Current Issue

• • 2017, Vol. 40 No. 6 Published date:28 December 2017 Last issue Next issue

  Review

  • Survey on Caching Technology in Mobile Edge Networks
  • WANG Ying, FEI Zi-xuan, ZHANG Xiang-yang, SUN Rui-jin, MIAO Zhong-yu
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 1-13. DOI:10.13190/j.jbupt.2017-066
  • Abstract ( 629 )     HTML     　　
  • The explosive growth of mobile video services puts forward higher requirements for future wireless communication networks. Caching technology will greatly decrease the radio resource pressure of the wireless network through content reuse. It is one of the key technologies in the 5th-generation mobile communication to improve the virtual reality, augmented reality and ultra high quality video services quality of experience. A survey on caching technology in mobile edge networks was given. Firstly, the architecture of the mobile edge network is analyzed, and the characteristics of the mobile edge caching are summarized. After the classification of the different caching modes, the technologies in mobility and social aware caching situations were concerned. Finally, the technical challenge and development directions of mobile edge caching are presented.
  • References | Supplementary Material | Related Articles

  Papers

  • A Cache Pollution Defense Mechanism Based on Trust Judgment of Face Abnormality in Content Centric Networking
  • ZHU Yi, WANG Xin-ping, HUANG Ru-hui, KANG Hao-hao, CAO Qing-hua
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 14-18. DOI:10.13190/j.jbupt.2017-104
  • Abstract ( 313 )     HTML     　　
  • To solve the problem of cache pollution attack in content centric networking, a traffic limiting control mechanism was proposed based on trusted judgment of face abnormality. By detecting the abnormality status of each face, the traffic of abnormal face was limited according to its request hit probability. Simulations show that, this mechanism can defend against both locality-disruption and false-locality attacks. In addition, using the trust judgment of face abnormality, the false-locality attack can be distinguished from the flash crowd event with large probability. So, it can avoid mistakenly restraining the normal network behavior.
  • References | Supplementary Material | Related Articles

  • A Content Pre-Caching Mechanism Based on Bipartite Graph in Mobile Cellular Network
  • WEI Liang, XIE Jun-feng, XIE Ren-chao, HUANG Tao, LIU Yun-jie
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 19-23,36. DOI:10.13190/j.jbupt.2017-035
  • Abstract ( 409 )     HTML     　　
  • In order to solve the problem of efficient deployment caching in mobile networks, a content caching mechanism based on bipartite graph was proposed. When selecting the content caching nodes, it is necessary to consider not only the content's interest degree in each node, but also the link states between nodes. Based on this scheme, those nodes which are most interested in the content and have the best network status will be selected to pre-cache the content, thereby improving the content distribution efficiency and reducing the content transmission delay. Simulation results are illustrated to show that the proposed scheme can improve the utilization efficiency of cache space, reduce the content transmission delay and enhance users' experience.
  • References | Supplementary Material | Related Articles

  • Blind Estimation of Underdetermined Mixing Matrix Based on Similarity Measurement
  • FU Wei-hong, ZHOU Xin-biao, NONG Bin, WANG Chuan-chuan
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 24-29. DOI:10.13190/j.jbupt.2016-288
  • Abstract ( 437 )     HTML     　　
  • A new algorithm based on similarity measurement was proposed in order to address the issue of low estimation accuracy and high computational complexity in the existing algorithms for underdetermined mixing matrix blind estimation. The proposed algorithm can estimate the number of source signals and the mixing matrix automatically without any prior information or much iteration. Compared with the existing algorithms such as the K-means clustering and the Laplace's potential function method, the simulations turn out that the proposed has obvious advantages in the estimation accuracy of the number of source signals and the estimation precision of mixing matrix and the computational complexity.
  • References | Supplementary Material | Related Articles

  • Optimal Base Station Density in Heterogeneous Networks Based on the Bursty Traffic
  • FAN Cong-shan, ZHANG Tian-kui, ZENG Zhi-min
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 30-36. DOI:10.13190/j.jbupt.2016-302
  • Abstract ( 433 )     HTML     　　
  • To cope with the bursty traffic caused by popularity of multimedia services, the optimal base station density in heterogeneous networks by taking into account the burst characteristics of the traffic was analyzed using stochastic geometry approach. Based on bursty traffic, the traffic coverage probability of the heterogeneous network was defined and its relation with the base station density was specifically derived. An optimization problem with the aim of minimizing the base station density was formulated under the constraint of traffic coverage probability. Using binary search algorithm, the optimal base station density and the bounds (both upper and lower bound) for simplified analysis are obtained. Simulation confirms the accuracy of theoretical analysis and verifies the impact of the burst characteristics on the optimal base station density.
  • References | Supplementary Material | Related Articles

