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German Researchers Hit 40 Gbps On Wireless Link

Unknown Lamer posted about a year ago | from the don't-stand-in-front-of-it dept.

Wireless Networking 104

judgecorp writes "German researchers from the Fraunhover and Karlsruhe institutes have achieved 40Gbps transfers over 1km using a wireless link. The new record raises the hope that point-to-point wireless could be used instead of expensive fibers in some rural broadband applications." Partially thanks to transmitting between 200GHz and 280GHz.

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yea (-1)

Anonymous Coward | about a year ago | (#43779587)

First YEA

2 obligatory questions (0)

Neo-Rio-101 (700494) | about a year ago | (#43779597)

1. How the hell is this going to fare in a real world test where a metropolis of people oversaturates the frequency?
2. How many Australian luddites are going to look at this say that the national fibre-optic broadband network rollout is going to be made obsolete by this wireless tech?

Re:2 obligatory questions (4, Funny)

Anonymous Coward | about a year ago | (#43779631)

Here's another obligatory question

3. How many Australian Luddites care about what's happening in Germany?

Enquiring minds want to know

Re:2 obligatory questions (5, Funny)

bytesex (112972) | about a year ago | (#43779773)

Well, I'm sure you've heard that Adolf Hitler was an Australian!

Re:2 obligatory questions (1)

davester666 (731373) | about a year ago | (#43783499)

So that's what WWII was about.

"If we can't have nice things, then I'm going to break everybody else's things!"

Re:2 obligatory questions (1)

dbIII (701233) | about a year ago | (#43780497)

Probably all of the ones that want an excuse to kill off the current broadband rollout.

Re:2 obligatory questions (3, Insightful)

Anonymous Coward | about a year ago | (#43779639)

1. How the hell is this going to fare in a real world test where a metropolis of people oversaturates the frequency?

What part of "point to point" did you not understand?

Re: 2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43779823)

there's a point in there somewhere, right?

Re: 2 obligatory questions (1)

Anonymous Coward | about a year ago | (#43779933)

No, two points!

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43780205)

This isn't a maser.

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43779671)

Rural areas are by definition not a metropolis. Just saying.

Re:2 obligatory questions (5, Insightful)

ikaruga (2725453) | about a year ago | (#43779695)

1. How the hell is this going to fare in a real world test where a metropolis of people oversaturates the frequency?

From the summary.

...used instead of expensive fibers in some rural broadband applications

Re:2 obligatory questions (1)

flyingfsck (986395) | about a year ago | (#43780127)

...and how many repeaters would you need to cross the Aussie Outback if the range is all of 1km?

Re:2 obligatory questions (5, Informative)

Anonymous Coward | about a year ago | (#43779713)

The higher the frequency, the more like light. It is a highly directional transmission, so unless there is another source of 200-280GHz signals within a few degrees of the transmitter sending in the direction of the receiver, there's not going to be interference.

When somebody tells you that fiber is a waste of money, ask them if we should stop building those expensive roads as well, because we can all fly helicopters instead.

Re:2 obligatory questions (2)

Rockoon (1252108) | about a year ago | (#43780041)

yeah but helicopters are expensive compared to cars. I'm fairly certain that this setup is cheaper than the amount of fiber its replacing.

Re:2 obligatory questions (1)

Karl Cocknozzle (514413) | about a year ago | (#43780069)

yeah but helicopters are expensive compared to cars. I'm fairly certain that this setup is cheaper than the amount of fiber its replacing.

Give this man a cigar!

Hopefully it will not rely on any "proprietary" tech so it can't be priced at $5 million per radio or, (cost of building fiber - 10%).

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43780085)

Sigh. Do you really need help understanding this easy analogy? Fiber: roads. Car: fiber transceiver. Helicopter: wireless transceiver. Helicopters don't need roads. Wireless transceivers don't need fiber. Cars are cheaper than helicopters. Fiber transceivers are cheaper than wireless transceivers. Cars use less energy than helicopters. Fiber transceivers use less power than wireless transceivers. Roads support much more freight than helicopters. Fiber links carry much more data than wireless links.

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43782581)

Were we're going, we won't need roads. The future must be "helicopters".

