无线传感器网络的分布扩散时钟自同步协议研究

针对大规模无线传感器网络同步协议的精度较低、可扩展性差的问题,提出一种分布式扩散时钟自同步协议(DDCSS);DDCSS是一个局部、并行执行的协议,基于分布式扩散的思想,以节点能量、分布和平均传输时延为依据,每轮动态地选取执行局部扩散的一组主节点和扩散节点,把主节点域内的节点平均时钟扩散有限的跳数,周围节点以接收的所有主节点域平均时钟取平均更新本地时钟,采用互扩散的方法使节点时钟近似同步到网络节点的平均时钟上,从而实现全网的时间同步;与RBS、TPSN协议相比较,该协议收敛速度较快,另外消除了误差累积,同步误差较低,扩展性较好。     

物联网环境下Web数据库异常数据检测方法研究

物联网环境下web数据库网络承载着不同的网络载体和网络信道,web数据库通过云储存的形式来实现资源共享,云储存产生的异常数据会给网络信息web数据库空间带来一种危机感和存储数据容量空间的不足,所以对物联网环境下web数据库异常数据的检测要求更精准。传统的异常数据检测方法采用简化梯度方法进行web数据库异常数据检测,对含有干扰频率成份的web异常数据不能准确的去除,检测性能低。为此,提出一种基于时空关联的分布式的web数据库异常数据检测方法,通过与集中式算法的精度和消耗量进行对比,仿真实验表明,所提方法进行异常数据检测,减少了web数据的能量消耗,信号幅值大于干扰噪声数据幅值,具有较好的抗干扰性能。     

基于改进蚁群算法的LEACH协议研究

针对LEACH协议在数据传输阶段,簇首与汇聚节点之间采用单跳模式传输数据使得能量消耗快并且不均衡的问题,提出一种基于改进蚁群算法的新型路由协议。该协议利用了能耗因子对蚁群转移概率以及信息素更新进行改进,充分考虑了节点的剩余能量和节点间距离,通过信息素的建立和更新,寻找簇首节点和基站之间的最优传输路径,进行多跳传输模式,从而均衡簇首节点能量消耗。仿真实验结果表明,改进后的ACO-BEC协议较之于LEACH协议,能够有效降低了整个网络能量消耗,延长了网络寿命。     

基于最大权重值纠缠分发的量子无线多跳网络路由协议研究

针对量子节点间建立链路所消耗纠缠资源的差异,使用权重数值来量化现实环境对各个量子节点的影响,并根据权值确定纠缠粒子的分发。在此基础上提出一种针对量子无线多跳网络的路由协议,该协议以纠缠利用率作为路由度量条件,通过基于最大权重值的纠缠粒子分发方式和并行纠缠交换建立量子信道,实现量子态的传输。仿真分析表明,使用该路由协议可以精确找出网络中符合度量条件的量子链路,同时该路由协议中使用并行纠缠交换的交换方式降低了量子态传输的时延,在节点数为15时,并行交换比串行交换的平均时延降低了50%,而且随着链路中节点数的增加,两者的时延差异将会越来越大。为方便分析各仿真节点的权重值均设置为1至15的随机整数,通过对5节点的链路进行多次仿真发现使用基于最大权重值纠缠粒子分发方式能够传送的量子态的平均个数为14,基于串行的分发方式能够传送的量子态的平均个数为7。     

基于概率感知和改进量子遗传算法的节点部署策略

为了最大化监测区域的网络覆盖率和实现网络的负载均衡,设计了一种基于改进概率感知模型和量子遗传算法的移动节点部署方法。首先,在传统概率感知模型中加入环境干扰噪声因素和节点剩余能量因素进而获得改进的概率感知模型,然后,对传统的量子遗传算法进行改进,设计了新的量子旋转门和量子比特变异方式,以加快全局收敛速度和防止陷入局部最优。最后,定义了基于改进量子遗传算法获取移动节点最优部署位置的算法。仿真实验表明：文中方法能有效地对网络区域进行部署,实现最大化网络的覆盖率和最小化能量消耗,与其它方法相比,具有较大的优越性,是一种可行的方法。     

