With the advance of the Internet of Things (IoT), the interaction between humans and smart objects is already a reality. New applications that are expected to operate in dynamic environments must support different modes of human/machine interaction (e.g., voice and sign language), exhibit same or better performance in heterogeneous wireless and optical networks, and be able to react in real time. In particular, dispersed computing has arisen as an approach to deal with latency issues in this context. In the work described herein, we design a smart lighting IoT system that allows control of light bulbs (turn on/off, color and brightness change) through voice and sign language. This work addresses the idea of dispersed computing, which is implemented through fog computing, and combines it with virtualized resources to mitigate latency in the convergence point between wireless and optical networks. The proof-of-concept implementation of our design demonstrates the viability of the approach.