A system for selecting a number of transmitting ports in an antenna at an access node includes an access node configured to deploy a first radio air interface to provide wireless services to wireless devices. The access node includes an antenna having ports and configured to communicate data with wireless devices through the ports and the first radio air interface. The access node also includes a processor configured to determine a trigger for dynamically selecting a number of transmitting ports in the antenna based on data received from the wireless devices relating to changes in levels of signals received at the wireless devices. The processor is also configured to estimate an amount of change based on the data relating to the changes. The processor is further configured to select a number of transmitting ports in the antenna based on the estimated amount of change.