Complex sentence: ITV Digital was a British digital terrestrial television broadcaster, which launched a pay-TV service on the world's first digital terrestrial television network as ONdigital in 1998 and briefly re-branded as ITV Digital in July 2001, before the service ceased in May 2002.
Split into simpler sentences: ITV Digital was a British digital terrestrial television broadcaster, which launched a pay-TV service on the world's first digital terrestrial television network. Started as ONdigital in 1998, the network was briefly re-branded as ITV Digital in July 2001, before the service ceased in May 2002.