UPDATE: Cat-7 copper
theorized to transmit 100 Gbps in excess of 100 meters using
future modems
Trendwatch
By Rick C. Hodgin
Wednesday, November
14, 2007 11:22
Recommend article:
Pittsburgh (PA) -
Penn State University professor of electrical engineering,
Mohsen Kavehrad, has been researching the possibility of
transmitting extremely high speed data over copper. He's
looking at 100 Gigabits per second on Category-7 wire at
distances in excess of 100 meters. Imagine a home or
office network using inexpensive copper, one that could
transmit over twelve complete Encyclopedia Britannicas per
second.
While 70 meters is possible today,
it's that last 30 meters which is just outside the reach
of theoretical modern technology. Future modems, which
are not the boxes we think of, but are the equivalent of
on-board chips modulating and demodulating the
high speed signals, will be required before practical
applications can be built which push copper so
far.
Today, the theoretical limitations are with the
65nm process technology. The internal
semiconductor-based hardware mechanisms which drive signals
over Cat-7 wire, which is basically a four twisted-pair heavy
gauge wire with extra insulation, cannot work beyond 70
meters. The limitations imposed by degradation, noise,
data races per bit line, bounce, cross-over, and other
factors, all conspire against the existing technology.
These result in limitations in just how fast an amplified data
signal can be switched off and on with minimal digital
waveform loss.
The research team is currently
identifying the requirements to create an entirely new class
of modems. They're looking at what designs will be
required to communicate beyond the 70 meter barrier.
They're actually hoping to exceed 100 meters with their
design. While the researchers conclude that this
technology is not even theoretically possible today with 65nm
technology, even under idea circumstances, it is believed that
at the 32nm node, or possibly the 22nm node, it will be
possible. Those modem chips would be able to handle the
signal switching with less bounce, less noise and
ultimately without data loss. This technology could be
available as early as 2013.
UPDATE: From the author, I
think there are bigger benefits than are being seen.
Consider what this much throughput, over such a long distance,
over one set of wires, means overall. At these speeds,
12.5 GB/s per link, machines will be able to communicate with
other machines and devices at speeds which are impossible
today. I think the true potential here is that the
benefits of having an ability to transmit so much data, at
such long lengths, at such high speeds, using such a simple
technology, will open the doors to countless new uses that we
haven't even dreamed of yet. Technology will be looked
at differently because there will be a new
baseline.
One of the biggest possibilities I see is the
use of a central, secure machine. It will transmit
multiple simultaneous streams of 1920 x 1440 video at 85 Hz
using 32-bit color (940 MB/s), to allow remote desktop
abilities on very simple portable devices. The central
machine will run many virtualized OSes, and instances of OSes,
allowing any authenticated end-user to flip back and forth
through the machines as necessary on a very low-power,
low-performing portable device, while the big iron desktop
machine does all the hard work in the background. And
multiple users can be fetching back to the main machine which
is running all of this simultaneously.
Each user just
needs to carry around their simple tablet-PC like device, the
one with almost no processing power, no real memory to speak
of, only a very small, secure version of Linux to handle
screen, mouse, keyboard, sound, etc., I/O. And then, no
matter where the user goes in the home or office, hook in to
that remote desktop ability and have an instantly responsive
machine. No delays in painting the screen, even
full-framed 3D games can be streamed remotely. Some kind
of receiver device could receive that full-framed video data
and then simplify it for wireless transmission if the need was
required.
I personally believe the idea of having a
secure machine, one which can be running and hosting however
many virtual OSes are needed, running whatever kind of
anti-virus software, etc., and then providing the remote
ability to flip between them in real-time, is
significant.
I see the 100 Gbps as another one of these
amazing tools which are coming our way in the next few
years. It will join the ranks of Terascale-like
processing, low-ower Moorestown-like platforms--which are
basically MIDs with no tactile buttons where everything is
touch-screen, WiMAX--which is always-on/always-connected
broadband that goes with you no matter where you go, fully
integrated 3D into the OS environment, etc. All of these
wizz-bang features will be there. And 100 Gbps ethernet
will simply be another one.