Virtualization is a key technology for the efficient operation of massive data centers. To minimize the communication costs among virtual machines (VMs) in a data center network, we formulate an optimization problem f...
详细信息
ISBN:
(纸本)9781467371315
Virtualization is a key technology for the efficient operation of massive data centers. To minimize the communication costs among virtual machines (VMs) in a data center network, we formulate an optimization problem for finding efficient VM placements. In this problem, a set of requests is received from customers, where each request is defined as the required number of VMs. the problem seeks to determine those physical machines in the network that host the requested VMs under a capacity constraint such that the number of VMs placed on each physical machine does not exceed that of the available slots. To minimize the load of the networks, for each request, we consider the connection cost of the VM placements, which is defined as the minimum length of networks connecting all physical host machines and the root node. the objective in the problem is to minimize the total connection costs. We present an approximation algorithm for this optimization problem.
We establish a network formation game for the Internet's Autonomous System (AS) interconnection topology. the game includes different types of players, accounting for the heterogeneity of ASs in the Internet. We i...
ISBN:
(纸本)9781479983810
We establish a network formation game for the Internet's Autonomous System (AS) interconnection topology. the game includes different types of players, accounting for the heterogeneity of ASs in the Internet. We incorporate reliability considerations in the player's utility function, and analyze static properties of the game as well as its dynamic evolution. We provide dynamic analysis of topological quantities, and explain the prevalence of some "network motifs" in the Internet graph. We assess our predictions with real-world data.
Barrier coverage in visual camera sensor networks (visual barrier coverage) has important real-world applications like battlefield surveillance, environmental monitoring, and protection of government property. Cost-ef...
详细信息
ISBN:
(纸本)9781479983810
Barrier coverage in visual camera sensor networks (visual barrier coverage) has important real-world applications like battlefield surveillance, environmental monitoring, and protection of government property. Cost-effective deployment, a fundamental issue of visual barrier coverage, considers how to deploy the fewest camera sensors along the barrier to detect intruders (e.g., capture faces) with desirable performance. Existing visual barrier coverage approaches like full-view coverage require numerous camera sensors for capturing intruders' faces deterministically for any trajectory and facing angle. However, intruders' trajectories and facing angles are bounded and deterministic intruder detection requires many camera sensors for rare intrusion cases. Certain practical applications can tolerate limited intrusion mis-detection given budget limitations. this paper proposes local face-view barrier coverage, a novel concept that achieves statistical barrier coverage in camera sensor networks leveraging intruders' trajectory lengths l along the barrier and head rotation angles delta. Using (l, delta) and other parameters, we derive a rigorous probability bound for intruder detection for local face-view barrier coverage via a feasible deployment pattern. Our detection probability bound and deployment pattern can guide practical camera sensor network deployments with camera sensor budgets. Extensive evaluations show that local face-view barrier coverage requires up to 50% fewer camera sensors than full-view barrier coverage.
Motivated by the recent push to deploy LTE in unlicensed spectrum, this paper develops a novel system to enable co-existence between LTE and WiFi. Our approach leverages LTE and WiFi antennas already available on smar...
详细信息
ISBN:
(纸本)9781479983810
Motivated by the recent push to deploy LTE in unlicensed spectrum, this paper develops a novel system to enable co-existence between LTE and WiFi. Our approach leverages LTE and WiFi antennas already available on smartphones to let LTE and WiFi transmit together and successfully decode the interfered signals. Our system offers several distinct advantages over existing MIMO work: (i) it can decode all the interfering signals under cross technology interference even when the interfering signals have similar power and occupy similar frequency, (ii) it does not need clean reference signals from either WiFi or LTE transmission, (iii) it can decode interfering WiFi MIMO and LTE transmissions, and (iv) it has a simple yet effective carrier sense mechanism for WiFi to access the medium under interfering LTE signals while avoiding other WiFi transmissions. We use USRP implementation and experiments to show its effectiveness.
Understanding the correlation between the underlie network structure and overlay cascade effects in the interdependent networks is one of major challenges in complex network studies. there are some existing metrics th...
详细信息
ISBN:
(纸本)9781467371315
Understanding the correlation between the underlie network structure and overlay cascade effects in the interdependent networks is one of major challenges in complex network studies. there are some existing metrics that can be used to measure the cascades. However, different metrics such as average node degree interpret different characteristic of network topological structure, especially less metrics have been identified to effectively measure the cascading performance in the interdependent networks. In this paper, we propose to use a combined Laplacian matrix to model the interdependent networks and their interconnectivity, and then use its effective resistance metric as an indicator to its cascading behavior. Moreover, we have conducted extensive comparative studies among different metrics such as average node degree, and the proposed effective resistance. We have found that the effective resistance metric can describe more accurate and finer characteristics of topological structure of the interdependent networksthan average node degree which is widely adapted by the existing research studies for measuring the cascading performance in the interdependent networks.
the Internet has become one of the most important elements in our daily lives. there are plenty of interactive applications available for billions of users that provide different kinds of interactions. these user inte...
