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    Guest Editorial
  • Guest Editorial
    Xiaolin Liang, Xiongwen Zhao, Shu Li, Qi Wang, Wenbing Lu
    2016, 13(10): 1-10.
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    In this paper, a three-dimensional (3D) geometry- based stochastic scattering model (GBSSM) for wideband multi-input multi-output (MIMO) vehicle-to-vehicle (V2V) relay-based cooperative fading channel based on geometrical three-cylinder is proposed. Non-line-of-sight (NLOS) propagation condition is assumed in amplify-and-forward (AF) cooperative networks from the source mobile station (S) to the destination mobile station (D) via the mobile relay station (R). We extend the proposed narrowband model to wideband and also introduce the carrier frequency and bandwidth into the model. To avoid complicated procedure in deriving the analytical expressions of the channel parameters and functions, the channel is realized first. By using the realized channel matrix, the channel properties are further investigated.
  • Guest Editorial
    Hoang-Sy NGUYEN, Anh-Hoa BUI, Dinh-Thuan DO, Miroslav VOZNAK
    2016, 13(10): 11-19.
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    Wireless information and powered transfer networks (WIPT) has recently been implemented in 5th generation wireless networks. In this paper, we consider half-duplex relaying system in which the energy constrained relay node collects energy via radio frequency (RF) signals from the surrounding resources. Regarding energy harvesting protocol, we propose power time switching-based relaying (PTSR) architecture for both amplify-and-forward (AF) and decode-and-forward (DF). Especially, we reveal the analytical expressions of achievable throughput, ergodic capacity and energy-efficient in case of imperfect channel state information (CSI) for both AF and DF network. Through numerical analysis, we analyse the throughput performance, energy-efficient and ergodic capacity for different parameters, including power splitting ratio and energy harvesting time. Moreover, we also depict the performance comparison between AF and DF network with perfect and imperfect CSI. The results in numerical analysis reveal that the result of AF relaying network is less significant than DF relaying network in the various scenarios.
  • Guest Editorial
    Yao Yu, Yuhuai Peng, Xiaoling Li, Jinfeng Gao, Xiaozhu Cong
    2016, 13(10): 20-28.
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    In this paper, we study transmission of packets with time constraints in cooperative 5G wireless networks. As we know, the packets which are transmitted with large delay become useless and have to be dropped. In order to minimize packet dropping probability, we consider multiple transmission methods and integrate packet scheduling with adaptive network coding method selection. Firstly we introduce queue length to obtain the gain of network. Based on this, we present the dynamic coding-aware routing metric, which can increase potential coding opportunities. Moreover, we propose a distributed packet-aware transmission routing scheme based on the above routing metric, which can discover the available paths timely and efficiently. Simulation results show that the proposed method can reduce average packet dropping probability with lower computational complexity.
  • Guest Editorial
    Cunqian Yu, Weigang Hou*, Yingying Guan, Yue Zong, Pengxing Guo
    2016, 13(10): 29-43.
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    The pursuit of the higher performance mobile communications forces the emergence of the fifth generation mobile communication (5G). 5G network, integrating wireless and wired domain, can be qualified for the complex virtual network work oriented to the cross-domain requirement. In this paper, we focus on the multi-domain virtual network embedding in a heterogeneous 5G network infrastructure, which facilitates the resource sharing for diverse-function demands from fixed/mobile end users. We proposed the mathematical ILP model for this problem. And based on the layered-substrate-resource auxiliary graph and an effective six-quadrant service-type-judgment method, 5G embedding demands can be classified accurately to match different user access densities. A collection of novel heuristic algorithms of virtual 5G network embedding are proposed. A great deal of numerical simulation results testified that our algorithm performed better in terms of average blocking rate, routing latency and wireless/wired resource utilization, compared with the benchmark.
  • WIRELESS COMMUNICATIONS
  • WIRELESS COMMUNICATIONS
    Bushra Mughal, Sajjad Hussain, Abdul Ghafoor
    2016, 13(10): 44-57.
