Embodiments of latency reduction for wireless data transmission are generally described herein. A user equipment (UE) identifies a shortened transmission time interval (xTTI) length configuration for a time division duplexing (TDD) component carrier (CC), the xTTI length configuration comprising a length in time or a length in orthogonal frequency division multiplexing (OFDM) symbols. The UE identifies scheduling timing and hybrid automatic repeat request (HARQ) timing of physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH) on the TDD CC based on the identified xTTI length configuration. The UE signals for transmission of a HARQ acknowledgement (HARQ-ACK) based on the identified xTTI length configuration.