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Artificial Intelligence for Wireless Sensor Networks Enhancement Part 8

Tham khảo tài liệu 'artificial intelligence for wireless sensor networks enhancement part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Optimizing Coverage in 3D Wireless Sensor Networks 199 Fig. 4. Number of nodes in the active cover set for different network sizes Fig. 5. Percentage of connected nodes in the active cover set vs. sensing range rs An important evaluation criteria of coverage alogorithms is how well the target region is covered by the sensor nodes. Figure 6 presents results for the observed coverage. 200 Smart Wireless Sensor Networks a Network Size 200 Observed coverage k Observed coverage k Observed coverage k b Network Size 300 c Network Size 400 Fig. 6. Percentage of point covered with respect to Observed coverage k in a N 200 b N 300 and c N 400 nodes As discussed in Section 4 a simple case is when a point is covered by at least one sensor the resultant coverage is said to be of the order 1. Although the DCA is designed with the object to provide best 1-coverage k 1 in the target region we ran a number of experiments to estimate the coverage of higher oders i.e k 1. For this set of experiments three network sizes of 200 300 and 400 nodes were selected. Simulations for each network size were Optimizing Coverage in 3D Wireless Sensor Networks 201 further repeated with three different values of sensing radius. The results from these experiments are presented in Figure 6. It can be observed that these results are in agreement with our analytical results presented in Section 4 we observe that for a sensing range of 25 m provides us a toplogy where 99 of nodes are covered by at least one sensor node. Moreover the the same value of sensing range yield the topolgy where approximately 60 of the points are 2-covered i.e k 2 . Figure 7 and Figure 8 depict the resultant topology and connectivity graph before and after the execution of DCA. It can be clearly seen that the DCA preserves connectivity while reducing extra nodes within a given deployment region. 100 80 60 40 20 0 100 50 100 y 00 Fig. 7. Network topology and connectivity graph before the execution of DCA network size 300 nodes .