News on UK Analogue switchover

lawhec

from the (usually) reliable dtt-tx-info.org website, those that may be of interest to many of us here are highlighted...

UK DTT Network - The Analogue Switchover
Questions to ask?? Ask in the Forum.
Overview.
The UK Government has announced plans to convert the terrestrial television network to a digital only network by the end of December 2012.
The conversion programme will start in late 2006/2007.
The programme will be completed on a region by region basis. (Region being defined by local BBC/ITV areas).
The first region planned to be converted will be the Border Television (covered by BBC NE & BBC Scotland) area.
All main Transmitting Stations will be re-engineered to allow for power increases and frequency changes.
Each main station and its relay stations will be converted over a period of around 4 months.
Main Transmitting Stations will operate at either -10dB or -7dB with respect to the current analogue services.
Many DTT multiplexes will change broadcast frequencies so to ensure that all services from a particular station are transmitted within the same 'group' (eg. group A, B, C/D etc)
All 1,154 main and relay stations currently in operation will transmit at least 3 of the 6 multiplexes, these 3 multiplexes will will carry services that have Public Service Broadcast (PSB) obligations (eg BBC1, BBC2, ITV, Ch4, Ch5).
Multiplex 1, 2 and either A or B will be classed as PSB multiplexes.
Initially at least 200 stations will carry all 6 multiplexes - see table below.
Full details of OFCOM's consultation on this subject can be found on www.ofcom.org.uk

Table indicates non main stations which will carry all 6 DTT multiplexes.

10668 Aberdare
10618 Abergavenny
10612 Abertillery
10504 Abington
10138 Alexandra Palace
11806 Arfon
13717 Barskeoch Hill
11002 Bath
16109 Berwick-on-Tweed
10707 Black Mountain
10617 Blaenavon
10614 Blaina
10203 Brierley Hill
11008 Bristol IC
11007 Bristol KW
10206 Bromsgrove
10314 Buxton
11005 Calne
15206 Campbeltown
13721 Cambret Hill
10740 Camlough
10702 Carnmoney Hill
10508 Cathcart
10228 Cheadle
10118 Chepping Wycombe
10405 Chesterfield
11803 Conway
10512 Cow Hill
12302 Crieff
10624 Cwmafon
12401 Dallington Park
10301 Darwen
13710 Douglas
10141 East Grinstead
13905 Eastbourne
10613 Ebbw Vale
16101 Eyemouth
10903 Fenham
10211 Fenton
10619 Ferndale
15205 Girvan
10505 Glasgow (West Central)
10313 Glossop
11916 Greenhill
13804 Guildford
11605 Guisborough
10303 Haslingden
13902 Hastings
16103 Hawick
10105 Hemel Hempstead
10110 Henley
10102 Hertford
10107 High Wycombe
11030 Hutton
10413 Idle
13112 Ilfracombe
10407 Keighley
10336 Kendal
10202 Kidderminster
10703 Kilkeel
10601 Kilvey Hill
15202 Kirkconnel
10309 Ladder Hill
10335 Lancaster
10208 Larkstoke
10701 Larne
10221 Leamington Spa
10210 Leek
15204 Lethanhill
13510 Llandinham
11904 Llandrindod Wells
11901 Llanelli
10622 Llangeinor
15217 Lochwinnoch
13001 Londonderry
13509 Long Mountain
12402 Luton
10604 Maesteg
10207 Malvern
10607 Merthyr Tydfil
15210 Millburn Muir
10910 Morpeth
10603 Mynydd Machen
10705 Newcastle
13901 Newhaven
10902 Newton
11101 Nottingham
10630 Ogmore Vale
12002 Olivers Mount
16107 Peebles
14701 Penicuik
10302 Pendle Forest
11802 Penmaen Rhos
12301 Perth
13105 Plympton
10615 Pontypool
10605 Pontypridd
10804 Poole
13712 Port St Mary (IOM)
10620 Porth
10103 Reigate
12916 Rheola
10602 Rhondda A
10609 Rhymney
11203 Rosehearty
15211 Roseneath
10714 Rostrevor
15215 Rothesay
10306 Saddleworth
10801 Salisbury
13744 Sedbergh
10408 Shatton Edge
10403 Sheffield
10404 Skipton
13201 St Thomas (Exeter)
11108 Stanton Moor
10307 Storeton
13004 Strabane
13719 Stranraer
11018 Stroud
12308 Tay Bridge
13203 Tiverton
10465 Todmorden
10510 Torosay
10623 Treharris
10104 Tunbridge Wells
11401 West Runton
13208 Weymouth
10401 Wharfedale
13701 Whitehaven
10805 Whitehawk Hill
10312 Whitworth
10810 Winterbourne Stickland
10109 Wooburn
10106 Woolwich
11903 Ystalyfera

If Arfon did Dtt,I'd guess I'd have almost 100% reception here, the analog from that relay in this part of south wicklow is truly amazingly strong.

What are the numbers beside the tx name? grid references?
I thought they were dates at first but they couldnt be.

lawhec

Earthman wrote:

If Arfon did Dtt,I'd guess I'd have almost 100% reception here, the analog from that relay in this part of south wicklow is truly amazingly strong.

What are the numbers beside the tx name? grid references?
I thought they were dates at first but they couldnt be.

The numbers are an indivudal code given to the transmitters, which relate to their parent station. Any analogue relay of Divis have the numbers 107xx for example.

