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。     

基于多播的移动IP位置管理的研究

提出了一种通过多播中组管理功能完成移动IP位置管理方法。每一个自治网络中都设置一个移动路由代理（MA），形成一个管理移动节点位置绑定信息的虚拟专用网，通过将与移动主机通信的节点联合起来构成一棵多播树，使网络中各节点相互合作维护移动节点的位置更新。设计了绑定信息表的存储结构和管理移动位置绑定信息的算法。模拟实验表明，提出的基于多播的位置管理方案能够使通信对端实时了解移动节点的转交地址，减少向家乡代理注册的时间和次数，减小了传输延迟，为实时业务传输提供较好的支持。同时减轻了家乡代理和各主机的负担，使移动IP的性能得到优化。     

A multi‐anchoring approach in mobile IP networks

Many recent mobility solutions, including derivatives of the well‐known Mobile IP as well as emerging protocols employed by future Internet architectures, propose to realize mobility management by distributing anchoring nodes (Home Agents or other indirection agents) over the Internet. One of their main goals is to address triangle routing by optimizing routes between mobile nodes and correspondent nodes. Thus, a key component of such proposals is the algorithm to select proper mobility anchoring nodes for mobile nodes. However, most current solutions adopt a single‐anchoring approach, which means each mobile node attaches to a sole mobility anchor at one time. In this paper, “we argue that the single‐anchoring approach has drawbacks when facing various mobility scenarios. Then, we offer a novel multi‐anchoring approach that allows each mobile node to select an independent mobility anchor for each correspondent node. We show that in most cases our proposal gains more performance benefits with an acceptable additional cost by evaluation based on real network topologies. For the cases that lead to potential high cost, we also provide a lightweight version of our solution which aims to preserve most performance benefits while keeping a lower cost. At last, we demonstrate how our proposal can be integrated into current Mobile IP networks. Copyright © 2017 John Wiley & Sons, Ltd.     

移动IP的移动性协议及管理机制

本主要从移动网络协议结构开始，讨论移动IP有关现行的和将来的Inernet移动性协议极其管理机制。     

一种改进的层次型移动组播协议

论文介绍了现有层次性移动组播协议——Mobi Cast协议,分析了该协议的优缺点。在Mobi Cast协议的基础上通过加入隧道技术,并减轻基站开销等方面进行了改进。仿真与分析表明,改进后的Mobi Cast协议具有组播数据丢包率低、网络维护开销小、切换延迟短等特点。     

基于扩展邻居发现协议的嵌套移动网络路由优化方案

嵌套移动网络在扩大通信范围的同时会带来严重的路由优化问题。针对已有优化方案在可部署性和性能等方面的不足提出了一种新的嵌套移动网络路由优化方案（NMNRO）,通过扩展邻居发现协议,在嵌套移动网络内通告相同的外地前缀,并更新接入路由器的邻居缓存和移动路由器的路由表,然后通过向对端发送绑定更新来实现路由优化。性能分析表明,该方案为嵌套移动网络提供了较为完整的路由优化方案,在降低优化开销的同时,具有较好的可部署性和兼容性。仿真实验结果表明该方案具有较低的切换时延和较高的有效吞吐量,且这些性能优势会随嵌套层数的增加而更加明显。     

一种时延受限的低代价移动IP组播路由算法

基于固定和移动IP混合网络，针对时延敏感的实时通信业务，建立了网络模型，提出了有时延约束的低代价组播路由问题，给出了一种分布启发式组播路由算法，证明了算法的正确性，分析了算法的复杂度。仿真结果表明，算法是有效的、稳定的。     

An efficient mesh‐based multicast routing protocol in mobile ad hoc networks

Mesh‐based multicast routing protocols for mobile ad hoc networks (MANETs) build multiple paths from senders to receivers to deliver packets even in the presence of links breaking. This redundancy results in high reliability/robustness but may significantly increase packet overhead. This paper proposes a mesh‐based multicast protocol, called centered protocol for unified multicasting through announcements (CPUMA), that achieves comparable reliability as existing mesh‐based multicast protocols, however, with significantly much less data overhead. In CPUMA, a distributed core‐selection and maintenance algorithm is used to find the source‐centric center of a shared mesh. We leverage data packets to center the core of each multicast group shared mesh instead of using GPS or any pre‐assignment of cores to groups (the case of existing protocols). The proposed centering scheme allows reducing data packet overhead and creating forwarding paths toward the nearest mesh member instead of the core to reduce latency. We show, via simulations, that CPUMA outperforms existing multicast protocols in terms of data packet overhead, and latency while maintaining a constant or better packet delivery ratio, at the cost of a small increase in control overhead in a few scenarios. Copyright © 2010 John Wiley & Sons, Ltd.     

QoS routing based on mobile agent for LEO satellite IP networks

Current quality of service (QoS) routing schemes for low earth orbit (LEO) satellites IP networks either neglect the varying population density or fail to guarantee end-to-end delay. As a remedy, QoS routing protocol based on mobile agent (QoSRP-MA) is proposed. QoSRP-MA is a source-based routing protocol. Once connection requests arrive, QoS mobile agents are dispatched from ingress satellite to explore routes, which migrate using satellite routing tables. Upon arriving in egress satellite, QoS mobile agents migrate back towards ingress satellite to reserve bandwidth. To construct satellite routing tables, load balancing routing algorithm based on mobile agent (LBRA-MA) is presented. In LBRP-MA, at regular intervals mobile agents launched on all satellites migrate autonomously to evaluate path cost and update routing tables. Moreover, path cost between source and destination is evaluated considering satellite geographical position as well as inter-satellite link (ISL) cost. Furthermore, ISL congestion index is considered to update routing table. Through simulations on a Courier-like constellation, it shows that QoSRP-MA can achieve guaranteed end-to-end delay bound with higher throughput, lower connection failing ratio and signaling overhead compared to high performance satellite routing (HPSR) scheme.     

