WO2020207745A1

WO2020207745A1 - Integrated access and backhaul (iab) distributed unit (du) resource allocation for dual connectivity

Info

Publication number: WO2020207745A1
Application number: PCT/EP2020/057640
Authority: WO
Inventors: Esa Tapani Tiirola; Keeth Saliya Jayasinghe LADDU; Ilkka Antero Keskitalo; Juha Sakari Korhonen; Mark Cudak
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2019-04-08
Filing date: 2020-03-19
Publication date: 2020-10-15
Anticipated expiration: 2021-10-08

Abstract

A method, apparatus, and a computer-readable storage medium are provided for IAB resource allocation for dual connectivity. In one example implementation, the method may include receiving at least two resource configurations corresponding to at least two different child links and determining a resource type and resource flavor of at least one time resource associated with the at least two resource configurations. The example method may further includes selecting at least one child link of the at least two different child links.

Description

INTEGRATED ACCESS AND BACKHAUL (IAB) DISTRIBUTED UNIT

(DU) RESOURCE ALLOCATION FOR DUAL CONNECTIVITY

TECHNICAL FIELD

[0001] This description relates to wireless communications, and in particular, to integrated access and backhaul (IAB) in wireless networks.

BACKGROUND

[0002] A communication system may be a facility that enables communication between two or more nodes or devices, such as fixed or mobile communication devices. Signals can be carried on wired or wireless carriers.

[0003] An example of a cellular communication system is an architecture that is being standardized by the 3rd Generation Partnership Project (3GPP). A recent development in this field is often referred to as the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology. E-UTRA (evolved UMTS Terrestrial Radio Access) is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. In LTE, base stations or access points (APs), which are referred to as enhanced Node AP or Evolved Node B (eNBs), provide wireless access within a coverage area or cell. In LTE, mobile devices, or mobile stations are referred to as user equipments (UE). LTE has included a number of improvements or developments.

[0004] 5G New Radio (NR) developments are part of a continued mobile broadband evolution process to meet the requirements of 5G, similar to earlier evolution of 3G & 4G wireless networks. In addition, 5G is also targeted at the new emerging use cases in addition to mobile broadband. A goal of 5G is to provide significant improvement in wireless performance, which may include new levels of data rate, latency, reliability, and security. 5G NR may also scale to efficiently connect the massive Internet of Things (IoT), and may offer new types of mission-critical services. Ultra-reliable and low-latency communications (URLLC) devices may require high reliability and very low latency.

SUMMARY

[0005] A method, apparatus, and a computer-readable storage medium are provided for IAB resource allocation for dual connectivity configurations. In an example implementation, the method may include receiving, by an integrated access and backhaul (IAB) node, at least two distributed unit (DU) resource configurations corresponding to at least two different distributed unit (DU) child links; determining, by the integrated access and backhaul (IAB) node, a resource type and resource flavor of at least one time resource associated with the at least two distributed unit (DU) resource configurations, the determining based at least on corresponding distributed unit (DU) resource

configurations of the at least two distributed unit (DU) resource configurations; and selecting, by the integrated access and backhaul (IAB) node, at least one distributed unit (DU) child link of the at least two different distributed unit (DU) child links, the selecting based at least on the determined resource type and resource flavor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a block diagram of a wireless network according to an example implementation.

[0007] FIG. 2 is a block diagram illustrating integrated access and backhaul (IAB) node in dual connectivity (DC) configurations, according to an example implementation.

[0008] FIG. 3 illustrates a flow chart for integrated access and backhaul (IAB) distributed unit (DU) resource allocation in dual connectivity (DC) configurations, according to an example implementation.

[0009] FIG. 4 is a flow chart illustrating integrated access and backhaul (IAB) distributed unit (DU) resource allocation in dual connectivity (DC) configurations, according to another example implementation.

[0010] FIG. 5 is a block diagram illustrating integrated access and backhaul (IAB) distributed unit (DU) operations, according to an example implementation.

[0011] FIG. 6 is a block diagram of a node or wireless station (e.g., base station/access point or mobile station/user device/UE), according to an example implementation.

DETAIFED DESCRIPTION

[0012] FIG. 1 is a block diagram of a wireless network 130 according to an example implementation. In the wireless network 130 of FIG. 1, user devices (UDs) 131, 132, 133 and 135, which may also be referred to as mobile stations (MSs) or user equipment (UEs), may be connected (and in communication) with a base station (BS) 134, which may also be referred to as an access point (AP), an enhanced Node B (eNB) or a network node. At least part of the functionalities of an access point (AP), base station (BS) or (e)Node B (eNB) may also be carried out by any node, server or host which may be operably coupled to a transceiver, such as a remote radio head. BS (or AP) 134 provides wireless coverage within a cell 136, including to user devices 131, 132, 133 and 135. Although only four user devices are shown as being connected or attached to BS 134, any number of user devices may be provided. BS 134 is also connected to a core network 150 via a SI interface 151. This is merely one simple example of a wireless network, and others may be used.

[0013] A user device (user terminal, user equipment (UE)) may refer to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (MS), a mobile phone, a cell phone, a smartphone, a personal digital assistant (PDA), a handset, a device using a wireless modem (alarm or measurement device, etc.), a laptop and/or touch screen computer, a tablet, a phablet, a game console, a notebook, and a multimedia device, as examples, or any other wireless device. It should be appreciated that a user device may also be a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network.

