Cable television in Ireland

Cable (originally known in Ireland as "piped" television) first started in the 1960s, when several companies, including state broadcaster RTÉ, started relaying the UK's terrestrial TV channels in some cities and larger towns. Today all Irish cities and many larger towns have cable networks.

Ireland's cable television networks are primarily digital DVB-C services. However, in most areas, a small number (approximately 16) analogue channels are still carried alongside digital services.

The legacy analogue cable television services provide unencrypted PAL System I television channels. Frequency plans vary from place to place and channels are carried in VHF Band I, Band III, Hyperband and sometimes UHF Band IV.

In the past, additional encrypted premium analogue channels were also available. To view these channels a set top box was required. Cablelink / NTL Ireland used Cryptovision, while some other companies, notably Cork Multichannel, used Jerrold (General Instrument) scrambling systems.

Cork City and other areas cabled by Cork Multichannel Television required an Jerrold (General Instrument)set top box for all channels. The entire Cork analogue cable network was encrypted from late 1980s onwards. The Cork network also carried more channels than other cable networks in Ireland at that time. When digital cable was launched in Cork, UPC Ireland rapidly swapped analogue set top boxes for digital boxes and then shutdown the analogue service entirely. The network still carries analogue terrestrial channels, RTÉ1, RTÉ2, TV3 and TG4 in some parts of the network. This means that Cork is the first city in Ireland with an exclusively digital cable network.

For analogue cable in Ireland there is no set frequency plan. Most cable networks for analogue use Harmonically related carriers (carrier frequencies of exact 8 MHz multiples). Some cable networks such as Limerick use Irish terrestrial channel alignments or even a mixture of the two-channel plans.

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