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    The idea of cooperation and the clustering amongst cognitive radios (CRs) has recently been focus of attention of research community, owing to its potential to improve performance of spectrum sensing (SS) schemes. This focus has led to the paradigm of cluster based cooperative spectrum sensing (CBCSS). In perspective of high date rate 4th generation wireless systems, which are characterized by orthogonal frequency division multiplexing (OFDM) and spatial diversity, there is a need to devise effective SS strategies. A novel CBCSS scheme is proposed for OFDM subcarrier detection in order to enable the non-contiguous OFDM (NC-OFDM) at the physical layer of CRs for efficient utilization of spectrum holes. Proposed scheme is based on the energy detection in MIMO CR network, using equal gain combiner as diversity combining technique, hard combining (AND, OR and Majority) rule as data fusion technique and antenna diversity based weighted clustering as virtual sub clustering algorithm. Results of proposed CBCSS are compared with conventional CBCSS scheme for AND, OR and Majority data fusion rules. Moreover the effects of antenna diversity, cooperation and cooperating clusters are also discussed.
  • WIRELESS COMMUNICATIONS
    Bing Hou, Xiaolin Zhang
    2016, 13(10): 58-68.
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    Global navigation satellite system could provide accurate positioning results in signal complete condition. However, the performance is severe when signal denied, especially for the single-mode BeiDou receiver. This paper proposes a dual-satellite positioning algorithm to promote the positioning performance in the satellite signal gap. The new algorithm utilizes the previous positioning data stored in complete condition to simplify the positioning equations. As the clock bias persists for a short period, this proposed method could work out accurate positioning results by only two visible satellites, without the need of computing the clock bias. Also, the Kalman filtering algorithm is used to smooth the trajectories, and improve the positioning results. During the incomplete period, only two satellites for 30 seconds and three satellites for 60 seconds, the preliminary experiment result shows that, the presented method could provide almost the same positioning results as in complete condition.
  • WIRELESS COMMUNICATIONS
    Long Cheng,Yan Wang, Xingming Sun, Nan Hu, Jian Zhang
    2016, 13(10): 69-78.
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    The problem of mobile localization for wireless sensor network has attracted considerable attention in recent years. The localization accuracy will drastically grade in non-line of sight (NLOS) conditions. In this paper, we propose a mobile localization strategy based on Kalman filter. The key technologies for the proposed method are the NLOS identification and mitigation. The proposed method does not need the prior knowledge of the NLOS error and it is independent of the physical measurement ways. Simulation results show that the proposed method owns the higher localization accuracy when compared with other methods.
  • WIRELESS COMMUNICATIONS
    Zhigang Wen, Xiaoqing Liu, Yancun Chen, Rui Wang, Zhimin Xie
    2016, 13(10): 79-85.
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    For the simultaneous wireless information and power transfer (SWIPT), the full-duplex MIMO system can achieve simultaneous transmission of information and energy more efficiently than the half-duplex. Based on the mean-square-error (MSE) criterion, the optimization problem of joint transceiver design with transmitting power constraint and energy harvesting constraint is formulated. Next, by semidefinite relaxation (SDR) and randomization method, the SDR-based scheme is proposed. In order to reduce the complexity, the closed-form scheme is presented with some simplified measures. Robust beamforming is then studied considering the practical condition. The simulation results such as MSE versus signal-noise-ratio (SNR), MSE versus the iteration number, well prove the performance of the proposed schemes for the system model.
  • COMMUNICATION NETWORKS
  • COMMUNICATION NETWORKS
    Haoqiu Huang, Lanlan Rui, Weiwei Zheng, Danmei Niu, Xuesong Qiu
    2016, 13(10): 86-107.
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    The recent evolution of the Internet towards “Information-centric” transfer modes has renewed the interest in exploiting proxies to enhance seamless mobility. In this work, we focus on the case of multiple levels of proxies in ICN architectures, in which content requests from mobile subscribers and the corresponding items are proactively cached to these proxies at different levels. Specifically, we present a multiple-level proactive caching model that selects the appropriate subset of proxies at different levels and supports distributed online decision procedures in terms of the tradeoff between delay and cache cost. We show via extensive simulations the reduction of up to 31.63% in the total cost relative to Full Caching, in which caching in all 1-level neighbor proxies is performed, and up to 84.21% relative to No Caching, in which no caching is used. Moreover, the proposed model outperforms other approaches with a flat cache structure in terms of the total cost.
  • COMMUNICATION NETWORKS
    Shu Tang, Lin Ma, Yubin Xu
    2016, 13(10): 108-118.
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    AP deployment is significant for indoor WLAN system to achieve seamless coverage. The available algorithms do not take user distribution into consideration so that poor user coverage and imbalanced network load occur. Therefore, this paper proposed a novel AP placement algorithm to bridge the AP deployment with user distribution. The proposed algorithm employs statistics theory to model the user distribution as its location and probability. Then we obtain the AP location based on the fuzzy C-clustering algorithm. The proposed algorithm is practical for implementation, which means the actual signal transmission isn’t required in our proposed method. The simulation results show that the proposed algorithm could automatically achieve a good AP deployment with different user distribution, and provide a good performance in the maximum users and AP load balance in WLAN.
