Systems and methods and apparatus for inter-host migration

Abstract

Systems, methods, devices, or computer-readable media and devices for inter-host migration are presented. A first network node may send information associated with an integrated access and backhaul (IAB) related migration to a second network node.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications, including but not limited to systems and methods and apparatus for inter-host migration. Background Art

[0002] The third generation partnership project (3GPP), a standardization organization, is currently in the process of specifying a new radio interface called 5G New Radio (5G NR) and the next generation packet core network (NG-CN or NGC). 5G NR will have three main components: 5G access network (5G-AN), 5G core network (5GC) and user equipment (UE). To facilitate enabling different data services and requirements, the elements of 5GC (also called network functions) have been simplified, some of which are software-based so that they can be adapted as needed. Summary of the invention

[0003] The exemplary embodiments disclosed herein are intended to solve problems related to one or more problems existing in the prior art, and to provide additional features that will become apparent by reference to the following detailed description in conjunction with the accompanying drawings. According to various embodiments, example systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not by way of limitation, and a person skilled in the art who reads this disclosure will understand that various modifications may be made to the disclosed embodiments while still being within the scope of this disclosure.

[0004] At least one aspect relates to a system, method, apparatus, or computer-readable medium and apparatus for inter-host migration. A first network node may transmit / send to a second network node information associated with an integrated access and backhaul (IAB)-related migration.

[0005] In some implementations, a first network node including a source host may send information to a second network node including a target host. The information may include at least one of: an indication of a distributed unit (DU) migration, a counter value of a mobile termination (MT) migration process, or an identification of a third network node having an F1 connection with the IAB-DU. In some implementations, the method may include determining (e.g., by the source host or the target host) whether to perform a DU or user equipment (UE) migration based on the information. The method may include sending an indication to the third network node whether to perform a DU or UE migration.

[0006] In some implementations, the method may include determining whether to perform DU or user equipment (UE) migration by comparing a counter value with a threshold number of MT migration procedures (e.g., operations / procedures on / for MT migration). In some implementations, the threshold number of MT migration procedures may be sent to: at least one of a source host or a target host, or an IAB node.

[0007] In some implementations, a first network node including a source host of an IAB node or an IAB-MT or a source host of a user equipment (UE) may send information to a second network node including a target host. The information may include IP address request information or an indication of a migration type. In some implementations, the method / apparatus / computer-readable medium may involve at least one of the following: the IP address request message may include at least one of the following: the number of IP addresses for the IAB node, or an indicator of two groups of IP addresses; or, the indication of the migration type may include at least one of the following: partial migration, full migration, distributed unit (DU) migration, user equipment (UE) migration, or F1 transport migration.

[0008] In some implementations, the first network node may send information to the second network node via a radio resource control (RRC) message, an F1 application protocol (F1AP) message, or an Xn application protocol (XnAP) message. In some implementations, the first network node including a host centralized unit (CU) may send information to the second network node including an IAB node. The information may include at least one of an F1 setup indication, a source logical DU indication, a target logical DU indication, a target host IP address, a new IAB host indication, a type of migration type, or one or more backhaul adaptation protocol (BAP) addresses, the F1 setup indication indicating to the IAB node that an F1 setup process is initiated, the source logical DU indication indicating that the associated information is for a source logical DU, the target logical DU indication indicating that the associated information is for a target logical DU, the target host IP address indication indicating an IP address of a target host, the new IAB host indication indicating that the associated information is for a new IAB host, and the migration type including at least one of partial migration, full migration, distributed unit (DU) migration, user equipment (UE) migration, or F1 transport migration.

[0009] In some implementations, the first network node may send information to the second network node via a radio resource control (RRC) message or an F1 application protocol (F1AP) message. In some implementations, one of the following is included: the first network node including the first IAB host may send information to the second network node including the second IAB host; or the first network node including the IAB node may send information to the second network node including the second IAB host.

[0010] In some implementations, the information may include at least one of: an identification of an IAB node, an identification of a target host, an identification of a target cell, an indication of an IAB mobile termination (IAB-MT) migration, an indication of an IAB distributed unit (IAB-DU) migration, or an indication of a user equipment (UE) migration. In some implementations, one of the following is included: a first network node including an IAB node may send information to a second network node including a second IAB host; or a first network node including a first IAB host may send information to a second network node including a second IAB host; or a first network node including a target host may send information to a second network node including a source host. The source host may send the information to the initial host. In some implementations, the information may include an old or source cell identifier (ID) of a distributed unit (DU) of the IAB node, and a new or target cell ID of the DU.

[0011] At least one aspect relates to a system, method, apparatus, or computer-readable medium and apparatus for inter-host migration. A second network node may receive / obtain / acquire / collect information associated with an integrated access and backhaul (IAB)-related migration from a first network node. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Various example embodiments of the present solution are described in detail below with reference to the accompanying drawings. The accompanying drawings are provided for illustrative purposes only and only describe example embodiments of the present solution to facilitate the reader's understanding of the present solution. Therefore, the accompanying drawings should not be considered as limiting the breadth, scope or applicability of the present solution. It should be noted that for clarity and ease of description, these drawings are not necessarily drawn to scale.

