Transparent Unicast Translation to Improve Quality of Multicast over Wireless LAN

Media broadcasting services using Internet protocol (IP) multicast are emerging and IEEE 802.11 wireless LAN (WLAN) has been widely deployed. Therefore, the opportunities to receive multicast streaming over WLAN are expected to grow. However, because of restrictions on the IEEE 802.11 standard, the transmission rate and the reliability of multicast over WLAN are lower than those of unicast. In this paper, we propose a transparent multicast / unicast translation method which translates a multicast packet into multiple unicast packets at the media access control (MAC) layer, so that we can utilize the higher transmission rates and retransmission function that are only available with unicast. Our theoretical analysis and experiment show that the proposed method improves the efficiency and reliability of multicast over WLAN.