July 17, 2014
Acoustic Technology, Inc. (ATI Systems), the world leader in Mass Notification Systems, today announced that a wireless Mass Notification System using Frequency-Hopping Spread Spectrum digital radios has been deployed at Camp Zama, Japan.
Camp Zama is an important U.S. Army post located in Kanagawa Prefecture, southwest of Tokyo, which serves as a base for the U.S. Army in Japan. The United States Army Japan (USARJ) is a key element in upholding the 1960 Treaty of Mutual Cooperation and Security between the United States and Japan, the most important U.S. bilateral relationship in the region and the key to maintaining western Pacific regional stability. A number of units of the U.S. military and the Japan Ground Self-Defense force are based on Camp Zama. Key elements include command, aviation, intelligence, and engineering units.
Camp Zama needed a new and reliable Mass Notification System capable of alerting people in case of emergency, an important function since the area has been subject to both earthquakes and terrorist attacks in the past. A major requirement was to cover three separate areas on the base due to the distributed nature of the facilities.
ATI provided a new outdoor warning system that covers the base in case of emergency. Three independent control stations and three ATI 1600 watt High Powered Speaker Stations (HPSS16) were installed to provide audible tones and voice announcements to designated areas of the base. After examining the alternatives, ATI provided solution pairs up one control station with one HPSS, providing operation as three separate systems.
An additional challenge arose when Camp Zama was unable to procure a licensed UHF/VHF frequency. ATI provided low power 2.4 GHz FHSS (Frequency-Hopping Spread Spectrum) digital radios, which operate in the unlicensed band. The FHSS communications—combined with sophisticated encryption, anti-interference features, and directional antennas—allow reliable and secure communication between units.
The nature of FHSS communications spreads a medium bandwidth signal across the entire available spectrum, providing greater flexibility. Many of the radio units can communicate on the same channel if they use the same hopping pattern, but many separate communication links can be created with minimal interference if different hopping patterns are used. In this case, ATI technicians configured each pair of digital radios to act as separate links while remaining invisible to the other units.
“This type of sophisticated spread spectrum radio is only one of many possible communication paths that have been successfully used in ATI-installed emergency warning systems,” said Claudia Markovich, Global Development Manager. “The flexibility in communications, along with ATI’s powerful electronics sirens and sophisticated software, helps us provide the best solution for each customer.”