Efficient vertical handover scheme for heterogeneous VLC-RF systems

Visible light communication (VLC) is a promising complementary technology to its radio frequency (RF) counterpart. Heterogeneous VLC-WiFi systems offer a solution for future indoor communications that combines VLC to support high data rate transmission and RF to support reliable connectivity. In such heterogeneous systems, vertical handover (VHO) is critical for improving the system performance. This paper investigates an efficient VHO scheme. We formulate it as a Markov decision process problem and adopt a dynamic approach to obtain a tradeoff between the switching cost and the delay requirement. The proposed scheme determines whether to perform VHO given the queue length and the condition of the optical wireless channel (available or unavailable). The simulation results demonstrate that the proposed scheme is able to save about 50% of the signaling cost of the VHO process without an obvious loss in system performance. Moreover, the proposed scheme is adaptable to different scenarios.