Management or facilitation of network connectivity in wireless communication systems

Abstract

Management or facilitation of network connectivity in wireless communication systems Disclosed are methods and apparatus for use in facilitating network connectivity of wireless communication devices in an Integrated Access and Backhaul (IAB) communication system. The method in the wireless communication device includes determining whether there is one or more preferred mobile cells other than a serving mobile cell serving the wireless communication device, the one or more preferred mobile cells being preferred target cells for the wireless communication device. In one example, the one or more preferred mobile cells are associated with one another, and the wireless communication device may determine whether a serving cell, such as a serving mobile cell serving the wireless communication device, is associated with one or more other cells, such as one or more other mobile cells. In the case of mobile cells, a cell may be associated with a mobile cell when the movement of the cell is related to the movement of the mobile cell. Also disclosed are methods in an IAB node associated with one or more cells, such as one or more mobile cells in an IAB communication system, and methods in an IAB donor node in an IAB communication system, which manages the connectivity between a wireless communication device and a serving cell, such as a serving mobile cell serving the wireless communication device.

Description

Technical Field

[0001] The present invention generally relates to managing or facilitating network connectivity in a wireless communication system. In particular, the present invention relates to a method and apparatus for managing or facilitating network connectivity of a wireless communication device in an Integrated Access and Backhaul (IAB) communication system, for example, including at least one mobile Integrated Access and Backhaul (IAB) node.

Background Art

[0002] Wireless communication systems are widely deployed to address 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...) via a radio access network (RAN) through one or more base stations. The 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-connectivity communication systems include systems based on 3rd Generation Partnership Project (3GPP (registered trademark)) standards such as 4th Generation (4G) Long Term Evolution (LTE) or the recent 5th Generation (5G) New Radio (NR) system, or systems based on IEEE802.11 standards such as WiFi.

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

[0005] Faced with the high deployment costs and time issues of wired backhaul networks as network density increases, 3GPP, in its recent Release 16 for 5G NR, proposed wireless backhaul (also known as Integrated Access and Backhaul (IAB), where a portion of the wireless (e.g., radio) spectrum is used for base station backhaul connections instead of fiber). Wireless backhaul communication (between base stations) can use the same radio resources as access communication (between base stations and UEs).

[0006] IAB has proven to be a competitive alternative to fiber-based backhaul in densely populated or hard-to-cover areas, enabling scalable and rapid deployment without the burden of cabling base stations.

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

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

[0009] 3GPP believes that such vehicles could offer an opportunity to increase network coverage and connectivity to UEs within the vehicle, or even to UEs in the vicinity of the vehicle, by installing onboard base stations (or base station elements) that act as repeaters on these vehicles. These repeaters would rely on 5G radio backhaul (typically IAB, or Integrated Access & Backhaul) to connect to fixed donor devices such as IAB donor central units (CUs) directly connected to the core network. Thus, building on the fixed IAB foundation described in Releases 16 and 17, 3GPP is now exploring mobile IAB systems and architectures as part of the Release 18 framework to address scenarios focusing on mobile IAB nodes mounted on vehicles (e.g., buses, trains, taxis). In such scenarios, the mobile IAB node could also be called a Vehicle-Mounted Relay (VMR), providing 5G coverage / capacity to onboard and / or surrounding UEs. The technical advantages of using vehicle-based relays include, among others, the ability of relay vehicles to achieve better coverage than nearby UEs, thanks to their superior RF / antenna capabilities, and thus providing UEs with better links to the macro network. Furthermore, vehicle-based relays are expected to have less stringent power / battery constraints than UEs.

[0010] Because VMR or mobile IAB (mIAB) nodes are static at one point in time (e.g., a taxi in a parking lot or taxi rank, a bus in a parking lot or bus stop, a train at a station, or a temporary installation during an event or emergency / disaster) and mobile at another, connectivity to mobile IAB (mIAB) nodes or vehicle-mounted relays (VMRs) can fluctuate based on their actual movement. Therefore, to benefit from the additional connectivity advantages resulting from the presence of mobile IAB nodes in the topology, while mitigating the connectivity impacts that may arise from their actual movement, the connectivity of network devices or user equipment (UEs) to the network via or through such mobile IAB nodes should be carefully managed.

[0011] In this regard, two types of UEs can be considered in the context of mobile IAB: 1) ambient UEs, which are connected to a mobile IAB node but whose movement is not correlated with the movement of the mobile IAB node (e.g., a smartphone used on a road near a bus station); and 2) on-board UEs (OB-UEs), which are connected to a mobile IAB node and whose movement is similar to that of the mobile IAB node. On-board UEs are typically UEs located inside a vehicle on which a VMR or mobile IAB node is installed (e.g., a smartphone used inside a bus or train).

[0012] Furthermore, in some long vehicles (for example, trains), several mIAB nodes may be installed on the vehicle, in which case several mIAB nodes and their respective mobile cells travel together. Such mIAB nodes and their respective mobile cells may be referred to as the associated mIAB node and associated mCell, respectively.

[0013] Therefore, several new mechanisms are needed to take advantage of the additional connectivity benefits arising from the presence of associated mobile cells in the topology, while limiting the complexity of processing at the UE or IAB node or IAB donor CU, as well as the delays resulting from such processing. [Overview of the project]

[0014] According to a first aspect of the present invention, a method is provided for use in facilitating network connectivity of a wireless communication device in an Integrated Access and Backhaul (IAB) communication system, as described in claim 1 of the appended claims.

[0015] Wireless communication devices can be user equipment (UEs) or mobile IAB nodes.

[0016] In one example, one or more preferred mobile cells are associated with each other. In mobile cells, a cell can be associated with another mobile cell when the movement of the cell is related to the movement of the mobile cell.

[0017] The decision may be based on measurements performed by the wireless communication device, or on information received by the wireless communication device, for example, from an IAB node or an IAB donor node. The advantage of the wireless communication device determining whether there is one or more preferred mobile cells other than the serving mobile cell, or whether the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells based on measurements performed by the wireless communication device, is that the wireless communication device can autonomously determine the associated cell. However, making the decision based on information received from other nodes means that the processing required in the wireless communication device is reduced compared to the wireless communication device making the decision.

[0018] A second aspect of the present invention provides a method for use in facilitating network connectivity of wireless communication devices in an Integrated Access and Backhaul (IAB) communication system, which includes an IAB node associated with one or more mobile cells as described in claim 27 of the appended claims.

[0019] For example, the method at an IAB node may include transmitting information in a BOUND CELL INFORMATION message broadcast by the IAB node to identify one or more other mobile cells as associated mobile cells to which at least one of the one or more mobile cells is associated.

[0020] A third aspect of the present invention provides a method for facilitating network connectivity of a wireless communication device in an Integrated Access and Backhaul (IAB) communication system, which includes an IAB donor node that manages the connection between the wireless communication device and a serving mobile cell serving the wireless communication device, as described in claim 35 of the appended claims.

[0021] For example, the method at an IAB donor node may include sending information to a wireless communication device, such as in a CONFIGURATION INFORMATION message, to identify one or more other mobile cells as associated mobile cells to which the serving mobile cell is associated.

[0022] A fourth aspect of the present invention provides a method for use in an Integrated Access and Backhaul (IAB) communication system, including an IAB donor node, as described in claim 44 of the appended claims.

[0023] For example, the method at an IAB donor node may include receiving configuration information, such as a bound cell global configuration, to identify one or more lists of mobile cells associated with one or more IAB nodes that are related to each other and managed by the IAB donor node.

[0024] A fifth aspect of the present invention provides a method for use in facilitating network connectivity of wireless communication devices in an Integrated Access and Backhaul (IAB) communication system, including an IAB donor node, as described in claim 49 of the appended claims.

[0025] For example, the method at an IAB donor node may include receiving a request, such as a CONNECTION SETUP REQUEST, from a wireless communication device to establish a connection with a mobile cell associated with an IAB node managed by the IAB donor node, and, if the mobile cell requesting the connection is associated with one or more other mobile cells, transmitting information to the wireless communication device to identify one or more other mobile cells as associated mobile cells associated with the mobile cell requesting the connection. For example, the information may be associated cell information transmitted in a CONNECTION SETUP RESPONSE.

[0026] In another embodiment, a method is provided for use in facilitating network connectivity of a wireless communication device in an Integrated Access and Backhaul (IAB) communication system, which includes an IAB donor node that manages the connection between the wireless communication device and a serving mobile cell serving the wireless communication device, wherein the wireless communication device is mounted on an IAB node associated with a serving mobile cell, and the method in the IAB donor node includes enabling a handover of the wireless communication device to an IAB node associated with one or more other mobile cells to which the serving mobile cell is associated, but not enabling a handover of the wireless communication device to an IAB node not associated with one or more other mobile cells to which the serving mobile cell is associated. In other words, the IAB donor node may only enable a handover of the wireless communication device to an IAB node associated with one or more other mobile cells to which the serving mobile cell is associated. An IAB donor node may only allow handovers to IAB nodes associated with one or more other mobile cells to which a serving mobile cell is associated, while the radio communication device is either on-board or remaining on-board with the IAB node associated with the serving mobile cell (for example, an IAB donor node will not allow handovers to IABs not associated with the associated mobile cell). A radio communication device is either on-board or remaining on-board with the IAB node if it is moving or similar to the movement of a mobile IAB node. For example, a radio communication device on-board with an IAB node is typically a radio communication device located inside the vehicle on which the IAB node is mounted (e.g., a UE). An IAB donor node may determine whether a radio communication device is on-board with the IAB node (e.g., the on-board status of the radio communication device) for example from measurements made by the IAB donor node itself or from information / notifications provided by the radio communication device.

[0027] According to a sixth aspect of the present invention, there is provided an apparatus for a wireless communication device as claimed in claim 63 of the appended claims.

[0028] According to a seventh aspect of the present invention, there is provided an apparatus for an IAB node as claimed in claim 64 of the appended patent claims.

[0029] According to an eighth aspect of the present invention, there is provided an apparatus for an IAB donor node as claimed in claim 65 of the appended patent claims.

[0030] Determining whether a serving mobile cell serving a wireless communication device is associated with one or more other mobile cells, or whether there are one or more preferred mobile cells other than the serving mobile cell, can mitigate the connectivity impact resulting from the actual movement states of the wireless communication device (e.g., UE) and the associated or preferred mobile cells, while benefiting from the additional connectivity resulting from the presence of the associated mobile cells (or preferred mobile cells) in the topology, in order to enhance service continuity or the cell reselection process. For example, by determining or identifying the associated mobile cells associated with the serving cell of a wireless communication device such as a UE, the UE can give a higher priority to the associated mobile cells than to the non-associated adjacent cells for cell reselection or conditional handover (CHO). When the UE is mounted in a vehicle (e.g., an in-vehicle UE device), ignoring the non-associated adjacent cells and giving a higher priority to the associated mobile cells for cell reselection or CHO can prevent the in-vehicle UE from temporarily connecting to a fixed or mobile cell that can enter the range of the in-vehicle UE device but only for a limited time, and a potential sequence of disconnection / reconnection that affects service continuity in the UE device can be avoided.

[0031] Further exemplary features of the present invention are described in the other independent and dependent claims.

[0032] 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, aspects of methods may be applied to aspects of apparatus / devices / units, and vice versa.

[0033] Furthermore, features implemented in hardware may also be implemented in software, and vice versa. Any references to software and hardware features in this specification should be interpreted accordingly. For example, according to another aspect of the present invention, a computer program is provided which includes instructions causing one or more processing units to perform any of the methods described above when the program is executed by one or more processing units, and a computer-readable storage medium for carrying the computer program. [Brief explanation of the drawing]

[0034] Herein, different aspects of the present invention will be described, merely as examples, with reference to the following drawings: [Figure 1] Figure 1 is a schematic diagram showing an exemplary wireless communication system in which the present invention may be carried out according to one or more embodiments; [Figure 2] Figures 2a and 2b are schematic diagrams showing the stack of several protocol layers involved in IAB operation; [Figure 3] Figure 3 is a schematic diagram showing the format of a BAP protocol data unit (PDU) or packet; [Figure 4] Figure 4 is a schematic diagram showing an exemplary wireless communication system (or IAB network) in which the present invention may be implemented according to one or more embodiments; [Figure 5] Figure 5 is a schematic and simplified diagram illustrating an exemplary message flow for managing or facilitating connectivity of wireless communication devices such as UEs to associated mobile cells, according to one or more embodiments of the present invention; [Figure 6]Figure 6 is a schematic and simplified diagram illustrating an exemplary message flow for managing or facilitating connectivity of wireless communication devices such as UEs to associated mobile cells, according to one or more embodiments of the present invention; [Figure 7] Figure 7 is a schematic and simplified diagram illustrating an exemplary message flow for managing or facilitating connectivity of wireless communication devices such as UEs to associated mobile cells, according to one or more embodiments of the present invention; [Figure 8a] Figure 8a is a flowchart of an exemplary method performed in a wireless communication device such as a UE to determine one or more cells associated with a serving cell, according to one or more embodiments of the present invention; [Figure 8b] Figure 8b is a flowchart illustrating an exemplary method, according to one or more embodiments of the present invention, for determining one or more cells associated with a serving cell by a wireless communication device such as a UE; [Figure 9] Figure 9 is a flowchart illustrating an exemplary method, according to one or more embodiments of the present invention, for a mobile IAB node to share information about cells associated with one or more cells it is serving; [Figure 10] Figure 10 is a flowchart illustrating an exemplary method, according to one or more embodiments of the present invention, for a network device such as an IAB donor node to share information about cells associated with cells to which a served wireless communication device (such as a UE) is connected; [Figure 11] Figure 11 is a flowchart illustrating an exemplary method, according to one or more embodiments of the present invention, for a network device such as an IAB donor node to share information about cells associated with cells to which a served wireless communication device (such as a UE) is connected; [Figure 12]Figure 12 is a flowchart illustrating an exemplary method for managing or facilitating network connectivity of a wireless communication device, such as a UE, to an associated mobile cell, according to one or more embodiments of the present invention; [Figure 13] Figure 13 is a flowchart illustrating an exemplary method for managing the connectivity of a wireless communication device, such as a UE, to an associated cell by a wireless communication device, according to one or more embodiments of the present invention; [Figure 14] Figure 14 is a flowchart illustrating an exemplary method, according to one or more embodiments of the present invention, for managing or facilitating the connectivity of a wireless communication device, such as a UE, to an associated cell by a network device, such as an IAB donor node; [Figure 15] Figure 15 is a schematic block diagram of an exemplary wireless communication device according to an embodiment of the present invention; [Figure 16] Figure 16 is a flowchart illustrating an exemplary method, according to one or more embodiments of the present invention, for managing or facilitating the connectivity of a wireless communication device, such as a UE, to an associated cell by a network device, such as an IAB donor node. [Modes for carrying out the invention]

[0035] Figure 1 shows an exemplary communication system 100 in which the present invention may be implemented according to one or more embodiments.

[0036] As shown in the figure, exemplary system 100 is a wireless communication system, in particular a mobile wireless communication system such as a fifth-generation (5G) New Radio (NR) system including a wireless Integrated Access and Backhaul (IAB) communication system or network. Although embodiments and examples of the present invention are described in relation to a 5G NR system in the following description, it will be understood that the present invention is not intended to be limited to a 5G NR system and can 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.

[0037] System 100 includes a plurality of UEs (User Equipment) 131, 132, 133, 134, 135, and 136, 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 or a mobile IAB node 123 installed in a vehicle 105 (e.g., a bus, train, taxi, car, etc.) in the example shown in Figure 1.

[0038] The main base station 120, also called IAB donor 120 (or IAB donor), is connected to the core network 110 via a wired link 101, preferably 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 gNB) having additional capabilities to support IAB functionality, as defined in the 3GPP TS 38.300v17.0.0 specification document.

[0039] To extend the network coverage of IAB donor 120 and reach remote UEs 132, 133, and 131, IAB stations 121 and 122, also known as IAB nodes 121 and 122, are installed by the operator. By acting as relay nodes between IAB donor 120 and UEs 131, 132, and 133, IAB nodes 121 and 122 enable overcoming reachability issues arising from the presence of building 108, which is an obstacle to radio wave propagation and therefore to direct connections and further communications between the UEs and IAB donor 120. This is especially true when communications between IAB donor 120 and UEs 131, 132, and 133 are operating at millimeter-wave frequencies, which are highly sensitive to shadowing phenomena.

[0040] IAB donor 120 also serves UE134, which is directly connected to it.

[0041] The mobile IAB station 123, also called the IAB node 123 or mIAB node 123, mounted on the vehicle 105, also provides expanded network coverage and capacity, enabling the IAB donor 120 to reach on-board remote UEs such as the remote UE 135, as well as UEs around or near the IAB node 123, such as the remote UE 136.

[0042] IAB donor 120 and IAB nodes 121, 122, and 123 thus form a backhaul network or IAB network (also called an IAB topology) accommodating UEs 131, 132, 133, 134, 135, and 136. The terms IAB network and IAB topology are used interchangeably below. An IAB network is referred to as forming a radio access network (RAN) or, in the case of 5G, next-generation (NG) RAN.

[0043] The Integrated Access and Backhaul (IAB) specification spans several 3GPP standards, 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).

