Earticle

We proposed the information traffic dynamics on scale-free networks considering the heterogeneous delivering capacity. In the previous researches, the delivering capacity is the same for all nodes in the system, which obviously contradicts the real observations. In this paper, a heuristic algorithm for the optimization of transport is proposed to enhance traffic efficiency in complex networks, where each node's capacity is set as ci = ki and ki is the degree of node i. Our algorithm balances traffic on a scale-free network by minimizing the maximum effective betweenness, which can avoid or reduce the overload in some busy nodes. The simulation result shows that the network capacity can reach a very high value, which is four times more than that of the efficient routing strategy. The distribution of traffic load is also studied and it is found that our optimal routing strategy can make a good balance between hub nodes and non-hub nodes, resulting in high network capacity.

IEEE802.11 wireless networks have become one of the most widely used networks. Due to open nature of wireless medium, hackers and intruders can make utilization of the loopholes of the wireless communication; as a result, there are many security threats associated with Wireless Local Area Network (WLAN). In this paper, we have worked an experimental analysis to study some of the well known attacks pertaining to IEEE 802.11 WLAN. At first, some of the open issues related to this fragile technology have been discussed. Based on this vulnerabilities and threats categories some of the major attack has been performed in a live environment by using open source software tools i.e Aircrak-nj, kismet. etc. The analysis and finding from this paper’s proved that the complexity of attacks had increased by time and the Wifi technology are becoming more dangerous to the end users and business environment.

Though the mostly used topologies in network-on-chip (NoC) based systems, mesh and torus can lead to a waste of resource and bandwidth when the processing elements(PEs) demand less communication, and fail to meet the requirements of PEs demanding mass communication since they connect all the PEs by the paths of the same type. In this paper, a configurable network and an efficient routing algorithm is designed so that the topology is regular and easy to expend while the adjustable density of transmission roads could satisfy the varied requirements of different PEs. Experimental results have shown that our design is more desirable in terms of network delay, power consumption and area cost among other important performance parameters of a network.

In the context of triple play Ominimedia is not just the simple combination of various media, but the aggregation of all media with different features, communication power and influences,and the interaction and mutual fusion among media of different forms and functions. This paper, based on the development trend of triple play, focused on the theme of Ominimedia, studied the traditional media development strategies to Ominimedia and analyzed in detail the strategies of cloud, tube, end and content aggregation. At the same time it explored the strategies for Ominimedia core competitive strength improvement from multiple dimensions of 3D media, communication channel, AirSharing and brand operation with the expectation of offering references to Ominimedia globalization in the context of triple play.

To have an efficient and successful communication in ad hoc networks, the use of Cognitive Radios (CR) has gained popularity in the recent past. These radios have spectrum sensing capabilities and thus can easily switch to free spectrum band. The use of such type of radios not only improves the routing performance but at the same time improves the overall throughput of the network. To show the same, we implement shortest path routing strategy in MATLAB-7.01. The routing scheme uses two types of radios one with spectrum sensing capability such as cognitive radios and the other which doesn’t. The following performance metrics such as Packet Delivery Ratio (PDR), Delay, Success Ratio and Hop count are taken into consideration for measuring the efficiency. The result shows that a node having spectrum sensing capability outperforms the other one.

We are concerned with the relay selection in a decode-and-forward cooperative network to minimize the bit error rate (BER) in a radio cell. This problem can be solved using maximum weighted (MW) matching algorithm, greedy matching algorithm or worst-link-first (WLF) matching algorithm. Among the algorithms, WLF matching algorithm has achieved much attention for its being less complex while the achieved performance is high. In order to further reduce the computational complexity, we propose an improved WLF relay selection scheme, in which relays are selected according to instantaneous channel state information (CSI) and a cooperative threshold is set up to eliminate some unsatisfying candidate relays from the set of alternative candidate relays and thus reduce the amount of calculation. Theory analysis and simulation results both show that the improved WLF relay selection scheme proposed can be easily implemented and achieve almost the same BER performance as that of WLF scheme while the computational complexity is much lower.

