## 7 Conclusions  
In this paper, a new autonomous scheduling design, based on Orchestra, is proposed for convergecast TSCH networks. This algorithm, named OSCAR, manages the number of timeslots allocated to each node using the value of the rank described by the RPL routing protocol. The nodes are distributed under different layers where each node is assigned a classID based on the proximity to the root. The goal being that the closer the node is to the root, the more slots it gets in order to maximize the transmission opportunities. To avoid wasted energy, OSCAR sets up a mechanism to adjust the radio duty cycle of each node by reducing the slots allocated to inactive nodes regardless of their classID.  
Performance analysis shows that OSCAR outperforms Orchestra on the average latency, especially when the traffic is heavy and congested. The performance of the Orchestra and OSCAR schedules was investigated by configuring various traffic intensities, ranging from 1 pkts/min to 6 pkts/min. The experimental results show that OSCAR reacts better to dense traffic and thus exhibits better latency overall by allocating more time slots when necessary, while Orchestra does not. Moreover, through simulations, the variation in the number of nodes has shown that OSCAR reacts better in large scale networks. As the network size increases and causes larger traffic load, OSCAR's latency and packet delivery advantages widen in comparison to that of Orchestra. This widening of the performance advantages enabled by OSCAR comes at the cost of added energy consumption for networks composed of 80 or more nodes. Regarding the energy consumed, we have seen that the average OSCAR duty cycle depends, as does the latency, on the position of the node in the network. In the two arrangements tested in the experiments, this is lower than Orchestra when the traffic load is low, due to the service cycle adjustment algorithm. However, it becomes important as the network traffic load increases because the network is constantly in demand and the nodes are more active compared to Orchestra. Finally, the packet delivery rate remains similar between OSCAR and Orchestra, whatever the position of the node with low traffic. However, OSCAR shows better performance as the traffic load increases.  
Fundamentally, this work paves the way for dynamic scheduling that attempts to reduce latency and packet delivery in congested convergecast scenarios, while reducing the impact on the network's energy consumption in smaller networks. Overall, this work gives perspective on efficient cell distribution mechanisms and introduces a solution that can serve as a new scheduling method for convergecast networks.  
All authors contributed to the main idea of this paper. M.O. designed and performed the experimental testing. F.N. supervised the work and provided expertise. All authors contributed to the writing of the paper. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), Mitacs, and the Ecole de technologie superieure (ETS).  
The authors would like to thank the Natural Sciences and Engineering Research Council of Canada (NSERC), Mitacs, and the Ecole de Technologie Superieure (ETS) for their financial support.