[0044] Since IAB nodes 121, 122, and 123 are connected to UEs 131, 132, 133, 134, 135, and 136 respectively, they are considered access IAB nodes for the connected UEs.

[0045] An IAB donor 120 is a logical node that provides NR-based radio backhaul and consists of a central unit (CU or gNB-CU function) and connected donor distributed units (DU or gNB-DU function). The IAB donor CU or donor CU (hereinafter also referred to as IAB donor CU or IAB donor CU) hosts higher layer protocols such as PDCP (Packet Data Convergence Protocol) and RRC (Radio Resource Control) protocols for controlling the operation of one or more DUs and one or more IAB donor DUs or donor DUs (hereinafter also referred to as IAB donor DU or IAB donor DU), and includes lower layer protocols such as RLC, MAC and physical layer protocols. The IAB donor CU and IAB donor DU may be located far apart from each other or may be located on the same physical device. The gNB-DU function is defined in 3GPP TS 38.401. The purpose is 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.

[0046] IAB nodes, capable of serving multiple wireless sectors or cells, are wirelessly backhauled to an IAB donor 120 via one or more hops (for example, via one or more IAB nodes). They form a directed acyclic graph (DAG) topology with the IAB donor as the root.

[0047] Each IAB node consists of an IAB-DU (IAB Distributed Unit) and an IAB-MT (IAB Mobile Termination). The gNB-DU function on an IAB node, also called an IAB-DU, enables downstream connectivity to the next hop IAB or UE (towards the UE). The IAB-MT function includes, for example, physical layer, Layer 2, RRC, and non-accessible stratum (NAS) functions for connecting to the gNB-DU of an upstream IAB node (including IAB donor 120, which in this case connects to the IAB donor gNB-CU, and therefore to the core network 110 for, for example, initialization, registration, and configuration).

[0048] In this DAG topology, adjacent nodes on the IAB-DU interface are called child nodes, and adjacent nodes on the IAB-MT interface are called parent nodes. The direction toward child nodes is further called downstream, while the direction toward parent nodes is called upstream.

[0049] IAB Donor 120 (e.g., 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.

[0050] Figures 2a and 2b schematically show the stack of several protocol layers involved in IAB operation.

[0051] The F1 interface supports the exchange of signaling information between endpoints and the transmission of data to each endpoint. From a logical standpoint, the F1 interface is a point-to-point interface between endpoints.

[0052] In 5G NR, F1-C is the functional interface in the control plane (CP) between the IAB donor CU and the IAB node-DU. F1-U is the functional interface in the user plane (UP) of the same unit. F1-C and F1-U are shown by reference no. 212 in Figure 2a. In this example, F1-U and F1-C are carried through two backhaul hops (from the IAB donor to IAB node 1, and from IAB node 1 to IAB node 2).

[0053] In the user plane, box 210 in the IAB donor CU and IAB node DU refers to the GTP-U layer, and box 211 refers to the UDP layer. GTP-U stands for GPRS Tunneling Protocol User Plane. A 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), in this case box 210 in the IAB donor CU and IAB node DU. The well-known User Datagram Protocol (UDP) is a transport layer protocol that provides best-effort datagram services and is adapted for use with the IP protocol.

[0054] In the control plane, box 210 represents the F1AP (F1 Application Protocol) layer, and box 211 represents the SCTP (Stream Controlled Transmission Protocol) layer. The F1 Application Protocol (as defined in 3GPP TS 38.473 and TS 38.401) provides signaling services between IAB donor CUs and IAB node DUs, or services related to UEs. These services include, for example, initialization and configuration. The well-known SCTP layer provides reliable sequential transmission of messages with congestion control.

[0055] 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 TS 38.401.

[0056] Transmission between an IAB donor DU and an IAB donor CU also uses the IP transport layer over various media, such as wired or fiber optic, when the IAB donor CU is located away from the IAB donor DU, or it is used locally in virtual instances of the IAB donor CU and IAB donor DU on the same physical machine. IAB-specific transmission between an IAB donor CU and an IAB donor DU is specified in 3GPP TS 38.401.

[0057] In the diagram, L1 and L2 represent the transport and physical layers appropriate for the medium being used, respectively.

[0058] The IP layer can also be used for non-F1 traffic, such as operational, management, and maintenance traffic.

[0059] In wireless backhaul, the IP layer itself is carried via a Backhaul Adaptive Protocol (BAP) sublayer, which enables routing across multiple hops. The BAP sublayer is defined in TS 38.340.

[0060] IP traffic in the IAB-DU is routed over the radio backhaul via the BAP sublayer. Downstream, 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. BAP packets are routed by the BAP layer of any intermediate IAB nodes (and corresponding BAP entities in the IAB-DU and IAB-MT). Finally, BAP packets are decapsulated by the BAP sublayer at the destination IAB node (which may be the access IAB node if the upper-layer packets in the BAP packet are destined for a UE).

[0061] Upstream, upper-layer packets are encapsulated by a BAP sublayer at the initiator IAB node (which may be the access IAB node if the upper-layer packets originate from the UE), thus forming a BAP packet, PDU, or data unit. The BAP packet is routed by the BAP layer of any intermediate IAB nodes (and the corresponding BAP entities in IAB-DU and IAB-MT). Finally, the BAP packet is decapsulated by the BAP sublayer at the IAB donor DU.

[0062] On the BAP sublayer, packets are carried within a BAP header and routed based on a BAP routing ID, which is set by the BAP sublayer of the network node in the IAB network that generates the BAP packet. Figure 3 shows the format of a BAP Data Protocol data unit (PDU) or packet, which is specified in paragraph 6.2 of the standardization version of 3GPP TS38.340 release 17.0.0.

[0063] Header 30 includes fields 301 to 306. Field 301 is called the D / C field and 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).

[0064] Fields 305 and 306 together represent the BAP routing ID for the BAP packet. The BAP address field 305, also known as the DESTINATION field, occupies the leftmost 10 bits, while the BAP path identification field 306, also known as the PATH field, occupies the rightmost 10 bits.

[0065] Field 305 carries the BAP address (e.g., on the BAP sublayer) of the destination IAB node or IAB donor DU for the BAP packet. For routing purposes, each IAB node and IAB donor DU is configured with the specified BAP address (by the IAB donor CU that controls the IAB network or topology to which the IAB node and IAB donor DU belong). Field 306 carries a path ID that identifies the routing path that the BAP packet should follow to this destination in the IAB topology. Routing paths, including their path IDs, are configured in the same way that BAP addresses are configured.

[0066] The BAP header is added to packets upon arrival at the BAP layer from higher layers and removed by the BAP layer upon reaching the destination node. The selection of the packet's BAP routing ID is determined by the IAB donor CU.

[0067] For example, when a BAP packet is generated by an IAB node, for instance, by an IAB donor for downstream transmission or by an initiator IAB node (which may be an access IAB node if the upper-layer packet is coming from a UE), the BAP header containing the BAP routing ID is constructed by this IAB node according to a configuration table defined in 3GPP TS 38.340. This table is called the Downlink Traffic to Routing ID Mapping Configuration table at the IAB donor, or the Uplink Traffic to Routing ID Mapping Configuration table at the initiator IAB node. At intermediate IAB nodes, the BAP header fields are already defined within the BAP packet being forwarded.

[0068] As described above, these configuration tables that define BAP paths (and therefore the routing strategies and configurations of IAB nodes in a given IAB network topology) are typically defined by the IAB donor CU that controls the IAB network and sent to the IAB nodes to configure them.

[0069] To handle the transmission of messages over the 5G NR radio medium, three additional sublayers (RLC, MAC, and PHY) are implemented beneath the BAP sublayer at each IAB node. The RLC (Radio Link Control) sublayer is responsible for segmenting or reconfiguring packets. It is also responsible for requesting the retransmission of missing packets. The RLC layer is further described in TS38.322. The MAC (Medium Access Channel) protocol sublayer is responsible for selecting available transmission formats for user data and mapping logical channels to transport channels. MAC also handles part of the Hybrid Automatic Repeat Request scheme. The MAC layer is detailed in TS 38.321. On the transmitting or transmitter side, MAC encapsulates data packets issued from the RLC. It adds a header that carries the information necessary for MAC functionality. On the receiving side, MAC decapsulates data packets issued from the PHY, removes its header, and passes the remaining data to the RLC. The PHY sublayer provides an electrical interface to the transmission medium (air) at the transmitting end by converting the information stream into a physically modulated signal and modulating the carrier frequency. At the receiving end, the PHY sublayer converts the physically modulated signal back into an information stream. The PHY layer is described in TS 38.201, TS 38.211, TS 38.212, TS 38.213, and TS 38.214.

[0070] To deliver messages to the user or control plane, the UE and IAB donor CU use either two other sublayers: the PDCP (Packet Data Convergence Protocol) sublayer, the SDAP (Service Data Adaptive Protocol) sublayer for user plane communication, or the RRC (Radio Resource Control) sublayer for control plane communication.

[0071] The PDCP sublayer handles IP header compression / decompression, encryption / decryption, and, if necessary, data packet integrity. It is essential that packets are numbered at the sender and reordered at the receiver. The PDCP sublayer is described in 3GPP TS38.323.

[0072] The user plane's SDAP sublayer 220 handles quality of service, as described in TS 38.324. On the UE side, the SDAP sublayer exchanges payload data with the user's applications (voice, video, etc., not shown in the diagram). On the IAB donor side, the SDAP sublayer exchanges data with the core network 110 (internet traffic, cloud, etc.).

[0073] The control plane's RRC sublayer 220 handles the configuration of protocol entities in the user plane protocol stack. It is described in TS 38.331. Among other things, it is responsible for broadcasting information necessary for the UE to communicate with the cell, sending paging messages, managing connections including bearer setup, handling mobility functions, measurement settings and reporting, and device capabilities.

[0074] The interface between nodes (for both CP and UP) using Layer PDCP, RLC, MAC, and PHY is called NR-Uu. This primarily concerns the interface with the UE.

[0075] The interface between nodes using Layer BAP, RLC, MAC, and PHY (for both CP and UP) is called a backhaul RLC channel (BH RLC channel). This primarily concerns interfaces between IAB nodes.

[0076] NR-Uu is the interface between the UE and the radio access network, such as its access IAB nodes (for both CP and UP).

[0077] Figure 2b, derived from 3GPP TS 38.300v17.0.0, shows the protocol stack for IAB-MT RRC and NAS connectivity support. The Non-Access Stratum (NAS) protocol handles messages between the core network and user equipment, in this case, IAB nodes. It manages the establishment of communication sessions and maintains communication with user equipment as it moves. 5G NAS is described in 3GPP TS 24.501. The 5G core Access and Mobility Management Function (AMF) is a function within the core network that receives all connectivity and session-related information from UEs connected to IAB nodes, and similar information for IAB nodes. The AMF is solely responsible for handling connectivity and mobility management tasks.

[0078] The IAB-MT establishes an IAB donor CU and a signaling radio bearer SRB (a bearer that carries RRC and NAS messages). These SRBs are transmitted between the IAB-MT and its parent node via the NR-Uu interface.

[0079] Figure 4 shows an example of a wireless communication system 400 (e.g., an IAB communication system) including an IAB network or IAB network system, in which embodiments and examples of embodiments of the present invention may be implemented. In one exemplary implementation, the radio link (referred to as a BH radio link) between an IAB node and an IAB donor DU node operates over a millimeter-wave frequency band (e.g., above 30 GHz) which is highly sensitive to radio channel disturbances. The IAB network is also called an IAB topology or topology, and therefore, in this application, the terms IAB network, IAB topology, and topology are used interchangeably.

[0080] The IAB network system in Figure 4 forms part of the NG RAN and consists of two IAB networks or IAB topologies 4001 and 4002, each IAB topology including a set of IAB nodes (for example, a set may include multiple IAB nodes or at least one IAB node) and an IAB donor CU for controlling or managing the set of IAB nodes. The set of IAB nodes may include one or more IAB nodes, such as initiator IAB nodes that generate BAP packets, and intermediate or relay IAB nodes. The set of IAB nodes may also include one or more IAB donor DUs. Each IAB node communicates with at least one other IAB node via a radio backhaul (BH) link.

[0081] Figure 4 shows two IAB topologies 4001 and 4002, but the present invention is not limited to these two IAB topologies, and as described above, can be implemented in an IAB communication system including three or more IAB topologies, each including a set of IAB nodes and an IAB donor CU.

[0082] IAB topology 4001 includes IAB donor CU401 (identified as donor 1CU in Figure 4), its associated IAB donor DU, IAB donor DU403 (identified as donor 1DU1 in Figure 4), and IAB donor DU404 (identified as donor 1DU2 in Figure 4), as well as several IAB nodes 410, 420, and 430 similar to IAB nodes 121 and 122, and mobile IAB nodes 460, 470, and 480 similar to mobile IAB node 123.

[0083] IAB topology 4002 includes IAB donor CU402 (identified as donor 2CU in Figure 4), its associated IAB donor DU405 (identified as donor 2DU1 in Figure 4), and several IAB nodes 440 and 450 similar to IAB nodes 121 and 122. The IAB network system in Figure 4 can provide network path diversity through several IAB donor DUs and different IAB networks or topologies.

[0084] As described above, each IAB node includes a mobile termination (MT) portion or unit controlled and configured by the IAB donor using RRC messaging as defined in 3GPP TS 38.331, and a distributed unit (DU) portion controlled and configured by the IAB donor using F1-AP messaging as defined in 3GPP TS 38.473. For example, IAB node 410 includes an MT portion or unit 411 and a DU portion 412.

[0085] The wired backhaul IP network interconnects IAB donors CU401 and 402, as well as IAB donors DU403, 404, and 405, via wired link 406. For example, this wired link consists of fiber optic cable.

[0086] IAB donor CU401, IAB donors DU403 and 404, IAB nodes 410, 420, 430, 460, 470, and IAB node 480 are part of the same IAB network or IAB topology 4001 controlled (e.g., configured and / or managed) by IAB donor CU401.

[0087] IAB donor CU402, IAB donor DU405, and IAB nodes 440 and 450 are part of the same IAB network or IAB topology 4002 controlled (e.g., configured and / or managed) by IAB donor CU402.

[0088] IAB node 460 is connected to parent IAB node 420 via BH link 4026. IAB node 460 is also connected to UE 409 via communication link or radio link 4069: IAB node 460 acts as an access node for UE 409. Although Figure 4 shows only one UE 409, it will be understood that there are multiple UEs connected to IAB nodes in a wireless communication system.

[0089] Each IAB node supports wireless communication within a coverage area called a cell. In other words, each IAB node is associated with a cell. For example, IAB nodes 420, 430, 460, 470, and 480 are associated with cells 4200, 4300, 4600, 4700, and 4800, respectively.

[0090] Wireless communication devices located within a cell (such as UEs or other IAB nodes) may connect to the IAB node serving the cell in order to communicate with other devices (e.g., other UEs, IAB nodes, servers providing access to the Internet) via the IAB node. Typically, an IAB node measures signals from IAB nodes in neighboring cells as part of a cell search procedure (e.g., when it first connects to the network as defined in 3GPP TS 38.300) or as part of a subsequent procedure. The measurements are reported to the IAB donor CU of the IAB node. For example, referring to Figure 4, IAB node 480 may report to its IAB donor CU 401, through the measurement report, the presence of a new cell served by IAB node 450. Based on an analysis of the measurement report (for example, indicating that the measurements in the report show that the signal strength provided by IAB node 450 exceeds the threshold required to support communication), IAB donor CU401 may request IAB donor CU402, to which IAB node 450 belongs, to establish dual connectivity for IAB node 470 via an additional connection through IAB node 450. IAB donor CU402 may accept the request and proceed with establishing the connection of IAB node 480 to IAB node 450 (represented by BH link 4058 in Figure 4) in accordance with the procedure described in section 10.2 of TS 37.340v17.0.0. As a result, IAB node 480, which still belongs to IAB topology 4001, is also connected to IAB node 450, which belongs to IAB topology 4002, and can therefore be called a boundary node between IAB topology 4001 and IAB topology 4002. In practice, IAB node 480 holds its F1 connection and its RRC connection to IAB donor CU 401 (which may be called an F1-terminated IAB donor CU), and has a second RRC connection to IAB donor CU 402 (which may be called a non-F1-terminated IAB donor CU).

[0091] Since IAB node or boundary node 480 is part of IAB topology 4001 (in terms of F1 connectivity), it is controlled (e.g., configured and / or managed) by IAB donor CU401 of IAB topology 4001. Through a second RRC connection, IAB donor CU402 assigns a second BAP address to be used for routing packets through IAB topology 4002. Thus, IAB node 480 acting as a boundary node is assigned two BAP addresses: one for IAB network 4001 and one for IAB network 4002. Such a boundary node can help provide network path diversity by providing alternative routing paths through IAB topology 4001 and 4002.