Re:2 obligatory questions (1)

wagnerrp (1305589) | about a year ago | (#43780505)

The issue is that this is only going to be replacing a single fiber. You never run a single fiber except short loops to your endpoint customers. This could potentially replace the point-to-point links for the "last mile", until such time as you get enough subscribers to make it worth your time to trench the land and run a bundle of fiber.

Re:2 obligatory questions (1)

Chrisq (894406) | about a year ago | (#43779755)

How many Australian luddites are going to look at this say that the national fibre-optic broadband network rollout is going to be made obsolete by this wireless tech?

A 1km range is next to nothing for rural Australian

Re:2 obligatory questions (1)

PolygamousRanchKid (1290638) | about a year ago | (#43779867)

A 1km range is next to nothing for rural Australian

For Texans, 1 mile is "neighbors" . . .

. . . 100 miles is "just down the road" . . .

. . . 1000 miles is "just down the road, aways" . . .

Re:2 obligatory questions (4, Insightful)

niftydude (1745144) | about a year ago | (#43780111)

A 1km range is next to nothing for rural Australian

For Texans, 1 mile is "neighbors" . . .

. . . 100 miles is "just down the road" . . .

. . . 1000 miles is "just down the road, aways" . . .

Heh, I know people in the US like to think Texas is big, but the truth of the matter is that the area of the state of Texas is just under 700 thousand sq km, while the area of the state of Western Australia is a bit over 2.5 million sq km.

That's about 3.5 Texii*.

* I know - Texii probably isn't the correct plural for Texas, but Texases just sounded wrong.

Re:2 obligatory questions (1)

sg_oneill (159032) | about a year ago | (#43780165)

Aye, I spent some time with family up "near" southern cross, "near" kalgoorlie, where the nearest house was around 200km away. Go bush around here, and distances get epic.

Re:2 obligatory questions (1)

PolygamousRanchKid (1290638) | about a year ago | (#43780391)

Go bush around here, and distances get epic.

. . . which is probably way off the rural scale in Germany, where the system was developed.

Folks in Germany see Australia on TV as a place where B-celebrities are sent to eat nasty looking creepy-crawlers and bathe in kangaroo poo. And then whine and bitch about each other to see who gets to stay the longest.

So how does one stay connected in southern cross . . . ?

Re:2 obligatory questions (1)

Shatrat (855151) | about a year ago | (#43780783)

There is no correct way to pluralize Texas, there can be only one Texas. Anyway, just because Australia or Alaska or Siberia are larger, doesn't mean Texas still isn't a big place. You can drive from Beaumont, Texas to Los Angeles and by the time you're halfway there, you're still in Texas.

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43783377)

That's because "Texas" is already plural. It used to be "The Texas" because there was more than one Texa, and they eventually dropped the "The."

Re:2 obligatory questions (1)

drkim (1559875) | about a year ago | (#43791143)

You can drive from Beaumont, Texas to Los Angeles and by the time you're halfway there, you're still in Texas.

This doesn't mean anything. You could say that New Mexico is bigger than Texas by saying, "You can drive from Farmington, New Mexico to Odessa, Texas and by the time you're halfway there, you're still in New Mexico."

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43797305)

Context is everything. Beaumont is in the middle of the country (East-West) and L.A. is on the coast.

Re:2 obligatory questions (1)

drkim (1559875) | about a year ago | (#43797445)

Context is everything. Beaumont is in the middle of the country (East-West) and L.A. is on the coast.

You're right about context...

Beaumont is on the Eastern-most edge of Texas and L.A. is at the Southern end of a tall, but narrow, state.

You can drive from Crescent City, California to El Paso, Texas and by the time you're halfway there, you're still in California."

Re:2 obligatory questions (1)

CastrTroy (595695) | about a year ago | (#43782349)

So, you got one large province, which has some pretty big empty expanses. But, being from Canada, I'd have to say you have nothing on us. And We probably having nothing on Russia. I mean, the Sakha [wikipedia.org] state/province consists of over 3 million square kilometers. They also have Krasnoyarsk Krai [wikipedia.org] which is 2.3 million square kilometers. And the size of the country is over 17 million square kilometers. Canada and Australia on the other hand both have much lower population densities than Russia.

Re:2 obligatory questions (1)

Krojack (575051) | about a year ago | (#43782657)

Are they planing on supplying Internet Porn to the Australian outback tribes or something? =)

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43784689)

Porn and alcohol. Then they take the children.

