Integrated Mobility Management Methods for Mobile IP and SIP in IP based Wireless Data Networks

With developments in voice over IP (VoIP), IP-based wireless data networks and their application services have received increased attention. While multimedia applications of mobile nodes are served by Session Initiation Protocol (SIP) as a signaling protocol, the mobility of mobile nodes may be supported via Mobile IP protocol. For a mobile node that uses both Mobile IP and SIP, there is a severe redundant registration overhead because the mobile node has to make location registration separately to a home agent for Mobile IP and to a home registrar for SIP, respectively. Therefore, we propose two new schemes that integrate mobility management functionality in Mobile IP and SIP. We show performance comparisons among the previous method, which makes separate registration for Mobile IP and SIP without integration, and our two integrated methods. Numerical results show that the proposed methods efficiently reduce the amount of signaling messages and delay time related to the idle handoff and the active handoff.     

An End-To-End Approach for Transparent Mobility Across Heterogeneous Wireless Networks

With the advent of a myriad of wireless networking technologies, a mobile host today can potentially be equipped with multiple wireless interfaces that have access to different wireless networks. It is widely perceived that future generation wireless networks will exhibit a similar trend in supporting a large variety of heterogeneous wireless access technologies that a mobile host can choose from. In this paper, we consider such a multi-homed mobile host and propose an end-to-end solution that enables the seamless use of heterogeneous wireless access technologies. The unique features of the proposed solution include: (i) a purely end-to-end approach to handle host mobility that requires no support from the underlying network infrastructure, (ii) seamless vertical handoffs when the mobile host migrates from one access network to another, (iii) ability to support different congestion control schemes for a live connection traversing different interfaces, and (iv) effective bandwidth aggregation when the mobile host has simultaneous access to multiple networks. We present the design and details of the proposed approach, and evaluate its performance through simulations and real-life field experiments.     

B3G无线异构网络的切换技术研究

移动性管理技术是实现异构网络融合的关键技术之一,而切换管理对移动性管理显得尤为重要.针对未来异构网络的特点,本文研究了相应的切换机制,并对不同方案进行了比较分析.结果表明,两种混合式方案具有较好的切换性能,极具应用潜力.     

Mobility Management for Hierarchical Wireless Networks

In this paper, we consider the mobility management in large, hierarchically organized multihop wireless networks. The examples of such networks range from battlefield networks, emergency disaster relief and law enforcement etc. We present a novel network addressing architecture to accommodate mobility using a Home Agent concept akin to mobile IP. We distinguish between the physical routing hierarchy (dictated by geographical relationships between nodes) and logical hierarchy of subnets in which the members move as a group (e.g., company, brigade, battalion in the battlefield). The performance of the mobility management scheme is investigated through simulation.     

Wireless IP and Its Challenges for the Heterogeneous Environment

The tremendous momentum toward building a mobile wireless Internet using the Internet Protocol (IP) has thrust many challenges upon the technology developers and the operators. These challenges encompass the 2.5G, 3G, and future solutions and standards. Some of the key issues deal with supporting IP traffic across different wireless and MAC protocols, end-to-end QoS and mobility, traffic engineering and scalability, protection/restoration, operations and management, authentication/privacy/security, billing, and content and context aware networking. This article addresses the drivers, the issues, and solutions (wherever possible) in the above areas, and concludes with a summarization of the challenges that lie ahead.     

Mobility and QoS Support in Mobile IP Networks

1　IntroductionAnall IP basedmobilenetworksuchas 4G ,whoseaccessandcorenetworksarebasedonIP ,hasintrinsicadvantagesoverits predecessors.Forstarters ,IPiscompatiblewith ,andindependentof,theactualradioaccesstechnology .WithIP ,onecanbasicallygetridofthelock inbetweenthecorenet workprotocol,thelinklayerandtheradioaccessprotocol.IPtoleratesavarietyofradioaccessproto cols.Itsupportsthedesignofacorenetworkthatgivescompleteflexibilitynomatterwhattheradioaccessnetworkis.Onecouldbeacorenetworkpro…     

