Digital TV offers opportunity for interoperability

The mandatory transition of TV to digital signals will open a door for change in public safety communications, but only if the right policy changes are made before the 2009 deadline, a Carnegie Mellon University researcher said.

Jon Peha, associate director of the Center for Wireless and Broadband Networking at the university and a professor of electrical engineering and public policy, presented a new paper on the subject as part of a panel discussion today. The New America Foundation hosted the discussion, which also included speakers from industry and the Washington, D.C., government.

Peha said local governments have the primary responsibility for public safety communications, which has led to the current patchwork quilt of systems and standards that make intercommunication difficult. Other assumptions that hamper interoperability are that public safety agencies, not contractors, must operate the systems and that the systems must use radio frequencies dedicated to public safety rather than sharing spectrum allocations with commercial or other government users. Finally, conventional wisdom regarding public safety communications still centers on voice communications. New services using broadband networks, such as data transmission, have received less attention.

But that could change in three years, Peha said. When time to switch to digital television arrives, 24 MHz of the spectrum that had been assigned to TV signals will be reallocated to public safety, roughly doubling the frequency bandwidth available for public safety. But unless policy-makers act soon, the same assumptions will govern the newly available spectrum.

Peha did not specify a single new policy that should pertain to the new spectrum. Instead he outlined several alternatives:

• Continue to rely on government agencies to run the systems, but move away from independence and to standardization, using a national architecture that the federal government chooses.
• Allow commercial wireless carriers to run the public safety networks. The existing carriers could offer upgraded versions of their commercial offerings to meet public safety standards, or there could be a bid process to select a nationwide system.
• If mission-critical voice services are established and a primary system set for them, consider options such as cellular carriers, a national commercial carrier or ad hoc networks for providing secondary services.

"This kind of public/private partnership requires billions of dollars," he said. "It's only going to come from the private sector."