Current Issue : October - December Volume : 2018 Issue Number : 4 Articles : 6 Articles
With the development of SDN, end-to-end network reservation becomes a reality. Resource reservation can\nbecome an online service for network users, and the network faces new challenges on how to allocate users�\nresource dynamically. To solve the problem, this paper proposed a bat-based algorithm for SDN network\nscheduling along with a network request model. The network resource request model is for characterizing users�\nsimultaneous network resource request in SDN. Based on the model, this paper transforms the resource reservation\nproblem into a multiple-knapsack problem and proposes a bat algorithm to optimize the solution. Experiments\nshow that the proposed algorithm is better than greedy and dynamic programming algorithm. The major\ncontribution of this paper is to model the SDN users� resource requests and apply bat algorithm for the solution....
Wireless sensors network (WSN) is widely used in the Internet of Things at present. However, limited energy source is a critical\nproblem in the improvement and practical applications of WSN, so it is necessary to improve the energy efficiency. As another\nimportant evaluation criterion of transmission performance, throughput should be improved too. Tomitigate both of the problems\nat the same time, by taking the advantages of Time DivisionMultiple Access (TDMA) and Carrier SenseMultiple Access (CSMA) at\nthemedium access control (MAC) layer ofWSN, we propose a hybrid TDMA/CSMAMAC layer protocol.Meanwhile, we design a\nnovel power control scheme to further reduce the energy consumption and optimize the transmission slots. The simulation results\ndemonstrate that the proposed protocol significantly improves the throughput and energy efficiency....
Because of the influence of comprehensive hub construction on network flow, this paper adopts the bi-level\nprogramming model (BPM) to solve the problem about the integrated optimization of multi-hub location and\nnetwork layout. The upper level model is designed to minimize the network operating cost, network transformation\ncost, and hub construction cost; the lower level is the user equilibrium distribution model at fixed demands.\nBesides, this paper designs the improved genetic algorithm to solve the bi-level programming model and validates\nthe model validity and algorithm feasibility through the computing example. The model has a high application\nvalue for solving the problem of comprehensive optimization of intercity passenger transport hub location and\nintercity passenger transport network design in the process of urban agglomeration development...
In previous work, the authors presented a 3D hexagonal wireless direct-interconnect\nnetwork for a massively parallel computer, with a focus on analysing processor utilisation.\nIn this study, we consider the characteristics of such an architecture in terms of link utilisation\nand power consumption. We have applied a store-and-forward packet-switching algorithm to\nboth our proposed architecture and a traditional wired 5D direct network (the same as IBM�s\nBlue Gene). Simulations show that for small and medium-size networks the link utility of the\nproposed architecture is comparable with (and in some cases even better than) traditional 5D\nnetworks. This work demonstrates that there is a potential for wireless processing array concepts to\naddress High-Performance Computing (HPC) challenges whilst alleviating some significant physical\nconstruction drawbacks of traditional systems....
A simultaneous wireless information and power transfer system in interference channels of multi-users is considered.\nIn this system, each transmitter sends one data stream to its targeted receiver, which causes interference to other\nreceivers. Since all transmitter-receiver links want to maximize their own average transmission rate, a power allocation\nproblem under the transmit power constraints and the energy-harvesting constraints is developed. To solve this\nproblem, we propose a game theory framework. Then, we convert the game into a variational inequalities problem by\nestablishing the connection between game theory and variational inequalities and solve the variational inequalities\nproblem. Through theoretical analysis, the existence and uniqueness of Nash equilibrium are both guaranteed by the\ntheory of variational inequalities. A distributed iterative alternating optimization water-filling algorithm is derived,\nwhich is proved to converge. Numerical results show that the proposed algorithm reaches fast convergence and\nachieves a higher sum rate than the unaided scheme....
The quest for faster data transport to improve web user experience is ongoing and attempts are conducted from various fronts to\nrealize it. On top of improving user experience, the implications of improving web data transport are also on the energy efficiency\nof wireless devices as well as user retention rates of service providers. HTTP/1.x allow the opening of multiple TCP connections\nper server and then using those connections for fetching multiple web objects through the use of HTTP pipelining. With the\nadvent of HTTP/2.0, multiplexing is done inside a single connection to fetch multiple objects. In this paper, we analyze the TCP\nconnections between the browser and the servers and examine their characteristics. We describe how an enhanced TCP variant\ncan take advantage of data transport connection patterns. We show the benefits that enhanced TCP system can bring with the\nunderstanding of connection usage patterns. We find that such transport protocol can have effect in the page idle times as well as\nthe connection concurrency during web page transfer. The results show significant improvement of page load times for both\nencryption heavy and unencrypted pages. We discuss the effect of the transport protocol on object transfer, connection duration,\nidle times during the page load, connections, and concurrency of flows that cumulate into page load times....
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