Mobility management in wireless ATM networks

Mobile ATM offers a common wired network infrastructure to support mobility of wireless terminals, independent of the wireless access protocol. In addition, it allows seamless migration to future wireless broadband services, such as wireless ATM, by enabling mobility of end-to-end ATM connections. In spite of the diversity in mobile networking technologies (e.g., cellular telephony, mobile-IP, packet data services, PCS), all of them require two fundamental mechanisms: location management and handoff. This article describes different schemes for augmenting a wired ATM network to support location management of mobile terminals and handoff protocols for rerouting a connection data path when the endpoint moves. A prototype implementation of mobile ATM integrating mobility support with ATM signaling and connection setup, is presented. It shows how mobile ATM may be used to provide mobility support to an IP terminal using non-ATM wireless access     

Fast and reliable handoff for vehicular networks

A layer-3 mobility management scheme for an all-IP Wireless Access Network (WAN), and in particular for vehicular networks, is developed in this paper. The proposed method enables fast and reliable handoff. This feature is extremely important for high speed vehicular networks. Since vehicles are characterized by likely-predictable path, as well as very high speed, handoff events can and should be predicted in order to achieve fast and reliable handoff. As it is shown in this study, the proposed scheme can significantly reduce the packet loss ratio caused by frequent handoff events experienced by high speed vehicles. This scheme is topology-independent in the sense that it does not assume any network topology. The key idea is to use a topology-learning algorithm that enables to perform localized mobility management, by efficiently re-selecting a Mobility Anchor Point (MAP) node. The goal of the proposed scheme is to maintain a continues connection subject to user-dependent delay constraints, while minimizing the signaling cost and packet loss ratio associated with handoff events. This scheme is consistent with the existing mobility management schemes currently used in Mobile IP (MIP) and cellular networks, and it fits into the Hierarchical Mobile IPv6 (HMIPv6) scheme defined in Mobile IPv6 (MIPv6) for integrating mobile terminals with the Internet wired backbone.     

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.     

Hybrid mobility management schemes integrating mobile IP and SIP for seamless invocation of services in All-IP network

The growing demand for seamless invocation of different multimedia services from handheld devices anytime anywhere is the main driving force for drawing attention in the area of mobility management. Although Session Initiation Protocol (SIP) based mobility solution is very efficient for real-time services, Mobile IP is required to handle mobility of the mobile node (MN) at the network layer. We have extensively studied and explored some existing mobility management methods integrating the functionalities of Mobile IP and SIP in this paper. These schemes require support of IP encapsulation at the protocol stack of correspondent node (CN). To address the above problem, we have proposed in this paper, certain modification at the IP layer of Base Station (BS) that also reduces the bandwidth consumption. Moreover, service provisioning in a continuous way in public places like airport, university campus etc., requires to integrate some micro-mobility protocol with the existing mobility management methods to reduce the handoff disruption time in case of intradomain handoff. Thus, in this paper, we have proposed two new hybrid mobility management schemes that integrate two existing Mobile IP and SIP-based schemes where the proposed modification in the IP layer of BS is incorporated separately with the micro-mobility protocol Hierarchical Mobile IP (HMIP). The numerical results show that the integration of HMIP into the existing methods reduces both the signaling cost and the delay, mainly the active handoff disruption time. Simulation results on NS-2 demonstrate the performance improvement of the proposed mobility management schemes over the existing methods in terms of handoff delay.     

A Robust Analytical Model of Mobile IP Handoff with Multiple Traffic Profiles

Mobile IP has been developed to provide the continuous information network access to mobile users. The performance of Mobile IP mobility management scheme is dependent on traffic characteristics and user mobility. Consequently, it is important to assess this performance in-depth through these factors. This paper introduces a novel analytical model of handoff management in mobile IP networks. The proposed model focuses on the effect the traffic types and their frame error rates on the handoff latency. It is derived based on general distribution of both successful transmission attempts and the residence time to be applicable in all cases of traffic characteristics and user mobility. The impact of the behavior of wireless connection, cell residence time, probability distribution of transmission time and the handoff time is investigated. Numerical results are obtained and presented for both TCP and UDP traffics. As expected, the reliability of TCP leads to higher handoff latency than UDP traffic. It is shown that, higher values of FER increase the probability of erroneous packet transfer across the link layer. A short retransmission time leads to end the connection most likely in the existing FA; however a long retransmission time leads to a large delivery time. The proposed model is robust in the sense that it covers the impact of all the effective parameters and can be easily extended to any distribution.     

