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Further questions

Posted: Sun Jan 28, 2007 6:57 am
by jfabiano-p40
Okay, do we know the characteristics of the DSL lines at the stake centers? Most DSL implementations are not symmetrical, ie different upload bandwidth vs. download. With a DSL connection available already the problem may be simplified somewhat. An MPEG4 or h.264 encoder can render compressed video stream that is usable for a large projection at about 1 Mb. Not that many DSL implementations have that much upload bandwidth but with the answer on the size of these lines we'll know for sure whether upload via the existing DSL is practical.
It was also mentioned earlier that people aren't that attracted to a solution with grainy video and they are right, poor video quality links often reduce the likelihood that the system will be listened to again. So implementing something that is compressed any lower than 1 Mb is probably not a good use of church resources. Given that, for a large multi-site meeting where there would be contributors or speakers present at multiple sites may be impractical with the current infrastructure list, we'll have to see once we get a few more answers.
The downlink side of that same DSL line is likely to be more capacious and could easily be in the 2-4 Mb/s range. Do we know who the carrier for these lines is? I'd assume that they are all purchased through some centralized deal so that a good price is obtained for the services. Some of the carriers have IGMP v.3 multicast enabled in their core and edge routers which would enable multicast of content via the DSL lines. Others don't have this available at all and multisite flows are treated as unicasts requiring more bandwidth at the origin server.
It still feels that the satellite interconnection system will need to be involved in this to have a good professional quality projection-size display at the receive sites. Does anyone know what the characteristics at the uplink site are? How much bandwidth is there in total? There are probably several compressed streams across a larger chunk of transponder bandwidth. Do we know of these are individually modulated and fed in SCPC fashion or if they are aggregated into a larger stream with a stat mux in MCPC mode? These questions would tell us what it would take in the way of equipment to feed a stream from a stake center out through the satellite system. Also what video compression formats are supported by the satellite recevers? My understanding is that the satellite receivers are from Wegener Corp but I don't know the model # to be able to look up the features available on the receive end. Does anyone know that info (or are they all different models)?
Sorry to ask so many questions but with a few answers we may be able to outline a practical implementation for at least one of these meeting scenarios, if not more.

Posted: Mon Jan 29, 2007 9:20 am
by thedqs
jfabiano wrote:Okay, do we know the characteristics of the DSL lines at the stake centers? Most DSL implementations are not symmetrical, ie different upload bandwidth vs. download. With a DSL connection available already the problem may be simplified somewhat.

You are right in that they are not semetrical, the one I refered to in my previous post has a 728Kb/s upload.

jfabiano wrote:An MPEG4 or h.264 encoder can render compressed video stream that is usable for a large projection at about 1 Mb. Not that many DSL implementations have that much upload bandwidth but with the answer on the size of these lines we'll know for sure whether upload via the existing DSL is practical.

As for Windows Media Encoder we got a video stream that was 600Kb/s

jfabiano wrote:It was also mentioned earlier that people aren't that attracted to a solution with grainy video and they are right, poor video quality links often reduce the likelihood that the system will be listened to again. So implementing something that is compressed any lower than 1 Mb is probably not a good use of church resources.

We had a great picture at 600Kb, although only one building would be able to connect, otherwise you get buffer underrun and the picture is jerky. Although in the last Conference this was solved by having a server that you uploaded to and then everyone connected to that server for download. (We only had two sites at the last conference.)

jfabiano wrote:Given that, for a large multi-site meeting where there would be contributors or speakers present at multiple sites may be impractical with the current infrastructure list, we'll have to see once we get a few more answers.
The downlink side of that same DSL line is likely to be more capacious and could easily be in the 2-4 Mb/s range. Do we know who the carrier for these lines is? I'd assume that they are all purchased through some centralized deal so that a good price is obtained for the services. Some of the carriers have IGMP v.3 multicast enabled in their core and edge routers which would enable multicast of content via the DSL lines. Others don't have this available at all and multisite flows are treated as unicasts requiring more bandwidth at the origin server.

