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Multicast Services (multicast + services)

Distribution by Scientific Domains
Engineering83%

Selected Abstracts

Distributed end-host multicast algorithms for the Knowledge Grid

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 15 2007
Wanqing Tu
Abstract The Knowledge Grid built on top of the peer-to-peer (P2P) network has been studied to implement scalable, available and sematic-based querying. In order to improve the efficiency and scalability of querying, this paper studies the problem of multicasting queries in the Knowledge Grid. An m -dimensional irregular mesh is a popular overlay topology of P2P networks. We present a set of novel distributed algorithms on top of an m -dimensional irregular mesh overlay for the short delay and low network resource consumption end-host multicast services. Our end-host multicast fully utilizes the advantages of an m -dimensional mesh to construct a two-layer architecture. Compared to previous approaches, the novelty and contribution here are: (1) cluster formation that partitions the group members into clusters in the lower layer where cluster consists of a small number of members; (2) cluster core selection that searches a core with the minimum sum of overlay hops to all other cluster members for each cluster; (3) weighted shortest path tree construction that guarantees the minimum number of shortest paths to be occupied by the multicast traffic; (4) distributed multicast routing that directs the multicast messages to be efficiently distributed along the two-layer multicast architecture in parallel, without a global control; the routing scheme enables the packets to be transmitted to the remote end hosts within short delays through some common shortest paths; and (5) multicast path maintenance that restores the normal communication once the membership alteration appears. Simulation results show that our end-host multicast can distributively achieve a shorter delay and lower network resource consumption multicast services as compared with some well-known end-host multicast systems. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Enhanced system design for download and streaming services using Raptor codes,,

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 2 2009
Tiago Gasiba
Raptor codes have been recently standardised by 3rd Generation Partnership Project (3GPP) to be used in the application layer (AL) for multimedia broadcast and multicast services (MBMS) including download delivery and streaming delivery. Furthermore, digital video broadcast (DVB) has also recommended the inclusion of these Raptor codes for IP-datacast services. In this paper, enhancements on the system and receiver design using Raptor codes are studied, namely the permeable layer receiver (PLR) and the individual post-repair mechanism. With the PLR, the partial information ignored in the conventional receiver is passed from lower layer to higher layer. We show how a practical and efficient implementation of the Raptor decoder as a PLR can be done, which can not only achieve huge performance gains, but the gains can be achieved at an affordable low decoding complexity. Whereas the PLR is employed for enhancing both download and streaming services, the post-repair aims at guaranteeing reliable download delivery when a feedback channel is available. We propose here two efficient post-repair algorithms which fully exploit the properties of the Raptor codes. One allows to find a minimum set of source symbols to be requested in the post-delivery, and another allows to find a sufficient number of consecutive repair symbols. Selected simulations verify the good performance of proposed techniques. Copyright © 2008 John Wiley & Sons, Ltd. [source]

A feedback suppression algorithm for reliable satellite multicast based on spatial,temporal prediction of the satellite channel

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 2 2009
Markos P. Anastasopoulos
Abstract The major problem limiting the scalability of large-scale multicast satellite networks is feedback implosion that arises whenever a large number of users simultaneously transmit feedback messages (FBMs) through the network, thus occupying a significant portion of satellite system resources. In satellite networks operating above 10,GHz, attenuation due to rain constitutes the dominant fading mechanism deteriorating the quality of service. In this paper, a novel scheme for providing large-scale reliable multicast services through a star-based geostationary satellite topology is presented incorporating accurate channel modeling of the propagation phenomena. The new protocol is based on the selection of an area representative that provides quick FBMs aiming at suppressing FBMs originating from the rest of the network users. The scheme provides a timely reaction to changes of either the channel conditions or the network topology by properly updating the selection of representatives. Through appropriate simulations, comparisons and examples it is demonstrated that the new approach suppresses FBMs very effectively. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Transport protocols in multicast via satellite

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 6 2004
Gun Akkor
Abstract In a wide variety of broadband applications, there is a need to distribute information to a potentially large number of receiver sites that are widely dispersed from each other. Communication satellites are a natural technology option and are extremely well suited for carrying such services because of the inherent broadcast capability of the satellite channel. Despite the potential of satellite multicast, there exists little support for multicast services over satellite networks. Although several multicast protocols have been proposed for use over the Internet, they are not optimized for satellite networks. One of the key multicast components that is affected when satellite networks are involved in the communication is the transport layer. In this paper, we attempt to provide an overview of the design space and the ways in which the network deployment and application requirements affect the solution space for transport layer schemes in a satellite environment. We also highlight some of the issues that are critical in the development of next generation satellite multicast services. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Reliable multicast via satellite: a comparison survey and taxonomy

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 1 2001
Martin W. Koyabe
Abstract IP multicasting is an important service, which will be provided by the next generation Internet. A range of applications has emerged which take the advantage of multicast delivery. However, several factors currently hinder large-scale deployment of terrestrial multicast services. It is particularly difficult to support delivery to large groups of users. Satellites offer a natural way to extend the multicast service to reach this large number of users. They may offer high capacity (especially when using next generation satellite systems) and also eliminate the need for a large number of intermediate routing hops. There are important differences in the way multicast applications operate over satellite. This paper therefore reviews the key design paradigm and offers a critical comparison between different reliable multicast protocol techniques based on a taxonomy. The suitability of a set of the most common reliable multicast protocols is assessed within a satellite environment and conclusions are presented. Copyright © 2001 John Wiley & Sons, Ltd. [source]