动态网络资源分配系统及其工程实现

随着移动通信业的发展,运营企业之间竞争程度的提升,话务拥塞现象越发突出,影响了网络的正常运行和用户对移动服务的满意度。本文提出了利用动态网络资源分配的方法来解决部分拥塞小区话务函数"负相关性"的问题,并具体阐述其实现的全过程。     

路由阻塞的预防和处理

介绍了电话交换网络发生话务拥塞的原因及作为NEAX61交换系统维护人员对NEAX61交换网话务络拥塞的预防和控制,对几种话务拥塞的处理方法进行了举例说明。     

浅谈Overlaid/Underlaid子小区在网络优化中的作用

从网络优化中出现的常见问题出发，分析了Overlaid/Underlaid子小区的技术特点并举例说明如何利用其实现频率的紧密复用，从而解决网络拥塞，达到增加话务容量的目的。     

tatelBTS基站载波搬移实施办法

在移动通信网络优化中,话务拥塞是主要问题之一。要解决话务拥塞,除了在建站时要合理选址,根据话务量配置适当的信道外,基站建成后的日常维护也是很重要的。首先要保证设备和信道的完好率,其次均衡基站间和基站内部小区间话务分配也不容忽视。本篇所要讲述的是,由于...     

GSM系统小区话务调整

本文主要就MOTOROLAGSM系统从硬件和软件参数两方面对小区话务调整作一些讨论 ,提出一些解决TCH拥塞的方法 ,希望能给维护相同网络以及其他GSM网络的工程师有所参考     

WCDMA网络高话务量场景下的优化措施

随着WCDMA网络的不断完善,用户的不断增加,在人口密集的地方出现高话务量的场景下,从而导致不同程度的网络拥塞。特别是在一些大型集会场所高话务量场景,如何解决高话务增长,防止网络拥塞。现结合日常保障工作中遇到的高话务量问题,分析网络容量相关资源、网络负荷功能性等来进行解决网络在高话务量冲击下的优化,为今后更进一步的做好WCDMA网络通信保障工作打下基础。     

随州GSM网络优化方案浅析

近年来，湖北随州的GSM用户发展迅速，已具备一定规模，对网络系统的质量要求也越来越高。一方面，随着网络规模的不断扩大，出现了许多问题：如话务信道(TCH)拥塞率高、呼叫成功率低、切换成功率低、掉话严重、中继电路配置不当及频率规划和参数设置不合理等，这些问题严重制约了GSM移     

解决GSM小区拥塞的方法

分析了GSM小区拥塞问题，提出解决拥塞问题的几种方法。     

CDMA网络掉话、话务拥塞的原因及解决办法

网络优化是一个非常重要的工作，同时又是一个不断进行的过程，它的好坏直接影响着各运营商的利益。在网络优化过程中，掉话和话务拥塞的优化尤为重要。本针对CDMA网络中的这两类问题的产生原因进行了详细的探讨，并提供了一些实用的解决办法。     

基于市场营销政策变化的网络应对策略

市场营销政策的变化影响用户的话务行为。会导致网络短时期拥塞和话务流失。文章着重介绍了几种有效吸收话务量和最大限度利用现有网络资源的主动应对策略。     

城市网络交通突发事件应急方案

随着我国城市现代化水平的不断提高和经济的快速发展,交通供需矛盾日渐突出,道路交通网络十分脆弱,一旦发生突发事件,极易引发大面积交通拥堵甚至瘫痪,这将引发严重的社会危害。因此,研究突发事件下城市路网交通应急方案具有重要意义。本文在BA网络模型的基础上重现突发事件下的交通拥堵的形成过程,收集形成过程中产生的各项特征参数,分析交通拥堵的形成机理。最后,提出了应对突发事件下交通拥堵的交通路径策略,从而降低突发事件对网络交通的影响。     

最小化路径代价和流量均衡模型及算法

流量均衡是流量工程中为避免网络拥塞经常采用的路由优化目标,如何选择路径以使流量达到均衡分布是流量路由的研究热点和难点.为了最小化网络拥塞,该文在指出网络拥塞决定于流量路由时所选路径的拥塞特征后,建立了流量分布的最小化路径代价和模型.在流量路由选择路径时,提出基于瓶颈链路的最小代价路径路由算法.在实际的网络拓扑和流量矩阵数据基础上对所提模型及算法进行了实验验证,结果显示:在网络负载较大时最大链路利用率相对于已有模型可降低近20%.     

Efficient and adaptive congestion control for heterogeneous delay-tolerant networks

Detecting and dealing with congestion in delay-tolerant networks (DTNs) is an important and challenging problem. Current DTN forwarding algorithms typically direct traffic towards more central nodes in order to maximise delivery ratios and minimise delays, but as traffic demands increase these nodes may become saturated and unusable. We propose CafRep, an adaptive congestion aware protocol that detects and reacts to congested nodes and congested parts of the network by using implicit hybrid contact and resources congestion heuristics. CafRep exploits localised relative utility based approach to offload the traffic from more to less congested parts of the network, and to replicate at adaptively lower rate in different parts of the network with non-uniform congestion levels. We extensively evaluate our work against benchmark and competitive protocols across a range of metrics over three real connectivity and GPS traces such as Sassy [44], San Francisco Cabs [45] and Infocom 2006 [33]. We show that CafRep performs well, independent of network connectivity and mobility patterns, and consistently outperforms the state-of-the-art DTN forwarding algorithms in the face of increasing rates of congestion. CafRep maintains higher availability and success ratios while keeping low delays, packet loss rates and delivery cost. We test CafRep in the presence of two application scenarios, with fixed rate traffic and with real world Facebook application traffic demands, showing that regardless of the type of traffic CafRep aims to deliver, it reduces congestion and improves forwarding performance.     

