电视信号, 声音信号和交互服务用电缆网络. 第10部分: 返回路径的系统性能(TA5)

[中文适用范围]： 本部分规定了在 5 MHz 至 85 MHz 频率范围内（或其部分）运行的有线电视网络的透明回传路径。其中，当有线电视网络中传输调频（FM）无线电信号时，回传路径的上限频率降低至 65 MHz。基于光纤的网络可使用更高的频率。注：此外，可以使用 0 MHz 至 5 MHz 的频率范围进行回传传输，例如用于网络管理系统（NMS）或其他控制、监控和信令目的。低于 5 MHz 的应用不在本标准覆盖范围内。本标准不涵盖传输系统（如 DOCSIS）的规范。 [外文原描述]： IEC 60728-10:2014 specifies the transparent return path of cable networks operated in the frequency range between 5 MHz and 85 MHz or parts thereof. The upper frequency limit of the return path is reduced to 65 MHz where FM radio signals are transmitted in a cable network. Higher frequencies may be used in fibre based networks. This third edition cancels and replaces the second edition published in 2005 and constitutes a technical revision. It includes the following changes: - update on the state-of-the-art of return path transmission in cable networks; - provisions for DOCSIS 3.0 and EuroDOCSIS 3.0 transmission standards; - revision of subclause 4.3 on measurement of channel level; - new subclause 4.12 for method of measurement of noise power ratio (NPR) on return paths; - new subclause 4.13 for 10-tone measurements; - new subclause 4.14 for method of measurement of modulation error ratio (MER); - revision of subclause 5.2 on analogue parameters influencing system performance.