ABSTRACT
The Internet of Things (IoT) is affecting our daily lives by realizing the interactions of human-to-human, machine-to-machine, and human-to-machine. Healthcare applications are one of the main drivers of the growth of the IoT. In this chapter, we build a two-dimensional queueing model of a healthcare IoT system subject to gateway failure and analyze the system performance based on different system parameters. The main components of the healthcare IoT system include biosensor nodes installed on wearables, a portable gateway device, and a cloud server. Wireless communications exist between the sensors and the gateway as well as between the gateway and the cloud server. The gateway may be subject to failure and thus cause communication failure. We derive the analytical solution for the system model and develop some important performance metrics for the system, including mean number of data packets in the system, mean sojourn time of data packets in the system, steady-state availability of the system, and mean busy period of the system. Numerical evaluation are presented for further understanding and verification of the analytical results. The proposed system modeling and evaluation method can serve as a useful reference for the general IoT system design and evaluation.
