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Australian Researchers Push Near-Broadband IP Over VHF
Curmudgeon Rick writes "A research group at the Australian National University is getting symmetrical 250K bps at 20km, using "empty" 7MHz-wide broadcast TV allocations in the 45MHz band. Story here, project homepage here. Aim is to put some bandwidth out beyond the reach of the wires, where users are few and far between."
So now even my TV can get b roadband!
...but doesn't this just mean one lucky bastard in the boonies will be getting good speeds or 50 unlucky bastards getting crap speed?
vampirical
I wonder if this will be marketed in the US for rural areas. I can hear the slogan now...
"VHF... Australian for Broadband."
i allways thought broadband was at least 10mbit, this is 'only' as fast as 4 isdn lines, sure better than dialup but nowhere near broadband..
It'd be nice, but unfortunately my VCR does not support the Australian internet.
;-)
:)
That's coming from an ebayer embittered by NTSC purchases
Isn't "nearbroadband" almost the same concept as being "almost pregnant"?
This could be a nice alternative for those of us who still aren't able to get broadband (No DSL where I am and Rogers Cable never bothered to run cable to the last three houses. Guess where I am! GRR), without all the potential problems with broadband over power lines (signal leakage, interfering with ham radio).
Does Telestra know this? Surely they'll want to put a stop to any competitors of theirs.
Sorry, but speaking from purely a capitalist's point of view, the keyword here is few. As cool as the technology is, it'll never take off.
IWARS.
People, in general, disappoint me. Politicians even more so.
Mesh networking would be a better idea than all of this. More bandwidth, more parallelism, less power.
It doesn't sound as if they are really ready to talk about frequency coordination with other users. I hope they don't go about asking for spectrum for anything but experimentation this early in their project.
Bruce
Bruce Perens.
ANU... go to bottom of page
Conquering that 'last mile'
Pioneering work by physicists and engineers at ANU to build a cheap, simple and robust wireless communication system may soon see regional Australia getting a workable connection to the Internet. The system is called BushLAN, and it's all about bridging that 'last mile'.
Regional Australia has never had adequate access to the Internet. It's either not available, too expensive or unreliable. A major part of the problem is the 'last mile' of access. This 'last mile' is the connection between the central communications hub in a local town to individual residences and businesses. Unfortunately, the 'last mile' is usually much more than just a mile. In rural areas such as Cowra, for example, the last mile has been measured to be anywhere from three to 100 kilometres from the town centre. In more isolated areas it can be much greater.
The cost of cabling to only a few customers over these distances is prohibitive and current wireless solutions aren't practical. Satellite connections are expensive and usually require a cable connection for a user to send information out (ie they receive downloads from a satellite but send information out via the telephone). There are ground-based wireless connections commercially available but these operate in microwave frequencies using directional antennas that require a clear line of sight to function. Given Australia's sparse population and frequently hilly terrain this would require a large number of repeater stations.
Dr Gerard Borg is a plasma physicist at the Research School of Physical Sciences and Engineering. His work with radio transmission has convinced him that the last mile could be effectively bridged using the low-VHF radio spectrum. This part of the radio spectrum has much longer wavelengths than the microwave frequencies used by other wireless systems and this allows signals to be transmitted further without the need for expensive repeaters or satellites. What's more, it doesn't depend on line of sight as the signal has the ability to go around mountains and other large obstacles in the landscape. At the moment the low VHF radio spectrum is used to transmit TV signals but with the decommissioning of some analogue TV bands in 2008 (digital TV uses higher frequency radio) there's an opportunity to switch this unused spectrum over to data connections for regional Australia.
BushLAN (Bush - Local Area Network), as the system is called, has the potential to provide remote users in regional Australia with a permanent, high-quality Internet connection (at more than 100 kb/sec) at an affordable price. However, to get BushLAN up and running, many technical and marketing aspects of this multi-faceted system have to be developed first. To achieve his goal, Dr Borg has enlisted the assistance of a wide range of students from the Faculty of Engineering and Information Technology who have taken on the various jobs associated with the system as part of their Honours, Masters or Doctoral projects.
