Wireless network systems, such as IEEE 802.11 wireless local area networks (WLANs) and Bluetooth, are increasingly constructed in our surrounding environment. Although devices running these two wireless systems operate with different technologies, they both work in the 2.4 GHz ISM (Industrial, Scientific, and Medical) band, and therefore lead to interference. The problem of Bluetooth interfering with a WLAN is particularly serious with a Bluetooth device located in an area with more than one overlapping WLAN. Interference is not a significant problem if it only degrades data throughput. However, it is unacceptable if it causes disconnection of the Bluetooth SCO link (i.e., voice connection). This study presents mechanisms to sustain the quality of Bluetooth SCO link, under the interference, with only at a minor cost of WLAN¡¦s data throughput.