There's a web site "time_domain.com" for a corporation holding the fundamental patents on Gaussian-wavelet radios. (Also search for Gaussian wavelet radio, or pulse radio)
Their technology works by making a wiggle of electromagnetic field. The central wiggle is <2ns wide. The average energy is 500 microwatts, but the peak energy is about a thousand-watts because the pulse is so brief.
The high peak energy means that a radio that transmits 500 microwatts can be received more than 10Km away.
The information is conveyed by sending periodic pulses, and shifting the pulse position a few nanoseconds forward for a zero, or a few back for a one. The center timing of the next wavelet is determined by a pseudo random sequence, so that each channel is private, and there is no periodic energy component to interefere with conventional coherent radio systems.
The technology resists fading because it transmits single pulses, whcih do not cancel in the way that classic coherent sinusoidal radio waves do.
The technology resists multipath interference because the receiver resynchronizes with the transmitter whenever a reflection changes the timing. Eventually the synchronization sticks with an unchanging reflection.
The technology permits location within a few centimeters because the central peak of the wavelet has features that can be distinguished within 30 picoseconds. The unchanging reflection tends to be a shortest-distance path.
Time Domain Inc. recently completed prototypes of a single-chip modem using IBM's new silicon-germanium high-speed IC process. The wavelet is perfect for digital technology, because it so strongly resenbles a noise wave created by digital logic.
The technology is currently illegal because it intentionally creates radio energy in safety-critical bands used for aircraft navigation and communication, including GPS. In practice these interferences might not be important, but the FCC currently forbids intentional emission, while permitting accidental emissions from computers and motors (which produce very similar wavelets). Industry comments mostly point this out, and point out high-attenuation of such wavelets in urban places, and then ask for a relaxation of regulation by intent.
There is an industry web site for UWB radio that has the FCC's request for information, and a series of industry comments. It's all vewry enlightneing, but I forget the industry web site, which is also available in a link from time_domain.com.
On Fri, 28 May 1999 12:01:29 -0400 Michael Wiik <email@example.com>
>Pardon my ignorance, my first exposure to localizers was in Vinge's
>_Deepness in the Sky_. Recently Bruce Sterling (via his Viridian Green
>list, not terribly extropic) posted a speech he made at SIGCHI 99
>future household localizers. Here's an excerpt:
>This idea is probably best filed under the grand
>conceptual heading of "tangible cyberspace," i.e., the
>process in which the products, programs, and innate nature
>of virtuality spill out of the computer screen and infect
>the physical world.
> People used to talk about "wiring the home." This is
>old-fashioned rhetoric now. Turn the term inside out, and
>it becomes "sheltering your network." It all becomes clear
>if you postulate that the net always comes first. My
>physical possessions are an aspect of the net.
> Today, right now, if you objectively compare my
>virtual possessions to my actual possessions, it rapidly
>becomes obvious that my actual possessions are violently
>out of control. I have all kinds of searching and
>cataloging devices and services for my desktop machine,
>and for the Internet. But I've been known to hunt for my
>socks or my car keys for almost an hour.
> My house is an awful mess, because my actual
>possessions are very stupid. They don't know what they
>are, they don't know where they are, and they don't know
>where they belong.
> All this could change with a small, cheap, network
>peripheral which is, I believe, just barely over the
>technical horizon. The device I imagine is very similar to
>a common antitheft device, but much smarter. We could
>call it a "tab," or a "localizer," or a "locator ID tag."
> I imagine this locator ID tag having about a hundred k
>of memory and costing about ten cents. It probably runs
>on household temperature fluctuations. Its primary
>activity is to emit a unique radio chirp every two seconds
>or so. This chirp is triangulated by a network of
>receivers in my house and my lawn. Basically, the chip
>says, "I'm what I am, and here's where I am," in other
>words, "I am Bruce Sterling's left cowboy boot, and here I
>am under the couch where the cat dragged me."
> Fine, you think: you're tagging everything you own,
>how anal and geeky of you. No, that's not how this works.
>I'm way too lazy to work that hard. Instead, I pay a
>professional interior designer to come in and tag
>everything for me. I pay this guy (most likely she's a
>very smart woman actually), to catalog and tag everything
>I own, and put it where it sensibly belongs == and record
>that data, and embed it in my system for me.
> Now I know nothing, but my house knows where all my
>stuff is. My possessions know what they are, and where
>they belong. Unskilled labor can enter my home, and
>restore everything to perfect order in maybe an hour.
> And of course no one can steal any of it, because
>it's all security tagged, automatically.
>Searching the web produced no useful hits on localizers. I would
>appreciate any references. I'm also interested in the intersection of
>localizer tech, nanofog, and, (as per _Deepness_), the idea of
>ubiquitous law enforcement, where (paraphrase) 'every object becomes a
>Messagenet Communications Research
>Washington DC Area Internet and WWW Consultants