Modeling energy consumption in IoT systems using stochastic reward nets

Today, internet of things (IoT) is widely used in various fields, such as health control, smart city, smart buildings, and so on. One of the severe concerns in IoT-based systems is the issue of energy consumption and its management. The IoT-based systems have limited resources. It is also difficult to access them in many situations; so, their energy sources must be appropriately consumed and managed. In order to design and build IoT systems, many factors, such as the usable chips, the type of communication protocols, the timing of data transfer, and so on, directly affect the system's energy consumption. Therefore, in the design phase of these systems, it is necessary to model and evaluate their energy consumption and their compliance with the requirements. In this paper, a stochastic reward nets (SRN) model is introduced for modeling and quantitative evaluation of energy consumption in IoT-based systems. In this method, first the modeling of the energy source and the influencing factors are explained, then the entire system is modeled using these basic models, Then, by changing the configuration of the system, the influencing factors on energy consumption are studied and measured, and the most suitable configuration is selected using the results. This method can lead to a significant reduction in the costs of a system before its operation. Using this model, a case study has been investigated and the effects of various factors, such as the number of nodes connected to the cluster head, the existence of sleep/wake mode, and different transmission rates on system performance and energy consumption are investigated. In this paper the effect of the system configuration on the amount of energy consumption has been evaluated and it has been shown that the packet delay increases with the increase in the number of nodes connected to the cluster head, and in order to reduce the number of packets in the buffer by 75% and reduce the end-to-end delay of the packets, a transmitter with a transmission rate of 0.037 should be used.