## 6 Discussion  
The experimental and simulation results have shown that OSCAR exhibits better performance with regards to end-to-end delay and packet delivery ratio compared to Orchestra. This is due to the better distribution of cells allocated to nodes introduced by Algorithm 1. Moreover, even with these gains, OSCAR does not significantly increase the average radio duty cycle. In fact, with Algorithm 2, the nodes save energy by switching off the inactive nodes. When the nodes are often active and transmitting data, the delay can be reduced because the additional slots that are allocated allow traffic to be evacuated. Whereas if the nodes become inactive, OSCAR starts to allocate fewer slots gradually and thus prevents the nodes from waking up more often. This limits the power consumption due to idle listening of nodes. Note that the gains that OSCAR exhibits are more significant when the traffic is dense and congested. However, for large-scale networks, there is a greater energy consumption for networks composed of 80 or more nodes. WSNs have conflicting requirements to operate with both low power consumption and low latency. As networks are designed with low power considerations, the latency of the entire system typically increases. Conversely, for networks where the optimization priority is at the level of latency, greater energy consumption is generally observed. However, the advantage of OSCAR here is that the gains in latency and reliability are far more important than the minimal losses in energy suffered by the network. Moreover, energy gains can be seen in less active nodes, balancing the increased energy usage of the more congested nodes. As seen previously, other solutions based on autonomous scheduling have been proposed. e-TSCH-Orch is one of these solutions and uses a strategy that when the slotframe has enough free time slots, the node can exploit them to empty its queue. However, this method aggravates the contention and collision problems because the nodes compete for free cells. For Escalator, nodes suffer more from idle listening overload, because when a node receives a packet, it immediately sends the received packet to its parent in the cell that follows consecutively. Idle listening is listed on all subtree nodes and amplifies wasted energy. ALICE allocates the same number of Tx/Rx slots in a slotframe under a directional link. However, as the traffic increases, ALICE also suffers from collisions leading to link losses. Compared to other solutions, OSCAR provides a concrete solution to the congestion problem present in data collection applications mainly around the sink. The main feature is that it distributes slots better for networks with convergecast traffic that suffer from severe latency problems when approaching the sink with other algorithms such as Orchestra. This is done with the distribution of nodes under different classes, introduced by OSCAR, which makes it possible to increase or reduce the number of slots allocated when the node is, respectively, near and far from the sink. With high traffic load, OSCAR exhibits a very low latency, at the cost of an additional energy consumption that is nevertheless mitigated by the mechanism of reduction of slots allocated to inactive nodes. The OSCAR experimental results presented here show that the energy consumption of the nodes around the root is increased. Indeed, OSCAR arbitrarily allocates slots to nodes based on their position relative to the root, and a fully dynamic allocation based on the real-time network traffic signature would be worthwhile to explore. OSCAR does not provide a solution to the potential problem of cell mismatch when the transmitter has not yet become aware of a change. In this case, a retransmission happens on a different cell. A future improvement would be to introduce a mechanism to allow the management of the cell mismatch when the system has not yet become aware of the traffic change.