Re: [vmeet] PLAN: Formulating a workplan for vMeet

["Brian Rosen" <[e-mail]>]

Someone must have solved the audio problem we're looking at, although it
would not be the WebEx audio client.  If not, we have work to do, but it's
applied engineering and not research.  It's a mix of in room, multiple mic,
plus the remote participants.  I've never seen it done well, but someone
must have solved the problems.

I'm not as enthused as you are to get chairs to run the WebEx session.  I
know when I'm running a meeting, it's nearly all I can do to run the slides
("Next Slide Please") as well as do real chairing.  It might be different if
everyone was on WebEx, but when you are chairing the live meeting, you don't
look at the screen much.  It's possible, but it's not great.

I do think we ought to concentrate on the regular work group meeting, and
not deal with the plenaries yet.  That puts us within the kind of range we
should easily be able to handle with the tools we are discussing.  If we can
get good WG meeting tools, we can extend to good plenary tools.



-----Original Message-----
From: Doug Otis [mailto:[e-mail]] 
Sent: Monday, April 20, 2009 12:51 PM
To: Brian Rosen
Cc: 'Henning Schulzrinne'; [e-mail]; [e-mail]
Subject: Re: [vmeet] PLAN: Formulating a workplan for vMeet


On Apr 19, 2009, at 3:13 PM, Brian Rosen wrote:

> Uh, probably you skipped several steps.
>
> First of all, it's not clear that we're using WebEx's VoIP audio  
> system. The test doesn't, right?  That mute control stuff only works  
> from the VoIP audio system I believe.

The issue of input audio affects those presenting, or for those asking  
questions (perhaps via voice mail??).  WebEx Event client does not  
support VoIP for MACs, for example.  The Event client can handle up to  
3000 participants, so the alternative to VoIP for a presenter would be  
to use a phone at $.20/minute.  VoIP is limited to 500 participants,  
although for the Event client 3000 participants can listen.  At most 7  
microphones can be active, 6 + host. A teleconference can allow as  
many as 125 users to have speaking privileges, with 375 listening only  
for 500 total.

> Then, the room audio, if it's fed into any bridge, is going to need  
> a pretty fancy echo cancellation box to deal with the room PA with  
> multiple mics. The basic echo cancel you get from a conference  
> bridge probably can't handle that.  You also probably need a better  
> automatic gain control than you get from the bridge.

WebEx provides the phone bridge, but it seems voice mail might be  
required to facilitate remote participant question queues.

> Then we're skating around the issue of who is running the WebEX UI,  
> unmuting participants, ....  We currently have two jobs that have a  
> volunteer, plus chairs usually are running slides.  I'm not sure we  
> can round up yet another volunteer, and I'm not sure I want a chair  
> doing more work.

The host would likely be one of the meeting chairs, which does not  
seem like an undue burden for them to select who is presenting.   
Control can be passed by presenters.  The level of flexibility changes  
between Meeting and Events clients.  It would appear that most  
Meetings will need to be limited to 500 participants, and that larger  
meetings will suffer from less compatible clients.

When considering that a Net-Box attached to a digital projector and  
the room PA can join an entire room with the meeting, this can scale  
beyond the 500/3000 participant limits.  WebEx offers some remote  
system controls, so special clients might be used by meeting chairs to  
enable and disable the Net-Box audio output when there is a need to  
enable a remote participant's ability to speak.

-Doug