北京上线北斗卫星短信应急通信服务

BEIJING, June 17 (Xinhua) -- In the event of extreme disasters during flood season, if terrestrial network communication signals are unavailable, residents in China's capital city Beijing can use the BeiDou Navigation Satellite System (BDS) short message service (SMS) for emergency communications and to seek help. According to a report by Beijing Daily on Wednesday, three major telecom operators in Beijing including China Mobile, China Unicom and China Telecom jointly launched such SMS emergency communication service for local residents on June 15. At present, more than 170 smartphone models support this SMS sending function, while no special requirements apply to the recipient's terminal device. The service enables users to transmit messages with accurate geolocation data for timely disaster reporting, safety confirmation and emergency rescue requests, even when terrestrial networks are completely down, provided that their smartphones support BeiDou satellite messaging. Residents can access the BeiDou satellite SMS interface just as they would when sending a regular text message, compose their messages, and tap send. The smartphones will then automatically initiate the satellite-searching procedure. By following the on-screen prompts and pointing the device toward the BeiDou satellites in the southwest sky, users can usually establish a connection and send their message within 5 to 15 seconds. Each message can be sent to up to four recipients simultaneously, with a maximum length of 20 Chinese characters. Both the message content and the attached location information are counted toward this limit. After each sending or receiving operation, a one-minute interval is required before the next action can be taken. The recipient can view the location on a map by clicking on the link embedded in the message, and may reply directly by composing a response of up to 10 Chinese characters. The service incurs no charges unless used. Once a message is sent, a per-message fee applies, while message reception remains free of charge, said the report. Residents can activate the BeiDou satellite SMS function directly in their smartphone settings and begin using it immediately. The BeiDou satellite SMS is specifically designed to address the challenge of sending and receiving text messages in areas without terrestrial signal coverage. It is applicable to scenarios such as flood prevention and disaster response, self-driving, field patrol, as well as expeditions and crossing…