基于业务监测的VoLTE核心侧语音质量MOS值优化解决方案

VoLTE即Voice over LTE,是基于LTE网络数据域的语音业务方案。该方案基于IMS网络,提供全IP语音通话。VoLTE通过全IP的4G网络和IMS服务器提供语音服务,运营商需要在网络侧做出大量投资和研发。如何保障重金投资的VoLTE网络和研发真正能带来更好的用户体验,如何保障VoLTE核心网和业务质量的稳定性将成为运营商维护部门所要面对的首要问题。文章提出一种测试系统对VoLTE服务进行准确、标准、可重复以及自动化的专业测试评价方案和工具来解决问题。     

基于IMS的语音增值业务融合发展思路探讨

IMS网络的引入为电信运营商带来新机会,多媒体业务的丰富可为IMS用户带来新的业务体验,但是,在引入IMS网络后,业务网络将基于IMS核心网络进行融合,现有的固定网络和移动网络上的语音增值业务将大大丰富IMS用户和融合业务用户的业务体验,同时提升不同网络接入用户语音业务体验一致性。文中针对中国电信IMS网语音增值业务融合发展需求,结合广东电信典型业务创新性地提出IMS网络初期阶段语音增值业务融合发展思路,包括三种业务融合实现方式,分析其优缺点并提供应用建议,为建设初期基于IMS的业务融合提供参考。     

VoLTE发展与运营商部署策略分析

VoLTE(基于IP多媒体子系统的语音业务)技术的应用是LTE发展的主要趋势之一,是LTE网络的最终语音解决方案。VoLTE的部署对于促进LTE网络演进具有重要作用,何时部署VoLTE以及如何部署Vo LTE对于运营商的业务发展具有重要意义。文章介绍VoLTE业务及产业链发展情况,对CSFB(电路域回落)、SVLTE(LTE与语音网同步)、OTT(Over the Top)等几种VoLTE部署前的语音过渡方案进行分析,指出运营商的网络现状及部署VoLTE面临的主要问题,对比几种过渡方案的特点,探讨运营商部署VoLTE的策略。     

语音业务发展趋势与核心网演进策略浅析

在分析语音业务发展趋势的基础上,提出了目前电信运营商核心网络发展与演进的趋势、策略与发展步骤,阐述了现网核心网向IMS架构演进的各阶段目标结构与重点建设方案。     

IMS网络在VoLTE阶段的发展及部署研究

当前我国已经正式迈进了4G时代的大门,语音和视频通信也朝着更加高清的方向发展,而VoLTE在此发挥了至关重要的作用.VoLTE是一种网络架构,通过将IMS网络语音业务融入其中,使得自身可以同时支持多种多媒体业务.而本文则以此为背景,分别从集中建设和分省建设两种部署方式出发,着重围绕IMS网络在VoLTE阶段的发展与部署进行简要研究.     

中国电信FDD 4G VoLTE语音感知MOS质量问题分析和优化提升的研究

随着终端、基站、EPC、IMS网元的大量端到端性能及配合问题解决,VoLTE业务在接通率、掉话率指标均已经基本达到了CDMA网络的水平,接入性能和保持性能方面的感知得到了较大改善。VoLTE作为LTE网络实现语音通话的最终方案,其通话质量、用户感知成为主要关注方向。本文主要介绍了衡水电信网优团队针对VoLTE语音通话在无线层问题导致的丢弃包、时延问题进行分析、定位的基本思路、优化方法。希望能够为网优工程师在VoLTE优化工作中提供帮助和支撑。     

IMS彩铃及现网彩铃业务融合方案探讨

随着IMS(IP多媒体子系统)网络大规模的建设,IMS网络的组网、技术和业务提供能力等成为运营商关注的焦点.彩铃业务作为电信运营商的一项增值业务,不仅为固网、C网用户提供,同时也为IMS用户提供.对IMS用户彩铃和现网用户彩铃业务的融合进行了探讨,提出了五种不同解决方案.     

VoLTE语数分层策略研究

随着4G用户数的快速增长,IMS系统的部署与完善,LTE网络不仅可以提供高速率的数据业务,同时还实现了高质量的音视频通话,即VoLTE。VoLTE语音业务的开通商用以及中国移动大规模建设FDD与TDD多网络融合组网,为不同业务类型承载于不同网络创造了条件,本文对LTE网络FDD、TDD多网模式下的VoLTE语音和数据业务承载策略进行研究实践,提出语音和数据分层承载策略,即通过将VoLTE业务指定到固定的频点,并且配置相应参数,成功实现VoLTE语音和数据业务分层,从而提升Vo LTE语音业务质量。     

基于IMS的VoLTE语音业务实现方案的研究及优化

针对TD-LTE网络、无线接入网E-UTRAN以及EPC的网络结构功能上的变化,指出TD-LTE语音业务面临的问题,分析基于IMS网络的VoLTE/SRVCC语音实现的系统架构,详细说明主叫VoLTE to VoLTE语音业务的信令流程,并提出一种信令优化方案,实践证明该方案能够降低VoLTE语音通话时延,有效提升4G用户语音业务感知.     

VoLTE测试与CMW500射频测试仪

VoLTE(Voice over LTE),即在LTE网络下承载语音业务。VoLTE是一个宽泛的概念,从运营商的角度来看,VoLTE包括SV-LTE、CSFB、IMS和SRVCC共4种方案。这些方案实现方式各不相同,在LTE演进的不同阶段,它们都将发挥各自重要的作用。罗德与施瓦茨(中国)科技有限公司刘轶旻所撰《VoLTE测试与CMW500射频测试仪》一文将就几种VoLTE(SV-LTE、CSFB、IMS和SRVCC)方案的基本原理以及罗德与施瓦茨(中国)科技有限公司的CMW500射频测试仪对VoLTE(SV-LTE、CSFB、IMS和SRVCC方案)的测试能力进行介绍。     

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks