共查询到18条相似文献,搜索用时 78 毫秒
1.
2.
3.
随着近年来网络技术的飞速发展,网络带宽的不断增加,许多新的多媒体应用开始涌现,例如视频广播、视频点播、会议电话等。如果仅仅使用传统的单播技术,将会给电信运营商带来巨大的带宽浪费。而组播技术能在一定范围内有效的缓解带宽消耗。本文通过深入研究IPTV组播技术,分析了基于MPLS网络实现组播策略需要解决的主要问题,探讨了将MPLS与组播技术相结合而产生的MPLS组播策略在IPTV业务应用中的优势。 相似文献
4.
在弹性光网络中,光树传输组播可以节省链路代价,但较长的光树需要选择更低的调制等级,消耗更多的频谱资源和发射机功耗.提出一种基于遗传算法的光森林组播和光树重配置(GAMF-TR)优化组播的能效路由、调制格式和频谱分配(RMSA)策略.GAMF-TR策略设计染色体编码表示光森林的组播目的节点划分和光路径组合,通过染色体的基因位概率交叉和变异得到更多的光森林RMSA策略,设计了一个频谱分配效率和发射机功耗折中的适应度函数选择能效最高的光森林RMSA策略,并设计在网络资源充足时将组播从光森林重配置到光树传输,进一步减少发射机功耗的消耗.仿真结果表明:提出的GAMF-TR策略获得了组播的最低带宽阻塞率和最高能效性能. 相似文献
5.
在战术通信系统中,一发多收的组播业务的应用越来越广泛。战术通信中的组播业务往往要求具备高适变性和高实时性,而民用网络中的IP组播、应用层组播均存在一定局限性,无法满足这些要求。针对这个问题,通过对现有IP组播和应用层组播技术特点和不足进行分析,提出了一种基于自定义协议和名址分离的战术通信数据组播设计与实现方案,可以很好地应对战术通信系统的高实时性、低带宽、高动态等特性需求。试验验证了此方案下组播业务需求的满足情况,测试结果表明,所提出的方案可有效提高组播数据在战术通信系统中的传输效率,为战术通信系统的通用组播方案设计提供了参考。 相似文献
6.
7.
车载通信业务的需求加剧了基站功率消耗,降低了其数据传输的可靠性.本文提出了一种蜂窝网络下基于两阶段组播的车载安全数据传输中继选择策略,以节约系统总功耗为前提来确定中继选择范围,计算出基站功耗最小的最优组播半径x0,并选择距最优组播半径x0最近的车辆作为中继.基于中继的社会属性建立基站群体和中继群体间的非对称演化博弈模型,设计了不影响安全数据传输的中继娱乐数据发送功率动态再分配的奖惩机制.仿真结果表明:当车辆数目超过临界值Kmin时,本文提出的中继选择策略和奖惩机制,可在保证安全数据两阶段组播可靠性的同时,使基站功耗相比直接组播的功耗至少降低25%. 相似文献
8.
针对无线网络中资源受限的组播路由问题,考虑网络节点的节点度限制和网络链路的带宽约束,以最小化组播路由开销为目标,提出了一种二进制编码方式的基于灰狼优化算法的组播路由策略.在给定的网络拓扑下,基于灰狼优化算法的组播路由策略可以迅速找到一棵包含源和目的节点的最小开销组播树.仿真结果表明,相比于遗传算法,所提出的基于灰狼优化... 相似文献
9.
监控系统做为确保安全播出的重要辅助系统,已经成为新一代播控系统的重要组成部分。本文结合温州广播电视总台新播总控系统建设的实际情况,对新播总控系统中监控系统的设计理念及监控系统架构、监控策略、系统安全性、系统功能和实现的方法等方面进行了论述。 相似文献
10.
基于案例分析,阐述8k IP视频系统的规模、用途,系统集成和应用,包括光纤选型、音频组播数量、其他IP系统对接点,探讨IP配置系统在融合应用中的策略。 相似文献
11.
一种基于混合策略的动态组播密钥管理方案 总被引:3,自引:2,他引:1
组播密钥管理是当前组播安全研究的热点问题。在分析现有方案的基础上,考虑一种混合策略:将基于组的层次结构机制Iolus与基于密钥层次结构机制LKH的优点结合起来,提出了一种适合大型动态组播的可扩展的分层分组方式的密钥管理方案。该方案有效地降低了密钥更新的代价,具有较高的效率与较好的可扩展性.适合于解决大型动态组播的密钥管理问题。 相似文献
12.
