A Novel Approach to Reduce the Unicast Bandwidth of an IPTV System in a High-Speed Access Network

Channel change time is a critical quality of experience (QOE) metric for IP-based video delivery systems such as Internet Protocol Television (IPTV). An interesting channel change acceleration scheme based on peer-assisted delivery was recently proposed, which consists of deploying one FCC server (Fast Channel Change Server) in the IP backbone in order to send the unicast stream to the STB (Set-Top Box) before sending the normal multicast stream after each channel change. However, deploying such a solution will cause high bandwidth usage in the network because of the huge unicast traffic sent by the FCC server to the STBs. In this paper, we propose a new solution to reduce the bandwidth occupancy of the unicast traffic, by deploying the FCC server capabilities on the user STB. This means that, after each channel change request, the STB will receive the unicast traffic from another STB instead of the central server. By using this method, the unicast traffic will not pass through the IP network; it will be a peer-to-peer communication via the Access Network only. Extensive simulation results are presented to demonstrate the robustness of our new solution

40 Gbps Access for Metro networks: Implications in terms of Sustainability and Innovation from an LCA Perspective

In this work, the implications of new technologies, more specifically the new optical FTTH technologies, are studied both from the functional and non-functional perspectives. In particular, some direct impacts are listed in the form of abandoning non-functional technologies, such as micro-registration, which would be implicitly required for having a functioning operation before arrival the new high-bandwidth access technologies. It is shown that such abandonment of non-functional best practices, which are mainly at the management level of ICT, immediately results in additional consumption and environmental footprint, and also there is a chance that some other new innovations might be 'missed.' Therefore, unconstrained deployment of these access technologies is not aligned with a possible sustainable ICT picture, except if they are regulated. An approach to pricing the best practices, including both functional and non-functional technologies, is proposed in order to develop a regulation and policy framework for a sustainable broadband access.Comment: 10 pages, 6 Tables, 1 Figure. Accepted to be presented at the ICT4S'15 Conferenc

IP-Based TV Technologies, Services and Multidisciplinary Applications

The move to Internet Protocol (IP)-based content delivery services has challenged the television industry by allowing high-quality television content to be delivered using the Internet, wired and wireless, private and public. The new convergence paradigm is already playing out its disruptive role as television is now associated with both a personal and social experience using an ecosystem of devices. The unidirectional flow of content from an operator to a device has thus morphed into a much richer combination of real-time on-demand web and user generated content complementing traditional programming

