Hose不确定模型下一种新的动态选路算法研究

该文讨论了全连接结构的光交换网络在Hose不确定模型下的动态选路问题,并基于Valiant负载平衡机制,提出了一种新的动态选路算法.分配系数可调的负载平衡选路算法(Load Balancing with Adjustable Distribution Fraction, LBADF)。LBADF算法根据网络中各条链路上空闲光路的数目对Valiant负载平衡机制中的分配系数进行动态的调整,从而达到优化网络性能的目的。计算机仿真表明LBADF算法相对于分配系数恒定的VLB算法具有更小的全网呼损率,同时也相应地降低了全网中所有节点对的最大呼损率。     

WDM网状网中鲁棒选路算法研究

研究了WDM网状网在hose业务模型下基于Valiant负载平衡的鲁棒选路问题。借助业务量疏导的方法,以hose模型吞吐量最大化为优化目标,采用整数线性规划（ILP）加以解决,进而提出了2种快速的启发式算法——最短路径选路的最小跳数优先（SPR＆MHF）算法和平衡选路的最小跳数优先（BR＆MHF）算法。计算机仿真表明,SPR＆MHF算法适用于链路数较少的小规模WPM网状网,而RR＆MHF适用于链路数较多的大规模WDM网状网。     

WDM网状网中支持业务量疏导的区分共享保护算法

该文综合考虑WDM网状网生存性及业务量疏导,采用部分光路共享保护机制为低速业务提供满足其可靠性和带宽需求的连接,提出了一种基于波长分层图的支持业务量疏导的区分共享保护算法—部分共享保护业务量疏导算法PSPTG(PartialShared-pathProtectionalgorithmsupportingTrafficGrooming)。仿真结果表明:该算法可以较好地利用资源。     

一种基于区域划分的虚拟网映射新算法

目前多数启发式虚拟网映射算法是通过在限制性约束条件上构建映射优化目标函数,从而求得虚拟网映射次优解,存在映射匹配方程求解复杂、计算开销大、缺乏具体路径选择方法等问题.该文基于负载平衡路由和小区分结构的思想设计一种虚拟网映射算法VLB-VNE(Valiant Load-Balancing-Virtual Network ...     

WDM网状网中基于共享风险链路组限制的业务量疏导算法

该文研究了业务量疏导WDM网状网中如何建立可靠的业务连接问题,提出一种新的基于共享风险链路组(SRLG)限制的共享通路保护算法。该算法既可以保证用户业务不同的可靠性要求,同时又能够有效提高全网的资源利用率,从而大大降低全网的业务阻塞率。该文还对所提算法进行了仿真研究,并给出了仿真结果。     

网状WDM网中双链路失效的共享路径保护设计

该文研究了WDM网状网中双链路失效问题,在假定所有链路共享风险链路组(Share Risk Link Group, SRLG)分离的条件下,提出了一种动态共享路径保护(Dynamic Shared-Path Protection,DSPP)算法。DSPP能根据网络状态动态调整链路代价,为每条业务请求选择一条最小代价的工作路由和两条最小代价且SRLG分离的保护路由。仿真表明,DSPP不仅能完全保护双链路失效,并且能在资源利用率、阻塞率和保护切换时间之间进行性能折衷。     

WDM网状网中基于光连接抗毁业务量疏导保护算法

研究了WDM网状网中基于光连接(connection)的抗毁业务量疏导通道(path)保护问题,以最大化网络的吞吐量为目标,提出了新的基于共享风险链路组(Shared Risk Link Group,SRL G)的共享保护算法和专用保护算法.并以NSFNET为仿真网络,比较说明了这两种算法在网络拥塞率和波长利用率方面的性能优劣.     

WDM网状网中一种新的考虑优先级的共享通路保护

研究了WDM网状网中考虑优先级的共享通路保护问题,综合考虑了负载均衡、资源利用率和路由跳数的影响因素,提出了一种新的动态共享通路保护LRP-SPP启发式算法.仿真实验表明LRP-SPP不仅能使网络业务更均衡,资源利用率更少,而且可满足不同优先级业务的需要.     

IP/MPLS over WDM网中考虑链路 负载平衡的保护设计

利用网络链路资源被占用的部分信息实现保护资源共享,可以极大地改善网络对业务的丢弃性能.这对采用多协议标记交换(MPLS,Multiprotocol Label Switching)技术的IP over WDM网络来说,并不需要太大的代价.基于此,本文提出了在IP over WDM网中考虑通路保护的动态路由算法.对工作通路的选取,算法对选路成本和路由长度作了折衷考虑;而对于保护通路,则对其共享能力和路由长度作了权衡.仿真结果表明,本文算法不管是对业务的丢弃性能,还是对网络的链路负载平衡度,均取得了较满意的结果.     

网状WDM网中的共享通路保护设计算法

本文研究了网状WDM网中的SRLG(Shared Risk Link Groups:共享风险链路组)分离约束下的静态共享通路保护设计问题－给定网络物理拓扑、业务量需求矩阵和工作路由,为每个波长需求确定保护路由,使得所需的备份资源最小.这个问题可以用整数线形规划公式来描述.由于这是一个NP-C问题,因此,本文提出一种启发式算法MSC(Maximally Share the Capacity)加以解决,该算法的核心思想是改变链路权重使得保护路由之间尽量共享资源.仿真结果表明,本文算法能有效地降低所需的备份资源,提高了网络的资源利用率.     

