用户体验质量评估方法浅析

全业务运营的环境下,客户竞争焦点逐步向以客户为中心的用户体验质量(QoE)转移。文章首先就新形势下,运营商的网络监控服务能力的转变需求进行分析,然后在详细讨论QoE评估复杂性的基础上,通过改进现有评估方法的不足,建立了一个标准的自上而下的QoE评估方法。     

面向精准农业的无线多媒体传感网设计(英文)

To satisfy the needs of modern precision agriculture, a Precision Agriculture Sensing System (PASS) is designed, which is based on wireless multimedia sensor network. Both hardware and software of PASS are tailored for sensing in wide farmland without human supervision. A dedicated single-chip sensor node platform is designed specially for wireless multi-media sensor network. To guarantee the bulky data transmission, a bitmap index reliable data transmission mechanism is proposed. And a battery-array switching system is design to power the sensor node to elongate the lifetime. The effectiveness and performance of PASS have been evaluated through comprehensive experiments and large-scale real-life deployment.     

无线传感网中轻型简单网络管理协议(英文)

A Light-Weight Simple Network Management Protocol (LW-SNMP) for the wireless sensor network is proposed, which is a kind of hierarchical network management system including a sink manager, cluster proxies, and node agents. Considering the resource limitations on the sensor nodes, we design new management messages, new data types and new management information base completely. The management messages between the cluster proxy and node agents are delivered as normal data packets. The experiment results show t...     

无线传感器网络在智能建筑中的优化实现与评估(英文)

A complete study for the implementation of wireless sensor networks in the intelligent building is presented. We carry out some experiments to find out the factors affecting the network performance. Several vital parameters which are related to the link quality are measured before deploying the actual system. And then, we propose an optimized routing protocol based on the analysis of the test data. We evaluate the deployment strategies to ensure the excellent performance of the wireless sensor networks unde...     

综合用户环路的性能分析——基本用户接入到ISDN(英文)

本文分析一个话音/数据综合数字用户环路。为有效利用现有环路,话音与数据均采用分组交换。用二维马尔可夫链来模型环路排队过程,用生成函数法来分析评价其性能。文中研究了典型的2B+D环路,因它是基本用户接入到ISDN的标准。文中考虑了话音与数据在分开信道和同一信道中传输时的排队性能。数值计算结果表明,综合方案可明显地增加数据业务。     

基于用户体验质量设计分组网络的QoS机制

在电信网络从电路交换网向多业务分组网络过渡的过程中．每一个运营商都必须考虑的一个关键问题是：在分组网络中是否能够向用户提供电信级的服务质量(QOS)?不过，对于用户而言，他们并不关心其服务提供商怎样去实现QoS机制．更多的是关注用户体验质量(QoE)。探讨了二者之间的关系。提出了影响QoE的的主要因素，以及在一个企业网络中基于QoE实现QoS机制的方法。     

一种3G业务用户体验质量评估方法

3G业务可以为终端用户提供各式各样的服务,参与性强、互动性好、有吸引力的3G业务对用户具备很强的吸引力,3G用户重视体验质量（QoE,Quality of Experience）。本文采用最小二乘算法实现QoE和KQI映射关系建模,构建了一种3G业务用户体验评估方法,实现以用户为中心,改进3G网络质量、增加收益。     

基于脑电的弹幕视频用户体验质量评估研究

弹幕视频是一种近年来发展迅速的新兴媒体传播形式,备受大众喜爱,但根据调查显示,部分用户认为弹幕严重影响了视频观看。为改善弹幕视频服务,用户体验质量（Quality of Experience,QoE）的评估迫在眉睫。然而,现有用户体验质量评价方法存在主观因素导致的虚假反馈、反馈不够及时、数据度量关系难以衡量等局限性。在这种情况下,脑电图（electroencephalogram,EEG）因具有无法伪装、高时间分辨率、数据更具统计学意义等优势,已经初步应用于视听刺激的主观评估。结合以上优势,本文提出将EEG突破性地应用于弹幕视频的QoE评估。本研究基于相锁值构建了功能连接特征脑网络,提取了高/低两种QoE水平下的成对差异网络,并基于该网络通过机器学习方法构建评估模型。该评估模型平均分类准确率达到80%,揭示了对于不同类型视频用户产生不同QoE时大脑区域协作的变化模式,并提出与QoE高度相关的额叶为主要会聚区域。以上研究结果表明,该评估模型能真实记录用户观看视频时的生理和心理活动,研究结果为改善弹幕视频服务提供了神经生理学依据。     

