Design and Implementation of a Novel HomePlug-Based Solution for Low Cost and High Performance Smart Home Networking

As the smart home is the end-point power consumer, it is the major part to be controlled in a smart micro grid. There are so many challenges for implementing a smart home system in which the most important ones are the cost and simplicity of the implementation method. It is clear that the major share of the total cost is referred to the internal controlling system network; although there are too many methods proposed but still there is not any satisfying method at the consumers’ point of view. In this paper, a novel solution for this demand is proposed, which not only minimizes the implementation cost, but also provides a high level of reliability and simplicity of operation; feasibility, extendibility, and flexibility are other leading properties of the design.     

Home Energy Management System Using NILM and Low-Cost HAN

Home energy management systems (HEMs) are used to provide comfortable life for consumers as well as to save energy. An essential component of HEMs is a home area network (HAN) that is used to remotely control the electric devices at homes and buildings. Although HAN prices have dropped in recent years but they are still expensive enough to prohibit a mass scale deployment. In this paper, a very low cost alternative to the expensive HANs is presented. We have applied a combination of non-intrusive load monitoring (NILM) and very low cost one-way HAN to develop a HEM. By using NILM and machine learning algorithms we find the status of devices and their energy consumption from a central meter and communicate with devices through the one-way HAN. The evaluations show that the proposed machine learning algorithm for NILM achieves up to 99% accuracy in certain cases. On the other hand our radio frequency (RF)-based one-way HAN achieves a range of 80 feet in all settings.     

无线数字家庭网络泛在接入技术

数字家庭网络是通信领域的一个重要分支，近年来发展非常迅速。基于电信网络的数字家庭网络体系结构在中国已经标准化，但就接入方式而言，只是定义了可以使用无线方式，如何组建无线数字家庭网络是未来研究的重点。文章提出了无线数字家庭网络泛在接入概念，给出了无线泛在接入网络体系结构，并就其中的关键技术进行了探讨，包括感知无线电、无线网状网（Mesh）网络理论、通用接入点链路转换机制、业务的QoS保障机制以及电磁兼容和异构系统共存机制等。     

Automatic Recognition Algorithm of AM Signals Based on Spectrum and Modulation Characters

To meet the actual requirement of automatic monitoring of the shortwave signals under wide band ranges, a technique for automatic recognition is studied in this paper. And basing upon the spectrum and modulation characters of amplitude modulation （AM） signals, an automatic recognition scheme for AM signals is proposed. The proposed scheme is achieved by a joint judgment with four different characteristic parameters. Experiment results indicate that the proposed scheme can effectively recognize AM signals in practice.     

Top-K Query Framework in Wireless Sensor Networks for Smart Grid

The smart grid has caught great attentions in recent years, which is poised to transform a centralized, producer-controlled network to a decentralized, consumer- interactive network that＇s supported by fine-grained monitoring. Large-scale WSNs （Wireless Sensor Networks） have been considered one of the very promising technologies to support the implementation of smart grid. WSNs are applied in almost every aspect of smart grid, including power generation, power transmission, power distribution, power utilization and power dispatch, and the data query processing of ＇WSNs in power grid＇ become an hotspot issue due to the amount of data of power grid is very large and the requirement of response time is very high. To meet the demands, top-k query processing is a good choice, which performs the cooperative query by aggregating the database objects＇ degree of match for each different query predicate and returning the best k matching objects. In this paper, a framework that can effectively apply top-k query to wireless sensor network in smart grid is proposed, which is based on the cluster-topology sensor network. In the new method, local indices are used to optimize the necessary query routing and process intermediate results inside the cluster to cut down the data traffic, and the hierarchical join query is executed based on the local results.Besides, top-k query results are verified by the clean-up process, and two schemes are taken to deal with the problem of node＇s dynamicity, which further reduce communication cost. Case studies and experimental results show that our algorithm has outperformed the current existing one with higher quality results and better efficiently.     

Study of Intrusion Detection Systems

Modern network systems have much trouble in security vulnerabilities such as buffer overflow, bugs in Microsoft Internet, sensor network routing protocol too simple, security flaws of applications, and operating systems. Moreover, wireless devices such as smart phones, personal digital assistants （PDAs）, and sensors have become economically feasible because of technological advances in wireless communication and manufacturing of small and low-cost sensors. There are typologies of vulnerabilities to be exploited in these devices. In order to improve securities, many mechanisms are adopted, including authentication, cryptography, access control, and intrusion detection systems （IDS）. In general, intrusion detection techniques can be categorized into two groups： misuse detection and anomaly detection. The misuse detection systems use patterns of weB-known attacks or weak spots of the systems to identify intrusions. The weakness of misuse detection systems is unable to detect any future （unknown） intrusion until corresponding attack signatures are intruded into the signature database. Anomaly detection methods try to determine whether the deviation is from the established normal usage patterns or not. The critical success of anomaly detection relies on the model of normal behaviors.     

