Management of Network Connectivity in a Wireless Communication System

Abstract

A method for use in managing network connectivity in a wireless communication system including at least one mobile integrated access and backhaul (mIAB) node is disclosed. The method at the mIAB node comprises providing a mobility message to a wireless communication device, the mobility message including at least one of mobility profile information indicative of the mobility capabilities of the mIAB node and guaranteed stationary time information indicative of a minimum period for which the mIAB node remains at a given location. The mobility profile information can include at least one of speed information indicative of the speed capabilities of the mIAB node, range information indicative of the mobility area of the mIAB node, stationary information indicative of the duration of one or more stationary periods that the mIAB node can experience, and itinerary information indicative of a sequence of mobility and stationary periods for an itinerary that the mIAB node can follow.

Description

Technical Field

[0001] The present invention generally relates to the management of network connectivity in a wireless communication system. In particular, the present invention relates to the management of network connectivity in a wireless communication system including at least one mobile integrated access and backhaul (IAB) node.

Background Art

[0002] Wireless communication systems are mainly deployed to handle a wide range of applications, from mobile broadband, massive machine type communication to ultra-reliable low-latency communication (URLLC). Such systems enable multiple user equipment (UE) or mobile terminals to share a wireless medium to exchange several types of data content (e.g., video, audio, messaging, etc.) via a radio access network (RAN) through one or more base stations. Base stations are conventionally wired-connected (e.g., via fiber) to a core network that forms an intermediate network called a backhaul (BH).

[0003] Examples of such wireless multi-connection communication systems include systems based on 3rd Generation Partnership Project (3GPP®-TM) standards such as 4th generation (4G) Long Term Evolution (LTE) or the recent 5th generation (5G) New Radio (NR) systems, or IEEE 802.11 standards based on system-based WiFi.

[0004] The demand for higher network density increases due to the increasing number of users and higher throughput requirements.

[0005] Facing the problems of high deployment costs and time for wired backhaul networks with increasing network density, 3GPP (registered trademark) has proposed in the most recent Release 16 for 5G NR a wireless backhaul (Integrated Access and Backhaul, also known as IAB), where a portion of the wireless (i.e., radio) spectrum is used for the backhaul connection of base stations instead of fiber. Wireless backhaul communication (between base stations) can use the same radio resources as access communication (between a base station and a UE).

[0006] IAB has been found to be a competitive alternative to fiber-based backhaul in dense or hard-to-cover areas as it enables scalable and rapid installation without the burden of cable connecting base stations.

[0007] IAB is most likely to operate in the millimeter wave (mmWave) band to achieve the required Gbps (gigabit per second) data rate.

[0008] Urban environments are typically characterized by a high density of users along with a significant number of vehicles (e.g., public / private passenger transport, goods delivery, food trucks...). The speeds of some of these vehicles can be quite low or at least similar to pedestrian speeds, and some of these vehicles may even be stationary temporarily. Some of these vehicles (e.g., buses, trains, or trams (streetcars)) can have predictable routes and / or limited movement areas (e.g., some vehicles such as food trucks or promotional vehicles can be located outside stadiums or exhibition venues), and others can have predictable stationary positions (e.g., taxis).

[0009] 3GPP (Registered Trademark) believes that by installing an in-vehicle base station (or base station element) assumed to function as a repeater in a vehicle, it can provide an opportunity to increase network coverage and connectivity to UEs within the vehicle and UEs in the vicinity of the vehicle. These relays will rely on 5G wireless backhaul (typically IAB, or integrated access and backhaul) to connect to a fixed donor device. Therefore, based on the fixed IAB infrastructure described in Releases 16 and 17, 3GPP (Registered Trademark) is currently considering mobile IAB systems and architectures as part of the Release 18 framework to address scenarios focused on mobile IAB nodes mounted on vehicles (e.g., buses, trains, taxis). In such scenarios, the mobile IAB node can also be called a vehicle-mounted relay (VMR) that provides 5G coverage / capacity to in-vehicle and / or surrounding UEs. The technical advantages of using vehicle relays include, among other things, the ability of the relay vehicle to obtain better coverage than nearby UEs, thanks to better RF / antenna capabilities, and thus provide a better link for the UEs to the macro network. Additionally, vehicle relays are expected to have fewer stringent power / battery constraints than UEs.

[0010] Since the VMR or mobile IAB (mIAB) node can be stationary at some point during movement (e.g., a taxi in a parking lot or taxi stand, a bus in a parking lot or bus stop, a train at a station, or a temporary installation in the case of an event or emergency / disaster), the connection to the mobile IAB (mIAB) node or vehicle-mounted relay (VMR) is likely to vary based on their actual movement. Therefore, while benefiting from the additional connectivity provided by the presence of mobile IAB nodes in the topology, in order to mitigate the impact on connectivity that can arise from their actual mobility status, the connection of any child IAB nodes, whether fixed or mobile, to the network via or through such mobile IAB nodes should be carefully managed and requires some dedicated signaling to other IAB nodes, including the IAB donor, for the purpose of connection setup or dynamic mobility status notification.

[0011] A given IAB topology can at some point be composed of both legacy IAB devices (belonging to previous releases 16 and 17) that do not have the ability to distinguish mobile IAB nodes from fixed IAB nodes, and more recent IAB devices (belonging to release 18 and further) that have the ability to handle mobile IAB connectivity, and it is also necessary to consider managing the connections of different types of IAB devices (e.g., legacy and more recent IAB devices) to the network via or through the mobile IAB device.

[0012] Also, considering the aforementioned variability of connectivity related to the mobile IAB node, it may sometimes be desirable to carefully manage the connectivity of both on-board and / or surrounding user equipment (UE) that can be within the range of the mobile IAB node.

[0013] Therefore, several new mechanisms are required to address at least some of the aforementioned problems while limiting the complexity of the processing at the IAB node and the latency resulting from such processing. SUMMARY OF THE INVENTION

[0014] According to a first aspect of the present invention, there is provided a method for use in managing network connectivity in a wireless communication system including at least one mobile integrated access and backhaul (mIAB) node, the method comprising, at the mIAB node, providing a mobility message to a wireless communication device, the mobility message including at least one of mobility profile information indicating the mobility capabilities of the mIAB node and guaranteed stationary time information indicating a minimum duration for which the mIAB node remains at a given location.

[0015] In one example, the mobility profile information includes at least one of speed information indicating the speed capabilities of the mIAB node, range information indicating the mobility area of the mIAB node, stationary information indicating the duration of one or more stationary periods that the mIAB node may experience, and itinerary information (alternatively, also referred to as movement trajectory information) indicating a sequence or succession of mobility and stationary periods for an itinerary that the mIAB node may follow.

[0016] By providing mobility profile information and / or guaranteed stationary time information (e.g., after one or more connections to a mobile IAB node are established), a receiving wireless communication device (such as an IAB donor CU, UE, or another IAB node) can receive information about the mobile capabilities and / or current stationary state of the mobile IAB node, and additional information about the mobility of the mobile IAB node can operate accordingly. In other words, the mIAB node can advertise its mobility capabilities and / or stationary state to one or more UEs and one or more other IAB nodes in the vicinity of the mIAB node. Using the additional information regarding the mobility capabilities of the mIAB node and / or the guaranteed stationary time information, the UE and / or other IAB nodes and / or IAB donor nodes have additional information and can thus operate more effectively. For example, the UE and / or another IAB node can decide not to connect to the network via the mIAB node for its mobility, or can decide to connect regardless of the mobility of the mIAB node (e.g., the information indicates that the mIAB node is moving slowly or is within a limited area). In another example, if the UE and / or another IAB node is already connected, the UE and / or another IAB node can decide to initiate a cell search procedure to look for connecting or handing over to another IAB node.

[0017] According to a second aspect of the present invention, a method in a wireless communication device of a wireless communication system according to claim 19 of the appended patent claims is provided.

[0018] According to a third aspect of the present invention, a method in an integrated access and backhaul (IAB) donor node of a wireless communication system according to claim 32 of the appended patent claims is provided.

[0019] According to a fourth aspect of the present invention, a method in an integrated access and backhaul (IAB) node for use in managing network connectivity in the wireless communication system according to claim 49 of the appended patent claims is provided.

[0020] According to a fifth aspect of the present invention, a method in a wireless communication device of the wireless communication system according to claim 59 of the appended patent claims is provided.

[0021] According to a sixth aspect of the present invention, an apparatus for an integrated access and backhaul IAB node of the wireless communication system according to claim 62 of the appended patent claims is provided.

[0022] According to a seventh aspect of the present invention, an apparatus for an integrated access and backhaul (IAB) donor node of the wireless communication system according to claim 63 of the appended patent claims is provided.

[0023] According to an eighth aspect of the present invention, an apparatus for a wireless communication device according to claim 64 of the appended patent claims is provided.

[0024] Further exemplary features of the present invention are described in other independent claims and dependent claims.

[0025] Any feature in one aspect of the present invention may be applied to other aspects of the present invention in any suitable combination. In particular, method aspects may be applied to apparatus / device / unit aspects and vice versa.

[0026] Furthermore, functions implemented in hardware may be implemented in software, and vice versa. Any reference to software and hardware functions in this specification should be construed accordingly. For example, according to another aspect of the present invention, when a program is executed by a processing unit, there is provided a computer program comprising instructions for causing the processing unit to execute the method of any of the above aspects or examples, and a computer-readable storage medium carrying the computer program.

[0027] It should also be understood that certain combinations of the various functions described and defined in any aspect of the present invention can be implemented and / or supplied and / or used independently.

Brief Description of the Drawings

[0028] Here, different aspects of the present invention will be described by way of example only with reference to the following drawings.

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DETAILED DESCRIPTION OF THE INVENTION

[0029] FIG. 1 shows an exemplary communication system 100 in which the present invention may be implemented in accordance with one or more embodiments.

[0030] As shown, the exemplary system 100 is a wireless communication system, particularly a mobile wireless communication system such as a wireless integrated access and backhaul (IAB) communication system or a 5th generation (5G) new radio (NR) system including a network. In the following description, embodiments and examples of the present invention will be described with respect to a 5G NR system, but the present invention is not limited to a 5G NR system and may be used in any wireless communication system having an integrated access and backhaul communication system that shares wireless resources for wireless access links and wireless backhaul links.

[0031] The system 100 includes a plurality of UEs (user equipment) 132, 133, 131, and 134, a remote core network 110, a main base station 120, two fixed integrated access and backhaul (IAB) stations 121 and 122, or IAB nodes 121 and 122 (hereinafter also referred to as IAB nodes), and a mobile integrated access and backhaul (IAB) station (station) or mobile IAB node 123 mounted on a vehicle 105 (e.g., a bus, train, taxi, car, etc.).

[0032] The main base station 120, also referred to as the IAB donor 120, is connected to the core network 110 via a wired link 101, preferably an optical fiber or any other wired means. In embodiments and examples of the present invention, the IAB donor 120 is a 5G NR base station (referred to as a gNB) with additional features that support the IAB function, as defined in the 3GPP (registered trademark) TS 38.300 v17.0.0 specification.

[0033] To extend the network coverage of the IAB donor 120 and reach the remote UEs 132, 133, and 131, IAB stations 121 and 122, also referred to as IAB nodes 121 and 122, are installed by the operator. By operating as relay nodes between the IAB donor 120 and the UEs 132 and 133, the IAB nodes 121 and 122 overcome the reachability problems caused by the presence of the building 108, which is an obstacle to radio wave propagation, and thus enable a direct connection and further communication between the UE and the IAB donor 120. This is particularly applicable when the communication between the IAB donor 120 and the UEs 132 and 133 operates at millimeter wave frequencies and is very sensitive to the shadowing phenomenon.

[0034] The IAB donor 120 also provides services to the UE 134 directly connected to it.

[0035] The mobile IAB station 123, also referred to as the IAB node 123 or mIAB node 123 mounted on the vehicle 105, also provides network coverage and capacity expansion, enabling the IAB donor 120 to reach on-board remote UEs such as the remote UE 135, as well as UEs in the vicinity or surrounding the IAB node 123 such as the remote UE 136.

[0036] The IAB donor 120 and the IAB nodes 121, 122, and 123 thus form a backhaul network or an IAB network (also referred to as an IAB topology) that accommodates the UEs 131, 132, 133, 134, 135, and 136. The terms IAB network and IAB topology are used interchangeably hereinafter. The IAB network forms a radio access network (RAN) or is referred to in relation to 5G, the next generation (NG) RAN.

[0037] The specifications for integrated access and backhaul (IAB) are described across several 3GPP (registered trademark) specifications, including the following: - TS 38.300 RAN Architecture (V17.0.0) - TS 38.321 MAC Protocol (V17.0.0) - TS 38.331 Radio Resource Control (RRC) Protocol (V17.0.0) - TS 38.340 Backhaul Adaptation Protocol Layer (V17.0.0) - TS 38.401 RAN Architecture (V17.0.0) - TS 38.473 F1 Application Protocol (V17.0.0).

[0038] Since the IAB nodes 121, 122, and 123 are each connected to the UEs 131, 132, 133, 134, 135, and 136, they are each considered access IAB nodes for the connected UEs.

[0039] The IAB donor 120 is a logical node that provides an NR-based wireless backhaul, consisting of a Central Unit (CU or gNB-CU function) and a connected donor Distributed Unit (DU or gNB-DU function). The IAB-donor-CU or donor CU (hereinafter also referred to as the IAB-donor CU or IAB donor CU) hosts upper layer protocols such as the PDCP (Packet Data Convergence Protocol) and RRC (Radio Resource Control) protocol to control the operation of each of one or more DUs and one or more IAB-donor-DUs or donor DUs (hereinafter also referred to as the IAB-donor DU or IAB donor DU), and includes lower layer protocols such as the RLC, MAC, and physical layer protocols. The IAB donor CU and the IAB donor DU may be located far from each other or may be located on the same physical device. The gNB-DU function is defined in 3GPP (registered trademark) TS 38.401. It aims to terminate the NR access interface to the UE and the next-hop IAB node and to terminate the F1 protocol to the IAB donor gNB-CU function.

[0040] IAB nodes that can serve multiple radio sectors are wireless backhauled to the IAB donor 120 via one or more hops (e.g., via one or more IAB nodes). They form a directed acyclic graph (DAG) topology having the IAB donor as the root.

[0041] Each IAB node consists of an IAB-DU (IAB Distributed Unit) and an IAB-MT (IAB Mobile Terminal). The gNB-DU function on the IAB node, also called the IAB-DU, enables a downstream connection to the next-hop IAB or the UE (towards the UE). The IAB-MT function includes, for example, physical layer, layer 2, RRC, and non-access stratum (NAS) functions for connecting to the gNB-DU of the upstream IAB node (including the IAB donor 120, in which case, for example, for initialization, registration, and configuration, it connects to the IAB donor gNB-CU, and thus to the core network 110).

[0042] In this DAG topology, neighboring nodes on the interface of the IAB-DU are called child nodes, and neighboring nodes on the interface of the IAB-MT are called parent nodes. The direction towards the child node is further referred to as the downstream side, and the direction towards the parent node is referred to as the upstream.

[0043] The IAB donor 120 (e.g., the IAB donor CU) performs centralized resource, topology, and route management for the entire IAB topology. This includes, for example, configuring IAB nodes according to the network topology to perform proper routing of data packets.

[0044] Figures 2(A) and 2(B) schematically show the stack of some protocol layers involved in IAB operation.

[0045] The F1 interface supports the exchange of signaling information between endpoints and the transmission of data to each endpoint. From a logical perspective, the F1 interface is a point-to-point interface between endpoints.

[0046] In 5G NR, F1-C is a functional interface in the control plane (CP) between the IAB donor CU and the IAB node DU. F1-U is a functional interface of the user plane (UP) of the same unit. F1-C and F1-U are indicated by reference number 212 in Figure 2(A). In this example, F1-U and F1-C are carried over two backhaul hops (from the IAB donor to IAB node 1, and then from IAB node 1 to IAB node 2).

[0047] In the user plane, box 210 in the IAB donor CU and the IAB node DU refers to the GTP-U layer, and box 211 refers to the UDP layer. GTP-U means the GPRS tunneling protocol user plane. The GTP-U tunnel is used to carry encapsulated PDUs and signaling messages between a given pair of GTP-U tunnel endpoints (see 3GPP™ TS 29.281 for details), here between box 210 in the IAB donor CU and the IAB node DU. The well-known User Datagram Protocol (UDP) provides a best-effort datagram service and is a transport layer protocol suitable for use with the IP protocol.

[0048] In the control plane, box 210 indicates the F1AP (F1 application protocol) layer, and box 211 indicates the SCTP (Stream Control Transmission Protocol) layer. The F1 application protocol (as defined in 3GPP™ TS 38.473 and TS 38.401) provides a signaling service or UE-related services between the IAB donor CU and the IAB node DU. These services are, for example, initialization, configuration, etc. The well-known SCTP layer provides reliability in the sequential transfer of messages with congestion control.

[0049] F1-U and F1-C depend on the IP transport layer between the IAB donor CU and the IAB node DU as defined in 3GPP (Registered Trademark) TS 38.401.

[0050] The transfer (transport) between the IAB donor DU and the IAB donor CU also uses the IP transport layer over various media such as wired or optical fiber, for example, when the IAB donor CU is remote from the IAB donor DU, or locally in the virtual instantiation of the IAB donor CU and the IAB donor DU on the same physical machine. The IAB-specific transfer between the IAB donor CU and the IAB donor DU is specified in 3GPP (Registered Trademark) TS 38.401.

