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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."
...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."
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.
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.
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?
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.
That's not entirely true.
In the land Down Under, Telstra is the dominant telco, and it's currently 51% government owned. The current Liberal Party (think: nice Republicans)-National Party (think: farmers) coalition government really wants to flog off the rest. The problem is that Telstra provides many services to the underpopulated areas (aka "the Bush", who are generally represented by the National Party half of the Coalition) that really don't make much economic sense but make a lot of political sense. Also, it's sort of halfway decent that the outback farmers get at least a phone service. Anyway, every man and his dog knows that if Telstra gets fully privatised, *bang* there goes any semblance of service to the bush, since it is just not econmical.
To that end, the government has brought in a Service Guarantee (including Universal Service Obligations) that says (amongst other things) Telstra must provide certain minimum standards to all subscribers, and if they don't they get smacked. The government hopes that after a few years we'll all see what a good corporate citizen Telstra is and give the Libs the OK to flog off the other 51% of Telstra.
Now, one big complaint from the bush is that they get bugger all access to broadband. Even getting net access at all can be tricky for them. Satellite (if available) is very expensive. This would almost certainly not improve under a toally privatised Telstra. However, if Telstra could provide near-broadband to the bush without having to string up hundreds of miles of cable, things would again be looking promising for the privatisation thing to be on the agenda again.
Speaking from a purely Australian voter/taxpayer POV, the keyphrase is the National Party might be the junior member of the coalition but they can wield a fair amount of power over the Libs when they want to.
.When they came for the communists, I said "He's next door. Take him away. Goddam commies."
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.