[0013] Figure 1 An example cellular communication network is shown in which the techniques disclosed herein may be implemented according to an embodiment of the present disclosure;

[0014] Figure 2 A block diagram showing example base station and user equipment apparatus according to some embodiments of the present disclosure is shown;

[0015] Figure 3 shows a block diagram of an environment for mobile integrated access and backhaul (IAB) according to an illustrative embodiment;

[0016] Figure 4A shows a block diagram of an integrated access and backhaul (IAB) architecture using a standalone (SA) mode with a next generation core (NGC) in accordance with an illustrative embodiment;

[0017] Figure 4Bshows a block diagram of an Integrated Access and Backhaul (IAB) architecture using Evolved Universal Mobile Telecommunications System New Radio (EN-DC) in accordance with an illustrative embodiment;

[0018] Figure 5 shows a block diagram of an integrated access and backhaul (IAB) node in a parent and child relationship in accordance with an illustrative embodiment;

[0019] Fig. 6A A block diagram of an integrated access and backhaul (IAB) mobile termination (MT) migrating from a first host distributed unit (DU1) of a first centralized unit (CU1) to a second host distributed unit (DU2) of a second host centralized unit (CU2) is shown in accordance with an illustrative embodiment;

[0020] Figure 6B A block diagram showing an integrated access and backhaul (IAB) mobile termination (MT) migrating from a second host distributed unit (DU2) of a second host centralized unit (CU2) to a third host distributed unit (DU3) of a third host centralized unit (CU3) in accordance with an illustrative embodiment;

[0021] Figure 6C A block diagram showing an integrated access and backhaul (IAB) distributed unit (DU) migrating from a first host centralized unit (CU1) to a third host centralized unit (CU3) according to an illustrative embodiment; and

[0022] Figure 7 A flow chart of a method and apparatus for inter-host migration is shown in accordance with an illustrative embodiment. DETAILED DESCRIPTION

[0023] Various example embodiments of the present solution are described below with reference to the accompanying drawings to enable those of ordinary skill in the art to make and use the present solution. It is obvious to those of ordinary skill in the art that, after reading this disclosure, various changes or modifications may be made to the examples described herein without departing from the scope of the present solution. Therefore, the present solution is not limited to the exemplary embodiments and applications described and shown herein. In addition, the specific order or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes may be rearranged while remaining within the scope of the present solution. Therefore, it will be understood by those of ordinary skill in the art that the methods and techniques disclosed herein present various steps or actions in a sample order, and that the present solution is not limited to the specific order or hierarchy presented unless otherwise expressly stated.

[0024] 1. Mobile communication technology and environment

[0025] Figure 1An example wireless communication network and / or system 100 is shown in which the techniques disclosed herein may be implemented according to an embodiment of the present disclosure. In the following discussion, the wireless communication network 100 may be any wireless network, such as a cellular network or a narrowband Internet of Things (NB-IoT) network, and is referred to herein as "network 100". This example network 100 includes a base station 102 (hereinafter referred to as "BS 102"; also referred to as a wireless communication node) and a user equipment device 104 (hereinafter referred to as "UE 104"; a wireless communication device that can communicate with a cluster of cells 126, 130, 132, 134, 136, 138 and 140 covering a geographic area 101 via a communication link 110 (e.g., a wireless communication channel). In Figure 1 1 , BS 102 and UE 104 are contained within respective geographic boundaries of cell 126. Each of the other cells 130, 132, 134, 136, 138, and 140 may include at least one base station operating on its allocated bandwidth to provide adequate radio coverage to its intended users.

[0026] For example, BS 102 can operate on the allocated channel transmission bandwidth to provide sufficient coverage to UE 104. BS 102 and UE 104 can communicate via downlink radio frame 118 and uplink radio frame 124, respectively. Each radio frame 118 / 124 can be further divided into subframes 120 / 127 that can include data symbols 122 / 128. In the present disclosure, BS 102 and UE 104 are described here as non-limiting examples of "communication nodes", which can practice the methods disclosed herein. According to various embodiments of the present solution, such communication nodes can perform wireless and / or wired communication.

[0027] Figure 2 A block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM / OFDMA signals) according to some embodiments of the present solution is shown. System 200 may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one illustrative embodiment, as described above, system 200 may be used in applications such as Figure 1 Data symbols are communicated (eg, sent and received) in a wireless communication environment 100 of the wireless communication environment.

[0028] System 200 generally includes a base station 202 (hereinafter referred to as "BS 202") and a user equipment device 204 (hereinafter referred to as "UE 204"). BS 202 includes a BS (base station) transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each of which is coupled to and interconnected with each other via a data communication bus 220 as needed. UE 204 includes a UE (user equipment) transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each of which is coupled to and interconnected with each other via a data communication bus 240 as needed. BS 202 communicates with UE 204 via a communication channel 250, which can be any wireless channel or other medium suitable for data transmission as described herein.

[0029] As will be appreciated by those skilled in the art, the system 200 may also include Figure 2 Any number of modules other than the modules shown. Those skilled in the art will appreciate that the various illustrative blocks, modules, circuits, and processing logic described in conjunction with the embodiments disclosed herein may be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. In order to clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps are generally described in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software may depend on the specific application and the design constraints imposed on the overall system. A technician familiar with the concepts described herein may implement such functionality in an appropriate manner for each specific application, but such implementation decisions should not be interpreted as limiting the scope of the invention.