Re:2 obligatory questions (1)

dbIII (701233) | about a year ago | (#43780519)

In rural Australia 100 miles is "neighbors" :(

Re:2 obligatory questions (2)

Chrisq (894406) | about a year ago | (#43781271)

In rural Australia 100 miles is "neighbors" :(

Please don't mention Australia and neighbours [neighbours.com] in the same sentence. Now I have that terrible signature tune going through my head.

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43779857)

Typical ./er; masturbating over an utterly wasteful pork-barrel program because it happens to benefit them personally.

Most people do not, and will not, any-time soon have any need for any bandwidth above and beyond what could be provided by copper. By the time any non-trivial fraction does, the cost considerations and available technologies will have changed drastically.

But by all means FTTH for everyone in a relatively sparely populated country. Genius. All on budget and schedule I assume?

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43779889)

You read 40Gbps and assumed the idea was for all that bandwidth to be used by only ONE person? Maybe, you know, the point is to create a point-to-point trunk that would serve a whole rural COMMUNITY. Use your brain for a moment instead of spouting off.

Re:2 obligatory questions (1)

Karl Cocknozzle (514413) | about a year ago | (#43780077)

You read 40Gbps and assumed the idea was for all that bandwidth to be used by only ONE person? Maybe, you know, the point is to create a point-to-point trunk that would serve a whole rural COMMUNITY.

That's the thrust of it: You get service into these communities and they can bury their own media, whatever they want it to be. Or redistribute on a different wireless band to neighborhood homes via Wi-Max...

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43785185)

I for one Completely agree with your point. I mean, everyone is using 640k of RAM just fine and 48.8k baud is more than enough for any communication that's worth its salt. Who the hell needs progress when there's greed to be had?

Re:2 obligatory questions (1)

bmo (77928) | about a year ago | (#43780453)

The question really is, why are there so many kangaroos in Austria?

--
BMO

Re:2 obligatory questions (1)

drkim (1559875) | about a year ago | (#43791151)

The question really is, why are there so many kangaroos in Austria?

--
BMO

Because kangaroo marriage is STILL illegal in the USA.

Re:2 obligatory questions (1)

bmo (77928) | about a year ago | (#43792553)

But if we legalize kangaroo marriage, people will be marrying their furniture!

We don't want that now, do we?

--
BMO

Re:2 obligatory questions (1)

drkim (1559875) | about a year ago | (#43797465)

But if we legalize kangaroo marriage, people will be marrying their furniture!

We don't want that now, do we?

--
BMO

That ottoman LIES! That stain is from leather polish.

Re:2 obligatory questions (1)

bmo (77928) | about a year ago | (#43798071)

I heard you talking sweetly to the ottoman. I thought you were on your cellphone, but then I saw the bluetooth earpiece on the kitchen counter.

Fess up!

--
BMO

Re:2 obligatory questions (0)

Anonymous Coward | about a year ago | (#43780597)

This isn't broadcast wifi like what your router puts out, it's a directional beam from a transmitter on a roof aimed at a directional antenna on a different roof. You're not going to see this in a normal router.

Re:2 obligatory questions (1)

KingMotley (944240) | about a year ago | (#43781819)

1. How the hell is this going to fare in a real world test where a metropolis of people oversaturates the frequency?

You do realize they said *point-to-point wireless could be used instead of expensive fibers in some rural broadband applications*, right? How many rural metropolises do you know of?

Bad news... (0)

hcs_$reboot (1536101) | about a year ago | (#43779617)

...for RIAA, SACEM and the like...

Re:Bad news... (1)

hcs_$reboot (1536101) | about a year ago | (#43780117)

Offtopic? This is not a secret that RIAA and the like are not investing any effort in building faster infrastructures ( quite the opposite ). If history was made based on their whims, we'd still be using vinyl records, without even a cassette to make a copy... At 40Gbps, a HD movie is copied within a second...

Re:Bad news... (0)

Anonymous Coward | about a year ago | (#43783561)

> At 40Gbps, a HD movie is copied within a second...

Really? HD movies are only 5 gigabytes? They are compressed better than I thought!

