Tham khảo tài liệu 'wireless sensor networks application centric design part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | MAC Mobility In Wireless Sensor Networks 289 energy consumption Delay and collisions occurrences. This effect is observed in Figure 10-A where we can see the gap of consumption between SEA-MAC and S-MAC. Fig. 10-A S-MAC vs. SEA-MAC energy consumption at 5 Duty-Cycle. Time s S-MAC A SEA-MAC Fig. 10-B S-MAC vs. SEA-MAC Delay average at 5 Duty-Cycle. 290 Wireless Sensor Networks Application-Centric Design Fig. 10-C S-MAC vs. SEA-MAC collisions ocurrances at 5 Duty-Cycle. Adding the proposed approach to both protocols resulted in a different operation than the original ones. Figure 11-A B C shows that it is observed that S-MAC was improved over SEA-MAC operation at low Duty-Cycle. This is due to the fact that S-MAC goes through four stages of operation SYNC RTS CST ACK while SEA-MAC has TONE SYNC RTS CTS ACK which leads to a longer operation even with the compression of two control packets SYNC RTS SEA-MAC has longer operation time than S-MAC at shorter duty-cycle. -----S-MAC-PP -----SEA-MAC-PP Fig. 11-A PP S-MAC vs. PP SEA-MAC energy consumption at 5 Duty-Cycle. MAC Mobility In Wireless Sensor Networks 291 Time s S-MAC-PP -A-SEA-MAC-PP Fig. 11-B S-MAC-PP vs. SEA-MAC-PP average Delay at 5 Duty-Cycle. Time s S-MAC-PP -a-sea-mac-pp Fig. 11-C S-MAC-PP vs. SEA-MAC-PP collisions at 5 Duty-Cycles. Pros and Cons of the proposed theory Overall the proposed approached satisfied the quest as it does improve the operation of both protocols at different ranges of duty-cycle we must note SEA-MAC with the proposed approach offered better energy consumption and delay operation at higher duty-cycles than S-MAC also implemented with the approach . Increasing the number of nodes result in collision occurance rather than the situation with the straight line deployment. Overall message delay is in favor of S-MAC at shorter duty-cycles and the advantage is to SEA-MAC at longer duty-cycle. In the next section we will discuss breifly the mobility issues in WSN as it is considered an .
