Building 'Communication Islands' During Infrastructure Breakdowns

Researchers at Networked Infrastructureless Cooperation for Emergency Response (NICER) research center at TU Darmstad in Germany are developing technologies that will help civilians communicate in the event of terror and cyberattacks, public emergencies, and large-scale disasters that cripple existing power and communications infrastructure.

“Despite our increasing dependence on infrastructure-based networks, no backup plans exist,” said Matthias Hollick, Professor on Security in Mobile Networks at the TU Darmstadt. “Civil protection and disaster assistance has even seen budget cuts in recent years. The authorities and armed forces are able to operate their communication networks for a considerable time, even in the absence of external power supply. In contrast, the civilian population would be mostly disconnected from any means of communications.”

NICER is exploring how infrastructureless information and communications technology can link people in a crisis situation, and spur them to work together to overcome that crisis. The center has three main research areas: (1) setting up autonomous, decentralized, and robust “communication islands”; (2) constructing “communication bridges” between communication islands; and (3) operating an “overall network” of services and applications to enable cooperation in the crisis situation.

Previously proposed means of emergency communication in times of crises include redundancy using RF over fiber links, which rely on an off-site backup, independent from the damaged local infrastructure, as well as portable radar devices as a disaster recovery tool.

Researchers at NICER, though, suggest building "communication islands" within a locally impacted area that utilize mobile devices linking to each other directly, even though the cellular base stations that normally act as communication nodes are suddenly brought down by a natural or man-made disaster.

To realize this emergency communication system, Hollick's team has developed a robust, ultra-low-latency forwarding mechanism for mobile devices to exchange status information, effectively acting as each other's forwarding and distribution nodes. A signal emanating from one device is picked up and broadcast to nearby devices in the immediate vicinity, and their signals propagate like a wave in a pond.

The NICER team is now re-engineering mobile devices and their firmware to make them more efficient at communicating, and at the same time, saving valuable power by restricting the processing to the radio module.

“If we succeed in managing the communications on the radio module processors, we could cut out several steps. Simple data packets could be processed in fractions of milliseconds, whereas using the operating system would take orders of magnitude longer. That’s a significant gain if we are operating hundreds of devices,” said Hollick.

In large-scale disasters, independent communication islands need to be bridged by mobile devices carried by a resident moving to another island.

The researchers also are looking at how existing sensors available within a communication island could be tapped to produce a shared situation report, to be made available to affected citizens through apps in their mobile devices. To this end, they are learning from communication mechanisms used in rescue robots deployed in harsh environments, such as during a nuclear meltdown.