基于移动IPv6移动管理信令的QoS信令技术研究

第三代移动通信和第三代以后的移动通信网络都将向全IP移动通信网络发展,如何在移动IP上提供QoS将是一个非常棘手的问题.介绍了基于移动IPv6移动管理信令的扩展QoS信令,并且描述了基于此信令进行QoS协商的操作过程.     

第四代无线网络中的移动管理协议分析

第四代无线网络(4G)将是一个全IP的异构无线网络,支持各种无线接入技术和无缝漫游.4G网络的挑战之一就是智能移动管理技术的设计,因此重点分析了现有的一组移动管理协议(MIP-RO、MIPv6、HAWAII、蜂窝IP、MIP-RR、分层MIP、分层MIPv6、快速切换、IDMP、TeleMIP和DMA)的切换管理性能,并且比较研究了它们的系统参数.最后,针对4G无线网络的特点提出了进一步研究的课题.     

MPLS支持移动IP的QoS机制研究

随着移动技术和应用的迅猛发展,移动设备的用户希望在移动过程中保持因特网接入和连续通信,且仍能获得如固定接入一样的网络QoS。近年来对固定IP网的QoS研究取得了一定的成果,但对移动IP网的QoS研究还很不足。分析研究了国内外各种QoS技术,在Y.1281［1］框架结构的基础上,提出了一种基于QoS代理的移动 IP QoS机制,能基本解决移动环境下的QoS保障问题。     

移动环境下的QoS保证技术

1 引言各种Internet业务在全世界范围内的广泛应用推动了Internet技术的发展,IP协议原有的“尽力发送“机制已经不能很好地适应业务的需求,因此,IETF提出了资源预留协议和实时传输协议等来保证传输业务流的服务质量。同时,越来越多的移动用户要求能够连续无缝地接入Internet,为此I-ETF设计了移动IP协议以满足移动用户的需求。但是,由于移动环境中通信链路质量经常变化,可用的系统资源较少,通信过程中的多次切换可能导致连接中断,因此在移动环境下提供QoS保证需要新的机制。本文第2部分简述了基于固定网络的QoS保证机制,探讨了移动性对QoS的影响,第3部分介绍了几种在移动环境下提供QoS保证的技术,着重介绍了移动资源预留协议,并给出了移动QoS保证技术的研究方向,第4部分提出了一个新的移动QoS框架,最后给出了下一步要做的主要工作。     

分析第三代移动通信技术的现状及发展

随着社会的进步,第三代移动通信技术得到了较大的发展.所谓的第三代移动通信技术,就是我们生活中常说的3G,其中文翻译过来就是数字通信.我们分别第三代移动通讯及其前两代,可以看出明显的区别就是现在第三代通讯技术良好的全球无缝漫游电话,在数据的速度和传输声音上得到提升,所以它可以更加良好的全球无缝漫游电话图片,音乐等方面有明显的改进,这种进步可以处理包括会议,网页浏览,电子商务等等多种媒体形式的信息服务,同时也拥有与已有第二代移动通讯系统良好的兼容性.下面我就第三代移动通讯技术的现状及发展做以下的探讨.     

TD-SCDMA系统业务QoS仿真分析

Qos问题是第三代移动通信系统的一个重要技术问题.本文主要研究TD-SCDMA系统的QoS问题.利用OPNET Modeler软件,根据无线接入网络的协议构建网络仿真模型,参照3GPP技术规范定义的业务要求,对各种业务的QoS性能和指标进行了比较和分析.     

MPLS和移动IP的结合应用

移动IP协议提供主机在移动状态下接入IP网络并保持通信的能力,在基于IP骨干网的第三代无线通信系统中,移动IP协议被认为是支持移动性的一项重要协议。MPLS技术结合了三层转发的灵活和二层交换的高速,为骨干网络解决方案提供了高速的数据包转发能力和极大的可扩展性。     

现代IP网络QoS路由技术

1.引言无线通信和个人通信系统的发展,使网络的接入方式多样化。未来的互联网络将向由固定网络(有线网)、基础结构移动网络(如蜂窝无线网)和非基础结构无线网络(如 Ad Hoc网,简称自组网)组成的综合网络发展。为保证此综合服务系统端到端的服务质量(QoS),实现用户的“无缝”通信,是未来综合网络一个具有挑战性的领域,其中解决不同类型网络的QoS路由问题以及异构网络间路由互操作性问题是一个研究重点。近年来,国内外学者在有线网QoS路由方面做了大量的工作,而涉及无线/移动网方面的论文很少。本文将以QoS路由算法为主线,根据有线网和无线网中存在的问题,阐述QoS路由技术发展的方向。     

