Measuring And Improving Internet Video Quality Of Experience

Streaming multimedia content over the IP-network is poised to be the dominant Internet traffic for the coming decade, predicted to account for more than 91% of all consumer traffic in the coming years. Streaming multimedia content ranges from Internet television (IPTV), video on demand (VoD), peer-to-peer streaming, and 3D television over IP to name a few. Widespread acceptance, growth, and subscriber retention are contingent upon network providers assuring superior Quality of Experience (QoE) on top of todays Internet. This work presents the first empirical understanding of Internet’s video-QoE capabilities, and tools and protocols to efficiently infer and improve them. To infer video-QoE at arbitrary nodes in the Internet, we design and implement MintMOS: a lightweight, real-time, noreference framework for capturing perceptual quality. We demonstrate that MintMOS’s projections closely match with subjective surveys in accessing perceptual quality. We use MintMOS to characterize Internet video-QoE both at the link level and end-to-end path level. As an input to our study, we use extensive measurements from a large number of Internet paths obtained from various measurement overlays deployed using PlanetLab. Link level degradations of intra– and inter–ISP Internet links are studied to create an empirical understanding of their shortcomings and ways to overcome them. Our studies show that intra–ISP links are often poorly engineered compared to peering links, and that iii degradations are induced due to transient network load imbalance within an ISP. Initial results also indicate that overlay networks could be a promising way to avoid such ISPs in times of degradations. A large number of end-to-end Internet paths are probed and we measure delay, jitter, and loss rates. The measurement data is analyzed offline to identify ways to enable a source to select alternate paths in an overlay network to improve video-QoE, without the need for background monitoring or apriori knowledge of path characteristics. We establish that for any unstructured overlay of N nodes, it is sufficient to reroute key frames using a random subset of k nodes in the overlay, where k is bounded by O(lnN). We analyze various properties of such random subsets to derive simple, scalable, and an efficient path selection strategy that results in a k-fold increase in path options for any source-destination pair; options that consistently outperform Internet path selection. Finally, we design a prototype called source initiated frame restoration (SIFR) that employs random subsets to derive alternate paths and demonstrate its effectiveness in improving Internet video-QoE

Dynamic Routing Framework for Wireless Sensor Networks

Numerous routing protocols have been proposed for wireless sensor networks. Each such protocol carries with it a set of assumptions about the trafï¬c type that it caters to, and hence has limited interoperability. Also, most protocols are validated over workloads which only form a fraction of an actual deployment’s requirement. Most real world and commercial deployments, however, would generate multiple trafï¬c types simultaneously throughout the lifetime of the network. For example, most deployments would want all of the following to happen concurrently from the network: periodic reliable sense and disseminate, real time streams, patched updates, network reprogramming, query-response dialogs, mission critical alerts and so on. Naturally, no one routing protocol can completely cater to all of a deployments requirements. This chapter presents a routing framework that captures the communication intent of an application by using just three bits. The traditional routing layer is replaced with a collection of routing components that can cater to various communication patterns. The framework dynamically switches routing component for every packet in question. Data structure requirements of component protocols are regularized, and core protocol features are distilled to build a highly composable collection of routing modules. This creates a framework for developing, testing, integrating, and validating protocols that are highly portable from one deployment to another. Communication patterns can be easily described to lower layer protocols using this framework. One such real world application scenario is also investigated: that of predictive maintenance (PdM). The requirements of a large scale PdM are used to generate a fairly complete and realistic trafï¬c workload to drive an evaluation of such a framework

A note on the food of young mackerel

THE food of the Indian mackerel, Rastrelliger kanagurta (Cuvier), has been investigated in some detail but the studies have largely been based upon samples of higher size-groups. Not only is the information available on the food of young mackerel limited, but there is also no agreement among the workers on the nature of their food

Effects Of Internet Path Selection On Video-Qoe

This paper presents large scale Internet measurements to understand and improve the effects of Internet path selection on perceived video quality. We systematically study a large number of Internet paths between popular video destinations and clients to create an empirical understanding of location, persistence and recurrence of failures. We map these failures to perceptual quality by reconstructing video clips obtained from the trace to quantify both the perceptual degradations from these failures as well as the fraction of such failures that can be recovered. We then investigate ways to recover from QoE degradation by choosing one-hop detour paths that preserve application specific policies. We seek simple, scalable path selection strategies without the need for background path monitoring or apriori path knowledge of any kind. To do this, we deployed five measurement overlays: one each in the US, Europe, Asia-Pacific, and two spread across the globe. We used these to stream IP-traces of a variety of clips between source-destination pairs while probing alternate paths for an entire week. Our results indicate that a source can recover from upto 90% of the degradations by attempting to restore QoE with any five randomly chosen nodes in an overlay. We argue that our results are robust across datasets. Finally, we design and implement a prototype packet forwarding module called source initiated frame restoration (SIFR). We deployed SIFR on PlanetLab nodes, and compared the performance of SIFR with the default Internet routing. We show that SIFR outperforms IP-path selection by providing higher on-screen perceptual quality. Copyright 2010 ACM

