Data centers based on Passive Optical Networks (PONs) can provide high capacity, low cost, scalability, elasticity and high energy-efficiency. This paper introduces the use of WDM-TDM multiple access in a PON-based data center that offers multipath routing via two-tier cascaded Arrayed Waveguide Grating Routers (AWGRs) to improve the utilization of resources. A Mixed Integer Linear Programming (MILP) model is developed to optimize resource allocation while considering multipath routing. The results show that all-to-all connectivity is achieved in the architecture through the use of two different wavelength within different time slots for the communication between racks in the same or different cells, as well as with the OLT switches.

翻译：基于无源光网络（PON）的数据中心能够提供高容量、低成本、可扩展性、弹性及高能效。本文提出在基于PON的数据中心中采用WDM-TDM多址接入技术，通过两级级联阵列波导光栅路由器（AWGRs）实现多路径路由以提升资源利用率。建立了混合整数线性规划（MILP）模型，在考虑多路径路由的同时优化资源分配。结果表明，通过在同一或不同单元内的机架间以及光线路终端（OLT）交换机通信时，在不同时隙内使用两种不同波长，该架构可实现全互联通信。