HUANG Ping; TIAN Hui; ZHANG Ming;ZHANG Ping
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0001-05
摘要 ( 2456 ) PDF (315 KB)( 450 )
Wireless sensor networks are being widely researched and are expected to be used in several scenarios. On the leading edge of treads, on-demand, high-reliability, and low-latency routing protocol is desirable for indoor environment applications. This article proposes a routing scheme called robust multi-path routing that establishes and uses multiple node-disjoint routes. Providing multiple routes helps to reduce the route recovery process and control the message overhead. The performance comparison of this protocol with dynamic source routing (DSR) by OPNET simulations shows that this protocol is able to achieve a remarkable improvement in the packet delivery ratio and average end-to-end delay.
XIAO Xiao;ZHENG Bao-yu; YAN Zhen-ya; CHEN Chao
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885(2007) 01-0006-06
摘要 ( 2624 ) PDF (309 KB)( 497 )
The design of media access control (MAC) protocol for wireless sensor networks (WSNs) with the idea of cross layer attracts more and more attention. People can improve the MAC protocol by obtaining certain information regarding the network layer and physical layer. This article synthesizes and optimizes certain cross-layer protocols which have existed. On the basis of the routing, topology information in the network layer, and transmission power information in the physical layer, the time slot assignment algorithm has been improved in the MAC layer. By using geographical adaptive fidelity algorithm (GAF) to divide the grids, controlling of transmission power and scheduling the work/sleep duty cycle for sensor nodes, a new MAC protocol has been proposed to decrease energy consumption and enlarge the lifetime of WSNs. Simulation results show that the MAC protocol functions well.
GUO Li; GUO Yan; LIN Jia-ru; LI Ning
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0012-04
摘要 ( 2374 ) PDF (249 KB)( 436 )
A novel sequential Monte Carlo (SMC) algorithm is provided for the multiple maneuvering Ad-hoc network terminals direction of arrival (DOA) tracking. A nonlinear mobility and observation model is adopted, which can describe the motion features of the Ad-hoc network terminal more practically. The algorithm does not need any additional measurement equipment. Simulation result shows its significant tracking accuracy.
ZHAO Xian-jing, ZHENG Bao-yu, CHEN Chao
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0016-06
摘要 ( 2431 ) PDF (260 KB)( 404 )
A novel weighted cooperative routing algorithm (WCRA) is proposed in this article, which was on the basis of a weighted metric with maximal remaining energy (MRE) of the relays and the maximal received SNR (MRS) of the nodes. Moreover, a cooperative routing protocol was implemented on the basis of WCRA. Then simulation is done on network simulation (NS-2) platform to compare the performances of MRS, MRE and WCRA with that of noncooperative destination-sequenced destination-sequenced distance-vector (DSDV) protocol. The simulative results show that WCRA obtains a performance tradeoff between MRE and MRS in terms of delivery ratio and network lifetime, which can effectively improve the network lifetime at an acceptable loss of delivery ratio.
XIE Sheng-dong, WU Meng
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0022-04
摘要 ( 2400 ) PDF (212 KB)( 463 )
The integration of cellular network (CN) and wireless local area network (WLAN) is the trend of the next generation mobile communication systems, and nodes will handoff between the two kinds of networks. The received signal strength (RSS) is the dominant factor considered when handoff occurs. In order to improve the handoff efficiency, this study proposes an adaptive decision algorithm for vertical handoff on the basis of fast Fourier transform (FFT). The algorithm makes handoff decision after analyzing the signal strength fluctuation which is caused by slow fading through FFT. Simulations show that the algorithm reduces the number of handoff by 35%, shortens the areas influenced by slow fading, and enables the nodes to make full use of WLAN in communication compared with traditional algorithms.
WANG Hai-yan; WANG Ru-chuan
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0026-06
摘要 ( 2776 ) PDF (242 KB)( 662 )
Effective grid authentication plays a critical role in grid security, which has been recognized as a key issue in the designing and extension of grid technologies. At present, public key infrastructure (PKI) has been widely applied for grid authentication, and this article proposes a novel grid authentication mechanism, which is based on combined public key (CPK) employing elliptic curve cryptography (ECC). The designing structure of the new grid authentication mechanism and its implementation procedure are described in details. Property analysis of the new mechanism is also made in comparison with that of the globus security infrastructure (GSI) authentication, which leads to the conclusion that CPK-based grid authentication, may be applied as an optimized approach towards efficient and effective grid authentication.
