激光混沌外部调制包络隐藏及相位隐藏编码方法及其在光纤保密通信中的应用研究

该文研究光纤混沌包络隐藏与光纤相位隐藏保密通信理论模型,分析包络隐藏调制解调特性,导出解码公式;分析光纤自相位调制和光功率以及光放大器个数对系统的影响,提出接入相位控制器以减小非线性相移对同步解调负面影响的设想。数值模拟了调制速率0.2Gbit/s的混沌包络隐藏编码以及调制速率0.05Gbit/s的混沌相位隐藏编码及其在波长1.55m远程光纤数字保密通信中的应用,表明系统确具有较高的保密性能。     

几种全光逻辑门浅析

全光逻辑门是实现高速光分组交换、全光地址识别、数据编码、奇偶校验、信号再生、光计算和未来高速大容量全光信号处理的关键器件,本文介绍了几种基于半导体光放大器非线性效应的全光逻辑门,分析了它们的系统结构和工作原理,并对各自的特点进行了比较,展望了光逻辑门在未来的发展方向.     

GSM网络寻呼承载能力及突发应对策略分析

着重分析了GSM网络Um接口和Abis接口的寻呼承载能力,阐述了寻呼容量对位置区承载话务量的限制,以实例说明了寻呼量突发的特点,并提出了多种应对寻呼量突发的策略。     

MPLS发展前景

对ＭＰＬＳ的地位、作用、ＭＰＬＳ～Ｐ－ＰＮＮＩ、设计思想及内部机制等方面的不同论述作了归纳,以此展示了ＭＰＬＳ的发展前景。     

GaAs MESFET开关模型的研究

讨论了开关 Ga As MESFET的开态模型和关态模型 ,介绍了利用高频器件建模软件 Modelling建立 Ga As MESFET开关模型的方法 ,给出了模型模拟与器件测量的曲线和模型参数。     

光电电流互感器测试与校验方法

本文分析了光电电流互感器的测试与校验的方法,阐述了光电电流互感器的结构和工作原理,并对光电电流互感器的测试系统进行了研究,同时还对光电电流互感器的虚拟校验仪进行了说明,最后总结了光电电流互感器测试与校验方法的要点,旨在研究出适合光电电流互感器的测试发展,从而推动光电电流互感器的发展和应用.     

A novel distributed scheduling approach powered by central databases in optical burst networks

In terms of the growth rate, network capacity is slower than network traffic. To solve the mismatch between them, utilization of available capacity can be maximized to provide “best-fit” service for emerging applications (e.g., eBanking, Peer-to-Peer (P2P) file exchanges, etc.). To satisfy such a requirement, we propose a three-dimensional label scheduling algorithm (TD-LSA), which is a distributed scheduling approach powered by central databases. In the proposal, all connections are provisioned in three dimensions (i.e., space, time and wavelength) in a distributed way and uniquely identified by three-dimensional labels. And in this way a three-dimensional connection is more robust than a single-dimensional connection because the three-dimensional approach can avoid potential scheduling conflicts as much as possible by using central databases in a network. Thus, the central databases can reduce bandwidth consumption and offer “best-fit” service for three-dimensional connections. Furthermore, in order to further reduce bandwidth consumption and to match with a priority of traffic, K-least hop first path (K-LHPF) and a rescheduling mechanism are applied to our proposal. Simulation experiments demonstrate that our proposal achieves the expected performance gain against existing alternates.

Performance analysis of an improved soft preemptive scheme for unevenly distributed traffic in optical wavelength-division multiplexing networks

In optical wavelength-division multiplexing (WDM) networks, traffic can be unevenly distributed across the network causing inefficient utilization of resources. To solve this problem, an improved soft preemptive (SP) scheme is proposed by considering dynamic resource distribution to deal with the uneven network utilization. A novel unevenly distributed traffic model in cross-time-zone networks is also presented to evaluate the efficiency of the new scheme. Compared with other schemes such as normal shortest path first (SPF) routing and wavelength conversion (WC), the new proposed scheme results demonstrate significantly better performance with respect to the network utilization and overall network blocking probability.

连续波腔衰荡技术原理推导及实验研究

基于无源腔的Q值定义,根据能量守恒原理,对连续波腔衰荡技术测量原理进行了推导,并基于多光束干涉理论,就入射光关断时间对腔出射光强信号衰荡线形及测量结果的影响进行了数值模拟和分析,分析表明：入射光的关断时间很大程度上决定着腔出射光功率信号的衰减线形,如果要消除入射光关断时间对测量结果的影响,入射光关断必须小于腔衰荡时间的1%。根据理论分析要求建立了一套测量系统,并对腔损耗约为50ppm的低损无源腔进行了实际测量,实验结果的分析显示,该测量系统测量误差约为0．15ppm。     

近年西方国家通信网发展动态

首先说明西方国家通信网近年发展变迁情况，然后对IP与WDM的结合使用、光数据网的发展、密集波分多路的应用和光网中通路的保护4个主要方面作了具体说明。