Digital terrestrial television in the United Kingdom encompasses over 100 television, radio and interactive services broadcast via the United Kingdom's terrestrial television network and receivable with a standard television set. The majority of digital terrestrial television (DTT) services, including the five former analogue channels, are broadcast free-to-air, and a further selection of encrypted pay TV services (such as Racing TV) are also available. Freeview is the only DTT service since Top Up TV closed in 2013. BT TV services are carried via IPTV signals. The digital broadcasting technology adopted in the UK is the DVB-T system (Digital Video Broadcasting – Terrestrial) carrying compressed digital audio, video and other data in a combined transport stream, using modulation. A total of eight national and one local 'multiplexes' are broadcast in the UK, guaranteed to reach over 90% of the country. Three of the multiplexes, carrying the free public service channels operated by the BBC, ITV, Channel 4, S4C and Channel 5, are guaranteed wider coverage still, reaching 98.5% of the country including areas dependent on low-power local relays. In the UK, the switchover from analogue to digital TV started on 17 October 2007 and was completed on 24 October 2012. Each group of regional transmitters had its analogue broadcasts switched off at a certain point between those dates. Receiving and recording Digital Terrestrial Television is commonly received by means of a compatible set-top box or integrated digital television (IDTV), connected to an appropriate receiving antenna. In most cases, reception is possible using aerials originally used for analogue television. Transmissions may be recorded in many ways – such as via the connection of a set-top-box to an existing 'analogue' video or DVD recorder, or by the use of newer models of such recorders which have built-in digital tuners. However, the most common option is by the use of set-top-boxes which incorporate a hard disk drive, and allow the recording of the digital signal directly to disk, for later replay. Recording on such boxes, known as Personal Video Recorders or PVRs, is more convenient, as programmes may be easily selected for recording from an on-screen programme guide, with no need to specify explicit start and end times for recordings, and no need to program more than one piece of equipment. Many television services which incorporate DTT channels in their service offering – e.g. Top Up TV, BT TV, and TalkTalk Plus TV, offer set