[0014] In LTE (as an example), core network 150 may be referred to as Evolved Packet Core (EPC), which may include a mobility management entity (MME) which may handle or assist with mobility/handover of user devices between BSs, one or more gateways that may forward data and control signals between the BSs and packet data networks or the Internet, and other control functions or blocks.

[0015] In addition, by way of illustrative example, the various example

implementations or techniques described herein may be applied to various types of user devices or data service types, or may apply to user devices that may have multiple applications running thereon that may be of different data service types. New Radio (5G) development may support a number of different applications or a number of different data service types, such as for example: machine type communications (MTC), enhanced machine type communication (eMTC), Internet of Things (IoT), and/or narrowband IoT user devices, enhanced mobile broadband (eMBB), and ultra-reliable and low-latency communications (URLLC).

[0016] IoT may refer to an ever-growing group of objects that may have Internet or network connectivity, so that these objects may send information to and receive information from other network devices. For example, many sensor type applications or devices may monitor a physical condition or a status, and may send a report to a server or other network device, e.g., when an event occurs. Machine Type Communications (MTC or machine to machine communications) may, for example, be characterized by fully automatic data generation, exchange, processing and actuation among intelligent machines, with or without intervention of humans. Enhanced mobile broadband (eMBB) may support much higher data rates than currently available in LTE.

[0017] Ultra-reliable and low-latency communications (URLLC) is a new data service type, or new usage scenario, which may be supported for New Radio (5G) systems. This enables emerging new applications and services, such as industrial automations, autonomous driving, vehicular safety, e-health services, and so on.

3GPP targets in providing up to e.g., 1 ms U-Plane (user/data plane) latency connectivity with 1-1 e-5 reliability, by way of an illustrative example. Thus, for example, URLLC user devices/UEs may require a significantly lower block error rate than other types of user devices/UEs as well as low latency. Thus, for example, a URLLC UE (or URLLC application on a UE) may require much shorter latency, as compared to an eMBB UE (or an eMBB application running on a UE).

[0018] The various example implementations may be applied to a wide variety of wireless technologies or wireless networks, such as LTE, LTE-A, 5G, IoT, MTC, eMTC, eMBB, URLLC, etc., or any other wireless network or wireless technology. These example networks, technologies or data service types are provided only as illustrative examples.

[0019] Multiple Input, Multiple Output (MIMO) may refer to a technique for increasing the capacity of a radio link using multiple transmit and receive antennas to exploit multipath propagation. MIMO may include the use of multiple antennas at the transmitter and/or the receiver. MIMO may include a multi-dimensional approach that transmits and receives two or more unique data streams through one radio channel.

For example, MIMO may refer to a technique for sending and receiving more than one data signal simultaneously over the same radio channel by exploiting multipath

propagation. According to an illustrative example, multi-user multiple input, multiple output (multi-user MIMIO, or MU-MIMO) enhances MIMO technology by allowing a base station (BS) or other wireless node to simultaneously transmit or receive multiple streams to different user devices or UEs, which may include simultaneously transmitting a first stream to a first UE, and a second stream to a second UE, via a same (or common or shared) set of physical resource blocks (PRBs) (e.g., where each PRB may include a set of time-frequency resources).

[0020] Also, a BS may use precoding to transmit data to a EfE (based on a precoder matrix or precoder vector for the EfE). For example, a EfE may receive reference signals or pilot signals, and may determine a quantized version of a DL channel estimate, and then provide the BS with an indication of the quantized DL channel estimate. The BS may determine a precoder matrix based on the quantized channel estimate, where the precoder matrix may be used to focus or direct transmitted signal energy in the best channel direction for the EfE. Also, each EfE may use a decoder matrix to determine, e.g., where the EfE may receive reference signals from the BS, determine a channel estimate of the DL channel, and then determine a decoder matrix for the DL channel based on the DL channel estimate. For example, a precoder matrix may indicate antenna weights (e.g., an amplitude/gain and phase for each weight) to be applied to an antenna array of a transmitting wireless device. Likewise, a decoder matrix may indicate antenna weights (e.g., an amplitude/gain and phase for each weight) to be applied to an antenna array of a receiving wireless device.

This applies to EfL as well when a EfE is transmitting data to a BS.

[0021] For example, according to an example aspect, a receiving wireless user device may determine a precoder matrix using Interference Rejection Combining (IRC) in which the user device may receive reference signals (or other signals) from a number of BSs (e.g., and may measure a signal strength, signal power, or other signal parameter for a signal received from each BS), and may generate a decoder matrix that may suppress or reduce signals from one or more interferers (or interfering cells or BSs), e.g., by providing a null (or very low antenna gain) in the direction of the interfering signal, in order to increase a signal-to interference plus noise ratio (SINR) of a desired signal. In order to reduce the overall interference from a number of different interferers, a receiver may use, for example, a Linear Minimum Mean Square Error Interference Rejection Combining (LMMSE-IRC) receiver to determine a decoding matrix. The IRC receiver and LMMSE-IRC receiver are merely examples, and other types of receivers or techniques may be used to determine a decoder matrix. After the decoder matrix has been determined, the receiving UE/user device may apply antenna weights (e.g., each antenna weight including amplitude and phase) to a plurality of antennas at the receiving UE or device based on the decoder matrix. Similarly, a precoder matrix may include antenna weights that may be applied to antennas of a transmitting wireless device or node. This applies to a receiving BS as well.

