Location updating method and device

Abstract

A method of wireless communication includes receiving, by an integrated access and backhaul (IAB) node, zone information, and broadcasting, by the IAB node, the zone information.

Description

Technical Field

[0001] This patent document relates generally to digital wireless communications. Background Art

[0002] Mobile communication technology is pushing the world towards an increasingly connected and networked society. Compared with existing wireless networks, the next generation of systems and wireless communication technologies will need to support a wider range of use case features and provide more complex and sophisticated access requirements and flexibility.

[0003] Long Term Evolution (LTE) is a wireless communication standard for mobile devices and data terminals developed by the Third Generation Partnership Project (3GPP). LTE-Advanced (LTE-A) is a wireless communication standard that enhances the LTE standard. The fifth generation wireless system, called 5G, advances the LTE and LTE-A wireless standards and is committed to supporting higher data rates, a large number of connections, ultra-low latency, high reliability, and other emerging business requirements. Summary of the invention

[0004] Techniques for performing a Tracking Area Update (TAU) for a user equipment (UE) on a mobile Integrated Access and Backhaul (IAB) node traveling from a source donor Central Unit (CU) to a target donor CU are disclosed.

[0005] A first example wireless communication method includes receiving, by an integrated access and backhaul (IAB) node, zone information, and broadcasting, by the IAB node, the zone information.

[0006] A second example wireless communication method includes sending, by an integrated access and backhaul (IAB) entity, IAB-related information.

[0007] A third example wireless communication method includes sending, by a network function, context information associated with an inactive wireless device.

[0008] A fourth example wireless communication method includes sending, by a Radio Access Network (RAN) node, RAN region information.

[0009] A fifth example wireless communication method includes receiving, by a network function, an Inactive Radio Network Temporary Identifier (I-RNTI) associated with a wireless device, and sending, by the network function, location information associated with the wireless device.

[0010] A sixth example wireless communication method includes receiving, by a network function, an inactive radio network temporary identifier (I-RNTI) associated with a wireless device. The method also includes sending, by the network function, a context retrieval request indication, and receiving, by the network function, context information associated with the wireless device.

[0011] A seventh example wireless communication method includes sending, by a network function, a radio access network-based Notification Area Update (RNAU)-related indication.

[0012] In another exemplary embodiment, a device configured or operable to perform the above method is disclosed. The device may include a processor configured to implement the above method.

[0013] In another exemplary embodiment, the above method is embodied in the form of processor executable code and stored in a non-transitory computer readable storage medium. When executed by a processor, the code included in the computer readable storage medium causes the processor to implement the method described in this patent document.

[0014] The above and other aspects and implementations thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 An exemplary block diagram of an integrated access and backhaul (IAB) network is illustrated.

[0016] Figure 2 An exemplary mobile IAB is illustrated.

[0017] Figure 3 An exemplary block diagram of a mobile IAB distributed unit (DU) changing a tracking area code (TAC) with a served cell of a target donor DU is illustrated.

[0018] Figure 4 An exemplary block diagram of moving an IAB DU to change a TAC configured by a target donor central unit (CU) is illustrated.

[0019] Figure 5 An exemplary block diagram is illustrated in which a mobile IAB DU does not change the TAC broadcasted by its served cell and maintains the TAC of the served cell of the new donor CU.

[0020] Figure 6 An exemplary block diagram for configuring a dedicated tracking area along a trajectory of a mobile IAB node is illustrated.

[0021] Figure 7 An exemplary block diagram of moving an IAB DU to change a radio access network area code (RANAC) configured by a target donor CU is illustrated.

[0022] Figure 8 An exemplary block diagram of moving the IAB DU without changing the RANAC is illustrated.

[0023] Fig. 9An exemplary block diagram of a user equipment (UE) replacing an old New Radio Cell Global Identifier (NCGI) with a new NCGI in a Notification Area (RNA) based on a radio access network is illustrated.

[0024] Fig.10 An exemplary block diagram is illustrated in which a target donor CU signals the location of an inactive UE to a last serving gNodeB (gNB).

[0025] Fig.11 is an exemplary flow chart for transmission of zone information.

[0026] Fig.12 is an exemplary flow chart for transmission of IAB-related information.

[0027] Fig.13 is an exemplary flow chart for transmission of context information.

[0028] Fig.14 is an exemplary flow chart for transmission of radio access network (RAN) region information.

[0029] Fig.15 is an exemplary flow chart for transmission of location information.

[0030] Fig.16 is an exemplary flow chart for receipt of context information.

[0031] Fig.17 is an exemplary flow chart for RAN-based transmission of Notification Area Update (RNAU) related information.

[0032] Fig.18 An exemplary block diagram of a hardware platform that may be part of a network device or a communication device is illustrated.

[0033] Fig.19 An exemplary wireless communication including a base station (BS) and a user equipment (UE) based on some implementations of the disclosed technology is illustrated. DETAILED DESCRIPTION

[0034] The example titles of the following sections are used to facilitate understanding of the disclosed subject matter and do not limit the scope of the claimed subject matter in any way. Therefore, one or more features of one example section can be combined with one or more features of another example section. In addition, for clarity of explanation, 5G terminology is used, but the technology disclosed in this document is not limited to 5G technology and can be used in wireless systems that implement other protocols.

[0035] I. Introduction

[0036] This patent document provides a technical solution to the Tracking Area Update (TAU) or Radio Access Network (RAN) Notification Area Update (RNAU) problem for UEs served by a mobile IAB node, etc., which attempts to reduce the number of area updates and ensure UE tracking reachability.

[0037] As the number of digital data applications and services continues to increase, the demands and challenges on network resources and operators will continue to increase. Being able to provide the wide range of network performance characteristics required by future services is one of the main technical challenges facing service providers today. The performance requirements placed on the network will require connectivity in terms of data rate, latency, QOS, security, availability and many other parameters, all of which will vary from service to service. Therefore, enabling the network to allocate resources in a flexible manner to provide customized connectivity for each different type of service will greatly enhance the network's ability to meet future demands.