[0030] According to some embodiments, the UE transceiver 230 may be referred to herein as an "uplink" transceiver 230, which includes a radio frequency (RF) transmitter and an RF receiver, each including circuitry coupled to an antenna 232. A duplex switch (not shown) may optionally couple the uplink transmitter or receiver to the uplink antenna in a time duplex manner. Similarly, according to some embodiments, the BS transceiver 210 may be referred to herein as a "downlink" transceiver 210, which includes an RF transmitter and an RF receiver, each including circuitry coupled to an antenna 212. A downlink duplex switch may optionally couple the downlink transmitter or receiver to the downlink antenna 212 in a time duplex manner. The operation of the two transceiver modules 210 and 230 may be coordinated in time such that the uplink receiver circuit is coupled to the uplink antenna 232 for receiving transmissions on the wireless transmission link 250 while the downlink transmitter is coupled to the downlink antenna 212. Instead, the operation of the two transceivers 210 and 230 may be coordinated in time such that the downlink receiver is coupled to the downlink antenna 212 for receiving transmissions on the wireless transmission link 250 at the same time as the uplink transmitter is coupled to the uplink antenna 232. In some embodiments, there is tight time synchronization with minimal guard times between changes in duplex direction.

[0031] The UE transceiver 230 and the base station transceiver 210 are configured to communicate via a wireless data communication link 250 and cooperate with an appropriately configured RF antenna device 212 / 232, which can support specific wireless communication protocols and modulation schemes. In some illustrative embodiments, the UE transceiver 210 and the base station transceiver 210 are configured to support industrial standards such as long-term evolution (LTE) and emerging 5G standards. However, it should be understood that the application of the present disclosure is not necessarily limited to specific standards and related protocols. Instead, the UE transceiver 230 and the base station transceiver 210 can be configured to support alternative or additional wireless data communication protocols, including future standards or variants thereof.

[0032] According to various embodiments, BS 202 may be, for example, an evolved Node B (eNB), a serving eNB, a target eNB, a femto base station, or a pico base station. In some embodiments, UE 204 may be implemented in various types of user equipment, such as a mobile phone, a smart phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, a wearable computing device, etc. Processor modules 214 and 236 may be implemented or implemented with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, which are designed to perform the functions described herein. In this manner, the processor may be implemented as a microprocessor, a controller, a microcontroller, a state machine, etc. The processor may also be implemented as a combination of computing devices, for example, a combination of a digital signal processor and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors and a digital signal processor core, or any other such configuration.

[0033] In addition, the steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be directly implemented in hardware, in firmware, in software modules executed by the processor modules 214 and 236, respectively, or in any practical combination thereof. The memory modules 216 and 234 may be implemented as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. In this regard, the memory modules 216 and 234 may be coupled to the processor modules 210 and 230, respectively, so that the processor modules 210 and 230 can read information from and write information to the memory modules 216 and 234, respectively. The memory modules 216 and 234 may also be integrated into their respective processor modules 210 and 230. In some embodiments, the memory modules 216 and 234 may each include a cache memory for storing temporary variables or other intermediate information during the execution of instructions to be executed by the processor modules 210 and 230, respectively. Memory modules 216 and 234 may also each include non-volatile memory for storing instructions to be executed by processor modules 210 and 230, respectively.

[0034] The network communication module 218 generally represents hardware, software, firmware, processing logic and / or other components of the base station 202 that enable bidirectional communication between the base station transceiver 210 and other network components and communication nodes configured to communicate with the base station 202. For example, the network communication module 218 can be configured to support Internet or WiMAX services. In a typical deployment, but not limited to, the network communication module 218 provides an 802.3 Ethernet interface so that the base station transceiver 210 can communicate with a traditional Ethernet-based computer network. In this way, the network communication module 218 can include a physical interface for connecting to a computer network (e.g., a mobile switching center (MSC)). As used herein with respect to a specified operation or function, the terms "configured for", "configured to" and variations thereof refer to a device, component, circuit, structure, machine, signal, etc. that is physically constructed, programmed, formatted and / or arranged to perform the specified operation or function.

[0035] The open systems interconnection (OSI) model (referred to herein as the "open systems interconnection model") is a conceptual and logical layout that defines network communications used by systems (e.g., wireless communication devices, wireless communication nodes) that are open to interconnection and communication with other systems. The model is divided into seven subcomponents or layers, each of which represents a conceptual set of services provided to the layers above and below it. The OSI model also defines a logical network and effectively describes computer packet transmission by using different layer protocols. The OSI model may also be referred to as a seven-layer OSI model or a seven-layer model. In some embodiments, the first layer may be a physical layer. In some embodiments, the second layer may be a media access control (MAC) layer. In some embodiments, the third layer may be a radio link control (RLC) layer. In some embodiments, the fourth layer may be a packet data convergence protocol (PDCP) layer. In some embodiments, the fifth layer may be a radio resource control (RRC) layer. In some embodiments, the sixth layer may be a non-access stratum (NAS) layer or an Internet protocol (IP) layer, and the seventh layer is another layer.

[0036] 2. Systems, methods and devices for inter-host migration

[0037] Reference now Figure 3, which shows a block diagram of an environment for mobile integrated access and backhaul (IAB). Integrated access and backhaul (IAB) can support wireless backhaul via new radio (NR), which enables flexible and very dense deployment of NR cells while reducing the need for wired transmission infrastructure. An intra-host centralized unit (CU) migration process can be provided, where both the source and target parent nodes are served by the same IAB host CU. However, inter-host CU migration in a migrating (mobile) IAB node can be static. It may be difficult to perform inter-host migration in the described mobile IAB usage scenario. In the mobile IAB use case, the IAB node is installed in a vehicle and can provide coverage and capacity enhancement to user equipment (UE) on board or around the vehicle.

[0038] Reference now Figure 4A , which shows a block diagram of the integrated access and backhaul (IAB) architecture using standalone (SA) mode with next generation core (NGC). Integrated access and backhaul (IAB) can implement wireless relay in NG-RAN. Relay nodes, referred to as IAB nodes, can support access and backhaul via NR. The terminating node of NR backhaul on the network side can be referred to as IAB host, which can represent a gNB with additional functions to support IAB. Backhaul can be performed through single hop or multi-hop.

