找考题网-背景图
单项选择题

A.VoiceGroupCallServiceB.VoiceBroadcastServiceC.enhance……

以下哪些属于GSM-R集群业务范畴()

A.VoiceGroupCallService
B.VoiceBroadcastService
C.enhancedMulti-LevelPrecedenceandPre-emption
D.以上都是