多层卫星网络链路中断容忍路由策略设计

链路中断和接续对卫星网络路由有重要影响,该文针对多层卫星网络,设计了链路中断容忍路由策略,利用非均匀时间段内卫星网络拓扑结构的可预测性进行路由表计算,采取动态的拥塞控制机制和洪泛策略,解决由于卫星运动、通信设备故障引发链路中断情况下的路由问题。仿真结果表明,该路由策略具有较高的链路利用率,能够减少动态路由计算中时延信息收集和星上路由表生成给卫星节点带来的时空开销。     

容迟网络中高传输性能随机路由协议

In Delay Tolerant Networks (DTNs), establishing routing path from a source node to a destination node may not be possible, so the opportunistic routings are widely used. The energy and buffer constraints are general in DTNs composed of the mobile phones or Pads. This paper proposes a novel opportunistic routing protocol, denoted by Large Opporturioty (LAOP ), for the energy and buffer constrained DTNs. The objective of LAOP is to reach many receivers of a message with a small number of transmissions. By LAOP, the sender floods a message when the number of its neighbors is not less than a threshold. We compare the delivery performance of LAOP with other four widely used Delay or Disruption Tolerant Network (DTN) routing protocols, Direct Delivery, Epidemic routing, SprayAndWait and PRoPHET and demonstrate that LAOP can improve the delivery performance and decrease the delivery latency simultaneously.     

WCDMA网络覆盖性能评估方案探析

在基于传统评估WCDMA／HSPA网络覆盖性能方案的基础上提出了新的评估方案,采用数学统计方法来评估网络质量,统计粒度小,能够客观真实反映网络覆盖问题,非常适用于网络评估及网络优化工作。     

An Efficient,Scalable Key Transport Scheme (ESKTS) for Delay/Disruption Tolerant Networks

In the past, security protocols including key transport protocols are designed with the assumption that there are two parties communication with each other and an adversary tries to intercept this communication. In Delay/Disruption Tolerant Networking (DTN), packet delivery relies on intermediate parties in the communication path to store and forward the packets. DTN security architecture requires that integrity and authentication should be verified at intermediate nodes as well as at end nodes and confidentiality should be maintained for end communicating parties. This requires new security protocols and key management to be defined for DTN as traditional end-to-end security protocols will not work with DTN. To contribute towards solving this problem, we propose a novel Efficient and Scalable Key Transport Scheme (ESKTS) to transport the symmetric key generated at a DTN node to other communicating body securely using public key cryptography and proxy signatures. It is unique effort to design a key transport protocol in compliance with DTN architecture. ESKTS ensures that integrity and authentication is achieved at hop-by-hop level as well as end-to-end level. It also ensures end-to-end confidentiality and freshness for end communicating parties. This scheme provides a secure symmetric key transport mechanism based on public key cryptography to exploit the unique bundle buffering characteristics of DTN to reduce communication and computation cost .     

一种协作网络编码方案的功率优化分配方法

该文针对传统双路无线中继系统中的源和中继采用等功率发送,导致系统资源利用率低的问题,提出一种译码转发-空时协作网络编码方案的功率优化分配方法。该方法以最小化两源用户中断概率中的较大者为目标,并利用中断概率的高阶近似解,通过迭代计算获得最优功率分配因子。所提功率优化分配方法计算复杂度低且仅需信道的平均增益信息。仿真结果表明,与平均功率分配方法相比,所提功率优化分配方法使系统的中断概率和误码率性能均得到有效提升。     

容迟／容断网络路由技术研究

容迟／容断网络（DTN）由于其长延迟、高误码率及频繁断路等网络特性不满足互联网较短传输延迟、低误码率及存在端到端路径的基本假设,传统Internet体系结构和协议无法直接用于DTN。DTN路由机制可以按照连接的确定性分为确定性路由和随机性路由。确定性路由主要有基于树的路由、时空路由和修正的最短路径路由等方法;随机性路由主要有流行性路由、基于历史消息的路由、基于模型的路由、可控移动路由和基于编码的路由。DTN在游牧计算、军事战场通信、紧急营救及灾后重建方面具有广泛应用前景。     

容迟／容断网络传输技术研究

容迟／容断网络（DTN）是从星际网络、卫星网络、AdHoc网络、传感网络等现实网络中抽象出来的一种特殊的网络模型。分析了DTN网络的研究背景和体系结构,重点研究了DTN网络的保管传输技术;通过仿真结果表明,与端到端的传输方式相比,保管传输技术在网络平均吞吐量和数据传输总量方面性能优越,适用于DTN网络。     

容断网络中的组播路由算法研究

容断网络是一种新型的网络架构,主要用来解决频繁发生分离的网络场景中的数据通信.它为很多面临挑战的网络 (如星际网络、传感器网络、陆地移动网络等) 提供了互操作性,同时也可以满足特殊场合的应用,如军事战场、灾难营救、深空通信、边远地区的因特网接入等等.文章给出了一种新的容断网络中组播路由算法分类,并剖析了现有主要的组播路由算法.为容断网络组播的路由算法进一步研究提了一定的参考价值.     