[0039] The IAB node may support gNB-DU functionality to terminate the NR access interface to the UE and the next-hop IAB node on the IAB host, and / or terminate the F1 protocol to the gNB-CU function. The gNB-DU function on the IAB node may also be referred to as the IAB distributed unit (DU) (IAB-DU). In addition to the gNB-DU functionality, the IAB node may also support a subset of UE functionality known as IAB mobile termination (MT), including, for example, physical layer, layer 2, radio resource control (RRC), and non-access stratum (NAS) functionality to connect to the gNB-DU of another IAB node or IAB host, to the gNB-CU on the IAB host, and to the core network, etc.

[0040] Reference now Figure 4B , which shows a block diagram of an integrated access and backhaul (IAB) architecture using Evolved Universal Mobile Telecommunications System New Radio (EN-DC). IAB nodes can access the network using SA mode or EN-DC. In EN-DC, IAB nodes are also connected to MeNB via E-UTRA, and the IAB host terminates X2-C to SgNB (e.g., as defined in TS 37.340).

[0041] Reference now Figure 5, which shows a block diagram of an integrated access and backhaul (IAB) node in a parent and child relationship. All IAB nodes connected to the IAB host via one or more hops can form a directed acyclic graph (DAG) topology with the IAB host at its root. In the DAG topology, the neighbor nodes on the IAB-DU interface can be referred to as child nodes, and the neighbor nodes on the IAB-MT interface are referred to as parent nodes. The direction toward the child node can be further referred to as downstream, and the direction toward the parent node is referred to as upstream. The IAB host can perform centralized resource, topology, and routing management for the IAB topology.

[0042] refer to Fig. 6A , which shows a block diagram of an integrated access and backhaul (IAB) mobile termination (MT) migrating from a first host distributed unit (DU1) of a first centralized unit (CU1) to a second host distributed unit (DU2) of a second host centralized unit (CU2). As shown in the figure, the mobile IAB-MT can migrate from host DU1 (belonging to host CU1) to host DU2 (belonging to host CU2). However, the mobile IAB-DU can maintain its F1 connection with the host CU1, and the UE context can be maintained in / with the host CU1. The F1-C / U traffic between the host CU1 and the mobile IAB-DU can be sent via the host DU2.

[0043] refer to Figure 6B , which shows a block diagram of an integrated access and backhaul (IAB) mobile termination (MT) migrating from a second host distributed unit (DU2) of a second host centralized unit (CU2) to a third host distributed unit (DU3) of a third host centralized unit (CU3). As shown in the figure, the mobile IAB-MT can migrate from host DU2 (belonging to host CU2) to host DU3 (belonging to host CU3). However, the mobile IAB-DU can maintain its F1 connection with the host CU1, and the UE context can be maintained in / with the host CU1. The F1-C / U traffic between the host CU1 and the mobile IAB-DU can be sent via the host DU3.

[0044] refer to Figure 6C , which shows a block diagram of an integrated access and backhaul (IAB) distributed unit (DU) migrating from a first host centralized unit (CU1) to a third host centralized unit (CU3). As shown, a mobile IAB-DU may migrate from host CU1 to host CU3. The UE may switch (or undergo switching / migration / switching) from host CU1 to host CU3. F1-C / U traffic between host CU3 and mobile IAB-DU may be sent via host DU3.

[0045] like Fig. 6A-C, each host CU may be associated or correspond to at least one of a source IAB host, a target IAB host, or an initial IAB host. For example, the source IAB host may represent a host including a host DU that was previously connected to or communicated with a mobile IAB-MT or UE 104. The target IAB host may represent a host CU to which the mobile IAB-MT or UE migrates. The initial IAB host may represent at least one IAB host having an F1-C connection with a mobile IAB node, or an IAB host that is a source IAB host for a UE, or an IAB host serving a UE 104 (e.g., a gNB, BS102, or a host CU serving a UE 104). In the following, a mobile IAB node and / or a mobile IAB-DU may sometimes be collectively referred to as an IAB node and / or an IAB-DU, respectively.

[0046] I. Implementation method 1: Determine whether to perform DU / UE migration

[0047] In various implementations, DU (e.g., IAB-DU) migration and / or UE 104 migration may be performed after, before, or after IAB-MT migration. IAB-MT and IAB-DU may be part of an IAB entity (e.g., host or node) (e.g., BS 102, gNB, or network node). Because DU / UE migration may be performed before or after IAB-MT migration, it may be challenging to determine who (e.g., which network node) and how (e.g., operation, method, or process) performs DU migration and / or UE migration (e.g., DU / UE migration). DU migration may refer to the migration of IAB-DU. UE migration may refer to the migration of UE 104. The systems and methods discussed herein may determine at least one IAB entity (e.g., network node) to determine whether to perform DU / UE migration and / or how the IAB entity triggers DU / UE migration. Determining who triggers and how to trigger DU / UE migration can be based on or according to the number of IAB-MT migration procedures / operations performed after the previous migration of the co-located IAB-DU (e.g., an IAB-DU co-located with the IAB-MT in the IAB node) (e.g., how many MT migrations have been performed by the IAB node and / or IAB-DU). Therefore, based on the number of IAB-MT migrations, the IAB-DU can determine / decide whether to perform DU / UE migration. In various embodiments, based on the examples / contexts detailed herein, the first, second, or third network node may be described as or correspond to an IAB node or an IAB host.

[0048] For example, a source host (eg, a source CU or a first network node, such as a combination of Fig. 6A-C) can transmit / send to the target host (e.g., the target CU of the second network node) to provide / signal MT migration related information (e.g., included / contained in the history information of UE 102). The MT migration related information may include at least one of the following:

[0049] 1) Indication / flag of DU migration. The DU migration indication may indicate that DU / UE migration is performed when (e.g., an occurrence or time frame) a co-located IAB-MT of an IAB node migrates from or to a corresponding cell (e.g., a cell associated with a source host);

[0050] 2) A counter (e.g., a counter value) for the IAB-MT migration process. The counter value may be incremented by 1 (e.g., among other pre-configured increment values) before / during / after an IAB-MT migration performed by a source host and / or a target host of the IAB-MT. The counter value may be reset to zero before / during / after a migration of a co-located IAB-DU; and / or

[0051] 3) An identifier of the initial IAB host (e.g., a third network node). For example, the initial IAB host may include an F1 connection with the IAB-DU. The identifier of the initial host may include or correspond to an identifier such as a gNB-ID.

[0052] In response to sending and / or receiving information (e.g., MT migration related information) from a source host, a source host and / or a target host associated with an IAB-MT may determine whether to perform DU / UE migration. For example, the source and / or target host may compare a counter value with a threshold value (e.g., a threshold number of MT migration processes performed). The threshold value may be determined / configured based on the implementation, for example, set to 2, 3, 4, or other threshold values. For example, the threshold value may be configured via operation, management, and maintenance (OAM) signaling to one or more IAB nodes or IAB hosts. If the counter value is greater than or equal to the threshold value, the source and / or target host may transmit / send a provision / signal notification of a DU / UE migration indication to the initial host.

[0053] In another example, reference Fig. 6A -C, the threshold number may be configured as 2. The counter value may be increased in response to MT migration (e.g., by at least one IAB entity). When the IAB-MT migrates to the host DU3, the counter value may be increased to 2, which is equal to the threshold. Thus, the source and / or target host receiving the information may determine to perform DU / UE migration based on the counter value being greater than or equal to the threshold.

[0054] In some cases, the threshold number of MT migration procedures may be coordinated / communicated between host CUs (e.g., between the first, second, and / or third host CUs, etc.) via XnAP signaling. For example, at least one host CU may send an indication of the threshold to one or more other host CUs via a handover request or a get UE context response message. The message may be sent together with or as part of the UE's historical information. The threshold number of MT migration procedures may be configured / updated / provided to the IAB node via RRC and / or F1AP signaling.

[0055] II. Implementation 2: Determine the migration type to perform IAB node migration

[0056] In various implementations, there may be different types of migration procedures / operations, such as partial migration, full migration, DU migration, UE migration, F1 transport migration, etc. Therefore, in these implementations, the IAB host (e.g., target host or target CU) needs to be informed / notified or know the migration type of the IAB node migration to be performed.

[0057] For example, the target host (e.g., the target host of the second network node) may receive / obtain the IAB migration related information from at least one of the IAB node or another IAB-CU (e.g., the source CU or the initial CU) (e.g., the first network node). The IAB migration related information may include at least one of the following information:

[0058] 1) IP address request information (e.g., as an implicit indication operation). The IP address request information may include at least one of multiple IP addresses of the IAB node and / or indicators of two sets of IP addresses. The indicators of the two sets of IP addresses may indicate that two sets of IP addresses are required (or not required). For example, the request for two sets of IP addresses may be an indication of performing at least one of a full migration process, a DU migration process, and / or a UE migration process, and other migration types.

[0059] 2) Indication of the migration type (e.g., operated as an explicit indication). The indication may include or be used to indicate the type of migration, such as at least one of the following: partial migration, full migration, DU migration, UE migration and / or F1 transport migration, etc. Partial migration may include migrating / switching / handing over the IAB-MT to a parent node under or associated with a different IAB host CU, while the configured IAB-DU and / or descendant IAB nodes (e.g., if any) may be in the initial IAB host CU.

[0060] The complete migration may include migrating the border IAB nodes and / or descendant IAB nodes (eg, RRC and F1 connections) from the first IAB host CU to the second IAB

[0061] Host CU. DU migration may include migrating an IAB-DU from one IAB host to another IAB host. UE migration may include migrating a UE 104 from one radio access network (RAN) node to another RAN node. F1 transport migration may include migrating a transport path of F1 traffic from one path to another path.

[0062] In some cases, the IAB node (e.g., the first network node) may transmit / send the IAB migration related information to the target host via a radio resource control (RRC) message and / or an F1 application protocol (F1AP) message. In some other cases, another IAB-CU (e.g., of the first network node) may send the IAB migration related information to the target host via an XnAP message (e.g., an XnAP handover request or an IAB transport migration management request message).

[0063] III. Implementation method 3: Notify IAB node of DU / UE migration

[0064] In various implementations, various types of migration procedures may be presented, such as partial migration, full migration, DU migration, UE migration, F1 transport migration, etc. Therefore, the IAB node needs to be informed / notified / instructed / triggered (e.g., via specific signaling) to perform / initiate / continue DU / UE migration.