网络疑似入侵环境下的最优接口访问控制模型仿真

在网络疑似入侵环境下通过最优接口访问控制实现网络入侵的可靠性拦截,保障网络安全。传统方法采用自由链路分散控制模型进行网络入侵检测和接口访问控制,在受到较大的特征干扰下,入侵访问控制和拦截性能不好。提出一种基于自适应循环堆栈接口调度的网络疑似入侵环境下的最优接口访问控制模型。进行接口访问控制模型总体设计及组件模块分析,接口访问控制系统包括通信库、协议库、核心控制库和资源库,采用小波包自适应波束调制方法进行入侵检测算法设计,作为接口访问控制系统软件核心。通过SDICmdCon寄存器设置网络疑似入侵环境下的最优接口的内核,在嵌入式Linux环境下通过自适应循环堆栈接口调度实现接口访问控制的软件开发。仿真结果表明,采用该模型进行网络入侵检测,准确检测性能较好,通过最优接口访问控制,实现对网络入侵数据的准确识别和拦截。     

水声通信网竞争式介质访问控制协议的研究

水声通信网介质访问控制(Media access control,MAC)协议决定了节点共享水声信道资源的方式,它直接影响到水声信道的利用率和网络的整体性能。本文简要介绍了Aloha、MACA-U和UW-CSMA/CA三种竞争式MAC协议的基本原理,并基于NS2仿真平台,在集中式单跳网络和分布式多跳网络两种拓扑结构中对Aloha、MACA-U和UW-CS/MACA三种竞争式MAC协议的吞吐量、平均端对端时延、冲突率和协议开销等性能进行对比,并分析数据包长度对三种协议性能的影响,为实用MAC协议的设计提供了有效的参考数据和策略。     

云计算环境下基于并行计算熵的负载均衡算法

针对云计算环境下大量并行任务运行所导致的某些节点负载过重,从而引起整个系统负载不均和效率低下的问题,提出了一种基于并行计算熵的资源负载均衡算法;首先,描述了云计算虚拟机部署原理并给出了适合云计算环境和异构集群的并行计算熵的计算方式,然后,定义了在系统并行计算熵低于阈值时迁移的源物理节点、迁移虚拟机和迁移目标物理节点的确定方式;最后,定义了基于并行计算熵的负载均衡算法;采用CloudSim云计算仿真工具对文中方法进行仿真实验,结果表明文中方法较其它方法的平均负载均衡度约低21.8%,具有较低的任务平均响应时间、合理的资源利用率和较小的负载均衡度,具有较大的优越性。     

基于灰色模型和SVD估计AR(p)参数的物联网数据传输控制

为了进一步提高基于物联网的监控系统的可靠性和延长其网络生命周期,设计了一种基于灰色模型GM(1,1)和自回归AR(p)的对物联网监测区域中的数据传输进行控制的有效方法。首先,定义了基于GM(1,1)和自回归AR(p)的预测混合模型并对其运行原理进行了描述,然后,提出了采用最小二乘法对GM(1,1)的参数进行估计以获得预测模型,以总体最小二乘为评价准则,设计了基于奇异值分解SVD的AR(p)参数估计方法,最后将两种预测模型获得的结果进行加权融合作为最终的预测值。仿真实验表明,文中设计的基于GM(1,1)和自回归AR(p)模型的预测方法能较为精确地传感器节点在未来时刻采集的数据进行预测,同时由于节点预测的精确性,避免了其与基站之间的冗余数据传输,延长了网络生命周期,具有很强的可行性。     

基于时序网络层间同构率动态演化的重要节点辨识

时序网络可以更加准确地描述网络节点在时空演化过程中的交互顺序变化和交互关联关系.为辨识时序网络中的重要节点,本文提出基于时序网络层间同构率动态演化的超邻接矩阵建模的重要节点辨识方法.首先,依托复杂网络的层间时序关联耦合关系,定义了相邻与跨层网络综合逼近关系系数.其次,依据层内连接关系和层间逼近关系构建时序网络超邻接矩阵.再次,使用特征向量中心性方法对时序网络中的节点重要性排序,分析计算时序全局效率差值,通过肯德尔相关系数验证.最后,实证数据仿真显示:与经典时序网络模型相比,本文模型所得Kendall’s t值在各时间层上平均提高,最高为8.37%和2.99%,结论表明时序网络层间同构率的度量方法科学有效.     

Prioritizing the multi-criterial features based on comparative approaches for enhancing security of IoT devices

The Internet of Things (IoT) technologies continuously expand with time due to the advances in automated, connected device technology, mobility, and wide access to information. IoT is the collection of many linked devices due to their unique features, such as scalability, maintainability, fault tolerance, reliability, accuracy, and much more. With the growing number of hybrid devices in large organizations, security and privacy concerns are becoming more challenging. Security is essential for protecting the hardware, network aspects of devices, and information access from unauthorized entities. Most of the security methods and procedures provided by researchers are based on existing Internet security practices. The top-ranking authentication feature categories included the most compatible and common authentication feature for all types of IoT-based devices as an elementary security requirement for protection from unauthorized access. The future challenge is to address the incompatibility of the authentication feature with IoT devices based on appropriate technologies. AI and machine learning are also implementable in order to detect the vulnerability of IoT devices and inform the concerned operator or administration for protection. This research highlights the authentication feature of IoT devices from literature studies and evaluates the significant feature using COPRAS approach to assist organization in enhancing security of IoT devices.     

