A cellular communication network may be configured to use a Long-Term Evolution (LTE) base station and a New Radio (NR) base station to implement a Non-Standalone Architecture (NSA) configuration, in an environment in which the NR base station uses multiple frequency bands that provide respective bandwidths. During an NSA connection with a mobile device, LTE signal strength is used as an indicator of whether the device is within the coverage area of a given NR frequency band. When the LTE signal strength indicates that the device has moved into the coverage area of a frequency band having a higher bandwidth than the currently active NR connection, the device is instructed to release and reestablish its NR connection in order to reconnect using the best available NR frequency band. LTE A1 and/or A5 event measurements may be used to evaluate signal strengths and as triggers for NR release/reestablish operations.