SON : a framework for Internet TV broadcast with incentive forwarding

In this thesis, we propose a framework, called Subscription Overlay Network (SON), for real-time Internet TV broadcast, where a subscriber can choose to watch at any time. This framework allows the source server to incrementally build a topology graph that contains the network connections not only from the server to each subscriber, but also among the subscribers themselves. With such topology graph in place, we consider efficient overlay multicast for scalable SON services. We first show that idling nodes, which do not receive video data for their own playback, can actually be used for data forwarding to significantly reduce the cost of overlay multicast. In light of this observation, we then propose a novel overlay multicast technique, which distinguishes itself from existing schemes in three aspects. First, the proposed technique is centered on the topology graph and can take advantage of the actual network connections among the subscribing nodes. Second, the new scheme is able to find and incorporate appropriate idling nodes in multicast to reduce network traffic. Third, with our approach, a node can be used in multiple multicast trees for data forwarding to improve the overall system performance. We evaluate the performance of the proposed technique through simulation. Our extensive studies show that the proposed framework has the potential to enable the Internet, a vehicle up to date mainly for transferring text and image data, for large-scale and cost-effective TV broadcast

ASSESSMENT AND EVALUATION OF ENHANCED MULTICAST ROUTING MECHANISM FOR EVOLVING NETWORK TOPOLOGIES

Routing protocols of mobile ad-hoc network tend to need different approaches from existing Internet protocols, since most of the existing Internet protocols were designed to support routing in a network with fixed structure. In the academic and industrial world, those who think about such things have written quite a few papers proposing various routing solutions for mobile ad-hoc networks. In most wireless networking environments in productive use today the users devices communicate either via some networking infrastructure in the form of base stations and a backbone network, or directly with their intended communication partner, e.g. using 802.11 in ad hoc networks. In the proposed work, the evaluation of the distributed island multicast Protocol with AODV for news broadcasting and software distribution often has a large number of users is to be simulated and compared with CIM. It requires scalable and distributed solutions for data delivery. In DIM, hosts in the same island elect a unique leader. All leaders form an overlay tree. Based on the leader tree, leaders select bridge-nodes for their islands and construct a delivery overlay in distributed manner

بروتوكول سماحية عطل جديد في الشبكات التطبيقية متعددة البث

تميّزت الشبكات التطبيقية متعددة البث بسهولة انتشارها، فهي لا تتطلب أي تغيير في طبقة الشبكة، حيث يتم إرسال البيانات في هذه الشبكة عبر شجرة التغطية المبنية باستخدام الاتصال أحادي البث بين العقد النهائية، والذين هم مضيفون أحرار يمكنهم الانضمام والمغادرة متى أرادوا ذلك، أو حتى المغادرة دون إعلام أية عقدة بذلك. يسبب ذلك انفصال العقد الأبناء لعقدة مغادرة عن الشجرة، وطلب إعادة الانضمام، بمعنى آخر ستنفصل هذه العقد عن شجرة التغطية ولا يمكنها الحصول على البيانات حتى تنضم من جديد. مما يتسبب بحدوث الفوضى ضمن الشجرة المبنية، وضياع العديد من رزم البيانات والتي يمكن أن تؤثر بشكل كبير على المستخدم. أحد التحديات الرئيسة في بناء بروتوكول شبكة تطبيقية متعدد البث ذو كفاءة وفعالية هو توفير آلية لمواجهة الخروج المفاجئ لعقدة ما من شجرة التغطية دون التأثير الكبير على أداء الشجرة المبنية. وهو ماسنعتمده في هذا البحث من خلال اقتراح بروتوكول جديد لحل المشاكل المذكورة سابقاً. Application-Level Multicast Networks are easy to deployment, it does not require any change in the network layer, where data is sent to the network via the built-up coverage of the tree using a single-contact transmission of the final contract, who are the hosts are free can join / leave whenever they want it, or even to leave without telling any node so. Causing the separation of the children of the leaved node from the tree, and the request for rejoin, in other words, these nodes will be separated from the overlay tree and cannot get the data even rejoin. This causes the distortion of the constructed tree, and the loss of several packets which can significantly impact the user. One of the key challenges in building a multi-efficiently and effectively overlay multicast protocol is to provide a robust mechanism to overcome the sudden departure of a node from the overlay tree without a significant impact on the performance of the constructed tree. In this research, we propose a new protocol to solve problems presented previously

