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Effective video multicast over wireless internet
With the rapid growth of wireless networks and great success of Internet video, wireless video services are expected to be widely deployed in the near future. As different types of wireless networks are converging into all IP networks, i.e., the Internet, it is important to study video delivery over the wireless Internet. This paper proposes a novel end-system based adaptation protocol calledWireless Hybrid Adaptation Layered Multicast (WHALM) protocol for layered video multicast over wireless Internet. In WHALM the sender dynamically collects bandwidth distribution from the receivers and uses an optimal layer rate allocation mechanism to reduce the mismatches between the coarse-grained layer subscription levels and the heterogeneous and dynamic rate requirements from the receivers, thus maximizing the degree of satisfaction of all the receivers in a multicast session. Based on sampling theory and theory of probability, we reduce the required number of bandwidth feedbacks to a reasonable degree and use a scalable feedback mechanism to control the feedback process practically. WHALM is also tuned to perform well in wireless networks by integrating an end-to-end loss differentiation algorithm (LDA) to differentiate error losses from congestion losses at the receiver side. With a series of simulation experiments over NS platform, WHALM has been proved to be able to greatly improve the degree of satisfaction of all the receivers while avoiding congestion collapse on the wireless Internet
System Support for Bandwidth Management and Content Adaptation in Internet Applications
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
A Framework for Controlling Quality of Sessions in Multimedia Systems
Collaborative multimedia systems demand overall session quality control beyond the level of quality of service (QoS) pertaining to individual connections in isolation of others. At every instant in time, the quality of the session depends on the actual QoS offered by the system to each of the application streams, as well as on the relative priorities of these streams according to the application semantics. We introduce a framework for achieving QoSess control and address the architectural issues involved in designing a QoSess control laver that realizes the proposed framework. In addition, we detail our contributions for two main components of the QoSess control layer. The first component is a scalable and robust feedback protocol, which allows for determining the worst case state among a group of receivers of a stream. This mechanism is used for controlling the transmission rates of multimedia sources in both cases of layered and single-rate multicast streams. The second component is a set of inter-stream adaptation algorithms that dynamically control the bandwidth shares of the streams belonging to a session. Additionally, in order to ensure stability and responsiveness in the inter-stream adaptation process, several measures are taken, including devising a domain rate control protocol. The performance of the proposed mechanisms is analyzed and their advantages are demonstrated by simulation and experimental results
Optimized Live 4K Video Multicast
4K videos are becoming increasingly popular. However, despite advances in
wireless technology, streaming 4K videos over mmWave to multiple users is
facing significant challenges arising from directional communication,
unpredictable channel fluctuation and high bandwidth requirements. This paper
develops a novel 4K layered video multicast system. We (i) develop a video
quality model for layered video coding, (ii) optimize resource allocation,
scheduling, and beamforming based on the channel conditions of different users,
and (iii) put forward a streaming strategy that uses fountain code to avoid
redundancy across multicast groups and a Leaky-Bucket-based congestion control.
We realize an end-to-end system on commodity-off-the-shelf (COTS) WiGig
devices. We demonstrate the effectiveness of our system with extensive testbed
experiments and emulation
Scalable Media Coding Enabling Content-Aware Networking
Increasingly popular multimedia services are expected to play a dominant role in the future of the Internet. In this context, it is essential that content-aware networking (CAN) architectures explicitly address the efficient delivery and processing of multimedia content. This article proposes the adoption of a content-aware approach into the network infrastructure, thus making it capable of identifying, processing, and manipulating media streams and objects in real time to maximize quality of service (QoS) and experience (QoE). Our proposal is built on the exploitation of scalable media coding technologies within such a content-aware networking environment. This discussion is based on four representative use cases for media delivery (unicast, multicast, peer-to-peer, and adaptive HTTP streaming) and reviews CAN challenges, specifically flow processing, caching/buffering, and QoS/QoE management
STAIR: Practical AIMD Multirate Congestion Control
Existing approaches for multirate multicast congestion control are either friendly to TCP only over large time scales or introduce unfortunate side effects, such as significant control traffic, wasted bandwidth, or the need for modifications to existing routers. We advocate a layered multicast approach in which steady-state receiver reception rates emulate the classical TCP sawtooth derived from additive-increase, multiplicative decrease (AIMD) principles. Our approach introduces the concept of dynamic stair layers to simulate various rates of additive increase for receivers with heterogeneous round-trip times (RTTs), facilitated by a minimal amount of IGMP control traffic. We employ a mix of cumulative and non-cumulative layering to minimize the amount of excess bandwidth consumed by receivers operating asynchronously behind a shared bottleneck. We integrate these techniques together into a congestion control scheme called STAIR which is amenable to those multicast applications which can make effective use of arbitrary and time-varying subscription levels.National Science Foundation (CAREER ANI-0093296, ANI-9986397
Adaptive Live Video Streaming by Priority Drop
In this paper we explore the use of Priority-progress streaming (PPS) for video surveillance applications. PPS is an adaptive streaming technique for the delivery of continuous media over variable bit-rate channels. It is based on the simple idea of reordering media components within a time window into priority order before transmission. The main concern when using PPS for live video streaming is the time delay introduced by reordering. In this paper we describe how PPS can be extended to support live streaming and show that the delay inherent in the approach can be tuned to satisfy a wide range of latency constraints while supporting fine-grain adaptation
Content-Aware Multimedia Communications
The demands for fast, economic and reliable dissemination of multimedia
information are steadily growing within our society. While people and
economy increasingly rely on communication technologies, engineers still
struggle with their growing complexity.
