Please wait a minute...

Current Issue

    15 February 2012, Volume 28 Issue 2
    Topics:information data management and analysis of the application
    Research on Data Quality Management and Data Audit&Monitor in Telecom Industry
    Yuhang Ye,Renlong He,Xiaoxu Cheng
    2012, 28(2):  1-6.  doi:10.3969/j.issn.1000-0801.2012.02.001
    Asbtract ( 982 )   HTML ( 29)   PDF (1384KB) ( 1496 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    The main aim of this paper is to research data quality management(TDQM)and data audit& monitor in telecom industry.Firstly,this paper introduces the theory of total data quality management and analyzes a TDQM closed-loop management plan that contains data quality definition,measurement,analysis and improvement in telecom enterprise.Then the scheme of data warehouse data audit and monitor for telecom enterprise is discussed.Lastly,based on authorˊs practice,a data quality management and audit&monitor platform architecture is proposed.This paper provides references for telecommunication industry to establish TDQM system.

    Research on Telecom Service Plan Assessment and Analysis Model
    Renlong He,Shanshan Wei,Chenxu Qiu
    2012, 28(2):  7-12.  doi:10.3969/j.issn.1000-0801.2012.02.002
    Asbtract ( 923 )   HTML ( 22)   PDF (1122KB) ( 1102 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    This article analyzes the risk of affecting the value of service plan in the operation flow and proposes the pointed measures.The article raises an assessment system to telecom service plan and analysis model.The assessment system provides 16 indicators in 8 dimensions to review service plan and indicate the overall rating and shortcoming for each plan.For the model application,the analysis has be done to more than 600 service plans from one telecommunication company,and furthermore,“My E Family”plan 49/89/209 has be assessed as example with radar chart.The model application effect is obvious and helpful in enhancing the competitive power of telecom service plan in the market.

    Applying DM Method on the Assets Profitability Analysis in Local Network
    Jinfei Xue,Zhongjiang He,Lihua Deng
    2012, 28(2):  13-17.  doi:10.3969/j.issn.1000-0801.2012.02.003
    Asbtract ( 861 )   HTML ( 15)   PDF (753KB) ( 277 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Generally through ROA we can judge of the assets income in local network.Although this method can find out the operation problems,it can't tell the administrator how to improve.In this paper,the author tries to combine the traditional financial analysis with the DM method to find out the way to improve the assets profitability.With a real case analysis,how to use this model in practice is shown.

    Research on Construction of the Telecom Industry's Data Warehouse System Based on Memory Computing Technology
    Xiaoyin Xi,Zhongjiang He,Dan Wang
    2012, 28(2):  18-21.  doi:10.3969/j.issn.1000-0801.2012.02.004
    Asbtract ( 814 )   HTML ( 17)   PDF (530KB) ( 348 )   Knowledge map   
    References | Related Articles | Metrics

    Currently the data warehouse in the telecom industry has been used widely,from decision analysis to business analysis,data warehouse for every field of data application provides a powerful support functions.However,with the depth of the application system,data warehouse performance problems begin to highlight,make the application of data warehouse have larger constraints.And,with the telecommunications operators' strategy transformation deepening,how to confirm the advantage of telecom itself in intelligent pipeline,comprehensive platform,and content provision is more and more urgent,and all of this need data warehouse's effective support.This article aims to explore in the telecommunications strategy transformation,how to benefit to the memory of computing technology,to find a feasible way for the construction of telecom industry's data warehouse system.

    Research on Basing Distributed Computing Framework to Achieve Accelerating the Data Analysis Application of Telecommunications
    Jianfeng Wen,Yirong Shi
    2012, 28(2):  22-26.  doi:10.3969/j.issn.1000-0801.2012.02.005
    Asbtract ( 928 )   HTML ( 19)   PDF (892KB) ( 365 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    The paper analyzes the problems of data analysis system of telecommunications.With the business needs and technology trends,it proposes a solution based on Hadoop distributed computing framework to accelerate data analysis for the telecommunications infrastructure services.Then,this paper describes a framework including technology solutions,functional model,and acceleration which based on distributed data analysis system.And also does a further analysis and comparison with the application of distributed computing.This paper will provide a useful reference for the industry of distributed computing applications in related fields.

