Slashdot Mirror
Broadband By Laser: Promises, Promises
Digital Quartz writes: "There's all manner of ways to get last-mile broadband access these days, from cable to DSL to microwave, but QuantumBeam, a Cambridge based company, wants you to surf by laser. Check out the article at The Wall Street Journal. I wonder how well it performs in the rain?" The promise of optical wireless is alluring, but it's also been said before ... I hope it actually pans out before it becomes old tech.
There's also this article on CN today about another vendor
a be am/index.html
http://www.cnn.com/2001/TECH/internet/02/27/ter
This is as dangerous as aiming a case of remote controls at your groin.
In 1993 I was working on "The Big Dig" - an extremely large construction project in Boston slated to be completed in 2004. During that year we needed to set up a network link between South Station and 185 Kneeland Street. In good weather it was a godsend. The roads and telephone lines were constantly being chewed up and thus unavailable for a hard link. However in light snow and light rain the network became very slow. This is in 1993 at 1993 levels of network traffic. Whatever technology they have it needs to be really kick ass. The level of weather that would disturb this thing back then was minimal and the only thing keeping this in place was absolute necessity.
--Peter
It's called Fiber optic. If you go to the trouble to dig a hole in the ground, you might as well make the most of it and string fibre through it.
Down that path lies madness. On the other hand, the road to hell is paved with melting snowballs.
I read the internet for the articles.
Sure can. 802.11b (Apple Airport, Lucent WaveLAN, et. al.) is a 2.4 GHz system and has a data rate of about 11Mbps. It can be extended to a distance of a few miles if you use a higher-gain directional antenna. Here's a slashdot article that talks about some folks in Australia who did something like this.
_____________
I don't want free as in beer. I just want free beer.
I can't see short distances being the use for these. It would be easier to make a parabolic mirror with an led to do the tx. This would make a larger beam, less susceptable to weather, but not as strong as a laser which would be better for long distances. Plus, someone in this thread mentioned fiber: fiber has to be laid. The point of wireless is to not have to lay fiber.
-no broken link
Metropoli have human population density distributions akin to the fairy ring fungus.
So, while city dwellers in the dead core have buildings to block their lasers, they are consoled by the relative lower cost of installing wire for the last mile, be it cable or a separate DSL connection.
I live in the pleasant semi-rural `burbs where my phone monopoly's C.O. doesn't provide DSL and where the cable TV stops about 1 km from my house. I'd love to have broadband access and can't get it under the current business model.
I'm willing to pay up to about US$100/month to get that access, but I doubt this technology satisfies that criterion yet.
Does anyone know if RF wireless technology, such as 2.4 GHz that is used in cordless phones, can be adapted to provide such access, say if enough neighbors installed them so a P2P net reached to someplace with a wire connection?
"Provided by the management for your protection."
You do not actually have to lay the fiber. Image that you wanted to connect two building but didn't own the land between them (possibly bisected by a road). Then you would want a wireless solution, although not this one, as there are better short range solutions. Let's say they were miles apart, then you would need something like a laser that does not degrade over great distances. I agree with another post stating essentially, that the TCP protocol will handle the data loss, and UDP data is (should be) designed to do well with a little corruption (a raindrop may screw an instant of voice data up, but it won't really be noticed by the listener (and you thought digital meant no quality loss, ha!)).
-no broken link
Why are you using a laser for such a short distance? There are many shorter distance viable wireless technologies that would be resistant to your heat problem.
-no broken link
Great link! Here's more:
r l ink.html
http://www.alphalink.com.au/~derekw/upntcvr.htm
http://www.hut.fi/Misc/Electronics/circuits/lase
http://www.k3pgp.org/
Another site worth going to if you are interested in lasercomm stuff:
http://www.repairfaq.org/sam/lasersam.htm
Finally, one that appears to be dead (?) is Ronja. In my opinion, this is one of the best projects out there - if it is still going. IIRC, it uses both lasers and high-brightness LEDs for the system. From the opencollector.org DB:
Ronja 115 Loopipe
Category: design
Clock 4 November 2000; 19:02
Ronja connects two PC's point-to-point, using visible light. The design is very simple, building is easy and complete guide will be availiable on the Web.
Schematics are availalble in the moment. Suitable for anybody who wants to communicate entirely freely in a direct line of sight. Building is cheap and requires only common tools available in home workshop. Communicates 115200 bps full duplex over 260m, but new, stronger version Ronja 666 Lucifer is in development.
Update
The Loopipe construction with HSDL1001 frontend has been successfully verified by another person, Pavouk.Two bugfixes resulted. He also designed a PCB. Pavouk tested the electronic part (not the optics), with success. The XTAL oscillator has been redesigned and HSDL1001 frontend was built for the first time and proved to be functional.
http://atrey.karlin.mff.cuni.cz/~clock/r0nj4
---
I remember the link working at one time though. I managed to get a copy of the info on the site. If anyone can confirm if the site is dead, alive, or moved, please let me know...
