BT “MAUD” Multicast Streaming Breakthrough- reducing lag?

[SPORTSLJM]

https://newsroom.bt.com/bt-group-announces-live-tv-technology-breakthrough-to-meet-growing-customer-...

Hello guys, hoping some of you better technically minded than me might be able to elaborate on the benefits of BTs Multicast Assisted Unicast Delivery technology  (that was a mouthful!).

As a paying Sports TV subscriber (both BT and Sky), I’ve tried pretty much all formats now- satellite, sky stream, and BT app. The sports lag between satellite and sky stream at about 30 seconds, BT multicast down to around 10.

Some of the 4K Sports quality is now superb on streaming and clearly it appears to be where the future is.

Im trying to understand with this BT announcement- are we essentially saying that BT have created something whereby all providers could have a multicast (one stream) sent to their subscribers, without the need to be a BT internet customer? And as a result, would all content providers live streaming lag reduce substantially to something similar to what BT TV multicast currently achieves?

Doss anyone know whether they’ve trialled and teamed up with Sky yet? I know they’ve worked with the BBC but would love to know who else is partnering in the trials. 

[Crimliar]

Based on what I understand, I could be so wrong on this!  The idea is to bunch multiple live streams into a single fat multicast bundle as they traverse the super-highways of the internet, giving them priority and preferential routing as they go.  These fat bundles are only stripped back into unicast streams at the nearest location to the end user which makes sense (or it would clog our puny gigabit and lower connections at this point).
It's not a totally new concept, BT, Virgin, and some of their content partners have been using a "lite" version of this for years.
It's a big thing (reducing overall latency and sheer quantity of data traversing the internet), that hopefully while working properly you, as a user, will never notice!

[stereohaven]

@SPORTSLJM 

Based on my limited understanding, MAUD enables the benefits of Multicast transmission (low latency etc.), but can present the stream  in a device agnostic way.

So it doesn’t matter if you have an EE TV Pro box (Multicast) or a Fire TV stick (Unicast), the apps on the devices get the stream they need at the point of delivery.

I suspect Sky are involved in some way and Sky Stream does have ‘low latency’ sports streams up in the 900 channel range (HD and UHD), but I cannot say with any certainty if that is related to MAUD or a separate trial.

There are a few BT/EE employees on the forum who may know more,  but whether they can tell you anything or not is another matter! 😁

On the 4K sports streams, I have a feeling in my water that either this year or next, we will finally see Sky Sports in UHD via BT/EE. 

[zulu17]

There was as linkup announced in March

https://broadpeak.tv/newsroom/bt-group-and-broadpeak-partner-on-new-multicast-technology-maud/

this states

A number of major broadcasters and content companies are expected to trial this breakthrough solution in 2024.

[DarrenDev]

The benefits of MAUD to the user will be minimal - in fact, the ideal scenario would be that they see no difference whatsoever.

The live streams you see in apps at the moment are serving small chunks of video specifically to each client. So if you have 2 devices in the house each watching a 5Mbps stream, you're using 10Mbps of your bandwidth. If 10 people in your street are watching the same, then that's 100Mbps of bandwidth to your cabinet that is being used. Multiply that by the entire country (e.g. when Freely launches), and we'll have an internet that cannot cope with us all streaming at the same time.

The purpose of MAUD is to use Multicast to deliver those streams all the way to your home as a single stream, and then have them split to your devices by your router. So that 5Mbps stream is being sent across the entire UK network and only using 5Mbps, but then the router in your home converts that Multicast back into the segments that your device asked for.

[Brucemeister5]

@stereohaven I’m not so sure that I share your confidence about 4K Sky Sports coming to EETV anymore. When Sky got BT Sport/TNT Sports Ultimate I expected that there would be a reciprocal agreement, but didn’t anticipate that TNT Sports Ultimate was going to be made available at no extra cost via Discovery+. 

There has been talk of Sky Sports Light being launched in the not too distant future via a survey of selected Sky & NOW customers which has been mentioned on another forum. It would include all of the Sky Sports channels except Premier League & F1 ( and would also need to exclude Main Event to my mind, although it doesn’t state this) It would cost £15pm and be available on Sky, Virgin & NOW. I’m not sure whether this would include EETV customers. This deal does look to be too good to be true for those who would simply downgrade to Sky Sports Light during the summer to watch the cricket.

[SPORTSLJM]

@DarrenDev 

Thanks Darren, makes sense.

Ive seen this week on Sky Stream there are two sky sports low latency test channels at the moment.

Channels 921 and 922 are trialling a HD and UHD version of Sky Sports main event I think.

Quick latency tests seem to show these as being around/upto 20 seconds ahead of the usual stream channel content. As the regular streams are approx 30 seconds behind the satellite feee, it looks as if the Sky Stream latency could therefore be reduced to just 10 seconds, which I believe is somewhere in line with BTs multi cast offering.

Does this mean Sky are trialling some sort of multicast delivery here that is reducing the latency? Obviously the key difference with Sky Stream is they are providing it to customers with a whole range of different internet providers as opposed to BT Multicast which is only BT internet- is this where MAUD comes in, in the sense that Sky are sending the multicast stream to all customers, then the individual ISP is decoding it into the unicast output?

Forgive my technical ignorance on this- I’m just keen to understand it and more than anything, I want Streamed TV providers to improve- especially latency! 

[DarrenDev]

The latency you see on streams at the moment isn't due to how long the data takes to download - that's only milliseconds.
The latency is in the encoding and packaging of that video into an ABR stream - i.e. splitting that stream into multiple different quality levels.

Low latency is a different way of packaging the video. It requires a server and client that support it, and (from memory) I believe it's more expensive to do.

[stereohaven]

@Brucemeister5 

Fair enough.

I only watch Sky Sports for Premier League and F1! 🤣

To be honest, I'm done with EE TV at the end of this current contract, so it doesn't really matter if it arrives or not any longer to me.

There are just too many compromises for us. I'll likely retain the broadband as that has been solid, and to get discounted access to Discovery+ Premium, but that is it. 

Weirdly, it was explaining the foibles of the TV service  over on the EE community that pushed me over the edge! 

[rbz5416]

Surely a huge stumbling block would be the number of non-BT routers that don't support multicast? I'm not sure that could be easily added in firmware, given the number of major brands that currently don't support it.

There's also the issues we see in these forums with Openreach infrastructure blocking multicast or it failing for "reasons". At the moment, as long as you have a connection then everything bar content via the BT EPG just works. If everything is multicast then the points of potential failure are multiplied significantly.