    Reflection on Construction of a Telecom Internet of Things Open Data Service System
    Jun Zhao
    2012, 28(2):  27-31.  doi:10.3969/j.issn.1000-0801.2012.02.006
    Asbtract ( 847 )   HTML ( 16)   PDF (993KB) ( 516 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    One of the characteristics of the IoT is intelligent processing.How to store,analyze,and share large volumes of IoT data is a problem that is worth of attention and needs to be solved.This article proposes a design on the construction of a telecom IoT open data service system based on the analysis of the current operation status and future development trend of telecom operators.It further designes the service functions and system framework of IoT data services.It analyzes the key technical points related to the construction of data service systems.In the end it gives recommendations of strategies for telecom operators to construct an IoT open data service system.

    Research on Flow Management of Data Analysis Method and Application
    Yan Tan,Renlong He,Chenxu Qiu
    2012, 28(2):  32-35.  doi:10.3969/j.issn.1000-0801.2012.02.007
    Asbtract ( 995 )   HTML ( 23)   PDF (677KB) ( 655 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    This article presents that the telecom industry is entering into 3G era of business operation characteristics,proposes the flow management is the key to the current development of 3G business.It studies the data analysis model for supporting the flow management,and actual application case,analysis added value of flow management through the data mining,it provides reference for the domestic telecom operators to establish an effective flow management mode.

    Research and development
    A Multi-Power Multi-Channel Data Collection Scheduling Algorithm in Dual-Radio Sensor Networks
    Bin Fan,Jinbao Li,Longjiang Guo,Xu Liu
    2012, 28(2):  36-45.  doi:10.3969/j.issn.1000-0801.2012.02.008
    Asbtract ( 833 )   HTML ( 20)   PDF (3530KB) ( 370 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Aiming at the data collection problem in dual-radio sensor networks,a multi-power multi-channel data collection scheduling algorithm named MMDC is proposed.MMDC first constructs the optimal path for data collection with each nodeˊs energy consumption,then considers the conflict within the network communications,data collection delays and other factors,to construct a multi-level power spanning tree called MPST,to reduce energy consumption,conflict,and delay of data collection.Finally,based on MPST,we use joint channel allocation and link scheduling algorithm for data collection,called CALS.CALS employs fewer radios and channels to eliminate the conflict and interference between the communication links,to achieve conflict-free parallel sending and receiving data in multiple links,and to optimize data collection efficiency.The results show that MMDC can effectively reduce the data forwarding delay,the data collection time and the network energy consumption,as well as increase the network throughput.

    Design and Application of the ZigBee&Bluetooth Technology Complementary Gateway
    Zhang Yi,Xiong Peng,Li Lin and Luo Yuan
    2012, 28(2):  46-51. 
    Asbtract ( 815 )   Knowledge map   
    Related Articles | Metrics
    With the development of Internet of Things, the researches on short-range wireless communications technology become more and more, but little of them are about a variety of complementary technologies. In this paper, with the comparative analysis of ZigBee and Bluetooth technology, the data frame format of information conversion between ZigBee and Bluetooth devices based on the ZigBee protocol stack is designed. The Bluetooth device is as the links and access media between ZigBee sensor network and mobile/internet. The gateway based on ZigBee and Bluetooth is designed and experimented. The experiment shows the design of ZigBee and Bluetooth connectivity is practical.
    Research on Usage Behavior of Mobile Consumers Under the Uncertainty of Consumer Demand
    Rong Wang,Xiaowo Tang,Yong Zhang
    2012, 28(2):  52-58.  doi:10.3969/j.issn.1000-0801.2012.02.009
    Asbtract ( 795 )   HTML ( 16)   PDF (1689KB) ( 454 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    The influence of these factors such as tariff choice and multi-service on usage action of consumer is discussed from microcosmic and a case study is given to validate the methodology based on above conclusion.The analysis indicates that there is positive correlation between local called duration and local caller demand.Message amount accepted has an obvious feedback effect on local caller demand.The confining effect of free call-duration on usage action is more and more obvious with tariff increase.Based on above analysis the usage model of tariff of selection-amendment is created.The estimation of model based on practical data shows a good result.

