Li-Fi: connecting through light

TECHNOLOGY

New data transmission method Light Fidelity - Li-Fi - is 100 times faster than traditional Wi-Fi and offers 10,000 times wider bandwidth.

Harald Haas

PROFESSOR OF MOBILE COMMUNICATIONS, UNIVERSITY OF EDINBURGH

Li-Fi was first demonstrated at a TED Global talk in 2011 by Professor Harald Haas, who coined the term. Although Li-Fi is very similar to Wi-Fi in the sense that it transmits data electromagnetically, Wi-Fi relies on radio waves while Li-Fi runs on visible light. Li-Fi can provide wireless communication between electronic devices. LED bulbs may act as wireless routers at very high speeds.

 

The current supplied to a LED bulb can fluctuate at extremely high speeds that can’t be perceived by the human eye. A photo-detector and signal processing element ‘reads’ the LED’s ‘dips’ and to converts them to an electrical signal, which is in turn converted into binary data streams. In this way, all the web applications and content that can be streamed over Wi-Fi may also be transmitted and received using light.

 

Li-Fi can also contribute to 5G and 6G cellular communications and support all kinds of monitoring and safety applications. Just over a year ago, scientists trialled Li-Fi in offices and industrial environments in Tallinn, Estonia, achieving data transmissions at 1 GB per second - 100 times faster than today’s average Wi-Fi connection. Li-Fi is not just a laboratory concept – there’s already a proposal for a commercial product with an usb dongle.

 

 

Possible solution to bandwidth hunger

 

“Let’s look at some of the possible advantages and applications of Li-Fi which are being discussed today,” says Lionel Provost, Prysmian Group R&D, Telecom, Optical Fibre. “For one thing, Li-Fi could be very beneficial for Internet of Things applications, providing a path for increasing numbers of bandwidth hungry devices that constantly receive and transmit data. Wireless infrastructures can be enhanced by providing an additional layer of small cells (or ‘attocells’). By avoiding ‘radio frequency spectrum crunch’, capacity can be increased significantly. This ‘spectrum crunch’ is the lack of sufficient wireless frequency spectrum, required to support more and more consumer devices and different types of radio frequency usage. We might also see very high peak data rates, up to 10 Gb/s.”

 

“The technology is useful in dense environments, as it doesn’t interfere with wireless infrastructures and operates at low energy levels. However, its operational range is limited to around 10 metres. The University of Edinburgh has announced that it has successfully transferred data over a 10 metre distance at 1.1Gb/s using micro LEDs, consuming less than 0.5W power. Such low power consumption could enable the use of solar panels, allowing the Li-Fi devices to power supply themselves. Combining data communication and illumination may also bring power savings. Researchers at the University of Oxford have even achieved bi-directional speeds of 224 Gb/s.”

Li-Fi

  • Extremely high speeds: up to 224 Gb/s
  • Signal can’t pass through walls – less interference between devices
  • Only usable in the presence of a switched-on light source
  • Shorter range makes it more secure than Wi-Fi

Wi-Fi

  • Available night and day
  • Signal passes through walls – chance of interference
  • Radio waves more suitable for public access networks
  • Greater range can compromise security

WATCH THE TED GLOBAL TALK

Li-Fi applications

Li-Fi is frequently referred to as Visible Light Communication (VLC), a class of technologies for wirelessly transmitting and receiving information using light instead of radio waves. The visible light spectrum (400 nm-800 nm) range is used.

Source: purelifi.com

For an extensive overview of application possibilities, please look here.

© Copyright Prysmian Group.

All rights reserved.

© Copyright Prysmian Group.

All rights reserved.