Electric light transmits data faster than Wi-Fi
techxplore.com
techxplore.com
We also had to engage with all the big Wi-Fi companies and in the end convince them of the benefits of Li-Fi. But when people began understanding that we’re not arguing for Li-Fi against Wi-Fi, but claiming a complementary use, they really began seeing the benefits of using light.”
The standard was developed for Li-Fi to work alongside Wi-Fi ... Li-Fi simply appears as if it was another band of Wi-Fi ... We are enabling interoperability of Li-Fi and Wi-Fi, positioning Li-Fi as a complementary and additive technology to the existing ecosystem.I can see applications for LiFi, but it will not replace WiFi any time soon.
Why do you speak of the feature as though it's a bug?
It's great for wiring contractors, great for LiFi vendors, what's the problem?
sigh
To think that this was right there the whole time and we settled on "WiFi" instead!
The advantage of the visible light approach is that it doesn't reach through walls.
It's inherently very dense, and can provide users in its footprint nearly unlimited bandwidth. If it reaches only 50% of users in a classroom or office building, then those 50% of users will have very fast connectivity, and wifi will be twice as fast for everyone else.
This could solve the problem of getting reliable speeds to devices without Ethernet, that are either hard to wire or don't want to plug in.
Higher density is more costly too of course, but even so depending on the performance that might well still be cheaper/easier then fiber drops everywhere, plus it'd avoid some of the minor but sticky end user physical interface issues of fiber connections. Whether the value is there remains to be seen and will no doubt vary, but as others have said a lot of typical office plans (with drop ceilings, ceiling rails or other designs meant to enable more modular ceiling use) on the surface seem pretty amenable to such an approach.
Ultimately all depends on what the actual implementations look like though, and at what cost.
There are other potential approaches but WiFi+LiFi hybrids could be neat. LiFi would also have the regulatory advantage of not needing to worry about typical licensing or bandwidth issues beyond basic emissions like anything with a power supply has, since those spectrums are of course fully public :). Although the industry could in principle muck the whole thing up with burdensome patents I suppose, but then again the basic principle are similar to fiber and free space optical transmission (including extremely high speed) has been done for ages so that might limit the scope of any potential claims to some degree.
I think an uplink with visible light might be too much to ask, but if we could just glue these two networks together, it becomes a lot more useful.
I wish more technologies could do one-to-many broadcast. for example a live video stream that many were watching, or tv/movies/presentations where many people were listening to the same audio with headsets or earbuds.
It strikes me that 400nm UV LEDs would be a good choice for this application: we can't perceive 400nm, it doesn't penetrate cells (FYI: this is why all "LED" sterilizers are snake-oil), and most importantly the UV spectrum is almost entirely blocked by regular glass-windows so the sun wouldn't interfere and the signal would attenuate to nothing at the bounds of a building.
> (FYI: this is why all "LED" sterilizers are snake-oil)
Most are snake oil, but there are definitely UV-C LEDs out there.
IMO, we should just use ordinary white LED lighting for this. Easy to ensure that no matter what the data, the lights are at 80% DC brightness, and you can still get an absurd amount of data throughput per light fixture.
Most people are not streaming 8k VR.
But that is the problem....
Power-line networking both suffers FROM interference, and causes interference TO licensed services. When it works, it works well, until randomly it stops working.
You can't expect to reuse allocated spectrum without encountering serious problems.
> The new standard for Li-Fi, IEEE 802.11bb, is designed to provide a global framework to deploy light-based devices that are compatible with each other. It was ratified in June [2023] ... Li-Fi simply appears as if it was another band of Wi-Fi ... It can achieve data rates of 1 Gbps or more from a range of 20 centimeters to 3 meters.
Any thats a low estimate, because physics lets you do massive MIMO, polarization, etc to get even more throughput.
(The other two PHYs were FHSS and DSSS on 2.4GHz, the latter of which morphed into the 802.11b that gained wide popularity.)
Can someone explain how this ensures security?
Because hackers always work in the dark? /s
Wi-Fi passes through walls, can be used to remotely infer keystrokes, human biometrics, position and activity.
> dark
Li-Fi can use infrared light, does not pass through walls.
It just means that visible or IR light (What are they using?) won't leak through walls the way Wi-Fi does. Depending on how wide the beam is and exactly how it all works, it _might_ still leak out of windows and under doors. But it's not like someone casually wardriving outside your house will get as much as they would from Wi-Fi, I would think.
The sun has a radius of about 700,000 km. Only a few hundred km is transparent enough for light to pass through and has a density of about 300 mg per cubic meter. Roughly the density of air at the altitude where airliners cruise.
The photons you see originate from a layer that’s just 0.5% of the radius of the sun. That layer is heated with other photons from inside. The core temp is 15 million K while the photosphere is around 5800 K. The spectrum of the core were the rest of the sun transparent would be much different and … unsafe. (Not that this really makes sense, if the rest of the star was transparent it would go nova)