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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?
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
Click the pencil/paper icon on the right hand side of the bar above the first comment. There's a pref for the old system.
Took me about 15 minutes to find it, since it wasn't in my user prefs.
(I'll stick with my modified 10-meter 1KW CB radio ...)
This article questions the validity of the company.
"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.
If the FCC was a local health and safety authority, the approval process would go something like this:
FCC: We see, Mr. Cacapoopoo, that your sewer technology takes raw human waste and dumps into rivers and aquifers.
Mr. Cacapoopoo: Yes, that's correct. My patented OneTube sewer device takes a large pipe from underneath each toilet and then promptly dumps into the nearest reservoir of drinking water.
FCC: And you've tested to make sure that this doesn't cause people to get sick.
Mr. Cacapoopoo: Oh my, yes. Our research shows that the human diet can be 1/3 fecal matter without any adverse health affects. I have a degree in Public Health and Theology from Patriot University, so you can believe me.
FCC: Well, Mr. Cacapoopoo, I'm overawed by your colorful diploma and your clearly laid out plans. I see no reason that you can't begin installing the devices as soon as possible. Would you like a glass of water?
Mr. Cacapoopoo: No, I only drink cream soda.
The world's burning. Moped Jesus spotted on I50. Details at 11.
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.