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A peer to peer mesh network based upon wireless unrestricted ultra wide band (UWB) technologies (such as unresticted http://time-domain.com/ has huge potential. High bandwidth rates over vast distances (20km+) between nodes with excellent obstacle penetration (due to the UWB). Since these devices are essentially digital pulse technology over a wide frequency band without the use of a power applifier in the transmitter they use very little power, about 1/1000 the power of a cell phone; yes, 1/1000.

The key is that it needs to be unrestricted; unfortunately the technology has been clamped down by the military in the USA (through the FCC) due to it's awesome capabilities for combat and other military applications. As a result most UWB devices for civilian use have extremely limited range. Also the detailed technical papers that were up on the Time Domain (Pulson) web site that explained the technology were removed (anybody have copies?); now the web site is little more than a lame product site.

Some of the military applications include: radar, secure and long range communications (many times greater than the best WiFi), accurate tracking (to the centimeter at 20km), imaging through walls. Another aspect that the military likes are the stealth capabilities of UWB which is very difficult to detect (with current technologies) since it appears as low power background noise (a.k.a. static); you have to know the transmission encrpytion codes to know how to decode which frequencies are the real ones at any moment. This also makes it highly secure. With these characteristics is no wonder that those in power don't want those not in power getting a hold of the full capabilities of this exotic technology.

The beauty of this technology is that it's perfect for creating self forming mesh peer to peer networks. It was the range, obstacle penetration, low power usage, and bandwidth needed. It's also all digital from the start. The low power enables the use of units placed in remote strategic locations with solar pannels to provide bridges and hubs into remote communities or in countries in the process of building an internet and voice based communicaitons infrastructure across wide swaths of land.

Imagine having a cell phone network where you didn't have to pay provider! Of course there could still be providers but an open commons would be best. Each cell phone in the network extends the range and capacity o the network (unless all the units converge at the same location).

Now maybe there are merits to having paid networks, after all we are in a capaitalist society. This can be built in and the costs computed and shared by the supplier routing paths with the supplier nodes bidding in real time for your communications. This can ride atop the existing protocols that compute the "cost" of network traffic. Of course anyone is free to provide true "network peering" arrangements. So there would be the need for open source communications licenses.

The major problem is that this needs to be approved by governments in various countries around the world.

The all the development going into WiFi maybe we'll get something similar and then make the jump to UWB once the hardware and software is ready for advanced mesh networks such as described above. The Dlink MiMo router is a step in the right direction at least in terms of range with its extra power; however it can only reach long distances with a directional antenna - UWB is generally omni directional. Imagine the range with a directional antenna.

Lobby your technology companies, your elected representatives, and your departments of your government that control communications and technologies in your country to allow for the best possible civilian capabiliites. DO NOT do this if you think you'll end up in jail or be put under survailance by your big brother style government - it's not worth the risk to your life as the next generation of WiFi units are likely to have the mesh portion put into them anyhow.

I know TimeDomain was pushing pretty heavliy into the Ultra Wide Band technology before it was fairly well known.

Last I heard they were in litigation with one of the national labs over IP. I'm not sure what the outcome is, but from the look of their website it looks like they've been pushing ahead in their research for more than just radar, but also for comms systems.

I think several (highly modded) contributors to this discussion are confusing
the concepts of information bandwidth and frequency bandwidth. Ultra-wideband
refers to the bandwidth in the frequency domain, which is only indirectly
connected to the concept of information bandwidth, in that a wide band in
the frequency domain translates to narrow pulse in the time domain. Coding
techniques also strongly affect the ultimate information bandwidth of the
system. UWB is nothing like IEEE 802.11b,
which operates in the narrow 2.4 GHz - 2.483 GHz band.

I have been working on a project for US Army STRICOM,
in which we are using 8 UWB devices manufactured by
Time Domain Inc. to perform position location. These devices
operate at 1.9 GHz center frequency with a 2 GHz bandwidth,
which translates to a 500 ps pulsewidth.
We have a short conference paper on UWB simulation, accepted for presentation
to the 2002 IEEE Antenna and PropagationSociety Symposium,
which you can access
here. Speaking in general and rather simplistic terms, the information
bandwidth of such a system would depend of the time frame over which you
will allocate these 500 ps slots to listen for the transmission of 1 bit
of information. For example, if we choose a 5 ns time frame, then we
could theoretically obtain 200 Mb/s information bandwidth, while (ideally)
allowing for 10 channels of operation. Of course, the previous analysis
neglects the need for redundancy, and you may want to choose a time slot
over which to listen for a pulse different than the pulsewidth itself, but
I think the discussion gives one a good idea about how to relate information
bandwidth to frequency domain bandwidth in a simple communication system.

Where do they get these guys? First he says that it doesn't use any spectrum...then he says that anything below 2 GHz will interfere with existing Nav and Comm systems. Gotta be one or the other. Can't be both.

