Wireless internet for miles

[HudzonHawk]

Is it possible to produce a non line of sight wireless signal that could reach very long distances? (eg a radius of one square mile)

How can this be implemented? What are the limitations of such a method? What would be the theoretical maximum speed? And how much would it cost?

Thanks in advance!

 

[Nigel Goodwin]

It would be illegal, and SERIOUSLY illegal in the UK where we take such things more seriously than most countries. Basically you would be looking at MUCH higher powers, and it would still be higly influenced by buildings.

 

[HudzonHawk]

Can you please elaborate?

Why would it be illegal? Is there a way to get a license for it to become legal?

How would the buildings influence it?

And if you're using very high powers, would it be safe for humans?

 

[Nigel Goodwin]

Can you please elaborate?

Why would it be illegal? Is there a way to get a license for it to become legal?

Radio transmissions are highly regulated, you MUST have a licence to transmit, or use a licence free frequency, but meet ALL the licence free conditions (the first of which is VERY low power).

Obtaining licences is expensive, VERY, VERY, VERY difficult, and in this case would be completely impossible.

Incidently,in the UK, penalties include confiscation of all connected equipment, fines (which can be large!), and even jail time - although it's not likely for a first offence.

Bear in mind you would be wiping out a good slice of spectrum over a considerable area, and there would be many legal users in that area that would have their use ruined.

How would the buildings influence it?

At high frequencies anything in the way stops (or at least attenuates) the signal.

And if you're using very high powers, would it be safe for humans?

We're not talking that high!.

 

[HudzonHawk]

So the main reason why its illegal is because I would be interfering with other wireless signals?
What kind of things would I be interfering with? Just wireless internet or radio and anything else?

If its illegal then why are the TV and radio companies allowed to broadcast stuff at large distances?

Incidently,in the UK, penalties include confiscation of all connected equipment, fines (which can be large!), and even jail time - although it's not likely for a first offence.

I'm not going to make anything illegal, but if there is a slightest chance of this being allowed then I would like to try getting a license.

If there is no way it's going to be possible to get a license for a radius of 1sqm, then what is the maximum area I am allowed to get a license for?

 

[Nigel Goodwin]

So the main reason why its illegal is because I would be interfering with other wireless signals?
What kind of things would I be interfering with? Just wireless internet or radio and anything else?

Anything in or near the same band, in the case of WiFi video senders use the same frequencies - so you can't use video senders and WiFi anywhere near each other.

If its illegal then why are the TV and radio companies allowed to broadcast stuff at large distances?

Becasue they have licences for it - VERY, VERY EXPENSIVE licences!. I hate to think what it costs?, I think ITV companies pay in the millions?.

I'm not going to make anything illegal, but if there is a slightest chance of this being allowed then I would like to try getting a license.

You don't have the slightest chance of getting a licence, but if you feel lucky first win the lottery jackpot a couple of times! - you may then have the financial 'clout' to spend it all failing to get a licence!.

If there is no way it's going to be possible to get a license for a radius of 1sqm, then what is the maximum area I am allowed to get a license for?

You won't, you can't just 'get a licence', it's an incredibly difficult and expensive procedure (when it's even possible). WiFi is in a licence free band, but it's severely restricted in it's use and power.

For an example, we used to have a radio telephone at work, you had to buy professional (EXPENSIVE!) equipment, apply for a licence and be allocated a frequency to use (if you were allowed at all!). You then have to pay a licence fee every year, if I remember correctly by the time we scrapped them (and replaced them with mobile phones) the licence cost over £1000 per year. Bear in mind this was for a narrowband voice channel, and by the time we stopped using it, it was barely useable due to other users being allocated the same frequencies - even though some distance away.

 

[bloody-orc]

What do you want to transfer using that Wireless network anyway? Want to get internet access to your local town? Right now I know WiMax has the largest range when it comes to wireless internet connection... But then again, I have no idea, what you really want to send. When talk, then use HAM radio or mobile phone.

 

[HudzonHawk]

Okay, I think I understand what you're trying to say about the price now. Thank you for the detailed explanation!

