ETSI ETS 300 392-10-13-1999 陆地集群无线电(TETRA).语音加数据(V+D).第10部分:补充业务阶段1.第13子部分:忙时用户呼叫接通(第2版)
Terrestrial Trunked Radio (TETRA); Voice Plus Data (V+D); Part 10: Supplementary Services Stage 1; Sub-Part 13: Call Completion to Busy Subscriber (Second Edition)