RELATED APPLICATIONS

[0001] This application claims the benefits of priority of U.S. Provisional Patent Application No. 63/422,115, entitled “Signaling for synchronized mobile IAB DU migration” and filed at the United States Patent and Trademark Office (USPTO) on November 3, 2022.

BACKGROUND

[0002] Integrated Access and Backhaul (IAB) Overview

[0003] Fifth Generation (5G) networks are being designed and deployed considering a dense deployment of small cells in order to simultaneously serve more User Equipment (UEs) with higher throughput and lower delay. However, building from scratch a completely new infrastructure is costly and takes time. Deploying a wireless backhaul is then envisioned to be an economically and technically viable approach to enable flexible and dense network.

[0004] This solution was standardized in Third Generation Partnership Project (3GPP) release (Rel.) 16, under the term Integrated Access and Backhaul (IAB), to support wireless relaying in New Generation- Radio Access Network (NG-RAN) and has continued in release 17.

[0005] IAB Architecture

[0006] IAB is based on the centralized unit (CU) - distributed unit (DU) split that was standardized in release 15. The CU is in charge of the radio resource control (RRC) and the packet data convergence protocol (PCDP), whereas the DU is in charge of the radio link control (RLC) and medium access control (MAC). 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. Fig. 1 shows the basic architecture of IAB. The main components of the IAB architecture are:

[0007] 1) IAB Node 2: A node that allows wireless access to the UEs 4 while also backhauling the traffic to other nodes. The IAB node 2 consists of a DU that provides access to connected UEs. The node also consists of a mobile termination (MT) that connects to other IAB nodes or donors in the uplink direction for backhaul.

[0008] 2) IAB Donor 6: A node that provides UEs 4 an interface to the core network 8and wireless functionality to other lAB-nodes to backhaul their traffic to the core network.

[0009] More specifically, Fig. 1 shows a single IAB donor 6 connected to the core network 30. The IAB donor 6 serves three direct IAB child nodes 2 through two collocated DUs at the donor 6 for wireless backhauling. The center IAB node 2 in turn serves two IAB nodes 10 through wireless backhaul. All IAB nodes 2 in the figure backhauls traffic both related to UEs 4 connected to it, and other backhaul traffic from downstream IAB nodes 2.

[0010] The defining feature of IAB is the use of wireless spectrum for both access of UEs 4 and backhauling of data through IAB donors 6. Thus, there needs to be clear separation of access and backhaul resources to avoid interference between them. This separation of access and backhaul resources cannot be handled during network planning due to the dynamic nature of IAB.

[0011] In release 16, IAB was standardized with basic support for multi -hop multi-path backhaul for directed acyclic graph (DAG) topology, no mesh-based topology was supported. Rel. 16 also supports Quality of Service (QoS) prioritization of backhaul traffic and flexible resource usage between access and backhaul. Current 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.

[0012] Mobile IAB

[0013] In release 18, it is expected that the different Radio Access Network (RAN) groups will work towards enhancing functionality of IAB through:

[0014] - Focus on mobile -IAB providing 5G coverage enhancement to onboard and surrounding UEs; and

[0015] - Smart repeaters that build on Long Term Evolution (LTE)-repeaters.

[0016] The initial use cases for mobile-I AB/Vehicle Mounted Relay (VMR) are expected to be based on 3GPP TR 22.839.

[0017] One of the main use cases of mobile IAB cell is to serve the UEs which are residing in the vehicle with the vehicle mounted relay, using Integrated access backhaul solutions. 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, during disasters. The nomadic IAB node provides access to surrounding UEs while the backhaul traffic from the nomadic IAB node is then transmitted wirelessly either with the help of IAB donors or Non-terrestrial networks (NTN). A nomadic IAB node also reduces or even eliminates signal strength loss due to vehicle penetration for UEs that are present in the vehicles.

[0018] Advantages of Mobile IAB are: reducing/eliminating the vehicle penetration loss (specially at high frequency); and reducing/eliminating group handover.

[0019] Most use cases of mobile IAB are expected to be mounted on public transport vehicles and to move to a large extent in a pre-determined route. Fig. 2 shows one such mobile IAB mounted on a bus travelling on a route that is covered by 4 different stationary parent IAB nodes (parent 1,2, 3, 4). The parent nodes backhaul their traffic through 2 donor nodes (donor X,Y).

[0020] An IAB node has a DU that provides access to UEs around it and an MT that provides a backhaul connection of the IAB node to its parent(s) and the rest of the network. The parent IAB nodes consist of DUs that provide access to UEs and the mobile IAB present in their coverage. They also consist of MTs that backhaul its traffic together with traffic from the mobile IAB node. Finally, the two donor nodes comprise a DU that provides access and CU that is connected to the core network. The CUs in both donor nodes maintain a Fl connection to the parent nodes under it. When the mobile IAB node moves from one area to the next, it passes through different areas covered by various cells of stationary parent nodes.

[0021] The mobile IAB node maintains an Fl connection to the donor (one donor at a time). In Fig. 2, the mobile IAB connects to the following nodes in the different positions as described below:

[0022] Position A: Backhaul (BH) through parent node 1, Fl connection to donor node X;

[0023] Position B: BH through parent node 2, Fl connection to donor node X;

[0024] Position C: BH through parent node 3, Fl connection to donor node Y ;

[0025] Position D: BH through parent node 4, Fl connection to donor node Y.

[0026] Partial/Full migration

[0027] From R3-212981, the following is provided:

RAN3 agreements in Rel-17 are provided:

[0028] - Boundary IAB node: lAB-node, whose IAB-DU is terminated to a different IAB- donor-CU than a parent DU

[0029] - Partial Migration: the boundary IAB-MT is migrated to the 2nd lAB-donor-CU, while the boundary IAB-DU and descendant IAB node(s) (if any) are terminated to the 1st IAB- donor-CU.

[0030] - Full Migration: the boundary IAB node and the descendant IAB node(s) (if any) are migrated (both RRC and Fl connection) to the 2nd lAB-donor-CU from 1st lAB-donor-CU.

[0031] It is considered to support Full Migration through the introduction of a logical IAB- DU. During the Full Migration, the UE connected to the boundary lAB-node will hand over from a cell of one logical DU (e.g. IAB-DU1) controlled by CUI to a cell of another logical DU (e.g. IAB-DU2) controlled by CU2. The two cells reside on the same physical lAB-node but on different logical Dus (e.g., DU1 and DU2), which each have a separate Fl connection to CUI and CU2, respectively, see Fig. 3. [0032] Two implementation alternatives, which involve two logical lAB-Dus at the boundary IAB node, are to be further discussed in the scope of Full Migration:

[0033] Alt. 1 : The two logical Dus use separate physical cell resources.

[0034] Alt. 2 : The two logical Dus use the same physical cell resources.

[0035] During RAN3#117-e, agreements were taken on scenarios where the mlAB node performs migration through supporting two logical Dus and performing Handovers (HOs) of the UEs connected from DU1 to DU2.

[0036] ‘For DU migration cases, to execute the handover of the served UEs, the mobile IAB- node concurrently supports two logical mobile lAB-DUs, which have F1AP associations with the source CU and the target CU, respectively.”

[0037] The agreements make it clear that the two logical DUs can be controlled, or in other words, have a Fl connection to two different IAB donors, or CUs. Thus, performing migration of the UEs from one logical DU to another will require coordination between the two donor CUs as shown in another agreement from the same meeting.

[0038] ‘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 F1AP association with the target CU.”

SUMMARY

[0039] There currently exists some problems. To support IAB node mobility of the Mobile IAB (mlAB), the specifications need to support inter-CU migration of both the mlAB-MT’s RRC connection and the co-located mlAB-DU’s F1AP connection, and the inter-donor handover of the UEs served by the mlAB node. This is commonly referred to as the full migration.

[0040] Full migration can roughly be divided into these stages:

[0041] - Inter-donor mlAB-MT handover;

[0042] - (optional) setting up partial migration, i.e., the migration of Fl traffic of the mlAB-

DU;

[0043] - Inter-donor migration of the mlAB-DU by setting up a second logical mlAB-DU that establishes an Fl connection with the target donor CU. This is followed by the inter-donor UE handover between the two logical mlAB-DUs.

[0044] The first problem addressed is this disclosure follows from the fact that executing both the RRC and F1AP connection migration at the same time (e.g., in parallel or immediately one after another) would result in a complicated procedure. Given that as many as 7 entities may be involved in mlAB node migration, (two source donors, two target donors, two logical mlAB-DUs, the mlAB-MT), it needs to be ensured that the mlAB-MT handover and the migration of the mlAB-DU are done in a synchronized, sequential manner, e.g., only after one of them is completed, the other one can start.

[0045] The second problem addressed is related to the earlier proposals in 3GPP that the two logical mlAB-DUs may directly share certain configuration parameters, instead of sending the parameters via the two donors. However, if this is the case, it is unclear how these configuration parameters are shared between the two logical DUs.

[0046] The third problem addressed is related to the following agreement from RAN2#119- bis-e meeting:

[0047] ‘RAN2 focuses on the scenario where, during full migration, the UE sees the two logical DU cells as different physical cells (e.g. with different Physical Cell Identity (PCI) if same carrier), and where the two logical DU cells use separate physical resources (i.e., different carriers, or orthogonal time and frequency resources of the same carrier, as supported by legacy El).” [0048] According to the above agreement, to support full migration, the mobile IAB-MT needs to manage traffic that belongs to two different groups of UEs, and also to two DUs. This is because, during full migration, the first logical mlAB-DU (still serving some of the UEs) will be connected to the source donor CU, while the second logical mlAB-DU is connected to the target donor CU (at the same time serving the UEs that have already been handed over to the second donor). Fig. 4 illustrates such an example, where group 1 of UEs is connected to the source Donor CU and Group 2 of UEs is connected to the Target Donor CU.

[0049] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. For example, there is provided a method in a first CU (such as a source donor CU), for performing full migration. There is also provided a method in a first DU (such as mlAB- DU1) for performing full migration.

[0050] More particularly, a method in a first CU may comprise sending a first message to the first DU, the first message comprising an indication to start a migration procedure, wherein the indication includes parameters for setting up a Fl connection between the second DU and the second CU; and receiving a second message from the first DU, in response to the first message. [0051] A method in a first DU may comprise receiving a first message from the first CU, the first message comprising an indication to start a migration procedure, wherein the indication includes parameters for setting up a Fl connection between the second DU and the second CU; and sending a second message to the first CU, in response to the first message.

[0052] A network node may be also provided, the network node comprising a network interface and processing circuitry configured to perform either of the methods above. [0053] The methods and solutions proposed in the present disclosure allow:

[0054] - to provide indications from the source CU to the mobile IAB node that: 1) the mlAB-

DU migration should start; 2) the mlAB-DU migration has been completed (see Fig. 5A).

[0055] - to provide signalling from the source CU to support the direct sharing of configuration parameters between the two logical mlAB-DUs of the mlAB node.

[0056] - to provide internal mlAB node signalling between the two logical mlAB-DUs (see

Fig. 5B).

[0057] For example, an explicit or implicit signaling can be provided to indicate to the mobile IAB node to start/stop/end the migration.

[0058] Certain embodiments may provide one or more of the following technical advantage(s).

[0059] The methods and solutions proposed in the present disclosure ensure that there is coordination between logical DUs for the case when the mobile IAB-DU is relocating its Fl transmission from one CU to another. This will ensure a smooth transition from one CU to another when full migration is triggered with a clear definition on when the full migration starts and/or ends. Also, with these methods and solutions, interference is minimized, migration-related signalling is reduced, and resources are not wasted.