传统IP组播面临的困境及源特定组播(SSM)

IP组播出现以来，尽管其技术上具有一定的优势，但并未得到广泛的应用。本文首先简要介绍IP组播的原理和体系结构．然后从ISP、用户、ASM模型等几个方面重点分析了传统IP组播没有得到大规模商业应用的原因，最后介绍了一种组播的改进模型——源特定组播(SSM)。     

A load‐balancing and coding‐aware multicast protocol for mobile ad hoc networks

In this paper, we propose a Load‐Balancing and Coding‐Aware Multicast (LCM) protocol for mobile ad hoc networks. In LCM protocol, a new route metric named Expected Transmission Time with Coding and Load Balancing (ETTCL) is presented at first, aiming at effectively selecting the path not only that has the possible coding opportunity but also where overflow due to network overload can be prevented. Then, we describe the route discovery phase by constructing the node‐disjoint multicast tree on the basis of ETTCL and employ network coding to encode the data flows for route maintenance. The effectiveness of LCM protocol is simulated and analyzed by NS‐2, which shows that this protocol has good performance in reducing average end‐to‐end delay and control overhead and can improve packet delivery ratio compared with the existing protocol. Copyright © 2015 John Wiley & Sons, Ltd.     

An efficient distributed routing protocol for wireless sensor networks with mobile sinks

Introducing mobile sinks into a wireless sensor network can effectively improve the network performance. However, sink mobility can bring excessive protocol overhead for route maintenance and may offset the benefit from using mobile sinks. In this paper, we propose a dynamic layered routing protocol to address this problem. The proposed protocol integrates dynamic layered Voronoi scoping and dynamic anchor selection to effectively reduce the dissemination scopes and frequencies of routing updates as the sinks move in the network. Simulation results show that the proposed protocol can effectively reduce the protocol overhead while ensuring high packet delivery ratio as compared with existing work. Copyright © 2014 John Wiley & Sons, Ltd.     

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。     

一种高效的具有用户匿名性的无线认证协议

提出了一种高效的具有用户匿名性的无线认证协议。利用Hash函数和Smart卡实现了协议的用户匿名性。协议充分考虑了无线网络自身的限制和移动设备存储资源及计算资源的局限性，在认证过程中移动用户只需要进行一次对称加密和解密运算，用户与访问网络、本地网络与访问网络都只进行一次信息交换，而且所有对称加密都使用一次性密钥。本协议具有实用、安全、高效的特点。     

移动IP路由优化性能分析及仿真

因特网技术的普及,使得人们实现了网际通信和信息共享,但基于有线方式的Internet受到空间和时间的限制,无法满足用户随时随地能够接入因特网的要求,这成为研究移动主机路由协议的驱动力.移动IP是一种简单、可扩展的全球IP移动性的解决方案,但三角路由问题的存在带来了网络花费问题和性能问题.路由优化移动IP协议是解决移动IP相关问题的侯选协议之一.本文对两种协议进行了理论分析和仿真.结果表明,是否采用路由优化协议,不能一概而论,要根据网络及业务到达特征决定.另外,两种协议都不能很好地支持将来的微小区带来的频繁切换,而解决该问题就是我们下一步的研究方向.     

改进的移动IP的注册性能分析

根据现有的IETF移动IP规范，当移动节点驻留在远离归属网络的外地网络时，将会产生严重的注册延迟，从而引起严重的包丢失和通信吞吐量的下降。本文利用改进后的移动IP网络结构，引入routing agent，使得大量的当地注册报文只需要在RA上处理即可，从而减少了注册延迟，改善了移动IP的性能。本文对其中的注册代价进行了深入的分析，并与标准移动IP中的注册代价进行了对比。     

SIM：应用于MANET的安全IP协议

参考IP Sec的核心思想,并结合MANET的具体实际,提出了一种安全的IP协议SIM（secure IP protocol for manet）。通过在网络层和数据链路层之间添加一个无连接的安全层,对进出协议栈的数据报文进行安全处理。通过将IP Sec的安全协定SA简化为轻量级的适合MANET的SSA,在保持IP安全性的同时降低了协议开销和部署复杂度。进行了基于Linux的协议栈设计和原型系统实现。     

一种基于LET预测和转发组成员数的优化组播路由协议

本文从综合考虑ODMRP协议转发组的有效性和健壮性出发,提出了一种基于LET(Link Expiration Time)预测和转发组成员数的组播路由协议LETFG-ODMRP(Optimal Multicast Protocol with LET and FGs based on ODMRP).LETFG-ODMRP通过对网络中传输路径保持连接时间LET的预测,得知路径的稳定度,然后结合考虑转发组成员数,建立一种新的路由选择标准PathMetric.采用此种路由选择标准,LETFG-ODMRP可调节权重在候选路由集中选择稳定或有效的传输路径构成转发组.模拟仿真结果证实LETFG-ODMRP提高了组播协议健壮性、有效性及自适应能力.     

在基于MPLS的层次化移动IP网络中支持DiffServ的研究

MPLS支持DiffServ、流量工程,能为网络提供较好的QoS保证,而移动IP(MIP)能为移动设备提供较好的移动性支持。文章探讨了在无线接入网中MPLS和MIP结合实现DiffServ的方案,并给出了一种在基于MPLS的层次化MIP网络结构中支持DiffServ的体系结构,设计了其节点功能模型和关键协议。方案中利用了层次化结构的区域注册和重路由机制,减少了切换时延和网络的信令负荷。