1그들 자신 is a mobile terrestrial digital audio/video and data broadcasting service in Japan, 아르헨티나, Brazil, Chile, 우루과이, 파라과이, Peru, 그리고 필리핀.

1 seg is designed as a component of ISDB-T, the terrestrial digital broadcast system used in those countries, as each channel is divided into 13 segments, with a further segment separating it from the next channel; an HDTV broadcast signal occupies 12 segments, leaving the remaining (13일) segment for mobile receivers, hence the name, “1그들 자신” 또는 “원세그”. See full seg.