The present disclosure relates a method, performed by a communication node of a cellular radio access network, for estimating a radio link quality of a direct link between a first user equipment and a second user equipment. The invention also provides a method performed in a user equipment, which method is used to monitor communication for the purpose of estimating communication in a possible direct link between a first user equipment and a second user equipment. The communication node instructs a user equipment to eavesdrop an uplink of an other user equipment UL1. The communication node obtaining data directly from the uplink UL1 and receives eavesdropped data from the user equipment. The communication node evaluates the radio link based on the data obtained from the uplink and the data eavesdropped from the uplink. The user equipment receives an instruction to eavesdrop the uplink UL1. The user equipment receives and obtains digital data from the uplink UL1, and reports to the network.