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In Florida, a Cell Phone Network With No Need For a Spectrum License
holy_calamity writes "Technology Review reports on a cell phone network in Fort Lauderdale, Florida, like no other. Instead of paying to reserve a section of wireless spectrum its owner, xG Technology, uses cognitive radios that steer signals through the unlicensed 900MHz band more normally used by cordless phones and baby monitors. The radios in both handset and base station scan for gaps left by other devices in that band and make dynamic connections that constantly hop frequencies to ensure a good link. The network is designed to show off the tech, which the company says could be used in conventional cellphones to access extra spectrum or white spaces devices."
and does it use a lot of "femto-cell" style towers? It would seemingly have to. Meaning, how well would it work in a car?
2^3 * 31 * 647
It's never going to work in the long term. I work for a wireless ISP, and our 900 mhz band is getting killed by utility/electriticy companies rolling out things like smart electric meters that exist in every home and do the same thing: hunt for the least noisy band and transmit. We've seen noise floors in the -40s straight across the spectrum on our worse days. We can't beat the noise more than a couple of miles from a cell tower using fixed, directional antennas. What makes them think they can beat it with tiny, handheld devices?
(zap)
Goodbye football game. I can easily imagine this device broadcasting directly over long-distance channel 17 while I'm trying to watch the game (or movie or Glee or whatever). The device will think the channel is "free" because it cannot detect it, and start broadcasting on 17, but in reality it will be occupied.
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>>>Feedback on this comment system?
Yeah it sucks. And it's slow (CPU intensive). And I can't get back to the classic (plain text) index even though I've un-checked and checked it multiple times.
"I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
You have to wonder, with all of these devices that use the rather spread-thin (no pun intended) "free" spectrum, just how much bandwidth is left in your average area? What with everyone's WiF, cordless phone, microwave, bluetooth, etc. devices running constantly, are we reaching a point where "free" consumer spaces simply need more bandwidth?
the system could augment emerging networks that operate in the unlicensed "white spaces" recently freed up by the end of analog TV broadcasts
The only channels "freed up" when US NTSC ended was 52-69 and they've already been designated for Cellular and Emergency Radio usage. These gadgets are verboten from broadcasting in that area.
A recent study by University of California-Berkeley academics revealed how the density of TV stations in metropolitan areas could reduce the availability of white spaces in such areas.
That's true. The "whitespace" idea only works in rural regions, not heavily-populated areas like the North, northeast, or mid-atlantic which use every channel from 1-51 (including the FM band).
"I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
(I'll stick with my modified 10-meter 1KW CB radio ...)
This article questions the validity of the company.
Americans are in a good situation here that an unlicensed 900MHz band even exists. This could be the proving grounds for a future distributed/mesh based mobile telephone network.
For now the only decent BTS an 'ordinary' consumer can get their hands on is USRP/OpenBTS which costs around $1000. The idea of normal people running a mobile network has been pretty much suppressed everywhere else so it would be interesting to do some long term real life testing with real users if its perfectly legal so the concept might gain some steam
Forget the company. I don't want anyone clogging up any unused unlicensed frequencies and causing interference for every other device that does use that space. It's unlicensed for a reason and that reason isn't so some douche can sidestep going through the proper channels to set up as a carrier whilst hosing everyone else's use of those frequencies.
These posts express my own personal views, not those of my employer
>>>The idea of normal people running a mobile network has been pretty much suppressed everywhere else
What do other regions (like EU) use the 900 MHz band for? According to wikipedia the US allocation is only 5 TV channels wide, so not a huge amount of room for data usage.
"I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
"Cognitive radio"?
A protocol that continually finds and hops to not-interfered-with frequencies is perhaps "intelligent" in a generic sort of way, but calling it "cognition" is a bit weird. It's pretty standard communications-theory stuff.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Try GE MDS Mercury 900MHz systems. We're getting between around 300-500Kbps average up and down between moving vehicles and the nearest access points almost anywhere in the whole city. Fixed locations such as traffic light controllers with small yagi antennas pointed back to an access point tower site easily hit 900-1000kbps symmetrical bandwidth up and down.
This company lies all the time. The company I work for tested this tech a few years ago in Missouri, but It was a failure. They have been trying to sell their product for the past 6+ years.
We use it for licenced GSM cellphones. In the UK, Telefonica O2 and Vodafhone operate on that band.
should be using licensed spectrum. I know these guys all want to use the same radio that's built into every device, but commercial operators competing to drive up the noise floor does no-body any good. Pretty soon there won't be any gaps in the spectrum to be found - these radios will not be so "cognitive", "sentient", "feeling" or whatever the crap they claim to be when they have simply made ISM, U-NII and other unlicensed bands unusable.
Nullius in verba
Assuming this works, does the frequency hopping make this kind of system more secure?
Oh goody, now we can block even more of the spectrum from scanners and owning an old scanner will be illegal.
To be clear, in Europe, the 900MHz band is currently used for straight GSM and EDGE. UMTS/WCDMA (GSM 3G) runs on the 1800/2100 MHz band pair. In the USA, the AWS band pair (used by T-Mobile) is a subset of that. It uses the lower half of the 1800MHz for uplink, and the lower half of the 2100MHz band for downlink (which is why it is referred to as the 1700/2100 MHz band pair). T-Mobile uses the 1900MHz band for GSM, but also supports the 850MHz band for roaming, since AT&T uses that band. AT&T's UMTS bands are 850MHz OR 1900MHz. Most areas use the 1900MHz band, but rural areas use 850MHz.
Ricochet did this in the 900MHz band using spread spectrum a decade ago, for wireless Internet access. They put up little nodes on street light poles, using a deal where the municipality got free data access. It worked fine, but only delivered dial-up speeds, so it was overrun by DSL and cable. Even back then, getting around narrowband interference was no big deal.
this is how the wireless functioned on the Enigma and was used by early cellphone companies that were all sued for killing babies
that Slashdot now needs a "Florida" tag?
The technology has existed for ages in the 2.4Ghz band, and it's used for radio control things.
Strap on your tinfoil hats, people, because this time it's the real deal!
Does this mean later, cell phone co can actually use this technology, and lower their prices, or will they just use this, and still charge us an arm and a leg.......as we ARE the world's most highly charged for cell phone calls in the world.
If this ever caught on all it would do is make the 900mhz band so crowded as to be useless and still not even take a significant number of cellular users off the existing networks.
These company behind these 'tests' appear to be complete and total frauds:
Google "Marc Dannenberg" and see some of the following:
http://xgtechnologyscam.blogspot.com/
After N.C.R. was closed down Dannenberg goes freelance, selling the shares of xG Technology, whilst projectile vomiting about xG all over the internet. Some of his ramping about xG going to $100 a share would make a psychologist gasp. (Check out the back records of iii.co.uk and look for Marcsanpedro.) All the time he was ramping on the bulletin boards and attacking any critic he was selling xG shares to unfortunate investors - even though he was not licensed, or ‘officially’ employed by xG. But these shares weren’t free market shares. Oh no. These shares are ‘Regulation S’ restricted shares owned by one of the xG Directors Palmi Sigmarsson.
Someone else mentioned this article earlier too:
http://www.ka9q.net/xmax.html