I'm a bit disappointed, though. Here I thought that ubiquitous computing wasn't possible because of some technological limit, but turns out it's just banned by the government and their laws

Hey, I remember you now! You helped me last year with a project I was making.
I also wanted to ask you that time what the kanji in your name meant.

 

[Nigel Goodwin]

Okay, I think I understand what you're trying to say about the price now. Thank you for the detailed explanation!

I'm a bit disappointed, though. Here I thought that ubiquitous computing wasn't possible because of some technological limit, but turns out it's just banned by the government and their laws

Not really banned by law, more like banned by 'laws of nature' - there's only a very small amount of spectrum available, so it's needs regulation to prevent abuse - your 'requirement' would be abusing it big style!. This is why the government expect to make millions (if not billions) by selling off the UHF TV space that will be cleared by the chaneg to digital TV.

Hey, I remember you now! You helped me last year with a project I was making.
I also wanted to ask you that time what the kanji in your name meant.

It's 'Jitsu' (art or technique), from Ju Jitsu (gentle art) in which I hold a 3rd dan black belt.

Quick thought! - not really any help? - but there are wireless internet connection schemes, which cover considerable areas. However, presumably the equipment is expensive?, requires expensive (and unobtainable) licencing - so probably wouldn't help?. I don't even know what band it uses?, but it's more expensive than ADSL, have a look at an example here - it's run by a radio communication company, who have a number of mast sites to provide the coverage.

 

[HarveyH42]

The small town I live in installed city-wide, free WiFi internet access. Don't remember the final cost, but it was a couple million at one time. Haven't used it myself, computer doesn't do WiFi, and too cheap to pay $40 to get it. Also, little concerned about the company who manages the system. Part of the name that stuck in my head, was 'marketing'.

 

[RadioRon]

Compared to the alternatives, buying wideband wireless access through cellular companies is not a bad deal. For example, in Reading, you can access the O2 service pretty much anywhere for 384 Kbps.
https://www.o2.co.uk/business/sme/mobiliseyouroffice/mobiliseyourlaptop/o2datacard

Most mobile phone companies offer 3G services which are evolving now to reach up to 2Mbps, typically using PCMCIA or ExpressCard plug in cards, like the AirCard for example.

 

[john1]

I reckon an infra red light beam could go for a mile or so.
Or maybe one of those little laser pointers could be adapted ...

"Ubiquitous computing" .... what do you mean by that ...

John

 

[stevez]

I attended an amateur radio club meeting where licensed amateurs demonstrated the use of modified WiFi gear over longer distances using surplus TV satellite dishes. WiFY frequencies overlap amateur freuquencies here in the US and only those frequencies common to both WiFi and the amateur bands could be used for this purpose.

You may want to research amateur radio digital modes. I think you might find some of what you need - if you are willing to persue a license - and of course - if it is permitted in your country.

I nearly forgot to mention that here in the US and possibly in other countries, most transmitting equipment intended for consumer use must be used only as intended by the manufacturer and as approved by the FCC or other entities. In general, it may not be modified except as provided for by the manufacturer. The licensed amateur can use this equipment as long as the use is compliant with the regulations governing that service.

 

[audioguru]

I reckon an infra red light beam could go for a mile or so.
Or maybe one of those little laser pointers could be adapted ...

How would you keep it aimed at the detector? If a fly moved anywhere near it then it would point in the wrong direction.

 

[TheVictim]

What you are asking actually is NOT impossible, just frought with a LOT of difficulty. In the U.S. You COULD use the unlicensed 2.4Ghz band with a spread spectrum signal with up to 1W of power. A close-to-isolinear antenna is NOT going to get you 1 sq. mi. of coverage however. You would need high gain antennas on both the base and remote unit(s) to even have a chance, and you would still need a line of sight. The air loss and loss from buildings is quite substantial at 2.4Ghz. You will have to sacrifice some ease of use to make this anywhere close to feasible.

