Cellular interference shuts down firefighter communications

November 2003. Portland police chase a carjacker into a wooded area and work to coordinate a perimeter around the assailant. Suddenly their radio transmissions become garbled, leaving them unable to communicate, even in close proximity. The carjacker escapes.

July 2004. As a Tualatin Valley fire company responds to an alarm, their FireCom radio network goes dead. Forced to backtrack several blocks to reestablish communication and regain a map and directions, their arrival at the fire is delayed.

What’s going on here?

As early as 1999, U.S. public safety personnel began reporting critical interruptions in their 800 MHz communication networks. The blackouts were traced to the proliferation of commercial mobile radio licensees (CMRLs): cellular phone towers, in lay terms.

With the exponential increase in cell phone use over the last five years, the problem has only gotten worse. Public safety personnel in Portland and at least 27 other states have experienced repeated communication problems, including garbling and black outs.

The problem leaves rescue personnel helpless, stranded in crisis situations without the ability to communicate. To date, no deaths or disasters have been directly linked to 800 MHz interference, but experts say it’s only a matter of time before the unthinkable happens.

“It’s definitely a problem,” Mark Schmidt said, Battalion Chief for Portland Fire District 2.

“The interference was first recognized here about four years ago. It desensitizes radios- they don’t pick up or receive or transmit the way they should.”

Although several cellular companies own licenses in the 800 MHz bandwidth, virtually all belong to the Nextel Corporation in full compliance with FCC licensure and regulations.

“Every day that goes by, there could be more interference and possibly a tragic situation. We want to solve this,” said Tim O’Regan, Public Affairs Manager in Nextel’s Virginia headquarters.

In theory, public safety organizations and CMRL users are supposed to operate on separate radio systems. However, the 800 MHz bandwidth is interleaved with many channels, and some of the channels used by cellular operators overlap with channels used by public safety officials.

Cellular transmission relies on a large number of short, widely dispersed towers operating at low power. In contrast, public safety operators use only a few very tall, “high-site, high power” towers. If a public safety radio is far from one of its own towers and close to a cell tower, communication is often affected.

About three years ago, a group of private wireless and CMRL organizations (including Nextel) sat down with public safety leaders from around the country to explore solutions. The result was “The Consensus Plan,” a proposed schema for realigning the jumbled spectrum.

The plan advocated a complete re-banding of the 800 MHz spectrum, a permanent, proactive solution that would stop interference before it happened.

After re-banding, public safety communications would be concentrated exclusively in the lower part of the 800 MHz spectrum, while CMRLs would operate at a safe distance in the higher 800 MHz frequencies. A mid-spectrum buffer would separate the two.

An alternative approach – favored by most of Nextel’s cellular competitors and some local governments – advocated a system of “as needed” technical fixes to solve interference as it occurred. Consensual swapping of radio spectrum would be encouraged but not mandatory, and there would be no comprehensive re-banding.

The FCC is responsible for allocating signals and licensing radios, and FCC chairman Michael Powell made solving the interference problem one of the agency’s priorities. In March 2002, the FCC opened a formal problem-solving process.

The first phase of the process ended on July 8, 2004, when the FCC made public a “Report and Order” that mirrored the Consensus Plan. The order required that Nextel pay for the re-banding process and surrender most of its 800 MHz channels. In exchange, Nextel would be given replacement spectrum at 1.9 gigahertz.

Nextel’s access to the exclusive 1.9 Ghz real estate is likely to have political ramifications.

“The other cell phone companies would also like this bandwidth. There’ll probably be law suits,” said Marco Benetti, Staff Captain of Logistics with the Portland Fire Department.

The several hundred-page FCC decision was released to the public on August 6, 2004. Its ultimate success requires that Nextel voice its approval.

According to O’Regan, Nextel has indicated its willingness to accept the order pending clarification of about a dozen details.

O’Regan’s tone is one of optimism.

“We have an obligation. We know that this is a problem for public safety. We want to help solve it.”

In the interim, Nextel has offered temporary first aid by retuning or swapping some of the problematic bands and signals.

“It’s helped a little bit,” Benetti said. “We haven’t had as many complaints but they still do exist.”

“We don’t want to be causing the interference anymore. We would like it gone, so it’s not an issue,” O’Regan said. “We’d like to be able to compete with the other cellular providers in a fair field.”

Once the decision is published in the federal register, it becomes the official decision of FCC. Nextel will then have 30 days to respond.

National re-banding will take about three years and is expected to cost considerably less than the $5 billion letter of credit posted by Nextel as required by the FCC mandate. Re-banding will begin in the most severely affected areas, including Portland.