Daniel Antonio Garcia Manzato

A survey of channel switching schemes for IPTV

In spite of the increasing deployment of IPTV services, various functionalities still need to be improved. One of the main challenges is a reduction in startup delays, especially in channel switching, a problem that is quite relevant in IPTV systems due to bandwidth limitations, as well as the employment of buffers and distribution structures. The problem is essentially more serious in P2P IPTV systems, since the dynamic nature of P2P networks requires larger buffers and the exchange of more signaling messages to establish the overlay structures. Since users expect to be able to switch channels quickly, IPTV services must reduce startup delays to just a few seconds or even milliseconds. The aim of this article is to provide a survey of existing channel switching schemes for IPTV systems.

Providing Fast Channel Switching in P2P IPTV Systems

In spite of the increasing deployment of IPTV services, various functionalities still need to be improved. One of the main challenges is a reduction in startup delays, especially in channel switchings, a problem which is quite relevant in P2P IPTV systems due to bandwidth limitations, as well as the employment of buffers and overlay structures. This paper presents and compares four novel schemes for providing fast channel switching that reduce the occurrence of latency. The results suggest that, in general, the proposed schemes are all capable of performing 68% of all channel switchings instantaneously on average. Moreover, the Fast 2 scheme, which presented the best performance, reduces the overall stream quality received less than 19%, on average.

Incentive mechanism for the CoopNet network

Selfish behavior and the limited time peers stay connected to the system are two major factors which significantly impact the efficiency of peer-to-peer networks with media streaming. This paper introduces an incentive mechanism to the CoopNet Network, which employs multiple distribution trees for the delivery of media streams, in order to address both problems. The mechanism comprises a barter trade economy-based component and a reputation-based remuneration component. Several questions are addressed in the paper such as the percentage of cooperative peers necessary to provide quality of service and whether or not it is worthwhile increasing the duration of sessions in order to reduce disruptions in multicast trees. Simulation results show that the barter trade component is essential to make peer-to-peer networks feasible for the provisioning of video on demand services, while the reputation component is advantageous only when arrival rates are reasonably high.

MMC04-1: An Incentive Mechanism for Peer-to-Peer Networks with Live Streaming

Although peer-to-peer networks are more scalable than client-server ones, they face efficiency challenges. One of them is the selfish behavior of non-cooperative peers. Another challenge is the short time peers stay connected to the system, which causes disruptions of the delivery of time-constrained content. This paper introduces an incentive mechanism to address both problems in peer-to-peer networks with live streaming.

A Channel Switching Scheme for IPTV Systems

One of the main challenges in IPTV systems is the reduction of startup delays, especially in channel switchings. While this problem does not exist in traditional television, in IPTV systems it is relevant, due to bandwidth limitation as well as the employment of buffers and overlay structures. Since the possibility of switching channels quickly is appreciated by users, the reduction of startup delays is an important issue to be addressed in IPTV systems. This paper proposes a novel scheme for fast channel switching that reduces the occurrences of latencies caused by buffers and overlay structures.

Incentive Mechanisms for Cooperation in Peer-to-Peer Networks

Peer-to-peer networks have recently emerged as a solution for the well-known problems of scalability imposed by client-server architecture. In these networks, the roles of serving and being served are not always asymmetrical, that is to say, one selfsame participant may at times cooperate and at others enjoy the cooperation of others. Moreover, quite often the figure of central authorities or servers is lacking, which implies an autonomy for the entities to decide on the patterns of behavior they will display, with the power to act selfishly, lavishly, selflessly or quite simply fairly, that is to say, cooperating only when possible. The feasibility of peer-to-peer systems is strongly based on the premise of cooperative behaviors. Moreover, the concept of synergy is fundamental to such systems, that is, it is expected to exploit the local resources of the participants so that their joint utilization results in a better result than the sum of the respective individual utilization. Thus, leaving the decision to cooperate or not under the sole responsibility of the participants, without any outside influence or incentive, entails putting at risk not only the system’s efficiency, but also its very feasibility. This chapter sets out a study of incentive mechanisms for cooperation. The chapter place greater emphasis on the different incentive patterns used in common by the various incentive schemes in peer-to-peer networks.

iPeer TV: A P2P IPTV architecture with fast channel switching

In spite of the increasing deployment of IPTV services, various functionalities still need to be improved. One of the main challenges is a reduction in startup delays, especially in channel switchings, a problem which is quite relevant in P2P IPTV systems. This paper evaluates the iPeer TV, a P2P IPTV architecture with fast channel switching. Our contribution is threefold. Firstly, we propose how our P2P IPTV architecture can be integrated with a previously evaluated channel switching scheme. Secondly, we propose a simple yet effective optimization for such scheme which is capable of improving the system performance. Thirdly, we provide an analysis of the minimum bandwidth requirements for the infrastructure layer of the architecture to ensure the best system performance.

A Comparison of Channel Switching Schemes for IPTV Systems

One of the main challenges in IPTV systems is the reduction of startup delays, especially in channel switchings. While this problem does not exist in traditional television, in IPTV systems it is relevant, due to bandwidth limitation as well as to buffering. This paper proposes three novel schemes for fast channel switching that reduces the occurrences of latencies caused by buffers and overlay structures.

Performance evaluation of the DCCP protocol in high-speed networks

The Internet transport layer protocols, TCP and UDP, do not provide an efficient transport for multimedia streams. In despite of that, UDP is often employded for such type of application, due to its low overhead. Since UDP does not implement any kind of congestion control mechanism, it has the potential of hindering Internet operability. To address such issue, a novel transport layer protocol, namely DCCP, has been proposed. It is designed to be used by multimedia applications with the aim of replacing the UDP protocol. This paper conducts a performance evaluation of the DCCP protocol in high-speed networks. The aim is to evaluate the scalability, the fairness, the convergence and the compatibility with TCP-Reno.

Incentive Mechanisms for a P2P IPTV System

P2P systems rely broadly on user cooperation to achieve performance and scalability, a problem which is aggravated with the transmission of time sensitive content, as it is the case of P2P IPTV systems. Since peers act rationally, cooperating only when they obtain benefits in exchange, incentive mechanisms constitute an essential component of such systems. This paper proposes incentive mechanisms to a P2P IPTV system evaluated previously by the authors.