  • LBS Privacy Preservation Scheme Based on Oblivious Transfer in Road Network Environment
  • ZHOU Chang-li, CAI Shao-bin, WANG Tian, MA Chun-guang
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 37-42. DOI:10.13190/j.jbupt.2017-103
  • Abstract ( 434 )     HTML     　　
  • There are three common defects in existing location based service (LBS) privacy-preserving methods:only considering privacy preservation of the user without caring about data security of LBS server. The stronger a privacy-preserving method is, the less practical it is. Privacy-preserving methods are usually proposed based on the Euclidean space without considering actual factors in road network, and the query accuracy declines consequently. To solve the above problems, an LBS privacy-preserving scheme was proposed based on oblivious transfer with special distribution information for points of interest in road network. This scheme ensures data security of LBS server while preserving the user's location privacy and query content privacy, at the same time, it is applicable for continuous query in road network and guarantees the query efficiency and accuracy. Performance analysis and extensive experiments show that this scheme ensures strong security and works efficiently.
  • References | Supplementary Material | Related Articles

  • Prediction of Power System Security Based on Stacked Sparse Auto-Enconder Neural Network
  • LI Xiao-yu, LI Shu-fang, LI Wen-qi, TIAN Shi-ming
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 43-49. DOI:10.13190/j.jbupt.2017-100
  • Abstract ( 265 )     HTML     　　
  • In order to satisfy the accuracy rate and timeliness performance for transition stability assessment(TSA) with a safety margin, a prediction model of stacked sparse auto-encoder network (SSAEN) is proposed based on deep learning. Firstly, the matrix obtained from the bus voltage can be treated as a pattern diagram with the TSA operating mechanism. Then, the dominant property of the pattern diagram hierarchically is mined by adopting SSAEN. And, the domination features and their evolution are described by analyzing the connection weights of the layers. Next, employing the logistic classifier can identify the dominant property. Finally, the system stability in the future time is successfully predicted. Competitive prediction speed and accuracy of the proposed SSAEN can be achieved from the simulation results in the IEEE-39-bus system, which is important to provide a sufficient safety margin when the system suffers from a temporary instability.
  • References | Supplementary Material | Related Articles

  • Optimal Correlation Prediction of User Behaviors Based on Mobile Social Environment
  • ZHANG Hui, WANG Min
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 50-56. DOI:10.13190/j.jbupt.2017-141
  • Abstract ( 418 )     HTML     　　
  • A multiple analysis and optimal prediction algorithm of user behaviors based on mobile social environment is proposed. First, for each social group of a target user, an optimization model based on representativeness degree is formulated to select the most representative correlated user from this social group for analyzing the service behaviors of target user caused by the corresponding social attribute; particularly, the representativeness degree consists of Kendall coefficient based similarity degree and interaction statistics based interaction degree. Second, by using Apriori theory, the correlation analyses for target user and its most representative correlated users are performed respectively, and then a least-square model based weighted fusion method is presented to integrate the above correlation analysis results optimally and predict user next behaviors accurately. Extensive simulation results verify the effectiveness of proposed algorithm.
  • References | Supplementary Material | Related Articles

  • Speech Hiding Algorithm Based on Mobile Circuit-Switched Domain
  • XUE Yi-ming, HE Ning-ning, CHEN Yao, HU Cai-e, NIU Shao-zhang
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 57-64. DOI:10.13190/j.jbupt.2017-021
  • Abstract ( 379 )     HTML     　　
  • Based on analysis of circuit-switched mobile channels, an algorithm for speech information hiding was proposed, which is robust for the speech vocoder discontinuous transmission (DTX) mechanism and the lossy compression. The algorithm performs 3-level discrete wavelet transform decomposition on the voiced speech frames decided by voice activity detector, and selects the 3rd level detail coefficients to implement fast Fourier transform(FFT). By means of the auditory masking theory, the rational dither modulation is used to embed the secret data on FFT coefficients within the frequency band of 0.5~1 kHz. The experimental results show that the Perceptual evaluation of speech quality score of stego speech is higher than 3.48, and the bit error rate is about 0.06 under the interference of DTX of the global system for mobile communication enhanced full rate vocoder, the lossy compression and some other attacks in the channels.
  • References | Supplementary Material | Related Articles