MPLS负载均衡实现技术

负载均衡是MPLS流量工程的一项重要应用,论文基于对负载均衡工作原理的分析,提出了一种在ATM交换机中的实现方法。     

Lateral Wolf Based Particle Swarm Optimization (LW-PSO) for Load Balancing on Cloud Computing

Wireless Personal Communications - Cloud services are rapidly evolving and has become a demand. Consequently, Load Balancing (LB) is needed to enhance the use of resources by optimal distribution...     

考虑负载均衡和用户体验的垂直切换算法

在超密集异构无线网络中,针对城区交通高峰期,大规模车载终端短时间聚集性移动引起的网络拥塞问题,该文提出一种考虑负载均衡和用户体验(LBUE)的垂直切换算法。首先,引入网络环境感知模型预测网络未来的拥塞程度,并提出一个融合自组织网络的网络架构,缓解网络拥塞。其次,定义业务适应度和负收益因子,并提出一种基于秩和比(RSR)的自适应切换判决算法,为用户筛选出当前环境下满意度最高的目标网络。实验结果表明,该算法能够有效降低终端接入网络的阻塞率和掉话率,实现网络间负载均衡并提升用户体验。     

基于临界触发的LTE负载均衡算法

考虑LTE用户信噪比,借助物理资源块的服务能力推算小区负载的变化状态,提出的CTLB算法能够动态地根据每个小区的负载,自动计算需要进行用户转移的小区。引入均衡因子,使所有小区最终达到预先设定的收敛目标,从而有效利用网络资源。最后,通过MATLAB搭建了一个仿真平台,验证算法的收敛性能、过载用户数及小区吞吐量的变化情况。     

Ring Protection and Survivability Mechanisms for Packet Transport Networks

Packet Transport Networks (PTNs) must resolve issues in their protection and recovery mechanisms. These issues include the detection performance of Operation, Administration and Maintenance (OAM), network resource optimization, resource allocation deadlock, and resource deployment blocking. Traditional protection and recovery mechanisms cannot meet the requirements of PTN. In order to improve the protection and recovery performance, network resource use, probability of service recovery, and to decrease the probability of service blocking, this paper introduces overlapped segment shared protection, Pre-configured Multi-Cycle (P-mcycle),conflict-free algorithm, and delay restoration algorithm. Only with appropriate protection and restoration mechanisms is it possible to achieve smooth evolution from TDM networks to integrated packet-based bearer networks and all-IP services.     

A load‐balancing and coding‐aware multicast protocol for mobile ad hoc networks

In this paper, we propose a Load‐Balancing and Coding‐Aware Multicast (LCM) protocol for mobile ad hoc networks. In LCM protocol, a new route metric named Expected Transmission Time with Coding and Load Balancing (ETTCL) is presented at first, aiming at effectively selecting the path not only that has the possible coding opportunity but also where overflow due to network overload can be prevented. Then, we describe the route discovery phase by constructing the node‐disjoint multicast tree on the basis of ETTCL and employ network coding to encode the data flows for route maintenance. The effectiveness of LCM protocol is simulated and analyzed by NS‐2, which shows that this protocol has good performance in reducing average end‐to‐end delay and control overhead and can improve packet delivery ratio compared with the existing protocol. Copyright © 2015 John Wiley & Sons, Ltd.     

ρp-Cycle based tree protection of optical multicast traffic for combined link and node failure recovery in WDM mesh networks

The extension of the p-cycle concept to tree protection enables p-cycles to protect the multicast traffic for combined link and node failure recovery. In this paper, we present an efficiency-score based heuristic algorithm of p-cycle based tree protection (ESHT). Simulation results show that the capacity efficiency of ESHT is close to that of optimal path pair (OPP) algorithm, while the blocking performance of ESHT is in between OPP-shared disjoint paths (OPP-SDP) algorithm and OPP shared disjoint segments (OPP-SDS) algorithm. However, p-cycle based protection approaches offer much faster restoration speed, because p-cycles are pre-cross-connected.     

A New Shared Segment Protection Method for Survivable Networks with Guaranteed Recovery Time

Shared segment protection (SSP), compared with shared path protection (SPP), and shared link protection (SLP), provides an optimal protection configuration due to the ability of maximizing spare capacity sharing, and reducing the restoration time in cases of a single link failure. This paper provides a thorough study on SSP under the GMPLS-based recovery framework, where an effective survivable routing algorithm for SSP is proposed. The tradeoff between the price (i.e., cost representing the amount of resources, and the blocking probability), and the restoration time is extensively studied by simulations on three networks with highly dynamic traffic. We demonstrate that the proposed survivable routing algorithm can be a powerful solution for meeting stringent delay upper bounds for achieving high restorability of transport services. This can significantly improve the network reliability, and enable more advanced, mission critical services in the networks. The comparison among the three protection types further verifies that the proposed scheme can yield significant advantages over shared path protection, and shared link protection.     

An efficient hybrid protection scheme with shared/dedicated backup paths on elastic optical networks

Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks under contiguity and continuity of available spectrum constraints. Two main hypotheses are used in this paper for backup paths computation. In the first case, it is assumed that backup paths resources are dedicated. In the second case, the assumption is that backup paths resources are available shared resources. The objective of the study is to minimize spectrum utilization to reduce blocking probability on a network. For this purpose, an efficient survivable Hybrid Protection Lightpath (HybPL) algorithm is proposed for providing shared or dedicated backup path protection based on the efficient energy calculation and resource availability. Traditional First-Fit and Best-Fit schemes are employed to search and assign the available spectrum resources. The simulation results show that HybPL presents better performance in terms of blocking probability, compared with the Minimum Resources Utilization Dedicated Protection (MRU-DP) algorithm which offers better performance than the Dedicated Protection (DP) algorithm.