Global voice chat over short message service of Beidou navigation system

Abstract

The capability of short message service (SMS) of Beidou navigation system (BDS) is an advantage over the GPS. Text-only SMS hinders the applicability of BDS. The global voice chat has been designed & tested over the BDS SMS, which can transmit voices of 2 seconds in a single 78-byte message. Field tests have been completed between two sites far apart over 2,500 km, one in the city of Xi'an and the other onboard a ship in the South China Sea. Results have shown that the voice chat over the BDS SMS is available to any subscriber even he cannot type a single word. More than 90% of interaction time is saved and authentication security is enhanced. The global voice chat is an effective supplement to the outdoor emergency communication systems nowadays.