Navigability and reachability index for emergency navigation systems using wireless sensor networks

Emergency navigation with a large number of sensors can serve as a safety service in emergencies. Recent studies have focused on navigation protocols to safely guide people to exits while helping them avoid hazardous areas. However, those approaches are not applicable in all circumstances. Both the dynamics of the environment and the mobility of users are key challenges for the efficiency and effectiveness of navigation protocols. The concepts of navigability and reachability are used to evaluate three typical navigation approaches. A large number of simulation results show that these two indicators effectively identify the performance levels of navigation protocols in changing environments.