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作为新一代的宽带无线接入技术IEEE 802.16d/e以自身固有的优势正越来越受到关注。相比于固定接入的WiMAX,移动版WiMAX,即IEEE 802.16e具有更好的市场前景,同时也面临更多的挑战。文章在分析和研究了IEEE 802.16e标准中定义的切换模式的基础上,总结了现有的IEEE 802.16e切换机制的研究现状,并建议为IEEE 802.16e的移动宽带接入网络提出一种具有QoS保证的支持无缝移动的移动性管理架构,从而实现了IEEE 802.16e的MS和网络中的通信对端之间实现具有端到端QoS保证的平滑服务。 相似文献
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1999年,IEEE成立了802.16工作组专门从事宽带无线接入标准的研究,到目前为止相继发布了IEEE 802.16、IEEE802.16a、IEEE 802.16d、IEEE 802.16e等一系列的技术标准.IEEE 802.16d对IEEE 802.16和IEEE 802.16a进行了整合和修订,是一项固定宽带无线接入技术的标准,主要用于固定、游牧等场景.而IEEE 802.16e是基于IEEE 802.16d标准的,能够后向兼容IEEE 802.16d的功能.该标准定义了可以同时支持固定和移动宽带无线接入的系统,工作在2~6 GHz适于移动性的频段,可支持车速移动(通常认为是120 km/h)的用户,同时固定无线接入用户能力并不因此受到影响.这种既能够提供高速数据业务又使用户具有移动性的技术被业界视为目前唯一能与3G竞争的下一代宽带无线技术.在物理层,802.16e可以支持2048点、1024点、512点的OFDMA,以适应不同的信道带宽.同时为了实现移动性,802.16e规定出了切换以及终端节电模式等技术.下文将对切换和终端节电模式这两种技术分别进行介绍. 相似文献
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IEEE802.16e标准在继承802.16d固定宽带无线接入技术优点的基础上,增加了对移动性的支持。文中介绍了802.16e标准的协议模型,给出了以802.16e为基础的宽带无线城域网技术WiMAX的网络架构;主要针对802.16e的移动性管理进行了探讨,重点讨论了ASN内切换和ASN间切换的过程。 相似文献
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基于IEEE802.16协议族的WiMAX网络将按照固定、游牧、移动的趋势发展,其中802.16e协议是面向全面移动性的。802.16e对接口物理媒体控制层(PHY)做了重大改进,并在媒体接入控制层(MAC)增加了切换流程等新特性。文中给出了WiMAX的网络系统结构,详细描述了WiMAX网络系统结构中有关系统内和系统间两种主要的切换方式,介绍了其切换机制,并给出了其切换流程图和主要切换步骤。 相似文献
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1999年,IEEE成立了802.16工作组专门从事宽带无线接入标准的研究,到目前为止相继发布了IEEE802.16、IEEE802.16a、IEEE802.16d、IEEE802.16e等一系列的技术标准。IEEE802.16d对IEEE802.16和IEEE802.16a进行了整合和修订,是一项固定宽带无线接入技术的标准,主要用于固定、游牧等场景。而IEEE802.16e是基于IEEE802.16d标准的,能够后向兼容IEEE802.16d的功能。该标准定义了可以同时支持固定和移动宽带无线接入的系统,工作在2~6GHz适于移动性的频段,可支持车速移动(通常认为是120km/h)的用户,同时固定无线接入用户能力并不… 相似文献
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城域宽带无线接入技术及其标准 总被引:4,自引:0,他引:4
阐述了无线城域网(WMAN)中BWA的原理,介绍了IEEE802.16标准制定的最新状况,并探讨了基于IEEE802.16a、IEEE802.16e及IEEE802.20标准的下一代WMANBWA系统的发展前景。 相似文献
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A Cross-Layering Design for IPv6 Fast Handover Support in an IEEE 802.16e Wireless MAN 总被引:1,自引:0,他引:1
Broadband wireless access networks, such as the IEEE 802.16 standard for wireless metropolitan area networks (WMANs), aim to provide high bandwidth, low-cost, scalable solutions that extend multimedia services from backbone networks to wireless users. Because of a larger coverage area, portability and mobility have become significant issues for providing high quality mobile services, as it is crucial to minimize handover latency and maintain IP session continuity. As a result, such issues were addressed by the IEEE 802.16e task group on the mobile WMAN. However, the scope of the IEEE 802.16e standard did not include cross-layering approaches for the enhancement of upper layer handover performance. This article proposes a new cross-layering design for fast IPv6 handover support over IEEE 802.16e. First, we describe the IEEE 802.16 deployment architectures, as well as the link layer, handover procedures in IEEE 802.16e. Next, we describe the operation of fast IPv6 handover and point out the need for interaction between the network layer and the link layer for proper performance. Then, we propose a new cross-layering design to achieve a proper behavior of the fast IPv6 handover over IEEE 802.16e. Finally, we present handover scenarios for the proposed techniques and discuss the major factors that contribute to the handover latency. 相似文献
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IEEE 802.16j切换模型研究 总被引:1,自引:0,他引:1
终端移动性是移动通信的重要特征。本文介绍了IEEE 802.16j标准中移动台切换的场景,并对其中的特殊情况——中继站内部切换进行了分析,并采用数学方法建立了移动台的切换模型。最后进行了网络仿真并对仿真结果进行了分析。 相似文献
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Anmin Fu Gongxuan Zhang Yuqing Zhang Zhenchao Zhu 《Wireless Personal Communications》2013,70(4):1793-1810
