移动泛在网络的发展趋势

随着无线接入技术的快速发展,通信网络的异构性特征变得更加突出,如何有效地实现不同网络间的互联互通以及获取所需的各类服务,并构建融合各网络异构性的移动泛在网络成为业界关注的重点。下一代移动网络(NGMN)项目综合考虑业务、终端和网络各方面的因素,是运营商主导的近期需求愿景,而移动泛在业务环境(MUSE)是学术界的学者们对于未来移动异构泛在网络的理想化的规划和设计,更着眼于远期的融合。未来的移动通信网络将逐渐向一个综合的网络体系平滑演进,为泛在移动宽带服务提供一个全新的平台。     

A survey of mobility management in next-generation all-IP-based wireless systems

Next-generation wireless systems are envisioned to have an IP-based infrastructure with the support of heterogeneous access technologies. One of the research challenges for next generation all-IP-based wireless systems is the design of intelligent mobility management techniques that take advantage of IP-based technologies to achieve global roaming among various access technologies. Next-generation wireless systems call for the integration and interoperation of mobility management techniques in heterogeneous networks. In this article the current state of the art for mobility management in next-generation all-IP-based wireless systems is presented. The previously proposed solutions based on different layers are reviewed, and their qualitative comparisons are given. A new wireless network architecture for mobility management is introduced, and related open research issues are discussed in detail.     

5G网络技术研究现状和发展趋势

摘要：首先分析了5G 网络中的新需求对移动通信网络的挑战,从而说明进行5G 网络技术研究的必要性。随后,介绍了目前国内外研究组织在5G 网络相关技术的研究进展,包括NGMN、5GPPP、IMT-2020等,同时也介绍了国内外标准化组织对5G网络技术的标准化研究进展。基于对5G网络中的新需求、新挑战的分析,结合国内外关于5G网络技术研究现状的总结,预测了未来5G网络技术的发展趋势并给出了相关的技术发展方向。最后对5G网络的发展进行了总结和展望。     

基于代理的VHE业务体系结构

将移动代理技术应用于网络业务的提供，提出一种基于代理的未来移动网业务体系结构，详细阐述了该结构的VHE业务提供机制和网络适配技术，并简要说明了系统设计方法。     

5G移动性增强关键技术及应用分析

3GPP在Rel-15版本中,NR移动性管理只引入了基本的切换功能,而NR切换0ms中断时延是为UE提供无缝切换感受的性能需求之一,且在高频移动时UE可能会遇到快速的信号恶化,切换的可靠性也会降低,如何减少切换过程中的数据中断时间以及提高移动鲁棒性是R16一个重要研究方向。针对以上问题,R16移动性增强提出了两个关键技术—双活动协议栈和条件切换。详细阐述了两种关键的增强技术以及各网元之间的协作情况,研究了与传统切换流程的差异、UE侧的协议栈变化,分析了两种移动性增强技术的应用场景,给出了中信科移动预规划的应用方案,为移动性增强技术的研究和应用提供参考。     

Mobility management approaches for SDN-enabled mobile networks

The evolving network technologies aim at meeting the envisioned communication demands of future smart cities and applications. Although software-defined networking (SDN) enables flexible network control, its applicability to mobile networks is still in its infancy. When it comes to introducing the SDN vision to mobile networks, handling of wireless events and mobility management operations stand out as major challenges. In this paper, we study the scalability issues of SDNized wireless networks, specifically those relevant to mobility management. We design and implement different mobility management approaches in SDNized wireless networks and investigate the impact of various system variables on the overall handover delays. We also study the improvements in handover delays: (i) when a proposed proactive mobility management algorithm is implemented; (ii) when the controller delegates partial control of mobility management to the forwarding entities. For the implementation of the proposed approaches on the OpenFlow network, the paper also suggests potential extensions to the OpenFlow protocol. The contributed approaches are validated on a full-scale demonstrator, with results showing that proactive outperforms reactive and that the delegated control approach performs better than proactive for smaller topology sizes. Furthermore, a proposal for LTE X2-specific control delegation is discussed as a use case.     

Network enablers for enhanced mobility management

The proliferation of network access technologies and the increased mobility of end users bring new challenges to operators who are willing to support their subscribers with seamless and context-aware services. This paper reviews the requirements that these challenges generate, focusing on the issues that are not entirely addressed by existing mobility protocols, the IMS set of specifications or by the IEEE802.21 standardisation efforts. A set of network enablers for enhanced mobility management addressing these issues is then proposed with an explanation of their positioning within future IMS-based mobility architectures.     

