A method and an apparatus for switching D2D data communications between a licensed and a license-exempt band are disclosed. A D2D device receives from a cellular network a pre-switch notification to prepare for a switch of its D2D communications, and in response adopts a temporary strategy for conducting its D2D transmissions prior to the switch. After the switch the D2D device discontinues the temporary strategy. In one embodiment the temporary strategy and its duration are indicated in the pre-switch notification. Two example temporary strategies are presented: ‘no-new-data’ where new data transmissions are suspended and data re-transmissions are sent with high reliability; and ‘no-feedback’ where new data is sent with high reliability and data re-transmissions are suspended. Different embodiments have the cellular network access node or D2D device contending for the radio resource in the license-exempt frequency band.