6698506
Multi-layer active queue management and congestion control for scalable video streaming
Video streaming is becoming an increasingly important part of the present Internet. To guarantee a high-quality streaming environment to end users, many video applications require a strict form of network QoS that is not available in the present Internet. Thus, to supplement the best-effort model of existing networks, we study a new video streaming framework that allows applications to mark their own packets with different priority and use multiqueue congestion control inside routers to effectively drop the less-important packets during buffer overflows. We describe priority AQM algorithms that provide "optimal" performance to video applications under arbitrary network loss and study a variation of Kelly's congestion control in combination with our framework. We call the combined architecture PELS - partitioned enhancement layer streaming.
16508634
SmartClick: An enabler for human-centered wireless Web service
Recently wireless Web services have been rapidly growing as a new way of information service. As the wireless Internet access grows, so do e-commerce opportunities through the wireless Web services. Wireless Internet access has inherent limitations since most handheld devices have much less display and means of operations. This imposes a particular problem to the design of mobile information services in terms of information and service navigation. In this paper, a novel approach called SmartClick is presented to achieve user-centered wireless Web services. SmartClick enables users to explicitly express their intentions or preferences with minimal clicks (user interaction). SmartClick with a middleware support provides users a way to get the desired Web contents more efficiently and easily.
5958118
Delayed stability and performance of distributed congestion control
Recent research efforts to design better Internet transport protocols combined with scalable Active Queue Management (AQM) have led to significant advances in congestion control. One of the hottest topics in this area is the design of discrete congestion control algorithms that are asymptotically stable under heterogeneous feedback delay and whose control equations do not explicitly depend on the RTTs of end-flows. In this paper, we show that max-min fair congestion control methods with a stable symmetric Jacobian remain stable under arbitrary feedback delay (including heterogeneous directional delays) and that the stability condition of such methods does not involve any of the delays. To demonstrate the practicality of the obtained result, we change the original controller in Kelly's work [14] to become robust under random feedback delay and fixed constants of the control equation. We call the resulting framework Max-min Kelly Control (MKC) and show that it offers smooth sending rate, exponential convergence to efficiency, and fast convergence to fairness, all of which make it appealing for future high-speed networks.
8305231
Packet-pair bandwidth estimation: stochastic analysis of a single congested node
We examine the problem of estimating the capacity of bottleneck links and available bandwidth of end-to-end paths under non-negligible cross-traffic conditions. We present a simple stochastic analysis of the problem in the context of a single congested node and derive several results that allow the construction of asymptotically-accurate bandwidth estimators. We first develop a generic queuing model of an Internet router and solve the estimation problem assuming renewal cross-traffic at the bottleneck link. Noticing that the renewal assumption on Internet flows is too strong, we investigate an alternative filtering solution that asymptotically converges to the desired values of the bottleneck capacity and available bandwidth under arbitrary (including non-stationary) cross-traffic. This is one of the first methods that simultaneously estimates both types of bandwidth and is provably accurate. We finish the paper by discussing the impossibility of a similar estimator for paths with two or more congested routers.
353647
On Estimating Tight-Link Bandwidth Characteristics over Multi-Hop Paths
In this paper, we explore multi-hop bandwidth estimation assuming arbitrary cross-traffic at each node and develop a new probing method called Envelope that can asymptotically estimate not only the available bandwidth but also the raw capacity of the tight link. Envelope is based on a multi-link recursive extension of unbiased single-hop estimators proposed in the past (e.g., [14]) and a variation of the packet-cartouche technique [6]. Through extensive simulations, we evaluate Envelope in various network settings and cross-traffic conditions and find that it can measure tight-link bandwidth characteristics with accuracy that significantly surpasses that of the existing methods. We also find that Envelope can measure non-tight links in certain path and cross-traffic configurations.
5454614
Impact of FEC overhead on scalable video streaming
Forward-error correction (FEC) is used in many streaming applications for protecting multimedia data over lossy network paths. However, studies in the literature [1, 3, 4] report conflicting results on the benefits of FEC. To address this uncertainty, we study the performance of FEC-based streaming and provide additional insight into how FEC overhead rate affects the performance of scalable video streaming under dynamically changing network packet loss. Through analytical investigation, we derive the relationship between packet loss, FEC overhead, and utility of received video, and propose a simple control mechanism that adjusts the amount of FEC based on packet loss information. We find that our FEC control allows the application to maintain high end-user utility and achieve better quality of video at the receiver.
589178
Multi-Layered Image-Based Rendering
In this article, we describe a multi-layered image-based rendering system that can use different types of input to produce and render new environments. Each separate input that can be manipulated independently is called a layer. In our implementation, the types of layers that can be manipulated are the image-based and 3-D-based layers. The computation required for rendering the newlycrafted environment is reduced by using cached composite snapshots of that environment at reference poses. These cached snapshots are used to directly generate novel views, and the original layers are used only when necessary. Another key concept is the identification of types of holes generated as a result of pixel transfer from the composite snapshots to the generated view. For optimal rendering quality, the algorithm used in filling these holes is specific to the hole type (either intralayer or interlayer). The ideas embodied in our multi-layered IBR system are useful in augmenting the capabilities of applications that require fast and geometrically consistent rendering of 3-D scenes such as video editing.
47117010
Stylizing 2.5-D video
In recent years considerable interest has been given to non-photorealistic rendering of photographs, video, and 3D models for illustrative or artistic purposes. Conventional 2D inputs such as photographs and video are easy to create and capture, while 3D models allow for a wider variety of stylization techniques, such as cross-hatching. In this paper, we propose using video with depth information (2.5-D video) to combine the advantages of 2D and 3D input. 2.5-D video is becoming increasingly easy to capture, and with the additional depth information, stylization techniques that require shape information can be applied. However, because 2.5-D video contains only limited shape information and 3D correspondence over time is unknown, it is difficult to create temporally coherent stylized animations directly from raw 2.5-D video. In this paper, we present techniques for processing 2.5-D video to overcome these drawbacks, and demonstrate several styles that can be created using these techniques.
46490262
Crosstalk noise minimization in domino logic design
Based on the new concept of crosstalk immunity set (CIS), procedures to minimize capacitive crosscoupling effects are developed for domino logic circuit. The nets in a CIS are by definition free from capacitive crosscoupling effects in any combination of input vectors. New algorithms for CIS identification and CIS-driven phase assignment are proposed to maximize the chance of crosstalk minimization in routing step. Our routing algorithm augmented with CIS information searches for optimal solution to minimize maximum crosstalk the circuit would experience. Experimental results show that the reduction of maximum crosstalk is as much as 30% with CIS-augmented routing.
14075641
Business process choreography for B2B collaboration
We describe a proposed methodology for business process choreography. We focus on two types of business processes (contract and executable) and provide an interface protocol to represent interoperability patterns between them. The approach is designed to let existing processes, usually managed by an enterprise's own internal workflow management system, collaborate.
45749208
A low-power reduced swing single clock flip-flop
A reduced swing single clock flip-flop (RS/sup 2/CFF) is developed to reduce power consumption significantly compared to conventional FFs. RS/sup 2/CFF avoids unnecessary internal node transition and reduce fighting currents. The overall power saving in flip-flop operation is estimated to be 33% with additional 64% power savings in clock network.