224 research outputs found

    Q-AIMD: A Congestion Aware Video Quality Control Mechanism

    Get PDF
    Following the constant increase of the multimedia traffic, it seems necessary to allow transport protocols to be aware of the video quality of the transmitted flows rather than the throughput. This paper proposes a novel transport mechanism adapted to video flows. Our proposal, called Q-AIMD for video quality AIMD (Additive Increase Multiplicative Decrease), enables fairness in video quality while transmitting multiple video flows. Targeting video quality fairness allows improving the overall video quality for all transmitted flows, especially when the transmitted videos provide various types of content with different spatial resolutions. In addition, Q-AIMD mitigates the occurrence of network congestion events, and dissolves the congestion whenever it occurs by decreasing the video quality and hence the bitrate. Using different video quality metrics, Q-AIMD is evaluated with different video contents and spatial resolutions. Simulation results show that Q-AIMD allows an improved overall video quality among the multiple transmitted video flows compared to a throughput-based congestion control by decreasing significantly the quality discrepancy between them

    Design and analysis for TCP-friendly window-based congestion control

    Get PDF
    The current congestion control mechanisms for the Internet date back to the early 1980’s and were primarily designed to stop congestion collapse with the typical traffic of that era. In recent years the amount of traffic generated by real-time multimedia applications has substantially increased, and the existing congestion control often does not opt to those types of applications. By this reason, the Internet can be fall into a uncontrolled system such that the overall throughput oscillates too much by a single flow which in turn can lead a poor application performance. Apart from the network level concerns, those types of applications greatly care of end-to-end delay and smoother throughput in which the conventional congestion control schemes do not suit. In this research, we will investigate improving the state of congestion control for real-time and interactive multimedia applications. The focus of this work is to provide fairness among applications using different types of congestion control mechanisms to get a better link utilization, and to achieve smoother and predictable throughput with suitable end-to-end packet delay

    Holographic and 3D teleconferencing and visualization: implications for terabit networked applications

    Get PDF
    Abstract not available

    VIRAL : coupling congestion control with fair video quality metric

    Get PDF
    Video streaming is often carried out by congestion controlled transport protocols to preserve network sustainability.However, the success of the growth of such non-live video flows is linked to the user quality of experience. Thus, onepossible solution is to deploy complex quality of service systems inside the core network. Another possibility would be tokeep the end-to-end principle while making aware transport protocols of video quality rather than throughput. The objectiveof this article is to investigate the latter by proposing a novel transport mechanism which targets video quality fairness amongvideo flows. Our proposal, called VIRAL for virtual rate-quality curve, allows congestion controlled transport protocols toprovide fairness in terms of both throughput and video quality. VIRAL is compliant with any rate-based congestion controlmechanisms that enable a smooth sending rate for multimedia applications. Implemented inside TFRC a TCP-friendlyprotocol, we show that VIRAL enables both intra-fairness between video flows in terms of video quality and inter-fairnessin terms of throughput between TCP and video flows

    Quality-driven management of video streaming services in segment-based cache networks

    Get PDF

    Real-time data flow models and congestion management for wire and wireless IP networks

    Get PDF
    Includes abstract.Includes bibliographical references (leaves 103-111).In video streaming, network congestion compromises the video throughput performance and impairs its perceptual quality and may interrupt the display. Congestion control may take the form of rate adjustment through mechanisms by attempt to minimize the probability of congestion by adjusting the rate of the streaming video to match the available capacity of the network. This can be achieved either by adapting the quantization parameter of the video encoder or by varying the rate through a scalable video technique. This thesis proposes a congestion control protocol for streaming video where an interaction between the video source and the receiver is essential to monitor the network state. The protocol consists of adjusting the video transmission rate at the encoder whenever a change in the network conditions is observed and reported back to the sender

    Investigating the Network Characteristics of Two Popular Web-Based Video Streaming Sites

    Get PDF
    The determinants of the strategies to be employed by video streaming sites are application (mobile devices or web browsers) and container of the video application. They affect video streaming network characteristics, which is often the traffic flow, and its quality. It is against this background that studies on streaming strategies suggested the need to investigate and identify the relationship between buffer time, video stream protocol, packet speed and size, upload time, and waiting period, specifically to aid network administrative support in case of network traffic bottlenecks. In view of this, this study investigates the network characteristics of YouTube and Vimeo, using experimental methodology, and involving WireShark as network analyzer. Google Chrome and Firefox are the web browsers employed, while packet size, protocols, packet interval, TCP window size and accumulation ratio are the metrics. Short ON-OFF, Long ON-OFF, and No ON-OFF cycles are the three streaming strategies identified. It is further shown that both Vimeo and YouTube employ these strategies but the choice depends on the container of the video streamed

    A survey on buffer and rate adaptation optimization in TCP-based streaming media studies

    Get PDF
    Contrary to the popular conventional wisdom that the best transport protocol for the streaming media is UDP, many findings found that most of the transport protocols used nowadays are TCP. Two main reasons that UDP is not being used widely are it is not friendly to other flows and some organizations are blocking this protocol. In the meantime,TCP is naturally reliable and friendly to other flows. But with so many controls inbuilt in the protocol; such as congestion control, flow control, and others with the heavy acknowledgement mechanism, resulting delays and jitters.Thus it’s naturally not friendly to the streaming media.But with all the inherited weaknesses, we have seen explosive growth of streaming media in the Internet. With these contrasting premises, it is very interesting to study and investigate the streaming media via TCP transport protocol,specifically on buffer and rate adaptation optimization
    corecore