In a wireless communication system, a wireless access node provides a wireless communication service to wireless communication devices over a first frequency band class and over a second frequency band class. A control system identifies a subset of the wireless communication devices operating over the first frequency band class that have been in an idle mode for a time period that exceeds a threshold. The wireless access node transfers a signal to the subset of the wireless communication devices to transition from the first frequency band class to the second frequency band class. The wireless access node then provides the wireless communication service to at least some of the subset of the wireless communication devices over the second frequency band class.