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Exemplary embodiments will be described in more detail with reference to the following figures, in which:

[0061] Fig. 1 illustrates a schematic example of an IAB architecture, with donor and child nodes.

[0062] Fig. 2 illustrates a schematic example of a Mobile lAB-Node which involves IntraDonor, Inter-Donor (same CU) and Inter CUs.

[0063] Fig. 3 illustrates an example of UE handover between cells pertaining to different logical lAB-DUs connected to separate CUs.

[0064] Fig. 4 illustrates an example of two groups of UEs served by two logical cells. The two logical cells are controlled by 2 DUs respectively with Fl connections to two donor CUs.

[0065] Fig. 5 A illustrates a signal diagram between a CU and a mobile-IAB for full migration, according to an embodiment.

[0066] Fig. 5B illustrates a signal diagram between a logical DU1 and logical DU2 for the full migration, according to an embodiment. [0067] Fig. 6 illustrates a signal diagram between a source CU, a target CU and a mobile IAB to perform a full migration of the mlAB from the source CU to the target CU, according to an embodiment.

[0068] Fig. 7 illustrates an example of a flow chart of a method in a CU (e.g. source donor CU), according to some embodiments.

[0069] Fig. 8 illustrates an example of a flow chart of a method in a network node (e.g. mlAB-

DU1), according to some embodiments.

[0070] Fig. 9 shows an example of a communication system, according to an embodiment.

[0071] Fig. 10 shows a schematic diagram of a UE, according to an embodiment.

[0072] Fig. 11 shows a schematic diagram of a network node, according to an embodiment.

[0073] Fig. 12 illustrates a block diagram of a host.

[0074] Fig. 13 illustrates a block diagram illustrating a virtualization environment.

[0075] Fig. 14 shows a communication diagram of a host.

DETAIEED DESCRIPTION

[0076] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0077] Now turning to Fig. 6, a signal diagram 10 between an mlAB node 12, a source CU 14 and a target CU 13 for performing a full migration of the mlAB node will be described. For example, the mlAB is to be migrated from the source CU 14 to the target CU 13. The migration of the mlAB-MT and mlAB-DU can be done separately/independently. In the full migration procedure, all the UEs connected to (served by) the mlAB are moved from the CU 14 to the CU 13. The UEs can be moved gradually, i.e. one group of UEs at the time, or all the UEs can be moved at the same time. In order to move the mlAB-DU, two logical mlAB-DUs are needed, i.e. a second mlAB-DU is created/generated. With the logical DUs, groups of UEs can be moved (see Fig. 4).

[0078] In step 15, the donor CU 14 serving as the CU serving the mlAB-MT and the CU serving the mlAB-DU coordinates about the migration of the entire mlAB node 12 or parts thereof (mlAB-MT and/or mlAB-DU) with the target CU 13, by exchanging messages, for example. It should be noted here that the mlAB-DU refers to the mlAB-DU before the mlAB-DU creates a second DU for migration purposes, for example. “Coordinate” may include or result in the decision that one or more of the following are to be executed:

[0079] 1) Only the mlAB-MT will be handed over to a target donor CU 13 and the mlAB-DU traffic will be forwarded between the CU 14 serving the mlAB-DU to the target donor for the mlAB-MT handover (HO). This implies that there is at least an active connection/network (e.g., IP connection) available between the target donor CU 13 and the CU 14 serving the mlAB-DU. [0080] 2) Both the mlAB-MT and mlAB-DU will be handed over, to the same or different target donor CUs 13. If the mlAB-MT is handed over first, as an intermediate step (between the mlAB-MT HO execution and mlAB-DU migration execution), the mlAB-DU traffic is temporarily forwarded between the source donor CU 14 of the mlAB-DU and the target donor for the mlAB-MT HO. Note that the target CUs 13 for the mlAB-DU migration and mlAB-MT HO may be the same or different. If the target donor CUs are different, once the mlAB-DU has also migrated, the mlAB-DU traffic is forwarded between the target CU serving the mlAB-DU and the target donor for the mlAB-MT HO.

[0081] Note that it is also possible to first migrate the mlAB-DU and then hand over the mlAB-MT (to the same or different donors). Between these two steps, it needs to be ensured that the traffic is forwarded between the donor CU serving the mlAB-DU at a certain time to the donor CU serving the mlAB-MT at that time.

[0082] The term full migration is used to refer to the scenario where both the mlAB-MT and mlAB-DU will be migrated.

[0083] In the above, traffic forwarding between the donor serving the mlAB-DU and the donor serving the mlAB-MT is enabled by means of XnAP IAB Transport Migration Management and IAB Transport Migration Modification procedures (with possible enhancements), for example.

[0084] It is also possible that the source CU for the mlAB-MT HO and the source CU for the mlAB-DU migration is the same CU.

[0085] Henceforth, it is assumed that the donor CU 14 determines that full migration will be executed, where the target donor CUs 13 for the mlAB-MT HO and mlAB-DU migration could be the same or different CUs. Note that, at this point, only the decision about executing the above migration is taken (by means of inter-donor coordination, for example in step 15), while the actual execution did not start yet. The decision may also include the “agreement” between the two donors about whether mlAB-MT HO or the mlAB-DU migration is to be executed first.

[0086] Optionally, in case the mlAB-MT HO is to be executed first, the source donor CU for the mlAB-DU migration is notified about this. Then, as mentioned earlier, XnAP IAB Transport Migration Management and IAB Transport Migration Modification procedures are used to temporarily forward the mlAB-DU traffic between the donor of the mlAB-DU and the donor of the mlAB-MT. Alternatively, the mlAB-DU migration may be executed first. Here the main aspect is that the mlAB-MT HO and mlAB-DU migration may be executed independently but the donor CU receiving the indication that one procedure has started/executed (e.g., the mlAB-MT HO or mlAB-DU migration) should delay the starting of the other procedure in order to not create race condition or collisions.