    An Improved V-BLAST Algorithm Based on LTE
    Xiaowen Li,Xu Ren
    2012, 28(2):  59-62.  doi:10.3969/j.issn.1000-0801.2012.02.010
    Asbtract ( 954 )   HTML ( 19)   PDF (1395KB) ( 327 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Signal detection is of great importance in LTE system.Conventional V-BLAST algorithm during signal detection has the spread of error,resulting in a decline in performance.This paper presents an improved V-BLAST algorithm,when it is first detected,this paper uses a new method which calculates the value of probability to make the symbols to be detected in order,and this layer retains the K Euclidean constellation points which are nearest to statistics judgment according to the modulate mode,and the other layers are still using V-BLAST algorithm.Compared with the conventional algorithm,the improved one has much better performance,which has been applied to TD-LTE wireless integrated test instrument.

    Interference Evaluation of GSM-R Network with Gray System Theory
    Junping Wang,Gang Zhu,Yuanyuan Shi,Zhangdui Zhong
    2012, 28(2):  63-68.  doi:10.3969/j.issn.1000-0801.2012.02.011
    Asbtract ( 855 )   HTML ( 16)   PDF (1383KB) ( 456 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    GSM-R network is the information transmission carrier of high-speed railway,in order to ensure that is in good condition,we must evaluate the interference of GSM-R network accurately.Comprehensive assessment of GSM-R network with gray system theory overcomes the shortcomings of the traditional methods.This paper first describes the importance of assessing GSM-R network and introduces the principles of the gray system theory,then presents GSM-R interference-related indicators and analyzes the assessing indicters through algorithm of gray incidence cluster.Finally the example is given in order to prove the effectiveness of assessing interference with cray system theory in GSM-R network.

    Transmission Mechanism of P2P Streaming Media Model
    Wenyu Chen,Weishun Li,Ru Zeng,Lingli Guo
    2012, 28(2):  69-73.  doi:10.3969/j.issn.1000-0801.2012.02.012
    Asbtract ( 986 )   HTML ( 22)   PDF (1536KB) ( 355 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    For realizing the basic service of streaming media,video on demand and live video,we present a proposal of application layer multicast,video on demand,build a video frequency streaming media model with two kinds of peers,SP and peer based on P2P,describe the structure of model,analyze resources transmissions.Finally,some test records of this model are expressed with the table,that show a solution of ALM(application layer multicast)and video on demand with P2P model.

    Study of Timing Synchronization Algorithms in TD-LTE System Under Multipath Channel
    Fatang Chen,Wang Teng
    2012, 28(2):  74-78.  doi:10.3969/j.issn.1000-0801.2012.02.013
    Asbtract ( 995 )   HTML ( 18)   PDF (1432KB) ( 542 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Multipath spread is an inherent characteristic of radio channel,time delay of channel can cause interval symbols interference(ISI)which influences the demodulation of receiver's signal seriously.This paper mainly studies the timing synchronization module in TD-LTE system under the multipath channel,optimists the algorithm of power differential based on cyclic prefix(CP) and estimates the position of timing synchronization accurately joint with primary synchronization signal(PSS).Simulation results demonstrate that the algorithm has good performance of timing synchronization under the multipath channel and can work stable especially the time delay is largely.

    Analysis and Design of Antennas with Miniaturiation and Wideband
    Zehui Xie,Yuqin Wang,Shuangyang Hao,Hongmei Zhao
    2012, 28(2):  79-81.  doi:10.3969/j.issn.1000-0801.2012.02.014
    Asbtract ( 846 )   HTML ( 18)   PDF (991KB) ( 612 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    In consideration of the miniaturization and integration of development tendency for mobile communications terminations,this paper presents an antennas with miniaturiation and wide-band.Based on theory about microstrip and typical structure of monopole antennas,the antennas is designed that can change the three-dimensional structure into a plane structure and the length of the dielectric slab.The experiments show that the antennas is a kind of wide-band antennas with size 16 mm× 17 mm and an absolute frequency bandwith for 3.2 GHz(S11<-10 dB).

