The Software System Design Of Embedded Communication Terminal Integrated With Heterogeneous Network

Data transmission plays an important role in environment monitoring and disaster relief. Remote data transmission needs a long-distance communication network and an emergency communication method under complex conditions. Besides, the transmission should be reliable and timely.Based on the research of remote data transmission, this paper presented a new embedded multi-mode communication terminal which integrated ethernet, 3G communication and BeiDou Satellite short message service, aiming to implement a reliable and efficient data transmission system. The embedded communication terminal applied ethernet to transmitting urban environment monitoring information, applied 3G telecommunication to remote sensor data transmission, and adopted BeiDou Navigation Satellite System to realize data transmission for emergency communication in disaster area. During our research, as the 3G device gets a dynamic local IP address assigned by the GPRS Gateway Supporting Node when dialing in 3G network, and the three telecommunication operators use different 3G protocols, the point to point communication between 3G devices can’t be realized. Aimed at this problem, the paper built a data transmission server for storing and forwarding 3G communication data, which supported working in real-time mode and non-real-time mode, therefore we realized 3G point to point communication crossing different 3G protocol. Meanwhile, aimed at the unreliable transmission of BeiDou Satellite communication, this paper designed a message retransmission mechanism based on feedback and confirmation to increase the robustness of communication.The paper presented communication experiment results based on the embedded communication terminal, and the results proved our design to be correct and reliable.