Communication in times of crisis

The basic idea is to network the population by means of infrastructureless information and communication technologies. To achieve this objective, NICER is focused on three key themes: the establishment of autonomous communication islands, the construction of bridges between the islands, and the operation of an overall network with special applications for use in crisis situations.

This is why the researchers want to establish communication islands. An island may be an urban district or a village. All mobile devices within the island would be able to communicate with one another without the need for any underlying infrastructure. Moreover, in case of large-scale disasters, there may be several such islands all existing independently of one another. Additional bridges would then need to be established to enable communications between islands. For example, a mobile device carried by a resident of one island who happens to travel to another island could function as a bridge between the two areas. It would store information destined for recipients in the other island and physically carry it there, thus enabling the exchange of information over longer distances.

One difficulty in setting up the islands is the fact that cellular base stations, which function as central coordination nodes, would no longer work. Mobile devices can only communicate directly over short distances and therefore depend on other devices that act as forwarding and distribution nodes. Data traffic management is particularly challenging following this loss in coordination capabilities. Still, to enable the prioritization of specific data types, devices need to be able to exchange status information. Hollick’s group has developed a robust, ultra-low-latency forwarding mechanism for such status information exchanges, in which the signal emitted from a given device is picked up and broadcast simultaneously by all devices in the immediate vicinity. The message propagation can be compared with the ring waves formed when throwing a stone into a pond. The collaboration of the involved devices needs to be precise enough for the emitted signals to overlap constructively – a level of precision that the researchers also want to achieve on standard commercial devices.

To ensure that the collaboration also functions in an energy-efficient manner, the NICER researchers have been re-engineering various mobile devices in their “Emergency Response Lab” to increase their performance. For instance, each device is equipped with a so-called firmware, which is the software empowering the processors of the radio module. Under standard operating conditions, the firmware forwards incoming data packets either to the operating system or application software. After processing, they are dispatched to the intended recipient again via the firmware and radio module.

“However,” Hollick explains, “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.” Confining the processing to the radio module also saves power, as it is no longer necessary to power up the main processor. This would extend the battery life of the devices in question – important when the power grid is down. In order to be able to utilize the firmware in this way, mobile devices would simply require a standardized emergency operating mode, which would kick in during crisis situations.

The scientists are also looking into ways of utilizing the various data available within a given island to produce a shared situation report: what sensors are available? Which of them would need to be queried to produce an accurate overview of the situation without overloading the network? Signal processing experts and robotics researchers are jointly investigating how to process this sensor data. To this end they build on the communication mechanisms for interaction with the rescue robots, which could be deployed in particular challenging environments such as for instance nuclear facilities following an accident.

Last, but not least, the services that should be available within each island are also a subject of research – Apps that, for example, provide citizens with situational updates or information about relief resources. The researchers are developing ways of operating the Apps distributed across the emergency network, thus making them resilient to infrastructure outages but also to the failure of individual devices. Hollick concludes: “We’re hoping that solutions based on the NICER research will soon be available to everybody. This facilitates that the affected population has the means to help themselves under catastrophic circumstances literally in its hands – namely by making use of the mobile devices they own already.”