ZHANG Li-he, KONG Xiang-wei, YANG Cheng
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0032-07
摘要 ( 3501 ) PDF (243 KB)( 542 )
At present, most mobile terminals do not have any functions of rights management, and the cryptology-based method cannot resolve all the copyright problems in the mobile digital distribution service. With the urgent demand of digital rights management in digital distribution service, a scheme independent of terminals is proposed in this article. It integrates the watermark and signature techniques. In this article the scheme theory, architecture, service process, and performance are mainly discussed. In the end, the functional relationship between the proposed digital rights management (DRM) and the cryptology-based open mobile alliance digital rights management (OMA-DRM) is given. The analysis shows that the scheme is feasible and secure.
ZHANG Deng-yin, WANG Qian-qian, XU Jian
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0039-06
摘要 ( 3118 ) PDF (203 KB)( 451 )
On the basis of various firewall-penetrated technologies, a novel firewall-penetrated technology based on trusted host, which can realize the communication between penetrating host and protected host, is proposed in this paper. Meanwhile, the firewall-penetrated evaluating model and its formalized statement is also proposed by quantizing penetrated level, penetrated quality, and penetrated hiding. Finally, the firewall-penetrated technology based on trusted host is analyzed under the firewall-penetrated evaluating model, and the experimental results show that this technology has obvious penetrating effect and high penetrating quality.
CHEN Shuai, ZHONG Xian-xin
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0045-04
摘要 ( 2527 ) PDF (200 KB)( 475 )
A pseudo-random sequence generator is a basic tool for cryptography. To realize a pseudo-random sequence generator, a new block iterating method using shifter, multiplier, and adder operations has been introduced. By increasing the iteration of the counter and by performing calculations based on the initial value, an approximate pseudo-random sequence was obtained after exchanging bits. The algorithm and the complexity of the generator were introduced. The result obtained from the calculation shows that the self-correlation of the “m” block sequence is two-valued; the block field value is [0, ], and the block period is .
GUO Shu-jie, ZHENG Jie, QU Yu-gui, ZHAO Bao-hua, PAN Quan-ke
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0049-09
摘要 ( 3294 ) PDF (418 KB)( 520 )
Clustering routing protocols excel in several aspects of wireless sensor networks (WSNs). This article proposes a clustering and multihop routing protocol (CMRP). In CMRP, a node independently makes its decision to compete for becoming a cluster head or join a cluster, according to its residual energy and average broadcast power of all its neighbors. To minimize the power consumption of the cluster head, CMRP sends the data in a power-aware multihop manner to the base station (BS) through a quasi-fixed route (QFR). In addition, CMRP presents a transmission power control algorithm with dynamic intercluster neighbor position estimation (DCNPE) to save energy. Simulation results show that the performance of CMRP is better than the hybrid, energy-efficient, distributed clustering approach (HEED). In the best case, CMRP increases the sensor network lifetime by 150.2%.
FAN Li-min, LIAO Jian-xin
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0058-03
摘要 ( 3008 ) PDF (135 KB)( 508 )
Using the idea of Payword, the new concept of master-slave payword chain (MSPC) is proposed in this article. MSPC consists of one master payword chain and one slave payword chain. On the basis of MSPC, a new micropayment protocol called discrete micropayment protocol (DMP), is presented in this article. DMP consists of three sub-protocols: registration, payment, and settlement. Both part fairness and non-unit-wise payment can be provided by DMP.
WEN Dan-hui, CHEN Rong-bang, LU Ting-jie
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0061-04
摘要 ( 2257 ) PDF (239 KB)( 385 )
This article analyses on why China Mobile and China Unicom have chosen price war rather than tacit collusion these years. On the basis of the analysis on factors that influence tacit collusion, and combined with the facts of wireless communication market, the author suggests that the market asymmetries, cost asymmetries, and product differentiation are the basic factors, which trigger price competition between the Chinese wireless operators. By constructing a game model based on Churn rate, this article discusses how these factors cause a fight between the operators and how vigorous the price competition will be. At last, the author suggests that to keep vigor in this industry, continuous structural adjustment is essential. Besides, the number portability policies may cause tacit collusion.
