移动IP网络中的组播技术研究

主要讨论了基于移动IP网下的组播技术。在给出了基本的两种移动组播机制：即远程签署RS和双向隧道BT的基础上，重点分析了RBMoM协议，即基于范围的移动组播协议，同时比较了三者的优缺点。最后给出RBMoM协议的实现流程图。     

DREAM : Density Aware Overlay Multicast Forwarding in Mobile Ad Hoc Networks

Instead of multicast functionality on a network entity, the overlay multicast schemes support multicast service with help of underlying unicast routing protocol. However, due to a node's free migration and communication based on broadcasting capability, effectiveness of overlay multicast scheme is not guaranteed in Mobile Ad Hoc Networks (MANET). Specially, nodes' density within some areas changes frequently so heterogeneous forwarding scheme based on density is strongly desired in order to reduce a number of collisions as well as enhance resource utilization. To achieve this, in this paper, we introduce a new forwarding scheme, called as DREAM (Density aware overlay Multicast forwarding). A key feature of DREAM is to introduce a scoped flooding where the nodes densely locates, on the other hand, data forwarding based on unicast routing protocol is maintained in sparse environment. Distinct advantages are evaluated by simulation. Ki-Il Kim received the M.S. and Ph.D. degrees in computer science from the Chungnam National University, Daejeon, Korea, in 2002 and 2005, respectively. He is currently with Department of Information Science, Gyeongsang National University as a faculty member. His research interests include routing for MANET, QoS in wireless network, multicast, and sensor networks. Sang-Ha Kim received the B.S. degree in chemistry from Seoul National University, Seoul, Korea, in 1980. He received the M.S. and Ph.D. degrees in quantum scattering and computer science from the University of Houston, Houston, TX, in 1984 and 1989, respectively. From 1990 to 1991, he was with the Supercomputing Center, SERI, Korean Institute of Science and Technology (KIST) as Senior Researcher. He joined Chungnam National University, Daejeon,Korea, in 1992, where he is a Professor. His current research interests include wireless networks, ad hoc networks, QoS, optical networks, and network analysis.     

A Domain-Based Routing Protocol for SSM Source Mobility in Mobile IPv6 Networks

In Mobile IP, the signaling traffic overhead will be too high since the new Care-of-Address (CoA) of the mobile node (MN) is registered all the way with the home agent (HA) whenever the MN has moved into a new foreign network. To complement Mobile IP in better handling local movement, several IP micro protocols have been proposed. These protocols introduce a hierarchical mobility management scheme, which divides the mobility into micro mobility and macro mobility according to whether the host's movement is intra-domain or inter-domain. Thus, the requirements on performance and flexibility are achieved, especially for frequently moving hosts. This paper introduces a routing protocol for multicast source mobility on the basis of the hierarchical mobile management scheme, which provides a unified global architecture for both uni- and multicast routing in mobile networks. The implementation of multicast services adopts an improved SSM (Source Specific Multicast) model, which combines the advantages of the existing protocols in scalability and mobility transparency. Simulation results show that the proposed protocol has better performance than the existing routing protocols for SSM source mobility.     

