Saturday, July 12, 2014

Li-Fi will replace Wi-Fi

Almost everyone uses Wi-Fi every day and Bluetooth every so often. But these wireless technologies have a fatal flaw: they use radio waves to communicate. The problem with radio waves is that, although they offer decent speeds, they transmit data slowly, and the signal is often blocked or affected by equipment as simple as the microwave in your kitchen. However, a team of scientists are hard at work developing a new, extremely fast method of wireless communication, and it doesn’t use radio waves; it uses light from LED bulbs.

Light-based wireless communication, coined as Li-Fi by Harald Haas at a TED talk in 2011, is a method of internet connectivity that doesn’t use cables or radio waves, instead flickering the light from a special LED to transmit data just like your Wi-Fi adapter would. The technology is still being developed by researchers at the University of Edinburgh in the UK, but it already looks like it will be more effective and more secure than traditional radio-based communication.

Wi-Fi works by spewing out radio waves in all directions around your home or business from a wireless router. When your wireless device, such as a smartphone, detects the wireless radio waves, it connects to your wireless router, which then connects you to the Internet. The idea behind Li-Fi is almost identical, but instead of wireless radio waves being sent in all directions, it instead sends light shooting out to connect to your smartphone, laptop, or other devices. You wouldn’t even notice, but your LED lights would flicker at high speed, sending data all around your house.

The difference between Li-Fi and Wi-Fi though is that Li-Fi is much more secure. Li-Fi can only work when your device can detect the light being emitted by the Li-Fi router, meaning it will only work if you’re in the same room or area the light is being emitted. This means people passing by cannot connect and piggyback off of your Internet connection. And did we mention that it’s unaffected by RF-emitting equipment operating in the same room, such as a microwave or radio.

Li-Fi is also way faster; the latest Wi-Fi standard, 801.11ac, has a maximum possible speed of about 867 Megabits per second for a typical handheld. Li-Fi, meanwhile, can reach speeds up to 3.5Gbit/s per color – meaning a typical Red-Green-Blue (RGB) LED can emit speeds up to 10.5Gbit/s – more than 10 times faster than the latest Wi-Fi technology. These speeds offer a lot of potential for wireless connectivity.

What you also may not know is that light already is the most popular means to transmit data across long distances. Fiber optic cables send data as light through tiny strands of silicon. Fiber optics are the arteries of much of the modern internet, allowing fast transmissions of data around the world. Li-Fi uses light just as fiber optics do to transmit the information, but instead of maintaining it through the thin strand of fiber, it allows the light to spread out in all directions so devices all over the room can connect.

While it may be a few years before we see this technology in our homes, the potential is impressive. Even laboratory testing behind this new Li-Fi technology is showing great promise and speeds way beyond what Wi-Fi can handle in any real-world environment. If Li-Fi continues to perform with flying colors though, the idea of having any wired internet at home may soon become a distant memory.

Of course, this also means that if you want to watch your iPad in bed, you may need to keep the light on.

"FIPEL" Lights May Offer Alternative to "LED" - Myth or Truth ???

LEDs may seem to be the peak of efficient lighting technology, but they aren't perfect, and that doesn't mean that other technologies aren't being explored. Recently, scientists from Wake Forest University announced a new kind of light called FIPEL, which stands for "field-induced polymer electroluminescent." If it performs as promised, it offers several advantages over LED and compact fluorescent lights. With commercial development already under way, lights using this technology are reportedly going to be available to consumers in 2013.

Researchers behind the project are promoting it for its improved color properties, as well as avoiding the use of mercury or the "annoying buzz" in fluorescent lights. Of course, the old style T-12 fluorescent bulbs, and their associated magnetic ballasts (which were the kind that could develop a hum) are already being phased out, and means and methods for warming the light from LEDs have long been available.
This is not to say that there are no benefits from FIPEL lights. One disadvantage that most LEDs present is that they are point sources, so the light is very directional. FIPEL light comes from the entire surface (similar to the ESL light, another alternative to CFL or LED lights).

A review posted in Ars Technica reveals a number of weaknesses in the data available about the FIPEL light. Ars notes that the new light is "based on FIPEL technology," and not necessarily a proper FIPEL light. The article from Ars also dissects the numbers around FIPEL light as compared with other technologies, and finds it seriously wanting.

For instance, the light level of the test FIPEL had a luminance of 100 cd/sq meter, which is only a tiny fraction of the luminance of a light such as a fluorescent tube (27,000 cd/sq meter) or even the Moon (2,500 cd/sq meter). However, the photo attached to the press release and used in other articles about the technology (as well as this one) show something in the researchers' hands that is more than a little bit brighter than the lab space. So the numbers may not add up, but something would appear to be working. Furthermore, glare can be reduced by spreading the light over a wider area, so a larger area, lower luminance light source is not necessarily a bad thing.

Tech review: The future is bright for LED bulbs — and your wallet

With the phase-out of traditional incandescent bulbs, the focus is shifting to compact fluorescents and LEDs.
CFLs have been around for a few years, and they're getting pretty cheap. But they have their drawbacks, including warm-up time, proper disposal and not being dimmable.
LEDs have technology and innovation on their side. I'm convinced that LED bulbs are going to be next big thing in consumer lighting.
Here's the cost breakdown for one 60-watt bulb:
With three hours of use per day, Cree 800-lumen LED bulbs ($10 from Home Depot) should last more than 22 years, and cost only $1.14 per year to operate.
Doing the math, one LED bulb will cost about $35 to buy and operate for 22 years.
Compare that with a 60-watt  ($2.60 from Amazon) that costs $7.23 per year to keep lit. It has a lifespan of just under 11 months.
Doing the math for electricity plus the cost of replacing 24 bulbs, using an incandescent in the same lamp will cost $221 over those same 22 years.
That's a $186 savings per bulb.
How many bulbs do you have in your house?
I can count 30 bulbs in my house, and that doesn't include flood lights outside. I bet most of you have at least that many bulbs.
Dropping $300 or more on LED bulbs isn't high up on anyone's list of fun things to do, but the quicker you start changing out your bulbs, the faster your savings will begin.