Distributed multicast address management in the global Internet 总被引:2,自引:0,他引:2
Pejhan S. Eleftheriadis A. Anastassiou D. 《Selected Areas in Communications, IEEE Journal on》1995,13(8):1445-1456
We describe a distributed architecture for managing multicast addresses in the global Internet. A multicast address space partitioning scheme is proposed, based on the unicast host address and a per-host address management entity. By noting that port numbers are an integral part of end-to-end multicast addressing we present a single, unified solution to the two problems of dynamic multicast address management and port resolution. We then present a framework for the evaluation of multicast address management schemes, and use it to compare our design with three approaches, as well as a random allocation strategy. The criteria used for the evaluation are blocking probability and consistency, address acquisition delay, the load on address management entities, robustness against failures, and processing and communications overhead. With the distributed scheme the probability of blocking for address acquisition is reduced by several orders of magnitude, to insignificant levels, while consistency is maintained. At the same time, the address acquisition delay is reduced to a minimum by serving the request within the host itself. It is also shown that the scheme generates much less control traffic, is more robust against failures, and puts much less load on address management entities as compared with the other three schemes. The random allocation strategy is shown to be attractive primarily due to its simplicity, although it does have several drawbacks stemming from its lack of consistency (addresses may be allocated more than once) 相似文献
13.
14.
门限技术在组播密钥管理中的应用 总被引:1,自引:0,他引:1
目前组播协议以其节省带宽等优点被广泛认可,但在安全性和可靠性方面存在着一些问题。针对组播应用中所涉及到的密钥管理问题,提出一种运用动态门限技术和组播安全代理结合的方案,通过构建一个IP组播安全管理系统来实现组播密钥的分发和恢复,进而讨论了由成员加入和退出引起的密钥更新问题,最后针对该系统给出实验测试并讨论了采用此方案引起的更新代价,说明采用该方案可以较好地解决组播应用中的授权管理问题,实现安全组播。 相似文献
15.
Won-Tae Kim Yong-Jin Park 《IEEE network》2000,14(5):26-31
A Mobile IP multicast prototype that integrates a label-switching wireless asynchronous transfer mode, the mobile core-based multicast architecture, and an Internet multicast infrastructure is presented. MCOM creates multiple core-based layer 2 multicast trees that are independently established in member networks. They are interconnected via the Internet using layer 3 multicast routing. Gateways on the border of the Internet and wireless ATM networks convert ATM multicast traffic to suitable IP packets as well as converting from IP packets to ATM cells for MCOM. To solve the cell interleaving problem that results, ATM block transfer/immediate transmission capability is reasonably modified. Additionally, class-based block buffer management for ATM multicast connections is built into wireless ATM switches for soft quality of service control. Dynamic group management, multicast channel rerouting, and reliable multicasting are also studied in relation to existing Internet protocols like Mobile IP, Internet group management protocols, and multicast routing protocols 相似文献
16.
为了在IP组播中实现用户身份认证等安全管理,避免IP组播中的不安全因素,提出了一种运用门限技术和椭圆曲线密钥体制相结合的方案,构建一个IP组播服务系统并在其上分层实现了组播密钥的分发与恢复。最后通过实验测试给出了此方案的管理代价,证明了此方案可以很好地实现IP组播应用中的密钥管理,有效地解决了用户身份认证和授权管理问题,实现了安全IP组播。 相似文献
17.
Multicast is a natural enabler for carrying high-bandwidth multimedia broadcasts and seminars on IP networks. Despite the increased need for IP multicast, its commercial deployment has not been widespread. The lack of appropriate network management tools for IP multicast has proven to be a major barrier to its deployment. In this paper we survey the currently available multicast management tools and discuss why they are insufficient. We describe the requirements of an operational multicast management platform and present mmon, a multicast network management system we have built, aimed primarily for use by engineering and operations personnel. Mmon has been tried by over 200 sites and is currently used at HP to manage the multicast network. We discuss some of the challenges and our experiences with designing, implementing, and deploying the system. 相似文献