FS-MAC: An Adaptive MAC Protocol With Fault-Tolerant Synchronous Switching for FANETs

Medium access control (MAC) is significant for guaranteeing the quality of service of Flying Ad-hoc NETworks (FANETs). The adaptive MAC protocol is recognized as a promising solution, which is able to improve the flexibility and robustness of FANETs. In this paper, we propose a fault-tolerant synchronous-MAC (FS-MAC) protocol that can switch between CSMA/CA and TDMA protocols for the FANETs. In FS-MAC, we propose a distributed Q-learning-based MAC switching scheme which contains a MAC pre-selection operation and a practical byzantine fault tolerance (PBFT)-based consensus decision procedure to produce a MAC switching decision. By the MAC pre-selection operation, each UAV can evaluate its own performance accurately and determine which MAC protocol is more appropriate. Then, all UAVs in FANETs can implement fault-tolerant synchronous switching with the help of the PBFT-based consensus decision procedure. The simulations are conducted to evaluate the various performance of the FS-MAC. It is shown that FS-MAC can significantly outperform the baseline protocols in terms of the average throughput, delay, and packet retransmission ratio performance.