DAB in Ireland: RTE multiplex closed

"niche stations for people in cars who don't have data packages" isn't much of a use case to go providing a nationwide infrastructure for.

That depends on what sort of choice is on offer.

In the UK there are plans to close FM though. And we tend to copy them, albeit in half-arsed way.

It's probably down to money. No increase in the licence fee since 2008.

Replace 2FM or Radio Highbrow? cause there is no way RTE is going to be allowed to have another national FM network even if they had the money to build one.

A very rough guesstimate, RTÉ/2RN currently has 42 FM transmitters around the country. For nationwide DAB you are going to need at least a similar number of new transmitters and associated aerial systems and interlinks. Add to that electricity to run all this and the numbers start rising VERY quickly.

Taking one thing at a time...

RTÉ Gold on FM - there is essentially no further frequencies available within the Irish bandplan for another national network that would match the coverage of the four main RTÉ FM radio networks at present (42 sites, all transmitting Radio 1 and 40 also transmitting 2FM, Lyric FM & RnaG). Spot coverage covering various locations, at best a quasi-national network like that of Newstalk (but Newstalk gets away with tighter frequency reuse thanks to not broadcasting in stereo) might be possible, though would likely give issues in certain localities where FM reception of the station wouldn't be possible. Any such proposal like what I've mentioned or even to take "off" one current FM network and replace it with programming from RTÉ Gold would have to go through the government, with objections by commercial operators likely to be submitted. The proliferation of FM transmission sites in the Republic are now coming to the point where reception of services are being increasingly limited by interference more than geography.

Next, DAB...

The BBC reckon that it's current DAB network (single ensemble/multiplex) is cheaper per listener to run that the national networks for its Radios 1-4, even though it requires more sites to broadcast from. Currently it uses around 400 sites to broadcast DAB which, from the UK "Frequency Finder" website, gives indoor coverage to 97.4% of the UK population (plus the Channel Isles & IoM), compared to approx. 215 sites for the national FM networks (Radios 1 - 4, plus Scotland, Cymru & Ulster in respective areas) that have stereo coverage at ~98.5% population (higher at over 99% for mono reception) as well as 23 sites for BBC 5 Live on medium wave and 12 sites for BBC Radio 4 on LW & MW (both stations definitely don't have 98% population coverage at night, and probably don't either during the day, though R4 LW is likely close) as well as the four small MW TX's for the BBC's Asian Network. However, each FM station is essentially single-channel per carrier (as opposed to DAB multiple channel per carrier), works on a multi-frequency network & transmits at various powers up to 250kW per station. DAB OTOH for the BBC can accommodate all "national" stations on one frequency block using one TX per site, which has a maximum ERP of up to 10kW depending on the site in question. For comparison, the two commercial DAB ensembles/multiplexes in the UK have about 91% indoor coverage for Digital 1 (around the same as those served by the commercial Freeview multiplexes on DTT) from around 200 sites and around 83-84% for Sound Digital from 64 transmitters.

When it comes to site planning, the needs for DAB(+) are a fair bit different to that for FM broadcast radio and are more relatable to 3G/4G/5G mobile networks albeit as a one-way broadcast medium instead of a two-way CSD/IP network. All the BBC & Digital 1 TX's are limited to a maximum of 10kW ERP per TX to avoid causing destructive interference in some locations (reception of two or more signals that lie more than 74km apart 'in time' from a receiving location will fall outside the guard interval that would otherwise cause constructive interference and reinforce reception where they're less than the 74km limit), though as Sound Digital uses less sites, they use up to 25kW at a few locations. Whereas very high prominent sites are seen as a boon for FM & DTT MFN broadcast coverage, they can cause issues for DAB planning because of their increased chance of causing destructive interference in the far distance - the general rule in European countries so far with mature or maturing DAB SFN networks involving prominent broadcast sites whom would otherwise broadcast FM transmissions at 50-100kW or more has been to keep DAB SFN ensemble transmissions to very modest power levels, for example at the Holme Moss site in northern England (pretty much their equivalent to Mt. Lenister in terms of prominence) the BBC limit the ERP of their DAB multiplex to just 2kW, while Digital 1 have theirs at 4.7kW.