The increasing demand for mobile data traffic brings new challenges on cellular networks in terms of network capacity and increased data throughput. In order to fulfill these demands, Heterogeneous Networks (HetNets) has been considered as a promising solution. On the other hand, Inter-Cell Interference Coordination (ICIC) is a big challenge toward HetNet deployments; in particular users in edge area of low power small cell are mostly vulnerable to stronger interference signals from high power macro cell. To resolve ICIC problem, 3GPP released some technologies based on TDM resource partitioning, FDM resource allocation along with power control, and still continue to find out the more suitable solutions. However, to date, a common platform of all possible solutions, particularly in TDM and FDM based, is not available to readers. In this context, this paper provides a holistic overview of ICIC strategies in this emerging wireless system. Towards this objective, the evolution of inter-cell interference management techniques is thoroughly investigated from TDM based enhanced inter-cell interference coordination (eICIC) techniques to more advanced Coordinated Multi-Point (CoMP) transmission/reception, while comparing and contrasting their common features and differences. Finally, Carrier Aggregation (CA) is explored in detail as an advanced and challenging mechanism in order to have an efficient resource allocation and inter-cell interference mitigation in LTE-Advanced HetNet environments.

Network traffic prediction is one of the significant issues. The model for network traffic prediction should meet the following requirements. First, the model should be taken into consideration the characteristics of the network flow such as burstiness, long-range dependence, periodicity and self-similarity. To achieve this, we decompose the original flow in a multi-scale manner into a set of linear and stable representations, and introduce chaos theory to improve the diversity and search coverage. Second, the model should be efficient and accurate. To this end, we propose a prediction model based on SVR, and utilize Ant Colony Optimization (ACO) algorithm for parameter selection of SVR. Besides, we conduct experiments to evaluate the proposed model.

The global trend of the information and network has changed the peoples’ life and work style. The traditional OA model can’t keep step with the rapid development of the information society. Time and space becomes a main obstacle to the OA. This paper puts forwards a new thought to solve this problem by designing a mobile message module. It can realize mobile OA and may promote the development of the E-government.

Orthogonal Frequency Division Multiplexing (OFDM) has made tremendous improvement possible in wireless technology. Wavelet analysis is used as an alternative to Fourier analysis in OFDM system to transform and map data onto orthogonal subcarriers, as it is a time-frequency domain operation thus it offers the advantages of optimal flexibility with less complexity. This paper presents performance analysis in terms of Bit Error rate (BER) of different wavelet families in OFDM System under the joint effect of path loss, multipath fading and noisy environment for Mobile WiMAX. The results obtained show that the performance of the mobile-multipath environments for 16-QAM modulation schemes is enhanced as Daubechies and Biorthogonal wavelet families offers lower BER with different Path loss model. The performance measurements and analysis was done in simulation developed in MATLAB.

Localization is increasingly becoming the focus of research in the filed of Wireless Sensor Networks (WSNs), as the data reported from a sensor is only useful when the position of that sensor is found. In this paper, we proposed an improved CPE (Convex Position Estimation) localization algorithm that reduces the localization error without requiring additional hardware and computational costs. In the proposed scheme, we first estimate the location of sensor nodes using Convex Position Estimation (CPE), and then refine the location of sensor nodes using the location of the two-hop anchor nodes. The simulation results show that the new localization algorithm effectively improves the positioning accuracy compared with the traditional CEP localization algorithms.

Five different service classes are supported in mobile WiMAX IEEE 802.16 standard in order different needs of the mobile users to be fulfilled. In this paper we analyze the impact of the propagation environments on the WiMAX service classes and we measure the QoS performances of the service classes that are utilized from the mobile users. Simulation experiments are done utilizing the ns-2.33 simulator where all five service classes of the WiMAX are properly configured. Performances analysis of the service classes in mobile WiMAx is done measuring the average throughput, average delay and average jitter in various propagation environments. Obtained results give important conclusions about the QoS of the five service classes in mobile WiMAX in various propagation environments.

Mobile Internet as a new information and communication technology is growing fast. The security challenges facing from the Mobile Internet come from the mobile devices and access networks. A new Mobile Internet device architecture is proposed in this paper. Focusing on the characteristics of the new architecture, a high secure operating system with internal network structure is designed. There are two sub-kernels in the secure operating system, an inter-kernel data transmission protocol is implemented for communicating between two sub-kernels, which is connection-oriented and can provide reliable peer-to-peer connectivity. In this paper, we proposed the data transmission protocol implementation procedure and analyze protocol transmission efficiency.

Mobile Ad hoc Network (MANET) is a self organizing wireless network for mobile devices. They do not need any fixed infrastructure to be configured which makes it more suitable to be used in environments that require on-the-fly setup. The present work discusses the challenging issues in MANET routing security. It presents improved DSR, a trust-based scheme for securing DSR routing protocol in MANET using the friendship mechanism and gateway. The path which is most optimum is chosen as the final route from source to destination. The gateway nodes should not be malicious .The nodes can evaluate the routing paths according to some selected features (such as node reputation and identity information) before forwarding the data through these routes. It is implemented in our scheme, simulation (using NS2). This scheme provides a robust environment where MANET nodes can trust each other in a secure community. Experimental results show that our gateway based DSR improves network performance to much extent.

