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IEEE802.16e标准是支持终端移动性的无线城域网接人标准.由于移动终端是由电池供电的,而休眠模式作为其必备功能,能有效管理其有限的电池容量,延长其单次充电使用时间.首先介绍了IEEE802.16e标准建议的睡眠模式,然后通过建立马尔可夫链模型对睡眠模式下的平均能量消耗及平均包延迟进行分析,最后NS2工具对分析结果进行NS2仿真和讨论. 相似文献
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IEEE 802.16e标准中使用了睡眠模式以达到降低移动台的功率消耗和基站接口资源的使用.本文将使用马尔可夫模型对IEEE 802.16e睡眠模式的功率消耗和时延进行分析.通过分析得知在功率消耗和时延之间有一个权衡,其中的关键因素就是初始的睡眠周期.为此提出一个根据传输速率调整初始睡眠周期大小的自适应算法.仿真结果表明与802.16e标准相比自适应算法能节约20%的功率,仅仅损失了一点时延. 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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文章分析了WiMAX系统中省电模式的特点和发展趋势,具体介绍了IEEE 802.16e中的睡眠和空闲模式,并对其工作原理和MAC流程进行了详细研究。 相似文献
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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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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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以太网供电标准IEEE802.3af定义的最大12.95W的功率限制制约了高功率网络设备的接入,鉴于此,简要介绍了IEEE802.3af标准,分析了高功率以太网供电系统的功能需求,采用MSP430F1481单片机、TPS23841以太网供电管理专用芯片和TPS2376-H,基于12C和RS232通信规范,开发了兼容标准的最大25W的可监控高级以太网供电系统。文中重点论述了此系统的设计实现过程。 相似文献
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作为WLAN第一个成熟的标准,IEEE 802.11成功地解决了无线介质给WLAN造成的困难。本文详细地分析了WLAN在物理层上存在的困难,并给出了IEEE 802.11相应的解决方案。 相似文献
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In this paper we introduce a new protocol, prioritized carrier sense multiple access with collision avoidance, for real-time wireless local area networking. Wireless networks increasingly will be called upon to carry mixed traffic, some portion of which will be devoted to real-time control and monitoring. Our protocol, based upon the IEEE 802.11 wireless standard, mixes real-time traffic with standard multimedia data in a way which assures loop stability. Scheduling the real-time traffic is the primary issue considered. Under our framework, we propose and validate several new algorithms for dynamically scheduling the traffic of wireless networked control systems: constant penalty, estimated error order and lag first-order schemes. All algorithms are compared via simulation and the results show that dynamic scheduling algorithms achieve better system performance on average than static scheduling algorithms like fixed-order polling. The results of a real experiment involving two dryer plants and three IEEE 802.11 nodes are reported with static scheduling employed as it lower bounds the closed-loop behavior 相似文献
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Feng Zhang Todd T.C. Dongmei Zhao Kezys V. 《Mobile Computing, IEEE Transactions on》2006,5(2):144-156
In the past decade, there has been a huge proliferation of wireless local area networks (WLANs) based on the IEEE 802.11 WLAN standard. As 802.11 connectivity becomes more ubiquitous, multihop communications will be increasingly used for access point range extension and coverage enhancement. In this paper, we present a design for an IEEE 802. 11 -based power saving access point (PSAP), intended for use in multihop battery and solar/battery powered applications. These types of APs have many practical applications and can be deployed very quickly and inexpensively to provide coverage enhancement in situations such as campuses, building complexes, and fast deployment scenarios. Unlike conventional wired access points, in this type of system, power saving on the AP itself is an important objective. A key design constraint is that the proposed PSAP be backward compatible to a wide range of IEEE 802.11 functionality and existing wired access points. In this paper, we introduce the protocols required to achieve this compatibility, show the constraints imposed by this restriction, and present performance results for the proposed system. 相似文献
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In recent years, remarkable market competition and economy of scale has resulted in the price erosion of wireless devices for consumer electronics. Especially for wireless data networks, IEEE project 802 provides the standards for mass markets. With ever-growing usage, the demand for ubiquitous wireless networks increases. However, the achievable data rates decrease with the increasing distance of client devices from the infrastructure, and a sufficiently dense deployment of infrastructure devices is required to fulfill the customers' demand for broadband access. Today, these infrastructure devices rely on a wired backbone for background services; however, to reduce their costly deployment, they should interconnect wirelessly. In this case, devices mutually serve as wireless relays that forward and route packets over multiple wireless hops, and wireless mesh networks come into existence. In this article we provide an overview of wireless mesh networking and provide insights into the related standardization efforts in IEEE 802. For a more in-depth analysis, we focus on the draft WLAN mesh standard IEEE 802.11s and identify challenges for medium access control in multihop communication. Derived from our proposal to 802.1 Is, the current draft incorporates an optional medium access scheme that circumvents a performance gap. By means of simulations, we compare the performance of both solutions and provide an outlook for future 802 wireless systems that will be more reliable. 相似文献
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《Communications Magazine, IEEE》2009,47(1):130-138
This article presents a high-level overview of the IEEE 802.22 standard for cognitive wireless regional area networks (WRANs) that is under development in the IEEE 802 LAN/MAN Standards Committee. 相似文献
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宽带无线接入技术IEEE802.20介绍 总被引:1,自引:0,他引:1
文中介绍了未来高速移动通信新标准IEEE802.20的总体情况,分析了IEEE802.20的技术特性,系统参数,无线接口特性,包括分层结构,延迟与切换要求,频谱效率,系统架构以及物理层和MAC的要求,分析了IEEE802.20网状拓扑结构的设计,最后对其前景进行了展望。 相似文献
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