Research on dynamic handover decision algorithm based on fuzzy logic control in mobile FSO networks

Because of multiple advantages such as high bandwidth, high security, and flexible networking, the free space optical communication (FSO) has attracted more and more attention. However, the narrow beam of laser and the constrained access degree of optical node limit the development of mobile FSO networks, especially in the aspect of handover. In this paper, we propose a fuzzy logic control-based handover decision (FLC-HD) algorithm to ensure real-time and reliable communication. First, according to the predictive position and the motion information of mobile nodes obtained by the error correction extend Kalman filter algorithm, we obtain the received signal strength and the relative motion angles at next transmission. Second, we put forward the concept of threshold to ensure the completion of handover operations before the current link breaking. Third, the fuzzy logic control method is designed to select the optimal access point (AP) with three critical parameters, i.e., the received signal strength, the relative motion angles, and the access degrees of nodes. Simulation results show that the FLC-HD algorithm can improve the handover efficiency and relieve the ping-pong effect in mobile FSO networks.