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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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Scalable Multicast Protocol in IP-Based Mobile Networks 总被引:4,自引:0,他引:4
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由于移动节点的位置是不断变化的,移动IPv6协议给出了支持移动节点的远程加入和双向隧道两种组播方法,但这两种方法都有各自的缺点.本文提出基于移动预测的快速分层移动组播体系结构(mobility prediction based fast and hierarchical mobile multicast architecture,简称MP-FHMM),通过移动预测,在切换前为移动节点配置好切换信息,并且在切换时使用基于FMIPv6改进的快速组播切换方法,有效减少了切换延迟以及由此引发的组播数据分组丢失.另外,由于采用层次型结构的移动组播管理,屏蔽了节点在子网内的移动,减少了因节点移动而重构组播树的频率. 相似文献
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Shengling Wang Yong Cui Sajal K. Das Jianping Wu 《Wireless Communications and Mobile Computing》2012,12(10):875-890
Traditional mobile multicast schemes have higher multicast tree reconfiguration cost or multicast packet delivery cost. Two costs are very critical because the former affects the service disruption time during handoff while the latter affects the packet delivery delay. Although the range‐based mobile multicast (RBMoM) scheme and its similar schemes offer the trade‐off between two costs to some extent, most of them do not determine the size of service region, which is critical to the network performance. Hence, we propose a dynamic region‐based mobile multicast (DRBMoM) to dynamically determine the optimal service region for reducing the multicast tree reconfiguration and multicast packet delivery costs. DRBMoM provides two versions: (i) the per‐user version, named DRBMoM‐U, and (ii) the aggregate‐users version, named DRBMoM‐A. Two versions have different applicability, which are the complementary technologies for pursuing efficient mobile multicast. Though having different data information and operations, two versions have the same method for finding the optimal service region. To that aim, DRBMoM models the users' mobility with arbitrary movement directional probabilities in 2‐D mesh network using Markov Chain, and predicts the behaviors of foreign agents' (FAs') joining in a multicast group. DRBMoM derives a cost function to formulate the average multicast tree reconfiguration cost and the average multicast packet delivery cost, which is a function of service region. DRBMoM finds the optimal service region that can minimize the cost function. The simulation tests some key parameters of DRBMoM. In addition, the simulation and numerical analyses show the cost in DRBMoM is about 22∼50% of that in RBMoM. At last, the applicability and computational complexity of DRBMoM and its similar scheme are analyzed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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互联网组播技术可以从根本上改善网络带宽的利用率,使发送者和路由器的处理消耗以及发送延迟降到最低的程度。IGMP是一种应用比较广泛的组播用户组管理协议,但是本身没有认证功能。PAP(密码认证协议)提供了一种简单的可以使端对端使用2次握手建立身份验证的协议。论文提出一种IGMP改进方案,把PAP认证协议添加在IGMP v3协议的扩展字段中,用于组播路由的最后一跳认证。 相似文献
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组播通信可以有效地减轻网络负担,避免资源浪费,是一种十分有效的通信方式。简要介绍IP组播技术的概念、原理及体系结构,描述IGMP Snooping协议在VOD系统中的应用,在此基础上设计基于IP组播技术的VOD系统。 相似文献
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To solve the problem that most of existing layered multicast protocols cannot adapt todynamic network conditions because their layers are coarsely granulated and static,a new congestioncontrol mechanism for dynamic adaptive layered multicast(DALM) is presented.In this mechanism,anovel feedback aggregating algorithm is put forward,which can dynamically determine the number oflayers and the rate of each layer,and can efficiently improve network bandwidth utilization ratio.Additionally,because all layers is transmitted in only one group,the intricate and time-consuminginternet group management protocol(IGMP) operations,caused by receiver joining a new layer orleaving the topmost subscribed layer,are thoroughly eliminated.And this mechanism also avoids otherproblems resulted from multiple groups.Simulation results show that DALM is adaptive and TCPfriendly. 相似文献
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本文提出一种改进的MobiCast方案来实现移动IP组播通信,主要解决MobiCast方案中进行区域间切换时组播数据包丢失问题。与MobiCast方案相比,在区域外地代理(DomainForeignAgent,DFA)处引入一种缓存的机制。当移动节点发生区域间切换时,移动节点的旧区域外地代理采用隧道技术,将移动节点的信息和缓存的组播数据包发送给移动节点的新区域外地代理处,减少移动节点进行区域间切换时丢失的组播数据包。 相似文献
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Heba Nashaat Rawya Rizk Hani Mahdi 《International Journal of Wireless Information Networks》2011,18(4):210-223
Mobile IP has been developed to provide the continuous information network access to mobile users. The performance of Mobile
IP mobility management scheme is dependent on traffic characteristics and user mobility. Consequently, it is important to
assess this performance in-depth through these factors. This paper introduces a novel analytical model of handoff management
in mobile IP networks. The proposed model focuses on the effect the traffic types and their frame error rates on the handoff
latency. It is derived based on general distribution of both successful transmission attempts and the residence time to be
applicable in all cases of traffic characteristics and user mobility. The impact of the behavior of wireless connection, cell