基于近距离无线技术的家电集中控制方法

家用电器的网络化是家庭网络化的基础,也是智能家电技术发展的必然趋势。文章以无线射频收发芯片作为家电控制网络底层实体传输媒介,构建了集中式家电近距离无线控制网络星型拓扑结构,并以室内温湿度信息为控制对象,设计了近距离无线收发模块、网关PC无线通信接口板等软硬件模块,并自定义了串口通信协议,改进了CRC-16冗余算法,完成了家电无线控制网中的温湿度集中监控及Internet接入试验,验证了基于近距离无线技术的家电集中控制方法的可行性、易用性。     

Interference Coordination for Secrecy Enhancement in Random Wireless Networks

The co-channel interference modeling is vital for evaluating the secrecy performance in random wireless networks,where the legitimate nodes and eavesdroppers are randomly distributed.In this paper,a new interference model is proposed from the userdominant perspective.The model can provide a better analytical assessment of secrecy performance with interference coordination for the presence of eavesdroppers.The typical legitimate is assumed to be located at the origin,and chooses the closest base station（BS） as its serving BS.The field of interferers is obtained by excluding the desired BSs（including the serving BS and its cooperative BS（s））.In contract with the exiting interference model,it is assumed that desired BSs and interferers belong to the same Poisson Point Process（PPP）,and eavesdroppers are distributed according to another independent PPP.Based on this model,the average secrecy transmission capacity is derived in simply analytical forms with interference coordination.Analysis and simulation results show that the secrecy performance can be significantly enhanced by exploiting interference coordination.Furthermore,the average secrecy transmission capacity increases with increasing number of cooperative BSs.     

基于GPRS远程家电控制系统的设计与实现

介绍以各种家用电器作为被控对象,结合近距离及远程无线通信技术,构成远程家电控制系统。居室内是一个小型无线网络,家电控制器作为网络中的节点,通过与无线遥控器进行命令/状态信息的交换,实现室内家电状态的无线控制;选择一家电控制器连接GPRS模块,使其作为客户端,以便访问远程PC机,实现信息与命令的交互。此系统可帮助人们有效的安排时间,节约各种能源,使家居生活更加简便舒适。     

An Energy Balancing Adaptive Routing Strategy Based on Interference Model in 6LoWPANs

IPv6-enabled low-power wireless personal area network （6LoWPAN） is an important part of the Internet of Things which will drastically transform the way our society functions. Designing an efficient routing strategy is crucial for optimizing traffic over 6LoWPAN resources and extending the network lifetime. This paper proposes an energy balancing adaptive routing strategy named EBAR. Considering the dynamic traffic and constrained energy in 6LoWPAN, EBAR adaptively updates paths between different source-destination pairs and balances the energy in 6LoWPAN. Simulation results indicate that EBAR can promote network performance and balance the energy in the network.     

Traffic Characteristics Based Dynamic Radio Resource Management in Heterogeneous Wireless Networks

The traffic with tidal phenomenon in Heterogeneous Wireless Networks （HWNs） has radically increased the complexity of radio resource management and its performance analysis. In this paper, a Simplified Dynamic Hierarchy Resource Management （SDHRM） algorithm exploiting the resources dynami- cally and intelligently is proposed with the consideration of tidal traffic. In network-level resource allocation, the proposed algorithm first adopts wavelet neural network to forecast the traffic of each sub-area and then allocates the resources to those sub-areas to maximise the network utility. In connection-level net- work selection, based on the above resource allocation and the pre-defined QoS require- ment, three typical network selection policies are provided to assign traffic flow to the most appropriate network. Furthermore, based on multidimensional Markov model, we analyse the performance of SDHRM in HWNs with heavy tailed traffic. Numerical results show that our theoretical values coincide with the simulation results and the SDHRM can im- prove the resource utilization.     

物联网引领智能家居进入应用时代

将家电通过无线网络联系起来的系统就是智能家居系统,其不仅能为人类提供一个更为舒适和安全的家居环境,而且还能减少生活能源的浪费.本文概述了智能家居这一理念,并对智能家居系统今后的发展进行了展望.     

Optimal Cooperative Inactive Secondary Sensing Order Using Users in Cognitive Radio Networks

A novel cooperative spectrum sensing or- der which utilizes inactive Secondary users （SUs） efficiently based on maximum throughput has been proposed in Cog- nitive radio networks （CRNs）. In order to predict the states of Primary users （PUs）, we build the PU＇s traffic pattern as a Continuous-time Markov chain （CTMC） pro- cess. CRNs obtain the maximum throughput while SUs sense the licensed channels with the optimal order. The numerical simulation results show that the proposed or- der based on spectrum sensing scheme can achieve larger channel utilization and lower sensing overhead as compared with the spectrum sensing scheme without using the opti- mal order sensing. After considering the report overhead of SUs, the optimal number of inactive SUs for the maxi- mum throughput can be found.     

