In my search for a perfect backbone link for the network design I’m working on I have come across a solution for short backhaul links, this option doesn’t slow down the further you get from the transmitter nor does it have issues that RF options currently produce. Its not a perfect option due to its packet loss in ail/Snow/Torrential Rain but it offer a solution to most issues faces by current consumer-available 802.x gear
As some of you may have guessed I’m talking about FSO or Free Space Optics. Until a few years ago this option would set you back at least 4 figures per link and when I briefly thought about it I drew the same conclusion. One day I stumbled across a link in IRC the contained the link to Ronja, The open source FSO option, estimated cost per link ~$200. Current design places its range and speed @ 10mb Full Duplex with a max link range of 1.4km. Not bad for a LED driven System. Because it’s LED based it has very few regulations in terms of power and output.
The Ronja project is just over 5 years old and is based in the Czech Republic, it was born out of need after 2.4 GHz and 5 GHz became regulated from what I understand
10mb @ 1.4k is good but it’s still only a 802.11b link full speed so there is a movement to create a 100mbit Ronja and a increased range Ronja, along with moving from LED to IR Laser based transmission. Given the correct amount of funding a 100mbit IR Laser link @ 2km is a feasible in the next 6-12 months and I have enough interest in the project to assist with the testing and development of this project. This will come in the form of money, current estimates put the overall dev cost of a 100mbit version @ $10k Koruny, which is just under $600 NZD, I’m currently talking with the curator of Ronja about setting up a paypal account in order to accept donations worldwide, given the possibility of a reliable fast backbone I have no queries about supporting the project.
I will also be building the current Ronja Design which I shall test in various spots in Wellington like Karori and Makara to find out its current operational capabilities in harsh weather like dense fog and heavy rain, should this prove to be steady with no more than 10-15% Packet loss during harsh weather then I shall invest more into testing and building prototype laser options.
Although the absolute LOS needed by the Ronja and future options is a problem I believe that Ronja project is a viable alternative to the crowded 2.4ghz and expensive 5ghz spectrum and I’m excited about its future possibilities.
I invite all feedback and questions, I will answer what I can and forward those I can’t to the Ronja Team
I'm building some soonish, farnel have down a NZ, Au and USA search for the LED and cant find any so a alt must be found, i will be willing to come to aucks tho for a workshop
Sounds like the perfect give me money without the pleaing for help of transfering funds to an overseas bin-laden bank account via email or fax lol.
Also you need to apply for a license from the Ministry of Economic Development's Radio Spectrum Management division before you can go zapping ionising radiation through or at things in open space. It's a lot more harmful that infrared LED's etc... this would servely stunt it's likelyhood to suceed.
Waving my laser point around though on a dark night outside has often made me thought a high powered laser link would be great, but the potential for safety to human eye-sight and the mega bucks you could be facing in public liability damage along with rain and snow and birds and bees and smoke and smog and the list goes on... a few 802.11g units would do the same thing for a fraction of the "pratical cost".
Would be a great experiment none the less with in confined lead lined walls and UV stabilised plastic protection over you nuts.
WHat? this is less harmful by far, than IR LEDs, which are EHF ( 802.11 is in UHF) freqs. and i doubt you need an MED license to use light... it ISNT laser...
Light is laser, laser is light, if a light is visable it is electro-magnetic radiation higher up the radio spectrum oscillating at a frequency our eyes are designed to receive.
My post I was referring to laser being much more dangerous than IR LED's as it's a more intense frequency. These guys were referring to using light therefore a much more intense radiation than IR LED's. (Closer to inonizing radiation whcih splits DNA at a cellular level, hence quite a dangerous thing to play with without someone knowing you're going to shoot it through the air).
Ever heard of the phrase look with your ears listen with your eyes? Eyes and ears are the same thing, just because our brain interperts them differently they are both radio frequencies or radiation at a different frequency from each other. Makes me laugh at that vodaphone or boost mobile spot on the TV at the moment with those bugged eyed aliens that can hear phone calls at 900MHz. Wonder if the birds and bee's hear it.
This is why I think it is a seemy scam for money or something the Radio Spectrum Management officers woudl throw you in jail for withotu consulting them......
Think of the Sun as a giant transmitter swamping the little light link for the PC, unless the link uses intensely high radiation focused in a beam stronger than the Sun's radiation emissions it won't work in the higher intesene spetrum at the top of the electro-magnetic spectrum we nick-name light.
I doubt the safety side of things would allow it for a sustained period of time, and you'd technically have to purchase that air space and alert teh public that, that air space contains harmful radiation that can defaintely cause health issues if in contact with the beam.
