Keeping Information Flowing

Dr. Choi
June 07, 2018

When a catastrophic event occurs—such as a terrorist attack, an earthquake, or even a small meteor attack—first responders need to have timely and reliable communication with each other and with people affected by the event, so they can perform their crucial work as efficiently and effectively as possible. However, the communications networks on which they normally rely are often severely damaged or rendered entirely non-functional by the catastrophe.

Following the September 2001 terrorist attack, the 9/11 Commission recommended that the U.S. government develop a broadband public safety network for this purpose. Congress established the initiative under the direction of the National Institute of Standards and Technology, which set about funding projects to modernize public safety communications under the Public Safety Innovation Accelerator Program.

Dr. Hyeong-Ah Choi and her research team received one of the grants and have been working for two years to develop a more resilient broadband public safety network. “The first responders need to be able to communicate with each other, but if the cell tower has been knocked out, you need to bring in mobile base stations,” Dr. Choi explains. “You have to decide the best locations for the mobile base stations, and that depends on where the first responders are located. But the first responders move around, so we are developing an algorithm that shows where to place the base stations so that good connectivity is provided to the first responders in a dynamic way.”

The team’s goal is to have a public safety network that intelligently adapts and extends its coverage to ensure the availability of the services, bandwidth, quality of service level, and reliability required by the first responders wherever they go, at the time that they need it. For example, while one first responder may be transmitting a video feed of the disaster area via a head-mounted video camera, another may be monitoring the temperature of the rubble, and a third may be downloading a three-dimensional model of the building interior. All of this information will need to be communicated, with the responders moving all the while.

Although extensive research has been conducted for commercial broadband networks, it is not particularly suited to Dr. Choi’s task, because communication via a public safety network is by nature less predictable and more dynamic than that in a commercial network. Her team is using and developing a variety of tools to explore this new territory, including algorithms, optimization, stochastic analysis, graph theory, and distributed and hybrid protocol design.

Dr. Choi is enthusiastic about the project, and particularly about its potential to make a valuable contribution to live-saving disaster response tactics. However, she is also motivated by the desire to teach her students.

“Research and education are tightly connected,” she remarks. “I like to develop good research and help my Ph.D. students grow and be able to develop their own careers through their research experience working with me.”