[0051] Layers L1 and L2 in the figure represent the transport layer and the physical layer suitable for the media in use, respectively.

[0052] The IP layer can also be used for non-F1 traffic such as operation, management, and maintenance traffic.

[0053] In the wireless backhaul, the IP layer itself is carried via the Backhaul Adaptation Protocol (BAP) sublayer, which enables routing over multiple hops. The BAP sublayer is specified in TS 38.340.

[0054] The IP traffic of the IAB-DU is routed via the wireless backhaul through the BAP sublayer. In the downstream direction, the upper layer packets are encapsulated by the BAP sublayer at the IAB donor DU, thus forming BAP packets or packet data units (PDUs) or data units. The BAP packets, if any, are routed by the BAP layer of the intermediate IAB nodes (and the corresponding BAP entities at the IAB-DU and IAB-MT). The BAP packets are finally decapsulated by the BAP sublayer at the destination IAB node (this can be the access IAB node to which the upper layer packets in the BAP packet are intended for the UE).

[0055] In the upstream direction, the upper layer packets are encapsulated by the BAP sublayer at the initiator IAB node (which can be the access IAB node if the upper layer packets arrive from the UE), thus forming BAP packets or PDUs or data units. The BAP packets, if any, are routed by the BAP layer of the intermediate IAB nodes (and the corresponding BAP entities at the IAB-DU and IAB-MT). The BAP packets are finally decapsulated by the BAP sublayer at the IAB donor DU.

[0056] On the BAP sublayer, the packets are carried within the BAP header and routed based on the BAP routing ID set by the BAP sublayer of the network nodes in the IAB network that generate the BAP packets. Figure 3 shows the format of the BAP data protocol data unit (PDU) or packet. This is defined in the standardized version 6.2 of 3GPP (registered trademark) TS38.340 Release 17.0.0.

[0057] Header 30 includes fields 301 to 306. Field 301, called the D / C field, is a boolean value indicating whether the corresponding BAP packet is a BAP data packet or a BAP control packet. Fields 302 to 304 are 1-bit reserved fields, preferably set to 0 (ignored by the receiver).

[0058] Fields 305 and 306 together indicate the BAP routing ID for the BAP packet. BAP address field 305, also called the DESTINATION field, is located in the leftmost 10 bits, and BAP path identification field 306, also called the PATH field, is located in the rightmost 10 bits.

[0059] Field 305 carries the BAP address of the destination IAB node or IAB donor DU for the BAP packet (i.e., on the BAP sublayer). For routing purposes, each IAB node and IAB donor DU is configured (by the IAB donor CU that controls the IAB network or topology to which the IAB node and IAB donor DU belong) using a specified BAP address. Field 306 carries a path ID that identifies the routing path that the BAP packet should follow to this destination in the IAB topology. The routing paths are set in the same way as the BAP addresses are set, including their path IDs.

[0060] The BAP header is added to the packet when it arrives from the upper layer to the BAP layer and removed by the BAP layer when it reaches the destination node. The selection of the BAP routing ID of the packet is configured by the IAB donor CU.

[0061] For example, when a BAP packet is generated by an IAB node, i.e., by an IAB donor for downlink transmission, or by an initiator IAB node for uplink transmission (the upper layer packet can be the access IAB node from which the UE should receive), the BAP header with the BAP routing ID is constructed by this IAB node according to the configuration table defined in 3GPP (registered trademark) TS 38.340. This table is called the Downlink Traffic to Routing ID Mapping Configuration table for the downlink traffic of the IAB donor and the routing ID mapping configuration, or the Uplink Traffic to Routing ID Mapping Configuration table for the uplink traffic of the initiator IAB node. In the intermediate IAB node, the BAP header field is already specified within the BAP packet to be transferred.

[0062] As described above, these configuration tables that define the BAP path (and thus the routing strategy and configuration of the IAB nodes given the IAB network topology) are usually defined by the IAB donor CU that controls the IAB network and sent to the IAB nodes to configure them.

[0063] To handle the transfer of messages over the 5G NR radio medium, three or more sublayers (RLC, MAC, and PHY) are implemented at each IAB node below the BAP sublayer. The RLC (Radio Link Control) sublayer is responsible for segmenting or reconstructing packets. It is also responsible for requesting retransmission of lost packets. The RLC layer is further described in TS38.322. The MAC (Media Access Control) protocol sublayer is responsible for selecting the available transmission format for user data and mapping logical channels to transport channels. MAC also processes part of the hybrid automatic repeat request scheme. The MAC layer is detailed in TS 38.321. On the emitter or transmitter side, MAC encapsulates the data packets issued from RLC. It adds a header that carries the information necessary for the MAC function. On the receiving side, MAC decapsulates the data packets issued from PHY, removes its header, and passes the remaining data to RLC. The PHY sublayer converts the stream of information into a physical modulation signal and provides an electrical interface to the transmission medium (air) by modulating the carrier frequency on the emitter side. On the receiver side, the PHY sublayer converts the physical modulation signal back into a stream of information. The PHY layer is described in TS 38.201, TS 38.211, TS 38.212, TS 38.213, TS 38.214.

[0064] To pass messages towards the user or control plane, two other sublayers are used at the UE and the IAB donor CU, namely, the PDCP (Packet Data Convergence Protocol) sublayer for user plane communication, the SDAP (Service Data Adaptation Protocol) sublayer for user plane communication, and the RRC (Radio Resource Control) sublayer for control plane communication.

[0065] The PDCP sublayer processes IP header compression / decompression, encryption / decryption, and, if necessary, the integrity of data packets. It essentially numbers the packets on the emitter side and reorders (reorders) the packets on the receiver side. The PDCP sublayer is described in 3GPP (registered trademark) TS 38.323.

[0066] The SDAP sublayer 220 of the user plane processes quality of service. This is described in TS38.324. On the UE side, the SDAP sublayer exchanges payload data with the user's application (such as voice, video (not shown)). On the IAB donor side, the SDAP sublayer exchanges data with the core network 110 (such as Internet traffic, cloud).

[0067] The RRC sublayer 220 for the control plane processes the configuration of the protocol entities of the user plane protocol stack. It is described in TS38.331. It is responsible, among other things, for broadcasting the information necessary for the UE to communicate with the cell, sending paging messages, managing connections including bearer setup, and handling mobility functions, measurement configurations, and reporting of device capabilities.

[0068] The interface between nodes using the PDCP, RLC, MAC, and PHY layers (for both CP and UP) is called NR-Uu. This mainly relates to the interface with the UE.

[0069] The interface between nodes using the BAP, RLC, MAC, and PHY layers (for both CP and UP) is called the backhaul RLC channel (BH RLC channel). This mainly relates to the interface between IAB nodes.

[0070] NR-Uu is the interface between the UE and the radio access network, i.e., its access IAB node (for both CP and UP).

[0071] Figure 2(B) is from 3GPP (Registered Trademark) TS 38.300 v17.0.0 and shows the protocol stack for supporting the RRC and NAS connections of the IAB-MT. The non-access stratum (NAS) protocol processes messages between the core network and the user equipment, here the IAB node. It manages the establishment of communication sessions and maintains communication with the user equipment as it moves. 5G NAS is described in 3GPP (Registered Trademark) TS 24.501. The 5G core access and mobility management function (AMF) is a function within the core network that receives all connection and session-related information from the UEs connected to the IAB node, as well as similar information for the IAB node. The AMF is only responsible for handling connection and mobility management tasks.

[0072] The IAB-MT establishes signaling radio bearers (SRBs, which carry RRC and NAS messages) with the IAB-donor-CU. These SRBs are transferred between the IAB-MT and its parent node via the NR-Uu interface.

[0073] Figure 4 shows an example of a wireless communication system 400 that includes an IAB network or IAB network system, in which embodiments and example embodiments of the present invention may be implemented. In one exemplary implementation, the wireless link (referred to as the BH wireless link) between the IAB node and the IAB donor DU node operates over a millimeter-wave frequency band (i.e., above 30 GHz) that is very sensitive to interference in the wireless channel. The IAB network is also called the IAB topology or topology, and thus, in this application, the terms IAB network and IAB topology and topology are used interchangeably.

[0074] The IAB network system of FIG. 4 forms part of the NG RAN and is composed of two IAB networks or IAB topologies 4001 and 4002. Each IAB topology includes a set of IAB nodes (for example, the set may comprise a plurality of IAB nodes or at least one IAB node), and an IAB donor CU for controlling or managing the plurality of IAB nodes. The set of IAB nodes may include one or more IAB nodes such as an initiator IAB node that generates BAP packets, and intermediate or relay IAB nodes. The set of IAB nodes may also include one or more IAB donor DUs. Each of the IAB nodes communicates with at least one other IAB node via a wireless backhaul (BH) link.

[0075] FIG. 4 shows two IAB topologies 4001 and 4002, but the present invention is not limited to the two IAB topologies 4001 and 4002. As described above, it can be implemented in an IAB communication system comprising three or more IAB topologies, where each topology includes a set of IAB nodes and an IAB donor CU.

[0076] IAB topology 4001 includes an IAB donor CU 401 (identified as donor 1 CU in FIG. 4), its associated IAB donor DU, IAB donor DUs 403 (identified as donor 1 DU1 in FIG. 4) and 404 (identified as donor 1 DU2 in FIG. 4), and a plurality of IAB nodes 410, 420, 430, 460, 480 similar to IAB nodes 121 and 122, and an IAB node 470 similar to mobile IAB node 123.

[0077] The IAB topology 4002 includes an IAB donor CU 402 (identified as donor 2 CU in FIG. 4), its associated IAB donor DU 405 (identified as donor 2 DU1 in FIG. 4), and a plurality of IAB nodes 440 and 450 similar to IAB nodes 121 and 122. The IAB network 400 can provide network path diversity via several IAB donor DUs and different IAB networks or topologies.

[0078] As described above, each IAB node includes a mobile termination (MT) part or unit controlled and configured by an IAB donor using RRC messaging defined in 3GPP™ TS 38.331, and a distributed unit (DU) part controlled and configured by an IAB donor using F1-AP messaging defined in 3GPP™ TS 38.473. For example, the IAB node 410 includes an MT part or unit 411 and a DU part 412.

[0079] The wired backhaul IP network interconnects the IAB donor CUs 401 and 402, and the IAB donor DUs 403, 404, and 405 via a wired link 406. For example, this wired link consists of optical fiber cable(s).

[0080] The IAB donor CU 401, the IAB donor DUs 403 and 404, the IAB nodes 410, 420, 430, 460, 470, and the IAB node 480 are part of the same IAB network or IAB topology 4001 controlled (e.g., configured and / or managed) by the IAB donor CU 401.

[0081] The IAB donor CU 402, the IAB donor DU 405, and the IAB nodes 440 and 450 are part of the same IAB network or IAB topology 4002 controlled (e.g., configured and / or managed) by the IAB donor CU 402.

[0082] The IAB node 470 is connected to the parent IAB node 430 via the BH link 4030. The IAB node 470 is also connected to the UE 390 via a communication link or a wireless link 4031, and the IAB node 470 is operating as an access node for the UE 390. Although FIG. 4 shows only one UE 390, it will be understood that there are multiple UEs connected to the IAB nodes of the wireless communication system. The IAB node 470 belongs to the IAB network 4001 (where the IAB node 430 functions as a parent node via the BH link 4030), but considering the proximity to the IAB network 4002, in particular the IAB node 450, the IAB node 470 can be connected to the IAB node 450 (which functions as a parent node to the IAB node 470) via the wireless BH link 4050. In addition to, or instead of, the connection to the IAB node 430, such a connection to the IAB node 450 is possible for a stationary IAB node and is very likely to occur when a mobile IAB node such as the IAB node 470 moves in the direction of the IAB topology 4002.

[0083] Each IAB node supports wireless communication in a coverage area called a cell. In other words, each IAB node is associated with a cell. A wireless communication device (such as a UE or another IAB node) located within the cell can connect to the IAB node serving the cell to communicate with other devices (such as other UEs, IAB nodes, servers providing access to the Internet, etc.). Typically, an IAB node measures signals from IAB nodes of neighboring cells as part of a cell search procedure (e.g., when initially connecting to a network defined in 3GPP (registered trademark) TS 38.300) or as part of subsequent procedures. The measurement values are reported to the IAB donor CU of the IAB node. For example, referring to FIG. 4, the IAB node 470 can report to its IAB donor CU 401 the presence of a new cell served by the IAB node 450 through a measurement report. Based on the analysis of the measurement report (e.g., the measurement values in the report indicate that the signal strength provided by the IAB node 450 exceeds a threshold for supporting communication), the IAB donor CU 401 can request the IAB donor CU 402 to which the IAB node 450 belongs to establish dual connectivity for the IAB node 470 having an additional connection through the IAB node 450. The IAB donor CU 402 can accept the request and proceed to establish a connection from the IAB node 470 to the IAB node 450 according to the procedures described in Section 10.2 of TS 37.340 v17.0.0. As a result, the IAB node 470, which still belongs to the IAB topology 4001, is also connected to the IAB node 450 belonging to the IAB topology 4002 and may thus be called a boundary node between the IAB topology 4001 and the IAB topology 4002. In practice, the IAB node 470 retains its F1 connection and its RRC connection to the IAB donor CU 401 (which can be called an F1 terminated IAB donor CU) and retains a second RRC connection to the IAB donor CU 402 (which can be called a non-F1 terminated IAB donor CU).

[0084] Since the IAB node or the boundary node 470 is part of the IAB topology 4001 (from the perspective of the F1 connection), it is controlled (e.g., configured and / or managed) by the IAB donor CU 401 of the IAB topology 4001. Through the second RRC connection, the IAB donor CU 402 allocates a second BAP address to be used for routing packets through the IAB topology 4002. Thus, the IAB node 470 functioning as a boundary node is allocated two BAP addresses, namely, one BAP address for the IAB network 4001 and one BAP address for the IAB network 4002. Such a boundary node can help provide network path diversity by providing alternative routing paths through the IAB topologies 4001 and 4002.

[0085] Since the IAB node 470 is a mobile IAB node (e.g., mounted on a vehicle), the IAB node 470 does not always remain stationary and moves so that the connections to the IAB nodes 430 and 450 can change over time. For example, if the movement of the IAB node 470 is small and the IAB node 470 and the IAB nodes 430 and 450 are still close enough to each other to meet the minimum requirements for supporting communication (e.g., the signal strength exceeds a threshold), the connections with the IAB nodes 430 and 450 may not change. However, if the movement of the IAB node 470 is such that the IAB node 470 moves from the cell associated with the IAB node 430 and / or from the cell associated with the IAB node 450, the IAB node 470 may lose its connection with the IAB node 430 and / or the IAB node 450, respectively. In such a case, the connections to the IAB nodes associated with the movement of the IAB node should be managed to avoid loss of service for the wireless devices connected to the IAB node 470 (e.g., the IAB node 430 and the UE 390 as shown in FIG. 4). For example, to ensure service continuity, a handover procedure may be initiated such that one or more connections of the IAB node 470 in the IAB communication system (e.g., to the IAB node 430) are handed over to a different cell. As discussed in the background art, using mobile IAB nodes helps increase connectivity (e.g., capacity) in a wireless communication system, but the connections to the mobile IAB nodes need to be managed considering the movement of the mobile IAB nodes.

[0086] Here, according to some embodiments of the present invention, a process for managing one or more network connections in a wireless communication system including one or more mobile IAB nodes will be described.

[0087] Figure 11 shows the steps of an exemplary method 1100 for use in managing network connectivity in a wireless communication system that includes at least one mobile integrated access and backhaul (mIAB) node, according to an embodiment of the present invention. The method 1100 may be used to manage a connection to a network (e.g., the IAB network system of FIG. 4 that provides connectivity to a core network or a connection to an NG RAN) via or through an mIAB node. The method 1100 of FIG. 11 is executed at an mIAB node. For example, with reference to the wireless communication system shown and described with respect to FIG. 4, the mIAB node that executes the method 1100 may be the IAB node 470 of the IAB topology 4001 controlled by the IAB donor CU 401. The method 1100 shown and described with respect to FIG. 11 may be executed by a software element and / or a hardware element. The mIAB node may be implemented in a communication device 1000 as shown and described with respect to FIG. 10, using the method shown and described with respect to FIG. 11, which is executed by one or more processing units such as a central processing unit 1011.

[0088] Briefly stated, in step 1101, the mIAB node (e.g., the IAB node 470) provides a mobility message to a wireless communication device, the mobility message including at least one of mobility profile information indicating the mobility capabilities of the mIAB node and guaranteed stationary time information indicating the minimum period of time the mIAB node will remain in a location. The wireless communication device may be an IAB donor node (e.g., the IAB donor CU), a UE, or another IAB node. More generally, the mIAB node may be a network node of a mobile communication network, and the wireless communication device may be a control node for managing the control plane and data plane of the wireless communication system (e.g., controlling the network node), a UE, or another network node. The following description also applies to this more general scenario.