[0022] In wireless networks, in some scenarios, an integrated access and backhaul (IAB) node may have two resource configurations - one resource configuration for a master cell group (MCG) link and another resource configuration for a secondary cell group (SCG) link. The cell groups, either MCG or SCG, served by an IAB distributed unit (DU), may be configured by the same or different central units (CUs) of different donor nodes (e.g., different IAB donor nodes). This is just one example scenario.

In other scenarios, the IAB node may have two resource configurations for two MCG links or two SCG links. In addition, in some scenarios, the MT of the IAB node may be connected to two central units (CUs) of two different IAB donor nodes (also referred to as donor IAB nodes or donor nodes). In the above described scenarios, the IAB node may not have consistent resource configurations leading to problems such as inefficient resource usage, resource conflicts, etc.

[0023] Therefore, there is a need/desire to ensure that an IAB node serving two (or more) connections, e.g., DU links (MCG/SCG, MCG/MCG, and SCG/SCG)_has a consistent resource configuration for the DU links such that IAB capabilities are maximally reused and resource conflicts due to IAB capability and/or link direction conflicts are avoided. [0024] The present disclosure describes a mechanism performed by an IAB node.

The mechanism includes, at least: receiving at least two DU resource configurations corresponding to at least two different DU child links, determining a resource type and resource flavor of at least one time resource associated with the at least two DU resource configurations, selecting at least one DU child link of the at least two different DU child links, and transmitting or receiving data on the at least one DU link selected by the IAB node.

[0025] FIG. 2 is a block diagram 200 illustrating an integrated access and backhaul (IAB) node in dual connectivity (DC) configuration, according to an example

implementation.

[0026] In an example implementation, FIG. 2 includes nodes 210, 220, 230, 240,

250, 260, 270, and/or 280. In some implementations, for example, nodes 210 and 220 may be IAB donor nodes; nodes 230, 240, 250, and/or 260 may be IAB nodes; and nodes 270 and 280 may be child IAB nodes. In some example implementations, nodes 270 and/or 280 may be user equipments (UEs).

[0027] The present disclosure describes functionality of an IAB node (e.g., IAB node 240) where time domain resources (also referred to as time resource, resource,

DU resource, DU time resource, etc.) for at least two links of the IAB node may be configured separately. In some implementations, for example, FIG. 2 illustrates IAB node 240 configured with MCG link 241 (also referred to MCG DU link 241) to child IAB node 270 and SCG link 242 (also referred to as SCG DU link 242) to child IAB node 280. In some implementations, links 241 and 242 may be MCG/MCG or SCG/SCG links as well. As illustrated in FIG. 2, links 241 and 242 may have same or different IAB donor nodes. In an example implementation, SCG link 232 and MCG link 241 of child IAB node 270 have the same IAB donor node, e.g., IAB donor node 210. In an additional example implementation, SCG link 242 and MCG link 251 of child IAB node 280 have different IAB donor nodes, e.g., IAB donor nodes 210 and 220.

[0028] In some implementations, the present disclosure further describes controlling the DU operation of a time domain resource based on resource configuration. In some implementations, the resource configuration may define resource type and resource flavor. For example, the resource type may indicate whether the resource may be used for uplink, downlink, uplink/downlink (e.g., an IAB node/DU may select the resource for uplink or downlink, also referred to as“flexible”), or whether the resource is unavailable for DU child link (e.g., DU child link communications). The resource flavor, for example, may indicate whether the resource is a hard resource or a soft resource. The hard resource may be defined as a resource that is always available (also referred to as a resource that is available persistently) for DU child link. The soft resource may be defined as a resource whose availability for the DU child link is explicitly or implicitly controlled by a parent IAB node.

[0029] In some implementations, for example, when the resource is a soft resource, the resource configuration may further include availability information of the soft resource. The availability information of the soft resource may indicate whether the soft resource is explicitly or implicitly indicated as available (e.g., referred to as IA) or unavailable (e.g., referred to as INA). The availability information may be dynamically changed based on, for example, the parent IAB node scheduling and/or higher layer configuration of various signals on the parent backhaul link of the IAB node.

[0030] In FIG. 2, in some implementations, a parent link (e.g., a backhaul link) may be the link between an IAB node (MT) and a parent IAB node (DU), e.g., 212; and a child link may be the link between an IAB node (DU) and another IAB node (MT part) or a user equipment (UE), e.g., 232.

[0031] In an example implementation, the proposed mechanism discloses an IAB node (e.g., IAB node 240) receiving two DU resource configurations corresponding to two different DU child links (e.g., 241 and 242) where the resource configurations may be defined at a resource level. For example, resource configurations generally include frequency domain configuration (such as bandwidth part(s)) or time domain

configuration. The present disclosure describes IAB DU resource allocation in dual connectivity scenarios based on time domain configuration. In some implementations, it is assumed that the IAB node may not able to transmit and receive at the same time (e.g., IAB half-duplex scenario). In some other implementations, it is assumed that the IAB node may not support simultaneous transmission or reception of child and parent links (e.g., Time Division Multiplexing (TDM) half-duplex scenario). In another half-duplex scenario (e.g., Space Division Multiplexing ( S D M )/Freq uency Division Multiplexing (FDM) half-duplex scenario), the IAB node may be able to transmit or receive at child and parent links simultaneously. The proposed mechanism further describes determining resource type and resource flavor of the time resources (e.g., one time resource for each of the two configurations) associated with each of the two distributed unit (DU) resource configurations based at least on corresponding DU resource configurations. Furthermore, the proposed mechanism may describe selecting one or more DU child links of the two different DU child links for transmitting or receiving data.