基于IPSec VPN的移动安全系统的设计与实现

为解决移动网络与固定IP网络之间跨网域的VPN安全接入问题，提出并实现了一种新型的基于IPSec VPN的移动安全系统。该系统在基于IPSec协议的虚拟专用网技术和远程访问服务的基础上，建立了一套完善的基于智能卡和X.509证书进行身份认证的机制，并且具有统一的安全信息服务平台。实验结果表明，该系统能够实现固网信息安全无缝地移动扩展。     

北电与德电信合作UMTS

近日,德国电信选择北电网络为其跨越欧洲的第三代通用移动电信系统(UMTS)网络提供无线因网基础设施的设备及服务,合同总金额达到3.2亿美元。根据协议,北电网络将为规划中的UMTS网络部署核心IP网络和部分无线电接入基础设施。     

QoS guaranteed integration methodology for a WLAN-WiMAX heterogeneous network

Wireless technologies which serve multimedia applications have to guarantee the Quality of Service (QoS) demands along with seamless connectivity. The complexity in attaining such demands increases if the network is heterogeneous in nature. This paper proposes a QoS guaranteed integration methodology for a heterogeneous wireless local area network (WLAN) - worldwide interoperability for microwave access (WiMAX) network. An integrated protocol stack for the mobile terminal which could work in a WLAN-WiMAX heterogeneous network is proposed. The proposed integrated protocol stack, a blend of two modules namely generic virtual link layer (GVLL) and media independent handover (MIH) is placed above the media access control (MAC) layer which includes both WLAN and WiMAX MAC. The impact of GVLL in guaranteeing the QoS on QoS deterioration and the impact of MIH in attaining seamless handover are analyzed and the results are presented.     

An IMS-based integration architecture for WiMax/LTE handover

To enable seamless handovers for broadband networks, many researchers have addressed the integration of heterogeneous access technologies to provide users with always-on connectivity. Currently, there are several researches reported in the literature that discuss the integration of beyond 3G networks such as 3GPP Long Term Evolution LTE and mobile WiMax networks. They mainly focused on providing mobile users with seamless mobility when switching between heterogeneous access networks. In this context, many solutions for integration architecture have been proposed with mobility management considerations such as loose and tight coupling, IP Multimedia Subsystem IMS-based architecture and Evolved Packet Core EPC-based solutions for the purpose of providing mobile users with seamless handovers. In this paper, we present the different integration solutions and propose an integration architecture for WiMax and LTE access technologies with EPC as core network and IMS for service provisioning. A vertical handover VHO scheme is presented based on cross-layer approach that enables vertical handover with less handover latency and signaling cost.     

A survey of vertical handover decision algorithms in Fourth Generation heterogeneous wireless networks

Vertical handover decision (VHD) algorithms are essential components of the architecture of the forthcoming Fourth Generation (4G) heterogeneous wireless networks. These algorithms need to be designed to provide the required Quality of Service (QoS) to a wide range of applications while allowing seamless roaming among a multitude of access network technologies. In this paper, we present a comprehensive survey of the VHD algorithms designed to satisfy these requirements. To offer a systematic comparison, we categorize the algorithms into four groups based on the main handover decision criterion used. Also, to evaluate tradeoffs between their complexity of implementation and efficiency, we discuss three representative VHD algorithms in each group.     

移动WiMAX的切换机制

实现链路的无缝切换是支持移动网络的关键技术。为了使切换过程中的包丢失和包延迟最小,对IEEE802.16e标准中规定的移动宽带无线接入系统的切换过程进行研究。针对WiMAX网络体系结构中的系统内切换、系统间切换以及实现端到端QoS保证的切换3种主要切换方式,介绍相应的切换机制,描述主要切换流程,并给出改进机制和最新研究成果。     

A novel terminal-controlled handover scheme in heterogeneous wireless networks

In the next generation heterogeneous wireless networks, a mobile terminal (MT) with a multi-interface may have network access from different service providers using various technologies. In spite of this heterogeneity, seamless intersystem mobility is a mandatory requirement. One of the major challenges for seamless mobility is the creation of a vertical handover scheme, which is for users that move between different types of networks. In this article a seamless mobility handover scheme is presented. The novelty of the proposed scheme is that handover is fully controlled by the terminal. To improve the performance of the proposed handover scheme, a network discovery algorithm with fuzzy logic and a handover decision algorithm using multi criteria decision making (MCDM) based on vague sets are derived, which are both user-centric. With these algorithms, the handover scheme is power-saving, cost-aware, and performance-aware. Simulation results show that the novel handover scheme can perform network discovery in time to reduce handover dropping rate and present unnecessary activation of its interface to save the battery power, while effectively choose the optimum network through making trade-off among the user preference, network condition, and system performance.     

