Flexible Verification of MPEG-4 Stream in Peer-to-Peer CDN

Abstract. The current packet based stream authentication schemes provide effective and efficient authentication over a group of packets transmitted on erasure channels. However, by fixing the packets in transmission, any packet manipulation will cause authentication failure. In p2p content delivery network where a proxy-in-the-middle is able to store, forward, transcode and transform the stream, previous schemes are simply unapplicable. To address the problem, we propose a flexible verification scheme that relies on special stream formats (i.e. Unequal Loss Protection ULP scheme [7]). We apply the so called Unequal Loss Verification ULV scheme into MPEG-4 framework. The encoding, packing, amortizing and verifying methods are elaborated in this paper. Our analysis shows that the scheme is secure and cost effective. The scheme is indeed content aware and ensures the verification rate intuitively reflecting a meaningful stream. Further on, we describe the general method of publishing and retrieving a stream in p2p CDN.

Real-time video streaming using peer-to-peer for video distribution

The growth of the Internet has led to research and development of several new and useful applications including video streaming. Commercial experiments are underway to determine the feasibility of multimedia broadcasting using packet based data networks alongside traditional over-the-air broadcasting. Broadcasting companies are offering low cost or free versions of video content online to both guage and at the same time generate popularity. In addition to television broadcasting, video streaming is used in a number of application areas including video conferencing, telecommuting and long distance education. Large scale video streaming has not become as widespread or widely deployed as could be expected. The reason for this is the high bandwidth requirement (and thus high cost) associated with video data. Provision of a constant stream of video data on a medium to large scale typically consumes a significant amount of bandwidth. An effect of this is that encoding bit rates are lowered and consequently video quality is degraded resulting in even slower uptake rates for video streaming services. The aim of this dissertation is to investigate peer-to-peer streaming as a potential solution to this bandwidth problem. The proposed peer-to-peer based solution relies on end user co-operation for video data distribution. This approach is highly effective in reducing the outgoing bandwidth requirement for the video streaming server. End users redistribute received video chunks amongst their respective peers and in so doing increase the potential capacity of the entire network for supporting more clients. A secondary effect of such a system is that encoding capabilities (including higher encoding bit rates or encoding of additional sub-channels) can be enhanced. Peer-to-peer distribution enables any regular user to stream video to large streaming networks with many viewers. This research includes a detailed overview of the fields of video streaming and peer-to-peer networking. Techniques for optimal video preparation and data distribution were investigated. A variety of academic and commercial peer-to-peer based multimedia broadcasting systems were analysed as a means to further define and place the proposed implementation in context with respect to other peercasting implementations. A proof-of-concept of the proposed implementation was developed, mathematically analyzed and simulated in a typical deployment scenario. Analysis was carried out to predict simulation performance and as a form of design evaluation and verification. The analysis highlighted some critical areas which resulted in adaptations to the initial design as well as conditions under which performance can be guaranteed. A simulation of the proof-of-concept system was used to determine the extent of bandwidth savings for the video server. The aim of the simulations was to show that it is possible to encode and deliver video data in real time over a peer-to-peer network. The proposed system achieved expectations and showed significant bandwidth savings for a sustantially large video streaming audience. The implementation was able to encode video in real time and continually stream video packets on time to connected peers while continually supporting network growth by connecting additional peers (or stream viewers). The system performed well and showed good performance under typical real world restrictions on available bandwith capacity.Dissertation (MEng)--University of Pretoria, 2009.Electrical, Electronic and Computer Engineeringunrestricte

