Resilient data gathering and communication algorithms for emergency scenarios

A typical application field of Wireless Sensor Networks (WSNs) is the collection of environmental data, which is sent to a base station. Routing protocols are needed to efficiently direct the information flows to the base station. Since sensor nodes have strict energy constraints, data gathering and communication schemes for WSNs need to be designed for an efficient utilization of the available resources. An emergency management scenario is investigated, where a sensor network is deployed as virtual lifeline for fire fighters entering a building. Besides of supporting their navigation, the virtual lifeline is also used for two further purposes. First it enables the exchange of short voice messages between fire fighter and command post. For this, a fast and reliable routing protocol (EMRO) has been developed based on a broadcasting scheme. Second, measuring data, like temperature and gas, in the environment and informing fire fighters and command post about it, is of high importance. For this purpose a network coding based data gathering algorithm has been designed. The feasibility of simultaneously using the virtual lifeline for data gathering and communication and thus the coexistence of a classical routing protocol with a network coding scheme is studied in this paper by means of simulation and real experiments. The resilience to packet loss and node failure, as well as the transmission delay are investigated by means of short voice messages for the communication part and temperature readings for data gathering.