全国一级干线电话网Ｎｏ．７信令网进入设计阶段由邮电部设计院和邮电部北京设计院共同承担的我国一级干线电话网Ｎｏ７信令网工程，目前正在进行紧张设计，这一可覆盖全国３０个省会城市的国际性标准化通用公共信道信令网，预计１９９５年第三季度完成设计，１９９６年第... National level telephone network No. 7 signaling network into the design phase of the Ministry of Posts and Telecommunications Design Institute and Beijing Institute of Posts and Telecommunications jointly assume China’s first-tier telephone network No7 signaling network project is currently under intense design, which covers 30 provinces of the country’s international capital Standardization of common public channel signaling network, is expected to be completed in the third quarter of 1995 design, 1996 ...