All-IP communication between wireless sensor networks and IPv6 networks based on location information

The paper proposes a scheme on achieving all-IP communication between wireless sensor networks and IPv6 networks based on sensor nodes' location information. The paper proposes the sensor node's IPv6 address structure based on location information, the IPv6-address configuration algorithm based on the proposed IPv6 address structure, the mobility handoff algorithm and the routing algorithm in the link layer. The location information of sensor nodes is utilized to achieve the IPv6-address configuration algorithm and the routing algorithm. In the mobility handoff algorithm, neither does a mobile sensor node need a care-of address during the mobility process, nor is involved in the mobility handoff process. Therefore, a mobile sensor node's power consumption is reduced and the life span is prolonged. The paper analyzes the performances of the proposed scheme and the existing schemes, and the analytical data show that the performance of the proposed scheme is better.     

High performance mobility without agent infrastructure for connection oriented service

Currently it is very difficult for connection oriented applications to use a mobile environment. One reason is that Mobile IP requires intermediate software agents to be deployed in the Internet. This infrastructure based mobility scheme offers connectivity to itinerant hosts but incurs significant handoff and tunneling delays along with deployment costs. These delays are particularly harmful for connection oriented applications. In this paper we investigate an alternate mobility scheme which does not require any such infrastructure but only uses an end-point technique and interestingly provides much faster loss-free handoff for connection oriented applications. This End-to-End scheme named Interactive Protocol for Mobile Networks (IPMN) intelligently performs handoff based on information provided by MAC Layer. The network address change is handled by renewing the existing connections by manipulating the TCP/IP stack at the end-points. Also, unlike several other recently proposed end-to-end techniques which require extensive modification of end-protocols, the proposed scheme does not require any functional change in the TCP/IP protocol software. Besides the difference in deployment scenarios, the IPMN offers blazingly fast event based handoff and much faster and simplified transport (no tunneling delay) than MIP. We have implemented IPMN over FreeBSD. In this paper we show the performance advantage of IPMN over MIP with real deployment for three interesting real-time traffic types — www, voice streaming and, steerable/interactive time critical video.     

基于多播树的HMIPv6快速切换方案

为了缩短移动节点的切换延迟时间,提出基于多播树的分层移动IPv6(HMIPv6)快速切换方案。该方案采用快速切换方式建立移动锚点与移动节点之间的多播隧道,移动节点在同一个区域内始终使用相同的多播地址。仿真结果表明,与现有HMIPv6方案相比,该方案的切换时间更短、丢包率更低、性能更好。     

A mobility management scheme for wireless mesh networks based on a hybrid routing protocol

Recent advances in wireless mesh networks (WMNs) have overcome the drawbacks of traditional wired networks and wireless ad hoc networks. WMNs will play a leading role in the next generation of networks, and the question of how to provide seamless mobility management for WMNs is the driving force behind the research. The inherent characteristics of WMNs, such as relatively static backbones and highly mobile clients, require new mobility management solutions to be designed and implemented.In this paper, a hybrid routing protocol for forwarding packets is proposed: this involves both link layer routing and network layer routing. Based on the hybrid routing protocol, a mobility management scheme for WMNs is presented. Both intra-domain and inter-domain mobility management have been designed to support seamless roaming in WiFi-based WMNs. During intra-domain handoff, gratuitous ARP messages are used to provide new routing information, thus avoiding re-routing and location update. For inter-domain handoff, redundant tunnels are removed in order to minimize forwarding latency. Comprehensive simulation results illustrate that our scheme has low packet latency, low packet loss ratio and short handoff latency. As a result, real-time applications over 802.11 WMNs such as VoIP can be supported.     

一种自适应的ICN移动性机制

信息中心网络（information-centric networking,ICN）内在地支持兴趣请求者移动而不支持内容提供者移动,然而在实际的场景中往往发生的是内容提供者移动。当前的移动性解决方案存在一些缺憾,如没有真正地考虑移动设备的加入/离开、机制过于单一不能应对各种移动场景、网络切换时延过长等。为解决上述问题,面向区域划分设计一种自适应的移动性机制,包括基于汇聚点的域内移动解决方案、基于兴趣转发的域间移动解决方案和基于回溯的基站间移动解决方案。仿真在GTS网络拓扑上进行,实验结果表明所提的移动性机制较基准机制有高的分发率、低的切换时延和少的路由跳数,说明所提的移动性机制具有广泛的应用价值,为推动诸如5G应用的全面落地具有现实的意义。     

