In emergencies or disaster situations, immediate on-site communication is key, but not always possible. When participating agencies' radios operate on different frequencies, cross-communication is impossible without the aid of an interoperability channel or device. The need for interoperability is a growing concern across the nation, and has state public safety agencies searching for solutions.

In New Jersey, regionwide interoperability channels, or shared channels, in each radio band allow daily radio interoperability. The state also uses caches of radios placed throughout the state at strategic locations and programmed with regional and local interoperability channels. However, some agencies' radios could not use the interoperability channels because they did not have the signal capacity, so another answer was needed.

The New Jersey Department of Law and Public Safety recently purchased 21 Incident Commanders Radio Interface (ICRI) interoperability units to enable communications interoperability across multiple agencies in the event of an emergency, and 21 more are coming soon. The ICRIs, manufactured by Communications-Applied Technology (C-AT), will allow agencies and jurisdictions with incompatible radios to communicate, despite their different frequency allocations.

Do You Copy?

New Jersey's ICRI bridges can establish a cohesive communications system in less than 5 minutes, and set up is simple, said Ray Hayling, New Jersey's chief public safety communications officer, who explained that this was an important factor in choosing the ICRI.

"We didn't want anything that would be overly complicated, but would do the job," he said.

Interconnect cables link up five different radios to the small, 3-pound ICRI box, and these radios automatically allow other radios using the same frequency to receive and transmit communications through the ICRI bridge. The audio from a transmitting radio is received by the ICRI and distributed to all other radios that have a similar or identical radio connected to the box, whether legacy, ultra high frequency (UHF), very high frequency (VHF), or 800 MHz, which creates communication across multiple frequencies.

The transmitting radio only needs a similar radio attached to the box to send communications, but any other type of radio attached to the box can receive the communications and distribute them to like radios on the same frequency.

"I can talk in an 800 MHz radio, and the box takes the audio and sends it back through the radios attached to the box, but on the UHF, VHF and other bands that it needs to," said Hayling. "The ICRI allows you to have interoperability across any frequency band."

Additionally two talk groups are possible using the ICRI bridge. Flipping a toggle switch above the port for each radio will either place the radio in one of the two talk groups, or render the radio temporarily inactive.

When creating the ICRI box, C-AT considered several attributes necessary in an emergency situation. "The ICRI had to be physically small, it had to be physically rugged, it had to be very simple to operate, and it had to run for a very long time on an internal power supply," said Seth Leyman, founder and president of C-AT.

The ICRI box runs on eight "AA" batteries for an average of 30 continuous hours. To sustain power, C-AT designed the ICRI with minimal lights and energy-efficient screen. Although the box can use an alternate current or direct current power source, some emergency situations prevent the use of external power, Leyman said. With an internal power supply, the ICRI box is a mobile unit that can be transported to where it's needed most.

One of the major concerns using interconnect switches like the ICRI, Hayling said, is their ability to interfere with other interconnect switches in close proximity. To address this issue, New Jersey's ICRI boxes have a function called Voice ID that identifies the box causing the problem so those in charge of distributing the boxes can

Sherry Watkins  |  Contributing Writer