[0032] FIG. 3 illustrates a flow chart 300 for IAB DU resource allocation in dual connectivity scenarios, according to an example implementation. In some implementations, for example, IAB DU resource allocation for DC may be performed at IAB node 240 of FIG. 2.

[0033] At block 310, an IAB node, e.g., IAB node 240, may receive at least two distributed unit (DU) resource configurations corresponding to at least two different distributed unit (DU) child links. For example, IAB node 240 may receive two DU resource configurations, e.g., RC1 and RC2. RC1 may be associated with a resource for DU child link 241 and RC2 may be associated with a resource for DU child link 242.

[0034] In an example implementation, the resource configurations may be received from and/or via IAB donor node(s) 210 and/or 220 (and/or CUs), with the IAB donor nodes communicating with each other via, e.g., an X_n interface. As shown in FIG. 2, IAB donor node 210 may be the IAB donor node for IAB 240 and IAB donor 220 may be the IAB donor node for IAB 250. In some implementations, as IAB donor nodes 210 and 220 are connected via an X_n interface, IAB node 240 may receive the configuration information, e.g., RC1 and RC2, from IAB donor node 210, as IAB donor nodes 210 and 220 could coordinate via, for example, X_n interface, or another network entity.

[0035] As illustrated in FIG. 2, in an example implementation, DU child link 241 may be an MCG link to IAB child node 270 and DU child link 242 may be an SCG link to IAB node 280. In another example implementation, DU child link 241 may be an MCG link to IAB node 270 and DU child link 242 may be an MCG link to IAB node 280. In one more example implementation, DU child link 241 may be an SCG link to IAB node 270 and DU child link 242 may be an SCG link to IAB node 280. In other words, DU child links 214/242 may be MCG or SCG links and may vary depending on their configurations. [0036] At block 320, the IAB node may determine a distributed unit (DU) resource type and resource flavor of at least one distributed unit (DU) resource associated with the at least two distributed unit (DU) resource configurations. For example, IAB node 240 may determine DU resource type and resource flavor of at least one DU resource associated with each of RC1 and RC2. The DU resource type and/or resource flavor may be determined based on the associated resource configurations.

[0037] As described above, in some implementations, the resource type of a resource may indicate whether the resource is an uplink resource, downlink resource, a flexible resource (e.g., may be used for either uplink or downlink), or that the resource is“Not Available” (NA). For example, a resource indicated as a uplink resource is available for uplink communications (e.g., communications from IAB child nodes 270/280 or UEs to IAB node 240), a resource indicated as a downlink resource is available for downlink communications (e.g., communications from IAB node 240 to IAB child nodes 270/280 or UEs), a resource indicated as a flexible resource is available for either uplink or downlink communications (e.g., communications from IAB child nodes 270/280 to IAB node 240 or communications from IAB node 240 to IAB child nodes 270/280), and/or a resource indicated as NA is not available for communications on DU child link(s). Similarly, as described above, in some implementations, for example, the resource flavor of a resource may indicate whether the resource is a hard resource or soft resource. A hard resource may be defined as a time resource that is always available for DU child link. The hard resource in this disclosure may be referred to as a persistent resource or a time resource that is persistently available. For a hard (persistent) resource, the IAB node may be able to determine the resource usage without considering the requirements of the parent link. A soft resource may be defined as a time resource whose availability is explicitly or implicitly controlled by a donor node (e.g., IAB donor node 210 or 220). For example, in some implementations, the availability of a soft resource may indicate whether the resource is explicitly or implicitly indicated as being available (IA) or Not Available (IN A). If a soft resource is IN A, IAB node may need to serve parent link instead of the DU link. [0038] At block 330, the IAB node may select at least one distributed unit (DU) child link of the at least two different distributed unit (DU) child links. For example, in some implementations, IAB node 240 may select one DU child link, e.g., DU child link 241 or 242. In some implementations, IAB node 240 may select both DU child links, e.g., DU child link 241 and 242. The selection of one or both DU child links may be based on resource type and resource flavor of the resources associated with DU child links 241 and 242. In some implementations, the IAB node may not select any DU links and as such no DU link may be available for transmission or reception of data.

[0039] In some implementations, the selection may be based on a logic (e.g., rule(s) procedure, mechanism, etc.) such that IAB 240 selects at least one DU child link (e.g., resource associated with a DU child link) to, for example, prioritize DU child links, eliminate or minimize link direction conflicts when there are link direction conflicts, etc. as described below in detail. It should be noted, however, that for each resource, there is one resource type and flavor for each DU child link and that the rule(s) are being applied separately for each time domain resource pairs (e.g., resource pairs associated with MCG/SCG; MCG/MCG; or SCG/SCG links). In other words, the mechanism being described in the present disclosure is applied for resource pairs and the resource pairs may be associated with MCG/SCG, MCG/MCG, or SCG/SCG links.

[0040] In an example implementation, the selection of the resources (or links for transmission/reception) may be based on the flowchart 400 of FIG. 4 which is further illustrated in block diagram 500 of FIG. 5. These are example implementations (and not limitations) and other logic/rules may be used to address resource conflicts to select a resource/link to achieve the benefits described above.

[0041] In some implementations, for example, IAB node 240 may determine that the resource type of the two resource configurations of the two child link configurations is different and may select a DU child link with a higher priority, as illustrated at, e.g., 426 of FIG. 4 and 502 of FIG. 5.

