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

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An appraisal of secure, wireless grid-enabled data warehousing

In most research, appropriate collections of data play a significant role in aiding decision-making processes. This is more critical if the data is being accessed across organisational barriers. Further, for the data to be mined and analysed efficiently, to aid decision-making processes, it must be harnessed in a suitably-structured fashion. There is, for example, a need to perform diverse data analyses and interpretation of structured (non-personal) HIV/AIDS patient-data from various quarters in South Africa. Although this data does exist, to some extent, it is autonomously owned and stored in disparate data storages, and not readily available to all interested parties. In order to put this data to meaningful use, it is imperative to integrate and store this data in a manner in which it can be better utilized by all those involved in the ontological field. This implies integration of (and hence, interoperability), and appropriate accessibility to, the information systems of the autonomous organizations providing data and data-processing. This is a typical problem-scenario for a Virtual Inter-Organisational Information System (VIOIS), proposed in this study. The VIOIS envisaged is a hypothetical, secure, Wireless Grid-enabled Data Warehouse (WGDW) that enables IOIS interaction, such as the storage and processing of HIV/AIDS patient-data to be utilized for HIV/AIDS-specific research. The proposed WDGW offers a methodical approach for arriving at such a collaborative (HIV/AIDS research) integrated system. The proposed WDGW is virtual community that consists mainly of data-providers, service-providers and information-consumers. The WGDW-basis resulted from systematic literaturesurvey that covered a variety of technologies and standards that support datastorage, data-management, computation and connectivity between virtual community members in Grid computing contexts. A Grid computing paradigm is proposed for data-storage, data management and computation in the WGDW. Informational or analytical processing will be enabled through data warehousing while connectivity will be attained wirelessly (for addressing the paucity of connectivity infrastructure in rural parts of developing countries, like South Africa)

An appraisal of secure, wireless grid-enabled data warehousing

In most research, appropriate collections of data play a significant role in aiding decision-making processes. This is more critical if the data is being accessed across organisational barriers. Further, for the data to be mined and analysed efficiently, to aid decision-making processes, it must be harnessed in a suitably-structured fashion. There is, for example, a need to perform diverse data analyses and interpretation of structured (non-personal) HIV/AIDS patient-data from various quarters in South Africa. Although this data does exist, to some extent, it is autonomously owned and stored in disparate data storages, and not readily available to all interested parties. In order to put this data to meaningful use, it is imperative to integrate and store this data in a manner in which it can be better utilized by all those involved in the ontological field. This implies integration of (and hence, interoperability), and appropriate accessibility to, the information systems of the autonomous organizations providing data and data-processing. This is a typical problem-scenario for a Virtual Inter-Organisational Information System (VIOIS), proposed in this study. The VIOIS envisaged is a hypothetical, secure, Wireless Grid-enabled Data Warehouse (WGDW) that enables IOIS interaction, such as the storage and processing of HIV/AIDS patient-data to be utilized for HIV/AIDS-specific research. The proposed WDGW offers a methodical approach for arriving at such a collaborative (HIV/AIDS research) integrated system. The proposed WDGW is virtual community that consists mainly of data-providers, service-providers and information-consumers. The WGDW-basis resulted from systematic literaturesurvey that covered a variety of technologies and standards that support datastorage, data-management, computation and connectivity between virtual community members in Grid computing contexts. A Grid computing paradigm is proposed for data-storage, data management and computation in the WGDW. Informational or analytical processing will be enabled through data warehousing while connectivity will be attained wirelessly (for addressing the paucity of connectivity infrastructure in rural parts of developing countries, like South Africa)

On the development of Voice over IP

This record of study documents the experience acquired during my internship at Sonus Networks, Inc. for the Doctor of Engineering Program. In this record of study, I have surveyed and analyzed the current standardization status of Voice over Internet Protocol (VoIP) security and proposed an Internet draft on secure retargeting and response identity. The draft provides a simple and comprehensive solution to the response identity, call recipient identity and intermediate server retargeting problems in the Session Initiation Protocol (SIP) call setup process. To support product line development and enable product evolution in the quickly growing VoIP market, I have proposed a generic development framework for SIP application servers. The common and open architecture of the framework supports multiple products development and facilitates integration of new service modules. The systematical reuse of proven software design and implementation enables companies to reduce the development cost and shorten the time-to-market. As the development and diffusion of VoIP can never be isolated from the social sphere, I have investigated the current status, influence and interaction of three most important factors: standardization, market forces and government regulation on the development and diffusion of VoIP. The worldwide deregulation and market privatization have caused the transition of the standards development model. This transition in turn influences the market diffusion. Other than standardization, market forces including customer needs, the revenue pressure on carriers and vendors, competitive and economic environment, social culture and regulation uncertainties create both threats and opportunities. I have examined market drivers and obstacles in the current VoIP adoption stage, analyzed current VoIP market players and their strategies, and predicted the direction of VoIP business. The regulation creates the macro environment in which VoIP develops and diffuses. I have explored modern telecommunications regulation principles based on which government makes decisions on most current issues, including 911 support, mergers and acquisitions, interconnection obligation and leasing rights, rate structure and universal service fees

A structural and functional specification of a SCIM for service interaction management and personalisation in the IMS

