Radio network interoperability: It's not just a convenience; it's a matter of life and death. If police, fire and EMS crews cannot talk to each other, the margin for error — and loss of life — can be profound.

Chicago's municipal government knows this well. In the two-mile-square downtown area known as the “Loop,” “Thirty to 35 public safety agencies operate on a daily basis,” said Rich Nowakowski, but adding, “None of them can talk to each other.”

A retired police officer, Nowakowski is Chicago's project manager for radio interoperability. His mission is to get public safety networks interconnected and talking with one another. That's no mean feat. For one thing, “The current radio situation in Chicago is similar to other cities across the country,” he said. “We have multiple agencies using all kinds of radio equipment, spread across various parts of the spectrum.”

The sheer size of Chicago and its outlying agencies also means that as many as 800 separate systems somehow have to be brought together. “These include both encrypted and non-encrypted radio systems,” said Nowakowski. “We're talking conventional analog, digital and trunked.”

Given this chaos, Nowakowski could be forgiven for throwing up his hands and taking off for the nearest desert island. However, that's not his plan, nor is it Chicago's. Instead, they intend to resolve the interoperability challenge in an effective, yet affordable manner. “Affordable,” in that it doesn't require public safety agencies to junk their existing equipment or to spend millions of dollars to move to one standard.

A switch in time

Chicago's Department of Emergency Communications has joined Illinois' Office of State and Local Disaster Preparedness Services to launch a pilot radio interoperability project. To advance their goals, the city and state turned to resources from the U.S. Department of Justice's Advanced Generation of Interoperability for Law Enforcement program. AGILE is a $4-million program that promotes interoperability among all levels of government. Using AGILE funds, the city purchased six TRP-1000 transportable interconnect systems from Raleigh, NC-based JPS Communications.

The heart of the TRP-1000 is the ACU-1000 intelligent interconnect unit. Built into a 19" rack-mounted case, the ACU-1000 serves as a telephone-style switch for public safety networks.

“Each one is a ten-radio suite with two telephone connections,” Nowakowski explained. “It allows us to interconnect radios of different frequencies and bands, along with mobile telephones, together.” These disparate radios include 800MHz trunking, VHF/UHF AM, lowband and highband VHF, 900MHz and conventional cellular phones.

The ACU-1000 is essentially a junction box for all these different inputs from radios that are packed into separate, transportable cases. Together, these radios can cover it all. Add the PC that controls the system, and you've got interconnection. (The TRP-1000 also comes with antennas, power supplies and everything else needed to create a “communications switch” in the field.)

This unit takes the incoming signal and converts it into receive/transmit audio. This audio is then recorded on the PC's hard drive. The outgoing radio is selected and commanded, and the signal is sent out.

To allow ease of operation, the ACU-1000's software supplies the necessary accessory-port control signals for each attached transceiver, making interoperability straightforward. The system uses voice prompts to set up connections (which can also be done using standard DTMF tones). This means that users can switch between radios remotely, without direct help from an operator.

Making the system ‘ambulatory’

Chicago's first goal is to get a TRP-1000 in the field for tests. To do this, “We've taken an old 1992 Ford ambulance and converted the back into a mobile communications office,” said Nowakowski. “Meanwhile, on the roof, we've installed 18 different antennas; all carefully spaced apart to minimize intermodulation and interference. The thing looks vaguely like a porcupine.”

When this rig is ready to roll, the city intends to deploy it within a 75-mile radius. This will mean that Chicago proper and the six counties that surround it — Cook, Dupage, Lake, Kane, McHenry and Will — will have access to a rolling radio interconnection center.

The next step will be to install one or two TRP-1000s at the Chicago Emergency Communications Center. The CECC, which opened in 1995, is a five-story, 161,000-square-foot complex that serves Chicago Police, Fire and EMS dispatch. (See MRT Public Safety Supplement, August 1995, “Chicago's New 9-1-1 System.”) As the site of 1,000 miles of telecom cables, including one of the world's largest privately owned fiber-optic networks, the CECC is a logical location for a radio-interconnect switch.

The third step Nowakowski hopes to see is the city's purchase of a new vehicle. It won't just supplement the first mobile unit. Instead, this rig — which will carry two TRP-1000s and boast a 52' extendable antenna mast — will serve as an onsite dispatch center. The mast will allow the unit to connect to the CECC through a relay station atop the Sears Tower, the tallest structure in the city. The result: Coordinated dispatching can be managed from the emergency scene, where public safety officials can see firsthand what's needed.

But that's not all. The reason the new truck will carry two TRP-1000s is to leave one in the field when necessary. For example, say a tornado wipes out Cook County's public safety infrastructure. No problem: Chicago takes a TRP-1000 to the scene, sets it up, and — presto — not only are public safety workers connected again, but now police, fire and EMS can talk to each other as well.

“In such cases, we'll be able to provide stricken areas with radio communications until their own systems are repaired,” Nowakowski said. “All we have to do is leave a technician to show how to operate the TRP-1000 and to keep it running.”

Marching to interoperability

Chicago isn't the only U.S. city to be testing TRP-1000 in interoperability trials. In fact, the $4 million provided by Congress is also funding trials in Washington, New York, the New Hampshire-Vermont Joint Interstate Project; Salt Lake City; Orlando; Las Vegas; College Station, TX; Los Angeles; and Anniston, AL.

At present, some cities are further ahead in their tests. For instance, Orlando staged a mock tornado at Universal Studios on Jan. 13, 2001, to test the system. Specifically, the Orlando Community Emergency Response Team, Orlando Fire Department and a team from National Disaster Medical Systems treated 150 teenaged volunteer “victims” at Universal Studios in Orlando.

In this five-hour drill, a TRP-1000 was deployed in about 15 minutes, using some ice machines and the carrying vehicle as a ground plane. According to OFD Engineer Bret D. Barker, “What we accomplished during the exercise was an initial test of the TRP-1000 by interfacing the UHF simplex communications of DMAT 6 to the Orange County/Orlando 800MHz Smartzone System,” he said. “The radios we used were the Bendix-King EMV and EMH mobiles installed in the TRP-1000 as shipped from JPS, Motorola MCS2000 800MHz mobile radios that I have retrofitted into the TRP-1000 chassis, and Motorola MTS2000 portable radios for which I have built interface cables.

“The way I have set up our TRP-1000, it is a simple matter to initiate operations within less than a half hour of arrival, provided that there is ac power and the supplied antennas suffice,” Barker said.

“The ability to network communications of several agencies in a field-portable piece of equipment makes operational interoperability a reality,” commented Orlando Asst. Fire Chief Robert Sorenson after the mock tornado exercise. “The TRP-1000 has, in this exercise, proven to be a reliable and useful piece of equipment.”

Winding out in the Windy City

Back in Chicago, due to the unfortunate and untimely death of Emergency Communications' Executive Director Gregory Bishop (see accompanying story), projects have been slowed down in Nowakowski's department. He is hoping to deploy the TRP-1000 — equipped Ford ambulance in a few weeks, but the timeline for the rest of the project — which includes setting up numerous intergovernmental and interagency committees — is still being worked out.

Still there's little doubt that interoperability is on its way for Chicago-area public safety networks — interoperability that's a lot less expensive than replacing thousands of radios.

Careless is a freelance telecommunications writer based in Ottawa, ON, Canada. His email address is