RF cables have limitations in that they suffer power loss and are subject to performance degradation over time due to damage or corrosion. A baseband unit (BBU) and radio head (RRH) are typically connected with a fiber link conforming to the common public radio interface, or CPRI. When installing a system with fiber connections, it is important to validate that the CPRI interface is performing to specification. By installing an optical Test Access Point (TAP) or splitter into the link, the spectrum of the uplink and downlink can be monitored for interference, passive intermodulation effects and noise.
Ferdinand Gerhardes, Anritsu on behalf of Livingston