The current 2RN network of broadcast sites was developed from the early 1960's onwards to carry VHF analogue television and FM radio, and did so quite well for this purpose, the switch to DTT was relatively painless and allowed 2RN to withdraw some sites for TV broadcasting. Unfortunately, the present network of sites, coupled with some unfortunate geography, makes this less than ideal to roll out a national DAB network without some very careful planning. It's not so much the hills & mountains that are a problem - Norway and Switzerland are even more mountainous than Ireland but have developed their DAB networks very well, and indeed use immunity against mutlipath interference often caused by such compared to FM reception as a bonus - but rather that Ireland is shaped somewhat like a bowl with raised edges and a flat-ish centre. Go to places like Longford, Westmeath, Offaly etc. and you'll find plenty of spots there that can receive RTÉ FM radio from a multitude of high-power 2rn sites like Truskmore, Maghera, Clermont Carn, Mt. Leinster etc. and it should not take much of an imagination to see how the likes of say Truskmore & Mt. Leinster broadcasting an SFN with considerable power (let alone any other sites) would cause destructive interference issues over a large area. Careful planning would be needed to ensure aerial radiation patterns would keep such areas to a minimum. Fortunately, 2RN already have two significant TX sites in this region in the form of Carin Hill & Kilduff that could fill otherwise weak signals from other main sites.

I'm no expert frequency planner, but there are currently 66 DTT (Saorview) sites and 42 National FM radio sites, the vast majority of the latter also carrying DTT (Alhlone is one exception off the top of my head). DTT coverage is though to be 98.5% of the population with a properly installed outdoor UHF receiving aerial, not sure what the RTÉ national FM population coverage is but I'd expect it to be similar (98-99% for stereo reception based on field strength contours). To have a DAB+ ensemble/multiplex match the current BBC population levels in the Republic of Ireland (97.4) I'd say you're looking at somewhere between 45-70 sites with most potential sites already having existing masts or towers with room available, with anything between 20-25 sites being enough to cover at least 85-90% of the population as well as the major road routes - the talk of "hundreds" of sites being needed would be well off the mark IMO.

However, all that talk would be essentially pointless if DAB+ is never to make any inroads in the state. IMO I would not rule out an attempted reintroduction of DAB (or at least DAB+ in a legal form i.e. no "FreeDAB") at some point in the future especially as more car head units will have DAB+ capabilities by default as time goes on though the one thing that would be clear is that RTÉ would never be able to fill an ensemble of content on their own and that any "first" national ensemble would really need to carry both RTÉ & commercial services - as a suggestion, Today FM & Newstalk and maybe Classic Hits could be offered a carrot of an automatic renewal of their FM contracts for going on to this ensemble (as what happened in the UK for FM services going on to local DAB ensembles), while other spaces could be offered up for other potential broadcasters that for their own carrot would have reduced commitments in certain programming areas compared to their FM counterparts. However, whatever regarding the technical hurdles, all of that would have to jump over several political hurdles. It's not just finances, it's also a matter of will.

I’m on a train to Dublin at the moment and just can’t get a stable stream of RTE Gold, it has rebuffered about 6 or 7 times in the last 20 minutes. It’s times like this that I wish there was an alternative to streaming it.

Honest question, is Vodafone not good enough? You'll never have anything near 100% geographic coverage on any mobile network.

Found Vodafone to be a bit patchy, but it's all kinda specific. I'd recommend trying another provider.

How much radio you listening to? I think it's 96 kbps on RTE and that not a lot, it's not like streaming lots of Youtube. Tesco do unlimited data for €20 and that's pretty good or there's GoMo for €15.

Mind you that's lots more bitrate on web radio than you get on DAB in the north so maybe not a fair comparison.

If the legislation passes in the UK to allow RTE to broadcast radio in the UK, how likely would it be that in Northern Ireland, and specifically Belfast (which has reception issues of RTE Radio) that the four main FM RTE radio stations would be transmitted within NI? I assume that DAB is likely how the stations would be broadcast if it ever came about. I know the legislation is aimed at RTE Radio 1 in the UK with the demise of 252 LW but wondering if in NI there would be provision of all four FM stations - is there even the capacity/space to do this on the DAB network at present?

RTE RnaG is already available on DTT in N. Ireland via NIMM with good coverage especially in the East.

Mobile Reception isn't even close to the signal coverage from DTT (or what DAB from the same sites) achieves, unlike the national broadcaster who has an obligation to provide coverage to the population, mobile providers do not; you'll note that even the oldest of the bunch will make a claim like X% Population and Y% Geographic with the latter being much smaller.

A good data package is not much use if you don't have adequate reception

This has echos of paying a Pay-TV provider (just to) watch our national broadcaster, for RTÉ I cannot see it happening, and, I can only hope it never happens for the other services; right now I get 100% of my TV and Radio free of charge, I don't want to be in a position where my choice is stream it on my PC or stream it on my phone, the idea of being forced to pay a third party just to watch television that's ordinarily free is anathema.

Having said that; with near-unaffordable charges to broadcast on DTT, no possibility of opening a local/regional/third national multiplex and, the relatively low cost (for now) to stream (to a limited audience) makes the online route appealing if you want to get a foot in the door.=

Other than you should not need to pay a mobile provider, to listen to radio, in your car, mobile coverage is still horrendously spotty outside of urban areas. It's absolute pot-luck if you can get a signal, much less an adequate data connection for streaming.