Self-reconfiguration aggregation scheduling to recover from node and interference faults in WSNs

摘要

Recovery from node faults and interference faults has been an important area of research in Wireless Sensor Networks (WSNs). Whilst faulty nodes hinder the data aggregation process, interference faults lead to faulty transmissions amongst the communicating sensor nodes. Sidelining the faulty nodes from the network and finding alternate paths for the affected nodes works out to be a good solution when (a) the nodes are in direct range of each other (b) localized interaction among the nodes leads to a connected path to the sink. But for cases where alternate path, active replicas, or stationary relays do not exist, and also in cases where the aggregation network is controlled by sink, reconstruction of hierarchical aggregation tree may turn out to be better solution. Further, for any aggregation-based link scheduling, the aggregation delay depends on the effect of interference among the simultaneous active links. In this paper, we develop an algorithm that attempts to establish the routing path to the sink after isolating the faulty nodes along the aggregation tree. The Self-Reconfiguration Aggregation Tree Scheduling (RAGTS) algorithm makes use of the Composite Interference Mapping (CIM) model developed by us earlier, to generate an interference fault free aggregation schedule for all links in WSN. We validate the approach through analytical and simulation studies.