Point is, light is radiation, laser is the same thing, only laser is a very high powered photon beam stronger than the sun's light, I haven't ever seen one of these yet (that is to say one that falls in the spectrum of light we see with our eyes) appart from an argon laser that's closer to ultra violet, the rest are in test labs with no suns radiation causing interference. Things like LED's would get swamped by natual radiation light from the sun, simple as that. Anything higher is mroe dangerous than the eletro-magnetic burns the Sun can give a good blow off without sunscreen, and therefore must be experimented with care when dealing with laser beams.
The RONJA project uses LEDs much like you would find in your stereo, on your computer or on the new-design traffic lights. are you seriously trying to tell us that we can be destroyed by simple light, like vampires on TV.
Also, not only is it a Vodafone add on TV, which is irrelevant. we don't actually hear any part of the RF spectrum, what we hear are vibrations in the air. RF is an electromagnetic wave. This is why radio-speakers must have moving parts, not just be an absolutely massive antenna. do more research on this...
The reason the LEDs in this project are not dulled by the sun, is, for one they are transmitting in a fixed direction (I'd love someone to try an make an omni for the project) and also light acts very much the same as use of a parabola in this project it is concentrated in one direction, you need to research this too...
The distance works, not because of some 'super powerful' 'DNA splitting' radiation (which I think is a load of ****) but because of controlling the direction of the light by reflectors and lenses. And there are sunshades. goto the website and research the project...
From what your saying, the MED requires you to register something like this? and buy a license to using red light? what rubbish, that would mean that basically all our electronic appliances need licenses to be turned on since they all have LEDs on them. in your world we'd need licenses to use the lights in our house and a license to take the torch out under the house at night to find something. Please research what you're going to say before you say it.
Also, light and lasers are not the same thing. Sure laser is light. but the light from your torch is not laser. Laser means light amplification by stimulated emission of radiation. and emits light in a controlled fashion, with no heat and at one wavelength only, which is why laser is never white. Lasers are dangerous to your eyes and soft tissue sure, but only because they are focussed light, a bit like focussing the sun onto your soft tissue. but if you hold your hand under a laser pointer for an hour, the most you might get is sore eyes from looking at it for that long, and flat batteries on the pointer.
Any radiation around visable light (which is ven more dangerous than IR LED's) and higher around EHF becomes ionizing radation so it pays to make sure it's safe Ionizing radiation does split DNA, why do you think x-ray workers wear lead and leave a lead lined room?
At minimal amounts (milliwatts) of EHF radiation is dangerous, unlike microwave ovens at 2.4Ghz that need some few hundred watts to started getting water molecules excited.
BUT the MED thing.... if it's a radio transmitting or electronic device which it is and being designed for use as, also means you're required to get a license to manfacture such equipment by law, simple as that (or think of it as an approval, all appliances including your stereo have one). Maybe the end user won't need a license to operate this (approved device) but the manufacture still has to obtain a license to create it, to prove it won't cause interfernce with other spectrum license holders elsewhere, that it doesn't give off dangerous amounts of radiation, unwated or spurious transmissions in the same or other bands, that can't effect other electronic devices, (there are some important one's like pace makers you know, and experimenting can be dangerous in this sense if your neighbour, who you until now forgot lived next door, may have one).
So if i owned one of those 1mill candle-power lamps, I would need a license, right? thats what your saying. and if I made a 15khz antenna and boradcast at that frequency, Id hear it would i??
Im gonna leave this till someone else clears it up, to my understanding, your second to last post was full of rubbish, and made no sense.
If it emits radiation on the radio spectrum which falls in to the radio spectrum managements job, the units would at least have to be cleared with them that it does not create any unwatned spruious emissions or hash. Same process the guys in the states would have to go through with their commercial units. Just because the end user can use it without (if cleared by the FCC). There's a reason for licensing transmitters for manufacture (not talking about the actual use now) to make sure it's up to standards and safe, and won't cause other devices problems.
How do u explain electro-static speakers then? Or like those fancy Japan speakers they put in cars now that allows each passenger to hear their own audio without effecting other passengers in the car? You can't make pressure waves that perfect, I would assume this is electro-static speakers.
Perhaps some lingo from MED might back you up a bit better kiwi rock, while I certainly dont disagree with you (as I dont know the legislation that well to base an agree/disagree decision on) it may help to solidify what you're saying.
However in saying that, I do think that what you're saying does make sense.
The Quest for the perfect backhaul link 
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