Performance analysis of proxy mobile IPv6 based on IEEE802.16e

Proxy mobile Internet protocol version 6 (PMIPv6) is a network-based mobility management protocol proposed by Internet Engineering Task Force (IETF), which allows nodes to remain service connectivity while moving around in the IPv6 Internet. PMIPv6 is different from the host-based mobility management protocols (mobile Internet protocol version (MIPv6), hierarchical mobile IPv6 (HMIPv6), fast handover for mobile IPv6 (FMIPv6), and fast handover in hierarchical mobile IPv6 (F-HMIPv6)), whose signaling are transferred among some network entities except mobile node (MN). This paper focuses on the analytical modeling of performance analysis for PMIPv6 and other protocols using IEEE802.16-based wireless metropolitan area networks as the wireless access network. The performances of these protocols are evaluated by some metrics like handover latency, service disruption time, and binding update cost. Numerical results show that PMIPv6 has better performance.     

Mobility and the Internet

The Internet Protocol (IP) was never intended for mobility. Nevertheless, we need to provide this functionality without changing the underlying protocol. If we could start over again, hindsight would provide a wealth of wisdom in implementing a mobility protocol. However, given the installed base, the overriding design requirement must be to remain compatible with the standard IP. Mobile-IP must be able to support mobility for both wired and wireless local area networks (LANs). The Mobile-IP must be able to function in the harsh, wireless world where high error rates are the norm and bandwidth is limited. The paper considers how the design must accommodate a mobile host moving between wireless LANs, as well as between a wire and wireless LAN. It discusses the design requirements, multicasting and tunneling     

TCP performance over mobile ad hoc networks

TCP is a transport protocol that guarantees reliable ordered delivery of data packets over wired networks. Although it is well tuned for wired networks, TCP performs poorly in mobile ad hoc networks (MANETs). This is because TCP's implicit assumption that any packet loss is due to congestion is invalid in mobile ad hoc networks where wireless channel errors, link contention, mobility and multipath routing may significantly corrupt or disorder packet delivery. If TCP misinterprets such losses as congestion and consequently invokes congestion control procedures, it will suffer from performance degradation and unfairness. To understand TCP behaviour and improve the TCP performance over multi-hop ad hoc networks, considerable research has been carried out. As the research in this area is still active and many problems are still wide open, an in-depth and timely survey is needed. In this paper, the challenges imposed on the standard TCP in the wireless ad hoc network environment are first identified. Then some existing solutions are discussed according to their design philosophy. Finally, some suggestions regarding future research issues are presented.     

网络移动路由优化技术探讨

网络移动性技术是下一代网络研究中的热点技术之一。文章介绍了网络移动性技术的基本概念以及移动网络的基本架构,重点分析了网络移动基本支持方案中的注册和分组传送过程,并结合M IPv6路由优化机制和M IP微移动技术对分组传送过程进行优化,基于网络移动技术尚存的一些主要问题,提出了下一步研究方向。     

基于负载感知和伪流言机制的高稳定性路由协议

通过建立无人机自组网可以有效满足无人机集群作战的组网通信需求,但相较于传统移动自组网,无人机自组网具有节点移动速度更快,网络拓扑高度动态变化的显著特征.针对链路频繁断开带来网络性能下降严重的问题,提出了一种基于负载感知和伪流言机制的高稳定性路由协议.网络拥塞和节点移动性是影响路径稳定性的两个主要因素.针对网络拥塞问题,提出了基于节点负载预测的伪流言受限洪泛机制,在发起路由请求过程中,通过动态调整节点转发概率,均衡了网络负载的同时降低了控制开销.针对无人机节点的高移动性特征,基于接收到分组信号功率强度,提出了链路稳定性的联合度量指标.仿真结果表明,与AODV协议及其他改进型协议相比,该协议有效减少了网络的控制开销,提高了分组投递率,降低了平均端到端时延,显著改善网络性能,增强了数据传输的实时性和可靠性.     

河北电力调度数据网建设的技术探讨

以河北电力调度数据网为例,对调度数据网络规划建设过程中涉及的技术问题,如网络拓扑、IP（internet protocol）地址规划、OSPF（open shortest path first）协议和VPN（virtual private network）部署等进行探讨,并提出解决方法和基本原则。     

移动IPv6设计实现的研究

移动IPv6作为下一代的移动技术,在IPv6网络上为所有的移动节点提供无缝移动的解决方案.为了支持移动性,需要通过信令架构来支持移动检测和传递机制来保障网络及节点的可达性.本文的研究重点为:设计一种具有普遍意义的、易于实现的系统软件架构来满足移动IPv6及其扩展应用的要求.架构将网络功能定义在2个平面.控制平面和数据平面.控制平面在用户空间实现信令协议,通过为移动IPv6设计的通信接口和内核空间交互,带给功能扩展上的优势,减少对内核空间的要求;数据平面处理移动IPv6的报文的转发,运用于网络处理器和多核处理器的快速路径,以提高转发的性能.这种分平面的软件架构适合开发复杂的协议,比如移动IPv6、移动网络(NEMO)及其快速切换等.文中具体给出了系统软件结构的设计原理与实现方法的论证.     

