Acknowledgment messaging for resource reservations
Methods, systems, and devices for wireless communications are described. The described techniques may enable a first wireless device (e.g., a parent node) to transmit a control message to a second wireless device (e.g., a child node). The control message may include a resource reservation for communication with the second wireless device. The second wireless device may receive the control message and may transmit an acknowledgment message acknowledging successful reception of the resource reservation. The first wireless device may monitor for the acknowledgment message and may communicate with the second wireless device based on whether the acknowledgment message is received. For example, if the first wireless device receives feedback acknowledging successful reception of the resource reservation at the second wireless device, the devices may communicate data in the reserved resources. Otherwise, the first wireless device may retransmit a control message if the first control message was not successfully received.
1. An apparatus for wireless communications at a first wireless device, comprising:
one or more memories; and
one or more processors coupled with the one or more memories, the one or more processors configured to cause the first wireless device to:
transmit, a control message that indicates a resource reservation for communication with a second wireless device;
monitor an uplink control channel for an acknowledgment message based at least in part on the control message, wherein the acknowledgment message acknowledges successful reception of the resource reservation at the second wireless device; and
communicate a data message with the second wireless device based at least in part on the resource reservation, the data message associated with the control message.
2. The apparatus of claim 1 , wherein an absence of the acknowledgment message is detected within a monitoring window based at least in part on the monitoring.
3. The apparatus of claim 2 , wherein, to communicate, the one or more processors are configured to cause the first wireless device to:
transmit a second control message based at least in part on the absence of the acknowledgment message, wherein the second control message comprises a second resource reservation for communication with the second wireless device.
4. The apparatus of claim 1 , wherein the resource reservation reserves a downlink resource of a physical downlink shared channel, and wherein:
to monitor for the acknowledgment message, the one or more processors are configured to cause the first wireless device to receive the acknowledgment message in response to the control message; and
to communicate, the one or more processors are configured to cause the first wireless device to transmit the data message using the reserved downlink resource via the physical downlink shared channel.
5. The apparatus of claim 1 , wherein the resource reservation reserves an uplink resource of a physical uplink shared channel, and wherein:
to monitor for the acknowledgment message, the one or more processors are configured to cause the first wireless device to receive the acknowledgment message in response to the control message based at least in part on the monitoring; and
to communicate, the one or more processors are configured to cause the first wireless device to receive the data message using the reserved uplink resource of the physical uplink shared channel.
6. The apparatus of claim 1 , wherein, to monitor, the one or more processors are configured to cause the first wireless device to:
monitor for the acknowledgment message in a monitoring window between a first resource in which the control message is transmitted and a reserved resource corresponding to the resource reservation.
7. The apparatus of claim 6 , wherein a starting point of the monitoring window, an ending point of the monitoring window, or both are based at least in part on a configuration of the first wireless device.
8. The apparatus of claim 1 , wherein the one or more processors are further configured to cause the first wireless device to:
activate a first pathloss mode, wherein to monitor, the one or more processors are configured to cause the first wireless device to:
monitor based at least in part on the activation of the first pathloss mode.
9. The apparatus of claim 8 , wherein the control message is separated in time from the resource reservation by a first time gap, and the one or more processors are further configured to cause the first wireless device to:
deactivate the first pathloss mode based at least in part on a pathloss measurement; and
transmit a second control message, wherein the second control message comprises a second resource reservation reserving a second reserved resource separated in time from the second resource by a second time gap based at least in part on the deactivated first pathloss mode.
10. The apparatus of claim 8 , wherein the first pathloss mode comprises a high pathloss mode.
11. The apparatus of claim 1 , wherein the control message indicates an acknowledgment resource for monitoring for the acknowledgment message.
12. An apparatus for wireless communications at a first wireless device, comprising:
one or more memories; and
one or more processors coupled with the one or more memories, the one or more processors configured to cause the first wireless device to:
receive a control message that indicates a resource reservation for communication with a second wireless device;
transmit an acknowledgment message on an uplink control channel, wherein the acknowledgment message acknowledges successful reception of the resource reservation at the first wireless device; and
communicate a data message with the second wireless device based at least in part on the resource reservation, the data message associated with the control message.
13. The apparatus of claim 12 , wherein the resource reservation reserves a downlink resource of a physical downlink shared channel, and wherein:
to communicate, the one or more processors are configured to cause the first wireless device to receive the data message using the reserved downlink resource via the physical downlink shared channel.
14. The apparatus of claim 12 , wherein the resource reservation reserves an uplink resource of a physical uplink shared channel, and wherein:
to communicate, the one or more processors are configured to cause the first wireless device to transmit the data message using the reserved uplink resource via the physical uplink shared channel.