[0092] Mobile IAB nodes 460, 470, and 480 may be mounted on the same vehicle 490 (for example, vehicle 490 may be a train or bus) to improve coverage while optimizing radio resource sharing. Thus, mobile IAB nodes 460, 470, and 480 are moving together, and cells 4600, 4700, and 4800 associated with mobile IAB nodes 460, 470, and 480 are also moving together and can be considered associated cells. In other words, cell 4600 is associated with (or associated with, linked to, or related to) cells 4700 and cell 4800, and similarly cell 4700 is associated with (or associated to, linked to, or related to) cells 4600 and cell 4800, and similarly cell 4800 is associated with (or associated to, linked to, or related to) cells 4600 and cell 4700. Cells can be considered related to one another when each movement of a cell is related or linked, such as when each movement of a cell is similar or substantially identical (for example, when the cells are moving together in substantially the same direction and at substantially the same speed). In the case shown in Figure 4, each movement of cells 4600, 4700, and 480 (and IAB nodes 460, 470, and 480) is related or linked because the IAB nodes 460, 470, and 480 associated with the cells are mounted on the same vehicle 490. In this application, cells that are related to one another (or are related, linked, or associated with one another) are referred to as related cells, and IAB nodes that are related to (for example, manage or control) related cells are referred to as related IAB nodes. An IAB node may control one or more cells. It will be understood that related cells may include one or more cells managed by the same IAB node. In other words, one or more cells managed by the same IAB node may be related to (or associated with, linked to, or associated with) one or more other cells.Therefore, for example, an IAB node associated with a serving mobile cell may be installed in the vehicle, and a mobile cell determined to be associated with the serving mobile cell may be managed by the same IAB node associated with the serving mobile cell (and thus installed in the vehicle), or a mobile cell determined to be associated with the serving cell may be managed by another IAB node that may be installed in that vehicle (where the wireless communication device is installed in the vehicle).

[0093] In another example, when there is a relationship between two or more fixed cells, the fixed cells can be considered related to each other (or linked to or associated with each other).

[0094] For example, several fixed cells belonging to a railway station or bus stop, or belonging to the same building located near a taxi or bus stop, may be associated together, allowing UE devices that are to remain at the railway station or the aforementioned building (e.g., people working at the station or the building) to preferentially connect to the associated fixed cells instead of another fixed cell or mobile cell (e.g., a train, bus, or taxi). Thus, more generally, two or more fixed cells belonging to the same building or fixed location, or related (e.g., located), may be identified as associated fixed cells if the building or fixed location is located near a place where there is a high probability that mobile cells (and fixed cells) are present nearby, and may be associated together to allow UEs that will remain at (or temporarily) the building or fixed location to preferentially connect to one of the associated fixed cells instead of an unrelated fixed cell or mobile cell.

[0095] Therefore, in general terms, two or more cells (whether mobile or stationary) can be associated with (or linked or related to) each other if there is a specific relationship between them. The description herein focuses on two or more mobile cells that are associated with each other. However, the description, examples, embodiments, and claims may instead apply to stationary associated cells. In one example, two or more cells (whether mobile or stationary) can be associated with (or linked or related to) each other when two or more cells are considered to be several preferred target cells for performing cell reselection for UE in one or more ranges of the two or more cells, regardless of their actual or relative positions.

[0096] UE409 may be an in-vehicle UE for vehicle 490, for example, the movement of UE409 is similar to the movement of vehicle 490. For example, the in-vehicle UE409 may be a smartphone located inside vehicle 490, which could be a bus or a train. Since UE409 is served by mobile IAB node 460 via cell 4600, UE409 can also be considered an in-vehicle UE for mobile IAB node 460.

[0097] Because the in-vehicle UE409 is moving with its serving mobile cell 4600, it may be in the vicinity of other potential access IAB nodes, such as fixed IAB nodes 420 or 430. However, due to the mobility of IAB node 460, the link quality between the in-vehicle UE409 and these potential fixed access IAB nodes is likely to develop rapidly. Therefore, the UE409 should maintain a connection with cell 4600 managed by mobile IAB node 460 or one of the cells associated with (or associated with, linked to, or associated with) cell 4600 (e.g., cells 4700 and 4800), and as long as it is the in-vehicle UE409 for vehicle 490, it should not perform any handover or cell reselection to other potential access IAB nodes.

[0098] A process for identifying associated cells among adjacent cells of a UE, along with a related connectivity management method, is described here according to some embodiments of the present invention.

[0099] Figure 8a is a flowchart of Method 810 performed in a wireless communication device. The wireless communication device may be a UE or a mobile IAB node. The following description relates to the case where the communication device is a UE, but the invention is not intended to be limited to UEs. Method 810 is intended for use in facilitating network connectivity of wireless communication devices in an Integrated Access and Backhaul (IAB) communication system, according to one or more embodiments of the invention. The IAB communication system may be, for example, IAB communication as shown in Figure 4 (Figure 1). With respect to the example shown in Figure 4, the wireless communication device performing Method 810 may be a UE 409. Method 810 shown and described in relation to Figure 8a may be performed by software elements and / or hardware elements. Thus, for example, a method as shown and described in Figure 8a may be performed by an apparatus for a wireless communication device including one or more processing units configured to perform the method. The wireless communication device may be implemented in a communication device 1500, such as the one shown and described with reference to Figure 15, using the method shown and described with reference to Figure 8a, which is performed by one or more processing units, such as a central processing unit 1511.

[0100] In short, in step 812, UE409 determines whether the serving mobile cell serving UE409 is associated with one or more other mobile cells. As described above, a cell can be associated with (or associated with, or linked to, or associated with) a mobile cell when the movement of a cell is related to (or linked to) the movement of a mobile cell, such as when the movement of each cell is similar or substantially identical (for example, when the cells are moving together in substantially the same direction and at substantially the same speed, such as when the IAB nodes associated with (or controlling or managing) the cells are mounted on the same moving vehicle). In the example shown in Figure 4, the IAB nodes 460, 470, and 480 that manage the mobile cells 4600, 4700, and 4800 are mounted on the same vehicle 490 (which could be a train, bus, or other similar long vehicle), and therefore the movement of the mobile cells 4600, 4700, and 4800 is related, and thus the mobile cells 4600, 4700, and 4800 are associated with each other.

[0101] After determining that an adjacent cell is an associated mobile cell linked to the serving mobile cell (for example, after UE409 has performed a discovery procedure and found one or more adjacent cells in UE409's vicinity or neighbors), UE409 may perform cell reselection (or conditional handover, CHO) to the associated mobile cell, with preference to other adjacent cells discovered by UE409 but not associated with UE409's serving mobile cell. In fact, when UE409 determines that an adjacent cell is an associated mobile cell, UE409 may ignore or not consider other adjacent cells that are unassociated mobile cells when performing cell reselection or CHO. Cell reselection is described in more detail with reference to Figure 12.

[0102] UE409 may determine whether the serving mobile cell serving UE409 is associated with one or more other mobile cells in several different ways. For example, UE409 may determine, based on measurements performed in the wireless communication device, whether an adjacent cell is an associated mobile cell associated with the serving mobile cell 4600 (as described below, for example, with reference to Figure 8b).

[0103] In addition to or alternatively, UE409 may determine, based on information received from an IAB node, whether the serving mobile cell serving UE409 is associated with one or more other mobile cells (for example, as described below with reference to Figures 5 and / or 9). For example, information sent to UE409 by an IAB node may include bound cell information that may be sent in a BOUND CELL INFORMATION message 532, as described below. The information may be broadcast by an IAB node. The IAB node providing the information may be IAB node 460, which manages the serving mobile cell 4600, or another IAB node, which manages one of the other mobile cells associated with the serving mobile cell 4600, such as mobile IAB node 470 or 480.

[0104] The UE 409 may, in addition or alternatively, determine whether the serving mobile cell serving the UE409 is associated with one or more other mobile cells based on information received from an IAB donor node, such as an IAB donor CU (see, for example, Figures 6 / 7 and / or 10 / 11 as described below).

[0105] In one example, UE409 may send a request to establish a connection with a mobile cell associated with an IAB node managed by an IAB donor node (e.g., IAB donor CU). Referring to Figure 4, when UE409 requests to establish a connection with mobile cell 4700 managed by IAB node 470, which is controlled by IAB donor CU401, it may send a request to IAB donor CU401 (such as a connection establishment request in CONNECTION SETUP REQUEST message 621, as described with reference to Figures 6 and 10). UE409 receives a response from IAB donor CU401, which includes information to identify one or more other mobile cells (cells 4600, 4800, etc.) as associated mobile cells to which the mobile cell 4700 for which the connection is requested is associated. For example, the information sent to UE409 by IAB donor CU401 may include bound cell information, which may be sent in CONNECTION SETUP RESPONSE message 622, as described below. After a connection is established with the requested mobile cell 4700, the requested mobile cell 4700 becomes the serving mobile cell serving UE409, and determining whether the serving mobile cell serving UE409 is associated with one or more other mobile cells may be done based on information contained in the response from IAB donor CU401 (for example, for cell reselection or CHO, as described below).

[0106] In one example, UE409 may receive information from an IAB donor node that manages the connection between UE409 and the serving mobile cell serving UE409 to identify one or more other mobile cells as associated mobile cells to which the serving mobile cell is associated. Referring to the example in Figure 4, UE409, served by mobile cell 4600 managed by IAB donor CU401, receives information from IAB donor CU401 that identifies mobile cells 4700 and 4800 as associated mobile cells to which the serving mobile cell 4600 is associated. For example, the information sent to UE409 by IAB donor CU401 may include bound cell information that may be sent in CONFIGURATION INFORMATION message 623, as described with reference to Figures 6 and 11. The information received from IAB donor CU401 may include update information that includes at least one of the following: information to identify one or more new mobile cells that have been added as associated mobile cells, and information to identify one or more mobile cells that have been removed as associated mobile cells.

[0107] The UE409 may also receive configuration information from an IAB donor node (e.g., an IAB donor CU) for a handover (HO) or conditional handover (CHO) for at least some of the one or more associated mobile cells (e.g., associated mobile cells included in the list of associated cells or table of associated cells provided in the UE409). The configuration information may be provided in MOBILITY CONFIGURATION INFORMATION message 725, as described below. After determining that the conditions for a conditional handover to at least one of the one or more associated mobile cells (the conditions for triggering a CHO, e.g., link quality, may be included in the configuration information provided by the IAB donor node) have been met, the UE409 may perform a handover to at least one associated mobile cell. Thus, a CHO may be performed on an associated mobile cell with preference over other adjacent cells.

[0108] The UE409 may receive cell access information that identifies one or more of the mobile cells that the UE409 has determined to be associated mobile cells (for example, one or more of the associated mobile cells in the list / table of associated mobile cells) as restricted cells that the wireless communication device is not permitted to access. For example, the cell access information may include Cell Access information transmitted in the UE CELL ACCESS CONFIGURATION message 625, as illustrated with reference to Figures 6 and 13.

[0109] As described above, Figure 8a was used to refer to an associated mobile cell, but the cell may also be an associated fixed cell. Therefore, the above description applies. For example, UE409 determines whether the serving cell serving UE409 is associated with one or more other fixed cells. The determination is made based on information received by UE409, as described with reference to Figures 9, 10, 11, and 13. After determining that an adjacent cell is an associated fixed cell associated with the serving cell (for example, after UE409 has performed a discovery procedure and found one or more adjacent cells in the vicinity or neighbors of UE409), UE409 may perform a cell reselection (or conditional handover, CHO) to the associated fixed cell, with preference to other adjacent cells discovered by UE409 but not associated with UE409's serving cell. In fact, when UE409 determines that an adjacent cell is an associated fixed cell, UE409 may ignore or not consider other adjacent cells that are not associated when performing a cell reselection or CHO. Cell reselection is described below with reference to Figure 12, and the following description may apply to cell reselection to associated fixed cells. Providing CHO settings to UE409 is described below with reference to Figure 14, and the following description may apply to providing CHO settings to UE409 for associated fixed cells.

[0110] Figure 8b is a flowchart illustrating an exemplary method for identifying or determining a mobile cell associated with a wireless communication device, according to one or more embodiments of the present invention.

[0111] For example, with reference to the wireless communication system shown and described therein, the wireless communication device performing method 800 in Figure 8b could be a UE409 or a mobile IAB node 460.

[0112] Method 800, shown and described in relation to Figure 8b, may be performed by software and / or hardware elements. Therefore, for example, Method 800, as shown and described in relation to Figure 8b, may be performed by an apparatus for a wireless communication device, which includes one or more processing units configured to perform the method. A UE or mobile IAB node may be implemented in a communication device 1500, as shown and described with reference to Figure 15, using the method shown and described in relation to Figure 15, which is performed by one or more processing units, such as a central processing unit 1511.

[0113] Returning to Figure 8b, UE409 currently served by a mobile cell such as cell 4600 may, in step 801, detect or identify that an adjacent cell is a mobile cell by receiving notification information from its neighboring mobile IAB node (such as IAB node 4700 or 4800) indicating that the cell is a mobile cell, such as a mobile IAB cell type notification associated with the adjacent mobile cell. In one embodiment, the mobile IAB cell type notification is received through a MOBILITY INFORMATION message 531, which is further described in Figure 5.

[0114] For example, UE409 currently served by mobile cell 4600 managed by mobile IAB node 460 may receive a mobile IAB cell type notification from mobile IAB node 470 indicating that cell 4700 is a mobile cell.

[0115] When an adjacent mobile cell is detected, the UE409 may activate or start a Bound Cell Detection timer that will be associated with the detected adjacent mobile cell.

[0116] Then, in step 802, UE409 continues to monitor the radio link quality associated with adjacent mobile cells detected before the Bound Cell Detection timer was activated in step 801. If there are two or more detected adjacent mobile cells, UE409 activates or starts the Bound Cell Detection timer for each of the detected adjacent mobile cells, and UE409 monitors the radio link quality associated with each of the previously detected adjacent mobile cells.

[0117] According to one embodiment, a UE may consider an adjacent mobile cell to be a mobile cell associated with its serving mobile cell if all or some of the following conditions are met: - A mobile neighboring cell is still detected when its associated bound cell detection timer expires (for example, a signal associated with the detected mobile neighboring cell, such as a broadcasted signal, is still detected when the timer expires); - The link quality of the signal strength measurement results related to the mobile adjacent cell remains above a predetermined threshold between the start and end of the associated bound cell detection timer (for example, the signal strength measurement of the signal (e.g., broadcast signal) related to the detected mobile cell remains above a certain threshold for the period from the start of the timer to the end of the timer); - The link quality of the signal strength measurement results associated with a mobile adjacent cell remains stable between the start and end of the associated bound cell detection timer, for example, between a first and a second predetermined threshold (for example, the signal strength measurement of the signal associated with the detected mobile cell (e.g., a broadcasted signal) is between a first and a second specific threshold during the period from the start of the timer to the end of the timer).

[0118] For example, signal intensity measurements may include all or some of the following indicators: - Reference Signal Received Power (RSRP): Provides a measure of the received power of the strongest reference signal from the cells considered. - Reference Signal Received Quality (RSRQ) provides a measure of the quality of the reference signal received from a considered cell relative to the interference level in the cell. - Signal-to-noise ratio (SNR) provides a measure of signal quality relative to the noise level in a cell and can be used to determine the strength of the signal from the cell under consideration. - Channel Quality Indicator (CQI), provides a measure of the quality of the received signal. - In addition to the above indicators, other measurements such as cell identification, beamforming quality, and channel state information may also be considered for signal intensity measurement.

[0119] If a UE considers a neighboring mobile cell to be a mobile cell associated with its serving mobile cell, it may record this information in a local associated cell table. For example, a list of associated mobile cells that identify one or more other mobile cells associated with the UE's serving cell may be provided or recorded in UE409. The list or table may include the cell identifier for each associated mobile cell.

[0120] The advantage of having Method 800 implemented by a UE device is that, as defined in Method 1200 in Figure 12, as in Method 1000 in Figure 10 and 1100 in Figure 11, the UE device can autonomously identify associated mobile cells and perform a cell reselection process (or conditional handover) accordingly, without requiring additional signaling issued by the mobile IAB node.

[0121] Figure 9 is a flowchart of an exemplary method 900 for sharing information of associated cells by a wireless communication device, according to one or more embodiments of the present invention.

[0122] For example, with reference to the IAB communication system shown and described therein in Figure 4, the wireless communication device performing Method 900 in Figure 9 may be a mobile IAB node 460, 470, or 480. For example, Method 900 is performed in an IAB node associated with one or more mobile cells (e.g., mobile IAB nodes) and is intended for use in facilitating network connectivity of wireless communication devices (such as UEs) in an IAB communication system. With reference to the example shown in Figure 4, the IAB node performing Method 900 may be a mobile IAB node 460 associated with or managing a mobile cell 4600.

[0123] The method 900 shown and described therein in Figure 9 may be performed by software and / or hardware elements. Therefore, for example, the method shown and described therein in Figure 9 may be performed by an apparatus for an IAB node including one or more processing units configured to perform the method. A mobile IAB node may be implemented in a communication device 1500 as shown and described therein in Figure 15, using the method shown and described therein, which is performed by one or more processing units, such as a central processing unit 1511.

[0124] Returning to Figure 9, in step 901, mobile IAB node 460 may detect or determine that the mobile cell it manages (mobile cell 4600) is associated with one or more other mobile cells that may be managed by the mobile IAB node itself, by remote mobile IAB nodes, or a combination thereof. In the example shown in Figure 4, the mobile cells 4600, 4700, and 4800 managed by each IAB node 460, 470, and 480 are associated with one another.

