共查询到20条相似文献,搜索用时 78 毫秒
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本文回顾了多种3G和WLAN相结合的网络结构,在讨论了它们的性能后提出两种新的结构设计方案,即把UMTS网络分别通过节点SGSN和GGSN接入WLAN网络.介绍了利用OPNET对这两种网络结构进行仿真的方法,并进行性能分析和比较. 相似文献
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3G网络与WLAN的综合结构设计 总被引:1,自引:0,他引:1
本文回顾了多种3G和WLAN相结合的网络结构,在讨论了它们的性能后提出两种新的结构设计方案,即把UMTS网络分别通过节点SGSN和GGSN接入WLAN网络,介绍了利用OPNET对这两种网络结构进行仿真的方法,并进行性能分析和比较。 相似文献
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无线网络具有使用方便、终端可移动、易于扩展等特点,随着校园内移动业务需求的增加以及无线网络的发展,在高校校园网内进行无线网络的部署必将成为一种趋势。这里首先介绍了WLAN的协议标准及组网方式,描述了高校WLAN部署中两种常见的场景,并给出了相应的AP部署方案。最后,针对室外布放建设方式的场景,使用OPNET软件进行了仿真分析,为校园网的WLAN实际部署提供了参考依据。 相似文献
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"随着WLAN网络的全面覆盖,基于WLAN的业务扩展运营、网络价值发掘等将逐步成为运营商关注的重点,WLAN设备也必须随着运营商的业务扩展而快速定制和升级改造。" 相似文献
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为了在高技术条件下的局部战争中把握战场的主动权,在减少泄密的情况下充分发挥现代战争的神经网络(通信系统)的作用,文章运用OPNET建模技术,设计了一个简单的IEEE 802.11战场无线局域网(WLAN)的拓扑结构.实现了对战场增援救助过程通信情况的仿真。通过对仿真数据分析,对网络的实时性、可靠性、稳定性等性能进行了评估,从而对战场WLAN的设计及使用提供技术上的参考。 相似文献
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传统的WLAN(无线局域网)认证模式其繁琐的认证流程不但降低了网络的效率,更重要的是影响了用户的体验效果。从WLAN用户认证便利性出发,给出了基于MAC(媒体接入控制)的无感知认证解决方案,EAP-SIM/AKA(扩展认证协议-用户识别模块/鉴权与密钥协商)无感知认证解决方案和PEAP(受保护的扩展认证协议)无感知认证解决方案等3种解决方案,并分析了各自的优缺点。 相似文献
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Abhijit Sarma Sandip Chakraborty Sukumar Nandi Anchal Choubey 《Wireless Personal Communications》2014,77(4):2587-2614
IEEE 802.11 has become very popular wireless technology to offer high speed Internet access at public places called the ‘Hot-Spots’. This has enabled users to access multimedia and other real time applications using wireless local area networks (WLAN). In IEEE 802.11 WLAN technology, associations between a mobile station and an access point (AP) is controlled by the mobile station, allowing the station to select an AP with the strongest signal in terms of either ‘Received Signal Strength Identifier’ or ‘Signal to Interference and Noise Ratio’. In real time scenarios, the traffic patterns of mobile users are dynamic in nature. This leads to a situation where the traffic loads on the APs are unevenly distributed in the WLAN. Such imbalance in traffic load causes severe degradation in performance of the applications running on the mobile stations associated with the overloaded APs. In this paper, we propose a scheme which dynamically improves the performance of the overloaded APs by handing off some of its associated stations to nearby APs. This handoff decision is taken by an AP in assistance with the mobile stations. The effectiveness of the load distribution through dynamic hand-over in a WLAN is analyzed through theoretical analysis. Simulation results show the overall improvements in terms of delay, throughput and number of stations that an AP can support. The performance improvement in the proposed scheme is also justified through the results obtained from a IEEE 802.11 WLAN testbed. 相似文献
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《Digital Communications & Networks》2019,5(4):226-236
