Cognitive Radio Technology

With the penetration of wireless communications technologies, the number of wireless subscribers has increased dramatically. Therefore, wireless bandwidth resources are becoming increasingly limited over time. How to improve the efficiency of radio resources is a pressing problem. The cognitive radio technology brings a new idea for solving this problem. Its basic idea is to make wireless terminals have the abilities of detecting 'spectrum holes' and making full use of them. This technology can be used to manage the valuable radio resources in a more flexible way, but for its practical use, some crucial technical problems still need to be solved, including spectrum detection, adaptive bandwidth allocation and spectrum management technologies.

Application of Remote Radio Head over Fiber Technology

The Remote Radio Head (RRH) over Fiber system is a new distributed network coverage mode.It processes the baseband parts concentratively by separating the baseband and Radio Frequency (RF).It moves the RF modules using fibers from the Base Stations (BSs) to the remote RF units.These RF modules are placed on the stations to be covered.This solution saves many equipment rooms required by conventional solutions.Meanwhile,it supports RRH over a large number of fibers through high-capacity macro BSs to realize the conversion between capacity and coverage.In addition,the RRH system also supports the coverage in other situations,such as high-speed railways and ultra-long distance.It is one of the most widely used technologies in the 3G network.

The Radio Technologies in City Emergency Response System

Ⅰ. WHAT’S CERSThe City Emergency Response System (CERS) is a comprehensive system that provides the emergency relief and services for the citizen through an integrated communication and IT platform. With CERS, the

Remanufacturing Closed-Loop Supply Chain Model with Radio Frequency Identification Affecting Recycling Rate

In order to construct a resource-saving and environment- friendly society, the advantages of radio frequency identification （RFID） were considered. And it put forward the idea of introducing RFID in the recycling activities of waste products. Taking into account such elements as the technical level of RFID, cost saving from remanufacturing and the cost of RFID tags, both centralized and decentralized supply chain models with different participants in waste product collection were created, in order to determine the optimal pricing strategy and RFID technical level. In the end, sensitivity analyses were conducted to analyze the impacts of scaling parameter for additional increased recovery rate with RFED on pricing and RFID technology level, and impacts of cost saving on the profits of participants in different remanufacturing closed-loop supply chain models.

Key MAC Layer Technologies of Cognitive Radio Network

As a smart spectrum sharing technology, Cognitive Radio (CR) is becoming a hot topic in the field of wireless telecommunications. Besides providing traditional services, the cognitive radio network Media Access Control (MAC) layer is required to perform an entirely new set of functions for effective reusing spectrum opportunity, without causing any harmful interference to incumbents. Spectrum sensing management selects and optimizes sensing strategies and parameters by the selection of sensing mode, sensing period, sensing time, sensing channel, and sensing quiet period. Access control avoids collision with primary users mainly by cooperation access and transparent access. Dynamic spectrum allocation optimizes the allocation of uncertain spectrum for binary interference model and accumulative interference model. Security mechanism adds authentication and encryption mechanisms to MAC frame to defense MAC layer security attacks. Cross-layer design combines MAC layer information with physical layer or higher layers information, such as network layer, transmission layer, to achieve global optimization.

Six Generation Load Cells Solution Based Congestion Management Control Purpose

Several assessing efforts are approved making both communication and information technologies available.In addition to being a part of universal access and service,we aim at assessing the impact of radio access technologies on universal access indicators.The proposed work demonstrates the possibility of inter-working of all existing Radio Access Technologies(RATs),in a limited area presented in the Six Generation Radio Resources Allocation(6 G-A)network.We propose a solution for the Vertical hand Over(VHO)in 6 G-A heterogeneous system,that adopts Media Independent Handover(MIH)protocol to benefit between different used technologies in a direct communication firstly and facilitate,in addition,coordination between congestion controlmechanisms with themobilitymanagement entity.The mathematical model has been developed to deal with locality coverage and broadband needs,based on a methodological approach consisting in integrating parameters linked to access index through radio technologies.This approach has been applied.In practice,it has contributed to highlighting its relative simplicity of implementation,but it is not enough for sixgeneration system radio access networks.The congestion control mechanism is integrated within the vertical handover process,this proposition is used to prevent each presented congestion state.The media independent handover IS equipment,as well as six G-A equipment which are both considered as the whole architecture key equipment,perform and guaranty this related process.Efficient communication is established besides information exchange between various technologies.Achieved evaluation results are performant and prove that proposed mechanisms are efficient.Both simulation and tests results are accomplished.