基于6LoWPAN的智慧校园空调监控系统设计

针对总线制空调监控系统存在布线施工成本高、联网结构复杂、维护难度大等问题,设计了一种基于6LoWPAN的智慧校园空调监控系统。首先给出了系统的整体功能及网络架构;然后,给出了传感器节点、系统核心模块及网关节点的硬件设计;接下来对6LoWPAN协议及简化进行了描述,给出了系统嵌入式软件的设计;最后给出了相关的空调控制策略。测试和实验结果表明,该空调监控系统具有结构简洁,扩展性高,实时在线响应,有效解决了校园空调物联网的信息互联问题,利用云平台智能管理达到节能减排目标。     

Hyperledger Fabric Access Control System for Internet of Things Layer in Blockchain-Based Applications

Blockchain-based applications are gaining traction in various application fields, including supply chain management, health care, and finance. The Internet of Things (IoT) is a critical component of these applications since it allows for data collection from the environment. In this work, we integrate the Hyperledger Fabric blockchain and IoT devices to demonstrate the access control and establish the root of trust for IoT devices. The Hyperledger Fabric is designed to be secure against unwanted access and use through encryption protocols, access restrictions, and cryptography algorithms. An attribute-based access control (ABAC) mechanism was created using Hyperledger Fabric components only to gain access to the IoT device. Single board computers based on the ARM architecture are becoming increasingly powerful and popular in automation applications. In this study, the Raspberry Pi 4 Model B based on ARM64 architecture is used as the IoT device. Because the ARM64 architecture is not supported by default, we build executable binaries and Docker images for the ARM64 architecture, using the Hyperledger Fabric source code. On an IoT device, we run the fabric node in native mode to evaluate the executable binaries generated for the ARM64 architecture. Through effective chaincode execution and testing, we successfully assess the Hyperledger fabric blockchain implementation and access control mechanism on the ARM64 architecture.     

一种用于塑料光纤接入网的多优先级控制协议设计

提出一种基于光码分多址(OCDMA)技术的塑料光纤接入网的多优先级控制协议.由于受传输误码率的限制,常规的光码分多址系统只允许有限个用户传输数据或接入网络,为了解决用有限的码字来实现多于码字数目的多媒体工作站间的信息通信,这种多优先级的控制协议通过使用预约和随机分配算法可以有效地解决信道冲突和目的地址的冲突问题, 该协议可以支持多媒体信息传输中各类信息不同的时间延迟要求.另外,在该接入网中,每个光网络单元均设有两套光编码器和光解码器,一套用于控制信道,另一套用于各个数据信道.利用本文提出的协议对塑料光纤接入网的网络吞吐量和平均延时时间进行了数值分析和仿真实验,结果证明了这种多优先级控制协议的有效性和高效性.     

Performance analysis of electronic code division multiple access based virtual private networks over passive optical networks

A solution for implementing multiple secure virtual private networks over a passive optical network using electronic code division multiple access is proposed and experimentally demonstrated. The multiple virtual private networking capability is experimentally demonstrated with 40 Mb/s data multiplexed with a 640 Mb/s electronic code that is unique to each of the virtual private networks in the passive optical network, and the transmission of the electronically coded data is carried out using Fabry-Perot laser diodes. A theoretical scalability analysis for electronic code division multiple access based virtual private networks over a passive optical network is also carried out to identify the performance limits of the scheme. Several sources of noise such as optical beat interference and multiple access interference that are present in the receiver are considered with different operating system parameters such as transmitted optical power, spectral width of the broadband optical source, and processing gain to study the scalability of the network.     