LI Li, LIU Yuan-an, TANG Bi-hua
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0065-06
摘要 ( 3191 ) PDF (322 KB)( 489 )
With the development of city road networks, the question of how to obtain information about the roads is becoming more and more important. In this article, sensor network with mobile station (SNMS), a novel two-tiered intelligent transportation system (ITS) network architecture based on wireless sensor network (WSN) and peer-to-peer (P2P) network, is proposed to provide significant traffic information about the road and thereby, assist travelers to take optimum decisions when they are driving. A detailed explanation with regard to the strategy of each level as well as the design of two main components in the network, sensor unit (SU) and mobile station (MS), is presented. Finally, a representative scenario is described to display the operation of the system.
XU Ning, YANG Geng
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0071-06
摘要 ( 2362 ) PDF (307 KB)( 371 )
We propose a finite element method to investigate the phenomena of shock wave and to simulate the hydrodynamic model in semiconductor devices . An introduction of this model is discussed first. Then some scaling factors and a relationship between the changing variables are discussed. And then, we use a finite element method (P1-iso-P2 element) to discrete the equations. Some boundary conditions are also discussed. Finally, a sub-micron n+-n-n+ silicon diode and Si MESFET device are simulated and the results are analyzed. Numerical results show that electronic fluids are transonic under some conditions.
YU Guo-yi, ZOU Xue-cheng, CHEN Wei-bing
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0077-03
摘要 ( 2966 ) PDF (272 KB)( 458 )
A new gate dielectric material HfTiON is deposited by reactive co-sputtering of Hf and Ti targets in N2/O2 ambient, followed by annealing in N2 at 600 ℃ and 800 ℃ respectively for 2 min. Capacitance-voltage and gate-leakage properties are characterized and compared for different anneal conditions. The results indicate that the sample annealed at 800 ℃ exhibits lower interface-state and oxide-charge densities, and better device reliability. This is attributed to the fact that the rapid thermal annealing at the higher temperature of 800 ℃ can effectively remove the damage-induced precipitation, forming a hardened dielectric/Si interface with high reliability.
ZHANG Hong-xin, LU Ying-hua, ZHANG Jin-ling
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0080-05
摘要 ( 2293 ) PDF (296 KB)( 413 )
Hierarchical clustering algorithms, such as Pearson’s correlation, Euclidean distance, Euclidean distance harmonic, Spearman rank correlation, Kendall’s tau, and City-block distance, were used to find the best way to establish theoretical MAPK/Erk signaling pathway on the basis of breast cancer line MCF-7 gene expressions. The algorithm constructs a hierarchy from top to bottom on the basis of a self-organizing tree. It dynamically finds the number of clusters at each level. It was found that only Euclidean distance harmonic is fit for the analysis of the cascade composed from a RAF1 (c-Raf), a MKNK1, a MAPKK (MEK1/2) to MAPK (Erk) in breast cancer line MCF-7. The result is consistent with the biological experimental MAP/Erk signaling pathway, and the theoretical MAPK/Erk signaling pathway on breast cancer line MCF-7 is set up.
YING Na, ZHAO Xiao-hui, DONG Jing
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0085-05
摘要 ( 2329 ) PDF (380 KB)( 540 )
Unvoiced/voiced classification of speech is a challenging problem especially under conditions of low signal-to-noise ratio or the non-white-stationary noise environment. To solve this problem, an algorithm for speech classification, and a technique for the estimation of pairwise magnitude frequency in voiced speech are proposed. By using third order spectrum of speech signal to remove noise, in this algorithm the least spectrum difference to get refined pitch and the max harmonic number is given. And this algorithm utilizes spectral envelope to estimate signal-to-noise ratio of speech harmonics. Speech classification, voicing probability, and harmonic parameters of the voiced frame can be obtained. Simulation results indicate that the proposed algorithm, under complicated background noise, especially Gaussian noise, can effectively classify speech in high accuracy for voicing probability and the voiced parameters.
ZOU Ting, DENG Gang, WANG Ying, ZHANG Ping
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0090-06
摘要 ( 2811 ) PDF (300 KB)( 421 )
This article proposes a dynamic subcarrier and power allocation algorithm for multicell orthogonal frequency division multiple access (OFDMA) downlink system, based on inter-cell interference (ICI) mitigation. Different from other ICI mitigation schemes, which pay little attention to power allocation in the system, the proposed algorithm assigns channels to each user, based on proportional-fair (PF) scheduling and ICI coordination, whereas allocating power is based on link gain distribution and the loading bit based on adaptive modulation and coding (AMC) in base transceiver station (BTS). Simulation results show that the algorithm yields better performance for data services under fast fading.