[0038] To meet these demands, the development of fifth generation (5G) mobile wireless technologies and standards is well underway. One such technology is a split network architecture in which the Radio Access Network (RAN) functionality is split between a Central Unit (CU) and multiple Distributed Units (DUs). For example, the RAN functionality may be split between the Packet Data Convergence Protocol (PDCP) layer and the Radio Link Control (RLC) layer of the 5G protocol stack, where the DU will handle all processes including the RLC layer functionality, while the CU will handle the PDCP layer and higher layer functionality before the core network. This decomposition of RAN functionality will provide many advantages to mobile network operators. For example, by isolating the stack from the PDCP layer and above, the CU will be able to act as a cloud-based aggregation point between multiple heterogeneous technologies in the provisioned network, and will thereby be able to serve multiple heterogeneous DUs.

[0039] Another technology developed for 5G networks is the integrated access and backhaul (IAB) architecture, which is used to provide high-speed wireless backhaul to cell sites (e.g., base stations). As data demand and the number of cell sites increase, it becomes increasingly difficult to provide traditional fiber backhaul access to each cell site, especially for small cell sites. For example, under the IAB architecture, the same infrastructure and resources (e.g., IAB nodes) can be used to provide access and backhaul to support user equipment (UE) packet data unit (PDU) sessions. The IAB architecture for new radio (NR) networks will provide wireless backhaul and relay links to enable flexible and dense deployment of NR cells without densifying the transport network in proportion. In addition, the IAB technology will allow dense networks of self-backhauled NR cells to be more easily deployed in a more integrated and robust manner. For example, the IAB technology in 5G NR networks will support multi-hop relay systems where the network topology also supports redundant connections.

[0040] Figure 1 A block diagram of an IAB architecture network 100 is illustrated, wherein a core network 102 is connected to a donor IAB node 104. As used herein, the term "connection" refers to a wired or cable connection (e.g., a fiber optic cable) between two nodes or devices. The donor IAB node 104 is wirelessly coupled to a number of intermediate IAB nodes 106a and 106b and two serving IAB nodes 106c and 106d. As used herein, the term "coupling" refers to direct or indirect and wired or wireless communication between two nodes or devices.

[0041] like Figure 1 As shown, serving IAB nodes 106c and 106d are directly coupled to UEs 108a and 108b, respectively, and serve as serving cell site base stations or access points for UEs 108a and 108b. UEs 108a and 108b are referred to herein as "access UEs." Serving IAB nodes 106c and 106d also serve as repeaters and may forward their respective UE signals to their respective next uplink nodes in the transmission path and forward downlink signals to their respective UEs 108a and 108b. Figure 1 As shown, the serving IAB node 106c can forward uplink UE signals to one or both of the intermediate IAB nodes 106a and 106b, and receive downlink UE signals from one or both of the intermediate IAB nodes 106a and 106b. The intermediate IAB nodes 106a and 106b can forward uplink UE signals to the donor IAB node 104, and forward downlink signals to the serving IAB node 106d. The serving IAB node 106c can forward uplink UE signals to the donor IAB node 104, which can then forward all received signals to the core network 102, and can forward downlink signals from the donor IAB node 104 to the access UE 108a.

[0042] Each of the IAB nodes 106a-106d can have two functions: a base station (BS) function and a mobile terminal (MT) function. The BS function means that the IAB node can work like a base station to provide a radio access function for the UE. As used herein, the "BS part" of the IAB node refers to that part of the IAB node, including all hardware, firmware and / or software related to performing the BS function of the IAB node. The MT function means that the IAB node can work like a mobile terminal to be controlled and scheduled by an IAB donor node or an upper-level IAB node. As used herein, the "MT part" of the IAB node refers to that part of the IAB node, including all hardware, firmware and / or software related to performing the MT function of the IAB node.

[0043] Still refer to Figure 1 If network 100 also implements a split architecture, donor IAB node 104 will be replaced by a donor CU (not shown) connected to core network 102 and a donor DU (not shown) connected to the donor CU. Each of IAB nodes 106a-106d will be coupled to the donor DU in a similar manner as they are coupled to donor IAB node 104, such as Figure 1 shown.

[0044] In a split architecture network, each of the IAB nodes 106a-106d may have two functions: a DU function and a mobile terminal (MT) function. The DU function means that the IAB node can work like a DU to provide a predetermined DU function to the UE. As used herein, the "DU portion" of the IAB node refers to that portion of the IAB node that includes all hardware, firmware, and / or software related to performing the DU function of the IAB node. The MT function and MT portion of the IAB node in the split architecture network are the same as those of the non-split architecture network described above.

[0045] Based on the IAB architecture, a mobile IAB is proposed, which focuses on scenarios where a mobile IAB node installed on a vehicle provides 5G coverage / capacity enhancement for on-board and / or surrounding UEs. Specifically, the mobile IAB can be used in outdoor environments to improve 5G coverage or connectivity, whether following a specific known / predictable itinerary (e.g., bus, tram, etc.) or located at a convenient location (e.g., outside a stadium, hotspot, or emergency location). The mobile IAB node provides connectivity for users or devices inside the vehicle itself, and uses a 5G wireless backhaul toward the macro network. It is assumed that the mobile IAB can obtain better macro coverage than nearby UEs, for example by leveraging better RF / antenna and power capabilities.

[0046] Implementing Mobile IAB in 5G networks will bring many challenges. One such challenge is to reduce the location update signaling overhead for a group of UEs within a vehicle and the mobility of the Mobile IAB node.

[0047] For cellular systems, the RRC_IDLE state is introduced to save power. Generally speaking, the gNB broadcasts TAC (tracking area code) for each subset of PLMNs within the cell. Generally speaking, the TAC broadcast by the gNB is configured by OAM, and the corresponding tracking area is geostationary. The gNB will send the supported TAI (PLMN ID + TAC) list information of the serving cell to the AMF. Based on this information, the AMF can know the tracking area of ​​each cell. For the UE, when it is in the RRC_Connected state, it can be configured with a TAI (ie, registration area) list from the AMF. The AMF can consider the TAI in which the UE is geographically located to generate a suitable registration area for the UE.

[0048] When the UE enters the RRC_IDLE state, it does not need to perform HO when moving across different cells. Instead, the RRC_IDLE UE only needs to perform periodic registration area updates (RAU, also known as tracking area updates, i.e. TAU) for UE reachability tracking and event-triggered RAU for UE registration area tracking (i.e., when accessing a radio cell in which none of the supported TACs of the RPLMN or RPLMN equivalent is part of the UE registration area). On the other hand, when DL data arrives for the RRC_IDLE UE, the AMF can issue a paging message to all gNBs involved in the registration area of ​​the UE. After receiving the paging message from the AMF, the gNB can determine which cell should participate in the paging based on the TAI information. When the RRC_IDLE UE receives the paging message, the RRC_IDLE will enter the RRC_Connected state and prepare for DL ​​data reception.