基于LTE流媒体业务的用户体验质量评估方法研究

针对LTE流媒体业务用户体验质量的评估,本文基于层次分析法的区间估计理论,筛选出了影响用户感知相对重要的关键性能指标KPI,然后从技术因素和非技术因素两个角度分析,建立改进的用户体验质量评估模型。最后采用模糊层次分析法对关键质量指标权重KQI的计算方法进行改进,从而建立了一套完善的评估方法。仿真结果表明,该评估方法兼顾网络客观因素与用户主观感知,能够更好地反映实际的网络质量。     

0.6可用于光纤用户网的 0.6μ mCMOS激光驱动器(英文)

基于国内的CMOS技术和EDA工具以及全定制的设计方法 ,采用无锡华晶上华 (CSMC HJ) 0 6 μmCMOS技术实现了可工作于 15 5Mb/s、6 2 2Mb/s的激光驱动器 .该激光驱动器在 5 0Ω负载上输出电流摆幅从 0到 5 0mA可调 .在输出级 3V直流偏置时最大输出电压摆幅可达 2 5Vpp.输出电压脉冲的上升、下降时间分别小于 471ps和 44 4ps.四个工作速率下均方根抖动都小于 30ps.电路在 5V单电源供电时功耗小于 410mW .芯片测试结果表明 ,该激光驱动器达到了世界同类集成电路的水平 .     

无线泛在网络下虚拟终端技术研究综述

首先,简要介绍了虚拟终端技术的产生背景及定义,然后对虚拟终端典型应用场景进行了描述。之后系统的介绍了虚拟终端系统架构并分析其优缺点,提出一种全新的系统架构方式。再次,对于虚拟终端通信协议及机制、虚拟终端资源优化策略进行了描述,最后提出了未来的研究方向。     

Statistical Analysis of a Subjective QoE Assessment for VVoIP Applications

A successful deployment of multimedia applications over wireless environments entails improving the quality of service (QoS), not only from a technical point of view, but also considering the quality of experience (QoE) from the final user's perception. Although objective QoE measure models avoid the difficulties of subjective surveys, subjective QoE assessments are essential to understand the way users evaluate the QoS. In this work, we study the effect of a wide range of parameters on the QoE of VVoIP applications in a real wireless scenario. Through a complete statistical analysis of users’ ratings, we identify the following facts. Although the use of VVoIP in wireless networks does not yet represent an advantage for users, there are great expectations for all applications under study, and with greater popularity comes higher expectations. It is easier for respondents to identify good behavior than poor behavior. Whereas the respondents’ frequency of Internet use does not impact on the scores, respondents’ gender does. Finally, the most determining parameters of quality from a user's perspective were instability, video quality, voice distortion, usefulness, and graphical interface.     

无线数字家庭网络泛在接入技术

数字家庭网络是通信领域的一个重要分支，近年来发展非常迅速。基于电信网络的数字家庭网络体系结构在中国已经标准化，但就接入方式而言，只是定义了可以使用无线方式，如何组建无线数字家庭网络是未来研究的重点。文章提出了无线数字家庭网络泛在接入概念，给出了无线泛在接入网络体系结构，并就其中的关键技术进行了探讨，包括感知无线电、无线网状网（Mesh）网络理论、通用接入点链路转换机制、业务的QoS保障机制以及电磁兼容和异构系统共存机制等。     

A Novel Optimal Channel Partitioning Algorithm for Integrated Wireless and Mobile Networks

