1сег is a mobile terrestrial digital audio/video and data broadcasting service in Japan, Аргентина, Бразилия, Чили, Уругвай, Парагвай, Перу, and the Philippines.

1 seg is designed as a component of ИӨБ-T, the terrestrial digital broadcast system used in those countries, as each channel is divided into 13 сегменттер, with a further segment separating it from the next channel; an HDTV broadcast signal occupies 12 сегменттер, leaving the remaining (13th) segment for mobile receivers, hence the name, “1сег” же “One Пнд”. See full seg.