Journal of Beijing University of Posts and Telecommunications

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- 2002, Vol. 25 No. 3 Published date:10 September 2002 Last issue Next issue
- Some Research Issues for Beyond 3G Mobile Systems
- ZHANG Ping
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 1-6.
- Abstract ( 277 ) HTML 　　
- The developing tendency of mobile communication in detail is analysed, and some key research issues related to the Beyond 3G mobile systems are described briefly. Some research achievements regarding these topicsare mentioned in WTI(wireless technology innovation) labs. Disscussions for theprediction of the next generation mobile systems are given.
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- Cooperative Adjusted RED for Two-Color Markers
- WANG Qian, LONG Ke-ping, CHENG Shi-duan,LE Hui-hua, ZHANG Run-tong
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 7-11.
- Abstract ( 207 ) HTML 　　
- A new implementation mechanism of RED, cooperative adjusted RED (CARED), is presented. It cooperates with two color marker to guarantee the fairness between different service classes in diffserv network. The mainidea of this scheme is to obtain the quantitative relationship between theactual rate and the committed service rate, on the basis of the marking probability of two color markers, and then adjust the dropping probability of CARED according to this relationship. To implement CARED in diffserv network, a marking probability metering algorithm NSWM is also proposed. Lots of simulations have proved the efficiency of CARED.
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- A New Visual Cryptography Algorithm to Hide a Two-ColorImagein a Single Shared Image
- XIA Guang-sheng, YUAN Zhong-lan, YANG Yi-xian, HU Zheng-ming
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 12-16.
- Abstract ( 211 ) HTML 　　
- A new visual cryptography algorithm to hide a two-color image in a single shared image is proposed. In order to make it easy to decode the secret in visual cryptography scheme, a new low-precision one is proposed.
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- Capacity Gain of Mobile Network Using Adaptive QoS Service
- ZHAO Peng, ZHANG Hui-min
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 17-21.
- Abstract ( 225 ) HTML 　　
- Adaptive QoS service in mobile network can improve the system capacity by decreasing its source rate when the network is busy. This merit is especially important when broadband services are provided. A new parameter P_D is defined to approximately describe the QoS of adaptive service, and the cell capacity with adaptive service is analyzed using a M/M/m(m) queuing model. The trade-off relationship between the QoS of adaptive serviceand call block ratio, system capacity, system efficiency is illustrated. The numeric result shows that using adaptive QoS service, the capacity and efficiencycan be effectively improved and the call block ratio can be largely reduced.Key words mobile communication networks; quality of service; adaptive QoS service
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- A Method to Depress Aliasing for Multirate Filter Banks
- LI Xue-bin, LIU Ze-min
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 22-26.
- Abstract ( 268 ) HTML 　　
- An aliasing component counteracting scheme for uniform maximally decimated filter banks by setting proper relations between analysisfilters and synthesis filtes is proposed. Theoretical analysis shows that the aliasing at interface frequencies can be canceled completely. If the frequency characters of adjacent filters is symmetrical nearly, the total aliasing may be small. Experimental results show the effectivity.
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- Study on the Micro Electronic Lottery Payment
- LI Ming-zhu, LI Zhi-jiang, YANG Yi-xian
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 27-30.
- Abstract ( 246 ) HTML 　　
- On the basis of micropayment of electronic lottery, an effective solution to win of micro electronic lottery is designed, which effectively solves the problem in the application of micropayment of electronic lottery.
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- New Test Platform for BSC Software System
- LUO Hong
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 31-35.
- Abstract ( 298 ) HTML 　　
- Considering the feature architecture of BSC in CDMA2000 system, a new software test platform is proposed. This platform is based on the general Ethernet environment. It can test the BSC software system independent of the under-test system's hardware equipment. A scripting language-Tcl is used in the test system. Tcl is a programming language more advanced than C/C++. Itcan execute more machine instructions for each language statement, so it is easy to programming and maintenance. This allows applications to be created more rapidly and managed more easily.
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- Study and Implementation of the Algorithm on Auto-Creating the Logical Diagrams of Telecommunication Facilities
- GENG Fang-ping, SUN Hai-wen, ZHU Xiang-hua
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 36-40.
- Abstract ( 218 ) HTML 　　
- The relationship between the telecommunication facilities is presented by the logical diagrams. Based on the mathematical model,an algorithm on auto-creating logical diagrams is put forward and discussed in details.Theoutput diagrams not only present logical relationship between the telecommunicaton facilities but also retain the real distribution of them in the geographic space. Finally, an example is given.
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- Test Flow Technology of CORBA Based Network Management Interface Conformance Testing
- RUI Lan-lan, MENG Luo-ming, QIU Xue-song,LEI You-xun, QI Feng
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 41-45.
- Abstract ( 251 ) HTML 　　
- Based on the test case organizing policy of communication protocol entity defined in OSI communication protocol conformance testing methodology, a test flow technology of CORBA based network management interface conformance testing is introduced, and a description about test flow control language is given. A design frame for implementing the test flow system is also involved.
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- Discussion on Fractal in Lightning
- DONG Ji-ping, GAO You-gang
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 46-49.
- Abstract ( 272 ) HTML 　　
- Application of fractal geometry in lightning and concerned methods are introduced. A fractal model for lightning is put forward and some corresponding relations between planar and three-dimensions are discussed according to the section agreement.
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- Analysis of RLP Performance over Wireless Fading Channel
- JI Hong, LUO Tao, DENG Jian-min, YUE Guang-xin
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 50-54.
