Hierarchical mobility management for fast handoff and load distribution in IPv6 networks

Hierarchical Mobile IPv6 (HMIPv6) has been proposed by the Internet engineering task force (IETF) to compensate for such problems as handover latency and signalling overhead when employing Mobile IPv6 (MIPv6). HMIPv6 supports micro‐mobility within a domain and introduces a new entity, namely mobility anchor point (MAP) as a local home agent (HA). However, HMIPv6 has caused load concentration at a particular MAP and longer handover latency when an inter‐domain handover occurs. In order to solve such problems, this paper establishes a virtual domain (VD) of a higher layer MAP and proposes a MAP changing scheme. The MAP changing scheme enables complete handover by using binding‐update of the on‐link care of address (LCoA) only when inter‐domain handover occurs. In addition, the concentrated load of a particular MAP is distributed as well. Copyright © 2008 John Wiley & Sons, Ltd.     

Performance Analysis of Hierarchical Mobile IPv6: Does it Improve Mobile IPv6 in Terms of Handover Speed?

There has been a rapid growth in the need to support mobile nodes in IPv6-based networks. IETF has completed to standardize Mobile IPv6 (MIPv6) and Hierarchical Mobile IPv6 (HMIPv6) for supporting IPv6 mobility. Even though existing literatures have asserted that HMIPv6 generally improves MIPv6 in terms of handover speed, they do not carefully consider the details of the whole handover procedures. In this paper, based on the current IETF standards of both MIPv6 and HMIPv6, we conduct a comprehensive study of all IP-level handover procedures: movement detection, duplicate address detection, and location registration. Based on this study, we provide a mathematical analysis on MIPv6 and HMIPv6 performance in terms of handover speed. From the analysis, we reveal that the average HMIPv6 handover latency is not always lower than the average MIPv6 handover latency. Furthermore, even the intra-domain handover latency of HMIPv6 is not reduced much compared with MIPv6 handover latency. A finding of our analysis is that optimization techniques for movement detection and duplicate address detection are essential to shortening HMIPv6 handover latency and increasing the benefit of HMIPv6.

移动IPv6分层管理费用的分析与自适应优化

为综合优化分层域内外以网络传输花费和带宽占用为代表的通信管理费用,论文对实施分层移动IPv6前后的费用变化进行了理论分析,得出了判决是否适宜使用分层移动管理的准则,并在此基础上提出一种允许移动节点动态地根据切换频度和流量强度等参数选择适宜的移动管理机制的自适应优化方案.仿真结果表明该方案能获得比静止使用某种移动管理机制更好的资源使用效率,可望具有较好的实际应用价值.     

A New Enhanced Fast Handover Algorithm in Hierarchical Mobile IPv6 Network

1　Introduction　MobileIPv6requirestheMobileNode (MN)toregisterwiththeHomeAgent (HA)andtheCorre spondentNode (CN)whenitchangesitspointofattachmentintheInternet[1～ 3] .Therefore ,thiscauseMobileIPv6toincurlongdelayintheregis tration process,andaddsignalingtraffictothebackbonenetworkespeciallywhentheHAandCNarefarawayfromtheMN .Inordertominimizethisdelay ,andthesignalingoverhead presentinMobileIPv6,literatures[4～7] proposeHierarchicalMobileIPv6(HMIPv6)architectureandafasthan dover…     

A cross‐layer partner‐based fast handoff mechanism for IEEE 802.11 wireless networks

In wireless/mobile networks, users freely and frequently change their access points (APs) while they are communicating with other users. To support the mobility of mobile nodes (MNs), Mobile IPv6 (MIPv6) is used to inform the information of MN's home address and current care‐of‐address (CoA) to its home agent. MIPv6 suffers from a long delay latency and high packet losses (PLs) because MIPv6 does not support micromobility. A Hierarchical Mobile IPv6 (HMIPv6) is proposed which provides micromobility and macromobility to reduce handoff latency (HL) by employing a hierarchical network structure. In this paper, we propose a cross‐layer partner‐based fast handoff mechanism based on HMIPv6, called the PHMIPv6 protocol. Our PHMIPv6 protocol is a cross‐layer, layer‐2 + layer‐3, and cooperative approach. A cooperative node, called a partner node (PN), is adopted in the PHMIPv6 protocol. A new layer‐2 trigger scheme used in the PHMIPv6 protocol accurately predicts the next AP and then invites a cooperative PN in the area of the next AP. With the cooperation of the PN, the CoA can be pre‐acquired and duplicate address detection operation can be pre‐executed by the PN before the MN initializes the handoff request. The PHMIPv6 protocol significantly reduces the handoff delay time and PLs. In the mathematical analysis, we verified that our PHMIPv6 protocol offers a better HL than the MIPv6, HMIPv6, and SHMIPv6 protocols. Finally, the experimental results also illustrate that the PHMIPv6 protocol actually achieves performance improvements in the handoff delay time, PL rate, and handoff delay jitter. Copyright © 2009 John Wiley & Sons, Ltd.     

