Conflict avoidance in random access channel (rach) resources in integrated access and backhaul (iab) networks

Patent metadata

Field	Value
Publication number	US-2019394799-A1
Application number	US-201916409400-A
Country	US
Kind code	A1
Filing date	May 10, 2019
Priority date	Jun 26, 2018
Publication date	Dec 26, 2019
Grant date	—

Abstract

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.

First claim

What is claimed is:

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.

11 . A method for wireless communication by a first Base Station (BS), comprising:
transmitting a random access channel (RACH) configuration to a second BS; receiving a configuration of a set of signals configured for the second BS; determining as invalid, based on the received configuration, one or more Physical RACH (PRACH) occasions according to the RACH configuration of the first BS that conflict with resources used for at least one of the set of signals configured for the second BS; and receiving a RACH preamble from the second BS on a PRACH occasion not conflicting with resources used for at least one of the set of signals configured for the second BS.

12 . The method of claim 11 , wherein the transmitting comprises transmitting the RACH configuration to the second BS via a parent BS of the second BS.

13 . The method of claim 11 , wherein the resources used for the at least one of the set of signals comprise time resources.

14 . The method of claim 11 , wherein the resources used for the at least one of the set of signals comprise time and frequency resources.

15 . The method of claim 11 , wherein the 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.

16 . The method of claim 11 , wherein the 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.

17 . The method of claim 11 , wherein the 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.

18 . The method of claim 11 , 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.

19 . A method for wireless communication by a first Base Station (BS), comprising:
obtaining a Random Access Channel (RACH) configuration to be used for transmitting a RACH signal in a cell served by the first BS or a neighboring cell; determining at least one symbol after at least one PRACH occasion according to the RACH configuration as invalid for one or more downlink transmissions by the first BS; and transmitting the downlink transmissions based on the determination.

20 . The method of claim 19 , wherein determining the at least one symbol invalid for the downlink transmissions avoids interference to the downlink transmissions from the RACH signal.

21 . The method of claim 19 , wherein the RACH signal is to be transmitted by a second BS in the neighboring cell using the at least one PRACH occasion.

22 . The method of claim 21 , wherein the second BS is in a vicinity of at least one of the first BS, a User Equipment (UE) served by the first BS, or another BS served by the first BS.

23 . The method of claim 19 , wherein the RACH signal is to be transmitted by a User Equipment (UE) served by the first BS using the at least one PRACH occasion.

24 . The method of claim 19 , wherein the RACH signal transmitted in the at least one PRACH occasion is to interfere with the downlink transmissions by the first BS in the at least one symbol after the at least one PRACH occasion.

25 . The method of claim 19 , wherein the downlink transmissions comprise downlink transmissions on at least one of an access link to at least one User Equipment (UE) or a wireless backhaul link to another BS.

26 . The method of claim 19 , wherein the at least one symbol is a default value.

27 . The method of claim 19 , wherein the at least one symbol is configured by the network.

28 . The method of claim 27 , where the network configures the at least one symbol via at least one of RMSI, OSI, DCI, RRC signaling, MAC-CE or a handover message.

29 . A method for wireless communication by a User Equipment (UE) served by a first Base Station (BS),

Assignees

• Qualcomm Inc

Inventors

• Islam Muhammad Nazmul
• Abedini Navid
• Li Junyi
• Hampel Karl Georg
• Luo Jianghong

Classifications

• H04W72/27

  between access points · CPC title

• H04W72/0446

  Resources in time domain, e.g. slots or frames · CPC title

• H04W72/1273

  of downlink data flows · CPC title

• H04W56/001

  Synchronization between nodes · CPC title

• H04W74/085 Primary

  collision avoidance · CPC title