DASH: Deadline-Aware Scheduling with Hybrid Resource Adaptation in 6TiSCH Networks

Overview

DASH is a deadline-aware framework for temporarily augmenting the schedule of a 6TiSCH network when a deadline-critical demand, such as a control transaction or a short traffic burst, cannot be served in time by the installed schedule alone.

Autonomous cells, 6P-negotiated cells, and controller-managed cells differ in activation delay, signalling cost, and coordination scope, so the mechanism with the most eventual capacity is not always the one that helps before the deadline. DASH builds baseline-only, 6P-only, managed-only, and mixed link-level plans, models setup outcomes, cell activation, and packet forwarding on a common Absolute Slot Number (ASN) timeline, and selects the lowest-cost plan that meets the timely-reliability target.

Key Highlights

• Formulates activation-aware hybrid schedule augmentation for finite deadline-critical demands
• Combines baseline service, 6P-negotiated soft cells, and controller-managed hard cells on different links of the same route
• Removes temporally useless cells whose occurrences cannot form a causal forwarding path before the deadline
• Uses bounded beam search to avoid exhaustive enumeration of resource plans
• ASN-ordered finite-state evaluator for joint timely reliability and expected adaptation cost
• Evaluated in Contiki-NG/Cooja: higher delivery, lower delay, radio duty cycle, and scheduling-control overhead than MSF and HPS