1ಸೆಗ್ is a mobile terrestrial digital audio/video and data broadcasting service in Japan, ಅರ್ಜೆಂಟೀನಾ, ಬ್ರೆಜಿಲ್, ಚಿಲಿ, ಉರುಗ್ವೆ, ಪೆರಗ್ವೆ, ಪೆರು, and the Philippines.

1 seg is designed as a component of ISDB-ಟಿ, the terrestrial digital broadcast system used in those countries, as each channel is divided into 13 ವಿಭಾಗಗಳು, with a further segment separating it from the next channel; an HDTV broadcast signal occupies 12 ವಿಭಾಗಗಳು, leaving the remaining (13ನೇ) segment for mobile receivers, hence the name, “1ಸೆಗ್” ಅಥವಾ “ಒಂದು Seg”. See full seg.