On-Line Data Link Layer Scheduling in Wireless Networked Control Systems
2015 27th Euromicro Conference on Real-Time Systems
Wireless networked control systems (WNCSs) have received tremendous research interests recently due to their great advantages in easy deployment, enhanced mobility, and reduced maintenance cost. A key design challenge in such systems is to develop efficient data link layer scheduling algorithms to achieve a reliable end-to-end real-time communication. Previous research has a common assumption that the network communication schedule of WNCS, once constructed and distributed, stays unchanged.
... tays unchanged. Using this method, however, cannot handle dynamic variations which are unavoidable in many WNCSs. In this paper, we consider the data link layer scheduling problem in WNCSs, where external disturbances occur sporadically. We employ a rhythmic task model to respond to external disturbances and introduce an effective approach to adjust the static schedule for the WNCS when the disturbances happen. The approach determines the time duration to apply a dynamic schedule and generates the schedule for that time duration to minimize the impact of network dynamics on existing network flows. The effectiveness and efficiency of the proposed algorithm are validated by extensive simulation. Results based on randomly generated task sets indicate that the proposed approach outperforms existing work both in terms of the number of feasible task sets (between 11% and 41% increase on average) and the number of feasible periodic packets (between 122% and 128% increase on average).