CAN-QTree: A Distributed Spatial Index for Peer-to-Peer Networks

We present a distributed spatial index called CANQTree based on a Content-Addressable Network (CAN) and QuadTree-alike structures. In our system, both spatial objects and their corresponding nodes in a QuadTree are identified by some points and mapped into CAN zones of peers. For a given spatial range query, CAN-QTree can provide O(n1/2) search performance. With a uniform distribution of spatial objects, given ε ≫ 0, CAN-QTree can provably maintain a load imbalance of at most 2+ε between a highest loaded peer and a lightest loaded peer. Simulations show that our CAN-QTree is an effective spatial index with a guarantee of good load-balancing.