Chunxue Wu

Tracking Mobile Sinks via Analysis of Movement Angle Changes in WSNs

Existing methods for tracking mobile sinks in Wireless Sensor Networks (WSNs) often incur considerable energy consumption and overhead. To address this issue, we propose a Detour-Aware Mobile Sink Tracking (DAMST) method via analysis of movement angle changes of mobile sinks, for collecting data in a low-overhead and energy efficient way. In the proposed method, while a mobile sink passes through a region, it appoints a specific node as a region agent to collect information of the whole region, and records nodes near or on its trajectory as footprints. If it needs information from the region agent in a future time it will construct an energy efficient path from the region agent to itself by calculating its own movement angles according to the footprints, as well as getting rid of detours by analyzing these movement angles. Finally, the performance of the tracking method is evaluated systematically under different trajectory patterns and footprint appointment intervals. The simulation results consolidate that DAMST has advantages in reducing energy consumption and data overhead.

Adjustable Trajectory Design Based on Node Density for Mobile Sink in WSNs

The design of movement trajectories for mobile sink plays an important role in data gathering for Wireless Sensor Networks (WSNs), as it affects the network coverage, and packet delivery ratio, as well as the network lifetime. In some scenarios, the whole network can be divided into subareas where the nodes are randomly deployed. The node densities of these subareas are quite different, which may result in a decreased packet delivery ratio and network lifetime if the movement trajectory of the mobile sink cannot adapt to these differences. To address these problems, we propose an adjustable trajectory design method based on node density for mobile sink in WSNs. The movement trajectory of the mobile sink in each subarea follows the Hilbert space-filling curve. Firstly, the trajectory is constructed based on network size. Secondly, the adjustable trajectory is established based on node density in specific subareas. Finally, the trajectories in each subarea are combined to acquire the whole network’s movement trajectory for the mobile sink. In addition, an adaptable power control scheme is designed to adjust nodes’ transmitting range dynamically according to the movement trajectory of the mobile sink in each subarea. The simulation results demonstrate that the proposed trajectories can adapt to network changes flexibly, thus outperform both in packet delivery ratio and in energy consumption the trajectories designed only based on the network size and the whole network node density.

Design and Analysis of a Data Fusion Scheme in Mobile Wireless Sensor Networks Based on Multi-Protocol Mobile Agents

Sensors are increasingly used in mobile environments with wireless network connections. Multiple sensor types measure distinct aspects of the same event. Their measurements are then combined to produce integrated, reliable results. As the number of sensors in networks increases, low energy requirements and changing network connections complicate event detection and measurement. We present a data fusion scheme for use in mobile wireless sensor networks with high energy efficiency and low network delays, that still produces reliable results. In the first phase, we used a network simulation where mobile agents dynamically select the next hop migration node based on the stability parameter of the link, and perform the data fusion at the migration node. Agents use the fusion results to decide if it should return the fusion results to the processing center or continue to collect more data. In the second phase. The feasibility of data fusion at the node level is confirmed by an experimental design where fused data from color sensors show near-identical results to actual physical temperatures. These results are potentially important for new large-scale sensor network applications.

A Clue Based Data Collection Routing Protocol for Mobile Sensor Networks

In recent years, mobile sinks are used more and more efficiently in sensor networks to collect data for the mobility advantage in balancing energy consumption than static sinks. However, it is still a challenge in both efficiency and network cost to avoid generating large amounts of overheads and lots of unnecessary energy consumption, when data source forward sensing data to mobile sink proactively according to their location information broadcasted all over the network. To reduce the overhead and balance the energy consumption in a network, we propose a clue-based data collection routing (CBDCR) protocol for mobile sensor networks. In CBDCR, a mobile sink moves randomly other than the following predesigned trajectories, during which it only broadcasts its location messages by limited hops instead of the whole network. The nodes getting these messages are called watchers who can obtain the upstream or downstream relations and infer the hop(s) from them to the mobile sink, and then a watcher stores this information as a “clue” to the location of mobile sink for data forwarding. As the movement of the mobile sink, more and more nodes are becoming watchers, and so a sensing data can be efficiently forwarded to the mobile sink according to these clues. Numerous simulations are conducted with mobile sinks in network to evaluate the performance of CBDCR, which demonstrate that CBDCR can both reduce the redundant transmission messages significantly and balance the network energy consumption.

Design and application of system with dual-control of water and electricity based on wireless sensor network and video recognition technology

In the industrial Internet of Things, water and electricity is the most important hidden project. Its requirements are very high, especially the intelligent control of water and electricity. Therefore, a design and application of system with dual-control of water and electricity is proposed and convolutional neural networks–based video recognition technology is used to identify the security issues that occur in the field. Some sensors are used to control the use of water and electricity, while others are used to collect scalar data which include user’s data and video multimedia data in the wireless sensor network. The scalar data are used to update the user’s database, and the video multimedia data are used to monitor and prevent anomalies from occurring in the field of dual-control of water and electricity. In order to solve the security problem of the user in wireless sensor network, this article proposes a radio frequency identification mutual security authentication protocol based on shared secret hash function. Finally, experiments show that the proposed secure authentication protocol can guarantee the secure transmission of data between the sensor node and the server, and the video recognition technology can recognize some abnormalities well.