residence time, probability distribution of transmission time and the handoff time is investigated. Numerical results are
obtained and presented for both TCP and UDP traffics. As expected, the reliability of TCP leads to higher handoff latency
than UDP traffic. It is shown that, higher values of FER increase the probability of erroneous packet transfer across the
link layer. A short retransmission time leads to end the connection most likely in the existing FA; however a long retransmission
time leads to a large delivery time. The proposed model is robust in the sense that it covers the impact of all the effective
parameters and can be easily extended to any distribution. 相似文献
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Wanjiun Liao De-Nian Yang 《Broadcasting, IEEE Transactions on》2004,50(3):279-288
This paper proposes a new group management protocol called Received-initiated Group Membership Protocol (RGMP) for IP multicasting. The dominant group management protocol on the Internet to date is the Internet Group Management Protocol (IGMP). Unlike IGMP based on a query/reply model, an RGMP host actively takes responsibility to refresh group membership on the neighboring multicast routers. Each RGMP host maintains a "refresh" timer per group. The refresh timer is reset once the suppression rule holds true for a received report message, where the report may be a join, departure, state change, or refresh message. The RGMP refresh timer is adjusted in a way to be adaptive and self-synchronized. This receiver-initiated, self-synchronized approach makes the RGMP suppression mechanism superior to that of IGMP v1/v2, because the latter can be applied only to periodical refresh messages. As a result, RGMP protocol overhead is significantly reduced over a wide variety of service scenarios compared to IGMP v3. In addition to the reduced protocol overhead, RGMP is robust, scalable and adaptive to serve as a group management protocol. 相似文献
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Future internetworks will include large numbers of portable devices moving among small wireless cells. We propose a hierarchical
mobility management scheme for such networks. Our scheme exploits locality in user mobility to restrict handoff processing
to the vicinity of a mobile node. It thus reduces handoff latency and the load on the internetwork. Our design is based on
the Internet Protocol (IP) and is compatible with the Mobile IP standard. We also present experimental results for the lowest
level of the hierarchy. We implemented our local handoff mechanism on Unix-based portable computers and base stations, and
evaluated its performance on a WaveLAN network. These experiments show that our handoffs are fast enough to avoid noticeable
disruptions in interactive audio traffic. For example, our handoff protocol completes less than 10 milliseconds after a mobile
node initiates it. Our mechanism also recovers from packet losses suffered during the transition from one cell to another.
This work helps extend Internet telephony and teleconferencing to mobile devices that communicate over wireless networks.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Andreas Festag Holger Karl Adam Wolisz 《Wireless Communications and Mobile Computing》2007,7(3):319-339
To solve the IP mobility problem, the use of multicast has been proposed in a number of different approaches, applying multicast in different characteristic ways. We provide a systematic discussion of fundamental options for multicast‐based mobility support and the definition and experimental performance evaluation of selected schemes. The discussion is based on an analysis of the architectural, performance‐related, and functional requirements. By using these requirements and selecting options regarding network architecture and multicast protocols, we identify promising combinations and derive four case studies for multicast‐based mobility in IP‐based cellular networks. These case studies include both the standard any‐source IP multicast model as well as non‐standard multicast models, which optimally utilize the underlying multicast. We describe network architecture and protocols as well as a flexible software environment that allows to easily implement these and other classes of mobility‐supporting multicast protocols. Multicast schemes enable a high degree of flexibility for mobility mechanisms in order to meet the service quality required by the applications with minimal protocol overhead. We evaluate this overhead using our software environment by implementing prototypes and quantifying handoff‐specific metrics, namely, handoff and paging latency, packet loss and duplication rates, as well as TCP goodput. The measurement results show that these multicast‐based schemes improve handoff performance for high mobility in comparison to the reference cases: basic and hierarchical Mobile IP. Comparing the multicast‐schemes among each other the performance for the evaluated metrics is very similar. As a result of the conceptual framework classification and our performance evaluations, we justify specific protocol mechanisms that utilize specific features of the multicast. Based on this justification, we advocate the usage of a source‐specific multicast service model for multicast‐based mobility support that adverts the weaknesses of the classical Internet any‐source multicast service model. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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安全问题一直是多播技术发展中一个亟待解决的问题,而在所有的安全问题中,安全多播准入控制是研究的焦点.研究了国内外现有的典型多播准入控制方案,对它们的优缺点进行了分析和比较研究.结合各种多播准入控制方案的优点,给出了一个基于IGMP协议的安全多播准入控制方案.实验表明该安全多播准入控制方案具有安全性高、稳定性好、扩展性好、易于迁移到IPv6环境和便于部署等特点,有较高的实际应用价值. 相似文献
