A NOVEL DISTRIBUTED FAULT-TOLERANT TOPOLOGY CONTROL ALGORITHM FOR HETEROGENEOUS WIRELESS SENSOR NETWORKS

In this abstract, we focus on a proactive fault-tolerant topology control algorithm in heterogeneous WSNs with a two-layered architecture where the lower layer consists of low-cost ordinary sensor nodes, with limited battery power and short transmission range. The upper layer consists of super nodes, which have more power reserves and better processing and storage capabilities. Links between super nodes have longer ranges and higher data rates; however, super nodes are fewer in number due to their higher cost. Super nodes can also have some special abilities like acting against an event or a certain condition. This type of super nodes are called actors (or actuators), and sensor networks that contain actors are called wireless sensor and actor networks (WSAN). In WSANs, data gathered by sensors is forwarded to actors for performing the required actions. This abstract introduces a new algorithm called the Disjoint Path Vector (DPV) algorithm for constructing a fault-tolerant topology to route data collected by sensor nodes to super nodes. In WSNs, guaranteeing k-connectivity of the communication graph is fundamental to obtain a certain degree of fault tolerance. The resulting topology is tolerant up to k-1 node failures in the worst case. We propose a distributed algorithm, namely the DPV algorithm, for solving this problem in an efficient way in terms of total transmission power of the resulting topologies, maximum transmission power assigned to sensor nodes, and total number of control message transmissions. Our simulation results show that our DPV algorithm achieves between 2.5-fold and 4-fold reduction in total transmission power required in the network, depending on the packet loss rate, and a 2-fold reduction in maximum transmission power required in a node compared to existing solutions.