The Experts below are selected from a list of 106833 Experts worldwide ranked by ideXlab platform
Zahir Tari - One of the best experts on this subject based on the ideXlab platform.
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MetaCDN: Harnessing 'Storage Clouds' for high performance Content Delivery
Journal of Network and Computer Applications, 2009Co-Authors: James Broberg, Rajkumar Buyya, Zahir TariAbstract:Content Delivery networks (CDNs) such as Akamai and Mirror Image place web server clusters in numerous geographical locations to improve the responsiveness and locality of the Content it hosts for end-users. However, their services are priced out of reach for all but the largest enterprise customers. An alternative approach to Content Delivery could be achieved by leveraging existing infrastructure provided by 'Storage Cloud' providers, who offer internet accessible data storage and Delivery at a fraction of the cost. In this paper, we introduce MetaCDN, a system that exploits 'Storage Cloud' resources, creating an integrated overlay network that provides a low cost, high performance CDN for Content creators. MetaCDN removes the complexity of dealing with multiple storage providers, by intelligently matching and placing users' Content onto one or many storage providers based on their quality of service, coverage and budget preferences. MetaCDN makes it trivial for Content creators and consumers to harness the performance and coverage of numerous 'Storage Clouds' by providing a single unified namespace that makes it easy to integrate into origin websites, and is transparent for end-users. We then demonstrate the utility of this new approach to Content Delivery by showing that the participating 'Storage Clouds' used by MetaCDN provide high performance (in terms of throughput and response time) and reliable Content Delivery for Content consumers, whilst the MetaCDN system itself introduces minimal overhead compared to using these 'Storage Clouds' directly. Crown Copyright ?? 2009.
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metacdn harnessing storage clouds for high performance Content Delivery
International Conference on Service Oriented Computing, 2008Co-Authors: James Broberg, Zahir TariAbstract:Content Delivery Networks (CDNs) such as Akamai and Mirror Image place web server clusters in numerous geographical locations to improve the responsiveness and locality of the Content it hosts for end-users. However, their services are priced out of reach for all but the largest enterprise customers. An alternative approach to Content Delivery could be achieved by harnessing existing infrastructure provided by `storage cloud' providers, at a fraction of the cost. MetaCDN is a system that leverages several existing `storage clouds', creating an integrated overlay network that provides a low cost, high performance Content Delivery network for Content creators. MetaCDN intelligently places Content onto one or many storage providers based on the quality of service, coverage and budget preferences of participants.
James Broberg - One of the best experts on this subject based on the ideXlab platform.
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MetaCDN: Harnessing 'Storage Clouds' for high performance Content Delivery
Journal of Network and Computer Applications, 2009Co-Authors: James Broberg, Rajkumar Buyya, Zahir TariAbstract:Content Delivery networks (CDNs) such as Akamai and Mirror Image place web server clusters in numerous geographical locations to improve the responsiveness and locality of the Content it hosts for end-users. However, their services are priced out of reach for all but the largest enterprise customers. An alternative approach to Content Delivery could be achieved by leveraging existing infrastructure provided by 'Storage Cloud' providers, who offer internet accessible data storage and Delivery at a fraction of the cost. In this paper, we introduce MetaCDN, a system that exploits 'Storage Cloud' resources, creating an integrated overlay network that provides a low cost, high performance CDN for Content creators. MetaCDN removes the complexity of dealing with multiple storage providers, by intelligently matching and placing users' Content onto one or many storage providers based on their quality of service, coverage and budget preferences. MetaCDN makes it trivial for Content creators and consumers to harness the performance and coverage of numerous 'Storage Clouds' by providing a single unified namespace that makes it easy to integrate into origin websites, and is transparent for end-users. We then demonstrate the utility of this new approach to Content Delivery by showing that the participating 'Storage Clouds' used by MetaCDN provide high performance (in terms of throughput and response time) and reliable Content Delivery for Content consumers, whilst the MetaCDN system itself introduces minimal overhead compared to using these 'Storage Clouds' directly. Crown Copyright ?? 2009.
