The design of packet transmission mechanisms of video and voice over wireless networks generally utilizes the characteristics of real-time data to improve the network performance, the energy efficiency of mobile devices, and etc. Unfortunately, WLAN medium access control (MAC) layer does not distinguish real-time and data packets during MAC frame transmission, and this design introduces network overheads and extra power consumption of video and voice over WLAN (V2oWLAN) stations (STAs). In this paper, we propose a transmission scheme to eliminate WLAN MAC acknowledgment frames of real-time packets dynamically in order to reduce the power consumption of V 2oWLAN STAs and to improve the network utilization without sacrificing video and voice qualities. The proposed transmission scheme utilizes the WLAN multicasting method that does not require MAC acknowledgment, and the method thus can be implemented on the existing WLAN infrastructures by only software upgrades. Simulation results demonstrate that the proposed scheme improves the network utilization and the energy efficiency of V 2oWLAN applications.