WO2022087603A1 - Multiple parent iab node resource allocation mechanism - Google Patents

Abstract

An apparatus and system to mitigate uplink scheduling conflicts among IAB nodes are described. An IAB node with multiple parents receives soft resource availability in DCI format 2 5 from one of the parents. If the DCI format 2_5 is transmitted from a master parent, the IAB node uses the soft resources for uplink transmissions. The other parents are informed of the DCI format 2 5 transmission and synchronize soft resource availability based on the DCI format 2_5 transmission. Availability of the soft resources is dependent on predetermined rules including whether TDM is required and simultaneous operation between the IAB node and multiple parents is permitted.

Description

MULTIPLE PARENT IAB NODE RESOURCE ALLOCATION MECHANISM

PRIORITY CLAIM

[0001] This application claims the benefit of priority to United States Provisional Patent Application Serial No. 63/094,734, filed October 21, 2020, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to next generation wireless communications. In particular, some embodiments relate to Integrated Access Backhaul (IAB) Mobile Termination (MT) in 5G networks.

BACKGROUND

[0003] The use and complexity of wireless systems, which include 5^th generation (5G) networks and are starting to include sixth generation (6G) networks among others, has increased due to both an increase in the types of devices user equipment (UEs) using network resources as well as the amount of data and bandwidth being used by various applications, such as video streaming, operating on these UEs. With the vast increase in number and diversity of communication devices, the corresponding network environment, including routers, switches, bridges, gateways, firewalls, and load balancers, has become increasingly complicated. As expected, a number of issues abound with the advent of any new technology.

BRIEF DESCRIPTION OF THE FIGURES

[0004] In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0005] FIG. 1 A illustrates an architecture of a network, in accordance with some aspects.

[0006] FIG. IB illustrates a non-roaming 5G system architecture in accordance with some aspects. [0007] FIG. 1C illustrates a non-roaming 5G system architecture in accordance with some aspects.

[0008] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments.

[0009] FIG. 3 illustrates different IAB link types in accordance with some aspects.

[0010] FIG. 4 illustrates a multi-parent IAB MT in accordance with some aspects.

[0011] FIG. 5 illustrates multi-parent IAB MT coordination in accordance with some aspects.

[0012] FIG. 6 illustrates multi-parent IAB MT information in accordance with some aspects.

[0013] FIG. 7 illustrates a flowchart of an IAB distributed unit (DU) process in accordance with some aspects.

[0014] FIG. 8 illustrates a flowchart of an IAB MT process in accordance with some aspects.

DETAILED DESCRIPTION

[0015] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0016] FIG. 1 A illustrates an architecture of a network in accordance with some aspects. The network 140A includes 3GPP LTE/4G and NG network functions that may be extended to 6G functions. Accordingly, although 5G will be referred to, it is to be understood that this is to extend as able to 6G structures, systems, and functions. A network function can be implemented as a discrete network element on a dedicated hardware, as a software instance running on dedicated hardware, and/or as a virtualized function instantiated on an appropriate platform, e.g., dedicated hardware or a cloud infrastructure.

[0017] The network 140A is shown to include user equipment (UE) 101 and UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also include any mobile or non-mobile computing device, such as portable (laptop) or desktop computers, wireless handsets, drones, or any other computing device including a wired and/or wireless communications interface. The UEs 101 and 102 can be collectively referred to herein as UE 101, and UE 101 can be used to perform one or more of the techniques disclosed herein.

[0018] Any of the radio links described herein (e.g., as used in the network 140A or any other illustrated network) may operate according to any exemplary radio communication technology and/or standard. Any spectrum management scheme including, for example, dedicated licensed spectrum, unlicensed spectrum, (licensed) shared spectrum (such as Licensed Shared Access (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and other frequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and other frequencies). Different Single Carrier or Orthogonal Frequency Domain Multiplexing (OFDM) modes (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.), and in particular 3 GPP NR, may be used by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

[0019] In some aspects, any of the UEs 101 and 102 can comprise an Intemet-of -Things (loT) UE or a Cellular loT (CIoT) UE, which can comprise a network access layer designed for low-power loT applications utilizing shortlived UE connections. In some aspects, any of the UEs 101 and 102 can include a narrowband (NB) IoT UE (e.g., such as an enhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An loT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity -Based Service (ProSe) or device-to-d evice (D2D) communication, sensor networks, or loT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An loT network includes interconnecting loT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The loT UEs may execute background applications (e.g., keepalive messages, status updates, etc.) to facilitate the connections of the loT network. In some aspects, any of the UEs 101 and 102 can include enhanced MTC (eMTC) UEs or further enhanced MTC (FeMTC) UEs.

[0020] The UEs 101 and 102 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 110. The RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN.

[0021] The UEs 101 and 102 utilize connections 103 and 104, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 103 and 104 are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a 5G protocol, a 6G protocol, and the like.

[0022] In an aspect, the UEs 101 and 102 may further directly exchange communication data via a ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink (SL) interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), a Physical Sidelink Broadcast Channel (PSBCH), and a Physical Sidelink Feedback Channel (PSFCH).

[0023] The UE 102 is shown to be configured to access an access point (AP) 106 via connection 107. The connection 107 can comprise a local wireless connection, such as, for example, a connection consistent with any IEEE 802.11 protocol, according to which the AP 106 can comprise a wireless fidelity (WiFi®) router. In this example, the AP 106 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[0024] The RAN 110 can include one or more access nodes that enable the connections 103 and 104. These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), Next Generation NodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). In some aspects, the communication nodes 111 and 112 can be transmission/reception points (TRPs). In instances when the communication nodes 111 and 112 are NodeBs (e.g., eNBs or gNBs), one or more TRPs can function within the communication cell of theNodeBs. The RAN 110 may include one or more RAN nodes for providing macrocells, e.g., macro RAN node 111, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 112. [0025] Any of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact forthe UEs 101 and 102. In some aspects, any of the RAN nodes 111 and 112 can fulfill various logical functions forthe RAN 110 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In an example, any of the nodes 111 and/or 112 can be a gNB, an eNB, or another type of RAN node.

[0026] The RAN 110 is shown to be communicatively coupled to a core network (CN) 120 via an SI interface 113. In aspects, the CN 120 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN (e.g., as illustrated in reference to FIGS. 1B-1C). In this aspect, the SI interface 113 is split into two parts: the Sl-U interface 114, which carries traffic data between the RAN nodes 111 and 112 and the serving gateway (S-GW) 122, and the SI -mobility management entity (MME) interface 115, which is a signaling interface between the RAN nodes 111 and 112 and MMEs

121.

