[Implementation Working Group] Service List Acquisition and Lifecycle

[Ben Poor]

Hello,

Another topic for discussion.

What steps should a device take to best manage the most relevant list of services?

Paraphrasing from Sebastian's steps in another posting, here is a simplified view of how a device could behave:

1) The device scans through all FM frequencies, DAB ensembles, other broadcast systems to get a list of available stations

2) For each station, do the following:

    i) Perform RadioDNS Lookup for the RadioEPG XSI

   ii) Store the station against the resolved XSI URL

3) For each unique XSI URL in the list, acquire and parse each document

This gives the device a master list of services. This includes broadcast services - to be compared against those discovered during the initial scan in step 1. Also, additional IP services can be found, allowing service following for the broadcast services, as well as adding to the services list (for IP-only stations or out-of-area broadcast services).

The band scanning should be repeated periodically, to capture any variations due to transmission strength or location. Additionally, a device *could* trigger a band scan repeat based on a known location change (more important in the case of in-car devices, for example), or a message is received such as a DAB ensemble change.

On subsequent repeats, we'd get a list of XSIs, as before. Since we're working with HTTP we'd use standard HTTP caching techniques to do a check whether the XSI has changed (Last-Modified/If-Modified-Since HTTP request headers). If it hasn't changed we dont reacquire and ingest the XSI.

As mentioned, the above is most effective on devices with multiple tuners. However, even on single tuner devices the process can be performed, albeit more gradually as the user scans through the band. The device would gradually build up a more complete list of services.

I'll follow this up with a diagram, but I'd like any thoughts on the above, especially from those more familiar with devices.

Ben

[Sebasti...@swr.de]

Hi Ben, hi All

Perfect summary. Agreed completely ... maybe we should add 1) i) Remove
duplicate (simulcast) stations.

Please find attached a master list for Berlin which I've hand-crafted
according to the points above. The concept seems to work ... however
practically it raises the following questions:

How do we handle simulcast stations that are provided by different
broadcasters?
After the RadioDNS lookup "Funkhaus Europa" appears as DAB-station from rbb
as well as Internet-station (plus the extra Funkhaus Europa channels) from
WDR. Should we delete the doublet? And which one? I'd prefer the internet
stream, but this has several 'children' channels. Or should the receiver
depose the dab variant from rbb behind WDR's Funkhaus Europa record (which
is identical either way)?

Can we ensure that a certain broadcaster can be listed before all other
broadcasters of the same family
This is a typical requirement of a large company ... the local top dog (rbb
in this example) requires the pole position of course and should be listed
before all other ARD broadcasters ... which is BR and MDR in this example.

Do we want just brand grouping or brand-family grouping as well?
Grouping of brand families doesn't really look good as you can see in the
Excel. Well ... however the ARD-stations will prefer it. Do the others as
well?

(See attached file: RadioEPG-service_listing_2013-01-09.xlsx)

Any comments? Thoughts from receiver manufacturers are of course highly
appreciated ...


Best
Sebastian

[Ben Poor]

Hi Sebastian,

Interesting situation - so in the case of Funkhaus Europa, are you saying there is a DAB variant from one broadcaster and an IP variant from another? Are they exactly the same service, or are there differences (such as adverts, etc.)

In terms of preference, the broadcaster can indicate preference using the cost attribute against a bearer, but the device will also have a sense of what it prefers to receive. For example, a mobile device may prefer a lower bitrate IP stream if it knows it has not got the available bandwidth for a higher bitrate one.

The groupings of broadcasters and 'families' as you mention is something I confess to not knowing enough about! its somewhat unfamiliar to my experience here in the UK, so it needs to be captured. 

When grouping stations, I cant think of any practical way to extend it beyond the current situation (where you can group services within the same XSI document) without encountering issues. Thats probably a discussion we should have over on the other topic though, so I'll raise that in my reply.

Ben

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[Sebasti...@swr.de]

Hi Ben,

Funkhaus Europa is a cooperative programme from Radio Bremen, rbb and WDR.
They're all broadcasting it (i.e. identical content) in their coverage
areas which are seperated from each other. Berlin is a special situation as
a few other ARD stations are broadcasting here via DAB as well. So due to
WDR2 via DAB we run into that problem. I wouldn't mind the doublet but this
will surely depend on the grouping in the 'master list'. If we prefer brand
grouping, we should try to eliminate it. If it is family grouping, it
wouldn't be so apparent and could be left in the listing.

Having written that I have to confess that my interpretation of brand
grouping was a bit crude until we began to speak about it :-)

If we say that we can't extend it beyond the grouping of the services
within the XSI document and that the list is basically in alphabetical
order, that means practically:

1. Just alphabetical order and no grouping ...

2. Brand grouping based on a leading brand. This would mean that we can
determine a leading brand in the XSI (e.g. Antenne Brandenburg) and that
all other stations from the same broadcaster are listed behind that leading
brand. By implication this would break the alphabetical order and resume it
afterwards ... somehow. Maybe too confusing for the listener?

3. Family grouping based on the orgininator/serviceProvider information in
the XSI. But who care's about the family his preferred brand belongs to?!

Any ideas what fit's best?


Best
Sebastian.

[Ben Poor]

Hi Sebastian,

Grouping is definitely something thats needed - again for Global Radio's case we have networks of similarly branded stations (Heart, Capital), which would be uncomfortable for a listener to always see 40 variants of. Having them grouped inside a 'Heart' or 'Capital' brand allows for the to be rolled up into a group on a device.