Network-aware video streaming for future media Internet

272 p

MediaSync: Handbook on Multimedia Synchronization

This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences

Semantics-aware content delivery framework for 3D Tele-immersion

3D Tele-immersion (3DTI) technology allows full-body, multimodal interaction among geographically dispersed users, which opens a variety of possibilities in cyber collaborative applications such as art performance, exergaming, and physical rehabilitation. However, with its great potential, the resource and quality demands of 3DTI rise inevitably, especially when some advanced applications target resource-limited computing environments with stringent scalability demands. Under these circumstances, the tradeoffs between 1) resource requirements, 2) content complexity, and 3) user satisfaction in delivery of 3DTI services are magnified. In this dissertation, we argue that these tradeoffs of 3DTI systems are actually avoidable when the underlying delivery framework of 3DTI takes the semantic information into consideration. We introduce the concept of semantic information into 3DTI, which encompasses information about the three factors: environment, activity, and user role in 3DTI applications. With semantic information, 3DTI systems are able to 1) identify the characteristics of its computing environment to allocate computing power and bandwidth to delivery of prioritized contents, 2) pinpoint and discard the dispensable content in activity capturing according to properties of target application, and 3) differentiate contents by their contributions on fulfilling the objectives and expectation of user’s role in the application so that the adaptation module can allocate resource budget accordingly. With these capabilities we can change the tradeoffs into synergy between resource requirements, content complexity, and user satisfaction. We implement semantics-aware 3DTI systems to verify the performance gain on the three phases in 3DTI systems’ delivery chain: capturing phase, dissemination phase, and receiving phase. By introducing semantics information to distinct 3DTI systems, the efficiency improvements brought by our semantics-aware content delivery framework are validated under different application requirements, different scalability bottlenecks, and different user and application models. To sum up, in this dissertation we aim to change the tradeoff between requirements, complexity, and satisfaction in 3DTI services by exploiting the semantic information about the computing environment, the activity, and the user role upon the underlying delivery systems of 3DTI. The devised mechanisms will enhance the efficiency of 3DTI systems targeting on serving different purposes and 3DTI applications with different computation and scalability requirements

Quality-driven resource utilization methods for video streaming in wireless communication networks

This research is focused on the optimisation of resource utilisation in wireless mobile networks with the consideration of the users’ experienced quality of video streaming services. The study specifically considers the new generation of mobile communication networks, i.e. 4G-LTE, as the main research context. The background study provides an overview of the main properties of the relevant technologies investigated. These include video streaming protocols and networks, video service quality assessment methods, the infrastructure and related functionalities of LTE, and resource allocation algorithms in mobile communication systems. A mathematical model based on an objective and no-reference quality assessment metric for video streaming, namely Pause Intensity, is developed in this work for the evaluation of the continuity of streaming services. The analytical model is verified by extensive simulation and subjective testing on the joint impairment effects of the pause duration and pause frequency. Various types of the video contents and different levels of the impairments have been used in the process of validation tests. It has been shown that Pause Intensity is closely correlated with the subjective quality measurement in terms of the Mean Opinion Score and this correlation property is content independent. Based on the Pause Intensity metric, an optimised resource allocation approach is proposed for the given user requirements, communication system specifications and network performances. This approach concerns both system efficiency and fairness when establishing appropriate resource allocation algorithms, together with the consideration of the correlation between the required and allocated data rates per user. Pause Intensity plays a key role here, representing the required level of Quality of Experience (QoE) to ensure the best balance between system efficiency and fairness. The 3GPP Long Term Evolution (LTE) system is used as the main application environment where the proposed research framework is examined and the results are compared with existing scheduling methods on the achievable fairness, efficiency and correlation. Adaptive video streaming technologies are also investigated and combined with our initiatives on determining the distribution of QoE performance across the network. The resulting scheduling process is controlled through the prioritization of users by considering their perceived quality for the services received. Meanwhile, a trade-off between fairness and efficiency is maintained through an online adjustment of the scheduler’s parameters. Furthermore, Pause Intensity is applied to act as a regulator to realise the rate adaptation function during the end user’s playback of the adaptive streaming service. The adaptive rates under various channel conditions and the shape of the QoE distribution amongst the users for different scheduling policies have been demonstrated in the context of LTE. Finally, the work for interworking between mobile communication system at the macro-cell level and the different deployments of WiFi technologies throughout the macro-cell is presented. A QoEdriven approach is proposed to analyse the offloading mechanism of the user’s data (e.g. video traffic) while the new rate distribution algorithm reshapes the network capacity across the macrocell. The scheduling policy derived is used to regulate the performance of the resource allocation across the fair-efficient spectrum. The associated offloading mechanism can properly control the number of the users within the coverages of the macro-cell base station and each of the WiFi access points involved. The performance of the non-seamless and user-controlled mobile traffic offloading (through the mobile WiFi devices) has been evaluated and compared with that of the standard operator-controlled WiFi hotspots

