近年來，如何提升P2P網路中檔案分享之效能一直是近年來學者關注的焦點之一。目前已有許多實驗數據顯示：若節點能有效的被分割成多個群組，則節點搜尋所需之資源將更有效率，且網路整體之時間複雜度及傳輸成本即能獲得改善。在無線行動網路中，節點的狀況相較於有線網路更能管理，因此如何有效管理無線行動網路上之節點資訊亦更加有挑戰性。在本研究中，每一個群組的管理者將維護一個矩陣，裡頭記錄著每一個節點擁有某一個檔案片斷的完成度。當有節點要求檔案片斷時，其將可更快速的獲知那些節點有其所需要之檔案片斷。

How to conduct an efficient file sharing in Peer-to-Peer (P2P) networks has been studied for years. Many experiments have showed that the average time complexity and the network traffic cost for the resource inquiry in the P2P network can be reduced if cooperative peers can be partitioned into clusters based on peers’ characteristics, such as peer’s location, content feature. In addition, under a clustered P2P network, how to maintain where the peers are and what resources in peers can be provided is an important issue. Furthermore, in a wireless environment, the states of mobile peers may be more undeterministic than stationary peers. In this study, we propose a novel piece-based clustering scheme for the P2P file sharing under wireless mobile networks. In our scheme, the cluster manager maintains the possession matrix, evaluates the completeness ratio if peers request to participate, and finds the requested pieces for requested peers. By this scheme, all peers can obtain the related information about source providers from cluster managers for the requested pieces and then get desired pieces effectively.