Yes, it can be both

UWB works by sending single-cycle pulses. The information is carried by when the pulse is transmitted with respect to a reference.

Since there is no carrier, it doesn't affect a specific part of the spectrum. However, since there is no carrier, it affects all parts of the spectrum by adding to the noise floor. That is what the big problem with this technology is and why the FCC is looking so closely at it. The UWB Consortium has more information.

Personally I don't see a problem with raising the noise floor for this technology because, as I understand it, it raises the floor uniformly and, if I understand this correctly, the actual number of devices transmitting doesn't play into this.

I've been interested in this for a while. Time Domain (warning, flash-heavy site) is a company which has been playing with this for a long long time. I was rather skeptical of this when I first heard of it but my opinions on it are changing. Hell even EDN had an article on it.

The only thing I don't quite grok is how they can get two devices to have such rock-solid stable time references (we're talking sub-picosecond jitter) without secondary clock transmitters and keep them that way. If anyone out there can help shed some light on it I'd love to hear from you.

I've been keeping my eye on Ultra WideBand for a while now; it has very surprising uses in positioning, communication and measurement. There's even a working group which tries to keep tabs on the entire area.

Years ago I heard about time-domain. I don't work for them but when I first heard of them I thought it was vaporware. I'm kind of sorry I didn't take them seriously the first time around.

The concept is simple, you can use any peer to peer radio communications system. But the stuff from www.time-domain.com looks the best.

With the time-domain stuff, anything can have private communications and location detection within centimeters. The key is to use a cooperative protocol that allows units to relay traffic for units not in range of each other. Actually, you have low power units, which only talk to other units, powered units which perform relay functions a well, and high power units which can compute routing decisions.

In a metropolitain area, like the San Francisco Bay Area, high speed IP access and phone service is free. Its not hard to imagine most homes having 1 to 5 devices that would do relaying and are idle most of the time, of course, this would take a few years for adoption. To get non-local access you gateway via your own home DSL, Cable, or other Internet connection. Alternatively, you buy connectivity out of the metropolitain area network from a communications provider, such as MCI, Sprint, etc...

Essentially, cell phone calling becomes free, you only pay for the phone, the power, and long-distance Internet access.

Since you can determine geographically where transmitters are, you can also track all property containing these devices. If a TV, with a small battery, is on its way from the factory to you and it leaves its expected travel route (at least in areas where there is coverage) an alarm could trigger. More importantly, if your child left school during school hours, or left the route to or from home you could be informed.

There are a couple of open source radio relay protocols that may sound similar, but I can never tell if they get the whole picture-- even after I send this description to them they don't reply. Go figure...

Arthur Britto
ahbritto@iat.com
-
I have lots of ideas, like this one, that make business sense yet never get fully developed. Other ideas include: a micro/macro transactions system, trusted Linux security solutions, performace based Internet advertising, anonymous file storage/sharing, etc...

When I approached time-domain with the concept, they reply was essentially: go away we don't want to talk to anyone now, we are busy patenting things.

Have you guys seen what Time Domain is up to?

They've got a technology to use the spectrum differently. Right now, information is transmitted by sending out continuous waves while modulating their frequency, and we've pretty much reached the limit of how much information we can send in one chunk of the spectrum.
These guys have a totally different idea -- instead of a continuous wave, they use wave pulses, millions pers second or more, I think, to transmit the information.

Any physics folks here have any idea about the potential? They claim it has a lot.

Have you guys seen what Time Domain is up to?

They've got a technology to use the spectrum differently. Right now, information is transmitted by sending out continuous waves while modulating their frequency, and we've pretty much reached the limit of how much information we can send in one chunk of the spectrum.
These guys have a totally different idea -- instead of a continuous wave, they use wave pulses, millions pers second or more, I think, to transmit the information.

Any physics folks here have any idea about the potential? They claim it has a lot.

Uhh. . .perhaps you've heard of this new thing called hyperlinks? It's this great thing you put in text that readers can click on and go to whatever you're talking about. Kind of like this: www.time-domain.com


--

'Impulse radio' is a lot more than just an "interesting wireless link," it is a technology that will revolutionize our use of the radio spectrum. Rather than transmitting information as modulations in an analogue radio wave's frequency or amplitude (FM or AM), Time Modulated Ultra Wideband transmits information in RF pulses (called monocylces), positioned with an accuracy of trillionths of a second. It operates with just miliwatts of power, yet signals can be received for over a mile.

I first read about TimeDomain several years ago. The technology sounded pretty much ready to go, but they were being stymied by the vast regulatory bueracracy that is the FCC (selling radio spectrum is a cash cow, and if you were the FCC, would you eagerly antiquate a profitable revenue stream?). TimeDomain was also duking it out with an Alphabet Soup Government agency (one of the national laboratories?) over who had patent rights, those issues have recently been resolved.

