For integration of Ethernet passive optical network and IEEE 802.16 WiMAX, it is imperative to provide end-to-end quality of service due to the heterogeneous MAC nature of EPON and WiMAX. To address this issue, this paper proposes a QoS-enabled transmission mechanism operated on a specially devised hybrid optical network unit-base station architecture for QoS support, especially delay differentiation, between EPON and WiMAX. Simulation results show that the proposed scheme outperforms the existing transmission mechanisms in terms of the end-to-end delay and jitter, due to its QoS continuity between them.