Performance analysis of IMS network: the proposal of new algorithms for S-CSCF assignment

This article is focused on the proposal of three load balancing methods which can be used for a selection of S-CSCF (Serving-Call Session Control Server) server in IP Multimedia Subsystem (IMS) during the registration procedures of subscribers. All presented methods are implemented and evaluated for various inter-arrival and service times in the mathematical model based on queueing theory. In this article, two methods based on performance parameters (such as utilizations, etc.) and one method based on number of registered subscribers to each of available S-CSCF server are described. The main advantage of third method is that all related information is obtained from traffic analysis through I-CSCF (Interrogating-CSCF) node. Also, the designed methods are compared with other selection algorithms presented in previous research works by others researchers (Hwang et col., Cho et col. or Tirana et col.). The article shows that the implemented methods can optimize the service latency of whole IMS network

A Unified Mobility Management Architecture for Interworked Heterogeneous Mobile Networks

The buzzword of this decade has been convergence: the convergence of telecommunications, Internet, entertainment, and information technologies for the seamless provisioning of multimedia services across different network types. Thus the future Next Generation Mobile Network (NGMN) can be envisioned as a group of co-existing heterogeneous mobile data networking technologies sharing a common Internet Protocol (IP) based backbone. In such all-IP based heterogeneous networking environments, ongoing sessions from roaming users are subjected to frequent vertical handoffs across network boundaries. Therefore, ensuring uninterrupted service continuity during session handoffs requires successful mobility and session management mechanisms to be implemented in these participating access networks. Therefore, it is essential for a common interworking framework to be in place for ensuring seamless service continuity over dissimilar networks to enable a potential user to freely roam from one network to another. For the best of our knowledge, the need for a suitable unified mobility and session management framework for the NGMN has not been successfully addressed as yet. This can be seen as the primary motivation of this research. Therefore, the key objectives of this thesis can be stated as: To propose a mobility-aware novel architecture for interworking between heterogeneous mobile data networks To propose a framework for facilitating unified real-time session management (inclusive of session establishment and seamless session handoff) across these different networks. In order to achieve the above goals, an interworking architecture is designed by incorporating the IP Multimedia Subsystem (IMS) as the coupling mediator between dissipate mobile data networking technologies. Subsequently, two different mobility management frameworks are proposed and implemented over the initial interworking architectural design. The first mobility management framework is fully handled by the IMS at the Application Layer. This framework is primarily dependant on the IMS’s default session management protocol, which is the Session Initiation Protocol (SIP). The second framework is a combined method based on SIP and the Mobile IP (MIP) protocols, which is essentially operated at the Network Layer. An analytical model is derived for evaluating the proposed scheme for analyzing the network Quality of Service (QoS) metrics and measures involved in session mobility management for the proposed mobility management frameworks. More precisely, these analyzed QoS metrics include vertical handoff delay, transient packet loss, jitter, and signaling overhead/cost. The results of the QoS analysis indicates that a MIP-SIP based mobility management framework performs better than its predecessor, the Pure-SIP based mobility management method. Also, the analysis results indicate that the QoS performances for the investigated parameters are within acceptable levels for real-time VoIP conversations. An OPNET based simulation platform is also used for modeling the proposed mobility management frameworks. All simulated scenarios prove to be capable of performing successful VoIP session handoffs between dissimilar networks whilst maintaining acceptable QoS levels. Lastly, based on the findings, the contributions made by this thesis can be summarized as: The development of a novel framework for interworked heterogeneous mobile data networks in a NGMN environment. The final design conveniently enables 3G cellular technologies (such as the Universal Mobile Telecommunications Systems (UMTS) or Code Division Multiple Access 2000 (CDMA2000) type systems), Wireless Local Area Networking (WLAN) technologies, and Wireless Metropolitan Area Networking (WMAN) technologies (e.g., Broadband Wireless Access (BWA) systems such as WiMAX) to interwork under a common signaling platform. The introduction of a novel unified/centralized mobility and session management platform by exploiting the IMS as a universal coupling mediator for real-time session negotiation and management. This enables a roaming user to seamlessly handoff sessions between different heterogeneous networks. As secondary outcomes of this thesis, an analytical framework and an OPNET simulation framework are developed for analyzing vertical handoff performance. This OPNET simulation platform is suitable for commercial use

Open Access to Resource Management in Multimedia Networks

The paper is dedicated to mechanisms for open access to resource management in the Internet Protocol (IP) multimedia networks. First we present the concept of IP Multimedia Subsystem (IMS) and explain the IMS functional architecture, principles of quality of service management and service control in IMS. Then we describe the idea behind the opening of network interfaces for third parties so that others besides the network operator can create and deploy services. Open Service Access (OSA) and Parlay appear to be the technologies for value-added service delivery in multimedia networks. In the paper we take a closer look to the Parlay/OSA interfaces that allow third party applications to access the resource management functions in IMS. OSA "Connectivity Manager" interfaces and OSA "Policy Management" interfaces are considered. Parlay X Web Services interfaces provide a higher level of abstraction than Parlay/OSA interfaces and gain an amazing amount of support among service developers. We address "Applicationdriven Quality of Service" Parlay X Web Service and "Policy" Parlay X Web Service also

Interworking QOS Management Subsystem into IMS-Based Architecture Multi Providers: IMS-IQMSMP

International audienceThe third-generation partnership project 3GPP and 3GPP2 have standardized the IP multimedia subsystem (IMS) to provide ubiquitous and access network-independent IP-based services for next-generation networks via merging cellular networks and the Internet. The IP Multimedia Subsystem (IMS) seems to be the technology that will prevail in Next Generation Networks (NGNs). The users wish to communicate through collections of networks using different protocols; rendering service mapping from one network to another with the similar QoS is a complex issue thereby. The heterogeneous networks are collections of communication platforms using different protocols. This heterogeneity implies the need to offer many different services on the market within short time. In this paper we propose a heterogeneous network model based on the IMS that provides guaranteed QoS. Our method presents, in the first, an informational solution. Decisional information is added to the HSS basis to enrich the knowledge base, which is expressed under the form of "profile of QoS R", where the new information informs directly the decisions to be taken according to the user’s profile (preferences QoS and pricing, bandwidth, location ...). In the second, a solution for multi provider’s context which can allow a subscriber to register with one or more operator(s) according to QoS offered. Thirdly, a mechanism which can be deployed in heterogeneous networks to preserve the original QoS values of the user session and thus eliminate the cumulative effect of QoS rounding across the entire communication path. And it is feasible via the “Interworking QoS Management Sub-network” while adding the new interworking management components, namely: SICs, DIC, QPA AS and HSS-PQoSr

Study, Analysis and Modeling of IP Multimedia systems on next generation networks providing mobile and fixed multimedia services

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