Responding to a new data indicator for a hybrid automatic repeat request process
Apparatuses, methods, and systems are disclosed for responding to a new data indicator for a hybrid automatic repeat request process. One method includes determining whether a current new data indicator in a current sidelink grant matches a last received new data indicator in a last received sidelink grant for a first hybrid automatic repeat request process. The method includes, in response to determining that the current new data indicator does not match the last received new data indicator, determining whether a negative acknowledgement has been transmitted in response to the last received sidelink grant.
1. A method comprising:
determining whether a current new data indicator in a current sidelink grant matches a last received new data indicator in a last received sidelink grant for a first hybrid automatic repeat request process;
in response to determining that the current new data indicator matches the last received new data indicator, determining whether a first positive acknowledgement has been transmitted in response to the last received sidelink grant; and
in response to determining that the first positive acknowledgement has been transmitted in response to the last received sidelink grant;
ignoring the current sidelink grant by skipping the current sidelink grant; and
transmitting a second positive acknowledgment.
2. The method of claim 1 , further comprising, in response to determining:
that a negative acknowledgement has been transmitted in response to the last received sidelink grant; and
that the current new data indicator does not match the last received new data indicator for the first hybrid automatic repeat request process;
switching from a first mode to a second mode for the first hybrid automatic repeat request process.
3. The method of claim 1 , further comprising, in response to determining:
that a negative acknowledgement has been transmitted in response to the last received sidelink grant; and
that the current new data indicator does not match the last received new data indicator for the first hybrid automatic repeat request process;
generating an autonomous hybrid automatic repeat request retransmission for a first transport block transmitted based on the last received sidelink grant.
4. The method of claim 1 , further comprising, in response to determining:
that a negative acknowledgement has been transmitted in response to the last received sidelink grant; and
that the current new data indicator does not match the last received new data indicator for the first hybrid automatic repeat request process;
selecting a second hybrid automatic repeat request process from a plurality of available hybrid automatic repeat request processes;
generating a second transport block corresponding to the current sidelink grant;
storing the second transport block in a hybrid automatic repeat request buffer corresponding to the second hybrid automatic repeat request process; and
transmitting the second transport block in the second hybrid automatic repeat request process.
5. The method of claim 1 , further comprising, in response to determining:
that a negative acknowledgement has been transmitted in response to the last received sidelink grant; and
that the current new data indicator does not match the last received new data indicator for the first hybrid automatic repeat request process;
ignoring or skipping the current sidelink grant and transmitting a positive acknowledgment to a base station.
6. The method of claim 1 , further comprising, in response to determining that the first positive acknowledgement has been transmitted in response to the last received sidelink grant:
generating a second transport block corresponding to the current sidelink grant; and
transmitting the second transport block in the first hybrid automatic repeat request process.
7. The method of claim 1 , further comprising, in response to determining that a negative acknowledgement has been transmitted in response to the last received sidelink grant:
performing a hybrid automatic repeat request retransmission of a first transport block stored in a hybrid automatic repeat request buffer for the first hybrid automatic repeat request process.
8. An apparatus comprising:
a processor that:
determines whether a current new data indicator in a current sidelink grant matches a last received new data indicator in a last received sidelink grant for a first hybrid automatic repeat request process;
in response to determining that the current new data indicator matches the last received new data indicator, determines whether a first positive acknowledgement has been transmitted in response to the last received sidelink grant; and
in response to determining that the first positive acknowledgement has been transmitted in response to the last received sidelink grant;
ignores the current sidelink grant by skipping the current sidelink grant; and
transmits a second positive acknowledgment.
9. The apparatus of claim 8 , wherein the processor, in response to determining:
that a negative acknowledgement has been transmitted in response to the last received sidelink grant; and
that the current new data indicator does not match the last received new data indicator for the first hybrid automatic repeat request process;
switches from a first mode to a second mode for the first hybrid automatic repeat request process.
10. A method comprising:
determining whether a current new data indicator in a current sidelink grant matches a last received new data indicator in a last received sidelink grant for a first hybrid automatic repeat request process; and
in response to determining that the current new data indicator matches the last received new data indicator, determining whether a positive acknowledgement has been transmitted in response to the last received sidelink grant.
11. The method of claim 10 , further comprising, in response to determining:
that the positive acknowledgement has been transmitted in response to the last received sidelink grant; and
that the current new data indicator matches the last received new data indicator for the first hybrid automatic repeat request process;
considering the new data indicator as toggled.
12. The method of claim 11 , further comprising generating a second transport block for the first hybrid automatic repeat request process according to the current sidelink grant.
13. The method of claim 12 , further comprising transmitting the second transport block in the first hybrid automatic repeat request process.
14. The method of claim 10 , further comprising, in response to determining that a negative acknowledgement has been transmitted in response to the last received sidelink grant:
performing a hybrid automatic repeat request retransmission of a first transport block stored in a hybrid automatic repeat request buffer for the first hybrid automatic repeat request process.
15. The method of claim 10 , further comprising, in response to the current new data indicator not matching the last received new data indicator, determining whether a negative acknowledgement has been transmitted in response to the last received sidelink grant.
16. The method of claim 15 , further comprising, in response to determining that the negative acknowledgement has been transmitted in response to the last received sidelink grant:
switching from a first mode to a second mode for the first hybrid automatic repeat request process;
generating an autonomous hybrid automatic repeat request retransmission for a first transport block transmitted based on the last received sidelink grant;
selecting a second hybrid automatic repeat request process from a plurality of available hybrid automatic repeat request processes;
generating a second transport block corresponding to the current sidelink grant;
storing the second transport block in a hybrid automatic repeat request buffer corresponding to the second hybrid automatic repeat request process; and
transmitting the second transport block in the second hybrid automatic repeat request process.
17. The method of claim 15 , further comprising, in response to determining that the positive acknowledgement has been transmitted in response to the last received sidelink grant:
generating a second transport block corresponding to the current sidelink grant; and
transmitting the second transport block in the first hybrid automatic repeat request process.
18. An apparatus comprising:
a processor that:
determines whether a current new data indicator in a current sidelink grant matches a last received new data indicator in a last received sidelink grant for a first hybrid automatic repeat request process; and
in response to determining that the current new data indicator matches the last received new data indicator, determines whether a positive acknowledgement has been transmitted in response to the last received sidelink grant.