This paper presents a formal description method using CCITT SDL/GR Language. The SDL/GR state pictures of interoffice signallings for a SPC tandem exchange under various junction conditions are discussed.

• 本文提出基于 CCITT SDL 语言基础上的信号系统格式化描述方法,并给出了一个程控市话汇接局在国内网中各种接口条件下的局间信号 SDL/GR 状态图。