    An Improved Codebook Design Algorithm of Vector Quantization Based on Hadamard Transform
    Jiaguo Wang,Shanxue Chen,Yan Zhang,Xuejiao Yin
    2012, 28(2):  82-85.  doi:10.3969/j.issn.1000-0801.2012.02.015
    Asbtract ( 863 )   HTML ( 23)   PDF (556KB) ( 338 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    This paper presents an improved codebook design algorithm of vector quantization which combines Hadamard-transform and K-means theory,according to the Chen's vector quantization algorithm which has two weaknesses of high randomness for the formation of initial codebook and low encoding quality(PSNR).The proposed algorithm uses the statistical features of classification average method of training vectors to generate initial codebook,and then improves the frequency of calculation the cell's centroid.Whenever a training vector is classified into lumen,the corresponding cell's centroid will be calculated to instead of the original code word.The proposed algorithm combines the advantages of LBG algorithm.The adjusted code word represents the characteristics of the lumen,accelerates the convergence speed of codebook,and improves the performance of codebook.Compared with the Chen's algorithm,the encoding quality can be improved by 0.5 dB,even when the iteration is low,the PSNR is improved by 0.9 dB.

    Self-Adaptive Concurrent Algorithm and Applications for Window Joins over Uncertain Data Streams
    Jiangbo Qian,Zhijie Wang,Huahui Chen,Haibin Wang
    2012, 28(2):  86-94.  doi:10.3969/j.issn.1000-0801.2012.02.016
    Asbtract ( 886 )   HTML ( 21)   PDF (2985KB) ( 298 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Recently there has witnessed emergence of uncertain data streams,with features of time-varying,uncertain,unpredictable and continuous,in many new application.The data process encounters many technical challenges,such as limited memory,very short response time,continuous processing and so on.Window join is one of the difficult problems as it cost many resources.Focusing on the problems on high-speed processing and memory overflow,a series of algorithms are proposed to tackle simultaneous window joins over large scale uncertain data streams.On this basis,an original application to monitor clone cars is presented.Experiments with real data,uniform data and Gaussian data show that the algorithms gain good performance,and its processing speeds faster than the memory database(Timesten)2~8times,to meet the requirements of monitoring clone cars in real traffic.

    A Modified Soft Interference Cancellation Algorithm Based on FG-Turbo Multiuser Detection
    Zhongyong Wang,Xiaomin Ren,Linlin Duan,Yan Xiao
    2012, 28(2):  95-98.  doi:10.3969/j.issn.1000-0801.2012.02.017
    Asbtract ( 794 )   HTML ( 15)   PDF (1273KB) ( 322 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    In this paper,based on the factor graph and sum-product algorithm,we get the extend model of FG-Turbo multiuser detection with LDPC coded,simulate and compare the performances of MAP algorithm and soft interference cancellation algorithm,and propose a new method to estimate interference symbols,that is based on sensitive bits algorithm.Simulation results show that in the case of the computational complexity unchanged,the soft interference cancellation algorithm modified can improve the performance of system effectively.

    Research on a Security Communication Scheme
    Lifang He,Gang Zhang,Tianqi Zhang
    2012, 28(2):  99-103.  doi:10.3969/j.issn.1000-0801.2012.02.018
    Asbtract ( 821 )   HTML ( 21)   PDF (2530KB) ( 452 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    The secure communications based on chaos synchronization have more great advantages than the traditional communications.Normally,the secure communications using chaos synchronization are achieved by chaotic mask.Two channels are required in this mode,one channel transmits signal to keep the system synchronized,while the other channel transmits confidential information after masked with the chaotic signal.In the case the growing shortages of spectrum resources,channel resource utilization in this means of communication is relatively low and therefore less cost-effective.A new system is proposed with a circled channel to transmit information and synchronous signal.The system is analyzed in detail,focusing on the time slot allocation and the simulation verification.It proves that the system can greatly improve the channel efficiency and the practical application of the system.