Design and Implementation of a Communication Protocol to Improve Multimedia QoS and QoE in Wireless Ad Hoc Networks

[EN] This dissertation addresses the problem of multimedia delivery over multi-hop ad hoc wireless networks, and especially over wireless sensor networks. Due to their characteristics of low power consumption, low processing capacity and low memory capacity, they have major difficulties in achieving optimal quality levels demanded by end users in such communications. In the first part of this work, it has been carried out a study to determine the behavior of a variety of multimedia streams and how they are affected by the network conditions when they are transmitted over topologies formed by devices of different technologies in multi hop wireless ad hoc mode. To achieve this goal, we have performed experimental tests using a test bench, which combine the main codecs used in audio and video streaming over IP networks with different sound and video captures representing the characteristic patterns of multimedia services such as phone calls, video communications, IPTV and video on demand (VOD). With the information gathered in the laboratory, we have been able to establish the correlation between the induced changes in the physical and logical topology and the network parameters that measure the quality of service (QoS) of a multimedia transmission, such as latency, jitter or packet loss. At this stage of the investigation, a study was performed to determine the state of the art of the proposed protocols, algorithms, and practical implementations that have been explicitly developed to optimize the multimedia transmission over wireless ad hoc networks, especially in ad hoc networks using clusters of nodes distributed over a geographic area and wireless sensor networks. Next step of this research was the development of an algorithm focused on the logical organization of clusters formed by nodes capable of adapting to the circumstances of real-time traffic. The stated goal was to achieve the maximum utilization of the resources offered by the set of nodes that forms the network, allowing simultaneously sending reliably and efficiently all types of content through them, and mixing conventional IP data traffic with multimedia traffic with stringent QoS and QoE requirements. Using the information gathered in the previous phase, we have developed a network architecture that improves overall network performance and multimedia streaming. In parallel, it has been designed and programmed a communication protocol that allows implementing the proposal and testing its operation on real network infrastructures. In the last phase of this thesis we have focused our work on sending multimedia in wireless sensor networks (WSN). Based on the above results, we have adapted both the architecture and the communication protocol for this particular type of network, whose use has been growing hugely in recent years.[ES] Esta tesis doctoral aborda el problema de la distribución de contenidos multimedia a través de redes inalámbricas ad hoc multisalto, especialmente las redes inalámbricas de sensores que, debido a sus características de bajo consumo energético, baja capacidad de procesamiento y baja capacidad de memoria, plantean grandes dificultades para alcanzar los niveles de calidad óptimos que exigen los usuarios finales en dicho tipo de comunicaciones. En la primera parte de este trabajo se ha llevado a cabo un estudio para determinar el comportamiento de una gran variedad de flujos multimedia y como se ven afectados por las condiciones de la red cuando son transmitidos a través topologías formadas por dispositivos de diferentes tecnologías que se comunican en modo ad hoc multisalto inalámbrico. Para ello, se han realizado pruebas experimentales sobre una maqueta de laboratorio, combinando los principales códecs empleados en la transmisión de audio y video a través de redes IP con diversas capturas de sonido y video que representan patrones característicos de servicios multimedia tales como las llamadas telefónicas, videoconferencias, IPTV o video bajo demanda (VOD). Con la información reunida en el laboratorio se ha podido establecer la correlación entre los cambios inducidos en la topología física y lógica de la red con los parámetros que miden la calidad de servicio (QoS) de una transmisión multimedia, tales como la latencia el jitter o la pérdida de paquetes. En esta fase de la investigación se realiza un estudio para determinar el estado del arte de las propuestas de desarrollo e implementación de protocolos y algoritmos que se han generado de forma explícita para optimizar la transmisión de tráfico multimedia sobre redes ad hoc inalámbricas, especialmente en las redes inalámbricas de