A Video Streaming System for Mobile Phones: Practice and Experience

This paper presents a case of video streaming system for mobile phone which has actually been implemented and deployed for commercial services in CDMA2000 1X cellular phone networks. As the computing environment and the network connection of cellular phones are significantly different from the wired desktop environment, the traditional desktop streaming method is not applicable. Therefore, a new architecture is required to suit the successfully streaming in the mobile phone environment. We have developed a very lightweight video player for use in mobile phone and the related authoring tool for the player. The streaming server has carefully been designed to provide high efficiency, reliability and scalability. Based on a specifically-designed suite of streaming protocol, the server employs an adaptive rate control mechanism which transmits the media packets appropriately into the network according to the change in network bandwidth.Hojung Cha is currently a professor in computer science at Yonsei University, Seoul, Korea. His research interests include multimedia computing system, multimedia communication networks, wireless and mobile communication systems and embedded system software. He received his B.S. and M.S. in computer engineering from Seoul National University, Korea, in 1985 and 1987, respectively. He received his Ph.D. in computer science from the University of Manchester, England, in 1991.Jongmin Lee is a Ph.D. candidiate in computer science at Yonsei University, Seoul, Korea. His research interests include wireless multimedia system, QoS architecture, multimedia communication networks. He received his B.S. and M.S. in computer science from Kwangwoon University in 1999 and 2001, respectively.Jongho Nang is a professor in the Department of Computer Science at Sogang University. He received his B.S. degree from Sogang University, Korea, in 1986 and M.S. and Ph.D. degree from KAIST, in 1988 and in 1992, respectively. His research interests are in the field of multimedia systems, digital video library, and Internet technologies. He is a member of KISS, ACM, and IEEE.Sung-Yong Park is an associate professor in the Department of Computer Science at Sogang University, Seoul, Korea. He received his B.S. degree in computer science from Sogang University, and both the M.S. and Ph.D. degrees in computer science from Syracuse University. From 1987 to 1992, he worked for LG Electronics, Korea, as a research engineer. From 1998 to 1999, he was a research scientist at Telcordia Technologies (formerly Bellcore) where he developed network management software for optical switches. His research interests include high performance distributed computing and systems, operating systems, and multimedia.Jin-Hwan Jeong received the B.S. and M.S. degrees in computer science from Korea University, Seoul, Korea, in 1997, and 1999, respectively. He is currently in Ph.D. course at Korea University. His research interests include video processing for thin devices, multimedia streaming and operating systems.Chuck Yoo received the B.S. degree in electronics engineering from Seoul National University, Seoul, Korea and the M.S. and Ph.D. in computer science in University of Michigan. He worked as a researcher in Sun Microsystems Lab. from 1990 to 1995. He joined the Computer Science and Enginnering Department, Korea University, Seoul, Korea in 1995, where he is currently a professor. His research interests include high performance network, multimedia streaming, and operating systems.Jin-Young Choi received the B.S. degree from Seoul National University, Seoul, Korea, in 1982, the M.S. degree from Drexel University in 1986, and the Ph.D. degree from University of Pennsylvania, in 1993. He is currently a professor of Computer Science and Engineering Department, Korea University, Seoul, Korea. His current research interests are in real-time computing, formal methods, programming languages, process algebras, security, software engineering, and protocol engineering.     

一种适用于动态/移动环境的新的组播协议

组播协议由于能够有效的利用网络带宽并降低服务器的负担因而受到广泛的关注.其中的共享树组播协议由于具有良好的扩展性而得到更多的支持,然而目前的共享树组播协议在动态移动环境中的性能很差,一些改进协议(单核移动协议)虽然可以很好的提高原有协议的性能但是所需要的额外开销很大.针对这种情况,本文提出了一种新的共享树组播协议-动态多核协议,该协议能够根据组播成员的分布动态的渐进的调整组播树的形状,从而能够在低开销的情况下为移动用户提供良好的性能.计算机仿真和数学分析都表明动态多核协议要明显优于共享树组播协议和单核移动协议.     

基于IPv4的可靠移动组播技术

移动组播技术是近几年来无线互联网领域的一个研究热点,其相当一部分应用要求移动环境下也能提供相当于有线链路的可靠性。但是移动环境下的突出特点就是链路差错率高,组播成员位置动态变化,这给移动组播尤其是可靠移动组播提出了很大的挑战。基于IPv4的可靠移动组播算法具有两种不同的设计思想,其中一部分算法是针对现有的移动组播算法存在的问题,进行可靠性方面的改进,另一部分算法是专门用于实现可靠移动组播的,它们大都引入了新的功能实体来保证可靠性。     

Resource-efficient network mobility support in Proxy Mobile IPv6 domain

The basic standard protocol for supporting network mobility (NEMO) (i.e., NEMO-BSP specified by IETF) introduces several performance problems, such as multiple tunneling overhead and packet delivery latency, because it exploits mobile IPv6 (MIPv6), which was proposed for host mobility. To improve the basic NEMO solution, two network-based NEMO approaches, rNEMO and N-PMIPv6, have been proposed. The rNEMO is able to reduce significant packet tunneling overhead. The N-PMIPv6, on the other hand, reduces location update cost, but it leads to packet tunneling overhead. Thus, they commonly waste network resources in both wired and especially wireless network. No efficient and practical solutions for minimizing both the location update overhead and packet tunneling overhead have been presented until now. This situation motivated us to propose a resource-efficient network mobility scheme (RENEMO), reducing resource utilization required for network mobility support. We show that the proposed RENEMO outperforms both rNEMO and N-PMIPv6 in terms of network resource.     

Investigation of multicast‐based mobility support in all‐IP cellular networks

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.     