Contribution to quality of user experience provision over wireless networks

The widespread expansion of wireless networks has brought new attractive possibilities to end users. In addition to the mobility capabilities provided by unwired devices, it is worth remarking the easy configuration process that a user has to follow to gain connectivity through a wireless network. Furthermore, the increasing bandwidth provided by the IEEE 802.11 family has made possible accessing to high-demanding services such as multimedia communications. Multimedia traffic has unique characteristics that make it greatly vulnerable against network impairments, such as packet losses, delay, or jitter. Voice over IP (VoIP) communications, video-conference, video-streaming, etc., are examples of these high-demanding services that need to meet very strict requirements in order to be served with acceptable levels of quality. Accomplishing these tough requirements will become extremely important during the next years, taking into account that consumer video traffic will be the predominant traffic in the Internet during the next years. In wired systems, these requirements are achieved by using Quality of Service (QoS) techniques, such as Differentiated Services (DiffServ), traffic engineering, etc. However, employing these methodologies in wireless networks is not that simple as many other factors impact on the quality of the provided service, e.g., fading, interferences, etc. Focusing on the IEEE 802.11g standard, which is the most extended technology for Wireless Local Area Networks (WLANs), it defines two different architecture schemes. On one hand, the infrastructure mode consists of a central point, which manages the network, assuming network controlling tasks such as IP assignment, routing, accessing security, etc. The rest of the nodes composing the network act as hosts, i.e., they send and receive traffic through the central point. On the other hand, the IEEE 802.11 ad-hoc configuration mode is less extended than the infrastructure one. Under this scheme, there is not a central point in the network, but all the nodes composing the network assume both host and router roles, which permits the quick deployment of a network without a pre-existent infrastructure. This type of networks, so called Mobile Ad-hoc NETworks (MANETs), presents interesting characteristics for situations when the fast deployment of a communication system is needed, e.g., tactics networks, disaster events, or temporary networks. The benefits provided by MANETs are varied, including high mobility possibilities provided to the nodes, network coverage extension, or network reliability avoiding single points of failure. The dynamic nature of these networks makes the nodes to react to topology changes as fast as possible. Moreover, as aforementioned, the transmission of multimedia traffic entails real-time constraints, necessary to provide these services with acceptable levels of quality. For those reasons, efficient routing protocols are needed, capable of providing enough reliability to the network and with the minimum impact to the quality of the service flowing through the nodes. Regarding quality measurements, the current trend is estimating what the end user actually perceives when consuming the service. This paradigm is called Quality of user Experience (QoE) and differs from the traditional Quality of Service (QoS) approach in the human perspective given to quality estimations. In order to measure the subjective opinion that a user has about a given service, different approaches can be taken. The most accurate methodology is performing subjective tests in which a panel of human testers rates the quality of the service under evaluation. This approach returns a quality score, so-called Mean Opinion Score (MOS), for the considered service in a scale 1 - 5. This methodology presents several drawbacks such as its high expenses and the impossibility of performing tests at real time. For those reasons, several mathematical models have been presented in order to provide an estimation of the QoE (MOS) reached by different multimedia services In this thesis, the focus is on evaluating and understanding the multimedia-content transmission-process in wireless networks from a QoE perspective. To this end, firstly, the QoE paradigm is explored aiming at understanding how to evaluate the quality of a given multimedia service. Then, the influence of the impairments introduced by the wireless transmission channel on the multimedia communications is analyzed. Besides, the functioning of different WLAN schemes in order to test their suitability to support highly demanding traffic such as the multimedia transmission is evaluated. Finally, as the main contribution of this thesis, new mechanisms or strategies to improve the quality of multimedia services distributed over IEEE 802.11 networks are presented. Concretely, the distribution of multimedia services over ad-hoc networks is deeply studied. Thus, a novel opportunistic routing protocol, so-called JOKER (auto-adJustable Opportunistic acK/timEr-based Routing) is presented. This proposal permits better support to multimedia services while reducing the energy consumption in comparison with the standard ad-hoc routing protocols.Universidad Politécnica de CartagenaPrograma Oficial de Doctorado en Tecnologías de la Información y Comunicacione

Improved Iptv Channel Change times Through Multicast Caching of Pre-selected Channels

Name: RAY, THOMAS Date of Degree: DECEMBER, 2014 Title of Study: IMPROVED IPTV CHANNEL CHANGE TIMES THROUGH MULTICAST CACHING OF PRE-SELECTED CHANNELSMajor Field: ELECTRICAL ENGINEERINGAbstract: IPTV has grown in recent years to an estimated 100 million users worldwide. IPTV uses IGMP processes to stream an individual channel to a user until the next channel change when the current channel is stopped and the new selection begins streaming. One of the critical factors determining customer satisfaction is the requirement to have reasonably rapid channel change times of 2 seconds or less, but current channel change times are frequently above that threshold. Numerous research efforts have been ongoing to reduce these times including edge servers, I-frame management, buffering improvements, dynamic video coding, and pre-selecting channels. Channel pre-selection involves sending additional channels in hopes that the user's next selection will already be present at the user's set top box to reduce the channel change time. While this pre-selection technique has previously been proposed, the proposals have been limited in scope, typically based on set top box replacement, and lack specific details regarding the expected channel change reductions attained. This research addressed all of these shortcomings beginning with laboratory testing to verify that the channel change time reduction for successful pre-selection is two times the network delay plus the IGMP processing time which equates to an average of 320 millisecond reduction per channel change. Several pre-selection models were developed and evaluated using theoretical calculations, functional testing, and performance simulations. Sample data was generated to reflect a wide range of user IPTV viewing behavior for use in the performance simulations. The top two models resulted in an average of well over 70% success rates in accurately pre-streaming the user's next selection in the multicast cache output. This approach also has the benefit of being implemented on IPTV provider equipment and would typically only require firmware upgrades without the need for expensive new equipment or changes to existing standards. Operational considerations were also discussed to reduce problems and delays during the implementation phase of the system. Additional applications and future improvements were also presented.Electrical Engineerin

