地域通信网干扰效果评估指标研究

目前地域通信网是战术通信网的主体和主要发展方向。介绍了地域通信网的特点,分析了对地域通信网的干扰方法。针对地域通信网的工作特性,提出了采用误码率和网络阻塞概率作为对地域网干线节点干扰的效果评估指标,最后以四个节点组成的栅格状地域通信网作为研究对象,采用数学仿真方法对多种情况下的误码率、网络阻塞概率进行了仿真评估。     

基于地域通信网流量攻击方法的仿真研究

地域通信网中各节点之间的正常通信是保障作战胜利的关键,由于地域通信网中各节点间的连接多采用无线链路,可以使用流量攻击的方法对链路进行攻击,使各节点通信中断。在分析流量控制和拥塞控制的基础上,结合OPNET仿真软件建立网络模型,通过仿真研究验证了流量攻击法可以有效地使地域通信网通信中断,达到攻击的目的。     

基于仿真的地域通信网规划与管理

针对地域通信网在开设和维护中的需求，提出了一种基于仿真的实时规划与管理方式，将仿真系统与地域通信网中的一些节点构成半实物仿真环境。根据网络的当前状态．快速仿真网络运行，预测网络未来的性能，并持续地对网络进行优化，以此来提高地域通信网性能，改善服务质量。     

地域通信网的干扰技术研究

本文在分析地域通信网结构及组成的基础上,研究了对地域通信网实施的节点破坏、末端信息封锁、局部阻塞瘫痪等对抗方法,并使用干扰地域通信网的程度、节点干扰率、末端节点封锁率和传递信息误差率等指标对干扰效果进行评估。     

地域通信网的干扰技术研究

本文在分析地域通信网结构及组成的基础上，研究了对地域通信网实施的节点破坏、末端信息封锁、局部阻塞瘫痪等对抗方法，并使用干扰地域通信网的程度、节点干扰率、末端节点封锁率和传递信息误差率等指标对干扰效果进行评估。     

聚合度在地域通信网关键节点识别中的应用

介绍了地域通信网的概念,分析了研究地域通信网关键节点识别的重要性。从网络的拓扑结构出发,给出了两种聚合度的定义方法,并把这两种定义方法应用到关键节点识别中,通过实例对两种方法进行分析对比它们的优缺点,得出方法二更适用于地域通信网这样复杂网络的关键节点识别中。     

一种野战地域通信网网络节点和链路重要性的评估方法

评估网络节点和链路的重要性,是研究野战地域通信网网络可靠性的重要内容。在采用节点收缩法判断网络节点重要性的基础上,结合实例,提出了利用层次分析法确定连接于核心节点的各条链路权重值的方法,进而得出野战地域通信网网络节点和链路重要性的评估方法,为野战地域通信网的可靠性研究和电子对抗作战提供参考。     

无人机覆盖搜索地域通信网交叉式航路规划

针对地域通信网的侦察搜索问题,提出一种以交叉式航路来实现对地域通信网部署区域完全覆盖搜索的无人机航路规划方法。首先,根据地域通信网结构特点以及干线节点天线波束特性,定性地分析得到无人机侦察干线节点时的最大侦察距离与盲区侦察距离,并分析得到无人机搜索干线节点的静态模型以及动态模型;其次,根据侦察模型,建立并优化无遗漏搜索的无人机交叉式搜索航路模型,该方法可保证搜索到地域通信网所有干线节点,并提高任务执行效率;最后,对无人机交叉搜索航路进行仿真,仿真结果表明,该方法能有效搜索到地域通信网每一个干线节点,并求解了无人机交叉式覆盖搜索航路代价。     

干扰条件下地域通信网链路阻塞率研究

链路是通信网络的重要组成部分。在干扰条件下,从理论上建立链路模型,并根据链路的分类和信道的误码率对链路阻塞率进行了研究。在此基础上,文章给出了某地域通信网一个四节点网络干扰时的链路选择示例,并进行了仿真。     

基于改进跳面节点法的地域通信网抗毁性评价

为了提高地域通信网对抗训练的有效性,需要对地域通信网的抗毁性和节点链路的重要性作出评价。针对跳面节点法的问题和不足,提出了一种基于改进跳面节点法的地域通信网抗毁性评价方法,并对改进的结果进行了对比,最后对抗毁性评价方法在地域通信网对抗训练中的应用情况进行了分析。     

基于发射功率自适应调节的无线通信网抗扰研究

为解决智能楼宇中ZigBee网络与WiFi网络之间的干扰问题,通过采用TI公司的CC2530芯片,设计了一种发射功率自适应调节的无线传感器网络节点。文中主要采用试验的方法对不同环境下的ZigBee节点之间通信的可靠性进行测试,得出通信距离、误包率和接收信号强度指示RSSI之间的关系。利用RSSI作为通信评价因子,根据实际应用环境的变化,自适应地改变ZigBee通信节点的发射功率。经实验测试,只需RSSI值＞-51 dBm,便可保证干扰环境下的误包率接近为0。     

Traffic scheduling method based on centralized control in named data networking

In order to address the global optimization problem for traffic scheduling in named data networking,related works were analyzed,a method based on centralized control was proposed.The proposed method took network performance and communication overhead into account.In the proposed scheme,appropriate nodes would be selected as E-NDN nodes,then the controller calculated the corresponding multi-path forwarding policies and sent them to E-NDN nodes according to the in-network cache,the aggregation of Interest packets,and the traffic demands of popular contents to achieve global optimization.The evaluation results indicate that the proposed method can significantly reduce the maximum link utilization and improve network performance.Simultaneously,the proposed method will not cause a large optimization cost,and communication overhead between the controller and nodes will increase slightly.     