  • COMMUNICATION NETWORKS
    Yan Wang, Qingxu Deng, Genghao Liu, Xiuping Hao , Baoyan Song
    2016, 13(10): 119-136.
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    The state-of-the-art query techniques in power grid monitoring systems focus on querying history data, which typically introduces an unwanted lag when the systems try to discover emergency situations. The monitoring data of large-scale smart grids are massive, dynamic and highly dimensional, so global query, the method widely adopted in continuous queries in Wireless Sensor Networks (WSN), is rendered not suitable for its high energy consumption. The situation is even worse with increasing application complexity. We propose an energy-efficient query technique for large-scale smart grids based on variable regions. This method can query an arbitrary region based on variable physical windows, and optimizes data retrieve paths by a key nodes selection strategy. According to the characteristics of sensing data, we introduce an efficient filter into the each query subtree to keep non-skyline data from being retrieved. Experimental results show that our method can efficiently return the overview situation of any query region. Compared to TAG and ESA, the average query efficiency of our approach is improved by 79% and 46%, respectively; the total energy consumption of regional query is decreased by 82% and 50%, respectively.
  • COMMUNICATION NETWORKS
    Xujie Li, Wenna Zhang, Honglang Zhang, Wenfeng Li
    2016, 13(10): 137-145.
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    As device-to-device (D2D) communications usually reuses the resource of cellular networks, call admission control (CAC) and power control are crucial problems. However in most power control schemes, total data rates or throughput are regarded as optimization criterion. In this paper, a combining call admission control (CAC) and power control scheme under guaranteeing QoS of every user equipment (UE) is proposed. First, a simple CAC scheme is introduced. Then based on the CAC scheme, a combining call admission control and power control scheme is proposed. Next, the performance of the proposed scheme is evaluated. Finally, maximum DUE pair number and average transmitting power is calculated. Simulation results show that D2D communications with the proposed combining call admission control and power control scheme can effectively improve the maximum DUE pair number under the premise of meeting necessary QoS.
  • COMMUNICATION NETWORKS
    Wanshu Yang, Yunxiao Zu
    2016, 13(10): 146-152.
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    Cognitive radio (CR) is a promising solution to improve the spectrum utilization. The cognitive radio networks includes the primary user (PU) system with authorized spectrum and the secondly user (SU) system without authorized spectrum. When the SUs want to use the spectrum, they have to find the idle channels that are not occupied by the PUs. So the QoS of the SUs will be affected not only by the characteristic of their own business, but also by the behavior of the PUs. Currently, in order to ensure the quality of the SU services, the M-LDWF algorithm is widely used in scheduling. However, the M-LWDF algorithm didn’t fully consider the difference among the SUs. For those SUs who are in the process of communication but have to change channel due to the return of the PU, they should have higher scheduling priority. In this paper, we put forward an improved algorithm based on M-LWDF. In order to guarantee the QoS of the SUs those were in the processing of communication, we gave the higher scheduling priority. Simulation results show that the improved algorithm can effectively decrease the dropping rate and improve the QoS of the SUs and the performance of the whole system.
  • COMMUNICATION NETWORKS
    Hua Tang, Wei Xu, Guohua Wu
    2016, 13(10): 153-159.
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    The propagation of vortex beam in atmospheric turbulence is of significant importance in theoretical study and practical applications. Based on extended Huygens-Fresnel integral and the Rytov approximation, the average capacity of orbital angular momentum (OAM)-multiplexed Laguerre-Gaussian (LG) beam propagating through non-Kolmogorov turbulence is presented, and the analytical expression of spiral spectrum of LG beam has been deduced. The average capacity of FSO system is numerically calculated and the influence of exponent parameter, transmission height, structure constant, wavelength, outer scale and inner scale on average capacity are also analyzed in detail. Outcomes show that smaller structure constant, outer scale, higher transmission height and larger wavelength, inner scale are conducive to improve average capacity in different extent. Results acquires in this paper have potential application value in optical communication within non-Kolmogorov turbulence.
  • COMMUNICATION NETWORKS
    Lei Gu, Shih-Chun Lin
    2016, 13(10): 160-168.
