Kazumi Kumazoe

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Various new transport protocols have been proposed with the aim of the efficient use of abundant resources in fast long-distance networks, and a number of experiments to investigate the performances of those protocols have already been reported. However, they have mainly focused on the throughput characteristics of a single connection or under a stable(More)
In this document, we introduce Cap Start TCP, an adaptive Slow Start scheme that consistently achieves fast TCP file transfer times regardless of high speed network scenario. Once the TCP session is established, we estimate TCP session path capacity scenario, and tune the transport protocol to deliver fast transfer times. We demonstrate significant(More)
Our group has been conducting a series of experiments on various recently available high-speed transport protocols over long-distance, 10-gigabit-class, international testbed networks. The study reported here focuses on the scenario of multiple coexisting flows along an end-to-end 10-Gbps path, where TCP-based transport protocols are used. The results show(More)
In this paper, we describe two distributed, data intensive applications that were demonstrated at iGrid 2005 (iGrid Demonstration US109 and iGrid Demonstration US121). One involves transporting astronomical data from the Sloan Digital Sky Survey (SDSS) and the other involves computing histograms from multiple high volume data streams. Both rely on newly(More)
While a variety of high-speed transport protocols have been proposed to meet the requirement of high throughput data transfer over fast long-distance networks, less attention has been paid to the problems involved when those transport protocols are deployed in heterogeneously shared network environments like the global Internet. We are investigating several(More)
With the rapid growth in Internet network infrastructure, there is an urgent need to deploy energy-efficient networking technology. In particular, there is a need for energy-efficient wireless local area networks (WLANs), which are widely used due to their ease of deployment and low installation costs. To realize this, radio-on-demand (ROD) have been(More)
In this paper, we address the problem of how TCP sessions ramp up their transmission windows in a controlled way. We introduce a conservative slow start scheme that reduces to the regular slow start when session path queues are empty, but slows down the control window increase speed as buffers start to build up. We show via event driven simulation and open(More)
The widespread deployment of wireless LANs (WLANs) has increased the importance of developing power-saving technologies. We have been involved in the research and development of Radio-On-Demand Networks (ROD) that reduce energy consumption in the operation of WLANs. In this paper, we evaluate the effectiveness of a power-saving scheme with that uses station(More)
We introduce a transmission control protocol with a delay based congestion avoidance. The protocol design follows a control theoretical approach, uses session path estimators, and is adaptive and stable to a wide range of path characteristics and network conditions. We demonstrate the competitive performance of the protocol via open source based network(More)