Cloud control for IIoT in a cloud-edge environment

The industrial Internet of Things(IIoT)is a new indus-trial idea that combines the latest information and communica-tion technologies with the industrial economy.In this paper,a cloud control structure is designed for IIoT in cloud-edge envi-ronment with three modes of 5G.For 5G based IIoT,the time sensitive network(TSN)service is introduced in transmission network.A 5G logical TSN bridge is designed to transport TSN streams over 5G framework to achieve end-to-end configuration.For a transmission control protocol(TCP)model with nonlinear disturbance,time delay and uncertainties,a robust adaptive fuzzy sliding mode controller(AFSMC)is given with control rule parameters.IIoT workflows are made up of a series of subtasks that are linked by the dependencies between sensor datasets and task flows.IIoT workflow scheduling is a non-deterministic polynomial(NP)-hard problem in cloud-edge environment.An adaptive and non-local-convergent particle swarm optimization(ANCPSO)is designed with nonlinear inertia weight to avoid falling into local optimum,which can reduce the makespan and cost dramatically.Simulation and experiments demonstrate that ANCPSO has better performances than other classical algo-rithms.

基于LwIP和Modbus TCP协议的网络控制器设计

为了实现对终端设备的网络远程控制和监测,该文设计了一款基于LwIP和Modbus TCP协议的网络控制器。该控制器以STM32F107RCT6和LAN9303芯片为核心,设计出了网络通信电路、网口电路、A/D采样电路、光耦隔离电路和IO口电路。软件设计主要完成了LwIP协议栈的移植、Modbus TCP协议程序和其他控制程序的编写。经过测试,所设计的网络控制器在对设备进行远程控制和监测时具有数据传输可靠、通讯稳定和实时性好的优点,能满足工厂使用。

Energy-Efficient and Reliable Transport Protocols for Wireless Sensor Networks: State-of-Art

New wireless sensor network applications (e.g., military surveillance) require higher reliability than a simple best effort service could provide. Classical reliable transport protocols like Transmission Control Protocol (TCP) are not well suited for wireless sensor networks due to both the characteristics of the network nodes (low computing power, strong energy constraints) and those of the main applications running on those nodes (low data rates). Recent researches present new transport protocols for wireless sensor networks providing various type of reliability and using new mechanisms for loss detection and recovery, and congestion control. This paper presents a survey on reliable transport protocol for WSNs.

BIFURCATIONS AND CHAOS CONTROL IN TCP-RED SYSTEM

Objective Analyzing the nonlinear dynamics of the TCP-RED congestion control system is of great importance. This study will help investigate the loss of stability in Internet and design a proper method for controlling bifurcation and chaos in such system. Methods Based on bifurcation diagram, the effect of parameter on system performance is discussed. By using the state feedback and parameter variation strategy, a simple real time control method is proposed to modify the existing RED scheme. Results With our control method, the parametric sensitivity of RED mechanism is attenuated. Moreover, a sufficient condition on the robust stability of the system is also derived to adjust the parameters in TCP-RED system. Conclusion The proposed method has the advantages of simple implementation and unnecessary knowledge of the exact system.

Novel satellite transport protocol with on-board spoofing proxy

As a result of the exponential growing rate of worldwide Internet usage, satellite systems are required to support broadband Internet applications. The transmission control protocol （TCP） which is widely used in the Internet, performs very well on wired networks. However, in the case of satellite channels, clue to the delay and transmission errors, TCP performance degrades significantly and bandwidth of satellite links can not be fully utilized. To improve the TCP performance, a new idea of placing a TCP spoofing proxy in the satellite is considered. A Novel Satellite Transport Protocol （NSTP） which takes advantage of the special properties of the satellite channel is also proposed. By using simulation, as compared with traditional TCPs, the on-board spoofing proxy integrated with the special transport protocol can significantly enhance throughput performance on the high BER satellite link, the time needed to transfer files and the bandwidth used in reverse path are sharply reduced.

TCP Window Based Congestion Control -Slow-Start Approach

Transmission control protocol (TCP) has undergone several transformations. Several proposals have been put forward to change the mechanisms of TCP congestion control to improve its performance. A line of research tends to reduce speed in the face of congestion thereby penalizing itself. In this group are the window based congestion control algorithms that use the size of congestion window to determine transmission speed. The two main algorithm of window based congestion control are the congestion avoidance and the slow start. The aim of this study is to survey the various modifications of window based congestion control. Much work has been done on congestion avoidance hence specific attention is placed on the slow start in order to motivate a new direction of research in network utility maximization. Mathematical modeling of the internet is discussed and proposals to improve TCP startup were reviewed. There are three lines of research on the improvement of slow start. A group uses the estimation of certain parameters to determine initial speed. The second group uses bandwidth estimation while the last group uses explicit request for network assistance to determine initial startup speed. The problems of each proposal are analyzed and a multiple startup for TCP is proposed. Multiple startups for TCP specify that startup speed is selectable from an n-arry set of algorithms. We then introduced the e-speed start which uses the prevailing network condition to determine a suitable starting speed.

