ATM业务流控制技术

业务流控制是ＡＴＭ的关键技术之一。业务警管和连接接纳控制构成了ＡＴＭ的业务流控制通过网络和用户共同签订并承诺履许的业务合约实现连接接纳控制，对于不同的业务类型其业务合约参数不同，具有相应的控制机制。业务流控制的国际标准化工作正在积极开展，１－ＴＵ－Ｔ建议的标准为１．３７１。     

ATM交换的优先控制方式

本文对采用ATM体制的宽带综合业务数字网业务流的优先控制进行了研究，提出了两种新的优先控制方法。     

多业务接入系统流量管理技术及其实现

通过分析基于ATM的多业务接入系统对流量管理的要求 ,对大唐电信光通信分公司开发的基于ATM的多业务接入系统 (LinkMasterA - 10 0 )中采取的流量管理技术 ,包括连接接纳控制、使用参数控制、加权公平排队、拥塞控制、帧丢弃、流量整形等算法及其具体实现进行了介绍与探讨     

基于静态流感知的接纳控制研究

维持链路正常负载是业务流性能指标保证的关键,接纳控制是链路负载有效控制方式。相对链路容量有固定业务区分速率界值的静态流感知接纳控制,应用与流拥塞状态相关的判决概率实现业务接入区分。同时,利用优先公平调度机制的隐性测量功能测量链路优先队列队长和链路公平速率值,共同对下游链路流承载状态进行评价,并作为接纳控制进行判决的依据。仿真显示,相对基于测量的接纳控制算法具有更好的链路状态自适应性和较高的链路资源效率。     

ATM业务流控制的一些有效方法

文章叙述了实现ATM业务流控制的一些可行的方法，即应用模糊控制技术来控制呼叫路由，用神经网络技术来预测输入业务流实现动态带宽分配控制、以及用神经网络技术实现业务呼叫的带宽分配控制。     

VBR业务下的ATM交换机缓冲策略研究

ATM交换机的缓冲信元是基于业务流的实时状态而动态赋值的,因此,不同类型的业务客观上对ATM交换机的缓冲器容量提出不同的要求。本文对可变比特速率(VBR)业务下的ATM交换机缓冲策略进行研究,并给出了计算机模拟结果。     

B-ISDN中的无连接业务

以ATM交换为基础的B-ISDN提供高速、面向连接、分组长度固定的信元交换.当代PC和高速LAN的发展需要面向连接的ATM网络传输无连接业务.本文重点介绍ATM网络中无连接业务的分类、协议结构和具体实现形式.     

ATM网的业务流控制

ＡＴＭ网络的拥塞现象是ＡＴＭ网推广运用过程中亟待解决的问题。本文对ＡＴＭ网中各种业务流控制方法进行了综述，包括呼叫／连接接纳控制，使用参数控制，选择性丢弃，反应式控制，业务流成形等。     

ATM网络业务量控制

ＡＴＭ网络的业务量控制是ＡＴＭ网中的关键技术之一。简要介绍了三种业务量控制的方法，即连接接纳控制、业务流警管和ＡＢＲ拥塞控制方法。     

ATM交换机IP业务优先级的设计与实现

ATM交换机由于执行了严格的基于连接的流量管理和拥塞控制,能为用户提供良好的QoS保证,在骨干网中得到了广泛应用。但如何解决IP业务优先级与ATM优先级的对应关系,及建立和撤除机制,是ATM交换机设计面临的重要问题。以ATM交换机无线ATM接口为例,对ATM交换机如何实现IP业务优先级与ATM优先级的对应,及建立和释放策略等方面,提出了一套完整的设计和实现方案。     

基于角色访问权限的运行故障管理系统

分析现有国内外的空管系统投入运行后的故障管理特点,借鉴基于角色的访问权限机制,提出了一种基于用户、角色和权限访问的空管故障管理系统的设计方法。通过构建基于角色权限的故障管理系统来支持空管系统对缺陷的收集、跟踪、处理和分析,为空管系统现场运行中的缺陷预防提供了有力的支持。     

自相似业务量的流量控制研究

由于自相似性是宽带网络中业务量的一个普遍特性,因此在进行宽带网络管理和流量控制时必须考虑它所带来的影响。目前,有关基于自相似业务量的流控机制的研究已经引起了人们广泛地注意。一些研究表明自相似业务量表现出了与传统模型不同的排队特征。本文围绕业务质量保证和流量控制机制,具体研究和分析了业务量的自相似性质对业务量成形、用法参数控制和呼叫接纳控制等流量控制机制的影响,并得到了一些重要结论。     

基于5G+原生体系的运营商流量中台分析

基于5G移动网络提出流量中台，具体介绍了流量中台的架构。流量中台高度抽象了5G连接管理和流量精确控制功能，简化运营商原有的复杂IT接口，并结合了数据的人工智能分析。它支持无线功能的开箱即用，解决5G工业互联网应用开发者繁杂的无线连接开发问题。     

