ETSI GSM 09.07-1994 欧洲数字蜂窝通信系统(第2阶段).公共陆地移动网(PLMN)与综合业务数字网(ISDN)或公共交换电话网(PSTN)互通的一般要求(ETS 300 604)
European Digital Cellular Telecommunications System (Phase 2); General Requirements on Interworking between the Public Land Mobile Network (PLMN) and the Integrated Services Digital Network (ISDN) or Public Switched Telephone Network (PSTN) (ETS 300 604)