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Network selection method based on MADM and VH-based multi-user access scheme for indoor VLC hybrid networks.

Recently, the visible light communication (VLC) based on LEDs has attracted much attention. In this paper, in order to realize multi-user wireless communication for VLC-based indoor hybrid networks, a network selection method based on Multi Attribute Decision Making (MADM) is proposed, which effectively combines the subjective preference of the user with the objective performance of each network. And then, a VH-based (virtual handover) multi-user access scheme is proposed, which considers different MAC and channel information. Wherein, a concept of backoff lock is presented to control the access request of the user to different channels; a concept of VH is also put forward to reduce access delay, and improve access success ratio. When VH is triggered, the user can use the backoff lock to lock the current access request and send access request to other networks. The expressions of collision probability, access delay, and access success ratio are given. Analytical and simulation results show that the proposed network selection method can effectively meet the users' requirement, and the evaluation value obtained by our method is also in accordance with the objective network performance, and that the VH-based multi-user access scheme can reduce the collision probability and the access delay, and increase the access success ratio for VLC-based hybrid networks.