In order to solve the problem of location privacy under big data and improve the user positioning experience, a new concept of anonymous crowdsourcing-based WLAN indoor localization is proposed by employing the Micro-Electro-Mechanical System (MEMS) motion sensors as well as WLAN module in off-the-shelf smartphones. First of all, the crowdsourced motion traces with similar Received Signal Strength(RSS) sequences are assembled into a motion graph. Second, the mobility map is constructed according to traces segmentation and clustering. Third, the pixel template matching is adopted to physically label the pre-constructed mobility map. Finally, the robust Extended Kalman Filter (EKF) is designed to perform localization by matching the newly-collected RSS measurements against the mobility map. The extensive experimental results show that the proposed approach is capable of constructing a physically-labeled mobility map from the sporadically-collected crowdsourced motion traces as well as achieving satisfactory localization accuracy in a cost-efficient manner. 相似文献
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随着3G移动通信应用业务不断丰富,通信网络的承载能力与大流量高宽带的业务需求之间的矛盾日益增加。3G技术难以支撑大量的数据用户的多媒体应用的需求。WLAN作为具有高性价比和大规模部署能力的无线数据技术,可以很好地卸载3G的压力。所以3G+WLAN互为补充的发展战略成为运营商的共同选择。本文回顾了多种3G和WLAN相结合... 相似文献
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目前从全球来看,WLAN在欧美发展较快,而其他地区所占比例很小,中国市场尚待开发。从欧美来看,主要运营商的市场扩张除了自己投入建设外,还依靠合作、收购,以及签署漫游协议等方式;而终端的发展趋势是种类不断丰富,并逐渐从笔记本向手机和其他电子消费产品类转移。 相似文献
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无线局域网中的负载均衡技术 总被引:5,自引:0,他引:5
随着无线局域网扩展服务集中的终端(STA)的移动和无线信道的时变,各个接入点(AP)上的负载会出现差异,需要加强负载均衡,平衡各个AP的差异,以达到最大化的网络资源利用。无线局域网中的负载均衡算法可以采用STA/AP主控负载均衡或接入式/切换式负载均衡技术。在时分双工的时分同步码分多址(TD—SCDMA)系统中,由于系统在最小资源单位和媒体访问机制等方面的差异,负载均衡可以在小到时隙和码道,大到终端和小区等不同的级别上进行,体现码分多址(CDMA)和时分双工(TDD)的特点,具体方式更加灵活多样。 相似文献
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随着无线局域网(WLAN, Wireless Local Area Networks)用户数据业务量的不断增长,无线局域网维护的工作量也不断增加,严重影响了无线局域网的性能和用户体验和满意度,为建设稳定、高效、安全的无线局域网,这里研究如何实现无线局域网热点智能安全监护系统(WASM,WhSM, h Smart Security Monitoring System of WLAN AP)。首先详细讨论了无线局域网系统的原理和组成,其次讨论使用智能探针方式,实现无线局域网热点远程性能监护和排障工作,有效解决无线局域网热点安全问题。 相似文献
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针对目前的WLAN应用,本文给出一个区域覆盖的大概方案,调制技术的选择;由于区域应用(不同于小区和单位)重点和不同之处在于覆盖,所以本文侧重的是室外覆盖情况下需要考虑的因素及如何扩大覆盖范围,提高无线性能,节约成本,从而提供一个性能优良的区域性WLAN. 相似文献
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Syed Faraz Hasan Nazmul H. Siddique Shyam Chakraborty 《Wireless Personal Communications》2012,63(1):65-82
Wireless Sensor Networks are being recently studied to monitor real-time traffic conditions on roads and highways. Idea of
using vehicles to convey information from sensors placed alongside roads to the dedicated base stations has also been under
scrutiny for some time. In this paper, we argue that a sensor placed on a vehicle instead of a fixed location can effectively
sense traffic congestion on the road and report it to the already available WLAN Access Points (APs) instead of the dedicated
base stations. This way, instead of deploying series of base stations to collect traffic information, congestion information
can be sent over the ISM links between the vehicular sensor nodes and the WLAN APs. This paper investigates, as we call it,
the Extended MULE concept by using actual experimental data obtained from the test drives across the city. Our results show
that adopting this idea is effective in reporting traffic congestion on the roads. 相似文献