[0027] In this aspect, the CN 120 comprises the MMEs 121, the S-GW

122, the Packet DataNetwork (PDN) Gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MMEs 121 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 121 may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS 124 may comprise a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The CN 120 may comprise one or several HSSs 124, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 124 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc.

[0028] The S-GW 122 may terminate the SI interface 113 towards the RAN 110, and routes data packets between the RAN 110 and the CN 120. In addition, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities of the S-GW 122 may include a lawful intercept, charging, and some policy enforcement.

[0029] The P-GW 123 may terminate an SGi interface toward aPDN. The P-GW 123 may route data packets between the CN 120 and external networks such as a network including the application server 184 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 125. The P-GW 123 can also communicate data to other external networks 131 A, which can include the Internet, IP multimedia subsystem (IPS) network, and other networks. Generally, the application server 184 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this aspect, the P-GW 123 is shown to be communicatively coupled to an application server 184 via an IP interface 125. The application server 184 can also be configured to support one or more communication services (e.g., Voice-over-Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs 101 and 102 via the CN 120.

[0030] The P-GW 123 may further be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In anon-roaming scenario, in some aspects, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with a local breakout of traffic, there may be two PCRFs associated with a UE's IP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be communicatively coupled to the application server 184 via theP-GW 123. [0031] In some aspects, the communication network 140A can be an loT network or a 5G or 6G network, including 5G new radio network using communications in the licensed (5G NR) and the unlicensed (5G NR-U) spectrum. One of the current enablers of loT is the narrowband -I oT (NB-IoT). Operation in the unlicensed spectrum may include dual connectivity (DC) operation and the standalone LTE system in the unlicensed spectrum, according to which LTE-based technology solely operates in unlicensed spectrum without the use of an “anchor” in the licensed spectrum, called MulteFire. Further enhanced operation of LTE systems in the licensed as well as unlicensed spectrum is expected in future releases and 5G systems. Such enhanced operations can include techniques for sidelink resource allocation and UE processing behaviors for NR sidelink V2X communications.

[0032] An NG system architecture (or 6G system architecture) can include the RAN 110 and a 5G core network (5GC) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBs and NG-eNBs. The CN 120 (e.g., a 5G core network/5GC) can include an access and mobility function (AMF) and/or a user plane function (UPF). The AMF and the UPF can be communicatively coupled to the gNBs and the NG-eNBs via NG interfaces. More specifically, in some aspects, the gNBs and the NG-eNBs can be connected to the AMF by NG-C interfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBs can be coupled to each other via Xn interfaces. [0033] In some aspects, the NG system architecture can use reference points between various nodes. In some aspects, each of the gNBs and the NG- eNBs can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so forth. In some aspects, a gNB can be a master node (MN) and NG-eNB can be a secondary node (SN) in a 5G architecture.

[0034] FIG. IB illustrates anon-roaming 5G system architecture in accordance with some aspects. In particular, FIG. IB illustrates a 5G system architecture 140B in a reference point representation, which may be extended to a 6G system architecture. More specifically, UE 102 can be in communication with RAN 110 as well as one or more other 5GC network entities. The 5G system architecture 140B includes a plurality of network functions (NFs), such as an AMF 132, session management function (SMF) 136, policy control function (PCF) 148, application function (AF) 150, UPF 134, network slice selection function (NSSF) 142, authentication server function (AUSF) 144, and unified data management (UDM)Zhome subscriber server (HSS) 146.

[0035] The UPF 134 can provide a connection to a data network (DN) 152, which can include, for example, operator services, Internet access, or third- party services. The AMF 132 can be used to manage access control and mobility and can also include network slice selection functionality. The AMF 132 may provide UE-based authentication, authorization, mobility management, etc., and may be independent of the access technologies. The SMF 136 can be configured to set up and manage various sessions according to network policy. The SMF 136 may thus be responsible for session management and allocation of IP addresses to UEs. The SMF 136 may also select and control the UPF 134 for data transfer. The SMF 136 may be associated with a single session of a UE 101 or multiple sessions of the UE 101. This is to say that the UE 101 may have multiple 5G sessions. Different SMFs may be allocated to each session. The use of different SMFs may permit each session to be individually managed. As a consequence, the functionalities of each session may be independent of each other.

[0036] The UPF 134 can be deployed in one or more configurations according to the desired service type and may be connected with a data network. The PCF 148 can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system).

[0037] The AF 150 may provide information on the packet flow to the PCF 148 responsible for policy control to support a desired QoS. The PCF 148 may set mobility and session management policies for the UE 101. To this end, the PCF 148 may use the packet flow information to determine the appropriate policies for proper operation of the AMF 132 and SMF 136. The AUSF 144 may store data for UE authentication.

[0038] In some aspects, the 5G system architecture 140B includes an IP multimedia subsystem (IMS) 168B as well as a plurality of IP multimedia core network subsystem entities, such as call session control functions (CSCFs). More specifically, the IMS 168B includes a CSCF, which can act as a proxy CSCF (P-CSCF) 162BE, a serving CSCF (S-CSCF) 164B, an emergency CSCF (E-CSCF) (not illustrated in FIG. IB), or interrogating CSCF (I -CSCF) 166B. The P-CSCF 162B can be configured to be the first contact point for the UE 102 within the IM subsystem (IMS) 168B. The S-CSCF 164B can be configured to handle the session states in the network, and the E-CSCF can be configured to handle certain aspects of emergency sessions such as routing an emergency request to the correct emergency center or PSAP. The I-CSCF 166B can be configured to function as the contact point within an operator's network for all IMS connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator's service area. In some aspects, the I-CSCF 166B can be connected to another IP multimedia network 170E, e.g. an IMS operated by a different network operator.

[0039] In some aspects, the UDM/HSS 146 can be coupled to an application server 160E, which can include a telephony application server (TAS) or another application server (AS). The AS 160B can be coupled to the IMS 168B via the S-CSCF 164B or the I-CSCF 166B.

[0040] A reference point representation shows that interaction can exist between corresponding NF services. For example, FIG. IB illustrates the following reference points: N1 (between theUE 102 and the AMF 132), N2 (between the RAN 110 and the AMF 132), N3 (between the RAN 110 and the UPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF 148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152), N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM 146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown), N10 (between the UDM 146 and the SMF 136, not shown), N11 (between the AMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and the AMF 132, not shown), N13 (between the AUSF 144 and the UDM 146, not shown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148 and the AMF 132 in case of anon-roaming scenario, or between the PCF 148 and a visited network and AMF 132 in case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between AMF 132 and NSSF 142, not shown). Other reference point representations not shown in FIG. IB can also be used. [0041] FIG. 1C illustrates a 5G system architecture 140C and a servicebased representation. In addition to the network entities illustrated in FIG. IB, system architecture 140C can also include a network exposure function (NEF) 154 and a network repository function (NRF) 156. In some aspects, 5G system architectures can be service-based and interaction between network functions can be represented by corresponding point-to-point reference points Ni or as service-based interfaces.

[0042] In some aspects, as illustrated in FIG. 1C, service-based representations can be used to represent network functions within the control plane that enable other authorized network functions to access their services. In this regard, 5G system architecture 140C can include the following servicebased interfaces: Namf 158H (a service-based interface exhibited by the AMF 132), Nsmf 1581 (a service-based interface exhibited by the SMF 136), Nnef 158B (a service-based interface exhibited by the NEF 154), Npcf 158D (a service-based interface exhibited by thePCF 148), aNudm !58E (a servicebased interface exhibited by the UDM 146), Naf 158F (a service-based interface exhibited by theAF 150), Nnrf 158C (a service-based interface exhibited by the NRF 156), Nnssf 158A (a service-based interface exhibited by theNSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF 144). Other service-based interfaces (e.g., Nudr,N5g-eir, and Nudsf)not shown in FIG. 1C can also be used.

[0043] NR-V2X architectures may support high-reliability low latency sidelink communications with a variety of traffic patterns, including periodic and aperiodic communications with random packet arrival time and size.

Techniques disclosed herein can be used for supporting high reliability in distributed communication systems with dynamic topologies, including sidelink NR V2X communication systems.

[0044] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments. The communication device 200 may be a UE such as a specialized computer, a personal or laptop computer (PC), a tablet PC, or a smart phone, dedicated network equipment such as an eNB, a server running software to configure the server to operate as a network device, a virtual device, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. For example, the communication device 200 may be implemented as one or more of the devices shown in FIGS. 1A-1C. Note that communications described herein may be encoded before transmission by the transmitting entity (e.g., UE, gNB) for reception by the receiving entity (e.g., gNB, UE) and decoded after reception by the receiving entity.

[0045] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules and components are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0046] Accordingly, the term “module” (and “component”) is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0047] The communication device 200 may include a hardware processor (or equivalently processing circuitry) 202 (e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), a main memory 204 and a static memory 206, some or all of which may communicate with each other via an interlink (e.g., bus) 208. The main memory 204 may contain any or all of removable storage and non-removable storage, volatile memory or non-volatile memory. The communication device 200 may further include a display unit 210 such as a video display, an alphanumeric input device 212 (e.g., a keyboard), and a user interface (UI) navigation device 214 (e.g., a mouse). In an example, the display unit 210, input device 212 and UI navigation device 214 may be a touch screen display. The communication device 200 may additionally include a storage device (e.g., drive unit) 216, a signal generation device 218 (e.g., a speaker), a network interface device 220, and one or more sensors, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The communication device 200 may further include an output controller, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0048] The storage device 216 may include a non-transitory machine readable medium 222 (hereinafter simply referred to as machine readable medium) on which is stored one or more sets of data structures or instructions 224 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 224 may also reside, completely or at least partially, within the main memory 204, within static memory 206, and/or within the hardware processor 202 during execution thereof by the communication device 200. While the machine readable medium 222 is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 224.

[0049] The term “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 200 and that cause the communication device 200 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks.

[0050] The instructions 224 may further be transmitted or received over a communications network using a transmission medium 226 via the network interface device 220 utilizing any one of a number of wireless local area network (WLAN) transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HUP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless datanetworks. Communications over the networks may include one or more different protocols, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi, IEEE 802.16 family of standards known as WiMax, IEEE

802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, a next generation (NG)/5^th generation (5G) standards among others. In an example, the network interface device 220 may include one or more physical jacks (e.g., Ethernet, coaxial, or phonejacks) or one or more antennas to connect to the transmission medium 226.

[0051] Note that the term “circuitry” as used herein refers to, is part of, or includes hardware components such as an electronic circuit, a logic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group), an Application Specific Integrated Circuit (ASIC), a field -programmable device (FPD) (e.g., a field -programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high-capacity PLD (HCPLD), a structured ASIC, or a programmable SoC), digital signal processors (DSPs), etc., that are configured to provide the described functionality. In some embodiments, the circuitry may execute one or more software or firmware programs to provide at least some of the described functionality. The term “circuitry” may also refer to a combination of one or more hardware elements (or a combination of circuits used in an electrical or electronic system) with the program code used to carry out the functionality of that program code. In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuitry.

[0052] The term “processor circuitry” or “processor” as used herein thus refers to, is part of, or includes circuitry capable of sequentially and automatically carrying out a sequence of arithmetic or logical operations, or recording, storing, and/or transferring digital data. The term “processor circuitry” or “processor” may refer to one or more application processors, one or more baseband processors, a physical central processing unit (CPU), a single- or multi-core processor, and/or any other device capable of executing or otherwise operating computer-executable instructions, such as program code, software modules, and/or functional processes.

