A communication unit has BT and LTE transceivers, and a BT processor. The BT processor sets up a BT connection over the BT transceiver; performs a legacy command to synchronize BT transactions over the BT connection based on LTE frames in a LTE connection over the LTE transceiver, so that a BT network clock is synchronized to LTE frames. The legacy command is a role switch command that is used to set a BT alignment time of a switch point between Bluetooth master/slave packets to a LTE switch between transmit and receive; and is specified in a BT Core Specification 4.0 or earlier. The processor can determine an expected alignment time to align BT master and slave packets to transmit and receive in the LTE frame based on a start time of the LTE frame, and can indicate the expected alignment time in the legacy command.