SAE AS5659/4物理层规范为光学系统的物理层提供了指导 AS5659 WDM LAN规范文件系列中使用波分复用（WDM）的网络。 物理层由网络功能组件之间的光互连组成。表演 描述了一般互连的要求。作为指导，确定了与以下各项相对应的标准: 几个描述物理层设计、安装、维护和培训的环境。

SAE AS5659/4 Physical Layer Specification provides guidance for the physical layer of optical networks which use Wavelength Division Multiplexing (WDM), within the AS5659 WDM LAN specification document family. The physical layer consists of the optical interconnections between the functional components of the network. Performance requirements for general interconnections are described. For guidance, standards are identified, corresponding to each of several environments, which describe physical layer design, installation, maintenance, and training.