Research And Simulation On Key Techniques Of Underwater Acoustic Sensor Networks Based On QualNet

Underwater Acoustic Sensor Networks (UASNs) are newly arisen network technique. It consists of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area. UASNs are envisioned to enable applications for oceanographic data collection, pollution monitoring offshore exploration, disaster prevention, assisted navigation, and tactical surveillance applications. In the paper the main purpose is to provide networking and communications for the system of sensors. This test researching effort and consequence are 5 pinots.(1).The applicability of three existent topologies in underwater acoustic networks is discussed. Then the characteristics of the self-configure topology are analyzed and its network system architecture is given. Then the communication architecture achieves real-time data for some long-distance equipment and transfer control information for the equipment.(2).Due to its spatial-temporal variant characters of underwater acoustic channel, limited nodes' energy and bandwidth resource, a cross-layer design in UASNs is proposed. The example simulated by QualNet is that implements communication between application layer and network layer by crossing UDP protocol, which increases the flexibility of information interaction and efficiency of protocol execution in nonadjacent layers so that improve transmission performance.(3).Routing algorithm of UASNs is researched. Aiming at AODV's defect, a kind of underwater mufti-route Ad-Hoc On-Demand Distance-vector(UMAODV) is bringed up, and the algorithm adopt mufti-nodes routing switch mechanism, after a link failure attach standby node conform new link for transmit data package. The UMAODV shorten preventive maintenance time, descend lost of data package and enhance routing algorithm ability of AODV.(4).The safety factor of UASNs is assayed and researched. Aiming at tampering with the routing table, security table entrance protection (STEP) mechanism is put forward. The efficient STEP (ESTEP) uses only one digital sign to judge veracity of information, avoiding intercepting and guaranteeing routing safe.(5).Based on QualNet software, the communications system structure of UASNs is founded. Then the network structure of UASNs, cross layer design and the route protocol algorithm is simulated. Findings offer reference for UASNs in research and application.