全球物联网发展及中国物联网建设若干思考

 本文首先对物联网的概念及内涵进行分析,并从"物联感知"角度统一了对物联网各类概念的理解;综述了全球物联网发展现状,包括美国,欧盟,日本和中国对物联网发展的战略规划和应用概况;然后详细探讨了当前物联网发展的若干关键技术,主要包括标识技术、体系架构、网络通信、搜索发现、数据处理、安全隐私、标准化和管理,并指出其中尚需研究的问题;最后从国家、企业和学术层面对我国物联网建设提出了若干建议,为中国物联网的发展和研究提供参考.     

物联网感知层低能耗时间同步方法研究

针对物联网感知层对时间同步的需求及节点能量有限的特点,提出一种低能耗时间同步(Low EnergyConsumption Time Synchronization,LECTS)的方法,从同步消息量、同步周期和占空比角度研究同步能耗的降低.对网络进行父子群的划分,为每个群选择PS(Pairwise Synchronization)节点,群内节点持续同步,群间节点按需同步;父节点和PS节点间以同步周期和占空比双向交换N次同步消息,群内其他节点侦听同步消息,基于参数抵消的联合极大似然法估计子节点与父节点间的相位偏移和频率偏移,将群内子节点同步到父节点;在给定同步精度下,汇聚节点定期评估网络同步误差,由时间同步控制器调整网络同步周期和占空比.仿真结果表明LECTS算法在保证同步精度的同时,降低了同步能耗、提高了网络的生存周期.     

AI技术在卫星通信/互联网领域的应用综述

卫星互联网的诞生带来新的发展机遇，同时也具备诸多挑战。主要调研了在空天地一体化的背景下，人工智能（AI）技术作为重要的辅助工具在卫星通信/卫星互联网领域的应用，涉及通信抗干扰、通信路由、星地网络系统架构、星座运营与管理等场景，其中涉及的AI算法包括传统机器学习、深度学习、强化学习等；最后，针对AI技术在卫星通信/互联网领域的发展趋势，提出了未来的研究方向，为我国卫星领域的智能化发展提供了思路和技术方案。     

Robust techniques for signal processing: A survey

In recent years there has been much interest in robustness issues in general and in robust signal processing schemes in particular. Robust schemes are useful in situations where imprecise a priori knowledge of input characteristics makes the sensitivity of performance to deviations from assumed conditions an important factor in the design of good signal processing schemes. In this survey we discuss the minimax approach for the design of robust methods for signal processing. This has proven to be a very useful approach because it leads to constructive procedures for designing robust schemes. Our emphasis is on the contributions which have been made in robust signal processing, although key results of other robust statistical procedures are also considered. Most of the results we survey have been obtained in the past fifteen years, although some interesting earlier ideas for minimax signal processing are also mentioned. This survey is organized into five main parts, which deal separately with robust linear filters for signal estimation, robust linear filters for signal detection and related applications, nonlinear methods for robust signal detection, nonlinear methods for robust estimation, and robust data quantization. The interrelationships among many of these results are also discussed in the survey.     

A survey of 5G technologies: regulatory,standardization and industrial perspectives

In recent years, there have been significant developments in the research on 5th Generation (5G) networks. Several enabling technologies are being explored for the 5G mobile system era. The aim is to evolve a cellular network that is intrinsically flexible and remarkably pushes forward the limits of legacy mobile systems across all dimensions of performance metrics. All the stakeholders, such as regulatory bodies, standardization authorities, industrial fora, mobile operators and vendors, must work in unison to bring 5G to fruition. In this paper, we aggregate the 5G-related information coming from the various stakeholders, in order to i) have a comprehensive overview of 5G and ii) to provide a survey of the envisioned 5G technologies; their development thus far from the perspective of those stakeholders will open up new frontiers of services and applications for next-generation wireless networks.     

基于PKI的电子商务安全中间件技术

信息安全技术在电子商务中备受到重视,作为基础软件的中间件技术,在信息安全中发挥着越来越大的作用。本文首先讨论了电子商务的安全需求,简要介绍了电子商务中采用的安全中间件, 详细分析了目前安全中间件中的关键技术。最后,对采用PKI的安全中间件技术做了进一步分析研究。     

无源物联网：背景、概念、挑战及研究进展

近年来,随着物联网(IoT)部署范围不断扩大,数以千亿计的智能设备将接入物联网,对网络接入能力、能量供应、成本等提出了极大挑战,无源物联网呼之欲出。该文梳理了无源物联网相关概念并给出其定义,首次系统研究了无源物联网面临的能量密度低、转化效率低、后向散射通信距离有限、能量信息同时传输兼顾难等4大挑战,详细分析了问题原因并对研究进展进行综述：针对能量密度低挑战,从波束成形、能量收集天线设计、智能反射表面3个方面综述;针对能量转换效率低挑战,从接收机架构优化、波形设计、阻抗匹配优化、整流器优化4个方面综述;针对后向散射通信距离有限挑战,从新的调制方式、频移型后向散射新机制、MIMO增强、新的信道编码机制、新的信号检测方法、智能反射表面增强以及半有源模式7个方面综述;针对能量信息同时传输兼顾难问题,从能量信息同时传输架构优化、能量信息兼容信道编码2个方面综述。针对每个优化方向,对比分析了各类方法的优劣并指出了未来研究方向。     

A state-of-the-art survey on wireless rechargeable sensor networks: perspectives and challenges

Wireless Networks - Wireless rechargeable sensor network (WRSN) is an emerging technology that has risen intending to enhance network lifetime of the conventional wireless sensor networks (WSNs)....     