Effectiveness of Reliable Routing Protocols in Mobile Ad Hoc Networks

Due to unpredictable topology change and frequent link failure, it becomes evident major challenge to provide the stable route between source and destination in mobile ad hoc networks. Unlike previous multipath routing schemes for redundancy and unicast routing protocol utilizing the longest route expiration time measured by geographical information supported by Global Positioning System (GPS), we develop a framework to establish the most stable route based on measured frequency of link failure, available battery as well as the number of actual connections. To evaluate performance of proposed scheme, we provide practical simulation results for multipath and unicast routing protocol in terms of packet delivery ratio, control overhead, average hop length as well as end-to-end delay. Through analysis of simulation results, we demonstrate that our scheme shows better performance than general unicast routing protocol as well as similar packet delivery ratio to multipath routing protocol with less maintenance overhead. Ki-Il Kim received the M.S. and Ph.D. degrees in computer science from the Chungnam National University, Daejeon, Korea, in 2002 and 2005, respectively. He is currently with Department of Information Science, Gyeongsang National University as a faculty member. His research interests include routing for MANET, QoS in wireless network, multicast, and sensor networks. Sang-Ha Kim received the B.S. degree in chemistry from Seoul National University, Seoul, Korea, in 1980. He received the M.S. and Ph.D. degrees in quantum scattering and computer science from the University of Houston, Houston, TX, in 1984 and 1989, respectively. From 1990 to 1991, he was with the Supercomputing Center, SERI, Korean Institute of Science and Technology (KIST) as Senior Researcher. He joined Chungnam National University, Daejeon, Korea, in 1992, where he is a Professor. His current research interests include wireless networks, ad hoc networks, QoS, optical networks, and network analysis.     

基于移动预测的快速分层移动组播体系结构

 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.     

Ant-Based Distributed Topology Control Algorithms for Mobile Ad hoc Networks

By adjusting the transmission power of mobile nodes, topology control aims to reduce wireless interference, reduce energy consumption, and increase effective network capacity, subject to connectivity constraints. In this paper, we introduce the Ant-Based Topology Control (ABTC) algorithm that adapts the biological metaphor of Swarm Intelligence to control topology of mobile ad hoc networks. ABTC is a distributed algorithm where each node asynchronously collects local information from nearby nodes, via sending and receiving ant packets, to determine its appropriate transmission power. The operations of ABTC do not require any geographical location, angle-of-arrival, topology, or routing information, and are scalable. In particular, ABTC attempts to minimize the maximum power used by any node in the network, or minimize the total power used by all of the nodes in the network. By adapting swarm intelligence as an adaptive search mechanism, ABTC converges quickly to a good power assignment with respect to minimization objectives, and adapts well to mobility. In addition, ABTC may achieve common power, or properly assign power to nodes with non-uniform distribution. Results from a thorough comparative simulation study demonstrate the effectiveness of ABTC for different mobility speed, various density, and diverse node distributions.This work is supported in part by National Science Foundation under grant ANI-0240398.Chien-Chung Shen received his B.S. and M.S. degrees from National Chiao Tung University, Taiwan, and his Ph.D. degree from UCLA, all in computer science. He was a research scientist at Bellcore Applied Research working on control and management of broadband networks. He is now an assistant professor in the Department of Computer and Information Sciences of the University of Delaware, and a recipient of NSF CAREER Award. His research interests include ad hoc and sensor networks, control and management of broadband networks, distributed object and peer-to-peer computing, and simulation.Zhuochuan Huang received his B.E. degree in Computer Science and Technology from Tsinghua University, P.R. China, in 1998, and his M.S. degree in Computer Science from University of Delaware in 2000. He is currently a PhD candidate with the Department of Computer and Information Sciences at the University of Delaware. His current research interests include the design and simulation of protocols for mobile ad hoc networks.Chaiporn Jaikaeo received his B.Eng degree in computer engineering from Kasetsart University, Thailand, and his M.S. and Ph.D. degrees in computer and information sciences from the University of Delaware in 1996, 1999 and 2004, respectively. He is currently a lecturer in the Department of Computer Engineering at Kasetsart University. His research interests include unicast and multicast routing, topology control, peer-to-peer computing and network management for mobile wireless ad hoc and sensor networks.     