[0125] In one example, the detection step is based on information to identify one or more other mobile cells to which at least one of the one or more mobile cells associated with an IAB node is associated, and this information may include some bound cell configuration information. The bound cell configuration information may include at least one of the following: a configuration list of associated cell identifiers that provides cell identifiers for the mobile cells associated with each cell managed by the mobile IAB node; and a configuration list of associated IAB nodes that provides each cell identifier in the configuration list of associated cell identifiers and the identifier of the mobile IAB node that manages the cell.

[0126] In one example, bound cell configuration information may be received from an IAB donor node (e.g., an IAB donor CU) that manages or serves a mobile IAB node (e.g., an IAB donor CU for mobile IAB node 460). In one embodiment, bound cell configuration information is received from the IAB donor CU through a BOUND CELL CONFIGURATION message 533, which is further described in Figure 5.

[0127] In another example, the bound cell configuration information is set on the mobile IAB node 460 through factory setup or the Operation, Management, and Maintenance (OAM) process. In such cases, the bound cell configuration information is not received from the IAB donor CU.

[0128] If mobile IAB node 460 detects that a mobile cell it manages is associated with one or more other mobile cells, the mobile IAB node sends information (for example, to its neighboring UEs) to identify the one or more other mobile cells as associated mobile cells to which at least one of the one or more mobile cells managed by mobile IAB node 460 is associated. The information sent by mobile IAB node 460 may include bound cell information sent in BOUND CELL INFORMATION message 532, as described below. For example, mobile IAB node 460 may broadcast bound cell information to its neighboring UEs, the bound cell information including at least one of: an associated cell group identifier that provides an identifier for the group of associated mobile cells relating to the broadcasted bound cell information; a list of associated cell identifiers that provides cell identifiers for all or some of the other mobile cells associated with one or more other mobile cells associated with the cell to which the bound cell information is broadcast; a list of associated IAB nodes that provide an identifier for each cell identifier in the list of associated cell identifiers, an identifier for the mobile IAB node managing the cell; and frequencies for all or some of the one or more other mobile cells associated with the cell to which the bound cell information is broadcast (for example, frequency information indicating the frequencies used for or for some or all of the associated mobile cells to which the serving mobile cell is associated).

[0129] By doing so, the UE device can be informed about its neighboring associated mobile cells without having to perform any processing or calculations at its own level. Furthermore, since information about associated mobile cells can be broadcast periodically, the UE device can obtain such information before initiating any cell connection process, and thus enable it to favorably select associated mobile cells when performing cell reselection or CHO as defined in method 1200 of Figure 12.

[0130] In one embodiment, bound cell information is broadcast through a BOUND CELL INFORMATION message 532, which is further explained in Figure 5.

[0131] In another embodiment, bound cell information is broadcast via MOBILITY INFORMATION message 531, which is further explained in Figure 5.

[0132] Figure 10 is a flowchart of an exemplary method 1000 for sharing information of associated cells by a wireless communication device, according to one or more embodiments of the present invention.

[0133] For example, with reference to the IAB communication system shown and described therein in Figure 4, the wireless communication device performing method 1000 in Figure 10 could be the IAB donor CU401.

[0134] For example, Method 1000 is performed in an IAB donor node (such as an IAB donor CU) in an IAB communication system and is intended for use in facilitating network connectivity of wireless communication devices (such as UEs) in the IAB communication system. In the example shown in Figure 4, the IAB donor node performing Method 1000 may be an IAB donor CU 401. Method 1000, shown and described in Figure 10, may be performed by software and / or hardware elements. Thus, for example, a method such as that shown and described in Figure 10 may be performed by an apparatus for an IAB donor node that includes one or more processing units configured to perform the Method. The IAB donor CU node may be implemented in a communication device 1500 as shown and described in Figure 15, using the Method shown and described in Figure 15, which is performed by one or more processing units such as a central processing unit 1511.

[0135] Returning to Figure 10, the IAB donor CU may receive connection establishment requests from UEs such as UE409 for new serving cells managed by an IAB node, such as mobile cell 4600 managed by mobile IAB node 460. In one embodiment, connection establishment requests are received via a CONNECTION SETUP REQUEST message 621, which is further described in Figure 6. For example, a request to establish a connection with a mobile cell associated with an IAB node managed by an IAB donor node (such as mobile cell 4700 managed by IAB node 470 managed by IAB donor CU401) is received by IAB donor CU401 from UE409 (e.g., in a CONNECTION SETUP REQUEST message 621).

[0136] If a cell requested by UE409 is associated with one or more cells, the IAB donor CU401 may provide or transmit information to UE409 to identify one or more other mobile cells as associated mobile cells to which the mobile cell requesting connection is associated. For example, the information may include some bound cell information about one or more cells associated with the requested cell in the CONNECTION SETUP REQUEST message 621. The bound cell information includes an associated cell group identifier that provides an identifier for the group of associated mobile cells with respect to the broadcasted bound cell information; a list of associated cell identifiers that provides cell identifiers for all or some of the other mobile cells associated with the cell to which the bound cell information is broadcast; a list of associated IAB nodes that provide an identifier for each cell identifier in the list of associated cell identifiers, the identifier of the mobile IAB node that manages the cell; and at least one of the frequencies for all or some of the other mobile cells associated with the cell to which the bound cell information is broadcast (for example, frequency information indicating the frequencies used for each of the one or more associated mobile cells to which the serving mobile cell is associated).

[0137] In one embodiment, bound cell information is transmitted to UE409 via the CONNECTION SETUP RESPONSE message 622, which is further explained in Figure 6.

[0138] By performing method 1000, bound cell information is favorably passed to the UE device by the IAB donor CU during the connection process, thus avoiding any systemic / periodic signaling, as in method 900 in Figure 9.

[0139] In one example, IAB donor CU401 determines the bound cell information based on some kind of bound cell global configuration information.

[0140] In one example, bound cell global configuration information may be received from a Core Network (CN) Access and Mobility Management (AMF) entity. In one embodiment, bound cell global configuration information is received from the AMF through a GLOBAL CONFIGURATION message 534, which is further described in Figure 5.

[0141] In another example, bound cell global configuration information is set on the IAB donor CU401 via factory setup or the Operation, Management, and Maintenance (OAM) process. In such cases, bound cell global configuration information is not received from the core network.

[0142] Figure 11 is a flowchart of an exemplary method 1100 for sharing information of associated cells by a wireless communication device, according to one or more embodiments of the present invention.

[0143] For example, with reference to the IAB communication system shown and described in Figure 4, the wireless communication device performing Method 1100 in Figure 11 may be the IAB donor CU 401. For example, Method 1100 is performed at an IAB donor node (such as an IAB donor CU) in an IAB communication system and is intended for use in facilitating network connectivity for wireless communication devices (such as UEs) in the IAB communication system. With reference to the example shown in Figure 4, the IAB donor node performing Method 1100 may be the IAB donor CU 401.

[0144] The method 1100 shown and described in Figure 11 may be performed by software and / or hardware elements. For example, the method shown and described in Figure 11 may be performed by an apparatus for an IAB donor node, which includes one or more processing units configured to perform the method. The IAB donor CU node may be implemented in a communication device 1500, as shown and described in Figure 15, using the method shown and described in Figure 15, which is performed by one or more processing units, such as a central processing unit 1511.

[0145] Returning to Figure 11, in step 1101, the IAB donor CU401 may manage the establishment of a connection between a UE device such as UE409 and a mobile serving cell managed by a mobile IAB node, such as a mobile cell 4600 managed by a mobile IAB node 460.

[0146] Then, in step 1102, if the mobile serving cell connected to the UE in step 1101 is associated with one or more mobile cells, or if at some point a new mobile cell is added, or a mobile cell is removed from the set or list of cells associated with the mobile serving cell connected to the UE in step 1101, the IAB donor CU401, which manages the connection of the UE to the mobile serving cell, provides or transmits information to the UE409 to identify one or more other mobile cells as associated mobile cells to which the serving mobile cell is associated. For example, this information may include some bound cell information relating to all or some of the cells associated with the mobile serving cell connected by the UE409 in step 1101.Bound cell information includes: an associated cell group identifier that provides an identifier for the associated mobile cell group related to the broadcasted bound cell information; a list of associated cell identifiers that provides cell identifiers for all or some of one or more other mobile cells related to the bound cell information; a list of associated IAB nodes that provide each cell identifier in the list of associated cell identifiers and the identifier of the mobile IAB node that manages the cell; a list of new associated cell identifiers that provides cell identifiers for all or some of the new mobile cells added to the list of associated cell identifiers of the associated cell group identifier considered in the bound cell information; a list of new associated IAB nodes that provide each cell identifier for the new mobile cells added to the list of associated cell identifiers and the identifier of the mobile IAB node that manages the cell; a list of removed associated cell identifiers that provides each cell identifier of the mobile cell removed from the list of associated cell identifiers of the associated cell group identifier considered in the bound cell information; and a list of removed associated IAB nodes that provide each cell identifier of the mobile cell removed from the list of associated cell identifiers and the identifier of the mobile IAB node that manages the cell. This may include at least one of the following: frequencies for all or some of the other mobile cells associated with the cell relating to the information (e.g., frequency information indicating the frequencies used for each or all of the associated mobile cells, some or all of the associated mobile cells to which the serving mobile cell is associated).

[0147] In one embodiment, bound cell information is sent to the UE via a CONFIGURATION INFORMATION message 623, which is further explained in Figure 6.

[0148] For example, IAB donor CU401 determines the bound cell information based on some kind of bound cell global configuration information, as explained above with reference to Figure 10.

[0149] By performing method 1100, the bound cell information is favorably passed to the UE device by the IAB donor CU once the connection process is complete, thus enabling dynamic updating of the bound cell information while avoiding any systemic / periodic signaling, as in method 900 in Figure 9, which would be impossible when the sharing of bound cell information is limited to the connection establishment process. Step 1101 is shown with a dotted line because it may be performed after the connection process is complete, and step 1102 may be performed immediately after step 1101, or at any time after step 1101.

[0150] Figure 12 is a flowchart of an exemplary method 1200 for managing connectivity to a cell associated with a wireless communication device or UE, according to one or more embodiments of the present invention.

[0151] For example, referring to the IAB communication system shown and described in Figure 4, the wireless communication device performing Method 1200 in Figure 12 could be a UE 409. For example, Method 1200 is performed in a UE and is intended for use in facilitating or managing the network connectivity of the UE in an IAB communication system.

[0152] The method 1200 shown and described in Figure 12 may be performed by software and / or hardware elements. Therefore, for example, the method shown and described in Figure 12 may be performed by an apparatus for a UE including one or more processing units configured to perform the method. The UE may be implemented in a communication device 1500, as shown and described with reference to Figure 15, using the method shown and described in Figure 15, which is performed by one or more processing units, such as a central processing unit 1511.

[0153] Returning to Figure 12, UE409 may determine in step 1201 that its serving cell is associated with one or more other cells.

[0154] In one embodiment, UE409 determines that its serving cell is associated with one or more other cells by performing method 800 shown in Figure 8b.

[0155] In another embodiment, UE409 determines that its serving cell is associated with one or more other cells by receiving information from the IAB node. For example, the information may include bound cell information sent in BOUND CELL INFORMATION message 532, as defined in Figure 5, which carries a non-empty Bound cell ID List in the bound cell information.

[0156] In another embodiment, UE409 determines that its serving cell is associated with one or more other cells by receiving information from an IAB donor node (e.g., an IAB donor CU). For example, the information may include bound cell information sent in the CONNECTION SETUP RESPONSE message 622, as defined in Figure 6, which carries a non-empty Bound cell ID List in the bound cell information.

[0157] In another embodiment, UE409 determines that its serving cell is associated with one or more other cells by receiving information from an IAB donor node (e.g., an IAB donor CU). For example, the information may include bound cell information sent in a CONFIGURATION INFORMATION message 623, as defined in Figure 6, which carries a non-empty Bound cell ID List in the bound cell information.

[0158] Then, at some point (step 1202), the UE409 may transition from a connected state (for example, the NR RRC_CONNECTED state as defined in 3GPP TS 38.331 V17.1.0) to a disconnected state such as an idle state (for example, the NR RRC_IDLE state as defined in 3GPP TS 38.331 V17.1.0) or an inactive state (for example, the NR RRC_INACTIVE state as defined in 3GPP TS 38.331 V17.1.0).

[0159] In a later stage (step 1203), UE409 identifies the need for cell reselection. This need may arise from the UE's serving cell having a link quality below a predetermined threshold.

[0160] Then, in step 1204, UE409 may identify one or more adjacent cells found in its vicinity (for example, one or more adjacent cells are discovered in the vicinity or near UE409 by UE409 performing a discovery procedure) if at least one of the discovered cells is a mobile cell associated with the previous serving mobile cell (for example, the cell to which UE409 was connected when UE409 transitioned from a connected to a disconnected state (for example, inactive or idle mode)). After determining that at least one of the discovered cells is a mobile cell associated with the serving mobile cell (for example, the mobile cell that was serving UE409 when UE409 switched to a disconnected state), UE409 selects the associated mobile cell for cell reselection, in preference to other discovered cells (for example, other cells that are not associated mobile cells), for example by checking whether any of the discovered cells are in the list / table of associated mobile cells provided to UE409. In other words, when UE409 determines that a discovered adjacent cell is an associated mobile cell, it ignores other discovered adjacent cells for cell reselection. If one or more mobile-associated cells are available, UE409 will select one of these associated mobile cells to perform cell reselection, while ignoring other adjacent cells that are not associated mobile cells.

[0161] Prioritizing the re-selection of associated mobile cells prevents vehicle-mounted UEs (e.g., in-vehicle UE devices) from temporarily connecting to fixed or mobile cells that may be within range of the in-vehicle UE device, thus preventing the UE device from experiencing a potential sequence of disconnections / reconnections that could impact the continuity of service at the UE device.

[0162] Figure 13 is a flowchart of an exemplary method 1300 for managing the conditional sharing of information of associated cells by a wireless communication device, according to one or more embodiments of the present invention. For example, method 1300 is for managing the connectivity of a wireless communication device, such as a UE, to associated mobile cells (e.g., managing wireless access to associated mobile cells), according to one or more embodiments of the present invention.

[0163] For example, referring to the IAB communication system shown and described in Figure 4, the wireless communication device performing method 1300 in Figure 13 could be a UE device such as UE device 409.

[0164] The method 1300 shown and described in Figure 13 may be performed by software and / or hardware elements. For example, the method shown and described in Figure 13 may be performed by an apparatus for a UE that includes one or more processing units configured to perform the method. A UE node may be implemented in a communication device 1500, such as the one shown and described in Figure 15, so that the method shown and described in Figure 15 is performed by one or more processing units, such as a central processing unit 1511.

[0165] Returning to Figure 13, the UE device 409 may select a mobile cell to be associated with one or more other mobile cells, as discussed in Figures 8, 9, 10, and 11, and may further attempt to connect to the selected mobile cell associated with one or more other mobile cells. However, such a connection may be conditional on the UE being permitted to connect to the selected cell (step 1301).

[0166] For example, a UE device could subscribe to a transit pass that grants access to all associated mobile cells of a local bus company. A UE device could also subscribe to a transit pass that grants access to all associated first-class mobile cells of the train it is on. In other words, a UE device could also subscribe to a transit pass that grants access to all mobile cells associated with the first-class carriages of the train it is on. Alternatively, a UE device could simply subscribe to a transit pass that grants access to all mobile cells associated with other classes of carriages (excluding first-class carriages) of the train it is on.

[0167] In one embodiment, an IAB donor CU may be pre-configured or (re)configured by a core network (e.g., an AMF entity) using some Cell Access information. The Cell Access information (e.g., Cell Access information) identifies one or more mobile cells in a list of associated mobile cells that the UE is not authorized to access (e.g., is not authorized to access or is not authorized to connect).

[0168] According to one embodiment, if Cell Access information indicates that the UE is not permitted to access the associated serving cell to which it is connected, the UE device should disconnect from its current serving cell.

[0169] In one embodiment, if Cell Access information indicates that the UE is not permitted to access a given group of associated mobile cells, the UE device should not consider these cells for connecting to the network, as described in step 1001 of Figure 10 (for example, when selecting a new serving cell for a connection establishment request) or step 1101 of Figure 11, or as described in step 1204 of Figure 12 in the context of cell reselection.

[0170] In one embodiment, a UE device may be pre-configured or (re)configured with some Cell Access information that does not allow the UE to access one or more sets of associated mobile cells, the Cell Access information includes at least one of a list of restricted associated cell identifiers, which provides cell identifiers for one or more associated mobile cells relating to information about associated cells to which the UE device's access is restricted.

[0171] In one embodiment, a UE may receive Cell Access information from an Access and Mobility Management Function (AMF) core network entity in the UE CELL ACCESS CONFIGURATION message 625 as defined in Figure 6, either through a UE configuration update procedure (as defined in 3GPP TS 23.501v17.5.0) after the registration procedure is completed, or by including new Cell Access information in a registration acceptance, registration rejection, deregistration request, or denial of service message as defined in 3GPP TS 23.501v17.5.0.

