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Forty-Five Mile Wireless Tech For the Smart Grid
holy_calamity writes "San Diego startup On-Ramp Wireless has put together a proprietary protocol that sends data over 2.4GHz (like WiFi) but over distances of up to forty-five miles. Links using the technology are slow, 50bps at most, but could reduce the cost of smartgrid deployments. Connecting up home energy meters today requires using cell networks or unlicensed spectrum with much shorter reach."
With a 45-mile line-of-sight link, sending 50 bits/s is hardly an achievement, especially when the antennas used are not specified. With a data rate that is "roughly 100,000 times less than the average U.S. broadband speed of five megabits per second", each bit has roughly 100,000 times more energy than bits in an "average U.S. broadband" signal -- which has the disadvantage of having to traverse a non-line-of-sight path.
On-Ramp Wireless may have some interesting technology, but this is not the way to advertise it.
Next stop, Dropping your phone for iPod VoIP service.
the interesting stuff would be to know how many such nodes you could fit on 10km x 10km square and still have the one's in the corners able to talk to each other. and what kind of chips you need for it? because, cellphone networks sound much better suited for the power meter etc use mentioned..
world was created 5 seconds before this post as it is.
I hope this isn't another service which may impair other devices working in the 2.4GHz range. That's got to be a strong signal.
A feeling of having made the same mistake before: Deja Foobar
So I could DOUBLE my speed with a 110 baud modem?
I don't understand why you would use something with this kind of range in an unlicensed band.
You are basically setting yourself up to fail when you get interference all over your supposed coverage area.
"No one is more miserable than the person who wills everything and can do nothing." -Emperor Claudius 10 BC - AD 54
The technology can even pick up signals that are weaker than the surrounding background noise
It sounds like they reinvented JT65.
-molo
Using your sig line to advertise for friends is lame.
The application for this is reading power meters and other continuous but low-bandwidth data. These generally operate in a mesh network. The devices used are generally low-cost and low-power, often in the "Part 15" section of the FCC rules for low-power devices that aren't allowed to interfere with licensed services. The problem is that some homes are too far from any other to link into the mesh, and the expense of reading those meters goes up significantly.
Signal processing theory allows you to trade bandwidth and time for range, such that a signal with a wider bandwidth or longer duration can be received over a greater distance. Hams have been doing this for decades using ultra-low-speed morse, PSK31, and other digital modes.
The achievement isn't really getting a long-range link, you can get 45 miles between mountaintops with wifi and parabolic antennas on a clear day. The achievement would be doing this for a very low installed parts cost and in unlicensed spectrum (which also reduces cost) while avoiding interference from wifi etc.
Bruce Perens.
Isn't the record for WiFi over 100 miles with amplifiers?
Isn't the record for WiFi about the same as this without amplifiers, just using bigass dishes?
Is there any actual need to have quite this much range for this particular application? Wouldn't it make more sense to just use mesh networking? Wires don't tend to run 45 miles into nowhere to serve a single customer.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
When I was growing up we would have just walked there. In the snow. Uphill. In both directions.
Having to work for a living is the root of all evil.
I tried to work out a way to semaphore at 50bps, but it can only be done if you prepare lots of colored flags lined up on a table so you can quickly grab the right one. That seems like cheating. The best practical one-person encode for just waving flags I can find is 9 bits per second. If you had six people waving flags at once, though... that would do it.
More seriously: Why is this being done in 2.4? Even if the customer utilities are too cheap to licence a little spectrum for themselves, there are ISM bands further down. There's one around 40MHz that should be perfect.
if only we could find a way of connecting to all of these electricity meters with wires somehow...
Nullius in verba
seriously, use mesh wherever possible (this would me more intelligent, as devices near each other could communicate and decide when to ramp up energy use for things like dryers so two neighbors don't both start dryers/hot water/dishwashers etc when they are in energy saving mode and would also limit the local ground noise for ham/short wave). For anything too far out of way to use mesh use power line communication.
Get a web developer
Why do they need to be wireless? They're coupled to an inherently wired technology, can't they use the power wires to transmit the signal? Isn't that how smart power meters work?