A method (200) for a cellular system (100), with an RBS (120) which controls a cell (110) with User Equipments UE (130, 140). The RBS and the UEs exchange data which may comprise sequence numbers, and exchange reports on whether or not data has been received successfully, so that both the UE and the RBS can be the reporting party and the report receiving party. The reporting party sends a report (210) to the report receiving party on whether or not data has been received successfully, together with data to the report receiving party or to another party in the cell. The reporting party decides (220) the contents of the report using one of the following priority rules: Data with lower delay tolerance is given priority, Data detected as received in error is given priority, Data is given priority according to block sequence numbers.