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metacdn harnessing storage clouds for high performance Content Delivery
International Conference on Service Oriented Computing, 2008Co-Authors: James Broberg, Zahir TariAbstract:Content Delivery Networks (CDNs) such as Akamai and Mirror Image place web server clusters in numerous geographical locations to improve the responsiveness and locality of the Content it hosts for end-users. However, their services are priced out of reach for all but the largest enterprise customers. An alternative approach to Content Delivery could be achieved by harnessing existing infrastructure provided by `storage cloud' providers, at a fraction of the cost. MetaCDN is a system that leverages several existing `storage clouds', creating an integrated overlay network that provides a low cost, high performance Content Delivery network for Content creators. MetaCDN intelligently places Content onto one or many storage providers based on the quality of service, coverage and budget preferences of participants.
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An Approach for QoS-Driven Performance Modeling of Peering Content Delivery Networks
2008Co-Authors: Al-mukaddim Khan Pathan, James Broberg, Rajkumar BuyyaAbstract:A Content Delivery Network (CDN) is expected to provide high performance Internet Content Delivery through global coverage, which might be an obstacle for new CDN providers, as well as affecting commercial viability of the existing ones. Peering of CDNs can be a way to allow cooperation between CDNs in a scalable manner and to achieve better overall service, as perceived by end-users. In this paper, we present a Quality of Service (QoS)-driven performance modeling approach for peering CDNs in order to predict the user performance. We also show that peering between CDNs upholds user perceived performance by satisfying the target QoS. The methodology presented in this paper provides CDNs a way to dynamically redirect user requests to other peering CDNs according to different request-redirection policies. The model-based approach helps an overloaded CDN to return to normal by offloading excess requests to the peers. It also assists in making concrete QoS guarantee for a CDN. Our approach endeavors to achieve scalability for a CDN in a user transparent manner
Mari Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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scalable Content Delivery with coded caching in multi antenna fading channels
IEEE Transactions on Wireless Communications, 2018Co-Authors: Sheng Yang, Mari KobayashiAbstract:We consider the Content Delivery problem in a fading multi-input single-output channel with cache-aided users. We are interested in the scalability of the equivalent Content Delivery rate when the number of users, $K$ , is large. Analytical results show that, using coded caching and wireless multicasting, without channel state information at the transmitter, linear scaling of the Content Delivery rate with respect to $K$ can be achieved in some different ways. First, if the multicast transmission spans over $L$ independent sub-channels, e.g., in quasi-static fading if $L = 1$ , and in block fading or multi-carrier systems if $L>1$ , linear scaling can be obtained, when the product of the number of transmit antennas and the number of sub-channels scales logarithmically with $K$ . Second, even with a fixed number of antennas, we can achieve the linear scaling with a threshold-based user selection requiring only one-bit feedbacks from the users. When CSIT is available, we propose a mixed strategy that combines spatial multiplexing and multicasting. Numerical results show that, by optimizing the power split between spatial multiplexing and multicasting, we can achieve a significant gain of the Content Delivery rate with moderate cache size.
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scalable Content Delivery with coded caching in multi antenna fading channels
arXiv: Information Theory, 2017Co-Authors: Sheng Yang, Mari KobayashiAbstract:We consider the Content Delivery problem in a fading multi-input single-output channel with cache-aided users. We are interested in the scalability of the equivalent Content Delivery rate when the number of users, K, is large. Analytical results show that, using coded caching and wireless multicasting, without channel state information at the transmitter (CSIT), linear scaling of the Content Delivery rate with respect to K can be achieved in three different ways. First, with quasi-static fading, it can be achieved when the number of transmit antennas grows logarithmically with K. Second, even with a fixed number of antennas, we can achieve the linear scaling with a threshold-based user selection requiring only one-bit feedbacks from the users. Third, if the multicast transmission can span over multiple independent sub-channels, e.g., in block fading or multi-carrier systems, linear scaling can be obtained when the product of the number of sub-channels and the number of transmit antennas scales logarithmically with K. When CSIT is available, we propose a mixed strategy that combines spatial multiplexing and multicasting. Numerical results show that, by optimizing the power split between spatial multiplexing and multicasting, we can achieve a significant gain of the Content Delivery rate with moderate cache size.
