Balloon mesh free space optical communication with tracking and link switching

Optical beam alignment is the key requirement to maintain a connection between two optical nodes in free space optical (FSO) communication networking. Google has proposed FSO embodiments for building a network at high altitude, the objective of which is to provide Internet connectivity to remote locations around the globe. FSO communication has the potential to build a high bandwidth backhaul network with wireless optical communication systems using a balloon mesh network. Due to winds, balloons can drift in space leading to the misalignment of FSO connections between adjacent balloons. In this paper, we propose an algorithm to track the drifting balloon and evaluate the tracking system by state estimation of the drifting balloon's position with respect to another nearest balloon. We also propose a backup optical link to keep the network intact in case of failure due to a balloon's misalignment with an adjacent balloon. Our approach uses Kalman filtering based state estimation technique for three dimensional movement and speed.