[0065] For example, the IAB node (e.g., the second network node) may receive IAB-related configuration information from a host CU (e.g., a source host, a target host, an initial host, and / or other IAB hosts) via RRC and / or F1AP signaling. The IAB-related configuration information may include at least one of the following:

[0066] 1) F1 establishment indication. This indication can indicate to the IAB node to initiate the F1 establishment process / operation;

[0067] 2) F1 handover indication. This indication can indicate to the IAB node to initiate the F1 handover process / operation;

[0068] 3) Source logical DU indication. This indication may indicate associated information (e.g., IAB

[0069] Related configuration information) is used for the source logical DU (for example, there may be multiple logical DUs in the IAB node, such as the source logical DU, the target logical DU, etc.);

[0070] 4) Target logical DU indication. This indication may indicate that the associated information is directed to, applicable to or belongs to the target logical DU;

[0071] 5) The IP address of the target host (e.g., the target CU). The IP address may represent or indicate the IP address of the target host;

[0072] 6) New IAB host indication. The indication may indicate that the associated information is for a new IAB host (eg, a third network node or another network node);

[0073] 7) Migration type indication. The indication may indicate the type of migration to be performed (eg, migration type), such as at least one of: partial migration, full migration, DU migration, UE migration, and / or F1 migration; and / or

[0074] 8) One or more Backhaul Adaptation Protocol (BAP) addresses. One or more BAP addresses may be assigned to the IAB node by the host CU, such as one BAP address for each logical DU.

[0075] IV. Implementation 4: Triggering DU / UE migration at the initial host CU

[0076] In various implementations, different types of migration procedures may be presented / introduced, such as partial migration, full migration, DU migration, UE migration, F1 transport migration, etc. Thus, for example, at the initial host (e.g., the initial CU connected to or communicating with the IAB-DU), there may be different procedures / operations / alternatives for triggering DU / UE migration. One or more of the following operations or procedures may be performed.

[0077] A) Triggered by the source host of IAB-MT (e.g., source CU)

[0078] In some cases, DU / UE migration may be triggered by a source host associated with or communicating with the IAB-MT. For example, the source host (e.g., the first network node or the first IAB host) may transmit / send IAB-related information to the initial IAB host (e.g., the second network node or the second IAB host). In this case, the IAB-related information may include at least one of the following:

[0079] 1) Identification of IAB node;

[0080] 2) an identifier of a target IAB host (eg, a target host or a target CU);

[0081] 3) an identification of a target cell (e.g., a cell associated with the target host);

[0082] 4) Indication of IAB-MT migration (sometimes also called MT migration);

[0083] 5) Instructions for IAB-DU migration; and / or

[0084] 6) Indication of UE migration.

[0085] B) Triggered by the target host of IAB-MT (e.g., target CU)

[0086] Additionally or alternatively, DU / UE migration may be triggered by the target host of the IAB-MT. For example, the target host (e.g., the first network node or the target CU of the first IAB host) may send / transmit IAB related information to the initial IAB host (e.g., the second network node or the second IAB host). The IAB related information may include at least one of the following:

[0087] 1) Identification of IAB node;

[0088] 2) The identification of the target cell;

[0089] 3) Indication of IAB-MT migration;

[0090] 4) Instructions for IAB-DU migration; and / or

[0091] 5) Indication of UE migration.

[0092] C) Triggered by IAB node

[0093] In addition, or alternatively, DU / UE migration may be triggered by an IAB node. For example, the IAB node (e.g., the first network node) may send IAB related information to the initial IAB host (e.g., the second network node). In this case, the IAB related information may include at least one of the following:

[0094] 1) Identification of the target IAB host;

[0095] 2) The identification of the target cell;

[0096] 3) Indication of IAB-MT migration;

[0097] 4) Instructions for IAB-DU migration; and / or

[0098] 5) Indication of UE migration.

[0099] V. Implementation 5: Determine the new / target cell ID of the IAB-DU cell serving the UE

[0100] In various implementations, the initial host (e.g., the initial CU) may transmit / send a signaling Xn handover request message to the target host (e.g., the target CU) to initiate a migration process for one or more UEs 104. The target cell identity / identifier (ID) may be included in the Xn handover request message. However, the initial host may not know the new / target cell ID of the IAB-DU cell serving the UE 104. Therefore, one or more IAB entities (e.g., an IAB node and / or another IAB host) may notify / indicate / signal the initial host of the new / target cell ID.

[0101] For example, an IAB node (e.g., a first network node including an IAB node) may transmit / send information including an old / source cell ID and / or a corresponding new / target cell ID of an IAB-DU (e.g., a DU of an IAB node) to an initial host (e.g., a second network node including a second IAB host). The IAB node may send the information via RRC and / or F1AP. Additionally or alternatively, a target host (e.g., a target CU or a first network node including a first IAB host) may send information (e.g., an old and / or corresponding new / target cell ID of an IAB-DU) to the initial host CU.

[0102] Additionally or alternatively, the target host (e.g., the target CU or a first network node including the target host) may send information (e.g., the old and corresponding new / target cell IDs of the IAB-DU) to the source host (e.g., the source CU or a second network node including the source host). In this case, the source host may send / forward the information to the initial host (e.g., a third network node including the initial host). Based on the information sent, received, or communicated between one or more IAB entities (e.g., IAB nodes and / or IAB hosts), the DU / UE migration process may be performed accordingly.

[0103] Reference now Figure 7 , a flow chart and apparatus of a method 700 for inter-host migration are shown. The method 700 may be implemented or performed using any of the components detailed above, such as UE 104 or 204 and BS 102 or 202, etc. In general, a first network node (e.g., a network entity such as an IAB node or an IAB host) may send information (702). A second network node (e.g., another network entity, such as another / different IAB host or IAB node) may receive information (704). The second network node may determine whether to perform migration (e.g., a DU / UE migration process) (706). The second network node may send an indication (708). A third network node may receive the indication (710).

