A method is disclosed for a centralized unit (CU) of a wireless communication network, wherein the CU is associated with each of one or more remote units (RU) of the wireless communication network via a respective communication interface. The CU is adapted to operate in one of a plurality of modes including at least a normal operation mode and a power saving operation mode, and the normal operation mode defines a plurality of functions to be performed by the CU. The method comprises (when the CU is in the normal operation mode) determining that a traffic load associated with the one or more RU fulfills a power saving operation criterion, configuring—via the respective communication interface each of the RU for autonomous operation, whereby each of the RU is configured to execute at least one of the plurality of functions, and transferring from the normal operation mode to the power saving operation mode. Corresponding method for a remote unit, computer program products, network node, and arrangements for CU and RU, respectively, are also disclosed.