plexi: adaptive re-scheduling web-service of time synchronized low-power wireless networks

Industrial IoT applications require highly dependable monitoring and actuation capabilities of remote interoperable low power devices. Time scheduling with channel hopping has been a well-attested mechanism to address these requirements in volatile environments. Yet, scheduling algorithms to date are not adaptive enough to changes in deployed applications and their environments. plexi is a restful web service API for monitoring and scheduling IEEE802.15.4e network resources hiding the complexity of schedule deployment and modification. On top, plexiflex allows any given scheduler to adapt to network performance changes by monitoring periodic data streams coming from the nodes. It triggers resource (de)allocation aiming at stable network performance. Both plexi API and plexiflex adaptive rescheduling algorithm allow for interoperability among devices, schedulers and applications. Experiments to real TSCH network deployments have shown significant gains of plexiflex compared to fixed offline scheduling. Via monitoring the interarrival time of those stream data packets, plexiflex can identify wiring new node joining and rewiring events and reschedule when and where is needed.