Systems and methodologies are described that facilitate processing service data units (SDU) in-order during communication handover in wireless networks. In particular, for mobile devices using re-transmission schemes, SDUs can be processed in-order by indicating to a target base station an index of a last SDU received in-order before handing off communication to the target base station. Additionally, SDUs received subsequent to one or more non-acknowledged SDUs can be forwarded to the target base station. Utilizing this information, the target base station can determine one or more SDUs the mobile device is preparing to re-transmit and can wait for this SDU before processing subsequently received SDUs. Also, a timer can be utilized to end a waiting period for the SDU.