As a scalable cost-efficient Internet-access network, we have studied the Wireless Internet-access Mesh Network (WIMNET) that is composed of multiple access point (APs) connected through the Wireless Distribution System (WDS). Because all the traffics pass through an Internet Gateway (GW), the resolution of link congestions around the GW is very important. To solve this problem, we have proposed a clustering algorithm to partition the APs into a set of clusters where each cluster consists of the APs sharing the same GW. In addition, we have considered the use of a smart antenna at a special AP called a Smart AP (SAP). In this paper, we extend this clustering algorithm for smart antenna use at SAPs. Besides, we investigate the link activation strategy for the smart antenna, because it allows a variety of link activations for packet transmissions. We evaluate the effectiveness through simulations using the WIMNET simulator.