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In this paper, we propose a mechanism to eliminate the performance anomaly of IEEE 802.11b. Performance anomaly happens when nodes that have different transmission rates are in the same wireless cell. All the nodes in the cell might experience the same throughput even though their transmission rates are different because DCF of WLAN provides equal(More)
Delay estimation is a difficult problem in computer networks. Accurate one-way delay estimation is crucial because it serves a very important role in network performance and thus application design. RTT (Round Trip Time) is often used as an approximation of the delay, but because it is a sum of the forward and reverse delays, the actual one-way delay cannot(More)
While a number of user-level protocols have been developed to reduce the gap between the performance capabilities of the physical network and the performance actually available, their compatibility issues with the existing sockets based applications and IP based infrastructure has been an area of major concern. To address these compatibility issues while(More)
In recent years, HTTP adaptive streaming (HAS) has attracted considerable attention as the state-of-the-art technology for video transport. HAS dynamically adjusts the quality of video streaming according to the network bandwidth and device capability of users. Content-Centric Networking (CCN) has also emerged as a future Internet architecture, which is a(More)
Service level agreements (SLAs) for storage performance in virtualized systems are difficult to guarantee, because different consolidated virtual machines have their own performance requirements. Moreover, hard disk drives (HDDs) in virtualized systems are being replaced by solid-state drives (SSDs). SSDs have higher throughput and lower latency than HDDs;(More)
A preliminary version of this paper appeared in ICONI 2011, December 15-19, Sepang, Malaysia. This version includes a concrete analysis and supporting implementation results on the performance isolation scheme of virtualized network. Abstract Network virtualization supports future Internet environments and cloud computing. Virtualization can mitigate many(More)
— H.264/SVC has been widely adopted to smart CE devices for network-adaptive video transmission. However , current H.264/SVC does not support sufficiently high subjective QoS (Quality of Service) because its scalability methods provide only coarse-grained network adaptivity. To address this problem, we propose a Scalable ROI (SROI) algorithm that applies(More)
This paper addresses the I/O latency issue within Xen-ARM. Although Xen-ARM's split driver presents reliable driver isolation, it requires additional inter-VM scheduling. Consequently, the credit scheduler within Xen-ARM results in unsatisfactory I/O latency for real-time guest OS. This paper analyzes the I/O latency in Xen-ARM's interrupt path, and(More)
— Reliable transport protocols such as TCP (Transmission Control Protocol) are tuned to perform well in traditional networks where packet losses occur mostly because of congestion. However, on the wireless links where packet losses frequently happen, TCP shows a serious drop in performance. In this paper, we propose a scheme, called BSF (Buffer State based(More)
Mobile phones have evolved into complex systems as they have more and more new applications built-in. As a result, they are less reliable and less secure than before. Virtual Machine Monitors (VMM) or hypervisors have been introduced to help the reliability and security of mobile phones but the existing research does not completely address three issues(More)