  One of the areas in which wireless networks based on visible light
communication (VLC) are considered superior to traditional radio-based
communication is security. The common slogan summarizing VLC security features
is: WYSIWYS - "What You See Is What You Send". However, especially in the case
of infrastructure downlink communication, security with respect to data
snooping, jamming and modification must be carefully provided for. This paper
examines the physical layer aspects of VLC networks with respect to possible
disruptions caused by rogue transmitters. We present the theoretical system
model that we use in simulations to evaluate various rogue transmission
scenarios in a typical office environment. We use estimated Bit Error Rate
(BER) as a measure of the effectiveness of jamming and rogue data transmission.
We find that it is quite easy to disrupt, and in some cases to even hijack
legitimate transmission.