[0042] In some implementations, for example, IAB node 240 may determine that the resource type of the two resource configurations of the two child link configurations is different and may select a DU child link with a lower priority when the resource type of higher priority DU child link is indicated as being NA, as illustrated at, e.g., 418 of FIG. 4 and 512 of FIG. 5.

[0043] In some implementations, for example, IAB node 240 may determine that the resource type and resource flavor are same for the at least two DU child link resource configurations and may select both the DU child links, if both the determined resource types are available, as illustrated at, e.g., 442 of FIG. 4 and 522 of FIG. 5. This applies to DL, UL, and Flexible resource types.

[0044] In some implementations, for example, IAB node 240 may determine that the resource type is same and the resource flavor is different for the at least two distributed unit (DU) child link resource configurations and may select one DU child link of the at least two distributed unit (DU) child links, as illustrated at 444 of FIG. 4.

[0045] In some implementations, for example, IAB node 240 may determine that the resource type is same and the resource flavor is different for the at least two distributed unit (DU) child link resource configurations and may select both of the at least two distributed unit (DU) child links, when a DU resource explicitly or implicitly controlled by an IAB donor node is indicated as being available, as illustrated at, e.g., 448/442 and 452/452 of FIG. 4 and 542 of FIG. 5.

[0046] In some implementations, for example, IAB node 240 may determine that the resource type is same and the resource flavor is different for the at least two distributed unit (DU) child link resource configurations and may select a distributed unit (DU) child link corresponding to a distributed unit (DU) resource that is persistently (e.g., always) available for distributed unit (DU) child link communications, when the distributed unit (DU) resource explicitly or implicitly controlled by a an IAB donor node is being indicated as not available, as illustrated at, e.g., 454/426 and 456/418 of FIG. 4 and 542 of FIG. 5.

[0047] In some implementations, for example, IAB node 240 may determine that the resource type for the at least two distributed unit (DU) resource configurations is different and may notify a second highest priority distributed unit (DU) link that is available. The notification may indicate to the second highest priority distributed unit (DU) link that it (e.g., the second highest priority distributed unit (DU) link) is not being served as a first highest priority distributed unit (DU) link was selected.

[0048] In some implementations, optionally, at block 340, the IAB node may transmit or receive data on the at least one distributed unit (DU) link selected by the IAB node. For example, in some implementations, IAB node 240 may transmit or receive data on the selected DU child link (e.g., DU child link 241, 242, or both) using, for instance, the resource associated with the selected link based on the resource

configuration. In some implementations, the data transmitted or received may include downlink/uplink user data or control data, for example, shared channel data

transmission/reception (e.g., PDSCH/PUSCH), control channel transmission/reception (e.g., PDCCH/PUSCH), reference signal transmission/reception (e.g., CSI-RS/SRS), signals related to initial access (e.g., SSB/PRACH), etc.

[0049] In some implementations, for example, IAB node 240 may consider the at least one selected DU link available for transmission or reception of data and may not use the at least one selected DU link for transmission or reception of data. In other words, IAB node 240 can decide whether it wants to use the selected resources/links for transmission or reception of data.

[0050] Therefore, the above described mechanism ensures that IAB DU resources are used efficiently and resource conflicts are properly handled to improve network performance and/or maximize resource usage.

[0051] FIG. 4 is a flow chart 400 illustrating IAB DU resource allocation for dual connectivity scenarios, according to an example implementation. In some

implementations, for example, IAB node 240 may determine the resource allocation based on a logic illustrated in the flow chart 400.

[0052] In some implementations, for example, the links may have a pre-defined priority order. The pre-defined priority order may be determined, explicitly or implicitly, for example, via higher layer signaling. In some implementations, for example, the implicit signaling may be based on link IDs of the DU child links. In addition, the signaling, in some implementations, may include radio resource control (RRC), FI application protocol (FI AP), or operation and maintenance (O&M) signaling.

Furthermore, the signaling may be controlled by CU and/or parent node and/or network entity responsible for O&M signaling.

[0053] The example described below relates to dual connectivity configuration where the MCG link is considered as a higher priority link and the SCG link is considered as a lower priority link.

[0054] In an example implementation:

a) If the resource type (D/U/F/NA) is different for MCG and SCG (412):

o Only one link (MCG or SCG) is active

^■ If MCG is NA (414)

• SCG is active and follows its configuration (418)

• MCG is NA (420)

^■ Otherwise (422)

• MCG is active and follows its configuration (426)

• SCG is NA (424)

o Another link is considered as NA (Not available) (420, 424)

b) If both resource type (D/U/F/NA) and resource flavor (hard/soft) are same for MCG and SCG (438):

o if both resource types are NA or both resource flavors are soft with INA (432):

^■ Both links are considered as NA (434)

o Otherwise (440)

^■ Both links are active and follow their configuration (442)

c) If resource type (D/U/F/NA) is same for MSG and SCG but resource flavor is different (hard/soft) (444)

o If SCG is soft (446) and IA (448) or MCG is soft (450) and IA (452)

^■ Both links are active and follow their configuration (442)

o If SCG is soft (446) and INA (454)

^■ MCG is active and follows its configuration (426)

^■ SCG is NA (424)

o If MCG is soft (450) and INA (456)

^■ SCG is active and follows its configuration (418)

^■ MCG is NA (420)

[0055] In some implementations, the operation at block 430 may be performed immediately after the operation at block 438 (in other words, blocks 430 are 438 are swapped), and other operations configured accordingly as described above.