[0087] With respect to the previous step, at this point, it is time to execute the mlAB-DU migration, for example. Then, a second mlAB-DU (or logical DU) is created/generated. The second mlAB-DU is referred to as mIAB-DU2 and the “original” mlAB-DU becomes the first mlAB-DU (and referred to as mlAB-DUl). As such, during the migration process, an additional logical mlAB-DU will be created (herein referred to as the second logical mlAB-DU or mlAB- DU2). In step 25, the source donor CU 14 for the mlAB-DU migration sends to the first logical mlAB-DU (mlAB-DUl) a message that includes an indication of mlAB-DU migration start. In this case the indication can just be explicit or implicit. Also, the mlAB-DU that has a F 1 connection with the source donor is referred to as the first logical mlAB-DU or mlAB-DUl. It is assumed that, during the mlAB-DU migration, the forwarding of traffic between the first and the second logical mlAB-DUs and their respective donors is always ensured, regardless of where the mlAB- MT is connected at the given moment.

[0088] In step 20, the source CU 14 can send a message to the mlAB-MT to indicate the start of migration.

[0089] In step 27, the mlAB-DUl (or the first logical mlAB-DU) responds to the source donor CU, confirming or rejecting the request to start the mlAB-DU migration, for some reasons of capabilities, for example. The response can be also to indicate the status of the migration (e.g. see signalling examples below).

[0090] In step 30, the mlAB node establishes the second logical mlAB-DU (mIAB-DU2) and sets up a Fl connection from the second logical mlAB-DU to the target donor CU 13 for the mlAB-DU migration (step 35). Furthermore, certain configuration parameters are shared, in step 40, directly between the logical mlAB-DUs (mlAB-DU 1 and mIAB-DU2), as instructed by the source donor CU 14, for example. Fig. 5B illustrates a signalling diagram between mlAB-DUl and mIAB-DU2. For example, mlAB-DUl can send a message to mIAB-DU2 about the start of the migration. The indication of the start of the migration can be an implicit message . Uater, mlAB- DU1 can also send a message to mIAB-DU2 to indicate that the migration process is over or complete. The indication that the migration process is over or complete can be an implicit message. This interaction between mlAB-DU 1 and mIAB-DU2 can be left to implementation, for example. [0091] In step 45, the first logical mlAB-DU informs the source donor CU 14, via an explicit or implicit indication, that the second logical mlAB-DU has been established, and that the second logical mlAB-DU established an Fl connection with the target donor CU 13 and that the UE handover between the source and target donor CUs may start.

[0092] Then, the UEs are gradually handed over between the two logical mlAB-DUs - some UEs perform handover immediately thereafter, whereas some UEs are still served by source CU 14. The gradual handover means that a first group of UEs can be handed over first (e.g. through a group of HOs), followed by a second group of UEs and so on. In one embodiment, the handover of the UEs from the first logical DU (e.g. mlAB-DUl) to the second logical DU (e.g. mIAB-DU2) is explicitly indicated by the source CU to the UE, via e.g., the existing handover procedure. Optionally, all the UEs can be handed over at the same time.

[0093] In another embodiment, the handover of the UEs from the first logical DU to the second logical DU is implicitly indicated to the UEs.

[0094] In one example, the source CU 14 may reduce the transmitted power of the first logical DU and increase the transmitted power of the second logical DU. In this case, the UEs in RRC_CONNECTED will soon experience that the signal strength over the second logical DU is much stronger than the signal strength over the first logical DU and thus will trigger the sending of a measurement report to the source CU 14 (with the expectation of being handed over to the second logical DU). The UEs in RRC IDLE and RRC INACTIVE instead, will trigger a cell (re)selection procedure and they will (re)select the second logical DU as the cell to which performing a possible random access procedure (since the signal strength over the second logical DU is much stronger than the signal strength over the first logical DU).

[0095] In step 50, the source donor CU 14 for the mlAB-DU migration determines that all connected UEs have been handed over from the first to the second logical mlAB-DU.

[0096] In step 55, the source donor CU 14 for the mlAB-DU migration sends to the first logical mlAB-DU a message comprising an indication of the end of migration, implying that the source cell can be released. The indication may be explicit or implicit. An example of implicit indication is the presence/absence of some Information Elements (IES) in the message, based on which the mlAB-DU understands that the migration is over.

[0097] In step 60, the first logical mlAB-DU sends a response to the source donor CU 14 for the mlAB-DU migration, acting as instructed, for example, to acknowledge the receipt of the end migration instruction or to respond that the mlAB-DU 1 has ended the migration.

[0098] In step 65, the first logical mlAB-DU releases its connection to the source donor CU 14, since all the UEs are migrated to CU 13.

[0099] Further details of the different steps in Fig. 6 are provided below. [0100] In step 25, the source donor CU 14 for the mlAB-DU migration sends to the first logical mlAB-DU a message comprising an indication of mlAB-DU migration start. The indication may be explicit. For example, the indication can be carried by a specific field/structure/IE that indicates that the state of the migration is set to “start”, “ON”, “enabled”, “activated”, or any other terms that indicate that the migration is (or is going to) start. For example, Fig. 5A shows a signaling diagram between CU 14 and the mlAB IAB, in which the CU 14 sends explicitly a message to indicate the start and/or end of the migration to the mobile IAB.

[0101] Alternatively, the indication may be also implicit. Examples of an implicit indication may the presence/absence of some IES in the message, based on which the first logical mlAB-DU understands that the migration is starting. Some detailed non-limiting examples of parameters whose presence implicitly indicates that the mlAB-DU migration is starting are:

[0102] - Parameters for setting up the F 1 connection between the second logical mlAB-DU and the target donor (e.g., Transport Network Layer addresses of target donor and second logical mlAB-DU, Stream Control Transmission Protocol (SCTP) and IPsec-related parameters, etc.) [0103] - The indication of parameters that are to be shared with the second logical mlAB-DU as discussed hereinbelow.