[0089] In one example, the mobility profile information can include at least one of speed information indicating the speed capabilities of the mIAB node, range information indicating the mobility area of the mIAB node, stationary information indicating the duration of one or more stationary periods that the mIAB node may experience, and itinerary information indicating the sequence of mobility and stationary periods for an itinerary that the mIAB node may follow. The speed information can include information indicating one or more of the minimum speed capability of the mIAB node, the average speed capability of the mIAB node, and the maximum speed capability of the mIAB node. The range information can include information indicating the area in which the mIAB node can move or the movement range of the mIAB node. For example, the range information can include the type or category of the mobility area in which the mIAB node can move, which can be an indication of the size or nature of the geographical area in which the mobile IAB node can move. For example, the type (or category) of the mobility area can indicate that the geographical area is a bus route, a train route, or a parking lot. Additionally or alternatively, the range information can include the size of the area in which the mIAB node can move (i.e., the mobility area), and / or a list of cell identifiers (IDs) of cells that the mIAB node has previously visited or can visit. Additionally or alternatively, the range information can include the distance that the mIAB node can move. The stationary information can include stationary time information indicating one or more of the minimum value of the duration of the stationary period, the average value of the duration of the stationary period, or the maximum value of the duration of the stationary period. The stationary information can also include stationary position information indicating the location where the mIAB is stationary. The itinerary information can include, for each of the mobility period and the stationary period, information indicating the duration of the period, the speed of the mIAB node during one or more of the mobility periods, and the location of the mIAB node during one or more of the stationary periods.

[0090] The mobility profile information can be configured at the mIAB node during or after setup. For example, the mobility profile information may be stored in a memory such as the ROM 1007 or the data storage means 1004 of the mIAB node. The setup can be performed at the factory or as part of the process of mounting the mIAB node on the vehicle when the mIAB node is a vehicle-mounted relay (VMR). The mobility profile information can be subsequently configured or updated based on specific or known changes to the mobility of the mIAB node that depend on specific or known changes to the mobility of the vehicle on which the mIAB node is mounted. The mobility profile information can be configured or updated based on tracking the previous movements of the mIAB node and / or the vehicle on which the mIAB node is mounted or will be mounted.

[0091] The guaranteed stationary time information (or minimum stationary time information) indicates the minimum period for which the mIAB node remains at a particular location. For example, this information indicates the actual period for which a currently stationary mIAB node has been stationary at a particular location. Thus, the guaranteed stationary time information corresponds to a dynamic parameter. For example, for an mIAB node mounted on a train that is currently stopped at a station, based on the train timetable and / or the train route information (e.g., provided in the mobility profile information), the guaranteed stationary time information can indicate the minimum time for which the mIAB node remains stationary. The guaranteed stationary time information can be determined by the mIAB node when the mIAB is stationary based on the mobility profile information and can be included in the mobility message. Thus, whenever the mIAB node is stationary at a given location and the mIAB node has determined the actual period for which it has remained stationary or placed at that location, a mobility message including the guaranteed stationary time information can be provided.

[0092] The mobility message provided by the mIAB node can further include at least one of mobile node indication information indicating whether the mIAB node is a mobile IAB or mobility status indication information indicating the current status of the mobility of the mIAB node. The current status of the mobility can include whether the mIAB node is currently moving or stationary, and can further include additional information regarding the nature of the movement, such as the current speed, regardless of whether the mIAB node is accelerating or decelerating.

[0093] In one example, the mIAB node obtains mobility profile information and / or stationary time information (e.g., from memory) and generates a mobility message based on the obtained information.

[0094] By providing mobility profile information and / or guaranteed stationary time information (e.g., at setup time and / or after one or more connections to the mobile IAB node are established), a receiving wireless communication device (such as an IAB donor CU, UE, or another IAB node) can receive information about the mobile capabilities and / or current mobility status of the mobile IAB node, and further, can operate appropriately based on additional information about the mobility of the mobile IAB node. For example, a UE or another IAB node may decide not to initiate a connection to a network (e.g., the IAB network system of FIG. 4 or the NG RAN) via or through the mobile IAB node based on the provided information, or a UE or another IAB may decide to initiate a connection through the mobile IAB node, but at the same time, may initiate a cell search procedure to find another IAB node to use for connecting to the network. In another example, the IAB donor CU can decide not to accept a connection request for a connection through the mobile IAB node from a new IAB node (or UE) for the mobility of the mobile IAB node. For example, the IAB donor CU can prevent a new UE / IAB node from connecting to the network through the mobile IAB node if the new UE / IAB node is a legacy device (this will be described in more detail below with reference to FIG. 8). In another example, after a connection is established, a mobility message is provided, and when the information in the mobility message indicates a change in the mobility of the mobile IAB node (e.g., a change in the mobility status and / or mobility capabilities of the mobile IAB (e.g., a change in the guaranteed stationary time information)), along with the additional information about the mobility of the mobile IAB node, the wireless communication device can operate accordingly. For example, if the change is significant, the IAB donor CU may decide to release the established connection.

[0095] The mobility message can be a mobility indication message (e.g., mobility indication message 521 described in more detail below) provided or sent by the mIAB node to the IAB donor node (such as IAB donor CU 401). The IAB donor node receiving the mobility message from the mIAB node (such as mIAB node 470) may be an IAB donor CU connected to the mIAB node. For example, it can be an IAB donor CU connected to and controlling the mIAB node (such as IAB donor CU 401 controlling mIAB node 470), or when the mIAB node operates as a boundary node, the IAB donor CU can be one or more IAB donor CUs to which the mIAB node is connected (such as IAB donor CUs 401 and / or 402 connected to mIAB node 470 when the mIAB node operates as a boundary node). Additionally or alternatively, the mobility message can be a mobility information message (e.g., mobility information message 531 described in more detail below) provided or sent by the mIAB node to one or more other IAB nodes (such as IAB nodes 430, 450, etc.) or one or more UEs (such as UE 390, etc.). For example, the mIAB node (such as mIAB node 470) can send a mobility indication message to an IAB donor CU (such as IAB donor CU 401) connected to the mIAB node, and can also send a mobility information message to one or more other IAB nodes and / or one or more UEs.

[0096] The mobility indication message provided by the mIAB node to the IAB donor node may further include at least one of mobile node indication information indicating whether the mIAB node is a mobile IAB, or mobility status indication information indicating the current status of the mIAB node's mobility. The current status of the mobility can include whether the mIAB node is currently moving or stationary, and can also include additional information regarding the characteristics of the movement, such as the current speed, regardless of whether the mIAB node is accelerating or decelerating.

[0097] The mobility indication message can be provided by the mIAB node to the IAB donor node (when the mIAB node is the IAB node 470 controlled by the IAB donor CU401, such as the IAB donor CU401, etc.) in response to one of the following events: 1) after the mIAB node starts an IAB node setup procedure such as a connection establishment procedure (for example, an RRC connection establishment procedure as specified in 3GPP (registered trademark) TS 38.331 and 3GPP (registered trademark) TS 38.401, or an F1 setup procedure, as discussed in more detail below with respect to FIGS. 5 and 6), 2) in response to the mIAB node determining that there is a change in the mobility of the mIAB node (for example, a change in the mobility status such as a change in speed and / or a change in mobility capabilities, and / or a change in mobility profile information such as a change in the journey, and / or a change in the guaranteed stationary time information such as when the mIAB stops at a location and determines a new period during which the mIAB remains stationary at that location), 3) after the elapse of a specific period since the previous mobility indication message was sent, which can be the same or variable between transmissions, such that the mobility indication message is provided periodically, 4) in response to a request from the IAB donor node (such as the IAB donor CU401). For example, the IAB donor node can send a request for the latest mobility status information, the mobility indication message includes the latest mobility status information (for example, the latest mobility profile information and / or the guaranteed stationary time information), and the mobility status indication information is provided in response to the request, as will be explained in more detail below.

[0098] The mobility information message provided (e.g., transmitted) by the mIAB node to one or more UEs (such as UE390) and / or one or more other IAB nodes (such as IAB nodes 430, 450, 460, 480) can be provided in response to one of the following events: 1) after completion of the IAB node setup procedure (e.g., the RRC connection establishment procedure or the F1 setup procedure discussed in more detail below with respect to FIGS. 5 and 6), 2) in response to the mIAB node determining that there has been a change in the mobility of the mIAB node (e.g., a change in the mobility status and / or mobility capabilities such as a change in speed, and / or a change in the mobility profile information such as a change in the journey, and / or a change in the guaranteed stationary time information such as when the mIAB stops at a location and the mIAB determines a new period of being stationary at that location), 3) after the elapse of a predetermined period since the previous mobility information message was transmitted, which can be the same or variable between transmissions, as a result of which the mobility indication message is provided periodically.

[0099] By providing or transmitting a mobility information message having mobility profile information and / or guaranteed stationary time information, the mIAB node can advertise its mobility capabilities and / or status to one or more UEs and one or more other IAB nodes in the vicinity of the mIAB node. Upon receiving the mobility information provided in the mobility information message, the UE and / or other IAB nodes can determine how to operate based on the mobility of the mIAB node as indicated by the provided mobility information. Using additional information regarding the mobility capabilities of the mIAB node and / or guaranteed stationary time information, the UE and / or other IAB nodes have additional information and can thus operate more effectively. For example, the UE and / or another IAB node can determine not to connect to the network via the mIAB node for its mobility, or can determine to connect regardless of the mobility of the mIAB node (e.g., for information indicating that the mIAB node is moving slowly or is within a limited area). In another example, if the UE and / or another IAB node is already connected, the UE and / or another IAB node can determine to initiate a cell search procedure to look for a connection or handover to another IAB node.

[0100] The mIAB node can provide a mobility information message to one or more UEs (such as UE390) and / or one or more other IAB nodes (such as IAB nodes 430, 450, 460, 480, etc.) by broadcasting, for example, in the SIB1 message.

[0101] The mobility information message provided by the mIAB node to one or more UEs and / or one or more other IAB nodes may further include a connectivity support indicator (also referred to as an IAB support indicator or IAB support information or connectivity support information) for indicating whether the mIAB node can support network connectivity for a wireless communication device (such as a UE or another IAB node). The ability of the mIAB node to support network connectivity for other wireless communication devices (e.g., whether a reliable wireless link can be established and maintained between the mIAB node and other wireless communication devices) depends on the mobility of the mIAB node (e.g., the mobility capability and / or current mobility status of the mIAB node). In some cases, the movement of the mIAB node may mean that the mIAB node cannot support network connectivity. In one example, when the mIAB node can support network connectivity, the mIAB node sets or enables the connectivity support indicator or IAB or connectivity support information by including the IAB support information or connectivity support information in the mobility information message (e.g., within a field of the mobility information message) to indicate that the network connectivity can be supported by the mIAB node. The IAB or connectivity support information may include information indicating that the mIAB node can support network connectivity and / or that the cell associated with the mIAB node can be considered as a candidate for cell (re)-selection. When the mIAB node cannot support network connectivity, the mIAB node does not set or invalidate the connectivity support indicator or IAB or connectivity support information by not including the IAB support information or connectivity support information in the mobility information message to indicate that the network connectivity cannot be supported by the mIAB node.For example, when the mIAB node can support network connectivity, a field indicating both the support by the mIAB node and the cell status is included in the mobility information message, and when the mIAB node cannot support network connectivity and / or when the cell associated with the mIAB node is prohibited for the wireless communication device, the field is not included. Therefore, the presence or absence of the field in the mobility information message provided by the mIAB node indicates whether network connectivity is supported respectively. In other words, the mIAB node performs conditional IAB support management to determine whether the mIAB node can support network connectivity, and based on the determination, determines whether to include IAB support information in the mobility information message or not. In an alternative configuration, the mobility information message may include a connectivity support indicator that can be set to one value indicating that the mIAB node cannot support network connectivity and another value indicating that the mIAB node can support network connectivity.

[0102] The mIAB node can determine whether the mIAB node can support network connectivity, and thus whether the mIAB node sets a connectivity support indicator or IAB support information or connectivity support information, based on the mobility of the mIAB node (e.g., based on the mobility capability of the mIAB node as indicated in the mobility profile information of the mIAB node) and / or based on the guaranteed stationary time information and / or the current mobility status of the mIAB node. As described above, the mobility profile information and / or the guaranteed stationary time information, and any subsequent updates if necessary, are stored in the IAB node (e.g., at setup or later) and can be used to determine whether the IAB node can support network connectivity.

[0103] In another configuration, an IAB donor node (e.g., IAB donor CU 401) connected to an IAB node (e.g., IAB node 470 managed by IAB donor CU 401) can determine whether an mIAB node can support network connectivity, and thus whether the mIAB node can set a connectivity support indicator or IAB support information or connectivity support information (e.g., including connectivity support information in a field or mobility information message having IAB) based on the mobility of the mIAB node. The IAB donor node can determine the mobility of the mIAB node based on mobility information (such as mobility profile information and / or guaranteed stationary time information, etc.) received from the mIAB node. The mobility information may be provided to the IAB donor node by the mIAB node during IAB node setup or subsequently, or in a mobility indication message as described above. Based on the mobility information provided in the mobility indication message, the IAB donor node can determine whether the mIAB node can support network connectivity, and can send a connectivity or IAB support configuration message (e.g., an RRC reconfiguration message described below with reference to FIG. 5) indicating whether the mIAB node can support network connectivity to the mIAB node. Next, the mIAB node can determine whether it can support network connectivity and whether the mIAB node can set a connectivity support indicator or IAB support information or connectivity support information based on the received connectivity or IAB support configuration message.

[0104] In response to determining that the mIAB node can support network connectivity, the mIAB node can provide a mobility information message including IAB support information for indicating network connectivity for wireless communication devices that can be supported by the IAB node.

[0105] In one example, either the mIAB node or the IAB donor node determines that the mIAB node is stationary or will be stationary for a period longer than a predetermined threshold (for example, the threshold may be as low as several tens of seconds), or when the mIAB node is moving with limited mobility, it is determined that the mIAB node can support network connectivity. The mobility of the mIAB node is restricted when at least one of the following criteria or conditions is met: the speed of the mIAB node is below a certain threshold (for example, the actual speed of the mIAB node (as indicated by, for example, speed-related information in mobility state (status) indication information or mobility profile information) is below a predefined threshold), the mobility area where the mIAB node is moving or will move is geographically restricted, the mobility area is within one topology or one network cell (for example, the information in the mobility profile information indicates that the mIAB node stays under the same topology or the same network cell). The geographically restricted mobility area is an area where the mIAB node is moving or will move, and may include an area whose size is below a predetermined or predefined threshold, or may include a type or category belonging to a type or category considered to be geographically restricted (that is, having a size below a certain threshold). Such a type or category having a limited size can include a parking lot.

[0106] In another example, when it is determined that the mIAB node is in motion or is a mobile node (i.e., has the ability to move), the mIAB node is determined to be unable to support network connectivity.

[0107] The mobility information message may further include at least one of mobile node indication information indicating whether the mIAB node is a mobile IAB node, mobility status indication information indicating the current status of the mobility of the mIAB node, and mobile IAB cell indication information for indicating the cell associated with the mobile IAB node (e.g., a cell ID may be included in the mobility information message). The current status of the mobility can include whether the mIAB node is currently moving or stationary, and can also include additional information regarding the nature of the movement such as the current speed, and / or whether the mIAB node is accelerating or decelerating.

[0108] Further details regarding the mobility indication message sent to the IAB donor node, and the mobility information message sent to other IAB nodes or UEs, are given below.

[0109] Next, referring to FIG. 12 showing the steps of an exemplary method 1200 according to an embodiment of the present invention, the method is executed at a wireless communication device upon receipt of a mobility information message transmitted by an IAB node of a wireless communication system, where the IAB node is controlled by an IAB donor node. The method 1200 may be used to manage network connectivity in a wireless communication system including at least one mobile integrated access and backhaul (mIAB). The wireless communication device executing the method 1200 may be another IAB node or a UE in the wireless communication system, and any of them may operate in the vicinity of the IAB node to receive the mobility information message. For example, with respect to the wireless communication system shown and described with respect to FIG. 4, the wireless communication device executing the method 1200 may be the IAB donor CU401 of the IAB topology 4002 controlled by the IAB donor CU402 or the IAB node 460 of the IAB topology 4001 controlled by the IAB node 440, or the UE 390 and the IAB node providing the mobility message may be the mobile IAB node, the IAB node 470, controlled by the IAB donor CU401. The method 1200 shown and described with respect to FIG. 12 may be executed by software elements and / or hardware elements. The wireless communication device executing the method 1200 may be implemented in the communication device 1000 as shown and described with respect to FIG. 10, using the method shown and described with respect to FIG. 12, executed by one or more processing units such as the central processing unit 1011.

[0110] Briefly stated, in step 1201, the wireless communication device receives a mobility information message from the IAB node. The wireless communication device then, in step 1202, executes an action based at least in part on the information provided by the received mobility information message. The IAB node transmitting the mobility information message may be a mobile IAB node or a fixed IAB node (in the sense that the IAB node is fixed at one location).

[0111] When the IAB node is a mobile IAB node, an mIAB node, the mobility information message includes at least one of mobility profile information indicating the mobility capability of the IAB node and guaranteed stationary time information indicating the minimum period for which the IAB node stays at a certain position. The mobility profile information can include at least one of speed information indicating the speed capability of the IAB node, range information indicating the mobility area of the IAB node, stationary information indicating the duration of one or more stationary periods that the IAB node can experience, and itinerary information indicating the sequence of mobility and stationary periods regarding the itinerary that the IAB node can follow. The mobility information message can further include at least one of mobile node indication information indicating whether the IAB node is a mobile IAB node, mobility status indication information indicating the current status of the mobility of the IAB node, mobile IAB cell indication information associated with the mobile IAB node for indicating a cell (for example, a cell ID is included in the mobility information message), and IAB support information or connectivity support information (also called a connectivity indicator) for indicating whether the IAB node can support network connectivity for a wireless communication device (such as a UE or another IAB node). Further details of the mobility information included in the mobility information message provided by the IAB node and received at the wireless communication device are given above in relation to FIG. 11.

[0112] When the IAB node is a fixed IAB node, the mobility information message can include mobile node indication information indicating that the IAB node is not a mobile IAB node.

