基于分解协调的SWCC-OBS网络路由选择研究

针对稀疏分布有限波长转换能力的光突发交换(SWCC-OBS)网络容易出现的高丢包率和负载不均 衡问题,建立了稀疏分布OBS全网丢包率的数学模型。为了克服模型求解过程中多 变量带来的非 线性问题,对影响全网突发丢包率的参变量进行分解预估和反馈更新,求得全网对应业务流 模型下的优化 路由路径,获得了全网突发数据的近似最低丢包率。仿真实验表明,在SWCC-OBS网络中, 本文提出的路由 选择模型及分解协调的路由选择算法,不仅能有效地避免突发数据包间的相互冲突、降低了 全网丢包率,而 且能很好地适应突发数据业务的动态变化,保证了网络的负载均衡和较低的丢包率。

A novel routing scheme based on decomposition coordination in SWCC-OBS networks

Optical burst switching (OBS) has been proposed as a promising switchi ng technology for the next generation of optical transport networks.Particular attention is paid to the co mmercial OBS networks with sparse wavelength conversion capabilities (SWCC-OBS).An overall burst packet loss pro bability,which adequately represents the congestion state of entire network,is the primary metric of inter est in an SWCC-OBS network.With the overall loss probability as the optimization objective,a novel routing mode l is proposed based on integer non-linear programming formulation.In order to overcome the computational comp lexity,a novel routing algorithm based on decomposition coordination is proposed to solve the problem b y decomposing and pre-forecasting the variables.Also it updates the values according to the feek back.Finally,it will obtain an optimal routing path and the global approximate optimal path to minimize the burst los s probability.The simulation results show that the proposed model and algorithm can give a near-optimal rout ing that avoids the conflict of burst data effectively and decreases the overall burst loss probability.At the same t ime,it also performs well in balancing payloads throughout the whole network under different kinds of burst data patter ns and network topologies.