1. A method comprising: determining, at a local node in a network that comprises a plurality of nodes, a first neighbor node of one or more neighbor nodes with which the local node is in direct communication based on a first number of nodes with which the first neighbor node is in direct communication; and selecting the first neighbor node as an aggregation node for information about the local node, wherein the aggregation node outputs data that is a combination of data received from a plurality of different nodes and a number of neighbor nodes with which the local node is in direct communication is called a local number.