ARROW-WTCP:A fast transport protocol based on explicit congestion notification over wired/wireless networks

An explicit congestion notification (ECN)-based distributed transport protocol,ARROW-WTCP (AcceleRate tRansmission towards Optimal Window size TCP for Wireless network),was proposed.The ARROW-WTCP enables feasible deployment of ARROW-TCP from wired to wireless networks by providing a joint design of source and router algorithms.The protocol obtains the actual capacity of the wireless channel by calculating the queue variation in base station (BS) and adjusts the congestion window by using the feedback from its bottleneck link.The simulation results show that the ARROW-WTCP achieves strong stability,max-min fairness in dynamic networks,fast convergence to efficiency without introducing much excess traffic,and almost full link utilization in the steady state.It outperforms the XCP-B (eXplicit Control Protocol Blind),the wireless version of XCP,in terms of stability,fairness,convergence and utilization in wireless networks.

A Feedback Scheme for Fountain Codes Based Transport Protocol in Space Communications

This paper proposed a practical- feedback scheme for fountain codes based transportprotocol in space communications. In the proposed scheme, the sender is signaled by two types of acknowledgment （ACK） packets.Before decoding, packet loss probability isestimated on the receiver side and encapsulated intoa soft ACKand sent to the sender.After decoding,decoding results are encapsulated into hard ACKsandsent to the sender. There are two contributionsin the proposed scheme： 1. Empl layer calculation instead layer statistics to estimate oying physical of application the packet loss probability of space channel, which can improvethe accuracy and practicality. 2. A cascade overhead-failure probability relationship between the sender and the receiver has been analyzed to help determine the exact numberof packetsneeded byfountain decoding.Simulations show that for space communications,compared with the existing space transport protocols, fountain codes based transport protoeolwith the proposed schemecan not only ensure transmission reliability, but also greatly improvelink utilization.

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.

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.

Proposal for Energy Consumption Reduction between Connected Objects in a Network Running on MQTT Protocol

The “Internet of Things” (IoT) refers to a set of intelligent “objects” that can communicate with each other directly or through a network. The IoT is the embodiment of the idea that everything can be connected anywhere and at any time. The concept can be applied to sectors such as e-health, e-government, automotive, geographic information systems, remote sensing, home networking, e-commerce and climate change mitigation. Unlike the Internet, the IoT has its own constraints, notably those linked to heterogeneity. This divergence is linked to different protocols, technologies and algorithms implemented in these connected objects for their interconnection. It should be noted that IoT devices can communicate with each other using different protocols and dedicated M2M (Machine to Machine) communication technologies. The aim of this work is to find solutions for optimising energy consumption during data exchanges between connected objects, with respect to certain constraints by using firstly this exchange for only Message Queuing Telemetry Transport (MQTT) and secondly the combination of the MQTT protocol and the Constrained Application Protocol (CoAP) protocol to check the quantity of the energy optimized. The MQTT protocol, for example, is one of the most widely used protocols for connected objects. Admittedly, this protocol consumes less energy, but in the situation of a very large number of users, the problem of saturation inevitably arises. In this article, we propose a solution of optimising energy consumption by combining the MQTT protocol with the CoAP protocol which can allow to use the standby mode contrary to the use of MQTT where the broker is always being turning. This solution has not yet been implemented but is being discussed. In this article, we’re going to use the joulemeter which is an application developed by Microsoft to measure and estimate the energy consumption of computers and applications. In our case, we take the example of the “Service Broker for network connections” of the Windows’s 10 Operating System, in my own computer to show the difference between the consumption of energy without the standby mode and with standby mode, because with the MQTT, the Broker’s MQTT is always on. Now, with the combination MQTT and CoAP, it is possible that we have standby mode and to compare these two cases in term of consumption of an energy. And to do it, we must use the joulemeter that we installed in our computer to simulate it. This is achieved by using the CoAP protocol combined with the MQTT protocol. The aim of our work is to reduce energy consumption in order to solve the problem of saturation of the MQTT by linking it to CoAP protocol by using Joulemeter mentioned above.