Diseño centrado en calidad para la difusión Peer-to-Peer de video en vivo

El uso de redes Peer-to-Peer (P2P) es una forma escalable para ofrecer servicios de video sobre Internet. Este documento hace foco en la definición, desarrollo y evaluación de una arquitectura P2P para distribuir video en vivo. El diseño global de la red es guiado por la calidad de experiencia (Quality of Experience - QoE), cuyo principal componente en este caso es la calidad del video percibida por los usuarios finales, en lugar del tradicional diseño basado en la calidad de servicio (Quality of Service - QoE) de la mayoría de los sistemas. Para medir la calidad percibida del video, en tiempo real y automáticamente, extendimos la recientemente propuesta metodología Pseudo-Subjective Quality Assessment (PSQA). Dos grandes líneas de investigación son desarrolladas. Primero, proponemos una técnica de distribución de video desde múltiples fuentes con las características de poder ser optimizada para maximizar la calidad percibida en contextos de muchas fallas y de poseer muy baja señalización (a diferencia de los sistemas existentes). Desarrollamos una metodología, basada en PSQA, que nos permite un control fino sobre la forma en que la señal de video es dividida en partes y la cantidad de redundancia agregada, como una función de la dinámica de los usuarios de la red. De esta forma es posible mejorar la robustez del sistema tanto como sea deseado, contemplando el límite de capacidad en la comunicación. En segundo lugar, presentamos un mecanismo estructurado para controlar la topología de la red. La selección de que usuarios servirán a que otros es importante para la robustez de la red, especialmente cuando los usuarios son heterogéneos en sus capacidades y en sus tiempos de conexión.Nuestro diseño maximiza la calidad global esperada (evaluada usando PSQA), seleccionado una topología que mejora la robustez del sistema. Además estudiamos como extender la red con dos servicios complementarios: el video bajo demanda (Video on Demand - VoD) y el servicio MyTV. El desafío en estos servicios es como realizar búsquedas eficientes sobre la librería de videos, dado al alto dinamismo del contenido. Presentamos una estrategia de "caching" para las búsquedas en estos servicios, que maximiza el número total de respuestas correctas a las consultas, considerando una dinámica particular en los contenidos y restricciones de ancho de banda. Nuestro diseño global considera escenarios reales, donde los casos de prueba y los parámetros de configuración surgen de datos reales de un servicio de referencia en producción. Nuestro prototipo es completamente funcional, de uso gratuito, y basado en tecnologías bien probadas de código abierto

ON MULTIMEDIA CONTENT DELIVERY AND MULTICASTING

Multimedia content now contribute to a huge amount of the Internet traffic due to the popularity and availability of anytime anywhere Internet connection. Unlike the circuit-switched telephone network - in which necessary resources are reserved for communication between two parties at the time the connection is established, a packet-switched network, like the Internet, only guarantees the reachability when the connection between two parties is established. In other words, the end-to-end delay and available bandwidth between two hosts depend on the amount of traffic on the network. The communication paths between the participating hosts are also determined by the routing policies and hence are not under control of the participating hosts. Hence how to improve the performance of delivering multimedia content on the Internet has become an interesting research topic.In this dissertation, we consider the problem of delivering multimedia contents using multicast wherein a group of participants are participating in the same com- munication session. We assume the networks are flexible such that the end hosts can specify the communication paths. A few examples of this type of networks are overlay networks and IPv6 network with source routing support. This problem is addressed from both routing and network traffic perspectives.First, we assume a two-layer approach which includes a well-provisioned service overlay network and the regular Internet. The participants in the multimedia group communication can take the advantage of the service overlay network by connecting to the nodes in the service overlay network through the Internet. We consider two major assignment problems - Server and Client Assignment Problem (SCAP, Client- Server model) and Client Assignment Problem (CAP, Peer-to-Peer model) as well as several variants of these problems. These problems are NP-hard and we have developed polynomial-time heuristic algorithms to assign the participants to appropriate service nodes such that some real-time constraint(s) are satisfied and the number of service nodes involved are minimal. Integer programming (IP) models for solving these problems are also developed for performance evaluation purpose. Empirical results show that the solution quality of the proposed algorithms compares favorably with the optimal ones obtained from the execution of IP models, while keeping the execution times significantly low.We have also considered the Multi-stream Multi-source Multicast Routing Prob- lem ( MMMRP). Given a network and a set of multicast sessions, each with one or more sources and multiple destinations. The goal of MMMRP is to determine mul- tiple multicast tree for these multicast sessions on the given network in such a way that the overall residual bandwidth on the links that are shared among the trees is maximized. We prove that MMMRP is NP-hard and apart from providing an IP formulation, we have also provided a heuristic algorithm MMForests which runs in polynomial-time. We compared and contrasted the performance of MMMRP with known algorithms for the multicast tree packing problem. Our exhaustive empirical evaluations show that our heuristic has a very low execution-time while achieving the optimal residual bandwidth. In addition, our heuristic is very scalable as it is able to produce results for networks with thousands of nodes, unlike the other ones which are based on Steiner tree heuristics

Recent Trends in Communication Networks

In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges