Mechanisms for integrated access and backhaul (IAB) mobile terminal distributed unit simultaneous operation

The present application claims priority to U.S. Provisional Patent Application No. 62/984,523, which was filed Mar. 3, 2020; U.S. Provisional Patent Application No. 62/984,532, which was filed Mar. 3, 2020; the disclosures of which are hereby incorporated by reference.

Embodiments relate generally to the technical field of wireless communications.

In an Integrated Access and Backhaul (IAB) network, an IAB node can connect to its parent node (an IAB donor or another IAB node) through a parent backhaul (BH) link, connect to a child user equipment (UE) through a child access (AC) link, and connect to its child IAB node through child BH link.

In current IAB network architectures, central unit (CU)/distributed unit (DU) split has been leveraged where each IAB node holds a DU and a Mobile-Termination (MT) function: Via the MT function, the IAB node connects to its parent IAB node or the IAB-donor like a UE; Via the DU function, the IAB node communicates with its child UEs and child MTs like a base station. RRC signaling is used between the CU in the IAB donor and the UE/MT; while F1AP signaling is used between the CU and the DU in an IAB node.

Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.

FIG. 1 illustrates an example of link types in an integrated access and backhaul (IAB) network, in accordance with various embodiments.

FIG. 2 illustrates an example of IAB centralized unit (CU)/distributed unit (DU) split architecture and signaling, in accordance with various embodiments.

FIG. 3 illustrates an example of timing alignment for simultaneous mobile terminal (MT) transmission (Tx) and DU Tx, in accordance with various embodiments.

FIG. 4 illustrates an example of timing alignment for simultaneous MT reception (Rx) and DU Rx, in accordance with various embodiments.

FIG. 5 illustrates an example of timing alignment for simultaneous MT Rx and DU Tx, in accordance with various embodiments.

FIG. 6 illustrates an example of timing alignment for simultaneous MT Tx and DU Rx, in accordance with various embodiments.

Example 7 illustrates eight resource transition cases with simultaneous MT Tx and DU Tx at slot n, in accordance with various embodiments.

FIG. 8 schematically illustrates a wireless network in accordance with various embodiments.

FIG. 9 schematically illustrates components of a wireless network in accordance with various embodiments.

FIG. 10 is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein.

FIG. 11 is a flowchart of an example process that may be performed by an IAB node, in accordance with various embodiments.

FIG. 12 is a flowchart of another example process that may be performed by an IAB node, in accordance with various embodiments.

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of various embodiments. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the various embodiments may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of the present document, the phrases “A or B” and “A/B” mean (A), (B), or (A and B).

In NR Rel-16 specifications, the Integrated Access and Backhaul (IAB) section are focused on supporting time-division multiplexing (TDM) based distributed unit (DU) function and mobile terminal (MT) function within an IAB node. Extended IAB work direction will include duplexing enhancements to increase spectral efficiency and reduce latency through the support of spatial division multiplexing (SDM) and/or frequency division multiplexing (FDM)-based resource management, through simultaneous transmissions and/or reception on IAB nodes.

Simultaneous operation (transmission (Tx) and/or reception (Rx)) of integrated access and backhaul (IAB) node's child and parent links includes four cases as below:

In the above, MT TX/DU TX means simultaneous MT transmission and DU transmission at one IAB node; MT TX/DU RX means simultaneous MT transmission and DU reception at one IAB node; etc.

Various embodiments herein provide slot-based and symbol-based timing alignment mechanisms to support the possible IAB MT/DU simultaneous operations. Additional signaling options from an IAB DU to its child IAB MT to carry parent link related information as needed in some slot-based timing alignment mechanisms are also described.

Additionally, in one IAB node, the co-located IAB DU and IAB MT may have resource transition in the adjacent slots. For an IAB node that only support TDM between parent backhaul and child links, Ng are provided for each of the eight possible transitions with potential overlaps.

Various embodiments herein provide mechanisms for guard symbol management when IAB MT/DU simultaneous operation is supported. In embodiments, when one of the simultaneous operations is supported, the related transition guard symbols (e.g., desired and provided) are not needed.

In addition, the current agreed semi-static F1AP configuration is to notify the simultaneous operation capability of an IAB node to the donor CU and the parent node. Whether the capability is actually used or not needs additional dynamic signaling to notify the parent node, so that the parent node can utilize the parent link resource accordingly. Various embodiments herein provide contents and methods for additional dynamical signaling regarding dynamic IAB multiplexing information.

IAB DU and IAB MT Simultaneous Operation

FIG. 1 illustrates an example Integrated Access and Backhaul (IAB) network, in accordance with various embodiments. In the IAB network, an IAB node can connect to its parent node (an IAB donor or another IAB node) through parent backhaul (BH) link; connect to a child user equipment (UE) through child access (AC) link; and connect to its child IAB node through child BH link.

In current IAB network architectures, central unit (CU)/distributed unit (DU) split has been leveraged where each IAB node holds a DU and a Mobile-Termination (MT) function: Via the MT function, the IAB node connects to its parent IAB node or the IAB-donor like a UE; Via the DU function, the IAB node communicates with its child UEs and child MTs like a base station. RRC signaling is used between the CU in the IAB donor and the UE/MT; while F1AP signaling is used between the CU and the DU in an IAB node.

FIG. 2 illustrates an example of the IAB CU/DU split architecture and signaling in FIG. 2 , where MT and DU in a parent IAB node are marked as P-MT/P-DU; MT and DU in a child IAB node as C-MT/C-DU; and a child UE as C-UE.

As discussed above, in NR Rel-16 specifications, the IAB section are focused on supporting TDM based DU function and MT function within an IAB node. Extended IAB work direction will include duplexing enhancements to increase spectral efficiency and reduce latency through the support of SDM/FDM-based resource management, through simultaneous transmissions and/or reception on IAB nodes.

Slot-Based Alignment and Symbol-Based Alignment for IAB MT/DU Simultaneous Operation

Described herein are slot-based and symbol-based timing alignment mechanisms to support those possible IAB MT/DU simultaneous operation. Additional signaling options from an IAB DU to its child IAB MT to carry parent link related information as needed in some slot-based timing alignment mechanisms are also described.

FIG. 3 illustrates the timing relationship if simultaneous operation of MT TX/DU TX is supported. The DU TX timing needs to be aligned with its parent-DU TX timing as RAN1 has agreed that all IAB DU's DL TX timing are aligned. The MT TX timing has timing advance control (TA 0 with parent link propagation delay T p0 ) regarding MT RX timing. The MT TX timing is shown in blue block in the figure and the corresponding parent-DU RX timing is also shown in blue block.

There are two timing alignment ways for simultaneous operation of MT TX/DU TX. One way is slot-based alignment, which means MT TX slot and DU TX slot need to start and end at the same time. To fulfil slot-based alignment for MT TX/DU TX, since DU TX timing is fixed, MT TX timing needs to be shifted (delayed) TA 0 −T p0 as the red block (MT TX shifted) in the figure and the corresponding parent-DU RX shifted timing is also shown in red block.

Another way for simultaneous operation of MT TX/DU TX is symbol-based alignment, which means MT TX and DU TX are symbol aligned and no large shift like the slot-based alignment case is needed. This has the benefit that current TA control mechanism and timing relationship between IAB node and its parent node can remain.

FIG. 4 illustrates the timing relationship if simultaneous operation of MT RX/DU RX is supported. The MT RX timing is related to parent link propagation delay T p0 . The child-MT TX has timing advance control (TA with child link propagation delay T p ) regarding child MT RX timing. The child MT TX timing is shown in green block in the figure and the corresponding DU RX timing is also shown in green block. The DU RX timing is TA−2T p ahead of DU TX timing and TA−2T p +T p0 ahead of MT RX timing as shown in the figure.

For the slot-based alignment, since MT RX timing is fixed, DU RX timing needs to be shifted (delayed) TA−2T p +T p0 as the red block (DU RX shifted) in the figure and the corresponding child-MT TX shifted timing is also shown in red block. We can observe that in order to fulfil slot-based alignment for MT RX/DU RX simultaneous operation, the child MT needs to know the parent backhaul propagation delay T p0 , which needs additional signaling.

For symbol-based alignment, there is no red block shifting. Current TA control mechanism and timing relationship between parent IAB node, IAB node and its child node can remain.

FIG. 5 illustrates the timing relationship if simultaneous operation of MT RX/DU TX is supported. The MT RX timing is related to parent link propagation delay T p0 . The DU TX timing is aligned with its parent DU TX timing.

For MT RX/DU TX simultaneous operation, slot-based alignment is not possible, since MT RX and DU TX timing are both fixed and cannot be shifted. Hence, only symbol-based alignment can be supported for MT RX/DU TX simultaneous operation.

FIG. 6 illustrates the timing relationship if simultaneous operation of MT TX/DU RX is supported. The MT TX timing has timing advance control (TA 0 with parent link propagation delay T p0 ) and is TA 0 −T p0 ahead of DL TX timing. Similarly, the child MT TX timing has timing advance control (TA with child link propagation delay T p ) and is TA−T p ahead of DL TX timing. Hence, the DU RX timing is TA−2 T p ahead of DL TX timing as shown in FIG. 6 .

For the slot-based alignment, there are two ways to shift:

shift DU RX block ahead of time (DU RX shifted 1 in red block), with corresponding child-MT TX shifted 1 block also shown in red; shift MT TX behind time (MT TX shifted 2), with corresponding parent-DU RX shifted 2 block also shown in red.

The shifting distance is ΔS=(TA 0 −T p0 )−(TA−2T p ). For child-MT TX shifted 1, we can observe that in order to fulfil slot-based alignment for MT TX/DU RX simultaneous operation, the child MT needs to know the parent backhaul propagation delay T p0 and the parent timing advance parameter TA 0 , which needs additional signalling.

For symbol-based alignment, there is no red block shifting. Current TA control mechanism and timing relationship between parent IAB node, IAB node and its child node can remain.

In summary, TA 0 defined as time advance control for MT TX with parent link propagation delay T p0 and TA defined as time advance control for child MT TX child link propagation delay T p , the slot-based alignment mechanism for the four cases can be described as follows.

MT TX/DU TX: MT TX timing needs to be shifted (delayed) TA 0 −T p0 to be aligned with DU TX timing. MT RX/DU RX: Child-MT TX timing needs to be shifted (delayed) TA−2 T p +T p0 , so that DU RX timing can be aligned with MT RX timing. Additional signaling is needed to inform the child MT with the parent backhaul propagation delay T p0 . MT RX/DU TX: there is no slot-based alignment mechanism for this case. MT TX/DU RX: there are two ways to fulfil slot-based alignment with ΔS=(TA 0 −T p0 )−(TA−2T p )

Slot-based alignment1: shift child-MT TX ΔS ahead of time, so that DU RX timing can be aligned with MT TX timing. Additional signaling is needed to inform the child MT with the parent link related parameters TA 0 −T p0 . Slot-based alignment1: shift MT TX ΔS behind time, so that MT TX timing can be aligned with DU RX timing.

Note that for the shifted value A in all cases, if A is negative, time delay A means time advance |A|.

For the symbol-based alignment mechanism, simultaneous operation does not require MT/DU slot to start and end at the same time. Current TA control mechanism and timing relationship between IAB node and its parent node can remain.

Additional Signaling for Slot-Based Alignment to Support IAB MT/DU Simultaneous Operation

As described above, for slot-based alignment to support IAB MT/DU simultaneous operation, additional signaling is needed for some scenarios to carry parent link related information to the child MT. In the case of MT RX/DU RX, parent backhaul propagation delay T p0 needs to be transmitted, while in the case of slot-based alignment1 for MT TX/DU RX, parent link related parameters TA 0 −T p0 needs to be transmitted.

For the signaling method for this purpose, there are several options to carry parent link related information form IAB DU to the child MT.

Option 1: Over MAC CE/PDSCH

For Option 1, the parent link related information is carried over medium access control (MAC) control element (CE) carried by physical downlink shared channel (PDSCH), which can be either dynamic triggered or configured grant.

In current NR specification (see 3GPP Technical Standard (TS) 38.321), the logic channel ID (LCID) field which 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 downlink shared channel (DL-SCH) is described in the following Table. In embodiments, one of the reserved LCID values (33-46) may be used to transmit the parent link related information from an IAB DU to its child IAB MT.

Option 2: Over Group-Common PDCCH

Regarding transmission over group-common PDCCH, a new field can be added in one of current DCI 2_0 formats, or a new DCI format can be added (e.g., if new field cannot be added in current DCI 2_0 formats).

Option 3: Over a New Defined L1 Channel

For Option 3, if a IA channel will be added in current specification, the IAB parent link related information can also be transmitted over this new defined IA channel.

Guard Symbol Management Mechanism for IAB MT/DU Simultaneous Operation

In one IAB node, the co-located IAB DU and IAB MT may have resource transition in the adjacent slots. For an IAB node that only support TDM between parent backhaul and child links, Ng are provided for each of the eight possible transitions with potential overlaps. RAN1 #98bis-RAN1 #99 have made the following agreements regarding guard symbols for transitions between an IAB MT and co-located IAB DU.

A parent IAB node can be made aware of the number of symbols Ng the child IAB node would like the parent IAB node not to use at the edge (beginning or end) of a slot when there is a transition between child MT and child DU. Separately or additionally, the child IAB node can be made aware of the number of guard symbols that the parent IAB node will provide.

Ng can be provided for each of the [8] possible transitions with potential overlap:

Ng can be provided for each of the [8] possible transitions with potential overlap: In Rel-16, a range of 0-4 symbols are supported for each transition. Additional entries are reserved for future use A new parameter GuardSymbol-SCS is also provided which indicates the reference SCS (FR1: {15 kHz, 30 kHz, 60 kHz}, FR2: {60 kHz, 120 kHz}) to be used for the guard symbols.

Various embodiments herein provide guard symbol management mechanism to support those possible IAB MT/DU simultaneous operation.

As an example, when simultaneous operation of MT TX/DU TX is supported, FIG. 7 illustrates eight possible transitions with MT TX/DU TX at slot n.

For Case A1/A2, when MT TX/DU TX at slot n followed by MT TX or DU TX at slot n+1, since simultaneous operation of MT TX/DU TX is supported, the transition guard symbols of DU TX to MT TX in the Ng table can be removed. Case A5 can also be proceeded without any MT TX to DU TX or DU TX to MT TX guard symbols restriction.

For Case A3, when MT TX/DU TX at slot n followed by MT RX at slot n+1, whether guard symbols are needed depends on whether simultaneous operation of DU TX/MT RX is supported. If it is supported, the transition guard symbols of DU TX to MT RX in the Ng table can be removed. Otherwise the transition guard symbol rule for DU TX to MT RX still needs to be followed.

For Case A4, when MT TX/DU TX at slot n followed by DU RX at slot n+1, whether guard symbols are needed depends on whether simultaneous operation of MT TX/DU RX is supported. If it is supported, the transition guard symbols of MT TX to DU RX in the Ng table can be removed. Otherwise the transition guard symbol rule for MT TX to DU RX still needs to be followed.

For Case A6, when MT TX/DU TX at slot n followed by simultaneous operation of MT TX/DU RX (which indicates this operation is supported), the transition guard symbols of both MT TX to DU RX and DU TX to MT TX in the Ng table should be removed.

For Case A7, when MT TX/DU TX at slot n followed by simultaneous operation of MT RX/DU TX (which indicates this operation is supported), the transition guard symbols of both MT TX to DU TX and DU TX to MT RX in the Ng table should be removed.

For Case A8, when MT TX/DU TX at slot n followed by simultaneous operation of MT RX/DU RX (which indicates this operation is supported), the transition guard symbols of MT TX to DU RX and DU TX to MT RX in the Ng table still need to be followed, unless the simultaneous operation of MT TX/DU RX and DU TX/MT RX are additionally supported.

Similarly, the eight transition cases with MT RX/DU RX at slot n, eight transition cases with MT RX/DU TX at slot n, and eight transition cases with MT TX/DU RX at slot n can be anal10ed. The common ground is that when one of the simultaneous operations is supported, the related transition guard symbols (desired and provided) are not needed. The summary on guard symbol management for IAB MT/DU simultaneous operations in the following Table 1.

Additional Signaling for Dynamic Indication of IAB MT/DU Simultaneous Operation

Regarding IAB MT/DU simultaneous operation, RAN1 #98bis-RAN1 #99 have made the following agreements.

The donor CU and the parent node can be made aware of the multiplexing capability between MT and DU (TDM required, TDM not required) of an IAB node to for any {MT CC, DU cell} pair.

Signaling details up to RAN2/RAN3.

The indication of the multiplexing capability for the case of no-TDM between IAB MT and IAB DU is additionally provided with respect to each transmission-direction combination (per MT CC/DU cell pair):

Note: This agreement does not require any additional specification impact in RAN1 in Rel-16, e.g. in Rel-16 the behaviour of the IAB node is only defined for TDM cases. The behaviour for no-TDM is left to IAB-node/network implementation in Rel-16.

In 3GPP RAN1 #98bis, F1AP signaling has been agreed to be used between CU and IAB node or Donor DU, to notify the donor CU and the parent node regarding the multiplexing capability between co-located MT and DU.

However, this is the semi-static F1AP configuration to notify the CU and the parent node that the simultaneous operation capability of an IAB node. Whether the capability is actually used or not needs additional dynamic signaling to notify the parent node, so that the parent node can utilize the parent link resource accordingly.

Signaling Contents

The signaling contents regarding dynamic IAB multiplexing information can have several options.

Option A1: Enumerate the transmission-direction combination that allowed dynamically from the set of {MT-TX/DU-TX, MT-TX/DU-RX, MT-RX/DU-TX, MT-RX/DU-RX} for each {MT CC, DU Cell} pair. Option A2: Use four bits to indicate the possible four transmission-direction combination for each {MT CC, DU Cell} pair. For example, fix the index order as {MT-TX/DU-TX, MT-TX/DU-RX, MT-RX/DU-TX, MT-RX/DU-RX}, then “1100” means MT-TX/DU-TX and MT-TX/DU-RX are currently allowed.

Signaling Methods

For signaling method, there can be several options to include the dynamic IAB multiplexing information through L1/L2 signaling to the parent DU.

Option B1: Over UCI/PUCCH

For Option B1, regarding dynamic IAB multiplexing information over uplink control information (UCI) from the IAB MT to the parent IAB DU, a new field can be added in one of current uplink control information (UCI) formats. Alternatively, a new UCI format can be added if new field cannot be added in current UCI formats, and can be carried by physical uplink control channel (PUCCH). The PUCCH resource used to carry the new UCI type may be semi-statically configured or based on semi-persistent scheduling or dynamic scheduling. Note that PUCCH may be piggyback transmitted on PUSCH.

Option B2: Over MAC CE/PUSCH

For Option B2, the dynamic IAB multiplexing information is over medium access control (MAC) control element (CE) carried by physical uplink shared channel (PUSCH), which can be either dynamic triggered or configured grant.

In current NR specification (see 3GPP Technical Standard 38.321), the logic channel ID (LCD) field which 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 some embodiments, one of the reserved LCID values (33-51) can be used to transmit the dynamic IAB multiplexing information from an IAB MT to its parent DU.

For Option B3, if a L1 channel will be added in current specification, the dynamic IAB multiplexing information can also be transmitted over this new defined L1 channel.

Systems and Implementations

FIGS. 8 - 10 illustrate various systems, devices, and components that may implement aspects of disclosed embodiments.

FIG. 8 illustrates a network 800 in accordance with various embodiments. The network 800 may operate in a manner consistent with 3GPP technical specifications for LTE or 5G/NR systems. However, the example embodiments are not limited in this regard and the described embodiments may apply to other networks that benefit from the principles described herein, such as future 3GPP systems, or the like.

The network 800 may include a UE 802 , which may include any mobile or non-mobile computing device designed to communicate with a RAN 804 via an over-the-air connection. The UE 802 may be, but is not limited to, a smartphone, tablet computer, wearable computer device, desktop computer, laptop computer, in-vehicle infotainment, in-car entertainment device, instrument cluster, head-up display device, onboard diagnostic device, dashtop mobile equipment, mobile data terminal, electronic engine management system, electronic/engine control unit, electronic/engine control module, embedded system, sensor, microcontroller, control module, engine management system, networked appliance, machine-type communication device, M2M or D2D device, IoT device, etc.

In some embodiments, the network 800 may include a plurality of UEs coupled directly with one another via a sidelink interface. The UEs may be M2M/D2D devices that communicate using physical sidelink channels such as, but not limited to, PSBCH, PSDCH, PSSCH, PSCCH, PSFCH, etc.

In some embodiments, the UE 802 may additionally communicate with an AP 806 via an over-the-air connection. The AP 806 may manage a WLAN connection, which may serve to offload some/all network traffic from the RAN 804 . The connection between the UE 802 and the AP 806 may be consistent with any IEEE 802.11 protocol, wherein the AP 806 could be a wireless fidelity (Wi-Fi®) router. In some embodiments, the UE 802 , RAN 804 , and AP 806 may utilize cellular-WLAN aggregation (for example, LWA/LWIP). Cellular-WLAN aggregation may involve the UE 802 being configured by the RAN 804 to utilize both cellular radio resources and WLAN resources.

The RAN 804 may include one or more access nodes, for example, AN 808 . AN 808 may terminate air-interface protocols for the UE 802 by providing access stratum protocols including RRC, PDCP, RLC, MAC, and L1 protocols. In this manner, the AN 808 may enable data/voice connectivity between CN 820 and the UE 802 . In some embodiments, the AN 808 may be implemented in a discrete device or as one or more software entities running on server computers as part of, for example, a virtual network, which may be referred to as a CRAN or virtual baseband unit pool. The AN 808 be referred to as a BS, gNB, RAN node, eNB, ng-eNB, NodeB, RSU, TRxP, TRP, etc. The AN 808 may be a macrocell base station or a low power base station for providing femtocells, picocells or other like cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells.

In embodiments in which the RAN 804 includes a plurality of ANs, they may be coupled with one another via an X2 interface (if the RAN 804 is an LTE RAN) or an Xn interface (if the RAN 804 is a 5G RAN). The X2/Xn interfaces, which may be separated into control/user plane interfaces in some embodiments, may allow the ANs to communicate information related to handovers, data/context transfers, mobility, load management, interference coordination, etc.

The ANs of the RAN 804 may each manage one or more cells, cell groups, component carriers, etc. to provide the UE 802 with an air interface for network access. The UE 802 may be simultaneously connected with a plurality of cells provided by the same or different ANs of the RAN 804 . For example, the UE 802 and RAN 804 may use carrier aggregation to allow the UE 802 to connect with a plurality of component carriers, each corresponding to a Pcell or Scell. In dual connectivity scenarios, a first AN may be a master node that provides an MCG and a second AN may be secondary node that provides an SCG. The first/second ANs may be any combination of eNB, gNB, ng-eNB, etc.

The RAN 804 may provide the air interface over a licensed spectrum or an unlicensed spectrum. To operate in the unlicensed spectrum, the nodes may use LAA, eLAA, and/or feLAA mechanisms based on CA technology with PCells/Scells. Prior to accessing the unlicensed spectrum, the nodes may perform medium/carrier-sensing operations based on, for example, a listen-before-talk (LBT) protocol.

In V2X scenarios the UE 802 or AN 808 may be or act as a RSU, which may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by a suitable AN or a stationary (or relatively stationary) UE. An RSU implemented in or by: a UE may be referred to as a “UE-type RSU”; an eNB may be referred to as an “eNB-type RSU”; a gNB may be referred to as a “gNB-type RSU”; and the like. In one example, an RSU is a computing device coupled with radio frequency circuitry located on a roadside that provides connectivity support to passing vehicle UEs. The RSU may also include internal data storage circuitry to store intersection map geometry, traffic statistics, media, as well as applications/software to sense and control ongoing vehicular and pedestrian traffic. The RSU may provide very low latency communications required for high speed events, such as crash avoidance, traffic warnings, and the like. Additionally or alternatively, the RSU may provide other cellular/WLAN communications services. The components of the RSU may be packaged in a weatherproof enclosure suitable for outdoor installation, and may include a network interface controller to provide a wired connection (e.g., Ethernet) to a traffic signal controller or a backhaul network.

In some embodiments, the RAN 804 may be an LTE RAN 810 with eNBs, for example, eNB 812 . The LTE RAN 810 may provide an LTE air interface with the following characteristics: SCS of 15 kHz; CP-OFDM waveform for DL and SC-FDMA waveform for UL; turbo codes for data and TBCC for control; etc. The LTE air interface may rely on CSI-RS for CSI acquisition and beam management; PDSCH/PDCCH DMRS for PDSCH/PDCCH demodulation; and CRS for cell search and initial acquisition, channel quality measurements, and channel estimation for coherent demodulation/detection at the UE. The LTE air interface may operating on sub-6 GHz bands.

In some embodiments, the RAN 804 may be an NG-RAN 814 with gNBs, for example, gNB 816 , or ng-eNBs, for example, ng-eNB 818 . The gNB 816 may connect with 5G-enabled UEs using a 5G NR interface. The gNB 816 may connect with a 5G core through an NG interface, which may include an N2 interface or an N3 interface. The ng-eNB 818 may also connect with the 5G core through an NG interface, but may connect with a UE via an LTE air interface. The gNB 816 and the ng-eNB 818 may connect with each other over an Xn interface.

In some embodiments, the NG interface may be split into two parts, an NG user plane (NG-U) interface, which carries traffic data between the nodes of the NG-RAN 814 and a UPF 848 (e.g., N3 interface), and an NG control plane (NG-C) interface, which is a signaling interface between the nodes of the NG-RAN 814 and an AMF 844 (e.g., N2 interface).

The NG-RAN 814 may provide a 5G-NR air interface with the following characteristics: variable SCS; CP-OFDM for DL, CP-OFDM and DFT-s-OFDM for UL; polar, repetition, simplex, and Reed-Muller codes for control and LDPC for data. The 5G-NR air interface may rely on CSI-RS, PDSCH/PDCCH DMRS similar to the LTE air interface. The 5G-NR air interface may not use a CRS, but may use PBCH DMRS for PBCH demodulation; PTRS for phase tracking for PDSCH; and tracking reference signal for time tracking. The 5G-NR air interface may operating on FR1 bands that include sub-6 GHz bands or FR2 bands that include bands from 24.25 GHz to 52.6 GHz. The 5G-NR air interface may include an SSB that is an area of a downlink resource grid that includes PSS/SSS/PBCH.

In some embodiments, the 5G-NR air interface may utilize BWPs for various purposes. For example, BWP can be used for dynamic adaptation of the SCS. For example, the UE 802 can be configured with multiple BWPs where each BWP configuration has a different SCS. When a BWP change is indicated to the UE 802 , the SCS of the transmission is changed as well. Another use case example of BWP is related to power saving. In particular, multiple BWPs can be configured for the UE 802 with different amount of frequency resources (for example, PRBs) to support data transmission under different traffic loading scenarios. A BWP containing a smaller number of PRBs can be used for data transmission with small traffic load while allowing power saving at the UE 802 and in some cases at the gNB 816 . A BWP containing a larger number of PRBs can be used for scenarios with higher traffic load.

The RAN 804 is communicatively coupled to CN 820 that includes network elements to provide various functions to support data and telecommunications services to customers/subscribers (for example, users of UE 802 ). The components of the CN 820 may be implemented in one physical node or separate physical nodes. In some embodiments, NFV may be utilized to virtualize any or all of the functions provided by the network elements of the CN 820 onto physical compute/storage resources in servers, switches, etc. A logical instantiation of the CN 820 may be referred to as a network slice, and a logical instantiation of a portion of the CN 820 may be referred to as a network sub-slice.

In some embodiments, the CN 820 may be an LTE CN 822 , which may also be referred to as an EPC. The LTE CN 822 may include MME 824 , SGW 826 , SGSN 828 , HSS 830 , PGW 832 , and PCRF 834 coupled with one another over interfaces (or “reference points”) as shown. Functions of the elements of the LTE CN 822 may be briefly introduced as follows.

The MME 824 may implement mobility management functions to track a current location of the UE 802 to facilitate paging, bearer activation/deactivation, handovers, gateway selection, authentication, etc.

The SGW 826 may terminate an Si interface toward the RAN and route data packets between the RAN and the LTE CN 822 . The SGW 826 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement.

The SGSN 828 may track a location of the UE 802 and perform security functions and access control. In addition, the SGSN 828 may perform inter-EPC node signaling for mobility between different RAT networks; PDN and S-GW selection as specified by MME 824 ; MME selection for handovers; etc. The S3 reference point between the MME 824 and the SGSN 828 may enable user and bearer information exchange for inter-3GPP access network mobility in idle/active states.

The HSS 830 may include a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The HSS 830 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc. An S6a reference point between the HSS 830 and the MME 824 may enable transfer of subscription and authentication data for authenticating/authorizing user access to the LTE CN 820 .

The PGW 832 may terminate an SGi interface toward a data network (DN) 836 that may include an application/content server 838 . The PGW 832 may route data packets between the LTE CN 822 and the data network 836 . The PGW 832 may be coupled with the SGW 826 by an S5 reference point to facilitate user plane tunneling and tunnel management. The PGW 832 may further include a node for policy enforcement and charging data collection (for example, PCEF). Additionally, the SGi reference point between the PGW 832 and the data network 836 may be an operator external public, a private PDN, or an intra-operator packet data network, for example, for provision of IMS services. The PGW 832 may be coupled with a PCRF 834 via a Gx reference point.

The PCRF 834 is the policy and charging control element of the LTE CN 822 . The PCRF 834 may be communicatively coupled to the app/content server 838 to determine appropriate QoS and charging parameters for service flows. The PCRF 832 may provision associated rules into a PCEF (via Gx reference point) with appropriate TFT and QCI.

In some embodiments, the CN 820 may be a 5GC 840 . The 5GC 840 may include an AUSF 842 , AMF 844 , SMF 846 , UPF 848 , NSSF 850 , NEF 852 , NRF 854 , PCF 856 , UDM 858 , and AF 860 coupled with one another over interfaces (or “reference points”) as shown. Functions of the elements of the 5GC 840 may be briefly introduced as follows.

The AUSF 842 may store data for authentication of UE 802 and handle authentication-related functionality. The AUSF 842 may facilitate a common authentication framework for various access types. In addition to communicating with other elements of the 5GC 840 over reference points as shown, the AUSF 842 may exhibit an Nausf service-based interface.

The AMF 844 may allow other functions of the 5GC 840 to communicate with the UE 802 and the RAN 804 and to subscribe to notifications about mobility events with respect to the UE 802 . The AMF 844 may be responsible for registration management (for example, for registering UE 802 ), connection management, reachability management, mobility management, lawful interception of AMF-related events, and access authentication and authorization. The AMF 844 may provide transport for SM messages between the UE 802 and the SMF 846 , and act as a transparent proxy for routing SM messages. AMF 844 may also provide transport for SMS messages between UE 802 and an SMSF. AMF 844 may interact with the AUSF 842 and the UE 802 to perform various security anchor and context management functions. Furthermore, AMF 844 may be a termination point of a RAN CP interface, which may include or be an N2 reference point between the RAN 804 and the AMF 844 ; and the AMF 844 may be a termination point of NAS (N1) signaling, and perform NAS ciphering and integrity protection. AMF 844 may also support NAS signaling with the UE 802 over an N3 IWF interface.

The SMF 846 may be responsible for SM (for example, session establishment, tunnel management between UPF 848 and AN 808 ); UE IP address allocation and management (including optional authorization); selection and control of UP function; configuring traffic steering at UPF 848 to route traffic to proper destination; termination of interfaces toward policy control functions; controlling part of policy enforcement, charging, and QoS; lawful intercept (for SM events and interface to LI system); termination of SM parts of NAS messages; downlink data notification; initiating AN specific SM information, sent via AMF 844 over N2 to AN 808 ; and determining SSC mode of a session. SM may refer to management of a PDU session, and a PDU session or “session” may refer to a PDU connectivity service that provides or enables the exchange of PDUs between the UE 802 and the data network 836 .

The UPF 848 may act as an anchor point for intra-RAT and inter-RAT mobility, an external PDU session point of interconnect to data network 836 , and a branching point to support multi-homed PDU session. The UPF 848 may also perform packet routing and forwarding, perform packet inspection, enforce the user plane part of policy rules, lawfully intercept packets (UP collection), perform traffic usage reporting, perform QoS handling for a user plane (e.g., packet filtering, gating, UL/DL rate enforcement), perform uplink traffic verification (e.g., SDF-to-QoS flow mapping), transport level packet marking in the uplink and downlink, and perform downlink packet buffering and downlink data notification triggering. UPF 848 may include an uplink classifier to support routing traffic flows to a data network.

The NSSF 850 may select a set of network slice instances serving the UE 802 . The NSSF 850 may also determine allowed NSSAI and the mapping to the subscribed S-NSSAIs, if needed. The NSSF 850 may also determine the AMF set to be used to serve the UE 802 , or a list of candidate AMFs based on a suitable configuration and possibly by querying the NRF 854 . The selection of a set of network slice instances for the UE 802 may be triggered by the AMF 844 with which the UE 802 is registered by interacting with the NSSF 850 , which may lead to a change of AMF. The NSSF 850 may interact with the AMF 844 via an N22 reference point; and may communicate with another NSSF in a visited network via an N31 reference point (not shown). Additionally, the NSSF 850 may exhibit an Nnssf service-based interface.

The NEF 852 may securely expose services and capabilities provided by 3GPP network functions for third party, internal exposure/re-exposure, AFs (e.g., AF 860 ), edge computing or fog computing systems, etc. In such embodiments, the NEF 852 may authenticate, authorize, or throttle the AFs. NEF 852 may also translate information exchanged with the AF 860 and information exchanged with internal network functions. For example, the NEF 852 may translate between an AF-Service-Identifier and an internal 5GC information. NEF 852 may also receive information from other NFs based on exposed capabilities of other NFs. This information may be stored at the NEF 852 as structured data, or at a data storage NF using standardized interfaces. The stored information can then be re-exposed by the NEF 852 to other NFs and AFs, or used for other purposes such as analytics. Additionally, the NEF 852 may exhibit an Nnef service-based interface.

The NRF 854 may support service discovery functions, receive NF discovery requests from NF instances, and provide the information of the discovered NF instances to the NF instances. NRF 854 also maintains information of available NF instances and their supported services. As used herein, the terms “instantiate,” “instantiation,” and the like may refer to the creation of an instance, and an “instance” may refer to a concrete occurrence of an object, which may occur, for example, during execution of program code. Additionally, the NRF 854 may exhibit the Nnrf service-based interface.

The PCF 856 may provide policy rules to control plane functions to enforce them, and may also support unified policy framework to govern network behavior. The PCF 856 may also implement a front end to access subscription information relevant for policy decisions in a UDR of the UDM 858 . In addition to communicating with functions over reference points as shown, the PCF 856 exhibit an Npcf service-based interface.

The UDM 858 may handle subscription-related information to support the network entities' handling of communication sessions, and may store subscription data of UE 802 . For example, subscription data may be communicated via an N8 reference point between the UDM 858 and the AMF 844 . The UDM 858 may include two parts, an application front end and a UDR. The UDR may store subscription data and policy data for the UDM 858 and the PCF 856 , and/or structured data for exposure and application data (including PFDs for application detection, application request information for multiple UEs 802 ) for the NEF 852 . The Nudr service-based interface may be exhibited by the UDR 221 to allow the UDM 858 , PCF 856 , and NEF 852 to access a particular set of the stored data, as well as to read, update (e.g., add, modify), delete, and subscribe to notification of relevant data changes in the UDR. The UDM may include a UDM-FE, which is in charge of processing credentials, location management, subscription management and so on. Several different front ends may serve the same user in different transactions. The UDM-FE accesses subscription information stored in the UDR and performs authentication credential processing, user identification handling, access authorization, registration/mobility management, and subscription management. In addition to communicating with other NFs over reference points as shown, the UDM 858 may exhibit the Nudm service-based interface.

The AF 860 may provide application influence on traffic routing, provide access to NEF, and interact with the policy framework for policy control.

In some embodiments, the 5GC 840 may enable edge computing by selecting operator/3rd party services to be geographically close to a point that the UE 802 is attached to the network. This may reduce latency and load on the network. To provide edge-computing implementations, the 5GC 840 may select a UPF 848 close to the UE 802 and execute traffic steering from the UPF 848 to data network 836 via the N6 interface. This may be based on the UE subscription data, UE location, and information provided by the AF 860 . In this way, the AF 860 may influence UPF (re)selection and traffic routing. Based on operator deployment, when AF 860 is considered to be a trusted entity, the network operator may permit AF 860 to interact directly with relevant NFs. Additionally, the AF 860 may exhibit an Naf service-based interface.

The data network 836 may represent various network operator services, Internet access, or third party services that may be provided by one or more servers including, for example, application/content server 838 .

FIG. 9 schematically illustrates a wireless network 900 in accordance with various embodiments. The wireless network 900 may include a UE 902 in wireless communication with an AN 904 . The UE 902 and AN 904 may be similar to, and substantially interchangeable with, like-named components described elsewhere herein.

The UE 902 may be communicatively coupled with the AN 904 via connection 906 . The connection 906 is illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols such as an LTE protocol or a 5G NR protocol operating at mmWave or sub-6 GHz frequencies.

