| With the increase in the number of mobile users, with the rapiddevelopment SMS and the proliferative business base on SMS, with thediversification proliferationbusiness,with IP and intelligent mobilenetworks,equipment providers need to provide a better solution. The main content ofthis dissertation is the CAMEL short message in MSC server based on theRelease-4 network architecture, to realize CAMEL in the traditional processof short message service, to facilitate the operators to achieve better businessexpansion. For example, to provide prepaid short message service, the callernumbers of short message revised achieving to conceal, to change shortmessagecenternumberfornetworkstructuraloptimization.M system board many points in the global investment business. In linewith its basic structure of the 3GPP R4 network architecture, the corenetwork of MSC circuit domain is divided into MSC Server (only forsignaling processing) and circuit switch media gateway (for dealing with themedia, etc.); M system also support IP transmission and the two-wayconversion between TDM and IP signaling. To facilitate expansion,replacement and test, M system is composed of a number of boards: serviceprocessing board, VLR board, central processing board, central databaseboard, the bottom signal processing board and media gateway controllerboard, etc.. The service processing board provides telecommunicationservices, supplementary services, intelligence services, value-added services,mobile management functions, security management functions, call controlfunctions, positioning and service switching function, in a word that Msystem iscomposedofgsmSSF,MSCandVLR.For the realization of the short message involve the access network andcore network which is consist of MSC Server, SMC, HLR and other entities.The internal software architect of MSC server is divided to two parts:network processing part and access processing part. The two parts areadopting hierarchical protocol structure, agreeing with open systems interconnection (OSI) reference model. The purpose is to allow eachstratifiedsignalingprotocol functional isolatedbyanindependent description.Each layer provides specific services for upper layer at its service accesspoint. The protocol stack is MTP3, SCCP, BSSAP, MM, CP, RP at accessside of MSC server; there are MTP3, SCCP, TCAP, MAP Provider, MAPUser, MAP_RL for MAP interface protocol stack at network side. We canreduce some layers, and integrate access and network processing part whenimplementation. Theprotocol stackintheMSC Server is BSSAP,MM,SMS,MAP Provider and TCAP after optimization. That merging less functionallayers can reduce the number of layers and primitives between layers, whichcanreducesystemoverheadsuchasmemoryandCPU.The various entities in R4 structure can be regarded as informationprocessors. Entities of each layer in MSC server can be regarded as theprimitives-drivenstatemachines.Tounderstandtheshortmessagerealization,it is necessary to first understand the primitives -driven charts and the statestransitionat everylevel. Locationupdatingand routinginformation flows arethe most basic processes which are supported by the MSC for the roamingmobile users. Location update for current users can let the network knowwhere the mobile subscriber is and determine whether users can enjoy therelated services, and can be found. If users complete the location updating,and has been permitted access to the network, they can send or receive shortmessage. Point-to-point short message is achieved by store and forwardthrough short message center. If mobile user A send one short message toanother mobile user B, this is divided into two separate process: shortmessage is first sent to SMC, SMC then relay short message to the user B.User A sending short message successful means that SMC instead of user Breceived a short message sent byA. As to function of everyinternal softwarelayer, BSSAP is mainly responsible for the management of A-interface, andthe transparent translation of upper layer information; MM is responsible formobility management (such as location updating process) and the accessprocess.Shortmessagecontentisdividedtothreelayers:CP,RPandTP,andSMS module can deal with those. Another function of SMS module is exchanging information with VLR and SMC. MAP Provider is responsiblefor primitive conversion between MAP and TC, and as MAP primitivedecoderorcoder.Chinese name of CAMEL is called smart, it does not mean that thenetwork is a smart, only represents the network is more business expansible.CAMEL separates business from control. The basic principle of intelligentnetwork structure is to increase the number of modules of existing network,and change business processes which is suspended in certain trigger point orevents point, and carried out certain operations of network modules whichoffer business. To integrate intelligent into existing short message process,that should acquire intelligent information and realize intelligent shortmessage trigger, event report and so on. When HLR insert subscriber dateinto VLR in location update procedure, VLR should decode and storeintelligent information. The best solution is achieving intelligent shortmessage trigger in SMS module. When SMS module receiver user data fromVLR,anddecidetotriggerCAMEL,SMSsendareporttotheSSP.SSPneedto add solution about interface with SMS ,and transparent pass message toSCPafteradapting.To meet the high reliability requirements of communication systems, itneeds totest product strictly.Testingcanbedividedintounit test,integrationtest andsystem test.Unit test is thelevel offunctiontest; integratedtestingisthelevel ofthemodulelevel test; system test treat thesystem as aBlack-box.This dissertation mainly describe using simulation tool for system testing ofthe M system. First structuring message, although the MSC Server can berealized within the hierarchical integration, the messages should act in strictaccordance with the hierarchical structures: to structure A interface messagesIn accordance with protocol stack of MTP3,SCCP,BSSAP; to structureMAP(or CAP) interface messages according to protocol stack structure ofMTP3, SCCP, TCAP and MAP (or CAP). Second we use TCL language toprepare simulation components. Components deal with messages received togetusefulinformationwhichisusedfordealingwithmessagessentout,soasto achieve the purpose of automated testing MSC Server. Because MSC Server supports IP transmission, and the simulator is running on the PC, weuse IP transmission between MSC Server and simulation tool. When testing,simulation tool load of the corresponding components and messages,simulating SCP, HLR or other entity receiving messages or sendingexpectative messages. After tests, the functional have passed thetelecommunications network testing now. The MSC Servers that realize thisfunctionhavebeenusedforexperimentalBureau. |
