یک الگوریتم Checkpointing ناهماهنگ مبتنی بر اعتماد در شبکه های Ad Hoc موبایل (MANETs) ☆

The paper presents a trust-value based uncoordinated check pointing algorithm in Mobile Ad Hoc Networks (MANETs). We aim to improve the overall check pointing overhead incurred in the execution of recovery protocols. Most check pointing algorithms do not consider the mobility rate of nodes while taking a periodic checkpoint, thereby, resulting in poor utilization of resources and increased latency. However, the proposed trust-value based check pointing scheme captures a check point only after a node has endured certain movements. Hence, whenever a node move from one cluster to another, the node moves from a cluster with high trust value to a cluster with low trust value and vice-versa. Therefore, nodes do not rely on any fixed threshold value in order to take a checkpoint. This is due to dependency of trust value of a node on the previous and current trust value of its cluster. Thus, each time a node moves or change to a new cluster, its cluster_change_count is compared with a fixed threshold value. The information, hence, is restrained for communication ifthe count is greater than threshold in order to maintain its safety. The proposed algorithm comprises of three phases, namely, multi-checkpointing phase, trust node evaluation phase and recovery phase. The analysis shows better performance of the proposed protocol over existing mobility- based protocol in terms of probability of recovery of failed nodes, residual energy and simulation time.