For RRU fiber - connection loss testing guarantees the integrity of the RRU with other components of the network like the BBU and the RRU. connection losses can arise due to poor splicing, damage of the fiber-optic cable, or flaws in the connectors. All these challenges can be effectively managed through routine loss monitoring. For instance, loss measurement can be done using OTDR. For RRU-BBU, lossy network components in the communication network, for RRUs and other parts need to be minimal.