Hi
Rick,
I've been working in the UWB industry for awhile, so I'll make a few
clarifications to your excellent overview of the technology.
UWB
has been around for decades, and actually has been, (and is) utilized far beyond
10Ghz. The FCC First Report and Order exactly a year ago today, capped it
for commercial usage at < 10Ghz, and above 3Ghz which is above the crowded
micowave and air traffic control. Subesequently another notch or exception
was presented to vendors in the 6-7Ghz range. Additional limitations
imposed by the FR&O is that the technology be used for indoor use only at
this time, and connections be point to point only.
If you
calculate the channel bandwidth with Shannon's Theorum, you can potentially have
~7Ghz, vs < 500Mhz channels of today's WiFi channels, so the scalability
potential is enormous, while WiFi solutions in the 2.4 and 5Ghz ranges
theoretically max out at ~25mbps, and ~75mbps, with the currently approved
encoding defnitions.
The
802.15.3a High Speed bluetooth extensions have not yet been ratified, but
several vendors want to cap it the highest speeds for interoperability, not at
100mbps, but at ~500mbps and beyond. These throughput ranges may not be
realizable at WiFi distances, but they may be usable for extremely short
distances such as between a PC and an adjacent printer.
There
has not been a set "distance limit", but there are limitations on gain, and as
mentioned above on spectrum usage. There are several emerging technologies
that may, within the allowed spectrum, allow for longer ranges than 10m.
HDTV has several approved modes, and can also be MPEG2
compressed. 20Mbps is an extremely high compressed rate. Typical
consumer gear of 1080i and 720p modes with high motion (e.g. sports) will likely
need upwards of 30-40Mbps. Some of the first JVC HDTV tapes, offer
throughput rates of up to 60Mbps.
Multispectral and Time Domain has been focusing on military, and
healthcare solutions for asset tracking. Xstremespectrum and others are
focusing on consumer video and multimedia distribution, as well as short
distance wireless data. The current generations of chipsets may not offer
much more than WiFi. Future generations will be able to offer
significantly more.
