# US 11,445,459 B2 · Method for synchronizing DU transmission timings of IAB nodes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,459 B2 - Document ID: US11445459B2 - Status: Granted - Kind: B2 - Application number: 17/671,293 - Filed: 2022-02-14 - Published: 2022-06-02 - Granted: 2022-09-13 - Earliest claimed: 2019-08-14 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Haewook Park; Byounghoon Kim; Kijun Kim; Sukhyon Yoon; Hyunsoo Ko - Web page: https://patentgrep.com/patent/US11445459B2 ## CPC - H04W 56/001: {Synchronization between nodes} - H04W 56/00: Synchronisation arrangements - H04W 74/004: {in the uplink, i.e. towards network} - H04W 84/04: Large scale networks; Deep hierarchical networks - H04W 74/002: {Transmission of channel access control information} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The present specification presents a method for synchronizing DU transmission timings of IAB nodes. ## Claims ### Claim 1 A synchronization method for a distributed unit (DU) transmission timing performed by an integrated access and backhaul (IAB) node in a wireless communication system, the method comprising: transmitting a random access preamble to a parent node; receiving a random access response from the parent node; receiving a first parameter related to a mobile termination (MT) transmission timing of the IAB node and a second parameter related to the DU transmission timing of the IAB node from the parent node; determining a time spacing between an MT reception timing and the DU transmission timing of the IAB node based on the first parameter and the second parameter; and performing synchronization for the DU transmission timing with the parent node based on the time spacing. ### Claim 2 (depends on 1) The method of claim 1, wherein an identical DU transmission timing is set to multiple nodes included in the IAB system for the synchronization. ### Claim 3 (depends on 1) The method of claim 1, wherein the MT transmission timing and the MT reception timing are timings related to operations between the IAB node and the parent node, and wherein the DU transmission timing is a timing related to an operation between a child node of the IAB node and the IAB node. ### Claim 4 (depends on 1) The method of claim 1, wherein the first parameter and the second parameter are independently transmitted with each other. ### Claim 5 (depends on 1) The method of claim 1, wherein the first parameter is transmitted using a timing advance (TA) command signal. ### Claim 6 (depends on 1) The method of claim 1, wherein the first parameter and the second parameter are included in a single signal and transmitted. ### Claim 7 (depends on 1) The method of claim 1, wherein the DU transmission timing is determined based on a summation of the first parameter and the second parameter. ### Claim 8 (depends on 1) The method of claim 1, wherein the IAB node receives each of the first parameter and the second parameter for multiple times, and wherein the DU transmission timing is determined based on a filtered value from each of the first parameter and the second parameter. ### Claim 9 (depends on 8) The method of claim 8, wherein the filtered value is an average value. ### Claim 10 (depends on 8) The method of claim 8, wherein the filtered value is a value determined based on values of a parameter transmitted by the parent node or a value determined based on values of a parameter received by the IAB node. ### Claim 11 (depends on 8) The method of claim 8, wherein the IAB node receives filtering information for the filtering from the parent node, and wherein the filtering information informs at least one of a coefficient used for the filtering or a window size to which the filtering is applied. ### Claim 12 (depends on 1) The method of claim 1, wherein the first parameter and the second parameter are independently transmitted. ### Claim 13 (depends on 1) The method of claim 1, wherein the IAB node transmits report information to the parent node, and wherein the report information includes information related to the timing spacing. ### Claim 14 (depends on 13) The method of claim 13, wherein the report information informs the first parameter. ### Claim 15 (depends on 1) The method of claim 1, wherein the second parameter is transmitted through a medium access control-control element (MAC-CE) signaling. ### Claim 16 A node comprising: one or more memories storing instructions; one or more transceivers; and one or more processors connecting the one or more memories with the one or more transceivers, wherein the one or more processors, by executing the instruction, are configured to perform: transmitting a random access preamble to a parent node; receiving a random access response from the parent node; receiving a first parameter related to a mobile termination (MT) transmission timing of an integrated access and backhaul (IAB) node and a second parameter related to a distributed unit (DU) transmission timing of the IAB node from the parent node; determining a time spacing between an MT reception timing and the DU transmission timing of the IAB node based on the first parameter and the second parameter; and performing synchronization for the DU transmission timing with the parent node based on the time spacing. ### Claim 17 (depends on 16) The node of claim 16, wherein the IAB node communicates with at least one of a mobile terminal, a network, or an autonomous driving vehicle except the node. ### Claim 18 (depends on 16) The node of claim 16, wherein the IAB node is a base station or a user equipment. ### Claim 19 An apparatus configured to control an integrated access and backhaul (IAB) node, comprising: one or more processors; and one or more memories workably connected to the one or more processors and store instructions, wherein the one or more processors, by executing the instruction, are configured to perform; transmitting a random access preamble to a parent node; receiving a random access response from the parent node; receiving a first parameter related to a mobile termination (MT) transmission timing of the IAB node and a second parameter related to a distributed unit DU) transmission timing of the IAB node from the parent node; determining a time spacing between an MT reception timing and the DU transmission timing of the IAB node based on the first parameter and the second parameter; and performing synchronization for the DU transmission timing with the parent node based on the time spacing.