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Not AvailableTHE food of the Indian mackerel, Rastrelliger kanagurta (Cuvier), has been investigated in some detail but the studies have largely been based upon samples of higher size-groups. Not only is the information available on the food of young mackerel limited, but there is also no agreement among the workers on the nature of their food.Not Availabl

Effects Of Internet Path Selection On Video-Qoe: Analysis And Improvements

This paper presents large-scale Internet measurements to understand and improve the effects of Internet path selection on perceived video quality, or quality of experience (QoE). We systematically study a large number of Internet paths between popular video destinations and clients to create an empirical understanding of location, persistence, and recurrence of failures. These failures are mapped to perceived video quality by reconstructing video clips and conducting surveys. We then investigate ways to recover from QoE degradation by choosing one-hop detour paths that preserve application-specific policies. We seek simple, scalable path selection strategies without the need for background path monitoring. Using five different measurement overlays spread across the globe, we show that a source can recover from over 75% of the degradations by attempting to restore QoE with any k randomly chosen nodes in an overlay, where $k$ is bounded by O(ln(N). We argue that our results are robust across datasets. Finally, we design and implement a prototype packet forwarding module called source initiated frame restoration (SIFR). We deployed SIFR on PlanetLab nodes and compared the performance of SIFR to the default Internet routing. We show that SIFR outperforms IP-path selection by providing higher on-screen perceptual quality. © 2013 IEEE

An Overlay Architecture For Fault Diagnosis In Video Delivery Networks

Today\u27s service providers of VoD, SDV and IPTV have a pressing need to proactively detect, isolate and fix outages within access networks. Network induced degradations prove to be detrimental for streaming applications. This typically leads to a poor quality of experience (QoE) for subscribers, leading to subscriber churn. Apart from isolating impairments, service providers often fall short of performing a whole host of other activities: performance discovery (e.g., measuring round trip times of TCPIUDP), topology discovery (e.g., part or full connectivity), service usage discovery (e.g., who is using what service), fraud discovery (e.g., illegal usage), and trend discovery (e.g., forecasting user demands and preferences). In this paper, we show how service providers can simply leverage their existing billing infrastructure which snoops into user traffic to create a whole host of the above mentioned services. We propose a hierarchy of exporters, collectors, and ANCON (ANalysis and CONtrol) nodes that can semi-autonomously monitor, detect and isolate impairments within an access network. Exporters gather and disseminate statistics for individual subnets, which are streamed onto collector nodes. Collector nodes aggregate traffic from various exporters, and stream them onto the root of the tree (ANCON). With an even placement of exporters, root cause analysis can now take the granularity of loss rates or delay rates in individual segments or subnets of an access network. As an extension to our architecture, we show that the overlay can support instrumentations of quality evaluation for streaming video. Logical extensions of this architecture can easily accommodate performance discovery, fraud discovery, trend forecasting and service usage discovery

Case Study Of Internet Links: What Degrades Video Qoe?

Recently, there has been increasing demand for video streams with high perceptual quality. The capability of present day Internet links in delivering high perceptual quality streaming services, however, is not completely understood. This paper presents a trace driven study to understand QoE capabilities of present day Internet links using 51 diverse ISPs with a major presence in US, Europe and Asia-Pacific.We study a rich collection of their intra-domain links and inter-domain peering links from 38 vantage points in the Internet using both passive tracing and active probing. We provide the first measurements of link level degradations from a multimedia standpoint. While we observe that ISP are internally well connected and their present peering policies are highly conducive to streaming services, the overall perceptual quality delivered is below acceptable . Our results indicate that the fault lies with poor intra-domain traffic engineering, BGP, and the usage of AS-path lenghts as the routing metric. We also provide a comprehensive case study for every scenario we investigate. Streaming services apart, our Internet measurement results can be used as an input to a variety of research problems. ©2010 IEEE

Traffic Based Dynamic Routing For Wireless Sensor Networks

Numerous routing protocols have been proposed for wireless sensor networks, each of which is highly optimized for a certain class of traffic, like real time, reliable sense and disseminate, network reprogramming, energy efficiency and so on. However, a typical deployment demands an arbitrary communication pattern that generates multiple traffic types simultaneously. Arguably, no single routing protocol can completely cater to a deployment\u27s various flavors. In this paper, we propose a dynamic routing framework that can replace the traditional routing layer with a collection of routing decisions. We allow application packets to carry a two-bit preamble that uniquely describes the nature of communication sought for. The framework dynamically wires the appropriate routing component from a set of well-defined suite. We conduct extensive simulation experiments that generates a concurrent mix of different traffic types - each having its own, and often conflicting, communication demands. For such an application, we show that we could meet each traffic types demands for reliability, delay, path distribution, link losses and congestion losses. We also show that service differentiation can indeed be met successfully, and practical deployments can be an imminent reality. © 2009 IEEE