A Novel Vertical Handover Algorithm in a Hybrid Visible Light Communication and LTE System

摘要

Visible light communication (VLC) is considered as a promising high speed wireless access technology. However, the line-of-sight (LOS) nature of visible light limits VLC coverage and user mobility. On the contrary, radio frequency (RF) provides much more extensive coverage, though its link bit rate is lower by contrast. A cooperation of VLC and RF can allow them to enhance each other in certain aspects. Therefore, following existing studies, a hybrid VLC-LTE system is employed. One big challenge for realizing such a heterogeneous network is mobility management due to dynamic traffic and network conditions. Based on two basic vertical handover (VHO) schemes, this paper proposes a VHO algorithm through prediction (PVHO). Interruption durations, message sizes and access delays are critical metrics for prejudging the system state. A mobile terminal (MT) records these key parameters in real time and then processes them to offer guidance for proper handover decisions. Through simulation, the advantages of PVHO are validated by comparing with existing algorithms. Analysis of the numeric results gives an indication that the performance of PVHO is superior under various circumstances.