15. The apparatus of claim 12 , wherein the one or more processors are further configured to cause the first wireless device to:
activate a first pathloss mode, wherein the acknowledgment message is transmitted based at least in part on the activation of the first pathloss mode.
16. The apparatus of claim 15 , wherein the one or more processors are further configured to cause the first wireless device to:
deactivate the first pathloss mode based at least in part on a pathloss measurement;
receive a second control message, wherein the second control message comprises a second resource reservation for communication with the second wireless device; and
communicate with the second wireless device based at least in part on the second resource reservation.
17. The apparatus of claim 15 , wherein the first pathloss mode comprises a high pathloss mode.
18. The apparatus of claim 12 , wherein, to transmit the acknowledgment message, the one or more processors are configured to cause the first wireless device to:
transmit the acknowledgment message using an acknowledgment resource subsequent to a first resource via which the control message is received and before a reserved resource corresponding to the resource reservation.
19. The apparatus of claim 18 , wherein the acknowledgment resource is based at least in part on the first resource via which the control message is received, the reserved resource corresponding to the resource reservation, or both.
20. The apparatus of claim 18 , wherein the acknowledgment resource is based at least in part on an acknowledgment resource allocation indicated by the control message.
21. A method for wireless communications at a first wireless device, comprising:
transmitting a control message indicating a resource reservation for communication with a second wireless device;
monitoring an uplink control channel for an acknowledgment message based at least in part on transmitting the control message, the acknowledgment message acknowledging successful reception of the resource reservation at the second wireless device; and
communicating a data message with the second wireless device based at least in part on the resource reservation, the data message associated with the control message.
22. The method of claim 21 , wherein an absence of the acknowledgment message is detected within a monitoring window based at least in part on the monitoring.
23. The method of claim 22 , wherein the communicating comprises:
transmitting a second control message based at least in part on the absence of the acknowledgment message, wherein the second control message comprises a second resource reservation for communication with the second wireless device.
24. The method of claim 21 , wherein the resource reservation reserves a downlink resource of a physical downlink shared channel, and wherein:
the monitoring for the acknowledgment message comprises receiving the acknowledgment message in response to the control message; and
the communicating comprises transmitting the data message using the reserved downlink resource via the physical downlink shared channel.
25. The method of claim 21 , wherein the resource reservation reserves an uplink resource of a physical uplink shared channel, and wherein:
the monitoring for the acknowledgment message comprises receiving the acknowledgment message in response to the control message based at least in part on the monitoring; and
the communicating comprises receiving the data message using the reserved uplink resource of the physical uplink shared channel.
26. The method of claim 21 , wherein the monitoring comprises:
monitoring for the acknowledgment message in a monitoring window between a first resource in which the control message is transmitted and a reserved resource corresponding to the resource reservation.
27. A method for wireless communications at a first wireless device, comprising:
receiving a control message indicating a resource reservation for communication with a second wireless device;
transmitting an acknowledgment message on an uplink control channel, the acknowledgment message acknowledging successful reception of the resource reservation at the first wireless device; and
communicating a data message with the second wireless device based at least in part on the resource reservation, the data message being associated with the control message.
28. The method of claim 27 , wherein the resource reservation reserves a downlink resource of a physical downlink shared channel, and wherein the communicating comprises:
receiving the data message using the reserved downlink resource via the physical downlink shared channel.
29. The method of claim 27 , wherein the resource reservation reserves an uplink resource of a physical uplink shared channel, and wherein the communicating comprises:
transmitting the data message using the reserved uplink resource via the physical uplink shared channel.
30. The method of claim 27 , further comprising: activating a first pathloss mode, wherein the acknowledgment message is transmitted based at least in part on activating the first pathloss mode.
31. The apparatus of claim 1 , wherein the first wireless device and the second wireless device are Integrated Access and Backhaul (IAB) nodes in an IAB network.
32. The apparatus of claim 12 , wherein the first wireless device and the second wireless device are Integrated Access and Backhaul (IAB) nodes in an IAB network.
33. A non-transitory computer-readable medium storing code for wireless communications at a first wireless device, the code comprising instructions executable by one or more processors to:
transmit a control message indicating a resource reservation for communication with a second wireless device;
monitor an uplink control channel for an acknowledgment message based at least in part on the control message, wherein the acknowledgment message acknowledges successful reception of the resource reservation at the second wireless device; and
communicate a data message with the second wireless device based at least in part on the resource reservation, the data message associated with the control message.
34. A non-transitory computer-readable medium storing code for wireless communications at a first wireless device, the code comprising instructions executable by one or more processors to:
receive a control message indicating a resource reservation for communication with a second wireless device;
transmit an acknowledgment message on an uplink control channel, wherein the acknowledgment message acknowledges successful reception of the resource reservation at the first wireless device; and
communicate a data message with the second wireless device based at least in part on the resource reservation, the data message associated with the control message.