Mobility Enhancement Technology for Scaling of CMOS Devices: Overview and Status

The aggressive downscaling of complementary metal–oxide–semiconductor (CMOS) technology to the sub-21-nm technology node is facing great challenges. Innovative technologies such as metal gate/high-k dielectric integration, source/drain engineering, mobility enhancement technology, new device architectures, and enhanced quasiballistic transport channels serve as possible solutions for nanoscaled CMOS. Among them, mobility enhancement technology is one of the most promising solutions for improving device performance. Technologies such as global and process-induced strain technology, hybrid-orientation channels, and new high-mobility channels are thoroughly discussed from the perspective of technological innovation and achievement. Uniaxial strain is superior to biaxial strain in extending metal–oxide–semiconductor field-effect transistor (MOSFET) scaling for various reasons. Typical uniaxial technologies, such as embedded or raised SiGe or SiC source/drains, Ge pre-amorphization source/drain extension technology, the stress memorization technique (SMT), and tensile or comprehensive capping layers, stress liners, and contact etch-stop layers (CESLs) are discussed in detail. The initial integration of these technologies and the associated reliability issues are also addressed. The hybrid-orientation channel is challenging due to the complicated process flow and the generation of defects. Applying new high-mobility channels is an attractive method for increasing carrier mobility; however, it is also challenging due to the introduction of new material systems. New processes with new substrates either based on hybrid orientation or composed of group III–V semiconductors must be simplified, and costs should be reduced. Different mobility enhancement technologies will have to be combined to boost device performance, but they must be compatible with each other. The high mobility offered by mobility enhancement technologies makes these technologies promising and an active area of device research down to the 21-nm technology node and beyond.     

Mobility support in wireless Internet

The tremendous advancement and popularity of wireless access technologies necessitates the convergence of multimedia (audio, video, and text) services on a unified global (seamless) network infrastructure. Circuit-switched proprietary telecommunication networks are evolving toward more cost-effective and uniform packet-switched networks such as those based on IP. However, one of the key challenges for the deployment of such wireless Internet infrastructure is to efficiently manage user mobility. To provide seamless services to mobile users, several protocols have been proposed over the years targeting different layers in the network protocol stack. In this article we present a cross-layer perspective on the mobility protocols by identifying the key features of their design principles and performance issues. An analysis of the signaling overhead and handoff delay for some representative protocols in each layer is also presented. Our conclusion is that although the application layer protocol is worse than the protocols operating in the lower layers, in terms of handoff delay and signaling overhead, it is better suited as a potential mobility solution for the next-generation heterogeneous networks, if we consider such factors as protocol stack modification, infrastructure change, and inherent operational complexity.     

面向5G通信网的D2D技术综述

在探讨D2D对通信技术未来发展的导向作用基础上,明确了影响D2D系统设计的多个因素,即D2D设备发现、资源分配、缓存技术、D2D-MIMO。从而勾画出基于D2D技术的光纤前传和软件定义网络实现数据/控制分离的扁平化5G架构,提出负责接入的下层宏/小基站蜂窝网和负责管理的上层网络云的管理机制。将D2D技术、SDN技术、边缘计算和物联网技术等关键技术引入未来移动通信网络已经成为研究领域的热点,针对与之相关的、未来大规模网络的移动性、QoS和大数据特性进行了讨论。     

A Generic Framework for Mobility Modeling and Performance Analysis in Next-Generation Heterogeneous Wireless Networks

Integration of different wireless radio cellular technologies is emerging as an effective approach to accommodate the increasing demand of next-generation multimedia-based applications. In such systems user roaming among different technologies, commonly known as vertical handoff, will significantly affect different aspects of network design and planning due to the characteristically wide-ranging diversity in access technologies and supported applications. Hence, the development of new mobility models that accurately depict vertical mobility is crucial for studying different design problems in these heterogeneous systems. This article presents a generic framework for mobility modeling and performance analysis of integrated heterogeneous networks using phase-type distributions. This framework realizes all modeling requirements in next-generation user mobility including accuracy, analytical tractability, and accommodating the correlation between different residence times within different access technologies. Additionally, we present general guidelines to evaluate application performance based on the new mobility models introduced in this article. We show the accuracy of our modeling approach through simulation and analysis given different applications.     

Mobility support across hybrid IP-based wireless environment: review of concepts, solutions, and related issues

The 4G or Beyond 3G wireless networks is consist of IP-based heterogeneous access networks from 3G cellular, WiFi, WiMAX to other emerging access technologies such as mesh networks. The key objective of designing the next generation wireless networks is to support of mobile subscribers. To support the mobile host in the hybrid wireless access technologies, many solutions based on network protocol stack have been proposed in the literature. In this article, after review of mobility concepts, a special attention is given to some of the mobility management methods as well as handover techniques across various wireless access networks. We have also compared the major mobility protocols in each layer for their features. Finally, some of the open issues that needed to be addressed in mobility management protocol in the next generation wireless networks are outlined.     