[0056] The above example implementation is described for MCG/SCG link configuration. However, the above described mechanism may apply for MCG/MCG or SCG/SCG link configurations.

[0057] In some implementations, the DU links may be configured separately (e.g., in a link specific manner or in a link group specific manner). This may require that the involved links have pre-defined priority information (similarly as in the DC scenario, which assumes that MCG has priority over SCG).

[0058] In some implementations, more than two DU links may be involved. In such a scenario, the prioritization process may be carried out sequentially. For example, a first prioritization may be made for the two DU links with the highest priorities, a second prioritization may be made between the outcome of the first prioritization and the third DU link, and so on.

[0059] In some implementations, the resources for the IAB node, e.g., IAB node 240, may be configured by via F1AP signalling from a central unit (CU) of IAB donor nodes and the configuration may be performed separately for the DU links. In some implementations, the CU may also perform MT configuration, separately for MCG and SCG. In addition, it should be noted that the applicability of the proposed procedures may be generalized so that the MCG/SCG pair discussed above is replaced by MCG pair or SCG pair served by a DU, as described above. In the latter cases, however, the priority between the two MCGs or SCGs should be known.

[0060] FIG. 5 is a block diagram 500 illustrating IAB DU operations based on time division multiplexing (TDM) between DU links, according to an example

implementation, as described above in reference to FIGs 2-4.

[0061] Additional example implementations are described herein.

[0062] Example 1. A method of communications, comprising: receiving, by an integrated access and backhaul (IAB) node, at least two distributed unit (DU) resource configurations corresponding to at least two different distributed unit (DU) child links; determining, by the integrated access and backhaul (IAB) node, a resource type and resource flavor of at least one time resource associated with the at least two distributed unit (DU) resource configurations, the determining based at least on corresponding distributed unit (DU) resource configurations of the at least two distributed unit (DU) resource configurations; and selecting, by the integrated access and backhaul (IAB) node, at least one distributed unit (DU) child link of the at least two different distributed unit (DU) child links, the selecting based at least on the determined resource type and resource flavor.

[0063] Example 2. The method of example 1, further comprising: transmitting or receiving data, by the integrated access and backhaul (IAB) node, on the at least one distributed unit (DU) link selected by the integrated access and backhaul (IAB) node.

[0064] Example 3. The method of any of examples 1-2, wherein the at least one selected distributed unit (DU) child link operates according to the received distributed unit (DU) resource configuration of the corresponding distributed unit (DU) child link.

[0065] Example 4. The method of any of examples 1-3, wherein the at least two different distributed unit (DU) child links include: a master cell group (MCG) distributed unit (DU) child link and a secondary cell group (SCG) distributed unit (DU) child link; or a first master cell group (MCG) distributed unit (DU) child link and a second master cell group (MCG) distributed unit (DU) child link; or a first secondary cell group (SCG) distributed unit (DU) child link and a second secondary cell group (SCG) distributed unit (DU) child link.

[0066] Example 5. The method of any of examples 1-4, wherein the at least two different distributed unit (DU) child links are served by same or different integrated access and backhaul (IAB) donor nodes.

[0067] Example 6. The method of any of examples 1-5, wherein the resource type of a time resource indicates whether the time resource is available for uplink

communications, downlink communications, uplink or downlink communications, or not available for communications on the distributed unit (DU) child link.

[0068] Example 7. The method of any of examples 1-6, wherein the resource flavor indicates: whether a time resource is available persistently for distributed unit (DU) child link communications; or whether an availability of a time resource available for distributed unit (DU) child link communications is explicitly or implicitly controlled by an integrated access and backhaul (IAB) donor node.

[0069] Example 8. The method of any of examples 1-7, wherein the availability further indicates whether the time resource is explicitly or implicitly indicated as available or not available.

[0070] Example 9. The method of any of examples 1-8, wherein the at least two distributed unit (DU) resource configurations corresponding to the at least two different distributed unit (DU) child links have a pre-defined priority order, and wherein the pre defined priority order is determined via higher layer signaling.

[0071] Example 10. The method of any of examples 1-9, wherein the receiving at least two distributed unit (DU) resource configurations corresponding to at least two different distributed unit (DU) child links includes receiving two distributed unit (DU) resource configurations corresponding to two different distributed unit (DU) child links, and wherein the determining the resource type and resource flavor of at least one time resource associated with each of the at least two distributed unit (DU) resource configurations further includes determining the resource type and resource flavor of one time resource each for the two distributed unit (DU) resource configurations, the time resources associated with the two distributed unit (DU) resource configurations being considered as a pair of time resources.

[0072] Example 11. The method of any of examples 1-10, wherein the determining further includes determining that the resource type of the two distributed unit (DU) child link configurations is different, and wherein the selecting further includes selecting a distributed unit (DU) child link with a higher priority.

[0073] Example 12. The method of any of examples 1-11, wherein the determining further includes determining that the resource type of the two distributed unit (DU) child link configurations is different, and wherein the selecting further includes selecting a distributed unit (DU) child link with a lower priority, if the resource type of higher priority distributed unit (DU) child link is not available.

[0074] Example 13. The method of any of examples 1-12, wherein the determining further includes determining that the resource type and resource flavor are same for the two distributed unit (DU) child link resource configurations, and wherein the selecting further includes selecting the two distributed unit (DU) child links, if both the determined resource types are available.

[0075] Example 14. The method of any of examples 1-13, wherein the determining further includes determining that the resource type is same and the resource flavor is different for the two distributed unit (DU) child link resource configurations, and wherein the selecting further includes selecting at least one distributed unit (DU) child link of the two distributed unit (DU) child links.