[0104] In more detail, a first network node (e.g., a network entity, a communication node, a BS, or a gNB) may send / provide / transmit / signal information to a second network node (702). The first network node, the second network node, and / or the third network node may include / contain one of an IAB node or an IAB host, and may be used interchangeably to describe another IAB entity described herein. The information may be associated with an IAB-related migration. The second network node may receive information from the first network node (704).

[0105] In some implementations, the first network node may include a source host. The first network node may send / transmit / provide information to a second network node including a target host. The information may include at least one of the following: an indication of DU migration, a counter value of the MT migration process (e.g., an indication number / occurrence number, or an occurrence count), and / or an identification (ID) of a third network node having an F1 connection with the IAB-DU.

[0106] In various implementations, the first network node may include a source host of an IAB node or an IAB-MT or a source host of a UE (e.g., a communication device). The first network node may send information to the second network node. The second network node may include a target host (e.g., a target host CU). The information may include at least one of an IP address request message and / or an indication of a migration type. The IP address request message may include at least one of the following: the number of IP addresses of the IAB node, and / or an indicator of two groups of IP addresses. The indication of the migration type may include at least one of the following: partial migration, full migration, distributed unit (DU) migration, user equipment (UE) migration, and / or F1 transport migration. In some embodiments, the first network node may send information to the second network node via a radio resource control (RRC) message, an F1 application protocol (F1AP) message, and / or an Xn application protocol (XnAP) message.

[0107] In some implementations, the first network node may include or correspond to a host CU. The second network node may include or correspond to an IAB node. The first network node may transmit / send information to the second network node including the IAB node. In this case, the information may include at least one of the following: an F1 establishment indication indicating to the IAB node that an F1 establishment process is initiated, indicating that the associated information is a source logical DU indication for a source logical DU, indicating that the associated information is a target logical DU indication for a target logical DU, indicating that the associated information is a target host IP address of the target host, indicating that the associated information is a new IAB host indication for a new IAB host, the type of migration type, and / or one or more backhaul adaptation protocol (BAP) addresses, and the type of migration type may include at least one of the following: partial migration, full migration, distributed unit (DU) migration, user equipment (UE) migration, or F1 transport migration. In some aspects, the first network node may send information to the second network node via an RRC message and / or an F1AP message.

[0108] In some cases, the first network node may include a first IAB host. The first node may send information to a second network node, and the second network node may include a second IAB host. In some cases, the first network node may include an IAB node. The first network node may send information to a second network node, and the second network node may include a second IAB host. In one or more of these cases, the information may include at least one of the following: an identifier of the IAB node, an identifier of the target host, an identifier of the target cell, an indication of IAB-MT migration, an indication of IAB-DU migration, and / or an indication of UE migration.

[0109] In some aspects, the first network node may include an IAB node. The first network node may send information to the second network node, and the second network node may include a second IAB host. In some other aspects, the first network node may include a first IAB host. The first network node may send information to the second network node, and the second network node may include a second IAB host. In other aspects, the first network node may include a target host. The first network node may send information to the second network node, and the second network node may include a source host. In this case, the source host may send information to the initial host (e.g., the second IAB host or another (e.g., third) network node that includes the initial host). In one or more of these cases, the information may include an old or source cell identifier (ID) of the DU of the IAB node, and / or a new or target cell ID of the DU.

[0110] After receiving the information, the second network node (e.g., including one of the source host or the target host) can determine whether to perform DU or UE (e.g., DU / UE) migration based on the information (706). For example, the information can include a counter value indicating the number of MT migration procedures performed. The second network node (and / or other network nodes) can compare the counter value with a threshold (or defined) number of MT migration procedures (e.g., MT migration occurs). By comparing the counter value with the threshold number, the second network node can determine whether to perform DU / UE migration.

[0111] For example, the second network node may determine to perform DU / UE migration based on the counter value being greater than or equal to a threshold number. According to some implementations, the second network node may determine not to perform DU / UE migration based on a counter value being less than a threshold number, or vice versa. In some implementations, the threshold number of MT migration procedures may be sent / transmitted / provided to at least one of the source host, the target host, and / or the IAB node.

[0112] Based on the determination, the second network node (e.g., the source host or the target host) may send an indication / message to the third network node regarding whether to perform DU or UE migration (708). The third network node (e.g., the initial host or another host having an F1 connection with the IAB-DU of the IAB node) may receive the indication (710) from the second network node. Thus, the third network node (and / or one or more other network nodes) may perform DU or UE migration based on information communicated to or from one or more network nodes or between one or more network nodes.

[0113] Although various embodiments of the present solution have been described above, it should be understood that they are presented merely as examples rather than as limitations. Similarly, various figures may depict exemplary architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present solution. However, these people will understand that the solution is not limited to the exemplary architectures or configurations shown, but can be implemented using various alternative architectures and configurations. In addition, as will be understood by those of ordinary skill in the art, one or more features of one or more embodiments / implementations may be combined with one or more features of another embodiment / implementation described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the above-described illustrative embodiments.

[0114] It should also be understood that any reference to an element using names such as "first," "second," etc. herein does not generally limit the number or order of these elements. Rather, these designations may be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to a first and a second element does not mean that only two elements may be employed, or that the first element must precede the second element in some manner.

[0115] In addition, those skilled in the art will appreciate that any of a variety of different technologies and methods may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, and symbols such as those referenced in the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0116] Those skilled in the art will further appreciate that any of the various illustrative logical blocks, modules, processors, components, circuits, methods, and functions described in connection with the aspects disclosed herein may be implemented by electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, various forms of program or design code incorporating instructions (which, for convenience, may be referred to herein as "software" or "software modules"), or any combination of these technologies. To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software, or a combination of these technologies, depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in various ways for each specific application, but such implementation decisions do not result in a departure from the scope of the present invention.

