浅析5G语音方案EPS Fallback时延因素

3GPP R15协议提出EPS Fallback和VoNR两种5G语音解决方案,其中EPS Fallback作为当前5G SA优先部署语音解决方案.为降低EPS Fallback时延大对用户语音业务感知影响,本文采用基于SIP协议呼叫流程的EPS Fallback信令分段分析方法,查找影响EPS Fallback流程时...     

EPS Fallback回落方案实践

EPS Fallback(回落4G的语音)是目前各大运营商商用的5G语音解决方案,相比VoLTE(长期演进语音承载),EPS Fallback需要用户从5G回落4G,再执行VoLTE呼叫建立流程,该回落过程是影响用户5G语音感知的关键,特别是呼叫建立时长。文章遵从3GPP(第三代合作伙伴计划),对几种不同的5G回落4G方式进行分析,基于信令大数据对关键性能指标进行评估,为网络部署和优化提供实践依据。     

基于信令消息的VoLTE接续时延优化

承载于LTE的语音业务(VoLTE)无线频谱利用效率优于传统CS语音,高清语音和视频编解码的引入显著提高了通信质量,VoLTE呼叫接续时长较传统CS语音大幅缩短.主要针对VoLTE的接续时延,提出基于信令消息的VoLTE接续时延优化,依据VoLTE终端在接续过程中不同阶段的网元间交互的信令消息,从寻呼、域选、资源预留3个阶段分别对影响VoLTE接续时延的因素进行针对性分析,并给出相应的解决方案.     

基于信令的EPS FB呼叫建立时长评估体系

呼叫建立时长是影响用户语音业务感知关键指标之一,EPS FB(回落4G的语音)作为目前5G商用的语音解决方案,其端到端呼叫建立时长明显高于VoLTE(长期演进语音承载),严重影响用户感知.采用一种分域分段的时延分析方法,提出基于该方法的EPS FB呼叫建立时长评估体系,实现对EPS FB呼叫建立时长的监控和指标劣化自动...     

一种分域分段的VoLTE业务时延优化方法

呼叫建立时延做为VoLTE关键性能指标,对其进行优化,可以提高用户对VoLTE业务满意度。本文以V2V呼叫端到端信令流程为基础,通过对VoLTE业务时延进行建模,提出一种分域分段的VoLTE时延优化和指标监控方法,旨在通过“分段监控、分段定位和分段优化”及时发现、定位和优化VoLTE时延问题。     

EPS回落和呼叫流程研究及优化

EPS Fallback(演进分组系统回落)作为5G SA(独立组网)建设初期的语音业务过渡方案,流程复杂、涉及多张网络,运维人员在投诉定位、语音质量分析时缺乏指导.文章分别系统介绍EPS Fallback、MO(发起)/MT(接收)呼叫会话流程,对信令流程各阶段进行梳理归纳,并对详细介绍信令流程涉及的关键参数含义.在...     

5G语音时延优化研究

5G网络部署初期采用EPS Fallback方案回落到4G,然后利用Vo LTE提供语音服务。EPS Fallback涉及IMS、5GC、EPS等领域,流程长、时延大。主要研究如何通过网络优化来缩短5G语音呼叫建立时延。通过对“E2E呼叫建立时延”指标分析优化中所用的到主要方法进行提炼和总结,从信令流程和参数着手,借助信令跟踪信息进行全面优化来缩短呼叫建立时延,为后续5G语音时延优化提供指导意见。     

5G参数与VoLTE配置优化降低EPS Fallback时延的研究

针对当前5G网络语音业务优化中,EPS Fallback(演进分组系统回落)时延较高影响语音感知的问题,对5G DRX(非连续接收)、事件发生到上报时间差参数优化与VoLTE(长期演进语音承载)配置优化进行研究.通过DCCH(专用控制信道)优先级、DRX功能、呼叫时延优化、事件上报时间差等关键参数优化,优化EPS Fa...     

5G EPS Fallback感知优化研究与应用

由于VoNR技术尚不成熟,当前5G SA语音仍需依靠EPS Fallback回落至VoLTE来解决.在现阶段,EPS Fallback仍然存在接通率低和接通时延大等问题,严重影响5G客户使用感知.本文通过对影响EPS Fallback语音感知的关键问题进行探究,形成一套面向不同场景的差异化优化方法,并实施验证,实现了5...     

在MTUP信令中增加EARLY_ACM功能

在GSM移动网中,由于智能新业务的不断增长,加之平等接入业务和就远入网路由原则的推广实施,呼叫接续的时间,尤其是主叫关口局至被叫端的接续过程会变得很长,超出等待ACM(AddressCompleteMessage)的时长,造成始发端因为后向接续超时而释放呼叫,导致呼叫失败。在ISUP中有early-ACM这样的机制,可以用来预防始发端因为后向接续超时而导致的呼叫被释放。可以在MTUP(MobileTelephoneUserPart)信令中引入early-ACM这样的机制来改善呼叫失败这样的情况。     

EPS网络CS Fallback技术研究

在现有2G和3G的基础上,3GPP推出了演进的分组系统EPS。在EPS网络建网初期,如果运营商已经有成熟的GERAN/UTRAN网络,出于对CS投资保护和LTE/EPC部署策略,运营商可以采用原有的CS域语音方案来提供语音服务。本文对CSFallback技术进行了分析,并对CSFallback业务的发展给出了建议。     

LTE终端类型分析及其测试

LTE终端存在多种类型以满足运营商的业务差异化需求。本文对标准化组织定义的4种LTE终端类型进行了分析,比较了不同类型终端与网络协商业务承载域的过程,介绍了不同类型之间的转换条件和过程,并对不同LTE终端类型的测试策略进行了比较说明。     

5G SA接入网共享语音技术

随着5G SA网络逐步演进成熟,针对多运营商共建共享现状,为了更好地提供其中的语音业务,梳理了SA共享组网方式及其对应的语音业务解决方案,深入研究了当前SA接入网共享方案下基于切换和重定向两种策略的EPS Fallback及Fast Return语音业务技术方案,并针对两种方案进行了分析,进行了外场测试,并给出了测试结...     

5G语音业务流程和典型问题分析

随着5G商用,5G语音业务解决方案备受关注,阶段解决方案为5G回落4G的语音解决方案EPS FB,最终解决方案为5G NR的语音解决方案VoNR,受限于5G网络覆盖和设备能力,目前主要采用阶段解决方案。针对5G语音回落方案,本文基于现网测试和商用体验,分析异常问题,制定基础优化流程,总结典型问题分类和解决方案,支撑5G语音感知提升。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.