[0053] Any of the radio links described herein may operate according to any one or more of the following radio communication technologies and/or standards including but not limited to: a Global System for Mobile Communications (GSM) radio communication technology, a General Packet Radio Service (GPRS) radio communication technology, an Enhanced Data Rates for GSM Evolution (EDGE) radio communication technology, and/or a Third Generation Partnership Project (3GPP) radio communication technology, for example Universal Mobile Telecommunications System (UMTS), Freedom of Multimedia Access (FOMA), 3GPP Long Term Evolution (LTE), 3GPP Long Term Evolution Advanced (LTE Advanced), Code division multiple access 2000 (CDMA2000), Cellular Digital Packet Data (CDPD), Mobitex, Third Generation (3G), Circuit Switched Data (CSD), High-Speed Circuit-Switched Data (HSCSD), Universal Mobile Telecommunications System (Third Generation) (UMTS (3G)), Wideband Code Division Multiple Access (Universal Mobile Telecommunications System) (W-CDMA (UMTS)), High Speed Packet Access (HSPA), High-Speed Downlink Packet Access (HSDPA), High-Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+), Universal Mobile Telecommunications System-Time-Division Duplex (UMTS-TDD), Time Division-Code Division Multiple Access (TD-CDMA), Time Division- Synchronous Code Division Multiple Access (TD-CDMA), 3rd Generation Partnership Project Release 8 (Pre-4th Generation) (3 GPP Rel. 8 (Pre-4G)), 3GPP Rel. 9 (3rd Generation Partnership Project Release 9), 3GPP Rel. 10 (3rd Generation Partnership Project Release 10) , 3GPP Rel. 11 (3rd Generation Partnership Project Release 11), 3GPP Rel. 12 (3rd Generation Partnership Project Release 12), 3GPP Rel. 13 (3rd Generation Partnership Project Release 13), 3GPP Rel. 14 (3rd Generation Partnership Project Release 14), 3GPP Rel. 15 (3rd Generation Partnership Project Release 15), 3GPP Rel. 16 (3rd Generation Partnership Project Release 16), 3GPP Rel. 17 (3rd Generation Partnership Project Release 17) and subsequent Releases (such as Rel. 18, Rel. 19, etc ), 3GPP 5G, 5G, 5GNew Radio (5GNR), 3GPP 5G New Radio, 3GPP LTE Extra, LTE-Advanced Pro, LTE Licensed -Assisted Access (LAA), MuLTEfire, UMTS Terrestrial Radio Access (UTRA), Evolved UMTS Terrestrial Radio Access (E-UTRA), Long Term Evolution Advanced (4th Generation) (LTE Advanced (4G)), cdmaOne (2G), Code division multiple access 2000 (Third generation) (CDMA2000 (3G)), Evolution-Data Optimized or Evolution-Data Only (EV -DO), Advanced Mobile Phone System (1st Generation) (AMPS (1 G)), Total Access Communication System/Extended Total Access Communication System (TACS/ETACS), Digital AMPS (2nd Generation) (D-AMPS (2G)), Push-to-talk (PIT), Mobile Telephone System (MTS), Improved Mobile Telephone System (IMTS), Advanced Mobile Telephone System (AMTS), OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile Telephony), MTD (Swedish abbreviation for Mobiltelefonisystem D, or Mobile telephony system D), Public Automated Land Mobile (Autotel/PALM), ARP (Finnish for Autoradiopuhelin, "car radio phone"), NMT (Nordic Mobile Telephony), High capacity version of NTT (Nippon Telegraph and Telephone) (Hicap), Cellular Digital Packet Data (CDPD), Mobitex, DataTAC, Integrated Digital Enhanced Network (iDEN), Personal Digital Cellular (PDC), Circuit Switched Data(CSD), Personal Handyphone System (PHS), Wideband Integrated Digital Enhanced Network (WiDEN), iBurst, Unlicensed Mobile Access (UMA), also referred to as also referred to as 3GPP Generic Access Network, or GAN standard), Zigbee, Bluetooth(r), Wireless Gigabit Alliance (WiGig) standard, mmWave standards in general (wireless systems operating at 10-300 GHz and above such as WiGig, IEEE 802. Had, IEEE 802.1 lay, etc.), technologies operating above 300 GHz and THz bands, (3GPP/LTE based or IEEE 802.1 Ip or IEEE 802.1 Ibd and other) Vehicle-to-Vehicle (V2V) and Vehicle-to-X (V2X) and Vehicle-to- Infrastructure (V2I) and Infrastructure-to-Vehicle (I2V) communication technologies, 3GPP cellular V2X, DSRC (Dedicated Short Range Communications) communication systems such as Intelligent-Transport-Systems and others (typically operating in 5850 MHz to 5925 MHz or above (typically up to 5935 MHz following change proposals in CEPT Report 71)), the European ITS-G5 system (i.e. the European flavor of IEEE 802. lip based DSRC, including ITS-G5A (i.e., Operation of ITS-G5 in European ITS frequency bands dedicated to ITS for safety re-lated applications in the frequency range 5,875 GHz to 5,905 GHz), ITS-G5B (i.e., Operation in European ITS frequency bands dedicated to ITS non- safety applications in the frequency range 5,855 GHz to 5,875 GHz), ITS-G5C (i.e., Operation of ITS applications in the frequency range 5,470 GHzto 5,725 GHz)), DSRC in Japan in the 700MHz band (including 715 MHz to 725 MHz), IEEE 802.1 Ibd based systems, etc.

