潜在完成话务量与应配电路数

在电信网管理过程中，如何根据现有电路群的完成话务量、呼损率等话务参量估算在满足指定呼损率条件下的应配电路数是一个重要的实际问题。本文引入潜在完成话务量等定义，并利用初次式呼到达率计算公式给出了一种实用的潜在完成话务量与应配电路数的估算方法。此外，本文还分析了潜在完成话务量换算系数与电路群呼损率，应答占用比及平均有效占用时长等的关系。     

移动通信话务研究

本文对大量的移动话单的统计分析，发现移动通信话务的特有规律，在此基础上介绍如何确定网络忙时、小区忙时、用户平均忙时话务量、漫游话务量及话务密度，并提出将预测话务量合理地分配到各小区的方法。     

程控交换局间话务量设计中的几个问题

本文主要对程控交换工程设计中局间话务量计算的重要作用和话务基础数据的取定、话务量的递减率、不同种类话务流量的合群计算、单向中继和双向中继的话务计算、远端用户模块局话务计算中应注意什么问题等工程设计中容易忽略的几个问题作了较为详细的论述.     

长途电路实需电路数的计算

针对传统经验估算方法的不足，根据话务流的基本特性，结合话务量强度和话务峰值系数，利用等效随机方法的原理，采用迭代方法计算实需电路数，并实例显示该方法的优越性。     

一种基于组呼的话务量模型

为解决调度系统容量设计的难题,文章提出了一种以爱尔兰话务理论为基础的基于组呼的话务量模型,阐述了模型的原理与应用。该模型引入了组用户平均忙时话务量与归属组成员数量的概念,可以准确计算信道数量与终端数量的关系。     

移动通信话务研究

本文对大量的移动话单的统计分析,发现移动通信话务的特有规律,在此基础上介绍如何确定网络忙时、小区忙时、用户平均忙时话务量、漫游话务量及话务密度,并提出将预测话务量合理地分配到各小区的方法。     

用话务理论分析163计费数据

一般情况下我们了解用户上网习惯以及系统负载大多是通过估计，通过不定时地观察网络设备瞬间状态来获得，这样的数据往往缺乏说服力。如果使用话务理论统计163拨入服务中的话务流量，就可以得到科学准确的数据，这对于分析设备利用率，掌握用户上网规律，以及系统的维护与升级都有很大的帮助。我们数据通信局统计话务量的主要目的是分析端口占用情况，为拨号接入服务器扩容提供依据。1话务理论基础话务量又称话务负载或电话负载，它的定义是：在时间T内，终端流入交换系统的话务的数量。即：二m允。这里。是在时间T内，由用户终端i发出的…     

基于时间序列的移动通信话务预测

文章根据话务量时间序列，对比研究了自回归、指数回归和多项式拟合等话务预测技术。并结合实际话务进行了相关验证，得出了结论：基于实际话务时间序列的预测方法可以对移动通信网络的话务进行比较准确的预测。     

浅淡话务趋势与话务控制

本文就话务的一般趋势及话务控制的一般方法进行了探讨，并论述了资费等因素对话务量的影响，及如何确定网路指标的考核。     

半速率的建模研究

提出了一种基于二维马氏链的半速率话务模型,从理论上分析并计算了不同话务量时的阻塞概率、半速率承载话务比例及半速率的最佳开启门限.分析表明,随着半速率开启门限和话务量的增大,半速率信道承载话务量比例也将相应增加,从而会影响系统服务质量.文中提出的业务模型和分析方法为实际系统动态调整半速率开启门限提供了理论指导,所得到的不同载波数下、对应不同开启门限的最优话务量范围计算结果也可直接用于实际系统配置.     

Data Transfer for HIPERLAN

HIPERLAN offers a high speed (23.5 Mbit/s) radio LAN and therefore HIPERLAN is likely to support various kinds of traffic requirements. A Data Transfer function is in charge of handling various traffics which can result in simultaneous services. HIPERLAN nodes are not necessarily within direct radio range; and in some cases packets are forwarded by intermediate stations from the source node to the destination node. Since HIPERLAN is more than a single hop network, the support of specific traffics like Time Bounded traffics require a dedicated architecture which can not be centralized. This paper describes the architecture of the Data Transfer in HIPERLAN which allows the support of various traffics. This approach is not based on a connection oriented protocol nor on a centralized architecture but on a connection-less mode where users provide quality of services parameters to indicate its requirements. HIPERLAN architecture for data transfer is based on a mix of two main mechanisms: hierarchically independent priority levels and an earliest dead line first algorithm. This paper describes and explains the architecture choices made in HIPERLAN. Results of simulation and analytical models are given.     

TDMA时隙分配对业务时延性能的影响分析

 在TDMA通信系统中,时隙分配是影响业务时延性能的重要因素,包括时隙数量分配(带宽分配)、时隙分配周期(TDMA帧长)和时隙位置分配三方面.本文针对可变速率和固定速率两类业务,基于随机服务系统理论和交通流理论建立了业务时延模型,得到了平均时延的解析式,分析了时隙数量、时隙位置和TDMA帧长度对业务时延影响的规律和特点.结果表明时隙位置分配越均匀,越能改善业务的平均时延和时延抖动性能;而在传统的时隙连续分配方式下,增加时隙数量分配对时延性能提高非常有限.在DVB-RCS卫星系统等具有较长帧设计的TDMA系统中,采用时隙均匀分配方式能够有效提高业务时延性能.计算机仿真验证了建模分析的正确性.     