The Internet Protocol Multimedia Subsystem (IMS) is a component of the 3G mobile network that has been specified by standards development organisations such as the 3GPP (3rd Generation Partnership Project) and ETSI (European Telecommunication Standards Institute). IMS seeks to guarantee that the telecommunication network of the future provides subscribers with seamless access to services across disparate networks. In order to achieve this, it defines a service architecture that hosts application servers that provide subscribers with value added services. Typically, an application server bundles all the functionality it needs to execute the services it delivers, however this view is currently being challenged. It is now thought that services should be synthesised from simple building blocks called service capabilities. This decomposition would facilitate the re-use of service capabilities across multiple services and would support the creation of new services that could not have originally been conceived. The shift from monolithic services to those built from service capabilities poses a challenge to the current service model in IMS. To accommodate this, the 3GPP has defined an entity known as a service capability interaction manager (SCIM) that would be responsible for managing the interactions between service capabilities in order to realise complex services. Some of these interactions could potentially lead to undesirable results, which the SCIM must work to avoid. As an added requirement, it is believed that the network should allow policies to be applied to network services which the SCIM should be responsible for enforcing. At the time of writing, the functional and structural architecture of the SCIM has not yet been standardised. This thesis explores the current serv ice architecture of the IMS in detail. Proposals that address the structure and functions of the SCIM are carefully compared and contrasted. This investigation leads to the presentation of key aspects of the SCIM, and provides solutions that explain how it should interact with service capabilities, manage undesirable interactions and factor user and network operator policies into its execution model. A modified design of the IMS service layer that embeds the SCIM is subsequently presented and described. The design uses existing IMS protocols and requires no change in the behaviour of the standard IMS entities. In order to develop a testbed for experimental verification of the design, the identification of suitable software platforms was required. This thesis presents some of the most popular platforms currently used by developers such as the Open IMS Core and OpenSER, as well as an open source, Java-based, multimedia communication platform called Mobicents. As a precursor to the development of the SCIM, a converged multimedia service is presented that describes how a video streaming application that is leveraged by a web portal was implemented for an IMS testbed using Mobicents components. The Mobicents SIP Servlets container was subsequently used to model an initial prototype of the SCIM, using a mUlti-component telephony service to illustrate the proposed service execution model. The design focuses on SIP-based services only, but should also work for other types of IMS application servers as well

Implementing a secured IMS-based Identity exchange

With the continuous development of telecommunications, networking and the ubiquitous computing the necessity of higher bandwidth and better quality of services is always one of the most important user requirements. In this background, IP Multimedia Subsystem (IMS) is becoming very important for the Next Generation Networking (NGN) and all-Internet Protocol (all-IP) infrastructure. This new tendency provides opportunities for new operators and service providers to enter the market and to be competitive. These developments will generate new challenges related to the user identity assurance. It will be more difficult to rely on the old paradigms of the static operator relationships guaranteeing end-to-end the identity of the users. In this case there is crucial need to find new mechanisms to provide to the end points assurance about the identity of their counterparts. In this work we implemented a solution that establishes a trust between two end points by taking advantage of IMS in a roaming scenario where the visited access network may not be entirely trustworthy. In essence, this means establishing an identity association so that the parties can have operator provided assurance regarding the used identities. This allows local trust decisions and does not rely on the existence of global Public Key Infrastructure (PKI). Concretely in this work we have modified the Session Initiation Protocol (SIP) “INVITE” messages by adding new SIP headers such as the identity and the signature of the SIP entities taking part in a multimedia conversation. Every SIP entity has to add its own identity and signature and also has to verify those of its counterparts in a typical SIP “INVITE” exchange. By this work we show that establishing this kind of identity association is feasible but some scalability issues have to be taken into account such as the time delay or the size of the new messages. In order to accomplish this master thesis work, we have used the Open Source IMS Core (OSIMS) platform developed by FOKUS, SailFin project as the Application Server (AS) and IMS Communicator as the IMS client. /Kir1

Integrating Context-Awareness in the IP Multimedia Subsystem for Enhanced Session Control and Service Provisioning Capabilities

The 3GPP-defined IP Multimedia Subsystem (IMS) is becoming the de-facto standard for IP-based multimedia communication services. It consists of an overlay control and service layer that is deployed on top of IP-based mobile and fixed networks. This layer encompasses a set of common functions (e.g. session control functions allowing the initiation/modification/termination of sessions) and service logics that are needed for the seamless provisioning of IP multimedia services to users, via different access technologies. As it continues to evolve, the IMS still faces several challenges including: the enabling of innovative and personalized services that would appeal to users and increase network operators' revenues; its interaction with other types of networks (e.g. wireless sensor networks) as means to enhance its capabilities; and the support of advanced QoS schemes that would manage the network resources in an efficient and adaptive manner. The context-awareness concept, which comes from the pervasive computing field, signifies the ability to use situational information (or context) in support to operations and decision making and for the provision of relevant services to the user. Context-awareness is considered to enhance users' experience and is seen as an enabler to adaptability and service personalization - two capabilities that could play important roles in telecommunication environments. This thesis focuses on the introduction of the context-awareness technology in the IMS, as means to enhance its session control and service provisioning capabilities. It starts by presenting the necessary background information, followed by a derivation of requirements and a review of the related work. To ensure the availability of contextual information within the network, we then propose an architecture for context information acquisition and management in the IMS. This architecture leverages and extends the 3GPP presence framework. Building on the capabilities of this architecture, we demonstrate how the managed information could be integrated in IMS operations, at the control and service levels. Showcasing control level integration, we propose a novel context-aware call differentiation framework as means to offer enhanced QoS support (for sessions/calls) in IMS-based networks. This framework enables the differentiation between different categories of calls at the IMS session control level, via dynamic and adaptive resource allocation, in addition to supporting a specialized charging model. Furthermore, we also propose a framework for enhanced IMS emergency communication services. This framework addresses the limitations of existing IP-based emergency solutions, by offering three main improvements: a QoS-enhanced emergency service; a context-aware personalized emergency service; and a conferencing-enhanced emergency service. We demonstrate the use of context awareness at the IMS service level using two new context-aware IMS applications. Finally, to validate our solutions and evaluate their performance, we build various proof-of-concept prototypes and OPNET simulation model