Fluid-Based Modeling of Large-Scale IEEE 802.15.4 Wireless Sensor Networks

In recent years, expectations for large-scale wireless sensor networks have been rapidly increased due to miniaturization, cost reduction, reduction in power consumption of wireless sensor devices, and the emergence of wireless sensor network applications such as IoT (Internet Of Things). However, in addition to the uncertainty inherent in wireless sensor networks, due to the uncertainty caused by the expansion of wireless sensor networks, it is not easy to realize a highly efficient and reliable large-scale wireless sensor network. The uncertainty of wireless sensor networks is classified into three types: the uncertainty of nodes such as sensor nodes and sink nodes, the uncertainty of wireless communication links among nodes, and the uncertainty of traffic transferred over the wireless sensor network. In this paper, as a wireless communication standard, we focus on IEEE 802.15.4, which is designed for short-range wireless networks called PANs (Personal Area Networks), and analyze large-scale wireless sensor networks using fluid approximation. Specifically, IEEE 802.15.4 large-scale wireless sensor networks are analyzed by extending the modeling approach for generic CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) wireless networks. Moreover, our analysis makes it possible to probabilistically model temporal fluctuation of wireless communication ranges of nodes as network uncertainty. As a result, our analysis clarifies the effect of link uncertainty on the average message delivery delay in wireless sensor networks.