[0113] Upon receiving the mobility information provided in the mobility information message, the UE and / or other IAB nodes can determine how to operate based on the mobility of the mIAB node as indicated by the provided mobility information. Using additional information regarding the mobility capabilities of the mIAB node and / or guaranteed stationary time information, the UE and / or other IAB nodes have additional information and can thus operate more effectively as described above.

[0114] In one example, performing the action at step 1202 may include determining whether to initiate a connection establishment procedure or setup procedure to establish a connection to the network (e.g., the IAB network system or NG RAN of FIG. 4) via an IAB node, such as an RRC connection establishment procedure, based on the mobility information message. The wireless communication device may determine not to initiate the connection establishment procedure when the information provided by the mobility information message indicates that the IAB node is a mobile IAB node. The wireless communication device may determine to initiate the connection establishment procedure when the information provided by the mobility information message indicates that several criteria are met. The predetermined criteria include: 1) the IAB node is not a mobile IAB node; 2) the IAB node is a mobile IAB node and is stationary or has been stationary for a period longer than a predetermined threshold; 3) the IAB node is a mobile IAB node and is moving with limited mobility. As described above, the criteria for limited mobility include that the speed of the mIAB node is below a predetermined threshold, the mobility area is geographically restricted, and the mobility area is within one topology or one network cell.

[0115] When the wireless communication device determines that the connection establishment procedure should be started, performing the action in step 1202 may further include sending a request to an IAB donor node (e.g., IAB donor CU 401) via an IAB node (e.g., IAB node 470) to request the establishment of a connection via the IAB node. The request is sent as part of a connection establishment procedure such as an RRC connection establishment procedure. When the wireless communication device is a UE (such as UE 390), the requested connection is with the IAB topology of an IAB node (IAB node 470) managed by an IAB donor node (e.g., topology 4001 managed by donor CU 401), and when the connection procedure is completed, the UE will be connected to the IAB node (IAB node 470) via a communication link or a wireless link. When the wireless communication device is an IAB node (such as IAB node 460), the requested connection involves the IAB topology of an IAB node (IAB node 470) managed by an IAB donor node (e.g., topology 4001 managed by donor CU 401), and when the connection procedure is completed, the IAB node (such as IAB node 460) or another IAB node will be connected to the IAB node (IAB node 470) via a backhaul (BH) communication link or a BH link. In response to the request, the wireless communication device receives a configuration message from the IAB donor node (e.g., donor CU 401). For example, the configuration message received at the wireless communication device (UE or IAB node) indicating that the connection via the IAB node has been accepted may be an RRCSetup message, or a configuration message indicating that the connection via the IAB node has been rejected may be an RRCReject message instead of the RRCSetup message specified in 3GPP (registered trademark) TS 38.331.The wireless communication device is an IAB node (such as IAB node 460), and after the IAB node 460 is connected to the IAB node 470, the configuration message may indicate that the BH link between the IAB node and the mobile IAB node has been rejected or configured. In this case, the configuration message may be an RRCReconfiguration message as defined in 3GPP (registered trademark) TS 38.331 (such as the CONFIGURATION INFORMATION message 732 described in FIG. 7).

[0116] In one example, when the connection via the IAB node is rejected because the IAB node is a mobile IAB node or the cell associated with the IAB node (or the cell during the requested connection) is a mobile cell, the configuration message indicates the reason for the connection rejection (e.g., indicates that the connection was rejected because the IAB node is a mobile IAB node or the cell associated with the IAB node (or the cell during the requested connection) is a mobile cell). The configuration message includes the IAB configuration rejection cause information. As will be described in more detail below with respect to FIG. 7, when the UE sends a request to establish a connection via the IAB node as part of the connection establishment procedure, the rejection cause information may include MobileCellConnectionReject indicating that the connection request (connection request) was rejected because an attempt was made to connect to the network via the mobile IAB node, or mobile cell connection rejection information (Mobile Cell connection rejection information). As will be described in more detail below with respect to FIG. 7, when the IAB node sends a request to establish a connection via the IAB node as part of the connection establishment procedure, the rejection cause information may include iab-configRejectCause, or IAB configuration rejection cause information (IAB configuration Rejection Cause information). The configuration message may further include IAB configuration rejection information indicating that the connection was rejected.

[0117] When a connection via an IAB node is accepted, the configuration message includes IAB configuration acceptance information indicating that the connection has been accepted. When the IAB node is a mobile IAB node, regardless of whether the connection via the IAB node is accepted or rejected, the configuration message can include mobility profile information indicating the mobility capabilities of the IAB node. Details of the mobility profile information have been described above. Such cause information, and when provided, the mobility profile information can help the wireless communication device efficiently determine what to do next, for example, select an alternative IAB node to attempt to establish a connection without using resources, retry the connection with the mobile IAB node, or if the information provided indicates that the mobile IAB node is moving slowly or within a limited area, the wireless communication device can attempt to re - establish the connection via the mobile IAB node.

[0118] When the IAB node is a mobile IAB node and the wireless communication device is another IAB node (e.g., a child IAB node), the configuration message can further include mobile parent IAB node indication information indicating that the parent IAB node is a mobile IAB node and the associated cell is a mobile cell.

[0119] When a wireless communication device is another IAB node (i.e., a child IAB node) connected to an IAB node (i.e., a parent IAB node), for example, the MT part of IAB node 460 is connected to the DU part of IAB node 470 after the completion of the connection establishment procedure, and performing an action is based on the information provided by the received mobility information message received from the IAB node, and includes providing a mobility capability message (such as mobility information (MOBILITY INFORMATION) message 541 described below with reference to FIG. 5) including information indicating the mobility capability of the IAB node. The mobility capability message includes information indicating the mobility capability of the IAB node based on the information provided by the received mobility information message received from the IAB node. The mobility capability message can be transmitted (e.g., via broadcast) to all nodes (e.g., UEs and IAB nodes) in the vicinity of the child IAB node. The mobility capability message can include all or part of the information received from the IAB node in the mobility information message, such as mobility profile information and / or guaranteed dwell time information, and / or mobile node indication information and / or mobility status indication information and / or IAB support information, etc., as described above. Further, the mobility capability message can further include identifier information for identifying the IAB node, such as the unique BAP address of the IAB node. When the IAB node is a boundary node, the BAP address included in the mobility capability message is the BAP address configured by the IAB donor CU that controls the child IAB node (i.e., the BAP address of the same topology to which the child IAB node belongs).

[0120] When the wireless communication device is another IAB node (i.e., a child IAB node) connected to an IAB node (i.e., a parent IAB node), for example, the MT part of IAB node 460 is connected to the DU part of IAB node 470 after the completion of the connection establishment procedure. Performing an action may include determining a radio link failure (RLF) for a radio link (i.e., a BH link) with the parent IAB node based on the information provided by the received mobility information message, and transmitting an RLF indication message. The RLF indication message includes information indicating that the cause of the RLF is related to the mobility of the parent IAB node. For example, the information provided by the received mobility information message may indicate that the parent IAB node is a mobile IAB node, or has recently become a mobile IAB node, or was previously a mobile IAB node but has recently changed its mobility status or capabilities (e.g., is moving out of range), as a result of which the RLF occurs on the BH link between the child IAB node and the parent IAB node. The RLF indication message is received by the child IAB node(s) of the child IAB node (currently operating as a parent), and the child IAB node(s) can operate accordingly.

[0121] Another exemplary method performed in a wireless communication device of a wireless communication system according to an embodiment of the present invention is described herein. The wireless communication system further comprises an IAB node controlled by an IAB donor node. Similar to the method described above, this method can be used to manage network connectivity in a wireless communication system including at least one mobile integrated access and backhaul (mIAB) node. The wireless communication device may be another IAB node or a UE within the wireless communication system. The wireless communication device determines to initiate a connection establishment procedure for connecting to a network (e.g., the IAB network system of FIG. 4 or the NG RAN) via an IAB node: for example, the wireless communication device is either operating in the vicinity of an IAB node or has previously operated in the vicinity of a moving IAB node. Referring to the wireless communication system shown and described in FIG. 4, for example, the wireless communication device may be an IAB node 460 of IAB topology 4001 controlled by an IAB donor CU401 or an IAB node 440 of IAB topology 4002 controlled by an IAB donor CU402 or a UE 390, and the IAB node to which the wireless communication device wishes to connect may be a mobile IAB node, IAB node 470, controlled by an IAB donor CU401. This method may be performed by software elements and / or hardware elements. The wireless communication device performing the method may be implemented in communication device 1000 by a method performed by one or more processing units such as central processing unit 1011, as shown in and described with reference to FIG. 10.

[0122] The wireless communication device sends a request to an IAB donor node (e.g., IAB donor CU 401) via an IAB node (e.g., IAB node 470) to request the establishment of a connection via the IAB node (IAB node 470). The request is sent as part of a connection establishment procedure such as an RRC connection establishment procedure. In response to the request, the wireless communication device receives a configuration message from the IAB donor node (e.g., donor CU 401). As described below, the configuration message can be an RRCSetup message or an RRCReject message or an RRCReconfiguration message. In one example, when the connection to the IAB node is rejected, the configuration message indicates the reason for the connection rejection (e.g., because the IAB node is a mobile IAB node or the cell associated with the IAB node (or the requested connection cell) is a mobile cell, indicating that the connection has been rejected), and includes IAB configuration rejection cause information. As described in more detail below with respect to FIG. 7, when the UE sends a request to establish a connection via an IAB node as part of a connection establishment procedure, the rejection cause information may include MobileCellConnectionReject indicating to the UE that the connection request was rejected because it attempted to connect to the network via a mobile IAB node, or mobile cell connection rejection information (Mobile Cell connection rejection information). As described in more detail below with respect to FIG. 7, when the IAB node sends a request to establish a connection via an IAB node as part of a connection establishment procedure, the rejection cause information can include iab-configRejectCause, or IAB configuration rejection cause information (IAB configuration Rejection Cause information). The configuration message may further include IAB configuration rejection information indicating that the connection has been rejected.

[0123] When a connection to an IAB node is accepted, the configuration message includes IAB configuration acceptance information (e.g., configured BH link) indicating that the connection has been accepted. When the IAB node is a mobile IAB node, the configuration message may include mobility profile information indicating the mobility capabilities of the IAB node, whether the connection to the IAB node has been accepted or rejected. Details of the mobility profile information are described above. The advantages of providing such cause information, and when provided, the mobility profile information, are described above.

[0124] When the IAB node is a mobile IAB node and the wireless communication device is another IAB node (e.g., a child IAB node), the configuration message may further include mobile parent IAB node indication information indicating that the parent IAB node is a mobile IAB node and the associated cell is a mobile cell.

[0125] Referring now to FIG. 13, which shows steps of an exemplary method 1300 according to an embodiment of the present invention, it is performed at an IAB donor node of a wireless communication system upon receipt of a mobility indication message sent by an IAB node, where the IAB node is connected to the IAB donor node. The IAB donor node may be an IAB donor CU (such as an IAB donor CU 401 that controls an IAB node 470) that is connected to the IAB node and controls the IAB node. When the IAB node operates as a boundary node, the IAB donor CU may be one or more IAB donor CUs to which the IAB node is connected (such as IAB donor CUs 401 and / or 402 both connected to the IAB node 470 when the IAB node 470 operates as a boundary node). The method 1300 may be used to manage network connectivity in a wireless communication system that includes at least one mobile integrated access and backhaul (mIAB). The IAB donor node may be an IAB donor CU. For example, referring to the wireless communication system shown and described with respect to FIG. 4, the IAB donor node may be an IAB donor CU 401, and the IAB node may be an IAB node 470 controlled by the IAB donor CU 401. The method 1300 shown and described with respect to FIG. 13 may be executed by software elements and / or hardware elements. The IAB donor node that executes the method 1300 may be implemented in a communication device 1000 as shown and described with respect to FIG. 10, in a method shown and described with respect to FIG. 13, and executed by one or more processing units such as a central processing unit 1011.

[0126] Briefly stated, in step 1301, the IAB donor node receives a mobility indication message from the IAB node. The IAB donor node then, in step 1302, executes an action based at least in part on the information provided by the received mobility indication message. The mobility indication message is received at the CU part of the IAB donor node (i.e., the IAB donor CU), and the IAB donor CU executes an operation (action). For example, the IAB donor CU 401 receives a mobility indication message from the IAB node 470.

[0127] The mobility indication message includes at least one of the mobility capabilities of the IAB node as specific mobility profile information and guaranteed stationary time information indicating the minimum period for which the IAB node stays at a given location. The mobility profile information can include at least one of speed information indicating the speed capability of the IAB node, range information indicating the mobility area of the IAB node, stationary information indicating the duration of one or more stationary periods that the IAB node may experience, and itinerary information indicating the sequence of mobility and stationary periods for an itinerary that the IAB node may follow.

[0128] The mobility indication message may further include at least one of mobile node indication information indicating whether the IAB node is a mobile IAB node and mobility status indication information indicating the current status of the mobility of the IAB node. The details of the information (e.g., mobility profile information, guaranteed stationary time information, etc.) included in the mobility indication message provided by the IAB node and received at the IAB donor node are given above in relation to FIG. 11.

[0129] Upon receiving the mobility information provided within the mobility indication message, the IAB donor node or the IAB donor CU can determine how to operate based on the mobility of the IAB node as indicated by the provided mobility information. Using additional information regarding the mobility capabilities and / or guaranteed stationary time information of the IAB node, the IAB donor node has the additional information and can thus operate more effectively as described above.

[0130] In one example, performing the action at step 1302 may include the IAB donor node sending a notification message, based on the information provided in the mobility indication message, to indicate that the IAB node is a mobile IAB node to one or more of another IAB node (e.g., IAB node 430), a UE (e.g., UE 390), or the CU of an IAB donor node of another IAB topology different from the topology controlled by the IAB donor node (e.g., IAB donor CU 401 sends a notification to IAB donor CU 402 of IAB topology 4002). By sending the notification, the IAB donor node can provide information regarding the mobility of the IAB node to other wireless communication devices within the wireless communication system, which can help other devices operate accordingly. By providing a notification message indicating the mobility of the IAB node to the CU of an IAB donor node of another IAB topology (e.g., IAB donor CU 402), when the IAB node moves into the coverage of another IAB topology (e.g., when IAB node 470 moves into the coverage of IAB topology 4002), the mobility information can be used by the IAB donor CU of the other topology to manage the migration of the IAB node to the other topology.

[0131] The IAB donor node can receive a mobility indication message as part of the IAB node setup procedure with an IAB node (e.g., the RRC connection establishment procedure specified in 3GPP (registered trademark) TS 38.331 or the F1 setup procedure, as will be described in more detail below with respect to FIGS. 5 and 6). Alternatively or additionally, the IAB donor node can receive a mobility indication message in response to a message sent by the donor IAB node. For example, the IAB donor node can send a request for the latest mobility status information, the mobility indication message includes the latest mobility status information (e.g., the latest mobility profile information and / or guaranteed stationary time information), and the mobility status indication information is provided in response to the request as will be described in more detail below. Alternatively or additionally, the IAB donor node can receive a mobility indication message in response to an IAB node that determines a change in mobility (e.g., there is a change in the mobility status such as a change in speed, and / or there is a change in the mobility profile information such as a change in the travel route, and / or there is a change in the guaranteed stationary time information). Alternatively or additionally, the IAB donor node can receive a mobility indication message from the IAB node periodically, and the time between receptions of the mobility indication message is the same or variable.

[0132] In one example, when a mobility indication message is received as part of the IAB node setup procedure, the IAB donor node completes the IAB node setup procedure with the IAB node. The information provided in the mobility indication message is stored by the IAB donor node for the IAB node. Subsequently, when receiving a request from a wireless communication device, which can be a UE or another IAB node, to establish a connection via the IAB node as part of a connection establishment procedure (e.g., an RRC connection establishment procedure), performing action 1302 can include determining whether to accept or reject (i.e., accept or not accept) the connection via the IAB node, at least partially based on the mobility of the IAB node. In response to determining whether to accept or reject the connection request, the IAB donor node then transmits a configuration message indicating whether the connection with the IAB node has been accepted or rejected to the wireless communication device (e.g., a UE or another IAB node). For example, the configuration message indicating that the connection via the IAB node has been accepted may be an RRCSetup message, or instead of the RRCSetup message, an RRCReject message, as defined in 3GPP™ TS 38.331 for a configuration message indicating that the connection via the IAB node has been rejected. If the wireless communication device is an IAB node (such as IAB node 460), after IAB node 460 is connected to IAB node 470, the configuration message may indicate that the BH link between the IAB node and the mobile IAB node has been rejected or configured. In this case, the configuration message can be an RRCReconfiguration message as defined in 3GPP™ TS 38.331 (such as CONFIGURATION INFORMATION message 732 as described in Figure 7).

[0133] The IAB donor node can determine whether to accept or reject a connection via an IAB node based on information provided by a mobility indication message received at the IAB donor node (e.g., received as part of a setup procedure or received later). As described above, the mobility indication message includes mobility profile information and / or guaranteed stationary time information, which can be used to determine whether a connection should be accepted or rejected. For example, the IAB donor node can make a determination based on the mobility profile information. The mobility indication message (e.g., periodically received from the IAB node when the IAB node detects a change in its mobility, such as a change in mobility status and / or mobility capabilities, received in response to a request from the IAB donor CU, received as part of a setup procedure, or received later) can further include mobility status information indicating the current status of the IAB node's mobility. In that case, the IAB donor node can determine whether to accept or reject a connection via the IAB node based on the current status of the IAB node's mobility. In one example, the IAB donor node can determine whether to accept or reject a connection via the IAB node based on the current status of the IAB node's mobility and the IAB node's mobility capabilities as indicated by the mobility profile information. The IAB donor node can decide to reject a connection request when the IAB node is a mobile IAB node or when the IAB node is a mobile IAB node with mobility capabilities and / or a current mobility status that is likely to cause problems for the connection (e.g., the mobility area of the IAB node is large, the average speed exceeds a threshold, the current speed exceeds a threshold, etc.).

