# Traffic Aware Scheduler for Time-Slotted Channel-Hopping-Based IPv6 Wireless Sensor Networks
## 7 Conclusions  
This article proposes a new scheduler for TSCH-based networks, a scheduler that is built on the principles of RBS Orchestra and adapts to traffic. In the case of high convergecast traffic, the most constrained nodes are the children of the root. In our approach, these nodes detect possible congestion by assessing the remaining number of packets in the queue and additional resources are allocated for the root and its children if they are needed. The subtree size is used to determine the number of additional cells that should be allocated for each child of the root. The subtree of a node contains all its descendants and can be obtained if RPL is in storing mode. It is important to consider the subtree size to avoid unfairness between the root's children in case the network topology is unbalanced. The new scheduler is evaluated in the Cooja simulator on two placement of nodes, each with one sink node and 20 sender nodes. The traffic load is varied to observe the adaptability of the scheduler. From the experiments, we observe that our scheduler makes  
Figure 16: Comparison between OSCAR and the new scheduler considering different topology sizes. (**a**) We observe that the new scheduler has a higher PDR when the number of nodes is less than 100. (**b**) We observe that the new scheduler has a lower delay when the number of nodes is less than 80. (**c**) We observe that the new scheduler has a higher radio duty cycle. RBS Orchestra adaptive to sudden traffic bursts: data transmission remains reliable, the delay is decreased, and the stability of the network is preserved. Allocating additional resources leads, of course, to an increase in radio duty cycle. The new scheduler is also compared with OSCAR, a scheduler that also uses an adaptive approach. In this context, the impact of the number of nodes on the scheduler's performance is also studied. Compared to OSCAR, the new scheduler slightly increases the PDR and decreases the delay with 70%, if the number of nodes in the network remains under a certain threshold, such that the congestion does not propagate farther than the root's children. The downside is an increase in radio duty cycle. When the number of nodes in the network is above a particular value, OSCAR proves to be the superior implementation because it adapts the scheduler for all the nodes in the network. Modifying the thresholds of our scheduler will allow to tune the approach to what is most important for the application, a decrease in latency and an increased PDR or longer lifetime. Future work should further analyze the thresholds for activating and deactivating the scheduler, and the number of needed cells. In case the traffic drops, the deactivation of the scheduler relies on the number of packets in the queue. It could be better to evaluate the use of the available cells instead of the remaining number of packets in the queue. Other traffic patterns can also be considered to further evaluate the proposed scheduler. It is also important to study the behavior of the new implementation on testbeds. Conceptualization, D.D. and R.V.G. ; methodology, D.D. and K.S. ; software, D.D. and R.V.G. ; validation, D.D. and K.S. ; formal analysis, D.D., A.B. and K.S. ; investigation, D.D. and E.T. ; resources, E.T. ; data curation, A.B., V.D. and K.S. ; writing--original draft preparation, D.D. ; writing--review and editing, E.T., V.D., A.B. and K.S. ; visualization, R.V.G. ; supervision, K.S. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The data that support the findings of this study are available from the corresponding author, K.S., upon reasonable request. The authors declare no conflict of interest.