A method performed by a first network node of a wireless communication network for handling uplink signals sent by a UE. The wireless communication network comprises a serving network node responsible for transmitting downlink signals to the UE, and a non-serving network node capable of receiving uplink signals sent by the UE. The non-serving network node is the first network node and the serving network node is a second network node of the communication network, or vice versa. The method comprises receiving an uplink signal from the UE, measuring signal quality on the received uplink signal, and receiving signal quality information from the second network node regarding signal quality measured by the second network node on the uplink signal received by the second network node, to detect imbalances in experienced signal quality between the first network node and the second network node.