[0134] In one example, when a connection via an IAB node is rejected based on the mobility of the IAB node (e.g., because the IAB node is a mobile IAB node or the cell associated with the IAB node is a mobile cell), the configuration message indicates the reason for the connection rejection (e.g., indicates that the connection was rejected because the IAB node is a mobile IAB node or the cell associated with the IAB node is a mobile cell), and includes IAB configuration rejection cause information. As will be described in more detail below with respect to FIG. 7, when the UE sends a request to establish a connection via an IAB node as part of the connection establishment procedure, the rejection cause information may indicate to the UE that the connection request was rejected because it attempted to connect to the network via a mobile IAB node, including MobileCellConnectionReject or mobile cell connection rejection information. As will be described in more detail below with respect to FIG. 7, when the IAB node sends a request to establish a connection via an IAB node as part of the connection establishment procedure, the rejection cause information may include iab-configRejectCause, or IAB configuration rejection cause information. The configuration message may further include IAB configuration rejection information indicating that the connection was rejected.

[0135] When a connection via an IAB node is accepted, the configuration message includes IAB configuration acceptance information indicating that the connection was accepted. When the IAB node is a mobile IAB node, regardless of whether the connection via the IAB node is accepted or rejected, the configuration message may include mobility profile information indicating the mobility capabilities of the IAB node. Details of the mobility profile information have been described above. The advantages of providing such cause information and, when provided, mobility profile information have been described above.

[0136] When the IAB node is a mobile IAB node and the wireless communication device is another IAB node (e.g., a child IAB node), the configuration message may further include mobile parent IAB node indication information indicating that the IAB node is a mobile parent IAB node and the associated cell is a mobile cell.

[0137] In one example, the IAB donor node performing action 1302 may include determining whether to enable or disable network connectivity support by the IAB node, at least in part based on the mobility of the IAB node, and based on the determination, transmitting a connectivity or IAB support configuration message (e.g., an RRC reconfiguration message described below with reference to FIG. 5) to the IAB node to indicate whether the IAB node can support network connectivity for the wireless communication device. The wireless communication device can be a UE or another IAB node. The IAB donor node can make a determination based on the information provided by the mobility indication message. In one example, the determination can be made based on the current status of the mobility of the IAB node (if the information is included in the mobility indication message) and / or the mobility capabilities of the IAB node, as indicated by the mobility profile information and / or the guaranteed stationary time information of the IAB node. Further details of the connectivity or IAB support configuration message are discussed above with reference to FIG. 11.

[0138] The IAB donor node may determine to disable network connectivity support when the IAB node is a mobile IAB node, or when the IAB node has mobility capabilities and / or a current mobility status that is likely to cause connection problems (for example, the mobility area of the IAB node is large, the average speed exceeds a threshold, the current speed exceeds a threshold, etc.). The IAB donor node can determine to enable network connectivity support when the IAB node is stationary or has been stationary for a period longer than a predetermined threshold, or when the IAB node is moving with limited mobility. In one example, the mobility of the IAB node is restricted when at least one of the following criteria or conditions is met: the speed of the IAB node is below a predetermined threshold; the mobility area is geographically restricted; the mobility area is within one topology or one network cell. For details of the restricted mobility criteria, see the above (for example, the description of FIG. 11).

[0139] In an example where the IAB donor node receives a new mobility indication message containing updated information compared to a previously received mobility indication message (for example, the mobility profile information has been updated and / or the mobility status information indicating the current status of the IAB node's mobility), performing an action involves determining whether one or more wireless communication devices connected to the IAB node (for example, one or more UEs and / or one or more other IAB nodes) should be released based on the information provided by the new mobility indication message, and transmitting a release notification to the one or more wireless communication devices in response to determining that the one or more wireless communication devices should be released.

[0140] FIG. 14 shows steps of an exemplary method 1400 for use in managing network connectivity in a wireless communication system including at least one integrated access and backhaul (IAB) node of the wireless communication system according to an embodiment of the present invention. The method 1400 of FIG. 14 is executed at an IAB node. For example, referring to the wireless communication system shown and described with respect to FIG. 4, the IAB node executing the method 1400 can be the IAB node 470 of the IAB topology 4001 controlled by the IAB donor CU 401. The method 1400 shown and described with respect to FIG. 14 can be executed by software elements and / or hardware elements. The IAB node can be implemented in the communication device 1000 shown and described with respect to FIG. 10 such that the method shown and described with respect to FIG. 14 is executed by one or more processing units such as the central processing unit 1011.

[0141] Briefly stated, in step 1401, an IAB node (e.g., IAB node 470) determines, based on the mobility of the IAB node, whether the IAB node can support network connectivity for a wireless communication device (e.g., another IAB node or a UE). In response to determining that the IAB node can support network connectivity, in step 1402, the IAB node provides a mobility information message including IAB support information or connectivity support information (also referred to as an IAB support indicator) to indicate the network connectivity for wireless communication devices (such as a UE or another IAB node) that can be supported by the IAB node. As described above with reference to FIG. 11, the ability of an IAB node to support network connectivity for other wireless communication devices (e.g., whether a reliable wireless link can be established and maintained between the IAB node and other wireless communication devices) depends on the mobility of the IAB node (e.g., the mobility capability and / or the current mobility status of the IAB node). The mobility information message can be provided to or transmitted to one or more wireless communication devices such as one or more other IAB nodes or one or more UEs. For example, the mobility information message can be broadcast in an SIB1 message.

[0142] The mobility information message may further include at least one of the following: mobility profile information indicating the mobility capabilities of the IAB node, guaranteed stationary time information indicating the minimum period for which the IAB node remains at a given location, mobile node indication information indicating whether the IAB node is a mobile IAB node, mobility status indication information indicating the current status of the mobility of the IAB node, and mobile IAB cell indication information for indicating a cell (for example, a cell ID may be included in the mobility information message) associated with the mobile IAB node. In one example, the mobility profile information may include at least one of speed information indicating the speed capabilities of the mIAB node, range information indicating the mobility area of the mIAB node, stationary information indicating the duration of one or more stationary periods that the mIAB node may experience, and itinerary information indicating the sequence of mobility and stationary periods regarding the itinerary that the mIAB node can follow. Further details regarding the mobility information message transmitted to other IAB nodes or UEs are provided above with respect to FIG. 11.

[0143] In one example, when an IAB node can support network connectivity, the IAB node includes IAB support information or connectivity support information in a mobility information message (e.g., within a field of the mobility information message) to indicate that network connectivity can be supported by the IAB node, thereby setting or enabling the IAB support information or connectivity support information or connectivity support indicator. The IAB support information or connectivity support information can include information indicating that the IAB node can support network connectivity and / or that a cell associated with the IAB node can be considered as a candidate for cell (re)selection. When the IAB node cannot support network connectivity, the IAB node does not include the IAB support information or connectivity support information in the mobility information message to indicate that the IAB node cannot support network connectivity, thereby not setting or disabling the IAB support information or connectivity support information or connectivity support indicator in the mobility information message. For example, when the IAB node can support network connectivity, a field indicating both the support by the IAB node and the cell status is included in the mobility information message, and when the IAB node cannot support network connectivity and / or when a cell associated with the IAB node is prohibited for a wireless communication device, the field is not included. Thus, the presence or absence of a field in the mobility information message provided by the IAB node indicates whether network connectivity is supported respectively.In an alternative configuration, the mobility information message may include a connectivity support indicator that can be set to one value indicating that the mIAB node cannot support network connectivity and another value indicating that the mIAB node can support network connectivity.

[0144] The IAB node can determine whether it can support network connectivity based on the mobility of the IAB node (e.g., based on the mobility profile information of the IAB node, as shown in the mobility profile information of the IAB node) and / or based on the guaranteed stationary time information of the IAB node and / or the current mobility status. As described above, the mobility profile information and / or the guaranteed stationary time information, and any subsequent updates if necessary, are stored at the IAB node (e.g., at setup or later) and can be used to determine whether the IAB node can support network connectivity.

[0145] In another example, an IAB node (e.g., IAB node 470) can receive a connectivity or IAB support configuration message (e.g., within the RRC reconfiguration message described below with reference to FIG. 5) from a donor CU node (e.g., IAB donor CU 401) connected to an IAB node (e.g., an IAB donor CU that controls the IAB node), indicating whether the IAB node can support network connectivity. The IAB node determines whether it can support network connectivity based on the received connectivity or IAB support configuration message. In this example, the IAB donor node (e.g., IAB donor CU 401) connected to the IAB node (e.g., IAB node 470 managed by IAB donor CU 401) can determine whether the IAB node can support network connectivity, and thus, based on the mobility of the IAB node, whether to include connectivity support information in the mobility information message (e.g., include a field in the mobility information message or not). For example, as described above with reference to FIGS. 11 and / or 13, the IAB donor node (e.g., IAB donor CU 401) can determine the mobility of the IAB node based on the mobility information (such as mobility profile information and / or guaranteed idle time information, etc.) received from the IAB node. The mobility information may be provided to the IAB donor node by the IAB node in the IAB node setup or later, or in the mobility indication message sent by the IAB node to the IAB donor node as described above. Based on the mobility information provided in the mobility indication message, the IAB donor node can determine whether the IAB node can support network connectivity.

[0146] In one example, when the IAB node determines that the IAB node has been stationary or will be stationary for a period longer than a predetermined threshold, or when the IAB node is moving with limited mobility, the IAB node determines that it can support network connectivity. The mobility of the IAB node is restricted when at least one of the following criteria or conditions is met: the speed of the IAB node is below a predetermined threshold; the mobility area is geographically restricted; the mobility area is within one topology or one network cell. For details of the restricted mobility criteria, see the above (e.g., the descriptions of FIGS. 11 and / or 13).

[0147] In another example, when it is determined that the mIAB node is in motion or is a mobile node (i.e., has the ability to move), the mIAB node determines that it cannot support network connectivity.

[0148] When it is determined that the mIAB node cannot support network connectivity, the IAB support information may be invalidated or not set (e.g., the IAB support information is not included in the mobility information message) in the mobility information message, but the mobility information message may still include at least one of mobility profile information, guaranteed stationary time information, mobile node indication information, mobility status indication information, mobile IAB cell indication information.

[0149] Next, also refer to FIG. 5, which is a schematic and simplified diagram that shows some exemplary message flows for use in managing network connectivity in a wireless communication system including at least one IAB node according to one or more embodiments of the present invention, and for managing the advertising by the IAB node of its mobility capabilities and state, along with its ability to support an IAB connection with a child IAB node.

[0150] According to one example, a mobile IAB node 501 (which may correspond to the IAB node 123 in FIG. 1 and the IAB node 470 in FIG. 4 as described above) can share some mobility information with its IAB donor 502 (which may correspond to the IAB donor node 120 in FIG. 1 and the IAB donor CU 401 in FIG. 4) by transmitting a MOBILITY INDICATION message 521. The MOBILITY INDICATION message 521 is an example of the mobility indication message described above with reference to FIGS. 11 to 14.

[0151] According to one example, this mobility information sharing can be performed at the time of setup of the mobile IAB node 501. According to another example, the mobility information sharing can be performed according to the purpose. In this regard, it can be triggered by a change in the mobility status of the mobile IAB node 501, or can be performed periodically, or can be performed in response to a request from the IAB donor 502 (for example, the IAB donor CU 401).

[0152] When the mobility information sharing is performed during the mobile IAB node setup, according to one example, such mobility information sharing is performed at the time of establishment of the RRC connection, and the MOBILITY INDICATION message 521 is the RRCSetupComplete message used to complete the RRC connection establishment process as specified in 3GPP (registered trademark) TS 38.331.

[0153] When the mobility information sharing is performed during the mobile IAB node setup, according to another example, the aforementioned mobility information sharing is performed as part of the F1 setup procedure, and the MOBILITY INDICATION message 521 is the SETUP REQUEST message as specified in 3GPP (registered trademark) TS 38.473.

[0154] When the sharing of mobility information is deliberately executed, according to one example, the MOBILITY INDICATION message 521 is any one of the MeasurementReport, FailureInformation, IABOtherInformation or UEInformationResponse message specified in 3GPP (registered trademark) TS 38.331, or the GNB-DU CONFIGURATION UPDATE message specified in 3GPP (registered trademark) TS 38.473.

[0155] According to one example, the MOBILITY INDICATION message 521 includes all or part of the following IAB node mobility information (for example, information indicating the mobility of the IAB node): - mobileiab-NodeIndication, or mobile IAB node indication information (also called mobile node indication information). This information is used to indicate that the device sending the MOBILITY INDICATION message 521 is a mobile IAB node (i.e., an IAB node with mobility capabilities), and in the case of connection establishment, the connection is established by the mobile IAB node. - mobility-StatusIndication, or mobility status indication information. This information is used to indicate the current status of the mobility of the mobile IAB node, such as whether the mobile IAB node is currently moving. This information can also include additional information related to the nature of the movement, for example, the speed of the mobile IAB node. - guaranteedStaticTime, or guaranteed static time information. This information indicates the minimum guaranteed period during which the mobile IAB node remains in a fixed position. For example, a bus that previously stopped at a bus stop can indicate the remaining time before moving to the next bus stop. -mobility-Profile or mobility profile information. This information provides an indication of the mobility function of the mobile IAB node. The mobility profile information can include at least one of the following information: · Speed-related information or speed information indicating the speed capabilities of the mobile IAB node, such as minimum speed, average speed, maximum speed, etc. · Information regarding the mobility area or mobility range of the mobile IAB node (e.g., range information indicating the mobility area of the mobile IAB node), such as the type of mobility area, the size of the mobility area, or a list collecting the cell IDs of some cells that the mobile IAB node has previously visited or can visit. The type (or category) of the mobility area can be an indication of the size or nature of the geographical area where the mobile IAB node can move. For example, the type (or category) of the mobility area can indicate that the geographical area is a bus route, a train route, or a parking lot. · Information indicating the duration of the stationary period that the mobile IAB node can experience (e.g., stationary information), such as the minimum duration of the stationary period, the average duration of the stationary period, or the maximum duration of the stationary period. The stationary information can also include stationary position information indicating the position where the mIAB is stationary. · Trip information formed by a sequence of mobility and stationary periods (e.g., indicating the sequence of mobility and stationary periods for a trip that the mIAB node can follow). The trip information can include, for each of the mobility period and the stationary period, the duration of the period and the speed of the mobile IAB node during this period.

[0156] According to one example, when the mobile IAB node 501 (e.g., IAB node 470) completes the connection setup process with the IAB donor 502 (e.g., IAB donor CU 401), the mobile IAB node 501 can provide or transmit a MOBILITY INFORMATION message 531 for advertising purposes to another wireless communication device such as the network device 503 (referred to as a network device in FIG. 5) in its vicinity (e.g., via broadcast). The MOBILITY INFORMATION message 531 is an example of the mobility information message described above with reference to FIGS. 11 to 14.

[0157] According to one example, the network device 503 is an IAB node such as the IAB node 121 or 123 in FIG. 1 and the IAB nodes 430, 450, 460, 480 in FIG. 4.

[0158] According to another example, the network device 503 is a UE such as the UE 135 or 136 in FIG. 1 and the UE 390 in FIG. 4.

[0159] This MOBILITY INFORMATION message 531 can be transmitted periodically.

[0160] In one aspect, the MOBILITY INFORMATION message 531 is an SIB1 message as defined in 3GPP (registered trademark) TS 38.331.

[0161] According to an example of an embodiment of the present invention, the MOBILITY INFORMATION message 531 includes all or part of the following IAB node mobility information: - iab-support, or IAB support information. For example, IAB support information (or connectivity support information) may indicate whether an IAB node can support network connectivity for a wireless communication device. As defined in 3GPP (registered trademark) TS 38.331, this information combines both IAB support and cell status for IAB. If this information is present in the MOBILITY INFORMATION message 531, the cell supports IAB and the cell is also considered a candidate for (re)selection of an IAB node's cell. If the field is absent, the cell does not support IAB and / or the cell is prohibited for an IAB node. - mobileiab-NodeIndication, or mobile IAB node indication information (also called mobile node indication information). This information is used to indicate that the device sending the MOBILITY INFORMATION message 531 is a mobile IAB node (i.e., an IAB node with mobility capabilities) and that the associated cell is a mobile cell. - mobility-StatusIndication, or mobility status indication information. This information is used to indicate the current status of the mobility of a mobile IAB node, such as whether the mobile IAB node is currently moving. This information can also include additional information related to the nature of the movement, e.g., the speed of the mobile IAB node. - guaranteedStaticTime or guaranteed static time information. This information indicates the minimum guaranteed period for which a mobile IAB node remains in a stationary position. For example, a bus that previously stopped at a bus stop can indicate the remaining time until it moves to the next bus stop. - mobility-Profile, or mobility profile information. This information provides an indication of the mobility function of the mobile IAB node. The mobility profile information can include at least one of the following information: · Speed-related information or speed information indicating the speed capabilities of the mobile IAB node, such as minimum speed, average speed, maximum speed, etc. · Information regarding the mobility area or mobility range of the mobile IAB node (e.g., range information indicating the mobility area of the mobile IAB node), such as the type of mobility area, the size of the mobility area, or a list collecting the cell IDs of some cells that the mobile IAB node has previously visited or can visit. The type (or category) of the mobility area can be an indication of the size or nature of the geographical area where the mobile IAB node can move. For example, the type (or category) of the mobility area can indicate that the geographical area is a bus route, a train route, or a parking lot. · Information indicating the duration of the stationary period that the mobile IAB node can experience (e.g., stationary information), such as the minimum duration of the stationary period, the average duration of the stationary period, or the maximum duration of the stationary period. The stationary information can also include stationary position information indicating the position where the mIAB will be stationary. · Itinerary information formed by a sequence of mobility and stationary periods (e.g., indicating the sequence of mobility and stationary periods for a journey that the mIAB node can follow). The itinerary information can include, for each of the mobility period and the stationary period, the duration of the period and the speed of the mobile IAB node during this period.

