New Developments in Vertical Handover Based on Media Independent Handover Standard

This paper proposes an enhanced approach for implementation of Media Independent Handover (MIH) information services (MIIS) based of the combination of a hierarchy of information servers and prediction of next point of attachment (PoA). While other recent proposals were validated only by simulations, we evaluated the implemented system with a real video streaming application. The preliminary results show performance improvements in streaming continuity when compared with our former proposal, the prediction of PoA based on unique MIIS server. We conclude that in a more complex situations the performances could increase even more, and we draw some new development directions we want to explore in our future work.     

Handover Management in Enhanced MIH Framework for Heterogeneous Wireless Networks Environment

Vertical handover decision making is one of the key problems in heterogeneous networks environment. In IEEE 802.21 standard, a Media Independent Handover (MIH) framework is proposed to improve user experience of mobile devices by facilitating handover in heterogeneous networks with measurements and triggers from link layers. However, vertical handover decision making can benefit from the information more than link layers. In this paper, an Enhanced Media Independent Handover (EMIH) framework is proposed by integrating more information from application layers, user context and network context. Given such information, there is also another important problem on how to select a favorite network. Two quite important problems from realistic scenario are as follows: (1) how to make use of partial knowledge due to incomplete value measurement on decision factors; (2) how to deal with robustness problem due to inaccurate measurement on decision factors. In order to tackle these problems, two novel Weighted Markov Chain (WMC) approaches based on rank aggregation are proposed in this paper, in which a favorite network is selected as the top one of rank aggregation result fused from multiple ranking lists based on decision factors. Moreover, an entropy weighting method, combined with WMC approach, is studied. The simulations demonstrate the effectiveness of these proposed approaches.     

Performance Metrics for IEEE 802.21 Media Independent Handover (MIH) Signaling

The IEEE 802.21 Media Independent Handover (MIH) working group is developing a set of mechanisms to facilitate migration of mobile users between access networks that use different link-layer technologies. Among these are mobility managers that create and process signaling messages to facilitate handovers. The MIH signaling architecture being developed in the Internet Engineering Task Force (IETF) allows any transport layer protocol to carry MIH messages. The IETF has considered using the unreliable but lightweight transport available with the User Datagram Protocol (UDP) as well as the reliable stream-oriented transport with congestion control offered by the Transmission Control Protocol (TCP). In this paper we develop mathematical models that result in expressions for the characteristic function of the time required to complete exchanges of an arbitrary number of MIH signaling messages between a mobile node (MN) and a remote mobility manager (MM). Our models also provide expressions for the average amount of overhead associated with MIH message exchanges due to retransmissions either by the MIH signaling entities or by the transport-layer protocol. In addition, we provide simulation results that confirm the results from the mathematical model and illustrate the effect of varying transport parameters such as the TCP maximum retransmission timeout.     

基于媒体独立切换并提供QoS保证的跨UMTS和WiMAX无线异构网络的网络切换方案

The rapid growth and innovation of the various mobile communication technologies have caused a change in the paradigm of internet access. Wireless technologies such as WiMAX, WiFi and UMTS/LTE networks have shown great potential in dominating the wireless access markets. The existence of various access technologies requires a means for seamless internetworking to provide anywhere, anytime services without interruption in the ongoing session, especially in multimedia applications with rigid Quality of Services (QoS) requirements. The IEEE 802.21 Media Independent Handover (MIH) working group was formed to develop a set of mechanisms under a standard framework with the capability to support migration of mobile users across heterogeneous networks. Therefore, the implementation of handover is extremely important in the heterogeneous network environment. In order to guarantee various QoS requirements during handover execution especially in multimedia applications, in this paper we propose a novel MIH-based capacity estimation algorithm to execute handover with QoS provision supporting both horizontal and vertical handovers across UMTS and WiMAX networks. Simulation shows that the proposed mechanism achieves lower call dropping rate (highest approximate 3% ) and higher system throughput (average 92% ) than the basic handover method does.     