[0049] On the other hand, in order to save power, the RRC_INACTIVE state is also introduced. The RRC_INACTIVE UE can be configured with a RAN Notification Area (RNA) by the last serving gNB. The RNA can cover one or more cells and should be a subset of the CN tracking area or equal to the CN tracking area. Specifically, the RNA can be configured via a list of cells or RAN area codes (RANAC) or TACs. On the other hand, the cell broadcasts a RAN area code in SIB1. Generally speaking, this RAN area code is configured by OAM.

[0050] RAN based Notification Area Update (RNAU) is issued by the UE periodically and also when the UE's cell reselection procedure selects a cell that is not part of the configured RNA. When the UE performs an RNAU, it can issue a RRCResumeRequest to the gNB to provide the I-RNTI assigned by the last serving gNB and an appropriate cause value, such as RAN Notification Area Update. If the gNB is able to resolve the gNB identity contained in the I-RNTI, the gNB can request the last serving gNB to provide the UE context. Finally, the UE can recover from RRC_INACTIVE to RRC_Connected / RRC_IDLE state or return to RRC_INACTIVE state. In addition, RAN paging can be triggered due to incoming DL user plane, DL signaling from 5GC, etc. In this case, RAN paging can be triggered in the cell controlled by the last serving gNB. In addition, it can be triggered by means of Xn RAN paging in cells controlled by other gNBs that are configured in the RNA to the UE. Assuming that the UE receives paging with its own I-RNTI, the UE attempts to recover from RRC_INACTIVE to RRC_CONNECTED.

[0051] For the mobile IAB scenario, the mobile IAB node moves with the vehicle and can cross different registration areas, such as Figure 2 As shown. The RAU in the mobile IAB scenario has to handle a large group of UEs and should be kept to a minimum. On the other hand, UE reachability should be ensured. Similar to the RAU, the RNAU in the mobile IAB scenario also involves a large group of UEs and should be avoided. On the other hand, UE reachability should be ensured. Examples of potential solutions attempt to address these issues.

[0052] II. Example 1

[0053] In this example, we focus on the RAU or TAU problem in a mobile IAB scenario.

[0054] Example 1.1

[0055] In this example, when the mobile IAB node performs HO from a source donor CU to a target donor CU, the TAC broadcasted by the mobile IAB node DU is always aligned with the parent DU or the target donor CU.

[0056] A passenger carries a UE and gets on a vehicle. The mobile IAB node is installed on the vehicle and provides access services for the onboard UE. When the vehicle moves, the mobile IAB node and the onboard UE also move. The mobile IAB node can perform a HO from the source parent DU1 to the target parent DU2. The source DU1 is connected to the source donor CU1, and the target DU2 is connected to the target CU2. The mobile IAB-MT can detect that the current TAI of the serving cell is not in the TAI list that the mobile IAB-MT receives from the AMF. In this case, the mobile IAB-MT determines that it is entering a new TA, and thereby performs a Tracking Area Update (TAU) procedure. During the TAU, the AMF will assign a set of new tracking areas in the TAI list to the mobile IAB-MT based on the current location of the mobile IAB-MT. On the other hand, the collocated mobile IAB-DU may change the broadcast TAC value to align with the TAC value broadcast by the target parent DU, such as Figure 3 shown.

[0057] Alternatively, the target donor CU2 may detect that the TAC of the cell served by the mobile IAB-DU is different from the TAC of all other served cells of the donor CU (e.g., via F1 establishment and gNB-DU configuration update procedures), and the donor CU may issue the new TAC per PLMN configuration to the mobile IAB-DU, such as Figure 4 As shown. The mobile IAB-DU may then broadcast a new TAC via SIB1. In this case, if the UE finds that the broadcast TAC of the served cell is not in the TAI list assigned by the UE's AMF, the UE served by the mobile IAB-DU may initiate a TAU procedure.

[0058] It should be noted that the mobile IAB node may perform only partial migration, i.e. the mobile IAB-MT performs HO from the source donor CU to the target donor CU, while the collocated IAB-DU and the descendant IAB node or UE maintain the connection with the source donor CU. In this case, since the mobile IAB-DU is still controlled by the source donor CU, the mobile IAB-DU does not need to change the TAC broadcasted via SIB1 to align with the target donor CU or target parent DU.

[0059] Example 1.2

[0060] In this example, the mobile IAB-DU does not change the TAC broadcasted by its served cell and retains the new donor CU of its served cell's TAC.

[0061] The mobile IAB-DU may be configured with TAC1 for the mobile IAB, and the mobile IAB-DU broadcasts the TAC1 in SIB1. TAC may be configured via OAM. Alternatively, Figure 5As shown, during the co-located mobile IAB-MT registration process, the TAC of the mobile IAB-DU can be received from the AMF. Afterwards, the served cell of the mobile IAB-DU broadcasts TAC1 in SIB1.

[0062] On the other hand, UE1 is connected to the network via a mobile IAB node and obtains a TAI list from the AMF during the registration process. The TAI list assigned by the UE's AMF should contain this TAC1. This means that the UE's AMF should know that the UE is served by a mobile IAB node. In fact, the donor CU can send user location information to the UE's AMF. The user location information sent by the donor CU to the AMF may include NCGI, TAC, and mobile IAB indication. After a period of time, UE1 enters the RRC_IDLE state.

[0063] Subsequently, the mobile IAB node performs a HO from the source donor CU1 to the target donor CU2. The mobile IAB-MT may detect that the target donor DU2 broadcasts TAC2. The mobile IAB-MT may then perform a mobility registration area update procedure to retrieve a new TAI list including TAC2. On the other hand, the mobile IAB-DU may send information about the served cell (including TAC1 and NCGI) to the target donor CU2 via the F1 establishment / gNB-DU configuration procedure. After receiving the served cell information from the mobile IAB node, the target donor CU2 may send the supported TA list (including TAC1) and NCGI information to the AMF via a RAN configuration update message. The AMF should then know that the TAC1 of the mobile IAB-DU is controlled by the target donor CU2.

