WO2024079636A1 - Coordination for mobile iab-node migration - Google Patents

Abstract

Systems and methods are disclosed for coordination for mobile Integrated Access and Backhaul (IAB) node migration. In one embodiment, a method performed by first IAB donor node serving a mobile IAB Distributed Unit (mlAB-DU) that is co-located in a same IAB node with a mobile IAB Mobile Termination (mlAB-MT) that is served by a second IAB donor node comprises communicating with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU and/or when to migrate the mlAB-DU to the target IAB donor node. In this manner, the IAB donor node serving a mobile IAB -DU is enabled to participate in choosing the target IAB node and when the ml AB -DU is going to be migrated.

Description

COORDINATION FOR MOBILE IAB-NODE MIGRATION

Related Applications

[0001] This application claims the benefit of provisional patent application serial number 63/414,874, filed October 10, 2022, the disclosure of which is hereby incorporated herein by reference in its entirety.

Technical Field

[0002] The present disclosure relates to Integrated Access and Backhaul (IAB) in a cellular communications system.

Background

IAB Architecture

[0003] Integrated Access and Backhaul (IAB) is based on the Centralized Unit (CU) - Distributed Unit (DU) split that was standardized in 3^rd Generation Partnership Project (3GPP) Release 15. The CU hosts the Radio Resource Control (RRC) and the Packet Data Convergence Protocol (PCDP) functions, whereas the DU hosts the Radio Link Control (RLC) and Medium Access Control (MAC) functions. The Fl interface connects the CU and the DU. The CU-DU split facilitates separate physical CU and DU, while also allowing a single CU to be connected to multiple DUs. Figure 1 shows the basic architecture of IAB in Stand-Alone (SA) mode.

[0004] Figure 1 consists of a single IAB donor connected to the core network. The IAB donor serves three direct IAB child nodes through two collocated DUs at the donor for wireless backhauling. The center IAB -node in turn serves two IAB -nodes through wireless backhaul. Each of the lAB-nodes in Figure 1 backhauls traffic both related to User Equipments (UEs) connected to it and other backhaul traffic from downstream lAB-nodes.

[0005] The main components of the IAB architecture are:

1) lAB-node: A node that provides wireless access to the UEs while also backhauling the traffic to other lAB-nodes. The lAB-node consists of an IAB DU (IAB -DU) that provides access to connected UEs and a Mobile Termination (MT) (IAB-MT) that connects to other lAB-nodes or donors in the uplink direction for backhaul.

2) lAB-donor: A node that provides UEs an interface to the core network and wireless functionality to other lAB-nodes to backhaul their traffic to/from the core network.

[0006] The defining feature of IAB is the use of wireless spectrum for both access of UEs and backhauling of data through lAB-nodes. Thus, there needs to be clear coordination of access and backhaul resources to avoid interference between them.

[0007] In 3GPP Releasel6, IAB was standardized with basic support for multi-hop multipath backhaul for Directed Acyclic Graph (DAG) topology, i.e., no mesh-based topology was supported. Release 16 also supports Quality of Service (QoS) prioritization of backhaul traffic and flexible resource usage between access and backhaul. Discussions in Release 17 are on topology enhancements for IAB with partial migration of IAB -nodes for Radio Link Failure (RLF) recovery and load balancing.

[0008] Refer to the following for further information about already standardized Release 16 IAB work:

• Madapatha, Charitha et al. “On Integrated Access and Backhaul Networks: Current Status and Potentials.” IEEE Open Journal of the Communications Society 1 (2020): 1374-1389

• 3GPP TS 38.300. V17.2.0: Section 4.7

• 3GPP TR 38.874 V16.0.0

[0009] Figure 2 shows some terminology that is sometimes used when discussing an IAB network or IAB architecture. As shown, the adjacent upstream node which is closer to the IAB- donor of an lAB-node is referred to as a parent lAB-node (or simply “parent node”) of the IAB- node. The adjacent downstream node which is further away from the IAB -donor of an lAB-node is referred to as a child lAB-node (or simply “child node”) of the lAB-node. The backhaul link between the parent lAB-node and the lAB-node is referred to as parent (backhaul) link, whereas the backhaul link between the lAB-node and the child lAB-node is referred to as child (backhaul) link.

Fl Interface

[0010] The Fl interface connects the CU to the DU in the split architecture which is also applicable to the IAB architecture. The Fl interface connects the CU from an IAB -donor to IAB-DU in the lAB-nodes. The Fl interface also supports control and user plane separation through Fl-C and Fl-U respectively.

[0011] This interface holds even during IAB mobility where an lAB-node moves and connects to parent/donor lAB-nodes. In such a scenario, the DU present in the mobile lAB-node connects to the CU present in the IAB donor.

[0012] The IAB-DU initiates a Fl setup with the IAB-CU with which it has a Transport Network Layer (TNL) connection and the initial Fl setup as shown in Figure 3 from section 8.5 of 3GPP Technical Specification (TS) 38.401 V17.2.0. Once the Fl setup is completed, the IAB donor CU sends a GNB-CU CONFIGURATION UPDATE to optionally indicate the DU cells to be activated. Figure 3 shows the Fl setup and cell activation in a SA 5G network.

BH RLC channel concept (Rel-16)

[0013] Backhaul (BH) RLC channels are used for transporting packets between lAB-nodes or between an lAB-donor DU and an lAB-node. When it comes to the mapping between UE radio bearers and backhaul RLC channels, two types of mappings are supported, namely N:1 and 1:1 mapping. The N:1 mapping multiplexes several UE radio bearers onto a single BH RLC channel based on specific parameters, such as QoS profile of the bearers. The N:1 mapping is designed for optimal use of BH RLC channels and requires less signaling overhead as a small number of BH RLC channels need to be established. The 1:1 mapping, on the other hand, maps each UE radio bearer onto a separate BH RLC channel, and is designed to ensure fine QoS granularity at UE radio bearer level. 1 : 1 mapping requires more backhaul RLC channels and more signaling overhead to setup and release BH RLC channels, one for each hop, for each UE radio bearer.

BAP Layer (Rel-16)

[0014] Efficient multi-hop forwarding is enabled via the newly introduced IAB -specific Backhaul Adaptation Protocol (BAP). The lAB-donor assigns a unique layer 2 (L2) address (BAP address) to each lAB-node that it controls. In case of multiple paths, multiple route identifiers (IDs) can be associated to each BAP address. The BAP of the origin node (lAB-donor DU for the downlink (DL) traffic, and the access lAB-node for the uplink (UL) traffic) will add a BAP header to packets they are transmitting, which will include a BAP routing ID (e.g., BAP address of the destination/source lAB-node and an optional path ID). Each lAB-node will have a routing table (configured by the lAB-donor CU) containing the next hop identifier for each BAP routing ID. Separate routing tables are kept for the DL and UL direction, where the DL table is used by the DU part of the lAB-node, while the MT part of the lAB-node uses the UL table.

Partial Inter-Donor Migration

[0015] Partial inter-donor migration was introduced in Release 17, with the aim to enable offloading of lAB-node traffic from one donor CU to another. The central concept in partial migration is the concept of a boundary lAB-node. A boundary lAB-node is an lAB-node with an RRC interface (of the IAB -MT) terminating at a different donor CU (in the following sometimes just CU) than the Fl interface (of the co-located IAB-DU). A single-connected lAB-node (static or mobile) can migrate its IAB -MT ’s RRC connection from CUI to CU2 as shown in Figure 4, wherein it retains the Fl to the CUI. Figure 4 illustrates an example scenario where an lAB- node, IAB3, is in the state of partial migration - the IAB-MT and IAB-DU are served by different donor CUs. Since the MT and DU of the node (i.e., IAB3) terminate at different CUs, the node is called boundary node. This type of migration has been standardized as partial migration and more information can be found in section 8.17.3.1 of 3GPP TS 38.401 vl7.2.

[0016] Inter-donor CU topology adaptation is accomplished by means of partial migration:

— The RRC connection of the boundary IAB-MT is migrated to a new donor CU (CUI in Figure 4). — The boundary IAB-DU, descendant lAB-node(s) and UEs remain connected to the current donor CU (CUI in Figure 4).

— The traffic to/from these devices is proxied from/to the current donor CU 1 via the new donor CU (CU2 in Figure 4) network.

[0017] For such a single-connected boundary node:

— the new donor CU (CU2) controls the radio resources assigned to boundary IAB-MT

— the current donor CU (CUI) controls the radio resources assigned to boundary IAB-DU [0018] One motivation for a partial migration can be load balancing or recovery from RLF. A load balancing case could be for example triggered when the parent link of an lAB-node, e.g., a link becomes congested or experiences unsatisfactory/unstable radio conditions. A typical case for RLF recovery would be if the parent link, e.g., completely fails. In either case, if the boundary lAB-node connects to a new parent lAB-node, the issue can be resolved.

[0019] The partial migration is applicable to both static and mobile lAB-nodes.

Mobile IAB

[0020] In Release 18, it is expected that the different RAN groups will work towards enhancing functionality of IAB with focus on Mobile IAB providing 5^th Generation (5G) coverage enhancement to, e.g., UEs onboard of a bus and surrounding UEs. The initial use cases for mobile-IAB are expected to be based on 3GPP Technical Report (TR) 22.839 vl 8.0.0.

[0021] One of the main use cases of mobile IAB cell is to serve UEs which are residing in a vehicle with a vehicle mounted relay. Other relevant use cases for mobile lABs involve a mobile/nomadic IAB network node mounted on a vehicle that provides extended coverage. This involves scenarios where additional coverage is required during special events like concerts, or in disaster scenarios. The nomadic lAB-node provides access to surrounding UEs while the backhaul traffic from the nomadic lAB-node is then transmitted wirelessly either with the help of IAB donors or Non-Terrestrial Networks (NTNs). A nomadic lAB-node also reduces or even eliminates signal strength loss due to vehicle penetration for UEs that are present in the vehicles.

[0022] Advantages of Mobile IAB are:

• reducing/eliminating the vehicle penetration loss (specially at high frequency), and

• reducing/eliminating group handover.

[0023] Consider that, in most use cases, a mobile lAB-node is expected to be mounted on public transport vehicles and to move to a large extent in a pre-determined route. Figure 5 shows one such mobile IAB mounted on a bus travelling on a route that is covered by four different parent lAB-nodes (IAB Parent 1,2, 3, 4). The parent nodes backhaul their traffic through two donor nodes (Donor IAB X and Y). [0024] An lAB-node has a DU that provides access to UEs around it and an MT that provides a backhaul connection of the lAB-node to its parent(s) and the rest of the network. The parent I AB -nodes consist of DUs that provide access to UEs and the mobile IAB present in their coverage. They also consist of MTs that backhaul traffic together with traffic from the mobile lAB-node. Finally, the two donor nodes consist of a donor DU that provides access and a donor CU that is connected to the core network. The CUs in both donor nodes usually maintain a Fl connectivity to parent lAB-nodes that are served by respective donor nodes.

[0025] The mobile lAB-node maintains an Fl connection to a donor (one donor at a time). In Figure 5, the mobile IAB connects to the following nodes in the different positions as described below:

1) Position A: BH through parent node 1, Fl connection to donor node X

2) Position B: BH through parent node 2, Fl connection to donor node X

3) Position C: BH through parent node 3, Fl connection to donor node Y

4) Position D: BH through parent node 4, Fl connection to donor node Y

The mobile IAB must change the Fl connection from donor X to donor Y when moving from position B to C, thus requiring a Fl handover and setup of backhaul REC channels.

3 GPP Agreements Related to Mobile IAB (Release 18)

[0026] So far, the following agreements related to mobile lAB-node migration have been made:

• As already supported in Release 17, a mobile IAB-MT and its co-located mobile IAB-DU may be served by different donor CUs.

• The mobile IAB donor that the co-located IAB-DU connects to may remain unchanged after the IAB-MT HO.

• RAN3 to discuss whether a mobile IAB-DU can execute inter-donor migration, while the co-located mobile IAB-MT stays connected to the same donor before and after the mobile IAB-DU migration.

• RAN3 to discuss whether a mobile IAB-DU can execute inter-donor migration, while the co-located mobile IAB-MT executes inter-donor migration.

• When Internet Protocol (IP) connectivity between target IAB -donor DU and source IAB- donor CU is available, and when Xn connectivity between source and target donor CU is available, the Release 17 partial migration is used as baseline for supporting the Fl transport migration and inter-donor routing when a mobile IAB-DU and its co-located mobile IAB-MT are connected to different donor CUs. • The mobile I AB -node may perform multiple consecutive partial migrations without interdonor migration of its mobile IAB-DU.

• RAN3 to discuss how inter-donor topology adaptation can be supported for mobile IAB in absence of Xn and/or inter-donor IP routability.

• Mobility of dual-connected mobile lAB-nodes is down prioritized in Release 18.

• Release 17 mechanisms support intra-donor CU migration of mobile IAB.

• For DU migration cases, to execute the handover of the served UEs, the mobile lAB-node concurrently supports two logical mobile lAB-DUs, which have F1AP associations with the source donor CU and the target donor CU, respectively.

• The UEs connected to the mobile lAB-node are handed over from the cell of the logical mobile IAB-DU (i.e., the source logical mobile IAB-DU) that has an F1AP association with the source CU to the cell of the logical mobile IAB-DU (i.e., the target logical mobile IAB-DU) that has an Fl Application Protocol (F1AP) association with the target CU.

• RAN3 to discuss whether a mobile IAB node may be configured with multiple configurations, each corresponding to a different target donor, that can be activated upon fulfillment of certain condition(s). The details of the configurations are for future study (FFS).

[0027] Systems and methods are disclosed for coordination for mobile Integrated Access and Backhaul (IAB) node migration. In one embodiment, a method performed by first IAB donor node serving a mobile IAB Distributed Unit (mlAB-DU) that is co-located in a same IAB node with a mobile IAB Mobile Termination (mlAB-MT) that is served by a second IAB donor node comprises communicating with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU and/or when to migrate the mlAB-DU to the target IAB donor node. In this manner, the IAB donor node serving a mobile IAB-DU is enabled to participate in choosing the target IAB node and when the ml AB -DU is going to be migrated.

[0028] In one embodiment, communicating with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU and/or when to migrate the mlAB-DU to the target IAB donor node comprises sending, to the second donor IAB node, a request or indication to initiate inter-donor migration of the mlAB-DU. In one embodiment, the request or indication comprises an indication to execute inter-donor migration for the mlAB-DU. In one embodiment, the request or indication comprises an identifier of the target IAB donor node. In one embodiment, the request or indication comprises an indication of a reason for the inter-donor migration for the mlAB-DU. In one embodiment, the request or indication comprises an indication of an urgency for the inter-donor migration for the mlAB-DU. In one embodiment, communicating with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU and/or when to migrate the mlAB-DU to the target IAB donor node further comprises receiving, from the second donor IAB node, a response that indicates either acceptance or rejection of the request or indication to initiate inter-donor migration of the mlAB-DU. In one embodiment, the method further comprises determining that the inter-donor migration of the mlAB-DU is desired prior to sending the request or indication.

[0029] In one embodiment, communicating with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU and/or when to migrate the mlAB-DU to the target IAB donor node comprises receiving, from the second IAB donor node, a request or indication about inter-donor migration of the mlAB-DU. In one embodiment, the request or indication about inter-donor migration of the mlAB-DU comprises an indication of the target donor. In one embodiment, the request or indication about inter-donor migration of the mlAB-DU comprises an indication of a reason for the inter-donor migration. In one embodiment, the request or indication about inter-donor migration of the mlAB-DU comprises an indication of an urgency for the inter-donor migration. In one embodiment, communicating with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU and/or when to migrate the ml AB -DU to the target IAB donor node further comprises sending, to the second donor IAB node, a response that indicates either acceptance or rejection of the request or indication to initiate inter-donor migration of the mlAB-DU.

[0030] In one embodiment, the first IAB donor node is a first IAB donor Centralized Unit (CU), and the second IAB donor node is a second IAB donor CU.

[0031] Corresponding embodiments of a first IAB donor node are also disclosed. In one embodiment, a first IAB donor node for serving a mlAB-DU that is co-located in a same IAB node with a mlAB-MT that is served by a second IAB donor node is adapted to communicate with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU and/or when to migrate the mlAB-DU to the target IAB donor node.

[0032] In one embodiment, a first IAB donor node are also disclosed. In one embodiment, a first IAB donor node for serving a mlAB-DU that is co-located in a same IAB node with a mlAB-MT that is served by a second IAB donor node comprises a communication interface and processing circuitry associated with the communication interface. The processing circuitry is configured to cause the first IAB donor node to communicate with the second IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU and/or when to migrate the mlAB-DU to the target IAB donor node.

[0033] Embodiments of a method performed by a second IAB donor node are also disclosed. In one embodiment, a method performed by a second IAB donor node serving a mlAB-MT that is co-located in a same IAB node with a mlAB-DU that is served by a first IAB donor node comprises communicating with the first IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU and/or when to migrate the mlAB-DU to the target IAB donor node.

[0034] Corresponding embodiments of a second IAB donor node are also disclosed. In one embodiment, a second IAB donor node for serving a mlAB-MT that is co-located in a same IAB node with a mlAB-DU that is served by a first IAB donor node is adapted to communicate with the first IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU and/or when to migrate the mlAB-DU to the target IAB donor node.

[0035] In one embodiment, a second IAB donor node for serving a mlAB-MT that is colocated in a same IAB node with a mlAB-DU that is served by a first IAB donor node comprises a communication interface and processing circuitry associated with the communication interface. The processing circuitry is configured to cause the second IAB node to communicate with the first IAB donor node to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU and/or when to migrate the ml AB -DU to the target IAB donor node.

Brief Description of the Drawings

[0036] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0037] Figure 1 shows the basic architecture of IAB in Stand-Alone (SA) mode;

[0038] Figure 2 shows some terminology that is sometimes used when discussing an IAB network or IAB architecture;

[0039] Figure 3 illustrates an Fl setup procedure from 3GPP TS 38.401 V17.2.0;

[0040] Figure 4 illustrates an example scenario where an lAB-node (IAB3) is in the state of partial migration - the IAB -MT and IAB -DU are served by different donor CUs;

[0041] Figure 5 shows an example of a mobile IAB mounted on a bus travelling on a route that is covered by four different parent IAB -nodes;

[0042] Figure 6 shows an example scenario for at least some embodiments of the present disclosure; [0043] Figure 7 is a flow chart that illustrates a procedure in accordance with one example embodiment of the present disclosure;

[0044] Figure 8 shows the coordination message exchange between CUI and CU2 for Solution A, for the case when the request from first donor CU is accepted by second donor CU, in accordance with an embodiment of the present disclosure;

[0045] Figure 9 illustrates the initial state for Solution B - the mlAB-MT has performed few subsequent handovers within CU2 and CU2 realizes that the mlAB-MT should be handed over to another target CU and that it is quite far from donor CU 1 ;

[0046] Figure 10 shows the coordination message exchange between CUI and CU2 for Solution B in case the suggestion from the second donor CU is accepted by the first donor CU, in accordance with an embodiment of the present disclosure;

[0047] Figure 11 shows an example of a communication system in accordance with some embodiments;

[0048] Figure 12 shows a UE in accordance with some embodiments;

[0049] Figure 13 shows a network node in accordance with some embodiments;

[0050] Figure 14 is a block diagram of a host, which may be an embodiment of the host of

Figure 11 , in accordance with various aspects described herein;

[0051] Figure 15 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized; and

[0052] Figure 16 shows a communication diagram of a host communicating via a network node with a UE over a partially wireless connection in accordance with some embodiments. Detailed Description

[0053] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments.

Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0054] There currently exist certain challenge(s). RAN3#117-e meeting agreements state the following:

• As already supported in Rel-17, a mobile IAB-MT and its co-located mobile IAB-DU may be served by different donor CUs.

• The mobile TAB donor that the co-located IAB-DU connects to may remain unchanged after the IAB-MT HO.

• The mobile lAB-node may perform multiple consecutive partial migrations without inter-donor migration of its mobile IAB-DU. [0055] According to the above agreements, a mobile I AB MT (ml AB -MT) may be handed over between different donor nodes multiple times, while the co-located mobile I AB DU (mlAB- DU) still stays connected to the same (e.g., initial) donor CU. This means that, at a given moment, after one or more handovers of the mlAB-MT, the mlAB-DU and the mlAB-MT of an mlAB-node can be served by two different CUs (say CUI and CU2, respectively). This is illustrated in Figure 4. In other words, Figure 4 illustrates an example scenario where a mobile mlAB-node (i.e., mIAB3) is in the state of partial migration - the mlAB-MT and mlAB-DU are served by different donor CUs. The traffic between the CU serving the mlAB-DU (CUI) and the mlAB-DU of the mobile lAB-node (i.e., mIAB3-DU) is sent over the following bidirectional path:

CUI - donor-DU2 - mIAB3-MT - mIAB3-DU

[0056] There are two open issues currently discussed in RAN3:

1) Whether a mobile IAB-DU (mlAB-DU) can execute inter-donor migration, while the colocated mobile IAB-MT stays connected to the same donor CU before and after the mobile IAB-DU migration.

2) Whether a mobile IAB-DU and a co-located mobile IAB-MT (mlAB-MT) can be handed over towards different donor CUs.

[0057] As mentioned earlier, a scenario where mlAB-DU and a co-located mlAB-MT are served by different donor CUs is possible.

[0058] With respect to the first open issue, one potential outcome is that RAN3 decides that a mobile IAB-DU can migrate from CUI to CU3 (yet another, hypothetical CU not shown in Figure 6 only if the co-located mlAB-MT is also (e.g., simultaneously, or immediately after or immediately before) handed over from CU2 to CU3. There are several consequences of this potential RAN3 outcome, i.e., mandating that an mlAB-DU can be migrated from a source donor CU (say CUI) to a target donor CU (say CU3) only if the co-located mlAB-MT is also handed over from another source donor (CU2) to the same target donor as mlAB-DU (CU3):

• The above implies that CU2, which has no Fl connection with mlAB-DU decides that the CUI side of the Fl connection between mlAB-DU and CUI is to be handed over to CU3.

• This would mean that the donor CU (CUI) serving the ml AB -DU has no say about when and towards which target CU the mlAB-DU will be migrated. This violates a well- established principle that only the entities that maintain a certain logical connection may decide that one of the two entities maintaining the connection is replaced by a third entity.

[0059] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Systems and methods are disclosed herein that provide a solution(s) for coordination between the donor lAB-node serving an ml AB -DU and the donor lAB-node serving the co-located mlAB-MT to coordinate with respect to choosing towards which target donor CU and when the mlAB-DU is going to be migrated. Embodiments disclosed herein are applicable for the scenarios where, prior to the mlAB-DU migration, the mlAB-DU and the colocated mlAB-MT are served by different donor CUs.

[0060] Embodiments of the solution(s) disclosed herein may also enable the donor CU serving the mlAB-MT to inquire the donor CU serving the mlAB-DU about whether there is a need to migrate the mlAB-DU to another donor CU.

[0061] Certain embodiments may provide one or more of the following technical advantage(s). Some embodiments provide a solution(s) that enables the donor CU serving a mobile IAB-DU to participate in choosing towards which target donor CU and when the mlAB- DU is going to be migrated.

[0062] Disclaimers

• Embodiments of the solution(s) are described herein using a non-limiting example where the mlAB-MT is handed over from a (source) donor CU2 to a (target) donor CU3, followed by, or done in parallel with, the migration of the co-located mlAB-DU from (source) donor CUI to (target) donor CU3.

• In addition, embodiments of the solution(s) also apply for the case where the mlAB-DU is migrated from donor CUI to donor CU3 before mlAB-MT is handed over from donor CU2 to donor CU3, and also for the case where the mlAB-MT and mlAB-DU are handed over towards different donor CUs, say towards donor CU4 and donor CU5, respectively.

• The terms “migrating an Fl connection of mlAB-DU”, “mlAB-DU handover” and “mlAB-DU migration” are equivalent.

• Embodiments of the solution(s) disclosed herein apply to New Radio (NR) as well as future Radio Access Technologies (RATs) such as 6^th Generation (6G), with the IAB-MT being a parent backhaul link terminating function and the IAB-DU being an access service providing function of a relay node.

• The terms “donor CU”, “donor-CU” and “CU” are used interchangeably.

• The terms “mlAB-MT”, “IAB-MT” and “MT” are used interchangeably, and they refer to the MT part of the mlAB-node or lAB-node.

• The terms “mlAB-DU”, “IAB-DU” and “DU” are used interchangeably, and they refer to the DU part of the mlAB-node or lAB-node.

• Embodiments of the solution(s) are presented herein using a non-limiting example of XnAP signaling used for inter-donor coordination, but it equally applies for coordination via NGAP signaling. [0063] Figure 6 shows an example scenario for at least some embodiments of the proposed solution(s). At a certain point in time:

• The ml AB -DU is served by donor CUI

• The co-located mlAB-MT is served by donor CU2

[0064] Figure 6 shows an example IAB network 600 in which embodiments of the present disclosure may be implemented. In Figure 6, the IAB network is in an initial state. As illustrated, the IAB network 600 includes a first donor CU 602-1 which is also referred to herein as “CUI” and a second donor CU 602-2 which is also referred to herein as “CU2”). The IAB network 600 also includes a first donor DU 604-1 which is also referred to herein as “DU1” and a second donor DU 604-2 which is also referred to herein as “DU2”). The IAB network 600 also includes a first lAB-node 606-1 which is also referred to herein as “IAB1” and a second IAB- node 606-2 which is also referred to herein as “IAB3”. IAB3 is, in the following description, a mobile lAB-node. The first lAB-node 606-1 (IAB1) includes a DU 608-1 providing wireless access to a number of UEs 610 and a MT 612-1 having wireless backhaul connectivity to the first donor DU 604-1 (DU1). The second lAB-node 606-2 (IAB3) includes a DU 608-2 (also referred to herein as a “mlAB-DU” or “mlAB-DU 608-2”) providing wireless access to a number of UEs 610 and a MT 612-2 (also referred to herein as a “mlAB-MT” or “mlAB-MT 612-2”) having wireless backhaul connectivity to the second donor DU 604-2 (DU2). Embodiments of the present disclosure provide a solution(s) for the donor CUI (serving the mlAB-DU 608-2) and donor CU2 (serving the mlAB-MT 612-2) to coordinate in order to determine when and towards which donor CU the mlAB-MT 612-2 and the mlAB-DU 608-2 are to be handed over/migrated. [0065] Figure 7 is a flow chart that illustrates a procedure in accordance with one example embodiment. The steps of Figure 7 are described in the following subsections. In the following description, the mobile lAB-node is the lAB-node 606-2 of Figure 6, the mlAB-DU is the mlAB- DU 608-2 of Figure 6, the mlAB-MT is the mlAB-MT 612-2 of Figure 6, CUI is the first donor CU 602-1 of Figure 6, and CU2 is the second donor CU 602-2 of Figure 6.

Step 700 (legacy): mlAB-node connects to the network and undergoes one or more partial inter-donor migrations

[0066] The mobile lAB-node connects to the network. In the beginning, both the mlAB-MT and mlAB-DU are served by the same donor, say donor CUI. After that, the mlAB-node undergoes one or more partial migrations, where the mlAB-MT is handed over one or more times between different donor CUs, while the ml AB -DU stays connected to the initial donor CUI (also referred to as the “first donor” in this description). It is assumed from now on that mlAB-DU is served by donor CUI, and mlAB-MT is served by donor CU2 (also referred to as the “second donor” in this description). [0067] In one variant, even the initial donors for the mlAB-MT and the mlAB-DU are different.

[0068] In one variant, the mlAB-DU may have also migrated previously, so it is served by a donor CU different than the initial donor CU, say donor CU6 or sixth donor.

Step 702: Coordination between first and second donors

[0069] Solution A: Coordination initiated by the donor CU of the mlAB-DU (first CU)

[0070] In one embodiment, the first donor CU (serving the mlAB-DU, donor CUI) determines that there is a need for the mlAB-DU to be migrated to another donor CU, say donor CU3 (or third donor). This can be determined based on several factors, where some non-limiting examples are:

• The first donor CU is overloaded or is bound to be overloaded. The overload can be, e.g., traffic overload or computational overload or any other type of overload.

• The latency of control plane and/or user plane traffic between the first donor CU and mlAB-DU is too high or is increasing or is bound/predicted to become too high. This can be determined based on network and/or UE measurements reported to the network.

• The quality of experience (QoE) for the services provided to the UEs is insufficient or deteriorating. This can be determined based on network and/or UE measurements reported to the network.

• The interference experienced at the mlAB-DU and/or the UEs is too high or increasing. This can be determined based on network and/or UE measurements reported to the network.

• The first donor CU realizes or is informed by another entity that another donor CU can better manage interference measurement and reporting configurations for the mlAB and the interfering nodes, based on for example mlAB-MT’s measurement.

• The geographical position of mlAB-node is too far from first CU or the mlAB-node is moving too fast, e.g., to provide a qualified Fl signaling in terms of latency etc.

• A donor CU is overloaded or is about to be overloaded (due to other migrating nodes). The overload can be, e.g., traffic overload or computational overload or any other type of overload.

[0071] The first donor CU indicates to the donor CU serving the mlAB-MT (second donor) the need for migrating the mlAB-DU, by sending a request message to the second donor CU. The indication can be via XnAP or NGAP signaling. The indication may contain one or more of the following:

• An indication of the intention to execute inter-donor migration for the mlAB-DU. o In the main scenario, the intention is to migrate the mlAB-DU to a donor CU (say third donor) which is different than the second donor CU (which serves the ml AB -MT). The indication can also contain the identifier (ID) of this intended target donor. o The identifier of the intended target donor can be, e.g., the ID of the target (CU) ID, gNodeB (gNB) ID, cell ID(s) of cells(s) served by the intended target.

■ The first donor CU can obtain this ID information in different ways, such as via UE measurements, from the Operations, Administration, and Maintenance (OAM), from neighbor gNBs via Xn, from non-neighbor gNBs via NGAP, etc. o In one sub-variant, the intended target donor CU for mlAB-DU migration is not stated, just the migration intention is stated. In this case, it is left for the second donor to determine the third donor CU to which the ml AB -MT and the mlAB- DU will be handed over. o The identity of the mlAB-MT for which the mlAB-DU needs to be migrated. The identity can be an identity assigned to recognize the UE/MT over the Uu interface (e.g., RNTI) or can be an identity assigned to recognize the UE/MT over the X2/Xn interface (e.g., UE XnAP ID) o In one variant there can be one intended target donor CU, in another variant there can be multiple intended target donors indicated.

• An indication of the reason for the migration, e.g., the reasons stated earlier in step 702: o Traffic or computational overload. o High interference. o High latency. o Low Quality of Experience (QoE) (e.g., QoE is less than a predefined threshold QoE). o Position and/or speed of the mlAB-node (e.g., too far from first donor CU or moving too fast away from the first donor CU) o ml AB trajectory planning o Resource compatibility (e.g., Time Division Duplexing (TDD) uplink (UL)/downlink (DL), Hard (H)/Soft (S)/Not Applicable (NA))

• An indication of urgency, for example: urgent, medium urgency, low urgency.

• A request on whether second donor CU can accommodate the migration of mlAB-DU o This is basically an explicit request that the first donor CU sends to the second donor CU on whether it is fine to accommodate the migration of the mlAB-DU.

[0072] The second donor CU receives the above described indication/request from the first donor CU (the request to determine the target donor CU for mlAB-DU migration) and based on its content decides to hand over the mlAB-MT to a donor CU, say third donor CU. As said earlier, this third donor CU may be explicitly indicated in the request received from first donor CU or it can be left by the first donor CU to be decided by the second donor CU.

• Alternatively, in case the third donor CU is decided by the second donor CU, then, when sending the response (as described below), the second donor CU may send an indication to the first donor CU to make the first donor CU aware about which donor CU the mlAB- MT has been handed over to, or is about to be handed over to, or is being handed over to. When deciding the target donor CU for mlAB-MT and ml AB -DU migration (third donor CU), the second donor CU considers the request from the first donor CU, as well as other information, such as e.g., measurements from the mlAB-MT. These additional factors need to be considered because the mlAB-MT must be handed over to a cell offering good signal quality. So, if the second donor CU finds a third donor CU that offers a good signal quality for the mlAB-MT, the second donor CU indicates the identity of that donor CU to the first donor CU.

[0073] In a further alternative, when the second donor CU receives the indication/request from the first donor CU, the second donor CU may decide to not hand over the mlAB-MT to a new third donor CU but rather indicate to the first donor CU that the mlAB-DU can be migrated to the second donor CU. Basically the second donor CU informs the first donor CU that it is willing to accommodate the migration of the mlAB-DU. Otherwise, the second donor CU may indicate to the first donor CU that the ml AB -MT will not be migrated and that the first donor CU can choose a target donor CU on its own.

[0074] So, in case the request is accepted by the second donor CU, a response message is sent to the first donor CU. The response may contain one or more of the following:

• An explicit or implicit indication that the request is accepted.

• Regardless of whether the third donor CU is decided by the first or the second donor CU, the response can contain an indication of the third donor CU and the information needed for the first donor CU to migrate the mlAB-DU to the third donor CU, i.e., to be able to send an mlAB-DU migration request to the third donor CU (e.g., the ID of the third donor, the IP address of the third donor CU, etc.). If the third donor CU is decided by the second donor, then also the identity of the third donor CU is included. • An indication of how much traffic resources for serving the mlAB-DU the target (third) donor CU can offer.

• An indication on whether the second donor CU is willing to accommodate the migration of the mlAB-DU from the first donor CU.

[0075] The response from the second donor CU may be sent before the mlAB-MT is handed over to third donor CU or during or after the handover of the mlAB-MT to the third donor CU. In case the second donor CU is willing to accommodate the migration of the ml AB -DU from the first donor CU, the response is sent without handing over the mlAB-MT.

[0076] The second donor CU may also reject the request.

[0077] The flow chart in Figure 8 shows the coordination message exchange between CU 1 and CU2 for Solution A, for the case when the request from first donor CU is accepted by second donor CU. Steps 806 and 808 can be done in arbitrary order. As illustrated, CUI sends, to CU2, a request or indication of intention of mlAB-DU migration (step 800). Details of this request or indication are provided above and those details are equally applicable here to step 800. CU2 performs target donor selection for the mlAB-DU migration (step 802). Details of this selection are provided above and those details are equally applicable here to step 802. CU2 sends a response to the request from step 800 to CUI (step 804). Details of this response are provided above and those details are equally applicable here to step 804. The mlAB-MT is handed over from CU2 to the selected target donor CU, which in this example is CU3 (step 806). The mlAB- DU is handed over from CUI to the selected target donor CU, which again in this example is CU3 (step 808). Note that while shown in Figure 8 for completeness, steps 806 and 808 are part of step 704 of Figure 7, which is described in detail below.

[0078] Solution B: Coordination initiated by the donor CU of the mlAB-MT (second CU) [0079] In another embodiment, the second donor CU (serving the mlAB-MT, donor CU2) determines that there is a need for the mlAB-MT to be handed over to another donor CU, say donor CU3 (or third donor) and then checks with the first donor CU whether it also wants to migrate the mlAB-DU towards this third donor CU.