MPEG标准VBR视频业务新模型及其性能研究

迄今为止,MPEG-1标准下的可变比特率(VBR)视频业务建模问题还没有得到很好的解决.鉴于此,本文在分析这类业务统计特性的基础上,对这类业务提出了一种新的帧层模型.该模型可以很好地体现这类业务的一、二阶统计特性.通过使用该模型模拟实际视频信号,也显示了该模型在体现实际业务排队性能上的有效性.     

Gamma Poisson混合业务流的自相似性及排队性能研究

参考MMPP的构造过程,提出模型参数更为简化的Gamma Poisson混合模型,通过仿真计算的方法考查业务流的自相似性,研究分析单排机情况下的排队性能。经与几种典型模型的对比分析,结果表明,Gamma Poisson混合模型能更适合于对实际业务流的建模。     

Dimensionnement de bout en bout des réseaux téléphoniques hiérarchisés et combinaison des trafics

The author considers the problem of determining the individual loss probabilities of each traffic stream in a hierarchical network operated as a loss system in the case of arbitrary call holding time distribution. He shows that, in order to separate out the distribution function of each traffic stream, it is necessary to modify not only the arrival processes but also the call holding time distribution functions. The usual concept of «traffic source», which is convenient for isolating a part of the network, no longer applies. Therefore care must be exercised when applying approximate occupancy distribution moment matching methods. «Pseudo — Poisson» traffics are shown to combine in «weighted» sums of pseudo-Poisson traffics. The weighting coefficients are boundary values having different properties and are directly related to end to end blocking probabilities.     

Performance analysis of modified accelerative preallocation MAC protocol for passive star-coupled WDMA networks

For the passive star-coupled wavelength-division multiple-access (WDMA) network, a modified accelerative preallocation WDMA (MAP-WDMA) media access control (MAC) protocol is proposed, which is based on AP-WDMA. To show the advantages of MAP-WDMA as an adequate MAC protocol for the network over AP-WDMA, the channel utilization, the channel-access delay, and the latency of MAP-WDMA are investigated and compared with those of AP-WDMA under various data traffic patterns, including uniform, quasi-uniform type, disconnected type, mesh type, and ring type data traffics, as well as the assumption that a given number of network stations is equal to that of channels, in other words, without channel sharing. As a result, the channel utilization of MAP-WDMA can be competitive with respect to that of AP-WDMA at the expense of insignificantly higher latency. Namely, if the number of network stations is small, MAP-WDMA provides better channel utilization for uniform, quasi-uniform-type, and disconnected-type data traffics at all data traffic loads, as well as for mesh and ring-type data traffics at low data traffic loads. Otherwise, MAP-WDMA only outperforms AP-WDMA for the first three data traffics at higher data traffic loads. In the aspect of channel-access delay, MAP-WDMA gives better performance than AP-WDMA, regardless of data traffic patterns and the number of network stations.     

Individual Overflow and Freed Carried Traffics for a Link with Trunk Reservation

Two traffic streams Φ₁, Φ₂ are offered a link. The calls of Φ_i require exponential holding times with parameter μ and are accepted if less than C_i trunks are occupied. Approximating the Φ_i by appropriate renewal processes meeting their first two moments, defined as the moments of the numbers of calls in virtual links of infinite capacity to which the traffic streams as freed traffics are virtually directed and where the calls get fresh exponential i.i.d. holding times with parameter μ, stable recursive algorithms of complexity O(max (C₁,C₂)) are derived for the first two defined as above moments of the individual overflow and freed carried traffics. The results offer a unified handling of both overflow and carried traffics in circuit switched networks with trunk reservation, providing a basis for new two-moment network dimensioning algorithms.This work was supported by a grant from the Siemens AG.     

静态波带交换中的一种波带粒度取值算法

波带交换可以有效地减少波长交换的交换端口数量,本文研究节点间业务量已知时静态波带交换中的波带粒度取值算法,提出了基于k均值聚类的波带粒度取值算法。算法将业务量相近的业务分为一组,一组内的业务用相同粒度的波带装载,以提高波带的利用率。研究表明,在没有业务疏导的环境下,与其他方法相比,算法使用的波带数量和波带内的空闲波长数量都比较少。本文还研究了静态疏导环境下不同波带粒度取值算法的性能,提出了多波带粒度下的业务装载策略。对于大粒度的波带,使用向下装载,而对于小粒度的波带,使用向上装载,意在减少波带的使用数量的同时提高波带利用率。仿真结果表明,使用静态业务疏导后,本文算法与其他方法相比,依然可以有效地减少波带数量,提高波带利用率。与基于组播路由的静态波带疏导算法相结合,使波带利用率可以达到98%以上。     

Analysis of a model of two overflow traffic components with different serving intensities

This paper seeks to provide the analysis of a model of two overflow traffic components that originated from several Poisson traffics served by a common primary trunk group. Overflow parts of two of them are served in a secondary trunk group, but with changed and different serving intensities. The general solution of the system was obtained by generating function techniques, and call losses, time losses and traffic losses were defined based on state probability and solved numerically. In order to illustrate specific characteristics of the analyzed model, loss values were compared with the losses in a corresponding system with averaged serving intensity for which there is a much simpler explicit solution.     

基于OPNET的IPTV业务网络仿真与实现

IPTV业务体现了三网融合的要求。文中通过对IPTV业务及承载网络架构的研究,利用OPNET仿真软件对网络中jPTV的典型业务进行仿真,得出了网络模型中各主干链路流量的对比分析并讨论了流量差异化的原因,同时,给出了IPTV视频类业务和其它数据业务的流量分析。仿真结果表明,网络的设计方案是可行的,实现了IPTV的基本业务。