[0064] Assuming that DL data of UE1 arrives, AMF needs to page UE1 served by the mobile IAB node within TAC1. AMF can send a paging message to the target donor CU2 involved in TAC1 of the mobile IAB-DU. Then, the target donor CU2 sends a paging message to the mobile IAB-DU that broadcasts TAC1. Finally, UE1 served by the mobile IAB-DU can receive the paging message and enter the RRC_Connected state to receive DL data. Since TAC1 broadcast by the mobile IAB-DU does not change with movement, the RRC_IDLE UE served by the mobile IAB-DU will not detect the TAC change and TAU can be avoided.

[0065] Example 1.3

[0066] In this example, a dedicated tracking area along the trajectory of the mobile IAB node is configured.

[0067] Assuming that the trajectory of the mobile IAB node is predictable, the potential parent DUs along the trajectory of the mobile IAB node can be pre-configured with a dedicated TAC for the mobile IAB (in addition to the dedicated TAC, other common TACs can also be configured for the parent DU), such as Figure 6 As shown. On the other hand, both the mobile IAB-DU and the mobile IAB node MT can be configured with a dedicated TAC for the mobile IAB, and the mobile IAB-DU broadcasts the dedicated TAC in SIB1. When the mobile IAB node performs a HO to the new target donor DU2, the mobile IAB-MT always detects that the current TAI of the serving cell is within the TAI list received by the mobile IAB-MT from the AMF. In this case, the mobile IAB-MT does not need to perform a tracking area update (TAU) procedure. Similarly, the mobile IAB-DU does not need to change its TAC broadcasted in the serving cell. Therefore, the UE served by the mobile IAB node does not detect the tracking area change, and the TAU can be avoided.

[0068] In order for the mobile IAB node to be configured with a dedicated TAC, the mobile IAB-MT can issue a mobile IAB indication to the AMF during the registration process. Based on the mobile IAB indication, the AMF can configure a TAI list to the mobile IAB-MT, which includes a dedicated TAC for the mobile IAB. For UEs served by mobile IAB nodes, the TAI list allocated by the UE's AMF should include the dedicated TAC. This means that the UE's AMF should know that the UE is served by a mobile IAB node, which can be achieved by the donor CU reporting user location information to the UE's AMF. In addition, the mobile IAB-MT can issue a mobile IAB indication to the donor CU. For UEs served by mobile IAB nodes, the donor CU can issue a mobile IAB indication as part of the UE's user location information. The AMF can take into account the TAI and / or mobile IAB indication in which the UE is geographically located to generate a suitable registration area for the UE.

[0069] III. Example 2

[0070] In this example, we focus on the RNAU problem in a mobile IAB scenario. RAN areas are defined in terms of RANAC.

[0071] Example 2.1

[0072] In this example, when the mobile IAB node performs HO from source donor CU1 to target donor CU2, the RANAC broadcasted by the mobile IAB node DU is always aligned with the parent DU or donor CU.

[0073] When the mobile IAB node performs a HO from the source parent DU1 to the target parent DU2, the mobile IAB-MT can detect that the RANAC of the cell of the target parent DU2 is different from the broadcast RANAC of the collocated mobile IAB-DU. In order to keep the UE reachability within the RAN area, the mobile IAB-DU can change the broadcast RANAC to keep aligned with the serving cell of the parent DU2.

[0074] On the other hand, when the mobile IAB node is connected to the target donor CU2, the mobile IAB-DU can send the served cell information (including NCGI, TAC and / or RANAC) to the target donor CU2 via the F1 establishment / gNB-DU configuration process. After receiving the served cell information of the mobile IAB node, the target donor CU2 can use the Xn interface to send the RANAC information of the served cell of the mobile IAB-DU to the neighboring donor CU.

[0075] The target donor CU2 may detect that the RANAC of the cell served by the mobile IAB-DU is different from the RANAC of all other served cells of the target donor CU2 (e.g., via the F1 establishment and gNB-DU configuration update procedures). In this case, the donor CU may consider that the RANAC is not supported, considering that the Xn connection with the last serving gNB of the mobile IAB node may not be available. Therefore, the target donor CU2 may not be able to retrieve the UE context configured with this RANAC, and the last serving gNB cannot deliver the RNA paging message to the new donor DU of the mobile IAB node. Based on this observation, the target donor CU2 preferably issues a new RANAC to the mobile IAB-DU for each PLMN configuration. And the mobile IAB-DU may broadcast the new RANAC for each PLMN configuration via SIB1.

[0076] In this case, if the UE finds that the broadcast RANAC of the served cell is different from the RANAC configured by the UE's last serving gNB, the RRC_INACTIVE UE served by the mobile IAB-DU can initiate the RNAU procedure. During the RNAU procedure, the context of the RRC_INACTIVE UE1 can be retrieved from the last serving gNB to the target donor CU2. After the RNAU procedure, the RRC_INACTIVE UE can be reconfigured with a new RANAC and the target donor CU2 becomes the last serving gNB.

[0077] Example 2.2

[0078] In this example, if the RANAC of the served cell of the mobile IAB-DU is the same as one of the RANACs of other served cells of the donor CU, the RANAC of the mobile IAB node DU remains unchanged.

[0079] When the mobile IAB node is connected to the new donor node, the mobile IAB-DU can send the served cell information (including NCGI, TAC and / or RANAC) to the new donor CU via the F1 establishment / gNB-DU configuration process. After receiving the served cell information of the mobile IAB node, the new donor CU can detect whether the RANAC of the served cell of the mobile IAB-DU is the same as one of the RANACs of other served cells of the donor CU. In this case, the new donor CU can consider the RANAC to be supported. The new donor CU does not need to request the mobile IAB node to change the RANAC configuration. It only needs to use the Xn interface to send the RANAC information of the served cell of the mobile IAB-DU to the adjacent donor CU.

[0080] Example 2.3

[0081] In this example, the RANAC of the mobile IAB node DU remains unchanged throughout. The context of the RRC_INACTIVE UE is transferred to the target gNB during the HO of the mobile IAB node.

[0082] Considering that the mobile IAB mode moves with the vehicle, it is recommended that the RRC_IDLE / INACTIVE UE remains camped on the served cell of the mobile IAB node during the mobility process. Based on this observation, a specific RAN area including the served cell of the mobile IAB node DU can be defined.

