Elastic Optical Networks (EONs) using a flexible wavelength allocation technique with smaller granularity of spectrum can improve the efficiency and flexibility for diverse traffic transmission. However, due to the small granularity in EONs, the resource allocation problems become more complicated than that of the existing network architecture. By classifying the integer linear programming (ILP) models for solving the resource allocation problem on EONs into four categories, i.e., path/slot, path/channel, node/slot and node/channel, the characteristics of each are reviewed and tighter lower bounds estimation schemes for these ILP models are designed. Also, for channel models (i.e., path/channel and node/channel models), we propose two improved channel generation methods in pre-processing to reduce the number of variables. In the comparative experiments, we show the superiority of our methods, and by using them, analyze the characteristics of the four models.

弹性光网络 (EON) 使用具有更小频谱粒度的灵活波长分配技术，可以提高各种流量传输的效率和灵活性。然而，由于 EON 的粒度较小，资源分配问题变得比现有网络架构更复杂。通过将求解 EON 上资源分配问题的整数线性规划 (ILP) 模型分为路径/槽、路径/通道、节点/槽和节点/通道四类，回顾了每类的特性并更严格的下界设计了这些 ILP 模型的估计方案。此外，对于通道模型（即路径/通道和节点/通道模型），我们在预处理中提出了两种改进的通道生成方法，以减少变量的数量。