复杂上下文感知的组合服务选择框架

泛在网络环境中,组合服务选择不仅需要考虑服务上下文还需要考虑用户上下文,而描述上下文属性的数据类型可能有实数、区间数、三角模糊数和直觉模糊集。为解决这种基于复杂上下文的组合服务选择难题,本文提出一个复杂上下文感知的组合服务选择框架,能够感知服务上下文和用户上下文。该框架基于智能主体设计,其中用户端框架完成用户上下文管理,服务端框架完成服务上下文管理和组合服务选择。通过相关工作的比较,验证了该框架的优越性和有效性。     

Supporting Adaptive Context-Aware Services and Novel Handover Scheme for Smart Ubiquitous Communication System

Since people communicate with each other by mobile phones more and more frequently in daily lives, they pay more attention on the quality and rating of communication and the battery consumption when using the mobile phones. In order to provide users the services with low price, high communication quality and less battery consumption in any environments, this paper selects the users’ acceptable communication services upon communication quality, communication rating and battery consumption when using mobile phones according to the users’ communication habits. Besides, in order to solve the problems of overhead and latency when the users switch network bases in the use of network phones, we propose a Novel Handover Scheme based on Host Identity Protocol et al. (Fan, A Novel handover scheme for HIP mobile networks. Master Thesis, National Dong Hwa University in Taiwan, 2007) to accelerate handover speed to fulfill Smart Ubiquitous Communication System.     

Vertical Handover Decision Algorithm for Multimedia Streaming in VANET

Wireless Personal Communications - Vehicular ad hoc networks represent one of the most important applications of wireless ad hoc networks. In highways, where different networks exist, frequent and...     

A Survey on Media Independent Handover (MIH) and IP Multimedia Subsystem (IMS) in Heterogeneous Wireless Networks

One challenge of wireless networks integration is to provide ubiquitous wireless access abilities and seamless handover for mobile communication devices between different types of technologies (3GPP and non-3GPP), such as Global System for Mobile Communication, Wireless Fidelity, Worldwide Interoperability for Microwave Access, Universal Mobile Telecommunications System and Long Term Evolution. This challenge is critical as mobile users are becoming increasingly demanding for services regardless of the technological complexities associated with them. To fulfil these requirements for seamless vertical handover (VHO) two main interworking frameworks have been proposed by IEEE Group and 3GPP for integration between the aforementioned technologies; namely, Media Independent Handover IEEE 802.21 and IP Multimedia Subsystem, where each of them requires mobility management protocol to complement its work, such as Mobile IP and Session Initiation Protocol, respectively. Various VHO approaches have been proposed in the literature based on these frameworks. In this paper, we survey the VHO approaches proposed in the literature and classify them into four categories based on these frameworks for which we present their objectives and performances issues.     

一种智能ABC支持型QoS切换决策机制

本文提出了一种总最佳连接ABC(Always Best Connected)支持型服务质量QoS(Quality of Service)切换决策机制,引入模糊数学和微观经济学等相关知识,刻画应用类型、QoS需求、接入网络和移动终端,综合考虑应用QoS需求、用户愿付费用、用户对接入网络编码制式偏好、用户对接入网络供应商偏...     

层次移动IPv6的增强切换方案

随着互联网技术与移动通信技术飞速发展,移动IPv6技术已经成为下一代移动互联网的研究热点。切换技术是影响移动互联网实时运行质量的重要技术之一。低延迟、低丢包的无缝切换方案对移动IPv6的性能至关重要。层次移动IPv6(HMIPv6)利用移动锚点(MAP)降低了延迟和数据丢失。然而,只有移动节点在同一MAP域的网络上进行切换时,HMIPv6才能有效减少延迟。当移动节点在不同MAP域的网络移动时,其切换性能并不优于标准移动IPv6。文章针对层次移动IPv6提出了一种增强切换方案(EHMIPv6),该方案在HMIPv6的基础上实现并行重复地址检测(PDAD),以减少不同区域网络间切换的延迟。分析表明,该方案比HMIPv6具有更好的性能。     