[0083] If the UE moves from a non-mobile node to a mobile IAB node, the RANAC or NCGI is likely not within the previous RAN area configured at the UE. In this case, the UE can perform RNAU and be configured with a new RAN area;

[0084] If the UE moves from a mobile node to a non-mobile node, the RANAC or NCGI is likely not in the previous RAN area configured at the UE. In this case, the UE can perform RNAU and be configured with a new RAN area;

[0085] If the UE moves from a mobile node to another mobile node, the RANAC or NCGI is also likely not within the previous RAN area configured at the UE. In this case, the UE can perform RNAU and be configured with a new RAN area for the new mobile node;

[0086] It is recommended to reduce RNAU for UEs on vehicles only when the UEs move with the mobile node.

[0087] It is assumed that the RAN area of ​​a specific mobile IAB node is defined based on the RANAC and the served cells of the mobile IAB node broadcast the RANAC. For an RRC_INACTIVE UE served by a mobile IAB node, it is not necessary to perform RNAU when it moves within the coverage area of ​​the mobile IAB node. However, when the RRC_INACTIVE UE moves out of the mobile IAB node, it needs to perform RNAU because the RAN area of ​​the mobile IAB node and other fixed nodes are different. To support UE reachability, when the mobile IAB node performs a HO from the source gNB to the target gNB, it is recommended that the source gNB send the UE context of the RRC_INACTIVE UE to the target gNB, such as Figure 8 As shown. In addition, a path switch of the RRC_INACTIVE UE from the source donor CU1 to the target donor CU2 should be performed. In this way, the RRC_INACTIVE UE is always reachable via the mobile IAB node.

[0088] Regarding the RANAC configuration of the mobile IAB node, it can be configured through OAM or received from the AMF or gNB-CU.

[0089] Example 2.4

[0090] Assuming that the trajectory of the mobile IAB node is predictable, potential parent DUs along the trajectory of the mobile IAB node may be pre-configured with a dedicated RANAC for the mobile IAB node (in addition to the dedicated RANAC, other ordinary RANACs may also be configured for the parent DU). On the other hand, the mobile IAB node DU may be configured with a dedicated RANAC for the mobile IAB, and the mobile IAB node DU broadcasts the dedicated RANAC in SIB1. When the mobile IAB node performs HO to a new target parent DU, the mobile IAB node MT always detects that the current RANAC of the serving cell is the same as the RANAC of the collocated mobile IAB node DU received from the AMF. In this case, the mobile IAB node DU does not need to change the RANAC broadcasted in its served cell. Therefore, the UE served by the mobile IAB node does not detect the RNA change, and RNAU can be avoided.

[0091] IV. Example 3

[0092] In this example, we focus on the RNAU problem in a mobile IAB scenario. The RAN area is defined based on a list of cells.

[0093] Example 3.1

[0094] Assuming that the RAN area is defined based on a cell list and the UE is configured with a cell list for RNA when entering the RRC_INACTIVE state, the UE served by the mobile IAB node DU can detect the NCGI change of the mobile IAB node DU when the mobile IAB node performs HO. The new NCGI of the mobile IAB node DU is likely not included in the cell list of the UE's RNA, and the RRC_INACTIVE UE served by the mobile IAB node DU will perform the RNAU procedure. In order to reduce unnecessary RNAU for RRC_INACTIVE UEs, the following options can be considered.

[0095] The UE initially connects to the network via a mobile IAB node. After a period of time, the gNB-CU sends an RRC release message to the UE and requests the UE to enter the RRC_INACTIVE state. The RRC release message includes RAN area information. In addition, the RRC release message may include a mobile IAB RAN area indication, such as Fig. 9 As shown. Based on the mobile IAB RAN area indication, when the NCGI of the served cell of the mobile IAB node changes, the RRC_INACTIVE UE will perform a replacement of the NCGI in the cell list of the RAN area.

[0096] Assuming that the mobile IAB node performs a HO from source donor DU1 / CU1 to target donor DU2 / CU2, and the mobile IAB node DU is allocated / configured with a new NCGI for its served cell, the served cell of the mobile node DU may broadcast the change of NCGI from old to new via SIB. After receiving the NCGI change, the UE served by the cell of the mobile IAB node DU replaces the old NCGI with the new NCGI in the cell list of its RAN area, e.g. Figure 8 In addition, the UE does not perform RNAU.

[0097] From the perspective of the source donor CU1, during the HO preparation process of the mobile IAB node, it can send the UE context of the RRC_INACTIVE UE served by the mobile node DU to the target donor CU2 of the mobile IAB node. In addition, path switching should be performed, and the NG path should be switched from the source donor CU1 to the target donor CU2. In this way, when the DL data of the RRC_INACTIVE UE arrives at the UPF, it can be delivered to the target donor CU2 currently serving the mobile IAB node DU. Then, the target donor CU2 can deliver the RAN paging message to the mobile IAB node DU, and the mobile IAB node DU broadcasts the RAN paging message to the RRC_INACTIVE UE.

[0098] Example 3.2

[0099] The context of the RRC_INACTIVE UE is stored in the last serving gNB (i.e., source donor CU1) of the RRC_INACTIVE UE served by the mobile IAB node. When the mobile IAB node performs a HO from the source donor CU1 to the target donor CU2, the source donor CU1 sends the I-RNTI of the RRC_INACTIVE UE served by the mobile IAB node to the target donor CU2 during the HO preparation process, as shown in Fig.10 If the target donor CU2 can identify the last serving gNB of the RRC_INACTIVE UE based on the I-RNTI, and there is an Xn connection between the target donor CU2 and the last serving gNB, the target donor CU2 can send the location information of the RRC_INACTIVE UE (such as gNB ID, I-RNTI, NCGI, etc.) to the last serving gNB, as shown in FIG. Fig.10 Later, when the last serving gNB needs to page the RRC_INACTIVE UE, the last serving gNB is able to issue a RAN paging message to the current serving gNB of the RRC_INACTIVE UE residing on the mobile IAB node.

