Could Li-Fi be the new Wi-Fi? [video]

http://www.bbc.com/news/technology-34380428

by pavornyoh • 11 years ago

20 19 11 years ago

I think it doesn't make sense for it not to be. It seems like a very good way to transfer data with almost no drawback given a decent setup. I don't understand why that isn't used more often.

xnzakg2• 11 years ago

almost no drawback

1. You need to purchase a Li-Fi "router" for each room (if not several) instead of purchasing a single router

2. Connecting the "routers" to internet: you would either need a lot of cables... or Wi-Fi.

3. Only works in line-of-sight, while Wi-Fi works through walls... and pockets. Li-Fi probably wouldn't be useful for smartphones.

Enough drawbacks?

dogma11383• 11 years ago

You don't need separated routers each LED light bulb can be used as an access point, there are already LED bulbs with WiFi because people will buy anything that looks like an Apple product.

You need WiFi still because the LiFi channel is only one way.

It can still sorta work through some pockets but rule of thumb is that if your mobile device is in your pocket you don't need the fastest speed possible and you can fallback to WiFi.

But yeah the tech is kinda silly in general.

smileysteve2• 11 years ago

I'm glad you mentioned pockets. That's what hit me first.

Also, everybody holds their smartphone differently, including at the top (where LED notification lights are), especially in landscape mode.

dogma11383• 11 years ago

too many issues, shadows refraction and most importantly power and LED stability if you take a slow motion capture of all current LED lights you see that the flicker quite a bit usually at much higher frequencies and more erratically than the solid 50/60hz incandescence bulbs do. And you still need to use Wi-Fi as your upload channel, communication protocols which require 2 separated mediums tend not to work very well.

Pretty much for Li-Fi to work reliably you need to build and power LED's that will produce a similar illumination stability to current laser diodes which are used in fiber optics, build light sensors on equipment and still maintain a Wireless network for your up channel, so I really don't understand why this is trying to become a thing at all.

Mithaldu• 11 years ago

Three drawbacks i can think of right away:

1. You need to maintain line-of-sight with the receiver on your receiving device, and the transmitter. No, you can't turn around with your cellphone in your hand.

2. Interference potential is high due to environmental other lights, reflective surfaces, etc.

3. The camera in the receive won't be particularly cheap.

wyldfire• 11 years ago

Algorithms and economics can mitigate 2 and 3. Requiring LOS absolutely kills this for replacing WiFi, though.

Maybe could find its way into applications where we need high throughput and we can easily get stable LOS.

IshKebab• 11 years ago

No.

maxlaumeister• 11 years ago

https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...

dang• 11 years ago

Please don't post unsubstantive comments to Hacker News.

acd• 11 years ago

How does it compare to 60GHz 802.11ad wifi? https://en.wikipedia.org/wiki/Wireless_Gigabit_Alliance

If only our celing lamp sockets had ethernet then you could wire up 60Ghz transmitters in every room and there would not be a lot of need for wired connection.

nyreed• 11 years ago

Could this work with powerline networking?

ajross• 11 years ago

Not at WiGig speeds. You might as well put a single-antenna 802.11n transmitter in there, no point in 60 GHz.

timthorn• 11 years ago

Perhaps not quite the same bandwidth, but Apple had optical networking as their wireless connectivity solution done time before WiFi: http://lowendmac.com/2015/irtalk-irda-and-the-mac/

smileysteve2• 11 years ago

The problem that this is trying to solve (Isolation) seem possible to solve once you get away from a mismanaged wifi setup.

Too many devices supported by one router. This can be solved with more chipsets per router, each with a slightly more directional antenna (as opposed to dipoles being standard).

Turning down transmitter power on routers, if you want fewer devices (such as one 20x20 area instead of pi(150)^2 ft) you can turn down the tx power. Moreover, using 5ghz already starts limiting wall penetration more.

ksec• 11 years ago

What "value" do we get from using LiFi? You will have to invest in a new Light Bulb, rewiring so that these LiFi are connected. And hoping your phone or devices actually supports it. And years, years away from possibly getting the infrastructure and devices widely available.

Compared to WiFi, we are finally seeing 802.11ac 2x2 866Mbps on phones and Tablet, 1.3Gbps on iMac. 802.11ax coming in 2017, that will offer 4x real world improvement. We are talking over 1 Gbps real world throughput on Smartphone. Line of Sight 60Ghz 10Gbps+ WiFi are in the work.

So LiFi is like a solution looking for problem.

Could Li-Fi be the new Wi-Fi? [video]

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