Complexity in multimedia communication originates from several sources. The
most prominent is the unreliability of packet networks like the Internet.
Recent advances in scheduling and error control mechanisms for streaming
protocols have shown that the quality and robustness of multimedia delivery
can be improved significantly when protocols are aware of the content they
deliver. However, the proposed mechanisms require close cooperation between
transport systems and application layers which increases the overall system
complexity. Current approaches also require expensive metrics and focus on
special encoding formats only. A general and efficient model is missing so
far.
This thesis presents efficient and format-independent solutions to support
cross-layer coordination in system architectures. In particular, the first
contribution of this work is a generic dependency model that enables
transport layers to access content-specific properties of media streams,
such as dependencies between data units and their importance. The second
contribution is the design of a programming model for streaming
communication and its implementation as a middleware architecture. The
programming model hides the complexity of protocol stacks behind simple
programming abstractions, but exposes cross-layer control and monitoring
options to application programmers. For example, our interfaces allow
programmers to choose appropriate failure semantics at design time while
they can refine error protection and visibility of low-level errors at
run-time.
Based on some examples we show how our middleware simplifies the
integration of stream-based communication into large-scale application
architectures. An important result of this work is that despite cross-layer
cooperation, neither application nor transport protocol designers
experience an increase in complexity. Application programmers can even
reuse existing streaming protocols which effectively increases system
robustness.Der Bedarf unsere Gesellschaft nach kostengĂŒnstiger und
zuverlÀssiger
Kommunikation wÀchst stetig. WÀhrend wir uns selbst immer mehr von modernen
Kommunikationstechnologien abhĂ€ngig machen, mĂŒssen die Ingenieure dieser
Technologien sowohl den Bedarf nach schneller EinfĂŒhrung neuer Produkte
befriedigen als auch die wachsende KomplexitÀt der Systeme beherrschen.
Gerade die Ăbertragung multimedialer Inhalte wie Video und Audiodaten ist
nicht trivial. Einer der prominentesten GrĂŒnde dafĂŒr ist die
UnzuverlÀssigkeit heutiger Netzwerke, wie z.B.~dem Internet. Paketverluste
und schwankende Laufzeiten können die DarstellungsqualitÀt massiv
beeintrĂ€chtigen. Wie jĂŒngste Entwicklungen im Bereich der
Streaming-Protokolle zeigen, sind jedoch QualitÀt und Robustheit der
Ăbertragung effizient kontrollierbar, wenn Streamingprotokolle
Informationen ĂŒber den Inhalt der transportierten Daten ausnutzen.
Existierende AnsÀtze, die den Inhalt von Multimediadatenströmen
beschreiben, sind allerdings meist auf einzelne Kompressionsverfahren
spezialisiert und verwenden berechnungsintensive Metriken. Das reduziert
ihren praktischen Nutzen deutlich. AuĂerdem erfordert der
Informationsaustausch eine enge Kooperation zwischen Applikationen und
Transportschichten. Da allerdings die Schnittstellen aktueller
Systemarchitekturen nicht darauf vorbereitet sind, mĂŒssen entweder die
Schnittstellen erweitert oder alternative Architekturkonzepte geschaffen
werden. Die Gefahr beider Varianten ist jedoch, dass sich die KomplexitÀt
eines Systems dadurch weiter erhöhen kann.
Das zentrale Ziel dieser Dissertation ist es deshalb,
schichtenĂŒbergreifende Koordination bei gleichzeitiger Reduzierung der
KomplexitÀt zu erreichen. Hier leistet die Arbeit zwei BetrÀge zum
aktuellen Stand der Forschung. Erstens definiert sie ein universelles
Modell zur Beschreibung von Inhaltsattributen, wie Wichtigkeiten und
AbhÀngigkeitsbeziehungen innerhalb eines Datenstroms. Transportschichten
können dieses Wissen zur effizienten Fehlerkontrolle verwenden. Zweitens
beschreibt die Arbeit das Noja Programmiermodell fĂŒr multimediale
Middleware. Noja definiert Abstraktionen zur Ăbertragung und Kontrolle
multimedialer Ströme, die die Koordination von Streamingprotokollen mit
Applikationen ermöglichen. Zum Beispiel können Programmierer geeignete
Fehlersemantiken und Kommunikationstopologien auswÀhlen und den konkreten
Fehlerschutz dann zur Laufzeit verfeinern und kontrolliere
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