First responders often have trouble communicating with each other in emergencies. They may use different types of radios, they may be working in rural areas lacking wireless coverage, or they may be deep inside large buildings that block connections. To demonstrate improvements to emergency communications and foster research on systems that can be quickly placed in strategic locations, the National Institute of Standards and Technology (NIST) worked with industry partners to integrate commercial technologies into a mobile wireless communications system.
The Rapidly Deployable Public Safety Research Platform, about the size of a large file cabinet, offers more capabilities and faster setup than typical “cell on wheels” systems. It enables more than 200 local users of broadband smartphones, Wi-Fi, data terminals, and older walkie-talkie radios to all communicate with each other using voice, text, instant messages, video, and data. The range is about 4 kilometers (2.5 miles) in a rural environment.
Crucially, the system interconnects Long Term Evolution (LTE) phones, the latest wireless standard, with the public safety community's traditional Land Mobile Radio (LMR) systems. LTE data transmission rates are 30 to 1,000 times higher than LMR.
The system is modeled after the U.S. Government's First Responder Network Authority's (FirstNet) vehicle-borne network system, and the public safety community's vision of a rapidly deployable system to be used when the nationwide network is not available.
NIST's research and demonstration platform is being used for research projects such as evaluating how to improve audio intelligibility amid crowds and background noise, and the development of a database of communications in high-stress, loud environments. The platform enables research into factors considered critical to the public safety mission, such as how to establish “push to talk” (i.e., using a button to switch from sending to receiving) capabilities over broadband systems.
Typically, it may take hours to deploy a “cell on wheels” system to provide coverage at an event, and multiple deployable systems are needed to enable both LTE and LMR. The NIST system provides LTE, LMR, video, and data. The system can be rolled from a vehicle into a building, and once connected to an AC power outlet, calls can be made in less than 5 minutes.
The mobile system can also be connected to the Internet, satellite, or a commercial cellular network to link users to a broader community. Requirements are being developed for linking up with both personal area networks that are already in place, as well as temporary Incident Area Networks, which are created as needed and can expand as an incident grows in size and complexity.