    A Roaming Access Authentication Protocol in WLAN Mesh Network
    Shengchao Fan,Guoan Zhang,Honghai Fei,Gongan Qiu
    2012, 28(2):  104-109.  doi:10.3969/j.issn.1000-0801.2012.02.019
    Asbtract ( 1340 )   HTML ( 18)   PDF (903KB) ( 459 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    The currently protocols about WLAN mesh network node have some deficiency in roaming access process.Based on the security links which was established by EMSA initial authentication process and the message authentication code technology,the improved DH key exchange process is introduced.A new access authentication protocol which can effectively conform to the performance and security in roaming access process is proposed.The proposed protocol not only has the basic SK security,but also has a smaller delay.Moreover,the protocol is suitable to the mesh networks with the characteristic of topology change.The finished mutual access authentication process also complete the key generation,and the protocol can better hide the ID information of the terminal node.

    A Method of Building 3D Vector Database for Ray Tracing
    Jinsheng Yang,Zisheng Hu,Weigang Chen
    2012, 28(2):  110-114.  doi:10.3969/j.issn.1000-0801.2012.02.020
    Asbtract ( 853 )   HTML ( 22)   PDF (1394KB) ( 940 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    3D vector database,including scenario database and visible elements(surface and wedge)database,is essential to ray tracing channel modeling method.In this paper,a method on building 3D vector database for urban microcellular and indoor scenarios is presented.First,a simplified method of 3D CAD modeling is applied in building the 3D models and database of scenarios.Then,a modified perspective projection method is employed to build 3D visible elements database of viewpoint in terms of the scenario.Further the computation complexity of ray tracing model based on visible elements database is analyzed.The simulation results show that the method can efficiently reduce the computation complexity of ray tracing channel modeling method.

    Interest Model for Location of the User Behavior Based on Small-World Network
    Shaozhong Zhang,Dongyun Yu
    2012, 28(2):  115-118.  doi:10.3969/j.issn.1000-0801.2012.02.021
    Asbtract ( 750 )   HTML ( 23)   PDF (755KB) ( 360 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Interest Model for Location of the User Behavior Based on Small-World Network Abstract The paper introduces a small-world network model to analyze user behavior characteristics and find the behavior of the user attributes and location-based clustering.The method using the recommended calculation method described the similarity between nodes and look at the user location as a root.It looks at the location of the userˊs interest in resources as nodes and convert interests computation problem to search shortest path.An improved algorithm is proposed to calculate the shortest path from the root each node and analyze the most interested node resources of users by his positions.Experimental results show that this method established by the location of the user interest model can describe the location of the userˊs interest and willingness.The algorithm has a good performance in accuracy and computing time.

    Study on Relationship Model Between GGSN Capacity and Content Billing Rules
    Liyu Cui
    2012, 28(2):  119-122.  doi:10.3969/j.issn.1000-0801.2012.02.022
    Asbtract ( 822 )   HTML ( 18)   PDF (1240KB) ( 331 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    To explore the relationship between the GGSN equipment capacity and content billing rules,this paper builds a GGSN capacity model with the number and the order of content billing rules.Proved by the measured data validation,the relational model is statistically reliable.

    Research on Routing Protocol for Underwater Seneor Network
    Jun Jin,Fang Zong,Miaoyuan Liang,Junjie Zheng
    2012, 28(2):  123-127.  doi:10.3969/j.issn.1000-0801.2012.02.023
    Asbtract ( 917 )   HTML ( 25)   PDF (903KB) ( 975 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    The existing underwater sensor network protocols are almost based on geographic routing mode,the underwater nodes must know the full-dimensional location information of all the nodes,this maybe lead to a lot of underwater communications.In this paper,a protocol based on depth and residual energy is designed.This protocol does not require full-dimensional location information,instead,it needs only local depth information,which can be obtained by using inexpensive depth sensor.The routing arithmetic is designed and the solving method for inanition is presented.