How to efficiently support multi-class services is a very important issue in integrated wireless and mobile networks because each type of services has distinct characteristics and quality of service (QoS) requirements. This paper presents an efficient algorithm for near optimal channel allocation when different types of services are to be provided in the next generation integrated wireless and mobile networks. We specifically propose a preemptive priority scheme for an integrated wireless and mobile network by first dividing channels into three independent groups and classifying traffic into four different types. The proposed system is modeled by a multi-dimension Markov chain model. Then such a model is used to obtain a set of relations that correlate performances with various system parameters. A novel recursive algorithm is developed to determine the minimal number of channels in each channel group that would be necessary to satisfy the QoS requirements. We also investigate the impact of load ratio for different types of traffic on channel assignment. Finally, we discuss some limitations of our approach and indicate possible future work. We believe that the partitioning scheme proposed in this paper can become a starting point for analysis of future integrated wireless and mobile networks.     

无线传感器网络恶意节点溯源追踪方法研究

 传感器节点可能被攻击者俘获用来发送大量虚假数据,从而耗尽整个网络的资源.本文提出一种实用的溯源追踪解决方案:基于概率包标记算法,每个节点按照一定概率标记其转发的包,标记信息填写于包头中的确定域,通过收集到足够多的数据包,汇聚节点能够重建一条到源节点的路径.本文证明了此方案能够应对所有类型的攻击,并针对基本标记方法的不足提出了两种改进标记方法.实验结果表明该溯源追踪解决方案是高效以及实用的.     

Dynamic Code Assignment Medium Access (DCAMA) Protocol for Wireless Integrated Services Networks

A medium access control (MAC) protocol for wireless mobile networks that supports integrated services and provides quality of service (QoS) support is presented and evaluated via simulation. A controlled random access protocol which allows all terminals to dynamically share a group of spread spectrum spreading codes is used. The protocol provides mobile terminals the access control required for efficient transfer of integrated traffic with QoS guarantees. Two service classes are provided; "best-effort" service, with priority queueing, and reserved bandwidth circuit service. The performance of the protocol is evaluated via simulation for traffic consisting of integrated voice, data and compressed video. The performance assessment measure is packet delay.     

无线传感器网络的自组织机制研究

无线传感器网络的自组织包含不依赖于固定通信基础设施的有规则联系和运动,本文在特定应用中研究这一过程.在定性分析无线传感器网络的自组织特性之后,提出自组织度和自组织单位能耗的自组织评价方法,在典型应用中以此量化分析无线传感器网络的自组织演化机制.仿真表明,在特定应用中的无线传感器网络表现出孕育、发育、成熟、衰退和死亡的自组织过程,自组织能耗依赖于特定的部署方式和无线模型.     

基于QoE评估的移动互联网优化策略研究

通过研究移动互联网中的QoE体系和评估方法,确定业务与网络之间的互相影响关系并建立统一优化模型,为进行移动互联网中业务与网络协同、提升用户体验奠定了基础。     

无线网状网技术与应用

无线网状网(WMNs)由网状路由器节点和客户机节点组成,其中的网状路由器节点组成了无线网状网的网络骨干,其移动性很小。他们一起为无线网状网和其他常规无线网络的客户机节点提供网络的无线接入。WMNs技术结合了中心式控制的蜂窝网与分布式控制的无线自组织网的优点,可有效克服这两种技术的缺陷并显著提高无线网络的性能,已经成为下一代无线通信网络的研究热点之一。WMNs可为无线个域网、局域网、校园网、城域网的一系列应用提供高速无线宽带接入服务。虽然目前WMNs技术发展很快,但其协议栈各层仍存在许多有待研究的课题。首先简要介绍了无线网状网的结构与特点;随后重点分析了其主要的几个应用领域;最后探讨了WMNs各协议层的研究现状与关键技术,并分析了该技术存在的问题及未来的研究方向。     

无线Mesh网络中激励机制研究

为了激励无线Mesh网络中自私节点转发数据,通过分析节点自私行为激励的原因和目标,将适用于无线Mesh网络中对节点自私行为的四类激励机制进行比较.讨论了无线Mesh网络博弈模型,并对无线Mesh网络中重复博弈模型进行理论分析.针对节点的自私行为提出了基于博弈论与信誉相结合的激励方案.仿真实验表明,该方案不仅降低了基于信誉的复杂度又能有效激励更多自私节点转发数据,从而提高了网络的整体性能.