[0054] Aspects described herein can be used in the context of any spectrum management scheme including dedicated licensed spectrum, unlicensed spectrum, license exempt spectrum, (licensed) shared spectrum (such as LSA = Licensed Shared Access in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz and further frequencies and SAS = Spectrum Access System / CBRS = Citizen Broadband Radio System in 3.55-3.7 GHz and further frequencies). Applicable spectrum bands include IMT (International Mobile Telecommunications) spectrum as well as other types of spectrum/bands, such as bands with national allocation (including 450 - 470 MHz, 902-928 MHz (note: allocated for example in US (FCC Part 15)), 863-868.6 MHz (note: allocated for example in European Union (ETSI EN 300220)), 915.9-929.7 MHz (note: allocated for example in Japan), 917-923.5 MHz (note: allocated for example in South Korea), 755-779 MHz and 779-787 MHz (note: allocated for example in China), 790 - 960 MHz, 1710 - 2025 MHz, 2110 - 2200 MHz, 2300 - 2400 MHz, 2.4-2.4835 GHz (note: it is an ISM band with global availability and it is used by Wi-Fi technology family (llb/g/n/ax) and also by Bluetooth), 2500 - 2690 MHz, 698-790 MHz, 610 - 790 MHz, 3400 - 3600 MHz, 3400 - 3800 MHz, 3800 - 4200 MHz, 3.55- 3.7 GHz (note: allocated for example in the US for Citizen Broadband Radio Service), 5.15-5.25 GHz and 5.25-5.35 GHz and 5.47-5.725 GHz and 5.725-5.85 GHz bands (note: allocated for example in the US (FCC part 15), consists four U-NII bands in total 500 MHz spectrum), 5.725-5.875 GHz (note: allocated for example in EU (ETSI EN 301 893)), 5.47-5.65 GHz (note: allocated for example in South Korea, 5925-7125 MHz and 5925-6425MHz band (note: under consideration in US and EU, respectively. Next generation Wi-Fi system is expected to include the 6 GHz spectrum as operating band but it is noted that, as of December 2017, Wi-Fi system is not yet allowed in this band. Regulation is expected to be finished in 2019-2020 time frame), IMT-advanced spectrum, IMT-2020 spectrum (expected to include 3600-3800 MHz, 3800 - 4200 MHz, 3.5 GHz bands, 700 MHz bands, bands within the 24.25-86 GHz range, etc.), spectrum made available under FCC's "Spectrum Frontier" 5G initiative (including 27.5 - 28.35 GHz, 29.1 - 29.25 GHz, 31 - 31.3 GHz, 37 - 38.6 GHz, 38.6 - 40 GHz, 42 - 42.5 GHz, 57 - 64 GHz, 71 - 76 GHz, 81 - 86 GHz and 92 - 94 GHz, etc), the ITS (Intelligent Transport Systems) band of 5.9 GHz (typically 5.85-5.925 GHz) and 63-64 GHz, bands currently allocated to WiGig such as WiGig Band 1 (57.24-59.40 GHz), WiGig Band 2 (59.40-61.56 GHz) and WiGig Band 3 (61.56-63.72 GHz) and WiGig Band 4 (63.72-65.88 GHz), 57- 64/66 GHz (note: this band has near-global designation for Multi-Gigabit Wireless Systems (MGWS)ZWiGig . In US (FCC part 15) allocates total 14 GHz spectrum, while EU (ETSI EN 302 567 and ETSI EN 301 217-2 forfixed P2P) allocates total 9 GHz spectrum), the 70.2 GHz - 71 GHz band, any band between 65.88 GHz and 71 GHz, bands currently allocated to automotive radar applications such as 76-81 GHz, and future bands including 94-300 GHz and above. Furthermore, the scheme can be used on a secondary basis on bands such as the TV White Space bands (typically below 790 MHz) where in particular the 400 MHz and 700 MHz bands are promising candidates. Besides cellular applications, specific applications for vertical markets may be addressed such as PMSE (Program Making and Special Events), medical, health, surgery, automotive, low-latency, drones, etc. applications.

[0055] Aspects described herein can also implement a hierarchical application of the scheme is possible, e.g., by introducing a hierarchical prioritization of usage for different types of users (e.g., low/medium/high priority, etc.), based on a prioritized access to the spectrum e.g., with highest priority to tier-1 users, followed by tier-2, then tier-3, etc. users, etc. [0056] Aspects described herein can also be applied to different Single Carrier or OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio) by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

[0057] Some of the features in this document are defined for the network side, such as APs, eNBs, NR or gNBs - note that this term is typically used in the context of 3GPP 5G and 6G communication systems, etc. Still, a UE may take this role as well and act as an AP, eNB, or gNB; that is some or all features defined for network equipment may be implemented by a UE.

[0058] As above, 5G networks support enhanced mobile broadband (eMBB) and ultra-reliable low latency communications (URLLC) using gigahertz (GHz). However, due to the shorter wavelengths in this spectrum have a smaller signal range and are more susceptible to interference and degradation. To counter this problem, the number of antennas may be increased, which leads to an increase in backhaul bandwidth capacity among the increased number of gNBs using IAB. IAB allows for multi-hop backhauling using the same frequencies employed for UEs. The IAB Mobile Termination (MT) antenna may include independent antenna arrays or shared antennas (virtual lAB-MTs (vIAB-MT)). Integrated Access and Backhaul specifications define two antenna system types: an IAB node and an IAB donor. IAB donors terminate the backhaul traffic from distributed IAB nodes. The nodes can be backhaul endpoints or relays between the endpoints and the donor. Both IAB donors and nodes serve mobile UEs.

[0059] IAB uses a radio access network (RAN) model similar to that employed in the Open RAN (O-RAN) architecture; that is, a distributed unit (DU) and a central unit (CU). The IAB nodes contain a DU and the IAB donors also include a CU. A single IAB system of one or more IAB nodes and the IAB donor form a gNB. This backhaul is insolated, so routing changes or problems are not propagated into the 5G core (5GC) or other adjacent gNBs.

[0060] In an IAB Network, an IAB node can connect to different nodes via different links. The IAB node can connect to its parent node (an IAB donor or another IAB node) through parent backhaul (BH) link, connect to a child UE through child access (AC) link, and connect to its child IAB node through child BH link. FIG. 3 illustrates different IAB link types in accordance with some aspects. Note that as used herein, parent node is an immediate parent node of the IAB node, rather than a multi-generational parent node (e.g., grandparent node), and a child node is an immediate child node of the IAB node rather than a multi-generational child node (e.g., grandchild node).

[0061] In current IAB network architectures, the CU/DU split has been leveraged such that each IAB node holds a DU and has a MT function. The IAB node connects to its parent IAB node or the IAB donor via the MT function in a manner similar to communications with a UE. The IAB node communicates with its child UEs and child MTs via the DU function in a manner similar to communications with a base station. Radio Resource Control (RRC) signaling is used between the CU in the IAB donor and the UE/MT, while F 1 AP signaling is used between the CU and the DU in an IAB node.

[0062] Enhancements for IAB are used to support for dual-connectivity (DC) scenarios defined by RAN2/RAN3 in the context of topology redundancy for improved robustness and load balancing. DC allows a device to simultaneously transmit/receive data on multiple component carriers (CCs) from two cell groups: a master cell group (MCG) and a secondary cell group (SCG). [0063] For multi-point transmission, the transmission to a given device can be carried out from multiple transmission and reception points (multi-TRPs) on the same time-frequency resource. In this case, either the point of transmission can change dynamically, referred to as dynamic point selection, or the transmission can be carried out jointly from multiple TRPs, referred to as joint transmission.

[0064] Each IAB MT may have multiple parents (also referred to as parent nodes or parent IAB nodes). As used herein, multiple parents include both DC and multi-TRP scenarios. In this case, both inter-carrier NR DC and intra-carrier NR DC are included. FIG. 4 illustrates a multi-parent IAB MT in accordance with some aspects. FIG. 4 illustrates a scenario in which an IAB MT has two parents, referred to “Parent DU1” and “Parent DU2”. These two parents can be either under the DC scenario (where transmissions are on different CCs for different parents) or under the multi-TRPs scenario (where transmission are on the same time-frequency resource for different parents). A co-located IAB DU can be connected with its own child nodes. [0065] For I AB nodes, time-domain resource allocation has certain characteristics. For example, from an MT point-of-view, downlink, uplink, and flexible time resources can be indicated for the parent link. From a DU point-of- view, the child link may have downlink, uplink, flexible, or not available time resources, the last of which is not to be used for communication on the DU child links. For each of the downlink, uplink and flexible time-resource types of the DU child link, there are two flavors: hard and soft (H/S). The hard-type resource indicates that the corresponding time resource is always available for the DU child link, while the soft-type resource indicates that the availability of the corresponding time resource for the DU child link is explicitly and/or implicitly controlled by the parent node.

