Help from space: grant-free massive access for satellite-based IoT in the 6G era

The Sixth-Generation (6G) standard for wireless communications is expected to realize ubiquitous coverage for massive Internet of Things (IoT) networks by 2030. Satellite-based communications are recognized as a highly promising technical enabler to satisfy IoT service requirements in the 6G era. This study analyzes multiple access technologies, which are essential for the effective deployment of satellite-based IoT. First, we thoroughly investigate the existing research related to massive access, including information-theory considerations as well as Non-Orthogonal Multiple Access (NOMA) and Random Access (RA) technologies.Then, we explore the influence of the satellite transmission environment on multiple access technologies. Based on this study, a Non-orthogonal Massive Grant-Free Access (NoMaGFA) scheme, which reaps the joint benefits of RA and NOMA, is proposed for asynchronous transmissions in satellite-based IoT to achieve improved system throughput and enhance the system robustness under varying traffics. Finally, we identify some important and interesting future developments for satellite-based IoT, including waveform design, transceiver design, resource allocation, and artificial intelligence-enhanced design.     

Blockchain-based fog radio access networks: Architecture,key technologies,and challenges

Fog Radio Access Network (F-RAN) has been regarded as a promising solution to the alleviation of the ever-increasing traffic burden on current and future wireless networks, for it shifts the caching and computing resources from remote cloud to the network edge. However, it makes wireless networks more vulnerable to security attacks as well. To resolve this issue, in this article, we propose a secure yet trustless Blockchain-based F-RAN (BF-RAN), which allows a massive number of trustless devices to form a large-scale trusted cooperative network by leveraging the key features of blockchain, such as decentralization, tamper-proof, and traceability. The architecture of BF-RAN is first presented. Then, the key technologies, including access control, dynamic resource management, and network deployment are discussed. Finally, challenges and open problems in the BF-RAN are identified.     

Design for database access control mechanism based on blockchain

Aiming at the current problems of database access control,the thought of blockchain technology applied to database access control was proposed.The implementation mechanism of database access control based on blockchain was designed from several aspects as blockchain hierarchical structure,logical hierarchical structure of access control process,implementation principle of access control,consensus authentication principle of access control,and construction mechanism of access control blockchain system.The performance of database access control system based on blockchain was assessed.A complete framework was provided for blockchain applied in database access control.Through strengthening the authentication and supervision of visitor identity,access permission and access behavior,the database access control ability is improved effectively.     

A blockchain and IoT-based lightweight framework for enabling information transparency in supply chain finance

Supply Chain Finance (SCF) refers to the financial service in which banks rely on core enterprises to manage the capital flow and logistics of upstream and downstream enterprises. SCF adopts a self-testing and closed-loop credit model to control funds and risks. The key factor in a successful SCF service is the deployment of SCF business-oriented information systems that allow businesses to form partnerships efficiently and expedite cash flows throughout the supply chain. Blockchain Technology (BCT), featuring decentralization, tamper-proofing, traceability, which is usually paired with the Internet of Things (IoT) in real-world contexts, has been widely adopted in the field of finance and is perfectly positioned to facilitate innovative collaborations among participants in supply chain networks. In this paper, we propose a BCT and IoT-based information management framework (named BC4Regu), which works as the regulatory to improve the information transparency in the business process of SCF. With BC4Regu, the operation cost of the whole supply chain can be significantly reduced through the coordination and integration of capital flow, information flow, logistics and trade flow in the supply chain. The contributions in this paper include: (1) proposing a novel information management framework which leverages Blockchain and IoT to solve the problem of information asymmetry in the trade of SCF; (2) proposing the technical design of BC4Regu, including the Blockchain infrastructure, distributed ledger-based integrated data flow service, and reshaped SCF process; and (3) applying BC4Regu to a group of scenarios and conducting theoretical analysis by introducing the principal-agent model to validate the BC4Regu.     

区块链技术在物联网中应用研究

区块链技术在物联网中的应用在很大程度上缓解了数据隐私、网络安全等现象,为了拓展区块链技术的应用,需要相关人员重视技术研究.本文阐述了区块链技术概述、区块链技术在物联网中的应用、针对物联网的区块链底层技术研究以及区块链为物联网带来的诸多挑战,希望能够促进区块链技术的应用,从而创造更大的效益.     