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    Efficient multi-machine cooperation and network dynamics still remain open that jeopardize great applications in large-scale machine-to-machine (M2M) networks. Among all possible machine cooperation controls, to synchronize tremendous machines in a timing-efficient brings one of the greatest challenge and serves as the foundation for any other network control policies. In this paper, we propose a linear-time synchronization protocol in large M2M networks. Specifically, a closed-form of synchronization rate is provided by developing the statistical bounds of the second smallest eigenvalue of the graph Laplacian matrix. These bounds enable the efficient control of network dynamics, facilitating the timing synchronization in networks. Through a practical study in Metropolis, simulation results confirm our theoretical analysis and provide effective selection of wireless technologies, including Zigbee, Wi-Fi, and cellular systems, with respect to the deployed density of machines. Therefore, this paper successfully demonstrates a practical timing synchronization, to make a breakthrough of network dynamic control in real-world machine systems, such as Internet of Things.
  • COMMUNICATION NETWORKS
    Zhen Wang, Xiaorong Zhu, Xu Bao, and Su Zhao
    2016, 13(10): 169-180.
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    In ultra-dense networks (UDNs), large-scale deployment of femto base stations is an important technique for improving the network throughput and quality of service (QoS). In this paper, a multidimensional resource allocation algorithm based on noncooperation game theory is proposed to manage the resource allocation in UDNs, including transmission point association, user channels, and power. The algorithm derives a multidimensional resource optimization model and converts into a noncooperation game model according to the analysis of transmission point association user channel and power allocation. The algorithm includes two phases: transmission point association, and channel and power allocation. Then, feasible domain and discrete variables relaxation approaches are introduced to derive an approximate optimal multidimensional resource allocation solution with low complexity. Simulation results show that this method has some advantages in suppressing interference and improves the overall system throughput, while ensuring the QoS of femtocell users.
  • SERVICES AND APPLICATIONS
  • SERVICES AND APPLICATIONS
    Bilin Shao, Genqing Bian, Xirui Quan, Zhixian Wang
    2016, 13(10): 181-197.
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    In the cloud computing environment, outsourcing service mode of data storage causes the security problem, the reliability of data cannot be guaranteed, and the privacy preservation problem has aroused wide concern. In order to solve the problem of inefficiency and high-complexity caused by traditional privacy preservation methods such as data encryption and access control technology, a privacy preservation method based on data coloring is proposed. The data coloring model is established and the coloring mechanism is adopted to deal with the sensitive data of numerical attributes, and the cloud model similarity measurement based on arithmetic average least-approximability is adopted to authenticate the ownership of privacy data. On the premise of high availability of data, the method strengthens the security of the privacy information. Then, the performance, validity and the parameter errors of the algorithm are quantitatively analyzed by the experiments using the UCI dataset. Under the same conditions of privacy preservation requirements, the proposed method can track privacy leakage efficiently and reduce privacy leakage risks. Compared with the k-anonymity approach, the proposed method enhances the computational time efficiency by 18.5%.
  • SERVICES AND APPLICATIONS
    Hongxia Zhang, Fei Wang, Yang Zhang, Jiuyun Xu
    2016, 13(10): 198-208.
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    With the increasing number of resources provided by cloud environments, identifying which types of resources should be rent when deploying an application is often a difficult and error-prone process. Currently, most cloud environments offer a wide range of configurable resources, which can be combined in many different ways. Finding an appropriate configuration under cost constraints while meeting requirements is still a challenge. In this paper, software product line engineering is introduced to describe cloud environments, and configurable resources are abstracted as features with attributes. Then, a Self-Tuning Particle Swarm Optimization approach (called STPSO) is proposed to configure the cloud environment. STPSO can automatically adjust the arbitrary configuration to a valid configuration. To evaluate the performance of the proposed approach, we conduct a series of comprehensive experiments. The empirical experiment shows that our approach reduces time and provides a reliable way to find a correct and suitable cloud configuration when dealing with a significant number of resources.
  • SERVICES AND APPLICATIONS
    Jingbo Yan, Yuqing Zhang, Xuefeng Liu
    2016, 13(10): 209-221.
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    As cloud computing is becoming prevalent, data owners are motivated to delegate complex data managements to the commercial cloud for economic savings. Sensitive data is usually encrypted before being uploaded to the cloud, which unfortunately makes the frequently-used search function a challenging problem. In this paper, we present a new multi-keyword dynamic search scheme with result ranking to make search over encrypted data more secure and practical. In the scheme, we employ a powerful function-hiding inner product encryption to enhance the security by preventing the leakage of search pattern. For the concern of efficiency, we adopt a tree-based index structure to facilitate the searching process and updating operations. A comprehensive security analysis is provided and experiments over the real world data show that our scheme is efficient.
