At a cluster head/first device there is received, from each of at least two other devices with which the cluster head has a respective wireless link, a quality indicator for the respective link observed by the respective other device. The cluster head compiles those received quality indicators into a compressed report, and sends the compressed report to a network entity. In a specific embodiment the cluster head also determines an additional quality indicator of each of those respective links observed by the cluster head by listening to a sounding reference signal sent by the respective other device to the network entity on a PUCCH. Those additional quality indicators are also compiled into the compressed report, as are further quality indicators received from the devices for D2D links between pairs of those other devices that exclude the cluster head. The compressed report can inform how many indicators are above/below a threshold.