Ngoc-Quan Pham, Ketema Mekonnen, Eduward Tangdiongga, Ali Mefleh, and Ton Koonen, “Efficient Mobility Management for Indoor Optical Wireless Communication System”, IEEE Photonics Technology Letters (PTL), 2021
Abstract: Beam-steered infrared light communication (BS-ILC) is a promising technology to establish high data rate links for next-generation indoor optical wireless networks. However, practical limitations such as localization latency and handover delay make challenging to implement a reliable BS-ILC system for mobile user devices. This paper studies mobility management, enabling the user devices to stay connected while they are on the move. Our BS-ILC system uses a wavelength domain where each wavelength covers one wireless cell. A camera-based localization determines the position of user devices relative to access points. With the help of a prediction algorithm, we demonstrated real-time localization with a <4mm tracking error. Furthermore, we propose and evaluate experimentally hard and soft handover mechanisms to support inter-cell user mobility. This is the first demonstration of seamless transmission in a BS-ILC system to the best of our knowledge.