  • SERVICES AND APPLICATIONS
    Yang Su , , Xiaoyuan Yang , , Yuechuan Wei ,
    2016, 13(10): 222-232.
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    Matrix multiplication plays a pivotal role in the symmetric cipher algorithms, but it is one of the most complex and time consuming units, its performance directly affects the efficiency of cipher algorithms. Combined with the characteristics of VLIW processor and matrix multiplication of symmetric cipher algorithms, this paper extracted the reconfigurable elements and analyzed the principle of matrix multiplication, then designed the reconfigurable architecture of matrix multiplication of VLIW processor further, at last we put forward single instructions for matrix multiplication between 4×1 and 4×4 matrix or two 4×4 matrix over GF(28), through the instructions extension, the instructions could support larger dimension operations. The experiment shows that the instructions we designed supports different dimensions matrix multiplication and improves the processing speed of multiplication greatly.
  • SERVICES AND APPLICATIONS
    Lei Huo, Zhiliang Wang
    2016, 13(10): 233-244.
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    Internet of things (IoT) imposes new challenges on service composition as it is difficult to manage a quick instantiation of a complex services from a growing number of dynamic candidate services. A cross-modified Artificial Bee Colony Algorithm (CMABC) is proposed to achieve the optimal solution services in an acceptable time and high accuracy. Firstly, web service instantiation model was established. What is more, to overcome the problem of discrete and chaotic solution space, the global optimal solution was used to accelerate convergence rate by imitating the cross operation of Genetic algorithm (GA). The simulation experiment result shows that CMABC exhibited faster convergence speed and better convergence accuracy than some other intelligent optimization algorithms.
  • SERVICES AND APPLICATIONS
    Xiaojie Tu, Mingzhu Wang, Ke Sun, Chunfei Zhang, Li Zhang
    2016, 13(10): 245-252.
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    With the background of China’s fast growing economy, Internet has become a key factor to keep the economy go steadily. It is important to quantitatively analyze the whole Internet industry and hence master its development direction clearly, which will provide regulators with reference for industry analysis, policy formulation, and policy evaluation. This article re-constructs the calculation method of traditional Prosperity Indexes, and builds up a new indicators portfolio for Internet Industry Prosperity Indexes. By calculation, the Internet Industry Coincidence Index value is 105.9. And the Leading Index and Coincidence Index are all within the up-going range, which suggests that China’s Internet Industry is likely to remain in its usual fast growing state.
  • SERVICES AND APPLICATIONS
    Lei Yang,Yu Dai, Bin Zhang
    2016, 13(10): 253-262.
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    Recently, virtualization has become more and more important in the cloud computing to support efficient flexible resource provisioning. However, performance interference among virtual machines (VMs) has become a challenge which may affect the effectiveness of resource provisioning. In a virtual cluster which runs the MapReduce applications, the performance interference can also affect the performance of the Map and Reduce tasks and thus cause a performance degradation of the MapReduce job. Accordingly, this paper presents a MapReduce scheduling framework to mitigate this performance degradation caused by the performance interference. The framework includes a performance interference prediction module and an interference aware scheduling algorithm. To verify its effectiveness, we have done a set of experiments on a 24-node virtual MapReduce cluster. The experiments illustrate that the proposed framework can achieve a performance improvement in the virtualized environment compared with other MapReduce schedulers.
  • SERVICES AND APPLICATIONS
    Wenliang Fu, Xin Xin, Ping Guo, Zhou Zhou
    2016, 13(10): 263-275.
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    Internet of Vehicles (henceforth called IoV) is a public network system and high-value target for intrusions that may cause efficiency issues, privacy leakages or even physical damage. Conventional intrusion detection methods are normally designed for the Internet infrastructures which cannot directly apply in the context of IoV. This work proposes an FPGA based intrusion detection method that can not only achieve real-time scanning performance but also be applied in vehicular environment. We evaluate our scheme on a Xilinx FPGA based platform. Experiments show that the proposed system can achieve a throughput of more than 39 Gbps on existing FPGA platform which is about 15% higher than state-of-the-art techniques,and the total power consumption for the prototype is about 7.5 w. Moreover, the processing latency of the prototype is about 4 us and is about one sixtieth part of the popular software IDS systems.