[AG-TECH] Rigging up a Temporary AG Node

[Osland, CD (Chris)]

John,

A few thoughts...

The choice between option a and the rest depends on the requirement,
not on the implementation!

Even in option b (lapel mic) the person with the mic needs to be
able to hear the far end; if this is via a loudspeaker, that means
the mic will hear it too and you will have echo problems.

Option d: don't even think of using switches - put all mics through
a mixer with linear faders and LABEL THE FADERS!  While the person
on the mixer has to stay awake, it's not an impossible task - I
regularly do it for meetings where 20 people share 10 gooseneck
mics and extra people are on mics on stands.  However ...

Whenever you change the 'acoustics' of your room (person walking
round with lapel mic, muting mics, flying faders up and down) you
are in danger of disturbing echo canceller balance.  In principle,
if you don't have an echo canceller and everyone else does, you
can get away with it by muting the incoming audio while anyone
at your end is speaking, and muting your outgoing audio when no-one
is, but this adds considerably to the mixer operator's workload.
Also the operator has a difficult decision to make if someone
remote replies to you before your end has finished speaking!

One consideration is how much your site's participation may
disrupt the remote meeting; only experience will answer that!

We also have a 150-200 seater auditorium from which we do
meetings - mainly video conferences so far, but the principles
are the same.  We find that handheld radiomics are the only
successful solution to getting questions from the floor to
remote sites.  Ceiling mics, rifle mics and mics in aisles on
stands have all been tried and all work worse and/or are more
confusing than handheld radiomics.

Cheers

Chris



____________________________________________________________________
Chris Osland                         Office tel: +44 (0) 1235 446565
Digital Media and Access Grid      Medialab tel: +44 (0) 1235 446459
BIT Department             Access Grid room tel: +44 (0) 1235 445666
e-mail:   C.D.Osland at rl.ac.uk               Fax: +44 (0) 1235 445597

CCLRC Rutherford Appleton Laboratory (Bldg. R18)
Chilton, DIDCOT, Oxon OX11 0QX, UK

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> -----Original Message-----
> From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov]On
> Behalf Of John Hodrien
> Sent: 10 February 2005 09:17
> To: ag-tech at mcs.anl.gov
> Subject: [AG-TECH] Rigging up a Temporary AG Node
> 
> 
> I have need to setup an AccessGrid temporarily, and was 
> seeking advice as to
> whether it's even remotely reasonable.
> 
> We currently have a multi-machine room based installation of 
> AG2 working just
> nicely.  But sadly it's in a room with a capacity of about 
> 12.  I've had a
> request to setup an AccessGrid in a completely different room in the
> university for a conference demo with approximately 120 
> people.  I'm not
> willing to tear apart our existing setup for one event.
> 
> Now I'm assuming this room has a projector and a set of 
> usable speakers.  I
> guess I could setup a laptop/shuttle with a camera or two.  
> But what would
> anyone suggest for the microphone end of the bargain?  Do I 
> have any hope of
> setting this up in any meaningful way without hardware echo 
> cancellation?
> 
> I guess the three possibilities I see are:
> 
> a) Read Only.  It's just a demo, don't let anyone 
> participate.  Hence no need
>     for microphones.   Just view lots of other people having 
> a meeting.
> 
> b) Just one person participating, with a small lapel/headset 
> microphone making
>     the echo cancellation a little easier.
> 
> c) Multiple microphones with full on associated nightmare
> 
> d) A gimp sat at the machine flicking switches faster than 
> colossus to mute
>     everything that doesn't need to be on.
> 
> Rental Gentner?
> 
> jh
> 
> -- 
> "A good scientist is a person with original ideas.  A good 
> engineer is a
> person who makes a design that works with as few original 
> ideas as possible.
> There are no prima donnas in engineering."           -- Freeman Dyson
>