[0080] The second donor CU can determine that it should hand over the ml AB -MT to the third donor CU based on several factors, where some non-limiting examples are:

• Based on the measurements received by the mlAB-MT. The measurements can be layer 3 (L3) measurement (e.g., filtered measurements) or layer 1 (LI) measurements (e.g., unfiltered measurements). The metric received in the measurements can be Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Received Strength of Signal Indicator (RSSI). • The second donor CU is overloaded or is bound to be overloaded. The overload can be, e.g., traffic overload or computational overload or any other type of overload.

• The latency measurement over the control plane and/or user plane traffic over the Uu link between the second donor CU and mlAB-MT is too high or is increasing or is bound to be too high. This can be determined based on network and/or UE measurements reported to the network.

• The QoE for the services provided to the UEs is insufficient (e.g., less than a predefined threshold) or deteriorating (e.g., decreasing at more than a predefined threshold rate). This can be determined based on network and/or UE measurements reported to the network.

• The interference experienced at the mlAB-MT and/or the UEs is too high (e.g., above a predefined threshold) or increasing. This can be determined based on network and/or UE measurements reported to the network.

• Based on an mlAB-MT trajectory or travel plan or flight plan.

• Donor CU2 considers that the necessary Fl configuration must be provided by the Donor CU2 rather than relying upon CUI Fl configuration, e.g., there may be a need to further update the BAP configuration to reach the mobile I AB -node since it is no longer connected to boundary lAB-node but has traversed a lot inside CU2 controlled area as shown in Figure 9. If CU2 has to perform F1AP updates such as updating BAP config., etc., it has to exchange 1^st via Xn to CUI and CUI has to update its Fl; this would be time consuming and as such CU2 would like to set up the Fl by itself where it can do such updates at ease.

• When the mlAB-MT is no longer connected to a parent node under CU2 that is close to the border between the CUI and CU2 areas. Instead, the lAB-node has travelled a long distance towards the central area of CU2, as shown below; for example, when mobile IAB-MT gets connected to lAB-node 3, which is far from the CU1-CU2 border, then CU2 requests for handover of mobile-IAB MT.

• When mobile IAB-MT has performed certain number of handovers in CU2, the CU2 may determine the need to manage the traffic directly by providing via its path rather than using Xn or relying on CU 1.

• When CU2 detects that routing of data traffic via Xn becomes cumbersome, the CU2 can request CUI to hand over the mobile-IAB -DU to be able to manage and serve the UEs well. This also implies decreasing Xn load, improving QoE. • Based on any of the reasons described in Solution A, that are applicable for the mlAB- MT (e.g., geographical position).

[0081] Figure 9: The initial state for Solution B. the mlAB-MT has performed few subsequent HO within CU2 and CU2 realizes that mlAB-MT should be handed over to another target CU, say donor CU3 (not shown in the figure) and that it is quite far from donor CUI.

[0082] The second donor CU indicates to the donor CU serving the mlAB-DU (first donor CU) the need for migrating the mlAB-MT, by sending a request message. The indication can be via XnAP or NGAP signaling. The indication may contain one or more of the following:

• An indication of the intended target donor CU (third donor) for the mlAB-MT. o In the main scenario, the intention for migrating the mlAB-MT is to migrate the ml AB -MT to a donor CU other than the donor CU serving the mlAB-DU (first donor). The intended donor CU is a third donor, CU3. In one sub-variant, the intended target donor CU for mlAB-MT migration is not stated, just the migration intention is stated. o The indication of the intended target can be, e.g., the ID of the target (CU ID, gNB ID, cell ID(s) of cells(s) served by the intended target.

■ The second donor CU can obtain this information in different ways, such as via UE measurements, from the 0AM, from neighbor gNBs via Xn, from non-neighbor gNBs via NGAP etc. o The identity of the mlAB-DU for which the mlAB-MT needs to be migrated. The identity can be an identity assigned to recognize the mlAB-DU over the Fl interface.

• An indication of the reason for the migration, e.g., the reasons stated earlier in step 702: o Traffic or computational overload. o High interference. o High latency. o Low QoE. o Position and/or speed of the mlAB-node (e.g., too far from first CU or moving too fast away from the first CU) o ml AB trajectory planning o Resource compatibility (e.g., TDD UL/DL, H/S/NA)

An indication of urgency, for example: urgent, medium urgency, low urgency.

A request on whether first donor CU can accommodate the handover of ml AB -MT o This is basically an explicit request that the second donor CU sends to the first donor CU on whether is fine to accommodate the handover of the mlAB-MT.

This also means that if this is fine for the first donor CU then both the ml AB -DU and mlAB-MT will have the same donor CU (i.e., the first donor CU).

[0083] The first donor CU receives the indication/request from the second donor CU, stating that the second donor plans to hand over or is handing over or has handed over the mlAB-MT to another donor (say third donor) CU. Based on the content of the indication, the first donor CU decides to hand over the mlAB-DU to a donor, say third donor CU. This third donor CU may be explicitly indicated in the request received from second donor CU or it can be decided by the first donor itself. In case the third donor CU is decided by the second donor CU, then the second donor CU may send an indication to the first donor CU to make the first donor CU aware to which donor the ml AB -MT has been or is about to be handed over or is being handed over to the third donor CU.

[0084] When deciding the target donor CU for the mlAB-DU migration (e.g., whether to accept the proposal from the second donor CU that the mlAB-DU is migrated to the third donor CU), the first donor CU considers the request from the second donor CU, as well as other information, such as, e.g., the geographical location of the third donor CU. For example, the third donor CU should not be too far from the first donor CU since large distance may incur increased latency.

[0085] In case the request is accepted by the first donor CU, a response message is sent to the second donor CU. The response may contain one or more of the following:

• An explicit or implicit indication that the request is accepted, and that the mlAB-DU will be migrated to the third donor CU, as suggested by the second donor CU. o The response by the first donor CU may be sent before the mlAB-DU is handed over to third donor CU or after the handover of the ml AB -DU to the third donor CU or during the handover of the mlAB-DU.

[0086] The first donor CU may also reject the request.

[0087] The flow chart in Figure 10 shows the coordination message exchange between CUI and CU2 for Solution B in case the suggestion from the second donor CU is accepted by the first donor CU. Steps 1006 and 1008 can be done in arbitrary order. As illustrated, CU2 performs target donor CU selection for the ml AB -DU migration (step 1000). Details of this selection are provided above and those details are equally applicable here to step 1000. CU2 sends, to CUI, a request or indication of intention of mlAB-DU migration (step 1002). Details of this request or indication are provided above and those details are equally applicable here to step 1002. CUI sends a response to the request from step 1002 to CU2 (step 1004). Details of this response are provided above and those details are equally applicable here to step 1004. The mlAB-DU is handed over from CUI to the selected target donor CU, which in this example is CU3 (step 1006). The mlAB-MT is handed over from CU2 to the selected target donor CU, which again in this example is CU3 (step 1008). Note that while shown in Figure 10 for completeness, steps 1006 and 1008 are part of step 704 of Figure 7, which is described in detail below.

Step 704: The mlAB-MT and mlAB-DU are handed over to another donor CU

[0088] After exchanging the coordination information, the first donor CU migrates the mlAB-DU to the third donor CU and the second donor CU hands over the mlAB-MT to the third donor CU. The two executions can be done in an arbitrary order. For example, see steps 806 and 808 of Figure 8 and steps 1006 and 1008 of Figure 10.

[0089] In one embodiment, the first donor CU coordinates directly with the third donor CU about the mlAB-DU migration, and the second donor CU does the same for mlAB-MT handover. In another embodiment, the second donor CU (the first donor CU or the second donor CU) acts as a relay for the migration-related messages between the first and third donor CU.

[0090] In one embodiment, the mlAB-MT and mlAB-DU can be handed over to different target CUs, say fourth donor CU (donor CU4) and fifth donor CU (donor CU5), respectively. The two target CUs may for example be in the same area or co-located, where the target CU for the mlAB-DU may be, e.g., a CU dedicated to serving mlAB-DUs or just a donor CU with enough capacity and direct Xn connection with the third CU.

Additional Description

[0091] Figure 11 shows an example of a communication system 1100 in accordance with some embodiments.

[0092] In the example, the communication system 1100 includes a telecommunication network 1102 that includes an access network 1104, such as a RAN, and a core network 1106, which includes one or more core network nodes 1108. The access network 1104 includes one or more access network nodes, such as network nodes 1110A and 1110B (one or more of which may be generally referred to as network nodes 1110), or any other similar 3GPP access node or non-3GPP Access Point (AP). The network nodes 1110 facilitate direct or indirect connection of UE, such as by connecting UEs 1112A, 1112B, 1112C, and 1112D (one or more of which may be generally referred to as UEs 1112) to the core network 1106 over one or more wireless connections.