[0172] Figure 14 is a flowchart of an exemplary method 1400 for managing the connectivity of wireless communication devices, such as UE devices (e.g., UEs), to cells associated by network devices such as IAB donor nodes, according to one or more embodiments of the present invention.

[0173] For example, with reference to the IAB communication system shown and described therein, a wireless communication device performing Method 1400 in Figure 14 could be an IAB donor CU 401. For example, Method 1400 is performed at an IAB donor node (e.g., an IAB donor CU) and is intended for use in facilitating network connectivity of wireless communication devices (such as UEs) in an IAB communication system.

[0174] The method 1400 shown and described therein in Figure 14 may be performed by software and / or hardware elements. Therefore, for example, the method shown and described therein in Figure 14 may be performed by an apparatus for an IAB donor node (e.g., an IAB donor CU) which includes one or more processing units configured to perform the method. The IAB donor CU node may be implemented in a communication device 1500 shown and described therein in Figure 15, using the method shown and described therein, which is performed by one or more processing units, such as a central processing unit 1511.

[0175] Returning to Figure 14, the IAB donor CU401 manages the connection of a new UE device, such as UE device 409, to a new serving cell managed by a mobile IAB node managed by the IAB donor CU401 (step 1401). For example, the new serving cell could be a mobile cell 4700 managed or associated with an IAB node 470, which is managed or controlled by the IAB donor CU401.

[0176] Then, in step 1402, IAB donor CU401 determines, based on some bound cell configuration information, whether the new serving cell is associated with one or more other cells.

[0177] In one example, bound cell configuration information may be received from a Core Network (CN) Access and Mobility Management (AMF) entity. In one embodiment, bound cell configuration information is received from the AMF through a GLOBAL CONFIGURATION message 534, which is further described in Figure 5.

[0178] In another example, bound cell configuration information is set on the mobile IAB donor CU401 through factory setup or the Operation, Management, and Maintenance (OAM) process. In such cases, bound cell configuration information is not received from the core network.

[0179] If IAB donor CU401 determines that a new serving cell is associated with one or more other cells, IAB donor CU negotiates several handovers (HOs) or conditional handovers (CHOs) with a mobile IAB node (e.g., mobile IAB DU) relating to all or some of the other cells associated with the new serving cell.

[0180] In one embodiment, handover (HO) or conditional handover (CHO) negotiation is performed by sending a MOBILITY SETUP REQUEST message 723 to a selected mobile IAB node (e.g., mobile IAB DU) and receiving a MOBILITY SETUP RESPONSE message 724. The MOBILITY SETUP REQUEST message 723 and the MOBILITY SETUP RESPONSE message 724 are further illustrated in Figure 7.

[0181] Finally, the IAB donor CU sends the handover (HO) or conditional handover (CHO) settings for each of the selected associated mobile cells to the UE device 409 using the MOBILITY CONFIGURATION INFORMATION message 725, which is further described in Figure 7.

[0182] Since a UE connected to a cell associated with one or more other cells is likely to move from its current serving cell to one of the cells associated with that serving cell, pre-configuring conditional handovers in the UE for such associated mobile cells solidifies the handover process and thus improves service continuity at the UE level, while preventing UE devices from temporarily connecting to fixed or mobile cells that may enter the UE's range or vicinity.

[0183] Herein, we also refer to Figure 5, a schematic and simplified diagram illustrating an exemplary message flow for management to facilitate connectivity to an associated mobile cell according to one or more embodiments of the present invention.

[0184] For example, an Access and Mobility Management Function (AMF) entity of the core network (CN) 504 may provide some bound cell global configuration information to a network device 503, such as an IAB donor node 503 (e.g., an IAB donor CU), using a GLOBAL CONFIGURATION message 534. For example, an IAB donor node 503 may receive configuration information (from the core network or in factory settings) to identify one or more lists of mobile cells that are associated with each other and managed by or associated with one or more IAB nodes managed by an IAB donor node 503.

[0185] According to one embodiment, configuration information such as bound cell global configuration information includes all or part of the following information for all or part of the mobile IAB nodes served by the IAB donor CU: - Global Bound cell group ID List, providing identifiers for each group of associated mobile cells, where the associated mobile cells in a group are managed by or associated with one or more mobile IAB nodes managed by IAB donor node 503; - Provides the cell IDs of the mobile cells associated with each of the associated cell groups in the Global Bound cell ID Configuration List and Global Bound cell group ID List. - Provide each cell ID in the Global Bound IAB node Configuration List and Global Bound cell ID Configuration List with an identifier for the mobile IA node associated with or managing the cell.

[0186] According to one embodiment, the GLOBAL CONFIGURATION message 534 is an INITIAL CONTEXT SETUP REQUEST as defined in 3GPP TS 38.401.

[0187] Based on the bound cell global configuration information received from the AMF of the core network 504, the IAB donor node 503 (for example, the IAB donor CU) may use the BOUND CELL CONFIGURATION message 533 to derive some bound cell configuration information to be shared with each of the considered served mobile IAB nodes for all or some of the mobile IAB nodes it serves. For example, based on the configuration information received at the IAB donor node 503, the IAB donor node 503 may send to at least one of the IAB nodes managed by the IAB donor node 503 information to identify one or more associated mobile cells to which at least one of the one or more mobile cells associated with at least one of the IAB nodes is associated.

[0188] According to one embodiment, the bound cell configuration information transmitted by the IAB donor node 503 includes all or part of the following information: - Bound cell group ID List: Provides identifiers for each group of associated mobile cells, which includes at least one mobile cell managed by the mobile IAB node receiving the bound cell configuration information. In other words, it provides identifiers for groups of associated mobile cells, which include the mobile cell associated with the bound cell configuration information. - For each bound cell group in the Bound cell ID Configuration List and Bound cell group ID List, provide the cell IDs of the mobile cells associated with each other. In other words, provide the cell IDs of the mobile cells associated with the cell from which the bound cell configuration is broadcast; - Provide each cell ID in the Bound IAB node Configuration List and Bound cell ID Configuration List with the identifier of the mobile IAB node associated with or managing the cell. - Bound cell Frequency List provides some information regarding the frequencies used by one or more associated mobile cells associated with a cell from which a bound cell configuration is broadcast, for each of the associated mobile cells, or by the frequency used by each of the associated mobile cells.

[0189] According to one embodiment, the BOUND CELL CONFIGURATION message 533 is a GNB CU CONFIGURATION UPDATE message as defined in 3GPP TS 38.401.

[0190] According to one embodiment, the BOUND CELL CONFIGURATION message 533 is an RRCReconfiguration message as defined in 3GPP TS 38.331.

[0191] Based on bound cell configuration information received from IAB donor node 503 (e.g., IAB donor CU), a mobile IAB node 501 (e.g., IAB node 460) may derive bound cell information that it can further broadcast for each of the mobile cells it manages, using the BOUND CELL INFORMATION message 532. For example, IAB node 460 may transmit information (e.g., via broadcast in the mobile cells associated with or managed by the IAB node) to identify one or more associated mobile cells to which at least some of the one or more mobile cells associated with or managed by IAB node 460 are associated.

[0192] According to one embodiment, the bound cell information conveyed in the BOUND CELL INFORMATION message 532 includes all or part of the following information: - Bound cell group ID: Provides an identifier for the group of associated mobile cells associated with bound cell information. In other words, it provides an identifier for the group of associated mobile cells, including the mobile cells associated with bound cell information. - The Bound cell ID List provides cell IDs for one or more mobile cells associated with the mobile cell associated with the bound cell information. In other words, it provides cell IDs for associated mobile cells belonging to the Bound cell group ID. For example, the cell ID may be a physical cell identifier (PCI), and the Bound cell ID List may be a list or range of PCIs. - Provide each cell ID in the Bound IAB node List and Bound cell ID List with the identifier of the mobile IAB node associated with or managing the cell. - Bound cell frequency list provides information about the cell frequencies used for or by one or more other mobile cells associated with the cell associated with bound cell information.

[0193] According to one embodiment, the BOUND CELL INFORMATION message 532 is one of the SIB1, SIB3, or SIB4 messages defined in 3GPP TS 38.331.

[0194] In one aspect of the present invention, the Bound cell ID List may also be called intraFreqBoundCellList, or when carried in an SIB3 message, it may be part of several broader intraFreqMobileCellList information elements that list in-frequency mobile cells using specific cell reselection parameters.

[0195] In one aspect of the present invention, the Bound cell ID List may also be called interFreqBoundCellList and, when carried in an SIB4 message, may be part of several interFreqMobileCellList information elements that list in-frequency mobile cells using specific cell reselection parameters.

[0196] In addition to the BOUND CELL INFORMATION message 532, the mobile IAB node 501 may broadcast some mobility notification to each of the mobile cells it manages, indicating that the cell on which the BOUND CELL INFORMATION message 532 is broadcast is indeed a mobile cell.

[0197] According to one embodiment, MOBILITY INFORMATION message 531 is an SIB1 message as defined in 3GPP TS 38.331.

[0198] Herein, we also refer to Figure 6, a schematic and simplified diagram illustrating an exemplary message flow for managing or facilitating connectivity of a UE to an associated mobile cell according to one or more embodiments of the present invention.

[0199] For example, UE602 may request a connection to a mobile IAB cell managed by or associated with mobile IAB node 601 by sending a connection setup request message 621 to the IAB donor node (e.g., IAB donor CU603) that is serving or managing mobile IAB node 601.

[0200] According to one embodiment, the CONNECTION SETUP REQUEST message 621 is an RRCSetupRequest message as defined in 3GPP TS 38.331.

[0201] IAB donor CU603 may respond to an received connection request by issuing a CONNECTION SETUP RESPONSE message 622, which may include some bound cell information to notify UE device 602 about one or more mobile cells associated with the mobile cell requested for connection in the CONNECTION SETUP REQUEST message 621. For example, IAB donor CU603 sends a response that includes information such as bound cell information to identify one or more associated mobile cells to which the mobile cell requested for connection is associated.

[0202] According to one embodiment, the bound cell information conveyed in the CONNECTION SETUP REQUEST message 621 includes all or part of the following information: - Bound cell group ID: Provides an identifier for the group of associated mobile cells related to the broadcasted bound cell information. In other words, it provides an identifier for the group of associated mobile cells that the UE device is trying to connect to; - Bound cell ID List: Provides cell IDs for all or some of one or more other mobile cells associated with the cell the UE device is trying to connect to; - For each cell ID in the Bound IAB node List and Bound cell ID List, provide the identifier of the mobile IAB that manages the cell. - Bound cell frequency list provides information about the cell frequencies used for or by one or more other mobile cells associated with the cell associated with bound cell information.

[0203] According to one embodiment, CONNECTION SETUP RESPONSE message 622 is an RRCSetup message as defined in 3GPP TS 38.331.

[0204] For example, UE device 602 may further attempt to register with the Core Network (CN) Access and Mobility Management Function (AMF) entity of the Core Network 604, and may provide some Cell Access information to UE device 602 using the CELL ACCESS CONFIGURATION message 625.

[0205] According to one embodiment, Cell Access information includes all or part of the following additional information: - Restricted Bound cell ID List: Provides cell IDs for one or more associated mobile cells whose access by the UE device is restricted; - Restricted Bound cell group ID: Provides an identifier for the associated mobile cell group whose access is restricted for UE devices. - For each cell ID in the Restricted Bound IAB node List and Restricted Bound cell ID List, provide identifiers for the one or more associated mobile cells that restrict UE device access or the associated mobile IAB nodes. - Restricted Bound Cell Frequency List provides information about the cell frequencies used by or for one or more other mobile cells associated with a cell associated with Cell Access information that restricts access for a UE device (for example, frequency information showing the frequencies for each associated mobile cell of one or more mobile cells in a list of associated mobile cells that the wireless communication device is not permitted to access).

[0206] In one embodiment, Cell Access information may also include a Closed Access Group (CAG) identifier that identifies a group of subscribers who are permitted to access one or more CAG cells associated with the CAG, as defined in 3GPP TS 23.501v17.5.0.

[0207] In one aspect of the present invention, the Bound cell ID List may also be an intraFreqCAG-CellList information element that lists in-frequency adjacent CAG cells as defined in TS 38.331 when carried in an SIB3 message.

[0208] In one aspect of the present invention, the Bound cell ID List may also be an interFreqCAG-CellList information element that lists inter-frequency adjacent CAG cells as defined in TS 38.331 when carried in an SIB4 message.

[0209] In one embodiment, the IAB donor CU603 may wish to notify the UE602 of one or more mobile cells associated with the mobile cell to which the UE device is connected by transmitting some bound cell information to the UE602 via the CONFIGURATION INFORMATION message 623.

[0210] In one embodiment, the IAB donor CU603 sends some bound cell information to the UE602 through both the CONNECTION SETUP RESPONSE message 622 and the CONFIGURATION INFORMATION message 623 as part of the UE connection establishment process.

[0211] In one embodiment, the IAB donor CU603 transmits some bound cell information to UE602 only through the CONNECTION SETUP RESPONSE message 622.

[0212] In one embodiment, the IAB donor CU603 transmits some bound cell information to the UE602 only via the CONFIGURATION INFORMATION message 623.

[0213] In one embodiment, the IAB donor CU603 may also provide the UE602 with an updated list of one or more mobile cells associated with the mobile cell to which it is connected, or notify the UE602 of several new mobile cells that have been added to the list of one or more mobile cells associated with the mobile cell to which it is connected (e.g., a serving mobile cell), by sending some bound cell information through the CONFIGURATION INFORMATION message 623. For example, the information sent in the CONFIGURATION INFORMATION message 623 may include updated information that includes information to identify one or more new mobile cells that have been added as associated mobile cells, and / or information to identify one or more new mobile cells that have been removed from the associated mobile cell.

[0214] According to one embodiment, the bound cell information conveyed in the CONFIGURATION INFORMATION message 623 includes all or part of the following information: - Bound cell group ID: Provides an identifier for the group of associated mobile cells linked to the bound cell information. In other words, it provides an identifier for the group of associated mobile cells, including the mobile cell to which the UE device is connected; - Bound cell ID List: Provides cell IDs for all or some of one or more other mobile cells related to bound cell information. In other words, it provides cell IDs for all or some of one or more other mobile cells associated with the mobile cell to which the UE device is connected; - Provide an identifier for the mobile IAB managing the cell for each cell ID in the Bound IAB node List and Bound cell ID List; - New bound cell ID List: Provides all or some of the cell IDs of new mobile cells added to the Bound cell ID List of Bound cell group IDs considered in bound cell information. - Bound cell frequency list provides information about the cell frequencies used for all or some of one or more other mobile cells associated with a cell, or by a bound cell information.

[0215] Herein, we also refer to Figure 7, a schematic and simplified diagram illustrating an exemplary message flow for managing UE connectivity to an associated mobile cell according to one or more embodiments of the present invention.

[0216] For example, UE702 initiates the connection process to a mobile cell managed by mobile IAB DU701 by sending a CONNECTION SETUP REQUEST message 721 to an IAB donor node (e.g., IAB donor CU703).

[0217] IAB donor CU703 may further accept the UE connection to the cell requested through CONNECTION SETUP REQUEST message 721 by sending back CONNECTION SETUP RESPONSE message 722 to UE702.

[0218] According to one embodiment, the CONNECTION SETUP REQUEST message 721 is an RRCSetupRequest message as defined in 3GPP TS 38.331.

[0219] According to one embodiment, the CONNECTION SETUP RESPONSE message 722 is an RRCSetup message as defined in 3GPP TS 38.331.

[0220] If IAB donor CU703 determines that a cell requested to connect by UE702 via CONNECTION SETUP REQUEST message 721 (for example, a mobile cell managed by IAB node 701) is associated with one or more other mobile cells, IAB donor CU703 may negotiate a conditional handover (CHO) between the IAB node and UE702 concerning or managing all or some of the other mobile cells associated with the cell requested to connect by UE702.

[0221] If the associated mobile cell being considered for CHO negotiation, also called the target cell for CHO, belongs to IAB node 704 served or managed by the same IAB donor CU703 as IAB node 701 serving or managing the cell for which connection by UE702 has been requested, then the MOBILITY SETUP REQUEST message 723a is used by IAB donor CU703 to create a UE context, establish one or more data bearers, and request an in-gNB conditional handover for the target cell being considered for CHO. The MOBILITY SETUP RESPONSE message 724a is used by IAB donor CU703 to acknowledge receipt of the MOBILITY SETUP REQUEST message 723a. The MOBILITY SETUP RESPONSE message 724a may include the cell ID of the target cell for CHO. For example, an IAB donor node (e.g., IAB donor CU703) may send an establishment request (e.g., MOBILITY SETUP REQUEST message 723a) to each of one or more IAB nodes to request a CHO for at least some of one or more other mobile cells associated with the cell being requested for connection. The IAB donor node (e.g., IAB donor CU703) may receive an establishment response (e.g., MOBILITY SETUP RESPONSE message 724a) acknowledging receipt of the establishment request. The establishment request may include information relating to or associated with UE702 in order to create a UE context and establish one or more data bearers at the IAB node receiving the establishment request. The information may include identification information for identifying UE702 (e.g., UE ID), authentication information for use when authenticating UE702, security context information (e.g., security parameters such as security keys and UE security capabilities), measurement settings, radio settings (e.g., UE radio capabilities), and information about the bearers.The establishment response from IAB node 704 may include identification information (e.g., cell ID) of the associated mobile cell managed or associated with IAB node 704, which is the target cell of the CHO. The establishment response may also include information on whether the data radio bearer (DRB) / signaling radio bearer (SRB) / BH RLC channel was successfully established or failed to be established.

