I am not privy to the PMBO code, but I would be extremely surprised
if "Active busy detection would stop all PMBO operations." All that
is required is for a PMBO in its idle state to not respond to an
incoming user request if the busy detector output was positive
anytime during the last X minutes; where 1 < X < 5.
A more likely concern is that adding a busy busy detector would make
PMBOs vulnerable to intentional QRM. This is one of the tradeoffs we
all make by using the amateur bands for communications as opposed to
commerical services. However, a WinLink PMBO could easily outlast a
human QRMer, and the delay in email delivery would likely have no
serious consequences. During emergencies, one would expect PMBO
operators to disable busy detection.
73,
Dave, AA6YQ
--- In digitalradio@yahoogroups.com, kv9u <[EMAIL PROTECTED]> wrote:
>
> The discussion of automatic signal detection and not transmitting
on a
> busy frequency has been a major item of discussion in the past day
on
> one of the Winlink 2000 groups and the impression that I got from
the
> main spokesperson/owner was that if they had to follow busy
detection
> rules, Winlink 2000 would be impossible to operate.
>
> The comment was made in response to the following question on
message 16782:
>
> "It's the PMBO side that's the issue; Because of the hidden
> transmitter problem, the client has no way of knowing when the PMBO
is
> stepping on another QSO."
>
> and the response was:
>
> "Where is this happening, Rich? You been down in the auto forward
> section operating in real-time? Active busy detection would stop
all
> PMBO operations."
>
> This could explain why they did not go any further with the testing
or
> adoption of this protocol that they invented two years ago,
including
> the release of the code coming from a GPL source.
>
> Some of you might remember my comments, when we were beta testing
back
> then, that the busy signal detection was almost too good. It was
more
> sensitive than a human who did not look closely at the waterfall
and was
> just casually listening if the frequency was clear.
>
> 73,
>
> Rick, KV9U
>
>
>
> Leigh L Klotz, Jr. wrote:
> > I join the voices of the many who call for the release of source
code
> > for this busy detection and any patents under royalty-free
license. If
> > SCAMP's busy detector, for example, were to be released now, it
would
> > show goodwill, and would also spur innovation. Closed and
unreleased,
> > it fuels conspiracy theories.
> > 73,
> > Leigh/WA5ZNU
> >
>
