上海热线的用户接入

文章重点介绍了上海热线的用户接入平台，使用的接入设备的特性以及普通电话接入、ＩＳＤＮ接入和ＤＤＮ专线接入的特点。最后还简单介绍了ＰＨＯＮＥＤＯＵＢＬＥ的接入方式。通过文章的介绍，读者可以对互连网的接入方式有一个大致的了解。     

利用数字数据网(DDN)建设湖北省农行综合业务网

本文讨论了ＤＤＮ网的特点、功能和用户接入方式，并具体介绍利用ＤＤＮ网建立专用的湖北省农行综合业务网络的实例以及相关技术     

通过ISDN接入Internet

通过介绍ＩＳＤＮ和Ｉｎｔｅｒｎｅｔ的协议，引出了通过ＩＳＤＮ接入Ｉｎｔｅｒｎｅｔ的业务，说明ＩＳＤＮ接入Ｉｎｔｅｒｎｅｔ比传统的接入方法更为优越。     

威海DDN本地网及用户接入方式

本文从威海ＤＤＮ本地网的实际制世与配置出发，面向网络建设介绍ＤＤＮ本地网规划 、建设、发展的策略，以及威海ＤＤＮ本地网、公用ＤＤＮ网提供的业务功能和用户层终端接入方式。     

ISDN与公用分组交换网的互通（下）

ＩＳＤＮ与公用分组交换网的互通（下）□张国宏赵慧玲杜森２ＩＳＤＮ与ＰＳＰＤＮ互通的实现方法２．１两种实现方法前面介绍了分组方式终端接入ＩＳＤＮ的两种方式，即方式Ａ和方式Ｂ。对于方式Ｂ，ＰＨ的实现有两种方法：一种方法是ＰＨ模块驻留在ＩＳＤＮ交换机内部，...     

广东省宽带数据通信实用试验网高速数据接入新技术

本文介绍了广东省邮电管理局宽带数据通信实用试验网中采用的几种高速数据接入技术，包括Ｎ－ＩＳＤＮ接入，ＡＤＳＬ接入和Ｃａｂｌｅｍｏｄｅｍ接入，并对其关键技术进行简要介绍。     

公用DDN业务功能及用户接入方式

本文从我国公用ＤＤＮ的实际制式与配置出发，面向专线或专网建设的决策者介绍公用ＤＤＮ提供的业务功能和用户层终端接入方式。     

AN—2000：一种新型的带V5接口的综合接入系统

介绍ＡＮ－２０００是一个比较完善的综合接入系统，现已能提供ＰＯＴＳ，ＤＤＮ、２／４Ｗ Ｅ＆Ｍ，ＩＳＤＮ接口（２Ｂ＋Ｄ，３０８＋Ｄ），子速率复用等综合业务接入，同时新的业务接入模块也正在不断推出；并且将ＡＮ－２０００与交换机远端模块的几个方面进行了比较。最后简介ＡＮ－２０００与Ｆ－１５０、Ｓ－１２４０的对接实验。     

CATV与综合业务数字通信

ＣＡＴＶ有能力提供电话和数据服务，有线电视分配与电视ＩＳＤＮ接入集合到户是实现宽带综合网络的便利途径，本文考虑了ＣＡＴＶ／ＩＳＤＮ结合的方法，ＩＳＤＮ主速率时分多址接入方式以及用户接口的规格。     

中兴ISDN的数据通信业务

文章简述了ＩＳＤＮ的概念及中兴ＩＳＤＮ数据通信网组成，介绍了通过中兴ＩＳＤＮ接入Ｉｎｔｒｎｅｔ分组网及ＤＤＮ等数据通信业务的方法。     

全面接入：面向未来的马可尼接入方案

马可尼的全面接入解决方案包括4个主要部分：Deep Fiber‘Advanced Copper、Skyband无线产品和ServiceOn接入管理系统。马可尼公司在接入领域的领先地位得益于它在过去一段时间内的成功收购以及在固定和无线技术方面各界的丰富经验。     

浅谈无线接入技术

无线接入技术可分为模拟无一接入技术和数字无线接入技术,数字无线接入系统又有多种解决方案,包括数字直接扩频技术、ＧＳＭ、ＣＤＭＡ、ＤＥＣＴ、ＰＨＳ和ＳＣＤＭＡ等。     

面向"光进铜退"的固网3G新一代FTTx光接入平台

“光进铜退”是固网发展的趋势,FTTH是固网发展的终极目标,xPON技术是实现“光进铜退”和综合业务接入的最佳选择。自上而下的网络融合不断推进,“后网络智能化时代”接入层网络演进将是部署的重点。描述了面向“光进铜退”的中兴通讯新一代FTTx光接入平台在新通信环境下的应用优势。     