基于LSTM的Modbus TCP协议模糊测试优化方法

针对工控系统传输协议模糊测试的路径爆炸和约束求解问题,提出一种基于长短时记忆(LSTM)网络的Modbus TCP协议模糊测试优化方法,挖掘出两种工控协议漏洞,分别为非法写入漏洞和数据值边界漏洞。抓取模糊测试数据包形成数据集,并根据状态码将其分为正常用例、异常用例和无效用例三种,通过LSTM识别出无效用例并剔除,提高漏洞挖掘效率。实验结果表明,LSTM识别模糊测试数据集的准确率达到93.87%,经过LSTM优化后的测试用例通过率从30.75%提升至33.99%。

AN ENHANCEMENT SCHEME OF TCP PROTOCOL IN MOBILE AD HOC NETWORKS:MME-TCP

Transmission Control Protocol (TCP) optimization in Mobile Ad hoc NETworks (MANETs) is a challenging issue because of some unique characteristics of MANETs. In this paper,a new end-to-end mechanism based on multiple metrics measurement is proposed to improve TCP performance in MANETs. Multi-metric Measurement based Enhancement of TCP (MME-TCP) designs the metrics and the identification algorithm according to the characteristics of MANETs and the experiment results. Furthermore,these metrics are measured at the sender node to reduce the overhead of control information over networks. Simulation results show that MME-TCP mechanism achieves a significant performance improvement over standard TCP in MANETs.

基于Modbus/TCP的无线通信网络安全加密控制系统设计

为控制明文加密时长、密文响应时长之间的相对时延量,实现无线网络对于通信数据的安全性加密,设计基于Modbus/TCP的无线通信网络安全加密控制系统;匹配PowerPC嵌入式架构与复位通信控制电路之间的实时连接关系,借助微处理器子模块,确定宿主机与客户机对通信网络的贡献价值,再按照Modbus/TCP协议连接标准,整合交换区中已存储的通信数据文本,完成无线通信网络安全加密控制系统硬件设计;根据基本协议要素,认证待加密数据的传输身份,实现对Modbus/TCP可信协议的定义;利用协议文件中的可信度条件,设置密钥模板,通过移植处理通信文本的方式,确定数据信息样本的扩容总量,完成安全加密接口设计,联合相关应用元件,实现基于Modbus/TCP的无线通信网络安全加密控制系统设计;实验结果表明,所设计系统明文加密时长、密文响应时长之间的相对时延量始终保持为0.1 ms,能够有效实现无线网络对于通信数据的安全性加密。

基于TCP/IP的多媒体技术支持系统设计和实现

随着网络技术的发展,网络技术逐渐渗透到各个行业领域,很多领域顺应时代发展进行多样化的变革。其中,实际生产和工作中使用多媒体技术支持系统可以共享网络资源,提高资源的利用率和工作效率。文章介绍了传输控制协议/网际协议(Transmission Control Protocol/Internet Protocol,TCP/IP),并对基于TCP/IP的多媒体技术支持系统进行了设计和实现。

适用于数据中心低延迟高吞吐量TCP的动态标记配置策略

在数据中心流量传输过程中,传输性能的好坏很大程度上取决于数据中心TCP是否可以满足长短数据流不同的传输性能需求,即长流的高吞吐率和短流的低排队延迟。由于数据中心网络应用主要是在线数据密集型应用(online data intensive application,OLDI)产生大量长流和短流混合的数据流,使长流占用大部分瓶颈链路带宽,造成短流高延迟,影响应用的服务质量。文章提出的动态标记配置(Dynamic-marking Configuration,DMC)策略动态调整瓶颈链路队列长度门限,实现流量的低延迟和高吞吐量传输,并降低数据流错过最后期限的比例。

网络通信中嵌入式TCP/IP单片机技术研究

嵌入式传输控制协议/网际协议(Transmission Control Protocol/Internet Protocol,TCP/IP)单片机技术是网络通信中一项重要的技术。主要从嵌入式TCP/IP单片机技术的概述、硬件结构、软件设计进行详细介绍,提出一种嵌入式TCP/IP单片机的软件设计方法,并将其应用于网络通信,以提高网络通信的稳定性和可靠性,并提高数据传输质量。

