A cellular communication device is configured to use Non-Standalone Architecture (NSA) for communicating with a cellular communication network using 4th-Generation (4G) Long-Term Evolution (LTE) and 5th-Generation (5G) New Radio (NR) radio access technologies. In NSA mode, the device may receive separate transmit power control commands for LTE and NR transmissions, respectively. In some situations, the cellular communication device may be commanded to use LTE and NR transmit powers that when combined would exceed regulatory limits or performance limits. In these situations, LTE and NR uplink transmissions are scheduled to implement time-division multiplexing, so that the LTE and NR uplink transmissions occur during different time intervals rather than concurrently.