移动IP与TeleMIP技术

移动IP是一种简单可扩展的全球Internet移动解决方案。但它不能实现快、无缝、平滑的切换，TeleMIP提供了一种方案以解决在无线蜂窝网络中实现快速、无缝、平滑的切换。最后根据这两种技术的互补性，提出二进行无缝结合的方案，并认为这种结合将成为未来移动互联技术的发展方向之一。     

An Empirical Analysis of Handoff Performance for SIP,Mobile IP,and SCTP Protocols

Over the last decade, we have witnessed a growing interest in the design and deployment of various network architectures and protocols aimed at supporting mobile users as they move across different types of networks. One of the goals of these emerging network solutions is to provide uninterrupted, seamless connectivity to mobile users giving them the ability to access information anywhere, anytime. Handoff management, an important component of mobility management, is crucial in enabling such seamless mobility across heterogeneous network infrastructures. In this work, we investigate the handoff performance of three of the most widely used mobility protocols namely, Mobile IP, Session Initiation Protocol (SIP), and Stream Control Transmission Protocol (SCTP). Our empirical handoff tests were executed on an actual heterogeneous network testbed consisting of wired, wireless local area, and cellular networks using performance metrics such as handoff delay and handoff signaling time. Our empirical results reveal that Mobile IP yields the highest handoff delay among the three mobility protocols. In addition, we also found that SIP and SCTP yield 33 and 55% lower handoff delays respectively compared to Mobile IP.     

Seamless Support for Mobile Internet Protocol Based Cellular Environments

Cellular is the inevitable architecture for the Personal Communication Service system (PCS) in the coming future. Access to the Internet via cellular networks is expected to become an essential portion of future wireless service offerings. Providing seamless support for IP based packet switched services has become an important issue.The Internet Engineering Task Force's (IETF's) mobile IP protocol offers a standard solution for wide-area mobility at the IP layer. However, Mobile IP does not solve all of the problems involved in providing mobile Internet access to cellular users, especially during handoff period. Thus, IPv6 might be a good candidate to solve this problem.IPv6 is a new version of the Internet Protocol that was standardized by the IETF. It supports mobility and is presently being standardized by the IETF Mobile IP Working Group. At the same time, cellular is an inevitable architecture for the Personal Communication Service system (PCS).This paper introduces the current cellular support based on the Mobile Internet Protocol version 6. We will point out the short-falls using Mobile IP and try to emphasize protocols especially for mobile management schemes that can optimize a high speed mobile station moving among small wireless cells. A comparison between those schemes and future work will be presented.     

A Proxy MIPv6 Handover Scheme for Vehicular Ad-hoc Networks

With the rapid growth in the number of mobile devices, such as cellular phones, PDAs and laptops, the need for seamless and ubiquitous Internet connectivity is tangible. Vehicular ad-hoc network (VANET) is a rapidly developing technology, which makes vehicle-to-vehicle and vehicle-to-infrastructure communication feasible. However, when a vehicle travels from one point of attachment to another, handoff delays and provision of seamless connectivity are considered as important issues. Ubiquitous and integrated Internet connectivity can be achieved if on road moving vehicles are connected. However, when vehicle density is small and/or vehicle velocities are different, end users may suffer from a high level of connection failure. IP mobility protocols are designed by Internet Engineering Task Force to provide acceptable levels of continuous Internet connectivity, maintaining mobile node communications as they travel amongst points of attachments. However, the current IP mobility approaches applied on VANET did not resolve the connection failure issues efficiently. Therefore, in this paper a new effective solution is proposed in order to eliminate the large amount of handover latency and eventually high packet loss ratio.     