Serious question.... (0)

rts008 (812749) | about a year ago | (#43779623)

Does anyone on /. know if any studies have been done to determine if all of this ever-increasing 'wireless' energy we are putting out has any significant effect on warming our environment?

I am not trying to be chicken little here, but the thought just occurred to me seeing this summary.

Re:Serious question.... (1)

Anonymous Coward | about a year ago | (#43779659)

It has more or less the same effect as the same amount of energy put into wired solutions. In other words, the only relevant question is how it affects total energy consumption.

Re:Serious question.... (5, Informative)

Anonymous Coward | about a year ago | (#43779745)

Wireless LAN access points send at less than 1W (much less, depending on the regulatory domain), which is eventually converted to heat. Your brain on the other hand turns more than 10W of chemical energy into waste heat and you have only that stupid comment to show for it.

Re:Serious question.... (0)

Anonymous Coward | about a year ago | (#43779895)

The original question was about warming the environment. It's not about the classic cell phone scare. The researchers used a narrow near-infrared beam. I have not seen a mention of its power. That beam will heat the air it's travelling through, that's a given. Nobody will ever hold it to their head anyway, it's more of a radio installation than a local receiver.
So the question stands, how much does it heat the air? And how much does that heat affect the local ecosystem, if at all?
Similarly, all other radio signals out there, from wifi routers over cell phones to amateur and professional radio stations; what's the total energy put into the air, and how does it affect its temperature?

Re:Serious question.... (0)

Anonymous Coward | about a year ago | (#43779945)

The energy you're wasting...

A smartphone battery holds roughly 6Wh, which runs the phone for at least a day. That's about 250mW on average, which includes everything the phone does, not just the radio transmission. In the meantime your body burns roughly 100W on average, including more than 10W for your brain. If you didn't get from the previous comment how low the amount of energy required for wireless transmissions is compared to the waste of energy that is the useless bag of water in front of your keyboard, now you should understand it.

Re:Serious question.... (0)

Anonymous Coward | about a year ago | (#43779955)

Less than your ignorant blabbering, for one.

Why do you think we're able to use radio? Because air doesn't fucking absorb it in any significant manner!

Empty space doesn't heat up just because there's a EM wave coming through, heat can be generated when non-empty spaces get in the way and absorb it, and there are not enough of those capable doing it to waves far below IR in the air to matter.

Re:Serious question.... (0)

Anonymous Coward | about a year ago | (#43779765)

This worries me too. I have this unlicensed 'wireless' energy source in 1THz-10PHz range bombarding my house every day from morning till night, it sure as hell warms it up.

Seriously tho, to warm something up, 'wireless' energy has to be absorbed and just transformed to heat by something in the way which is not what's happening with RF radiation.

Re:Serious question.... (2)

cheater512 (783349) | about a year ago | (#43779989)

Your average wifi antenna radiates 100mW.
Doing some very rough calculations in an hour that will heat a litre of water by about 0.08 degrees Celsius assuming that the water can't lose any heat to its environment.

Compared to say 2000 Watts for a microwave that does cook food with 'wireless energy'.

Also compare that with just the temperature from your car's engine and exhaust gasses.
I think the latter wins hands down.

Re:Serious question.... (1)

rts008 (812749) | about a year ago | (#43797151)

Thanks for the info.

I figured it was probably not a problem, but did not really know.

I'm sure weather will have no effect at all (1)

3.5 stripes (578410) | about a year ago | (#43779635)

on the link quality. I'd bet a light mist will halve the throughput.

Re:I'm sure weather will have no effect at all (0)

Anonymous Coward | about a year ago | (#43779677)

Just make the link power high enough to cause a significant heating along the path. Then you'll no longer have to care about the possibility of mist. ;-)

Re:I'm sure weather will have no effect at all (1)

Bearhouse (1034238) | about a year ago | (#43779757)

FTA: "According to researchers, the atmosphere shows especially low attenuation in this frequency range, and the technology has already been tested with distances over one kilometre."

Does not say if this includes in rainy conditions, since you're right that - normally - the higher the freqency the more it is impacted by atmospheric moisture.
Still, you get TV and your cell phone works when it rains...