[0104] The meaning of the “migration start” indication (explicit or implicit) may be one of the following options:

[0105] - In one example, the meaning of the indication is that mlAB-DU 1 should establish the second logical mlAB-DU, and optionally, wait for further instructions.

[0106] - In another example, the instruction is to establish the second logical mlAB-DU and establish the Fl connection to the target donor mlAB-DU.

[0107] - In one example, the first logical mlAB-DU is also instructed to notify the source donor CU when the Fl between the second logical mlAB-DU and the target donor CU has been established.

[0108] In step 55, the source donor CU 14 for the mlAB-DU migration sends to the first logical mlAB-DU a message comprising an indication of mlAB-DU migration end. The indication can be explicit or implicit. In case of explicit indication, the indication can be carried by a specific field/structure/IE that indicates that the state of the migration is set to “stop”, “OFF”, “disabled”, “deactivated”, or any other term that indicates that the migration is (or is going to) stop. In case of implicit indication, an example of implicit indication can be the presence/absence of some IEs in the message, based on which the first logical mlAB-DU understands that the migration is ending. Some detailed non-limiting examples are:

[0109] - An indication that all the UEs have been handed over to the target donor CU 13. [0110] - An Fl REMOVAL REQUEST MESSAGE, where the source donor CU 14 requests the removal of Fl connection with the first logical mlAB-DU.

[oni] The meaning of the “migration end” indication in step 55 (explicit or implicit) may be one of the following options:

[0112] - In one variant, the meaning of the indication is that first logical mlAB-DU should initiate the Fl connection release towards the source donor CU.

[0113] In step 25, the message may also contain an indication of which configuration parameters are to be shared directly from the first logical mlAB-DU to the second logical mlAB- DU (see step 40). So, the source donor CU indicates to the mlAB-DUl which configuration parameters the mlAB-DUl should share with the second logical mIAB-DU2.

[0114] For example, the parameters to be shared are indicated in the form of a bitmap, where each bit corresponds to a configuration parameter, and the bit value “1” indicates that the parameter should be shared with the second logical mlAB-DU, while the bit value “0” indicates that this parameter should not be shared or it can be vice-versa.

[0115] In one variant, the parameter to be shared are explicitly indicated in a separate structure, sequence, or information element.

[0116] In one variant, the parameters are shared between the first logical DU and the second logical DU via the XnAP interface.

[0117] In one variant, the parameters are shared between the first logical DU and the second logical DU via a direct interface (proprietary or non-3GPP specific) that enables a connection between the logical DUs.

[0118] In one variant, the CU 14 creates a duplicate of the configuration parameters that need to be shared between the first logical DU and second logical DU and send one copy to a DU (e.g. mlAB-DUl) and one copy to the other DU (e.g. mIAB-DU2) when the Fl connection is established with the first logical DU and the second logical DU.

[0119] Examples of parameters shared between the logical mlAB-DUs are:

[0120] - Cell-level resource configuration parameters, such as new Physical Cell Identities

(PCIs), Time Division Duplexing (TDD) slot patterns, Synchronization Signal Block (SSB)- related parameters;

[0121] - UE contexts;

[0122] - The number of served UEs;

[0123] - Backhaul Adaptation Protocol (BAP) configurations;

[0124] - TNL address configurations;

[0125] - Backhaul (BH) Radio link control (RLC) channel configurations; [0126] - Backhaul mapping for UL traffic;

[0127] - Default BAP and mlAB-MT configurations.

[0128] Signaling Examples

[0129] Below is an example of signalling from a CU (e.g. source CU 14) to a Mobile-IAB- DU via FlAP .

[0130] NOTE: the example below is a general one, where different interpretations of the indication have been discussed above. The example assumes a newly defined F1AP signalling, but the solution proposed herein can be implementing by enhancing the existing signalling as well.

9.2.9.x IAB-DU MIGRATION STATUS REQUEST This message is sent by the gNB-CU to indicate to the mlAB-DU that the mlAB-DU should start inter-donor migration, or that the migration is completed, as well as the configurations to be shared between the recipient and the second logical mlAB-DU.

Direction: gNB-CU - gNB-DU. 9.2.9.x IAB-DU MIGRATION STATUS RESPONSE

This message is sent by the gNB-DU to indicate the status of mlAB-DU migration Direction: gNB-DU - gNB-CU.

[0131] Signaling (Message Exchange) between two logical DUs

[0132] Apart from the start signaling (to set the new logical DU operational), other parameters that can be exchanged are current configurations of the cell/Transmission Reception Point (TRP) that belongs to logical DU1 such as:

[0133] - Cell resource (Bandwidth; Active (Utilized) Physical Resource Blocks);

[0134] - Transmission Power;

[0135] - Radio bearer configuration (e.g., RadioBearerConfig IE);

[0136] - Cell group configuration (e.g., CellGroupConfig IE);

[0137] - Measurement configuration;

[0138] - SSB configuration;

[0139] - TCI state configuration;

[0140] - BWP(s) configuration.

[0141] Fig. 7 is a flow chart of a method 100, performed in a network node (e.g. source CU 14) for performing a full migration of a mobile IAB node. The mlAB node can be the mlAB node 12 of Fig. 6 and comprises a mlAB-MT and two logical DUs (mlAB-DUl and mIAB-DU2). Method 100 comprises:

[0142] Step 110: Sending a first message to the first DU, the first message comprising an indication to start a migration procedure, wherein the indication includes parameters for setting up a Fl connection between the second DU and the second CU; and

[0143] Step 120: Receiving a second message from the first DU, in response to the first message.

