
Could Li-Fi be the new Wi-Fi? [video] - pavornyoh
http://www.bbc.com/news/technology-34380428
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acd
How does it compare to 60GHz 802.11ad wifi?
[https://en.wikipedia.org/wiki/Wireless_Gigabit_Alliance](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.

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nyreed
Could this work with powerline networking?

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

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ksec
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.

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smileysteve
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.

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timthorn
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/](http://lowendmac.com/2015/irtalk-irda-and-the-mac/)

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LightMachine
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.

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xnzakg
> 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?

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dogma1138
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.

~~~
xnzakg
> You don't need separated routers each LED light bulb can be used as an
> access point

But you need to buy one that supports LiFi, and LiFi bulbs will probably be
more expensive than normal lightbulbs (if they become a thing)

And if you still need WiFi, what's the point of buying LiFi bulbs and setting
them up when you can just keep using WiFi? It just doesn't seem to be worth it
unless you're in a place with hundreds of WiFi devices (and it still probably
won't help a lot).

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dogma1138
You would have to buy special light bulbs anyhow, you won't be able to use a
commercial of the shelf bulb for this no matter what the BBC thinks.

The LED's need to be able to turn on and off in nano-seconds so you can't just
twitch the AC power because the voltage regulator will not respond fast enough
(there is enough juice in the capacitors to drive the LED's for a few seconds
usually this is why cheap LED light bulbs don't turn off straight away, the
more expensive ones have usually have a current shunt that will clear the
capacitors to ground when you hit the light switch) and most likely simply die
after a few minutes.

So you need to do in-circuit modulation which means a dedicated light bulb.

Well in theory you start building light bulbs that can be effectively turned
on and off about about a billion times a second which is not going to happen
and even then you'll still need some device that will modulate the light so
instead of a dedicated light bulb you'll have a dedicated lamp.

Considering the engineering limitations and the cost involved having normal
light bulbs that can connect to your network via either WiFi or well via
basically "DSL" via sending a phase modulated signal over the AC wiring in
your house similar to how those power plug Ethernet / WiFi extenders work.

[https://en.wikipedia.org/wiki/Power-
line_communication](https://en.wikipedia.org/wiki/Power-line_communication)

Again this is a very kickstarter / TED talk worthy idea that sounds brilliant
but it will probably go the way of the GyroJet because it's just so dumb on so
many levels.

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IshKebab
No.

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dang
Please don't post unsubstantive comments to Hacker News.

