Modelling contents status for IPTV delivery networks

Since IPTV has been invented, IPTV is considered a dominant technology to distribute high quality videos and live channels anytime anywhere over challenging environment to end users who are having different preferences and demands. Presently, IPTV service providers manage IPTV delivery networks, in terms of contents, channels, resources, based on contents popularity distribution and/or users’ preferences only. Although content popularity and users’ preferences play an important role to cope with the increasing demand of IPTV contents/channels, these two measures fail in producing efficient IPTV delivery networks For that, IPTV delivery network designing should integrate the IPTV content characteristics like size, interactivity, the rapid changing lifetime. Therefore, the idea of this paper is to build a mathematical model that integrates all these factors in one concept called IPTV content status. Modeling the contents status according to its characteristics is an important point to design Content-Aware IPTV delivery networks.The experimental results showed the superiority of modeling IPTV content status in balancing the load and reducing the resources waste

Design of Scalable Continuous Media Servers with Dynamic Replication

Multimedia applications place high demands for quality-of-service (QoS), performance, and reliability on systems. These stringent requirements make design of cost-effective and scalable systems difficult. Therefore efficient adaptive and dynamic resource management techniques in conjunction with data placement techniques can be of great help in improving performance, scalability and reliability of such systems. In this paper, we first focus on data placement. In the recent past, a great deal of work has focused on "wide" data striping as a way of dealing with load imbalance problems caused by skews in data access patterns. Another approach to dealing with load imbalance problems is replication. The appropriate compromise between the degree of striping and the degree of replication is key to the design of scalable continuous media (CM) servers. In this work we focus on evaluation of this compromise in the context of a hybrid CM server design. Changes in data access patterns lead to other questions: (1) when should the system alter the number of copies of a CM object, and (2) how to accomplish this change. We address (1) through an adaptive threshold-based approach, and we use dynamic replication policies in conjunction with a mathematical model of user behavior to address (2). We do this without any knowledge of data access patterns and with provisions for full use of VCR functionality. Through a performance study, we show that not only does the use of this mathematical model in conjunction with dynamic resource management policies improves the system's performance but that it also facilitates reduced sensitivity to changes in:(a) workload characteristics, (b) skewness of data access patterns, and (c) frequency of changes in data access patterns. We believe that not only is this a desirable property for a CM server, in general, but that furthermore, it suggests the usefulness of these techniques across a wide range of continuous media applications. (Cross-referenced as UMIACS-TR-2001-21

Threshold-Based Dynamic Replication in Large-Scale Video-on-Demand Systems

Recent advances in high speed networking technologies and video compression techniques have made Video-on-Demand (VOD) services feasible. A large-scale VOD system imposes a large demand on I/O bandwidth and storage resources, and therefore, parallel disks are typically used for providing VOD service. Although striping of movie data across a large number of disks can balance the utilization among these disks, such a striping technique can exhibit additional complexity, for instance, in data management, such as synchronization among disks during data delivery, as well as in supporting fault tolerant behavior. Therefore, it is more practical to limit the extent of data striping, for example, by arranging the disks in groups (or nodes) and then allowing intra-group (or intra-node) data striping only. With multiple striping groups, however, we may need to assign a movie to multiple nodes so as to satisfy the total demand of requests for that movie. Such an approach gives rise to several design issues, including: (1) what is the right number of copies of each movie we need so as to satisfy the demand and at the same time not waste storage capacity, (2) how to assign these movies to dierent nodes in the system, and (3) what are ecient approaches to altering the number of copies of each movie (and their placement) when the need for that arises. In this paper, we study an approach to dynamically recon guring the VOD system so as to alter the number of copies of each movie maintained on the server as the access demand for these movies uctuates. We propose various approaches to addressing the above stated issues, which result in a VOD design that is adaptive to the changes in data access patterns. Performance evaluation is carried out to quantify the costs and the performance g..