Expect to hear a whole lot more about Li-Fi - a wireless technology that transmits high-speed data using visible light communication (VLC) - in the coming months. With scientists achieving speeds of 224 gigabits per second in the lab using Li-Fi earlier this year, the potential for this technology to change everything about the way we use the Internet is huge. Now, scientists have taken Li-Fi out of the lab for the first time, trialing it in offices and industrial environments in Tallinn, Estonia, reporting that they can achieve data transmission at 1 GB per second - that's 100 times faster than current average Wi-Fi speeds.
Sure its feasible. You can achieve lots of capacity, when using optical frequencies, simply because you're so high up in the spectrum. A tiny sliver of spectrum has huge potential, because that tiny sliver can be a lot wider, in terms of Hz of bandwidth, than anything remotely feasible in the radio frequency bands.
The problem will be obstructions, though, because light won't diffract around obstacles as radio frequencies do. So range will be limited. Can't cover an entire house with just one access point, as you can with WiFi. Can't go through bad weather as you can with radio, either.
The irony in this is that modulating light, incoherent light such as that used in VLC, is really primitive stuff. Because the source is incoherent, you're limited to using either on-off keying (like Morse code) or intensity modulation (like AM radio). The huge capacity is possible regardless, but the modulation techniques are definitely early 20th century!
Sure its feasible. You can achieve lots of capacity, when using optical frequencies, simply because you're so high up in the spectrum. A tiny sliver of spectrum has huge potential, because that tiny sliver can be a lot wider, in terms of Hz of bandwidth, than anything remotely feasible in the radio frequency bands.
The problem will be obstructions, though, because light won't diffract around obstacles as radio frequencies do. So range will be limited. Can't cover an entire house with just one access point, as you can with WiFi. Can't go through bad weather as you can with radio, either.
The irony in this is that modulating light, incoherent light such as that used in VLC, is really primitive stuff. Because the source is incoherent, you're limited to using either on-off keying (like Morse code) or intensity modulation (like AM radio). The huge capacity is possible regardless, but the modulation techniques are definitely early 20th century!
It is indeed an exciting technology that can provide huge data rates under the right conditions. The question is only what the practical use case will be. WiFi technology such as IEEE 802.11ac and IEEE 802.11ad can already provide great capacity in similar use cases as LiFi.
The main bottleneck with current wireless technologies is the non-uniform coverage and availability. What we really need is a breakthrough technology that can provide uniform connectivity that is available everywhere.
Ahmed,
You ask an good question. It seems like the researchers are trying to solve a problem that, so far, does not exist and probably won't. The problem is that their solution is very localized to the last 5-20 meters of a network and a huge amount of 'wired' or fiber infrastructure would be needed to support it. For example, It would not improve the speed of communication over the internet where speeds are limited by fiber and router infrastructure. Optical links are well known for faults such as light interference and multipath interference. People moving in the environment will sometimes block the signal path. Finally, visible light will be very annoying to people in the environment. I can't think of a good application for this. Good luck. Steve
Dear colleague
Thank you to share me this question , I agree with Albert Manfredi
Regards
I agree with the general ideas mentioned in the above answers. This technology is certainly feasible but many difficulties will need more consideration especially those related to visible light itself.
Regards
SM Najim
I think that Li-Fi technology may occupy some small niche for limited data transmitting but not more. Tallinn, Estonia is a worldwide leader for communication systems - it sounds like a joke. Estonia is a small country with a limited research potential. Estonia has no resources for great discoveries in the field of high technologies.
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