Business TeleCommunications (BTC); Planning of loudness rating and echo values for private networks digitally connected to the public network
商业电信(BTC);规划数字连接到公共网络的专用网络的响度等级和回声值
Definition of harmonized loudness rating/echo values for the call path within a PBN, when accessing the PSTN (ISDN) via a digital interface, with a fully digital call path within the PSTN (or ISDN)