[AG-TECH] Better use of bandwidth in the AG

[John I. Quebedeaux, Jr]

Hey George,

Well, my thinking is: no matter how low you go - the Access Grid is not a
fixed bandwidth system due to how it scales in terms of participation -
unlike simple broadcasting where the receiving site just gets one fixed
stream for audio and video. Then the onus is placed on the transmitting
site(s), not the receiving site. For the Access Grid both it's positive
feature as well as a negative feature with video and audio (and any other
data) as you add participants with video and audio to "interact". It's
simply a different model...

Having said that:

I've conducted Access Grid events with sites that only had a T1 or two tied
together by carefully orchestrating the video and audio to fit and still
allow them to participate - but only since I literally conducted the event
to that affect (everyone else muted except the site whose turn it was for
Q&A, etc - only primary videos from each site, etc, etc,). In this type of
event, I deliberately had people scale back their frame rates from 24 down
to 15, bring down the quality settings except for the primary sites, etc.
What could be useful here is to do this from a venue perspective: i.e.
Actually have the venue server dictate the vic settings (max?) to have such
a "location" for people to go for lower quality video (and audio) settings
enforced. I would presume it's possible, as long as participants didn't
manually tweak their vic settings afterwards (can't control that!).
Generally these types of events push the need at those sites for more
bandwidth and help overall by giving those sites justification (after the
fact, the see the potential they're missing out on) to get that additional
bandwidth.

Solutions?:

Could (which Jason may have referenced) the real solution in the "Access
Grid Land" (as one presenter referred to the AG) would be to allow a low
bandwidth site to "bridge" and pick only the stream/audio they want to
receive what they can afford to receive. It's letting them choose what
traffic that will be forwarded to them from a bridge would be ideal for
those sites in terms of video and audio. Sure, they'll miss out on all the
rest of the video - and there would be some questions about limiting the
audio this way because they'll miss the interaction if they only hear one
site... but it would help them I suppose.

What do other sites do?:

One thing I've noticed is some sites have gone to multiple solutions - a
tiered solution with regards to technologies. As a major
transmission/seminar/meeting point, one site will support ALL the
technologies and transmit (and receive as applicable) each one, letting the
recipients decide which they want to participate on. Thus: Access Grid,
Polycom, Web/video/multicast/unicast video/audio all receivable but the
receiving site decides which type to participate (or as I'm noticing, many
just choose to receive and watch without participating) thus allowing the
receiving site to decide what amount of interaction (with the Access Grid
being the most and web/video viewing the least) and bandwidth to incur for
an event.

My 2 cents,

John Q!
-- 
John I. Quebedeaux, Jr.; Louisiana State University
Computer Manager LBRN; 131 Life Sciences Bldg.
e-mail: johnq at lsu.edu; web: http://lbrn.lsu.edu
phone: 225-578-0062 / fax: 225-578-2597



> From: George Estes <gestes at ncsa.uiuc.edu>
> Date: Thu, 5 Feb 2009 11:25:51 -0600 (CST)
> To: ag-tech mailing list <ag-tech at mcs.anl.gov>
> Subject: [AG-TECH] Better use of bandwidth in the AG
> 
> Hello,
> 
>   Is anyone out there looking at video and audio codecs that use less
> bandwidth than the current AG codecs?
> I know it's not as glamorous a topic as HD codecs but there's a large
> potential AG community out there that only has maybe a T1 connection.
>   One of our PI's has expressed interest in providing some funds toward
> developing a "low bandwidth AG".
> 
> Thanks,
> George