  Demands for broadband wireless access services is expected to outstrip the
spectrum capacity in the near-term - "spectrum crunch". Deploying additional
femotocells to address this challenge is cost-inefficient, due to the backhaul
challenge and the exorbitant system maintenance. According to an Alcatel-Lucent
report, most of the mobile Internet access traffic happens indoor. Leveraging
power line communication and the available indoor infrastructure, visible light
communication (VLC) can be utilized with small one-time cost. VLC also
facilitates the great advantage of being able to jointly perform illumination
and communications, and little extra power beyond illumination is required to
empower communications, thus rendering wireless access with small power
consumption. In this study, we investigate the problem of minimizing total
power consumption of a general multi-user VLC indoor network while satisfying
users' traffic demands and maintaining an acceptable level of illumination. We
utilize the column generation method to obtain an $\epsilon$-bounded solution.
Several practical implementation issues are integrated with the proposed
algorithm, including different configurations of light source and ways of
resolving the interference among VLC links. Through extensive simulations, we
show that our approach reduces the power consumption of the state-of-art
VLC-based scheduling algorithms by more than 60\% while maintaining the
required illumination.
