Work on so-called ‘smart cities’ is happening around the world, and one suggestion is to use LED lighting as a substitute for WiFi or 5G in cities equipped with ‘smart’ street lights. The concept is simple, although whether it will catch on in the face of widespread WiFi and development of 5G connectivity is another question.
The upside benefit is that LED-based LiFi is very fast, and highly efficient. The concept was introduced back in 2011 in work by Professor Harold Hass, a physicist at the University of Edinburgh. LiFi is described as an advanced photosensitive wireless communication technology that is used to provide unprecedented connectivity within a confined data centric environment. LiFi generally uses LED or some other light source for transmitting the data.
It is often allied to a similar technology, Visible Light Communications (VLC), and both techniques work in the open air, or in environments (offices, hospitals, schools, etc., where the LED lights are ‘on’) although do not penetrate walls. Both are capable of handling high-speed data transfer in parallel and with “thousands” of data streams, including video.
In a ‘smart’ street the systems suggest using overhead lighting as a transmitter and a mobile phone camera as a receiver. Devices could easily be built into vehicles (including buses).
“The streetlights receive data via a Programmable Logic Controller (a rugged PC) which modulates the information to be sent by light pulses through the LED bulb. The modulator functionality is the one to be designed and tested within the work presented here. In turn, streetlights forward the data received by the optical link to the mobile user terminal which receives through a photodiode integrated in a camera. For the uplink, LiFi is integrated with existing technologies such as Bluetooth, ZigBee or Wi-Fi,” says a study from Transparency Market Research.