A frame-construction format is defined. High-level bata link control is used as transmission-control-procedure, and ACK, NAK control frame is accepted as acknowledgement or negative acknowledgement.

• 文中还定义了一种帧结构格式；传输控制规程采用HDLC；规定ACK、NAK控制帧作为传输中的肯定应答和否定应答.