Map Dissemination in Disaster Scenarios

Disconnected environments such as battlefield scenarios and natural disasters are characterized by lack of network connectivity and power grid access [1, 2, 3]. A primary challenge in such disconnected environments is access to information for end users such as soldiers, survivors, and first responders. For instance, consider the aftermath of the Tokyo earthquake [4]. The power grid and the Internet was unavailable for months. Consequently, users did not have access to information that could guide them to the nearest relief camp or food store. A similar situation can arise during a military operation. While satellite radio-enabled devices are available for communication between military vehicles, due to inhibitive costs, large amounts of data can not be disseminated using satellite channels [5]. Another consequence of disconnected operation during emergency scenarios is lack of data that experts can use in the future for better disaster preparedness. The state-of-the-art techniques use satellite images that provide a one-dimensional view of the affected scene, and often are of a coarse resolution [5]. To address the above challenges, we propose the design of a solar powered self configurable wireless mesh that can serve rich GIS information to users after natural disasters and during military operations. The mesh will serve map-based data to users on their handheld devices such as mobile phones and laptops. Additionally, users can annotate maps with images and dangerous regions, using standard web browsers, and the annotated map layers can be disseminated using the mesh to geographically distant users. The mesh serves as a sustainable distributed repository of rich, up-to-date, user-annotated map data that can act as a black-box data source after a natural disaster (similar to a flight data recorder in aircrafts), a channel of critical information dissemination for first responders, and a substrate to locate survivors during a natural calamity. There are several practical challenges that must be addressed before a large scale deployment of such a mesh is feasible. First, for self-sustainability, the mesh nodes should frugally consume power, and hence should be built using low power embedded hardware. However, the mesh should be highly available for users, should be highly responsive, and compute capable to serve rich map data to users. Hence, balancing energy consumption with functionality and availability is a fundamental design pillar. Second, the software stack on the low power embedded devices should be capable of rendering high resolution maps to survivors of natural disasters and soldiers during a military operation. The problem amounts to intelligent porting of resource hungry software modules to function seamlessly on ultra-low power embedded platforms. Third, the mesh should be self adapting and dynamic. During natural disasters, the topology of the environment changes rapidly —a bridge might have fallen or a road might be flooded. Since a backhaul connection to a map server is unavailable, the system should use alternate mechanisms to maintain up-to-date map based data. The users (soldiers or survivors) should have the capability of annotating maps on their handheld devices with images and tags corresponding to dangerous zones, and should be able to push such updates to the mesh. The up-to-date maps can be downloaded by other users in geographically distant locations. The information would act as a repository of data collected during the disaster, and can be used for later analysis for future improvements to emergency response and battlefield tactics. We propose to address the above research challenges through a three fold agenda.