QoT- and SLA-Aware Survivable Resource Allocation in Translucent Optical Networks

Survivability is a critical issue in high-capacity wavelength division multiplexing based optical networks, since even a disruption for a very short time could result in the loss of a large amount of data. Each accepted connection request brings revenue to the network. On the other hand, a service level agreement (SLA) requirement (e.g., 99.9% uptime in terms of availability) is associated with a connection, and a penalty is paid if the requirement is violated. In addition, physical impairments degrade the quality of signals as they traverse along lightpaths. In this paper, the survivable routing and wavelength assignment problem is studied for dynamic traffic in translucent optical networks considering randomly occurring failures of optical fibers and nodes, so that the quality of transmission (QoT) requirement of each connection is satisfied, and the network-level performance metric of total profit is maximized. Two heuristics are developed - the first one aims to allocate resources to each connection to minimize the expected penalty; while the other heuristic prefers to allocate the minimum possible resources to each connection. Simulation results are presented to demonstrate their effectiveness.

在基于大容量波分复用的光网络中，生存性是一个关键问题，因为即使是很短时间的中断也可能导致大量数据丢失。每个被接受的连接请求都会给网络带来收益。另一方面，一个服务水平协议（SLA）要求（例如，在可用性方面99.9%的正常运行时间）与一个连接相关联，如果该要求被违反则要支付罚金。此外，当信号沿着光路传输时，物理损伤会降低信号质量。在本文中，针对半透明光网络中的动态流量，考虑光纤和节点随机发生的故障，研究了可生存路由和波长分配问题，以便满足每个连接的传输质量（QoT）要求，并使总利润的网络级性能指标最大化。开发了两种启发式算法——第一种旨在为每个连接分配资源以最小化预期罚金；而另一种启发式算法则倾向于为每个连接分配尽可能少的资源。给出了仿真结果以证明它们的有效性。