Home / Standards / GB/T 28500-2012 GB/T 28500-2012 Active Technical requirements of 900/1800MHz TDMA digital cellular mobile network signaling system NO.7 ISUP 900/1800MHz TDMA 数字蜂窝移动通信网No.7 ISUP信令技术要求 Standard Type GBT ICS 33.040.30 CCS M12 Status 现行 Issue Date 2012-06-29 Implementation 2012-10-01 Responsible Dept 工业和信息化部（通信） Drafting Unit N/A