The UE 902 may include a host platform 908 coupled with a modem platform 910 . The host platform 908 may include application processing circuitry 912 , which may be coupled with protocol processing circuitry 914 of the modem platform 910 . The application processing circuitry 912 may run various applications for the UE 902 that source/sink application data. The application processing circuitry 912 may further implement one or more layer operations to transmit/receive application data to/from a data network. These layer operations may include transport (for example UDP) and Internet (for example, IP) operations

The protocol processing circuitry 914 may implement one or more of layer operations to facilitate transmission or reception of data over the connection 906 . The layer operations implemented by the protocol processing circuitry 914 may include, for example, MAC, RLC, PDCP, RRC and NAS operations.

The modem platform 910 may further include digital baseband circuitry 916 that may implement one or more layer operations that are “below” layer operations performed by the protocol processing circuitry 914 in a network protocol stack. These operations may include, for example, PHY operations including one or more of HARQ-ACK functions, scrambling/descrambling, encoding/decoding, layer mapping/de-mapping, modulation symbol mapping, received symbol/bit metric determination, multi-antenna port precoding/decoding, which may include one or more of space-time, space-frequency or spatial coding, reference signal generation/detection, preamble sequence generation and/or decoding, synchronization sequence generation/detection, control channel signal blind decoding, and other related functions.

The modem platform 910 may further include transmit circuitry 918 , receive circuitry 920 , RF circuitry 922 , and RF front end (RFFE) 924 , which may include or connect to one or more antenna panels 926 . Briefly, the transmit circuitry 918 may include a digital-to-analog converter, mixer, intermediate frequency (IF) components, etc.; the receive circuitry 920 may include an analog-to-digital converter, mixer, IF components, etc.; the RF circuitry 922 may include a low-noise amplifier, a power amplifier, power tracking components, etc.; RFFE 924 may include filters (for example, surface/bulk acoustic wave filters), switches, antenna tuners, beamforming components (for example, phase-array antenna components), etc. The selection and arrangement of the components of the transmit circuitry 918 , receive circuitry 920 , RF circuitry 922 , RFFE 924 , and antenna panels 926 (referred generically as “transmit/receive components”) may be specific to details of a specific implementation such as, for example, whether communication is TDM or FDM, in mmWave or sub-6 gHz frequencies, etc. In some embodiments, the transmit/receive components may be arranged in multiple parallel transmit/receive chains, may be disposed in the same or different chips/modules, etc.

In some embodiments, the protocol processing circuitry 914 may include one or more instances of control circuitry (not shown) to provide control functions for the transmit/receive components.

A UE reception may be established by and via the antenna panels 926 , RFFE 924 , RF circuitry 922 , receive circuitry 920 , digital baseband circuitry 916 , and protocol processing circuitry 914 . In some embodiments, the antenna panels 926 may receive a transmission from the AN 904 by receive-beamforming signals received by a plurality of antennas/antenna elements of the one or more antenna panels 926 .

A UE transmission may be established by and via the protocol processing circuitry 914 , digital baseband circuitry 916 , transmit circuitry 918 , RF circuitry 922 , RFFE 924 , and antenna panels 926 . In some embodiments, the transmit components of the UE 904 may apply a spatial filter to the data to be transmitted to form a transmit beam emitted by the antenna elements of the antenna panels 926 .

Similar to the UE 902 , the AN 904 may include a host platform 928 coupled with a modem platform 930 . The host platform 928 may include application processing circuitry 932 coupled with protocol processing circuitry 934 of the modem platform 930 . The modem platform may further include digital baseband circuitry 936 , transmit circuitry 938 , receive circuitry 940 , RF circuitry 942 , RFFE circuitry 944 , and antenna panels 946 . The components of the AN 904 may be similar to and substantially interchangeable with like-named components of the UE 902 . In addition to performing data transmission/reception as described above, the components of the AN 908 may perform various logical functions that include, for example, RNC functions such as radio bearer management, uplink and downlink dynamic radio resource management, and data packet scheduling.

FIG. 10 is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically, FIG. 10 shows a diagrammatic representation of hardware resources 1000 including one or more processors (or processor cores) 1010 , one or more memory/storage devices 1020 , and one or more communication resources 1030 , each of which may be communicatively coupled via a bus 1040 or other interface circuitry. For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor 1002 may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources 1000 .

The processors 1010 may include, for example, a processor 1012 and a processor 1014 . The processors 1010 may be, for example, a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a DSP such as a baseband processor, an ASIC, an FPGA, a radiofrequency integrated circuit (RFIC), another processor (including those discussed herein), or any suitable combination thereof.

The memory/storage devices 1020 may include main memory, disk storage, or any suitable combination thereof. The memory/storage devices 1020 may include, but are not limited to, any type of volatile, non-volatile, or semi-volatile memory such as dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), Flash memory, solid-state storage, etc.

The communication resources 1030 may include interconnection or network interface controllers, components, or other suitable devices to communicate with one or more peripheral devices 1004 or one or more databases 1006 or other network elements via a network 1008 . For example, the communication resources 1030 may include wired communication components (e.g., for coupling via USB, Ethernet, etc.), cellular communication components, NFC components, Bluetooth® (or Bluetooth® Low Energy) components, Wi-Fi® components, and other communication components.

Instructions 1050 may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors 1010 to perform any one or more of the methodologies discussed herein. The instructions 1050 may reside, completely or partially, within at least one of the processors 1010 (e.g., within the processor's cache memory), the memory/storage devices 1020 , or any suitable combination thereof. Furthermore, any portion of the instructions 1050 may be transferred to the hardware resources 1000 from any combination of the peripheral devices 1004 or the databases 1006 . Accordingly, the memory of processors 1010 , the memory/storage devices 1020 , the peripheral devices 1004 , and the databases 1006 are examples of computer-readable and machine-readable media.

Example Procedures

In some embodiments, the electronic device(s), network(s), system(s), chip(s) or component(s), or portions or implementations thereof, of FIGS. 8 - 10 , or some other figure herein, may be configured to perform one or more processes, techniques, or methods as described herein, or portions thereof. One such process 1100 is depicted in FIG. 11 . In some embodiments, the process 1100 may be performed by an IAB node or a portion thereof (e.g., baseband circuitry of the IAB node).

For example, the process 1100 may include, at 1102 , determining an operational mode for simultaneous operation of a mobile terminal (MT) communication and a distributed unit (DU) communication. In some embodiments, the operational mode may be one of: a first mode in which the MT communication is an MT transmission and the DU communication is a DU transmission; a second mode in which the MT communication is an MT transmission and the DU communication is a DU reception; a third mode in which the MT communication is an MT reception and the DU communication is a DU transmission; and/or a fourth mode in which the MT communication is an MT reception and the DU communication is a DU reception.

The process 1100 may further include, at 1104 , aligning the MT communication and the DU communication based on the determined operational mode. The alignment may be slot-based alignment or symbol-based alignment. In some embodiments, aligning may include encoding parent link timing information for transmission to a child MT, e.g., to enable the child MT to shift the timing of its child MT transmission. The parent link timing information may include, for example a TA 0 value and/or a T p0 value. In one example, the parent link timing information may include one value that corresponds to TA 0 −T p0 .

FIG. 12 illustrates another process 1200 in accordance with various embodiments. In some embodiments, the process 1200 may be performed by an IAB node or a portion thereof (e.g., baseband circuitry of the IAB node).

For example, the process 1200 may include, at 1202 , communicating, in a first slot, a first mobile terminal (MT) communication and a first distributed unit (DU) communication simultaneously. In various embodiments, the first MT communication is one of a first MT transmission or a first MT reception; the first DU communication is one of a first DU transmission or a first DU reception; the second MT communication is one of a second MT transmission or a second MT reception; and/or the second DU communication is one of a second DU transmission or a second DU reception.

The process 1200 may further include, at 1204 , communicating, in a second slot after and adjacent to the first slot, a second MT communication and/or a second DU communication with no guard period. In some embodiments, the communicating in the second slot includes the second MT communication, and the guard period is omitted based on a determination that the IAB node supports simultaneous operation of the second MT communication and the first DU communication. Additionally, or alternatively, in some embodiments, the communicating in the second slot includes the second DU communication, and the guard period is omitted based on a determination that the IAB node supports simultaneous operation of the second DU communication and the first MT communication.

In some embodiments, the process 1200 may further include transmitting, to a parent node, IAB multiplexing information to indicate one or more IAB multiplexing modes that are used by the IAB node. In one example, the IAB multiplexing information enumerates the one or more IAB multiplexing modes that are used by the IAB node. In another example, the IAB multiplexing information includes a plurality of bits, wherein individual bits of the plurality of bits indicate whether a corresponding individual IAB multiplexing mode is used by the IAB node.

For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and/or methods as set forth in the example section below. For example, the baseband circuitry as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below in the example section.

Example 1 may include a method of an integrated access and backhaul (IAB) node, the method comprising: determining an operational mode for simultaneous operation of a mobile terminal (MT) communication and a distributed unit (DU) communication; and aligning the MT communication and the DU communication based on the determined operational mode.

Example 2 may include the method of example 1 or some other example herein, wherein the aligning is a slot-based alignment.

Example 3 may include the method of example 1 or some other example herein, wherein the aligning is a symbol-based alignment.

Example 4 may include the method of example 1-3 or some other example herein, wherein the operational mode is one of: a first mode in which the MT communication is an MT transmission and the DU communication is a DU transmission; a second mode in which the MT communication is an MT transmission and the DU communication is a DU reception; a third mode in which the MT communication is an MT reception and the DU communication is a DU transmission; and/or a fourth mode in which the MT communication is an MT reception and the DU communication is a DU reception.

Example 5 may include the method of example 1-4 or some other example herein, wherein the MT communication is an MT transmission and the DU communication is a DU transmission, and wherein the aligning includes delaying the MT transmission to align with the DU transmission.

Example 6 may include the method of example 5 or some other example herein, wherein the delay corresponds to TA 0 −T p0 , wherein TA 0 is a time advance control for the MT transmission and T p0 is a parent link propagation delay.

Example 7 may include the method of example 1-4 or some other example herein, wherein the MT communication is an MT reception and the DU communication is a DU reception, wherein the aligning includes delaying a child MT transmission to align the DU reception with the MT reception.

Example 8 may include the method of example 7 or some other example herein, wherein the delay corresponds to TA−2T p +T p0 , wherein TA is a time advance control for the child MT transmission, T p is a child link propagation delay, and T p0 is a parent link propagation delay.

Example 9 may include the method of example 7-8 or some other example herein, wherein the aligning includes transmitting, to a child MT, a parent link propagation delay to cause the alignment.

Example 10 may include the method of example 1-4 or some other example herein, wherein the MT communication is a MT transmission and the DU communication is a DU reception, and wherein the aligning includes shifting a child MT transmission to align the DU reception with the MT transmission.

Example 11 may include the method of example 10 or some other example herein, wherein the shifting includes moving the child MT transmission ahead in time by ΔS=(TA 0 −T p0 )−(TA−2T p ), wherein TA 0 is a time advance control for the MT transmission, T p0 is a parent link propagation delay TA is a time advance control for the child MT transmission, and T p is a child link propagation delay.

Example 12 may include the method of example 11 or some other example herein, further comprising transmitting, to a child MT that is to transmit the child MT transmission, parent link timing parameters TA 0 and T p0 .

Example 13 may include the method of example 1-4 or some other example herein, wherein the MT communication is a MT transmission and the DU communication is a DU reception, and wherein the aligning includes shifting the MT transmission to align with the DU reception.

Example 14 may include the method of example 13 or some other example herein, wherein the shifting includes delaying the MT transmission by ΔS=(TA 0 −T p0 )−(TA−2T p ), wherein TA 0 is a time advance control for the MT transmission, T p0 is a parent link propagation delay TA is a time advance control for the child MT transmission, and T p is a child link propagation delay.

Example 15 may include the method of example 1-14 or some other example herein, wherein the aligning includes transmitting, to a child MT, parent link timing information to cause the alignment.

Example 16 may include the method of example 15 or some other example herein, wherein the parent link timing information includes a time advance control for an MT transmission (TA 0 ) and/or a parent link propagation delay (T p0 ).

Example 17 may include the method of example 15-16 or some other example herein, wherein the parent link timing information is transmitted via a MAC CE on a PDSCH.

Example 18 may include the method of example 15-16 or some other example herein, wherein the parent link timing information is transmitted via a group-common PDCCH.

Example 19 may include the method of example 15-16 or some other example herein, wherein the parent link timing information is transmitted via an L1 channel.

Example 20 may include a method of an integrated access and backhaul (IAB) node, the method comprising: communicating, in a first slot, a first mobile terminal (MT) communication and a first distributed unit (DU) communication simultaneously; and communicating, in a second slot after and adjacent to the first slot, a second MT communication and/or a second DU communication with no guard period.

Example 21 may include the method of example 20 or some other example herein, wherein the communicating in the second slot includes the second MT communication, and wherein the guard period is omitted based on a determination that the IAB node supports simultaneous operation of the second MT communication and the first DU communication.

Example 22 may include the method of example 20 or some other example herein, wherein the communicating in the second slot includes the second DU communication, and wherein the guard period is omitted based on a determination that the IAB node supports simultaneous operation of the second DU communication and the first MT communication.

Example 23 may include the method of example 20-22 or some other example herein, wherein:

the first MT communication is one of a first MT transmission or a first MT reception;

the first DU communication is one of a first DU transmission or a first DU reception;

the second MT communication is one of a second MT transmission or a second MT reception; and

the second DU communication is one of a second DU transmission or a second DU reception.

Example 24 may include the method of an IAB node, the method comprising: determining one or more IAB multiplexing modes that are used by the IAB node; and encoding, for transmission to a parent node, IAB multiplexing information to indicate the one or more IAB multiplexing modes that are used by the IAB node.

Example 25 may include the method of example 24 or some other example herein, wherein the one or more IAB multiplexing modes include one or more of: a first mode in which an MT transmission is simultaneous with a DU transmission, a second mode in which an MT transmission is simultaneous with a DU reception, a third mode in which an MT reception is simultaneous with a DU transmission, and a fourth mode in which an MT reception is simultaneous with a DU reception.

Example 26 may include the method of example 24-25 or some other example herein, wherein the IAB multiplexing information enumerates the one or more IAB multiplexing modes that are used by the IAB node.

Example 27 may include the method of example 24-25 or some other example herein, wherein the IAB multiplexing information includes a plurality of bits, wherein individual bits of the plurality of bits indicate whether a corresponding individual IAB multiplexing mode is used by the IAB node.

Example 28 may include the method of example 24-27 or some other example herein, wherein the IAB multiplexing information is transmitted in uplink control information (UCI).

Example 29 may include the method of example 24-27 or some other example herein, wherein the IAB multiplexing information is transmitted in a MAC CE.

Example 30 may include the method of example 24-27 or some other example herein, wherein the IAB multiplexing information is transmitted in an L1 channel.

Example 31 may include an apparatus comprising means to perform one or more elements of a method described in or related to any of examples 1-30, or any other method or process described herein.

