A radio access network comprises a serving radio network controller (S-RNC). The S-RNC receives successfully received medium access control (MAC) packet data units (PDUs), discards duplicates of MAC PDUs, reorders the non-discarded MAC PDUs based on serial numbers of the MAC PDUs and delivers the MAC PDUs to a radio link control protocol layer. A controlling radio network controller (C-RNC) provides information to Node-Bs under its control for use in scheduling uplink transmissions. A plurality of Node-Bs schedule uplink transmissions in response to the information provided by its C-RNC, transmit scheduling information to user equipments of its cells, receive MAC PDUs from user equipments of its cells using hybrid automatic repeat request and forward the successfully received MAC PDUs to an associated S-RNC.