Design & Implementation Of A3/A7 Interface Translation

With the rapidly development of 3G mobile communication system and the network technology,mutual communication is becoming an urgent problem.Conjuntioned with the third mobile communication system project-CMT, one of A interface -A3/A7,the interface between BSCs is analysised . This paper centres on the theme which is brought out by the interconnection between the BSCs based on IP framework in CMT and the ones based on ATM defined by the standard.Different characteristics of the CMT system based on IP and the cdma2000 system based on ATM defined by the criterion is discussed in this article at first, the related concepts and the different protocol layers between the two kinds of network frameworks in the A3/A7 interface are descripted. After profoundly understanding some related specifications of the 3GPP2 IOS ,the traditional voice-traffic theory is introduced in this paper, and correspond traffice model as well, then the performance which is should be provided by the designed interface is analysised ,then the critical parameter of the interface-equivalent channel number is determined. According to the specific instance in CMT system, hardware implementation scheme is established. The software design is concentrated on the ATM driver specificly applied in CMT system and the uplayer application program. This thesis introduces the basic principles and the main points during the designation and implementation of the two main content-AAL5 and AAL2 about ATM driver and the MUX interface of Vxworks. Uplayer software design is the emphasis of the article, which includes three module that are message processing module,socket interface manegement and property configuration table and two key issues that are the correspondence between TCP link and ATM vitual cicuit and the message translation. At last ,the thesis provides some improving ideas about A3/A7 protocol process in the interface and the network efficiency.