    Overview
    Analysis on Development Trends of Cyber Physical Systems
    Junhai Luo,Zhihui Xiao,Changping Zhong
    2012, 28(2):  127-132.  doi:10.3969/j.issn.1000-0801.2012.02.024
    Asbtract ( 1269 )   HTML ( 72)   PDF (1330KB) ( 1992 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Cyber physical system(CPS)is the network-physical-equipment-system based on the depth context awareness,fusion computing,communication and control(3C)abilities,which realizes the real world and cyber world coordination and interactive to increase or expand new functions,and provides the real-time perception,dynamic control and cyber feedback and other services with the influence and feedback loop between the calculation process and physical process.The paper introduces the background and concept of CPS,gives a detailed analysis about the opportunities and challenges of the research on CPS.Some important scientific basis and key technology are analyzed.The future research and the new development trends of CPS are surveyed in this paper.

    Research on Architecture of Flexible Reconfiguration Network
    Liang Zhao,Binqiang Wang,Peng Zhang
    2012, 28(2):  133-137.  doi:10.3969/j.issn.1000-0801.2012.02.025
    Asbtract ( 911 )   HTML ( 14)   PDF (948KB) ( 619 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    Next internet should to be a network to satisfy user's individuality.Reconfiguration has its special advantages in the self-adaptation to satisfy the environment and change for application object of the system.Therefore,this paper import reconfiguration to network architecture design,and propose the conception of flexible reconfiguration network,then the reference model and formalization description to the network.Finally,application situation and advantage of the flexible reconfiguration network are given.

    Research on Anti-Collision Technology in RFID
    Yong Liu,Xingzhong Xiong,Xiaohua Li
    2012, 28(2):  138-143.  doi:10.3969/j.issn.1000-0801.2012.02.026
    Asbtract ( 835 )   HTML ( 24)   PDF (759KB) ( 749 )   Knowledge map   
    References | Related Articles | Metrics

    RFID is one kind of contactless automatic recognition technologies,used widely in manufacturing,logistic management,and public security fields and so on.But in practical application RFID system still has a lot of problems to solve.Problems of not unified of standards,hidden danger,diversity and complexity,and data collision.Especially,the data concllsion will directly lead to efficiency reduce of label identifcation and waste of resources.Not only the paper summarizes all kinds of data anti-collision technology,but also shows its advantages of disadvantages and progress and direction of research.

    Operational support technology innovation forum
    Construction and Operation Program of Enterprise-Class Database Cloud Platform
    Yong Liang,Panxiang Zhang,Qiuhua Chen
    2012, 28(2):  146-155.  doi:10.3969/j.issn.1000-0801.2012.02.028
    Asbtract ( 858 )   HTML ( 22)   PDF (5001KB) ( 857 )   Knowledge map   
    Figures and Tables | References | Related Articles | Metrics

    In recent years,cloud computing is gaining more and more concern especially in telecommunication company.When telecom company searches for a low-cost,centralized,the whole network of operation method,cloud computing is the most appreciated solution.In this paper,we describe cloud computing related requirements of telecommunications business,especially in database cloud area,the architecture of database cloud,and the best practice to realize those database cloud platform and architecture.We also analysis the change of operation and maintenance the database cloud bring to us.

Copyright Information
Authorized by: China Association for Science and Technology
Sponsored by: China Institute of Communications
Posts and Telecom Press Co., Ltd.
Publisher: Beijing Xintong Media Co., Ltd.
Editor-in-Chief: Chen Shanzhi
Editorial Director: Li Caishan
Address: F2, Beiyang Chenguang Building, Shunbatiao No.1 Courtyard, Fengtai District, Beijing, China
Postal Code: 100079
Tel: 010-53879277
        010-53879278
        010-53879279
E-mail: dxkx@ptpress.com.cn
Mailing Code: 2-397
ISSN 1000-0801
CN 11-2103/TN
Visited
Total visitors:
Visitors of today:
Now online: