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Genetic algorithm based coding aware routing for wireless mesh networks

Advances in Information Sciences and Service Sciences 2012年第5期4卷 235-243页

作者： Shao, Xing Wang, Ruchuan Xu, He Huang, Haiping Sun, Lijuan College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China College of Computer Nanjing University of Posts and Telecommunications Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing 210003 China

network coding has been confirmed as a potential technology to improve performance of wireless mesh networks (WMNs) and a few network coding aware routings have been proposed. However, these mechanisms detect coding opportunities through local traffic pattern checking, which hardly obtains optimal routes. This paper proposes a Genetic algorithm based Coding Aware Routing (GCAR) for wireless mesh networks, which employs genetic algorithm to optimize routes and coding opportunities. In addition, the key ingredients in GCAR, e.g., chromosome representation, genetic operation of crossover and mutation, fitness function considering coding opportunity and interference, are carefully designed. Through simulations on a randomly generated wireless mesh network, GCAR is shown to find optimal routes within a short time, and achieve more improvements than the previously proposed methods on route setup time, throughput and load balancing.

关键词： Genetic algorithms

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A real-time video watermarking algorithm for streaming media

International Journal of Digital Content Technology and its ...

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International Journal of Digital Content technology and its Applications 2012年第14期6卷 504-511页

作者： Cheng, Chunling Wan, Teng Wei, Lei Zhu, Hong Zhang, Dengyin College of Computer Nanjing University of Posts and Telecommunications Nanjing Jiangsu 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing Jiangsu 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Jiangsu Province Nanjing Jiangsu 210003 China Power Dispatching Centre Nanjing Power Supply Company Nanjing 210008 China

Video watermarking technology is a useful method to track piracy for digital videos. However, most watermarking algorithms cannot be directly applied to H.264 streaming media because of their poor real-time performance, which may cause users to watch the video unsmoothly. In order to solve this problem, a real-time H.264 video watermarking algorithm (RVWA) is proposed. First, the video is segmented before embedding watermark, which makes watermark embedding and video transmission be carried on at the same time. Then, the concept of watermark embedding margin of frame (WEMF) is proposed to shorten the watermark embedding time. By calculating the value of WEMF for each B frame, which is related to its frame bits, suitable B-frames can be selected to embed watermark without decoding it completely. Finally, with the characteristic of variable macro block size in H.264 coding standard, a simplified formula is presented to quickly calculate the just noticeable difference (JND) value of the macro block, and then the macro blocks with larger JND value are selected to embed watermark into their motion vectors, which also provides good invisibility. Experimental results show that the proposed algorithm can find suitable embedding positions and embed watermark quickly with good invisibility and less increase of the bit-rate of video. RVWA algorithm can be used in stream media environment in real time.

关键词： Multimedia systems

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Differential space-time block coding based cooperative spectrum sensing over fading environments in cognitive radio sensor networks

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Journal of Information and Computational Science 2012年第15期9卷 4599-4606页

作者： Chen, Zhi Yue, Wenjing College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory for Novel Software Technology Nanjing University Nanjing 210093 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China

Incorporating cognitive radio capability in recource-constrainted multihop wireless sensor networks may help realize the deployment of multiple overlaid sensor networks, and eliminate collision and excessive contention delay incurred by dense node deployment. One of the main requirements of cognitive radio sensor networks is the ability to detect the presence of the primary user with fast speed and high accuracy in wireless environments. Cooperative spectrum sensing emerges as a promising candidate to meet these requirements. In practice, however, since the local sensing observations are forwarded to a sink through fading channels, the sensing performance of cooperative spectrum sensing is deteriorated due to the reporting errors introduced by the fading channels. To deal with this limitation, we propose a differential space-time block coding based cooperative spectrum sensing scheme to improve the sensing performance by decreasing the probability of reporting error. The sensing performance is also derived. Numerical results verify that better sensing performance can be achieved in proposed scheme compared to the conventional cooperative spectrum sensing. © 2012 by Binary Information Press.

关键词： Cognitive radio

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A new algorithm of spectrum allocation based on the balance between supply and demand in cognitive radio networks

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Journal of networks 2012年第7期7卷 1017-1023页

作者： Ma, Liang Zhu, Qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

This paper investigates a new spectrum sharing algorithm based on price in cognitive radio networks. A supply and demand model between primary users and secondary users is established to decide the price of free spectrum leased by primary users. Considering the utility of primary users and the total bandwidth while deciding the price per bandwidth using supply and demand balance (the spectrum supplied by primary users is the same as which demanded by secondary users) and each secondary user competes with each other according to the price to share the available bandwidth allocated by primary users. At the same time, the battery capacity of secondary users and the reliance degree that how primary users trust secondary users in the spectrum sharing process are also considered,a new secondary utility and spectrum sharing algorithm are designed based on above factors. The existence and uniqueness of Nash equilibrium are proved from both theoretic and simulated aspects. The simulation results show that primary users could receive maximum revenues by allocating spectrum in equilibrium price, and the spectrum shared by secondary users is directly affected by the reliance degree and remaining battery capacity of secondary users. © 2012 ACADEMY PUBLISHER.