[0162] The IAB donor 502 can determine whether to enable or disable the presence of iab-support information in the MOBILITY INFORMATION message 531 by sending an IAB SUPPORT CONFIGURATION message 522 to the mobile IAB node 501 based on the IAB node mobility information in the previously received MOBILITY INFORMATION message 521. The IAB SUPPORT CONFIGURATION message 522 is an example of a connectivity or IAB support configuration message as described above with reference to FIGS. 11 to 14.

[0163] According to an example, the IAB SUPPORT CONFIGURATION message 522 is an RRCReconfiguration message defined in 3GPP (registered trademark) TS 38.331.

[0164] According to an example, when the network device 503 is an IAB node connected to the mobile IAB node 501 as a child IAB node, the IAB node 503 can also provide or transmit (e.g., via broadcast) a MOBILITY INFORMATION message 541 to some possible IAB nodes (and / or UEs) in its vicinity for advertising purposes. The MOBILITY INFORMATION message 541 may include all or part of the IAB node mobility information carried by the previously received MOBILITY INFORMATION message 531 from the mobile IAB node 501. Further, the MOBILITY INFORMATION message 541 may include some information indicating the identifier of the mobile IAB node 501, or identifier information for identifying the IAB node 501 such as a BAP address (defined in 3GPP (registered trademark) TS 38.340). The MOBILITY INFORMATION message 541 is an example of the mobility capability message described above with reference to FIG. 12.

[0165] According to another example, if the network device 503 is an IAB node connected to the mobile IAB node 501 as a child IAB node, the IAB node 503 may experience some backhaul (BH) radio link failure (RLF), for example, when the mobile IAB node 501 has moved too far away and is out of range. The IAB node 503 then sends an RLF INDICATION message 542 to each of its child IAB nodes, and some information can be added to this message to notify the child IAB nodes that the radio link failure is caused by the mobility of its parent IAB node 501. For example, the RLF INDICATION message 542 can include information indicating that the cause of the RLF is related to the mobility of the parent IAB node.

[0166] FIG. 6 shows an exemplary method for managing the connectivity of a mobile IAB node according to some embodiments of the present invention using a flowchart 600. The flowchart 600 shows steps executed at the mobile IAB node and the IAB donor node, and is an example of steps executed at the mobile IAB node and the IAB donor node as described above with reference to FIGS. 11-14. The method as shown and described with respect to FIG. 6 may be executed by software elements and / or hardware elements.

[0167] The process starts at step 601 where a mobile IAB node, such as the mobile IAB node 501 of FIG. 5 and the IAB node 470 of FIG. 4, initiates a connection setup with an IAB donor CU (such as the IAB donor 502 of FIG. 5 and the IAB donor CU 401 of FIG. 4), for example, by starting an IAB node setup procedure, or detects a change in the mobility status and / or capabilities.

[0168] According to one example, in step 601, the mobile IAB node 470 can start the connection setup process by sending an RRC Setup Request message to the IAB donor CU 401 as part of the RRC connection establishment procedure specified in 3GPP (registered trademark) TS 38.331. According to another example, in step 601, the mobile IAB node 470 can start the connection setup process by sending an F1 SETUP REQUEST message to the IAB donor CU 401 as part of the F1 setup procedure specified in 3GPP (registered trademark) TS 38.473, which is used to exchange the application level data required for the gNB-DU and gNB-CU to operate correctly with each other on the F1 interface. According to another example, in step 601, the mobile IAB node 470 can detect a change in its mobility, such as a change in mobility status and / or capabilities. This change can include, for example, a change in speed, a change in its guaranteed stationary duration, or an update to its mobility profile, as described above in relation to FIG. 5.

[0169] In step 601, the mobile IAB node 470 can further send some IAB node mobility information to the IAB donor (e.g., the IAB donor CU 401) via a MOBILITY INDICATION message 521, for example, as described with reference to FIG. 5.

[0170] In step 601, when the mobile IAB node sends some IAB node mobility information to the IAB donor via the MOBILITY INDICATION message 521, the IAB donor determines, in step 602, whether the IAB support or connectivity support by the mobile IAB node should be enabled (for example, when the IAB node can support network connectivity for a wireless communication device), or whether it should be disabled (for example, when the IAB node cannot support network connectivity for a wireless communication device), and can further notify the mobile IAB node of this by sending, for example, the IAB SUPPORT CONFIGURATION message 522 as described with reference to FIG. 5. As described above, if the mobile IAB node indication information (mobileiab-NodeIndication) in the MOBILITY INDICATION message 521 sent by the IAB node indicates that the node is a mobile IAB node, the IAB donor may determine that the IAB support for that IAB node is invalid. In step 601, the IAB donor can determine to enable the IAB support for the mobile IAB node as long as the mobile IAB node is stationary or remains stationary for a significant period (i.e., a duration exceeding a threshold that can be as low as several tens of seconds) as determined based on the information provided in the MOBILITY INDICATION message 521 (such as mobility status indication information and / or guaranteed stationary time information).

[0171] In one example, the IAB donor can determine in step 601 to enable IAB support for the mobile IAB node as long as its mobility is restricted as determined based on the information provided in the MOBILITY INDICATION message 521, regardless of its actual movement. For details of the restricted mobility criteria / conditions, refer to the above (e.g., the descriptions of FIGS. 11 and / or FIGS. 13 and 14).

[0172] In step 603, the mobile IAB node 470 performs conditional IAB support management along with the relevant mobility information by providing (e.g., broadcasting) the MOBILITY INFORMATION message 531 to potential child IAB nodes (and / or UEs), as described with reference to FIG. 5 for example. The mobile IAB node 470 can disable the transmission of IAB support information in the MOBILITY INFORMATION message 531 (e.g., by not including the IAB support information in the MOBILITY INFORMATION message 531) as long as the mobile IAB node is actually moving. The mobile IAB node 470 can enable the advertisement of IAB support information in the MOBILITY INFORMATION message 531 (e.g., by including the IAB support information in the MOBILITY INFORMATION message 531) if its mobility remains restricted despite the fact that it is currently moving. For more details of the restricted mobility criteria / conditions that the mobile IAB node 470 may consider when determining whether its mobility is restricted, refer to the above (e.g., the descriptions of FIGS. 11 and / or FIGS. 13 and 14).

[0173] According to another example, in step 602, the mobile IAB node 470 can determine to enable or disable the advertisement of IAB support information in the MOBILITY INFORMATION message 531 based on the information embedded in the IAB SUPPORT CONFIGURATION message 522 received from an IAB donor (e.g., the IAB donor CU 401), as described with reference to FIG. 5 for example.

[0174] In an exemplary embodiment, when the mobile IAB node 470 enables the advertisement of IAB support in step 603 (i.e., when transmitting IAB support information in the MOBILITY INFORMATION message 531), it can advertise its mobility profile in the MOBILITY INFORMATION message 531. For example, when the IAB node 470 can support network connectivity for a wireless communication device (such as an IAB node / UE), the MOBILITY INFORMATION message 531 may include mobility profile information and IAB support information. In another exemplary implementation, when the mobile IAB node 470 disables IAB support in step 603 (i.e., when not transmitting IAB support information in the MOBILITY INFORMATION message 531), it may still advertise its mobility profile in the MOBILITY INFORMATION message 531. For example, when the IAB node 470 cannot support network connectivity for a wireless communication device (such as an IAB node / UE), the MOBILITY INFORMATION message 531 transmitted by the mobile IAB node 470 may still include mobility profile information even though the IAB support information is configured (e.g., not included in the MOBILITY INFORMATION message 531).

[0175] Also refer to FIG. 7, which is a schematic and simplified diagram showing some exemplary message flows used for managing the connection of a wireless communication device (referred to as a network device in FIG. 7) to a mobile IAB node according to some embodiments of the present invention. The network device or wireless communication device can be an IAB node where the mobile IAB node is the parent mobile IAB node, or an IAB node where the mobile IAB node is an access node, such as the UE135 or 136 in FIG. 1 and the UE390 in FIG. 4 as described above.

[0176] According to one example, the mobile IAB node 701 (which may correspond to the IAB node 123 in FIG. 1 and the IAB node 470 in FIG. 4 as described above) may share IAB node mobility information with the IAB donor 702 (which may correspond to the IAB donor node 120 in FIG. 1 and the IAB donor CU401 in FIG. 4 as described above) by transmitting a MOBILITY INDICATION message 521. The MOBILITY INDICATION message 521 is an example of the mobility indication message described above with reference to FIGS. 5, 11 to 14.

[0177] The new network device 703 may desire to participate in a topology managed by the IAB donor 702 (e.g., an IAB topology or the network 4001 managed by the IAB donor 401). According to one example, the network device 703 is an IAB node similar to the IAB node 121 or 123. According to another example, the network device 703 is a UE similar to the UE135 or 136.

[0178] To participate in the topology managed by the IAB donor 702, the network device 703 attempts to connect to the topology via the mobile IAB node 701 (acting as the parent IAB node for the network device 703 if the network device 703 is an IAB node) by performing an RRC connection establishment procedure 731 with the IAB donor 702 via the mobile IAB node 701 as specified in 3GPP (R) TS 38.331 and 3GPP (R) TS 38.401. During this procedure, the network device 703 exchanges RRCSetupRequest, RRCSetup, and RRCSetupComplete messages with the DU part of the mobile IAB node 701 via the Uu interface, while the DU part of the mobile IAB node 701 uses the F1 AP protocol to convey these messages to the CU part of the IAB donor 702.

[0179] The IAB donor 702 can reject the connection of the network device 703 by sending an RRCReject message instead of an RRCSetup message as specified in 3GPP (R) TS 38.331.

[0180] When a connection is established between the IAB node 703 and the network, if the network device 703 is an IAB node, the IAB donor 702 may decide to configure or reject the configuration of the BH link between the IAB node 703 and the mobile IAB node 701 by sending a CONFIGURATION INFORMATION message 732 to the IAB node 703.

[0181] According to one example, the CONFIGURATION INFORMATION message 732 is an RRCReconfiguration message defined in 3GPP (R) TS 38.331.

[0182] The CONFIGURATION INFORMATION message 732 and the RRCReject message / RRCSetup message are examples of the configuration messages described above with reference to FIGS. 11 to 14.

[0183] The CONFIGURATION INFORMATION message 732 (or the RRCReject message / RRCSetup message) sent to the network device 703 can include at least one of the following information (which information is included depends on whether the network device 703 is an IAB node or a UE): - iab-configReject, or IAB configuration Reject information. If present in the CONFIGURATION INFORMATION message 732, this information indicates to the IAB node 703 that the IAB donor 702 does not permit the IAB node 703 to be a child IAB node of the mobile IAB node 701. - MobileCellConnectionReject, or Mobile Cell connection rejection information. If present in the CONFIGURATION INFORMATION message 732, this information indicates to the UE 703 that the connection request was rejected because the UE attempted to connect to the network via the mobile IAB node. - iab-configRejectCause, or IAB configuration Rejection Cause information. If present in the CONFIGURATION INFORMATION message 732, this information indicates to the IAB node 703 the reason why the iab-configReject information is present in the CONFIGURATION INFORMATION message 732, i.e., the reason why the IAB donor 702 does not permit the IAB node 703 to become a child IAB node of the mobile IAB node 701. In one example, the IAB configuration Rejection Cause information may notify the IAB node 703 that the IAB donor CU 702 does not permit the IAB node 703 to become a child IAB node of the mobile IAB node 701 because the IAB node 701 is a mobile IAB node. - mobility-Profile, or mobility profile information. This information provides an indication of the mobility capabilities of the mobile IAB node 701. The mobility profile information can include at least one of the following information: · Speed-related information or speed information indicating the speed capabilities of the mobile IAB node, such as minimum speed, average speed, maximum speed, etc. · Information regarding the mobility area or mobility range of the mobile IAB node (e.g., range information indicating the mobility area of the mobile IAB node), such as the type of mobility area, the size of the mobility area, or a list that collects the cell IDs of several cells that the mobile IAB node has previously visited or can visit. The type (or category) of the mobility area can be an indication of the size or nature of the geographical area where the mobile IAB node can move. For example, the type (or category) of the mobility area can indicate that the geographical area is a bus route, a train route, or a parking lot. · Information (e.g., quiescence information) indicating the duration of the quiescent period that a mobile IAB node can experience, such as the duration of the minimum quiescent period, the average quiescent period, or the maximum quiescent period. · Itinerary information made up of a sequence of mobility and quiescent periods (e.g., indicating the sequence of mobility and quiescent periods for which an mIAB node can continue). The itinerary information can include, for each of the mobility period and the quiescent period, the duration of the period and the speed of the mobile IAB node during this period. - mobileParentiab-NodeIndication, or mobile Parent IAB node indication information. This information is used to indicate that the parent IAB node (i.e., IAB node 701) is a mobile IAB node (i.e., an IAB node having mobility capabilities) and that the associated cell is a mobile cell.

[0184] FIG. 8 shows an exemplary method for managing the connection of a wireless communication device (referred to as a network device with respect to FIG. 8) to a network (e.g., an IAB network or topology) of a wireless communication system via a mobile IAB node according to some embodiments of the present invention using flowchart 800. Flowchart 800 shows steps executed at a wireless communication device (or network device) and an IAB donor node and is an example of steps executed at a wireless communication device and an IAB donor node as described above with reference to FIGS. 11-14. The mobile IAB node can be an access node, and the network device or wireless communication device can be an IAB node or a UE (such as UE135 or 136 in FIG. 1 and UE390 in FIG. 4 as described above). The method as shown and described with respect to FIG. 8 can be executed by software elements and / or hardware elements.

[0185] The process starts at step 801 and requests to participate in a topology managed by an IAB donor 702, such as a CU part of the IAB donor 702 or a CU (e.g., topology or network 4001 managed by the IAB donor 401 in FIG. 4), via a mobile IAB node 701 (such as the mobile IAB node 470 in FIG. 4), also called the IAB node 701 where a new network device similar to the network device 703 (such as the IAB node 460 or UE 390 in FIG. 4) is connecting.

[0186] According to one example, the new network device 703 is an IAB node similar to the IAB node 121 or 123 or IAB node 460.

[0187] According to another example, the new network device 703 is a UE similar to the UE 135 or 136 or UE 390.

[0188] To participate in a topology or network managed by the CU of the IAB donor 702, the new network device 703 may attempt to connect to the network by performing an RRC connection establishment procedure with the IAB donor 702 and sending a request to the IAB donor 702, via the connected IAB node 701 (which acts as the parent IAB node for the network device 703 when the network device 703 is an IAB node).

[0189] In step 802, the CU of the IAB donor 702 (e.g., the IAB donor CU 401) executes a connection procedure with the new network device 703, checks the mobility capabilities and status information associated with the connected IAB node 701, and determines whether to permit the connection of the network device 703 to the network via the connected IAB node 701. If the network device 703 is an IAB node, the CU part of the IAB donor 702 determines whether to permit the configuration of the BH link between the new network device 703 and the connected IAB node 701 (which will then act as the parent IAB node of the new network device 703).

[0190] In one example, the CU of the IAB donor 702 (e.g., the IAB donor CU 401) checks the IAB node mobility information embedded in the MOBILITY INDICATION message 521 previously received from the connected IAB node 701 to determine whether to permit or reject the connection, and if the new network device 703 is an IAB node, determines whether to permit the configuration of the BH link between the new network device 703 and the connected IAB node 701 (which will then act as the parent IAB node of the new network device 703).

[0191] The CU of the IAB donor 702 can request the transmission of the MOBILITY INDICATION message 521 to the connected IAB node 701 to obtain the latest IAB node mobility information. In one example, the MOBILITY INDICATION message 521 is a UEInformationResponse message transmitted by the connected IAB node 701 to the CU of the IAB donor node 702 in response to a UEInformationRequest message defined in 3GPP (registered trademark) TS 38.331 and transmitted by the IAB donor 702 to the connected IAB node 701.

[0192] In one example, if the CU of the IAB donor 702 is indicated by the mobile IAB node indication information (mobileiab-NodeIndication) in the MOBILITY INDICATION message 521 previously received from the connected IAB node that the connected IAB node 701 is a mobile IAB node, the CU may not permit the connection of the new network device 703 to the topology or network it manages. In another example when the new network device 703 is an IAB node, if the mobile IAB node indication information (mobileiab-NodeIndication) in the MOBILITY INDICATION message 521 previously received from the connected IAB node by the CU of the IAB donor 702 indicates that the required parent IAB node 701 is a mobile IAB node, the configuration of the BH link between the new network device 703 and the connected IAB node may not be permitted.