Worldcom - Generation Duh!
Reason is the Path to God - Anon
There was an article here a while back on exactly that.
I guess this means that if I try to check the weather online in the morning and I can't get through, it's already gotten bad.
Kurdt
Kurdt
I'm not anti-social. Just pro-technology.
I'm afraid that's not quite to the point...
In fact, electrical impulses propagate down the wire at a speed much faster then the motion of the electrons themselves (which as you say, is around 1 to 2 m/sec). Depending on the medium, electrical impulses typically propagate at 10-90% of the speed of light, I think (I don't have figures handy).
This is because what I'm calling an electrical impulse is essentially a ripple in an electro-magnetic field: also known as a photon.
Consider transatlantic, for example. About 5000km, which is 5 million meters. At light-speed, that would take about 17ms. In fact, my ping time to US sites can be as low as 70ms -- so my internet conenction already has 50% lightspeed latency.
In fact, latency is more-or-less orthogonal to bandwidth anyhow (compare bps and baud, not that anyone gets those terms correct anyhow).
Jules
-- Any sufficiently advanced technology is indistinguishable from a perl script.
Pardon me if I'm wrong, but I had this strange idea that lasers require a direct line of sight. Any bouncing, and they lose their coherency.
So.
How the hell is this going to solve the "last mile" problem? For consumers in fairly large metropolises (any other takes on the plural?) there are too many bloody buildings in the way. Plus, the problem has already been solved with DSL, cable, etc. For consumers not in the last mile - well, the laser's going to max out at 5 kilometers, right? So those farmers still plodding along on a 28k are going to stay plodding.
I fail to see how this can be of any use at all.
Lucent have a division called Lucent Optical which are (unsurprisingly) world leaders at this sort of thing.
A good article about what they do can be found here
Incidentally, a company called Global Crossing plan to implement a network based upon lasers.
..from the local council. We once considered a 155 Mbit link between to offices - but tell the local council it's laser and they start thinking Star wars (of the Reagan kind). And then there is the optical issues with heat off roofs and stuff - it get's hot here =))
--
Jon - TheSpork
So it looks like it is growing, but not so much that we have to be worried about standards. YET.
Standards are going to be important. I would hate to imagine what would happen if you had multiple receptors from multiple companies that were not highly directional (like lasers, etc). The problems of crosstalk or interferance from competing systems in the same space would be rather bad.
heck, I wonder if they would be vulnerable to jamming?
"It is a greater offense to steal men's labor, than their clothes"
Back in 1985 when I was in Cambridge at a little company named Symbolics (the first registered .com domain for you trivia buffs) we got our network connectivity over an IR link from MIT. This is probably very similar to what they'll be doing with the laser links. Our biggest problem? Window washers! Typically for an hour a month the rope/washers would block the beam and we'd be down. Took a few months to figure it out.
Just because my intelligence is artificial, doesn't mean my problems aren't real.
If you want to impress me come up with a way for access to be provided via your household wiring.
In fact if all communication could be done this way then all you would need to do is plug the machine in. Don't hook the monitor to the box, just plug it in. Need access for an Internet Appliance, just plug it into an outlet.
Whenever an idea comes up that obviously requires new infrastructure it bothers me. We should find ways to function within existing infrastructure. With most homes wired for electricity it would seem that this infrastructure has the greatest promise.
> In my opinion the chance of a very small laser beam being hit by a rain drop are very small.
Well, around where i live it's not uncommon that it rains enough that i can't see stuff a mile a way. What is the odds that a laser would traverse the same distance unchanged...
/J
How will it affect surrounding wildlife to have lasers beamed through the air every which way? Will birds have to worry about being cooked as they fly?
Ok, risking to be troll I have to say, Read the fucking article!
-- "There are no fried pigeons or blinded pedestrians," Mr. Redgrave asserts.
The lasers are limited to 100 milliwats, compared to up to 500 milliwats used by the military, and have been deemed eye-safe."You can do more damage by looking directly at the sun than by looking at one of these things," he says.
The lasers have to meet public safety standards for electro-magnetic fields and power level restrictions set by the European Commission. --
Oh, that's a shame. Living in London, I think it would be a great idea to crank the power up a wee bit, just enough to take out a pigeon. I guess that would give a whole new meaning to the old 'ping of death'
On the other hand people know not to look at the sun, (a) they have been tought not too as a child, (b) it hurts when they do it. These things apparently arn't visable, so you might do it without knowing it, if the emitter is sufficently intresting looking...
(no, I don't think it is a huge threat, but I just had to point it out)
This tech has been around for several years now.
The only difference now is it's significantly cheaper than it used to be, so you can build redundant links in through different paths.
Laser works well, for lower bandwidth, RF works well, but in the end, both are more prone to outage than fiber/cable, so if you can build proper redundant/meshed networks, you can approach the same reliability.