A Design of WCDMA RF Transceiver with Its Performance Measuring

A 2-GHz radio frequency transceiver is presented and implemented for third generation mobile communications using wide-band code division multiple access （WCDMA） scheme. Performance measuring systems are introduced for transmitter channel and receiver sensitivity, respectively. The transceiver achieves maximum output power of 22 dBm, dynamic range of 85 dB, adjacent channel power rejection ratio （ACPR） of -41dB@5MHz, and receiver sensitivity of-119.6 dBm for 128-kb/s data at 3.84-Mcps spreading rate. The measured results indicate the conformity to the required commercial 2.0-GHz WCDMA specification and 3GPP requirements.

Wireless sensing system for environmental humidity and temperature monitoring

Aiming at the actual demand for monitoring environmental information,a wireless sensing system for temperature and relative humidity(RH)monitoring based on radio frequency(RF)technology and mobile network was designed.This paper introduces the architecture of the system.The system uses AVR micro controller unit(MCU),KYL-1020U RF module and SHT71 to complete real-time temperature and humidity monitoring,and uses SIM900A module to realize remote alarming and monitoring with short message system(SMS)through global system for mobile communication(GSM).Experimental results show that the designed system has good stability of measurement and real-time performance,and it can be used in some small temperature and humidity monitoring occasions.

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.

Large Intelligent Surface/Antennas (LISA): Making Reflective Radios Smart

Large intelligent surface/antennas(LISA),a two-dimensional artificial structure with a large number of reflective-surface/antenna elements,is a promising reflective radio technology to construct programmable wireless environments in a smart way.Specifically,each element of the LISA adjusts the reflection of the incident electromagnetic waves with unnatural properties,such as negative refraction,perfect absorption,and anomalous reflection,thus the wireless environments can be software-defined according to various design objectives.In this paper,we introduce the reflective radio basics,including backscattering principles,backscatter communication,reflective relay,the fundamentals and implementations of LISA technology.Then,we present an overview of the state-of-the-art research on emerging applications of LISA-aided wireless networks.Finally,the limitations,challenges,and open issues associated with LISA for future wireless applications are discussed.

Research on robust multi-period inventory inaccuracy based on RFID technology

Inventory inaccuracy has great influence on the supply chain performance and it has attracted much attention of large numbers of researchers. This paper mainly studies the robust multi-period inventory inaccuracy problem by attaching radio frequency identification(RFID) technology. In particular, the typical retailer-supplier flexible commitment(RSFC) problem is considered to cope with the uncertain environment. After modeling, robust optimization(RO) and the affinely adjustable robust counterpart(AARC) methodology are applied to solve the model. Finally, this paper uses a numerical example for the analysis of how RFID technology can be exploited in supply chain, and the effect of demand uncertainty on the systems. The results highlight the importance of inventory availability related rates and variable uncertainty in determining the profitability of RFID adoption, which can provide managerial guidelines to supply chain firms.

A cognitive spectrum allocation scheme for data transmission in smart distribution grids

As the communication needs in the smart distribution grid continue to rise,using existing resources to meet this growing demand poses a significant challenge.This paper researches on spectrum allocation strategies utilizing cognitive radio(CR)technology.We consider a model containing strong time-sensitive and regular communication service requirements such as distribution terminal communication services,which can be seen as a user with primary data(PD)and weak time-sensitive services such as power quality monitoring,which can be seen as a user with secondary data(SD).To fit the diversity of services in smart distribution grids(SDGs),we formulate an optimization problem with two indicators,including the sum of SD transmission rates and the maximum latency of them.Then,we analyze the two convex sub-problems and utilize convex optimization methods to obtain the optimal power and frequency bandwidth allocation for the users with SD.The simulation results indicate that,when the available transmission power of SD is low,Maximization of Transmission Sum Rate(MTSR)achieves lower maximum transmit time.Conversely,when the available transmission power is high,the performance of Minimization of the Maximum Latency(MML)is better,compared with MTSR.

Stackelberg-based dynamic incentive pricing algorithm in heterogeneous ubiquitous network

A challenge in the convergence of heterogeneous networks is how to combine the ubiquitous resources and provide the diversified individual services. This paper designs a market model for aggregating reconfiguration in heterogeneous networks based on the tradeoff between resource allocation and consumers＇ requirement. To unify the benefits of operators and consumers, a novel Stackelberg-based dynamic incentive pricing algorithm is proposed. The results of the theoretical analysis and simulation demonstrate that the proposed strategy provides incentive for cooperation by means of appropriate resource allocation, and improves the utilization of network resources, thereby effectively realizing the optimization of the whole network performance.