[0222] In one embodiment, the MOBILITY SETUP REQUEST message 723a is a UE CONTEXT SETUP REQUEST message as defined in 3GPP TS 38.401.

[0223] In one embodiment, the MOBILITY SETUP RESPONSE message 724a is a UE CONTEXT SETUP RESPONSE message as defined in 3GPP TS 38.401.

[0224] If the associated mobile cell being considered for CHO negotiation, also known as the CHO target cell, belongs to an IAB node 704 served or managed by a different IAB donor node (e.g., IAB donor CU705) than the IAB donor CU703 that serves or manages the IAB node 701 serving the cell being requested to connect by UE702, then the MOBILITY SETUP REQUEST message 723b is used by IAB donor CU703 to request the CHO for the target cell. Some admission controls may be performed at IAB donor CU705, which then decides whether to accept or reject the CHO for the target cell. The MOBILITY SETUP RESPONSE message 724b is used by IAB donor CU705 to acknowledge the conditional handover request received through the MOBILITY SETUP REQUEST message 723b, based on the results of the admission control processing. For example, if an IAB donor node (e.g., IAB donor CU703) determines that a mobile cell requesting a connection is associated with one or more other mobile cells, and at least one IAB node associated with at least some of those other mobile cells is managed by another IAB donor node (e.g., IAB donor CU705), then IAB donor CU703 negotiates a Conditional Handover (CHO) with the other IAB donor CU705. IAB donor CU703 may send an establishment request (e.g., MOBILITY SETUP REQUEST message 723b) to the other IAB donor node to request a CHO. The IAB donor node (e.g., IAB donor CU703) may receive an establishment response (e.g., MOBILITY SETUP RESPONSE message 724b) acknowledging receipt of the establishment request. The establishment request may include information related to or associated with UE702 in order to create a UE context and establish one or more data bearers in the IAB node associated with the associated mobile cell.The information may include identification information for identifying UE702 (e.g., UE ID), authentication information for use when authenticating UE702, security context information (e.g., security parameters such as security keys and UE security capabilities), measurement settings, radio settings (e.g., UE radio capabilities), and bearer information. The establishment response from the IAB donor node (e.g., IAB donor CU705) may include identification information (e.g., cell ID) of the associated mobile cell managed or associated by IAB node 704, which is the target cell of the CHO. The establishment response may also indicate whether the conditional handover request was accepted or rejected by IAB donor CU705. The establishment response may also include information on whether the data radio bearer (DRB) / signaling radio bearer (SRB) / BH RLC channel was successfully established or failed to be established.

[0225] According to one embodiment, the MOBILITY SETUP REQUEST message 723b is a HANDOVER REQUEST message as defined in 3GPP TS 38.300.

[0226] According to one embodiment, the MOBILITY SETUP RESPONSE message 724b is a HANDOVER ACKNOWLEDGE message as defined in 3GPP TS 38.300.

[0227] Upon receiving either MOBILITY SETUP RESPONSE message 723a or MOBILITY SETUP RESPONSE message 724a, IAB donor CU 703 may ultimately send MOBILITY CONFIGURATION INFORMATION message 725 to UE 702, which contains configuration parameters (such as data bearer information, the cell ID of the target cell, and the frequency used by the target cell) that UE device 702 will use to perform a conditional handover with the target cell from which IAB donor CU 703 has negotiated the CHO.

[0228] Figure 16 is a flowchart of an exemplary method 1600 for managing the connectivity of wireless communication devices, such as UE devices (e.g., UEs), to cells associated by network devices such as IAB donor nodes or donor CUs, according to one or more embodiments of the present invention.

[0229] For example, with reference to the IAB communication system shown and described therein in Figure 4, the network device performing method 1600 in Figure 16 could be the IAB donor CU401.

[0230] The method 1600 shown and described therein in Figure 16 may be performed by software and / or hardware elements. Therefore, for example, the method shown and described therein in Figure 16 may be performed by an apparatus for an IAB donor node (e.g., an IAB donor CU) which includes one or more processing units configured to perform the method. The IAB donor CU node may be implemented in a communication device 1500 shown and described therein in Figure 15, using the method shown and described therein, which is performed by one or more processing units, such as a central processing unit 1511.

[0231] Returning to Figure 16, the IAB donor CU 401 manages the connection of a new UE device, such as UE device 409, to a new serving cell managed by a mobile IAB node managed by the IAB donor CU 401 (step 1601). For example, the new serving cell may be a mobile cell 4700 managed or associated with an IAB node 470, which is managed or controlled by the IAB donor CU 401 (e.g., a serving donor CU). The IAB donor CU 401 may then determine that the new UE device is to be mounted on a mobile IAB node that manages the mobile IAB cell 4700 (e.g., the new serving cell). In one embodiment, the IAB donor CU 401 itself determines the mounting status of the new UE device based on at least several measurement reports received from the new UE device 409. In another embodiment, the new UE device 409 itself determines its mounting status based on at least several signal intensity measurements with the new serving cell and further notifies the IAB donor CU 401 of its mounting status.

[0232] Then, as previously shown in Figure 14, IAB donor CU401 determines whether the new serving cell is associated with one or more other cells based on some bound cell configuration information.

[0233] In one embodiment, if a new serving cell is associated with one or more other cells, the serving donor CU (e.g., IAB donor CU 401) may allow the handover of the UE (e.g., UE device 409) only with one or more mobile IAB nodes associated with one or more associated mobile cells, as long as the new UE device remains installed on the mobile IAB node managing the new serving cell (step 1602). In other words, the serving donor CU does not have to perform a handover of the UE with any IAB node or base station not associated with one or more associated mobile cells, as long as the new UE device remains installed on the mobile IAB node managing the new serving cell.

[0234] Figure 15 shows a schematic diagram of an exemplary communication device (apparatus) or station according to one or more exemplary embodiments of the present disclosure.

[0235] The communication device 1500 may be a device such as a microcomputer, workstation, or light portable device. The communication device 1400 may include a communication bus 1513 to which it is connected: - A central processing unit 1511, such as a microprocessor, referred to as a CPU. The central processing unit 1511 may be a single processing unit or processor, or it may include two or more processing units or processors that perform the processing necessary for the operation of the communication device 1500. The number of processors and the assignment of processing functions to the central processing unit 1511 are design choices for those skilled in the art; - A computer program including memory for storing data and instructions for the operation of the communication device 1500. The computer program may include several different program elements (modules) or subroutines, each containing instructions for various operations or for carrying out methods according to one or more embodiments of the present invention; - At least one communication interface 1502 for communicating with other devices or nodes in a wireless communication system, such as the wireless communication system in Figure 1 or Figure 4. The at least one communication interface 1502 may be connected to a wireless communication network 1503, such as a wireless communication network for 5G NR (e.g., by release 16 and / or subsequent releases), to which digital data packets or frames or control frames are transmitted. Frames are written to the communication interface for transmission from the FIFO transmit memory in RAM 1512, or read from the communication interface for reception, or written to the FIFO receive memory in RAM 1512 under the control of a software application running in CPU 1511.

[0236] Each of the donor CU, donor DU, IAB node, and UE may include such communication device 1500.

[0237] Memory is: - A read-only memory 1507, called ROM, for storing a computer program for carrying out a method according to one or more embodiments of the present invention; - A random access memory 1512 for storing code for performing a method according to one or more embodiments of the present invention, and registers suitable for recording variables and parameters necessary for performing a method according to one or more embodiments of the present invention.

[0238] Optionally (and depending on the functionality of the communication device), the communication device 1500 may also include the following elements: - A data storage means 1504 such as a hard disk for storing a computer program for carrying out a method according to one or more embodiments of the present invention; - Disk drive 1505 for disk 1506, the disk drive is adapted to read data from disk 1506 or write data to said disk; - A screen 1509 for displaying data decoded by the keyboard 1510 or any other input / output means, and / or for serving as a graphical interface with the user.

[0239] In an exemplary configuration, the communication bus provides communication and interoperability between various elements included in or connected to the communication device 1500. The representation of the bus is not limited, and in particular, the central processing unit can operate to communicate instructions directly to any element of the communication device 1500 or through another element of the communication device 1500.

[0240] Disk 1506 may optionally be replaced by any information medium, such as a rewritable or non-rewritable compact disk (CD-ROM), ZIP disk, USB key, or memory card, which is generally an information storage means readable by a microcomputer or microprocessor, integrated into or not integrated into a communication device, and optionally removable, and adapted to store one or more programs that can be used to implement the method according to this embodiment.

[0241] The executable code may optionally be stored in read-only memory 1507, hard disk 1504, or a removable digital medium such as disk 1506 as described above. According to an optional modification, the program's executable code may be received by the communication network 1503 via interface 1502 to be stored in one of the storage means of the communication device 1500, such as hard disk 1504, before execution.

[0242] The central processing unit 1511 may be adapted to control and direct the execution of program instructions or portions of software code according to embodiments of the present invention, the instructions of which are stored in one of the aforementioned storage means. Upon power-up, the program stored in non-volatile memory, such as the hard disk 1504 or read-only memory 1507, is transferred to random access memory 1512, which includes the executable code of the program and registers for storing variables and parameters necessary to carry out the present invention.

[0243] In exemplary implementations, a communication device (apparatus) is a programmable device / apparatus that uses software to implement the present invention. Instructions may 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 discrete logic circuits. Thus, the term “central processing unit” as used herein may refer to any of the aforementioned 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 application-specific integrated circuits or ASICs or other logic elements).

[0244] While the present invention has been described with reference to examples and embodiments, it will be understood that the present invention is not limited to the disclosed examples and 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 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 disclosed so herein can be combined in any combination, except for 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 function that serves the same, equivalent, or similar purpose unless otherwise expressly stated. Thus, unless specifically stated otherwise, each disclosed feature is merely an example of a general set of equivalent or similar functions.

[0245] In a claim, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude the plural. The mere fact that different features are described in different dependent claims does not imply that combinations of these features cannot be used advantageously.

[0246] In the embodiments described above, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or codes on a computer-readable medium or transmitted via a 3D printer and executed by a hardware-based processing unit.

[0247] Computer-readable media may include computer-readable storage media corresponding to tangible media such as data storage media, or communication media including any media that facilitates the transfer of computer programs from one location to another, for example, according to a communication protocol. Thus, computer-readable media may generally correspond to (1) non-transient tangible computer-readable storage media, or (2) communication media such as signals or carrier waves. Data storage media may be any available media 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 herein. Computer program products may include computer-readable media.

[0248] As an example, and not an limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, flash memory, or any other media accessible by a computer that can be used to store desired program code in the form of instructions or data structures. Also, any connection is appropriately called a computer-readable medium. For example, if instructions are transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave may be included in the definition of a medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carriers, signals, or other temporary media, but instead refer to non-temporary tangible storage media. As used herein, the terms "Disk" and "Disc" include compact discs (CDs), laser discs, optical discs, digital multipurpose discs (DVDs), floppy disks, and Blu-ray discs. A "Disk" typically reproduces data magnetically, while a "Disc" reproduces data optically using a laser. Any combination of the above should also be included within the scope of computer-readable media.

[0249] Further information regarding this disclosure as described above is provided in the following description:

[0250] At RAN2 #122, based on the 3GPPP R2-2306871 document, RAN2 identified the need for assistance in helping UEs that are physically located on a mobile vehicle but not camped on a mobile IAB cell (e.g., a UE is camped on a stationary cell) to identify adjacent mobile IAB cells, prioritize these mobile IAB cells (frequency and cell), and "pull" the UE to these mobile IAB cells. This is also referred to as "Issue 1" in RAN2 #122.

[0251] Furthermore, to prevent service discontinuities resulting from an in-vehicle UE device camped on a mobile IAB cell disconnecting from that mobile IAB cell and temporarily camping to a stationary cell (managed by a gNB or fixed IAB node) or some other mobile IAB cell passing nearby, an in-vehicle UE in the IDLE / INACTIVE state may no longer perform cell reselection and associated neighbor cell measurements, as long as it remains mounted for the mobile IAB node being considered. This relates to "Issue 2," identified in RAN2 #122 and discussed in the 3GPPP R2-2306871 document.

[0252] In relation to both Issue 1 and Issue 2, RAN2 confirmed that in RAN2 #122, when a UE in the IDLE / INACTIVE state broadcasts the mIAB cell type indicator in SIB1 for cell reselection, it may prioritize the cell with the highest rank in frequency. The UE may use SIB4 support information to identify the presence of such mobile IAB cells when broadcast. SIB4 support information may include the mIAB cell frequency. Identifying the UEs in Issues 1 and 2 is the FFS on Stage 2 / 3.

[0253] Therefore, considering issues 1 and 2, it can be proposed that an in-vehicle UE in the IDLE / INACTIVE state may restrict cell reselection and associated adjacent cell measurements to mobile IAB cells whose frequencies are identified in the SIB4 support information.

[0254] Clauses establishing further aspects and embodiments 1. A method for use in an Integrated Access and Backhaul (IAB) communication system implemented in a wireless communication device, for facilitating the network connectivity of the wireless communication device, This includes determining whether the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells.

[0255] 2. The decision is, When it is identified that a cell adjacent to the aforementioned serving mobile cell is a mobile cell, the timer is started. The method according to item 1, comprising determining that the identified mobile cell is the mobile cell associated with the serving mobile cell if one or more specific conditions are met when the timer expires.

[0256] 3. Receiving notification information from a cell adjacent to the serving mobile cell indicating that the cell is a mobile cell, The method of item 2, further comprising the fact that the cell adjacent to the serving mobile cell is identified as a mobile cell based on the received notification information.

[0257] 4. The aforementioned specific conditions are: The signal associated with the identified mobile cell is still detected when the timer expires, The signal strength measurement of the signal associated with the identified mobile cell exceeds a certain threshold for the period from the start of the timer to the end of the timer, The method according to item 2 or item 3, comprising one or more of the following: a signal strength measurement of the signal associated with the identified mobile cell is between a first specific threshold and a second specific threshold for the period from the start of the timer to the end of the timer.

[0258] 5. Further includes receiving information from an IAB node to identify one or more other mobile cells as associated mobile cells to which the serving mobile cell is associated, The method according to Clause 1, which includes determining, based on received information, whether a serving mobile cell serving a wireless communication device is associated with one or more other mobile cells.

[0259] 6. The above information is, A group identifier for identifying a group of associated mobile cells associated with the one or more associated mobile cells associated with the serving mobile cell, A list of one or more identifiers of the one or more associated mobile cells associated with the serving mobile cell, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more associated mobile cells associated with the serving mobile cell, The method according to item 5, comprising at least one of the following: some or all of the associated mobile cells associated with the serving mobile cell; frequency information indicating the respective frequencies of the associated mobile cells.

[0260] 7. Send a request to the IAB donor node to establish a connection with the mobile cell associated with the IAB node managed by the IAB donor node, The method according to item 1, further comprising receiving a response from the IAB donor node containing information for identifying one or more other mobile cells as associated mobile cells to which the mobile cell requesting connection is associated.

[0261] 8. When a connection with the mobile cell is established, the mobile cell is the serving mobile cell that serves the wireless communication device. The method according to item 7, wherein determining whether the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells is based on the information contained in the received response.

[0262] 9. The above information is A group identifier for identifying a group of associated mobile cells associated with one or more associated mobile cells associated with the mobile cell that requested a connection, A list of one or more identifiers of the one or more associated mobile cells associated with the mobile cell that requested the connection, A list of one or more identifiers of one or more mobile IAB nodes associated with one or more associated mobile cells associated with the mobile cell that requested a connection, The method of item 7 or item 8, comprising at least one of the following: frequency information indicating the frequency of each of the associated mobile cells, some or all of the associated mobile cells associated with the mobile cell that has requested a connection.

[0263] 10. Further includes receiving information from an IAB donor node that manages the connection between the wireless communication device and the serving mobile cell to identify one or more other mobile cells as associated mobile cells associated with the serving mobile cell, Determining includes determining whether a mobile cell adjacent to the serving mobile cell serving the wireless communication device is associated with the serving mobile cell based on the received information, the method according to any one of items 1 or 7 to 9.

[0264] 11. The information is a group identifier for identifying a group of associated mobile cells associated with the one or more associated mobile cells associated with the serving mobile cell, a list of one or more identifiers of the one or more associated mobile cells associated with the serving mobile cell, a list of one or more identifiers of one or more mobile IAB nodes associated with the one or more associated mobile cells associated with the serving mobile cell, frequency information indicating the respective frequencies of some or all of the associated mobile cells of the one or more associated mobile cells associated with the serving mobile cell, the method according to item 10 including at least one of them.

[0265] 12. The information received from the IAB donor node includes update information including at least one of information for identifying one or more new mobile cells added as associated mobile cells and information for identifying one or more mobile cells removed from the associated mobile cells, the method according to item 10 or item 11.

