Connection resume for user equipment released to inactive by wireless access backhaul node

Abstract

A method is provided that includes providing a radio network service to at least one user equipment (UE) by a mobile wireless access backhaul (MWAB) node having context information associated with the UE(s). The method includes sending a release message from the MWAB node to the UE(s) to trigger the UE(s) to transition to an inactive state. The method includes making a determination at the MWAB node to release a network interface connection with one or more radio access nodes. And based on the determination, the method includes forwarding the context information associated with the UE(s) triggered to transition to the inactive state by the MWAB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the UE(s).

Description

CONNECTION RESUME FOR USER EQUIPMENT RELEASED TO INACTIVE BY WIRELESS ACCESS BACKHAUL NODETECHNOLOGICAL FIELD

[0001] The present disclosure relates generally to telecommunications and, in particular, to wireless access backhaul in a telecommunications system.BACKGROUND

[0002] A telecommunications system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and / or other nodes by providing carriers between the various entities involved in the communications path. A telecommunications system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email), text message, multimedia and / or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

[0003] In a wireless telecommunications system at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems comprise public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). Some wireless systems can be divided into cells, and are therefore often referred to as cellular systems.

[0004] A user can access the telecommunications system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and / or receive communications on the carrier.

[0005] The telecommunications system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entitiesassociated with the system are permitted to do and how that should be achieved. Communication protocols and / or parameters which shall be used for the connection are also typically defined. One example of a telecommunications system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunications systems are Long-Term Evolution (LTE), LTE Advanced and the so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP).BRIEF SUMMARY

[0006] Example implementations of the present disclosure are directed to telecommunications and, in particular, to wireless access backhaul (WAB) in a telecommunications system. More specifically, example implementations relate to resuming a connection of a user equipment released to an inactive state by a mobile WAB (MWAB) node. The present disclosure includes, without limitation, the following example implementations.

[0007] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; send a release message from the MWAB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; make a determination at the MWAB node to release a network interface connection with one or more radio access nodes; and based on the determination, forward the context information associated with the at least one user equipment triggered to transition to the inactive state by the MWAB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0008] Some example implementations provide an apparatus comprising: means for providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; means for sending a release message from the MWAB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; means for making a determination at the MWAB node to release a network interface connection with one or more radio access nodes;and based on the determination, means for forwarding the context information associated with the at least one user equipment triggered to transition to the inactive state by the MWAB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0009] Some example implementations provide a method comprising: providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; sending a release message from the MWAB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; making a determination at the MWAB node to release a network interface connection with one or more radio access nodes; and based on the determination, forwarding the context information associated with the at least one user equipment triggered to transition to the inactive state by the MWAB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0010] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; send a release message from the MWAB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; make a determination at the MWAB node to release a network interface connection with one or more radio access nodes; and based on the determination, forward the context information associated with the at least one user equipment triggered to transition to the inactive state by the MWAB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0011] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one userequipment, the MWAB node served over a wireless backhaul by a radio access node; make a determination at the MWAB node to send the at least one user equipment to an inactive state; and based on the determination, carry out a handover procedure to hand over each user equipment of the at least one user equipment from the MWAB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0012] Some example implementations provide an apparatus comprising: means for providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; means for making a determination at the MWAB node to send the at least one user equipment to an inactive state; and based on the determination, means for carrying out a handover procedure to hand over each user equipment of the at least one user equipment from the MWAB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0013] Some example implementations provide a method comprising: providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; making a determination at the MWAB node to send the at least one user equipment to an inactive state; and based on the determination, carrying out a handover procedure to hand over each user equipment of the at least one user equipment from the MWAB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0014] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; make a determination at the MWAB node to send the atleast one user equipment to an inactive state; and based on the determination, carry out a handover procedure to hand over each user equipment of the at least one user equipment from the MWAB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0015] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: receive context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MWAB) node served over a wireless backhaul by a radio access node; receive a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state; determine the context information is available without retrieving the context information from the MWAB node; and provide the continued radio network service to the user equipment based on the context information.

[0016] Some example implementations provide an apparatus comprising: means for receiving context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MWAB) node served over a wireless backhaul by a radio access node; means for receiving a request to provide a continued radio network service to an user equipment of the at least one user equipment in the inactive state; means for determining the context information is available without retrieving the context information from the MWAB node; and means for providing the continued radio network service to the user equipment based on the context information.

[0017] Some example implementations provide a method comprising: receiving context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MWAB) node served over a wireless backhaul by a radio access node; receiving a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state; determining the context information is available without retrieving the context information from the MWAB node; and providing the continued radio network service to the user equipment based on the context information.

[0018] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least oneprocessing circuitry, causes an apparatus to at least: receive context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MWAB) node served over a wireless backhaul by a radio access node; receive a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state; determine the context information is available without retrieving the context information from the MWAB node; and provide the continued radio network service to the user equipment based on the context information.

[0019] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: receive a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNU) assigned to the user equipment by a mobile wireless access backhaul (MWAB) node that sent the user equipment to the inactive mode; determine a network node other than the MWAB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNU; retrieve the context information from the network node based on the I-RNU; and provide the continued radio network service to the user equipment based on the context information.

