Survey on DAG Based Fault Tolerance in Wireless Multimedia Sensor Network

Data aggregation, information trust, and fault tolerance is considered to enhance the correctness and trustworthiness of collected information. It is based on the multilayer aggregation architecture of WMSNs, existing trust-based framework for data aggregation with fault tolerance with a goal to reduce the impact of erroneous data and provide measurable trustworthiness for aggregated result. DAG method provides fault tolerance for packet loss by forming a Directed Acyclic Graph (DAG), which allows a node to have multiple parent nodes. This method can ensure correct data transmission timing, according to the actual hop count of the edge of the DAG.