基于Mobile Agent的服务移动性实现

本文提出了一种基于Mobile Agent的服务移动性系统(MASM,Mobile Agent Based Service Mobility),并在模拟环境中加以实现.MASM系统充分利用了Mobile Agent和Java技术的优势,提出了用“打点”和模块化等技术设计Mobile Agent的新方法,从而有效地减少了网络传输负载,灵活地实现了跨不同网络的服务移动.本文着重在MASM系统和Mobile Agent结构设计上以及具体服务移动的实现上.     

Services via mobility portals

This paper examines the importance of mobility portal services and the technologies that will be essential in delivering content over next generation network technologies. A broad range of related issues is discussed, from the devices the service user can employ and the underlying technology and infrastructure required, through to the challenges faced by the providers of such services     

无线传感器网络MAC协议移动性支持问题的研究

在以往的无线传感器网络研究过程中,研究者通常假设网络中节点的位置不发生变化,忽略了移动性对网络的影响.近期研究表明,支持无线传感器节点移动性,研究移动无线传感器网络MAC协议是十分必要的.本文在研究移动性对MAC协议设计所带来的挑战基础上,分析和总结了移动性对现有MAC协议的影响,以及当前在支持节点移动性方而所作的工作.最后,文章重点探讨了未来移动传感器网络MAC协议研究过程中值得深入研究的内容.     

Mobility management and control protocol for wireless ATM networks

The introduction of wireless ATM (WATM) in customer premises network environments necessitates the design of mobility protocols, since the existing versions of B-ISDN signaling do not support terminal mobility. Such protocols can be deployed either as extensions to the standard signaling capabilities, or as individual solutions that have little or no impact on existing infrastructures (switches, signaling software, etc.). A WATM architecture that adopts the latter approach is presented. After a discussion of the problems encountered in the integration of wireless networking and B-ISDN ATM technologies, a mobility management and control (MMC) protocol is proposed. Finally, in the framework of the proposed MMC protocol, algorithms for implementing mobility procedures (handover and registration) are described     

Scalability in Global Mobile Information Systems (GloMo): Issues,Evaluation Methodology and Experiences

The GloMo (Global Mobile Information Systems) project¹ has focused on developing new wireless ad hoc networking technologies. These new technologies rely on a broad and varied set of techniques to help cope with the problems inherent in the wireless environment. One of the most critical design elements of all the various technologies is their applicability in large scale deployments. The main objective of our work is to develop and implement a simulation methodology to help evaluate the scalability of these new ad hoc networking technologies and gain some insight into the various aspects of ad hoc network performance scalability issues. To achieve that we have developed a scalability performance evaluation framework and plan, that spans all the various dimensions of scalability: size (number of nodes and density), traffic, operational environment (i.e. propagation models, terrain etc.), mobility. For demonstration purposes we have applied this process on a representative integrated protocol suite designed to provide communication services in mobile ad hoc wireless networks. The corresponding results of the two most critical aspects of scalability properties in tactical networks (i.e. network initialization time and traffic scalability) are also presented here, and demonstrate that a very extensive evaluation of the corresponding scalability metrics under a combination of the various scalability dimensions defined in this paper, is necessary in order to provide an in-depth analysis of the scalability properties in wireless mobile ad hoc networking environments.     

Mobility and session management: UMTS vs. cdma2000

This article describes the mobility and session management mechanisms for UMTS and cdma2000 packet-switched (PS) service domains, and compares the design guidelines for these two third-generation technologies. We first introduce the network architectures and protocols for UMTS and cdma2000, and then elaborate on the PS service domain's mobility management, session management, and IP-level mobility mechanisms. Based on the mobility and session management mechanisms of the UMTS and cdma2000 PS service domains, an integrated architecture and intersystem roaming procedures are proposed to show the implementation feasibility of UMTS-cdma2000 IP-level interworking.     

802.16/WiMAX组网关键技术研究

对802.16/WiMAX组网关键技术进行深入的研究和分析,提出并研究基于OFDM技术小区规划的频率复用问题,详细分析其媒体访问机制和资源分配策略,对移动性管理及人网与初始化的问题也进行了详细的探讨.并在此基础上,探讨并指出组网时应该注意的问题和新技术.     

Inversion layer mobility of MOSFET's fabricated with NMOS Submicrometer technology

In this letter results are presented on the inversion layer mobility of our NMOS devices fabricated with fine-line technology. These devices do not follow the universal mobility curve reported for standard MOS technologies with design rules ≥ 2.5 µm. Annealing of these devices (fabricated with the fine-line technology) in H2at 700°C results in an improvement of mobility for all measured values of the vertical electric field. However, even after 700°C annealing, the devices do not follow the universal mobility curve. The universal mobility curve can not be applied to fine-line devices with thin gate oxides and with surfaces that have been exposed to reactive sputter etching processes.