[0093] Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 1100 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 1100 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

[0094] The UEs 1112 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 1110 and other communication devices. Similarly, the network nodes 1110 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 1112 and/or with other network nodes or equipment in the telecommunication network 1102 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 1102.

[0095] In the depicted example, the core network 1106 connects the network nodes 1110 to one or more hosts, such as host 1116. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 1106 includes one more core network nodes (e.g., core network node 1108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 1108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-Concealing Function (SIDE), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

[0096] The host 1116 may be under the ownership or control of a service provider other than an operator or provider of the access network 1104 and/or the telecommunication network 1102, and may be operated by the service provider or on behalf of the service provider. The host 1116 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server. [0097] As a whole, the communication system 1100 of Figure 11 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 1100 may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM);

Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, or 5G standards, or any applicable future generation standard (e.g., Sixth Generation (6G)); Wireless Local Area Network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any Low Power Wide Area Network (LPWAN) standards such as LoRa and Sigfox. [0098] In some examples, the telecommunication network 1102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunication network 1102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 1102. For example, the telecommunication network 1102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing enhanced Mobile Broadband (eMBB) services to other UEs, and/or massive Machine Type Communication (mMTC)/massive Internet of Things (loT) services to yet further UEs.

[0099] In some examples, the UEs 1112 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 1104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi- standard mode. For example, a UE may operate with any one or combination of WiFi, NR, and LTE, i.e. be configured for Multi-Radio Dual Connectivity (MR-DC), such as Evolved UMTS Terrestrial RAN (E-UTRAN) NR - Dual Connectivity (EN-DC).

[0100] In the example, a hub 1114 communicates with the access network 1104 to facilitate indirect communication between one or more UEs (e.g., UE 1112C and/or 1112D) and network nodes (e.g., network node 1 HOB). In some examples, the hub 1114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1114 may be a broadband router enabling access to the core network 1106 for the UEs. As another example, the hub 1114 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1110, or by executable code, script, process, or other instructions in the hub 1114. As another example, the hub 1114 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 1114 may be a content source. For example, for a UE that is a Virtual Reality (VR) headset, display, loudspeaker or other media delivery device, the hub 1114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1114 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 1114 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

[0101] The hub 1114 may have a constant/persistent or intermittent connection to the network node 1110B. The hub 1114 may also allow for a different communication scheme and/or schedule between the hub 1114 and UEs (e.g., UE 1112C and/or 1112D), and between the hub 1114 and the core network 1106. In other examples, the hub 1114 is connected to the core network 1106 and/or one or more UEs via a wired connection. Moreover, the hub 1114 may be configured to connect to a Machine-to-Machine (M2M) service provider over the access network 1104 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1110 while still connected via the hub 1114 via a wired or wireless connection. In some embodiments, the hub 1114 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 1110B. In other embodiments, the hub 1114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and the network node 1110B, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

[0102] Figure 12 shows a UE 1200 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged, and/or operable to communicate wirelessly with network nodes and/or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, Voice over Internet Protocol (VoIP) phone, wireless local loop phone, desktop computer, Personal Digital Assistant (PDA), wireless camera, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), smart device, wireless Customer Premise Equipment (CPE), vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by the 3GPP, including a Narrowband Internet of Things (NB-IoT) UE, a Machine Type Communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. [0103] A UE may support Device-to-Device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), Vehicle-to- Vehicle (V2V), Vehicle-to-Infrastructure (V2I), or Vehicle- to-Everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller).

Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0104] The UE 1200 includes processing circuitry 1202 that is operatively coupled via a bus 1204 to an input/output interface 1206, a power source 1208, memory 1210, a communication interface 1212, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 12. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0105] The processing circuitry 1202 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 1210. The processing circuitry 1202 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1202 may include multiple Central Processing Units (CPUs). [0106] In the example, the input/output interface 1206 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices.

[0107] In some embodiments, the power source 1208 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 1208 may further include power circuitry for delivering power from the power source 1208 itself, and/or an external power source, to the various parts of the UE 1200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging the power source 1208. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 1208 to make the power suitable for the respective components of the UE 1200 to which power is supplied.

[0108] The memory 1210 may be or be configured to include memory such as Random Access Memory (RAM), Read Only Memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), Electrically EPROM (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 1210 includes one or more application programs 1214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1216. The memory 1210 may store, for use by the UE 1200, any of a variety of various operating systems or combinations of operating systems.

[0109] The memory 1210 may be configured to include a number of physical drive units, such as Redundant Array of Independent Disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, High Density Digital Versatile Disc (HD- DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, Holographic Digital Data Storage (HDDS) optical disc drive, external mini Dual In-line Memory Module (DIMM), Synchronous Dynamic RAM (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a tamper resistant module in the form of a Universal Integrated Circuit Card (UICC) including one or more Subscriber Identity Modules (SIMs), such as a Universal SIM (USIM) and/or Internet Protocol Multimedia Services Identity Module (ISIM), other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as a ‘SIM card.’ The memory 1210 may allow the UE 1200 to access instructions, application programs, and the like stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system, may be tangibly embodied as or in the memory 1210, which may be or comprise a device-readable storage medium.

[0110] The processing circuitry 1202 may be configured to communicate with an access network or other network using the communication interface 1212. The communication interface 1212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1222. The communication interface 1212 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 1218 and/or a receiver 1220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 1218 and receiver 1220 may be coupled to one or more antennas (e.g., the antenna 1222) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0111] In the illustrated embodiment, communication functions of the communication interface 1212 may include cellular communication, WiFi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, NFC, location-based communication such as the use of the Global Positioning System (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and/or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband CDMA (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, Transmission Control Protocol/Internet Protocol (TCP/IP), Synchronous Optical Networking (SONET), Asynchronous Transfer Mode (ATM), Quick User Datagram Protocol Internet Connection (QUIC), Hypertext Transfer Protocol (HTTP), and so forth.

[0112] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1212, or via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE.

[0113] As another example, a UE comprises an actuator, a motor, or a switch related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change.

[0114] A UE, when in the form of an loT device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application, and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a television, a connected lighting device, an electricity meter, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot, etc. A UE in the form of an loT device comprises circuitry and/or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 1200 shown in Figure 12.

[0115] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and/or measurements and transmits the results of such monitoring and/or measurements to another UE and/or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship, an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

[0116] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator and handle communication of data for both the speed sensor and the actuators.

[0117] Figure 13 shows a network node 1300 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged, and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment in a telecommunication network. Examples of network nodes include, but are not limited to, APs (e.g., radio APs), Base Stations (BSs) (e.g., radio BSs, Node Bs (NBs), evolved NBs (eNBs), NR NBs (gNBs)), IAB nodes, lAB-donors, or the like.

[0118] BSs may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto BSs, pico BSs, micro BSs, or macro BSs. A BS may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio BS such as centralized digital units and/or Remote Radio Units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such RRUs may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio BS may also be referred to as nodes in a Distributed Antenna System (DAS).

[0119] Other examples of network nodes include multiple Transmission Point (multi-TRP) 5G access nodes, Multi-Standard Radio (MSR) equipment such as MSR BSs, network controllers such as Radio Network Controllers (RNCs) or BS Controllers (BSCs), Base Transceiver Stations (BTSs), transmission points, transmission nodes, Multi-Cell/Multicast Coordination Entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

[0120] The network node 1300 includes processing circuitry 1302, memory 1304, a communication interface 1306, and a power source 1308. The network node 1300 may be composed of multiple physically separate components (e.g., a NB component and an RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 1300 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple Node Bs. In such a scenario, each unique Node B and RNC pair may in some instances be considered a single separate network node. In some embodiments, the network node 1300 may be configured to support multiple RATs. In such embodiments, some components may be duplicated (e.g., separate memory 1304 for different RATs) and some components may be reused (e.g., an antenna 1310 may be shared by different RATs). The network node 1300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1300, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z- wave, Long Range Wide Area Network (LoRaWAN), Radio Frequency Identification (RFID), or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within the network node 1300.

[0121] The processing circuitry 1302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, CPU, DSP, ASIC, FPGA, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other network node 1300 components, such as the memory 1304, to provide network node 1300 functionality (e.g., the functionality of any of Figures 7 to 10).

[0122] In some embodiments, the processing circuitry 1302 includes a System on a Chip (SOC). In some embodiments, the processing circuitry 1302 includes one or more of Radio Frequency (RF) transceiver circuitry 1312 and baseband processing circuitry 1314. In some embodiments, the RF transceiver circuitry 1312 and the baseband processing circuitry 1314 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of the RF transceiver circuitry 1312 and the baseband processing circuitry 1314 may be on the same chip or set of chips, boards, or units.

[0123] The memory 1304 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, RAM, ROM, mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD), or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable, and/or computer-executable memory devices that store information, data, and/or instructions that may be used by the processing circuitry 1302. The memory 1304 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions capable of being executed by the processing circuitry 1302 and utilized by the network node 1300. The memory 1304 may be used to store any calculations made by the processing circuitry 1302 and/or any data received via the communication interface 1306. In some embodiments, the processing circuitry 1302 and the memory 1304 are integrated.

