A transmitter (e.g. a packet data convergence protocol, PDCP, in the transmitter), which may be a base station for downlink communications or a user equipment device for uplink communications, may control timing of the delivery of duplicate (same) packets to multiple (e.g. two) wireless links (e.g. radio link control links) for transmission to a receiver, based at least on synchronization information received from the receiver. The duplicate packets may be transmitted over the multiple wireless links to the receiver, which may receive the duplicate packets over the multiple wireless links. The receiver may collect and/or generate synchronization information indicative of the timing or latency between the multiple wireless links, based at least on the respective receive timings of the duplicate packets over the multiple wireless links. The receiver may transmit a report containing the synchronization information to the transmitter periodically and/or in response to a trigger event.