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opportunistic Content Delivery in fading broadcast channels
arXiv: Information Theory, 2017Co-Authors: Asma Ghorbel, Khac-hoang Ngo, Richard Combes, Mari Kobayashi, Sheng YangAbstract:We consider Content Delivery over fading broadcast channels. A server wants to transmit K files to K users, each equipped with a cache of finite size. Using the coded caching scheme of Maddah-Ali and Niesen, we design an opportunistic Delivery scheme where the long-term sum Content Delivery rate scales with K the number of users in the system. The proposed Delivery scheme combines superposition coding together with appropriate power allocation across sub-files intended to different subsets of users. We analyze the long-term average sum Content Delivery rate achieved by two special cases of our scheme: a) a selection scheme that chooses the subset of users with the largest weighted rate, and b) a baseline scheme that transmits to K users using the scheme of Maddah-Ali and Niesen. We prove that coded caching with appropriate user selection is scalable since it yields a linear increase of the average sum Content Delivery rate.
Zhenjiang Dong - One of the best experts on this subject based on the ideXlab platform.
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greening the smart cities energy efficient massive Content Delivery via d2d communications
IEEE Transactions on Industrial Informatics, 2018Co-Authors: Liang Zhou, Dan Wu, Jianxin Chen, Zhenjiang DongAbstract:Massive multimedia services have been considered as one the most prominent characteristics for smart cities. In this paper, we propose an energy-efficient Content Delivery system via the device-to-device communications, which realizes the large-scale Content Delivery among mobile devices with constrained energy, unpredictable demand, limited storage, random mobility, and opportunistic transmission. The highlights of this paper lie in two parts. On the theoretical end, through exploring the relationship among the coding, storage, and transmission, a systematic energy-saving Content Delivery fashion is investigated. On the technical end, a totally distributed Content Delivery system is designed in a simple and efficient manner, in which each device only utilizes local information to make decisions and implements its own scheme individually. Importantly, the proposed scheme is realized in a practical smart city system, and numerical results demonstrate that it is flexible to various users’ needs and communication environments.
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when collaboration hugs intelligence Content Delivery over ultra dense networks
IEEE Communications Magazine, 2017Co-Authors: Liang Zhou, Zhenjiang DongAbstract:With the increasing popularity of traffic-intensive video applications, UDNs are treated as one of the most promising technologies for massive video Delivery. However, due to the drastic interference between neighboring cells, how to achieve high energy and spectrum efficiency is still an open and challenging problem. This work proposes a systematic solution for Content Delivery over UDNs by integrating collaboration with intelligence. In particular, we first design a hybrid video coding scheme that is flexible and robust to the dynamic wireless environment. Then an active and proactive video update strategy is designed by intelligently alleviating the impact of the interference. Finally, a collaborative video scheduling scheme is developed to maximize the video quality as well as the energy and spectrum efficiency. Importantly, we summarize three fundamental design guidelines, and believe that they are useful for improving the transmission capacity of UDNs.
Borja Bergua - One of the best experts on this subject based on the ideXlab platform.
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skycds a resilient Content Delivery service based on diversified cloud storage
Simulation Modelling Practice and Theory, 2015Co-Authors: J L Gonzalez, Jesus Carretero Perez, Victor J Sosasosa, Luis Miguel Sanchez, Borja BerguaAbstract:Cloud-based storage is a popular outsourcing solution for organizations to deliver Contents to end-users. However, there is a need for contingency plans to ensure service provision when the provider either suffers outages or is going out of business. This paper presents SkyCDS: a resilient Content Delivery service based on a publish/subscribe overlay over diversified cloud storage. SkyCDS splits the Content Delivery into metadata and Content storage flow layers. The metadata flow layer is based on publish–subscribe patterns for insourcing the metadata control back to Content owner. The storage layer is based on dispersal information over multiple cloud locations with which organizations outsource Content storage in a controlled manner. In SkyCDS, the Content dispersion is performed on the publisher side and the Content retrieving process on the end-user side (the subscriber), which reduces the load on the organization side only to metadata management. SkyCDS also lowers the overhead of the Content dispersion and retrieving processes by taking advantage of multi-core technology. A new allocation strategy based on cloud storage diversification and failure masking mechanisms minimize side effects of temporary, permanent cloud-based service outages and vendor lock-in. We developed a SkyCDS prototype that was evaluated by using synthetic workloads and a study case with real traces. Publish/subscribe queuing patterns were evaluated by using a simulation tool based on characterized metrics taken from experimental evaluation. The evaluation revealed the feasibility of SkyCDS in terms of performance, reliability and storage space profitability. It also shows a novel way to compare the storage/Delivery options through risk assessment.