弹性光网络中多播结构与多播算法研究

Due to its attractive features, i.e., the flexibility in spectrum allocation, the efficiency in resource utilization, and the variety in service transmission, an elastic optical network is regarded as a very promising technology for the next generation high-speed optical network. However, limited by its network architecture, such network cannot support multicast data transmissions directly. Instead, an elastic optical network decomposes a multicast data stream into several unicast data streams, and then delivers these streams independently, which thus greatly affects the efficiency in data transmission. However, with diverse kinds of services available nowadays, the network has to be flexible and efficient enough to cope with both unicast and multicast transmissions. Therefore, to study the multicasting technique is especially crucial to realize efficient and flexible data transmission in an elastic optical network. But the recent research work on the multicasting technique in an elastic optical network is mainly focus on the design of multicast-enabled algorithms, which lacks diversity in both research approach and technique scheme. In this research proposal, we realize efficient multicast data transmission in an elastic optical network by employing either a multicast-enabled network architecture, a mathematic model for multicast transmission, or a multicast-enabled algorithm according to different application scenarios of the network and its characteristics in multicast data transmission. Besides, we employ symmetrical structure in designing the multicast-enabled network architecture to realize the cross-use of the network resources. And we introduce time variable into both the mathematic model and the multicast-enabled algorithm, which can not only increase the time-efficiency of the model and the algorithm, but also gives a way to comprehensively optimize various kinds of performances of the network based on time information.

弹性光网络由于具有带宽分配灵活，资源利用高效，传输业务多样等优点而被视为非常有潜力的下一代高速光网络技术。但这种网络由于受结构的限制，不能直接传输多播数据，而是将多播数据分解成多个单播数据后再按照单播方式进行传输，因而极大地影响了数据传输的效率。然而，现今网络中的各种业务，要求网络必须灵活高效地传输单播和多播数据。因此，研究多播技术对于实现弹性光网络中高效灵活的数据传输显得至关重要。但相关的研究目前主要集中在算法上，研究手段和技术方案单一。在本项目中，申请人针对不同的网络应用场景及其中多播数据的传输特点，分别采用多播网络结构设计、数学模型分析以及算法仿真三种不同的技术方案来实现高效的多播数据传输。并且，在多播网络结构设计中采用对称式结构以实现资源的交叉复用；在数学模型分析以及算法仿真中引入时间变量，使相应的模型和算法具有更好的时效性，并方便对网络的多种性能在时间纬度上进行综合优化。

随着网络中超高速业务的兴起，现有的波分复用光网络由于在资源分配灵活性方面的局限，已无法满足新兴网络业务的需求。相比之下，新型的弹性光网络由于具有带宽分配灵活，资源利用高效等优势而被认为是极具潜力的下一代高速光网络技术。但这种网络由于其结构的限制，不能直接高效地传输多播数据，而需要将多播数据分解成多个单播数据后再按照单播方式进行传输，因而极大地影响了数据传输的效率。本项目针对如何在弹性光网络中实现高效的多播数据传输这一核心目标，并根据不同的网络应用场景，从多播结构和多播算法两个方面进行了研究。在多播结构研究方面，本项目研究了频谱交叠技术以及基于该技术的直接重调制网络结构，实验表明这种网络结构可以有效地减少弹性光网络构建中光源的使用，提升频谱资源的使用效率。在多播算法研究方面，本项目深入研究了弹性光网络中的路由与带宽分配算法，并提出了可以有效降低多播数据传输中频谱碎片、业务阻塞率等性能指标的一系列算法，这些算法可以为今后网络升级提供算法支持。以上研究成果均以论文形式发表。目前，项目负责人已发表SCI论文11篇（其中第一/通信作者7篇），EI论文4篇（均为第一/通信作者）。在已发表论文中12篇以该项目为第一标注。