Should public safety network be public/private?
Agencies and industry spar over use of coveted spectrum
- By William Jackson
- Oct 01, 2010
Sen. John Rockefeller (D-W.Va.) has pledged to advance a bill that allocates radio frequency spectrum for a national broadband public safety network, but public safety agencies and the telecom industry are sparring over whether the spectrum can and should support both of them.
Representatives of the public safety community told the Senate Commerce, Science and Transportation Committee that agencies must control the spectrum and network it will support.
“We cannot have commercial providers deciding what is and what is not an emergency,” said Jeffrey Johnson, president of International Association Of Fire Chiefs.
But the telecom industry said the Long Term Evolution (LTE) technology favored for such a network would let a sharing arrangement supported by the Federal Communications Commission provide first responders with the resources they need — and do so more efficiently and economically than existing networks can.
“There is a new kid on the block,” said Dennis Roberson of technology consulting firm Roberson and Associates. “LTE has really moved the ball forward” and can “make the system available to public safety when it is needed and make it available to others when it isn’t.”
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The debate centers on two 5 MHz swaths of spectrum, collectively known as the D Block in the 700 MHz band, that were recently freed by the switch to digital TV broadcasting. Two adjacent 5 MHz swaths already have been set aside for a dedicated public safety network to carry video and data traffic. The question is whether the D Block will be a core part of a 20 MHz public safety network or become a separate commercial network that would provide public safety agencies with additional capacity during emergencies.
FCC established three priorities for the public safety network in its National Broadband Plan: It must be nationwide, interoperable, and technologically and economically feasible. Economic feasibility is likely to be a greater challenge than the technology, retired Adm. James Barnett, chief of FCC’s Public Safety Bureau, told the Senate committee.
“Interoperability costs money,” Barnett said. Allowing commercial development of the D Block, on which the public safety community could piggyback, could help provide that money.
Ranking committee Republican Kay Bailey Hutchison of Texas expressed concerns about the cost of a public safety network and said she was willing to consider using commercial development as a means of funding it.
T-Mobile commissioned a technical analysis from Roberson of network capacity using LTE, which has been identified as the preferred technology for public safety and is being adopted for commercial 4G networks. The study concluded that the 10 MHz set aside as dedicated spectrum would be adequate for the day-to-day data and video broadband needs of public safety for wide-area networking when coordinated with wireless spectrum already available for local-area communications.
LTE includes 15 levels of traffic priority that could give public safety agencies immediate access to the D Block when needed without degrading the service, the study states. The performance of packet-based LTE networks would not be affected the same way as existing circuit-based networks when overloaded during an emergency. Low-priority packets could be slowed, and high-priority packet streams could be put onto the network even when all channels were fully loaded.
Whatever model is chosen for the public safety network, Congress needs to act quickly, Barnett told the committee. The large carriers already are making plans to build next-generation LTE networks, and the public safety community risks developing a silo of expensive, specialized, proprietary equipment that would not be able to take advantage of technological innovation if it does not work in concert with industry.
William Jackson is a Maryland-based freelance writer.