下一代ROADM节点结构及其光网络性能的优化设计研究

发布时间：2018-09-10 12:01

【摘要】：近年来,电信业有着最显著的发展趋势,以云计算、网络电视(IPTV)、O2O (Online To Offline)、物联网等为代表的新型业务日益兴起。数据业务爆发式增长以及下一代网络技术的发展,使电信运营商纷纷建设基于IP/MPLS over WDM的大容量、多业务承载网。下一代新型的电信业务与传统电信业务相比,具有更高的动态特性和不可预测性,因此需要作为物理层的光网络提供更高的灵活性和智能化功能,以便在网络拓扑及业务分布发生变化时能够快速响应,实现业务的灵活调度。在骨干承载网中,交换节点ROADM (Reconfigurable Optical Add/Drop Multiplexers)具有远程配置功能,即可动态改变波长信道的上下路状态,实现了网络资源的动态、灵活分配,大大简化了网络部署规划,提高了网络资源利用率。ROADM使得WDM光网络具有可重构能力,使光网络向智能化进一步发展。下一代的ROADM要求具备无色无向无竞争(CDC, Colorless, Directionless, Contentionless)的特性,其中无竞争性的实现需要在ROADM结构中增加“竞争消除”结构以避免节点内部的波长竞争。这必然额外地增加了ROADM节点的硬件成本和功耗。因此本文在意识到节点内部竞争的ROADM光网络中,研究不同的收发机资源配置对光网络性能的影响,去除节点内冗余的“竞争消除”硬件。这样,在实际应用中,优化设计的ROADM节点不仅表现出无竞争特性,又使得光网络获得最佳的网络性能。本文设计了一种具有业务疏导功能的ROADM交换节点结构,建立网络资源调度算法的整数线性规划(ILP, Integer Linear Programming)模型,设计相应的意识到节点内部竞争的启发性算法(INCF-RWA, Intra-node Contention-free RWA)。分析不同收发机资源配置与网络性能之间的关系,在满足最佳网络性能的前提下,优化ROADM结构,降低节点成本,减少节点功耗,最后分析了业务阻塞的原因。实验仿真中,分别采用了主／备收发机模块结构和共享式收发机模块结构进行了研究。仿真结果显示,每个模块中的收发机数目与光纤链路中的波长数相等时,仅配置两个收发机模块的ROADM节点结构即可实现“无竞争”特性。同时,对于主／备收发机模块结构,备用模块中的收发机数目可以减少为主模块收发机数目的37.5%;对于共享式收发机模块结构,每个模块中的收发机数目可以减少为波长数目的68.7%。通过优化设计的ROADM结构,不仅去除了冗余硬件,又可获得与“完全无竞争”ROADM结构近似相同的网络性能,从而有效降低了网络节点硬件成本和功耗。
[Abstract]:In recent years, the telecommunications industry has the most remarkable development trend, such as cloud computing, network television (IPTV) and O2O (Online To Offline), Internet of things as the representative of the new business is emerging. With the explosive growth of data services and the development of next generation network technology, telecom operators have built large capacity and multi-service carrying networks based on IP/MPLS over WDM. Compared with traditional telecommunication services, the next generation of new telecommunication services has higher dynamic characteristics and unpredictability. Therefore, optical networks as physical layer need to provide higher flexibility and intelligent functions. In order to quickly respond to the changes in network topology and service distribution, the flexible scheduling of services can be realized. In the backbone bearer network, the switching node ROADM (Reconfigurable Optical Add/Drop Multiplexers has the function of remote configuration, which can dynamically change the upper and lower state of the wavelength channel, realize the dynamic distribution of the network resources, and greatly simplify the network deployment planning. WDM optical network can be reconfigurable by improving the utilization ratio of network resource. ROADM makes the optical network develop intelligently. The next generation of ROADM requires a colorless, direction-free, non-competitive (CDC, Colorless, Directionless, Contentionless), in which a non-competitive implementation needs to add a "competition elimination" structure to the ROADM structure to avoid wavelength competition within the node. This inevitably increases the hardware cost and power consumption of ROADM nodes. Therefore, in the ROADM optical network, which is aware of the intra-node competition, the effects of different transceiver resource configurations on the performance of the optical network are studied, and the redundant "competition elimination" hardware in the node is removed. Thus, in practical applications, the optimized ROADM nodes not only show no competition, but also make the optical network obtain the best network performance. In this paper, a ROADM switching node structure with traffic grooming function is designed. The integer linear programming (ILP, Integer Linear Programming) model of network resource scheduling algorithm is established, and the corresponding heuristic algorithm (INCF-RWA, Intra-node Contention-free RWA).) is designed, which is aware of the intra-node competition. This paper analyzes the relationship between resource allocation of different transceivers and network performance, optimizes the ROADM structure, reduces node cost and reduces node power consumption under the premise of satisfying the optimal network performance. Finally, the causes of traffic congestion are analyzed. In the experiment simulation, the main / standby transceiver module structure and the shared transceiver module structure are studied. The simulation results show that when the number of transceivers in each module is equal to the number of wavelengths in the fiber link, the ROADM node structure with only two transceiver modules can achieve "no competition". At the same time, for the main / standby transceiver module structure, the number of transceivers in the standby module can be reduced to 37.5of the number of transceivers in the main module, and for the shared transceiver module structure, the number of transceivers in each module can be reduced to 68.7 percent of the wavelength number. By optimizing the ROADM structure, not only the redundant hardware is removed, but also the network performance is approximately the same as the "completely non-competitive" ROADM structure, which effectively reduces the network node hardware cost and power consumption.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.1

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