The display of a group could still be within an Alphabetical sort (as in my previous diagram) - so the service would appear as 'Heart'. Within the group, it would show stations as indicated by the broadcaster within that group, so perhaps with a leading service, or in a specific order.

You're right in that showing groups around a provider or company is not meaningful to the user. So having services underneath 'Global Radio' wouldn't be a good thing - it has to be centred around recognisable groups and brands.

Your example of Funkhaus is interesting, and is a more complex scenario then I've ever considered. So its a shared service between different broadcasters in different areas of Germany? Is there a situation where it is broadcast (i.e. broadcast bearer) by two different providers in a single location?

Ben

[Sebasti...@swr.de]

Hi Ben,

I agree with the grouping mechanism as you described it for Heart/Capital
and I'am confident that it will also work for ARD's brands. Although we've
got a slight difference ... as I can see on the Global website, Heart and
Capital are networks of independant stations. In ARD's (public radio) case
our regional radio brands are only regional/local windows of a main
programme which are onAir for a few hours per day. So e.g. SWR4 (in my
case) wouldn't be just a grouping record but also a station that can be
listened to (and in that sense would be the leading station of SWR4).

However I'm happy with brand grouping (not family grouping) in alphabetical
order as everything else proves to be impracticable.

Funkhaus Europa is indeed a shared station between different broadcasters.
It never comes to the situation that two providers distribute it in the
same location. It would become problem if we include every internet radio
station in the XSI in the master list. But I agree with Nick that we should
let that be ...


Best
Sebastian

[Ben Poor]

Hi Sebastian,

I think the situations between the UK and Germany are more similar than I thought, albeit with the difference that the market in the UK is national, but in Germany it is far more regional. I'll describe what our arrangement is, then what I think yours is - correct me if I'm wrong!

Global Radio

So, Heart and Capital are networks of local FM stations, which generally carry networked content across the majority of their output. For example, Capital will operate networked content across all of its stations except at breakfast (06:00-10:00) and drivetime (16:00-19:00) weekdays. Weekends are networked except from 08:00 to 12:00. Each station carries its own local advertising.

On DAB we carry the local FM stations, where one exists. Where one does not exist, we have a 'national' variant, which is essentially the same as the 'lead station' for the network - Capital London.

In this case, each Capital station would be its own service within an XSI. Each would be a member of the 'Capital' group, representing the national network. On a device, this network could be shown as a 'grouped' list of stations (so you'd see Capital in the service list, until that group is expanded to show the individual stations). The lead station would be defined as 'Capital London'.

SWR

Now heres where I am on less confident ground, but I'll have a go with the help of Google Translate...

SWR has a number of radio brands (8, apparently), including SWR4. This brand is carried by local stations on FM - and a single station across the whole region on DAB.

So in terms of an XSI, you would have (as you mention)  a list of services for SWR. You would have an SWR4 group, containing the individual stations (across the two 'families'? which I how I think you refer to the Baden-Wurttemburg and Rhineland-Palatinate groupings?), so this would be:

* Baden Radio

* Bodensee Radio

* Franken Radio

* Kurpfalz Radio

* Radio Stuttgart

* Radio Südbaden

* Radio Tübingen

* Radio Schwaben

(couldnt find the stations in RP, but maybe I'm misunderstanding)

* Koblenz

* Trier

* Mainz

* Kaiserslauten

* Ludwigshafen

Again, I guess you'd have a station representing the overall brand that is carried on DAB and also any regional IP streams? Is this what you mean by the SWR4 station?

Please do point out if I'm hopelessly off-target with the above!

Ben

[Sebasti...@swr.de]

Hi Ben

Perfect summary. And you're right ... the similarities are striking :-)

SWR4 (Baden-Württemberg and Rhineland-Palatine are distinct due to the
federal structure but you can also take Bayern 1 for instance) corresponds
to Heart and Capital although I'd never be allowed to say that it's a
network.

The majority of their output in FM is also networked content, except
breakfast (6-9am), noon (12.30-1pm) and drivetime (4-5pm). But officially a
leading station does not exist. The networked content is produced in our
broadcasting centres in Stuttgart and Mainz, but 'Radio Stuttgart' (for
SWR4 BW) or 'Radio Mainz' (for SWR4 RP) only appear during the non-network
times mentioned above (although using the same studio in Stuttgart and
Mainz). During the rest of the day it's just SWR4 BW or SWR4 RP.

Okay - on DAB and IP we're currently transmitting just 'Radio Mainz' and
'Radio Stuttgart', but this is due to capacity constraints.


So in the XSI I'd very probably do the same set up as you'd do for Heart
and Capital. But I would expect that, when I click on "SWR4 BW" on the
device, the group not only expands and shows all the regional variants of
SWR4 BW, but also starts playing 'SWR4 BW'. And yes ... I'd then run into
problems during network-times when 'SWR4 BW' is not apparent (i.e. is
replaced by 'SWR4 Radio Stuttgart' in this example). But non-network times
predominate. For SWR4 BW it's 19.5h every day.


*Ahem* ... thinking again about the last paragraph, the definition of a
lead station would surely also fit for my use case. But the device should
also tune to the lead station (e.g. 'Radio Stuttgart') when clicking on the
group name ('SWR4 BW' in this example). I know this is the attempt to break
something political down into a technical requirement ... but that's
life :-)


Best
Sebastian