具有负载均衡和蚁群优化的移动P2P路由策略

分析了移动P2P网络的移动节点设备资源更加短缺,网络更加动态多变,建立健壮的路由策略是非常重要的。通过研究移动P2P网络的特征,从路由发现、路由选择、路由保持三个方面入手,提出了一种新的具有负载均衡和蚁群优化的路由策略。利用蚁群算法理论来指导移动agent的全局搜索的路由发现工作,并且结合通用的能量消耗公式计算得到的节点剩余能量和节点业务执行等候队列长度来优化路由选择工作。从仿真实验可以看到,该路由策略在平均端到端的延迟、路由控制负载方面具有性能优势。同时,节约了节点的能量,延长了节点在网络中的生存时间。     

An Efficient Handoff Decision Algorithm for Vertical Handoff Between WWAN and WLAN

Vertical handoff is one significant challenge for mobility management in heterogeneous wireless networks. Compared with horizontal handoff, vertical handoff involves different wireless network technologies varying widely in terms of bandwidth, delay, coverage area, power consumption, etc. In this paper, we analyze the signal strength model of mobile node and present a new vertical handoff decision algorithm. This algorithm can adapt to the change of mobile node＇s velocity and improve the handoff efficiency significantly. We analyze the algorithm＇s performance and the effect of different parameters on handoff triggering. In addition, we propose three performance evaluation models and verify the algorithm＇s feasibility and effectiveness in simulations.     

移动场景下的节点高效寻路RPL路由算法优化

在低功耗有损网络(low power and lossy networks)中,现有的移动性支持路由算法存在控制消息冗余,应用场景不具有普适应,网络丢包率和移动节点能耗较高等问题.针对这些问题,提出一种移动场景下的节点高效寻路RPL路由算法(efficient pathfinding RPL routing algorithm for nodes in mobile scenarios,MSE-RPL).该算法提出的优化思路如下:首先,精简了移动节点的控制消息,并采用自适应黑名单机制建立备选父节点集,从而降低了移动节点的能耗;其次,基于移动节点的移动速度和方向,从备选父节点集中选择移出通信范围预估时间最短的节点作为最优父节点,不但适用于随机移动场景,还降低了平均端到端时延;最后,在链路中断前,利用DIS计时器及时通告DIS消息以快速重构拓扑,降低了丢包率.仿真结果表明,MSE-RPL算法在平均端到端时延、移动节点能耗、丢包率等性能指标方面均有明显改善.     

WLAN中基于接入点的快速切换方案

移动终端在接入点(AP)之间切换产生的时延和抖动严重影响实时业务的质量。为解决该问题,提出一种基于接入点的快速切换方案,采用两级触发机制减轻移动终端和AP的工作量,利用改进的先应式邻居缓存机制避免频繁切换导致的AP缓存溢出问题,通过邻居AP信息表和切换决策算法找到最佳目标AP。实验结果表明,该方案具有较高的安全性及较低的网络吞吐量和功耗,可以减少77.1%的切换时延。     

移动IP切换对TCP性能影响的分析

介绍了移动IP切换的发展过程及原理,描述了切换造成TCP性能下降原因和一些实验验证数据。说明为了更好地满足用户需求,移动IP和TCP需要作进一步改进,并提出了相应的解决办法。     

基于位置预查询的因特网移动支持方案

提出一种预查询移动支持方案(mobile Internet protocol_based on location pre-query,简称MIP_Q),以解决家乡网络的流量瓶颈和单点故障问题,从而提高移动通信的效率和可靠性.MIP_Q通过扩展域名服务系统管理和跟踪移动节点的当前位置信息,省去了家乡代理;采用并行切换控制方式,同时避免了MIP(mobile Internet protocol,简称MIP)中的三角路由和隧道路由问题;借助有效的计算方法,分析和比较了MIP_Q与MIP,MIP_LR的平均移动通信成本和切换时延;在实现方面与广泛应用的广域蜂窝移动网络进行了类比.结果表明:MIP_Q在切换效率和新增实体数等方面优于同类方案;MIP_Q可以极大地降低节点的移动通信成本,减小切换时延;MIP_Q具有良好的可行性.最后提出MIP_Q的仿真和实现方案.     

移动式网络中快速认证方法设计与仿真

作为移动IP技术的新的发展方向,移动式网络技术是将节点移动性向网络移动性(NEMO)扩展的关键技术,降低移动式网络在注册和认证过程中的延时,能够提高移动式网络技术的实际应用.提出了新的基于Mobile IP/AAA模型的移动式网络认证方法,研究了AAAL与AAAH之间的距离以及本地切换率对认证延时的影响,并提交了NS2仿真试验结果和安全性分析.该方法能够实现低切换时延,并保证移动式网络注册和切换中的安全性.     