[0266] 13. The update information is a list of one or more identifiers of one or more new mobile cells added as the associated mobile cells, a list of one or more identifiers of one or more mobile IAB nodes associated with the one or more new mobile cells added as the associated mobile cells, A list of one or more identifiers of one or more mobile cells removed from the associated mobile cell, The method according to item 13, comprising at least one of the following: a list of one or more identifiers of one or more mobile IAB nodes associated with one or more mobile cells removed from the associated mobile cell; and

[0267] 14. The method according to any one of claims 7 to 12, further comprising receiving configuration information from the IAB donor node for a handover (HO) or conditional handover (CHO) for at least some of the one or more associated mobile cells.

[0268] 15. The method of item 14, further comprising performing a handover to at least one of the one or more associated mobile cells after determining that the conditions for a conditional handover to at least one of the associated mobile cells are met.

[0269] 16. The method according to any one of the preceding items, provided in the wireless communication device on the basis that a list of associated mobile cells identifying one or more other mobile cells associated with the serving mobile cell determines that the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells.

[0270] 17. The method of item 16, further comprising the wireless communication device receiving cell access information that identifies one or more of the mobile cells in the list of associated mobile cells as restricted cells to which it is not permitted access.

[0271] 18. The cell access information is The wireless communication device is not permitted to access one or more associated mobile cells in the list of such mobile cells, and each of the one or more such mobile cells has one or more identifiers. A group identifier for identifying the group of associated mobile cells that the wireless communication device is not permitted to access, The wireless communication device is not permitted to access one or more associated mobile cells, and one or more identifiers of one or more mobile IAB nodes associated with one or more of the mobile cells in the list of associated mobile cells, The method of item 17, comprising at least one of the following: frequency information indicating the frequencies for each of the associated mobile cells in the list of associated mobile cells to which the wireless communication device is not permitted to access, in part or in whole of the associated mobile cells.

[0272] 19. The method of item 17 or 18, further comprising disconnecting from the serving mobile cell if the serving mobile cell is identified by the received cell access information as a mobile cell to which the wireless communication device is not permitted access.

[0273] 20. When the wireless communication device determines that the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells, and when the wireless communication device is in an RRC disconnection state, it determines the need for cell reselection. After determining the need for cell reselection, it is determined whether at least one of the one or more adjacent cells discovered by the wireless communication device is one of the one or more associated mobile cells associated with the serving mobile cell, The method of any one of the preceding items, further comprising: determining that at least one adjacent cell is an associated mobile cell, and then performing cell reselection to the associated mobile cell.

[0274] 21. When the wireless communication device determines that the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells, and when the wireless communication device is in an RRC-disconnected state, it determines the need for cell reselection, After determining the need for cell reselection, it is determined whether at least one of the one or more adjacent cells discovered by the wireless communication device is one of the one or more associated mobile cells associated with the serving mobile cell, After determining that at least one adjacent cell is an associated mobile cell, the wireless communication device is to determine, based on cell access information, whether it is permitted to access the associated mobile cell. The method according to any one of items 17 to 19, further comprising performing cell reselection to the associated mobile cell after the wireless communication device has determined that it is permitted to access the associated mobile cell.

[0275] 22. The method of item 21, further comprising not performing cell reselection to the associated mobile cell after the wireless communication device has determined that it is not permitted to access the associated mobile cell.

[0276] 23. Determining whether at least one of the one or more adjacent cells discovered by the wireless communication device is one of the one or more associated mobile cells associated with the serving mobile cell, To determine whether any of the one or more adjacent cells found corresponds to one of the one or more associated mobile cells associated with the serving mobile cell, When at least one adjacent cell corresponds to one of the one or more associated mobile cells associated with the serving mobile cell, selecting the at least one adjacent cell corresponding to the associated mobile cell to perform cell reselection, The method according to any one of items 20 to 22, including:

[0277] 24. A list of associated mobile cells identifying one or more other mobile cells associated with the serving mobile cell is provided in the wireless communication device, The method according to item 23, including checking whether any of the one or more adjacent cells discovered by the wireless communication device corresponds to one of the one or more associated mobile cells, whether any of the one or more discovered adjacent cells corresponds to an associated mobile cell in the list of associated mobile cells.

[0278] 25. The method according to any one of items 20 to 24, selecting one of the two or more adjacent cells for cell reselection when two or more adjacent cells are determined to be associated mobile cells.

[0279] 26. The method according to any one of the preceding items, where the movement of the wireless communication device is related to the movement of the serving mobile cell.

[0280] 27. The method according to any one of the preceding items, where the IAB node associated with the serving mobile cell is mounted on a vehicle, another IAB node for controlling the mobile cell determined to be associated with the IAB node or the serving mobile cell is mounted on the vehicle, and the wireless communication device is mounted on the vehicle.

[0281] 28. A method for facilitating network connectivity of wireless communication devices in an IAB communication system including an Integrated Access and Backhaul (IAB) node associated with one or more mobile cells, wherein in the IAB node, A method comprising transmitting information for identifying one or more mobile cells as associated mobile cells to which at least one of the one or more mobile cells is associated.

[0282] 29. Further comprising determining that the one or more mobile cells associated with the IAB node are associated with one or more other mobile cells as associated mobile cells, A method comprising transmitting information to identify one or more other mobile cells as associated mobile cells associated with at least one of the one or more mobile cells, after it has been determined that one or more mobile cells associated with the IAB node are associated with one or more other mobile cells.

[0283] 30. Further includes receiving information from an IAB donor node managing the IAB node to identify one or more other mobile cells associated with at least one of the one or more cells to which the IAB node is associated, The method of item 28 or 29, wherein transmitting includes transmitting information to identify one or more associated cells to which at least one of the one or more mobile cells is associated, based on the received information.

[0284] 31. The information received is: One or more group identifiers, each of which identifies a group of associated mobile cells, including at least one mobile cell associated with the IAB node. For each group of associated mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of the associated mobile cell in the group, For each group of associated mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of mobile IAB nodes associated with the associated mobile cell in the group, The method according to item 30, comprising at least one of the following: for each group of associated mobile cells, which includes at least one mobile cell associated with the IAB node, frequency information indicating the frequency for each of the associated mobile cells in the group, which may be some or all of the associated mobile cells.

[0285] 32. The information transmitted by the IAB node is: A group identifier for identifying a group of associated mobile cells associated with at least one of the one or more associated mobile cells, A list of one or more identifiers of the one or more associated mobile cells associated with at least one of the one or more mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with one or more associated mobile cells associated with at least one of the one or more mobile cells, The method according to any one of items 30 to 31, comprising at least one of the following: frequency information indicating the frequency for each of the associated mobile cells, which is part or all of the associated mobile cells associated with at least one of the one or more associated mobile cells.

[0286] 33. Transmitting, including broadcasting the information, as described in any one of items 28 to 32.

[0287] 34. A method for facilitating network connectivity of a wireless communication device in an IAB communication system including an Integrated Access and Backhaul (IAB) donor node that manages the connection between the wireless communication device and a serving mobile cell that serves the wireless communication device, wherein the IAB donor node comprises: A method comprising transmitting information to a wireless communication device for identifying one or more other mobile cells as associated mobile cells associated with the serving mobile cell.

[0288] 35. The information transmitted to the wireless communication device is: A group identifier for identifying a group of associated mobile cells associated with the one or more associated mobile cells associated with the serving mobile cell, A list of one or more identifiers of the one or more associated mobile cells associated with the serving mobile cell, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more associated mobile cells associated with the serving mobile cell, The method according to item 34, comprising at least one of the following: frequency information indicating the frequency for each of the one or more associated mobile cells associated with the serving mobile cell.

[0289] 36. Further including determining whether one or more new mobile cells should be added as associated mobile cells, and whether one or more mobile cells should be removed from associated mobile cells, The method according to item 34 or 35, wherein transmitting includes transmitting the information to the wireless communication device after it has been determined that at least one of one or more new mobile cells should be added as an associated mobile cell, or that one or more mobile cells should be removed from an associated cell, the information transmitted to the wireless communication device includes update information which includes at least one of information which includes information which includes information which includes information which includes information which includes one or more new mobile cells that have been added as an associated mobile cell, and information which includes information which includes information which includes one or more mobile cells that have been removed from an associated mobile cell.

[0290] 37. The above update information is: A list of one or more identifiers of the one or more new mobile cells added as associated mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more new mobile cells that have been added as associated mobile cells, A list of one or more identifiers of the one or more mobile cells removed from the associated mobile cell, The method according to item 36, comprising at least one of the following: a list of one or more identifiers of one or more mobile IAB nodes associated with one or more mobile cells removed from the associated mobile cell.

[0291] 38. Further including determining that the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells, The method of item 34, wherein transmitting includes transmitting the information to the wireless communication device after it has been determined that the serving mobile cell is associated with one or more other mobile cells.

[0292] 39. Further includes receiving configuration information for identifying one or more lists of mobile cells that are interconnected and associated with one or more IAB nodes managed by the IAB donor node, The method according to item 38, wherein determining whether the serving mobile cell serving the wireless communication device is associated with one or more other mobile cells, based on the received configuration information.

[0293] 40. The configuration information is received from the core network entity or in the factory configuration, as described in item 39.

[0294] 41. The above setting information is, One or more group identifiers, and each group identifier identifies the group of mobile cells associated with it. For each group of associated mobile cells, a list of one or more identifiers of the one or more associated mobile cells in the group, The method according to item 39 or item 40, comprising, for each group of associated mobile cells, a list of one or more identifiers of one or more mobile IAB nodes associated with one or more associated mobile cells in the group, and at least one of the following:

[0295] 42. A method for use in an IAB communication system including an Integrated Access and Backhaul (IAB) donor node, wherein in the IAB donor node, Receiving configuration information for identifying one or more lists of mobile cells that are interconnected and associated with one or more IAB nodes managed by the IAB donor node, A method comprising transmitting to at least one IAB node managed by the IAB donor node information for identifying one or more associated mobile cells associated with at least some of the mobile cells associated with one or more mobile cells associated with the at least one IAB node.

[0296] 43. The configuration information is received from the core network entity or in the factory configuration, as described in item 42.

[0297] 44. The above setting information is, One or more group identifiers, and each of the group identifiers identifies the group of mobile cells associated with it. For each group of associated mobile cells, a list of one or more identifiers of the one or more associated mobile cells in the group, The method according to either item 42 or item 43, comprising, for each group of associated mobile cells, a list of one or more identifiers of one or more mobile IAB nodes associated with one or more associated mobile cells in the group, and at least one of the following:

[0298] 45. The information transmitted to the at least one IAB node managed by the IAB donor node shall, for each IAB node, One or more group identifiers, each of which identifies a group of associated mobile cells, including at least one mobile cell associated with the IAB node. For each group of associated mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of the one or more associated mobile cells in the group, For each group of associated mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of one or more mobile IAB nodes associated with the one or more associated mobile cells in the group, For each group of associated mobile cells, which includes at least one mobile cell associated with the IAB node, frequency information indicating the frequency for each of the associated mobile cells, which is part of or all of the associated mobile cells in the group, The method according to any one of items 42 to 44, further comprising at least one of the following: for each group of associated mobile cells, which includes at least one mobile cell associated with the IAB node, frequency information indicating the frequency for each of the associated mobile cells, which is a subset or all of the associated mobile cells in the group of one or more associated mobile cells.

[0299] 46. ​​A method for facilitating network connectivity of wireless communication devices in an IAB communication system including an Integrated Access and Backhaul (IAB) donor node, wherein at the IAB donor node, The wireless communication device receives a request to establish a connection with a mobile cell associated with an IAB node managed by the IAB donor node, A method comprising: if the mobile cell requesting connection is associated with one or more other mobile cells, transmitting information to the wireless communication device to identify one or more other mobile cells as associated mobile cells associated with the mobile cell requesting connection.

[0300] 47. The above information is, A group identifier for identifying a group of associated mobile cells associated with the one or more associated mobile cells to which the mobile cell requesting connection is associated, A list of one or more identifiers of the one or more associated mobile cells to which the mobile cell requesting connection is associated, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more associated mobile cells to which the mobile cell requesting a connection is associated, The method of item 46, comprising at least one of the following: frequency information indicating the frequency for each of the associated mobile cells, some or all of the associated mobile cells to which the mobile cell requesting connection is associated.

[0301] 48. The method of item 46 or 47, further comprising determining whether the mobile cell that has requested a connection is associated with one or more other mobile cells.

[0302] 49. Further includes receiving configuration information for identifying one or more lists of mobile cells that are interconnected and associated with one or more IAB nodes managed by the IAB donor node, The method of item 48, wherein determining whether the mobile cell requested for connection is associated with one or more other mobile cells, based on the received configuration information.

[0303] 50. The configuration information is received from the core network entity or in the factory configuration, as described in item 49.

[0304] 51. The above setting information is, One or more group identifiers, and each of the group identifiers identifies the group of mobile cells associated with it. For each group of associated mobile cells, a list of one or more identifiers of the one or more associated mobile cells in the group, The method according to item 49 or item 50, comprising, for each group of associated mobile cells, at least one list of identifiers for one or more mobile IAB nodes associated with one or more associated mobile cells in the group.

[0305] 52. If the IAB donor node determines that the mobile cell for which connection has been requested is associated with one or more other mobile cells, it shall negotiate a Conditional Handover (CHO) with one or more IAB nodes, and the one or more IAB nodes shall be associated with at least some of the one or more other mobile cells. The method according to any one of items 46 to 51, further comprising transmitting configuration information for CHO for at least some of the one or more other mobile cells to the wireless communication device based on the aforementioned negotiation.

[0306] 53. Negotiating with the CHO is Sending an establishment request to each of the one or more IAB nodes to request a CHO to each of the IAB nodes, The method according to item 52, comprising receiving an establishment response from at least one of the one or more IAB nodes acknowledging receipt of the establishment request.

[0307] 54. If the IAB donor node determines that the mobile cell requesting connection is associated with one or more other mobile cells, and at least one IAB node associated with at least some of the one or more other mobile cells is managed by another IAB donor node, then negotiate a conditional handover (CHO) with the other IAB donor node, The method according to any one of items 46 to 53, further comprising transmitting configuration information for CHO for at least some of the one or more other mobile cells associated with at least one IAB node managed by the other IAB donor node, based on the aforementioned negotiations, to the wireless communication device.

[0308] 55. Negotiating with the CHO is Sending an establishment request to the other IAB donor node that manages the at least one IAB node to request a CHO to the at least one IAB node, The method according to item 54, comprising receiving an establishment response from the other IAB donor node acknowledging receipt of the establishment request.

[0309] 56. The method of item 53 or item 55, wherein the transmitted establishment request includes information about the wireless communication device for creating a context for the wireless communication device at each of the IAB nodes.

[0310] 57. When the movement of a cell is related to the movement of the mobile cell, the cell is associated with the mobile cell, according to the method of any one of the preceding items.

[0311] 58. The method according to any one of the preceding items, wherein the wireless communication device is a user equipment (UE) or a mobile IAB node.

[0312] 59. Apparatus for wireless communication devices, An apparatus comprising one or more processing units configured to perform the method described in any one of items 1 to 27, 57, or 58.

[0313] 60. Device for an IAB node of an Integrated Access Backhaul (IAB) communication system, An apparatus comprising one or more processing units configured to perform the method described in any one of items 28 to 33, item 57, or item 58.

[0314] 61. Equipment for an IAB donor node of an Integrated Access Backhaul (IAB) communication system, An apparatus comprising one or more processing units configured to perform the method described in any one of items 34 to 58.

[0315] 62. A computer program that, when executed by a computer, includes instructions causing the computer to perform any of the methods described in items 1 through 58.

[0316] 63. A computer-readable medium for carrying the computer programs described in item 62.

Claims

1. A method for use in facilitating network connectivity of a wireless communication device in an Integrated Access and Backhaul (IAB) communication system implemented in the wireless communication device, A method for determining whether there are one or more preferred mobile cells other than a serving mobile cell serving the wireless communication device, wherein the one or more preferred mobile cells are preferred target cells for the wireless communication device.

2. The further includes receiving information for identifying one or more mobile cells as preferred mobile cells, The method according to claim 1, wherein determining whether there are one or more preferred mobile cells other than the serving mobile cell serving the wireless communication device, based on the received information.

3. To decide, When it is identified that a cell adjacent to the serving mobile cell is a mobile cell, the timer is started. The method according to claim 1, comprising determining that the identified mobile cell is a preferred mobile cell if one or more specific conditions are met when the timer expires.

4. The further includes receiving notification information from a cell adjacent to the serving mobile cell indicating that the cell is a mobile cell, The method according to claim 3, further comprising the fact that the cell adjacent to the serving mobile cell is identified as a mobile cell based on the received notification information.

5. The aforementioned specific conditions are, The signal associated with the identified mobile cell is still detected when the timer expires, The signal strength measurement of the signal associated with the identified mobile cell exceeds a certain threshold for the period from the start of the timer to the end of the timer, The method according to claim 3 or 4, comprising one or more of the following: a signal intensity measurement of the signal associated with the identified mobile cell is between a first specific threshold and a second specific threshold for a period from the start of the timer to the end of the timer.