一种基于无线局域网的移动检测优化方案

无线局域网采用移动IP实现移动性管理.移动IP切换存在切换时延大,数据包易丢失的问题.切换时延由移动检测时延和注册时延组成,而移动检测时延在其中占主要部分.文章提出了一种移动检测优化方案,采用了自适应绑定的算法,同时充分考虑了域内小范围高频度切换的情况,使移动节点在无线局域网环境中进行快速有效的切换.     

A Proactive mobile‐initiated fast handoff scheme using the multihomed approach

Mobile IP (MIP) defines a mobility management for mobile users to continuously access data when the currently attachment is changed to another network. However, when mobile node (MN) roams between network segments, the handoff latency results in packet losses and transmission delay. In this paper, we propose a multihomed fast handoff scheme (MFH‐MIP) to decrease the handoff cost. In the proposed MFH‐MIP scheme, each MN is implemeted with the link layer trigger and multihomed techniques. Based on the link layer trigger, MN can collect signal strengths of nearby access points (APs) and switch to a new link automatically when the old link becomes unsuitable to connect. Using the multihomed technique, MN can prepare for handoff using two (or more) interfaces, in which (i) one is connected with the old link to receive packets and (ii) the other one is used to access nearby APs and select the most suitable one as the new link, in parellel. In this way, MN can continuously transmit and receive packets during handoff. Based on the proposed method, MN can roam smoothly among different networks in the wireless environment. Copyright © 2008 John Wiley & Sons, Ltd.     

A Comparison of Performance between Macro-mobility Protocol and Micro-mobility Protocol

1　IntroductionAlthoughthemobileIP protocol[1～3] workswellinthemacromobilitysituation ,someproblemsoccurinthemicromobilitysituation .Therearetwomainconcerns.First,theregistrationdelaycon tributestothehandoffdelay .Thedelayissignifi cantwhenanMNisfarawayfromhomeandcausessignificantpacketdropanddrasticreductionincom municationthroughput.Second ,frequentlocationupdatesincurextensiveoverheadforlocationcachemanagementinrouteoptimizationthatrequiresac curatelocationinformationinordertotunnelIPda…     

一种新的WLAN和GPRS融合的移动性管理方案

无线蜂窝网络和无线局域网的融合能充分利用两者的互补能力,提供更加全面的无线服务。本文针对GPRS蜂窝网络和无线局域网现有融合技术中的不足,提出了一种新的基于移动IP技术的松耦合移动性管理方案,旨在减少切换时延、解决三角路由等问题,将有利于移动通信网络的升级和演进发展。     

A seamless handoff scheme for IEEE 802.11 wireless networks

The advance of computer network technologies such as IEEE 802.11 wireless local area network has made it possible for users to connect to Internet almost anywhere. A mobile node (MN) is likely to move between different base stations while running applications. The IETF has defined the Mobile IP (MIP) to allow MNs to maintain their communication uninterrupted while roaming across different IP subnets. However, the mechanisms defined in MIP may cause undesired connection disruptions or packet losses, which will significantly degrade the quality of real‐time applications. It is an important and challenging issue to support seamless handoff management. To achieve seamless handoff, we propose a unified scheme to address application quality degradation. Our main contribution is the concept and implementation of utilising buffering and resending method to eliminate the packet losses while keeping the end‐to‐end delay of real‐time traffic flow in an acceptable value. The NS‐2 simulation results show that our proposed scheme can significantly maintain application quality during layer‐2 and ‐3 handoffs. Copyright © 2011 John Wiley & Sons, Ltd.     

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。     

Intelligent Handoff for Mobile Wireless Internet

This paper presents an intelligent mobility management scheme for Mobile Wireless InterNet – MWIN. MWIN is a wireless service networks wherein its core network consisting of Internet routers and its access network can be built from any Internet-capable radio network. Two major standards are currently available for MWIN, i.e., the mobile IP and wireless LAN. Mobile IP solves address mobility problem with the Internet protocol while wireless LAN provides a wireless Internet access in the local area. However, both schemes solve problems independently at different layers, thereby some additional problems occur, e.g., delayed handoff, packet loss, and inefficient routing. This paper identifies these new problems and performs analyses and some real measurements on the handoff within MWIN. Then, a new handoff architecture that extends the features of both mobile IP and wireless LAN handoff mechanism was proposed. This new architecture consists of mobile IP extensions and a modified wireless LAN handoff algorithm. The effect of this enhancement provides a linkage between different layers for preventing packet loss and reducing handoff latency. Finally, some optimization issues regarding network planning and routing are addressed.     