[0076] Example 15. The method of any of examples 1-14, wherein the determining further includes determining that the resource type is same and the resource flavor is different for the two distributed unit (DU) child link resource configurations, and wherein the selecting further includes selecting both distributed unit (DU) child links, when a time resource explicitly or implicitly controlled by an integrated access and backhaul (IAB) donor node is indicated as available.

[0077] Example 16. The method of any of examples 1-15, wherein the determining further includes determining that the resource type is same and the resource flavor is different for the two distributed unit (DU) child link resource configurations, and wherein the selecting further includes selecting a distributed unit (DU) child link corresponding to a time resource that is persistently available for distributed unit (DU) child link communications, when the time resource explicitly or implicitly controlled by an integrated access and backhaul (IAB) donor node is being indicated as not available.

[0078] Example 17. The method of any of examples 1-16, wherein determining further includes determining that the resource type for the two distributed unit (DU) resource configurations is different, and wherein the selecting further includes notifying a second highest priority distributed unit (DU) link that is available that the second highest priority distributed unit (DU) link is not being served as a first highest priority distributed unit (DU) link is selected.

[0079] Example 18. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 1-17.

[0080] Example 19. An apparatus comprising means for performing a method of any of examples 1-17.

[0081] Example 20. A non-transitory computer-readable storage medium having stored thereon computer executable program code which, when executed on a computer system, causes the computer system to perform the steps of any of examples 1-17.

[0082] FIG. 6 is a block diagram of a wireless station (e.g., user equipment (UE)/user device or AP/gNB/MgNB/SgNB) 600 according to an example implementation. The wireless station 600 may include, for example, one or more RF (radio frequency) or wireless transceivers 602A, 602B, where each wireless transceiver includes a transmitter to transmit signals and a receiver to receive signals.

The wireless station also includes a processor or control unit/entity (controller) 604/608 to execute instructions or software and control transmission and receptions of signals, and a memory 606 to store data and/or instructions.

[0083] Processor 604 may also make decisions or determinations, generate frames, packets or messages for transmission, decode received frames or messages for further processing, and other tasks or functions described herein. Processor 604, which may be a baseband processor, for example, may generate messages, packets, frames or other signals for transmission via wireless transceiver 602 (602A or 602B). Processor 604 may control transmission of signals or messages over a wireless network, and may control the reception of signals or messages, etc., via a wireless network (e.g., after being down-converted by wireless transceiver 602, for example). Processor 604 may be programmable and capable of executing software or other instructions stored in memory or on other computer media to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. Processor 604 may be (or may include), for example, hardware, programmable logic, a programmable processor that executes software or firmware, and/or any combination of these. Using other terminology, processor 604 and transceiver 602 together may be considered as a wireless transmitter/receiver system, for example.

[0084] In addition, referring to FIG. 6, a controller (or processor) 608 may execute software and instructions, and may provide overall control for the station 600, and may provide control for other systems not shown in FIG. 6, such as controlling input/output devices (e.g., display, keypad), and/or may execute software for one or more applications that may be provided on wireless station 600, such as, for example, an email program, audio/video applications, a word processor, a Voice over IP application, or other application or software. Moreover, a storage medium may be provided that includes stored instructions, which when executed by a controller or processor may result in the processor 604, or other controller or processor, performing one or more of the functions or tasks described above. [0085] According to another example implementation, RF or wireless transceiver(s) 602A/602B may receive signals or data and/or transmit or send signals or data. Processor 604 (and possibly transceivers 602A/602B) may control the RF or wireless transceiver 602A or 602B to receive, send, broadcast or transmit signals or data.

[0086] The aspects are not, however, restricted to the system that is given as an example, but a person skilled in the art may apply the solution to other communication systems. Another example of a suitable communications system is the 5G concept.

It is assumed that network architecture in 5G will be quite similar to that of the LTE- advanced. 5G is likely to use multiple input - multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and perhaps also employing a variety of radio technologies for better coverage and enhanced data rates.

[0087] It should be appreciated that future networks will most probably utilize network functions virtualization (NFV) which is a network architecture concept that proposes virtualizing network node functions into“building blocks” or entities that may be operationally connected or linked together to provide services. A virtualized network function (VNF) may comprise one or more virtual machines running computer program codes using standard or general type servers instead of customized hardware. Cloud computing or data storage may also be utilized. In radio communications this may mean node operations may be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. It should also be understood that the distribution of labor between core network operations and base station operations may differ from that of the LTE or even be non-existent.

[0088] Implementations of the various techniques described herein may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Implementations may be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, a data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. Implementations may also be provided on a computer readable medium or computer readable storage medium, which may be a non-transitory medium. Implementations of the various techniques may also include implementations provided via transitory signals or media, and/or programs and/or software implementations that are downloadable via the Internet or other network(s), either wired networks and/or wireless networks. In addition, implementations may be provided via machine type communications (MTC), and also via an Internet of Things (IOT).

[0089] The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers.

[0090] Furthermore, implementations of the various techniques described herein may use a cyber-physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers,...) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

The rise in popularity of smartphones has increased interest in the area of mobile cyber-physical systems. Therefore, various implementations of techniques described herein may be provided via one or more of these technologies.

[0091] A computer program, such as the computer program(s) described above, can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit or part of it suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.