Example 32 may include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-30, or any other method or process described herein.

Example 33 may include an apparatus comprising logic, modules, or circuitry to perform one or more elements of a method described in or related to any of examples 1-30, or any other method or process described herein.

Example 34 may include a method, technique, or process as described in or related to any of examples 1-30, or portions or parts thereof.

Example 35 may include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 1-30, or portions thereof.

Example 36 may include a signal as described in or related to any of examples 1-30, or portions or parts thereof.

Example 37 may include a datagram, packet, frame, segment, protocol data unit (PDU), or message as described in or related to any of examples 1-30, or portions or parts thereof, or otherwise described in the present disclosure.

Example 38 may include a signal encoded with data as described in or related to any of examples 1-30, or portions or parts thereof, or otherwise described in the present disclosure.

Example 39 may include a signal encoded with a datagram, packet, frame, segment, protocol data unit (PDU), or message as described in or related to any of examples 1-30, or portions or parts thereof, or otherwise described in the present disclosure.

Example 40 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors is to cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 1-30, or portions thereof.

Example 41 may include a computer program comprising instructions, wherein execution of the program by a processing element is to cause the processing element to carry out the method, techniques, or process as described in or related to any of examples 1-30, or portions thereof.

Example 42 may include a signal in a wireless network as shown and described herein.

Example 43 may include a method of communicating in a wireless network as shown and described herein.

Example 44 may include a system for providing wireless communication as shown and described herein.

Example 45 may include a device for providing wireless communication as shown and described herein.

Any of the above-described examples may be combined with any other example (or combination of examples), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

Unless used differently herein, terms, definitions, and abbreviations may be consistent with terms, definitions, and abbreviations defined in 3GPP TR 21.905 v16.0.0 (2019 June). For the purposes of the present document, the following abbreviations may apply to the examples and embodiments discussed herein.

For the purposes of the present document, the following terms and definitions are applicable to the examples and embodiments discussed herein.

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.

The term “processor circuitry” as used herein 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. Processing circuitry may include one or more processing cores to execute instructions and one or more memory structures to store program and data information. The term “processor circuitry” may refer to one or more application processors, one or more baseband processors, a physical central processing unit (CPU), a single-core processor, a dual-core processor, a triple-core processor, a quad-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. Processing circuitry may include more hardware accelerators, which may be microprocessors, programmable processing devices, or the like. The one or more hardware accelerators may include, for example, computer vision (CV) and/or deep learning (DL) accelerators. The terms “application circuitry” and/or “baseband circuitry” may be considered synonymous to, and may be referred to as, “processor circuitry.”

The term “interface circuitry” as used herein refers to, is part of, or includes circuitry that enables the exchange of information between two or more components or devices. The term “interface circuitry” may refer to one or more hardware interfaces, for example, buses, I/O interfaces, peripheral component interfaces, network interface cards, and/or the like.

The term “user equipment” or “UE” as used herein refers to a device with radio communication capabilities and may describe a remote user of network resources in a communications network. The term “user equipment” or “UE” may be considered synonymous to, and may be referred to as, client, mobile, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, reconfigurable mobile device, etc. Furthermore, the term “user equipment” or “UE” may include any type of wireless/wired device or any computing device including a wireless communications interface.

The term “network element” as used herein refers to physical or virtualized equipment and/or infrastructure used to provide wired or wireless communication network services. The term “network element” may be considered synonymous to and/or referred to as a networked computer, networking hardware, network equipment, network node, router, switch, hub, bridge, radio network controller, RAN device, RAN node, gateway, server, virtualized VNF, NFVI, and/or the like.

The term “computer system” as used herein refers to any type interconnected electronic devices, computer devices, or components thereof. Additionally, the term “computer system” and/or “system” may refer to various components of a computer that are communicatively coupled with one another. Furthermore, the term “computer system” and/or “system” may refer to multiple computer devices and/or multiple computing systems that are communicatively coupled with one another and configured to share computing and/or networking resources.

The term “appliance,” “computer appliance,” or the like, as used herein refers to a computer device or computer system with program code (e.g., software or firmware) that is specifically designed to provide a specific computing resource. A “virtual appliance” is a virtual machine image to be implemented by a hypervisor-equipped device that virtualizes or emulates a computer appliance or otherwise is dedicated to provide a specific computing resource.

The term “resource” as used herein refers to a physical or virtual device, a physical or virtual component within a computing environment, and/or a physical or virtual component within a particular device, such as computer devices, mechanical devices, memory space, processor/CPU time, processor/CPU usage, processor and accelerator loads, hardware time or usage, electrical power, input/output operations, ports or network sockets, channel/link allocation, throughput, memory usage, storage, network, database and applications, workload units, and/or the like. A “hardware resource” may refer to compute, storage, and/or network resources provided by physical hardware element(s). A “virtualized resource” may refer to compute, storage, and/or network resources provided by virtualization infrastructure to an application, device, system, etc. The term “network resource” or “communication resource” may refer to resources that are accessible by computer devices/systems via a communications network. The term “system resources” may refer to any kind of shared entities to provide services, and may include computing and/or network resources. System resources may be considered as a set of coherent functions, network data objects or services, accessible through a server where such system resources reside on a single host or multiple hosts and are clearly identifiable.

The term “channel” as used herein refers to any transmission medium, either tangible or intangible, which is used to communicate data or a data stream. The term “channel” may be synonymous with and/or equivalent to “communications channel,” “data communications channel,” “transmission channel,” “data transmission channel,” “access channel,” “data access channel,” “link,” “data link,” “carrier,” “radiofrequency carrier,” and/or any other like term denoting a pathway or medium through which data is communicated. Additionally, the term “link” as used herein refers to a connection between two devices through a RAT for the purpose of transmitting and receiving information.

The terms “instantiate,” “instantiation,” and the like as used herein refers to the creation of an instance. An “instance” also refers to a concrete occurrence of an object, which may occur, for example, during execution of program code.

The terms “coupled,” “communicatively coupled,” along with derivatives thereof are used herein. The term “coupled” may mean two or more elements are in direct physical or electrical contact with one another, may mean that two or more elements indirectly contact each other but still cooperate or interact with each other, and/or may mean that one or more other elements are coupled or connected between the elements that are said to be coupled with each other. The term “directly coupled” may mean that two or more elements are in direct contact with one another. The term “communicatively coupled” may mean that two or more elements may be in contact with one another by a means of communication including through a wire or other interconnect connection, through a wireless communication channel or link, and/or the like.

The term “information element” refers to a structural element containing one or more fields. The term “field” refers to individual contents of an information element, or a data element that contains content.

The term “SMTC” refers to an SSB-based measurement timing configuration configured by SSB-MeasurementTimingConfiguration.

The term “SSB” refers to an SS/PBCH block.

The term “a “Primary Cell” refers to the MCG cell, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure.

The term “Primary SCG Cell” refers to the SCG cell in which the UE performs random access when performing the Reconfiguration with Sync procedure for DC operation.

The term “Secondary Cell” refers to a cell providing additional radio resources on top of a Special Cell for a UE configured with CA.

The term “Secondary Cell Group” refers to the subset of serving cells comprising the PSCell and zero or more secondary cells for a UE configured with DC.

The term “Serving Cell” refers to the primary cell for a UE in RRC_CONNECTED not configured with CA/DC there is only one serving cell comprising of the primary cell.

The term “serving cell” or “serving cells” refers to the set of cells comprising the Special Cell(s) and all secondary cells for a UE in RRC_CONNECTED configured with CA/.

The term “Special Cell” refers to the PCell of the MCG or the PSCell of the SCG for DC operation; otherwise, the term “Special Cell” refers to the Pcell.