Self-Organization Approaches for Optimization in Cognitive Radio Networks

Cognitive radio （CR） is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access techniques. However, cognitive radio networks （CRNs） may also impose some challenges due to the ever increasing complexity of network architecture, the increasing complexity with configuration and management of large-scale networks, fluctuating nature of the available spectrum, diverse Quality-of-Service （QoS） requirements of various applications, and the intensifying difficulties of centralized control, etc. Spectrum management functions with self-organization features can be used to address these challenges and realize this new network paradigm. In this paper, fundamentals of CR, including spectrum sensing, spectrum management, spectrum mobility and spectrum sharing, have been surveyed, with their paradigms of self-organization being emphasized. Variant aspects of self- organization paradigms in CRNs, including critical functionalities of Media Access Control （MAC）- and network-layer operations, are surveyed and compared. Furthermore, new directions and open problems in CRNs are also identified in this survey.     

家庭交互控制网络中手持交互设备的功能设计

以家庭网络为背景,从家庭网络的概念及逻辑结构入手,提出了家庭交互控制网络的概念,分析并比较了家庭交互控制网络中分散交互控制方式和集中交互控制方式两种网络参考模型,并基于集中交互控制网络参考模型提出了一种用于改善人机交互界面、并能隔离不同设备交互逻辑的家用无线手持交互设备的功能设计方案,给出了详细的功能分析、人机接口设计及系统功能结构设计,最后对家用手持交互设备与集成家电控制功能的手机之间的关系进行了简要的分析.     

Time Agility Optimization for Dual-stage Collaborative Spectrum Sensing

Cooperative spectrum sensing has been shown to be an effective method to mitigate the impact of hidden terminal and shadow fading in cognitive radio networks. Currently most works focused on either coop- erative sensing or sensing scheduling as a viable means to improve the detection performance without studying their interactions. This paper proposed a dynamic and variable time-division multiple-access scheduling mechanism that was incorporated into a Dual-stage collaborative spectrum sensing （DCSS） model in a less ideal radio environment. Moreover, this paper derived closed-form expressions of sensing time for DCSS, and addressed the critical range of timeslot length. An optimized algorithm to minimize sens- ing time was deduced and verified. The simulation results indicate that average sensing time with DCSS is shortened by 11.5~V0 when compared with that of the Single collabora- tive spectrum sensing （SCSS） while guaranteeing detection error rate requirement of less than 1%.     

Optimal and Suboptimal Access and Transmission Polices for Dynamic Spectrum Access over Fading Channels in Cognitive Radio Networks

We propose a cross-layer optimal access and transmission framework for dynamic spectrum access to maximize expected long-term average throughput under power and collision constraints by a dynamic programming method namely Constrained Markov decision process （CMDP）. The optimal policy for CMDP is capable of guiding transmitter to choose an available channel and transmission rate at the beginning of each frame for its long-term goals according to current channel sensing results and prior channel fading information. The complexity of finding the optimal policy by Linear programming （LP） approach increases exponentially with the number of channels and fading levels, which incurs so-called curse of dimensionality. Therefore we propose two complexity- reduced suboptimal policies, namely, policy separation and heuristic algorithms. Finally, we compare the performances of policies by numerical results.     

Optimal Spectrum Sensing in Energy Harvesting Cognitive Radio Systems

In this paper,we consider a cognitive radio system with energy harvesting,in which the secondary user operates in a saving-sensing-transmitting（SST） fashion.We investigate the tradeoff between energy harvesting,channel sensing and data transmission and focus on the optimal SST structure to maximize the SU＇s expected achievable throughput.We consider imperfect knowledge of energy harvesting rate,which cannot be exactly known and only its statistical information is available.By formulating the problem of expected achievable throughput optimization as a mixed-integer non-linear programming one,we derive the optimal saveratio and number of sensed channels with indepth analysis.Simulation results show that the optimal SST structure outperforms random one and performance gain can be enhanced by increasing the SU＇s energy harvesting rate.     

Variable Persistence Sensing Schemes for Opportunistic Spectrum Access

Cognition technologies can significantly enhance spectrum utilization through secondary usage. Secondary users （SUs） search for spectrum holes which are not used by Primary users （PUs） and communicate through them. The design and analysis of simple opportunistic spectrum access schemes for maximizing utilization efficiency and minimizing delay of SUs under limited sensing bandwidth and energy is still at infancy. In this work, we consider PU＇s frequency occupancy patterns and propose three simple variable persistence sensing schemes for maximum exploitation of idle spectrum chunks by SUs, and perform their theoretical analysis. Numerical case studies are presented to verify the theoretical analysis and illustrate the performance of the schemes proposed.