DIN ETS 300580-4:1995 欧洲数字移动电话远程通信系统(阶段2).第4部分:全价话务通道用噪声缓解特性; 英文版本 ETS 300580-4:1994
European digital cellular telecommunications system (Phase 2) - Part 4: Comfort noise aspects for full rate speech traffic channels; English version ETS 300580-4:1994