Locomotion trajectory with cooperative metrics in wireless sensor networks

Detection coverage control is one of the most important topics in the intrusion detection problem of wireless sensor networks (WSN). However, its converse, i.e., to design an object locomotion trajectory in WSN, has not received enough attention. This article proposes a heuristic algorithm, namely, the security & speed (SS) algorithm, to depict such a trajectory that takes into consideration both security and speed. The merit of the SS algorithm is its topology independency. When compared with traditional algorithms, the SS algorithm approaches the optimal trajectory better, and enjoys considerably lower computational load, and a better and adjustable tradeoff between trajectory security and speed.     

无线网状网络的安全性：挑战和解决方案

Wireless mesh network is a new emerging field with its potential applications in extremely unpredictable and dynamic environments. However, it is particularly vulnerable due to its features of open medium, dynamic changing topology, cooperative routing algorithms. The article surveys the state of the art in security for wireless mesh networks. Firstly, we analyze various possible threats to security in wireless mesh networks. Secondly, we introduce some representative solutions to these threats, including solutions to the problems of key management, secure network routing, and intrusion detection. We also provide a comparison and discussion of their respective merits and drawbacks, and propose some improvements for these drawbacks. Finally, we also discuss the remaining challenges in the area.     

RFID in the Air Industry and Land Transport

As the RFID business grows strongly from $2.8 billion in 2006 to $26 billion in 2016, transport will be taking its fair share. Indeed, RFID in civil air transport alone will rise from $42 million in 2006 to $667 million in 2016, a major component being baggage tagging systems and tags at $20 million in 2006 rising to $100 million in 2016. Here a seminal decision was the unanimous vote of IATA, in     

Multi-branch query tree protocol for solving RFID tag collision problem

The technology of anti-collision is a key point in radio frequency identification （RFID） system. To avoid data collision, there are two approaches： ALOHA based algorithm and binary tree （BT） based algorithm. However, these cannot solve the collision problem completely, especially when the tag quantity is big and the tag ID is long. In this article, we present a multi-branch query tree （MBQT） protocol based on balanced incomplete block design （BIBD） code, and use 16-bit vectors derived from the BIBD as query prefix symbols of RFID reader. Compared with the conventional anti-collision algorithm, the theoretic analysis and simulation show that the proposed protocol improves the identification efficiency.     

An Overview of Anti-Collision Protocols for Radio Frequency Identification Devices

Radio frequency identification （RFID） is a new type of non-contact automatic identification technology. Due to its low energy consumption, low cost, and its adaptability to harsh environments, it has been applied to many fields. In the RFID systems, data collision is inevitable when the reader sends a communication request and multiple tags respond with simultaneous data transmission. Data collision is prone to causing problems such as： identification delay, spectrum resource waste, a decreased system throughput rate, etc. Therefore, an efficient, stable anti-collision protocol is crucial for RFID systems. This research analysed the current research into RFID anticollision protocols and summarised means for its improvement through the mechanism of implementation of different types anticollision protocols. Finally, a new direction is proposed for the future development of RFID anti-collision protocol systems.     

Novel error resilient tag estimation for RFID system in interference scenarios

In a radio frequency identification （RFID） system, the backscattered signal is small and prone to interference. The performance of RFID tag identification in interference scenarios is degraded compared to that in error-free scenarios. In this paper, a novel Mahalanobis distance estimate （MDE） method is proposed to jointly estimate the number of tags and packet error rate （PER）. The MDE method is error resilient owing to its ability to achieve a stable estimation when interference is impairing the observed information. The proposed method achieves significantly enhanced accuracy over existing methods by taking all the information and correlations among the observed results into account. The MDE method improves the estimate performance based on efficient decorrelation and classification of the observed information. Moreover, the performance of the PER estimate is analyzed both in theory and through simulations. It can be concluded from the analysis that the estimated PER is unbiased and variance-bounded. Simulations show that the proposed estimate outperforms the previous proposals in terms of accuracy and stability, which makes it suitable for application in interference scenarios.     