Network mobility protocol for vehicular ad hoc networks

The goal of the network mobility management is to effectively reduce the complexity of handoff procedure and keep mobile devices connecting to the Internet. When users are going to leave an old subnet and enter a new subnet, the handoff procedure is executed on the mobile device, and it may break off the real‐time service, such as VoIP or mobile TV, because of the mobility of mobile devices. Because a vehicle is moving so fast, it may cause the handoff and packet loss problems. Both of the problems will lower down the throughput of the network. To overcome these problems, we propose a novel network mobility protocol for vehicular ad hoc networks. In a highway, because every car is moving in a fixed direction at a high speed, a car adopting our protocol can acquire an IP address from the vehicular ad hoc network through the vehicle‐to‐vehicle communications. The vehicle can rely on the assistance of a front vehicle to execute the prehandoff procedure, or it may acquire a new IP address through multihop relays from the car on the lanes of the same or opposite direction and thus may reduce the handoff delay and maintain the connectivity to the Internet. Simulation results have shown that the proposed scheme is able to reduce both the handoff delay and packet loss rate. Copyright © 2013 John Wiley & Sons, Ltd.     

快速IP切换在无线局域网中的实现

在移动网络中,无缝切换是提供QoS的基础,也是支持实时业务应用(如视频点播和语音传输等)的保证。针对无线局域网(WLAN)的节点切换问题,建立了各种网络模型,提出了链路层、网络层和传输层的解决方案。文章根据切换过程的技术特征,研究了WLAN中网络层切换的各种方案,包括移动IP方案、TAP-DANCE方案以及网络辅助的IP移动支持,具体分析了上述方案的实现过程,比较了性能指标,指出了存在的问题及进一步研究方向。     

Micro mobility in the IP networks

Wireless access to Internet services will become typical, rather than the exception as it is today. Such a vision presents great demands on mobile networks. Mobile IP represents a simple and scalable global mobility solution but lacks the support for fast handoff control and paging found in cellular telephony networks. In contrast, second- and third-generation cellular systems offer seamless mobility support but are built on complex and costly connection-oriented networking infrastructure that lacks the inherent flexibility, robustness, and scalability found in IP networks. This paper presents an overview and performance comparison of two of the main micro-mobility protocols, namely Cellular IP and Hierarchical Mobile IP with regards to the handoff process for UDP applications. The differences in the handoff quality of the two protocols are small and can be traced to design choices within the typical model. There are however significant differences regarding the processing requirement, routing efficiency and parameters relating to implementation and deployment.     

A Cross-Layer (Layer 2 + 3) Handoff Management Protocol for Next-Generation Wireless Systems

Next-generation wireless systems (NGWS) integrate different wireless networks, each of which is optimized for some specific services and coverage area to provide ubiquitous communications to the mobile users. It is an important and challenging issue to support seamless handoff management in this integrated architecture. The existing handoff management protocols are not sufficient to guarantee handoff support that is transparent to the applications in NGWS. In this work, a cross-layer (Layer 2 + 3) handoff management protocol, CHMP, is developed to support seamless intra and intersystem handoff management in NGWS. Cross-layer handoff management protocol uses mobile's speed and handoff signaling delay information to enhance the handoff performance of Mobile IP that is proposed to support mobility management in wireless IP networks. First, the handoff performance of Mobile IP is analyzed with respect to its sensitivity to the link layer (Layer 2) and network layer (Layer 3) parameters. Then, a cross-layer handoff management architecture is developed using the insights learnt from the analysis. Based on this architecture, the detailed design of CHMP is carried out. Finally, extensive simulation experiments are carried out to evaluate the performance of CHMP. The theoretical analysis and simulation results show that CHMP significantly enhances the performance of both intra and intersystem handoffs.