[0144] In some examples, the source CU may send a third message to the first DU, the third message comprising an indication to end the migration procedure. In some examples, the second message may indicate a status of the migration procedure. In some examples, the source CU may send a fourth message to the MT, the fourth message comprising an indication to start a migration procedure of the MT from the first CU to the second CU. In some examples, the migration procedure may be to migrate the first DU from the first CU to the second CU. In some examples, the first CU can coordinate with the second CU for the migration procedure. In some examples, the first message may further comprise an indication of configuration parameters to be shared between the first DU and the second DU. In some examples, the indication can be in a form of a bitmap, where each bit corresponds to a configuration parameter. In some examples, the source CU can create duplicates of the configuration parameters that need to be shared and sending a first copy to the first DU and a second copy to the second DU. In some examples, the first message is sent to the first DU via F1AP. In some examples, the source DU determines that all UEs or a first group of UEs connected to the first DU are migrated to the second DU. Optionally, the migration or handover of the UEs can be done gradually, e.g. a first group of UEs is migrated, then a second group of UEs can be migrated. In some examples, the third message is sent in response to determining that all the UEs or a first group of UEs connected to the first DU are migrated to the second DU. In some examples, the source CU can send a fifth message to UEs connected to the first DU to indicate a handover. In some examples, the source CU can receive a sixth message from the first DU, the message comprising an indication that the second DU has established a Fl connection with the second CU and that UE handover can start.

[0145] Now turning to Fig. 8, flow chart of a method 200 in a network node, such as a first DU, such as mlAB DU1, for performing a migration (e.g. full migration) in the same context as method 100 will be described. Method 200 comprises:

[0146] Step 210: Receiving a first message from the first CU, the first message comprising an indication to start a migration procedure, wherein the indication includes parameters for setting up a Fl connection between the second DU and the second CU; and

[0147] Step 220: sending a second message to the first CU, in response to the first message.

[0148] In some examples, the first DU may receive a third message from the first CU, the third message comprising an indication to stop/end the migration procedure. In some examples, the first DU may set up or establish the second DU. In some examples, the migration procedure is to migrate the first DU from the first CU to the second CU. In some examples, the first message further comprises an indication of configuration parameters to be shared between the first DU and the second DU. In some examples, the first DU sends an indication of configuration parameters to be shared to the second DU. In some examples, the indication is in a form of a bitmap, where each bit corresponds to a configuration parameter. In some examples, the indication is sent via XnAP interface or a direct interface. In some examples, the second message indicates a status of the migration procedure. In some examples, the first message is received by the first DU via F1AP. In some examples, the first DU sends a fourth message to the first CU, the fourth message comprising an indication of performing the migration procedure. In some examples, the first DU releases a connection with the first CU. In some examples, the first DU and second DU are logical DUs. In some examples, the first DU sends a fifth message to the first CU, the fifth message comprising an indication that the second DU has established a Fl connection with the first CU and that UE handover can start.

[0149] Fig. 9 shows an example of a communication system 900 in accordance with some embodiments.

[0150] In the example, the communication system 900 includes a telecommunication network 902 that includes an access network 904, such as a radio access network (RAN), and a core network 906 (corresponding to CN 8 of Fig. 1), which includes one or more core network nodes 908. The access network 904 includes one or more access network nodes, such as network nodes 910a and 910b (one or more of which may be generally referred to as network nodes 910), or any other similar 3GPP access node or non-3GPP access point. The network nodes 910 facilitate direct or indirect connection of UE, such as by connecting UEs 912a, 912b, 912c, and 912d (one or more of which may be generally referred to as UEs 912) to the core network 906 over one or more wireless connections. Furthermore, the network node 910 can be a source DU 14, target CU 13, a mlAB node 12 as shown in Fig. 6.

[0151] 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 900 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 900 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

[0152] The UEs 912 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 910 and other communication devices. Similarly, the network nodes 910 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 912 and/or with other network nodes or equipment in the telecommunication network 902 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 902.

[0153] In the depicted example, the core network 906 connects the network nodes 910 to one or more hosts, such as host 916. 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 906 includes one more core network nodes (e.g., core network node 908) 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 908. 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 (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

[0154] The host 916 may be under the ownership or control of a service provider other than an operator or provider of the access network 904 and/or the telecommunication network 902, and may be operated by the service provider or on behalf of the service provider. The host 916 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.

[0155] As a whole, the communication system 900 of Fig. 9 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 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, 5G standards, or any applicable future generation standard (e.g., 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.

[0156] In some examples, the telecommunication network 902 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 902 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 902. For example, the telecommunications network 902 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)ZMassive loT services to yet further UEs.

[0157] In some examples, the UEs 912 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 904 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 904. 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 Wi-Fi, NR and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0158] In the example, the hub 914 communicates with the access network 904 to facilitate indirect communication between one or more UEs (e.g., UE 912c and/or 912d) and network nodes (e.g., network node 910b). In some examples, the hub 914 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 914 may be a broadband router enabling access to the core network 906 for the UEs. As another example, the hub 914 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 910, or by executable code, script, process, or other instructions in the hub 914. As another example, the hub 914 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 914 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 914 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 914 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 914 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.

[0159] The hub 914 may have a constant/persistent or intermittent connection to the network node 910b. The hub 914 may also allow for a different communication scheme and/or schedule between the hub 914 and UEs (e.g., UE 912c and/or 912d), and between the hub 914 and the core network 906. In other examples, the hub 914 is connected to the core network 906 and/or one or more UEs via a wired connection. Moreover, the hub 914 may be configured to connect to an M2M service provider over the access network 904 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 910 while still connected via the hub 914 via a wired or wireless connection. In some embodiments, the hub 914 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 910b. In other embodiments, the hub 914 may be a nondedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 910b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

[0160] Fig. 10 shows a UE 1000 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 IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, 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 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

[0161] 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).

[0162] The UE 1000 includes processing circuitry 1002 that is operatively coupled via a bus 1004 to an input/output interface 1006, a power source 1008, a memory 1010, a communication interface 1012, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Fig. 10. 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. [0163] The processing circuitry 1002 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 1010. The processing circuitry 1002 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 1002 may include multiple central processing units (CPUs). For example, the processing circuitry 1002 is configured to perform any actions/operations/blocks of a UE.