DMAP-FR: Dynamic Mobility Anchor Points for Mobility,Service and Failure Recovery Management in Mobile IPv6 Systems

In this paper, we propose and analyze DMAP-FR, a mobility and service management scheme with failure recovery (FR) control in Mobile IPv6 systems. The basic idea behind DMAP-FR is to leverage access routers (ARs) running as regional mobility anchor points (MAPs) as in Hierarchical Mobile IPv6 (HMIPv6) for mobility and service management for mobile nodes (MNs). However, unlike HMIPv6, DMAP-FR allows the MAP of each MN to be determined dynamically based on the mobility and service characteristics of the MN and the failure behavior of ARs with the goal to minimize the network traffic. DMAP-FR incorporates fault tolerance mechanisms to allow the system to quickly recover from AR and MAP failures. We identify the best dynamic regional area size for the selection of MAP for each MN such that the overall network traffic due to servicing mobility, service and fault tolerance related operations is minimized. We demonstrate that DMAP-FR outperforms HMIPv6 for the same AR failure rate.     

移动IPv6分层式路由管理模型的分析与研究

分层移动IPV6协议减少了注册延迟，但仍具有路由不够优化等问题。通过分析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、域间移动时实现快速切换以减少延迟．提高网络资源利用率。仿真分析结果验证模型的有效性．     

A Scheme for Supporting Fast Handover in Hierarchical Mobile IPv6 Networks

This Letter proposes a scheme that supports a fast handover effectively in hierarchical mobile IPv6 networks (F‐HMIPv6) by optimizing the associated data and control flows during the handover. By NS‐2 simulation, we show that the proposed scheme can give better handover performance than a simple combination of existing schemes.     

乒乓切换在移动IPv6扩展协议中的性能分析

 综合评价了多种移动IPv6扩展协议在基于端到端的TCP协议L3层的切换性能,模拟仿真了乒乓切换在MIPv6、FMIPv6、HMIPv6和FHMIPv6中的时延、吞吐量和丢包现象,提出了一种优化的FHMIPv6方案.该方案通过定义新的Hop-by－Hop 选项报头TM、 PCoA表和双向隧道表,实现MN的快速、平滑切换,比FHMIPv6进一步减少了时延,提高了吞吐量,降低了丢包率.     

A mobility-based load control scheme in Hierarchical Mobile IPv6 networks

By introducing a mobility anchor point (MAP), Hierarchical Mobile IPv6 (HMIPv6) reduces the signaling overhead and handoff latency associated with Mobile IPv6. In this paper, we propose a mobility-based load control (MLC) scheme, which mitigates the burden of the MAP in fully distributed and adaptive manners. The MLC scheme combines two algorithms: a threshold-based admission control algorithm and a session-to-mobility ratio (SMR)-based replacement algorithm. The threshold-based admission control algorithm gives higher priority to ongoing mobile nodes (MNs) than new MNs, by blocking new MNs when the number of MNs being serviced by the MAP is greater than a predetermined threshold. On the other hand, the SMR-based replacement algorithm achieves efficient MAP load distribution by considering MNs’ traffic and mobility patterns. We analyze the MLC scheme using the continuous time Markov chain in terms of the new MN blocking probability, ongoing MN dropping probability, and binding update cost. Also, the MAP processing latency is evaluated based on the M/G/1 queueing model. Analytical and simulation results demonstrate that the MLC scheme outperforms other schemes and thus it is a viable solution for scalable HMIPv6 networks.     

