دانلود رایگان مقاله انگلیسی تشخیص و اندازه گیری شکاف در شبکه سنسور بی سیم - الزویر 2018

abstract

Area detection and measuring is one of the most important problems in Wireless Sensor Network (WSN) because it mainly relates to the continuity and functionality of most routing protocols applied to the Region of Interest (ROI). Electronics failure, random deployment of nodes, software errors or some phenomena such as fire spreading or water flood could lead to wide death of sensor nodes. The damage on ROI can be controlled by detecting and calculating the area of the holes, resulting from the damaged sensor networks. In this paper, a new mathematical algorithm, Wireless sensor Hole Detection algorithm (WHD), is developed to detect and calculate the holes area in ROI where the sensor nodes are spread randomly. WHD is developed for achieving Quality of Service (QoS) in terms of power consumption and average hole detection time. The dynamic behavior of the proposed WHD depends on executing the following steps. Firstly, WHD algorithm cuts down the ROI into many cells using the advantage of the grid construction to physically partition the ROI into many small individual cells. Secondly, WHD algorithm works on each cell individually by allocating the nearest three sensor nodes to each of the cell’s coordinates by comparing their positions, WHD connects each cell’s coordinate points with the selected sensor nodes by lines which construct a group of triangles, then WHD calculates the area of upcoming triangles. Repeating the previous step on all the cells, WHD can calculate and locate each hole in the ROI. The performance evaluation depends on the NS-2 Simulator as a simulation technique to study and analyze the performance of WHD algorithm. Results show that WHD outperforms, in terms of average energy consumption and average hole discovery time, Path Density algorithm (PD), novel Coverage Hole Discovery Algorithm (VCHDA) and Distriputed Coverage Hole Detection (DCHD).

Conclusion and future work

Accurate detection and calculation of holes in WSNs do not only help the routing protocols to avoid the detected holes area and modify their routing paths to the destination, but also help in the field of movement tracking such as that of animals, people and vehicles, Also some other phenomena such as fire spreading or water flood. This paper has presented the WHD (Wireless Hole Detection) algorithm to calculate the total holes area in the wireless sensor networks ROI, where the network nodes operate on limited battery energy. The reduction of the consumed communication time and computational power is considered the main challenge regarding this network. The WHD offers the advantage of small transmission distances for most of the sensor nodes. This concept leads to increasing the network lifetime and decreasing the communication and computation overheads as well as enhancing the quality of the network. The basic concept of the WHD is as follows.
WHD divides the WSN into a number of similar cells by using the grid algorithm.
WHD works on each cell individually by storing each cell’s coordinate positions and finds the nearest number of sensor nodes (depending on the application) to each coordinate.
WHD begins to cut each cell into a number of triangles by drawing lines between each coordinate and the selected number of sensor nodes.
WHD algorithm calculates the area of the formed triangles in each cell which represents the holes area in that cell.
WHD sums the total holes areas in every cell to calculate the total holes area in the ROI.