sensores y redes ad hoc utilizando clústeres de nodos distribuidos en un espacio geográfico. El siguiente paso en la investigación ha consistido en el desarrollo de un algoritmo propio para la organización lógica de clústeres formados por nodos capaces de adaptarse a las circunstancias del tráfico en tiempo real. El objetivo planteado es conseguir un aprovechamiento máximo de los recursos ofrecidos por el conjunto de nodos que forman la red, permitiendo de forma simultánea el envío de todo tipo de contenidos a través de ellos de forma confiable y eficiente, permitiendo la convivencia de tráfico de datos IP convencional con tráfico multimedia con requisitos exigentes de QoS y QoE. A partir de la información conseguida en la fase anterior, se ha desarrollado una arquitectura de red que mejora el rendimiento general de la red y el de las transmisiones multimedia de audio y video en particular. De forma paralela, se ha diseñado y programado un protocolo de comunicación que permite implementar el modelo y testear su funcionamiento sobre infraestructuras de red reales. En la última fase de esta tesis se ha dirigido la atención hacia la transmisión multimedia en las redes de sensores inalámbricos (WSN). Partiendo de los resultados anteriores, se ha adaptado tanto la arquitectura como el protocolo de comunicaciones para este tipo concreto de red, cuyo uso se ha extendido en los últimos años de forma considerable[CA] Esta tesi doctoral aborda el problema de la distribució de continguts multimèdia a través de xarxes sense fil ad hoc multi salt, especialment les xarxes sense fil de sensors que, a causa de les seues característiques de baix consum energètic, baixa capacitat de processament i baixa capacitat de memòria, plantegen grans dificultats per a aconseguir els nivells de qualitat òptims que exigixen els usuaris finals en eixos tipus de comunicacions. En la primera part d'este treball s'ha dut a terme un estudi per a determinar el comportament d'una gran varietat de fluxos multimèdia i com es veuen afectats per les condicions de la xarxa quan són transmesos a través topologies formades per dispositius de diferents tecnologies que es comuniquen en mode ad hoc multi salt sense fil. Per a això, s'han realitzat proves experimentals sobre una maqueta de laboratori, combinant els principals códecs empleats en la transmissió d'àudio i vídeo a través de xarxes IP amb diverses captures de so i vídeo que representen patrons característics de serveis multimèdia com son les cridades telefòniques, videoconferències, IPTV o vídeo baix demanda (VOD). Amb la informació reunida en el laboratori s'ha pogut establir la correlació entre els canvis induïts en la topologia física i lògica de la xarxa amb els paràmetres que mesuren la qualitat de servei (QoS) d'una transmissió multimèdia, com la latència el jitter o la pèrdua de paquets. En esta fase de la investigació es realitza un estudi per a determinar l'estat de l'art de les propostes de desenvolupament i implementació de protocols i algoritmes que s'han generat de forma explícita per a optimitzar la transmissió de tràfic multimèdia sobre xarxes ad hoc sense fil, especialment en les xarxes sense fil de sensors and xarxes ad hoc utilitzant clusters de nodes distribuïts en un espai geogràfic. El següent pas en la investigació ha consistit en el desenvolupament d'un algoritme propi per a l'organització lògica de clusters formats per nodes capaços d'adaptar-se a les circumstàncies del tràfic en temps real. L'objectiu plantejat és aconseguir un aprofitament màxim dels recursos oferits pel conjunt de nodes que formen la xarxa, permetent de forma simultània l'enviament de qualsevol tipus de continguts a través d'ells de forma confiable i eficient, permetent la convivència de tràfic de dades IP convencional amb tràfic multimèdia amb requisits exigents de QoS i QoE. A partir de la informació aconseguida en la fase anterior, s'ha desenvolupat una arquitectura de xarxa que millora el rendiment general de la xarxa i el de les transmissions multimèdia d'àudio i vídeo en particular. De forma paral¿lela, s'ha dissenyat i programat un protocol de comunicació que permet implementar el model i testejar el seu funcionament sobre infraestructures de xarxa reals. En l'última fase d'esta tesi s'ha dirigit l'atenció cap a la transmissió multimèdia en les xarxes de sensors sense fil (WSN). Partint dels resultats anteriors, s'ha adaptat tant l'arquitectura com el protocol de comunicacions per a aquest tipus concret de xarxa, l'ús del qual s'ha estés en els últims anys de forma considerable.Díaz Santos, JR. (2016). Design and Implementation of a Communication Protocol to Improve Multimedia QoS and QoE in Wireless Ad Hoc Networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62162TESI