer… more