The Research Of Hybrid Multi-Source Data Communication Technology For Application Based On Linux

With the rapid development of technology and the increasing amount of marine transportation, marine communications nowadays include analog voice, fax, data services, videos and other types of services. Communication equipments used between ships and monitoring center on shore and the type of information is not unified, which leads to trivial operations, a lower degree of terminator intelligence, high communication costs and so on. Thus, there are urgent needs for a unified communications platform to process and transmit multi-source of data. Under this requirement, a hybrid marine data transmission system based on Linux technology is designed.In this system common types of marine information can be captured and stored which includes sensor messages, voice messages, picture messages and so on. At the meantime, different type of data is mixed and the unified data stream after mixing is transmitted to modulation transmission system.Embedded hybrid multi-source data communication system is basically designed to meet the marine communication needs.The main contents are as follows:(1)Specific types of information necessary of cabin equipment used to monitor the ship, offshore radio call and. special ships are analyzed and studied.Data types and mainly characters are analyzed and hybrid transmission system is designed as a whole.(2) According to multiple sources of data needed in ship communications, the Linux mixed-platform is built. Based on the hardware configuration and features of S3C2440CPU, U-Boot and kernel source codes are modified and transplanted. The Linux mixed-platform is viable.Finally root file system is established under the FHS standards. The platform can uniformly manages and store all types of data collected, and transmit multi-source data after mixing.(3)After building the mixed-platform for multi-source data, the first thing is to achieve multi-source data collection. Ship operating status are monitored and DTH11temperature and humidity sensors are set as an example of driver development in sensor devices.The kerneal support program of UDA1341chip driver for voice collection is designed. Finally, a USB camera driver and collection procedures are developed using JPEG compression to compress and process the images captured. (4)The frame structure of mixed data is designed in detail. In order to ensure the accuracy of data transmission, Ethernet communication program under Linux environment is written using stream socket to achieve mixed data LAN transmission.