"The practical nature of BushLAN and its relevance to regional Australia really attracts the students," says Dr Borg. "Once they're involved, they become highly motivated about what we're trying to achieve. Quite often they finish the formal part of their work for their thesis, but then they stay on working on the project through the Christmas vacation."
The next step for BushLAN is to set up local trials to test transmissions, and then work with interested Internet service providers to see how BushLAN can be integrated into existing information systems. The hope is that with BushLAN as part of the system, the 'final mile' will no longer be an unbeatable hurdle.
Science Reporter is brought to you by the National Institute of Bioscience, the National Institute of Engineering and Information Sciences, the National Institute for the Environment, the National Institute of Health and Human Sciences and the National Institute of Physical Sciences. Written by David Salt.
For more information on any of the stories presented here please visit http://ni.anu.edu.au/
Quidquid latine dictum sit altum viditur
In Australia the ACCC defines BroadBand as 200kps and over.
But the term "broadband" has come to mean "fast" in the common language. Thank the media for that.
In the olden days, the highest speed things tended to be broadband, so the meaning just got twisted.
I'd say, considering speeds and waht is noramlly known as broadband in the US... 250kbps qualifies as "near broadband"... people usually think 1mbps is broadband.
As a frequency this low will generally pass through buildings and obstructions much more effectively, it's probably a more likely candidate for inner-city wireless broadband than 802.11 -- on a commercial level.
If some ISP can obtain the correct licenses and find an existing 802.11 chipset with firmware-programmable frequency, they'd be the winners of all time.
er, that would be no.
The channel-width is 7MHz, the frequency is around 45MHz.
Visit CryptoGnome in his home.
I think that the market is UNDER estimated for this than anything. with 20-40k coverage, it is fantastic for rural coverage. And for a country where the majority of the population are active online, this means for rural areas that are spread out over large areas, it is feasible. The expense to cable an area with 10,000 people over a 20km radius is very prohibitive. However, the market for internet of 10,000 people, where network expansion means grabbing a bit more spectrum and setting up another station, is relatively small. I think this is fantastic for our rural areas here in Australia, because FAR too many cannot even support decent dialup. Who makes long distance calls for a 56k connection? Or worse, an unstable one?
Finally, Pr0n on the TV...oh wait...
Generally the problem using VHF is that its pretty limited to a few miles unless you are pumping some serious Watts with a gigantic antenna. Also I am pretty sure 45MHz is used for Military VHF communications(I believe the band to 30MHz to 87.975 or some such) but I am not sure about Australia and its Military freqs. I seem to remmember we could send "data" over VHF when I was in but it was hardly used(I just don't think anybody knew how) We did a bunch of teletype stuff that was pretty annoying.
Back to the topic we did hve some mobile but high powered VHF stuff but it was pretty much limited to LOS(line of sight) maybe if your lucky 30 or so miles.
HF would be more impresive because you could bounce that sucker half way accross the world but you crazy antenna configs like sloping V's and such. Then you would have to worry about weather, TOD, and the infamous sunspots.
I am always surprised that satalite internet never really took off in that more people could access the same bird regardless of remote thier location and steup is pretty minimal while the range is outstanding.
But really sucks is when you have to carry them...
It's all Politics
Let's see them push this streaming chrismas carol over their VHF connection :)
Also, the article had this quote which I found interesting: Dr Borg said, any possible license conflicts - with digital radio advocates, and with the remaining users of the appropriate spectrum - would have to be resolved..
I wonder if the resolution will sound like this? All your VHF Bandwidth are belong to US! Resistance is futile. We will use your bandwith for irrelevant Christmas Music Remixes.
Ding Fries are Done! Merry Christmas!
