A system to communicate via modulated optical signals of the Li-Fi signal type to transmit data to and from a plurality of defined privileged spaces. The communicating system includes a plurality of first light sources, each first light source emitting, in the infrared, a first modulated optical signal. A plurality of optical fibers, each optical fiber guiding the first modulated optical signal from a single first light source in the direction of an optical interface. The optical interface transmitting the first modulated optical signal into a defined privileged space. Each optical fiber also transporting a second modulated optical signal from the associated defined privileged space in the direction of a device configured to acquire the second modulated optical signal.