DMAP: integrated mobility and service management in mobile IPv6 systems

Mobile IPv6 (MIPv6) is a work in progress IETF standard for enabling mobility in IPv6 networks and is expected to have wide deployment. We investigate an integrated mobility and service management scheme based on MIPv6 with the goal to minimize the overall network signaling cost in MIPv6 systems for serving mobility and service management related operations. Our design extends IETF work-in-progress Hierarchical Mobile IPv6 (HMIPv6) with the notion of dynamic mobility anchor points (DMAPs) for each mobile node (MN) instead of static ones for all MNs. These DMAPs are access routers chosen by individual MNs to act as a regional router to reduce the signaling overhead for intra-regional movements. The DMAP domain size, i.e., the number of subnets covered by a DMAP, is based on the MN’s mobility and service characteristics. Under our DMAP protocol, a MN interacts with its home agent and application servers as in the MIPv6 protocol, but optimally determines when and where to launch a DMAP to minimize the network cost in serving the user’s mobility and service management operations. We demonstrate that our DMAP protocol for integrated mobility and service management yields significantly improved performance over basic MIPv6 and HMIPv6.     

Predictive versus Reactive—Analysis of Handover Performance and Its Implications on IPv6 and Multicast Mobility

Handovers in mobile packet networks commonly produce packet loss, delay and jitter, thereby significantly degrading network performance. Mobile IPv6 handover performance is strongly topology dependent and results in inferior service quality in wide area scenarios. To approach seamless mobility in IPv6 networks predictive, reactive and proxy schemes have been proposed for improvement. In this article we analyse and compare handover performance and frequencies for the corresponding protocols, as they are an immediate measure on service quality. Using analytical methods as well as stochastic simulations, we calculate the performance decreases originating from different handover schemes, the expected number of handovers as functions of mobility and proxy ratios, as well as the mean correctness of predictions. In detail we treat the more delicate case of these rates in mobile multicast communication. It is obtained that performance benefits, expected from simple analysis of predictive schemes, do not hold in practice. Reactive and predictive handovers rather admit comparable performance. Hierarchical proxy environments—foremost in regions of high mobility—can significantly reduce the processing of inter–network changes. Reliability of handover predictions is found on average at about 50%.     

Adaptive Route Optimization in Hierarchical Mobile IPv6 Networks

By introducing a mobility anchor point (MAP), Hierarchical Mobile IPv6 (HMIP6) reduces the signaling overhead and handoff latency associated with Mobile IPv6. However, if a mobile node (MN)'s session activity is high and its mobility is relatively low, HMIPv6 may degrade end-to-end data throughput due to the additional packet tunneling at the MAP. In this paper, we propose an adaptive route optimization (ARO) scheme to improve the throughput performance in HMIPv6 networks. Depending on the measured session-to-mobility ratio (SMR), ARO chooses one of the two different route optimization algorithms adaptively. Specifically, an MN informs a correspondent node (CN) of its on-link care-of address (LCoA) if the CN's SMR is greater than a predefined threshold. If the SMR is equal to or lower than the threshold, the CN is informed with the MN's regional CoA (RCoA). We analyze the performance of ARO in terms of balancing the signaling overhead reduction and the data throughput improvement. We also derive the optimal SMR threshold explicitly to achieve such a balance. Analytical and simulation results demonstrate that ARO is a viable scheme for deployment in HMIPv6 networks.     

Enhancing QoS of Mobile Devices by a New Handover Process in PMIPv6 Networks

The handover processes in present IP mobility management protocols incur significant latency, thus aggravating QoS of consumer devices. In this paper, we introduce an enhanced handover process for the Proxy Mobile IPv6 (PMIPv6) protocol, which is a recently developed IP mobility management protocol aiming at providing network-based mobility support. The proposed handover process further improves handover performance of PMIPv6 by allowing a new access network obtains handover context before a consumer??s mobile node (MN) moves to the new access network. Data packets destined for the MN are buffered to prevent packet loss and immediately delivered to the MN as the MN moves to the new access network. We evaluate the handover latency and data packet loss of the proposed handover process compared to the basic one of PMIPv6. The conducted analysis results confirm that the proposed handover process yields the reduced handover latency compared to that of the basic PMIPv6 and also prevents data packet loss. We moreover evaluate the buffering cost of the proposed handover process.     

