基于信令分析的LTE网络CSFB优化策略

针对LTE网络下采用CSFB方式实现语音业务存在时延过大的问题，探索基于信令分析的CSFB优化策略，通过信令流程拆分法、信令追溯分析法等精确定位出CSFB回落失败及时延过长的原因，并给出具体解决方案。实验结果表明该策略能够有效改善回落成功率或降低时延，提升了LTE网络的用户感知     

LTE网络CSFB回落时延优化分析

文章主要针对LTE网络CSFB语音回落时延长的问题,采用诸多创新性的优化手段,从信令流程分析、网络功能特性、网络参数配置、邻区关系等角度进行优化,最终成功大幅降低CSFB时延,提升了用户感知。     

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。     

基于LTE网络的CSFB语音业务设计与实现

针对LTE建网初期覆盖不足的现状,提出了基于LTE网络的CSFB语音业务方案和实现办法。目前,CSFB回落方案采用3GPP R8重定向回落方案,同时要求终端支持缓读System Information 13系统消息功能以缩短呼叫建立时延、优化方案性能。总体来说,CSFB呼叫建立过程包括三个阶段:UE在LTE网络发起呼叫/被叫接收寻呼、UE在LTE网络指引下回落并搜索合适的W小区接入、UE读取W小区系统广播消息并建立语音通话。在CSFB部署过程中,因参数配置或者设备功能缺陷,将导致CSFB呼叫建立过程出现异常情况。解决了被叫语音用户由4G网络回落到3G网络过程中出现的"被叫关机"问题,对于今后的网络优化具有参考价值。     

降低LTE CSFB建立时延的解决方案

本文主要是中国联通河北分公司针对LTE网络CSFB建立时延较大问题采用了诸多优化手段,分别从网络规划、参数设置、启用新功能等角度人手,最终成功的降低CSFB建立时延,提高用户感知.     

CSFB呼叫时延优化研究

受限于VoLTE终端的普及率,目前CSFB仍是LTE网络语音业务的主流,但其一个重要的技术劣势是呼叫时延不够理想,因此呼叫时延优化显得尤为重要。文章基于点阐述了一般呼叫时延的时优化思路。     

网络游戏业务在LTE系统中信令时延分析

随着移动通信技术的迅猛发展,LTE作为目前移动通信系统的主要演进方向,越来越多的用户使用其网络业务。本文就以网络游戏业务的随机接入过程中信令优化为叙述重点。首先介绍了网络游戏业务,然后结合网络游戏业务的特点和随机接入的信令流程,找出在随机接入信令中影响网络游戏业务的时延参数,并进行信令参数优化。     

Flash CSFB功能提升用户感知研究

在LTE网络中用CSFB实现语音功能时,系统消息的读取时间在CSFB时延中占比较大.盲重定向通过在RRCConnection Release消息中加上邻区的系统消息内容,使UE重定向后接入的小区即为已经被下发系统消息的邻区,节省系统消息的读取时间.Flash CSFB通常用这种盲重定向的方式实现,缩短语音回落时延,提升用户感知.     

SSCOP信令传输时延分析与检测

SSCOP协议是ATM宽带网络信令系统数据链路层的一部分,SSCOP信令链路为ATM网络元素之间提供可靠的信令信息传输。信令链路传输时延是ATM网络传输质量的一个重要参数,SSCOP协议的很多重要参数的取值都依赖于传输时延的大小。介绍一种SSCOP信令链路传输时延的检测方法,通过构造一种特殊的SSCOP报文来测试信令网络的传输质量,并计算信令报文的传输时延。对提高ATM信令系统的网络质量和优化SSCOP协议参数具有一定的现实意义。     

华为完成LTE至GSM的语音回落优化测试，加快移动宽带产业发展

2012年9月27日,华为在上海实验室完成了从LTE到GSM的CSFB（电路交换回落）语音优化测试,使终端用户从LTE切换至GSM网络的语音通话建立时延减少2s以上,同时语音通话建立成功率获得较大提升,保证终端用户在GL双模网络上优良的语音体验。     

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