Design and implementation of reliable data transmission system for emergency communications based on 3G and BeiDou Navigation Satellite

In recent years, natural disasters and environmental pollution events occur frequently and seriously threaten people's lives and property. The first step of disaster prevention and mitigation is obtaining the monitoring data of disaster situation. Currently, there are two main problems in transferring monitoring data, one is that disaster monitoring sensors are always located in remote, which are hard to access the Internet to send and receive data effectively; the other is that when major natural disasters occurs, traditional communication network, like GSM, GPRS or Internet could not provide a reliable data transmission link or even totally failed. And our studies aimed to design and implement an embedded heterogeneous communication network router (EHCNR), which integrated three communication techniques: Ethernet, the third-generation telecommunication (3G) and the short message service (SMS) of BeiDou Navigation Satellite System (BDS). Based on EHCNR, we built communication mechanism to achieve the efficient and reliable transmission of disaster monitoring data. Environmental information monitored in our study was gathered by special designed sensors. All of the monitoring data would finally be transmitted to central data warehouse server (CDWS) and stored in database. In addition, we defined transmission priority for the three heterogeneous communication networks in the protocol layer of EHCNR, and realized the device-to-device (D2D) communication in 3G network crossing different telecom operators; also we designed and implemented the data transmission through SMS of BDS. Finally, we did experiments based on EHCNR under complicated conditions, and the test results were reliable and efficient.