Systems and methods for reliable MAC CE ACK/NACK confirmation
Systems and methods for reliable Medium Access Control (MAC) Control Element (CE) ACK/NACK confirmation are provided. In some embodiments, a method performed by a wireless device includes: being configured with at least one feedback enabled Hybrid Automatic Repeat Request (HARQ) process while the remaining HARQ processes of the wireless device have feedback disabled; receiving an activation/deactivation command requiring feedback, where the receiving uses the at least one feedback enabled HARQ process; and/or transmitting feedback regarding the activation/deactivation command. In this way, the wireless device is enabled to send HARQ ACK/NACK feedback related to critical activation/deactivation MAC CE commands in a Non-Terrestrial Network (NTN). Furthermore, in the presence of large one way delay, this ensures that there is no mismatch between the base station and the wireless device as to when the wireless device can assume the activation/deactivation information in the MAC CE command can takes effect at the wireless device.
1. A method performed by a wireless device for transmitting feedback, the method comprising one or more of:
being configured by a network node with at least one feedback enabled Hybrid Automatic Repeat Request, HARQ, process while remaining HARQ processes of the wireless device have the feedback disabled;
receiving an indication of a number of slots, X, as part of a System Information Block, SIB, wherein X is specific to a delay associated with HARQ Acknowledgement/Negative Acknowledgement, ACK/NACK, feedback;
receiving, from the network node, a first Physical Downlink Shared Channel, PDSCH, carrying a Medium Access Control, MAC, Control Element, CE, activation/deactivation command requiring a HARQ ACK/NACK feedback on a Physical Uplink Control Channel, PUCCH, using the at least one feedback enabled HARQ process;
transmitting the HARQ ACK/NACK feedback on the PUCCH in a slot n corresponding to the first PDSCH on the PUCCH;
determining a delay term via multiplying X by a number of slots per subframe for a subcarrier spacing, SCS, μ associated with the PUCCH; and
assuming that an information in the MAC CE activation/deactivation command is applied at the wireless device from a slot n′ where the slot n′ is after a delay given by the determined delay term from the slot n.
2. The method of claim 1 wherein the value of X is indicated as part of a Radio Resource Control, RRC, configuration.
3. The method of claim 1 further comprising one or more of:
receiving a second activation/deactivation command requiring feedback, where the receiving uses one of the feedback disabled HARQ processes; and
not applying information in the second activation/deactivation command.
4. The method of claim 3 wherein not applying the information in the second activation/deactivation command comprises ignoring the second activation/deactivation command.
5. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for the first PDSCH giving mapping of one or more Transmission Configuration Indicator, TCI, States to codepoints of a TCI field of a Downlink Control Indicator, DCI.
6. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for an sCell.
7. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for a spatial relation update of the PUCCH.
8. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for providing Transmission Configuration Indicator, TCI, state information for a Control Resource Set, CORESET.
9. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for a semi-persistent Zero-Power Channel State Information Reference Signal, ZP CSI-RS.
10. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for semi-persistent Channel State Information, CSI, resource settings.
11. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for semi-persistent CSI report settings.
12. The method of claim 1 wherein the activation/deactivation command comprises an activation/deactivation MAC CE for a semi-persistent Sounding Reference Signal, SRS.