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EP-3841814-B1 - INTEGRATED ACCESS BACKHAUL CONFIGURATION

EP3841814B1EP 3841814 B1EP3841814 B1EP 3841814B1EP-3841814-B1

Inventors

  • WU, SHANGBIN
  • QI, Yinan

Dates

Publication Date
20260506
Application Date
20190930

Claims (15)

  1. A method of operating an Integrated Access Backhaul, IAB, node in a wireless communication network, the IAB node being arranged to communicate backhaul traffic wirelessly with a parent node and a child node, the method comprising: receiving a first duplexing pattern configuration message from the parent node, the first duplexing pattern configuration message including a duplexing pattern; transmitting a second duplexing pattern configuration message to the child node based on the first duplexing pattern configuration message; receiving a first duplexing pattern configuration acknowledgment message from the child node as a response to the second duplexing pattern configuration message; after receiving the first duplexing pattern configuration acknowledgment message from the child node, applying a duplexing pattern included in the first duplexing pattern configuration message received from the parent node; and transmitting a second duplexing pattern configuration acknowledgement message to the parent node.
  2. The method of claim 1, wherein the first duplexing pattern configuration message received from the parent node includes: the duplexing pattern for the IAB node; and the second duplexing pattern configuration message to be transmitted to the child node.
  3. The method of claim 1, wherein the duplexing pattern included in the first duplexing pattern configuration message received from the parent node is for that IAB node.
  4. The method of claim 3, further comprising: determining a duplexing pattern for the child node, to be included in the second duplexing pattern configuration message transmitted to the child node, based on the duplexing pattern included in the first duplexing pattern configuration message received from the parent node.
  5. The method of claim 4, wherein determining the duplexing pattern for the child node comprises determining the duplexing pattern for the child node arranged to prevent data transmission and data reception conflict for the IAB node in a particular time period.
  6. The method of claim 1, wherein the duplexing pattern indicates at least one of transmission slots, symbols or subframes within a transmission frame within which the IAB node communicates with its parent node.
  7. The method of claim 1, wherein the duplexing pattern includes an X transmission slot, symbol or subframe between a downlink transmission slot, symbol or subframe and a subsequent uplink transmission slot, symbol or subframe.
  8. The method of claim 1, wherein the duplex pattern indicates slots, symbols or subframes for an IAB node to perform: backhaul uplink, BHU; backhaul downlink, BHD; uplink, U, from a child node or an access device; or downlink, D, to a child device or an access device.
  9. The method of claim 8, wherein the duplexing pattern included in the second duplexing pattern configuration message transmitted to the child node includes a BHD slot, symbol or subframe matching a BHU slot, symbol or subframe of the duplexing pattern received from the parent node and a BHU slot, symbol or subframe matching a BHD slot, symbol or subframe of the duplexing pattern received from the parent node.
  10. The method of claim 8, further comprising: converting a BHD or BHU slot, symbol or subframe within the duplex pattern received from the parent node into a D or U slot, symbol or subframe.
  11. The method of claim 1, wherein the first and second duplexing pattern configuration messages are transmitted by semi-persistent configuration, via radio resource control, RRC, signalling or dynamic configuration, via downlink control information, DCI; and the first and the second duplexing pattern configuration acknowledgement messages are transmitted via uplink control information, UCI.
  12. The method of claim 1, wherein duplexing patterns are defined by a table shared by all IAB nodes.
  13. An Integrated Access Backhaul, IAB, node in a wireless communication network, the IAB node being arranged to communicate backhaul traffic wirelessly with a parent node and a child node, the IAB node comprising a transmitter and a receiver; and a controller coupled with the transmitter and the receiver and configured to: control the receiver to receive a first duplexing pattern configuration message from the parent node, the first duplexing pattern configuration message including a duplexing pattern, control the transmitter to transmit a second duplexing pattern configuration message to the child node based on the first duplexing pattern configuration message, control the receiver to receive a first duplexing pattern configuration acknowledgment message from the child node as a response to the second duplexing pattern configuration message, after receiving the first duplexing pattern configuration acknowledgment message from the child node, apply a duplexing pattern included in the first duplexing pattern configuration message received from the parent node, and control the transmitter to transmit a second duplexing pattern configuration acknowledgement message to the parent node.
  14. The IAB node of claim 13, wherein the first duplexing pattern configuration message received from the parent node includes: the duplexing pattern for the IAB node; and the second duplexing pattern configuration message to be transmitted to the child node.
  15. The IAB node of claim 13, wherein the duplexing pattern indicates at least one of transmission slots, symbols or subframes within a transmission frame within which the IAB node communicates with its parent node.