A survey on communication protocols and performance evaluations for Internet of Things

The Internet of Things (IoT) is a large-scale network of devices capable of sensing, data processing, and communicating with each other through different communication protocols. In today's technology ecosystem, IoT interacts with many application areas such as smart city, smart building, security, traffic, remote monitoring, health, energy, disaster, agriculture, industry. The IoT network in these scenarios comprises tiny devices, gateways, and cloud platforms. An IoT network is able to keep these fundamental components in transmission under many conditions with lightweight communication protocols taking into account the limited hardware features (memory, processor, energy, etc.) of tiny devices. These lightweight communication protocols affect the network traffic, reliability, bandwidth, and energy consumption of the IoT application. Therefore, determining the most proper communication protocol for application developers emerges as an important engineering problem. This paper presents a straightforward overview of the lightweight communication protocols, technological advancements in application layer for the IoT ecosystem. The survey then analyzes various recent lightweight communication protocols and reviews their strengths and limitations. In addition, the paper explains the experimental comparison of Constrained Applications Protocol (CoAP), Message Queuing Telemetry (MQTT), and WebSocket protocols, more convenient for tiny IoT devices. Finally, we discuss future research directions of communication protocols for IoT.     

Strategies and techniques for node placement in wireless sensor networks: A survey

The major challenge in designing wireless sensor networks (WSNs) is the support of the functional, such as data latency, and the non-functional, such as data integrity, requirements while coping with the computation, energy and communication constraints. Careful node placement can be a very effective optimization means for achieving the desired design goals. In this paper, we report on the current state of the research on optimized node placement in WSNs. We highlight the issues, identify the various objectives and enumerate the different models and formulations. We categorize the placement strategies into static and dynamic depending on whether the optimization is performed at the time of deployment or while the network is operational, respectively. We further classify the published techniques based on the role that the node plays in the network and the primary performance objective considered. The paper also highlights open problems in this area of research.     

A Review on the Security of the Internet of Things: Challenges and Solutions

The Internet of Things (IoT) has emerged as a modern wave of Internet technologies that promises great transformation of life in areas such as smart health, smart cities, smart homes, intelligent transport, amongst others. However, security often serves as a critical reason for the widespread adoption of any innovation. While the IoT has increased business productivity and enriched diverse areas of life over the years, the world is yet to see a methodical revolution of its humongous application and transformation given its ubiquity and highly interconnected global network structure. The main culprit for such lapses is principally attributed to security and privacy issues which have been widely discussed in research articles and reviews but remain largely unaddressed in the literature. Hence, this paper provides a state-of-the-art review of IoT security and its challenges. It overviews technical and legal solutions that are useful to private, organizational, and governmental enterprises. The study encompasses the review and security analysis of IoT’s evolution and revolution, IoT security assessments, requirements, current research challenges in security and much more. Consequently, it offers potential solutions to address the security challenges discussed and further present open research issues, research gaps, opportunities, future development, and recommendations. This overview is intended to serve as a knowledgebase that will proffer novel foresight to guide users and administrators in positioning themselves and their organizations in a manner that is consistent with their overall objectives, mission, and vision for remarkable outcomes. Likewise, interested scholars and researchers can explore topics and directions from the study in providing better solutions to the numerous problems in IoT security.

     

FPGA-based implementation of classification techniques: A survey

Recently, a number of classification techniques have been introduced. However, processing large dataset in a reasonable time has become a major challenge. This made classification task more complex and expensive in calculation. Thus, the need for solutions to overcome these constraints such as field programmable gate arrays (FPGAs). In this paper, we give an overview of the various classification techniques. Then, we present the existing FPGA based implementation of these classification methods. After that, we investigate the confronted challenges and the optimizations strategies. Finally, we highlight the hardware accelerator architectures and tools for hardware design suggested to improve the FPGA implementation of classification methods.     

A survey of analytical techniques for cross-section estimation

To serve as a general introduction to the theoretical papers immediately following, the analytical techniques available for estimating the backscattering cross section of a metal target are reviewed. These are classified according to the dimension-to-wavelength ranges for which they are appropriate, and an attempt is made to interpret them in the light of the scattering processes involved. Some examples are discussed.     

