ETSI PRETS 300 729-1999 数字蜂窝通信系统.增强型全速率(EFR)语音信道的不连续传输(DTX).第2版.GSM 06.81第5.2.0版1996年发布
Digital Cellular Telecommunications System; Discontinuous Transmission (DTX) for Enhanced Full Rate (EFR) Speech Traffic Channels Second Edition; GSM 06.81 Version 5.2.0 Release 1996