| An overview of Digital Mobile Communication Network and Code Division Multiple Access to Digital Cellular System is first introduced in this paper, including the system structure and transmission mode. Based on these theories, the configuration and the functions of the CDMA Base Station System are briefly described, followed by the compartmentalization about the CDMA_BSS_SOFTWARE modules. The software structure of Service Process Subsystem and the SPS_SOFTWARE modules located in CCM board, consisting of Radio Control Module and Control Channel Signaling Process Module, are explained in particular, where RCM deals with the managements of the radio resource and CCHSP does the control channel signals. At the same time, their positions, interfaces between other subsystems, and so on, are primarily discussed in this paper. In the process of the modules designing, these key techniques are involved in, such as Hash arithmetic which is used for CDMA-BSS to fix on Mobile Stations by finding out corresponding IMSI & ESN quickly in the control channels and the access channel overload control arithmetic which is dealt with the control of access channels overload in the system. Finally, the new functions of the CCM are emphatically discussed in this paper, including Wilting & Blossoming of a cell, Breathing of a cell and the controls of the BS Transmission Power Track Loop (TPTL), which are all relevant to programming the special function control software. Besides these, the design for CCM to control a mix system, in which CHM-95 (using CSM1.5 chips) and CHM-IX (using CSM5000 chips) are compatible, belongs to the new functions. On the one hand, these functions purport the system will be more and more perfect in order to adapt the developments in future. On the other hand, it is helpful for the system to transit from CDMA IS-95 to COM A-IX smoothly. In addition, a tool, namely Telelogic Tau 4.0 (SDT), is roughly introduced with which most SPS software modules are designed and realized.
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