Experimental evaluation of video transmission through LED illumination devices

In this paper we describe the implementation of a prototype of an optical wireless system based on visible white LED lamps, which allows a video broadcasting to reach a bit rate of 2 Mbps. This technology is usually called VLC or Visible Light Communications and presents several advantages as the robustness against EM interference, safety for human eye and security against undesired network access. These conditions make this system suitable for co-existing with commercial RF networks -WiFi, Bluetooth, etc.-, especially for in-house applications. For the uplink channel we have also included in the prototype an infrared 115 kbps transceiver. This VLC system could be used for supporting data transmission applied to low-speed sensor network connections as well. The electronic structure of a low-cost VLC transceiver, based on commercial off-the-shelf components and LED lamps is presented too. The modulation process and the Ethernet interface implemented in each access point are also described. Finally, some conclusions and application scenarios are drawn.