多目标遗传优化ABC支持型切换决策机制

异构无线网络中的切换决策机制,需要综合考虑应用服务质量(quality of service,QoS)需求、服务费用、用户偏好、移动终端状态和接入网络状态等多维因素,进而实现用户和网络提供商的双赢.引入模糊数学和微观经济学知识,对影响切换决策的因素进行了刻画.在此基础上,提出了一种多目标遗传优化总最佳连接(always best connected,ABC)支持型切换决策机制,通过精英选择和个体迁移提高决策质量,基于博弈分析,寻求多终端对多接入网络的最佳切换决策方案,使用户和网络提供商效用达到或接近Nash均衡下的Pareto最优.仿真实验结果表明,该机制是可行和有效的,同现有机制相比具有更好的性能.     

基于快速连续蚁群算法的QoS切换决策机制

随着人们对移动网络服务需求的日益增长,用户需要在复杂的异构网络中实现不同接入技术之间的无缝切换,因此选择总最佳连接并提供服务质量保证的切换决策成为下一代互联网研究的关键内容.为了更好地满足用户的需求,在综合考虑网络信息的不确定性、用户服务质量需求、用户偏好、用户愿意支付的费用以及网络供应商的收益等因素的前提下,设计了基于快速连续蚁群算法的切换决策机制,并引入协商博弈和Nash均衡思想来解决用户之间的串谋问题以保证切换决策的公平性.仿真结果表明,设计的切换决策机制在满足用户服务质量需求的同时,不仅使双方的效用最大,并且最契合用户的偏好,能够很好地解决下一代互联网中支持总最佳连接的切换决策问题.     

网络与终端协同选择及切换机制的研究

提出了一种智能切换机制,用于实现在异构网络中网络与终端的协同选择及切换功能。随着各种业务和应用的发展,异构网络融合是信息和通信技术的必然趋势。根据多接入、多终端等应用环境的要求,采用AHP与URA等多属性决策理论,为用户选择最佳的目标网络和目标终端,并提出相应的智能切换信令流程,包括网络切换、终端切换、网络与终端联合切换方式,最终构建以用户为中心的多终端智能空间,实现个人移动性管理。仿真表明,该智能切换机制可以有效地实现网络和终端的协同选择,并可以保证在异构网络切换QoS性能,为现代服务业的业务及应用的发展提供可靠的理论依据。     

基于RTP/RTCP的VoIP智能切换技术的实现方法研究

为满足通信接入需求的多样性,接入网络的异构融合将成为下一代网络的必然趋势。为了解决由于异构网络和终端性能的不稳定及用户需求的实时变化而导致的通话连续性差的问题,提出了一种面向用户的基于RTP/RTCP的VoIP系统智能切换技术。通过对RTP/RTCP协议的应用扩展,系统实时检测VoIP会话的端到端网络的QoS性能,并对终端和网络性能、用户信息进行采集,从而使系统可根据用户所需的业务性能需求、所处的网络环境、终端性能、用户偏好等,智能地将用户切换到最佳的可用网络和终端,以满足服务连续性与接入方式多样性的需求。     

移动互联异构网络下多终端协同的垂直切换决策算法

针对移动互联网用户的多终端协同的垂直切换问题,提出一种UMTS与WLAN异构网络环境下的多终端协同的垂直切换决策算法,其包含切换时间判断与多终端协同算法。首先利用模糊逻辑判断网络切换时机,然后综合考虑主观因素和客观因素,采用AHP（Analytic Hierarchy Process）合理定义权值并结合TOPSIS（Technique for Order Preference by Similarity to an Ideal Solution）实现不同接入策略的性能评价,为用户提供最佳QoE（Quality of Experience）的多终端协同方案。实验结果表明：所提方法和基于迟滞算法相比,切换次数平均降低7.9次,切换失败率平均降低2.25%;网络选择结果与应用需求和用户需求保持较好的一致性。实现了多终端协同用户在异构网络环境下高效实时的垂直切换。     

认知无线电网络中终端群的接入网切换算法

在集中式认知无线电网络中,认知用户终端需要首先接入次基站才能够进行网络通信,而认知无线电网络的特性也决定了,多个用户终端可能会因某主用户的出现或网络环境质量的恶化,而在某一时刻同时发出网络切换请求.他们之间由于缺少协调会造成某些次基站的拥堵以及用户终端的频繁网络切换.提出一种终端群接入网切换网络侧控制算法,通过核心网侧的网络切换控制器来实现次基站的负载均衡及认知终端群的公平切换.通过模拟仿真,我们发现相较于传统切换算法,本算法可以有效地均衡各次基站的负载,极大地提高网络的整体性能.     

