Tao Sun

The Implementation of Wireless Sensor Network Visualization Platform Based on Wetland Monitoring

In sensor networks concerning about data, data management and representation have become a crucial issue. In this paper, sensor networks deployed to monitor wetland are built with the visualization of their data and topology. The environmental data, such as temperature, humidity, both in atmosphere and soil, illumination intensity and PH around the wetland are sent by the wireless sensor networks to a base station which is connected to the visualization platform on a PC. The approach presented in this paper utilizes serial communication, database management, data and topology visualization to visualize the data gathered by the wireless sensor networks. The data visualization platform can get and display real time information of networks and makes the system convenient to users.

A Distributed and Effective Cluster Routing Protocol of Sensor Networks

Routing protocol is very important in wireless sensor networks (WSNs), which decides the network organization and the route for data transmitting. As many routing protocols have been proposed, they can be divided into hierarchical routing, location-based routing and on-demand routing protocol. Hierarchical routing protocols such as LEACH, PEGASIS can only be used in small scale network; location-based routing protocols are restricted by the geographical information and the nodes must contain GPS equipment; on-demand routing protocols such as AODV can be used in large scale WSNs, but they bring control messages and long delay. This paper proposes a new routing protocol named DECROP (distributed and effective cluster routing protocol). It has following characteristics: It is simple but efficient. It only has a few control messages with high reliability. It also takes clustering and low energy consumption into consideration. DECROP has three processes: initialization, distributed cluster forming, data transmitting and route maintenance. We compare DECROP with AODV, and simulation results indicate that DECROP has fewer control messages, shorter end-to-end delay in the application of transmitting data to base station (BS) and the residual energy is close to AODV. DECROP is especially suitable for large scale WSNs with homogenous sensors.

A Priority Based Dynamic Adaptive Routing Protocol for Wireless Sensor Networks

Wireless sensor networks (WSNs) are becoming a viable tool for many monitoring applications. In many cases these applications may be of critical nature where the transmitting of vital information from sensors to base station or sink is crucial, and data loss cannot be tolerated. As a result, the information transmission of wireless sensor networks has various different requirements in performance, such as real-time, reliability and delay. Traditional ad hoc network routing protocols are lack of a priority scheduling routing selection strategy, and are mainly based on the condition ldquoshortest pathrdquo, so after the load increase to a certain extent, a vital packet may be dropped in order to send an ordinary message. To this point, across-layer design method is used to present a new routing protocol which is named as priority based dynamic adaptive routing (PDAR), PDAR uses a priority scheduling adaptive routing mechanism to improve the reliability of sending a packet with high priority and the performance of WSNs. Simulation results show that PDAR significantly decreases end-to end delays by 40.3% and packet loss ratio by 15.3% for high-priority flows without starvation of ordinary traffic, which performs much better than dynamic source routing (DSR) protocol.

Architecture of Underwater Acoustic Sensor Networks: A Survey

Recently, there has been a growing interest in monitoring aqueous environments using underwater acoustic sensor network (UASNs), which is considered as a novel tool in exploring ocean also in small aqueous environments such as lakes, rivers. Network topology is a crucial factor in determining energy consumption, capacity and reliability of a network, its necessary for us to know the feasible architectures and their characteristics of UASNs. In this paper, we do a survey on the architecture of UASNs, and classify the architecture into three groups using the node characters as a rule. We also analyze the open questions should to be faced in further research works. The architecture of USANs would be important for application network design, topology control, communication protocols and related study.

A wave-like amendment-based time-division medium access slot allocation mechanism for underwater acoustic sensor networks

Recently, there has been a growing interest in monitoring aqueous environments using Underwater Acoustic Sensor Networks (UASNs). In these networks, the Medium Access Control (MAC) protocols are responsible for coordinating the access from active nodes into the acoustic channel, which is characterized by high propagation delay and low data rate, which is challenging for system synchronization, energy consumption and network output. Most researches in MAC protocol used for UASNs adopt collision avoidance mechanism with handshaking methods at present. But the long acoustic propagation delay results in low throughput and poor energy efficiency. In this paper, we propose a new amendment-based TDMA slot allocation mechanism, which is named WA-TDMA. Slot allocation starts from the node which launched as the center outward to form the wave-like proliferation and the slot allocation and amendment are continuously, which like the performance of wave. This can shorten the initialization time of the network. With the help of amendment, protocol can adjust slot usage to improve slots utilization and deal with slots reuse problem. The main function of the amendment is to avoid the slot collision, and improve the efficiency of slot using. The key characteristic of our mechanism is that it deals with holistic slot allocation problem well, and improve the slots utilization with certain protect distance at the same time.

Base-station driven routing protocol for wireless sensor networks

Routing protocols in sensor networks play an important role and have obtained much attention. There are two main routing mechanisms for sensor networks: proactive routing and on-demand routing. As for the disadvantages of energy un-efficiency for the two traditional protocols, and the disadvantages of the mode to trigger the routing, this paper proposed another kind of routing protocol called BS (short for base-station) driven routing protocol, it is special in the way to start routing by the BS-node (the node connected to the base station). And simulation results show that by utilizing this protocol, we spent less time and energy during routing process than the traditional protocols.

Monitoring Bolt Stress for Cut Slope Based on Wireless Sensor Network

Grasping the variation regularity of cut-slope protection structures and monitoring the side-slope steady state, one wireless sensor network technology is applied to monitoring cut slope and a remotely automatic and intelligentized monitoring slope system is designed. The stress data、 environmental temperature and humidity data collected by sensors are transmitted to base station with IEEE802.15.4 protocol, and then the base station transmits these data to GSM network through GPRS. The slope state would be real-timely monitored with the data which be forwarded to a computer in monitoring centre through Internet network. The application software in monitoring computer displays, stores and processes these data, and indicates an alarm while they exceed some allowed threshold. The system solves problems of conventional slope monitoring one that is difficult in a real-time awareness of slope state and it has practical use for traffic safety in mountainous expressway sections and debris flow range

A Side Slope Remote Monitoring System Based on Wireless Sensor Networks

To solve the problems in the slope monitoring that needs man on scene to get real time monitoring data, this paper designs a remote monitoring system based on wireless sensor networks for side slope. With this system, users can get the quasi-real time monitoring data far from monitoring spot. This project adopts the wireless sensor networks technology, and the design comprises four modules according to the system function. The frame of the system, the design and function of each module are introduced in this paper. It proves that the system is feasible by experimental results, and the design has its practical value.