3G无线网络的IP技术研究

论述了当前主要研究的支持3G无线网络的IP技术、移动IP、蜂窝IP、HAWAII和TeleMIP，并对它们进行了比较分析，总结了当前的无线IP技术的特点和发展趋势。     

On the Impact of Quality of Protection in Wireless Local Area Networks with IP Mobility

Wireless local area networks (LANs) are vulnerable to malicious attacks due to their shared medium in unlicensed frequency spectrum, thus requiring security features for a variety of applications even at the cost of quality of service (QoS). However, there is very little work on investigating to what extent system performance is affected by security configurations with respect to mobility scenarios, heterogeneous networks, and different applications. In order to exploit the full potential of existing security solutions, we present a detailed experimental study to demonstrate the impacts of security features on performance by integrating cross-layer security protocols in a wireless LAN testbed with IP mobility. We introduce a quality of protection (QoP) model to indicate the benefits of security protocols and then measure the performance cost of security protocols in terms of authentication time, cryptographic overhead and throughput. Our measurements demonstrate that the effects of security protocols on QoS parameters span a wide range; for example, authentication time is between 0.11 and 6.28 s, which can potentially affect packet loss dramatically. We also find that for the same security protocol throughput in non-roaming scenarios can be up to two times higher than that in roaming scenarios. However, some protocols are robust against mobility with little variation in system performance; thus, it is possible to provision steady service by choosing security protocols when users’ mobility pattern is unknown. Furthermore, we provide observations on cross-layer security protocols and suggestions to the design of future security protocols for real-time services in wireless LANs.

基于双向匹配模型的异构网络垂直切换算法

针对当前垂直切换判决算法存在的单一性,即切换判决时以用户或网络单方面为中心,没有充分考虑两者对切换判决的综合影响,导致垂直切换性能不佳的问题,该文提出一种基于双向匹配模型的垂直切换算法。该算法的主要思想是：首先分别以用户和网络为中心,设计各自的评估模型,用于评估双方对彼此的偏好顺序,并建立相应的排序值矩阵;其次利用排序值信息,基于一对多双向匹配模型对用户侧和网络侧的双向匹配行为进行建模和求解,以获得最优匹配解;最后根据最优匹配结果,进行垂直切换。仿真表明,该文设计的评估模型是合理的,并且所提出的算法能较好地兼顾用户侧的高性价比需求和网络侧的低阻塞率需求。     

全IP通信网络中的移动性管理

文章描述了全IP网络各个层次上的移动性管理需求以及全IP网络目前的标准和规范，详细介绍了移动性管理中的宏移动性管理、微移动性管理、空中接口移动性管理。指出了全IP网络中移动管理的研究方向。     

Traffic Characteristics Based Dynamic Radio Resource Management in Heterogeneous Wireless Networks

The traffic with tidal phenomenon in Heterogeneous Wireless Networks （HWNs） has radically increased the complexity of radio resource management and its performance analysis. In this paper, a Simplified Dynamic Hierarchy Resource Management （SDHRM） algorithm exploiting the resources dynami- cally and intelligently is proposed with the consideration of tidal traffic. In network-level resource allocation, the proposed algorithm first adopts wavelet neural network to forecast the traffic of each sub-area and then allocates the resources to those sub-areas to maximise the network utility. In connection-level net- work selection, based on the above resource allocation and the pre-defined QoS require- ment, three typical network selection policies are provided to assign traffic flow to the most appropriate network. Furthermore, based on multidimensional Markov model, we analyse the performance of SDHRM in HWNs with heavy tailed traffic. Numerical results show that our theoretical values coincide with the simulation results and the SDHRM can im- prove the resource utilization.     

一种LTE异构网络下的移动性优化方法

长期演进(LTE)网络是3GPP定义的先进移动网络系统,相比现有的2G和3G网络,LTE网络的用户(UE)更加密集、站间距更小、更多的小基站加入系统,从而使UE移动性管理面临更大的挑战.为此,提出了一种新型UE切换方法.仿真结果显示,新方法能够很好地解决密集LTE异构网络中UE切换失败率高的问题,性能优化显著.     