一种融合网络语音业务系统的实现方法的研究

目前,基于信息与通信技术以及现代管理理念的现代服务行业迅速发展。现代服务业中用户通信需求的差异性以及通信接入方式的多样性,决定了支撑现代服务业发展的通信网络呈现为包含固定、移动多种接入方式在内的异构形态。用户对通信业务的连续性以及服务体验的一致性要求,对复杂的异构通信网络中的切换机制提出了挑战。文中研究并提出了一种适用于异构网络的,以用户为中心的语音业务系统的实现方法。该系统可根据终端及网络信息选择合理的终端进行最好的网络接入,并以智能切换保持语音业务的连续性和一致性。     

基于博弈论的异构融合网络接入选择方法研究

各种异构接入网络的无缝融合是下一代网络的显著特征之一,不同网络技术接入形式的多样化使得多网络接口的用户终端可自主选择对用户最为有利的接入网络(或SP,Service Provider)获得互联网服务.文中给出一种面向用户可视化可操作的异种网络接入选择实现机制,该机制采用一种量化接入系统服务质量的统一评价模型及基于最优用户性价比的网络选择决策方法,同时依据不同接入网络之间的合作与非合作关系以及SP与用户之间的竞争关系,引入博弈论方法建立网络价格策略的两种博弈模型,通过求解模型的纳什均衡价格及共谋价格,确定网络优化定价机制.仿真结果比较了异构网络融合环境下的各接入网络在非合作和合作博弈模式中的优化定价机制及获得的收益特性,并比较了不同博弈场景下用户选择接入网络的性价比.     

基于SDN的无线接入网络切换决策方法

由于5G接入平面中多种接入技术并存,以及用户不规则的、趋向按需的主动式移动性特点,接入网络之间的负载不均衡问题更加突出,并导致了接入网络的资源浪费以及较低的用户体验。针对这一问题,文章提出了一种基于SDN的无线接入网络切换决策方法,从网络侧和用户侧考虑为用户选取AP进行切换,以均衡接入网络之间的负载,并最大化用户的需求满意度。     

移动网络可信匿名认证协议

针对终端接入移动网络缺乏可信性验证问题,提出一种移动网络可信匿名认证协议,移动终端在接入网络时进行身份验证和平台完整性认证。在可信网络连接架构下,给出了可信漫游认证和可信切换认证的具体步骤,在认证时利用移动终端中预存的假名和对应公私钥对实现了用户匿名隐私的保护。安全性分析表明,协议满足双向认证、强用户匿名性、不可追踪性和有条件隐私保护。协议中首次漫游认证需要2轮交互,切换认证需1轮即可完成,消息交换轮数和终端计算代价优于同类可信认证协议。     

A novel terminal-controlled handover scheme in heterogeneous wireless networks

In the next generation heterogeneous wireless networks, a mobile terminal (MT) with a multi-interface may have network access from different service providers using various technologies. In spite of this heterogeneity, seamless intersystem mobility is a mandatory requirement. One of the major challenges for seamless mobility is the creation of a vertical handover scheme, which is for users that move between different types of networks. In this article a seamless mobility handover scheme is presented. The novelty of the proposed scheme is that handover is fully controlled by the terminal. To improve the performance of the proposed handover scheme, a network discovery algorithm with fuzzy logic and a handover decision algorithm using multi criteria decision making (MCDM) based on vague sets are derived, which are both user-centric. With these algorithms, the handover scheme is power-saving, cost-aware, and performance-aware. Simulation results show that the novel handover scheme can perform network discovery in time to reduce handover dropping rate and present unnecessary activation of its interface to save the battery power, while effectively choose the optimum network through making trade-off among the user preference, network condition, and system performance.     