IEEE 802.16m is now under consideration by the International Telecommunication Union (ITU) to become the International Mobile Telecommunications (IMT)-Advanced standard. However, handover authentication is a critical issue in this area. In this paper, we propose an efficient group-based handover authentication mechanism, named as GHAP, for correlated mobile stations (MSs) in IEEE 802.16m networks. In our scheme, the correlated MSs who have the similar Signal to Interference-plus-Noise Ratio and history handover information etc. are divided into the same handover group. When the first MS of the handover group members moves from the service base station (BS) to a target BS, the service BS transmits all the handover group members’ security context to the target BS utilizing the security context transfer (SCT) method and then all these MSs in the same handover group can easily perform the handover authentication with the target BS. Different from the conventional SCT schemes, our scheme uses the MSs’ security context as a symmetric key of Cipher-based message authentication code (CMAC) but not the key material of deriving new session key. Therefore, the proposed scheme can effectively resist the domino effect existing in the previous SCT schemes. Moreover, security analysis shows that the proposed scheme also meets the other security requirements in handover authentication semantics. Furthermore, performance analysis demonstrates that the proposed scheme is very efficient in reducing average handover latency. 相似文献
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介绍了一种可实施的改进WiMAX网络小区切换方案.方案中运用了与IEEE802.16规范一致的基站容量估计和邻居广播功能,并设计了基于基站容量的小区切换触发条件和目标小区决策算法.该方案带来的系统性能提升最后在NS-2仿真环境中得到验证. 相似文献
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Industry is defining a new generation of mobile wireless technologies, called in cellular terminology "fourth generation" or "4G." This article shows that a system combining extensions of two radio access technologies, IEEE 802.11 and IEEE 802.16, meets the ITU-R's "IMT-Advanced" or 4G requirements. The extensions are 802.16 m (100 Mb/s, 250 km/h) and 802.11VHT (1 Gb/s, low velocity). The focus of this article is to show how IEEE 802.21 (the emerging IEEE standard for media-independent handover services) supports ";seamless"; mobility between these two radio access technologies. This mobility integrates the two radio access technologies into one system. We conclude that an 802.11VHT + 802.16 m + 802.21 system is likely to be proposed to the ITU-R for IMT- Advanced 4G. 相似文献
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This paper presents a novel utility-based connection admission control (CAC) scheme for IEEE 802.16e broadband wireless access networks. We develop specific utility functions for real-time and non-real-time services coupled with a handover process. Given these utility functions we characterize the network utility with respect to the allocated bandwidth, and further propose a CAC algorithm which admits a connection that conducts to the greatest utility so as to maximize the total resource utilization. The simulation results demonstrate the effectiveness of the proposed CAC algorithm in terms of network utility. 相似文献
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Pavel Mach Zdenek Becvar Robert Bestak 《Wireless Communications and Mobile Computing》2013,13(2):170-183
The load balancing in wireless networks is a very effective way for maximization of a system throughput. The paper proposes a new load balancing scheme in order to avoid a congestion of base stations (BSs) in IEEE 802.16 standards. While in many technical studies the load balancing is achieved by a handover (HO) of mobile stations (MSs), the novelty of our approach lies in the utilization of the HO of relay stations (RSs). Hence, the algorithm enabling load balancing via RSs is developed and optimized. Furthermore, the paper contemplates the implementation of the proposed mechanism to networks based on IEEE 802.16 standards. The performance of the mechanism is evaluated in terms of achieved system throughput and signaling overhead both at the air interface and over the wired backbone. The obtained results indicate that the load balancing mechanism through the HO of RSs outperforms existing load balancing mechanisms exploiting conventional HO of MSs. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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一种分级WFQ的宽带无线接入系统QoS架构 总被引:3,自引:0,他引:3
文章介绍了加权公平排队(WFQ)分组调度算法和IEEE 802 16的QoS架构.在此基础上,文章结合分级WFQ分组调度算法和IEEE 802 16协议中所提供的控制机制提出了一种适合于BWA系统的QoS架构.该架构充分利用IEEE 802.16提供的控制机制,结合分级WFQ公平队列调度算法,在主动授予业务(UGS)、实时轮询业务(rtS)、非实时轮询业务(nrtPS)和尽力传输业务(BE)之间公平分配带宽,并保证各种业务的QoS特性,完成了在IEEE 802 16协议中留给用户自己定义的调度策略. 相似文献