  • Network Traffic Prediction Based on ARIMA with Gaussian Process Regression Compensation
  • TIAN Zhong-da, LI Shu-jiang, WANG Yan-hong, WANG Xiang-dong
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 65-73. DOI:10.13190/j.jbupt.2017-019
  • Abstract ( 558 )     HTML     　　
  • In order to improve the medium-term prediction accuracy of network traffic, a network traffic prediction method based on auto regressive integrated moving average (ARIMA) with Gaussian process regression compensation was proposed. Firstly, the linear and nonlinear characteristics of network traffic can be determined by Brock-Dechert-Scheinkman statistics. Then, ARIMA model was used for modeling the non-stationary network traffic time series. The linear model of network traffic sequence was obtained. The artificial bee colony algorithm optimized Gaussian process regression model was used as the prediction model of predictive error sequences with the nonlinear characteristic. Finally, the final prediction value was obtained by adding predictive values of ARIMA model and predictive error values of Gaussian process regression model. Simulation comparison shows that the proposed prediction method has higher prediction accuracy with the smaller prediction error.
  • References | Supplementary Material | Related Articles

  • Wavelength Allocation Scheme Based on User Traffic Prediction in TWDM-PON
  • WANG Ying-jie, LIU Xiao-ning, LUO Huan-huan, ZHOU Gui-ping, WANG Yan-ru
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 74-79. DOI:10.13190/j.jbupt.2017-140
  • Abstract ( 455 )     HTML     　　
  • In order to solve the problems of unbalanced load, low resource efficiency and large tuning cost in the existing wavelength assignment algorithms of time wave division multiple passive optical network(TWDM-PON), the periodic distribution of wavelengths in the large scale time range of user traffic request behavior was studied. A switching cycle fixed-dynamic(SC-FD) wavelength assignment scheme was proposed, which allocates the optical netork unit assigned to multiple available wavelengths by validating the future bandwidth request of the user, and finally allocating the wavelength resources. The proposed scheme combines the advantages of fixed wavelength algorithm(FWA) and the earliest idle wavelength priority(EIWP) mechanism. Simulations show that the proposed scheme can effectively reduce the wavelength tuning cost, make the user load at different wavelengths more balanced, and improve the efficiency of resource allocation.
  • References | Supplementary Material | Related Articles

  Reports

  • Optimization Strategy of Efficient Periodic Mobile Location
  • DU Hui-ying, DU Wu-gong
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 80-85. DOI:10.13190/j.jbupt.2017-129
  • Abstract ( 467 )     HTML     　　
  • Location based services(LBS) has become the basic ability of mobile Internet, mobile positioning technology gradually penetrated all aspects of social life. At present, there are many problems in the application of periodic monitoring, and the location strategy has many limitations, so the power consumption of mobile terminal is large and the accuracy is low. Based on game theory and econometrics, an efficient positioning optimization strategy model was established. According to user scenarios, this article analyzed the history of mobile location data and proposed a dynamic mobile positioning strategy when considering the positioning method and its success rate of wireless fidelity, assistant global positioning system, global positioning system and base station. Simulations show that the periodic mobile location strategy can increase the accuracy of first-time location, carry out the next mobile location quickly and accurately. It can reduce the pressure of the communication network and the mobile terminal system as well.
  • References | Supplementary Material | Related Articles

  • Pre-Coding Design of Asynchronous Interference Suppression for Multi-Base Station Cooperative
  • XIAO Hai-lin, WANG Ru, YAN Xiao-juan, JIANG Wei
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 86-91. DOI:10.13190/j.jbupt.2016-192
  • Abstract ( 493 )     HTML     　　
  • In multi-base station cooperative systems, the distances are different between the base stations and the users which will result in asynchronous interference of users received signals. To suppress asynchronous interference, a pre-coding design for muti-base station cooperative communication is proposed based on particle swarm optimization algorithm. The pre-coding design converts the pre-coding matrixes into the position parameters matrixes of the optimization particle, updates the optimization position parameters by intelligent learning among the particles, and adjusts the fitness function to maximize the signal to interference plus noise ratio of user. Thus, the pre-coding design can be used to suppress asynchronous interference of users received signals. Numerical simulations show that, compared with the improved block diagonalization algorithm, the proposed algorithm the proposed algorithm will increase the sum rate of system 2~7 bit/s with a good convergence.
  • References | Supplementary Material | Related Articles

  • Two Step Cooperative Spectrum Sensing Scheme over Fading Channels for Cognitive Radio
  • CHU Guang-qian, NIU Kai, WU Wei-ling, YANG Fang-liao
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 92-97. DOI:10.13190/j.jbupt.2017-046
  • Abstract ( 464 )     HTML     　　
  • In the cognitive radio network, the performance of spectrum sensing by a single user with a single antenna may degrade significantly. In order to improve the detection performance and reduce spectrum sensing data transmission overhead, a two step cooperative spectrum sensing scheme was proposed. Simulations show that proposed scheme can significantly improve the detection reliability by overcoming multi-path fading, shadowing and the receiver uncertainty problem. The proposed scheme combines the advantages of the soft combination and the hard combination schemes. In addition, it will reduce the network overload and improves the detection performance.
  • References | Supplementary Material | Related Articles