Intra-Refresh Provision for WiMAX Data-Partitioned Video Streaming

Mobile, broadband wireless access is increasingly being used for video streaming. This paper is a study of the impact of intra-refresh provision upon a robust video streaming scheme intended for WiMAX. The paper demonstrates the use of intra-refresh macroblocks within inter-coded video frames as an alternative to periodic intra-refresh video frames. In fact, the proposed scheme combines intra-refresh macroblocks with data-partitioned video compression, both error resilience tools from the H.264 video codec. Redundant video packets along with adaptive channel coding are also used to protect video streams. In harsh wireless channel conditions, it is found that all the proposed measures are necessary. This is because error bursts, arising from both slow and fast fading, as well as other channel impairments, are possible. The main conclusions from a detailed analysis are that: because of the effect on packet size it is important to select a moderate quantization parameter; and because of the higher overhead from cyclic intra macroblock line update it is better to select a low percentage per frame of intra-refresh macroblocks. The proposed video streaming scheme will be applicable to other 4G wireless technologies such as LTE

Broadcasting services amendment (Media Ownership) Bill 2006 and related bills

To help better explore the potential implications associated with the proposed legislation, we conducted a survey of 919 WA television viewers drawing from our TV Panel of 3000 viewers. Our panel has been recruited from a variety of sources including through lists acquired through marketing research firms, as well as direct mail and newspaper advertising recruitment drives. In many ways, our panel is better informed regarding future possibilities because they participate in regular studies where such scenarios are tested. In this way, the panel is better positioned to understand potential futures

Single-Frequency Network Terrestrial Broadcasting with 5GNR Numerology

L'abstract è presente nell'allegato / the abstract is in the attachmen

Quality of experience and access network traffic management of HTTP adaptive video streaming

The thesis focuses on Quality of Experience (QoE) of HTTP adaptive video streaming (HAS) and traffic management in access networks to improve the QoE of HAS. First, the QoE impact of adaptation parameters and time on layer was investigated with subjective crowdsourcing studies. The results were used to compute a QoE-optimal adaptation strategy for given video and network conditions. This allows video service providers to develop and benchmark improved adaptation logics for HAS. Furthermore, the thesis investigated concepts to monitor video QoE on application and network layer, which can be used by network providers in the QoE-aware traffic management cycle. Moreover, an analytic and simulative performance evaluation of QoE-aware traffic management on a bottleneck link was conducted. Finally, the thesis investigated socially-aware traffic management for HAS via Wi-Fi offloading of mobile HAS flows. A model for the distribution of public Wi-Fi hotspots and a platform for socially-aware traffic management on private home routers was presented. A simulative performance evaluation investigated the impact of Wi-Fi offloading on the QoE and energy consumption of mobile HAS.Die Doktorarbeit beschäftigt sich mit Quality of Experience (QoE) – der subjektiv empfundenen Dienstgüte – von adaptivem HTTP Videostreaming (HAS) und mit Verkehrsmanagement, das in Zugangsnetzwerken eingesetzt werden kann, um die QoE des adaptiven Videostreamings zu verbessern. Zuerst wurde der Einfluss von Adaptionsparameters und der Zeit pro Qualitätsstufe auf die QoE von adaptivem Videostreaming mittels subjektiver Crowdsourcingstudien untersucht. Die Ergebnisse wurden benutzt, um die QoE-optimale Adaptionsstrategie für gegebene Videos und Netzwerkbedingungen zu berechnen. Dies ermöglicht Dienstanbietern von Videostreaming verbesserte Adaptionsstrategien für adaptives Videostreaming zu entwerfen und zu benchmarken. Weiterhin untersuchte die Arbeit Konzepte zum Überwachen von QoE von Videostreaming in der Applikation und im Netzwerk, die von Netzwerkbetreibern im Kreislauf des QoE-bewussten Verkehrsmanagements eingesetzt werden können. Außerdem wurde eine analytische und simulative Leistungsbewertung von QoE-bewusstem Verkehrsmanagement auf einer Engpassverbindung durchgeführt. Schließlich untersuchte diese Arbeit sozialbewusstes Verkehrsmanagement für adaptives Videostreaming mittels WLAN Offloading, also dem Auslagern von mobilen Videoflüssen über WLAN Netzwerke. Es wurde ein Modell für die Verteilung von öffentlichen WLAN Zugangspunkte und eine Plattform für sozialbewusstes Verkehrsmanagement auf privaten, häuslichen WLAN Routern vorgestellt. Abschließend untersuchte eine simulative Leistungsbewertung den Einfluss von WLAN Offloading auf die QoE und den Energieverbrauch von mobilem adaptivem Videostreaming