一种分层多跳无线网中的移动性管理策略

该文介绍一种分层多跳无线网与其他骨干网络互连情况下的网络层移动性管理方案。它使用了包含逻辑家乡代理的宏移动性管理和将位置管理与路由和寻呼机制结合起来的微移动性管理的思想,以提高网络在战场等特殊情况下使用的可靠性和抗毁性,减小位置管理的开销,节省无线信道的带宽。     

异构无线网络中基于业务转移和接入控制的混合负载均衡

 针对现有异构无线网络负载均衡方法未能综合考虑重载网络业务转移和新业务接入控制的问题,提出了一种混合负载均衡算法.该算法首先根据各小区负载水平和终端移动性,将重载小区的适量业务向重叠覆盖的轻载小区转移;其次通过资源预留和强占优先的接入控制策略,为不同优先级的新到业务提供有差别的服务.仿真结果表明,本文算法在保证系统资源利用率的同时,保障了实时与非实时业务的QoS,并相对于参考算法有效降低了系统阻塞率和业务切换概率.     

一种改进的支持无线IP网络的资源预留协议

移动IP技术能够支持基于IP的无线网络,资源预留协议(RSVP)用来保证多媒体传输的服务质量。然而把现有的RSVP应用于移动IP网络就会存在许多问题。提出了一种改进的RSVP支持方案(ERSVP)来实现无线IP网络的服务质量保证。ERSVP在分层网络中结合了MRSVP和RSVP隧道技术。根据性能分析,ERSVP方案能够获得比MRSVP较少的信令延迟、信令负载和资源耗费。     

异构无线网络环境下的网络接入选择算法研究

针对QoS对网络选择的影响,分析了当前的网络选择算法的SAW,GRA,MEW和TOPSIS,提出改进的RafoQ(Ranking for QoS)网络选择算法。仿真结果表明,与现有的网络选择算法相比,改进的RafoQ选择算法在时延、抖动性以及丢包率方面具有明显的优势。     

交互式异构无线网络垂直切换的中间件架构

异构无线网络研究的关键之一在于按照用户的应用要求,在不同网络之间实现垂直切换。文章面向多模移动终端提出交互式垂直切换中间件架构,描述了架构的功能组成体系,阐明了在多模移动终端上交互式简单快速地设置垂直切换所需参数或权重的界面。给出了按层次分析法AHP进行垂直切换的中间件实现流程的一个例子。     

支持移动无线接入的IP网络QoS保证技术

针对服务质量(QoS)保证技术问题,从移动性、无线链路特性和IP网络传统的QoS保证技术的改进几个方面出发,对下一代支持多种移动无线接入的IP网络中,QoS保证技术的相关研究热点及技术现状进行了分析和总结,并提出了本研究方向QoS分层模型和进一步的研究建议。     

LTE-A中异构蜂窝网络下的切换技术研究

随着小型蜂窝基站的大量部署,异构网络环境越来越复杂,为了保证用户在小型蜂窝基站和宏基站的无缝移动,用户对移动性管理也提出了更高的要求。因此,异构蜂窝网络的移动性管理成为未来通信的一个重要技术。本文针对小型蜂窝基站的大量部署和用户的频繁移动带来的切换问题进行分析,总结了LTE-A切换的基本知识,并进一步归纳了LTE-A中异构蜂窝网络下切换技术的关键研究点。     

异构网络中基于角度移动模型的垂直切换率分析

异构网络中终端的移动特性是无线资源分配的一个重要因素,本文给出了一种终端的角度移动模型,分析了该模型下终端移动的方向角特点。根据终端移动的方向角特点,推导了用户在固定的时间间隔T内运动方向不变时的切换率闭合公式,并将时间间隔T趋于零时的切换率的理论极限值作为一个特例,从切换率的理论极限值可以明显看出,切换率与用户分布密度、用户移动速度以及小区半径之间的关系,通过切换率的计算说明了在一定条件下,小区内用户数是动态平衡的。然后进一步推导了异构网络中垂直切换率的闭合公式,并仿真证明了理论分析的正确性。仿真结果表明,在终端移动方向改变频繁、终端移动速率很低或者小区半径足够小时,可以利用切换率的理论极限值来近似实际切换率,这样可以有效降低理论计算切换率的复杂度。