[0066] In addition, DCI format 2 5 has been defined (transmitting from a parent DU to an IAB MT) to indicate the soft resource availability of the IAB DU. The soft resource availability may take eight values to indicate the availability of soft D, soft U and soft F resource, as shown in Table 1.

Table 1

[0067] An IAB MT with multiple parents may run into issues, however. In particular, an IAB MT with multiple parents may run into scheduling conflicts when a DCI format 2 5 received from different parent nodes indicates different soft resource availability for the same DU resource on the IAB node’s child link. For example, in FIG. 4 parent DU1 has sent DCI format 2 5 to indicate the IAB DU’s soft resource availability, while parent DU2 has no knowledge of the soft resource availability of parent DU1. In this case, the following transmission between parent DU2 to IAB MT and IAB DU child links may cause collision or interference. In another example, if the IAB MT receives two DCI format 2 5, one from each parent, and each DCI format 2 5 carries different values, the IAB DU may be confused as to the manner to apply to its soft resources.

[0068] Mechanisms for DCI format 2 5 indication regarding an IAB MT with multiple parents

[0069] Several mechanisms may be used to avoid the above issues for a DCI format 2 5 soft resource indication transmitted to an IAB MT with multiple parents. Note that these mechanisms can be combined to work together.

[0070] Mechanism 1: Define master parent to transmit DCI format 2_5

[0071] In this mechanism, there is only one parent node configured to transmit DCI format 2 5. This parent node may be referred to as a “master parent”. There are several options to define the master parent, and these options can be applied independently or jointly.

[0072] Optionl-1: Define master parent based on existing NR parent category (implicit indication)

[0073] In this option, an existing NR parent category defined in DC or multi-TRPs can be used to differentiate the master parent from secondary parents. For example, in a DC scenario, the parent node in the MCG is defined as the master parent and allowed to transmit DCI format 2 5. In a multi-TRP scenario, when a single physical downlink control channel (PDCCH) from one TRP schedules a PDSCH on separate layers transmitted from separate TRPs, the TRP transmitting the PDCCH is defined as the master parent and allowed to transmit DCI format 2 5.

[0074] Optionl-2: Define master parent with explicit signaling through F1AP signaling

[0075] In this option, new explicit F1AP signaling is introduced from the CU to the parent DU. The new Fl AP signaling may define the master parent to transmit DCI format 2 5 for an IAB MT with multiple parents.

[0076] There can be several Fl AP protocol extension embodiment options. Note that the options can be further extended to other F1AP messages (not limited to those options listed below).

[0077] Option 1-2A: Enhancement of the existing Backhaul Adaptation Protocol (BAP) MAPPING CONFIGURATION Fl AP message

[0078] Option 1-2B: Enhancement of the existing GNB-DU RESOURCE CONFIGURATION Fl AP message

[0079] Option 1-2C: Enhancement of the existing IAB Info lAB-donor- CU F1AP message

[0080] Option 1-2D: Enhancement of the existing GNB-CU CONFIGURATION UPDATE Fl AP message

[0081] Option 1-2E: Introduction of a new dedicated Fl AP message [0082] One embodiment of Option 1-2A is provided below. The embodiments of Option 1-2B/2C/2D/2E can be defined in a similar manner.

[0083] Optionl-3: Define master parent with explicit signaling through RRC signaling

[0084] In this option, new explicit RRC signaling is introduced from the CU to the I AB MT. The new RRC signaling indicates to the master parent to transmit DCI format 2 5 for an I AB MT with multiple parents.

[0085] There can be several RRC message/information element (IE) extension options as follows. Note that the options can be further extended to other RRC messages/IEs (not limited to those options listed below). [0086] Option 1-3 A: Enhancement of the existing RRC IE SpCellConfig

[0087] Option 1-3B: Enhancement of the existing RRC IE

ServingCellConflg

[0088] Option 1-3C: Enhancement of the existing RRC IE

CellGroupConflg [0089] Option 1-3D: Enhancement of the existing SIB1 message

[0090] Option 1-3E: Introduction of a new dedicated RRC message

[0091] One embodiment of Option 1-3 A is shown below. Embodiments of Option 1-3B/3C/3D/3E can be defined a similar manner.

SpCellConfig ::= SEQUENCE { servCelllndex ServCelllndex OPTIONAL, masterparentindex ENUMERATED {0,1} OPTIONAL, reconfigurationWithSync ReconfigurationWithSync OPTIONAL, rlf-TimersAndConstants SetupRelease { RLF-

TimersAndConstants } OPTIONAL, rlmlnSyncOutOfSyncThreshold ENUMERATED {nl} OPTIONAL, spCellConfigDedicated ServingCellConfig OPTIONAL,

[0092] Mechanism 2: When one parent node transmits DCI format 2 5 to an IAB MT, all other parents are informed

[0093] In this mechanism, when one parent node transmits DCI format 2 5 to an IAB MT to indicate a co-located DU’s soft resource availability, all other parent nodes are informed. Two options can be used to inform other parent nodes: through coordination between the parent nodes (for example in multi-TRPs scenario) or through L1/L2 signaling from the IAB MT to the parent nodes.

[0094] Option2-1: Other parents are informed by coordination between parent nodes

[0095] In this option, coordination between parent nodes (similar to the multi-TRP scenario) is applied to synchronize the DCI format 2 5 information between parent nodes. The parent coordination can be based on the X2 interface or more dynamic coordination on NR interface can be used. FIG. 5 illustrates multi-parent IAB MT coordination in accordance with some aspects. In particular, FIG. 5 illustrates that parent -to-parent communication is used to indicate to other parents of the IAB MT that DCI format 2 5 has been sent to the IAB MT. [0096] Option -2: The I AB MT informs other parents after receiving

PCI format 2 5

[0097] In this option, after an I AB MT receives DCI format 2 5 from one parent, the IAB MT informs all other parent nodes through L1/L2 signaling.

