Round-Trip Delay Modeling for Smart Body Area Networks

This letter presents the first round-trip delay study of the recently proposed smart body area networks (SmartBANs) to address the challenge of achieving ultra-low round-trip delay for ubiquitous e-health applications. Based on the SmartBAN medium access control (MAC) protocol, an embedded Markov chain is developed for queuing and delay analysis of downlink packets broadcasted by the central hub to the attached nodes. The uplink delay caused by a time division multiple access mechanism is formulated by an M/D/1 queue with a vacation model. Finally, the round-trip delay, as the combination of both uplink and downlink delays, is derived. Based on our proposed model, we highlight a tradeoff between uplink and downlink delays under varying downlink transmission durations, providing an understanding of how the predefined MAC timing parameters impact the round-trip delay. The accuracy of our models is validated by extensive simulations.