The Road to Multiband Interoperable Communications: Interoperability in the Palm of Your Hand

In the late 1980s, the U.S. Air Force needed a perimeter security radio communications system that could deploy worldwide and operate on a variety of frequency bands depending on location. Racal Communications, Inc. (now Thales Communications, Inc.) was awarded the Scope Shield program contract to develop and manufacture a series of radios that could operate in the 30-88 MHz, 136-174 MHz, and 403-470 MHz bands. At the time, the most cost-effective approach was a series of interchangeable transceiver modules, one for each band. Although not the ideal solution by today's standards, the Scope Shield radio gave the Air Force significant flexibility and economy in the deployment of multi-band capable radios.

In the early 1990s, the U.S. Government identified the requirement for multiband communications as significant. Warfighters were carrying more than 60 pounds of communications equipment into combat. A program was awarded to Thales to develop and manufacture a single, tactical military portable radio that could cover all of the primary military frequency bands and operate on a variety of modulation schemes. The result was the AN/PRC-148 Multiband Inter/Intra Team Radio, or MBITR. This ground-breaking new software-defined radio offered, for the first time, operation from 30-512 MHz with SINCGARS and HAVEQUICK frequency hopping and a host of other military modulation schemes all packaged in a single handheld radio. The need for this type of multiband solution is clearly evidenced by the almost 200,000 AN/PRC-148 radios in service today supporting U.S. and allied warfighters around the globe.

Public safety and military radio communications spectrum requirements have increased dramatically over the last two decades as the need for more communication talk paths, more data channels, and more connectivity is required by a growing universe of government agencies and first responders.

To keep up with this voracious appetite for additional channels, talk groups, and network capacity, the U.S. Federal Communication Commission and the National Telecommunications and Information Agency have allocated spectrum in a variety of different frequency bands from 30-870 MHz. The first band was 30-50 MHz, which is still in use today by many agencies. Then, a progressive series of bands at higher frequencies was released from 136-174 MHz, 402-420 MHz, 450-470 MHz, 470-520 MHz, 800 MHz, and, most recently, 380-400 MHz and 700 MHz bands. Each band has required a separate, specific, single-band radio. The traditional components and radio design approaches limited an economically-viable design to a single band for each portable radio.

The tragic events of Oklahoma City, 9-11, and Hurricane Katrina brought communications interoperability into the focus of government agencies across the nation. Although rudimentary patching and switching equipment was available, and there was a common over-the-air standard under the APCO Project 25 (P25) effort, there were still no single transceivers available that could operate in all of the bands. It remained common for incident commanders and personnel to be carrying two, three, or even four radios.

With 2.2 million first responders in the U.S. today, it is the expectation that each one will be able to connect with other personnel on scene, as well as with their dispatch center, with clear reliable voice and data communications. In most cases, lives are at stake and the radio is an essential tool to accomplish the mission.

What if users had a single portable radio solution that covered all frequency bands? And this radio was the same size, weight, and power as the old single-band portable?

Enter the Liberty™ multiband, multimode, software-defined, land mobile radio. The Liberty radio is a P25 digital portable radio and is the first multiband radio covering the entire public safety spectrum to be approved by the U.S. Federal Communications Commission. For the first time, federal, state, local, and U.S. Department of Defense (DoD) agencies can communicate across all the public safety bands – 136-174 MHz, 380-520 MHz, 700 MHz, and 800 MHz – with a single portable radio. The Liberty radio operates in P25 digital, conventional, and trunked, as well as legacy analog. It offers OFB DES and AES with over-the-air-rekey for secure communications. Mil Spec rugged, the Liberty radio is submersible to two meters.

In early 2008, the U.S. Department of Homeland Security (DHS), Science and Technology Directorate, awarded a contract to Thales to demonstrate this exciting new radio. Thales Communication has leveraged more than 10 years of P25 public safety experience and an unequaled software-defined radio technology base serving the DoD to offer a truly unique solution to DHS and the nation's first responders.

The Liberty radio takes advantage of existing infrastructure but can also operate without infrastructure. It allows migration to new digital systems. The radio is the perfect solution for bridging between established regional P25 trunked systems and conventional radio users from adjacent municipalities using other bands. It can serve a single incident commander, a group of agency commanders, all squad leaders in an agency, or every team member, as required.

The Liberty radio provides maximum spectrum utilization and unprecedented efficiency. Local users who have moved to 800 MHz systems, but have kept older VHF and UHF conventional frequencies for back-up, can access all of these bands for additional talk paths. Federal users who have been frustrated by VHF spectrum crowding are now free to use the 406-420 MHz band in a single portable radio.

Easy to operate, the Liberty radio requires minimal training and can be deployed quickly. With day-to-day use, first responders become intimately familiar with its operation, and, in crisis situations, this familiarity can be life-saving.

Having undergone operational evaluation during 2009 – including use at the Presidential Inauguration, Kentucky Derby, multiple live burns, and other events – the Liberty radio is now ready for pilot testing under the DHS Multi-Band Radio Program. In July, DHS announced the agencies and sites participating in the pilots. Each agency will conduct a minimum 30-day pilot this fall. The pilots are designed to focus on the capabilities and effectiveness of the technology, with users primarily in a command-and-control role or involved in special operations with multiple entities. Factors such as operating bands, partner agencies and disciplines, interoperable conditions, and geographic landscapes were considered when selecting pilot sites. Feedback provided by participants of the pilot program will help ensure that true interoperability is delivered to our nation's first responders.

The road to multiband interoperable communications has been a long one: For the first time, interoperability is available in the palm of your hand.

Photo credit: Photos of live burn, Carmel, Indiana, courtesy of DHS S&T Command, Control and Interoperability Division.