本指南涵盖了用于保护远程无线电头（RRH）直流电源馈电的SPD的应用，以及为天线系统馈电的光纤电缆系统的电源。

This guide covers the application of SPDs used to protect the dc power feeds of remote radio heads (RRHs) and power supplies of optical fiber cable systems feeding the antenna systems.