[0117] In addition, those skilled in the art will appreciate that the various illustrative logical blocks, modules, devices, components, and circuits described herein may be implemented within or performed by an integrated circuit (IC), which may include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits may also include antennas and / or transceivers to communicate with various components within a network or within a device. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors combined with a DSP core, or any other suitable configuration to perform the functions described herein.

[0118] If implemented in software, these functions may be stored as one or more instructions or codes on a computer-readable medium. Therefore, the steps of the method or algorithm disclosed herein may be implemented as software stored on a computer-readable medium. Computer-readable media include computer storage media and communication media, and communication media include any medium capable of transmitting a computer program or code from one place to another. The storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer.

[0119] In this article, the term "module" as used herein refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. In addition, for the purpose of discussion, each module is described as a discrete module; however, it is obvious to a person skilled in the art that two or more modules can be combined to form a single module that performs the associated functions of an embodiment of the present solution.

[0120] In addition, in the embodiment of the present scheme, memory or other memory and communication components can be adopted.It should be understood that, for the sake of clarity, the above description has described the embodiment of the present scheme with reference to different functional units and processors.However, it is obvious that any appropriate functional distribution between different functional units, processing logic elements or domains can be used without detracting from the present scheme.For example, the function shown as being performed by a separate processing logic element or controller can be performed by the same processing logic element or controller.Therefore, the reference to a specific functional unit is only a reference to the appropriate device for providing the function, rather than representing a strict logical or physical structure or organization.

[0121] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the embodiments shown herein, but is to be consistent with the widest scope consistent with the novel features and principles disclosed, as described in the following claims.

Claims

1. A method comprising: Information associated with an integrated access and backhaul (IAB) related migration is sent by a first network node to a second network node.

2. The method according to claim 1, comprising: The first network node including the source host sends the information to the second network node including the target host, The information includes at least one of the following: Distributed Unit (DU) migration instructions, The counter value of the Mobile Terminated (MT) migration process, or The identification of the third network node having a connection to F1 of the IAB-DU.

3. The method according to claim 2, comprising: determining whether to perform DU or user equipment (UE) migration based on the information; as well as and sending an indication to the third network node of whether to perform the DU or UE migration.

4. The method according to claim 2, comprising: Whether to perform DU or user equipment (UE) migration is determined by comparing the counter value with a threshold number of MT migration procedures.

5. The method of claim 4, wherein the threshold number of MT migration processes is sent to: At least one of the source host or the target host, or IAB node.

6. The method according to claim 1, comprising: The information is sent by the first network node including a source host of an IAB node or an IAB-MT or a source host of a user equipment (UE) to the second network node including a target host, wherein the information includes IP address request information or an indication of a migration type.

7. The method according to claim 6, wherein at least one of the following: The IP address request information includes at least one of the following: the number of IP addresses for the IAB node, or indicators of two groups of IP addresses; or The indication of the migration type includes at least one of: partial migration, full migration, distributed unit (DU) migration, user equipment (UE) migration, or F1 transmission migration.

8. The method according to claim 6, comprising: The information is sent by the first network node to the second network node via a radio resource control (RRC) message, a F1 application protocol (F1AP) message, or a Xn application protocol (XnAP) message.

9. The method according to claim 1, comprising: The information is sent by the first network node including a host centralized unit (CU) to the second network node including an IAB node, The information includes at least one of the following: F1 establishment indication, which indicates to the IAB node to initiate the F1 establishment process, a source logical DU indication, which indicates that the associated information is for a source logical DU, a target logical DU indication, which indicates that the associated information is for a target logical DU, Target host IP address, which indicates the IP address of the target host, a new IAB host indication, which indicates that the associated information is for a new IAB host, The type of migration type, including at least one of the following: partial migration, full migration, distributed unit (DU) migration, user equipment (UE) migration, or F1 transport migration, or One or more Backhaul Adaptation Protocol (BAP) addresses.

10. The method according to claim 9, comprising: The information is sent by the first network node to the second network node via a radio resource control (RRC) message or a F1 application protocol (F1AP) message.

11. The method according to claim 1, comprising one of the following: The first network node including a first IAB host sends the information to the second network node including a second IAB host; or The information is sent by the first network node including an IAB node to the second network node including the second IAB host.

12. The method according to claim 11, wherein the information includes at least one of the following: the identity of the IAB node, The target host's ID, The target cell ID, Instructions for IAB Mobile Termination (IAB-MT) migration, Instructions for migration of the IAB Distributed Unit (IAB-DU), or An indication of user equipment (UE) migration.

13. The method according to claim 1, comprising one of the following: The first network node including the IAB node sends the information to the second network node including the second IAB host; or The first network node including the first IAB host sends the information to the second network node including the second IAB host; or The information is sent by the first network node including the target host to the second network node including the source host; The source host sends the information to the initial host.

14. The method of claim 13, wherein the information includes an old or source cell identifier (ID) of a distributed unit (DU) of the IAB node, and a new or target cell ID of the DU.

15. A method comprising: Information associated with an integrated access and backhaul (IAB)-related migration is received by a second network node from a first network node.

16. A non-transitory computer-readable storage medium storing instructions which, when executed by one or more processors, cause the one or more processors to perform the method according to any one of claims 1-15.

17. A device comprising at least one processor, the at least one processor being configured to implement the method according to any one of claims 1-15.

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