Link quality estimation (LQE) is an effective basic building block in wireless sensor networks (WSNs) and higher cross layer design of network protocol. Some researchers have investigated the statistical properties of the link quality estimators independently from higher-layer protocols, and their impact on the Collection Tree Routing Protocol (CTP). Then they set up a dedicated LQE, independent of the protocol interface, which has in total of four bits information: one from the physical layer, one from the link layer, and two from the network layer. Four-bit has been found to be a good estimator; however its performance heavily depends on the tuning of its parameters. But we found that Four-bit couldn’t be working effectively in responding to the burst situation after repeated experiments. So we redesigned the link estimation method, called Stable Link Quality Estimation (SLQE), which combines active probing with passive snooping to make estimation more stable. We have found that the new design can cope with the emergency. Moreover it also enhances the robustness of the network, and saves the overall energy consumption of the network.

Traditional beamforming and power control algo-rithms in cognitive radio (CR) are based on the assumption of perfect channel state information (CSI) however; this may lead to performance degradation in realistic systems. In this paper, the problem of joint beamforming and power control is investigated in underlay CR networks with imperfect CSI. Our objective is to maximize the sum utility of secondary users (SUs) under the primary users (PUs) interference power constraints and the transmission power constraint of SUs. First, the joint beamforming and power control problem is formulated under game theory framework, where the SUs compete with each other over the beamforming vectors and transmission power level made available by the PUs. Moreover, the channel uncertainty is described using ellipsoid sets and the interference power constraints can be converted into robust interference power constraints. Besides, Nash equilibrium (NE) is considered as the solution of this game. Finally, simulation results show that the proposed scheme can converge to a locally optimal pair of beamforming vector and transmission power level in the presence of channel uncertainty.

Road safety and increasing transport efficiency are the important goals for intelligent transport system (ITS). Vehicular Ad hoc Network is such a network which can help to achieve these goals. VANET routing is a crucial task for reliable communication among vehicles. The impact of fading on network throughput and packet drop is explored in this paper. Interesting results show the performance evaluation of without fading environment and Rayleigh fading in different scenarios. NCTUns 6.0 (National Chiao Tung University Network Simulator) is used to justify our results that is a GUI based open source platform for vehicular Ad-Hoc network. Various performance issues are also surveyed with the help of this simulator.

To investigate the impact of weights on the traffic driven epidemic spreading in weighted homogeneous networks, an epidemic model in pseudo-random network with adjustable weights is presented. In the scenario that epidemic pathway is defined and driven by traffic flows, the epidemic spreading velocity of SI model in weighted homogeneous networks is obviously accelerated when the edge weight is different. And in traffic driven SIS model, the epidemic threshold is found to be proportional to the inverse of the average node betweenness. It is better to control the epidemic spreading when the edges have the same weight. Simulation results have confirmed the theoretical predictions.

Most RFID applications in the Internet of Things (IoTs) use multiple readers to read the IDs of multiple tags and form the RFID network. In such a network, unguarded reader deployment may generate over-crowded readers, cause interferences and, as a result, increases the deployment cost while degrading tag detection. Seeing that desirable reader deployment is crucial for RFID system performance, this paper introduces an optimization-based IGAA approach which outperforms existing RFID topology designs by turning up more favorable reader deployment and system performance. The new approach employs an advanced multi-objective fitness function and improved genetic annealing algorithms (GAA) to pursue a better RFID topology design. By involving an improved gene-stirring operation to help preserve good genes and locate optimal solutions for reader deployment, it is simple in operation but effective in practice. Experimental evaluation shows that when compared with related approaches, IGAA can yield better solution quality with less search time.

Aiming at energy-constrained of Ad Hoc network, this paper proposes a multi-path routing protocol (EM-AODV)I n AODV that based on nodes energy. EM-AODV designs methods of obtaining nodes energy by upgrading the route discovery and route maintenance process of AODV, calculates the path of comprehensive energy derived path priority by routes total hops and nodes energy to format the multi-path routing mechanism. The energy as the metric prerequisite during the routing process, by setting nodes energy bound and balancing nodes data forwarding to postpone network lifetime. Simulation results show that EM-AODV has lower average end-to-end delay, well improve the energy consumption.

