The Architecture Of Ip Multimedia Subsystem(IMS) And The Construction Of Trial Network

The IMS (IP Multimedia Subsystem) was produced by the 3GPP standards organization based on the R5 version,which provide multimedia services on a common network architecture of IP-based networks.And it is also the kernel of the 3GPP2 (mobile) and TISPAN / ITU-T (fixed ) network architecture.The IMS R5 version defines the kernel architecture,element function,interface and scenario etc.The IMS R6 version add some characteristic of IMS services,interrogating standard of other network and the WLAN access.R7 version enhances the standard development of the fixed and mobile Convergence, required IMS to support xDSL, cable and other fixed access methods.Compared with the NGN technique,IMS make a further separation of control layer,which achieves the functional separation of session control entity CSCF (CallSessionControlFunction) and bearer control entities MGCF (Media Gateway Control Function) and make the network architecture more open and flexible.The IMS with the complete separation in horizontal architecture of service,control,bear and the centralized user properties and characteristics of access independence,on the one hand,can solve the problems which NGN technique can't resolve,such as mobility support,open and standard service interface,flexible IP multi-media service applications.On the other hand,the access independence will make IMS the basis of the fixed and mobile convergence. In short, IMS is an open system architecture provide the most-wide IP-based services in PS network of mobile carrier and CS network of fixed carrier at the same time via wireless and wireline access technique.For the telecom carrier of the transformation towards the whole services,IMS can produce cost-effective network and achieve the convergence of vioce and data,which in spite of the restriction of access type.This convergence make an important step toward the full-IP network perspective of internet,fixed and mobile network combination.Throught IMS,the telecom carrier can acquire the ability of providing variety service at the same network,and it can also integrate these services for the new business pattern via fixed and mobile transmission.So it's the more and more urgent task for the carrier of construct the IMS network. Regarding the importance of IMS network,China telecom has deployed a trial network in GuangDong Telecom Technique Institute.The purpose of this network is to make the further step of IMS technology research that includes network integration,technology maturity,capability to support different kind of services and the compatible test of different manufactory.This thesis demonstrates the architecture and integration pattern of this trial network.This trial network supports the traditional telnetcom applications and many kinds of new applications,for instance:voice(fixed and mobile),data,fax,video,sip,epon.