Availability objectives for a hypothetical reference circuits and hypothetical reference digital paths when used for telephony using pulse code modulation, or as part of an integrated services digital network hypothetical reference connection, in the fixed-satellite service operating below 15 GHz
假设参考电路和假设参考数字路径的可用性目标 当在15 GHz以下运行的固定卫星服务中 用于使用脉冲编码调制的电话 或作为综合业务数字网络假设参考连接的一部分时