1பகுதி is a mobile terrestrial digital audio/video and data broadcasting service in Japan, அர்ஜென்டீனா, பிரேசில், சிலி, உருகுவே, பராகுவே, பெரு, and the Philippines.

1 seg is designed as a component of ஐஎஸ்டிபி-டி, the terrestrial digital broadcast system used in those countries, as each channel is divided into 13 பிரிவுகள், with a further segment separating it from the next channel; an HDTV broadcast signal occupies 12 பிரிவுகள், leaving the remaining (13th) segment for mobile receivers, hence the name, “1பகுதி” அல்லது “ஒரு Seg”. See full seg.