Wireless unicast connections, such as those used for Web browsing and downloading data files, have a lower priority than those that require multicast streaming for functions such as videoconferencing or Internet radio or TV. When one client begins multicast streaming, those using unicast connections may experience slower speeds.
Set the multicast rate to 2 and try your unicast connection. If your connection improves, continue increasing the multicast rate until you find the speed that provides the best combination of connections for unicast and multicast clients. In a wireless network with both 802.11b and 802.11g clients connected to the access point, you can increase the multicast rate up to 9. In a wireless network with only 802.11g clients connected to the access point, you can increase the multicast rate up to 54.