Performance evaluation of e-commerce requests in wireless cellular networks

Recent technological advances in mobile devices and wireless networks enable mobile users to order goods in an anywhere and anytime fashion. Quality of Service (QoS) provision is one of the most challenging issues in the heterogeneous wireless network-based e-commerce systems. Such e-commerce systems enable users to roam between different wireless networks operators and geographical areas while providing interactive broadband services and seamless connectivity. Due to movement of users during e-commerce requests, one of the most important QoS factors for successful completion of users' requests is related to handover of request from one cell to another. A handover could fail due to unavailability of sufficient bandwidth in the destination cell. Such failure of ongoing e-commerce requests is highly undesirable and can cause serious problems to the e-commerce users and the service providers. This paper proposes an enhanced priority queuing based handover scheme in order to ensure a seamless connectivity of e-commerce requests. It focuses on the performance anaylsis of the proposed scheme. Experimental study demonstrates that the proposed scheme provides QoS with low connection failure and mean response time for handover of e-commerce requests.     

Optimization for adaptive bandwidth reservation in wireless multimedia networks

In future wireless multimedia networks, user mobility management for seamless connection regarding realtime multimedia applications is one of the most important problems. In this paper we propose an opportunity-cost concept-based approach for adaptive bandwidth reservation with admission control for handover calls utilizing network traffic information. Excessive reservation guarantees low blocking probability of handover calls at the cost of high blocking probability of new calls. According to our survey, however, it may degrade bandwidth utilization while no prioritization for handover admissions degrades quality of service (QoS) for ongoing calls. We consider both QoS assurance and bandwidth utilization in order to optimize the amount of bandwidth to reserve for handover admissions. We believe that our scheme could be utilized as a guideline for cost-effective radio resource allocation in mobile multimedia networks.     

Optimization of QoS parameters using scheduling techniques in heterogeneous network

Multimedia applications in wireless communication have been increased in recent years. A variety of wireless access technologies is introduced for various needs. The abundant increase in mobile computing devices and different networking systems leads to the support of user’s mobility on heterogeneous network. In general, the roaming users migrate between two different wireless technologies and their service must be supported by vertical handover (HO). Since the roaming users expect a rapid handover experience while switching from one wireless network to another, the handover operation must be enhanced by the networks. Various wireless technologies such as wireless LAN, Worldwide Interoperability for Microwave Access (WiMAX), and the 3G Partnership Project (3GPP) are interlaced to support many wireless services in rural, urban, and global scenarios. Moreover, quality of service (QoS) has become more significant in many applications where wireless network resources are utilized. In this paper, a handover management scheme is proposed for QoS enhancement in roaming users between WiMAX and WLAN by subscribers of networks belonging to the 3GPP standards. The proposed algorithms genetic queuing, proportionally fair queuing, and WiMAX aware load balancing are analyzed in the scheduling process during handover. The simulation is implemented using NS–2 and the experimental results are obtained for the proposed algorithms and compared with the standard scheme.     

An efficient design and validation technique for secure handover between 3GPP LTE and WLANs systems

Future generations wireless systems, which integrate different wireless access networks together, will support a secured seamless mobility and a wide variety of applications and services with different quality of service (QoS) requirements. Most of the existing re-authentication protocols during vertical handover still have certain limitations such as man in the middle, eavesdropping and session hijacking attacks, and unacceptable delay for real time applications. In this article, we propose two re-authentication schemes to secure handover between 3GPP LTE and WLANs systems: Initial Handover Re-authentication Protocol, and Local Re-authentication Protocol. The second proposed protocol is executed locally in a WLAN network without contacting the authentication server of the home network for credentials verification. In fact, after a successful execution of the Initial Handover Re-authentication Protocol, the local key (LK) is shared between USIM and the authentication server of the WLAN. It is then used for securing handover and traffic in WLAN networks. Performance evaluation results obtained using simulation analysis show that the proposed re-authentication protocol enhances handover parameters such as handover latency, handover blocking rate and packet loss rate. Additionally, the proposed enhanced fast re-authentication protocol has been modeled and verified using the software AVISPA and is found to be safe.     

A survey on applications of IEEE 802.21 Media Independent Handover framework in next generation wireless networks

Integration of various wireless access technologies is one of the major concerns in recent wireless systems in which multi-technology mobile devices are provided to users to roam between different access networks. Being an essential part in heterogeneous wireless systems, vertical handover is more complex than conventional horizontal handover. As IEEE 802.21 Media Independent Handover (MIH) is the standard addressing a uniform and media-independent framework for seamless handover between different access technologies, many works have been carried out in the literature to employ MIH services in handover management This paper presents a comprehensive survey of the proposed mobility management mechanisms that are using this framework. As a comparative view, the paper categorizes the efforts according to the layer of mobility management and evaluates some of the representative methods discussing about their advantages and disadvantages The paper also looks into recent handover decision and interface management methods that are exploiting MIH Moreover, the extensions and the amendments proposed on MIH are overviewed.