How LiFi could transform broadband

Sunday, 2 December, 2018

By now, most of us are familiar with the concept of Wireless Fidelity, or WiFi.

Domestic and commercial broadband internet is underpinned by wireless data transmitted across the radio frequency spectrum via dedicated routers, usually at either 2.4GHz or 5GHz.

The former is an internationally-agreed radio frequency, known as the Industrial, Scientific and Medical band (or ISM to its friends.)

Unfortunately, ISM isn’t an especially efficient method of data transfer.

An ever-growing number of devices are competing for access to this limited bandwidth, which is relatively slow and can’t be used in certain environments like on planes.

The light fantastic

As early as 1880, Alexander Graham Bell was using light waves to transmit data for his newly-invented photophone.

Marconi’s development of radio communications quickly eclipsed Bell’s work, and the 20th century came to be dominated by Radio Frequency communication – RF for short.

We had to wait until 2011 for proof that Visible Light Communications (or VLC) could meet our internet connectivity needs – and the proof came using a rather unexpected source.

An LED light is either on or off, creating the binary settings underpinning the distribution of all digital data.

When an LED is turned on and off hundreds or thousands of times a second, it can distribute data at incredible speeds without any flickering being noticeable to the human eye.

This ultra-fast data distribution can be achieved from any LED, and received by any object equipped with a sensor equipped to detect and interpret these light signals.

A professor at the University of Edinburgh has christened it Light Fidelity, or LiFi.

Light-based internet connectivity offers numerous advantages over broadband, including:

  • Performance. While WiFi struggles to transmit data above 70Mbps, LiFi has already been recorded at 1Gbps, and could theoretically throughput an astonishing 224Gbps
  • Bandwidth. There is over a million times as much available bandwidth for LiFi as WiFi, which will be crucial when we have 100 billion connected Internet of Things devices
  • Stability. The light spectrum is less congested than the radio frequency spectrum (where devices like baby monitors and car alarms operate), so there’s less interference
  • Security. Because light can’t penetrate dense objects, drawing the curtains or closing the door should prevent anyone outside from eavesdropping on internet data transfers
  • Environmentalism. There’s no need to manufacture plastic routers or phone sockets. Plus, repeatedly dimming the lights further cuts already-low LED energy consumption
  • Simplicity. There will be no need for contemporary technologies like modems, dongles or Powerline adaptors – just a hardwired internet connection somewhere in our homes
  • Versatility. VLC eliminates interference from electronic equipment, so Flight Mode will be irrelevant. Phones will be safe to use on planes, in hospitals and anywhere else
  • Stability. LiFi is incredibly stable if line of sight is maintained. Tomorrow’s LED lights will have banks of individual lighting elements, preventing bulbs from “blowing”
  • Availability. Any LED light source could potentially be used to distribute data – car headlamps, street lights, etc. Internet connectivity will be all around us, inside and out.

So where are we with LiFi?

A global task group of manufacturers and experts is currently working on an international communications standard for VLC, which will be known as 802.11bb.

There are already over a hundred proof of concept trials taking place around the world, including several in Scotland where much of this pioneering science has been developed.

A classroom in Ayr is receiving LiFi from eight enabled ceiling light sources; among its many benefits, surrounding classrooms have reported significantly more WiFi availability.

Scientists envisage it complementing (rather than competing against or eradicating) forthcoming 5G technology, which will still be needed when there’s no line of sight.

You might receive a push email notification via 5G, but instantly connect to LiFi to read the message when you remove the device from your bag or pocket (where light can’t reach).

As for timescales, it’s anticipated this technology will be on sale to the general public within five years.

That would ensure the forthcoming IoT transformation has enough bandwidth to deliver the life-changing advances we’ve been promised.

It will also help to maintain the always-on connectivity essential for self-driving vehicles, remote surgical procedures and other proposed technologies.

Once this is approved, we can expect to see light fidelity-compatible devices reaching the market shortly afterwards.

Neil Cumins author picture


Neil is our resident tech expert. He's written guides on loads of broadband head-scratchers and is determined to solve all your technology problems!