Clustering and multi-hop routing with power control in wireless sensor networks

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%.     

一种用于RFID读写器的高集成CMOS功率放大器的设计与分析

To implement a fully-integrated on-chip CMOS power amplifier（PA） for RFID readers,the resonant frequency of each matching network is derived in detail.The highlight of the design is the adoption of a bonding wire as the output-stage inductor.Compared with the on-chip inductors in a CMOS process,the merit of the bondwire inductor is its high quality factor,leading to a higher output power and efficiency.The disadvantage of the bondwire inductor is that it is hard to control.A highly integrated class-E PA is implemented with 0.18-μm CMOS process.It can provide a maximum output power of 20 dBm and a 1 dB output power of 14.5 dBm.The maximum power-added efficiency（PAE） is 32.1%.Also,the spectral performance of the PA is analyzed for the specified RFID protocol.     

Visible light optical coherence tomography in biomedical imaging

Optical coherence tomography (OCT) is a widely used optical imaging modality for three-dimensional structural and functional imaging. The prevalent OCT systems use an invisible light laser source beyond 800 nm and up to 1 500 nm to allow deep image penetration in biological tissues. Recently, visible light OCT (vis-OCT) using a short wavelength range between 400 nm to 700 nm has gained significant progress and attracted interest in its unique capability of high resolution imaging and spatially-resolved spectroscopy. In this article, we will briefly review the recent advance of vis-OCT imaging and its potential biomedical applications.     

Enhanced solutions for resource conflict in GMPLS controlled optical network

This article discusses the issue of resource conflict in the generalized multi-protocol label switching （GMPLS） controlled optical network. Based on the analysis of the current random rebuilding mechanism and its drawbacks, this article presents two enhanced solutions for improvement, namely, the priority-based resource allocation mechanism and the network management system （NMS） based sequential resource allocation mechanism. Experimental results show that the presented mechanisms perform better than the original random rebuilding solution in terms of the connection setup/recovery time and successful rate.     

CPK-based grid authentication:a step forward

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.     

Pilot power based rate control in CDMA 2000 1x EV-DO Rev-A

This article proposes a new algorithm to improve the rate control efficiency of enhanced reverse link medium access control （RLMAC） in the code division multiple access （CDMA） 1x EV-DO release A（Rev. A） system. The new algorithm brings reverse access terminal （AT） pilot power to the RLMAC rate control procedure and makes it easier for a low pilot power user to increase its data rate when the system is slightly loaded and harder to decrease its date rate when the system is heavily loaded. Numerical results of system level simulations show that the new algorithm can bring higher system throughput, lower AT transmission power, and lower system load.     

Compressed sensing based multi-rate sub-Nyquist sampling system

Signal sampling is a vital component in modern information technology. As the signal bandwidth becomes wider, the sampling rate of analog-to-digital conversion(ADC) based on Shannon-Nyquist theorem is more and more high and may be beyond its capacity. However the analog to information converter(AIC) based on compressed sensing(CS) is designed to sample the analog signals at a sub-Nyquist sampling rate. A new multi-rate sub-Nyquist sampling(MSS) system was proposed in this article, it has one mixer, one integrator and several parallel ADCs with different sampling rates. Simulation shows the signals can be reconstructed in high probability even though the sampling rate is much lower than the Nyquist sampling rate.     

An ultra-low-power area-efficient non-volatile memory in a 0.18 μ m single-poly CMOS process for passive RFID tags

This paper presents an ultra-low-power area-efficient non-volatile memory(NVM) in a 0.18μm singlepoly standard CMOS process for passive radio frequency identification(RFID) tags.In the memory cell,a novel low-power operation method is proposed to realize bi-directional Fowler-Nordheim tunneling during write operation. Furthermore,the cell is designed with PMOS transistors and coupling capacitors to minimize its area.In order to improve its reliability,the cell consists of double floating gates to store the data,and the 1 kbit NVM was implemented in a 0.18μm single-poly standard CMOS process.The area of the memory cell and 1 kbit memory array is 96μm~2 and 0.12 mm~2,respectively.The measured results indicate that the program/erase voltage ranges from 5 to 6 V.The power consumption of the read/write operation is 0.19μW/0.69μW at a read/write rate of (268 kb/s)/(3.0 kb/s).     