[0100] On the other hand, if the target donor CU2 cannot identify the last serving gNB of the RRC_INACTIVE UE based on the I-RNTI, or there is no Xn connection between the target donor CU2 and the last serving gNB, the target donor CU2 may also request the source gNB to obtain the context of the RRC_INACTIVE UE from the last serving gNB and send it to the target donor CU2. In addition, the target donor CU2 may request a path switch for the RRC_INACTIVE UE from the last serving gNB to the target donor CU2.

[0101] In addition, if the target donor CU2 cannot identify the last serving gNB of the RRC_INACTIVE UE based on I-RNTI, or there is no Xn connection between the target donor CU2 and the last serving gNB, the target donor CU2 may do nothing. Later, when the RRC_INACTIVE UE performs RNAU, the target donor CU2 may ask the UE to establish a new RRC connection. Alternatively, when the DL data of the RRC_INACTIVE UE reaches the last serving gNB, the last serving gNB may not be able to reach the RRC_INACTIVE UE, and CN paging will be triggered to reach the RRC_INACTIVE UE.

[0102] Example 3.3

[0103] The gNB or mobile IAB node DU may issue an RNAU disable or enable indication via system information. The gNB may also issue an indication of RNAU that a given RNAC is disabled via RRC release signaling. In addition, the gNB-CU may issue an RNAU disable indication to the mobile IAB node DU. When the RRC_INACTIVE UE receives such an indication, it does not perform RNAU. This indicates that the current gNB or gNB-CU has retrieved the UE context of the RRC_INACTIVE UE served by the mobile IAB node. The RRC_INACTIVE UE does not need to perform RNAU even if the NCGI changes. On the other hand, if the RRC_INACTIVE UE moves to a cell that does not broadcast an RNAU disable indication, and the RRC_INACTIVE UE detects a RAN area change, the RRC_INACTIVE UE should perform RNAU. In addition, if the RRC_INACTIVE UE moves to a cell that broadcasts an RNAU disable indication, and the configured RAN area of ​​the RRC_INACTIVE UE does not allow disabling of RNAU, the RRC_INACTIVE UE still needs to perform RNAU when necessary.

[0104] Example 3.4

[0105] Assuming that the NGCI of the served cell of the mobile IAB node DU is configured specifically, it will not cause NCGI conflict and does not need to change with the gNB ID of the donor CU. In this case, when the RAN area is configured with the help of a cell list, the RRC_INACTIVE UE served by the mobile IAB node DU will not detect the RAN area change because the NCGI is included in the cell list of the RAN area. Therefore, RNAU will not be triggered due to the RAN area change.

[0106] When the mobile IAB node performs HO from the source gNB to the target gNB, the source gNB sends the I-RNTI of the RRC_INACTIVE UE served by the mobile IAB to the target gNB during the HO preparation process. On the other hand, the target gNB can send the location information (such as gNB ID, I-RNTI, NCGI, etc.) of the RRC_INACTIVE UE to the last serving gNB. Later, when the last serving gNB needs to page the RRC_INACTIVE UE, the last serving gNB is able to send a RAN paging message to the current serving gNB of the RRC_INACTIVE UE residing on the mobile IAB node.

[0107] If the target gNB cannot identify the last serving gNB of the RRC_INACTIVE UE based on I-RNTI, or there is no Xn connection between the target gNB and the last serving gNB, the target gNB may do nothing. Later, when the RRC_INACTIVE UE performs RNAU, the target gNB may ask the UE to establish a new RRC connection. Alternatively, when the DL data of the RRC_INACTIVE UE reaches the last serving gNB, the last serving gNB may not be able to reach the RRC_INACTIVE UE, and CN paging will be triggered to reach the RRC_INACTIVE UE.

[0108] Fig.11 is an exemplary flow chart for transmission of zone information. Operation 1102 includes receiving zone information by an integrated access and backhaul (IAB) node. Operation 1104 includes broadcasting zone information by the IAB node. In some embodiments, the method may be implemented according to Example 1.1.

[0109] In some embodiments, receiving the area information comprises receiving the area information from a donor central unit (CU), an IAB donor, a gNodeB (gNB), or an access and mobility management function (AMF). In some embodiments, the area information comprises at least one of: a cell identity, a tracking area code (TAC), public land mobile network (PLMN) information, and a radio access network area code (RANAC). In some embodiments, the TAC comprises an old TAC or a new TAC, and the RANAC comprises an old RANAC or a new RANAC.

[0110] Fig.12 is an exemplary flow chart for transmission of IAB-related information. Operation 1202 includes sending, by an integrated access and backhaul (IAB) entity, IAB-related information. In some embodiments, the method may be implemented according to Example 1.2.

[0111] In some embodiments, the IAB entity includes an IAB donor or an IAB node. In some embodiments, issuing the IAB related information includes issuing the IAB related information to the IAB donor or an access and mobility management function (AMF). In some embodiments, the IAB related information includes at least one of the following: a new radio cell global identifier (NCGI), a tracking area code (TAC), and a mobile IAB indication.

[0112] Fig.13 is an exemplary flow chart for transmission of context information. Operation 1302 includes sending, by a network function, context information associated with an inactive wireless device. In some embodiments, the method may be implemented according to Example 2.3.

[0113] In some embodiments, the method further comprises: initiating, by the network function, a handover or migration procedure for an integrated access and backhaul (IAB) node serving or hosted by the inactive wireless device before sending the context information. In some embodiments, the method further comprises: performing, by the network function, a path switching procedure for the inactive wireless device. In some embodiments, the network function comprises a gNodeB (gNB) or a gNB central unit (CU). In some embodiments, issuing the context information comprises issuing the context information to another network function comprising a gNB or a gNB CU.

[0114] Fig.14 is an exemplary flow chart for transmission of radio access network (RAN) region information. Operation 1402 includes transmitting, by a radio access network (RAN) node, RAN region information. In some embodiments, the method may be implemented according to Example 2.4.

[0115] In some embodiments, the RAN node comprises a gNodeB (gNB) or an integrated access and backhaul (IAB) donor. In some embodiments, issuing the RAN area information comprises issuing the RAN area information to the wireless device. In some embodiments, the RAN area information comprises at least one of: a RAN area code (RANAC), a tracking area code (TAC), a cell list, and a mobile IABRAN area indication.

[0116] Fig.15 is an exemplary flow chart for transmission of location information. Operation 1502 includes receiving, by a network function, an inactive radio network temporary identifier (I-RNTI) associated with a wireless device. Operation 1504 includes sending, by a network function, location information associated with the wireless device. In some embodiments, the method may be implemented according to Example 3.2.