A MIH-based approach for best network selection in heterogeneous wireless networks

In the next generation wireless networks, different technologies belonging to one or more operators should be integrated to form a heterogeneous environment based on an IP core network infrastructure. This ensures user mobility and service continuity by maintaining connections when switching between various technologies and it introduces new resources and possibilities for applications. In this context, an automatic interface selection based on instantaneous and practical constraints and user preferences (Quality of Service (QoS) parameters, available resources, security, power consumption, etc.) is therefore required. The different network selection and handover schemes proposed in the literature can be classified into three approaches according to who is responsible for making the handover decision: the terminal, the network or by a cooperation between both of them. However, these approaches keep presenting some drawbacks; namely the problem of resources management and network load balancing whenever the selection is controlled by the mobile terminal (MT) and the problem of scalability and unknown operator's management policy whenever the selection is rather controlled by the network.In this article, first we propose a MIH based approach for handover initiation and preparation for heterogeneous wireless network. The proposed framework is based on the principals of IEEE 802.21 for context information gathering and optimized handover decision making. Second, we propose a new architecture and new network selection scheme that explicitly take into account the current resource usage and the user preferences. Furthermore, our solution ensures the selection of the most suitable network for each flow while taking into consideration its expectations in terms of QoS. A feasibility study of implementing a new architecture on a single MT is evaluated by using typical scenarios and using various algorithms. Thanks to the introduced function entities and modules in the proposed architecture, network utilization balancing and user and application expectations, which are successfully assured without operator intervention. Performance analysis shows that the proposed algorithm best meets the common quality requirements.     

粒子群优化ABC支持型QoS单播路由机制

设计了一种ABC支持型QoS单播路由机制,采用区间形式描述不精确用户QoS需求和边（链路）参数,引入用户满意度、边评价和精英解集,通过博弈分析,应用粒子群优化算法,寻找使用户和网络提供方效用达到或接近Nash均衡下Pareto最优的QoS单播路径。仿真结果表明,该机制是可行和有效的。     

5G异构网络中基于群组的切换认证方案

随着5G网络的发展,各类网络服务质量极大提升的同时网络环境也愈加复杂,从而带来了一系列安全挑战。切换认证可以解决用户在不同类型网络间的接入认证问题,但现存方案仍存在一些不足,还需要解决如全局切换认证、密钥协商、隐私保护、抵抗伪装攻击、抵抗中间人攻击、抵抗重放攻击以及群组用户切换效率等问题。针对这些问题,提出了一个5G异构网络中基于群组的切换认证方案。在所提出的方案中,注册域服务器在区块链上为每个用户存入一个通行证,任何实体都可以利用该通行证对用户进行认证,从而实现全局切换认证。对于群组用户,各用户分别设置可聚合的认证参数,验证者通过验证聚合签名实现对群组用户的批量验证。新方案不仅提升了群组用户切换时的效率,同时还满足上述安全性要求。基于形式化分析软件AVISPA的分析结果表明,所提出的方案是安全的。性能分析表明,所提出的方案执行批量验证时的效率比现存方案至少提升了89.8％。     

基于分离机制网络的可信域内快速认证协议

分离机制网络明确地分离了主机身份与位置信息,将互联网体系划分为接入网与核心网两大类,很好地解决了互联网的扩展性和移动性等问题.基于分离机制网络,结合可信计算技术,提出一种终端域内切换时的快速认证方案,在对终端用户身份进行认证的同时,对终端平台进行身份认证和完整性校验.在本方案中,终端进行域内切换时不需要本域的认证中心再次参与,仅由接入交换路由器通过Token即可完成认证.认证过程可以保持用户身份和平台信息的匿名性,减轻了认证中心的负担.与其他方案相比,本方案在认证开销、认证延迟以及安全性等方面均有明显优势.安全性分析结果表明本方案是安全高效的.     

