# A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks
## 6 Simulation
It is realized that the delay increases as the number of devices increases  
Figure 10: Validation of reliability for different beacon order. Figure 9: Comparison of throughput of our proposed scheme with the IEEE 802.15.4e standard. irrespective of the beacon order. When the data payload of 100 bytes and 500 sensor devices are considered, the delay is nearly 74 ms, if the beacon order is 10. We have compared our work with IEEE 802.15.4e standard setting beacon and superframe orders as 2 as shown in Figure 13. It is noticed that delay of our work is significantly less and the simulation result matches with the analytic one. This happens as our proposed method avoids the unnecessary backoff durations. The delay suddenly increases in case of IEEE 802.15.4e when the number of devices reaches to 70. This situation occurs due to channel access failure or transmission failure by a device and  
Figure 11: Comparison of reliability of our proposed scheme with the IEEE 802.15.4e standard. Figure 6:0 Validation of packet delay for different beacon order. the device has to wait for the start of the next superframe. It is to be noted that the device has to wait for the CFP period before accessing the channel again. However, in our protocol, the chance of accessing the channel in the next superframe is significantly less due to the high transmission success rate as compared to the IEEE 802.15.4e. Figure 14, shows the minimum GTS packet delay with respect to different numbers of beacon order. It is observed that the minimum GTS retransmission delay remain constant irrespective of the beacon order. This happens as the MAC scheme of our scheme allows the failed devices to retransmit data during the CAP without waiting for the next allotted retransmission slots. As shown in Figure 15, we compare our scheme with IEEE 802.15.4e standard taking beacon order from 1 through 5 and superframe order as 1. It is found that coordinator discovery delay of our scheme remains constant though it exponentially increases in case of IEEE 802.15.4e. This happens as the coordinator broadcasts the beacon sequentially in every channel in our proposed scheme. Figure 6:1 Comparison of GTS retransmission delay of our scheme with IEEE 802.15.4e standard. Figure 6:2 Comparison of packet delay of our scheme with IEEE 802.15.4e standard. As shown in Figure 16, different numbers of devices are considered to evaluate the corresponding energy consumption in joule. It is observed that the energy consumption increases as the numbers of devices attached to a coordinator increase irrespective of the beacon order. When the data payload of 100 bytes and five hundred number of devices are considered, the energy consumption is nearly \(1.64\times 10^{-5}\) joule, if the beacon order is 10. As shown in Figure 17, our work is compared with IEEE 802.15.4e standard for equal number of beacon and superframe order. It is found that the energy consumption of our scheme is less as compared to the IEEE 802.15.4e standard. This happens as the numbers of sensors in our scheme are restricted to access the channel within one CAP by which number of collisions is reduced significantly. Besides, the simulation result of our scheme matches with the analytic one. Figure 6:3 Validation of energy consumption for different beacon order. Figure 6:4 Comparison of minimum coordinator discovery delay of our proposed scheme with the IEEE 802.15.4e standard.