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通过对移动蜂窝网络模型的分析,提出了一种基于IPv6协议的分层网络移动IP切换方案,利用网络层快速切换以及层管理域的适当选取,有效地减少了微移动中的切换时延;在域间切换中,引入对端通信节点与网络外部代理的直达路径,降低了三角路由对切换过程的影响。 相似文献
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IETF制定的基本移动IP协议不仅存在所谓的“三角路由”问题,而且当移动节点频繁的在网络间移动时,给家乡代理和网络造成了很大的负担。本文在现有的各种切换解决技术的基础上,提出了一种分层次的暂时性家乡代理切换技术,以解决切换过程存在的问题。这种技术不仅缩短了路由路径,避免了三角路由问题,减少了额外的信令开销,而且在解决微移动的同时提高了移动IP的可靠性。 相似文献
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文章介绍了一种基于流的移动IPv6快速切换方法.即路由器利用IPv6的业务流的信息把各个业务流重定向到移动节点的新转交地址上.这种重定向的方式是在MN绑定更新注册的过程中进行的.使得移动节点在向家乡代理的注册还未完成之前.便能与通信对端进行正常通信,这样大大减少了切换时延.提高了切换效率.另外.本文通过理论分析.将此方法与常规的移动IPv6和分层移动IPv6机制进行了比较.并利用NS-2网络模拟器的仿真数椐对在此方法下不同类型的业务流的传输进行了分析,验证其具有较为良好的性能。 相似文献
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本文介绍了移动IP的基本概念和工作原理,并着重探讨了移动检测方法。按链路上有无代理广播消息,移动检测通常分为两种情况进行。移动节点收到代理广播消息后,可用生存时间域和网络前缀做移动检测;如果收不到代理广播消息,在本地链路上,移动节点设法按固定节点通信的方式进行通信尝试,在外地链路上移动节点将通过DHCP协议或手工配置进行通信,或对TCP进程进行监测并检查链路的数据包以确定自己在移动网络中的位置。 相似文献
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移动IPv6切换技术 总被引:1,自引:1,他引:0
基本的移动IPv6切换时延太大,无法满足实时业务的要求。文章在分析了现有移动IPv6网络切换技术的基础上,提出了一种基于分层移动IPv6网络模型的快速切换方案F-HMIPv6。该方案实现了移动节点在不同移动锚点域移动的快速切换操作。从理论分析得出结论,该方案可以弥补现有移动IPv6网络切换技术中的一些缺陷。 相似文献
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以通用移动通信系统(UMTS)与无线局域网(WLAN)融合为例,研究无线异构网络的垂直切换算法。由于垂直切换算法应考虑因素的复杂性以及不同网络性能的各异性,有必要对现有算法作出归纳总结比较,并据此提出新的垂直切换算法。该算法以代价函数为基础,将稳定周期与切换目标网络和当前服务网络的效用函数联系起来,实现移动节点自适应的切换判决。提出的算法能有效减少不必要的切换,增强异构网络的适应性。 相似文献
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蓝牙网络接入点切换问题的研究对于解决蓝牙移动性有很重要的现实意义。提出了一种频繁路径选择算法,接入点实时检测同移动点间链路,根据接收功率强度和前一段时间从当前位置切换到相邻接点的概率,确定最佳侯选接入点集,当从当前接入点AP接收到的功率下降到1个阈值时,移动主机MH开始切换。这种算法能够减少不必要的切换,降低链路负荷,而且切换时间较短。 相似文献
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未来无线网络将为固定和移动用户提供多媒体通信和计算业务.为移动用户提供无线多媒体业务的一个最关键的挑战是保证端到端连接的业务质量.通过重复使用无线频谱的微蜂窝或微微蜂窝结构是一个有前途的改善移动多媒体网络容量的方式.但切换次数随着蜂窝大小的降低而增加.移动多媒体网络的一个至关重要的问题是需要可以满足各种QoS需要且有更高资源利用率的有效切换方式.该文提出了一种称为基于动态信道预约的自适应QoS切换算法,并与其它切换方式进行了性能比较. 相似文献
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S. Mojtaba Matinkhah Siavash Khorsandi Shantia Yarahmadian 《International Journal of Communication Systems》2014,27(7):1020-1033
In heterogeneous wireless access networks, each mobile terminal may frequently need to change its base station (BS); this change is called a ‘handoff’. BSs have static parameters, which are related to their radio access technologies (RATs); however, they also contain dynamic parameters such as load and signal quality. Therefore, the problem of handoff decision includes two subproblems of RAT selection and BS selection. In this paper, first a ‘heterogeneous handoff management system’ for gathering all different required parameters is proposed. Second, a RAT Selection algorithm based on analytic hierarchy process and a BS Selection algorithm based on data envelopment analysis are designed. Finally, by means of ‘weight restriction’ technique, we develop a method for studying the impact of RAT Selection parameters on the performance of the network. Simulation results indicate that RAT Selection parameters have significant impact on the bandwidth utilization, energy consumption and the whole satisfaction of the users in heterogeneous wireless access networks.Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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The Internet has become ubiquitous and there has been tremendous growth in wireless communications in recent years. Many wireless communication techniques are commercially available, such as the Wireless LAN, Bluetooth, GSM, GPRS and CDMA. Because an all-IP network will be a trend, access to the Internet via wireless communication devices has become an important issue.To reduce power consumption and reuse the limited radio spectrum resources, a cellular network was formed. Cell size is one of the factors in the channel reuse rate. Basically, the channel reuse rate in a smaller cell size is higher than the channel reuse rate in a bigger cell size. Micro-mobility is therefore the inevitable direction for future mobile systems. Frequent and fast movements usually characterize micro-mobility. A cellular architecture would then present a challenge to the frequent handover procedures for a smaller cell size would usually induce a higher handoff frequency.In addition to cellular networks, the ad-hoc network is another network architecture for wireless networks. The ad-hoc network is a non-infrastructure architecture; in which nodes can access services from one another regardless where they are. An excellent routing protocol is crucial for an ad-hoc networking to function at high performance. The main difference between a cellular environment and ad-hoc network is that the ad-hoc method has no fixed infrastructure, allowing nodes to communicate with one another at any time and anywhere.We have mentioned that micro-mobility in a cellular environment would introduce a greater number of handoffs than before. The handoff probability drives the mobile IP mechanism due to signal changes. Using the Mobile IP mechanism, handoff breaking would take place within a micro-mobility environment. Therefore, in this paper, some handoff strategies that take the advantage of the ad-hoc mechanism to improve the handoff performance are investigated. 相似文献
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A Simple and Robust Vertical Handoff Algorithm for Heterogeneous Wireless Mobile Networks 总被引:2,自引:0,他引:2
Daojing He Caixia Chi Sammy Chan Chun Chen Jiajun Bu Mingjian Yin 《Wireless Personal Communications》2011,59(2):361-373
Wireless networking is becoming an increasingly important and popular way of providing global information access to users
on the move. One of the main challenges for seamless mobility is the availability of simple and robust vertical handoff algorithms,
which allow a mobile node to roam among heterogeneous wireless networks. In this paper, motivated by the facts that vertical
handoff procedure is done on mobile nodes and battery power may be one crucial parameter for certain mobile nodes, a simple
and robust two-step vertical handoff decision algorithm is proposed for heterogeneous wireless mobile networks. To the best
of our knowledge, this is the first vertical handoff algorithm that takes the classification of mobile nodes into consideration,
one is resource-poor mobile nodes, and the other is resource-rich mobile nodes. This new feature makes it more applicable
in the real world. In addition, dynamic new call blocking probability is firstly introduced by this paper to make handoff
decision for wireless networks. The experiment results have shown that the proposed algorithm outperforms traditional algorithms
in bandwidth utilization, handoff dropping rate and handoff rate. 相似文献
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本文提出一种组播选路算法,在组播连接路由树的代价函数中计入了移动成员的越区切换发生概率,使为移动成员服务的接入节点(AP)尽可能成为组播路由树的树叶节点。当移动成员发生越区切换以后,可减去原来为之服务的AP和相应的树枝通道链路,从而保证了网络资源得以有效地利用。数值模拟分析的结果表明,我们提出的算法达到了这一目的。 相似文献
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针对微观移动协议现有切换机制存在的问题,提出了基于预测的平滑切换机制,该机制利用移动预测技术,在切换发生前预测移动主机将要切换的下一蜂窝以及切换的时刻,为移动主机预先建立新路径;为了保证基于预测的平滑切换机制的实现,提出了一个易于实现的简单移动预测算法--SMPA算法;通过理论分析和系统仿真的方法对基于预测的平滑切换机制进行了性能评价,结果表明该切换机制以相对较小的代价获得了可观的性能改善. 相似文献