Reliable and efficient multicast protocol for mobile IP networks

To provide a multicasting service, several multicast protocols for mobile hosts (MHs) have been proposed. However, all of these protocols have faults, such as non‐optimal delivery routes and data loss when hosts move to another network, resulting in insecure multicast data transmissions. Thus, this paper presents a new reliable and efficient multicast routing protocol for mobile IP networks. The proposed protocol provides a reliable multicast transmission by compensating the data loss from the previous mobile agent when a MH moves to another network. In addition, an additional function allows for direct connection to the multicast tree according to the status of agents, thereby providing a more efficient and optimal multicast path. The performance of the proposed protocol is confirmed based on simulations under various conditions. Copyright © 2008 John Wiley & Sons, Ltd.     

基于移动组的全序可靠多播协议的研究

丈章给出一种基于移动组的全序可靠多播协议-MGTOM(Mobile-group-based Totally Ordered Reliable Multicast)协议,借助于逻辑令牌环来实现.MGTOM协议实现了移动组多播的原子性和全序性,原子性用于保证多播消息能够最终传递到移动组内的所有移动Agent,全序性则保证任意一对多播消息都按照相同顺序被所有组内移动Agent传递.在多播算法中,为了保证原子性,所有收到多播消息的组成员必须回复,然后持有令牌的组成员作为Sequencer,对多播消息进行排序.     

Link Synchronous Mobile IPv4 Handover Algorithms

The performance of the base Mobile IP handover algorithm for moving the Mobile Node’s network layer point of attachment from one subnet to another has been recognized as a potential performance bottleneck for some time. In this paper, we discuss a collection of algorithms that use a link synchronous approach to Mobile IP handover. In the link synchronous approach, information on the progress of switching the link is used to drive handover at the IP level. We present a comprehensive analysis of handover packet drop, and develop analytical models of how the link synchronous algorithms help to mitigate it. We use data from a handover emulator to test the analytical models, and to compare the performance of the different algorithms under a variety of link conditions. Data from implementations on IS-2000 and 802.11b show how the link synchronous algorithms behave on real radio protocols. The results indicate that the link synchronous algorithms can reduce packet loss substantially, with best results possible if the link layer provides information on the move prior to the link switch. James Kempf is a Research Fellow at DoCoMo USA Laboratories. He holds a Ph.D. from the University of Arizona, Tucson, AZ. Previously, James worked at Sun Microsystems for 13 years, and contributed to numerous research projects involving wireless networking, mobile computing, and service discovery. James is a former member of the Internet Architecture Board, and co-chaired the SEND and Seamoby IETF Working Groups. James continues to be an active contributor to Internet standards in the areas of security and mobility for next generation, Internet protocol-based mobile systems. Ajoy Singh is a Principal Staff Engineer at Motorola GTSS Division where he has led the development of radio network controllers and the various components of core networks for 3GPP-based HSDPA and 3GPP2-based CDMA prototype systems. He holds a Master’s degree from DePaul University, Chicago, IL. Ajoy is the co-developer of several pending patents on cellular radio technology, and has contributed to the standardization of seamless mobility protocols through the Seamoby and Mobile IP IETF Working Groups and through IEEE 802.21. Jonathan Wood is an independent contractor and has been working with DoCoMo Labs since 2001. He is currently contributing to research on next generation mobility and networking infrastructures. Previously at Sun Microsystems, Jonathan focused on Solaris networking and 4G wireless network research. Atsushi Takeshita is a Director at the NTT DoCoMo Multimedia Laboratories in Yokoska Research Park, Japan. Prior to that, he was Director of the Autonomous Communication Laboratory in DoCoMo USA Laboratories, and one of the founding members of DoCoMo USA Laboratories. Atsushi joined NTT DoCoMo in 1988 and has since been engaged in the research and development of multimedia information retreival and delivery, the mobile Internet, and mobile terminal architectures. He is a member of the Association for Computing Machinery (ACM) and Information Processing Society of Japan. Nat Natarajan joined Motorola in 1993, and is a Fellow of the Technical Staff at Motorola. He received his Ph.D. from Ohio State University in Columbus, OH. Prior to working at Motorola, Nat served as a research staff member for over 12 years with IBM Thomas J. Watson Research Center, Yorktown Heights, NY, working primarily on packet switched data, voice and integrated networks as well as wireless data and satellite networks, and he has been a major contributor to the IEEE 802.11 standard approved in 1997. Nat is a Motorola Distinguished Innovator, holding 30 patents, and is a Senior Member of IEEE. Nat’s current technical interests are Beyond 3G/4G mobile networking systems based on IP technologies.     