Access network selection strategy using position prediction in heterogeneous wireless networks

Access network selection (ANS) strategy is one of the most important issues in future heterogeneous networks. The current solutions for this issue are not very efficient because they do not consider the motion scenarios and cannot predict the next location for mobile node. In this paper, an effective ANS strategy based on global positioning system (GPS) is proposed. Making use of information such as position coordinates and moving velocity acquired by GPS, the ANS proposed can predict the next point of attachment for mobile node (MN), assist existing ANS strategy to make more reasonable decision, and achieve better performance.     

WLAN和Cellular IP融合

为能提供更好的移动接入Internet的服务,文中通过Mobile IP技术融合WLAN和Cellular IP两种网络,形成一种新的网络.这个新的综合网可以为移动Internet用户提供更高的接入速率,更广阔的漫游范围.     

Is microwave backhaul up to the 4G task?

Recent developments in the microwave industry support both the lowest cost per Mb/s transport and maximum Mb/s/MHz. With the evolution toward the fourth generation of mobile networks, the backhaul network--that portion of the network infrastructure that provides interconnectivity between the base stations and the core network--is expected to come under intense pressure as capacity requirements increase to support new mobile broadband services. There are many who fear that the backhaul network may well inhibit or delay the introduction of these new services, negatively impacting the end-user's quality of experience. As a key technology used in backhaul networks around the world, point-to-point microwave is rapidly evolving to support this increasing capacity demand, improve network efficiency, and allow operators to reduce network operational costs. This article details how recent developments in the microwave industry support both the lowest cost per Mb/s transport and also the maximum Mb/s/MHz. These developments embrace the dramatic shift to support Internet protocol (IP) network convergence, including the key features to enable link capacities not previously seen in the industry, and the new methods developed to enable every last drop to be squeezed out of the finite resource that is the available frequency spectrum.     

多模终端切换管理模块的设计

未来网络的发展趋势必然是多种异构网络的融合。为了能够随时接入最合适的网络,并在异构网络之间进行无缝切换,多模终端切换管理模块的设计就成为了一个关键问题。本文正是针对这一问题,设计了多模终端基于802.21协议的无缝切换功能架构。本文提出的切换管理模块具体分为切换测量模块、切换判决模块和切换执行3个模块,具体定义了各个子模块分别与TCP/IP的不同层次进行的信息交互,各个子模块之间进行的信息传递。通过该切换管理模块,既可以充分考虑到不同层面的需求,又可以及时开始并完成切换过程,最大限度的减少切换中断时间,从而实现完整的无缝切换机制。     

基于网络的局域性移动性管理研究

目前的全局性移动性管理方案存在着许多缺点,不适合未来移动性对于低时延、低复杂度、易于管理的要求。为此本文分析了全局性移动性管理的局限性,针对移动终端局部的小范围的移动需求,提出了一种基于网络的局域性移动性管理解决方案F-PMIPv6,该方案将快速切换的方法应用到PMIPv6协议中,极大地缩短了切换时延,可以适用于时延敏感的业务。     

Challenges of intervehicle ad hoc networks

Intervehicle communication (IVC) networks, a subclass of mobile ad hoc networks (MANETs), have no fixed infrastructure and instead rely on the nodes themselves to provide network functionality. However, due to mobility constraints, driver behavior, and high mobility, IVC networks exhibit characteristics that are dramatically different from many generic MANETs. This paper elicits these differences through simulations and mathematical models and then explores the impact of the differences on the IVC communication architecture, including important security implications.     

海洋监测无线传感器网络的节点数目量化分析

随着无线传感器网络技术应用于海洋监测,节点的部署及网络的性能必然受到海面环境的影响。文中引入并改进了在海洋搜救中常用的Leeway漂流模型,对随机部署在海洋表面的传感器节点运动状态进行建模。仿真分析了在不同海况下,传感器网络区域覆盖率及网络连通性受其运动状态的影响。最后,从工程应用的角度提出对于特定区域的持续监测时间这一概念,来衡量运动的传感器网络对于特定海域的监测能力,仿真并验证给出了满足该指标所要部署节点的具体数目。     

面向城市能源互联网的电力物联网内涵、架构和关键技术

电力物联网是保障电力系统安全可靠、经济高效运行的重要基础,也是支撑城市能源互联网的基础平台。为此,文章对面向城市能源互联网的电力物联网内涵、架构和关键技术进行了深入探讨和分析。首先,梳理和分析了城市能源互联网和电力物联网的区别,并指出了面向城市能源互联网的电力物联网内涵;其次,分别提出了面向城市能源互联网的电力物联网的体系架构、物理架构和系统架构;最后,结合现有的“云大物移”、电力光纤入户、“四网融合”和“三表集抄”等技术,从信息化和通信化2个角度阐述了面向城市能源互联网的电力物联网关键技术内容及其现存的不足,以期为未来城市能源互联网的发展和研究提供一定的借鉴。     

