Three influential members of the U.S. Senate today announced their support for legislation that would reallocate the 700 MHz D Block to public safety and for a funding source that would help pay for a nationwide, interoperable broadband wireless network for first responders.

Sen. John McCain (R-Ariz.) and Joe Lieberman (ID-Conn.) are co-sponsoring a bill calling for both reallocation of the 10 MHz D Block — broadband airwaves adjacent to the 10 MHz of spectrum licensed to the Public Safety Spectrum Trust (PSST) — to public safety and $11 billion from future spectrum auction to help fund the deployment and maintenance of the proposed broadband network.

“It’s time to put first responders first,” Lieberman said in a prepared statement. “This is a once-in-a-lifetime opportunity to build a coast-to-coast communications network for our nation’s first responders that is secure, robust and resilient.”

Jay Rockefeller (D-W.Va.), chairman of the Senate commerce committee — the body that oversees spectrum issues for the Senate — announced plans to introduce legislation that would reallocate the D Block to public safety and would authorize the FCC to conduct incentive auctions of commercial spectrum to provide a revenue stream for funding the public-safety network.

These announcements represent a significant shift regarding the D Block on Capitol Hill, where public safety’s efforts to secure the D Block appear to be gathering momentum. Previously, the Senate had been silent on the issue from a legislation perspective.

In the House of Representatives, a bill that would reallocate the D Block to public safety now has 55 co-sponsors, while a draft bill from Rep. Henry Waxman (D-Calif.) that would call for the D Block to be auctioned to a commercial operator still has not been introduced.

“Six months ago, people would say it just couldn’t be done,” Dick Mirgon, president of the Association of Public-Safety Communications Officials (APCO), said about public safety’s momentum. “Today is a significant milestone, but we still have work to do.”

While public safety has been calling for D Block reallocation, FCC officials have stated repeatedly that first responders do not need the D Block, recommending that the spectrum be auctioned for commercial use.

A senior FCC official applauded Rockefeller’s support of incentive auctions and funding for the public-safety broadband network. When asked about the Capitol Hill support of the D Block reallocation, the FCC official said reallocation would be determined by Congress and the agency was still reviewing the Rockefeller proposal.