HD viewers will now find the standard definition version on channel 141. Viewers outside of Northern Ireland are unaffected.
Sky first announced the facility to swap standard with high definition broadcasts in 2010. Only HD channels that were identical to the standard definition service where eligible to swap. However Sky indicated at the time:
Sky is currently minded, subject to any further representations on the matter, to require that the swap is implemented for relevant Nations for any National Variants where the HD and SD versions are exact simulcasts in respect of such Nation.
“National Variant” means a single variant of the channel available to all of a Nation. “Nation” means the whole of: England, Scotland, Wales, the Republic of Ireland or Northern Ireland.
With the introduction of national versions of BBC One HD, BBC Northern Ireland now fits the eligibility criteria for the swap. UTV's recent launch of its HD channel on Sky 103 appears to have given the BBC the impetuous to activate the HD/SD swap facility.
There are no changes to BBC services on other platforms.
Earlier this year, the BBC confirmed that it is in favour of swapping standard definition services with high definition services as part of a consultation about Freeview HD channel numbers. In its consultation response to terrestrial TV platform manager Digital UK, the BBC said that such swaps “could be the best way to ensure that audiences enjoy the full benefit of the substantial investment that HD channels have made in the production and distribution of their services, and indeed the viewer has made in his or her choice of television receiving equipment”.
The BBC also stated that it "would require the right to substitute channels on a nation-by-nation and region-by-region basis", thus indicating that it wanted to swap standard and high definition versions as national and regional variants went live.
Digital UK: No swaps on Freeview
Following the recent consultation on Freeview HD channel numbers, Digital UK decided against such swaps for the time being - except for children's and adult services - meaning that BBC One HD versions in the nations are not allowed to swap, even though the BBC may want to do so. There is currently no SD/HD swap facility on Freesat, with HD services replacing standard definition channels outright.
The Communications Act 2003 is currently being reviewed, with the possibility that platform operators will have to give HD services the same prominence as standard definition channels, especially where the HD version has the same regionality as the standard definition version.