FIG. 6 illustrates multi-parent IAB MT information in accordance with some aspects. In particular, FIG. 6 illustrates that the multi-parent IAB MT disseminates to other parents that DCI format 2 5 has been received from one of the parents.

[0098] Various options may be used to indicate DCI format 2_5-related information to a parent node.

[0099] Option 2-2A: Over uplink control information (UCI)/Physical uplink control channel (PUCCH)

[00100] In one embodiment, the UCI in a PUCCH transmission from the IAB MT to the parent IAB DU may be used to provide DCI format 2 5 information. In this case, a new field may be added in one of current UCI formats. Alternatively, a new UCI format may be used if a new field cannot be added in the current UCI formats. The PUCCH resource used to carry the new UCI type may be semi-statically configured or based on semi-persistent scheduling or dynamic scheduling.

[00101] Option 2-2B: Over Media Access Control (MAC) Element (CE)ZPUSCH

[00102] In one embodiment, transmission of multiplexing capability information of the IAB node is over a MAC CE carried by the PUSCH. The PUS CH can be either dynamically triggered or triggered via a configured grant. [00103] In current NR specification, the logic channel ID (LCID) field that identifies the logical channel instance of the corresponding MAC service data unit (SDU) or the type of the corresponding MAC CE or padding for the uplink shared channel (UL-SCH) is described in the following Table. In one embodiment, one of the reserved LCID indexes (35-44) may be used to transmit that the IAB MT received DCI format 2 5 information from an IAB MT from a parent DU. Table 6.2.1-2 Values of LCID for UL-SCH

[00104] Option 2-2C: Over a new defined LI channel

[00105] In this embodiment, if a LI channel is added, the multiplexing capability -related information of the IAB node may be transmitted over this newly defined LI channel.

[00106] Mechanism 3: Define rules for an IAB MT after receiving DCI format 2 5 when connected to multiple parents [00107] In this mechanism, action rules for an IAB MT after receiving

DCI format 2 5 are pre-defined when connected to multiple parents. There can be several options, which can be applied independently or jointly. [00108] Option3-1: For time domain multiplexed (TDM) required I AB MT/DU, DU soft resource becomes available when PCI format 2 5 indicated from master parent (if defined) or indicated as available from all parents [00109] In this embodiment, as TDM is used at the I AB MT/DU, the parent links and child links may not operate simultaneously. If a master parent is defined, the soft resource of the DU becomes available for child links when the DCI format 2 5 is indicated from the master parent. Otherwise, the soft resource of the DU becomes available only after receiving the DCI format 2 5 indicated as available from all parents. This gives priority to the parent links. [00110] Option3-2: For TDM required IAB MT/DU. DU soft resource becomes available when DCI format 2 5 indicated as available from one parent node

[00111] In this option, as TDM is used at the IAB MT/DU, the parent links and child links may not operate simultaneously. Unlike Option 3-1, the priority is given to the child links instead of the parent links. The soft resource of the DU becomes available when receiving DCI format 2 5 indicated as available from one parent node. Other parents may be informed (for example, with mechanism 2 above) so that the parent links stop further parent link transmission.

[00112] Option3-3: For TDM not required IAB MT/DU. DU soft resource becomes available when DCI 2 5 format indicated as available from one parent node and corresponding simultaneous operations are allowed between other parent links and child links

[00113] In this option, as TDM is not used at the IAB MT/DU, the parent links and child links may operate simultaneously using multiplexing. After DCI format 2_5 is received from one parent node, the indicated soft resource availability further depends on whether the corresponding simultaneous operations are enabled between other parent links and child links.

[00114] Option3-4: After receiving DCI format 2 5 to indicate soft resource availability from one parent, whether the priority gives to other parent links or child links, or whether enable simultaneous transmission between parent links and child links, depend the IAB node’s implementation and multiplexing capability [00115] In this option, after receiving DCI format 2 5 to indicate soft resource availability from one parent, the rules for whether the priority is given to other parent links or child links are not strictly defined and left for dynamical implementation of thelAB node. If simultaneous operation is allowed, after receiving DCI format 2 5 from one parent node, the other parent backhaul links and child links may or may not cooperate to transmit simultaneously. Simultaneous operation may also depend on the implementation and multiplexing capability of the I AB node.

[00116] Note: the mechanisms and options above can be applied independently or jointly.

[00117] FIG. 7 illustrates a flowchart of an IAB DU process in accordance with some aspects. FIG. 7 may be implemented by an IAB DU (e.g., a first IAB DU that is one of multiple parent nodes for an IAB MT) or a portion thereof. Other operations may be present, but are not shown for convenience. For example, the process may include, at operation 702, determining that the IAB DU is a master parent for an IAB MT. For example, the determination may be made implicitly and/or via F1AP signaling from a CU. At operation 704, based on the determination, encoding a DCI format 2 5 for transmission to the IAB MT. The other parent nodes may not send DCI format 2 5 to the IAB MT.

[00118] FIG. 8 illustrates a flowchart of an IAB MT process in accordance with some aspects. FIG. 8 may be implemented by an IAB MT or a portion thereof. Other operations may be present, but are not shown for convenience. For example, the process may include, at operation 802, receiving, from an IAB CU, a message to indicate that a first IAB DU is a master parent for the IAB MT. The IAB MT is configured with multiple parent nodes including the first IAB DU. In some embodiments, the message may be received via RRC signaling. At operation 804, the process may further include receiving a DCI with a soft scheduling indication from the first IAB DU. For example, the DCI may be DCI format 2 5.

[00119] Although an embodiment has been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[00120] The subject matter may be referred to herein, individually and/or collectively, by the term “embodiment” merely for convenience and without intending to voluntarily limit the scope of this application to any single inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. [00121] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, UE, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. [00122] The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMS What is claimed is:

1. An apparatus for an Integrated Access Backhaul (IAB) node, the apparatus comprising: processing circuitry configured to: decode, from one parent IAB node of a plurality of parent IAB nodes, a downlink control information (DCI) format 2 5; determine whether a master parent IAB node has been defined; in response to a determination that the master parent IAB node has been defined, determine whether the one parent IAB node is the master parent IAB node; and use resources indicated in information of the DCI format 2 5 in response to a determination that the DCI format 2 5 is from the master parent IAB node; and a memory configured to store the information.

