Research On Medium Access Control Protocol Of Low Energy Wide Coverage Networks

Low power wide area (LPWA) network has the characteristics of short and infrequent transmission data, low energy consumption, wide coverage, etc. The LPWA network will be widely used in oil and gas pipeline monitoring, water leakage detection, soil monitoring and so on. In2013, IEEE TG4group has proposed a draft standard for low energy, critical infrastructure monitoring (LECIM) network, which is one of typical LPWA network. Due to the mechanism of media access control (MAC) has much effect on network performance, the research on IEEE802.15.4k MAC protocol is important for both academic and industry.This thesis is organized as follows. Firstly, we introduce the development of wireless access technology and wireless personal area network, especially the architecture of wireless sensor network. Then, the key technologies of IEEE802.15.4k, including network topology, operation mode of system, frame structure, function of physical layer, MAC layer and service primitives, are fully investigated. In addition, the existing carrier sense multiple access with collision avoidance (CSMA/CA) protocol and the corresponding Markov models are reviewed. The modeling process, advantages and disadvantages of the models are deeply analyzed.In the second part of this thesis, the MAC protocol of IEEE802.15.4k, CSMA/CA-PCA, is modeled through a Markov chain for the first time. The unsaturated traffic is also considered for the model, which meets the characteristics of LECIM network. Moreover, we have derived a closed-form expression of successful packet delivery rate. According to the analytical results, the successful delivery rate is mainly influenced by MAC parameters, the number of nodes and the probability of idle state. Our work could provide fundamental for the analysis of network performance. Monte Carlo simulations are also carried out and the results confirm that the proposed Markov chain model is correct and accurate.