Update-Based Cache Access and Replacement in Wireless Data Access

Cache has been applied for wireless data access with different replacement policies in wireless networks. Most of the current cache replacement schemes are access-based replacement policies since they are based on object access frequency/recency information. Access-based replacement policies either ignore or do not focus on update information. However, update information is extremely important since it can make access information almost useless. In this paper, we consider two fundamental and strongly consistent access algorithms: poll-per-read (PER) and call-back (CB). We propose a server-based PER (SB-PER) cache access mechanism in which the server makes replacement decisions and a client-based CB cache access mechanism in which clients make replacement decisions. Both mechanisms have been designed to be suitable for using both update frequency and access frequency. We further propose two update-based replacement policies, least access-to-update ratio (LA2U) and least access-to-update difference (LAUD). We provide a thorough performance analysis via extensive simulations for evaluating these algorithms in terms of access rate, update rate, cache size, database size, object size, etc. Our study shows that although effective hit ratio is a better metric than cache hit ratio, it is a worse metric than transmission cost, and a higher effective hit ratio does not always mean a lower cost. In addition, the proposed SB-PER mechanism is better than the original PER algorithm in terms of effective hit ratio and cost, and the update-based policies outperform access-based policies in most cases     

Access Control Policy Analysis and Access Denial Method for Cloud Services

Personal cloud computing is an emerging trend in the computer industry. For a sustainable service, cloud computing services must control user access. The essential business characteristics of cloud computing are payment status and service level agreement. This work proposes a novel access control method for personal cloud service business. The proposed method sets metadata, policy analysis rules, and access denying rules. Metadata define the structure of access control policies and user requirements for cloud services. The policy analysis rules are used to compare conflicts and redundancies between access control policies. The access denying rules apply policies for inhibiting inappropriate access. The ontology is a theoretical foundation of this method. In this work, ontologies for payment status, access permission, service level, and the cloud provide semantic information needed to execute rules. A scenario of personal data backup cloud service is also provided in this work. This work potentially provides cloud service providers with a convenient method of controlling user access according to changeable business and marketing strategies.     

Performance Analysis of Cognitive Radio Spectrum Access with Different Primary User Access Schemes

The cognitive access process based on different access schemes of the primary user in the spectrum sharing system of cognitive radio is studied. In the cognitive system with finite user population, the primary users access the licensed channels through random access, real-reservation access, pseudo-reservation access and non-random access. The cognitive users access the licensed channels without interfering the primary users. Their access process is modeled using the three-dimensional continuous Markov model. The performance analysis is presented with variation of the number of cognitive users. It is known from the simulated results that the handoff probability, the blocking probability and the forced termination probability of the cognitive users increase with the increase of the number of cognitive users. It is also found that the random access scheme has the highest handoff probability. And the real-reservation access scheme has the highest blocking probability and forced termination probability. In addition, the non-random access scheme has the maximum channel utilization.     

用户接入网技术和天津建设用户接入网方案的建议

对用户接入网技术和基本结构进行了讨论，并在此基础上对天津市用户接入网的建设方案提出了建议。     

基于访问控制日志的访问控制策略生成方法

为解决其他访问控制机制向基于属性的访问控制机制迁移过程中所面临的策略生成问题,该文提出一种基于访问控制日志的访问控制策略生成方法,利用基于机器学习分类器的递归属性消除法实现策略属性的选择,基于信息不纯度从日志记录中提炼出蕴含的属性-权限关系,结合实体属性选择的结果,构建策略结构树,实现基于属性的访问控制(ABAC)策略...     

无线接入技术及宽带IP无线移动接入网

介绍几种主要的无线接入技术。阐述宽带IP无线移动接入技术。     

Performance Analysis of Random Access Packet-Switched Code Division Multiple Access Systems

Analytical techniques for performance evaluation of synchronous random access packet switching in code division multiple access (CDMA) systems are presented. Steady-state throughput characteristics using several packet generation models are obtained. A number of example random access CDMA systems are compared in terms of their throughput versus offered traffic and utilization-delay characteristics. Numerical results indicate that appropriate use of multiaccess coding can provide utilization-delay characteristics superior to that of ALOHA. System stability is evaluated using a general finite user model, and the dynamic behavior of some example random access CDMA schemes is investigated.