[0117] In some embodiments, the network function includes a target integrated access and backhaul (IAB) donor of an IAB node serving the wireless device. In some embodiments, receiving the I-RNTI includes receiving the I-RNTI from a source IAB donor. In some embodiments, issuing the location information includes issuing the location information to a gNodeB (gNB) indicated by the I-RNTI. In some embodiments, the location information includes at least one of: a gNB identity, an I-RNTI, a new radio cell global identifier (NCGI), and a physical cell identity (PCI).

[0118] Fig.16is an exemplary flow chart for receiving context information. Operation 1602 includes receiving, by a network function, an inactive radio network temporary identifier (I-RNTI) associated with a wireless device. Operation 1604 includes sending, by a network function, a context retrieval request indication. Operation 1606 includes receiving, by a network function, context information associated with a wireless device. In some embodiments, the method may be implemented according to Example 3.2.

[0119] In some embodiments, the network function includes a target integrated access and backhaul (IAB) donor of an IAB node serving the wireless device. In some embodiments, receiving the I-RNTI includes receiving the I-RNTI from a source IAB donor, and issuing the context retrieval request indication includes issuing the context retrieval request indication to the source IAB donor. In some embodiments, the context retrieval request indication includes at least one of an identity of the wireless device and the I-RNTI. In some embodiments, receiving the context information includes receiving the context information from a source IAB donor or a gNodeB (gNB) indicated by the I-RNTI.

[0120] Fig.17 is an exemplary flow chart for transmission of RAN-based Notification Area Update (RNAU) related information. Operation 1702 includes sending, by a network function, a Radio Access Network-based Notification Area Update (RNAU) related indication. In some embodiments, the method may be implemented according to Example 3.3.

[0121] In some embodiments, the network function includes a gNodeB (gNB), an integrated access and backhaul (IAB) donor, an IAB central unit (CU), or an IAB distributed unit (DU). In some embodiments, issuing an RNAU-related indication includes issuing an RNAU-related indication to a wireless device. In some embodiments, issuing an RNAU-related indication includes issuing an RNAU-related indication via system information, radio resource control (RRC) signaling, or a media access control (MAC) control element (CE). In some embodiments, issuing an RNAU-related indication includes issuing an RNAU-related indication to an IAB node. In some embodiments, issuing an RNAU-related indication includes issuing an RNAU-related indication via F1 signaling, an RRC message, a MAC CE, or a backhaul adaptation protocol (BAP) layer information. In some embodiments, the RNAU-related indication includes an enable indication or a disable indication.

[0122] Apparatus configured or operable to perform the above-described methods are within the scope and spirit of this patent document.

[0123] In some embodiments, the above method is embodied in the form of processor executable code and stored in a non-transitory computer readable storage medium. The code included in the computer readable storage medium causes the processor to implement the method described in this patent document when executed by the processor.

[0124] Fig.18 An exemplary block diagram of a hardware platform 1800 is shown, which may be part of a network device (e.g., a base station) or a communication device (e.g., a user equipment (UE)). The hardware platform 1800 includes at least one processor 1810 and a memory 1805 having instructions stored thereon. The instructions, when executed by the processor 1810, configure the hardware platform 1800 to perform Figures 1 to 17 The operations described in the various embodiments described in and in this patent document. Transmitter 1815 sends or issues information or data to another device. For example, a network device transmitter can send a message to a user device. Receiver 1820 receives information or data sent or issued by another device. For example, a user device can receive a message from a network device. For example, as described in this document, an IAB node, an IAB entity, a network function, a RAN node can be implemented using hardware platform 1800.

[0125] The implementation described above will be applied to wireless communications. Fig.19 An example of a wireless communication system (e.g., a 5G or NR cellular network) including a base station 1920 and one or more user equipment (UE) 1911, 1912, and 1913 is illustrated. In some embodiments, the UE uses a communication link to the network (sometimes referred to as an uplink direction, as shown by dashed arrows 1931, 1932, 1933) to access the BS (e.g., the network), which then enables subsequent communication from the BS to the UE (e.g., shown in the direction from the network to the UE, sometimes referred to as a downlink direction, as shown by arrows 1941, 1942, 1943). In some embodiments, the BS sends information to the UE (sometimes referred to as a downlink direction, as shown by arrows 1941, 1942, 1943), which then enables subsequent communication from the UE to the BS (e.g., shown in the direction from the UE to the BS, sometimes referred to as an uplink direction, as shown by dashed arrows 1931, 1932, 1933). The UE can be, for example, a smart phone, a tablet, a mobile computer, a machine-to-machine (M2M) device, an Internet of Things (IoT) device, etc. The network functions, IAB nodes, and IAB entities described in this document may be communicatively coupled via base station 1920 (e.g., as Figure 1 shown) to Fig.19 UE described in .

[0126] In this document, the term "exemplary" is used to mean "an example of," and not to indicate an ideal or preferred embodiment unless otherwise stated.

[0127] Some of the embodiments described herein are described in the general context of methods or processes, which in one embodiment can be implemented by a computer program product embodied in a computer-readable medium, which includes computer-executable instructions, such as program code, executed by a computer in a networked environment. Computer-readable media may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), compact disk (CD), digital versatile disk (DVD), etc. Therefore, computer-readable media may include non-transitory storage media. Typically, program modules may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. Computer or processor executable instructions, associated data structures, and program modules represent examples of program codes for executing the steps of the methods disclosed herein. A specific sequence of such executable instructions or associated data structures represents an example of corresponding actions for implementing the functions described in such steps or processes.

[0128] Some of the disclosed embodiments may be implemented as devices or modules using hardware circuits, software, or a combination thereof. For example, a hardware circuit implementation may include discrete analog and / or digital components that are, for example, integrated as a part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as application specific integrated circuits (ASICs) and / or field programmable gate arrays (FPGAs) devices. Some implementations may additionally or alternatively include a digital signal processor (DSP), which is a dedicated microprocessor with an architecture optimized for the operational requirements of digital signal processing associated with the disclosed functions of the present application. Similarly, various components or subcomponents within each module may be implemented with software, hardware, or firmware. The connection between the modules and / or components within the modules may be provided using any of the connection methods and media known in the art, including but not limited to communications using appropriate protocols over the Internet, wired, or wireless networks.