Design and Implementation of a Composite Performance Evaluation Model for Heterogeneous Network Management Applications

This article examines the place of analytical models in realtime performance management applications. The main objectives are to define, specify and implement a system based on a composite model that provides the optimal software environment for performance analysis and tuning of heterogeneous networks.     

Integrated Sized-Based Buffer Management Policy for Resource-Constrained Delay Tolerant Network

Wireless Personal Communications - Delay tolerant network is a type of network where the end-to-end path is not available from source to destination due to the node mobility, dynamic topology and...     

非线性网络管理方案的设计

本文分析了非线性网络系统与传统编辑系统的不同，提出了非线性网络管理方面的一些技术方案，详尽论述了在网管工作中，为提高网络的稳定性与安全性所采取的一些具体措施。     

容迟与容断网络的研究进展

本文简要介绍了容迟与容断网络的基本特征、体系结构、应用领域和比较活跃的研究机构及其主要工作。采用分析和比较的方法,总结了容迟与容断网络路由协议和传输协议的主要研究成果,探讨了相关研究问题,分析比较了容迟与容断网络的仿真工具。最后总结并展望了容迟与容断网络进一步的发展方向。     

无线传感器网络密钥管理方案评估研究

针对如何选取有效密钥管理方案是实现无线传感器网络安全的关键问题,提出一种密钥管理方案的综合评估方法。该方法利用总结出的密钥管理方案的评估指标,构造了评估指标层次分析结构模型。结合模糊综合评判法,把评估密钥管理方案性能的主观因素限制在很小的范围内,有效地提高评估结果的准确度和可信度,可根据需要快速选择合适的密钥管理方案。实验验证该方法是有效的。     

An Index-Based Location Management Scheme for PCS Network

Location management provides the guarantee to deliver a call to mobile user during the mobility of user and it is a key challenge in wireless cellular networks. In this paper, we are introducing a new index-based location management scheme. It is based on indexing of location update information at the home agent of network. A tuple of index will keep track of range of location update information and corresponding thread of it, connected to stack of information table. To register a new mobile user, the mobile switching centre will generate a new identification number with the help of mobile switching centre identification number and temporary mobile subscriber identity of subscriber. If, the identification number is with in the range of index then, the Care of Address of mobile subscriber is added to information table else, the index will be reconstruct based on new range of identification number. It has been observed that in proposed technique, the call setup delay and network overheads is reduces over the limitation of minor increment of registration delay. The analytical model and numerical result represents the effectiveness of proposed scheme over the existing schemes.     

一种10 bit电流型DAC电流源晶体管的抗失配设计

在高速高精度电流型DAC的设计中,电流源晶体管的匹配问题是设计的关键。针对10 bit DAC提出了一种对梯度误差和边缘效应不灵敏的电流源晶体管布局方案,并从单元电流源晶体管尺寸的选取到该方案具有这种特性的原因及他的具体实现都做了详细的讨论。该方案已应用于四川登巅微电子有限公司的10 bit 500 M DAC中。     

一种基于QoS的空间延迟/中断容忍网络拥塞控制方法

为缓解网络拥塞对空间延迟/中断容忍网络产生的影响,该文提出一种基于QoS的网络拥塞控制算法。该算法包括接触拥塞判断和基于QoS的数据转发两种机制,分别从接触剩余可用容量和节点剩余存储空间两方面对每一段接触的拥塞程度进行预测,将接触划分为不同的拥塞等级。在计算路由时,以整段路径中所包含接触的最高拥塞等级为该路径的拥塞等级,并根据该拥塞等级发送不同优先级的数据。实验表明,基于QoS的拥塞控制算法可以提高低优先级数据的传递率并在节点存储空间不足时降低最高优先级数据的传递时延。     

野战地域网网管系统性能评估研究

野战地域网在军用通信系统中是重要的分组交换网络。介绍了野战地域网及其网管系统组成结构,阐述了网络管理系统评估技术的原则和内容,并根据评估内容提出了针对野战地域网网管系统的具体评估指标。最后简述在网络管理评估系统平台搭建过程中用到的一些技术及方法,通过框图的方式给出了网管评估系统的方案。     

一种神经网络控制器的容错设计与可靠性评估方法

本文以应用于电力控制系统中的人工神经网络快速汽门非线性适应控制器为例,详细论述了一种神经网络控制器的容错设计与可靠性评估方法,文中首先提出网络可靠性研究的重要性,以及本文所提出和容错设计与可靠性评估方法的通用性,然后详细介绍了一种神经网络快速汽门非线性适应控制器的设计结构和容错设计原理,最后根据设计的结果,得出了可靠性评估公式及其推广。