JIANG Feng, SONG Mei, GUO Da, SONG Jun-de
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0096-04
摘要 ( 2404 ) PDF (220 KB)( 484 )
The article presents a novel orthogonal frequency division multiplexing (OFDM) frame synchronization method. The method uses the preamble that contains two identical halves, and the energy difference of the two similar parts of the received preamble in receiver is used to obtain the frame’s correct starting point. Furthermore, an improvement of the proposed method is presented, which uses the preamble that can be divided into four similar portions, and the energy difference of the four similar parts of the received preamble in receiver is used to obtain the frame’s correct starting point. The performances of the frame synchronization methods in multipath channel are compared in terms of mean square error (MSE) obtained by simulations. It can be seen from the simulation results that the proposed methods have better performances than Schmidl’s, Minn’s, and Park’s method in multipath channel.
LIU Zhi-qing, DOU Qing
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0100-06
摘要 ( 2328 ) PDF (175 KB)( 466 )
Computer programs of GO are typically constructed using a knowledge-based approach with heuristics and pattern matching because of enormous complexities of the game. In this approach, quantity, quality, and consistency of patterns used in computer programs of GO to a large extent determine the strengths of the programs. This study presents an effective method to acquire automatically comprehensive GO patterns from large collections of game records. Statistical usages of the patterns ensure consistency and quality of the patterns, which in turn can help improve the strengths of computer GO programs. Additionally, statistical usages of patterns from different sources of game records clearly show subtle and significant discrepancies among various types of GO players, and clarify certain myths in the playing of GO.
GAN Zong-liang, ZHU Xiu-chang
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0106-05
摘要 ( 2348 ) PDF (366 KB)( 416 )
In this study, a low complexity frame-rate up conversion method using compressed domain information for H.264 decoder is proposed. In the proposed scheme, the motion vectors (MVs) are estimated using constant acceleration motion model, and the MVs regarded as no credibility are corrected, and the interpolation method is applied on the basis of the macroblock (MB) coded types. Applied to the H.264 decoder, the proposed method provides high quality interpolation frames and an obvious decrease of the block artifacts.
YANG Yu-yong, JIA Huai-jing
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0111-04
摘要 ( 2465 ) PDF (232 KB)( 405 )
This article used panel data and the Stochastic frontier analysis (SFA) model to analyze and compare the technical efficiencies of the telecommunication industry in 28 Asian countries from 1994 to 2003. In conclusion, the technical efficiencies of the Asian countries were found to steadily increase in the past decade. The high-income countries have the highest technical efficiency; however, income is not the only factor that affects the technical efficiency.
DU Chong-dong, LI Su-man
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0115-07
摘要 ( 2282 ) PDF (380 KB)( 423 )
This article analyzes interest-rate risks faced by the postal savings bureau (PSB) based on the complete balance sheet. It presents the extended gap model and the extended duration gap model to measure the interest-rate risk, and discusses the inner balance-sheet strategies and the off-balance-sheet strategies to manage the interest-rate risks.
ZHANG Ai-hua, ZHAO Lian-qiang, SHU Hua-ying
中国邮电高校学报(英文版), 2007, 14 (1). doi： 1005-8885 (2007) 01-0122-07
摘要 ( 2221 ) PDF (246 KB)( 385 )
This essay analyzes the data of Chinese telecommuni- cation market, telecommunication investments and investment benefits over the past 20 years. On the basis of these data, the essay reviews Chinese changing telecommunication policies and discusses the major events in the course of China’s telecommunication development. It is argued that telecommunication policies, regime backgrounds and market demand characteristics have a significant impact on investment decision mode in telecommunication industry. The evolution of network investments decision mode in China’s telecommunication has corresponded to the transformation of these key factors. Considering the special events in the development of Chinese telecommunication as divisions, the essay discusses three stages of the evolution of investments decision mode in China’s telecommunication. With the firm environment and problems that Chinese telecommunication operators have been facing since 2000 analyzed. it is demonstrated that Chinese telecommunication operators should change their mode of investment decision into the “profit-oriented investment decision mode” in order to achieve a high growth performance in the capital market,. This investment decision mode will result in increase of the investment profit with limited investment capital. The main procedure of profit-oriented investment decision mode is set out, which is abstracted to a mathematical model eventually.