P2P group game. Multiple ppl create a virtual enviroment. There is a map, ppl move from one place to anther place. Whenever a player move to a new place, it need to know the other players there, join their session. So how to know that? First, he divide the map into cells (6 edges) and when node move he knows which cell it belongs to. It use the cell id as a key and hash to a node with DHT such as Pastry. Then it contact that node. That node tells this node who is the master of this cell. and the node will contact the master in this cell. The master maintains the membership of this cell. Every cell there is a master and many slaves. The master-slave relationship is decided as in the scatter net in Bluetooth.
