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IMS Core Functionality & Features
The IMS is designed to provide number of key capabilities required to enable new IPservices via mobile and fixed networks. The important key functionalities whichenable new mobile IP services are: Multimedia session negotiation and management Quality of service management Mobility management Service execution, control and interaction Now we discuss the important features of IMS like…
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IMS Charging and QoS
IMS Charging Accounting is the process of collecting information about resource consumption. While accounting data can be used for multiple purposes such as capacity and trend analysis or cost allocation, it particularly forms the basis for the charging and latter billing of a user. The IMS defines two charging modes: online and offline. Online charging…
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IMS Session Management
After the registration, the user is able to access the services and starts session establishment process. This process is briefly explained as follows and depicted in figure The Caller’s UE (UE-A) constructs an INVITE request that includes registered public user identity of called user (UE-B). All SIP messages must traverse the Proxy Call Session Control…
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Addressing and Registration in IMS
The addressing in IMS is called SIP URI (Uniform Resource Identifier) and looks like an email address. In order to use IMS services, the UE must perform IMS registration. First the UE must obtain an IP connectivity bearer and discover an IMS entry point i.e. P-CSCF. After the P-CSCF discovery, the UE sends a SIP…
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IMS Architecture and Key Protocols
The IMS defines service provision architecture, and it can be considered as the next generation service delivery platform framework. It consists of modular design with open interfaces and enables the flexibility for providing multimedia services over IP technology. The IMS does not standardize specific services but uses standard service enablers e.g. presence, and supports inherently…
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IP Multimedia Subsystem (IMS) Security Challenges
Security and information protection is the core of all computer networks and communication systems. The convergence of fixed-mobile and voice-data networks has opened the door for the innovative and fancy next generation services and applications like integrated multimedia services, combining web browsing, email, instant messaging, presence, VoIP, video conferencing, application sharing, telephony, unified messaging, multimedia…