Look in 1xRTT ie the current 3g offerings by Verizon Wireless and Sprint we use 1.25Mhz of bandwidth and we can push 155kbps.. I even think our EVDO pushes that envelope further.. so I'd think you could do more on 7Mhz of frequency
As a transmission engineer, you should already know that, in the US, that part of the spectrum (45MHz +/- 3.5MHz) is already allocated and HEAVILY used by all kinds of two-way land mobile radio systems. In fact, the band is sliced up so that even various Federal agencies (including the military) are using it. TV starts at 54MHz, and those frequencies (TV channels 2-59) will be used for HDTV.
Go read 47CFR Part 2...
FAQ...etc.
CC.
TaijiQuan (Huang, 5 loosenings)
Yes they do. I am a licensed amateur radio operator (with moorse code, a nifty skill to have, though now kinda useless lol). It is called packet radio. I myself haven't gotten into it, but it is a different protocol which you can tunnel others through (tcp/ip). Some are internet repeaters, basically hooking up their cable modem to their ham radio. Problem is, that only one person can transmit at a time, collisions aren't too common though.
If you are about to mod me down, keep in mind that this post was most likely sarcastic.
This might fly in Australia, but probably not in the US or other large nations. The radio spectrum is a limited resource and as such, a highly competitive one. Amateur radio operators (myself included) are constantly trying to defend our allocated bands here in the US against commercial entities who would like to have it for their own usage. I don't see a system that uses this much bandwidth being practical for US usage.
Also, MUCH less bandwidth. 1200 baud is still quite common, and 9600 baud is newer technology. Regonal backbones are frequently 56k.
17W of power to get 40km?
I use/test/setup equipment that goes 50km at 0.5W of power. OK, they're using a non-optimal antenna, but the antennas really aren't that expensive. 17W would kill a bettery quick. No surfing for pron at night anymore.
200kbps is interesting, and as Bruce Perens mentions, they should have been able to get a lot more bandwidth out of the spectrum they are using. None-the-less, they could be making a robustness/raw data rate tradeoff in the modulation scheme. I am probably just blind right now, but I can find any real details on any of the linked to.
One comment above askes about inter-city propgation, and whether this technology would/could be an answer. I think 3G and or 802.15(MAN) are better because they have been designed for intercity communications, and meet or beat the 200kbps mark, which much less power used (this is very important!)
Any aussies here know what would be using channels 0 and 1? Did Australia follow the US when it reallocated the frequencies back in the sixties? I can't even remember what channel 1 got reused for here in the states. I think it was business band radio like for taxicabs and such.
Liberals call everyone Nazis yet they are the closest thing to it.
You would get more bandwidth as well.
AU has few people so they have more unused spectrum to play with.
I would think a higher frequency and better enginering would yield better results.
At around 45 Mhz the antennas are still quite large though the signal does tend to travel well over hilly terain in this frequency range and it can propigate via the E layer at the right time of year as well.
Well at least it's not in the middle of the Ham bands for once (being a Ham myself.)
If you don't like what I write don't be a CS and mod it down. Refute it.
Yea I can't spell. So what is your point?
Analogue television channels in Australia are 7MHz wide. The channels of interest are between 45 and 75MHz. BushLAN is not necessarily tied to using a particular block of spectrum, or an entire television channel. BushLAN subdivides available spectrum into 300kHz channels. As always, there is a tradeoff between transmitter power, communications range, and the data rate.
Using two 300kHz channels [for a symmetric full-duplex connection] low power, relatively short range links with a raw data rate of 115.2kbps have already been created.
As to propagation. VHF achieves beyond line of sight range whereas microwave links are limited to LOS. Long distance propagation is largely due to diffraction over hill tops. Atmospheric attenuation is much smaller at VHF (wavelength is roughly 6 metres) than it is at microwave frequencies (wavelength: ~10cm). This allows greater reliability during adverse weather conditions.
Great. So first I'm +1 Funny, then -1 Troll, and then -1 Overrated. If I'm a 0 Troll, how can I be Overrated? Sometimes moderators don't make a whole lot of sense.
The higher the technology, the sharper that two-edged sword.