关键词： Game theory

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Reliability based radio frequency identification reader redundant optimization model in electronic product code network

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International Journal of Advancements in Computing technology 2012年第18期4卷 577-584页

作者： Xu, He Wang, Suo-Ping Wang, Ru-Chuan College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China College of Automation Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Jiangsu Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Jiangsu Province Nanjing 210003 China

The Electronic Product Code (EPC) network, originally developed by the Auto-ID Center with its standards now managed by EPCglobal, is designed and implemented to enable all objects in the world to be linked via the Internet for all time. EPC is the next evolution of product identification, utilizing Radio Frequency Identification (RFID) technology to identify objects. RFID technology has been widely used in many areas, and how to deploy of a large number of readers becomes a core challenge due to the limited read range between reader and tag. This paper proposes a novel reader redundant optimization model for finding optimal redundant number of readers and their positions to cover all tags with using optimization algorithm in EPC network. Firstly, we give an overview of the collision problems in RFID system. Secondly, we propose reliability based RFID reader system model. Thirdly, we use ant colony algorithm to solve this optimization problem. Analysis results show the effectiveness of the proposed system model and simulation results show that the algorithm is effective in achieving the goal of this optimal solution.

关键词： Ant colony optimization

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Detecting Encrypted Botnet Traffic Using Spatial-Temporal Correlation

Detecting Encrypted Botnet Traffic Using Spatial-Temporal Co...

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第六届中国可信计算与信息安全学术会议

作者： Chen Wei Yu Le Yang Geng College of Computer Nanjing University of Posts and TelecommunicationsNanjing 210003P.R.China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003P.R.Chin Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of Educati

In this paper,we propose a novel method to detect encrypted bother *** the traffic preprocessing stage,the proposed payload extraction method can identify a large amount of encrypted applications *** can filter out a large amount of non-malicious traffic,greatly improving the detection efficiency.A Sequential Probability Ratio Test (SPRT)-based method can find spatialtemporal correlations in suspicious botnet traffic and make an accurate *** results show that the false positive and false negative rates can be controlled within a certain range.

关键词： botnet encrypted traffic spatial-temporal correlation

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Dynamic configuration of physical carrier sensing threshold and throughput analysis

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Journal of Computational Information Systems 2012年第11期8卷 4561-4568页

作者： Ran, Wenwen Zhu, Qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab. on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

The choice of physical carrier sensing threshold affects the performance of the MAC layer protocol in multi-hop networks. This paper takes the effect of carrier sensing threshold on QoS into account, and develop an analytical model to dynamically achieve the carrier sensing threshold and analyse the impact on QoS. On the occasion of path loss only (a = 4), the paper proposes a method to get CST, which is to tradeoff the areas of hidden and exposed nodes, in other words, the numbers of both can reach compromise and the total number is least. In this way, we can get CST of every node that makes spatial reuse and throughput achieve balanced. It is found that the ratio of CST to the distance of sender and receiver has important effect on system throughput. At last, the paper compares the performance of the proposed method to that one of [1], and finds that this method improves the system throughput and spatial reuse. © 2012 Binary Information Press.

关键词： Packet loss

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Secure query in wireless sensor network using underground parties

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Journal of networks 2012年第12期7卷 2063-2069页

作者： Huang, Haiping Dou, Yi Chen, Jiutian Feng, Juan Qin, Xiaolin College of Computer Sci. and Tech. Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Nanjing China University of Posts and Telecommunications Nanjing 210003 China

Recently, secure query has become a significant issue for researchers. It proposes the concept of secure multi-party query in Internet of things or sensor networks making use of "underground parties" to guarantee network security. Based on a novel network model assumption, it adopts homomorphic privacy and secure multi-party computation techniques to realize the above mentioned secure query, and then it puts forward the horizontal and vertical query algorithm in the top-k query through cooperation of underground parties. Thereafter, by the simulation tests it compares the time efficiency of the proposed algorithm with other typical sort algorithms under different top-k scenarios. At last, it analyzes the relationship between query time and number of underground party nodes. © 2012 ACADEMY PUBLISHER.

关键词： Wireless sensor networks

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Automatic modulation classification based on the combination of clustering and neural network

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The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 13-19,38页

作者： LIUAi-sheng ZHU Qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory on Wideband Wireless Communications and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

In this paper, we propose a new modulation classification method based on the combination of clustering and neural network, in which a new algorithm is introduced to extract key features. In order to recognize modulation types based on the constellation diagram such as phase shift keying （PSK） and quadrature amplitude modulation （QAM）, fuzzy C-means （FCM） clustering is adopted for recovering the constellation under different number of clusters. Then cluster validity measure is applied to extract key features which discriminate between different modulation types. The features are sent to neural network so that modulation types can be recognized. In order to conquer the disadvantages of standard back propagation （BP） neural network, conjugate gradient learning algorithm of Polak-Ribiere update is employed to improve the speed of convergence and the performance of modulation recognition. Simulation results show that classification rates of the algorithm proposed in this paper are much higher than those of clustering algorithm.

关键词： modulation classification clustering BP neural network FCM

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Performance Analysis for Intrusion Target Detection in Wireless sensor networks

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电子学报(英文版) 2011年第4期20卷 725-729页

作者： FAN Gaojuan WANG Ruchuan HUANG Haiping SUN Lijuan XIAO Fu College of Computer Nanjing University of Posts and Telecommunications Nanjing Chin School of Computer and Information Engineering Henan University Kaifeng China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications) Ministry of Education of Jiangsu Province Nanjing China

Target detection and field surveillance are among the most prominent applications of wireless sensor networks. The quality of detection achieved by a sensor network can be quantified by evaluating the probability of detecting a mobile target crossing a sensing field. Detection probability of sensor nodes has been studied in sensor networks for many purposes such as quality of service and decision making. However, the sensing capabilities of sensors are affected by environmental factors in real deployment. This paper investigates the problem of detecting probability in a log-normal shadow fading environment. It presents an analytic method to evaluate the detection probability by at least k sensors under practical considerations. Furthermore, we also shows that shadow fading makes significant influence in detection probability compared to unit disk sensing model through extensive simulation experiments.

关键词：无线传感器网络目标检测性能分析入侵检测概率环境因素阴影衰落传感器节点

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