A Virtual MAC Address Scheme for Mobile Ethernet

Heterogeneous wireless access is being integrated into IP networks to support future wireless systems. The enhanced IP technologies being developed must address both handover issues related to mobility management and security issues related to wireless access. We previously proposed a network architecture, Mobile Ethernet, based on wide area Ethernet technologies, that reduces overhead involving handover by managing mobility in the IEEE802 MAC layer. We also proposed a virtual MAC address scheme that introduces a host identifier into layer 2 to accommodate heterogeneous wireless access, manage handover between wireless accesses, provide scalability, and ensure security. In this paper, we design the virtual MAC address scheme for Mobile Ethernet and describe the sequence diagrams of the scheme. We also clarify the effect of our proposed scheme from the viewpoint of scalability by comparing the simulated signaling traffic load at handover with that using FMIPv6. Yoshia Saito received his B.E. and M.E. degrees from Shizuoka University, Shizuoka, Japan, in 2002 and 2003 respectively. He is currently a student in Ph.D. course in the university. From January 2004, he is also working as a visiting researcher at National Institute of Information and Communications Technology, Yokosuka, Japan. His research interests include mobile computing and next generation wireless systems. Masahiro Kuroda received the M.E. degree in systems science from the Tokyo Institute of Technology, Japan, in 1980, the M.S. degree in computer science from University of California, Santa Barbara, CA, in 1989, and received the Ph.D. degree in computer science from Shizuoka University, Japan, in 2000. He joined Mitsubishi Electric Corporation, Kamakura, Japan in 1980. Since then, he was engaged in OS/network developments, mobile network computing R&D, and cellular Java standardizations. He is currently working as a group leader at National Institute of Information and Communications Technology, Yokosuka, Japan. His current research interests includes wireless network, wireless security, mobile systems, ubiquitous systems, and next generation wireless systems architecture. He is a member of the IEEE Computer Society. Tadanori Mizuno received the B.E. degree in industrial engineering from the Nagoya Institute of Technology in 1968 and received the Ph.D. degree in computer science from Kyushu University, Japan, in 1987. In 1968, he joined Mitsubishi Electric Corp. Since 1993, he is a Professor of Faculty of Engineering, Shizuoka University, Japan. He moved to the Faculty of Information, Shizuoka University in 1995. His research interests include mobile computing, distributed computing, computer networks, broadcast communication and computing, and protocol engineering. He is a member of Information Processing Society of Japan, the institute of electronics, information and Communication Engineers, the IEEE Computer Society and ACM.     

基于THMLD的移动多点发送方法的性能分析

Mobile multicast is important for the emerging applications such as mobile video or audio conference and mobile IPTV. Some mobile multicast schemes have been proposed in the past few years, but most of them study the reconstruction ofmulticast delivery tree, and few consider the group membership management for mobile subscribers. In this paper, we propose a new mobile multicast method based on the Two-Hop Multicast Listener Discovery （THMLD） protocol which provides the mobile multicast membership management function by forwarding the traditional MLD messages to its neighboring subnets. To evaluate its performance, we analyze the THMLD and set up the simulation platform to compare it with the several traditional mobile multicast methods. The results show that THMLD can reduce the multicast join time, and the THMLD-based mobile multicast method can reduce the multicast join delay at a cost of increasing additional multicast maintenance cost.     

An Efficient Multicast Routing Protocol in Wireless Mobile Networks

Providing multicast service to mobile hosts in wireless mobile networking environments is difficult due to frequent changes of mobile host location and group membership. If a conventional multicast routing protocol is used in wireless mobile networks, several problems may be experienced since existing multicast routing protocols assume static hosts when they construct the multicast delivery tree. To overcome the problems, several multicast routing protocols for mobile hosts have been proposed. Although the protocols solve several problems inherent in multicast routing proposals for static hosts, they still have problems such as non-optimal delivery path, datagram duplication, overheads resulting from frequent reconstruction of a multicast tree, etc. In this paper, we summarize these problems of multicast routing protocols and propose an efficient multicast routing protocol based on IEFT mobile IP in wireless mobile networks. The proposed protocol introduces a multicast agent, where a mobile host receives a tunneled multicast datagram from a multicast agent located in a network close to it or directly from the multicast router in the current network. While receiving a tunneled multicast datagram from a remote multicast agent, the local multicast agent may start multicast join process, which makes the multicast delivery route optimal. The proposed protocol reduces data delivery path length and decreases the amount of duplicate copies of multicast datagrams. We examined and compared the performance of the proposed protocol and existing protocols by simulation under various environments and we got an improved performance over the existing proposals.