物联网技术架构

文章基于物联网的三维概念模型,提出了一个由信息物品、自主网络和智能应用技术构成的物联网技术架构,并且分析了这3类物联网技术的特征,建议物联网研究和开发不仅需要关注信息物品的标识和传感技术,还需要关注自主网络和智能应用中的核心技术。     

IoT的数据管理与智能处理

在物联网（IoT）中物与物、人与物的智能交互的实现要依赖于数据的智能处理,而数据管理则是数据智能处理的基础。由于物联网中的数据具有异构、海量和不确定等特点,因此要实现对其数据管理与智能处理,必须在运用已有技术的基础上进一步采用新的技术和方法。文章基于物联网中数据的特点、物联网新的数据管理与智能处理技术,提出了数据空间技术、不确定数据推理技术以及云计算在物联网中的应用思路,揭示了需要研究的关键内容。     

面向大规模物联网的随机接入:现状、挑战与机遇

在传统通信系统中,随机接入是终端与网络之间建立无线链路的必经过程,只有在随机接入完成之后,终端与网络之间才能正常进行数据传输.聚焦大规模节点物联网,首先阐述了大规模物联网随机接入的基本特征,分析了传统授权随机接入(RA)方法对于大规模物联网应用的局限性;然后从系统模型、协议框架、算法流程、系统性能等多个角度,讨论免授权...     

一种基于可视化界面和物联网技术的智能用能需求侧管理平台

文章提出了一种智能的基于可视化和物联网技术的用能需求侧管理平台。平台在探索物联网在用能需求侧管理中的具体应用,搭建基于物联网与可视化界面的用能智能分析及控制环境,采集智能终端及传感器传导的用能信息的基础上,通过各种实时网络分析等高级应用软件对采集数据进行分析和处理,实现了重点耗能设备与客户或电网企业间进行实时高效的信息交互,可为客户提供全面、多维的用能管理辅助决策支持,也可为变频设备、同步调相机、无功补偿装置等设备的一体化运行提供数据支持和接入策略等优化方案。     

实验室上网控制系统WebACL的设计

分析了高校在网络化教学和考试中面临的网络访问控制和管理方面的问题,提出了一种在现有网络行为管理系统的基础上进行局域网内部精细化管理的解决方案.设计并实现了基于Web的上网控制系统WebACL,通过自动生成基于时间段的交换机ACL规则实现网络管理,并在实际管理中通过验证并取得了较好的效果.     

基于上下文学习的电力物联网接入控制方法

针对6G时代电力物联网海量终端接入冲突严重、队列积压大、能量效率低等问题,提出了一种基于上下文学习的接入控制算法。所提算法基于强化学习和快速上行链路授权技术,考虑终端活跃与休眠2种状态,优化目标为在终端接入服务质量需求的长期约束下最大化网络总能量效率。利用李雅普诺夫优化对长期优化目标与约束进行解耦,将长期优化问题转化为单时隙独立的确定性子问题,并利用基于终端状态感知的上置信界算法进行求解。仿真结果表明,所提算法能够在满足终端接入服务质量需求的同时,有效提高网络总能量效率。相较于传统快速上行链路授权算法,所提算法可提高平均能量效率48.11%,提高满足接入服务质量需求的终端比例54.95%,降低平均队列积压83.83%。     

Blockchain-Based Reliable Fog-Cloud Service Solution for I IoT

Industrial Internet of things (IIoT) deploys a large number of smart devices to obtain industrial data, which will be transmitted to cloud for analysis to improve industrial productivity. The management of large-scale devices is complicated, and it's also a challenge to choose a high-quality cloud service for data analysis as the number of service with similar functions increases. To address these issues, we propose a reliable fog-cloud service solution with blockchain-based fog-cloud architecture. In fog layer, we build a management blockchain between fog servers and design a management method for industrial devices; In cloud layer, we construct a service blockchain between cloud service providers to form an open"service market". Quality of service and reputation based matching algorithm and reputation-based consensus algorithm are designed. The simulation results show correctness and efficiency of algorithms, and validate effectiveness of our proposed solution.     

