Sorry, i have been working with acoustic echoes, not|
very familiar with modem designs. Could u explain
'determined through an exchange between the end-points
during startup' in a bit more details? Or sugguest
some good ref.?
--- "Shaw, David G (David)" <> wrote:
> For modem, the bulk delay is determined through an
> exchange between the end-points during the startup
> of the modem.
> For voice calls, you will have to come up with a
> clever algorithm to determine the delay.
> Dave Shaw
> -----Original Message-----
> From: Huo Jiaquan [mailto:]
> Sent: Monday, November 17, 2003 8:50 PM
> Subject: Re: [echocancel] Re: LEC and NEC > How do u determine the bulk delay for the far-end
> --- anjuman2 <> wrote: > --- In
> , "lee"
> > <hao_li@y...> wrote:
> > > Can someone tell me what the difference is
> > a Line Echo
> > > Canceller and a Network Echo Canceller? To me,
> > seems that the
> > only
> > > difference is the echo path delay. Or say, they
> > are just different
> > > echo paths.
> > >
> > > If that's right, then a echo canceller with,
> > 128ms delay
> > should
> > > be able to cancel near end and far end echos. Or
> > is there a better
> > > approach?
> > >
> > > Please advice. Thanks.
> > Dont know the terminology difference between line
> > and network EC's.
> > But there's a big difference between how to
> > implement a near LEC or a
> > far LEC. Having one long EC of (say) 128msec is
> > optimal if in
> > fact, there are two distinct sources--a near and a
> > far one. The best
> > way there is to have two short EC's, one that
> > the near-echo
> > (typically <16msec) and another that spans the
> > far-end echo but with
> > a large (also called bulk) delay in front. But the
> > second EC could
> > also be spanning only 16msec of echo. This
> > arrangment is used in
> > modems a lot and is computationally very
> http://personals.yahoo.com.au - Yahoo! Personals
> New people, new possibilities. FREE for a limited
> time. >
> Note: If you do a simple "reply" with your email
> client, only the author of
> this message will receive your answer. You need to
> do a "reply all" if you
> want your answer to be distributed to the entire
> About this discussion group:
> To Join:
> To Post:
> To Leave:
> Other DSP-Related Groups: http://www.dsprelated.com > ">http://docs.yahoo.com/info/terms/ >
http://personals.yahoo.com.au - Yahoo! Personals
New people, new possibilities. FREE for a limited time.
RE: Re: LEC and NEC
Started by ●November 21, 2003