A Transport Protocol and Its Formal Description for Local Networks

This paper discusses a transport protocol and its formal description techniques for local network. The transport layer function, the transport services and a transport protocol design in a local network architecture model are presented. A transport protocol specification using the finite state automata (FSA) is given. The correctness of the protocol is verified by using the reachability tree technique with respect to the protocol properties of completeness, deadlock and livelock freeness, termination and reachability.

Implementation and Evaluation of Transport Layer Protocol Executing Error Correction (ECP)

Technologies for retransmission control and error correction are available for communications over the Internet to improve reliability of data. For communications that require the data reliability be ensured, TCP, which performs retransmission control, is often employed. However, for environments and services where response confirmation and retransmission are difficult, error correction technologies are employed. Error correction is generally implemented on UDP, but the existing framework implemented on UDP frequently does not consider the maximum frame size of the data link layer and relegates data division to the IP module. The IP module divides data according to the maximum size for the data link, and the receiving IP module reconstructs the divided data. For a data link layer typified by the current Ethernet with an error detection function, the frame is often destroyed upon error detection. At the IP module, the specification allows destruction of the entire dataset whenever divided data necessary for reconstruction is incomplete. Consequently, an error in a single bit results in a total loss of data handed to the IP module, and thus error correction performance declines with the increase in data size handed to the IP module. The present study considers the MTU of the data link layer and proposes error correction protocol (ECP) over IP, which decreases the transfer data volume flowing to the data link layer by dividing data into blocks of appropriate size based on designated error correction code and its parameters (thus improving error correction performance) and assesses the performance of ECP. Experimental results demonstrate that performance is comparable or better than existing error correction frameworks. Results also show that when a specification not ensuring the reliability of the data link layer was employed, error correction was superior to existing frameworks on UDP.

区块链网络综述

区块链是典型的分布式系统,底层网络的性能和安全性至关重要.区块链网络的本质是P2P网络,然而在安全模型、传输协议和性能指标等方面与传统P2P网络存在明显差异.首先,针对区块链网络的传输流程进行全面、深入地分析,阐明区块链网络所面临的瓶颈挑战.其次,针对区块链网络拓扑结构和传输协议的最新研究工作,从节点异构性、编码方案、广播算法和中继网络等方面系统性地分类梳理,并归纳总结跨链网络实现和网络仿真工具.最后,探讨区块链网络的未来研究趋势.

基于信息熵与服务器识别的DoH流量检测

DNS over HTTPS(DoH)协议是一种针对域名系统(DNS)的最新改进方案,然而用户可使用第三方DoH服务规避内网原有的监管,所以异常流量检测方法不再适用于检测DoH流量。针对该问题提出了一种DTESI算法。首先,基于信息熵将DoH流量作为异常流量从全部网络流量中筛选出来;然后,利用DoH服务器与同一客户端建立TLS连接时响应方式总是相同的特性,用指纹识别检测客户端与DoH服务器之间的TLS协商,确定DoH服务器身份;最后,使用Top-K抽样算法选出一定时段内网络中前K台活跃主机着重进行流量检测,使算法能应用于中大型组织的网络。实验结果表明,针对发现的异常流量,DTESI算法检测出的DoH服务提供商准确率超过94%。在此基础上比较了在不同K值下的算法检测时间和对网络中全部DoH流量的检测覆盖率,结果表明合理选择K值可以提升算法的整体效能。

基于数字孪生体的智慧城市轨道交通线网自动化控制系统

为保证智慧城市轨道交通的服务能力,设计基于数字孪生体的智慧城市轨道交通线网自动化控制系统。通过实时和历史数据采集模块,获取轨道交通的实时和历史数据,并通过网络模块传送至数字孪生模块。利用数字孪生映射技术和数据融合技术构建轨道交通线网数字孪生体模型。通过遗传算法优化布局控制模型,实现轨道交通线网的布局优化和自动化控制。测试结果显示,该系统网络的传输负载率和平均延时百分比最大值分别为7.44%和4.11%;数据融合后协方差的结果均在0.10以下;该模型能够有效构建数字孪生体模型,控制轨道线网的分布平均度。