Analysis and Evaluation of Mobile IPv6 Handovers over Wireless LAN

In this paper, we analyze the IPv6 handover over wireless LANs. Mobile IPv6 is designed to manage mobile nodes movements between wireless IPv6 networks. Nevertheless, a mobile node cannot receive IP packets on its new point of attachment until the handover completes. Therefore, a number of extensions to Mobile IPv6 have been proposed to reduce the handover latency and the number of lost packets. We focus on Fast Mobile IPv6 which is an extension of Mobile IPv6 that allows the use of L2 triggers to anticipate the handover. We compare the handover latency in four specific cases: basic Mobile IPv6, the forwarding method of Mobile IPv6, the Anticipated method, and the Tunnel-Based Handover. The results of the handover latency are calculated with the L2 properties of IEEE 802.11b. In particular, we take into account the L2 handover for different configurations of the wireless network.     

集成AAA的HMIPv6认证与注册方案

在下一代互联网中,需要使用AAA保证网络安全和网络资源合理使用,但是AAA与移动IPv6的结合,对切换性能及网络安全带来影响,而切换与安全是移动环境的关键问题。论文提出了新的解决方案,将HMIPv6与AAA结合,实现认证与注册过程的统一及本地认证,提高切换性能,并在注册与认证的过程中对消息进行加密,保证传输的安全。分析表明,本方案实现了AAA机制与移动管理机制安全高效的融合。     

RSVP Extensions for Real-Time Services in Hierarchical Mobile IPv6

The Mobile IPv6 (MIPv6) provides many great features, such as sufficient addressing space, mobility, and security; MIPv6 is one of the most important protocols for next generation mobile Internet. Simultaneously, with the rapid improvement of wireless technologies, the real-time multi-media IP services such as video on demand, videoconference, interactive games, IP telephony and video IP phone will be delivered in the near future. Thus, to furnish accurate QoS for real-time services is one of the most important thing in the next generation mobile Internet. Although RSVP, which is a resource reservation protocol, processes signaling messages to establish QoS paths between senders and receivers, RSVP was originally designed for stationary networks and not aware of the mobility of MNs. Therefore, this paper proposes a novel RSVP extension to support real-time services in Hierarchical Mobile IPv6 (HMIPv6) environments. For intra-site mobility, the concept of QoS Agent (QA) is proposed to handle the RSVP QoS update messages and provide the advanced reservation models for real-time services. For inter-site mobility, IP multicast can help to invite inter-site QAs to make pre-reservation and minimize the service disruption caused by re-routing the data path during handover. Simulation results show that the proposed scheme over HMIPv6 is more suitable for real-time services than the famous RSVP tunnel-based solution.     

移动IPv6切换时延优化新方法

移动IPv6中,移动节点(MN)在不同子网间移动时,既不中断与通信对端(CN)的通信,也不用改变其本身的IP地址.但是当MN与其家乡代理(HA)之间相距较远时,移动IPv6切换时延较大,对于实时性要求较高的业务无法适用.本文分析比较了目前移动IPv6常用的切换时延优化方法,提出了一种自适应快速层次移动IPv6切换时延优化方法,减小了移动IPv6切换时延,提高了网络的性能.     

快速层次移动IPv6切换性能分析及优化

移动IPv6技术中切换延时对实时应用影响很大。介绍了目前移动IPv6常用的快速移动和层次移动切换技术,描述其切换原理和过程。结合2种技术的优缺点,给出了一种新的快速层次移动IPv6的切换方案。利用NS-2对这3种切换方法进行仿真得到的结果表明,快速层次移动IPv6切换延时要小于快速移动IPv6和层次移动IPv6的切换延时,且降低了数据包丢失率,提高了网络的性能。     

Low-cost binding update scheme based on pointer forwarding in HMIPv6 network

By introducing a mobility anchor point(MAP),hierarchical mobile IPv6(HMIPv6)reduces the binding update signaling cost associated with mobile IPv6,but there still exist deficiencies.For instance,a mobile node(MN)needs to orderly accomplish two binding updates with the MAP and home agent(HA)when the MN performs inter-MAP mobility.This results in a high signaling cost,thus affecting network performance.To reduce the inter-MAP binding update cost of idle MN in HMIPv6,an optimization scheme based on pointer forwarding with a threshold is proposed.The scheme can reduces the binding update cost of idle MN by using the binding update between MAP to replace several home binding updates.The signaling cost difference is derived by analyzing the cost of the basic scheme and the optimization scheme between two successive sessions.Simulation results show that,the optimization scheme can reduce the binding update signaling cost and improve the network performance as long as a suitable threshold is chosen.The discussions on the sensitivity of tele-parameters are also given.