[0164] In the example, the input/output interface 1006 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 1000. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, atrackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0165] In some embodiments, the power source 1008 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 1008 may further include power circuitry for delivering power from the power source 1008 itself, and/or an external power source, to the various parts of the UE 1000 via input circuitry or an interface such as an electrical power cable . Delivering power may be, for example, for charging of the power source 1008. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 1008 to make the power suitable for the respective components of the UE 1000 to which power is supplied.

[0166] The memory 1010 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 1010 includes one or more application programs 1014, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1016. The memory 1010 may store, for use by the UE 1000, any of a variety of various operating systems or combinations of operating systems.

[0167] The memory 1010 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 random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and/or 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 ‘SIM card.’ The memory 1010 may allow the UE 1000 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 1010, which may be or comprise a device-readable storage medium.

[0168] The processing circuitry 1002 may be configured to communicate with an access network or other network using the communication interface 1012. The communication interface 1012 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1022. The communication interface 1012 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 1018 and/or a receiver 1020 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 1018 and receiver 1020 may be coupled to one or more antennas (e.g., antenna 1022) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0169] In the illustrated embodiment, communication functions of the communication interface 1012 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, near-field communication, 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 in according to one or more communication protocols and/or standards, such as IEEE 802. 11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol/intemet protocol (TCP/IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0170] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1012, 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. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient). [0171] A UE, when in the form of an Internet of Things (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 TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, , an industrial robot, 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 1000 shown in Fig. 10.

[0172] 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, such 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 and an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

[0173] 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.

[0174] Fig. 11 shows a network node 1100 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, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs (NBs), evolved NBs (eNBs) and NRNBs (gNBs)), mlAB nodes, IAB doner CU, a mlAB-DU.

[0175] Base stations 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 base stations, pico base stations, micro base stations, or macro base stations. A base station 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 base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0176] 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 base station 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).

[0177] The network node 1100 includes a processing circuitry 1102, a memory 1104, a communication interface 1106, and a power source 1108. The network node 1100 may be composed of multiple physically separate components (e.g., a NodeB component and a 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 1100 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 NBs. In such a scenario, each unique NB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 1100 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1104 for different RATs) and some components may be reused (e.g., a same antenna 1110 may be shared by different RATs). The network node 1100 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1100, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z- wave, 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 network node 1100.

[0178] The processing circuitry 1102 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, 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 1100 components, such as the memory 1104, to provide network node 1100 functionality. For example, the processing circuitry 1102 is configured to perform any actions/operations of method 100 of Fig. 7, when the network node is a donor CU. For example, the processing circuitry 1102 is further configured to perform any actions/operations of method 200 of Fig. 8, when the network node is a mlAB-DU.

[0179] In some embodiments, the processing circuitry 1102 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1102 includes one or more of radio frequency (RF) transceiver circuitry 1112 and baseband processing circuitry 1114. In some embodiments, the radio frequency (RF) transceiver circuitry 1112 and the baseband processing circuitry 1114 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 RF transceiver circuitry 1112 and baseband processing circuitry 1114 may be on the same chip or set of chips, boards, or units.

[0180] The memory 1104 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, random access memory (RAM), read-only memory (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 1102. The memory 1104 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 1102 and utilized by the network node 1100. The memory 1104 may be used to store any calculations made by the processing circuitry 1102 and/or any data received via the communication interface 1106. In some embodiments, the processing circuitry 1102 and memory 1104 is integrated.

[0181] The communication interface 1106 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 1106 comprises port(s)/terminal(s) 1116 to send and receive data, for example to and from a network over a wired connection. The communication interface 1106 also includes radio front-end circuitry 1118 that may be coupled to, or in certain embodiments a part of, the antenna 1110. Radio front-end circuitry 1118 comprises filters 1120 and amplifiers 1122. The radio front-end circuitry 1118 may be connected to an antenna 1110 and processing circuitry 1102. The radio front-end circuitry may be configured to condition signals communicated between antenna 1110 and processing circuitry 1102. The radio front-end circuitry 1118 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio frontend circuitry 1118 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1120 and/or amplifiers 1122. The radio signal may then be transmitted via the antenna 1110. Similarly, when receiving data, the antenna 1110 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1118. The digital data may be passed to the processing circuitry 1102. In other embodiments, the communication interface may comprise different components and/or different combinations of components.

[0182] In certain alternative embodiments, the network node 1100 does not include separate radio front-end circuitry 1118, instead, the processing circuitry 1102 includes radio front-end circuitry and is connected to the antenna 1110. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1112 is part of the communication interface 1106. In still other embodiments, the communication interface 1106 includes one or more ports or terminals 1116, the radio front-end circuitry 1118, and the RF transceiver circuitry 1112, as part of a radio unit (not shown), and the communication interface 1106 communicates with the baseband processing circuitry 1114, which is part of a digital unit (not shown).

[0183] The antenna 1110 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 1110 may be coupled to the radio front-end circuitry 1118 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 1110 is separate from the network node 1100 and connectable to the network node 1100 through an interface or port.

[0184] The antenna 1110, communication interface 1106, and/or the processing circuitry 1102 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, the antenna 1110, the communication interface 1106, and/or the processing circuitry 1102 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.

[0185] The power source 1108 provides power to the various components of network node 1100 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1108 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1100 with power for performing the functionality described herein. For example, the network node 1100 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1108. As an example, the power source 1108 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.

[0186] Embodiments of the network node 1100 may include additional components beyond those shown in Fig. 11 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 1100 may include user interface equipment to allow input of information into the network node 1100 and to allow output of information from the network node 1100. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1100.

[0187] Fig. 12 is a block diagram of a host 1200, which may be an embodiment of the host 916 of Fig. 9, in accordance with various aspects described herein. As used herein, the host 1200 may be or comprise various combinations 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 1200 may provide one or more services to one or more UEs. [0188] The host 1200 includes processing circuitry 1202 that is operatively coupled via a bus 1204 to an input/output interface 1206, a network interface 1208, a power source 1210, and a memory 1212. 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 Figs. 10 and 11, such that the descriptions thereof are generally applicable to the corresponding components of host 1200.

