Towards tactile internet capable e-health: A delay performance study of downlink-dominated SmartBANs

Wireless body area networks (WBANs) are expected to support control/steering and haptic communication via on-body actuators in future Tactile Internet enabled e-health systems. However, little is known to date about the capability of WBANs in realizing remotely-controlled applications since current WBANs are uplink-transmission dominated for the purpose of health monitoring and supervision. In this paper, we present the first downlink delay performance evaluation based on the recently-proposed Smart Body Area Network (SmartBAN). To meet the stringent 1-ms Tactile Internet delay requirement for real-time tactile feedback and control delivery, we make comparisons between two downlink transmission mechanisms: (a) conventional exhaustive transmission; and (b) fixed-length exhaustive transmission based on the SmartBAN medium access control (MAC) layer protocol. M/D/1 and embedded Markov chain models are developed to evaluate downlink delay for SmartBANs adopting the transmission mechanisms above. The accuracy of our models is validated by simulations. Analytical and simulation results show that compared to the conventional mechanism, the fixed-length exhaustive transmission can effectively reduce downlink delay to less than 1 ms by increasing downlink transmission duration and improved energy performance can potentially be achieved thanks to the fixed MAC configuration. Further, with our model, suitable downlink durations can be determined by considering delay constraints in practical applications.