ETSI TS 123 093-2017 数字蜂窝通信系统(第2+阶段)(GSM全球移动通信系统);通用移动通信系统(UMTS);忙线用户呼叫(CCBS)的技术实现;第2阶段(V14.0.0;3GPP TS 23.093 版本14.0.0 发行版本14)
Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); Technical realization of Completion of Calls to Busy Subscriber (CCBS); Stage 2 (V14.0.0; 3GPP TS 23.093 version 14.0.0 Release 14)