The Design And Implementation Of MOST Network And Internet Gateway

As entertainment needs of people for car audio and video improve continually, in-vehiclemultimedia network technology is constantly developing. Today’s in-vehicle multimedianetwork technology are MOST network technology, IDB-1394network technology andEthernet technology to the mainstream, and three kinds of in-vehicle network technology havetheir own characteristics and advantages. MOST network technology can transfer many typesof data, and use different transmission medium, and use standard technology, and have a largenumber of standard vendor support; IDB-1394network technology has the highest datatransfer rate, and provides digital transmission content protection technology in the chip, andthe other two kinds of technology in terms of relatively lower hardware costs; automotiveEthernet technology originated in the traditional Ethernet, which has a wider application space,and it has the most flexible topology. By the view of markets and development status on threekinds of in-vehicle multimedia network technology, MOST network technology dominates.MOST network technology was proposed in1998, and it has ten years development. There isthree generations of specifications, and they are MOST25network technology, MOST50network technology and MOST150network technology. Comparing to the other two kinds ofin-vehicle multimedia network technologies, MOST network technology has a strongeranti-interference ability and electromagnetic properties of electrical isolation, and has astandard application framework, add and reuse to which is very simple and convenient.Internet is the world’s most widely used multimedia network, multimedia resources onwhich is very rich. If you can introduce network multimedia resources into MOST networkdirectly, you can make the in-vehicle multimedia network functions to be strengthened, andthen can make the car’s functionality, comfort and entertainment have been greatly improved.Therefore, the MOST network and Internet gateway is designed and implemented, throughwhich MOST network and Internet can have a safe and reliable communication, and then itcan enhance the functionality of MOST network.The first chapter focuses on kinds of in-vehicle multimedia networks and the technicalcharacteristics of the various networks. The history of development, the basic characteristicsand the research status of MOST network technology are discussed; the basic features ofIDB-1394network technology, and the strengths and weaknesses relativing to the other twokinds of network technology are discussed; the real-time Ethernet protocol standard ofautomotive Ethernet technology and a single pair of unshielded twisted pair are discussed.Three kinds of network have their own advantages and disadvantages.In this paper, the second chapter focuses on the MOST network protocol architecture and Internet protocol architecture. MOST network protocol is composed by application layerprotocol, data link layer protocol and port message protocol. Internet is composed by physicallayer protocol, data link layer protocol, network layer protocol, transport layer protocol andapplication layer protocol. Then, based on the MOST high protocol and TCP/IP protocolstack，the MOST network and Internet communication gateway protocol is designed. Finally,the design reference and the function of each domain are given.The third chapter presents the system architecture design of the gateway. According tothe design principles of heterogeneous network gateway, the gateway consists of total controlmodule, MOST network frame transceiver module, MOST network interface module,wireless LAN module, power module and serial port module. Each part works synergistically,so that the gateway can operate stably.The fourth chapter gives the application software design of the gateway, and firstlytransplants the MOST network program based on microcontroller to the embedded Linuxoperating system and gives the work flow chart of gateway program according to the specificfeatures of the gateway, then gives part of the data processing flow chart of the program,finally introduces notification service, and expounds how to combine congestion control andnotification service.The fifth chapter gives the overall implementation of the gateway by actual situation, andin order to control costs and make full use of existing resources, designs and implements agateway that can be controlled by touching. The experiments prove that the gateway has highavailability and stability.In summary, the MOST network and Internet gateway can make two kinds ofheterogeneous networks communicate reliably and stably, and improve MOST networkfunction, and make contribution to the development of MOST network technology.