SciTech

Paul Gilster: Wireless data demands drive search for WiFi alternative

Those of us fortunate enough to have broadband and WiFi live in a comfortable cocoon of Net connectivity. How helpful to be able to move about the house at will, checking email on a laptop or a tablet, keeping up with friends on Facebook and blasting out the occasional tweet. Or we settle into the WiFi envelope of the local coffee house, working on whatever projects are in hand. WiFi is so easy to take for granted, and so likely to run into problems ahead.

The issue is this: We’re getting so enamored with wireless data – and it’s so much in the thinking of companies planning our digital future – that we’re headed for serious frequency congestion. That can lead to failed connections or performance slowed to a crawl, and it’s hard to see how WiFi escapes the data influx that’s coming. We’re entering the era of the Internet of Things, when many of the gadgets and appliances we use need to be able to talk to each other.

These are big numbers. I was dazzled by the numbers Gartner released not long ago, predicting that 25 billion devices will be connected by the time we reach the end of the decade. Can you do that with WiFi? Think in particular about those who live in population-dense neighborhoods, where WiFi interference is already an issue for some. What’s clearly needed is more bandwidth to carry all that traffic, but the radio frequency spectrum is simply getting maxed out.

Brilliant solution

What to do? A company in Edinburgh has been developing what I consider a totally brilliant solution. Building on work that traces its lineage all the way back to Alexander Graham Bell, pureLiFi is using pulsated light from off the shelf LEDs (light emitting diodes). We’re getting more and more familiar with LED lighting because it’s replacing conventional light bulbs, offering considerably longer lifetimes and major advantages in power usage. pureLiFi has come up with a way to use off-the-shelf LED bulbs as the access points to the network we need.

Like many brilliant solutions, this one became blindingly obvious once someone thought to apply it. Transmitting information through the visible light spectrum using pureLiFi’s receiver hardware puts Internet access points everywhere in a building that there are LED fixtures. We’re still in the early stages here, but researchers have demonstrated high data rates that should be perfectly sufficient for everything from checking email to playing YouTube videos.

There is no problem of radio frequency interference here because we’ve got huge bandwidth available up in the visible part of the electromagnetic spectrum. WiFi in your house often spills out into areas immediately adjacent to you, but what we’re learning to call LiFi can be contained inside the room where the light fixture you’re using is located, enhancing basic security. You’ll also have noticed that this is a technology that demands no new infrastructure, because it’s using the power lines that are already available wherever light fixtures are located.

LiFi in space

Data moving through LiFi modulates at so fast a rate that there is no “flicker” to distract you, but the LED signal is nonetheless carrying vast amounts of information. No wonder that NASA has recently inked a deal with LVX System Corp. to explore using LiFi aboard the International Space Station, where WiFi currently handles the traffic. In Berlin, the Fraunhofer Heinrich Hertz Institute is implementing optical broadband to replace WiFi at one of its facilities. PureLiFi, meanwhile, shipped its first wireless optical networking product in the fourth quarter of last year. Called Li-Flame, it makes standard LED fixtures into access points for Internet devices.

This is going to be big, and it corresponds to how we are moving from radio to laser communications as we look toward space missions of the future. The bandwidth available at these wavelengths is even higher than LiFi, which is in turn about ten times faster than WiFi. When it comes to frequency, the direction is ever upward, a phenomenon we’ll need to sustain the incessant demand for spectrum that our future generations of products will generate.

Paul A. Gilster is the author of several books on technology. Reach him at gilster@mindspring.com.

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