10G1G共存以太网无源光网络的自适应动态带宽分配

近年来,以太网无源光网络(EPON)深受运营商的青睐,因其结合了以太网和无源光网络两种技术的优势,成为宽带接入网的最佳解决方案之一.但随着高带宽业务发展,如高清电视(HDTV)、视频会议等,传统的EPON技术在满足用户对带宽的需求这一方面显得无能为力;迫切需要新一代EPON技术一10G EPON,10G EPON-不仅传承了1G EPON的优点,而且带宽提高了10倍.但是,并非所有的接入网都需要升级为10G光纤链路,因为不同用户对于带宽的需求是不同的,因此1G EPON和10G EPON共存模式将在一段时间内长期存在.     

10G EPON宽带光纤接入网设计

在阐述10G EPON系统结构和技术特点的基础上,分析了10G EPON的应用场合,针对用户的带宽需求并结合今后的发展,提出一种基于10G EPON的FTTB+DSL接入网方案,对网络结构、光功率预算进行了设计与分析,并针对原EPON系统升级到10G EPON进行了详细说明,具有较高的可行性和优越性.     

2016将成10G PON规模部署关键一年

视频、游戏、4K电视、智能家居、物联网等业务高速发展,离不开宽带网络的支撑,同时这些业务对带宽的巨大需求也推动着宽带技术的进步. 对称型10G EPON将成主流 PON技术以提升带宽为主要目标,为高速宽带提供了强劲动力.目前EPON/GPON已广泛部署.但随着用户大容量、高带宽业务需求的高速发展,现有PON口带宽出现瓶颈,EPON和GPON已无法满足未来每户100M～1G的带宽需求.在当前诸多接入技术中,10G PON技术提供的带宽能力很好地匹配了未来用户的业务需求.     

10G EPON技术的研究与应用

分析了IEEE 802.3av工作组规定的10G EPON分层模型相对于1G EPON的改进,比较分析了10G EPON的技术优势,进而研究了现有1G EPON向10G EPON系统升级的过程和可能存在的技术瓶颈,提出了三种可分别运用在家庭、企业和移动基站中且支持高带宽网络服务的10G EPON组网模型,为将来10G EPON接入网系统的发展提供了参考.     

基于PON的时间同步技术

无线业务的迅速发展需要回传网络提供越来越大的带宽。PON作为可选的无线回传网络技术之一,得到了广大运营商的认可。而cdma2000,TD-SCDMA,LTE等无线技术都要求回传网络具有精确的时间同步能力。ITU-T已经发布了GPON/10G GPON的时间同步技术的标准,IEEE也即将发布EPON/10G EPON的时间同步技术标准。本文对GPON/10G GPON和EPON/10G EPON的时间同步技术标准进行了阐述和分析。     

中国电信千兆宽带接入网用户带宽模型探讨

当前,EPON/GPON作为宽带接入网的主要接入方式,当用户带宽速率持续提升的情况下,接入带宽往往不能满足需求.从E/GPON向10G PON网络升级演进中,本文根据10G PON新建、10G PON与EPON/GPON共存两种组网模式下的用户带宽模型计算,得出10G PON网络在建设中的用户带宽和最佳用户数配置,以确定增加PON带宽或降低分光比达到千兆宽带接入网建设的最佳选择,为千兆宽带接入建设、快速部署10G PON网络提供参考.     

10G EPON典型应用场景探索

2010年江苏电信在南通分公司和泰州分公司进行了10G EPON性能测试,并于2011年委派南京电信和苏州电信进行10G EPON的规模商用。FTTx是"城市光网"主要解决方案,而10G EPON技术可更快速提升现有网络带宽能力,更经济地建设优质的光纤接入网络。为了解决用户日益增长的带宽需求,增强对高清视频等新兴视频业务的承载能力,江苏电信积极引入10G EPON技术进行宽带提速建设,探索FTTx网络的演进方案,提升网络全业务运营的能力。     

EPON关键技术及其展望

无源光网络接入技术由于其支持高带宽和长距离等特性,将成为解决最后一公里问题的最佳方案.文章对以太无源光网络(EPON)的ONU自动发现、ONU测距、动态带宽分配等关键技术进行了分析和研究,最后对其技术发展方向10G EPON以及WDM-PON进行了展望.     

某小区千兆接入10G EPON建设方案

随着大流量、大宽带业务的开展和普及,每用户的带宽需求将会在50~100 Mbit/s之间,10G EPON技术的成熟有望解决现有EPON/GPON的PON口带宽瓶颈。文章通过实例列举出如何应用10G EPON技术满足用户未来高带宽的需求。     

10G EPON最新进展及在三网融合中的应用

随着三网融合的具体实施,用户对带宽的需求不断提升,10 G EPON作为下一代宽带接入技术备受关注。10 G EPON具备高带宽、大分光比、长距离的特点,满足＂三网融合＂后以视频业务为主的高带宽发展需求,满足FTTH、FTTB、FTTO、FTTN各种高带宽需求的应用场景,从10 G EPON的进展情况、10 G EPON的关键技术及其实际应用等几个方面进行了分析。     

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.     

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.     

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.     

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