Time-Efficient Handover Using Enhanced Route Optimization in Global PMIPv6

With the development of the wireless internet, there are more and more mobile terminals. Without mobility management protocol, mobile terminals could not communicate with others terminals when they are away from their home network. Mobile IPv6 was proposed which is host-based mobility management protocol. But it has several drawbacks, such as wireless link resource waste, load or consumption of power in mobile terminal is large. To overcome the weakness of host-based mobility management protocol, network-based mobility management protocol called Proxy Mobile IPv6 (PMIPv6) is standardized by the internet engineering task force network-based localized mobility management working group, and it is starting to attract considerable attentions. Although several proposals have been made for handover and Route Optimization (RO) in PMIPv6, they still need too many communications, do not consider about seamless-handover and RO without out-of-sequence problem simultaneously. In this paper we proposed a time-efficient handover mechanism in PMIPv6 by using the improved RO. We use the characteristic of anycast to achieve the time efficiency. By the mathematical analysis we prove that the proposed protocol has shorter latency and supports faster mobility of the mobile terminals.     

交互式异构无线网络垂直切换的中间件架构

异构无线网络研究的关键之一在于按照用户的应用要求,在不同网络之间实现垂直切换。文章面向多模移动终端提出交互式垂直切换中间件架构,描述了架构的功能组成体系,阐明了在多模移动终端上交互式简单快速地设置垂直切换所需参数或权重的界面。给出了按层次分析法AHP进行垂直切换的中间件实现流程的一个例子。     

自主体系结构框架研究

体系结构框架是体系结构研究的规范和标准,对信息系统设计来说十分重要.世界各国制定并使用了多种体系结构框架.但这些框架的文化背景和应用环境与中国实际情况存在差别,在中国的信息系统设计时存在诸多不便,影响了其体系结构研究工作的开展.需要在国外体系结构框架的基础上,结合中国具体情况自主的体系结构框架,以推动信息系统体系结构研究工作的发展.     

BehavDT: A Behavioral Decision Tree Learning to Build User-Centric Context-Aware Predictive Model

Mobile Networks and Applications - This paper formulates the problem of building a context-aware predictive model based on user diverse behavioral activities with smartphones. In the area of...     

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…     

Vertical Handover Over Intermediate Switching Framework: Assuring Service Quality for Mobile Users

Ensuring quality of service (QoS) for the mobile users during vertical handover between IEEE 802.11 wireless local area networks (WLAN) and data network provided by Ultramodern Telecommunication Systems (UMTS) is one of the key requirements for seamless mobility and transfer of existing connections from one network to another. QoS fulfillment is a complex problem and requires participation of both the mobile users as well as the connection networks. The QoS assurance criteria for existing connections can be affected by fluctuations of data rates when a user moves from the high speed WLAN network to the low speed UMTS network, even in the presence of another WLAN network in its vicinity. This can happen if the alternate WLAN network is highly loaded. Therefore handover from a high speed network to a low speed network should be avoided, whenever possible. This paper proposes a QoS based handover procedure that prioritizes the existing connection over the new connections so that rate fluctuations due to handover can be avoided if there exist another WLAN network in the range of the mobile user. Whenever the possibility of handover is detected, a pre-handover bandwidth reservation technique is used to reserve bandwidth at the alternate WLAN networks to avoid QoS degradation. The proposed scheme is implemented in Qualnet network simulator and the performance is analyzed and compared with traditional handover techniques.     

Enhanced and Optimized Power-Distance Handover Algorithms for High-Speed Trains for WINNER-II Channel Model

Wireless Personal Communications - Very high-speed trains (HSTs) undergo a significant number of handovers/handoffs between cells. The handover triggering point varies with train speed. This...     

Intelligent Decision Making Framework for 6G Network

Sixth Generation(6G) wireless communication network has been expected to provide global coverage, enhanced spectral efficiency, and AI(Artificial Intelligence)-native intelligence, etc. To meet these requirements, the computational concept of Decision-Making of cognition intelligence, its implementation framework adapting to foreseen innovations on networks and services, and its empirical evaluations are key techniques to guarantee the generationagnostic intelligence evolution of wireless commun...