物联网统一接入研究

结合物联网发展趋势,针对现有物联网存在的问题,提出物联网统一接入的系统架构,实现物联网系统跨网络、跨运营商、跨国际的接入能力。     

Secure and reliable computation offloading in blockchain-assisted cyber-physical IoT systems

With the development of the Cyber-Physical Internet of Things System (CPIoTS), the number of Cyber-Physical System (CPS) applications accessed in networks has increased dramatically. Latency-sensitive resource orchestration in CPS applications is extraordinarily essential for maintaining the Quality of Experience (QoE) for users. Although edge-cloud computing performs effectively in achieving latency-aware resource allocation in CPIoTS, existing methods fail to jointly consider the security and reliability requirements, thereby increasing the process latency of tasks and degrading the QoE of users. This paper aims to minimize the system latency of edge-cloud computing coupled with CPS while simultaneously considering the security and reliability requirements. We first consider a time-varying channel model as a Finite-State Markov Channel (FSMC) and propose a distributed blockchain-assisted CPIoTS to realize secure consensus and reliable resource orchestration by offloading computation tasks in edge-cloud computing. Moreover, we propose an efficient resource allocation algorithm, PPO-SRRA, that optimizes computing offloading and multi-dimension resource (e.g., communication, computation, and consensus resource) allocation by using a policy-based Deep Reinforcement Learning (DRL) method. The experimental results show that the proposed resource allocation scheme can reduce the system latency and ensure consensus security.     

移动无线互联网接入中视频编码率控制策略

建立了用于移动无线互联网接入的视频编码转换模型,提出了自适应运动矢量估值方法.将编码转换码率控制分为图像层控制和宏块层两级,首先在总体上对每帧图像的编码比特数进行预分配,然后采用小波变换系数来表征图像特征,为帧内不同特征的宏块选用不同的量化因子,提出了一种新的码率控制策略.模拟实验表明:该方法在视频图像质量没有明显失真的前提下,提高了视频编码转换速度;编码转换输出码流和编码转换缓冲区占用量较稳定,重建图像的信噪比得到了明显的改善.     

我国物联网应用市场思考与发展建议

物联网可以广泛应用到经济运行、基础设施、社会生活、军事国防等各个领域,通过对物理实体和自然资源的感知、识别、分析、处理和控制,大大提升生产生活和社会管理与服务的智能水平。通过分析我国物联网应用市场的现状和特点,提出促进物联网应用发展的策略和建议。     

物联网安全研究

物联网是计算机、互联网与移动通信网等相关技术的演进和延伸,其安全问题愈来愈受到关注。该文对物联网安全进行深入研究,对其体系结构进行分析,并将其应用模型抽象为“物、网、应用”;将其安全需求概括为“谁家的物归谁管,谁家的物归谁用”。该文将“物”抽象为四类,即感知类物、被感知类物、被控制类物及感知和被控制类物,并针对每一类“物”的应用提出了具体的解决方案,同时也提出了“网”与“应用”的安全解决方案。     

Research advances on blockchain-as-a-service: architectures,applications and challenges

Due to the complexity of blockchain technology, it usually costs too much effort to build, maintain and monitor a blockchain system that supports a targeted application. To this end, the emerging “Blockchain as a Service” (BaaS) makes the blockchain and distributed ledgers more accessible, particularly for businesses, by reducing costs and overheads. BaaS combines the high computing power of cloud computing, the pervasiveness of IoT and the decentralization of blockchain, allowing people to build their own applications while ensuring the transparency and openness of the system. This paper surveys the research outputs of both academia and industry. First, it introduces the representative architectures of BaaS systems and then summarizes the research contributions of BaaS from the technologies for service provision, roles, container and virtualization, interfaces, customization and evaluation. The typical applications of BaaS in both academic and practical domains are also introduced. At present, the research on the blockchain is abundant, but research on BaaS is still in its infancy. Six challenges of BaaS are concluded in this paper for further study directions.     

新型的使用访问控制模型

对传统访问控制模型进行了扩展，提出了一种新的访问控制模型——使用控制模型UCON(usage control)。这种模型包含授权、证书和条件组成成分，能解决作为访问结果而对主体客体属性进行更新的问题，以及在访问过程中对访问权限延续和即时回收的问题。同时对该模型的核心模型进行了形式化描述和定义。     

IoT/CPS的安全体系结构及关键技术

物联网（IoT）和信息物理融合系统（CPS）作为下一代网络的核心技术,被业界广泛关注。与传统网络不同,IoT/CPS异构融合、协同自治、开放互连的网络特性带来了巨大的系统安全方面的挑战。挑战包括安全协议的无缝衔接、用户隐私保护等。研发新的安全模型、关键安全技术和方法是IoT/CPS发展中的重点。文章基于IoT/CPS安全需求和威胁模型,提出了一种层次化的安全体系结构,并针对隐私保护、跨网认证和安全控制等IoT/CPS的关键安全技术展开讨论。