Scheduling of frequently communicating tasks

Gang scheduling is an efficient resource management scheme for distributed systems which combines elements of time sharing and space sharing. It is a suitable technique particularly in the case when parallel tasks have to be running concurrently to make progress in communication. This paper studies the impact on scheduling performance when dynamically generated sequential gangs exist in the workload. In the case of sequential gangs, a subsequent gang can be dynamically generated after the execution of the initial gang based on affinity information which resides on the caches of the previously seized processors. The performance of different gang‐scheduling algorithms is examined for various cases of workload compositions which range from cases with a low demand for dynamically generated gangs to cases with a high ratio of sequential gangs to solitary gangs. A simulation model is implemented to address associated performance issues. Copyright © 2011 John Wiley & Sons, Ltd.     

卫星通信系统安全技术综述

由于空间环境的特殊性,地面网络中的安全机制不能直接用于卫星通信.介绍了卫星通信系统安全技术的最新进展.首先从空间信道环境、卫星节点能力、星座网络结构等方面指出了卫星通信系统的安全弱点.然后总结了物理层、数据链路层、网络层和传输层所面临的安全威胁和防护对策.着重介绍了抗损毁技术、抗干扰技术、认证机制和密钥管理协议,并对有代表性的安全策略进行了分析、对比和讨论.最后对卫星通信系统安全技术发展方向做出预测.     

基于微纳光纤的通信器件研究进展

详细介绍了基于不同种类微纳光纤的光源、光耦合器、光开关和滤波器的结构、工作过程及性能参数,总结了基于微纳光纤的光纤通信器件的研究进展情况。指出微纳光纤器件的实用化是光纤通信器件的发展方向。     

New Type of Y-junction Hybrid Polymer Waveguide Couplers

Optical couplers are the key components for signal distribution in optoelectronic transmitters and receivers. A new low-loss, large-angle Y-junction hybrid polymer optical coupler with an integrated microprism has been fabricated and demonstrated experimentally for use in a mixed-signal module environment. The results show that the radiation loss is small with relatively wide branching angle as compared to a conventional Y-junction coupler.     

电信重组后,湖北省移动通信的发展策略

邮电分营后，中国电信面临着资产重组和机构调查，中国移动通信公司作为专业化公司直接面向市场，与中国联通及国外公司一起参与市场竞争。如何发展湖北省ＴＡＣＳ、ＧＳＭ、ＣＤＭＡ第三代移动通信系统，是一项重要的研究课题。本文就此论述，并提出移动通信网的智能化以及与ＩＳＤＮ相结合等综合发展设想。     

地铁中的移动通信系统

提出了地铁专用移动通信系统的功能要求；介绍和分析了一个满足系统功能要求的集群方案；另外还简单介绍了地铁公用移动通信引入系统。     

The Analysis of Frequency Reuse Irregular Patterns in Mobile Telephone Network

Some frequency reuse irregular patterns in radionetwork design are proposed,the characteristic and applica-tion measures of these patterns are analyzed.Then this paperaccounts that frequency reuse irregular patterns is a usefulway to impove spectrum efficiency and it is significative forartificial intelligence to be applied in this field.     

基于DCC+OSPF协议的光网络组网技术研究

提出了一种基于DCC+OSPF协议的光网络组网技术方案,分析了该方案的关键技术并给出了实现方法,最后对该组网技术进行了验证,试验结果表明该技术方案是正确可行的。     

Preparation and tomographic reconstruction of an arbitrary single-photon path qubit

We report methods for preparation and tomographic reconstruction of an arbitrary single-photon path qubit. The arbitrary single-photon path qubit is prepared losslessly by passing the heralded single-photon state from spontaneous parametric down-conversion through variable beam splitter. Quantum state tomography of the single-photon path qubit is implemented by introducing path-projection measurements based on the first-order single-photon quantum interference. Using the state preparation and path-projection measurements methods for the single-photon path qubit, we demonstrate preparation and complete tomographic reconstruction of the single-photon path qubit with arbitrary purity.     

光通信中高科PCM设备的分析与优化配置

文中给出了电力通信网中光通信的连接方式与光通信网的整体结构拓扑图。光通信中的核心部件PCM设备,其主要功能是处理光通信中的主要业务。通过分析PCM设备的板卡特性,进而对其应用进行了配置和分析。通过比较不同的测试方法,分析不同方法的优劣,得出较好的测试方法。