Re:I'm sure weather will have no effect at all (0)

Anonymous Coward | about a year ago | (#43779947)

Speaking as someone who has designed and validated microwave paths, this band is not reliable. We do include significant path loss for fade margins, but some fade margins get ridiculous. In abstract http://link.springer.com/article/10.1007%2FBF01041347 the authors point out that "The measured attenuations showed quadratic dependences on atmospheric water vapor density, and absorptions in excess of theoretical predictions were observed at both frequencies, while the measured refractive dispersion between these two frequencies showed a linear dependence on water vapor density and was in good agreement with theoretical prediction."

In other words, diversity reception would be wise, and so would a big, fat fade margin. The fact that it works on a sunny day is no consolation when a temperature inversion ducts your signal in to space.

Re:I'm sure weather will have no effect at all (1)

solidraven (1633185) | about a year ago | (#43788681)

Yeah, but the 2.4 GHz band goes through walls and humans easily. 240 GHz is a different story. 50 GHz already has trouble getting through on a rainy day, 240 GHz won't do much better. You'll need some insane receivers for this thing.

Re:I'm sure weather will have no effect at all (2, Insightful)

Anonymous Coward | about a year ago | (#43779835)

The important facts are missing from both the summary and the English article. The german original has more info:

http://www.kit.edu/visit/pi_2013_12950.php [kit.edu]

Basically, the important news is that they build new send/receive integrated chips that can be feed directly a optical link, transmit over radio waves and on the other side feed directly back to optical (fibre).

Formerly, you either have to:

* transcode from optical to radio link, and back on the other side, which is expensive (extra components), draws more power and is bulkier.

* OR use a laser, which is optical, and thus skips the transcoding, but fares bad in wether conditions like rain and fog

The new system combines the advantage of having an small 84x1.5mm) integrated chip system, which uses less power and can thus be cheaper with the advantage of a radio link over a laser link.

Of course it won't be unaffected by weather like a fibre laying in the ground - but it is still better (smaller, more robust, and still as simple as) than the existing laser links. And it is meant to be used where you can't just lay a cable, anyway.

Re:I'm sure weather will have no effect at all (1)

dbIII (701233) | about a year ago | (#43780565)

Microwaves attenuate in wet weather due to the wavelength being close to the length of the hydrogen-oxygen bonds in water. This stuff has a different wavelength so it might go through mist as if it isn't there.

Re:I'm sure weather will have no effect at all (1)

3.5 stripes (578410) | about a year ago | (#43783445)

Little tiny waveforms react really badly to little tiny droplets of water in their way..

Re:I'm sure weather will have no effect at all (0)

Anonymous Coward | about a year ago | (#43783829)

The length of the bonds between single hydrogen-oxygen bonds in water molecules is close to wavelengths at 2.4GHz. This runs on 200+GHz, with much, much shorter wavelengths still.

Quite obviously you're not going to get "little tiny droplets of rain" smaller than the bond between hydrogen and oxygen atoms as that would make the droplets smaller than the matter that they're made of.

why? (0)

stenvar (2789879) | about a year ago | (#43779645)

Those frequencies are probably affected just as much by rain and fog as optical, and pretty much as directional. You can easily get multiple Gbps systems off the shelf.

Re:why? (1)

Anonymous Coward | about a year ago | (#43779729)

this can be usefull for tower-to-tower comunication. the last mile can be 3/4G or even wifi.

Re:why? (0)

Anonymous Coward | about a year ago | (#43779741)

Where, and price?

Fraunhofer not Fraunhover (1)

Anonymous Coward | about a year ago | (#43779789)

Has nothing todo with hovering ;)

Bad naming in summary (1)

Anonymous Coward | about a year ago | (#43779801)

For those not wanting to read TFA:
It's two institutes: The Fraunhofer Institute for Applied Solid State Physics and the Karlsruhe Institute for Technology. Karlsruhe is a city, not an institute.

Re:Bad naming in summary (1)

Anonymous Coward | about a year ago | (#43779817)

Not enough fun is made of the University of Karlsruhe for renaming themselves Karlsruhe Institute of Technology to create a mental association with the Massachusetts Institute of Technology.

Re:Bad naming in summary (0)

Anonymous Coward | about a year ago | (#43780159)

I've known people that worked at KIT for a while, and this is the first time that even crossed my mind.

Re:Bad naming in summary (0)

Anonymous Coward | about a year ago | (#43784959)

Perhaps there was not enough non-technical subjects in the UK, so they became the KIT (tee-hee). Similar naming transitions have been made in other institutions, only in the opposite way though.

