term, it is unlikely existing free-to-air channels will convert to pay TV. This is because, firstly, Multiplex B is run by the BBC, which is not expected to request the removal of the free-to-air requirement. Secondly, due to the nature of the contracts the channel broadcasters hold with multiplex operators and content providers, it is unlikely a channel will be able to change to pay TV. It was announced on 8 February 2007 that BSkyB intended to withdraw Sky Three, Sky News and Sky Sports News from the platform in the summer of 2007. BSkyB had said that it intended to replace them with 4 of its subscription channels. It also said that it would use an alternative (MPEG4) codec, which would enable a greater number of channels to be broadcast, but would require the purchase of new equipment for those who wished to receive the new service. On 6 October 2007 Ofcom said that the plans for a new subscription service raised competition concerns and may have to be scrapped. 2008 update issues During 2008, a rolling programme of transmitter updates caused approximately 250,000 set-top boxes to stop working. Freeview had warned consumers in advance of the update, which was phased over a three-month period. The problem affected a specific range of older units, and was caused by an increased Network Information Table (channel list) exceeding the memory available in some set-top boxes. This had been part of the specification that was available and implemented in the very early OnDigital boxes, but not in those using the SetPal chip set. Affected consumers were advised to buy new set-top boxes. Digital switchover Summary The UK Government's intention was that digital terrestrial television would completely replace analogue terrestrial television in the United Kingdom by 24 October 2012. This process was known as "Digital Switchover", or DSO. The industry association for digital television in the UK, Digital TV Group, was responsible for co-ordination between Freeview and other digital services. DTG licensed suitable equipment to bear the Digital Tick and Freeview Playback Logos to identify PVRs and other devices designed to work through switchover, and to raise awareness of DTT product quality and standards. Digital terrestrial television is broadcast using the DVB-T international standard for standard-definition content and DVB-T2 for high definition content. The digital switchover process involved discontinuing analogue terrestrial TV broadcasts, which in some areas allowed for greater signal strength and/or