Dl harq timing with short tti operations in tdd

A wireless device for a cellular communications network, comprising:

• at least one transceiver;
• at least one processor;
• and
• memory comprising instructions executable by the at least one processor whereby the wireless device is operable to:
• determine a downlink Hybrid Automatic Repeat Request, HARQ, timing k for transmission of downlink HARQ feedback for a downlink transmission received in a downlink short Transmission Time Interval, sTTI, nDL based on a Time Division Duplexing, TDD, uplink/downlink configuration;
• and
• transmit, in an uplink sTTI nDL+k, downlink HARQ feedback for the transmission received in the downlink sTTI nDL.

A method of operation of a radio access node in a cellular communications network, comprising:

• transmitting a downlink transmission to a wireless device in a downlink short Transmission Time Interval, sTTI, nDL;
• determining, based on a Time Division Duplexing, TDD, uplink/downlink configuration, a downlink Hybrid Automatic Repeat Request, HARQ, timing k for reception of downlink HARQ feedback from the wireless device for the downlink transmission transmitted in the downlink sTTI nDL;
• and
• receiving, in an uplink sTTI nDL+k, downlink HARQ feedback from the wireless device for the downlink transmission transmitted to the wireless device in the downlink sTTI nDL.

A radio access node for a cellular communications network, comprising:

• at least one transceiver;
• at least one processor;
• and
• memory comprising instructions executable by the at least one processor whereby the radio access node is operable to:
• transmit a downlink transmission to a wireless device in a downlink short Transmission Time Interval, sTTI, nDL;
• determine, based on a Time Division Duplexing, TDD, uplink/downlink configuration, a downlink Hybrid Automatic Repeat Request, HARQ, timing k for reception of downlink HARQ feedback from the wireless device for the downlink transmission transmitted in the downlink sTTI nDL;
• and
• receive, in an uplink sTTI nDL+k, downlink HARQ feedback from the wireless device for the downlink transmission transmitted to the wireless device in the downlink sTTI nDL.