[0189] The memory 1212 may include one or more computer programs including one or more host application programs 1214 and data 1216, which may include user data, e.g., data generated by a UE for the host 1200 or data generated by the host 1200 for a UE. Embodiments of the host 1200 may utilize only a subset or all of the components shown. The host application programs 1214 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), MPEG, VP9) and audio codecs (e.g., 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, heads-up display systems). The host application programs 1214 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 1200 may select and/or indicate a different host for over-the-top services for a UE. The host application programs 1214 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 (MPEG-DASH), etc.

[0190] Fig. 13 is a block diagram illustrating a virtualization environment 1300 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 1300 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. [0191] Applications 1302 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

[0192] Hardware 1304 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 1306 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1308a and 1308b (one or more of which may be generally referred to as VMs 1308), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. The virtualization layer 1306 may present a virtual operating platform that appears like networking hardware to the VMs 1308.

[0193] The VMs 1308 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1306. Different embodiments of the instance of a virtual appliance 1302 may be implemented on one or more of VMs 1308, 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.

[0194] In the context of NFV, a VM 1308 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 1308, and that part of hardware 1304 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs, 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 1308 on top of the hardware 1304 and corresponds to the application 1302.

[0195] Hardware 1304 may be implemented in a standalone network node with generic or specific components. Hardware 1304 may implement some functions via virtualization. Alternatively, hardware 1304 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 1310, which, among others, oversees lifecycle management of applications 1302. In some embodiments, hardware 1304 is coupled to one or more radio units that each include one or more transmiters 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 radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1312 which may alternatively be used for communication between hardware nodes and radio units.

[0196] Fig. 14 shows a communication diagram of a host 1402 communicating via a network node 1404 with a UE 1406 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 912a of Fig. 9 and/or UE 1000 of Fig. 10), network node (such as network node 910a of Fig. 9 and/or network node 1100 of Fig. 11), and host (such as host 916 of Fig. 9 and/or host 1200 of Fig. 12) discussed in the preceding paragraphs will now be described with reference to Fig. 14.

[0197] Like host 1200, embodiments of host 1402 include hardware, such as a communication interface, processing circuitry, and memory. The host 1402 also includes software, which is stored in or accessible by the host 1402 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 1406 connecting via an over-the-top (OTT) connection 1450 extending between the UE 1406 and host 1402. In providing the service to the remote user, a host application may provide user data which is transmited using the OTT connection 1450. The network node 1404 includes hardware enabling it to communicate with the host 1402 and UE 1406. The connection 1460 may be direct or pass through a core network (e.g. core network 906 of Fig. 9) and/or one or more other intermediate networks, e.g. one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

[0198] The UE 1406 includes hardware and software, which is stored in or accessible by UE 1406 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 UE 1406 with the support of the host 1402. In the host 1402, an executing host application may communicate with the executing client application via the OTT connection 1450 terminating at the UE 1406 and host 1402. 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 1450 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 1450. [0199] The OTT connection 1450 may extend via a connection 1460 between the host 1402 and the network node 1404 and via a wireless connection 1470 between the network node 1404 and the UE 1406 to provide the connection between the host 1402 and the UE 1406. The connection 1460 and wireless connection 1470, over which the OTT connection 1450 may be provided, have been drawn abstractly to illustrate the communication between the host 1402 and the UE 1406 via the network node 1404, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

[0200] As an example of transmitting data via the OTT connection 1450, in step 1408, the host 1402 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 1406. In other embodiments, the user data is associated with a UE 1406 that shares data with the host 1402 without explicit human interaction. In step 1410, the host 1402 initiates a transmission carrying the user data towards the UE 1406. The host 1402 may initiate the transmission responsive to a request transmitted by the UE 1406. The request may be caused by human interaction with the UE 1406 or by operation of the client application executing on the UE 1406. The transmission may pass via the network node 1404, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1412, the network node 1404 sends to the UE 1406 the user data that was carried in the transmission that the host 1402 initiated, according to the teachings of the embodiments in this disclosure. In step 1414, the UE 1406 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1406 associated with the host application executed by the host 1402.

[0201] In some examples, the UE 1406 executes a client application which provides user data to the host 1402. The user data may be provided in reaction or response to the data received from the host 1402. Accordingly, in step 1416, the UE 1406 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 1406. Regardless of the specific manner in which the user data was provided, the UE 1406 initiates, in step 1418, transmission of the user data towards the host 1402 via the network node 1404. In step 1420, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1404 receives user data from the UE 1406 and initiates transmission of the received user data towards the host 1402. In step 1422, the host 1402 receives the user data carried in the transmission initiated by the UE 1406.

[0202] One or more of the various embodiments improve the performance of OTT services provided to the UE 1406 using the OTT connection 1450, in which the wireless connection 1470 forms the last segment. More precisely, the teachings of these embodiments may improve the, e.g., data rate, latency, power consumption and thereby provide benefits such as, e.g., reduced user waiting time, relaxed restriction on file size, improved content resolution, better responsiveness, extended battery lifetime.

[0203] In an example scenario, factory status information may be collected and analyzed by the host 1402. As another example, the host 1402 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1402 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1402 may store surveillance video uploaded by a UE. As another example, the host 1402 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 1402 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.

[0204] 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 1450 between the host 1402 and UE 1406, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host 1402 and/or UE 1406. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1450 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1450 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node 1404. 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 1402. The measurements may be implemented in that software causes messages to be transmitted, e.g. in empty or ‘dummy’ messages, using the OTT connection 1450 while monitoring propagation times, errors, etc.

[0205] 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.

[0206] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on 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 hard-wired 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.

[0207] The above-described embodiments are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the description.