Serviços multimédia multicast de próxima geração

Mestrado em Engenharia Electrónica e TelecomunicaçõesUma das mais recentes conquistas na evolução móvel foi o 3G, permitindo o acesso a serviços multimédia com qualidade de serviço assegurada. No entanto, a tecnologia UMTS, tal como definida na sua Release ’99, é apenas capaz de transmitir em modo unicast, sendo manifestamente ineficiente para comunicações multimédia almejando grupos de utilizadores. A tecnologia IMS surge na Release 5 do 3GPP que começou a responder já a algumas necessidades, permitindo comunicações sobre IP oferecendo serviços Internet a qualquer momento e em qualquer lugar sobre tecnologias de comunicação móveis fornecendo pela primeira vez sessões multimédia satisfatórias. A Release 6 por sua vez trouxe a tecnologia MBMS que permite transmissões em broadcast e multicast para redes móveis. O MBMS fornece os serviços de aplicações multimédia que todos estavam à espera, tanto para os utilizadores como para os prestadores de serviços. O operador pode agora fazer uso da tecnologia existente aumentando todo o tipo de benefícios no serviço prestado ao cliente. Com a possível integração destas duas tecnologias passa a ser possível desenvolver serviços assentes em redes convergentes em que os conteúdos são entregues usando tecnologias unicast, multicast ou broadcast. Neste contexto, o principal motivo deste trabalho consiste essencialmente em fazer uso dos recursos da rede terminando com o desperdício dos mesmos e aumentando a eficiência dos serviços através da integração das tecnologias IMS e MBMS. O trabalho realizado começa com o estudo do estado da arte das telecomunicações móveis com referência às tecnologias referidas, seguindo-se a apresentação da possível integração IMS-MBMS e terminando com o projecto de uma plataforma de demonstração que no futuro possa ser uma implementação de serviço multimédia multicast. O objectivo principal é mostrar os benefícios de um serviço que era normalmente executado em unicast relativamente ao modo multicast, fazendo uso da nova convergência de tecnologias IMS e MBMS. Na conclusão do trabalho são referidas as vantagens do uso de portadoras multicast e broadcast, tendo como perspectiva de que este trabalho possa ser um ponto de partida para um novo conjunto de serviços poupando recursos de rede e permitindo uma eficiência considerável em serviços inovadores.3G is bang up to date in the mobile phone industry. It allows access to multimedia services and gives a guarantee of quality of service. The UMTS technology, defined in 3GPP Release ’99, provides an unicast transmission, but it is completely inefficient when it comes to multimedia group communications. The IMS technology first appeared in Release 5 that has already started to consider the interests of the clients. It provides communications over IP, offering Internet services anytime, anywhere on mobile communication technologies. Also, it offers for the first time satisfactory multimedia sessions. On the other hand, Release 6 gave rise to the MBMS technology that provides broadcast and multicast transmissions for mobile networks. The MBMS provides multimedia applications services that everyone was waiting, including users and service providers. Now the operator makes use of existing technology in order to provide better costumer services. The possible integration of these two technologies will contribute to develop services based on converged networks in which contents are delivered through the unicast, multicast or broadcast technologies. Therefore, the objective of this work is basically to make use of network resources avoiding wastes and improving customer services through the integration of the IMS and the MBMS technologies. The executed work starts with the mobile telecommunications state of the art with reference to the referred technologies, followed by the IMS-MBMS convergence presentation and finishing with the proposal for implementation of a service platform that can be used for a multimedia multicast service. The main point is to show the benefits of a service that has been normally executed in unicast mode over the multicast mode, making use of the new IMS and MBMS technologies integration. To closure the work it is referred the advantages to use multicast and broadcast bearers, with the perspective that this work could be a starting point to a new set of services, saving network resources and allowing for innovate services a considerable efficency

Improved internet protocol multimedia subsystem authentication for long term evolution

Long Term Evolution (LTE) is a major technology to be used in the 4th generation (4G) mobile network and the core network is evolving towards a converged packet based framework for all services. As a part of the evolved core network, Internet Protocol (IP) Multimedia Subsystem (IMS) provides multimedia services (data, voice, video and variations) over packet switched networks. LTE and IMS are both defined by the 3rd Generation Partnership Project (3GPP) group, and the specification identifies that a LTE user device has to carry out two authentication steps to access IP multimedia services. The first authentication step is used to gain LTE network admission and the second authentication step is the IMS authentication used to gain access to the multimedia services. It is observed that the 4G standardized authentication protocols include double execution of the Authentication and Key Agreement (AKA) which increases the system’s complexity, results in significant authentication delay and high terminal energy consumption. Authentication is very important for a terminal to gain access to a network and therefore considerable previous research into this topic has occurred. However a common limitation of previously proposed authentication systems is either a lack of security or significant system modification. This research proposes the Improved AKA (IAKA) authentication protocol which binds the two layer’s authentication procedures by using the unified IP Multimedia Private-user Identity (IMPI). The proposed IAKA only executes the AKA protocol once in the network layer and generates authentication credentials which would be used in the second IMS service layer authentication. This research work included providing IAKA authentication protocol, developing a LTE IMS integrated network by using OPNET Modeller, simulation of the IAKA and the legacy 3GPP defined 4G LTE AKA authentication protocol under different environments, and in-depth analysis of the system performance, security and terminal’s energy consumption. It is shown that the proposed IAKA carries out terminal authentication correctly, improves security, reduces IMS layer authentication delay by up to 38%, and provides an 81.82% terminal energy consumption saving

