Latency reduction techniques for radio access networks are described. In various embodiments, a reduced transmission time interval (rTTI) may be implemented in order to reduce air interface latency in a radio access network. In some embodiments, an rTTI block may be defined, and some operations may be performed in rTTI block-wise fashion in order to reduce the marginal overhead associated with implementation of the rTTI. In various embodiments in which an rTTI is implemented, DM-RS granularity may be improved by use of techniques that enable data and reference signals to be multiplexed within a same OFDM symbol. In some embodiments, a current transmission time interval (TTI) may be maintained, and latency reduction may be achieved via the use of novel techniques for one or more of code block (CB) segmentation, uplink (UL) resource element (RE) mapping, and HARQ cycle timing. Other embodiments are described and claimed.