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Author

ZhangHui

Bio: ZhangHui is an academic researcher. The author has contributed to research in topics: The Internet & IP multicast. The author has an hindex of 1, co-authored 1 publications receiving 109 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the authors advocate an alternate architecture for supporting group communication applications in IP Multicast, in response to the serious scalability and deployment concerns with IP multicast.
Abstract: In response to the serious scalability and deployment concerns with IP Multicast, we and other researchers have advocated an alternate architecture for supporting group communication applications o...

109 citations


Cited by
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Journal ArticleDOI
TL;DR: The existing technologies and a wide array of past and state-of-the-art projects on network virtualization are surveyed followed by a discussion of major challenges in this area.

1,235 citations

Journal ArticleDOI
15 Jan 2019-Sensors
TL;DR: This work proposes a novel framework of modified blockchain models suitable for IoT devices that rely on their distributed nature and other additional privacy and security properties of the network that make IoT application data and transactions more secure and anonymous over a blockchain-based network.
Abstract: Medical care has become one of the most indispensable parts of human lives, leading to a dramatic increase in medical big data. To streamline the diagnosis and treatment process, healthcare professionals are now adopting Internet of Things (IoT)-based wearable technology. Recent years have witnessed billions of sensors, devices, and vehicles being connected through the Internet. One such technology—remote patient monitoring—is common nowadays for the treatment and care of patients. However, these technologies also pose grave privacy risks and security concerns about the data transfer and the logging of data transactions. These security and privacy problems of medical data could result from a delay in treatment progress, even endangering the patient’s life. We propose the use of a blockchain to provide secure management and analysis of healthcare big data. However, blockchains are computationally expensive, demand high bandwidth and extra computational power, and are therefore not completely suitable for most resource-constrained IoT devices meant for smart cities. In this work, we try to resolve the above-mentioned issues of using blockchain with IoT devices. We propose a novel framework of modified blockchain models suitable for IoT devices that rely on their distributed nature and other additional privacy and security properties of the network. These additional privacy and security properties in our model are based on advanced cryptographic primitives. The solutions given here make IoT application data and transactions more secure and anonymous over a blockchain-based network.

552 citations

Proceedings ArticleDOI
04 Nov 2003
TL;DR: A simple tree management algorithm is presented that provides the necessary path diversity and an adaptation framework for MDC based on scalable receiver feedback is described, which shows very significant benefits in using multiple distribution trees and MDC, with a 22 dB improvement in PSNR in some cases.
Abstract: We consider the problem of distributing "live" streaming media content to a potentially large and highly dynamic population of hosts. Peer-to-peer content distribution is attractive in this setting because the bandwidth available to serve content scales with demand. A key challenge, however, is making content distribution robust to peer transience. Our approach to providing robustness is to introduce redundance; both in network paths and in data. We use multiple, diverse distribution trees to provide redundancy in network paths and multiple description coding (MDC) to provide redundancy in data. We present a simple tree management algorithm that provides the necessary path diversity and describe an adaptation framework for MDC based on scalable receiver feedback. We evaluate these using MDC applied to real video data coupled with real usage traces from a major news site that experienced a large flash crowd for live streaming content. Our results show very significant benefits in using multiple distribution trees and MDC, with a 22 dB improvement in PSNR in some cases.

484 citations

Journal ArticleDOI
TL;DR: In Zigzag, the multicast tree has a height logarithmic with the number of clients, and a node degree bounded by a constant, so that the end-to-end delay is kept small.
Abstract: Given that the Internet does not widely support Internet protocol multicast while content-distribution-network technologies are costly, the concept of peer-to-peer could be a promising start for enabling large-scale streaming systems In our so-called Zigzag approach, we propose a method for clustering peers into a hierarchy called the administrative organization for easy management, and a method for building the multicast tree atop this hierarchy for efficient content transmission In Zigzag, the multicast tree has a height logarithmic with the number of clients, and a node degree bounded by a constant This helps reduce the number of processing hops on the delivery path to a client while avoiding network bottlenecks Consequently, the end-to-end delay is kept small Although one could build a tree satisfying such properties easily, an efficient control protocol between the nodes must be in place to maintain the tree under the effects of network dynamics Zigzag handles such situations gracefully, requiring a constant amortized worst-case control overhead Especially, failure recovery is done regionally with impact on, at most, a constant number of existing clients and with mostly no burden on the server

386 citations

Journal ArticleDOI
TL;DR: It is demonstrated through a large-scale measurement study that the existing cloud infrastructure is unable to meet the strict latency requirements necessary for acceptable on-demand game play, and the effectiveness of incorporating edge servers, which are servers located near end-users (e.g., CDN servers), to improve end-user coverage is investigated.
Abstract: The cloud was originally designed to provide general-purpose computing using commodity hardware and its focus was on increasing resource consolidation as a means to lower cost. Hence, it was not particularly adapted to the requirements of multimedia applications that are highly latency sensitive and require specialized hardware, such as graphical processing units. Existing cloud infrastructure is dimensioned to serve general-purpose workloads and to meet end-user requirements by providing high throughput. In this paper, we investigate the effectiveness of using this general-purpose infrastructure for serving latency-sensitive multimedia applications. In particular, we examine on-demand gaming, also known as cloud gaming, which has the potential to change the video game industry. We demonstrate through a large-scale measurement study that the existing cloud infrastructure is unable to meet the strict latency requirements necessary for acceptable on-demand game play. Furthermore, we investigate the effectiveness of incorporating edge servers, which are servers located near end-users (e.g., CDN servers), to improve end-user coverage. Specifically, we examine an edge-server-only infrastructure and a hybrid infrastructure that consists of using edge servers in addition to the cloud. We find that a hybrid infrastructure significantly improves the number of end-users served. However, the number of satisfied end-users in a hybrid deployment largely depends on the various deployment parameters. Therefore, we evaluate various strategies that determine two such parameters, namely, the location of on-demand gaming servers and the games that are placed on these servers. We find that, through both a careful selection of on-demand gaming servers and the games to place on these servers, we significantly increase the number of end-users served over the basic random selection and placement strategies.

113 citations