Doc - What an unexpected surprise!
Thanks Doc,
Your not from Goldman Saks, are you?
Just kidding!
That's the way I like it, straight concise statements. Invaluable, and most appreciated.
It is becoming very appearent, that there are more than just a few who are quite impressed with Amati's President and CEO, Jim Steenburgen.
Tried posting this morning before heading to the CAPE for a few hours to support some testing, but SI was out, and yea I know, it's Sunday.
Anyway I wanted to try an answer the main question your had:
8)DMT-VDSL solution 3 years ago did not work so everyone abandoned it.
Amati said "How can we make it work?" and worked hard to do so. Amati
developed a "ping-pong solution" (not sure what this exactly is) that
has now been proven to work just fine and first silicon of ).25 micron chips is
expected shortly from NEC with production quantities expected in first quarter 1998.
ping-pong DMT for VDSL, is known as synchronized DMT (SDMT)
This solution is Low Complexity............
With SDMT there is only one FFT per modem.
The power consumption of SDMT is also very low.
The same VDSL transceiver can be configured for symmetric or asymmetric transmission, the same cannot be said for CAP, which has to change the bandwidths of the upstream and downstream bands to change symmetries.
As I have stated in many different ways in the past, CAP is affected much more severely by RFI than is DMT, this is due to the need for generating deep notches in the CAP spectrum.
Now I can hear those gears turning in many of the minds out there. You may be remembering Robert Hawley's post. techstocks.com
Well what can I say to refute such statements? ( he even gave a URL to the source)
I am not a Comm Engineer, Main Frame CPU's are my area of expertise, though I do understand much of what I read on ADSL, and VDSL, not to mention what sometimes appears in my E-Mail Inbox. This time around my only recourse is to say, if ask you personnel from the following companies you'll find they are all working on VDSL/SDMT, since I can not point to you to a single source at this time.
Alcatel
Amati
Cadence
NEC America
NEC Japan
Rockwell
Samsung
SGS-Thomson
Spectrum Signal Processing
Texas Instruments
More on VDSL/DMT later if anyone is interested???
JW@KSC |
