Abstract
During the last few years, wireless low-power communications experienced an increasing coexistence and traction as a result of the higher demand posed by power constrained applications. On the other hand, this increasing wireless coexistence is a growing concern and Low-power wireless communication protocols have been shown to experience a significant timeliness and reliability degradation under certain interference profiles. Therefore, the support of real-time communications over license-free bands in open environments, encompassing multiple real-time stations with an unknown number of unconstrained stations, is a challenging task. Provided that this impairment has hindered their wide adoption in demanding real-time scenarios, the Wireless Flexible Time Triggered (WFTT) protocol has been recently proposed targeting applications with stringent timeliness requirements. This protocol works on the medium access determinism granted by the bandjacking technique in open environments, where different technologies may contend for the medium. Besides providing a deeper definition of the WFTT architecture and protocol operation, this paper presents a thorough analysis addressing its specifications, implementation feasibility and testbed based results. These provide strong evidence that the WFTT protocol is able to support real-time communications, even in environments affected by high levels of interference from neighboring contention-based communication technologies such as Wi-Fi.