Description

[Technical Field] This invention relates to techniques for configuring Integrated Access Backhaul (IAB). In particular, certain examples relate to IAB configuration for a New Radio (NR) air interface of a wireless communication network, such as has been proposed for Fifth Generation (5G) wireless communication networks. [Background Art] Wireless or mobile (cellular) communications networks in which a mobile terminal (UE, such as a mobile handset) communicates via a radio link with a network of base stations, or other wireless access points or nodes, have undergone rapid development through a number of generations. The 3rd Generation Partnership Project (3GPP) design, specify and standardise technologies for mobile wireless communication networks. Fourth Generation (4G) systems are now widely deployed. 3GPP standards for 4G systems include an Evolved Packet Core (EPC) and an Enhanced-UTRAN (E-UTRAN: an Enhanced Universal Terrestrial Radio Access Network). The E-UTRAN uses Long Term Evolution (LTE) radio technology. LTE is commonly used to refer to the whole system including both the EPC and the E-UTRAN, and LTE is used in this sense in the remainder of this document. LTE should also be taken to include LTE enhancements such as LTE Advanced and LTE Pro, which offer enhanced data rates compared to LTE. The trend towards greater data throughput continues with 3GPP currently working to standardise Fifth Generation (5G) network technologies. As part of this, a new air interface is being developed, which may be referred to as 5G New Radio (5G NR) or simply NR. NR is designed to support the wide variety of services and use case scenarios envisaged for 5G networks, though builds upon established LTE technologies. One aspect of NR is the use of wireless backhaul to reduce network deployment costs and enhance network flexibility by allowing for the topology of the network to be reconfigured. For a conventional wireless communication network, such as LTE, base stations (referred to in LTE as enhanced Node Bs, eNBs) via connected to the core network via wired backhaul (BH) links. The base stations are responsible for communicating with mobile devices wirelessly such that those devices may access the core network. Alternatively, a base station may be connected to a core network via a dedicated point-to-point wireless link, quite separate from the process of allowing a device to wirelessly access the base station. As part of NR it is proposed that access for devices to the core network and wireless backhaul may be integrated, which may be referred to as Integrated Access Backhaul (IAB). That is, within a single transmission frame for an NR base station, referred to herein as an IAB node, both backhaul communications and mobile device access communications may be incorporated. It will be appreciated that transmission timing and coordination for IAB present challenges that have not been fully resolved. IAB is a feature whereby the air interface between nodes or base stations is used to provide backhaul connectivity as well as access to User Equipment, UE. The configuration of such a system involves careful selection of signalling to ensure reliable and effective connectivity both between nodes and with UEs. Certain network features have been agreed at a standardisation level. These are summarised below and serve to provide background information for the present invention. Physical layer specification [RAN1-led, RAN2, RAN3, RAN4]: ·Specification of Synchronisation Signal Block (SSB)/ Remaining Minimum System Information (RMSI) periodicity for NR initial access assumed by an IAB-node.·Specification of extensions to Rel. 15 to support the use of SSBs orthogonal to SSBs used for UEs (via Time Division Multiplexing (TDM) and/or Frequency Division Multiplexing (FDM)), for inter-IAB-node discovery and measurements, including additional SSB-based RRM Measurement Timing Configuration (SMTC) periodicities and time-domain mapping of SSB locations (e.g. enable muting patterns to deal with half-duplex constraint).·Specification of extension of Random Access Channel (RACH) occasions and periodicities for backhaul RACH resources. w.r.t. access RACH resources, and associated network coordination mechanisms for selection of such parameters (in order to orthogonalize access and Backhaul (BH) due to the half-duplex constraints i.e. that nodes are unable to transmit and receive simultaneoulsy)·Specification of mechanisms for resource multiplexing among backhaul and access links. This includes: ·Specification of semi-static configuration for IAB-node/IAB-donor Distributed Unit (DU) resources in case of TDM operation subject to half-duplex constraint. This shall be forward compatible to allow the support of half-duplex scenarios with FDM and Spatial Division Multiplexing (SDM) resource sharing among backhaul and access links.·Specification of time resource types for the DU's child links: DL hard, DL soft, UL hard, UL soft, Flexible hard, Flexibl