LED-Fi: Replacement for WiFi Hotspots

Before we start, I have to confess that I made up LED-Fi. I was thinking more of LiFi but there is already a LiFi technology from Panasonic (not al all related ti this one though).
According to a post in cellular news, Lightbulbs Could Replace Wi-Fi Hotpsots in future:

­Boston University's College of Engineering is launching a program, under a National Science Foundation grant, to develop the next generation of wireless communications technology based on visible light instead of radio waves. Researchers expect to piggyback data communications capabilities on low-power light emitting diodes, or LEDs, to create "Smart Lighting" that would be faster and more secure than current network technology.

This initiative aims to develop an optical communication technology that would make an LED light the equivalent of a Wi-Fi access point.

"Imagine if your computer, iPhone, TV, radio and thermostat could all communicate with you when you walked in a room just by flipping the wall light switch and without the usual cluster of wires," said BU Engineering Professor Thomas Little. "This could be done with an LED-based communications network that also provides light - all over existing power lines with low power consumption, high reliability and no electromagnetic interference. Ultimately, the system is expected to be applicable from existing illumination devices, like swapping light bulbs for LEDs."

Little envisions indoor optical wireless communications systems that use white LED lighting within a room - akin to the television remote control device - to provide Internet connections to computers, personal digital assistants, television and radio reception, telephone connections and thermostat temperature control.

With widespread LED lighting, a vast network of light-based communication is possible, Little noted. A wireless device within sight of an enabled LED could send and receive data though the air - initially at speeds in the 1 to 10 megabit per second range - with each LED serving as an access point to the network. Such a network would have the potential to offer users greater bandwidth than current RF technology.

Moreover, since this white light does not penetrate opaque surfaces such as walls, there is a higher level of security, as eavesdropping is not possible. LED lights also consume far less energy than RF technology, offering the opportunity to build a communication network without added energy costs and reducing carbon emissions over the long term.

The ability to rapidly turn LED lights on and off - so fast the change is imperceptible to the human eye - is key to the technology. Flickering light in patterns enables data transmission without any noticeable change in room lighting. And the technology is not limited to indoor lights; its first real test may very well come outdoors, in the automotive industry.

I can understand how the downlink would work but not sure how uplink data transfer would work.

Similar technology using Light Bulbs has been available for some time. See this and this.