Slashdot Mirror
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."
...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."
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.
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.
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?
Narrowband: less than 2Mbps (POTS, ISDN, etc)
Broadband: greater than or = 2Mbps.
Most DSL lines work at under 1Mbps (home users don't need more and it's damned expensive if telcos offer it at all), but in full flight, it can reach around 8Mbps, so it's technically broadband.
One man's *near* broadband is another man's 2B+D.
I believe than in Australia Telstra urged the government to defind broadband as "128Kbps and up" so that they (Telstra) could then claim that (whatever the exact statistic is) the vast majority of Australians have access to internet at broadband speeds.
Something to do with Telstra being legally required to provide said "broadband" coverage, by a certain date, or be subject to fines/limitations on expansion into other markets/or something.
No surprises here, just Yet Another Big Business redefining reality so that they can wipe their hands of their legally bound responsibilities and rape their customers for further profits.
Visit CryptoGnome in his home.
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.
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.