基于共享存储技术的乱序TCP分段重排电路设计

传输控制协议(Transmission Control Protocol,TCP)处理引擎可以广泛应用于数据中心的各类型服务器,降低处理器负荷。为提高TCP协议处理引擎处理数据的分段效率,设计了一种基于共享存储技术的乱序TCP分段重排电路,其采用静态随机存储器(Static Random Access Memory,SRAM)存储,具有结构简单、存储资源利用率高、低时延的特性,可有效克服内容寻址存储器(Content Addressable Memory,CAM)或三态内容可寻址存储器(Ternary Content Addressable Memory,TCAM)高功耗以及可扩展性差的缺点,同时满足上千条连接的工作需求;分析了电路的具体结构、关键调度算法和工作流程,并进行了仿真。电路基于Xilinx ZYNQ 7000系列的现场可编程门阵列(Field-Programmable Gate Array,FPGA)实现,对主要硬件资源消耗进行了综合分析。

MANET中TCP改进研究综述

传统TCP(transmission control protocol)本是为有线网络设计,它假设包丢失全是由网络拥塞引起,这个假设不能适应于MANET (mobile ad hoc network),因为MANET 中除了拥塞丢包以外,还存在由于较高比特误码率、路由故障等因素引起的丢包现象.当出现非拥塞因素丢包时,传统 TCP 将错误地触发拥塞控制,从而引起TCP 性能低下.任何改进机制都可以分为发现问题和解决问题两个阶段.首先概括了 MANET 中影响 TCP 性能的若干问题;然后针对发现问题和解决问题两个阶段,详细地对每一阶段中存在的各种可行方法进行了分类、分析和比较;最后指出了 MANET 中 TCP 性能优化的研究方向.

带宽非对称网络中TCP性能分析

考察了带宽非对称对基于端到端的 TCP协议性能的影响程度 .通过数学建模推导出了带宽大量对称情况下 TCP平均吞吐量的计算公式 ,并仿真验证了推导的有效性 .结果表明 ,在带宽非对称网络中 ,正向吞吐量的取得不仅依赖于正向的业务特性和链路的性能 ,而且在很大程度上取决于反向的业务特性和链路的性能 .结论是反向带宽和队列容量将使 TCP性能成非线性变化 .

分离TCP拥塞控制和可靠传输机制

提出了将拥塞控制从传输控制协议 ( TCP)分离而改变为一个独立于各传输协议的拥塞控制代理方法 .拥塞控制代理一方面执行主动拥塞检测协议 ,检测网络可用带宽 ,控制各网络连接都以线性增加、成倍递减方式调整发送数据速率 ,可有效保证网络稳定 ;另一方面通过一个应用接口提供网络连接的状态信息 ,利于网络多媒体应用采用自适应传输机制而提高传输质量 .模拟结果证明 ,受拥塞控制代理控制的网络连接对

一种新的适用于异构网络的TCP算法

提出了一种新的适用于异构网络的传输控制协议(TCP)算法。该算法不仅能够动态寻求网络中的性能最优点,尽量使网络流量保持在该点,而且能够判断网络中数据包丢失的原因,合理地调整参数,避免了TCP-Reno中盲目将发送窗口减半的机制。仿真实验的结果表明,新算法的性能优于TCP-Reno和其他同类改进协议。

无线链路的TCP性能问题及其改善

介绍了无线链路上的TCP性能问题和相关的工作。提出了一种改进从移动主机到固定网络方向TCP性能的方案,在基站处设置TCP代理来监视在无线链路上丢失的TCP报文段,通过复制和发送重复的ACK来触发MH端TCP的快速重传,有效地防止超时重传的发生。计算机仿真结果表明此方案具有良好的性能。

一种异构网络TCP拥塞控制算法

针对互联网中端对端带宽、时延和丢包率等的差异性日益加剧,导致TCP传输性能严重退化,该文提出一种链路自适应TCP拥塞控制算法(INVS)。INVS在拥塞避免阶段初期采用基于指数函数的凸窗口增长函数,以提高链路利用率;在窗口增长函数中引入了自适应增长因子实现窗口增长速率与链路状态相匹配;采用了自适应队列门限的丢包区分策略以提高无线环境下TCP的性能。性能分析和评估表明,INVS提高了TCP拥塞控制算法的吞吐量、公平性、链路利用率和RTT公平性。

基于TCP和UDP混合协议的远程控制软件的设计与实现

针对目前网络远程控制软件存在的数据传输问题,提出一种在Windows系统平台下运行的基于TCP和UDP混合协议的远程控制软件的设计思路与开发技术。使用柯达公司的ImgEdit控件对截屏后的图像文件进行了压缩,便于数据的传输;系统使用Winsock网络编程技术,基于C/S模式,Client端调用Winsock发送相关控制命令,Server端主要运用Winsock和API函数实现远程屏幕抓取、控制操作和数据传输等功能。实验结果表明,该方法能方便、快捷地实现远程计算机的控制以及数据的传输,从而为远程智能控制的发展提供了发展方向。