FED ( Framing Error Detection) allows the receiving controller to check for valid stop bits. 帧错误检测通过检测一帧信息的停止位来判断该帧是否有效。
The core technologies of GPON, including the framing and adaptation of the frames, ranging and time delay compensation, dynamic bandwidth allocation, encryption and decryption and error control are all implemented in this layer. GPON的核心技术,包括上下行成帧和适配、测距和延时补偿、动态带宽分配、加解密及差错控制等,都是在该层实现的。