A survey of optimization techniques for integrated-circuit design

We survey contemporary optimization techniques and relate these to optimization problems which arise in the design of integrated circuits. Theory, algorithms and programs are reviewed, and an assessment is made of the impact optimization has had and will have on integrated-circuit design. Integrated circuits are characterized by complex tradeoffs between multiple nonlinear objectives with multiple nonlinear and sometimes nonconvex constraints. Function and gradient evaluations require the solution of very large sets of nonlinear differential equations, consequently they are inaccurate and extremely expensive. Furthermore, the partmeters to be optimized are subject to inherent statistical fluctuations. We focus on those multiobjective constrained optimization techniques which are appropriate to this environment.     

A survey of data multicast techniques, architectures, andalgorithms

This article presents a survey of architectures, techniques, and algorithms for multicasting data in communication switching networks. We start with a broadcast architecture using a separate copy network and a routing network. A few versions of this idea using Delta and Benes networks exist. Another multicast architecture is a recycling network where internal nodes act as relay points, accept packets from the switching fabric, and recycle them back into the fabric after relabeling the packets. Next, we give an overview of a system that uses the Boolean splitting multicast algorithm. In this system a nonblocking self routing broadcast banyan copy network has been proposed. The network consists of several components including a running adder network to generate running sums of copy numbers specified in the headers of input packets. We then describe a multicasting technique presented for a different class of switching networks called deflection-routing networks. Finally, the idea of extending a nonblocking network to a three-dimensional structure consisting of multiple parallel planes is also presented. At the end of this article, we compare the efficiencies of the presented multicast architectures     

Data-centric approaches in the Internet of Vehicles: A systematic review on techniques,open issues,and future directions

The Internet of Vehicles (IoV) is an emerging network of connected vehicles as a branch of dynamic objects in the Internet of Things (IoT) ecosystem. With the rapid development of IoV, real-time data-centric applications would be a significant concern in academia and industry to promote efficiency and realize modern services in such high dynamic networks. In this paper, we aim to present a systematic literature review (SLR) for the IoV networks to investigate the different attitudes in the field of data-centric approaches. This paper systematically categorizes the 48 recent articles on data-driven techniques in the IoV field published from 2017 to March 2022. A complete technical taxonomy is presented for the data-centric approaches in IoV according to the content of current studies. Collected methods are chosen with the SLR process, and they are investigated considering some technical classifications including IoV security, data traffic, vehicular social network, data propagation, energy, and multimedia categories. The achievements, drawbacks, and new findings of studies are carefully investigated for addressing the deficiencies, as well as emphasizing future research direction and open issues of data-driven approaches in IoV.     

Challenges and research directions for Internet of Things

The emergence of Internet of Things (IoT) is empowered by the availability of the high volume of smart sensors, Radio Frequency Identification, a suitable communication technologies and protocols. In the near future, the Internet will be full of heterogeneous connected devices. In recent years, the IoT has drawn significant attention as it can solve difficult problems. However, the heterogeneity of devices and the large scale networks expose the IoT to many challenges that must be addressed; otherwise, the systems performance will deteriorate. As an attempt to identify these challenges, this paper comprehensibly cites the main IoT concepts, the serious IoT challenges and the quality of services presented in the recent literature. It also investigates the corresponding main research directions and the proposed solutions. This paper can increase the knowledge of the reader since it is the first IoT survey that presents load balancing algorithms utilized in solving the extreme data storage challenge.     

A survey on deployment techniques,localization algorithms,and research challenges for underwater acoustic sensor networks

In recent years, wireless sensor networks (WSNs) have attracted the attention of both the research community and the industry, and this has eventually lead to the widespread use of WSNs in various applications. The significant advancements in WSNs and the advantages brought by WSNs have also enabled the rapid development of underwater acoustic sensor networks (UASNs). In UASNs, in addition to deployment, determining the locations of underwater sensor nodes after they have been deployed is important since it plays a critical role in many applications. Various localization techniques have been proposed for UASNs, and each one is suitable for specific scenarios and has unique challenges. In this paper, after presenting an overview of potential UASN applications, a survey of the deployment techniques and localization algorithms for UASNs has been presented based on their major advantages and disadvantages. Finally, research challenges and open research issues of UASNs have been discussed to provide an insight into future research opportunities.     

Interoperability in Internet of Things: Taxonomies and Open Challenges

Mobile Networks and Applications - In the last few years, many smart objects found in the physical world are interconnected and communicate through the existing internet infrastructure which...     

A survey of design techniques for system-level dynamic powermanagement

Dynamic power management (DPM) is a design methodology for dynamically reconfiguring systems to provide the requested services and performance levels with a minimum number of active components or a minimum load on such components. DPM encompasses a set of techniques that achieves energy-efficient computation by selectively turning off (or reducing the performance of) system components when they are idle (or partially unexploited). In this paper, we survey several approaches to system-level dynamic power management. We first describe how systems employ power-manageable components and how the use of dynamic reconfiguration can impact the overall power consumption. We then analyze DPM implementation issues in electronic systems, and we survey recent initiatives in standardizing the hardware/software interface to enable software-controlled power management of hardware components