利用用户移动提高WiFi业务分担能力的用户激励机制研究

WiFi网络可以分担蜂窝网络的通信业务压力,缓解其拥塞状况。然而,WiFi网络的业务分担只能在其覆盖范围内进行。由于用户具有移动性,如果通过提供一些奖励引导WiFi网络覆盖范围之外的用户延迟其在蜂窝网络中的业务、直至其进入WiFi覆盖区再接受服务,WiFi网络的业务分担能力将得到显著提升。该文探讨了运营商通过激励机制鼓励用户延迟其蜂窝网络业务转而接入WiFi网络的过程,并将其建模为两阶段斯塔克博格(Stackelberg)博弈。在该博弈中,运营商期望采取最优的奖励方案,能够兼顾蜂窝网络拥塞和付出的用户奖励。该文推导出了运营商的最优奖励方案。数值结果表明,所提激励机制可以有效降低包括蜂窝网络拥塞代价和奖励用户代价在内的运营商总代价。     

基于时延耦合映象格子的相继拥堵模型

实际网络中由于拥塞、带宽、传输速度等因素,通常存在耦合时延。该文提出一种带时延耦合映象格子的相继拥堵模型,在此基础上研究交通路网上各个节点的非线性动力学特征,交通拥堵在路网上的形成机理与传播的复杂动力学行为,拥堵故障在网络中扩散的过程。模拟网络中随机发生拥堵和蓄意攻击所引发的两种相继拥堵策略,并推导出网络中故障承受能力的阈值范围。     

Threshold-based congestion control for the SS7 signaling network inthe GSM digital cellular network

This paper considers the congestion control scheme for the SS7 signaling network in the group special mobile (GSM) digital cellular network. This congestion control scheme is based on monitoring the SS7 link buffer occupancy. In this scheme, a congestion onset message is sent to the user parts of the SS7 network when the buffer occupancy exceeds a certain threshold, and, subsequently, a congestion abatement message is sent when the buffer occupancy goes below another threshold. Upon receipt of the congestion onset message, the user parts are expected to “intelligently” throttle the user traffic (reduce the traffic rate) so as to yield speedy recovery from congestion. Subsequently, on receipt of the abatement message, the user traffic is restored to precongestion levels. This paper primarily proposes appropriate choice of throttles and an algorithmic procedure to size the thresholds so as to yield good performance during congestion. The paper also addresses some implementation issues related to the throttles. Finally, it considers the effects of delays for the onset and abatement messages in reaching the user parts on the performance and parameters of the congestion control scheme     

The frequency of CFVD speed report for highway traffic

The control signals of cellular networks have been used to infer the traffic conditions of the road network. In particular, consecutive handover events are being used to estimate the traffic speed. During traffic congestion, consecutive handover events may be rare because vehicles move slowly, and thus very few or no speed reports would be generated from the congested area.However, the traffic speed report rate during traffic congestion has not been investigated in the literature. In this paper, we present an analytic model to estimate the speed report rate from cellular network signaling in steady traffic conditions, that is, the traffic speed and flow are assumed constant. Real field trial data were used to validate our analytic model. In addition, computer simulations were conducted to study how speed reports are generated in dynamic traffic conditions when traffic speed and flow change rapidly. Our study indicates that in a typical cell of length 1.5 km with a typical expected call holding time of 1 min, no speed report was generated from a congested three‐lane highway. Our study demonstrates that the lack of speed reports from consecutive handover events during rush hours indicates severe traffic congestion, and new methods that can estimate traffic speed from cellular network data during severe traffic congestion need to be developed. Copyright © 2013 John Wiley & Sons, Ltd.     

An analysis of the congestion effects of link failures in wide areanetworks

The authors present the results of a study to determine the effects of link failures on the performance of a network in terms of the occurrence of congestion due to traffic restoration after a failure. The network studied is a virtual circuit based packet switched wide area network. A generic queueing framework is developed to study the effect of failures and the subsequent traffic restoration on network performance. In general, the congestion resulting after a failure is a transient phenomenon. Hence, a numerical methods based nonstationary queueing analysis is conducted in order to quantify the effects of failures in terms of the transient behavior of queue lengths and packet loss probabilities. A bounding relationship is developed whereby a network node can determine whether or not congestion will occur as the result of traffic restoration after a failure     

业务优先级感知的网络流量调度机制

针对网络中业务数据流过大、分布不均匀所造成的网络拥塞,提出一种优先级感知的动态网络流量调度机制.利用令牌桶算法,根据业务优先级的不同为不同业务分配不同速率的令牌,以实现业务优先级的划分;综合考虑业务的优先级及用户节点剩余缓存空间,对不同的业务采取不同的处理方式;同时,以流量到达因素、服务因素及节点缓存为指标定义了一种网络流量调度机制性能指标——分组丢失率.数值结果表明,所提机制可以对网络中业务优先级进行合理的划分,从而有效利用网络资源,预防网络拥塞,提升网络性能,为用户提供更加稳定可靠的网络服务.