## 3 Related Work
However, it does result in higher energy consumption, as each Rx cell needs to wake up to sense the channel. ALICE [25], a link-based autonomous scheduling scheme, has been developed, where authors claim that node-based schedulers are inefficient. Unlike Orchestra, this method does not suffer from the contention problem as it allocates a unique cell for every link. It uses a minimum slotframe size equal to (2N \(-\) 2)/3 for a network with N nodes and 2N-2 directional links. It determines the cell location by hashing the MAC addresses of the sender and receiver. The hash function can schedule the identical cell for multiple links. To address this problem, ALICE uses ASN to vary the cell location in every slotframe. Autonomous and traffic-aware scheduling [26], an enhanced Orchestra-based scheduler for TSCH networks, has been proposed that schedules cells dynamically based on traffic handled by the nodes. This technique significantly reduces delay while maintaining higher PDR. Monitoring the packets in a queue evaluates the cell count to be allocated for a node. Without any information negotiation, it computes the number of Tx cells towards its parent. The time offset of the cell is calculated using the Orchestra method, which allocates consecutive cells equal to pending packets at the node. Accordingly, the number of Rx cells for the parent node is adjusted. By allocating multiple cells as per traffic conditions, this technique improves performance in terms of latency. However, this scheme becomes less scalable in dense networks, as consecutively allocated cells may collide. The A\({}^{3}\) Adaptive Autonomous Allocation scheme [27], integrated with existing autonomous scheduling protocols such as Orchestra and ALICE, suggests a solution to address this problem. A\({}^{3}\) dynamically selects the slots in a slotframe to accommodate changing traffic needs. Its main advantage is the ability to estimate receiver traffic without requiring explicit control messages. It enhances throughput and PDR while reducing latency compared to previous methods. It allocates one primary cell and several secondary cells. The slotframe is divided into different zones, and one is used for a primary cell allocation while the other zones are for secondary cells, a maximum of up to eight cells. When the cell utilization exceeds the specified higher threshold, the number of secondary cells is doubled. Conversely, they are reduced by half when the utilization is below the specified lower threshold. Also, it uses an ASN number to change the cell location in every slotframe, which avoids collision on any particular slot. TESLA [28] is designed to optimize energy consumption and ensure reliable packet delivery in wireless networks. Nodes monitor the traffic load and adjust their Rx slot scheduling accordingly. When a node detects idle Rx slots, it expands its slotframe size to conserve energy by minimizing idle listening. Conversely, when facing a high packet flood, the node reduces its slotframe size to minimize contention and packet drop among neighboring nodes. TESLA enables dynamic adjustment of the slotframe size based on incoming traffic load without incurring additional control overhead. While scheduling schemes like Orchestra, ALICE, and A\({}^{3}\) support autonomous and adaptive operations, they present significant limitations. Orchestra uses node-based periodic scheduling but fails to address traffic heterogeneity. Its fixed slotframes lead to over-provisioning of cells for sparse node distributions and under-provisioning in dense regions. This results in high contention near the root due to shared Rx slots when multiple child nodes attempt to send packets to the same parent. Moreover, Orchestra does not account for topology changes or traffic bursts, affecting both latency and PDR. ALICE improves latency by employing link-based scheduling and leveraging parent-child relationship knowledge through RPL topology. However, it still relies on static slot assignments, making it inefficient under dynamic traffic conditions.