There have been some comments about bandwidth congestion - ultrawideband technology will virtually eliminate all such concerns. Sending out around a milliwatt of power, spread over several GHz of bandwidth, makes it difficult to tell the difference between signal and background noise.

TimeDomain's homepage - http://www.time-domain.com/
The Ultra Wideband Working Group site - http://www.uwb.org/
NY Times Article (1998) - http://www.n ytimes.com/library/tech/98/12/biztech/articles/21t ime.html
Time Domain's Coverage in national media - http://www.time-domain.com/news/newss ect.html

'Impulse radio' is a lot more than just an "interesting wireless link," it is a technology that will revolutionize our use of the radio spectrum. Rather than transmitting information as modulations in an analogue radio wave's frequency or amplitude (FM or AM), Time Modulated Ultra Wideband transmits information in RF pulses (called monocylces), positioned with an accuracy of trillionths of a second. It operates with just miliwatts of power, yet signals can be received for over a mile.

I first read about TimeDomain several years ago. The technology sounded pretty much ready to go, but they were being stymied by the vast regulatory bueracracy that is the FCC (selling radio spectrum is a cash cow, and if you were the FCC, would you eagerly antiquate a profitable revenue stream?). TimeDomain was also duking it out with an Alphabet Soup Government agency (one of the national laboratories?) over who had patent rights, those issues have recently been resolved.

There have been some comments about bandwidth congestion - ultrawideband technology will virtually eliminate all such concerns. Sending out around a milliwatt of power, spread over several GHz of bandwidth, makes it difficult to tell the difference between signal and background noise.

TimeDomain's homepage - http://www.time-domain.com/
The Ultra Wideband Working Group site - http://www.uwb.org/
NY Times Article (1998) - http://www.n ytimes.com/library/tech/98/12/biztech/articles/21t ime.html
Time Domain's Coverage in national media - http://www.time-domain.com/news/newss ect.html

Here is a list of other interesting wireless links
found at FreakTech

Plasma antennas are radiofrequency antennas that employ plasma as the guiding medium for electromagnetic radiation.
DIRC is a self learning, intelligent, and self organising network of small transmitting and receiving stations.
Impulse Radio a whole new wireless medium.
AIRNET Adaptive Interferometric Radio Network Enhancement Technology.

Actually, there is a group in Alabama who have developed time modulated ultra wideband chips that promise extraordinary wireless bit rates and nearly perfect security. Check out Time Domain. In addition to wireless LAN, you can use the stuff for pocket sized radar (see through walls!) and GPS to within centimeters! Anyway, I think it looks cool and haven't yet seen a story about it on /. (I submitted it 10 months ago, though)

It's too bad, too, because I'd like to believe in them! The idea of an undectable, unjammable, milliwatt radio that works over a hundred miles is enticing. Ultra-wideband radars that detect anything is exciting. These things should be possible, but are hard to realize.

There's a company called Aetherwire that was mentioned in /. a few months ago. They've actually got some reasonable working pulse-radio hardware.

This reminds me of the pulse radio technology.
Measured before on slashdot.org and FreakTech
Maybe they have combined the pulse radio technology in a power grid modem.
The companies claim of gigabit/s is far faster that the europaen experiments, whish have transferee speed around megabit/s.
Knud

There's a lot of really cool stuff happening out there. One of my favorites is incubating down in Huntsville Alabama. If their stuff does what they say it will, then Time Domain will revolutionize wireless communications and a bunch of other stuff too!

"Content provided in this web site contains internally prepared forward-looking statements. Such forward-looking statements are subject to numerous risks and uncertainties which could cause actual results to differ significantly. Information presented in this web site should not be considered an offer to sell or a solicitation of an offer to buy securities from Time Domain Corporation."

It's a "don't-sue-us-this-is-Sci-Fi" statement. Doesn't that really tell you what these snake-oil salesmen are all about (and after?)

The trekker in me would love to see some of this stuff work. I will admit -- some of the applications worry me. Who says (without sounding too paranoid) that certain factions (cough) NSA (hack) don't have these capabilities right now?

"Content provided in this web site contains internally prepared forward-looking statements. Such forward-looking statements are subject to numerous risks and uncertainties which could cause actual results to differ significantly. Information presented in this web site should not be considered an offer to sell or a solicitation of an offer to buy securities from Time Domain Corporation."

It's a "don't-sue-us-this-is-Sci-Fi" statement. Doesn't that really tell you what these snake-oil salesmen are all about (and after?)

The trekker in me would love to see some of this stuff work. I will admit -- some of the applications worry me. Who says (without sounding too paranoid) that certain factions (cough) NSA (hack) don't have these capabilities right now?

The Companies web site can be found at http://www.time-domain.com
Privately held.... for how long?