IEEE 802.11 wireless LANs can provide easy deployment and configuration for broadband wireless data services without dealing with a cable. However, when MSs roam in IEEE 802.11 wireless networks, the conventional handoff process is not suitable for seamless mobile services. In this paper, we propose a channel-switched AP architecture in which the neighboring APs cooperate in changing the RF channel periodically in a manner determined by an AP manager so that a MS can maintain a wireless connection to APs through a RF channel even if it moves to the neighboring AP service areas. Therefore, even though a MS moves between APs, it does not require the conventional handoff process since it recognizes all the APs as one AP. Performance results verify that the proposed scheme outperforms the conventional WLANs in the seamless mobility management.