Dynamic time slot allocation method for deterministic communication in UAV formation

Recently, UAV formations have been designed to support latency-sensitive tasks, such as situational awareness and emergency command, which require deterministic end-to-end data transmission. However, due to the dynamic networking of UAV formation, the traditional static TDMA method cannot meet the deterministic transmission requirements. Consequently, to satisfy the deterministic transmission of time-sensitive services, a hybrid CSMA/TDMA resource dynamic allocation scheme is proposed, which not only supports dynamic node access but also flexibly adapts to dynamic changes in services. Firstly, to tackle the issue of uncertain access delay caused by node collisions, a Random Backoff with Centralized Collision Avoidance (RB-CCA) algorithm is proposed; a Markov chain is proposed to model the entire state transition process, to analyze the collision probability and access success probability of existing and unconnected nodes. Secondly, we establish a minimum time-sensitive service delay model, and design a DySTMap Ivy Algorithm (DIvyA) to obtain the minimum delay and required slot length for nodes. The simulation results in Exata demonstrate that RB-CCA can reduce idle listening by 30% compared to existing random backoff algorithms; during the service transmission phase, the proposed scheme reduces end-to-end delay by 20% compared to existing slot allocation schemes. Finally, the proposed solution is implemented on an FPGA platform, and semi-physical scenario experimental results show that the end-to-end delay is below 5ms, with jitter less than 0.12ms.