- Abstract ( 246 ) HTML 　　
- Considering the packets loss caused by burst errors over wireless fading channel, RLP performance is analyzed using the first-order two-state Markov model. The formula to calculate the RLP throughput efficiency is also deduced while the maximal numbers of allowed retransmission is limited. Results show that when FER is small, the RLP throughput efficiency hardly decrease as the retransmission numbers increasing, and when FER is large, there exists a “floor effect” in RLP throughput efficiency for Go-Back-N. Further study shows that the RLP throughput efficiency decreases when the numbers of allowed retransmission increase, meanwhile the residual FER, which is reported to TCPby RLP, is reduced.
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- Improvement and Implementation of Matched Filter for Primary Synchronous Channel in WCDMA System
- ZHU Chun-mei, NIU Kai, WU Wei-ling
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 55-59.
- Abstract ( 244 ) HTML 　　
- A novel two-dimension concatenate matched filter isproposed according to the frame structure of primary synchronous channel and the feature of PSC. We simulate this architecture. Moreover, FPGA chip design is accomplished. It is verified that this matched filter can reduce thehardware resource and improve the operation speed.
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- Wavelet and Its Hilbert Transform Based Multi-Carrier CDMA
- LI Wei-hua, ZHAO Ya-hong, WU Wei-ling
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 60-63.
- Abstract ( 225 ) HTML 　　
- Three novel MC-CDMA systems, using wavelet and its Hilbert transform for multi-carrier CDMA,were presented. Such systems are basedon that Hilbert transform of a wavelet is orthogonal to its time shifts and itis also orthogonal to the corresponding wavelet and its translation. We investigated the advantages and performance of the system by the comparison with the conventional MC-CDMA system. In the AWGN channel, the systems possess the same BERas the MC/BPSK-CDMA and MC/QPSK-CDMA system, double the bit rate without increasing the bandwidth than the conventional MC-CDMA system.
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- Polarization Mode Dispersion Effect in DenselyDispersion-Managed Soliton Systems
- ZHANG Fan, YE Pei-da
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 64-67.
- Abstract ( 302 ) HTML 　　
- Polarization mode dispersion (PMD) effect in denselydispersion-managed soliton (DDMS) systems is studied by numerical simulations.For DDMS with map strength S＞4, the larger the dispersion section number, the larger the map depth, which corresponds to large power enhancement factor compared with conventional solitons and strong nonlinear trap to enhance the tolerance the DDM solitons to PMD. For S＜2, DDMS systems with different map depthexhibit the same PMD robustness since different section number corresponds to the same power enhancement factor. Moreover, the same tolerance is proved in lossand lossless systems.
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- Research on the Depth Distribution of Linear Code
- ZHANG Zhen-tao, YANG Yi-xian, HU Zheng-ming, NIU Xin-xin
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 68-72.
- Abstract ( 196 ) HTML 　　
- The work of T.Etzion and Y.Luo, et al are summarized, and different proof of their main results from the definition of depth of codeword and its elementary property is given. Meanwhile, some discussions about the application foreground of depth distribution are given.
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- Study on a Standard for Media Gateway Control
- ZHANG Hui-yuan, YANG Fang-chun, ZHAN Shu-bo
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 73-77.
- Abstract ( 276 ) HTML 　　
- The protocols used between elements of a physically decomposed VoIP gateway are discussed. The content and some advantages of Megaco/H.248 are analyzed and the improvements are proposed.
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- Performance Analysis of EF Service under DiffServ Architecture
- HU Ying-feng, WANG Chong-gang, CHENG Shi-duan
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 78-82.
- Abstract ( 224 ) HTML 　　
- The diffServ's ability to provide EF service and theinfluence that EF service put on AF service is studied. Through simulation and corresponding analysis, the EF performance under diffServ and its influence degree to AF services were obtained.
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- The Mobile IP Handoff between Hybrid Networks
- YE Min-hua, ZHANG Hui-min, LIU Yu
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 83-87.
- Abstract ( 217 ) HTML 　　
- The trends of wireless data networks and two main technologies GPRS and IEEE 802.11 WLAN are introduced. It also introduces the scheme to support mobility in these two networks and analyzes the Mobile IP handoffbetween the hybrid networks. A new handoff scheme is proposed to reduce the handoff delay, packet loss and to prevent the ping-pong effect utilizing the dwelltimer and multi-tunnel technology.
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- Study of Access Control Algorithm in Hierachical Storage VOD Systems
- RONG Bo, SUN Jing-ao, CAI An-ni
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 88-92.
- Abstract ( 238 ) HTML 　　
- As the core of VOD system, video servers need a largestorage capacity. Therefore, a hierachical storage structure is inevitable. Asa result, it's an urgent problem to find a suitable access control algorithm forVOD system based on hierachical storage structure. In this thesis, an unfair access control algorithm based cost factor is discussed. The computer simulation of the performance of this algorithm is shown, and satisfied results are achieved.
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- Image Watermarking Based on Second-Generation Wavelet Transform
- YUAN Chao-wei, WANG Tao-rong
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 93-97.
- Abstract ( 228 ) HTML 　　
- We combines the advantages of second-generation wavelet transform and the traditional image watermarking method using wavelet multiresolution transform, proposing a scheme of images watermarking based on second-generation wavelet transform. The scheme has the advantage of simple implementation with a DSP; only a smaller memory is needed. The simulation result shows that our scheme keeps the advantage of the traditional one with a higher speed andno particular requiments for image size.
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- The Designs for the 3GPP Authentication and Key Generation Functions
- YAO Hui-ming, SUI Ai-fen, YANG Yi-xian
- Journal of Beijing University of Posts and Telecommunications. 2002, 25(3): 98-103.
- Abstract ( 243 ) HTML 　　
- The requirement for the 3GPP authentication and key generation functions is analysed. The two designs given by 3GPP TSG SA S3 is summarized. A new design about the structure and specific inner algorithm is given.Besides the same and different points about efficiency and security among thesedesigns are compared.
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