AVN-AHH-VBF: Avoiding Void Node with Adaptive Hop-by-Hop Vector Based Forwarding for Underwater Wireless Sensor Networks

摘要

In this paper, we propose a routing protocol AVN-AHH-VBF for underwater wireless sensor networks (UWSNs). Sensor nodes forward data packets in multi-hop fashion within a virtual pipeline. As nodes outside pipeline do not forward data packets, thus, flooding is avoided in the network. Mitigating flooding in network, in turn, decreases energy consumption and improves delivery ratio. Moreover, on each hop, forwarding towards void region of the network is avoided with the help of two hop information. Avoiding void hole on each hop reduces number of transmissions for a data packet, for which route to sink does not exist. Thus, energy wastage by each dropped packet is reduced. In addition, taking the benefit of broadcast nature of the network, best forwarder (non-void) is selected from the transmission range of a node. Best forwarder selection results in increased delivery ratio. Furthermore, we incorporate two new factors in holding time calculation. First, the number of hops a data packet has already traversed along its journey that is started from source node. Second, the number of neighbors of a node which is calculating the holding time, is incorporated. A sensor node with less number of neighbors holds data packet for long duration of time than the node with more neighbors. By doing so, holding time is reduced on each hop throughout the journey of a data packet. Extensive simulations verify that AVN-AHH-VBF minimizes end-to-end delay upto 57% as compared to existing AHH-VBF. Also, in the proposed technique, energy wasted by a dropped packet is about 54% less than counterpart technique. At the same time, compared with AHH-VBF, delivery ratio of AVN-AHH-VBF is approximately 8% improved.