According to the network-side teachings herein, transmission adaptations taken with respect to a secondary serving cell provide improved operation in the context of serving a half-duplex wireless device having a carrier aggregation configuration involving primary and secondary cells with different Time Division Duplex (TDD) uplink/downlink configurations. Transmission adaptations are taken with respect to a normal downlink subframe in a secondary cell that is time-wise overlapped by a special subframe in the primary cell. Similarly, improved operations are obtained on the device-side according to reception adaptations taken with respect to normal downlink subframes in a secondary cell that are overlapped by special subframes in the primary cell. Non-limiting improvements include better channel estimation and link adaptation, improved scheduling, and revised timings for the transmission and reception of user or control data targeting the device.