  • Analysis of a Dual Band-Notched UWB Antenna Based on Parasitic Strips
  • YANG Hui-chun, ZHANG Zhen, BI Zhan-hong
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 98-102. DOI:10.13190/j.jbupt.2017-050
  • Abstract ( 479 )     HTML     　　
  • For solving the problem of band overlap between the ultra-wideband (UWB) communication and existing civil communication,a new type of coplanar waveguide fed UWB antenna with Dual band-notched characteristics is proposed. Two parasitic strips on earth plate was applied to realize the band-notched characteristics. The designed antenna operates on the ultra-wideband efficiently, except for the bandwidth of 5.15~5.35 GHz and 5.75~5.85 GHz for wireless local area network application. Research results show that the antenna provides perfect input impedance and pattern properties within 3.1~10.6 GHz.
  • References | Supplementary Material | Related Articles

  • Energy Scheduling and Adaptive Transmission Power Algorithm for a Transmitter with Hybrid Energy Sources
  • LIU Di-di, MA Li-na, Frank Jiang
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 103-108. DOI:10.13190/j.jbupt.2017-074
  • Abstract ( 351 )     HTML     　　
  • The problems of energy scheduling and adaptive transmission power were explored for a point to point wireless communication link, where, the transmitter is driven by hybrid energy sources. The problems are further constrained by the unknown information including 1) the energy harvesting process, 2) time-varying channel condition as well as 3) the statistics of dynamic/opportunistic data arrivals. To minimize the time average energy consumption from power grid over subject to a certain communication performance, i.e., utilizing efficiently the harvested energy, a new dynamic algorithm with low complexity was proposed based on Lyapunov optimization. Analysis shows that the proposed algorithm performs arbitrarily close to the optimal objective value, meanwhile ensures that the maximum time delay of the data queue would tolerate the data packets aggregated from the users' requirements. Simulations demonstrates that the proposed algorithm not only outperforms but also has smaller time delay than the other two greedy algorithms.
  • References | Supplementary Material | Related Articles

  • Feature Extraction Research in Signal Process with Phi-OTDR Technology
  • HU Yan-zhu, WANG Song, LI Lei-yuan
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 109-114. DOI:10.13190/j.jbupt.2017-030
  • Abstract ( 626 )     HTML     　　
  • In the phase-sensitive optical time domain reflectometer (Phi-OTDR), noise-signal ratio on time axis and effective range on length axis are two important factors. Reservation of signal characteristics and rapid processing in time domain are also two important conditions. To optimize these factors and conditions, the signal by signal-noise classification, signal reservation and noise reduction was processed. In signal-noise classification, the time encode signal processing algorithm was improved for coding and extract feature of distributed vibration signal in time domain. The signal range on the length axis and the signal-to-noise ratio of each point on the time axis can be improved. At the same time, the calculation speed is also improved.
  • References | Supplementary Material | Related Articles

  • Entity Discovery and Linking Approach Based on Random Walk with Restart
  • TAN Yong-mei, ZHENG Di, LIU Shu-wen, LÜ Xue-qiang
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 115-119. DOI:10.13190/j.jbupt.2016-220
  • Abstract ( 1273 )     HTML     　　
  • An entity discovery and linking approach based on random walk with restart was presented. Unified semantic representation for entities and documents-the probability distribution obtained from a random walk on a subgraph of the knowledge based was adopted. According to this distributed representation, the entities that are similar with mentions as the linking results was obtained. This method achieved 0.665 F value on entity linking section of TAC 2015 TEDL task, it performs better than other participating systems. It is illustrated that the method can overcome the feature sparsity issue and is less amenable to feature sparsity bias.
  • References | Supplementary Material | Related Articles

  • Blockchain Model of Cloud Forensics
  • HUANG Xiao-fang, XU Lei, YANG Xi
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(6): 120-124. DOI:10.13190/j.jbupt.2017-079
  • Abstract ( 610 )     HTML     　　
  • An electronic forensics model of cloud computing based on blockchain was proposed, in which, an evidence prevention scheme based on Merkle Tree and an improved consensus algorithm were designed to implement the decentralized electronic forensics under cloud computing environment. This model can prevent any involved party-forensic investigators, cloud service providers, users, etc.-from colluding to tamper with the digital evidence. Experiments show that the model can effectively preserve and verify the electronic evidence, and guarantee the integrity and timeliness of the data.
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