Conflict avoidance in Random Access Channel (RACH) resources in Integrated Access and Backhaul (IAB) networks
Certain aspects of the present disclosure provide techniques for avoiding conflicts of resources assigned to one or more signals with resources assigned to Random Access Channel (RACH) in an Integrated Access and Backhaul (IAB) network. Configurations for first and second sets of signals are obtained for a first and second base station (BS) respectively. Based on the obtained configurations, a RACH configuration is determined for the first BS for performing a RACH procedure with the second BS over a wireless backhaul link, wherein one or more Physical RACH (PRACH) occasions according to the determined RACH configuration do not conflict with resources used for at least one of the first or the second set of signals. The determined RACH configuration is communicated to the second BS, wherein the second BS transmits a RACH signal to the first BS based on the determined RACH configuration.
1. A method for wireless communications, comprising:
obtaining a first configuration of a first set of signals configured for a first Base Station (BS);
obtaining a second configuration of a second set of signals configured for a second BS;
determining, based on the obtained first and second configurations, a Random Access Channel (RACH) configuration for the first BS for performing a RACH procedure with the second BS over a wireless backhaul link, wherein one or more Physical RACH (PRACH) occasions according to the determined RACH configuration do not conflict with resources used for at least one of the first set of signals or the second set of signals; and
communicating the determined RACH configuration to the second BS, wherein the second BS transmits a RACH signal to the first BS based on the determined RACH configuration.
2. The method of claim 1 , wherein the first BS comprises a first Integrated Access and Backhaul (IAB) node of an IAB network and the second BS comprises a second IAB node of the IAB network, wherein a User Equipment (UE) function of the second IAB node is to perform the RACH procedure with an access node (AN) function of the first IAB node over the wireless backhaul link between the first and the second IAB nodes.
3. The method of claim 2 , wherein the method is performed by a network node of the IAB network.
4. The method of claim 3 , wherein obtaining the first configuration comprises receiving the first configuration from the first IAB node, and wherein obtaining the second configuration comprises receiving the second configuration from the second IAB node.
5. The method of claim 1 , wherein the resources used for the at least one of the first set of signals or the second set of signals comprise time resources.
6. The method of claim 1 , wherein the resources used for the at least one of the first set of signals or the second set of signals comprise time and frequency resources.
7. The method of claim 1 , wherein the second set of signals comprises one or more uplink transmissions configured for an access link between the second BS and a UE served by the second BS.
8. The method of claim 1 , wherein the second set of signals comprises one or more downlink transmissions configured for an access link between the second BS and a UE served by the second BS.
9. The method of claim 1 , wherein the first and second set of signals comprises at least one of uplink transmissions, a primary synchronization signal, a secondary synchronization signal, a PBCH signal, remaining minimum system information, other system information, random access response from one or more UEs, Channel State Information Reference Signals (CSI-RS), or paging signals.
10. The method of claim 1 , wherein the RACH signal comprises a RACH preamble, wherein the second BS transmits the RACH preamble to the first BS on one of the PRACH occasions not conflicting with resources used for at least one of the first set of signals or the second set of signals.