Mike 1972

Surely once Analouge has ceased completly the digital stuff can revert to SFN (single frequency network operation) so that the same six channels can be used throughout the UK

Apart from enabling All transmitters and relays to carry all six multiplexes this would free up more bandwidth for additional channels HTDV and/or non broadcast services

lawhec

Mike 1972 wrote:

Surely once Analouge has ceased completly the digital stuff can revert to SFN (single frequency network operation) so that the same six channels can be used throughout the UK

Apart from enabling All transmitters and relays to carry all six multiplexes this would free up more bandwidth for additional channels HTDV and/or non broadcast services

The main problems would be...

1. Muxs 1, 2 and A carry regional services
2. An SFN using 2K mode is very restrictive
3. Not all STBs, including some recent ones, are 8K mode compatible.
4. It's thought that a national 8K SFN would only be able to cover 85% of the country due to multipath reflections and reception from distant transmitters interfering with wanted transmissions
5. Arguement of different types of grouped aerial required.
6. Huge cost that would be involved in upgrading all transmitters to carrying all six services. Personally I doubt every analogue relay transmitter will be upgraded as many of them were installed to cure reception problems that DTT are reasonably immune to.

There is the possibility though,for example, that the whole of Northern Ireland could have it's own SFN.

Mike 1972

Muxs 1, 2 and A carry regional services

Yes but for most people the multiplex carrying their local region would be by far the strongest and in "overlap" areas aerial directivity would select the appropriate region would it not ?

Not all STBs, including some recent ones, are 8K mode compatible

I was under the impression that all "freeview" branded boxes were dual standard. The government should really have insisted on this but then again If we are to have any realistic prospect of a digital switchover this decade they should have made internal DTT tuners mandatory on all new TV's and VCR's long before now. Its a bit late now I suppose

It's thought that a national 8K SFN would only be able to cover 85% of the country due to multipath reflections and reception from distant transmitters interfering with wanted transmissions

I thought one of the main reasons for switching to digital was to overcome problems like this but given that DTT has already been shown to be notoriously prone to reception problems barely noticeable on analouge I would say youre probably right

5.

Arguement of different types of grouped aerial required/There is the possibility though,for example, that the whole of Northern Ireland could have it's own SFN

Ummm Limavady are on a different group to Divis/Brouger

Personally I doubt every analogue relay transmitter will be upgraded as many of them were installed to cure reception problems that DTT are reasonably immune to.

Again youre probably right on this one but what differecnce would it make If all main TX's were configured on a SFN ?

lawhec

Mike 1972 wrote:

Yes but for most people the multiplex carrying their local region would be by far the strongest and in "overlap" areas aerial directivity would select the appropriate region would it not ?

All if and buts really, down to indivudal circumstances, but it shouldn't matter much in the north.

I was under the impression that all "freeview" branded boxes were dual standard. The government should really have insisted on this but then again If we are to have any realistic prospect of a digital switchover this decade they should have made internal DTT tuners mandatory on all new TV's and VCR's long before now. Its a bit late now I suppose

EU laws afaik would forbid the UK government making DTT tuners mandatory, as is specifying a chipset.

I thought one of the main reasons for switching to digital was to overcome problems like this but given that DTT has already been shown to be notoriously prone to reception problems barely noticeable on analouge I would say youre probably right

It's all down to time delay. In problems of local ghosting where the bounced object is not usually more than 6/7 miles away, the current DTT setup in the UK can usually cope with it without problems. However if as an extreme example the reflected object was say 25/30 miles away the time delay between the wanted received signal and the unwanted signal being received can be too big and the receiver gets confused. In an 8K enviroment a transmitter say 50 miles away on the same frequency as a local station could give a strong enough signal to corrupt the wanted signal. It's a fine balancing act through setting the right parameters. In theroy almost 100% coverage could be achieved across the UK on a SFN but to configure the multiplexes to do so would seriously comprimise the data rate. DTT SFNs abroad use SFNs on a regional basis, with the transmitters reasonably close together.

Ummm Limavady are on a different group to Divis/Brouger

True - however if sufficient power was used some existing aerial installiations could get away with it; a group c/d aerial with work better with group A frequencies than a group A aerial on group c/d frequencies, though I wouldn't recommend such a pracitce.

Again youre probably right on this one but what differecnce would it make If all main TX's were configured on a SFN ?

I would say cost and practacalbility - in areas where there is a relay because of a weak signal from a main transmitter there is a justification; where there is a relay because of a poor analogue signal but where those that have decided to upgrade to Freeview (with new aerials if necessary) there would probably be a commerical case in not doing so and would probably work out cheaper in upgrading receiving aerial installiations in the area.

Capt'n Midnight

http://www.dgtvi.it/faq/index.html

Il contributo statale è a termine o si prorogherà fintanto che tutti gli utenti acquistino il decoder? Chi usufruirà del contributo?
Per il 2004 lo Stato ha stanziato 110 milioni di euro per incentivare la diffusione dei decoder in vista del passaggio completo al digitale previsto a norma di legge entro la fine del 2006. La condizione per poter usufruire del contributo statale pari a 150 euro per l'acquisto di un decoder interattivo è essere in regola con il pagamento del canone di abbonamento TV. Per quanto riguarda la durata del contributo nel 2004, lo stesso verrà garantito fino ad esaurimento dei fondi. È auspicabile che lo Stato preveda anche per il 2005 una politica di finanziamento in vista dell'ambizioso obiettivo, fissato dalla legge, del passaggio completo al digitale entro il 2006.

state are spending 110 Million Euro on subsidising the decoders.
passing completely to digital within 2006.

Any idea when we are going to start ?

byte

We'll probably start when UK have finished!

It's bad that not even one Tx in ROI has been running DTT. It woudl remain to be seen what channels, apart from the main 4, would be carried on the service.