Its.... (0)

Anonymous Coward | about a year ago | (#43779811)

It's Fraunhofer, you insensitive clod!

Birds (0)

Anonymous Coward | about a year ago | (#43779927)

All birds and insects within a kilometer of the test dead.

Bird Torch (0)

Anonymous Coward | about a year ago | (#43780025)

The picture in the article shows a directional transceiver, which is capable of sending a full DVD 1Km in under a second. I'm not sure about the signal power they use, but I'm going to propose naming this device the Bird Torch.

Re:Bird Torch (0)

Anonymous Coward | about a year ago | (#43780057)

Oops, sorry. Here's the German translation: Volgel fackel
Wir haben eine 40 Gbps Vogel Fackel erstellt.

Re:Bird Torch (0)

Anonymous Coward | about a year ago | (#43781011)

Go home you are drunk. You don't speak German and it shows.

1. It would be Vogelfackel

2. There is no such word (not even closely) and it doesn't make any sense whatsoever. It's not even funny. It's just nonsense.

Source : I am German.

Re:Bird Torch (0)

Anonymous Coward | about a year ago | (#43782597)

I have to ask you to please stop posting comments that confirm the prejudice that all Germans are arrogant humorless nitpickers.

Source: a German cooler than you, at home, currently sober.

Re:Bird Torch (0)

Anonymous Coward | about a year ago | (#43783843)

Wenn es zum Lachen gewesen wäre, hätte ich nichts gesagt. Aber es waren einfach nur zwei Zufallsworte zusammen getackert.
Wer sich übrigens als cool bezeichnet ist es in den seltensten Fällen. ;-P
ÄtschiBätsch.

Auch noch nüchtern. Aber nicht mehr lange...

Prost.

Re:Bird Torch (0)

Anonymous Coward | about a year ago | (#43783031)

We now have a new unit of measurement. DVDs-KMs/sec

In other news... (0)

Anonymous Coward | about a year ago | (#43780031)

... german chicken produces boiled egg.

Not good for long haul use (5, Interesting)

Muad'Dave (255648) | about a year ago | (#43780093)

This band is not useful for long haul carriage due to atmospheric water vapor absorption. According to this chart [eoportal.org] , absorption between 200 and 280 GHz varies between 3 and 40 dB/km. That means at the low end only 50% of your signal is absorbed every km. At the high end, only 1/10,000th of your signal remains after each km.

this post [slashdot.org] speaks to similar issues including refraction.

Re:Not good for long haul use (1)

Anonymous Coward | about a year ago | (#43780471)

Easily solved. Just use RF waveguides between the repeaters. The wavelengths at the given frequencies would be a bit larger than 1 mm, so the waveguides would be about the size of fiber optic cables.

Uh ... wait ...

Re:Not good for long haul use (1)

xtal (49134) | about a year ago | (#43782689)

They're not proposing using this for longhaul - although, there are lots of longhaul microwave links. You design for the fade margin and availability you need taking into consideration the rain fade. No big deal. These issues are common to all microwave links.

The point of TFA, and the exciting thing about this technology is it provides a way to do last mile distribution potentially to homes, in a multi-gigbit class. If the manufacturing cost goes down, this does provide a interesting solution to the distribution problem for low-density areas.

Running fiber along main trunks isn't that expensive. Getting it off the main trunks to people's houses in the country makes it cost-prohibitive.

Re:Not good for long haul use (1)

Muad'Dave (255648) | about a year ago | (#43783437)

Designing a microwave link below 50 GHz where the path loss is at most 0.2 dB/km is MUCH easier than designing one that can range from 3dB/km to 40dB/km. For every km of path, 37dB of dynamic range/headroom is a factor of around 5000x (closer to 5012, actually). If you need 1W to achieve your desired S/N ratio in dry air (3dB loss) over 1 km, you'll need 5kW when it's raining. Make that 2 km and you go from needing 2W (6dB loss) to needing 50 MW (yes, megawatts at 80dB loss).

Even if the required signal levels are 3 orders of magnitude lower (i.e. 1mW will work over 1 km of dry air) you will still need ridiculous amounts of power past a few km. Even at 2 km you're looking at 50kW at 80dB/2 km.

