A set of consecutive digit time slots in which the position of each digit time slot can be identified by reference to a frame alignment signal. 一组连续的数字时间片段，每一数字时间片段在组内的位置可参考帧同步信号来标识。
Experiments show that this method can implement the frame synchronization head detection, and thus realize the correct de-multiplexing of the digital signals. 实验表明，此方案成功地在光纤通信系统的接收端检测到帧同步信号，从而实现了数据的正确分接。