基于无线传感技术的变电站开关柜故障自动化监测系统

为可靠掌握变电站开关柜的运行状态,保证变电站的稳定运行,该文设计基于无线传感技术的变电站开关柜故障自动化监测系统。传感节点采集开关柜运行数据,组建分层分簇的无线传感网络,结合能量-周期更新机制,采用双簇头的传输方式传输采集的开关柜运行数据,利用概率神经网络实现开关柜故障自动化诊断,输出故障类别结果。测试结果显示,无线传感网络中节点覆盖率以及网络区域连通率均在93.34%以上,各个节点接收功率的热力分布情况均匀,可以实现开关柜故障的频率可视化。

铜与卵巢癌的研究进展

卵巢癌是常见的妇科恶性肿瘤之一,多数患者在发现时已是晚期,治疗效果及预后差,严重影响患者的生存质量。铜是人体内重要的微量元素,参与多种关键生物过程,并与多种恶性肿瘤的进展密切相关。目前,越来越多的研究探索了铜与卵巢癌的关系,发现卵巢癌患者血浆、腹水及肿瘤组织中铜水平较健康人群明显升高,并且多种铜转运蛋白的异常表达与卵巢癌铂类药物化疗耐药密切相关。近年来,针对铜代谢的抗肿瘤治疗方式成为了研究的热点,大量的研究证明了铜螯合剂和铜离子载体在体内外对卵巢癌的显著抑制作用。综述铜与卵巢癌的密切关系,深入了解基于铜代谢的药物及治疗方法在卵巢癌中的应用,以期为卵巢癌的治疗提供新的方向。

数字孪生系统在建筑智能运维中的运用

以全球先进的开发引擎——虚幻引擎5为开发平台,开发数字孪生软件。以实验室行业的使用、运行、维护作为技术切入点,数据以Json数据类型为软件,读取数据进行读取写入,各厂家设备数据传输协议进行互联,以参考基准进行主要涵盖的系统的开发:新排风系统、试剂管理系统、VAV控制系统、安防系统、冷热源系统、气路系统、低温冰箱、报警管理、实验仪器管理系统等。精细化地将现实系统全面搬运至软件中,仿真运行;利用现实数据传输信号生成虚拟模型进行数字化模拟,主要用于监控范围内运动物体的运动状态及运动设备的运行状态;实时查看整个监控范围运行的情况,将现实投射至虚拟软件中。

VoIP管制指挥的双冗余通信设计

首先,针对目前国内各大军民航机场语音通信交换系统的高可靠性要求,结合集中式系统架构分析了主用和备用交换服务双冗余通信设计方案的可行性;然后,从冗余协同运行的角度提出了主从倒换决策及节点分布式的同步方法和设计流程;最后,通过双冗余通信的同步测试,验证了该方法的实时性和高可靠性能。该方法与传统的双机备份通信模式相比,设计更加合理,系统部署更加便捷灵活,可作为未来军民航管制指挥领域高可靠通信应用的指导。

IP时代的电视系统同步技术综述

随着电视系统由传统的串行数字接口(Serial Digital Interface,SDI)架构逐渐向网际互连协议(Internet Protocol,IP)架构转变,网络时钟协议(Network Time Protocol,NTP)、精确时间协议(Precision Time Protocol,PTP)、实时传输协议(Real-time Transport Protocol,RTP)时间戳(Timestamp)、电影和电视工程师协会(The Society of Motion Picture and Television Engineers,SMPTE)ST 2059等信号取代了传统SDI架构中的黑场(Black Burst,BB)信号,成为IP化电视系统的设备同步、流同步信号。基于此,详细介绍PTP的同步原理、RTP数据包的重要数据格式、RTP时间戳在视音频流同步中的原理及SMPTE ST 2059的定义及相关应用。

