Enhanced Feedback Signalling

An apparatus comprising

• at least one processor;
• and
• at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to at least to:
• detect a number of failed code blocks in a transport block received from a second apparatus and a corresponding feedback size indicator;
• select a format of a hybrid automatic repeat request (HARQ) feedback message to be generated based on the corresponding feedback size indicator;
• generate the HARQ feedback message based on the number of failed code blocks in the transport block, wherein the generated HARQ feedback message is of the selected format and indicates each failed code block in the transport block if any;
• transmit the generated HARQ feedback message to the second apparatus;
• and at least one of:
• receive the feedback size indicator from the second apparatus via control channel signalling, or
• receive the feedback size indicator from the second apparatus as the number of code blocks in the transport block, as a transport block size, or as other information indicated in the transport block.

An apparatus comprising

• at least one processor;
• and
• at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to:
• transmit a feedback size indicator to another apparatus via control channel signalling, and/or
• transmit the feedback size indicator to the other apparatus as a number of code blocks in the transport block, as a transport block size, as other information indicated in the transport block;
• receive a hybrid automatic repeat request (HARQ) feedback message from the other apparatus based on a number of failed code blocks in the transport block, wherein the HARQ feedback message indicates each failed code block in the transport block if any;
• generate a retransmission for the transport block based on a format of the received HARQ feedback message, wherein the retransmission includes each or some of the code blocks in the transport block;
• and
• transmit the generated retransmission to the other apparatus.

A method comprising causing transmission of a transport block and a corresponding feedback size indicator to a first apparatus from a second apparatus of a communications system, and at least one of:

• causing, in the second apparatus, the transmission of the feedback size indicator to the first apparatus via control channel signalling, or
• causing, in the second apparatus, the transmission of the feedback size indicator to the first apparatus as the number of code blocks in the transport block, as a transport block size, or as other information indicated in the transport block;
• and wherein the method further comprises:
• receiving, in the second apparatus, a HARQ feedback message generated in the first apparatus based on the number of failed code blocks in the transport block, wherein the HARQ feedback message indicates each failed code block in the transport block if any;
• generating, in the second apparatus, a retransmission for the transport block based on the format of the received HARQ feedback message, wherein the retransmission includes each or some of the original code blocks in the transport block;
• and
• causing, in the second apparatus, transmission of the generated retransmission to the first apparatus.