基于移动IPv6的分层式路由

移动节点在两个不同子网之间移动时将产生切换,这里简单介绍了移动IPv6的原理,对移动节点越区切换技术作了详细的分析HMIPv6,提出一种基于分层机制的移动IPv6路由管理模型。该模型支持路由优化,能在域内、域问移动时实现快速切换以减少延迟,提高网络资源利用率。     

Mobility-based predictive call admission control and bandwidth reservation in wireless cellular networks

This paper presents call admission control and bandwidth reservation schemes in wireless cellular networks that have been developed based on assumptions more realistic than existing proposals. In order to guarantee the handoff dropping probability, we propose to statistically predict user mobility based on the mobility history of users. Our mobility prediction scheme is motivated by computational learning theory, which has shown that prediction is synonymous with data compression. We derive our mobility prediction scheme from data compression techniques that are both theoretically optimal and good in practice. In order to utilize resource more efficiently, we predict not only the cell to which the mobile will handoff but also when the handoff will occur. Based on the mobility prediction, bandwidth is reserved to guarantee some target handoff dropping probability. We also adaptively control the admission threshold to achieve a better balance between guaranteeing handoff dropping probability and maximizing resource utilization. Simulation results show that the proposed schemes meet our design goals and outperform the static-reservation and cell-reservation schemes.     

基于OLSR协议的无人机自组网多径路由策略

针对现有文献在研究路由协议时选择的路由度量未能结合无人机自组织网络当时的性能水平进而造成路由决策不合理的问题,提出了一种具有负载感知和网络拓扑变动感知能力的多指标多径优化链路状态路由协议（optimized link state routing protocol based on multi-indicator and multi-path,MIMP-OLSR）。该协议首先考虑了无人机场景的节点移动特性和网络的生存时间,并定义了三个用于进行路由选择的指标,即节点的MAC层阻塞度、节点的邻居变化率和节点的多点中继选择节点（multi-point relay selector,MPR_S）邻居数目;其次,结合HELLO和TC两种控制消息提出了一种指标通告机制,用于将指标信息洪泛给全网节点;最后,根据指标信息提出了一种多径路由方案。仿真结果表明,与OLSR、SETT_MPOLSR和UAV-OLSR协议相比,所提协议MIMP-OLSR在成功率、端到端时延和吞吐量性能上均有明显提高,进而证明所提多径路由方案的合理性。     

蓝牙技术的快速连接转移模式

由于一个移动设备所属的微微网只有10 m距离,因此就有可能发生频繁的连接转移.连接转移需要移动设备与新的基站之间建立连接,这在频跳系统中是费时的过程,这种状态将引起许多连接的丢失从而影响网络性能.提出了一种新的模式用来改善连接转移的性能.模拟的结果显示,提出的模式显著的减少了连接转移的延时.     

基于行动预测的支持移动自组网QoS的路由方案

从研究高斯-马尔可夫运动模型出发，提出了一个可用于预测移动自组网中节点间最大链路有效时间的模型。从提供Qos路由度量和改进被动路由协议两个方面阐述了提供移动自组网Qos支持的机制。仿真实验表明，新的路由方案具有网络吞吐量大、抖动小和时延可控制的特点。     

基于混沌映射组播技术的无线移动自组织网络路由研究

为解决无线移动自组织网络在高速运转过程中存在严重时延,导致组播困难的问题,本文提出一种基于混沌映射组播技术的无线移动自组织网络路由。引入数学群论中的直积,构造无穷混沌图谱节点;再通过强镜面性来给移动节点坐标进行映射处理,将整个无线移动自组织网络纳入超球面中;最后,利用超球面良好的拓扑性能来实现源节点组播信息及网络路由的维护。仿真实验表明：与当前网络路由相比,本新路由在时延、网络控制开销及分组投递指标上有明显的优势,特别是在规模较大时的优势更加明显。     

基于生命期预测的移动Ad hoc网络多径路由策略

在移动自组网中,由于网络节点的移动性和拓扑结构的多态性,多路径路由在稳定性,均衡负载方面优于单路径路由,非常适合Ad hoc网络。考虑到移动自组网中节点能量的局限性,在DSR协议的基础上提出了一种新型的多径路由算法。该算法结合节点路径的能量消耗率,预测出链路的生命期,以求找到多条有效路径并进行传输。仿真结果表明,该协议比DSR具有更好的吞吐量和端到端延迟。