Analysis of multi-hop traffic grooming in WDM mesh networks

Traffic grooming is an essential functionality of WDM optical networks to provision multi-granularity subwavelength connections. Depending on the number of lightpaths allowed in a connection route, traffic grooming can be classified as single-hop traffic grooming (SH-TG) and multi-hop traffic grooming (MH-TG). MH-TG is more general and resource-efficient than SH-TG, because it allows connections from different source-destination pairs to share the bandwidth of a lightpath. In this paper, we propose a MH-TG algorithm, namely the fixed-order multi-hop (FOMH) grooming algorithm, based on the fixed-alternate routing approach. We introduce the grooming node selection (GNS) problem in MH-TG and propose three grooming policies, namely exhaustive sequential (ES), limited-hop sequential (LHS) and load sharing (LS) policies, to address the GNS problem. These policies represent different trade-offs among blocking probability, computational complexity and transceiver requirements. Given that the analysis of MH-TG is a relatively unexplored area, we propose an analytical model to evaluate the blocking performance of MH-TG using FOMH and the LS grooming policy. To address the multi-layered routing and multi-rate connection characteristics of traffic grooming, we introduce a novel multi-level decomposition approach in our analytical model which decomposes traffic at four different levels, namely alternate path, connection route, lightpath and link levels. The model also addresses various factors that affect connection blocking probability. These factors include wavelength continuity constraint, channel continuity constraint and route dependence. The Erlang fixed-point approximation method is used to solve the analytical model. Numerical results show that analytical results match well with simulation results. We also evaluate the effect of the grooming policies, the number of virtual hops (lightpaths) within a connection route and the number of alternate paths on the performance of the grooming algorithm.     

Allocating point-to-point connections over point-to-multipoint optical channels

Optical channels are currently able to carry 10 Gbit/s and even 40 Gbit/s traffic flows. However, it is not usual to have such amounts of traffic between any pair of client nodes. This article proposes using point-to-multipoint optical channels for the allocation of point-to-point connections in transparent wavelength-routed optical networks. Specifically, when an optical connection between a source-destination node pair has to be established, the optical signal is also sent to some adjacent nodes by introducing passive optical splitters; in this way a light-tree is built. Then, the already established point-to-multipoint optical channel can be used to groom further point-to-point connections between the same source node and each of the other nodes composing the light-tree. The benefits of this strategy are 2-fold: first, the reduction of optical transmission equipments allowing cost savings with respect to the traditional typical point-to-point approach and, second, the optimization of the optical channels utilization meeting in such a way Traffic Engineering objectives. The merits of proposed approach are evaluated by simulation.     

一种城市交通出行掌务通系统的研究

介绍一种利用城市智能交通数据提供城市出行信息的系统,通过此系统,用户智能手机终端应用软件可以及时获取城市道路出行路线建议和周边实时交通信息,该系统是移动互联网技术与智能交通技术相结合的尝试性应用。     

Minimal Delay Traffic Grooming in WDM Optical Star Networks

All-optical networks face the challenge of reducing slower opto-electronic conversions by managing assignment of traffic streams to wavelengths in an intelligent manner, while maximizing the bandwidth resources utilization. This challenge becomes harder in networks closer to the end users that have insufficient data to saturate single wavelengths as well as traffic streams outnumbering the usable wavelengths. Traffic grooming has been proposed as a possible solution in the network closer to the end users. However, it requires costly traffic analysis at access nodes. We study the problem of traffic grooming that reduces the need to analyze traffic, for a class of network architecture mostly used by Metropolitan Area Networks; the star network. We first prove that the problem is NP-hard, then provide an efficient greedy heuristics that can be used to intelligently groom traffics at the LANs to reduce latency at the access nodes. Simulation results show that our greedy heuristics achieves a near-optimal solution.     

Benefits of Link Protection at Connection Granularity

This paper develops a connection establishment framework for protecting connections against single-link failures using link protection at the granularity of a connection, referred to as Connection Switched Link Protection (CSLP). As a connection is routed only around a failed link, the channel assignment for the connection on the backup path of the failed link must be consistent with that of the primary path. Such a consistency is guaranteed at the time of call admission. The advantages of employing link protection at the connection level is established by comparing its performance through extensive simulations against link protection at the granularity of a fiber, referred to as Fiber Switched Link Protection (FSLP). Link protection at the connection level is shown to significantly outperform that at the granularity of a fiber, specifically when some traffic requires protection while others do not.     

基于物联网技术的城市交通出行管理与服务体系研究

随着城市人口的增多和汽车数量的持续增加,交通堵塞现象日趋严重,由此引发了环境噪声、大气污染、能源消耗等严峻问题,为解决这些问题可从源头上进行思考。城市交通出行问题作为源头上的重要交通事件,对其进行深入研究、合理引导,将能有效改善城市交通问题。该文对交通出行的制约因素及其解决方法进行了综合分析,提出了基于物联网技术的交通出行解决方案,建立了面向交通出行管理与服务模型框架体系,通过对制约交通出行因素信息的全面采集,综合分析,实现对交通参与者的实时诱导与服务,从而提高公安机关交通管理与服务水平。