Improvement Research Of Underwater Acoustic Sensor Network Routing Protocol HHVBF

In recent years the efforts in the exploration and use of marine resources havebeen enhanced, which has made the underwater network communication attracts moreand more attention from researchers. Radio’s waving limitations in seawater has madeunderwater acoustic transmission a better choice for underwater communicationregion, and UnderWater acoustic Sensor Network (UWSN) has become a researchhotspot. UWSN has a wide range of application scenarios, including oceanographicenvironmental monitoring, tsunami warning, underwater device control, marinepollution detection, oil exploration and climate monitoring. Compared to thetransmission of radio in the air, underwater acoustic transmission in seawater is muchslower, easy to loss energy and susceptible to multi-path and Doppler Effect whenpropagating. Those make the UWSN often just have relatively narrow bandwidth andlarge network delay, and the life cycle of the whole network is constrained by thenode energy.This thesis firstly studies a significant routing protocol based on the locationinformation, which is HHVBF. Theoretical analysis and experimental verificationrevealed that the protocol has several problems, including energy uneven consumption,over redundancy and unreliable transmission. This paper proposed a Reliable HHVBF(RHHVBF) routing protocol based on addressing these issues. RHHVBF ensures thereliability of the entire transmission reliability by ensuring the transmission reliabilitybetween each hop among the path from the source node to the destination node.Firstly RHHVBF using packet acknowledgment and retransmission mechanisms torealize the transmission reliability between each hop, and proposes local neighborrouting table to assist the choice of the next hop node, which reduces invalid datapacket forwarding and improves bandwidth utilization. This paper proposes the linkquality evaluation model node by node, based on which this paper also presents theforward link (the link towards the destination node) state prediction model. Throughthe forward link quality prediction of next hops, RHHVBF can avoid choosing nodewith poor forward links which may cause excessive retransmissions. This paperdesign RHHVBF routing protocol using the cross-layer protocol designing principles.RHHVBF will also consider the energy balance designing goals when selecting the next hop node, which tries to make the network consume energy averagely andprolong the network lifetime.As UWSN field experiments cost much, researchers often use modeling andsimulation approach to evaluate the performance of protocols. This paper has realizedthe RHHVBF protocol in Aqua-Sim based on the NS2simulation tools. This paperthen compares the RHHVBF and HHVBF in network throughput, data transmission,resource consumption, and energy efficiency. The experiment results confirmed thatthe performance of RHHVBF has a steady improvement in the above areas than thoseof HHVBF.