1,892 research outputs found

    Adaptive Multicast of Multi-Layered Video: Rate-Based and Credit-Based Approaches

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    Network architectures that can efficiently transport high quality, multicast video are rapidly becoming a basic requirement of emerging multimedia applications. The main problem complicating multicast video transport is variation in network bandwidth constraints. An attractive solution to this problem is to use an adaptive, multi-layered video encoding mechanism. In this paper, we consider two such mechanisms for the support of video multicast; one is a rate-based mechanism that relies on explicit rate congestion feedback from the network, and the other is a credit-based mechanism that relies on hop-by-hop congestion feedback. The responsiveness, bandwidth utilization, scalability and fairness of the two mechanisms are evaluated through simulations. Results suggest that while the two mechanisms exhibit performance trade-offs, both are capable of providing a high quality video service in the presence of varying bandwidth constraints.Comment: 11 page

    Performance of active multicast congestion control

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    This paper aims to provide insight into the behavior of congestion control mechanisms for reliable multicast protocols. A multicast congestion control based on active networks has been proposed and simulated using ns-2 over a network topology obtained using the Tiers tool. The congestion control mechanism has been simulated under different network conditions and with different settings of its configuration parameters. The objective is to analyze its performance and the impact of the different configuration parameters on its behavior. The simulation results show that the performance of the protocol is good in terms of delay and bandwidth utilization. The compatibility of the protocol with TCP flows has not been demonstrated, but the simulations performed show that by altering the parameter settings, the proportion of total bandwidth taken up by the two types of flow, multicast and TCP, may be modified.Publicad

    Network-supported layered multicast transport control for streaming media

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    Multicast is very efficient in distributing large volume of data to multiple receivers over the Internet. Layered multicast helps solve the heterogeneity problem in multicast delivery. Extensive work has been done in the area of layered multicast, for both congestion control and error control. In this paper, we focus on network-supported protocols for streaming media. Most of the existing work solves the congestion control and error control problems separately, and do not give an integrated, efficient solution. In this paper, after reviewing related work, we introduce our proposed protocols, RALM and RALF. The former is a congestion control protocol and the latter is an error control protocol. They work under the same framework and provide an integrated solution. We also extend RALM to RALM-II, which is compatible with TCP traffic. We analyze the complexity of the proposed protocols in the network and investigated their performance through simulations. We show that our solution achieves significant performance gains with reasonable additional complexity. © 2007 IEEE.published_or_final_versio

    Fast-response receiver-driven layered multicast with multiple servers

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    Almost all the proposed layered multicast algorithms support a single server, i.e. a receiver can only subscribe to at most one server. A common restriction to single server approach Is that the maximum number of subscribed layers, as well as the maximum achievable throughput Is limited by the specific bottleneck link between a receiver and the server. In this paper, a new layered multicast protocol, called Fast-response Receiver-driven Layered Multicast with Multiple Servers (FRLM-MS) Is proposed. Our design allows a receiver to subscribe to more than one servers. A FRLM-MS receiver can benefit from multiple paths to the multiple servers, resulting In a higher achievable bandwidth. It In turn allows the receiver to have a higher layer subscription, and thus a better playback performance. © 2005 IEEE.published_or_final_versio

    Adaptive Applications over Active Networks: Case Study on Layered Multicast

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    peer reviewedIn this paper we study the potential and limitations of active networks in the context of adaptive applications. We present a survey of active networking research applied to adaptive applications, and a case study on a layered multicast active application. This active application is a congestion control protocol that selectively discards data in the active routers, and prunes multicast tree branches affected by persistent congestion. Our first results indicate that active networks can indeed help such an application to adapt to heterogeneous receivers, with a minimum amount of state overhead, equivalent to that of a single IP multicast group

    Random Linear Network Coding for 5G Mobile Video Delivery

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    An exponential increase in mobile video delivery will continue with the demand for higher resolution, multi-view and large-scale multicast video services. Novel fifth generation (5G) 3GPP New Radio (NR) standard will bring a number of new opportunities for optimizing video delivery across both 5G core and radio access networks. One of the promising approaches for video quality adaptation, throughput enhancement and erasure protection is the use of packet-level random linear network coding (RLNC). In this review paper, we discuss the integration of RLNC into the 5G NR standard, building upon the ideas and opportunities identified in 4G LTE. We explicitly identify and discuss in detail novel 5G NR features that provide support for RLNC-based video delivery in 5G, thus pointing out to the promising avenues for future research.Comment: Invited paper for Special Issue "Network and Rateless Coding for Video Streaming" - MDPI Informatio

    Multi-user video streaming using unequal error protection network coding in wireless networks

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    In this paper, we investigate a multi-user video streaming system applying unequal error protection (UEP) network coding (NC) for simultaneous real-time exchange of scalable video streams among multiple users. We focus on a simple wireless scenario where users exchange encoded data packets over a common central network node (e.g., a base station or an access point) that aims to capture the fundamental system behaviour. Our goal is to present analytical tools that provide both the decoding probability analysis and the expected delay guarantees for different importance layers of scalable video streams. Using the proposed tools, we offer a simple framework for design and analysis of UEP NC based multi-user video streaming systems and provide examples of system design for video conferencing scenario in broadband wireless cellular networks

    System Support for Bandwidth Management and Content Adaptation in Internet Applications

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    This paper describes the implementation and evaluation of an operating system module, the Congestion Manager (CM), which provides integrated network flow management and exports a convenient programming interface that allows applications to be notified of, and adapt to, changing network conditions. We describe the API by which applications interface with the CM, and the architectural considerations that factored into the design. To evaluate the architecture and API, we describe our implementations of TCP; a streaming layered audio/video application; and an interactive audio application using the CM, and show that they achieve adaptive behavior without incurring much end-system overhead. All flows including TCP benefit from the sharing of congestion information, and applications are able to incorporate new functionality such as congestion control and adaptive behavior.Comment: 14 pages, appeared in OSDI 200
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