Abstract Elastic optical networks have recently emerged as one of the most promising technologies for creating next-generation optical core networks thanks to the adaptive spectrum allocation mechanism. In order to achieve higher spectrum efficiency and exploit elastic optical networking technology, in this paper, we introduce a novel perspective on re-designing dedicated path protection for elastic optical networks. First, inspired by the observation that, in distance-diverse network topologies, the transmission margin between the working and protection route could be wide enough and therefore, the most feasibly spectrum-efficient modulation format could be assigned according to the specific condition of each route rather than applying a single modulation format that is able to cope with the worse condition of the route as currently adopted in traditional designs. Such more granular in transmission adaption is powered by the fast reconfiguration of state-of-the-art elastic transponders and this paves new opportunities in leveraging the spectrum efficiency. Second, the characteristics of traffic traveling in fiber links could be furthermore exploited to tailor the protection services to the actual requirement instead of enforcing the same level of protection for the entire traffic. Specifically, premium traffic today accounts for only 25 % and the remained traffic is best-effort and in taking advantage of this insight, dedicated path protection could be re-designed to ensure just-enough bandwidth provision for premium traffic in case of failures while possibly accepting best-effort traffic discard. In exploiting both the reconfiguration capability and traffic differentiation, a new quality-of-service aware protection framework for the design of elastic optical networks with the capability of distance-adaptive and reconfigurable modulation format assignment is provided. We introduce the node architecture supporting our proposal and provide an optimal design formulation in the form of integer linear programming model to maximize the spectral utilization efficiency. We have also applied extensively experimental simulations to evaluate the performance of our proposed solution in comparison with that of appropriate conventional approaches on a realistic network topology, i.e. COST239. The obtained numerical results prove that our developed solution significantly outperforms the conventional ones, in terms of spectrum efficiency, and it has been revealed that permitting reconfiguration of transmission parameters in switching from working routes to protection ones could result up to 20 % spectral saving in most favorable conditions. Furthermore, incorporating the protection service differentiation could substantially boost spectrum efficiency. For the present ratio of premium traffic– roughly 25 % , our proposal reveals that a spectral saving of up to more than 80 % could be attained and on the whole, the developed solution tends to be more profitable with the medium and high-load traffic conditions.

中文翻译：

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具有距离自适应和可重构调制格式的弹性光网络中的 QoS 感知保护

摘要 由于自适应频谱分配机制，弹性光网络最近成为创建下一代光核心网络最有前途的技术之一。为了实现更高的频谱效率并利用弹性光网络技术，在本文中，我们介绍了重新设计弹性光网络专用路径保护的新视角。首先，受到观察的启发，在不同距离的网络拓扑中，工作和保护路由之间的传输余量可能足够宽，因此，可以根据每条路由的具体情况分配最可行的频谱效率调制格式，而不是像目前传统设计中采用的那样应用能够应对路由更差条件的单一调制格式。这种更精细的传输适应由最先进的弹性转发器的快速重新配置提供支持，这为利用频谱效率提供了新的机会。其次，可以进一步利用在光纤链路中传输的流量特性，根据实际需求定制保护服务，而不是对整个流量实施相同级别的保护。具体来说，今天的优质流量仅占 25%，剩下的流量是尽力而为，并利用这种洞察力，可以重新设计专用路径保护，以确保在发生故障时为优质流量提供足够的带宽，同时可能接受尽力而为的流量丢弃。在利用重新配置能力和流量差异化的同时，提供了一种新的服务质量感知保护框架，用于设计具有距离自适应和可重新配置调制格式分配能力的弹性光网络。我们介绍了支持我们提议的节点架构，并以整数线性规划模型的形式提供优化设计公式，以最大限度地提高频谱利用效率。我们还应用了广泛的实验模拟来评估我们提出的解决方案的性能，并与现实网络拓扑上的适当传统方法（即 COST239）的性能进行比较。获得的数值结果证明，我们开发的解决方案在频谱效率方面明显优于传统解决方案，并且表明在从工作路由切换到保护路由时允许重新配置传输参数可以在大多数情况下节省高达 20% 的频谱。有利条件。此外，结合保护服务差异化可以显着提高频谱效率。对于目前大约 25% 的优质流量比例，我们的建议表明，可以实现高达 80% 以上的频谱节省，并且总的来说，