[0124] The communication interface 1306 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, the communication interface 1306 comprises port(s)/terminal(s) 1316 to send and receive data, for example to and from a network over a wired connection. The communication interface 1306 also includes radio front-end circuitry 1318 that may be coupled to, or in certain embodiments a part of, the antenna 1310. The radio front-end circuitry 1318 comprises filters 1320 and amplifiers 1322. The radio front-end circuitry 1318 may be connected to the antenna 1310 and the processing circuitry 1302. The radio front-end circuitry 1318 may be configured to condition signals communicated between the antenna 1310 and the processing circuitry 1302. The radio front-end circuitry 1318 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 1318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of the filters 1320 and/or the amplifiers 1322. The radio signal may then be transmitted via the antenna 1310. Similarly, when receiving data, the antenna 1310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1318. The digital data may be passed to the processing circuitry 1302. In other embodiments, the communication interface 1306 may comprise different components and/or different combinations of components.

[0125] In certain alternative embodiments, the network node 1300 does not include separate radio front-end circuitry 1318; instead, the processing circuitry 1302 includes radio front-end circuitry and is connected to the antenna 1310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1312 is part of the communication interface 1306. In still other embodiments, the communication interface 1306 includes the one or more ports or terminals 1316, the radio front-end circuitry 1318, and the RF transceiver circuitry 1312 as part of a radio unit (not shown), and the communication interface 1306 communicates with the baseband processing circuitry 1314, which is part of a digital unit (not shown).

[0126] The antenna 1310 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 1310 may be coupled to the radio front-end circuitry 1318 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 1310 is separate from the network node 1300 and connectable to the network node 1300 through an interface or port. [0127] The antenna 1310, the communication interface 1306, and/or the processing circuitry 1302 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node 1300. Any information, data, and/or signals may be received from a UE, another network node, and/or any other network equipment. Similarly, the antenna 1310, the communication interface 1306, and/or the processing circuitry 1302 may be configured to perform any transmitting operations described herein as being performed by the network node 1300. Any information, data, and/or signals may be transmitted to a UE, another network node, and/or any other network equipment.

[0128] The power source 1308 provides power to the various components of the network node 1300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1300 with power for performing the functionality described herein. For example, the network node 1300 may be connectable to an external power source (e.g., the power grid or an electricity outlet) via input circuitry or an interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1308. As a further example, the power source 1308 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0129] Embodiments of the network node 1300 may include additional components beyond those shown in Figure 13 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, the network node 1300 may include user interface equipment to allow input of information into the network node 1300 and to allow output of information from the network node 1300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1300.

[0130] Figure 14 is a block diagram of a host 1400, which may be an embodiment of the host 1116 of Figure 11, in accordance with various aspects described herein. As used herein, the host 1400 may be or comprise various combinations of hardware and/or software including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host 1400 may provide one or more services to one or more UEs.

[0131] The host 1400 includes processing circuitry 1402 that is operatively coupled via a bus 1404 to an input/output interface 1406, a network interface 1408, a power source 1410, and memory 1412. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 12 and 13, such that the descriptions thereof are generally applicable to the corresponding components of the host 1400.

[0132] The memory 1412 may include one or more computer programs including one or more host application programs 1414 and data 1416, which may include user data, e.g. data generated by a UE for the host 1400 or data generated by the host 1400 for a UE. Embodiments of the host 1400 may utilize only a subset or all of the components shown. The host application programs 1414 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), Moving Picture Experts Group (MPEG), VP9) and audio codecs (e.g., Free Lossless Audio Codec (FLAC), Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, and heads-up display systems). The host application programs 1414 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host 1400 may select and/or indicate a different host for Over-The-Top (OTT) services for a UE. The host application programs 1414 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (DASH or MPEG-DASH), etc.

[0133] Figure 15 is a block diagram illustrating a virtualization environment 1500 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices, and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more Virtual Machines (VMs) implemented in one or more virtual environments 1500 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized.

[0134] Applications 1502 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1400 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

[0135] Hardware 1504 includes processing circuitry, memory that stores software and/or instructions executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1506 (also referred to as hypervisors or VM Monitors (VMMs)), provide VMs 1508A and 1508B (one or more of which may be generally referred to as VMs 1508), and/or perform any of the functions, features, and/or benefits described in relation with some embodiments described herein. The virtualization layer 1506 may present a virtual operating platform that appears like networking hardware to the VMs 1508.

[0136] The VMs 1508 comprise virtual processing, virtual memory, virtual networking, or interface and virtual storage, and may be run by a corresponding virtualization layer 1506. Different embodiments of the instance of a virtual appliance 1502 may be implemented on one or more of the VMs 1508, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as Network Function Virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers and customer premise equipment.

[0137] In the context of NFV, a VM 1508 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non- virtualized machine. Each of the VMs 1508, and that part of the hardware 1504 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs 1508, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1508 on top of the hardware 1504 and corresponds to the application 1502.

[0138] The hardware 1504 may be implemented in a standalone network node with generic or specific components. The hardware 1504 may implement some functions via virtualization. Alternatively, the hardware 1504 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1510, which, among others, oversees lifecycle management of the applications 1502. In some embodiments, the hardware 1504 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a RAN or a BS. In some embodiments, some signaling can be provided with the use of a control system 1512 which may alternatively be used for communication between hardware nodes and radio units.

[0139] Figure 16 shows a communication diagram of a host 1602 communicating via a network node 1604 with a UE 1606 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as the UE 1112A of Figure 11 and/or the UE 1200 of Figure 12), the network node (such as the network node 1110A of Figure 11 and/or the network node 1300 of Figure 13), and the host (such as the host 1116 of Figure 11 and/or the host 1400 of Figure 14) discussed in the preceding paragraphs will now be described with reference to Figure 16.

[0140] Like the host 1400, embodiments of the host 1602 include hardware, such as a communication interface, processing circuitry, and memory. The host 1602 also includes software, which is stored in or is accessible by the host 1602 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 1606 connecting via an OTT connection 1650 extending between the UE 1606 and the host 1602. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1650.

[0141] The network node 1604 includes hardware enabling it to communicate with the host 1602 and the UE 1606 via a connection 1660. The connection 1660 may be direct or pass through a core network (like the core network 1106 of Figure 11) and/or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

[0142] The UE 1606 includes hardware and software, which is stored in or accessible by the UE 1606 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via the UE 1606 with the support of the host 1602. In the host 1602, an executing host application may communicate with the executing client application via the OTT connection 1650 terminating at the UE 1606 and the host 1602. In providing the service to the user, the UE’s client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 1650 may transfer both the request data and the user data. The UE’s client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 1650.

[0143] The OTT connection 1650 may extend via the connection 1660 between the host 1602 and the network node 1604 and via a wireless connection 1670 between the network node 1604 and the UE 1606 to provide the connection between the host 1602 and the UE 1606. The connection 1660 and the wireless connection 1670, over which the OTT connection 1650 may be provided, have been drawn abstractly to illustrate the communication between the host 1602 and the UE 1606 via the network node 1604, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

[0144] As an example of transmitting data via the OTT connection 1650, in step 1608, the host 1602 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 1606. In other embodiments, the user data is associated with a UE 1606 that shares data with the host 1602 without explicit human interaction. In step 1610, the host 1602 initiates a transmission carrying the user data towards the UE 1606. The host 1602 may initiate the transmission responsive to a request transmitted by the UE 1606. The request may be caused by human interaction with the UE 1606 or by operation of the client application executing on the UE 1606. The transmission may pass via the network node 1604 in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1612, the network node 1604 transmits to the UE 1606 the user data that was carried in the transmission that the host 1602 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1614, the UE 1606 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1606 associated with the host application executed by the host 1602.

[0145] In some examples, the UE 1606 executes a client application which provides user data to the host 1602. The user data may be provided in reaction or response to the data received from the host 1602. Accordingly, in step 1616, the UE 1606 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input/output interface of the UE 1606. Regardless of the specific manner in which the user data was provided, the UE 1606 initiates, in step 1618, transmission of the user data towards the host 1602 via the network node 1604. In step 1620, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1604 receives user data from the UE 1606 and initiates transmission of the received user data towards the host 1602. In step 1622, the host 1602 receives the user data carried in the transmission initiated by the UE 1606.

[0146] One or more of the various embodiments improve the performance of OTT services provided to the UE 1606 using the OTT connection 1650, in which the wireless connection 1670 forms the last segment. [0147] In an example scenario, factory status information may be collected and analyzed by the host 1602. As another example, the host 1602 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1602 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1602 may store surveillance video uploaded by a UE. As another example, the host 1602 may store or control access to media content such as video, audio, VR, or AR which it can broadcast, multicast, or unicast to UEs. As other examples, the host 1602 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing, and/or transmitting data.