大规模低轨卫星互联网传输层关键技术研究与展望

随着卫星技术的发展,低轨卫星网络因其低成本、高容量、低时延等优势正在被越来越多的组织采用,如One Web、Space X等。低轨卫星网络不仅能够提供全覆盖的服务,甚至还能在超远距离数据传输中实现比地面网络更低的延迟。随着卫星星座技术的逐渐成熟,大规模低轨卫星互联网有望为全球用户提供无缝高速互联网接入。在大规模低轨卫星互联网中,传输层协议对于提供高可靠、低延迟的通信服务至关重要。然而,大规模低轨卫星网络的高误码率、星地切换以及频繁的网络拓扑变化等特点,使得传统地面网络传输协议难以满足大规模卫星互联网服务质量要求。因此,开发适用于大规模低轨卫星互联网的新型传输协议机制势在必行。针对大规模低轨卫星互联网新特征与传输服务需求,从传输层协议、拥塞控制算法、传输层编码技术以及多路径传输协议等多个方面,探讨了大规模低轨卫星网络下传输层关键技术发展,分析了当前大规模低轨卫星互联网传输服务面临的主要挑战。将为大规模低轨卫星互联网传输层关键技术的研究提供一定的发展思路与技术参考。

无线传输技术在通信工程中的应用价值与方法研究

文章深入探讨无线传输技术在通信工程中的应用价值及其方法。随着信息技术的飞速发展,无线传输技术凭借其灵活性、便捷性及高效性,在通信工程中占据重要地位。分析无线传输技术的核心价值,包括降低成本、提高通信效率等。然后,详细阐述无线传输技术在通信工程中的具体应用方法,包括无线网络构建、无线数据传输协议设计、无线信号处理以及无线信息存储等。通过实际案例分析,验证了无线传输技术在通信工程中的有效性和优势。

一种VoIP中继通信的设计方法及系统

针对集中式基于网际互连协议的语音传输(Voice over Internet Protocol,VoIP)语音通信交换系统(Voice Communication Switching System,VCCS)的互操作性需求,提出一种基于VoIP技术的中继通信解决方案。在集中式VoIP通信架构的基础上构建中继通信模型,结合局向管理、冠号管理、路由管理以及会议管理等模块的协同运行给出VoIP中继通信的业务处理流程,并详细阐述中继会议的核心模块。最后,通过两种异型语音通信交换系统的中继通信对比测试,验证了文章提出的VoIP中继通信方法的可靠性和互操作性。

基于广域信息分析的电力调度信息可视化通信系统设计

设计并提出一种基于广域信息分析的电力调度信息可视化通信系统,该系统通过实时数据采集与门控循环单元(Gated Recurrent Unit,GRU)神经网络模型,结合灰狼优化算法(Grey Wolf Optimizer,GWO),预测电力调度信息。系统采用消息队列遥测传输(Message Queuing Telemetry Transport,MQTT)协议保障数据传输的安全性与实时性,并提供一个3维可视化用户界面,提高信息的可访问性和决策效率。

基于MQTT协议的电力物联网络边缘网关通信架构优化设计研究

针对现有方法应用效果不佳的问题,文章提出一种基于消息队列遥测传输(Message Queuing Telemetry Transport,MQTT)协议的电力物联网络边缘网关通信架构。首先,部署电力物联网络边缘网关通信场景,便于通信数据传输和任务收集。其次,基于MQTT协议构建物联网络边缘网关通信框架,以避免资源消耗的问题。最后,采用分层结构协议与MQTT协议结合的方式优化物联网边缘网关跨层通信拥塞机制。实验结果表明,该架构优化效果更佳,不仅可以提升电力物联网的整体性能,而且可以为智能电网的智能化、自动化管理提供有力支持。