| For the increasingly fierce competition in the 3G wireless network card market and improving demands of users for more functions of the wireless network card products, this paper researches and developes value-added functions for EVDO wireless network card systematieally, include removable storage, CD-free installation and MMS (Multimedia Messaging Service).First of all, this paper proposes and verifies the total design solution to the software system, analyzes and introduces related hardware framework, Qualcomm AMSS 6XXX software system and REX operating system. Secondly, this paper intensively researches and analyzes the USB module, including USB2.0 protocol specification and the total design solution of the USB module. On this basis, this paper develops and implements new functions of the USB module, that is U-disk and CD-ROM. U-disk supplies removable storage function while CD-ROM is used to store PC client software and drivers in order to achieve CD-free installation. Thirdly, after introduction of the PC client software, this paper describes and analyzes packaging and coding defined in WAP2.0 and MMS1.2 protocol specification, network structure and operating principle of MMS, and developes MMS transceiver module. Finally, this paper tests and verifies the operability and stability of the three new function.Wireless network card and the PC Client software joint debugging results demonstrate the effectiveness and reliability of the design. The research and development results have been successfully applied to the commercialized EVDO wireless network card products, and have achieved good results. Therefore, this article should have some reference value for related technology and product development. |