A utility-based fuzzy TOPSIS method for energy efficient network selection in heterogeneous wireless networks

Mobile terminals in 4G heterogeneous wireless networks continuously undergo horizontal and vertical handovers. In order for a mobile terminal to be connected to a network in the best possible way in terms of QoS performance and energy consumption, access network selection as the main decision within the handover process is obviously crucial. This paper presents a novel method that takes into account user preferences, network conditions, QoS and energy consumption requirements in order to select the optimal network which achieves the best balance between performance and energy consumption. The proposed network selection method incorporates the use of parameterized utility functions in order to model diverse QoS elasticities of different applications, and adopts different energy consumption metrics for real-time and non-real-time applications. User preferences are easily configured for different application and situation contexts through the use of linguistic assessments and their representation as triangular fuzzy numbers. The aggregation of multiple criteria for the calculation of the overall rating of the networks is performed through the use of the Fuzzy Set Representation TOPSIS method that resolves the issue of inconsistency related to conflicting decision criteria and is modified through the use of the employed utility functions for the elimination of the ranking abnormality problem. Finally, simulations are conducted in order to demonstrate how the proposed method would work and confirm its suitability and effectiveness.     

A user-centric and context-aware solution to interface management and access network selection in heterogeneous wireless environments

This paper investigates issues related to handover management of mobile terminals in heterogeneous wireless environments. The mobile terminals are equipped with multiple wireless radio interfaces and have a limited lifetime battery. Seamless mobility and power utilization efficiency become two important aspects of the handover management. We propose in this work user-centric network selection, power-saving interface management and adaptive handover initiation solutions at the terminal side to support seamless terminal-initiated and terminal-controlled vertical handover. The proposed access network selection is situation-aware and application-aware to suit different communication contexts. It enables terminals to select the most suitable access network according to various access network characteristics. Multiple wireless interfaces of a terminal device are handled in both idle and active communication modes to optimize the power consumption. We also address an adaptive handover initiation scheme to assist the service continuity. We conduct simulations and analyses of the proposed solutions to show their suitability and their efficiency.     

Exploiting mobility patterns for inter-technology handover in mobile environments

Mobile terminals with multi-radio devices have become increasingly prevalent. This makes it possible for Internet applications to be supported by heterogeneous wireless networks while the terminal is on the move. As the user is constantly moving, it is highly desirable that the terminal connects to the best network and retains high performance of network connections. Handovers can be made within the same type of network (horizontal handover) or different types of networks (vertical handover). This paper focuses on link-layer inter-technology vertical handovers. Vertical handovers present several great challenges, such as user mobility randomness, high handover overhead and optimality requirement. Existing work often focuses only on the current network condition when making handover decisions, ignoring future performance of the terminal. As a result, a handover decision good for the current moment may soon become poor when the user moves to another place. This paper is motivated by the observation that users in a given mobile environment, such as university or enterprise campus, exhibit clear mobility patterns. We propose an approach for making handover decisions, which explicitly exploits user mobility patterns. This approach can produce high-performance handover decisions in the long run. Employing a comprehensive framework for preference customization, the approach supports user customization caring for different user preferences. Extensive real trace driven simulations and comparative study show our algorithm is better than the conventional vertical handover algorithms.     

移动IPv6网络基于身份的层次化接入认证机制

设计了一种基于身份的层次化签名方案,并在该方案基础上提出了一种适用于移动IPv6网络环境的层次化接入认证方法.该方法使用分级NAI(Network Access Identifier)作为公钥,简化了无线移动环境中的密钥管理;利用层次化思想对接入认证和移动注册进行层次化管理,减少了切换认证处理流程;基于签名机制实现了用户与接入网络的双向认证.作者用设计的切换延时分析模型,对该方法和几种传统方法进行了比较,证明当移动节点远离家乡域及在一定范围内频繁微移动时,该方法比传统方法的效率更高.通过安全性分析证明了该方法在一定程度上实现了私钥的保密性、签名的不可伪造性等功能.最后还讨论了该方法的一种可扩展变形,用于实现多级层次化移动IPv6框架下的接入认证.