Gb接口IP化研究与性能分析

从Gb接口IP化的工作原理以及组网变化研究入手,探讨了Gb接口由帧中继承载转变为IP化承载后带来的优势,同时结合现网Gb接口IP化测试,分析了Gb接口IP化改造前后GPRS网络基本功能和业务性能的变化     

面向移动业务IP化的分组传送解决方案

移动通信业务IP化对传输的要求 在移动网中,核心网流量采用IP承载已经或为现实。移动基站传输接口也正从2G的E1、3G初期的ATM IMA E1转为以以太网接口为主（不同制式的IP化进程稍有差别）,2G RAN的IP化也在进行中。与此相应,传输网络也必须适应移动网络IP化的趋势。     

移动软交换模式下小区短信系统实现方案

GSM无线接入网络正在实现IP化,正在建设的3G网络又拥有固有的IP技术体系,其相应的接口包括Nb／Mc、Gb／lu—PS、A／lu—CS都会发生相应的变化,从而对现有的业务系统如信令监测等都提出了新的技术要求。     

面向宽带业务的网络全IP化解决方案

1 引言 传统的网络组织架构和电信传输网络面临从满足窄带的移动语音业务到满足移动分组业务和宽带业务转变的挑战,从技术角度看,这种挑战体现在移动网络的IP化和移动通信网络的宽带化.更具体一些,就是传统移动通信网络向3G网络的演进,而与此同时传统电信传输网络也需要实现IP化,以适应移动宽带业务的要求.     

陕西移动GPRS核心网IP化探讨

当前,移动网络IP化、宽带化呈现快速增长、应用不断丰富的发展态势,同时3G、网络融合也给移动通信系统的发展带来了机遇和挑战。面临ALLIP的挑战,陕西移动率先在阿尔卡特GPRS核心网IP化方面做了探索,对Gn接口如何接入IP承载网、GboverIP的技术实现方式等难题进行了积极的探索和研究,文章将一些经验与业界同仁共享。     

cdma2000 IOS的演进（一）

3G移动通信的技术和标准正在逐步走向成熟。3G之后的网络发展趋势也是业界一直探索的问题,目前比较一致的看法是网络融合、向全IP网络演进。全IP移动通信网(All-IPMobile Network)是因特网IP技术和移动通信技术迅速发展相结合的产物,其基本概念是将各种无线接口标准和接入手段的数据信号通过IP技术连接到互联网,最终使用IP技术实现端到端的通信。A接口是cdma2000网络中无线网络和核心网络之间的接口,在从电路到分组的发展过程中,A接口包含了很多内容,从A1／A2,一直到A10／A11。A接口使用的标准系列是IOSx.x,在向全IP网络演进的过程中,A接口也要支持IP技术。摩托罗拉(中国)电子有限公司左卫东所撰《cdma2000IOS的演进》一文,较为详细地描述了在向全IP网络演进的过程中A接口的标准发展,以及A接口的标准中用到的一些关键技术,为感兴趣的读者提供了有益的信息。     

Mobile Evolution Transport Architecture面向移动业务IP化的分组传送解决方案

移动通信业务IP化对传输的要求 在移动网中,核心网流量采用IP承载已经成为现实.移动基站传输接口也正从2G的E1、3G初期的ATM IMA E1转为以以太网接口为主(不同制式的IP化进程稍有差别),2G RAN的IP化也在进行中.     

CDMA2000网络中的接口问题

计算机网络和通信技术飞速发展带来的是网络融合趋势日益加大,网络中协议的拟定和实现难度越来越大,随着3G移动通信技术的发展,全球IP化成为未来移动通信网络发展的新趋势,而基于IP架构的CDMA2000系统中MSC与BSC接口协议研究与设计实现是关键技术之一,本文简要回顾了CDMA系统A接口的形成过程及标准版本演进历史,然后对中国电信cdma2000核心网络接口协议技术规范所定义的标准做了一些概括介绍和简单分析。     

GSM网Abis接口IP化改造分析

目前,我国移动通信的承载网和核心网IP化改造正逐步完成,庞大的GSM无线接入网IP化成为了向全IP网络演进的关键。Abis接口IP化是现阶段技术的热点和建设的重点。文章通过对GSM（全球移动系统）网络BSS（基站子系统）中Abis接口IP化的基本原理和实现技术进行分析对比,对在组网时需要注意的问题进行研究,结合厂家设备...     

2G/3G网络IP化语音编解码协商策略部署研究

A接口IP化改造的规模部署,使2G/3G网络电路域具备了IP化语音实现TrFO的条件。本文针对A接口IP化后实现TrFO中遇到的问题,分析了统一编解码策略(GCP)部署的必要性。同时结合GCP测试中出现的问题,重点研究基于A接口IP化的GCP部署中面临的一些问题,并给出了相应的解决方案。     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-