Mobile technology expanding inclusive early warning communication
Community-based (CB) and location-based (LB)- Short Message Service (SMS) are technologies that allow mobile network infrastructure to send messages to handsets. LB-SMS can send SMS messages to devices within a defined geographic area. CB can send instant, loud, distinctive alerts to millions of devices in seconds, also within a defined geographic area. Countries like Brazil, the Solomon Islands and Cambodia are strengthening multi-hazard early warning systems (MHEWS) through mobile-based strategies tailored to local contexts and resource realities.
In Brazil, the integration of CB technology into the national Public Alert Dissemination Interface has significantly broadened the reach of emergency messages. CB allows geo-targeted alerts to be sent instantly to all mobile phones within a hazard zone - without requiring prior registration or internet access. Led by the National Secretariat for Civil Protection and Defence, in collaboration with ANATEL and mobile operators, this approach improved warning speed and coverage, particularly in flood-prone regions, while addressing structural inequalities in access to lifesaving information.
A similar CB approach was piloted in the Solomon Islands in 2025, supported by GSMA, the Pacific Islands Telecommunications Association, and Omnitouch. By delivering real-time warnings to all mobile devices, including those without credit or registration, this system complements alerts that are already being disseminated by limited SMS, mass media, social media and traditional channels. Hosted within the Solomon Islands Government ICT services (SIG-ICT) office and integrated with the outputs from multiple warning agencies, this successful pilot has paved the way for the regional roll-out of this CB-based solution whilst also demonstrating the importance of stakeholder training and strong local ownership.
In contrast, Cambodia's EWS1294 showcases how a subscription-based, low-cost model can still yield substantial preparedness gains. Built by People in Need in collaboration with national disaster authorities, EWS1294 delivers flood alerts via interactive voice response) calls, public loudspeakers, Telegram groups, radio broadcasts, and SMS. In Siem Reap Province, a local disaster officer's outreach helped register over 25,000 residents, resulting in improved response, reduced damage, and a strong multiplier effect - nearly 80% of those alerted helped inform others. While effective, post-event assessments revealed gaps in coverage, particularly among remote populations, spurring efforts to expand awareness and launch broader SMS broadcasting with telecom partners.
India's National Disaster Alert Portal, SACHET, piloted in Tamil Nadu from 2019 to 2021 and now operational nationwide, was developed to address longstanding challenges in delivering timely, inclusive, and geo-targeted disaster alerts to over a billion people at risk. Led by NDMA and the Centre for Development of Telematics, and integrated with all 36 states and union territories and major mobile operators, the CAP-based platform combines LB-SMS and CB (still undergoing testing) to deliver multilingual alerts in 23 languages, with accessibility features for persons with disabilities. It incorporates real-time dashboards, GIS targeting, automated workflows, and multichannel dissemination across phones, sirens, broadcast media, and display boards. With over 44 billion alerts issued across 30,000 hazardous events, the system has improved speed, reach, and public trust. Challenges such as device compatibility and over-alerting were addressed through training, standard operating procedures and public awareness efforts, positioning SACHET as a scalable model for digital risk communication.