[0129] Although this document contains a lot of details, these details should not be interpreted as limitations on the scope of the claimed invention or the content that can be claimed, but rather as descriptions of the features of a particular embodiment. Certain features described in this document in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working in certain combinations, and even initially claimed as such, in some cases, one or more features from the claimed combination may be deleted from the combination, and the claimed combination may involve a sub-combination or a variant of a sub-combination. Similarly, although operations are described in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in sequence or requiring all the operations shown to be performed to obtain the desired result.

[0130] Only a few implementations and examples are described, and other implementations, enhancements, and variations may be made based on what is described and illustrated in this disclosure.

Claims

1. A wireless communication method, comprising: receiving the zone information by an integrated access and backhaul (IAB) node; as well as The area information is broadcasted by the IAB node.

2. The method of claim 1, wherein receiving the region information comprises: The area information is received from a donor central unit (CU), an IAB donor, a gNodeB (gNB), or an access and mobility management function (AMF).

3. The method according to any one of claims 1 and 2, wherein the area information comprises at least one of the following: a cell identity, a tracking area code (TAC), public land mobile network (PLMN) information, and a radio access network area code (RANAC). 4 . The method of claim 3 , wherein the TAC comprises an old TAC or a new TAC, and wherein the RANAC comprises an old RANAC or a new RANAC.

5. A wireless communication method, comprising: The IAB related information is sent by the Integrated Access and Backhaul (IAB) entity. The method of claim 5 , wherein the IAB entity comprises an IAB Donor or an IAB Node.

7. The method according to any one of claims 5 and 6, wherein sending the IAB-related information comprises: The IAB related information is sent to the IAB donor or access and mobility management function (AMF).

8. The method according to any one of claims 5 to 7, wherein the IAB-related information comprises at least one of: a New Radio Cell Global Identifier (NCGI), a Tracking Area Code (TAC), and a Mobile IAB Indication.

9. A wireless communication method, comprising: Context information associated with the inactive wireless device is sent by the network function.

10. The method according to claim 9, further comprising: A handover or migration procedure is initiated by the network function for an integrated access and backhaul (IAB) node serving the inactive wireless device or where the inactive wireless device resides before sending the context information.

11. The method according to any one of claims 9 and 10, further comprising: A path switching process is performed by the network function for the inactive wireless device.

12. The method according to any one of claims 9 to 11, wherein the network function comprises a gNodeB (gNB) or a gNB central unit (CU).

13. The method according to any one of claims 9 to 12, wherein issuing the context information comprises: The context information is sent to another network function including a gNB or a gNB CU.

14. A wireless communication method, comprising: The Radio Access Network (RAN) area information is sent by the RAN node.

15. The method of claim 14, wherein the RAN node comprises: gNodeB (gNB) or Integrated Access and Backhaul (IAB) Donor.

16. The method according to any one of claims 14 and 15, wherein issuing the RAN area information comprises: The RAN area information is sent to the wireless device.

17. The method according to any one of claims 14 to 16, wherein the RAN area information comprises at least one of: a RAN area code (RANAC), a tracking area code (TAC), a cell list, and a mobile IAB RAN area indication.

18. A wireless communication method, comprising: receiving, by a network function, an inactive radio network temporary identifier (I-RNTI) associated with a wireless device; as well as Location information associated with the wireless device is sent by the network function.

19. The method of claim 18, wherein the network function comprises: A target integrated access and backhaul (IAB) donor of an IAB node serving the wireless device.

20. The method according to any one of claims 18 and 19, wherein receiving the I-RNTI comprises: The I-RNTI is received from a source IAB donor.

21. The method according to any one of claims 18 to 20, wherein issuing the location information comprises: The location information is sent to the gNodeB (gNB) indicated by the I-RNTI.

22. The method according to any one of claims 18 to 21, wherein the location information comprises at least one of the following: a gNB identity, an I-RNTI, a new radio cell global identifier (NCGI), and a physical cell identity (PCI).

23. A wireless communication method, comprising: receiving, by a network function, an inactive radio network temporary identifier (I-RNTI) associated with a wireless device; Sending a context retrieval request indication by the network function; as well as Context information associated with the wireless device is received by the network function.

24. The method of claim 23, wherein the network functions include: A target integrated access and backhaul (IAB) donor of an IAB node serving the wireless device.

25. The method according to any one of claims 23 and 24, wherein receiving the I-RNTI comprises: The I-RNTI is received from a source IAB donor, and wherein issuing the context retrieval request indication comprises issuing the context retrieval request indication to the source IAB donor.

26. The method according to any one of claims 23 to 25, wherein the context retrieval request indication comprises: At least one of an identity of the wireless device and the I-RNTI.

27. The method of any one of claims 23 to 26, wherein receiving the context information comprises: The context information is received from a source IAB donor or gNodeB (gNB) indicated by the I-RNTI.

28. A wireless communication method, comprising: Radio access network based Notification Area Update (RNAU) related indications are sent by the network function.

29. The method of claim 28, wherein the network function comprises: gNodeB (gNB), Integrated Access and Backhaul (IAB) Donor, IAB Central Unit (CU), or IAB Distributed Unit (DU).

30. The method according to any one of claims 28 and 29, wherein issuing the RNAU-related indication comprises: The RNAU-related indication is sent to the wireless device.

31. The method according to any one of claims 28 to 30, wherein issuing the RNAU-related indication comprises: The RNAU-related indication is sent via system information, radio resource control (RRC) signaling, or medium access control (MAC) control element (CE).

32. The method according to any one of claims 28 and 29, wherein issuing the RNAU-related indication comprises: Send the RNAU related indication to the IAB node.

33. The method according to any one of claims 28, 29 and 32, wherein issuing the RNAU-related indication comprises: The RNAU related indication is issued via F1 signaling, RRC message, MAC CE or backhaul adaptation protocol (BAP) layer information.

34. The method of any one of claims 28 to 33, wherein the RNAU-related indication comprises: Enable indication or disable indication.

35. A wireless communication device comprising a processor, wherein the processor is configured to implement the method according to any one of claims 1 to 34.

36. A computer-readable program storage medium having codes stored thereon, which, when executed by a processor, cause the processor to implement the method according to any one of claims 1 to 34.

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