[0193] In another example, the CU of the IAB donor 702 may permit the connection of the new network device 703 via the connected IAB node 701, or when the network device 703 is an IAB node, even if the connected IAB node 701 is a mobile IAB node, as long as the mobile IAB node 701 remains stationary or continues to be stationary for a period longer than a predetermined threshold (which may be a low threshold of about several tens of seconds), the CU of the IAB donor 702 may permit the configuration of the BH link between the new IAB node 703 and the connected IAB node 701 (in this case, acting as the parent IAB node), and the predetermined threshold is determined based on the mobility status indication information and / or guaranteed static time information in the MOBILITY INDICATION message 521 previously received from the connected IAB node 701.

[0194] According to another example, the CU of the IAB donor 702 can enable the connection of a new device 703 to the network via the connected IAB node 701, or if the network device 703 is an IAB node, the CU of the IAB donor 702 can configure the BH link between the new IAB node 703 and the connected IAB node 701 as long as the mobility of the mobile IAB node 701 is restricted (in this case, acting as the parent IAB node). In other words, as long as the connected IAB node 701 is moving with limited mobility.

[0195] The mobility of a mobile IAB node can be considered restricted if one or any combination of the restricted mobility criteria / conditions as described above (for example, in the description of FIGS. 11 and / or FIGS. 13 and 14) is met.

[0196] In an example where, in step 803, the CU of the IAB donor 702 determines not to permit the configuration of the BH link between the new IAB node 703 and the connected IAB node 701, the CU of the IAB donor 702 sends a CONFIGURATION INFORMATION message 732 including all or part of the following information to the new IAB node 703 as defined above with reference to FIG. 7: - iab-configReject or IAB configuration Reject information to indicate that the connection or configuration has been rejected - iab-configRejectCause, or IAB configuration Rejection Cause information, to indicate the reason for the connection rejection (for example, because the connected IAB node 701 is a mobile IAB node) - A mobility-Profile, or mobility profile information, for indicating the mobility capabilities of the connected IAB node 701.

[0197] In the example where, in step 803, the CU of the IAB donor 702 decides to permit the configuration of the BH link between the new IAB node and the requested parent IAB node, the CU of the IAB donor 702 sends a configuration information message 732 to the new IAB node 703 that does not include the following information as defined in FIG. 7: - iab-configReject, or IAB configuration Reject information - iab-configRejectCause, or IAB configuration Reject Cause information Still, in the latter case, the CONFIGURATION INFORMATION message 732 sent to the new IAB node 703 can include the following information as defined above with reference to FIG. 7: - A mobility-Profile, or mobility profile information, for indicating the mobility capabilities of the connected IAB node 701.

[0198] In the example where, in step 803, the CU of the IAB donor 702 decides not to permit the connection of the new network device 703 to the network, the CU of the IAB donor 702 sends an RRCReject message to the network device 703 and can add all or some of the following information to this message: - RRCRejectCause, or RRC Rejection Cause information. When present in the RRCReject message, this information indicates to the network device 703 the reason why the connection of the network device 703 to the network was rejected. According to one example, the RRC Rejection Cause indicates that the network device 703 attempted to connect to the network via a mobile node such as a mobile IAB node or a mobile IAB donor DU. MobileCellConnectionReject, or Mobile Cell connection rejection information is an example of the RRCRejectCause, or RRC Rejection Cause information and may be included in the RRCReject message sent to the UE 703 when the connection request was rejected because the UE attempted to connect to the network via a mobile IAB node.

[0199] - A mobility-Profile, or mobility profile information, as defined above with reference to FIG. 7, for indicating the mobility capabilities of the connected IAB node 701.

[0200] FIG. 9 shows an exemplary method for a wireless communication device (referred to as a network device with respect to FIG. 9) for managing a connection to a network (e.g., an IAB network or topology) of a wireless communication system via a mobile IAB node based on the mobility capabilities and status of the mobile IAB node using flowchart 900. The method as shown and described with respect to FIG. 9 may be executed by software elements and / or hardware elements.

[0201] The process starts at step 901 where a new network device, similar to network device 703 (such as IAB node 460 or UE 390 in FIG. 4), receives some mobility information from a neighboring mobile IAB node, such as mobile IAB node 701 (e.g., mobile IAB node 470 in FIG. 4), which is also referred to as the connected IAB node 701.

[0202] According to one example, the new network device 703 is an IAB node similar to IAB node 121 or 123 or IAB node 460.

[0203] According to another example, the new network device 703 is a UE similar to UE 135 or 136 or UE 390.

[0204] In an exemplary embodiment, the mobility information relates to all or part of the IAB node mobility information carried in the MOBILITY INFORMATION message 531 as described with reference to FIG. 5. The MOBILITY INFORMATION message 531 is an example of the mobility information message described above with reference to FIGS. 11 - 14. At step 902, based on the mobility information received at step 901, the new network device 703 determines whether it should attempt to connect to the network via the mobile IAB 701 node by starting the RRC connection establishment procedure 731 as described above with reference to FIG. 7.

[0205] According to one example, the new network device 703 may not attempt to connect to the network via the connected IAB node 701 when the mobile IAB node indication (mobileiab-NodeIndication) information in the MOBILITY INFORMATION message 531 indicates that the IAB node 701 is a mobile IAB node.

[0206] According to another example, even though the connected IAB node 701 is a mobile IAB node, the new network device 703 can attempt to connect to the network via the connected IAB node 701 as long as the mobile IAB node 701 is stationary or has been stationary for a period longer than a predetermined threshold (e.g., a threshold as low as several tens of seconds) determined based on the mobility status indication information and / or the guaranteed stationary time information of the MOBILITY INFORMATION message 531 previously received from the connected IAB node 701.

[0207] According to another example, the new network device 703 can attempt to connect to the network via the connected IAB node 701 even if the connected IAB node 701 is a mobile IAB node as long as the mobility of the mobile IAB node 701 is restricted. In other words, as long as the connected IAB node 701 is moving with limited mobility. The mobility of the mobile IAB node 701 can be considered restricted if one or any combination of the restricted mobility criteria / conditions as described above (e.g., in the descriptions of FIGS. 11 and / or FIGS. 13 and 14) is satisfied.

[0208] Hereinafter, for the purpose of clarity, some aspects of the present invention are illustrated.

[0209] During recent discussions in 3GPP (registered trademark) (RAN3 #117e meeting), it was agreed that the IAB donor CU should recognize the "mobile" capabilities of IAB nodes. On the other hand, RAN2 initiated discussions on whether the mobile IAB-MT needs to send a mobile IAB indication (capability or mobility) to the IAB donor CU.

[0210] Therefore, some specific mobility signaling to the IAB donor CU can be considered at the mobile IAB node level to enable efficient network connectivity management in the IAB donor CU.

[0211] In 3GPP (registered trademark), it has been proposed that the mobile IAB node reports mobility-related information to the network, whereby the CU can include such information in the UE handover decision, simplify some RRC procedures, enable the network to create a mobile IAB mobility history, and reject the connection request of the IAB node to the mobile IAB node as the parent node. Having knowledge of the mobile characteristics of the IAB node may also enable the IAB donor CU to determine a complete handover instead of a partial handover in the context of topology adaptation.

[0212] The mobility-related information to be shared with the IAB donor CU is: - Speed (minimum, average or maximum), - Mobility area (mobility area type, distance, etc.), - Movement trajectory (including the continuity of movement periods and stationary periods) Therefore, in addition to notifying the IAB donor CU about its mobile capabilities, the mobile IAB node can share several mobility profiles with the IAB donor CU. Such mobility profiles may include information related to IAB node mobility characteristics such as speed, mobility range, or movement trajectory.

[0213] The RRC setup procedure already enables the IAB-MT to indicate to its IAB donor CU that a connection has been established by the IAB node. Similarly, the signaling of mobile capabilities may be performed as part of the mobile IAB node RRC setup procedure, and then the mobile capability signaling is performed by the IAB-MT. In other words, the IAB node indication has already been sent by the IAB-MT to the IAB donor CU using RRC (iab-NodeIndication information in the RRCSetupComplete message).

[0214] Therefore, the IAB-MT should use RRC to send the mobile IAB node indication to the IAB donor CU, along with the existing iab-NodeIndication and some mobility capability information.

[0215] Since some of the mobility parameters (e.g., speed) of the IAB nodes are likely to evolve, it may be beneficial for the IAB donor CU to be informed about such evolution. Therefore, some signaling of the mobile capabilities can be issued by the mobile IAB node upon detection of a change in the IAB node mobility status or periodically.

[0216] Therefore, the signaling of the mobile capabilities can be performed as part of the mobile IAB node setup procedure. Nevertheless, some mobility signaling can also be performed periodically or upon detection of a change in the IAB node mobility status.

[0217] Release 18 introduces the concept of mobile IAB cells. So, if a UE desires to connect to one of them, it may be beneficial for the UE to have some knowledge about the fixed or mobile characteristics of the cells in its vicinity. This does not apply to legacy UEs (i.e., UEs that do not support the Rel.18 standard). For example, when connecting to a new cell, the UE may have some preference for connecting to a fixed cell rather than a mobile cell. Knowledge of the characteristics of the mobile IAB cells can make it possible to reduce the need for cell reselection or measurement reporting for handover. In other words, the UE can benefit from knowledge about the mobile characteristics of the IAB nodes in its vicinity (so that it can determine whether it should connect to a mobile cell or try to find some other fixed cell).

[0218] Therefore, the mobile IAB node can use SIB signaling to broadcast some mobile capability signaling towards the UEs in its vicinity. This mobile capability signaling may include a mobility profile similar to that shared with the IAB donor CU, and thus may include some information such as speed, mobility range, or movement trajectory.

[0219] Some UEs may prefer to connect to a fixed cell (e.g., when the UE is stationary while the mobile IAB node is away, to avoid any handover requirements). Therefore, a mobile IAB node that is not currently moving (e.g., a parked taxi, bus, or subway train waiting at a station) can notify the UEs in its vicinity of its stationary state, along with the duration for which it remains stationary.

[0220] Therefore, the mobile IAB node can use SIB signaling to broadcast some signaling of its mobile capabilities towards the UEs in its vicinity. This signaling of mobile capabilities may include a mobility profile similar to that shared with the IAB donor CU.

[0221] Also, when the mobile IAB node is stationary, it can notify the UEs in its vicinity about its stationary state and the duration for which it remains stationary.

[0222] Considering the scope of the Release 18 mobile IAB framework, the mobile IAB node shall not have descendant IAB nodes, i.e., it shall serve only UEs. In this regard, it was agreed at 3GPP that a way of not broadcasting the "IAB-Support" indication is sufficient to prevent other IAB nodes from accessing the mobile IAB (without further specification impacts).

[0223] However, the mobile IAB node can be stationary at some point and remain stationary for a period of time, and the duration can even be predictable. For example, a bus may stop at a bus stop for a duration of 30 seconds to 1 minute, and a train may remain idle for up to 5 minutes at an intermediate station or for 30 minutes to over 1 hour at a terminal station.

[0224] The mobile IAB node can also have its movement limited to a very restricted geographical area, such as a promotional vehicle that circulates around an Olympic stadium.

[0225] In summary, the mobile IAB node can be stationary at some point and remain stationary for a period of time, and the duration can be predictable. The mobile IAB node can also have its movement limited to a very restricted geographical area.

[0226] In both cases, the impact of the mobile characteristics of the IAB node on its potential connectivity with other surrounding IAB nodes is either null or very limited. Therefore, a mobile IAB node that is stationary or has a very limited range of movement can be regarded as a fixed IAB node, and thus has temporary descendant IAB nodes as long as it is stationary or within a limited geographical area.

[0227] Therefore, a stationary mobile IAB node can be regarded as a fixed IAB node and thus can have temporary descendant IAB nodes as long as it remains stationary.

[0228] Similarly, a mobile IAB node whose movement is restricted to a geographical area with little movement can be regarded as a fixed IAB node and thus can have temporary descendant IAB nodes as long as it remains stationary.

[0229] FIG. 10 shows a schematic diagram of an exemplary communication device (apparatus) or station according to one or more exemplary embodiments of the present disclosure.

[0230] The communication device 1000 may be a device such as a microcomputer, a workstation, or a lightweight portable device. The communication device 1000 may include a communication bus 1013 connected thereto: - A central processing unit 1011 such as a microprocessor called a CPU. The central processing unit 1111 may be a single processing unit or processor, or may include two or more processing units or processors that execute the processing required for the operation of the communication device 1100. The number of processors and the allocation of processing functions to the central processing unit 1111 are design choices for those skilled in the art - A memory for storing data and a computer program including instructions for the operation of the communication device 1000. The computer program may include several different program elements (modules) or subroutines including instructions for various operations for implementing the method according to one or more embodiments of the present invention - It may include at least one communication interface 1002 for communicating with other devices or nodes within a wireless communication system, such as the wireless communication system of FIG. 1 or FIG. 4. The at least one communication interface 1002 may be connected to a wireless communication network 1003, such as a 5G NR (e.g., according to Release 16 and / or subsequent releases) wireless communication network where digital data packets or frames or control frames are transmitted. The frame is written to the communication interface for transmission from the FIFO transmission memory in the RAM 1012, or read from the communication interface for reception and writing to the FIFO reception memory in the RAM 1012 under the control of a software application executed within the CPU 1011.

[0231] Each of the donor CU, donor DU, IAB node, and UE may include such a communication device 1100.

[0232] The memory may include the following: - A read-only memory 1007 represented by a ROM for storing a computer program for implementing a method according to one or more embodiments of the present invention - A random access memory 1012 represented by a RAM stores executable code of a method according to one or more embodiments of the present invention, as well as registers adapted to record variables and parameters necessary for implementing the method according to one or more embodiments of the present invention.

[0233] Optionally (and according to the function of the communication device), the communication device 1000 may also include the following components: - A data storage storage means 1004 such as a hard disk for storing a computer program for implementing a method according to one or more embodiments of the present invention - A hard disk drive 1005 for a hard disk 1006, the hard disk drive being adapted to read data from or write data to the hard disk 1006 - A screen 1009 for displaying the decoded data by means of a keyboard 1010 or any other input / output means and / or for serving as a graphical interface with the user.

[0234] In an exemplary configuration, a communication bus is included in or connected to the communication device 1000 to provide communication and interoperability between various elements. The representation of the bus is not limiting, and in particular, the central processing unit is operable to communicate instructions directly to any element of the communication device 1000 or by means of another element of the communication device 1000.

[0235] The disk 1006 can optionally be replaced by any information medium such as, for example, a compact disk (CD-ROM), a rewritable or non-rewritable compact disk, a ZIP disk, a USB key or a memory card, and generally by information storage means readable by a microcomputer or a microprocessor, and can in some cases be removable and is adapted to store one or more programs capable of implementing the method according to the present embodiment by execution.

[0236] The executable code can optionally be stored in any of the read-only memory 1007, the hard disk 1004, or a removable digital medium such as the disk 1006 as described above. According to an optional variant, the executable code of the program can be received by the communication network 1003 via the interface 1002 in order to be stored in one of the storage means of the communication device 1000 such as the hard disk 1004 before being executed.

[0237] The central processing unit 1011 can be adapted to control and direct the execution of the instructions or a part of the software code of the program according to the embodiment of the present invention, the instructions being stored in one of the aforementioned storage means. When powered on, the program stored in a non-volatile memory, such as the hard disk 1004 or the read-only memory 1007, is transferred to the random access memory 1012, which memory contains the executable code of the program as well as registers for storing the variables and parameters necessary for implementing the present invention.

[0238] In an exemplary embodiment, the communication device (apparatus) is a programmable device / apparatus that uses software to implement the present invention. The instructions can be executed by one or more processors, such as one or more digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable logic arrays (FPGAs), or other equivalent integrated or dedicated logic circuits. Thus, the term "central processing unit" as used herein may refer to any of the foregoing structures, or any other structure suitable for implementing the techniques described herein. However, alternatively, the present invention may be implemented in hardware (e.g., in the form of an application-specific integrated circuit or ASIC or other logic elements).

[0239] As described above, the present invention has been described using embodiments, but the present invention is not limited to these embodiments. It will be understood by those skilled in the art that various changes and modifications can be made without departing from the scope of the present invention as defined in the appended claims. All features disclosed in the specification (including any appended claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Each feature disclosed in the specification (including any appended claims, abstract, and drawings) may be replaced by an alternative feature serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless otherwise specified, each disclosed feature is merely an example of a general series of equivalent or similar functions.

[0240] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used advantageously.

[0241] In the foregoing embodiments, the described functions may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code and executed by a hardware-based processing unit.

[0242] The computer-readable medium may include a computer-readable storage medium corresponding to a tangible medium such as a data storage medium, or a communication medium including any medium that facilitates transfer of a computer program from one place to another, for example, according to a communication protocol. Thus, the computer-readable medium may generally correspond to (1) a tangible computer-readable storage medium that is non-transitory, or (2) a communication medium such as a signal or a carrier wave. The data storage medium may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, code, and / or data structures for implementing the techniques described in this disclosure. A computer program product may include a computer-readable medium.

[0243] By way of example and not limitation, such computer-readable storage media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, flash memory, or any other medium which can be used to store the desired program code in the form of instructions or data structures and which can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. However, it should be understood that the computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but instead are directed to non-transitory, tangible storage media. As used herein, disks and discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically with a laser. Combinations of the above should also be included within the scope of computer-readable media.

Claims

1. A method for use in managing network connectivity in a wireless communication system including at least one mobile integrated access and backhaul (mIAB) node, wherein the method at the mIAB node comprises: providing a mobility message to a wireless communication device, wherein the mobility message comprises: mobility profile information indicating the mobility capabilities of the mIAB node; and guaranteed stationary time information indicating a minimum period for which the mIAB node remains at a given location, and the method comprises at least one of the above.