Investigation of an intelligent personalised service recommendation system in an IMS based cellular mobile network

Success or failure of future information and communication services in general and mobile communications in particular is greatly dependent on the level of personalisations they can offer. While the provision of anytime, anywhere, anyhow services has been the focus of wireless telecommunications in recent years, personalisation however has gained more and more attention as the unique selling point of mobile devices. Smart phones should be intelligent enough to match user’s unique needs and preferences to provide a truly personalised service tailored for the individual user. In the first part of this thesis, the importance and role of personalisation in future mobile networks is studied. This is followed, by an agent based futuristic user scenario that addresses the provision of rich data services independent of location. Scenario analysis identifies the requirements and challenges to be solved for the realisation of a personalised service. An architecture based on IP Multimedia Subsystem is proposed for mobility and to provide service continuity whilst roaming between two different access standards. Another aspect of personalisation, which is user preference modelling, is investigated in the context of service selection in a multi 3rd party service provider environment. A model is proposed for the automatic acquisition of user preferences to assist in service selection decision-making. User preferences are modelled based on a two-level Bayesian Metanetwork. Personal agents incorporating the proposed model provide answers to preference related queries such as cost, QoS and service provider reputation. This allows users to have their preferences considered automatically

Efficient Handoff for QoS Enhancement in Heterogeneous Wireless Networks (UMTS/WLAN Interworking)

Today’s Wireless Communications technologies prove us that wireless communications will in the long run be composed of different communication networks as a way to benefit from each other. This can however be achieved from cellular networks and wireless local area networks that show some compatible characteristics that enable them be integrated. Scenarios typically behind these integrations is the UMTS and WLAN interworking where UMTS network is known for its wide area of coverage and nearly roaming however, known for lack of enough data rate. This is contrary with WLAN which is known for high data rate and cheaper compared to UMTS. WLAN however has a small area of coverage and lacks roaming. This in regard brings the idea that the two different networks being integrated could provide the means for mobile users to be gratified with a supported coverage and quality at anywhere and anytime with seamless access to internet

Next generation mobile wireless hybrid network interworking architecture

It is a universally stated design requirement that next generation mobile systems will be compatible and interoperable with IPv6 and with various access technologies such as IEEE 802.11x. Discussion in the literature is currently as to whether the recently developed High Speed Packet Access (HSPA) or the developing Long Term Evaluation (LTE) technology is appropriate for the next generation mobile wireless system. However, the HSPA and the LTE technologies are not sufficient in their current form to provide ubiquitous data services. The third–generation mobile wireless network (3G) provides a highly developed global service to customers through either circuit switched or packet switched networks; new mobile multimedia services (e.g. streaming/mobile TV, location base services, downloads, multiuser games and other applications) that provide greater flexibility for the operator to introduce new services to its portfolio and from the user point of view, more services to select and a variety of higher, on-demand data rates compared with 2.5-2.75G mobile wireless system. However cellular networks suffer from a limited data rate and expensive deployment. In contrast, wireless local area networks (WLAN) are deployed widely in small areas or hotspots, because of their cost-effectiveness, ease of deployment and high data rates in an unlicensed frequency band. On the other hand, WLAN (IEEE 802.11x) cannot provide wide coverage cost-efficiently and is therefore at a disadvantage to 3G in the provision of wide coverage. In order to provide more services at high data rates in the hotspots and campus-wide areas, 3G service providers regard WLAN as a technology that compliments the 3G mobile wireless system. The recent evolution and successful deployment of WLANs worldwide has yielded demand to integrate WLANs with 3G mobile wireless technologies seamlessly. The key goal of this integration is to develop heterogeneous mobile data networks, capable of supporting ubiquitous data services with high data rates in hotspots. The effort to develop heterogeneous networks – also referred to fourth-generation (4G) mobile wireless data networks – is linked with many technical challenges including seamless vertical handovers across WLAN and 3G radio technologies, security, common authentication, unified accounting & billing, WLAN sharing (by several mobile wireless networks – different operators), consistent QoS and service provisioning, etc. This research included modelling a hybrid UMTS/WLAN network with two competent couplings: Tight Coupling and Loose Coupling. The coupling techniques were used in conjunction with EAP-AKA for authentication and Mobile IP for mobility management. The research provides an analysis of the coupling techniques and highlights the advantages and disadvantages of the coupling techniques. A large matrix of performance figures were generated for each of the coupling techniques using Opnet Modeller, a network simulation tool

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

Not availabl

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)