RFID＇s Impacts on Business Value： A Case Study of Supply Chain in the Discrete Manufacturing Industry

Radio frequency identification （RFID） shall be a revolutionary technological innovation in recent years. Various solutions employing RFID technology have proved their functionality already in such industries as pharmaceuticals, express parcel carrying, and automotive manufacturing, and the increased efficiency and effectiveness has provided a good payback for the investments. But, up to now, fewer researches concentrate on applying REID to heavy-machinery manufacturing enterprises, which are a typical kind of enterprises in discrete manufacturing industry. The main objective of this case study is to extend our understanding of the potential for RFID to delivery of the heavy-machinery manufacturing enterprise, which involves one specific supply chain. A trial to automate the verification activities of delivery is designed and performed. Results show that the stops currently designed into the processes can be eliminated by employing RFID technology and that RFID should be a revolutionary technology as it redesigns the existing processes, eliminate some current inefficiency, improve the accuracy of delivering the products, increases information sharing between supply chain members.     

Research and Development of New Broadband Wireless Access System

Broadband Wireless Access (BWA) has become one of the major evolution trends in the fields of broadband access and mobile communications. However,some difficulties emerged during the application and industrialization of the BWA system,which calls for typical service models,key technology innovations and backbone support from broadband Internet. This article introduces a Broadband Wireless Multimedia (BWM) access system. It aims to build a new-type "triple play" BWA network by integrating terrestrial digital TV system and the BWA system,and by taking broadband Internet as its core network platform. A primary research shows that the new BWA system is an effective solution to the existing difficulties of BWA system. Moreover,it is quite competitive in service provision,service coverage,frequency planning,terminal power consumption and cost for network construction.     

Simulation of structural design with high coupling efficiency in external cavity semiconductor laser

For external cavity semiconductor lasers(ECSLs),high coupling efficiency is critical to reducing the linewidth.In this paper,the coupling efficiency between the laser diode and the waveguide grating has been improved,with proposals for its improvement presented,including adding spot-size conversion(SSC)and using a silicon-on-insulator(SOI)waveguide.The results indicate an increase of coupling efficiency from 41.5%to 93.1%,which exhibits an improvement of approximately 51.6%over conventional schemes.The relationship between coupling efficiency and SOI waveguide structures is mainly concerned in this article.These findings provide a new way for the future research of the narrow linewidth of ECSL.     

Thought on the RFID Technology Development in China

In China,RFID technology has been applied to some extents,and also has a huge market and development margin. During this progress,the government will help to build up the basic information construction,then to make the basic informa- tion resource open,at the same time to avoid the policy management over-commercialized,and push RFID technology applica- tion forward and speed up its development.     

Organizational Behavior Research in Transition Time of China

The article is to introduce author's research results in recent years in the field of leadership behavior. The main researches conducted in this field include competency model of senior executives in communication industry and family firms; transformational leadership and its relationship with leadership effectiveness, the impact of supervisor's feedback on employees' behavior and the cross-culture study of supervisor's feedback. Theoretical and practical contributions of these researches are explained. Directions for future research are discussed.     

China Unicom's Experience in Network Evolution towards NGN

The article introduces China Unicom's valuable experience obtained in theconstruction and operation of its IP-based data and fixed services network.In the construction of the network,China Unicom aimed at the quickdeployment of telecom-level integrated services by building up multi-levelmetropolitan area networks and access networks;in the operation of thenetwork,China Unicorn made great efforts with equipment manufactures,software developers and system integration providers and achieved stableand improved network performance.