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Low-latency mobile IP handoff for infrastructure-mode wireless LANs 总被引:13,自引:0,他引:13
Sharma S. Ningning Zhu Tzi-cker Chiueh 《Selected Areas in Communications, IEEE Journal on》2004,22(4):643-652
The increasing popularity of IEEE 802.11-based wireless local area networks (LANs) lends them credibility as a viable alternative to third-generation (3G) wireless technologies. Even though wireless LANs support much higher channel bandwidth than 3G networks, their network-layer handoff latency is still too high to be usable for interactive multimedia applications such as voice over IP or video streaming. Specifically, the peculiarities of commercially available IEEE 802.11b wireless LAN hardware prevent existing mobile Internet protocol (IP) implementations from achieving subsecond Mobile IP handoff latency when the wireless LANs are operating in the infrastructure mode, which is also the prevailing operating mode used in most deployed IEEE 802.11b LANs. In this paper, we propose a low-latency mobile IP handoff scheme that can reduce the handoff latency of infrastructure-mode wireless LANs to less than 100 ms, the fastest known handoff performance for such networks. The proposed scheme overcomes the inability of mobility software to sense the signal strengths of multiple-access points when operating in an infrastructure-mode wireless LAN. It expedites link-layer handoff detection and speeds up network-layer handoff by replaying cached foreign agent advertisements. The proposed scheme strictly adheres to the mobile IP standard specification, and does not require any modifications to existing mobile IP implementations. That is, the proposed mechanism is completely transparent to the existing mobile IP software installed on mobile nodes and wired nodes. As a demonstration of this technology, we show how this low-latency handoff scheme together with a wireless LAN bandwidth guarantee mechanism supports undisrupted playback of remote video streams on mobile stations that are traveling across wireless LAN segments. 相似文献
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This paper proposes a fast handover mechanism to provide a seamless multicast service for Mobile IPv6 hosts. With the proposed
Fast handover based on a Mobile IP-Multi casting (FMIP-M) protocol, the selection of a new multicast service method, service
preparation, and initialization procedures are all performed during the fast handover period, thereby enabling a reliable
and efficient multicast service. When mobile hosts move to other networks, they can encounter data loss, out-of-synch problems
for multicast data, and multicast service exchange latency. Therefore, the proposed FMIP-M allows the new access router to
select a suitable multicast service method according to the multicast service-related network conditions and supports a reliable
multicast transmission by compensating for data losses from the previous access router. An analysis is conducted of the overheads
associated with a fast multicast handover, including the signaling cost and multicast packet-forwarding cost, where the costs
are formulated based on timing diagrams, and compared with a fast handover using Mobile IPv6. The performance analysis and
numerical results confirm that the proposed FMIP-M provides a fast multicast handover and reliable service with a relatively
small signaling cost and packet-delivery cost. 相似文献
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This paper presents the design and evaluation of a highly efficient on-demand multicast routing protocol for mobile ad hoc
networks (MANETs). The protocol, called Geography-aided Multicast Zone Routing Protocol (GMZRP), eliminates as much as possible
duplicate route queries by using a simple yet effective strategy for propagating the multicast route request (MRREQ) packets.
GMZRP is the first hybrid multicast protocol taking the advantages of both topological routing and geographical routing. It
partitions the network coverage area into small zones and guarantees that each geographic zone is queried only once. GMZRP
maintains a multicast forwarding tree at two levels of granularities, i.e., the zone granularity and the node granularity.
By doing this, it can easily handle route breakage since the zone level information can help recover the link failure at the
node level. The results of the performance evaluation of GMZRP using simulation show that, comparing with the well-known multicast
protocol ODMRP (On-Demand Multicast Routing Protocol), GMZRP has much lower protocol overhead in terms of query packets and,
meanwhile, achieves competing packet delivery ratio and shorter delivery latency.
相似文献
Xiaopeng FanEmail: |