[0148] In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency, and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1650 between the host 1602 and the UE 1606 in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1650 may be implemented in software and hardware of the host 1602 and/or the UE 1606. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1650 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or by supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1650 may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not directly alter the operation of the network node 1604. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency, and the like by the host 1602. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1650 while monitoring propagation times, errors, etc.

[0149] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and/or software needed to perform the tasks, features, functions, and methods disclosed herein. Determining, calculating, obtaining, or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box or nested within multiple boxes, in practice computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and/or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0150] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hardwired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole and/or by end users and a wireless network generally.

[0151] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims

1. A method performed by first Integrated Access and Backhaul, IAB, donor node (602-1) serving a mobile IAB Distributed Unit, mlAB-DU, (608-2) that is co-located in a same IAB node (606-2) with a mobile IAB Mobile Termination, mlAB-MT, (612-2) that is served by a second IAB donor node (602-2), the method comprising: communicating (702; 800, 804; 1002-1004) with the second IAB donor node (602-2) to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node.

2. The method of claim 1 wherein communicating (702) with the second IAB donor node (602-2) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node comprises: sending (800), to the second donor IAB node (602-2), a request or indication to initiate inter-donor migration of the mlAB-DU (608-2).

3. The method of claim 2 wherein the request or indication comprises an indication to execute inter-donor migration for the mlAB-DU (608-2).

4. The method of claim 2 or 3 wherein the request or indication comprises an identifier of the target IAB donor node.

5. The method of any of claims 2 to 4 wherein the request or indication comprises an indication of a reason for the inter-donor migration for the mlAB-DU (608-2).

6. The method of any of claims 2 to 5 wherein the request or indication comprises an indication of an urgency for the inter-donor migration for the mlAB-DU (608-2).

7. The method of any of claims 2 to 6 wherein communicating (702, 800) with the second IAB donor node (602-2) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node further comprises receiving (804), from the second donor IAB node (602-2), a response that indicates either acceptance or rejection of the request or indication to initiate interdonor migration of the mlAB-DU (608-2).

8. The method of any of claims 2 to 7 further comprising determining (702; 800) that the inter-donor migration of the mlAB-DU (608-2) is desired prior to sending the request or indication.

9. The method of claim 1 wherein communicating (1002) with the second IAB donor node (602-2) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node comprises: receiving (1002), from the second IAB donor node (602-2), a request or indication about inter-donor migration of the mlAB-DU (608-2).

10. The method of claim 9 wherein the request or indication about inter-donor migration of the mlAB-DU (608-2) comprises an indication of the target donor.

11. The method of claim 9 or 10 wherein the request or indication about inter-donor migration of the mlAB-DU (608-2) comprises an indication of a reason for the inter-donor migration.

12. The method of any of claims 9 to 11 wherein the request or indication about inter-donor migration of the mlAB-DU (608-2) comprises an indication of an urgency for the inter-donor migration.

13. The method of any of claims 9 to 12 wherein communicating (1002, 1004) with the second IAB donor node (602-2) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node further comprises: sending (1004), to the second donor IAB node (602-2), a response that indicates either acceptance or rejection of the request or indication to initiate inter-donor migration of the mlAB- DU (608-2).

14. The method of any of claims 1 to 13, wherein the first IAB donor node is a first IAB donor Centralized Unit, CU, (602-1), and the second IAB donor node (602-2) is a second IAB donor CU (602-2).

15. A first Integrated Access and Backhaul, IAB, donor node (602-1) for serving a mobile IAB Distributed Unit, mlAB-DU, (608-2) that is co-located in a same IAB node (606-2) with a mobile IAB Mobile Termination, mlAB-MT, (612-2) that is served by a second IAB donor node (602-2), the first IAB donor node (602-1) adapted to: communicate (702; 800, 804; 1002-1004) with the second IAB donor node (602-2) to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node.

16. The first IAB donor node (602-1) of claim 15 further adapted to perform the method of any of claims 2 to 14.

17. A first Integrated Access and Backhaul, IAB, donor node (602-1; 1300) for serving a mobile IAB Distributed Unit, mlAB-DU, (608-2) that is co-located in a same IAB node (606-2) with a mobile IAB Mobile Termination, mlAB-MT, (612-2) that is served by a second IAB donor node (602-2), the first IAB donor node (602-1; 1300) comprising: a communication interface (1306); and processing circuitry (1302) associated with the communication interface (1306), the processing circuitry (1302) configured to cause the first IAB donor node (602-1; 1300) to communicate (702; 800, 804; 1002-1004) with the second IAB donor node (602-2) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node.

18. The first IAB donor node (602-1) of claim 17 wherein the processing circuitry (1302) is further configured to cause the first IAB donor node (602-1; 1300) to perform the method of any of claims 2 to 14.

19. A method performed by a second Integrated Access and Backhaul, IAB, donor node (602-2) serving a mobile IAB Mobile Termination, mlAB-MT, (612-2) that is co-located in a same IAB node (606-2) with a mobile IAB Distributed Unit, mlAB-DU, (608-2) that is served by a first IAB donor node (602-1), the method comprising: communicating (702; 800, 804; 1002-1004) with the first IAB donor node (602-1) to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node.

20. The method of claim 19 wherein communicating (800) with the first IAB donor node (602-1) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node comprises: receiving (800), from the first donor IAB node (602-1), a request or indication to initiate inter-donor migration of the mlAB-DU (608-2).

21. The method of claim 20 wherein the request or indication comprises an indication to execute inter-donor migration for the mlAB-DU (608-2).

22. The method of claim 20 or 21 wherein the request or indication comprises an identifier of the target IAB donor node.

23. The method of any of claims 20 to 22 wherein the request or indication comprises an indication of a reason for the inter-donor migration for the mlAB-DU (608-2).

24. The method of any of claims 20 to 23 wherein the request or indication comprises an indication of an urgency for the inter-donor migration for the mlAB-DU (608-2).

25. The method of any of claims 20 to 24 wherein communicating (802, 804) with the first IAB donor node (602-1) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node further comprises sending (804), to the first donor IAB node (602-1), a response that indicates either acceptance or rejection of the request or indication to initiate inter-donor migration of the mlAB-DU (608-2).

26. The method of claim 19 wherein communicating (1002) with the first IAB donor node (602-1) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node comprises: sending (1002), to the first IAB donor node (602-1), a request or indication about interdonor migration of the mlAB-DU (608-2).

27. The method of claim 26 wherein the request or indication about inter-donor migration of the mlAB-DU (608-2) comprises an indication of the target donor.

28. The method of claim 26 or 27 wherein the request or indication about inter-donor migration of the mlAB-DU (608-2) comprises an indication of a reason for the inter-donor migration.

29. The method of any of claims 26 to 28 wherein the request or indication about inter-donor migration of the mlAB-DU (608-2) comprises an indication of an urgency for the inter-donor migration.

30. The method of any of claims 26 to 29 wherein communicating (1002, 1004) with the first IAB donor node (602-1) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node further comprises: receiving (1004), from the first donor IAB node (602-1), a response that indicates either acceptance or rejection of the request or indication to initiate inter-donor migration of the mlAB- DU (608-2).

31. The method of any of claims 26 to 30 further comprising determining that the inter-donor migration of the mlAB-DU (608-2) is desired prior to sending the request or indication.

32. The method of any of claims 19 to 31, wherein the first IAB donor node is a first IAB donor Centralized Unit, CU, (602-1), and the second IAB donor node (602-2) is a second IAB donor CU (602-2).

33. A second Integrated Access and Backhaul, IAB, donor node (602-2) for serving a mobile IAB Mobile Termination, mlAB-MT, (612-2) that is co-located in a same IAB node (606-2) with a mobile IAB Distributed Unit, mlAB-DU, (608-2) that is served by a first IAB donor node (602- 1), the second IAB donor node (602-2) adapted to: communicate (702; 800, 804; 1002-1004) with the first IAB donor node (602-1) to coordinate with respect to choosing a target IAB donor node to which to migrate the ml AB -DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node.

34. The second IAB donor node (602-2) of claim 33 further adapted to perform the method of any of claims 20 to 32.

35. A second Integrated Access and Backhaul, IAB, donor node (602-2; 1300) for serving a mobile IAB Mobile Termination, mlAB-MT, (612-2) that is co-located in a same IAB node (606- 2) with a mobile IAB Distributed Unit, mlAB-DU, (608-2) that is served by a first IAB donor node (602-1), the second IAB donor node (602-2) comprising: a communication interface (1306); and processing circuitry (1302) associated with the communication interface (1306), the processing circuitry (1302) configured to cause the second IAB donor node (602-2; 1300) to communicate (702; 800, 804; 1002-1004) with the first IAB donor node (602-1) to coordinate with respect to choosing a target IAB donor node to which to migrate the mlAB-DU (608-2) and/or when to migrate the mlAB-DU (608-2) to the target IAB donor node.

36. The second IAB donor node (602-2) of claim 35 wherein the processing circuitry (1302) is further configured to cause the second IAB donor node (602-2; 1300) to perform the method of any of claims 20 to 32.