详细信息
ISBN:
(纸本)9781467371315
the Internet has become one of the most important elements in our daily lives. there are plenty of interactive applications available for billions of users that provide different kinds of interactions. these user interactions may form an intermittently connected network for information propagation. In such networks, e.g., interactive forum, website, and tweeter-like online social applications, user behavior generally exhibits temporally varying features due to the extensive temporal-spatial diversity and sparsity among user interactions ( such as users' online/offline activities). It is easy to see that at any time and area, any pair of users in a temporally varying interaction network are not necessarily connected since there may not exist such a path between them. Usually each piece of information between them is transmitted intermittently at different discrete time series, and thus, form a path in a chronological order.
Mobile video delivery forms the largest part of the traffic in cellular networks. thus optimizing the resource allocation to satisfy a user's quality of experience is becoming paramount in modern communications. T...
详细信息
ISBN:
(纸本)9781467371315
Mobile video delivery forms the largest part of the traffic in cellular networks. thus optimizing the resource allocation to satisfy a user's quality of experience is becoming paramount in modern communications. this paper belongs to the line of research known as anticipatory networking that makes use of prediction of wireless capacity to improve communication performance. In particular, we focus on the problem of optimal resource allocation for steady video delivery under maximum average quality constraints for multiple users. We formulate the problem as a piecewise linear program and provide a heuristic algorithm, which solution is close to optimal. Based on our formulation we are now able to trade off minimum video quality, average quality and offered network capacity.
the performance of wide area network (WAN) has a direct impact on user experience of cloud usage. In order to provide on-demand and performance-assured WAN connections, we design and implement a SDN-based system calle...
详细信息
ISBN:
(纸本)9781467371315
the performance of wide area network (WAN) has a direct impact on user experience of cloud usage. In order to provide on-demand and performance-assured WAN connections, we design and implement a SDN-based system called Grace, which abstracts the underlying network resources into life-cycle network services to provide the predefined network performance via open APIs. Withthe advantages of this system, we demonstrate that WAN as a service for cloud can be achieved in event of the deployed Grace.
We place in the context of Information-Centric networks a special class of segment-based caching, named partition-based caching, whereby information items are cached in partitions at different caches in the network. O...
详细信息
ISBN:
(纸本)9781467371315
We place in the context of Information-Centric networks a special class of segment-based caching, named partition-based caching, whereby information items are cached in partitions at different caches in the network. Our rationale lies in exploiting the merits of parallel data transmission, which however may come at the expense of increased network utilization. the study of this cost-benefit trade-off underlines our work. Following a theoretical analysis on the benefits of partition-based caching over single replication caching, we propose three traffic engineering algorithms for assigning content partitions to caches and respective routes. Simulation results indicate that partition-based caching can indeed improve average content transfer time (up to 65%) at the expense of a tolerable increase in network load (up to 25%), for moderate numbers of content partitions (less than 6), balancing at the same time network load better (at the level of 50%), compared to single replication caching.
Emerging heterogeneous wireless architectures consist of a dense deployment of local-coverage wireless access points (APs) with high data rates, along with sparsely-distributed, large-coverage macro-cell base stations...
详细信息
ISBN:
(纸本)9781479983810
Emerging heterogeneous wireless architectures consist of a dense deployment of local-coverage wireless access points (APs) with high data rates, along with sparsely-distributed, large-coverage macro-cell base stations (BS). We design a coded caching-and-delivery scheme for such architectures that equips APs with storage, enabling content pre-fetching prior to knowing user demands. Users requesting content are served by connecting to local APs with cached content, as well as by listening to a BS broadcast transmission. For any given content popularity profile, the goal is to design the caching-and-delivery scheme so as to optimally trade off the transmission cost at the BS against the storage cost at the APs and the user cost of connecting to multiple APs. We design a coded caching scheme for non-uniform content popularity that dynamically allocates user access to APs based on requested content. We demonstrate the approximate optimality of our scheme with respect to information-theoretic bounds. We numerically evaluate it on a YouTube dataset and quantify the trade-off between transmission rate, storage, and access cost. Our numerical results also suggest the intriguing possibility that, to gain most of the benefits of coded caching, it suffices to divide the content into a small number of popularity classes.
暂无评论