[0092] Method steps may be performed by one or more programmable processors executing a computer program or computer program portions to perform functions by operating on input data and generating output. Method steps also may be performed by, and an apparatus may be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0093] Processors suitable for the execution of a computer program include, e.g., both general and special purpose microprocessors, and any one or more processors of any kind of digital computer, chip or chipset. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. Elements of a computer may include at least one processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer also may include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.

Claims

WHAT IS CLAIMED IS:

1. A method of communications, comprising:

receiving, by an integrated access and backhaul (IAB) node, at least two distributed unit (DU) resource configurations corresponding to at least two different distributed unit (DU) child links;

determining, by the integrated access and backhaul (IAB) node, a resource type and resource flavor of at least one time resource associated with the at least two distributed unit (DU) resource configurations, the determining based at least on corresponding distributed unit (DU) resource configurations of the at least two distributed unit (DU) resource configurations; and

selecting, by the integrated access and backhaul (IAB) node, at least one distributed unit (DU) child link of the at least two different distributed unit (DU) child links, the selecting based at least on the determined resource type and resource flavor.

2. The method of claim 1, further comprising:

transmitting or receiving data, by the integrated access and backhaul (IAB) node, on the at least one distributed unit (DU) link selected by the integrated access and backhaul (IAB) node.

3. The method of one of claim 1 or 2, wherein the at least one selected distributed unit (DU) child link operates according to the received distributed unit (DU) resource configuration of the corresponding distributed unit (DU) child link.

4. The method of claim 1 , wherein the at least two different distributed unit (DU) child links include:

a master cell group (MCG) distributed unit (DU) child link and a secondary cell group (SCG) distributed unit (DU) child link; or

a first master cell group (MCG) distributed unit (DU) child link and a second master cell group (MCG) distributed unit (DU) child link; or a first secondary cell group (SCG) distributed unit (DU) child link and a second secondary cell group (SCG) distributed unit (DU) child link.

5. The method of claim 1, wherein the at least two different distributed unit (DU) child links are served by same or different integrated access and backhaul (IAB) donor nodes.

6. The method of claim 1 , wherein the resource type of a time resource indicates whether the time resource is available for uplink communications, downlink

communications, uplink or downlink communications, or not available for

communications on the distributed unit (DU) child link.

7. The method of claim 1, wherein the resource flavor indicates:

whether a time resource is available persistently for distributed unit (DU) child link communications; or

whether an availability of a time resource available for distributed unit (DU) child link communications is explicitly or implicitly controlled by an integrated access and backhaul (IAB) donor node.

8. The method of claim 7, wherein the availability further indicates whether the time resource is explicitly or implicitly indicated as available or not available.

9. The method of claim 1, wherein the at least two distributed unit (DU) resource configurations corresponding to the at least two different distributed unit (DU) child links have a pre-defined priority order, and wherein the pre-defined priority order is determined via higher layer signaling.

10. The method of claim 1,

wherein the receiving at least two distributed unit (DU) resource configurations corresponding to at least two different distributed unit (DU) child links includes receiving two distributed unit (DU) resource configurations corresponding to two different distributed unit (DU) child links, and

wherein the determining the resource type and resource flavor of at least one time resource associated with each of the at least two distributed unit (DU) resource

configurations further includes determining the resource type and resource flavor of one time resource each for the two distributed unit (DU) resource configurations, the time resources associated with the two distributed unit (DU) resource configurations being considered as a pair of time resources.

11. The method of one of claim 1 or 10,

wherein the determining further includes determining that the resource type of the two distributed unit (DU) child link configurations is different, and

wherein the selecting further includes selecting a distributed unit (DU) child link with a higher priority.

12. The method of one of claim 1 or 10,

wherein the selecting further includes selecting a distributed unit (DU) child link with a lower priority, if the resource type of higher priority distributed unit (DU) child link is not available.

13. The method of one of claim 1 or 10,

wherein the determining further includes determining that the resource type and resource flavor are same for the two distributed unit (DU) child link resource configurations, and wherein the selecting further includes selecting the two distributed unit (DU) child links, if both the determined resource types are available.

14. The method of one of claim 1 or 10,

wherein the determining further includes determining that the resource type is same and the resource flavor is different for the two distributed unit (DU) child link resource configurations, and wherein the selecting further includes selecting at least one distributed unit (DU) child link of the two distributed unit (DU) child links.

15. The method of one of claim 1 or 10,

wherein the determining further includes determining that the resource type is same and the resource flavor is different for the two distributed unit (DU) child link resource configurations, and

wherein the selecting further includes selecting both distributed unit (DU) child links, when a time resource explicitly or implicitly controlled by an integrated access and backhaul (IAB) donor node is indicated as available.

16. The method of one of claim 1 or 10,

wherein the selecting further includes selecting a distributed unit (DU) child link corresponding to a time resource that is persistently available for distributed unit (DU) child link communications, when the time resource explicitly or implicitly controlled by an integrated access and backhaul (IAB) donor node is being indicated as not available.

17. The method of one of claim 1 or 10,

wherein determining further includes determining that the resource type for the two distributed unit (DU) resource configurations is different, and

wherein the selecting further includes notifying a second highest priority distributed unit (DU) link that is available that the second highest priority distributed unit (DU) link is not being served as a first highest priority distributed unit (DU) link is selected.

18. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of claims 1-17.

19. An apparatus comprising means for performing a method of any of claims 1-17.

20. A non-transitory computer-readable storage medium having stored thereon computer executable program code which, when executed on a computer system, causes the computer system to perform the steps of any of claims 1-17.