IAB MT signaling of released resources

1. An apparatus comprising:

a memory; and

at least one processor in communication with the memory, wherein the at least one processor is configured to cause an Integrated Access and Backhaul (IAB) node to:

detect that a time-domain resource assigned to a child communication link of the IAB node is available;

encode an uplink message for transmission by a mobile terminal (MT) function of the IAB node to a parent IAB node, the uplink message indicating availability of the time-domain resource for a parent backhaul link between the IAB node and the parent IAB node; and

decode a downlink message from the parent IAB node, the downlink message received via the parent backhaul link and using the time-domain resource.

2. The apparatus of claim 1 ,

wherein the at least one processor is further configured to cause the IAB node to:

decode F1-AP signaling from a central unit (CU) of an IAB donor, the F1-AP signaling including an indication of the time-domain resource assigned to the child communication link.

3. The apparatus of claim 1 ,

wherein the child communication link is a child backhaul link, and wherein the time-domain resource is assigned to a child IAB node of the IAB node for uplink or downlink communication using the child backhaul link.

4. The apparatus of claim 1 ,

wherein the child communication link is a child access link, and wherein the time-domain resource is assigned to a child user equipment (UE) of the IAB node for uplink or downlink communication using the child access link.

5. The apparatus of claim 1 ,

wherein the at least one processor is further configured to cause the IAB node to:

encode a physical uplink control channel (PUCCH) for transmission to a parent distributed unit (P-DU) function of the parent IAB node, the PUCCH encoded to include an uplink control information (UCI) format with the uplink message.

6. The apparatus of claim 1 ,

wherein the at least one processor is further configured to cause the IAB node to:

encode a physical uplink shared channel (PUSCH) for transmission to a parent distributed unit (P-DU) function of the parent IAB node, the PUSCH encoded to include a medium access control (MAC) control element (CE) with the uplink message.

7. The apparatus of claim 6 ,

wherein the MAC CE includes a logic channel identification (LCID) information with the uplink message.

8. The apparatus of claim 7 ,

wherein the uplink message is encoded within a reserved field of the LCID information.

9. The apparatus of claim 1 ,

wherein the at least one processor is further configured to cause the IAB node to:

encode a physical uplink shared channel (PUSCH) for transmission to a parent distributed unit (P-DU) function of the parent IAB node using a grant-free uplink resource, wherein the PUSCH is encoded to include the uplink message.

10. The apparatus of claim 1 ,

wherein the at least one processor is further configured to cause the IAB node to:

encode a layer 1 (L1) channel for transmission to a parent distributed unit (P-DU) function of the parent IAB node, wherein the L1 channel is encoded to include the uplink message.

11. The apparatus of claim 1 ,

further comprising:

transceiver circuitry coupled to the at least one processor; and

one or more antennas coupled to the transceiver circuitry.

12. An apparatus comprising:

a memory; and

at least one processor in communication with the memory, wherein the at least one processor is configured to cause an Integrated Access and Backhaul (IAB) node to:

decode F1-AP signaling from a central unit (CU) of an IAB donor, the F1-AP signaling including an indication of time-domain resource assigned to a child communication link of the IAB node;

detect, using a distributed unit (DU) function of the IAB node, that the time-domain resource assigned to the child communication link of the IAB node is unused;

encode an uplink message for transmission by a mobile terminal (MT) function of the IAB node to a parent IAB node, the uplink message indicating availability of the time-domain resource for a parent backhaul link between the IAB node and the parent IAB node; and

decode a downlink message from the parent IAB node, the downlink message received via the parent backhaul link and using the time-domain resource.

13. The apparatus of claim 12 ,

wherein the at least one processor is further configured to cause the IAB node to:

encode a physical uplink shared channel (PUSCH) for transmission to the parent IAB node via the parent backhaul link and using the time-domain resource, wherein the PUSCH is encoded to include uplink data.

14. The apparatus of claim 12 ,

wherein the at least one processor is further configured to cause the IAB node to:

encode a physical uplink control channel (PUCCH) for transmission to a parent distributed unit (P-DU) function of the parent IAB node, wherein the PUCCH is encoded to include an uplink control information (UCI) format with the uplink message.

15. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of an Integrated Access and Backhaul (IAB) node, the instructions to configure the IAB node for time-domain resource management within an IAB network, and to cause the IAB node to:

detect that a time-domain resource assigned to a child communication link of the IAB node is available;

encode an uplink message for transmission by a mobile terminal (MT) function of the IAB node to a parent IAB node, the uplink message indicating availability of the time-domain resource for a parent backhaul link between the IAB node and the parent IAB node; and

decode a downlink message from the parent IAB node, the downlink message received via the parent backhaul link and using the time-domain resource.

16. The non-transitory computer-readable storage medium of claim 15 ,

wherein the instructions further cause the IAB node to:

decode F1-AP signaling from a central unit (CU) of an IAB donor, the F1-AP signaling including an indication of the time-domain resource assigned to the child communication link.

17. The non-transitory computer-readable storage medium of claim 15 ,

wherein the instructions further cause the IAB node to:

encode a physical uplink control channel (PUCCH) for transmission to a parent distributed unit (P-DU) function of the parent IAB node, wherein the PUCCH is encoded to include an uplink control information (UCI) format with the uplink message.

18. The non-transitory computer-readable storage medium of claim 15 ,

wherein the instructions further cause the IAB node to:

encode a physical uplink shared channel (PUSCH) for transmission to a parent distributed unit (P-DU) function of the parent IAB node, the PUSCH encoded to include a medium access control (MAC) control element (CE) with the uplink message.

19. The non-transitory computer-readable storage medium of claim 18 ,

wherein the MAC CE includes a logic channel identification (LCID) information with the uplink message, and wherein the uplink message is encoded within a reserved field of the LCID information.

20. The computer-readable storage medium of claim 15 ,

wherein the instructions further cause the IAB node to:

encode a physical uplink shared channel (PUSCH) for transmission to a parent distributed unit (P-DU) function of the parent IAB node using a grant-free uplink resource, wherein the PUSCH is encoded to include the uplink message.