A Programmable Framework for the Deployment of Services and Protocols in Mobile Ad Hoc Networks

Mobile ad hoc networks (MANETs) are characterized by their heterogeneity and the diverse capabilities of their nodes given that almost any device with a wireless network interface can join such a network. In such an environment it is difficult to dynamically deploy services and protocols without a common understanding among the participating nodes and their capabilities. A deployment/provisioning framework must cope with the high-level of device heterogeneity, degree of mobility, and should also take into account the potentially limited device resources. This paper presents a context-based programmable framework for dynamic service/protocol deployment that allows the nodes of a mobile ad hoc network to download and safely activate required service/protocol software dynamically. Downloading and activation can be triggered through preconditions evaluated according to available contextual information. This strategy leads to the alignment of the nodes' capabilities so that common services and protocols can be deployed even if they are not available at every node. In addition, dynamic context-driven deployment may lead to a degree of network self-optimization. We present the programmable framework and functionality and evaluate its various aspects through testbed experimentation, simulation and analytical modeling. The results demonstrate good performance with respect to the supported functionality.     

Beyond 3G

Beyond 3G is the official IEEE designation for the next stage of wireless technology that some people call 4G or fourth-generation radio. Over the years, every conceptual shift in wireless technology has been characterized as a generational change. Third generation includes wideband mobile multimedia networks and broadband mixed wireless systems. The mobile systems support variable data rates depending on demand and the level of mobility. Typically 144 kb/s is supported for full vehicular mobility and higher bandwidths for pedestrian levels of mobility. Switched packet radio techniques and wideband CDMA-like systems (as the physical channel is) rather than assigned physical channel schemes (referred to as circuit switched) are required to support this bandwidth-on-demand environment. There are two essential concepts beyond 3G. One of these is the provision of data transmission at rates of 100 Mb/s while mobile and 1 Gb/s while stationary. The other concept is that of pervasive networks where a handset supports many access technologies (e.g., cellular, UMTS, and WiFi) perhaps simultaneously and smoothly transitions between them     

基于改进深度信念网络模型的中长期径流预测

为提高流域中长期径流预测效果,提出径流综合指数构建、因子筛选和改进深度信念网络模型相结合的预测方法。首先研究不同水文站点(细粒度)月平均径流的一致性,构造流域径流综合指数(粗粒度),在较宏观层面研究流域水情丰枯变化;接着采用基于信息熵的因子筛选方法,获得影响流域水情丰枯变化的关键因子集,形成深度学习的输入;然后利用改进的深度信念网络(IDBN)模型进行预测。以雅砻江流域为例,将所建模型与多元线性回归、自回归移动平均、反向传播(BP)神经网络、支持向量机和传统深度信念网络等预测模型进行对比分析。结果表明:所提方法具有较好的实用性,且IDBN模型具有更好的预测速度和精度。研究结果可为流域中长期径流变化趋势预测提供参考。     

An optimized collaborative filtering method to construct spatial‐temporal behavior pattern‐based user interest model

Mobile social network (MSN ) has properties of real time, mobility, and social relationship, and provides more real‐time, more dimensional, and more heterogeneous metadata. The traditional user interest models represent mobile users' interests unsatisfactorily because of these inherent characteristics. This paper aims to combine the characteristics of mobile social networks appropriately to build a user interest model effectively for representing user interests. The constructed model is supposed to enable users to filter uninterested information, to provide personalized mobile service, to solve information overload, and to gain a good user experience. In order to realize these, first, we explore various issues of the traditional user interest model, and analyze the numerous problems in using traditional models to represent mobile user interests. Then a user spatial‐temporal behavior pattern in conjunction with mobile personalization attributes and context information is proposed, which is followed by a proposal of a user interest model to represent user interests. Second, we introduce a hybrid collaborative filtering method based on users and subjects to calculate user interests and to build the user interest model, considering the user interest extensive degree, the subject popularity, as well as the user influence. Finally, a model construction algorithm is proposed based on the user's spatial‐temporal behavior pattern. Experimental results show that the proposed model can represent user interests effectively under the mobile social network. Furthermore, it is verified that the adaptability and accuracy of the construction algorithm are significantly improved by considering the user interest extensive degree, the subject popularity, and the user influence. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于网络仿真器NS2的Ad hoc网络路由协议仿真

NS2是一种免费的功能强大的网络仿真器。无线Ad hoc网络作为一种典型的自组织网络,其路由协议一直是应用研究的重点问题。本文介绍了基于Linux平台的NS2仿真器针对Ad Hoc网络路由协议的仿真过程。以仿真AODV(Ad hoc on-demand distance vector)协议为例介绍了NS2仿真路由协议的详细步骤,给出了仿真中使用的TCL脚本程序、gawk性能分析程序、仿真结果图和一些性能分析。结果表明,业务源数目增加的情况下,分组投递率、路由发现频率、归一化路由开销和端到端平均时延等性能都有所下降。