We haven't even considered the reflectivity/opacity of leaves/plants/etc if you're proposing this for "last mile" use. You'll need a very clear line-of-sight path for this.

Re:Not good for long haul use (1)

Crypto Gnome (651401) | about a year ago | (#43790069)

This band is not useful for long haul carriage due to atmospheric water vapor absorption. According to this chart [eoportal.org] , absorption between 200 and 280 GHz varies between 3 and 40 dB/km. That means at the low end only 50% of your signal is absorbed every km. At the high end, only 1/10,000th of your signal remains after each km.

this post [slashdot.org] speaks to similar issues including refraction.

That has not and will NEVER stop $TELCO from selling services across this with "UP TO" marketingspeak which means "we fuck you royally for a service which is online but effectively unuseable".

Impressive but, (1)

Adult film producer (866485) | about a year ago | (#43780517)

shouldn't we be investing research into subspace communications? Seems to me that would be the next logical step forward

Great speed, but probably years away. (1)

Virtucon (127420) | about a year ago | (#43780849)

Given the standards organizations' propensity to drag things out (802.11n anyone? [wikipedia.org] (7 years)) This is nice from a research perspective but probably years away from having practical equipment you can use.

Why not FSO [wikipedia.org] , or microwave? Running wireless at long distances has already been done. http://en.wikipedia.org/wiki/Long-range_Wi-Fi [wikipedia.org] If you look at that long range Wi-Fi link, those are some substantial distances. Sure, not 1Gbps but they work.

I have a customer with an openWRT setup running 802.11a at 1/2 mile, un-amplified with off the shelf antennas. That's basically, off-the-shelf running in already allocated spectrum.

Of course if you're looking for very low cost, you can get IP running on waxed string. (I remember seeing a demonstration at INTEROP where IP communications occurred over a piece of string between two systems.)

Re:Great speed, but probably years away. (1)

Teun (17872) | about a year ago | (#43785311)

This system is designed for last mile use, not long distance.

40Gbps is verboten! (1)

Pf0tzenpfritz (1402005) | about a year ago | (#43781559)

German researchers from the Fraunhover and Karlsruhe institutes have achieved 40Gbps transfers over 1km using a wireless link.

Technicians from the German Telekom immediately showed up to cap the link to 300kbps due to excessive use of bandwith...

Re:40Gbps is verboten! (0)

Anonymous Coward | about a year ago | (#43782573)

German researchers from the Fraunhover and Karlsruhe institutes have achieved 40Gbps transfers over 1km using a wireless link.

Technicians from the German Telekom immediately showed up to cap the link to 300kbps due to excessive use of bandwith...

They managed to evade that by only testing with offerings from Telekom partners, which are exempt from that cap.

proofreading editor wanted (0)

Anonymous Coward | about a year ago | (#43782525)

Please... proofread the submissions just ONCE... it's Fraunhofer with "f" and the Karlsruher Institut für Technologie aka KIT. *goddamnit*

Meanwhile, Telekom is planning 384kB in 2014 (1)

ReallyEvilCanine (991886) | about a year ago | (#43782713)

Limits and caps [nytimes.com] at 75GB unless you pay a lot more. "Former" monopoly Telekom owns a hell of a lot more than just that last mile of copper.

The article is a puff piece which ignores the massive amount of data lost through connection drops, forced restarts & reloads YouTube and many other sites cause/require, as well as the ever-increasing bandwidth necessary due to "cloud" services, software-as-a-service, growing page programming/scripting and third-party & indirect loads (predictive actions, agents, ads, iFrames, etc.).

surly not suited to long ptp links (1)

mjwalshe (1680392) | about a year ago | (#43782977)

you are not going to have massive range at 200 and 280 GHz

Challenging installation, but still cool. (1)

JimtownKelly (634785) | about a year ago | (#43789691)

I've aimed microwave STLs before and that was a royal pain in the ass. In the hundreds of gigahertz range aiming the antennas has got to be a bitch. And damn well better make sure the mast and mountings will never shift under wind pressure.

Useless (0)

Anonymous Coward | about a year ago | (#43793033)

To be honest its useless,
24ghz only goes 6-10kms in real world deployments because it gets absorbed by rain.
You would be lucky if you could get 1-2kms out of a 200ghz link.

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