An Agreement-Based Fault Detection Mechanism for Under Water Sensor Networks

In this paper, we propose an agreement-based fault detection mechanism for detecting cluster-head failures in clustered UnderWater Sensor Networks (UWSNs). The proposed detection mechanism aims to accurately detect the failure of a cluster head in order to avoid unnecessary energy consumption caused by a mistaken detection. For this purpose, it allows each cluster member to independently detect the fault status of its cluster head and at the same time employs a distributed agreement protocol to reach an agreement on the fault status of the cluster head among multiple cluster members. The detection mechanism is based a TDMA MAC protocol used in the network and runs concurrently with normal network operation by periodically performing a distributed detection process at each cluster member. To reduce energy consumption, it makes use of the data periodically sent by a cluster head as the heartbeats for fault detection. A couple of forward and backward TDM frames are specially structured for enabling multiple cluster members to reach an agreement within two frames in each detection process. Moreover, a schedule generation algorithm is also proposed for a cluster head to generate the transmission schedule of the forward and backward frames. Through simulation results, we show that the proposed detection mechanism can achieve high detection accuracy under high packet loss rates in the harsh underwater environment, and can faster detect a cluster-head failure than a traditional fault detection mechanism.