6. The aforementioned information is, A group identifier for identifying a group of preferred mobile cells associated with the one or more preferred mobile cells, A list of one or more identifiers for the one or more preferred mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more preferred mobile cells, The method according to claim 2, comprising at least one of the following: frequency information indicating the frequency of each of the one or more preferred mobile cells.

7. The further includes receiving information from an IAB donor node that manages the connection between the wireless communication device and the serving mobile cell to identify one or more mobile cells as preferred mobile cells, The method according to claim 1, wherein determining whether a mobile cell adjacent to the serving mobile cell serving the wireless communication device is a preferred mobile cell based on the received information.

8. The aforementioned information is, A group identifier for identifying a group of preferred mobile cells associated with the one or more preferred mobile cells, A list of one or more identifiers for the one or more preferred mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more preferred mobile cells, The method according to claim 7, comprising at least one of the following: frequency information indicating the frequency of each of the one or more preferred mobile cells.

9. The method according to claim 2 or 7, wherein the information includes a list of one or more identifiers of the one or more preferred mobile cells.

10. The method according to any one of claims 6, 8, or 9, wherein the list of one or more identifiers includes a list or range of physical cell identifiers (PCIs).

11. The method according to claim 7 or 8, wherein the information received from the IAB donor node includes update information comprising at least one of the following: information for identifying one or more new mobile cells added as preferred mobile cells; and information for identifying one or more mobile cells removed from preferred mobile cells.

12. The aforementioned update information is, A list of one or more identifiers of one or more new mobile cells added as preferred mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with one or more new mobile cells added as preferred mobile cells, A list of one or more identifiers of one or more mobile cells removed from the preferred mobile cell, The method according to claim 11, further comprising at least one of the following: a list of identifiers for one or more mobile IAB nodes associated with one or more mobile cells removed from the preferred mobile cells; and

13. The method according to any one of claims 7 to 12, further comprising receiving configuration information from the IAB donor node for a handover (HO) or conditional handover (CHO) for at least some of the one or more preferred mobile cells.

14. The method according to claim 13, further comprising determining the conditions for a conditional handover to at least one of the one or more preferred mobile cells, and then performing a handover to the at least one preferred mobile cell.

15. The method according to any one of the preceding claims, provided in the wireless communication device, on the basis that a list of preferred mobile cells identifying one or more preferred mobile cells determines that there are one or more preferred mobile cells other than the serving mobile cell.

16. The method of claim 15, further comprising the wireless communication device receiving cell access information that identifies one or more of the mobile cells in the list of preferred mobile cells as restricted cells that are not permitted to access.

17. The aforementioned cell access information is, One or more identifiers for each of the one or more mobile cells in the list of preferred mobile cells that the wireless communication device is not permitted to access, A group identifier for identifying a group of preferred mobile cells that the wireless communication device is not permitted to access, The wireless communication device is not permitted to access one or more identifiers of one or more mobile IAB nodes associated with one or more of the mobile cells in the list of preferred mobile cells, The method according to claim 16, comprising at least one of the following: frequency information indicating the frequencies for each of the preferred mobile cells in the list of preferred mobile cells to which the wireless communication device is not permitted to access.

18. The method according to claim 16 or 17, further comprising disconnecting from the serving mobile cell if the serving mobile cell is identified by the received cell access information as a mobile cell that the wireless communication device is not authorized to access.

19. When the wireless communication device determines that there is one or more preferred mobile cells other than the serving mobile cell serving the wireless communication device, and when the wireless communication device is in an RRC non-connection state, it determines the need for cell reselection. After determining the need for cell reselection, it is determined whether at least one of the one or more adjacent cells discovered by the wireless communication device is one of the one or more preferred mobile cells. The method according to any one of the preceding claims, further comprising: determining that at least one adjacent cell is a preferred mobile cell, and then performing cell reselection to the preferred mobile cell.

20. When the wireless communication device determines that there is one or more preferred mobile cells other than the serving mobile cell serving the wireless communication device, and when the wireless communication device is in an RRC non-connection state, the need for cell reselection is determined. After determining the need for cell reselection, it is determined whether at least one of the one or more adjacent cells discovered by the wireless communication device is one of the one or more preferred mobile cells. After determining that at least one adjacent cell is a preferred mobile cell, the wireless communication device is determined, based on cell access information, to determine whether it is permitted to access the preferred mobile cell. The method according to any one of claims 16 to 18, further comprising performing cell reselection to the preferred mobile cell after determining that the wireless communication device is permitted to access the preferred mobile cell.

21. The method according to claim 20, further comprising the wireless communication device not performing cell reselection to the preferred mobile cell after determining that it is not permitted to access the preferred mobile cell.

22. Determining whether at least one of the one or more adjacent cells discovered by the wireless communication device is one of the one or more preferred mobile cells, To confirm whether any of the one or more discovered adjacent cells corresponds to one of the one or more preferred mobile cells, The method according to any one of claims 19 to 21, further comprising: selecting the at least one adjacent cell corresponding to the preferred mobile cell if at least one adjacent cell corresponds to one of the one or more preferred mobile cells, in order to perform cell reselection.

23. A list of preferred mobile cells that identify one or more preferred mobile cells is provided in the wireless communication device. The method of claim 22, wherein determining whether any of the one or more adjacent cells discovered by the wireless communication device corresponds to one of the one or more preferred mobile cells includes determining whether any of the one or more discovered adjacent cells corresponds to a preferred mobile cell in the list of preferred mobile cells.

24. The method according to any one of claims 19 to 23, wherein if two or more adjacent cells are determined to be preferred mobile cells, one of the two or more adjacent cells is selected for cell reselection.

25. The method according to any one of the preceding claims, wherein the movement of the wireless communication device relates to the movement of the serving mobile cell.

26. The method according to any one of the preceding claims, wherein an IAB node associated with the serving mobile cell is mounted in the vehicle, another IAB node controlling the IAB node or a preferred mobile cell is mounted in the vehicle, and the wireless communication device is mounted in the vehicle.

27. A method for facilitating network connectivity of wireless communication devices in an IAB communication system including an Integrated Access and Backhaul (IAB) node associated with one or more mobile cells, wherein in the IAB node, A method comprising transmitting information for identifying one or more mobile cells as preferred mobile cells, wherein the one or more preferred mobile cells are preferred target cells for a wireless communication device.

28. The further includes determining that the one or more mobile cells associated with the IAB node are preferred mobile cells, The method according to claim 27, wherein the information for identifying one or more mobile cells as preferred mobile cells includes information for identifying one or more mobile cells associated with the IAB node as preferred mobile cells.

29. Receiving information from an IAB donor node managing the aforementioned IAB node to identify one or more mobile cells as preferred mobile cells, The method according to claim 27 or 28, wherein transmitting includes transmitting information for identifying one or more preferred mobile cells based on the received information.

30. The received information is, One or more group identifiers, each of which identifies a preferred group of mobile cells including at least one mobile cell associated with the IAB node, For each group of preferred mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of the preferred mobile cell in the group, For each group of preferred mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of mobile IAB nodes associated with the preferred mobile cell in the group, The method according to claim 29, comprising at least one of the following: for each group of preferred mobile cells, which includes at least one mobile cell associated with the IAB node, frequency information indicating the frequency for each of the preferred mobile cells in the group, which may be some or all of the preferred mobile cells.

31. The information transmitted by the IAB node is, A group identifier for identifying preferred mobile cell groups, A list of one or more identifiers for the one or more preferred mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more preferred mobile cells, The method according to any one of claims 29 to 30, comprising at least one of the following: frequency information indicating the frequency for each of the one or more preferred mobile cells.

32. The method according to claim 31, wherein the list of one or more identifiers of the one or more preferred mobile cells includes a list or range of physical cell identifiers (PCIs).

33. The method according to any one of claims 27 to 32, wherein transmitting includes broadcasting the information.

34. The method according to any one of claims 27 to 32, wherein transmission includes broadcasting the information in an SIB4 message.

35. A method for facilitating network connectivity of a wireless communication device in an IAB communication system including an Integrated Access and Backhaul (IAB) donor node that manages the connection between the wireless communication device and a serving mobile cell that serves the wireless communication device, wherein the IAB donor node, A method comprising transmitting information to a wireless communication device for identifying one or more mobile cells as preferred mobile cells, wherein the one or more preferred mobile cells are preferred target cells for the wireless communication device, and the serving mobile cell is a preferred mobile cell.

36. The information transmitted to the wireless communication device is A group identifier for identifying a group of preferred mobile cells associated with the one or more preferred mobile cells, A list of one or more identifiers for the one or more preferred mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more preferred mobile cells, The method of claim 35, comprising at least one of the following: frequency information indicating the frequency for each of the one or more preferred mobile cells.

37. The method according to claim 36, wherein the list of one or more identifiers of the one or more preferred mobile cells includes a list or range of physical cell identifiers (PCIs).

38. The process further includes determining whether one or more new mobile cells should be added as preferred mobile cells, and whether one or more mobile cells should be removed from the preferred mobile cells. Transmitting includes transmitting the information to the wireless communication device after it has been determined that at least one of one or more new mobile cells should be added as a preferred cell, or that one or more mobile cells should be removed from being preferred cells. The method according to any one of claims 35, 36, or 37, wherein the information transmitted to the wireless communication device includes update information comprising at least one of the following: information for identifying one or more new mobile cells added as preferred mobile cells, and information for identifying one or more mobile cells removed from preferred mobile cells.

39. The aforementioned update information is, A list of one or more identifiers of the one or more new mobile cells added as preferred mobile cells, A list of one or more identifiers of one or more mobile IAB nodes associated with the one or more new mobile cells added as preferred mobile cells, A list of one or more identifiers of the one or more mobile cells removed from the preferred mobile cells, The method of claim 38, comprising at least one of the following: a list of identifiers for one or more mobile IAB nodes associated with one or more mobile cells removed from preferred mobile cells.

40. The process further includes determining whether the serving mobile cell to be served to the wireless communication device is a preferred mobile cell. The method of claim 35, wherein transmitting includes transmitting the information to the wireless communication device after it has been determined that the serving mobile cell is a preferred mobile cell.

41. The further includes receiving configuration information for identifying one or more lists of mobile cells that are preferred mobile cells, associated with one or more IAB nodes managed by the IAB donor node, The method according to claim 40, wherein determining whether the serving mobile cell to be served to the wireless communication device is a preferred mobile cell is a determination based on the received configuration information.

42. The method according to claim 41, wherein the configuration information is received from a core network entity or received in the factory settings.

43. The aforementioned configuration information is, One or more group identifiers, and each of the group identifiers identifies a preferred group of mobile cells. For each group of preferred mobile cells, a list of one or more identifiers of the one or more preferred mobile cells in the group, The method according to claim 41 or claim 42, comprising, for each group of preferred mobile cells, a list of one or more identifiers of one or more mobile IAB nodes associated with one or more preferred mobile cells in the group.

44. A method for use in an IAB communication system including an Integrated Access and Backhaul (IAB) donor node, wherein in the IAB donor node, Receiving configuration information to identify one or more lists of mobile cells, which are preferred mobile cells, which are preferred target cells, and which are associated with one or more IAB nodes managed by the IAB donor node, A method comprising transmitting information for identifying one or more preferred mobile cells to at least one IAB node managed by the IAB donor node.

45. The method according to claim 44, wherein the information includes information for identifying one or more mobile cells associated with the at least one IAB node as preferred mobile cells.

46. The method according to claim 44 or 45, wherein the configuration information is received from a core network entity or received in the factory configuration.

47. The aforementioned configuration information is, One or more group identifiers, and each of the group identifiers identifies a preferred group of mobile cells. For each group of preferred mobile cells, a list of one or more identifiers of the one or more preferred mobile cells in the group, The method according to any one of claims 44 to 46, comprising, for each group of preferred mobile cells, a list of one or more identifiers of one or more mobile IAB nodes associated with one or more preferred mobile cells in the group.

48. The information transmitted to the at least one IAB node managed by the IAB donor node is, for each IAB node, One or more group identifiers, each of which identifies a preferred group of mobile cells including at least one mobile cell associated with the IAB node, For each group of preferred mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of the one or more preferred mobile cells in the group, For each group of preferred mobile cells, which includes at least one mobile cell associated with the IAB node, a list of one or more identifiers of one or more mobile IAB nodes associated with the one or more preferred mobile cells in the group, For each group of preferred mobile cells, which includes at least one mobile cell associated with the IAB node, frequency information indicating the frequency for each of the preferred mobile cells, which is part or all of the preferred mobile cells in the group, The method according to any one of claims 44 to 47, comprising at least one of the following: for each group of preferred mobile cells, which includes at least one mobile cell associated with the IAB node, frequency information indicating the frequency for each of the preferred mobile cells, which is a subset or all of the preferred mobile cells in the group of one or more preferred mobile cells.

49. A method for facilitating network connectivity of wireless communication devices in an IAB communication system including an Integrated Access and Backhaul (IAB) donor node, wherein in the IAB donor node, The wireless communication device receives a request to establish a connection with a mobile cell associated with an IAB node managed by the IAB donor node, A method comprising: transmitting information to the wireless communication device to identify the preferred mobile cell if the mobile cell requesting connection is one of two or more preferred mobile cells, and the two or more preferred mobile cells are preferred target cells for the wireless communication device.

50. The aforementioned information is, A group identifier for identifying a group of preferred mobile cells associated with the aforementioned preferred mobile cell, A list of one or more identifiers for the preferred mobile cell, A list of one or more identifiers of one or more mobile IAB nodes associated with the preferred mobile cell, The method according to claim 49, comprising at least one of the following: frequency information indicating the frequency for each of the preferred mobile cells, some or all of the preferred mobile cells.

51. The method according to claim 49 or 50, further comprising determining whether the mobile cell requesting connection is one of the preferred mobile cells.

52. A preferred mobile cell further includes receiving configuration information to identify one or more lists of mobile cells associated with one or more IAB nodes managed by the IAB donor node, The method according to claim 51, wherein determining whether the mobile cell requested for connection is a preferred mobile cell is based on the received configuration information.

53. The method according to claim 52, wherein the configuration information is received from a core network entity or received in the factory settings.

54. The aforementioned configuration information is, One or more group identifiers, and each of the group identifiers identifies a preferred group of mobile cells. For each group of preferred mobile cells, a list of one or more identifiers of the one or more preferred mobile cells in the group, The method according to claim 52 or 53, comprising, for each group of preferred mobile cells, at least one list of identifiers for one or more mobile IAB nodes associated with one or more preferred mobile cells in the group.

55. If the IAB donor node determines that the mobile cell for which connection has been requested is one of two or more preferred mobile cells, it shall negotiate a conditional handover (CHO) with one or more IAB nodes, and the one or more IAB nodes shall be associated with at least some of one or more other preferred mobile cells. The method according to any one of claims 49 to 54, further comprising transmitting setting information for CHO for at least some of the one or other preferred mobile cells to the wireless communication device based on the aforementioned negotiation.

56. Negotiating with the CHO is Sending an establishment request to each of the one or more IAB nodes to request CHO to each of the IAB nodes, The method according to claim 55, comprising receiving an establishment response from at least one of the one or more IAB nodes acknowledging receipt of the establishment request.

57. If the IAB donor node determines that the mobile cell requesting connection is one of two or more preferred mobile cells, and at least one IAB node associated with at least some of the other preferred mobile cells is managed by another IAB donor node, then negotiate a conditional handover (CHO) with the other IAB donor node, The method according to any one of claims 49 to 56, further comprising transmitting configuration information for CHO for at least some of the one or more other preferred mobile cells associated with at least one IAB node managed by the other IAB donor node, based on the negotiations, to the wireless communication device.

58. Negotiating with the CHO is Sending an establishment request to the other IAB donor node that manages the at least one IAB node to request CHO to the at least one IAB node, The method according to claim 57, further comprising receiving an establishment response from the other IAB donor node acknowledging receipt of the establishment request.

59. The method according to claim 56 or 58, wherein the transmitted establishment request includes information about the wireless communication device for creating a context for the wireless communication device at each of the IAB nodes.

60. The method according to any one of the preceding claims, wherein when the movement of a cell is related to the movement of the mobile cell, the cell is a preferred mobile cell accompanied by another mobile cell.

61. The method according to any one of the preceding claims, wherein one or more preferred mobile cells are associated with one another.

62. The method according to any one of the preceding claims, wherein the wireless communication device is a user device (UE) or a mobile IAB node.

63. A device for wireless communication devices, An apparatus comprising one or more processing units configured to perform the method described in any one of claims 1 to 26, 60, 61, or 62.

64. Device for an IAB node of an Integrated Access Backhaul (IAB) communication system, An apparatus comprising one or more processing units configured to perform the method described in any one of claims 27 to 34, 60, 61, or 62.

65. A device for an IAB donor node in an Integrated Access Backhaul (IAB) communication system, An apparatus comprising one or more processing units configured to perform the method described in any one of claims 35 to 62.

66. A computer program that includes instructions causing a computer to perform the method according to any one of claims 1 to 62 when the program is executed by the computer.

67. A computer-readable medium for transporting the computer program described in claim 66.

Images