The carrier has to be local, for WA it is verizon since Qwest has no presence there, but I think for Utah they are linked through Quest, please correct me if I am wrong.

jfabiano wrote:It still feels that the satellite interconnection system will need to be involved in this to have a good professional quality projection-size display at the receive sites.

From what our emperical results have been you don't need to use the satilite system. Also this would require installing transmission stations at each stake building, not very cheap.

jfabiano wrote:Also what video compression formats are supported by the satellite recevers? My understanding is that the satellite receivers are from Wegener Corp but I don't know the model # to be able to look up the features available on the receive end. Does anyone know that info (or are they all different models)?

Sorry don't know the model but they use MPEG-2 encoding and decoding.

jfabiano wrote:Sorry to ask so many questions but with a few answers we may be able to outline a practical implementation for at least one of these meeting scenarios, if not more.


Ideas are the source of inginutity, continue to give them and ask more questions.

Posted: Thu Feb 01, 2007 11:56 am
by tedarchdeacon
pwhiting wrote:The problem we are focused on with the current building-to-building effort is to allow site-to-multisite one-way streams.


This would be ideal for our Stake. Some of our members drive over three hours to the Stake Center. We also have outgrown the capacity of the Stake Center.

What is available from the Church now? Who do we call? What will they provide?

Thanks!

Posted: Thu Feb 01, 2007 12:04 pm
by thedqs
Currently there is no position from the church what is available, there have been many different solutions posted from many stakes, but it depends mostly on what you have available to your stake, budget wise and tech wise.

Posted: Thu Feb 01, 2007 12:07 pm
by tedarchdeacon
thedqs wrote:Currently there is no position from the church what is available, there have been many different solutions posted from many stakes, but it depends mostly on what you have available to your stake, budget wise and tech wise.


Thanks. We'll have to go without then...

Posted: Thu Feb 01, 2007 12:16 pm
by thedqs
If your stake center has a Family History Center that has a DSL connection you could do what I mentioned in this post /forum/showthread.php?p=314#post314 (it is also the cheapest) but as I mentioned it depends on what resources your stake already has.

This is my personal opinion. It is also the one I am most familiar with.

Posted: Thu Feb 01, 2007 12:53 pm
by tedarchdeacon
Thanks again! I'm going to take this to SPEC and see if we have anybody with any know-how! I really appreciate the help. Can we hire you? :0)

Posted: Thu Feb 08, 2007 12:41 pm
by KGBurton
pwhiting wrote:The problem we are focused on with the current building-to-building effort is to allow site-to-multisite one-way streams. Yesterday someone voiced a strong opinion that we instead should be providing multisite-to-multisite two-way interactive communications (video conferencing) - allowing speakers to be in each of the participating buildings. The tradeoff involves some quality (smaller buffers due to real-time constraints) and perhaps some reliability (due to the added complexity). I'm interested in your opinions/views wrt this tradeoff. How important is it to have multiple source locations?


Our stake needs are facility capacity ... one way is all that we need.

KB

Posted: Mon Feb 12, 2007 2:26 pm
by BlackRG
Has internet reliability been considered here? While in general, outages should be few and far between, they do happen, and with more regularity than other types of traditional media. Peering issues also crop up between networks to cause issues and I'm not sure it's a safe assumption that an entire stake will all use the same provider (my stake includes parts of 3 states with no universal cable provider or ILEC).

Now if the meeting involved is one that can live with this possibility, no big deal. If however, it can't, the only possibility that comes to mind off the top of my head is to use one or more prerecorded streams (and since they're prerecorded, limits on upload bandwidth aren't as big of an issue) sent over the internet to be spliced together (if needed) for either a satellite feed or a scheduled internet download prior to the event.

While going with a prerecorded approach isn't quite as nice as a live approach, it does simplify a whole host of technical issues. For a Stake conference, I can see a prerecorded approach being acceptable (correct me if I've missed something).

Posted: Mon Feb 12, 2007 7:58 pm
by pwhiting-p40
gblack wrote:Has internet reliability been considered here?


Yes - when we get to the point of recommending a solution it will be coupled with a strong recommendation to set up and test an audio backup that uses the PTSN.