Evaluating the performability of tactical communications networks

Tactical communications networks are multihop wireless networks in which switches and endpoints are mobile nodes. In a tactical environment, system performance degrades when switching nodes and/or communication links fail to operate. Fast algorithms for performance analysis are desirable for optimizing the network in a timely fashion. Further, tactical networks commonly use preemptive priorities to achieve low blocking probabilities for high-priority calls when the loss of equipment in the battlefield is not trivial. This paper discusses three measures and analytical algorithms for the performability evaluation of a two-tier tactical communications network where preemptive priority service discipline is employed and traffic is divided into multiple classes to provide multiple grades of service. Each class of traffic has its distinct characteristics, such as average call-arrival rate, average call-holding time, and service priority. The three performability measures are devised to evaluate the impact of nodes/links failures on system performance. Experiments show that the preemption does provide robust service for higher priority traffic. The techniques for performability evaluation presented in this paper may also be useful in other rapidly deployable networks, where mobility, communication efficiency, and computational complexity for adapting the network to unpredictable environments are of significant concern.     

业务优先级感知的网络流量调度机制

针对网络中业务数据流过大、分布不均匀所造成的网络拥塞,提出一种优先级感知的动态网络流量调度机制.利用令牌桶算法,根据业务优先级的不同为不同业务分配不同速率的令牌,以实现业务优先级的划分;综合考虑业务的优先级及用户节点剩余缓存空间,对不同的业务采取不同的处理方式;同时,以流量到达因素、服务因素及节点缓存为指标定义了一种网络流量调度机制性能指标——分组丢失率.数值结果表明,所提机制可以对网络中业务优先级进行合理的划分,从而有效利用网络资源,预防网络拥塞,提升网络性能,为用户提供更加稳定可靠的网络服务.     

Mitigation of Packet Loss Using Data Rate Adaptation Scheme in MANETs

Node’s mobility, bursty data traffic, and dynamic nature of the network make congestion avoidance and control a challenging task in Mobile Adhoc Networks (MANETs). Congestion results in high packet loss rate, increased delays, and wastage of network resources due to re-transmissions. In this paper, we propose In-route data rate adaptation to avoid packet loss. Proposed scheme is based on the analysis of queue length of the forwarding nodes, number of data source nodes, and rate of link changes. In proposed technique, queue length of forwarding nodes is communicated periodically to the neighbor nodes using existing control messages of the underlying routing protocol. Keeping in view the queue length of forwarding nodes, number of data source nodes, and rate of link changes, initially the intermediate nodes buffer the incoming data packets upto some threshold and then, gradually shift the effect of congestion to the data source nodes. Then, the source node adapts its sending data rate to avoid congestion and to ensure reliable data communication. We have performed simulations in NS-2 simulator by varying different network metrics such as data rate, number of source nodes, and node speed. Results show that proposed technique improves network performance in terms of packet delivery ratio upto 15 %, reduction of average end-to-end delay and packet loss due to interface queue overflow upto 25 % and 14 % respectively, as compared to the static rate adaptation scheme.     

网络编码调度策略的研究

网络编码是通信领域的一项重大突破,其基本思想是建立在网络信息流的基础之上,通过网络节点对来自不同链路的信息流进行编码处理,使其既能实现传统路由功能,又能实现对信息的编码处理。分析了等速率的网络编码调度策略,并把自适应传输技术应用到网络编码的调度策略,然后通过Matlab仿真分析,验证了自适应的网络编码策略可提高通信系统的网络编码增益、吞吐量和减少数据传输延时方面的贡献。     

The Modular WDM-Gridconnect as a Passive Routing Structure with Distributed Interfacing Capabilities

For communication services over transparent optical paths, specified in terms of bit rate and bit error probability, the maximum length is determined by detrimental physical effects like dispersion, crosstalk, noise or nonlinearities. Therefore, fiber-optic wide area networks employing wavelength division multiplexing (WDM) and optical bypassing have to be divided into several small transparent partitions. In this paper a scheme accounting for sufficiently short optical paths is introduced which is called Modular WDM-Gridconnect. In this approach the burden of interconnecting different network partitions (i.e., by using an overlay transport system as an interface) is spread over almost all nodes of the network. This property is referred to as distributed interfacing. The network can be extended step-by-step in a modular fashion adding no more than two nodes to the coverage area at a time. The advantageous properties of such an arrangement as compared to a straightforward partitioning are characterized by the cumulative transit traffic and the path lengths in a Modular WDM-Gridconnect cluster.     

无线通信网络中流量分析技术综述

对无线网络流量的分析和准确预测是无线网络管理与安全领域的重要研究内容之一,在网络规划、网络监控、流量趋势分析、网络优化以及入侵检测和异常检测等方面发挥着重要作用。介绍了目前典型的无线网络流量分析的模型与常用流量分析方法,综述了传统无线通信网络(如无线局域网和物联网)中的流量分析技术,指出了流量分析技术应用于无线自组网系统的可能性与面临的几点挑战,以及无线自组网系统与流量分析技术结合的发展方向。     

大型IP网络时延的主成分分析

网络时延是评估网络性能的关键指标之一。主成分分析(PCA)是数据挖掘领域常用的一种多变量分析和降维算法。通过对大型IP网络时延进行PCA分析,旨在挖掘网络时延的深层原因及网络各节点间的相互依赖关系,并搭建一个科学合理的网络时延评价体系,最终得到IP网络建设、优化改造的有效建议。对历史网络时延进行离线分析只是主成分分析方法的一种初步应用,今后可结合网络拓扑结构、现网流量流向、路由、距离等相关因素,将主成分分析方法应用到针对网络流量、网络时延、网络丢包等网络性能的实时在线监测分析中,进一步提升网络运营的效率和质量。