Disruption tolerant communications for large scale emergency evacuation

In urban emergencies and disasters, emergency support systems enabled by ubiquitous computing and mobile communications can prove very beneficial by providing alerts, guidance and other crucial information to civilians and emergency responders. However, the communication infrastructure that such systems depend upon is usually adversely affected in emergencies due to failures or congestion. Thus we consider the problem of providing emergency support when existing communication infrastructure is unavailable. We propose the use of opportunistic communications (Oppcomms) among mobile devices for the dissemination of emergency information. With Oppcomms, devices exchange messages at a close range of a few to tens of meters with limited or no infrastructure and messages are carried over multiple hops in a “store-carry-forward” manner by exploiting human mobility. We present an emergency support system (ESS) based on Oppcomms to provide evacuation guidance to civilians in large-scale urban emergencies in the absence of other means of communication. We evaluate the performance of ESS with simulation experiments of large-scale evacuation of a district of London, UK. Our evaluations show the improvement Oppcomms can offer.