<Structured superpeers:Leveraging Heterogeneity to provide constant-time lookup>
Use 2 Chord rings. The super peers in the inner ring and take charge of an arc of the out ring. The super peer maitains a complete other superpeer table and a local peer table. The query is sent to the super peer. If it cannot resolve the query, it forward the query to super peer in charge of the key arc.and that super peer will forward the query to the succssor of the key.