The up side of this is you can use existing 802.11b/g equipment with some antenna mods and a 1W linear amp on your base station. The mobile equipment would depend on how bulky and complicated you wanted to get. You can get about 6db gain on a mobile antenna at 2.4Ghz just by mounting the radiating element in a soup can and pointing it at the base. You need good cabling to avoid significant insertion losses.

With OPTIMUM conditions, experimenters have been able to get up to 3mi. legally, but that is on a clear dry day, line of sight (nothing but air, and NO TREES around the base station), and antennas with about 14-16db of gain.

You can try, but your odds of success still are not good if you wish to remain legal.

I once made a bug which worked by syncing the frequency control to the audio of a station at the end of the FM band and spreading the transmitted signal over the lower frequency portions of the band. I needed distance and it ran at 7W. It was never discovered (by either the FCC or the bug-ee). Your mileage may vary.

 

[TheVictim]

I've been thinking about this for a while, and if you wish to flaunt the law (not recommended) there IS a better way.

There is a modulation form known as Single Sinewave Temporal Spread Spectrum modulation (SSTSS) that is absolutely indistinguishable from noise. It works by agreeing on the specific transmission frequency using a Pseudo Noise mask much like many other forms of spread spectrum. ONE unmodulated sinewave is transmitted at the predetermined frequency, but time shifted from the predetermined time by the modulating data. Considerable distance is possible since higher power transmissions will appear as spikes, since they are just unmodulated sine waves spread 'randomly' over the band. HF bands capable of long distance propagation (over 1500mi) can even be used.

The drawbacks to this are:

1) It's illegal, even if it is undetectable.

2) Attainable speeds would be fairly low.

3) You would need some method of sync for the starting point within your Pseudo Noise mask. You could use a broadcast signal like I did with the FM bug instead of a PN mask.

4) Your mobile equipment would be quite bulky if lower frequency HF bands were used. Existing 11 meter (CB) equipment could be adapted however. 11 meters propagates well under the right conditions and the bands are CLOGGED with noise. Your transmissions would go unnoticed, but your error rate would be high.

 

[3iMaJ]

So theres a method that can go large distances with a high error rate? Why even bother?

If you're trying to fool the FCC (or whatever is similar) the underlying assumption is always to assume that Oscar (the FCC) has your hardware, so you've reallly fooled no one.

 

[TheVictim]

Yes, they would have your hardware. They might even know that SOMETHING is a couple db above the noise floor over an entire octave of bandwidth...

 

[Oznog]

So the main reason why its illegal is because I would be interfering with other wireless signals?
What kind of things would I be interfering with? Just wireless internet or radio and anything else?

If its illegal then why are the TV and radio companies allowed to broadcast stuff at large distances?

Well because they pay for licenses... and you're messing with their purchased rights if you mess with their spectrum.

There aren't ANY sections of the spectrum which "aren't being used" anymore. It's a wild fragmentation, some big areas reserved for TV channels, AM FM radio, stuff you know, then you see a hundred other things, including odd stuff like a tiny sliver for emergency locating beacons for crashed planes, some locating system you've never heard of, etc etc. Everything's being used, sometimes you won't find anyone using it at that time but rest assured it's owned.

Well, CB radio and the FRS radios here in the USA can potentially go for miles with the right antenna and terrain and anybody can use them legally. However, the WAY you can use them legally is limited. For example transmitting digital data or recorded advertising is illegal even if the format is maintained.

Realistically, nobody's going to bust you if your hacked FRS radio sends a squak of digital data to announce that the mailman's opened the box. Highly unlikely anyone would ever notice. Using it for continuous comm ain't gonna fly.

People have achieved remarkable WiFi range- curiously, legally too- with directional antennas. When your angle is 0.01% the spread it had before you sure can go a long way. But you wanted omni...

 

[TheVictim]

There are a few frequencies that nobody CARES about because they are virtually impossible to use, such as 60Hz. Good luck building transmitters small enough to use and strong enough to get above the noise floor. Oh, and don't bother with 8 or 9Hz, you'll interefere with government mind control satellites and/or black helicopters and you DON'T want to mess with them.