As a scalable Internet-access network, we have studied Wireless Internet-access Mesh Network (WIMNET) using multiple access point (APs) that are connected through wireless communications. In previous studies, we proposed a clustering algorithm for efficiently composing a large scale WIMNET by partitioning the APs into a set of clusters. This algorithm assumes that any link speed is constant for simplicity, whereas our preliminary experiments found that it is greatly changed as the link distance increases due to interferences when adopting the new high-speed IEEE802.11n protocol. In this paper, we extend our clustering algorithm to consider this link speed change to introduce IEEE802.11n into WIMNET. We verify the effectiveness of the extended algorithm through simulations in a grid topology instance using the WIMNET simulator.