Optical Tech Can Boost Wi-Fi Systems' Capacity With LEDs

chasm22 writes: Researchers at Oregon State University have invented a new technology that can increase the bandwidth of WiFi systems by 10 times, using LED lights to transmit information. The system can potentially send data at up to 100 megabits per second. Although some current WiFi systems have similar bandwidth, it has to be divided by the number of devices, so each user might be receiving just 5 to 10 megabits per second, whereas the hybrid system could deliver 50-100 megabits to each user.

Comments

Requires Line of sight

[Archangel Michael]

Drawbacks are huge.

Re:Requires Line of sight

[mlts]

The drawbacks are significant. In fact, this has been done before in the early 1990s with Macintosh LocalTalk-based NICs which one would aim every NIC in a room (assuming the usual cubicle based office) to a spot on the ceiling, adjust aim until all the devices sported a green LED, then they all could communicate with each other. It wasn't fast (LocalTalk did most of its stuff via broadcasts), but it was a way to network a bunch of machines in a dynamic environment without hardwiring and before the days of Wi-Fi.

After seeing this device reviewed in MacWorld, I've not seen hide nor hair or this being used since, so it apparently flopped, or just was overtaken by 10baseT.

I wonder why this technology can't get folded into basic IR output. Until 2012, MacBooks have had this built in... perhaps this might be something useful to put in a spec as a NIC option?

Of course, the downside are the security issues, but IR has been around quite a long time, and might just need a protocol update for this.

So.... line of sight only?

[iamwhoiamtoday]

Wouldn't this technology be limited to line of sight, in addition to being annoying anywhere outside of a rave?

If you really need solid bandwidth.... RUN AN ETHERNET CABLE. Please. I keep running into people who insist on running everything over wireless..... no. just no.

Re:So.... line of sight only?

[rockout]

being annoying anywhere outside of a rave?

I know it's not fashionable to RTFA at Slashdot, but really....

The prototype uses LEDs that are beyond the visual spectrum for humans

Re:So.... line of sight only?

[locopuyo]

They don't use visible light so it wouldn't be so bad. But there have been a million articles like this in the past. It is a very niche technology.

Re:So.... line of sight only?

[Anonymous Coward]

I keep running into people who insist on running everything over wireless.

Then slow down and watch where you are going.

Re:So.... line of sight only?

[ceoyoyo]

The point is that it's line of sight. You have to be directly under the emitter. So, for example, you could stick one over every chair in the airport. Everybody gets their own bandwidth, no interference.

The trick in the article seems to be a system where you can switch between the optical units and regular wifi if you lose contact.

Oh great

[jeffmeden]

IRDA is back. Hey I have an idea, why not just have an access point that, for each user, drops a little cord out of the ceiling (where all access points are, right) and you plug it in for GIGABIT SPEEEDZZZS!!!1.

No but seriously why are we doing this when channels in the 5 Ghz spectrum are easy to come by.

Re:Oh great

[poison1701]

The lure of non-shared bandwidth is huge, if you have more than a handful of clients on a single radio, they can still consume the device easily. Clearly this won't be the answer, but it's nice someone is trying to think outside the box.

Re:Oh great

[hawguy]

IRDA is back. Hey I have an idea, why not just have an access point that, for each user, drops a little cord out of the ceiling (where all access points are, right) and you plug it in for GIGABIT SPEEEDZZZS!!!1.

No but seriously why are we doing this when channels in the 5 Ghz spectrum are easy to come by.

This is as close to IrDA as RS-232 is to ethernet.

This technology purportedly creates small one meter hot-zones of light, so instead of an AP having one (or a few) 5Ghz channels shared by everyone in range, it can have dozens of separate hotzones so each , and an AP in one room won't interfere with one in the next room.

I could see this being very useful in offices -- instead of spending tens of thousands of dollars pulling wire to each desk back to a central wiring closet, a few AP's can be hung on the ceiling with receivers on top of everyone's monitor with much better total throughput and less interference than RF.

Re:Oh great

[hawguy]

But if you're already have the power cord plugged in, it should be easy to provide a wired network connection right next to it.

Getting the wired network to the laptop is not a problem -- most laptops in the office get to the wired network through the same cable they use to plug in to the monitor, but that wired network doesn't come for free, my company paid $50,000 to wire up cat-6 for an office that we only plan on being in for 2 years - and it already constraints where we can place desks. This doesn't include the $40 - $50K spent on access switches in the server room.

We have Wifi, which works well for phones, tablets, and laptops in conference rooms, but it's no substitute for the wired network since when the graphics guys are saving gigabytes of photoshop files to the file server, the rest of the network suffers.

Expensive and fragile

[jandrese]

Optical networking startups are littered through history. Ultimately the tech works, but has caveats like you can't move your machine around without losing connectivity, and you also lose connectivity whenever someone walks in front of the beam. Also, they tend to be expensive, and since the machine ends up having to be basically immobile anyway it usually makes sense to just run cables instead.

Even for Point to Point links where you can't easily run cables (to a building across the street for example), you end up with a reasonably fast link that still cuts out when there is heavy rain or a bird lands in front of it or something. 100Mbps is really nothing to write home about either. In 2015 you should be pushing more like 1Gbps over an optical link to make it even somewhat attractive compared to plain old WiFi.

Pointing the right way.

[TechyImmigrant]

All schemes that involves knowing which direction to point the EM waves ahead of time is structurally incapable of being a WiFi physical layer.

Re:Pointing the right way.

[schlachter]

i could see this working at a desk, where the user plops down their laptop and instead of jumping on their company's wifi, they're linked to the company's optical net by an LED on their desk which transmits at gigabits/second.

Re:Pointing the right way.

[TechyImmigrant]

So it might work in some constructed scenario, but not in the general case, which is what a WiFi physical layer needs to address.

There are plenty of directional antennas that are manually configured by the installer, but that's different to trying to track a STA with a beamformed ray from an AP. That's crazy talk.

This is an important fix, and wired isn't an anwer

[Aqualung812]

First off, this has nothing to do with Wifi in your home or office where there is little line of sight and lots of RF-soaking walls to help isolate your access points.

When you're dealing with a large area with dense users (airport, lecture hall, arena, etc), wireless becomes really hard. The shared medium and limited number of non-overlapping channels becomes a real issue.

You can get directional antennas to try to isolate the overlapping channels, but there is reflection to deal with. It is a constant battle of too little power to work, and too much power and you are interfering with another access point.

Are you really going to run Cat6 all over the lecture hall or airport? To everyone's handheld device? No.

LED lights are far more directional, so even though you still have a shared medium, you're not dealing with the same issues at gigahertz RF.

This is a niche, but a very important one.

Re:This is an important fix, and wired isn't an an

[schlachter]

and since we're all dropping LED lights into our home already, one could imagine a future scenarios where the power socket of your bulbs can transmit data from your router to a local sub-room data broadcast (i.e. directly above your location in the home). Uploads could still be wifi based.

Re:This is an important fix, and wired isn't an an

[Aqualung812]

That's because they insist on using the small (3-4 channels) and crowded 2.4GHz band.

First off, there are still a LOT of devices without 5ghz support. I know many companies that are still ordering 2.4ghz-only laptops in 2015. Seriously. 2.4ghz is going to die as slow of a death as IPv4.

Second, 5ghz gives you 9 channels instead of 3, true. In a room that can have 500 people, though, that is still 55 people per channel. That is slow.

Rugged Smartphone dock

[John.Banister]

I've often thought connectorless optical data would be a nice docking technology for a water resistant smartphone.

Re:Seizures?

[Thud457]

You only need 1 bit if the only message you send is " DIE! ".