A base station transmits a radio resource control message. The radio resource control message comprises a periodicity parameter indicating a number of symbols. A downlink control information is transmitted. The downlink control information indicates activation of a periodic resource allocation. The downlink control information comprises one or more fields indicating a numerology. Transport block associated with a hybrid automatic repeat request (HARQ) process identifier is received a via radio resources associated with the periodic resource allocation. The HARQ identifier is based on the numerology and the number of symbols.