2. The method according to claim 1, wherein the mobility profile information comprises: speed information indicating the speed capabilities of the mIAB node; range information indicating the mobility area of the mIAB node; stationary information indicating the duration of one or more stationary periods that the mIAB node may experience; and itinerary information indicating a sequence of mobility and stationary periods for an itinerary that the mIAB node may follow, and the method comprises at least one of the above.

3. The method according to claim 1 or 2, wherein the mobility message further comprises: mobile node indication information indicating that the mIAB node is a mobile IAB; and mobility state indication information indicating the current state of the mobility of the mIAB node, and the method further comprises at least one of the above.

4. The method according to any one of claims 1 to 3, wherein the wireless communication device is an IAB donor node, the mobility message is a mobility indication message, and providing comprises providing the mobility indication message to the IAB donor node.

5. The method according to claim 4, wherein providing comprises: providing the mobility indication message by the mIAB node after initiating an IAB node setup procedure for the IAB node; providing the mobility indication message in response to the mIAB node determining a change in the mobility of the IAB node; periodically providing the mobility indication message; and providing the mobility indication message in response to a request from the IAB donor node, and the method comprises the above.

6. The method according to any one of claims 1 to 3, wherein the wireless communication device is an IAB node or a UE of the wireless communication system, the mobility message is a mobility information message, and providing includes providing the mobility information message to the IAB node or the UE.

7. The method according to claim 6, wherein providing providing the mobility information message after completion of the IAB node setup procedure; providing the mobility information message in response to the mIAB node determining a change in mobility; periodically providing the mobility information message; and including.

8. The method according to claim 6 or 7, wherein providing includes broadcasting the mobility information message.

9. The method according to any one of claims 6 to 8, wherein the mobility information message further further includes a connectivity support indicator for indicating whether the mIAB node can support network connectivity for a wireless communication device.

10. The method according to any one of claims 6 to 9, wherein when the mIAB node can support network connectivity, including IAB support information in the mobility information message to indicate that the network connectivity can be supported by the mIAB node.

11. The method according to any one of claims 6 to 10, wherein when the mIAB node cannot support network connectivity, not including IAB support information in the mobility information message to indicate that the network connectivity cannot be supported by the mIAB node.

12. The method according to any one of claims 9 to 11, further comprising receiving a connectivity support configuration message from the IAB donor node, wherein the connectivity support configuration message indicates whether the mIAB node can support network connectivity, and the mIAB node determines whether the mIAB node can support network connectivity based on the received connectivity support configuration message.

13. The method according to any one of claims 9 to 11, further comprising determining, by the mIAB node, whether the mIAB node can support network connectivity based on the mobility of the mIAB node.

14. The method according to claim 13, when the mIAB node has been stationary for a period longer than a certain threshold or when the mIAB node is moving with limited mobility, it is determined that the mIAB node can support network connectivity.

15. The method according to claim 14, wherein the mobility of the mIAB node is the following criteria, the speed of the mIAB node is below a predetermined threshold, the mobility area is geographically restricted, the mobility area is within one topology or one network cell, and is restricted when at least one of the criteria is met.

16. The method according to any one of claims 12 to 15, further comprising providing a mobility information message including IAB support information for indicating that network connectivity for a wireless communication device can be supported by the IAB node in response to determining that the mIAB node can support network connectivity.

17. The method according to claim 12 or 13, further comprising determining that the mIAB node cannot support network connectivity when the mIAB node is moving.

18. The method according to any one of claims 1 to 17, wherein the mobility message further further includes mobile IAB cell indication information indicating that a cell is associated with a mobile IAB node.

19. A method in a wireless communication device of a wireless communication system, wherein the wireless communication system further includes an IAB node controlled by an integrated access and backhaul (IAB) donor node, and the method in the wireless communication device includes receiving, from the IAB node, a mobility information message; and performing an operation based at least in part on information provided by the received mobility information message, wherein the mobility information message includes mobility profile information indicating the mobility capability of the IAB node; and guaranteed stationary time information indicating a minimum period for which the IAB node remains at a predetermined position, and includes at least one of the foregoing.

20. The method according to claim 19, wherein the mobility profile information includes speed information indicating the speed capability of the IAB node; range information indicating the mobility area of the IAB node; stationary information indicating the duration of one or more stationary periods that the IAB node may experience; and route information indicating a sequence of mobility and stationary periods for a route that the IAB node may follow, and includes at least one of the foregoing.

21. The method according to claim 19 or 20, wherein the mobility information message further includes mobile node indication information indicating that the IAB node is a mobile IAB node (mIAB node); mobility state indication information indicating the current state of the mobility of the IAB node; mobile IAB cell indication information indicating a cell associated with the mobile IAB node; and IAB support information for indicating whether the IAB node can support network connectivity for the wireless communication device, and includes at least one of the foregoing.

22. The method according to any one of claims 19 to 21, wherein the wireless communication device is another IAB node or a UE.

23. The method according to any one of claims 19 to 22, wherein performing the operation is A method including determining whether to start a connection establishment procedure for establishing a connection via the IAB node based on the mobility information message.

24. The method according to claim 23, wherein the determining includes determining not to start a connection establishment procedure when the information provided by the mobility information message indicates that the IAB node is a mobile IAB node.

25. The method according to claim 23, wherein the determining includes determining to start a connection establishment procedure when the information provided by the mobility information message indicates that the information satisfies a predetermined criterion, and the predetermined criterion includes that the IAB node is not a mobile IAB node, that the IAB node is a mobile IAB node and has been stationary for a period longer than a predetermined threshold, and that the IAB node is a mobile IAB node and is moving with limited mobility.

26. The method according to claim 25, wherein the mobility of the IAB node is the following criterion, the speed of the IAB node is below a predetermined threshold, the mobility area is geographically restricted, the mobility area is within one topology or one network cell, and is restricted when at least one of the above is satisfied.

27. The method according to any one of claims 23 to 26, wherein further performing an operation includes, sending a request to the IAB donor node via the IAB node to request establishment of a connection via the IAB node in response to determining to start a connection establishment procedure, receiving a configuration message from the IAB donor node in response to the request, when the connection via the IAB node is rejected because the IAB node is a mobile IAB node, the configuration message includes IAB configuration rejection cause information indicating that the connection has been rejected because the IAB node is a mobile IAB node.

28. The method according to any one of claims 19 to 21, wherein the wireless communication device is a child IAB node of the IAB node, and performing the operation is after a connection via the IAB node is established, providing, by the child IAB node, a mobility capability message including mobility capability information indicating the mobility capability of the IAB node based on information provided by the received mobility information message received from the IAB node. **Claim 29** The method according to claim 28, wherein the mobility capability information included in the mobility capability message is speed information indicating the speed capability of the IAB node, range information indicating the mobility area of the IAB node, stationary information indicating the duration of one or more stationary periods that the IAB node may experience, travel information indicating a sequence of mobility and stationary periods regarding a travel that the IAB node may follow, and includes at least one of **Claim 30** The method according to claim 28 or 29, wherein the mobility capability message further includes mobile node indication information indicating whether the IAB node is a mobile IAB node (mIAB node), mobility state indication information indicating the current state of mobility of the IAB node, mobile IAB cell indication information indicating a cell associated with the mobile IAB node, IAB support information for indicating whether the IAB node can support network connectivity for the wireless communication device, guaranteed stationary time information indicating a minimum period for which the IAB node stays at a predetermined position, identifier information for identifying the IAB node, and includes at least one of **Claim 31** The method according to any one of claims 19 to 21, wherein the wireless communication device is a child IAB node of the IAB node operating as a parent IAB node, and performing the operation is determining, based on information provided by the received mobility information message, a radio link failure (RLF) for a radio link with the parent IAB node. An RLF indication message, transmitting the RLF indication message including information indicating the cause of the RLF related to the mobility of the parent IAB node; A method comprising the above.

32. A method in an integrated access and backhaul (IAB) donor node of a wireless communication system, the wireless communication system comprising IAB nodes controlled by the IAB donor node, the method comprising: Receiving a mobility indication message from the IAB node; Performing an action based at least in part on information provided by the received mobility indication message; Including; The mobility indication message is Mobility profile information indicating the mobility capability of the IAB node; Guaranteed stationary time information indicating the minimum period for which the IAB node remains at a given position; A method comprising at least one of the above.

33. The method according to claim 32, wherein the mobility profile information is Speed information indicating the speed capability of the IAB node; Range information indicating the mobility area of the IAB node; Stationary information indicating the duration of one or more stationary periods that the IAB node may experience; Route information indicating a sequence of mobility and static periods regarding a route that the IAB node may follow; A method comprising at least one of the above.

34. The method according to claim 32 or 33, wherein the mobility indication message further comprises Mobile node indication information indicating whether the IAB node is a mobile IAB node (mIAB node); Mobility state indication information indicating the current state of the mobility of the IAB node; A method comprising at least one of the above.

35. The method according to any one of claims 32 to 34, wherein receiving the mobility indication message comprises Receiving a mobility indication message as part of an IAB node setup procedure with the IAB node; Receiving the mobility indication message in response to a message transmitted by the donor IAB node; Receiving the mobility indication message periodically; A method comprising the above.

36. The method according to any one of claims 32 to 35, wherein performing the operation comprises based on the information provided in the mobility indication message, sending a notification message for indicating that the IAB node is a mobile IAB node, to an IAB donor node in another IAB topology, another IAB node, a UE, including sending to one or more of them.

37. The method according to any one of claims 32 to 35, wherein the method further comprises receiving from a wireless communication device a request for establishing a connection via the IAB node as part of a connection establishment procedure, performing the action comprises determining whether to accept or reject the connection via the IAB node, based at least in part on the mobility of the IAB node, sending to the wireless communication device a configuration message indicating whether the connection via the IAB node has been accepted or rejected, including.

38. The method according to claim 37, wherein determining whether to accept or reject the connection via the IAB node comprises determining whether to accept or reject the connection via the IAB node, based at least in part on the information provided by the mobility indication message.

39. The method according to claim 37 or 38, wherein the received mobility indication message includes information indicating the current status of the mobility of the IAB node, determining whether to accept or reject the connection via the IAB node comprises determining whether to accept or reject the connection via the IAB node, based at least in part on the current status of the mobility of the IAB node.

40. The method according to any one of claims 37 to 39, wherein if the connection via the IAB node is rejected based on the mobility of the IAB node, the configuration message includes IAB configuration rejection cause information indicating the reason for which the connection was rejected.

41. A method according to any one of claims 37 to 40, wherein when the connection via the IAB node is rejected because the IAB node is a mobile IAB node, the configuration message includes IAB configuration rejection cause information indicating that the connection has been rejected because the IAB node is a mobile IAB node.

42. A method according to any one of claims 37 to 41, wherein when the connection via the IAB node is rejected or accepted, the configuration message includes mobility profile information indicating the mobility capability of the IAB node, The mobility profile information includes the following: Speed information indicating the speed capability of the IAB node; Range information indicating the mobility area of the IAB node; Stationary information indicating the duration of one or more stationary periods that the IAB node may experience; Route information indicating the sequence of mobility and stationary periods for a route that the IAB node may follow; The method includes at least one of the above.

43. A method according to any one of claims 37 to 42, wherein when the IAB node is a mobile IAB node and the wireless communication device is another IAB node, the configuration message further includes mobile parent IAB node indication information indicating that the IAB node is a mobile parent IAB node.

44. A method according to any one of claims 32 to 35, wherein performing an action Determining whether to enable or disable support for network connectivity by the IAB node, based at least in part on the mobility of the IAB node; Sending a connectivity support configuration message to the IAB node to indicate whether the IAB node can support network connectivity for a wireless communication device; The method includes the above.

45. The method according to claim 44, further comprising Determining whether to enable or disable support for network connectivity based on the information provided by the mobility indication message.

46. The method according to claim 44 or 45, wherein when the IAB node has been stationary for a period longer than a predetermined threshold, or when the IAB node is moving with limited mobility, it is determined to enable network connectivity support.

47. The method according to claim 46, wherein the mobility of the IAB node is based on the following criteria: the speed of the IAB node being below a predetermined threshold; the mobility area being geographically restricted; the mobility area being within one topology or one network cell; and is restricted when at least one of the above is satisfied.

48. The method according to any one of claims 32 to 35, wherein receiving a mobility indication message includes receiving a new mobility indication message containing updated information compared to a previously received mobility indication message, and performing an operation includes: determining whether one or more wireless communication devices connected to the IAB node should be released based on the information provided by the new mobility indication message; transmitting a release notification to the one or more wireless communication devices in response to determining that the one or more wireless communication devices should be released; and the method includes the above.

49. A method for use in managing network connectivity in a wireless communication system including at least one integrated access and backhaul (IAB) node, wherein the method at the IAB node includes: determining, based on the mobility of the IAB node, whether the IAB node can support network connectivity for wireless communication devices; providing a mobility information message including IAB support information indicating that network connectivity for wireless communication devices can be supported by the IAB node in response to determining that the IAB node can support network connectivity; and the method includes the above.

50. The method according to claim 49, wherein the mobility information message further includes: Mobility profile information indicating the mobility capabilities of the IAB node, Guaranteed stationary time information indicating the minimum period for which the IAB node remains at a given location, Mobile node indication information indicating that the IAB is a mobile IAB, Mobility state indication information indicating the current state of mobility of the IAB node, Mobile IAB cell indication information indicating that a cell is associated with a mobile IAB node, A method comprising at least one of the above.

51. The method according to claim 50, wherein the mobility profile information comprises at least one of the following: Speed information indicating the speed capabilities of the IAB node, Range information indicating the mobility area of the IAB node, Stationary information indicating the duration of one or more stationary periods that the IAB node can experience, Route information indicating the sequence of mobility and stationary periods regarding the route that the IAB node can follow, A method comprising at least one of the above.

52. The method according to any one of claims 49 to 51, wherein it is determined based on at least one of the mobility capabilities of the IAB node and the current mobility status of the IAB node whether the IAB node can support network connectivity for a wireless communication device.

53. The method according to any one of claims 49 to 52, wherein in response to determining that the IAB cannot support network connectivity, IAB support information is not included in the mobility information message to indicate that the IAB node cannot support network connectivity.

54. The method according to any one of claims 49 to 53, further comprising determining that the IAB node can support network connectivity when the IAB node has been stationary for a period longer than a predetermined threshold or when the IAB node is moving with limited mobility.

55. The method according to claim 54, wherein the mobility of the IAB node is based on the following criteria: The speed of the IAB node being below a predetermined threshold, The mobility area being geographically restricted, The mobility area is within one topology or one network cell, and a method that is restricted when at least one of them is satisfied. **Claim 56** A method according to any one of claims 49 to 51, further comprising receiving, from an IAB donor node connected to the IAB node, a connectivity support configuration message indicating whether the IAB node can support network connectivity, wherein the IAB node determines whether the IAB node can support network connectivity based on the received connectivity support configuration message. **Claim 57** A method according to any one of claims 49 to 56, further comprising transmitting a mobility indication message to an IAB donor node connected to the IAB node, the mobility indication message including mobility profile information indicating the mobility capability of the IAB node, guaranteed stationary time information indicating the minimum period for which the IAB node remains at a given position, mobile node indication information indicating that the IAB is a mobile IAB, mobility state indication information indicating the current state of the mobility of the IAB node, and including at least one of them. **Claim 58** A method according to claim 57, wherein the mobility profile information includes speed information indicating the speed capability of the IAB node, range information indicating the mobility area of the IAB node, stationary information indicating the duration of one or more stationary periods that the IAB node can experience, route information indicating the sequence of mobility and stationary periods regarding the route that the IAB node can follow, and including at least one of them. **Claim 59** A method in a wireless communication device of a wireless communication system, the wireless communication system further comprising an integrated access and backhaul (IAB) node controlled by an IAB donor node, the method comprising transmitting a request to the IAB donor node via the IAB node to request establishment of a connection via the IAB node. Receiving a configuration message from the IAB donor node in response to the request; including, when the connection via the IAB node is rejected because the IAB node is a mobile IAB node, the configuration message including IAB configuration rejection cause information indicating that the connection has been rejected because the IAB node is a mobile IAB node, a method.

60. The method according to claim 59, wherein when the connection via the IAB node is rejected, the configuration message further includes IAB configuration rejection information indicating that the connection has been rejected, a method.

61. The method according to claim 59 or 60, wherein when the IAB node is a mobile IAB node, the configuration message includes mobility profile information indicating the mobility capability of the IAB node, the mobility profile information includes the following, speed information indicating the speed capability of the IAB node, range information indicating the mobility area of the IAB node, stationary information indicating the duration of one or more stationary periods that the IAB node may experience, travel information indicating the sequence of mobility and stationary periods regarding the travel that the IAB node may follow, including at least one of the above, a method.

62. An apparatus for an integrated access and backhaul (IAB) node of a wireless communication system, comprising one or more central processing units configured to execute the method according to any one of claims 1 to 18, 49 to 58, an apparatus.

63. An apparatus for an integrated access and backhaul (IAB) donor node of a wireless communication system, comprising one or more processing units configured to execute the method according to any one of claims 32 to 48, an apparatus.

64. An apparatus for a wireless communication device, comprising one or more processing units configured to execute the method according to any one of claims 19 to 31, 59 to 61, an apparatus.

65. A computer program including instructions that, when executed by a computer, cause the computer to execute the control method according to any one of claims 1 to 61.

66. A computer-readable medium storing the computer program according to claim 65.

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