In a wireless communication network, a primary access node controls the amount of secondary access nodes that serve User Equipment (UE). The primary access node exchanges data with the UE, corrects errors, and determines an error rate. The primary access node exchanges the data over backhaul links and determines backhaul throughput. The primary access node determines a target number of the secondary access nodes based on the error rate and the backhaul throughput. The primary access node identifies a qualifying set of the secondary access nodes that have adequate received signal strength. The primary access node selects a serving set having the target number of secondary access nodes from the qualifying set. The primary access node indicates the UE to the serving set and indicates the serving set to the UE. The serving set of the secondary access nodes exchange data with the UE.