What is SACHET, the India-made system used to send Emergency Alerts on phones?

The government pushed Emergency Alerts on multiple phones across India on Saturday using the indigenously developed SACHET system. Developed by Centre for Development of Telematics (C-DOT), SACHET is based on the internationally-recommended Common Alerting Protocol. It is operational in every part of India and delivers emergency-related alerts via SMS to mobile users within geo-targeted areas.