# A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks
## 2 Related Works
On the other hand, these schemes are based on ideal channel condition only and are not realistic. An analytical model is designed in [23] to predict the throughput and energy consumption of the IEEE 802.15.4 networks under non-saturated wireless environment. Authors in [24] have designed one additional carrier sensing (ACS) algorithm to get the information of busy channel due to data or an acknowledge packet transmission during the second CCA. However, it is wastage of energy if the second CCA is found busy due to data. In order to increase the chance of transmission by ignoring the channel busy condition due to end of ACK packet transmission during first CCA, authors in [25] propose one segmented CCA. However, it has no improvements for the data transmission, if it is a data packet instead of ACK one. In order to avoid collision in a dense network, a new variable Clear Channel Assessment MAC scheme for WSNs along with performance analysis is designed in [26]. However, these schemes consumes significant amount of energy for CCAs. A mathematical model for deriving the energy consumptions in clustered IEEE 802.15.4 WSNs is designed in [27], which is suitable only for non beacon-enabled WSNs. Performance study of sending and receiving capabilities of commonly used devices in wireless network are made in [28]. Though, they investigate the communication performances of various devices, data reliability, energy consumption and other related performance metrics have not been studied in their work. Authors in [29] have experimentally analyzed the aggregate throughput with different traffic loads and under interference of IEEE 802.11b. Performance of IEEE 802.15.4e Time Slotted Channel Hopping (TSCH) and DSME have been studied in [30] to analyze the energy consumption of the system. However, none of these work proposes new MAC mechanism for the IEEE 802.15.4e DSME. Besides, none of the work also analyze the performance in terms of reliability and latency. A discrete-time Markov chain model is used in [31] to analyze the throughput of IEEE 802.15.4 MAC scheme in presence of the hidden devices. Most of the existing analytical models of IEEE 802.15.4 MAC scheme assume ideal channel conditions. However, wireless channels exhibit burst errors in real world scenarios. A three-dimensional discrete-time Markov Chain model is proposed in [32], which is applied to analyze the performance of IEEE 802.15.4 MAC scheme under burst channel errors. In [33], authors evaluate the impact of losing synchronization in beacon-enabled IEEE 802.15.4 network with star topology. However, they did not considered how to reduce synchronization time for orphan or mobile devices. To study the aggregate network throughput and packet delivery delay, authors in [34] propose an analytical framework. However, they do not consider the transmission reliability. From the survey of the current literature, it is observed that most of the performance analysis are based on the IEEE 802.15.4 standard. In typical WSN applications such as smart home, smart industrial automation and smart health care, all devices are connected to a coordinator, which is a single hop scenario. It can be extended to multihop networks by considering the communications among coordinators. In this paper, we focus on how to optimize the performance of the single hop network. This paper not only proposes the DSME MAC schemes for single hop WSN, but also designs the analytical models to evaluate the performance in terms of maximum throughput, delay, energy consumption and reliability based on the IEEE 802.15.4e instead of IEEE 802.15.4 standard.