2. The apparatus of claim 1, wherein the master parent IAB node is a parent IAB node in a master cell group in dual connectivity (DC) or a transmission/reception point (TRP) from which a physical downlink control channel (PDCCH) is received.

3. The apparatus of claim 1, wherein: the processing circuitry is further configured to: decode Fl AP signaling from a IAB central unit (CU), and limit the use of the resources indicated in the information of the DCI format 2 5 to resources indicated in the information of the DCI format 2 5 from the master parent IAB node based on the Fl AP signaling, and the F1AP signaling indicates that the one parent IAB node is the master parent IAB node.

4. The apparatus of claim 3, wherein: the Fl AP signaling comprises a master parent assignment parameter, and the F1AP signaling is incorporated in one of a Backhaul Adaptation Protocol (BAP) BAP MAPPING CONFIGURATION Fl AP message, a gNB- DU RESOURCE CONFIGURATION Fl AP message, an IAB Info lAB-donor- CU F1AP message, a gNB-CU CONFIGURATION UPDATE F1AP message, or a dedicated Fl AP message that is dedicated to indication of the master parent IAB node.

5. The apparatus of claim 1, wherein: the processing circuitry is further configured to: decode radio resource control (RRC) signaling from a IAB central unit (CU), and limit the use of the resources indicated in the information of the DCI format 2 5 to resources indicated in the information of the DCI format 2 5 from the master parent IAB node based on the RRC signaling, and the RRC signaling comprises an information element (IE) that indicates that the one parent IAB node is the master parent IAB node.

6. The apparatus of claim 5, wherein the IE is provided in one of an RRC IE SpCellConfig, an RRC IE ServingCellConfig, an RRC IE CellGroupConfig, a system information broad castl (SIB1) or a dedicated RRC message.

7. The apparatus of claim 1, wherein transmission of the DCI format 2 5 is limited to the master parent IAB node, and the information of the DCI format 2 5 is synchronized through coordination between the plurality of parent IAB nodes over an X2 or new radio (NR) interface.

8. The apparatus of claim 1, wherein: transmission of the DCI format 2 5 is limited to the master parent IAB node, and in response to reception of the DCI format 2_5, the processing circuitry is further configured to encode, for transmission to at least one other parent IAB node of the plurality of parent IAB nodes, the information of the DCI format 2 5 through at least one of LI or L2 signaling.

9. The apparatus of claim 8, wherein the processing circuitry is configured to encode, for transmission to the at least one other parent IAB node, the information of the DCI format 2 5 in uplink control information (UCI) of a physical uplink control channel (PUCCH) transmission.

10. The apparatus of claim 8, wherein the processing circuitry is configured to encode, for transmission to the at least one other parent IAB node, the information of the DCI format 2 5 in a medium access control (MAC) control element (CE) of a physical uplink shared channel (PUSCH) transmission.

11. The apparatus of claim 10, wherein the processing circuitry is configured to use a reserved index of a logic channel identification (LCID) field of the MAC CE to indicate the information of the DCI format 2 5.

12. The apparatus of claim 1, wherein in time domain multiplexed (TDM) required operation, the processing circuitry is further configured to, in response to the determination that the master parent IAB node has been defined, limit use of soft resources to soft resources indicated as available in information of a DCI format 2 5 from the master parent IAB node.

13. The apparatus of claim 1, wherein in time domain multiplexed (TDM) required operation, the processing circuitry is further configured to, in response to the determination that the master parent IAB node has not been defined, use soft resources indicated as available in the information of the DCI format 2 5 from the one parent IAB node, the soft resources indicated as available by each of the plurality of parent IAB nodes.

14. The apparatus of claim 1, wherein in time domain multiplexed (TDM) required operation, the processing circuitry is further configured to use soft resources indicated as available in the information of the DCI format 2 5 from the one parent IAB node, the soft resources indicated as unavailable to each of the plurality of parent IAB nodes in response to reception of the DCI format 2 5 at the IAB node.

15. The apparatus of claim 1, wherein in non-time domain multiplexed (TDM) required operation, the processing circuitry is further configured to use soft resources indicated as available in the information of the DCI format 2 5 from the one parent IAB node dependent on whether corresponding simultaneous operations are enabled between the IAB node and other parent IAB nodes of the plurality of parent IAB nodes.

16. The apparatus of claim 1, wherein the processing circuitry is further configured to use soft resources indicated as available in the information of the DCI format 2 5 from the one parent IAB node dependent on dynamic implementation and multiplexing capability of the IAB node.

17. An apparatus for an Integrated Access Backhaul (IAB) node, the apparatus comprising: processing circuitry configured to: decode, from one parent IAB node of a plurality of parent IAB nodes, a downlink control information (DCI) format 2 5 indicating soft resources for uplink transmission; determine whether a master parent IAB node has been defined; in response to a determination that the master parent IAB node has been defined, determine whether the one parent IAB node is the master parent IAB node; and in response to a determination that the DCI format 2 5 is from the master parent IAB node, use at least one of LI or L2 signaling to indicate reception of the DCI format 2 5 to other parent IAB nodes of the plurality of parent IAB nodes; and a memory configured to store the information.

18. The apparatus of claim 17, wherein the processing circuitry is further configured to use preconfigured rules to determine whether the soft resources are available for transmission of a physical uplink control channel (PUCCH) transmission and a physical uplink shared channel (PUS CH) transmission, the preconfigured rules dependent on whethertime domain multiplexed (TDM) required operation is used by the I AB node.

19. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of an Integrated Access Backhaul (IAB) node, the one or more processors to configure the IAB node to, when the instructions are executed: decode, from one parent IAB node of a plurality of parent IAB nodes, a downlink control information (DCI) format 2 5; determine whether a master parent IAB node has been defined; in response to a determination that the master parent IAB node has been defined, determine whether the one parent IAB node is the master parent IAB node; and use soft resources indicated in information of the DCI format 2 5 in response to a determination that the DCI format 2 5 is from the master parent IAB node.

20. The medium of claim 19, wherein the instructions, when executed, further cause the one or more processors to configure the IAB node to in response to reception of the DCI format 2_5, encode, for transmission to at least one other parent IAB node of the plurality of parent IAB nodes, the information of the DCI format 2 5 through at least one of: uplink control information (UCI) of a physical uplink control channel (PUCCH) transmission or a medium access control (MAC) control element (CE) of a physical uplink shared channel (PUS CH) transmission.