A novel multipriority reservation protocol for plastic optical fiber access network

In this paper, a novel multipriority reservation protocol for plastic optical fiber access network based on optical code division multiplexing access (OCDMA) technology is proposed. Conventional OCDMA system only allows finite units to transmit and access simultaneously according to the number of channels. The protocol is proposed to resolve this problem. By using the reservation scheme and a distributed arbitration algorithm, channel collision and destination conflict can be avoided. The protocol can efficiently support the transmission of multimedia messages that require the different time-delays. At the same time, each optical network unit is equipped with a fixed optical encoder/decoder that is always tuned to channel for control and the tunable optical encoder/decoder that is tuned to any of channel for data. The network throughput and average delay have been investigated by numerical analysis and simulation experiments. It is shown that the multipriority reservation protocol in this POF access net     

基于串口转WiFi的物联网终端远程控制实现方法

随着物联网技术的高速发展,对同一无线局域网内的设备进行控制时,存在传输距离短、可移动性差等缺点。针对此问题,提出了一种物联网终端远程控制的实现方法,采用串口转WiFi模块,通过Socket模式下的透传机制,传统的串口设备能够无线接入到互网络中基于MQTT消息传输协议的服务器上,完成数据的接收和发送,从而使终端设备突破无线通信距离的限制,达到数据交互和远程控制的目的。实验结果表明该方法正确、可靠,可广泛应用于智能家居、工业控制等领域。     

An IOT based smart grid system for advanced cooperative transmission and communication

In the Internet of Things (IoT) ecosystem, devices will predominate, using it in a manner similar to how people used it. Devices will cooperating in a multicast network to collect, share, and forward information way while interacting with one another autonomously and without centralised supervision. The building of an intelligent environment the capability of real-time collection of data, which is crucial for maximising the value of the IoT, will make this possible. A typical electric grid is made up of many power plants that use various power generating units, such as coal-based units, gas-based units, hydro units, etc. The majority of the infrastructure and wires that make up the conventional electricity grid have been in existence for a long time, it should be mentioned. They require significant investments, so providing them could take years. As a result, many grid components are outmoded and must be maintained and monitored on a regular basis to keep power flowing. A sophisticated technology is the smart grid (SG) system that makes it easier to integrate green technology and environmental considerations. The SG cyber–physical system was implemented thanks to the advancement and use of communication technologies in the conventional power system. The Internet of Things (IoT) and essential devices are both present in the complicated architecture of the SG systems. The traditional electric grids are been transformed into smart and efficient grid known as “Smart grid”. The Internet of Things’ smart grid allows for two-way communications among connected devices and technology that can recognise and respond to human needs. The cost and reliability of a smart grid are superior to that of conventional power infrastructure. Through use and data maintenance, smart grid technology will assist in reducing energy use and costs. One of the primary contributions made to grids is the integration of IoT with producing facilities using sustainable energy at various levels. To enhance the smart grid for bidirectional information exchange, improve power quality, and increase reliability Internet of Things (IOT) devices are becoming an important part of smart electric grid. IOT Infrastructure (IOTI) provide a flexible, efficient and secure platform providing strategic management for monitoring and controlling of different operations under different working conditions. This paper discusses cyber security on IOT based infrastructure for electric power systems. A comprehensive study is highlighted which includes type of IOTs, architecture used for smart grid, and future challenges.     

Control packet signaling mechanism using electronic code division multiple access for packet-based networks

We propose and experimentally demonstrate the feasibility of a control packet signaling technique using electronic code division multiple access for a wavelength division multiplexing packet-based network, whereby each wavelength channel is assigned a unique electronic code based label on a radio frequency subcarrier. Such a technique allows each wavelength channel to be electronically identified without requiring the use of a WDM demultiplexer. We experimentally demonstrate this technique with two wavelength channels each with 1.25 Gb/s baseband payload data and 10 Mb/s header coded onto an electronic code at 160 Mb/s. A performance study of the electronic code division multiple access based control signaling scheme in a wavelength division multiplexed packet-based access network is also performed in terms of the required power budget to monitor the electronic code division multiple access control signals in the presence of several sources of noise for error-free transmission of both payload data and electronic code division multiple access based control signals. It is shown that the modulation depth of each signal impacts the amount of required optical tap power. As the modulation depth of the electronic code division multiple access based control signal is increased, the required optical tap power is reduced. However, this increases the bit-error-rate for the payload data. Therefore, there lies a maximum and a minimum of the required tap optical power for the successful recovery of both signals. The lower bound of this range is usually determined by the successful recovery of electronic code division multiple access based control signal while the upper bound is determined by the successful recovery of payload data. The required optical tap power is analyzed for different transmission bit rates of the payload data for various receiver architecture scenarios without an optical amplifier at the receiver. The scalability analyses were repeated with an optical amplifier placed in the receiver terminal of the network. The resulting optical tap power that is required for the successful monitoring of the electronic code division multiple access based control signals are compared with that of the case without the amplifier.