Fiber-connected distributed antenna systems (DAS) have been recognized as an effective means to accommodate the coverage and capacity demands of future heterogeneous networks (HetNet). Among various opportunities realized by the architecture, our focus in this paper is on the spectral efficiency (SE) advantages achieved by cooperative transmission and the associated power consumption that may affect the energy efficiency (EE) of the system. A detailed power model is developed to benchmark the various sources of energy consumption in fiber-connected DAS. Then a simple but efficient pre-coding scheme is proposed to reduce the computation complexity associated with cooperative transmission, thus lowering the power consumed by baseband processing while at the same time maintaining a high throughput performance. Through detailed and extensive simulations, this paper demonstrates the SE and EE advantages of the application of fiber-connected DAS in HetNet.

Deflection routing is an effective way to improve the efficiency and reliability of data transmission in the network. Information theory, which is the foundation of channel communications, has not yet had a direct impact on network communications. In this paper, we study the deflection routing processes of point-to-point networks from an information-theoretic perspective. It is found that the packet routing processes, which can further be divided into path determination and path switching, are quite analogous to channel communications. And such a corresponding relationship makes it possible to analyze routing processes and its performance with models and concepts in the information theory.

This paper combines the link reliability and the shortest time delay and a joint strategy for cognitive route, the policy routing process combined with spectrum allocation, adopt cross-layer approach, in the process of routing implementation spectrum availability judgment and update, ensuring the continuity of the routing process, reduce the high rate of the circuit. In this method assumes that each cognitive are equipped with a radio transceiver; A wireless communication interface; Transceiver can correctly perceive available spectrum, and when the spectrum utilization changes, can adaptively adjust; Wireless communication will result in the creation of public control channel, used for the exchange of information, the simulation results demonstrate the superiority of the algorithm.

Efficient task scheduling mechanism in cloud computing can improve the resource utilization and enhance the overall performance of the cloud computing environment. However, the existing strategies based on static task requirements are difficult to guarantee the stability of the system, while dynamic mechanisms have higher complexity. In this paper, a new task scheduling algorithm based on potential game is proposed. We prove that the potential game will reach Nash equilibrium quickly. Also, the system load balancing level is adaptive with the number of users’ task changing. The experimental results show the priority of the proposed algorithm.

Antenna is a significant component of wireless communication system. Radio Frequency Identification (RFID) is one of the activities of Automatic Identification (AUID) system which comes under wireless system. To track any object wirelessly in RFID system, antenna acts as the primary and critical component. Radio Frequency (RF) micromachining technology provides an innovative approach in the development of effective antenna. In this paper, initially we present rectangular patch antenna resonant at 40GHz on silicon substrate. In the consecutive step, in order to improve performance of the antenna silicon micromachining has done by etching the substrate between the ground and the patch. Ansoft High Frequency Structure Simulator (HFSS) provides the simulation result and the different performance parameters like gain, return loss, bandwidths etc. are analyzed.

Now-a-days the transportation network traffic plays a vital role in the society. People are focusing on arriving at our destination as quickly as possible. With this lifestyle, people are not always aware of all the traffic conditions that are experienced while operating an automobile. In the existing system, reduction of green house gas emissions from transportation network based on road network graphs where all edges are annotated with accurate weight that capture environmental cost, fuel usage are needed for eco-routing. However, such weights are not readily available on the road network. So, randomly assign the weights for each road segments and it typically lack the speed pattern of the road network. This paper address these limitation, proposes two stage routing algorithm and weight propagation model to predict the cost of an arbitrary path on road network and accurately detects the traffic environment and also provides the optimal alternate route for destination.

In wireless sensor networks (WSNs), cryptographic primitives alone cannot provide a sufficient solution to the secure information fusion problem, therefore reputation systems have been introduced into WSNs. In a cluster, each sensor node has a single reputation value that is evaluated by the other sensor nodes in the same cluster. In this paper, we propose a novel, reliable information fusion algorithm, called reputation-driven information fusion (RDIF). In this work, a clustering algorithm is employed to divide all of the sensor nodes into many clusters. Then, a reputation system is established for each cluster, and an information fusion algorithm driven by reputation values is performed by the cluster head. In addition to the sensor nodes’ reputation values, we also consider the values of the readings collected by the sensor nodes and eliminate the outliers before fusing information. The simulation results show that RDIF can improve the reliability and accuracy of fusion results significantly when some compromised nodes appear in the WSNs.