[0020] Some example implementations provide an apparatus comprising: means for receiving a request to provide a continued radio network service to an user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNU) assigned to the user equipment by a mobile wireless access backhaul (MWAB) node that sent the user equipment to the inactive mode; means for determining a network node other than the MWAB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNU; means for retrieving the context information from the network node based on the I-RNU; and means for providing the continued radio network service to the user equipment based on the context information.

[0021] Some example implementations provide a method comprising: receiving a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNU) assigned to the user equipment by a mobile wireless access backhaul (MWAB) node that sent the user equipment to the inactive mode; determining a network node other than the MWAB node storing context information associated with the user equipment to enable the continued radio network service, the networknode determined based on the I-RNU; retrieving the context information from the network node based on the I-RNU; and providing the continued radio network service to the user equipment based on the context information.

[0022] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: receive a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNU) assigned to the user equipment by a mobile wireless access backhaul (MWAB) node that sent the user equipment to the inactive mode; determine a network node other than the MWAB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNU; retrieve the context information from the network node based on the I-RNTI; and provide the continued radio network service to the user equipment based on the context information.

[0023] These and other features, aspects, and advantages of the present disclosure will be apparent from a reading of the following detailed description together with the accompanying figures, which are briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined or otherwise recited in a specific example implementation described herein. This disclosure is intended to be read holistically such that any separable features or elements of the disclosure, in any of its aspects and example implementations, should be viewed as combinable unless the context of the disclosure clearly dictates otherwise.

[0024] It will therefore be appreciated that this Brief Summary is provided merely for purposes of summarizing some example implementations so as to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above described example implementations are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. Other example implementations, aspects and advantages will become apparent from the following detailed description taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of some described example implementations.BRIEF DESCRIPTION OF THE FIGURE(S)

[0025] Having thus described example implementations of the disclosure in general terms, reference will now be made to the accompanying figures, which are not necessarily drawn to scale, and wherein:

[0026] FIG. 1 illustrates a telecommunications system that includes one or more public land mobile networks (PLMNs) coupled to one or more external data networks, according to some example implementations of the present disclosure;

[0027] FIG. 2 illustrates a deployment of a PLMN, according to some example implementations;

[0028] FIG. 3 illustrates a deployment of a PLMN including multiple radio access nodes, according to some example implementations;

[0029] FIG. 4 illustrates a deployment of wireless access backhaul in relation to a serving network, according to some example implementations;

[0030] FIGS. 5Aand 5B illustrate a signaling chart of procedures of a UE sent to an inactive state by a mobile wireless access backhaul (MWAB) node that forwards UE context information to a radio access node at which the UE returns to a connected state, according to some example implementations;

[0031] FIGS. 6A and 6B illustrate a signaling chart of procedures of a UE sent to an inactive state by a MWAB node that forwards UE context information to one or more radio access nodes having a network interface connection with the MWAB node, and at one of which the UE returns to a connected state, according to some example implementations;

[0032] FIGS. 7A and 7B illustrate a signaling chart of procedures of a UE sent to an inactive state by a MWAB node that forwards UE context information to radio access nodes in a notification area of the UE, and at one of which the UE returns to a connected state, according to some example implementations;

[0033] FIGS. 8 A, 8B and 8C illustrate a signaling chart of procedures of a UE sent to an inactive state by a MWAB node that forwards UE context information to an anchor node from which the UE context information is retrieved by a radio access node at which the UE returns to a connected state, according to some example implementations;

[0034] FIGS. 9A, 9B, 9C and 9D illustrate a signaling chart of procedures of a UE sent to an inactive state by a MWAB node that forwards UE context information to an anchor node from which the UE context information is retrieved by a radio access node at which the UE returns to a connected state, according to other example implementations;

[0035] FIGS. 10A, 10B and IOC illustrate a signaling chart of procedures for a MWAB node sending a UE to an inactive state, and forwarding the UE context to an anchor node with at least one condition on which the UE context may be discarded or otherwise released, according to other example implementations;

[0036] FIGS. 11 A and 1 IB illustrate a signaling chart of procedures for a MWAB node handing off a UE to a radio access node before the UE is sent to an inactive state, and the UE returning to a connected state with the radio access node, according to other example implementations;

[0037] FIGS. 12, 13, 14 and 15 are flowchart illustrating various steps in methods according to various example implementations

[0038] FIG. 16 illustrates an apparatus according to some example implementations.DETAILED DESCRIPTION

[0039] Some implementations of the present disclosure will now be described more fully hereinafter with reference to the accompanying figures, in which some, but not all implementations of the disclosure are shown. Indeed, various implementations of the disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these example implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0040] Unless specified otherwise or clear from context, references to first, second or the like should not be construed to imply a particular order. A feature described as being above another feature (unless specified otherwise or clear from context) may instead be below, and vice versa; and similarly, features described as being to the left of another feature else may instead be to the right, and vice versa. Also, while reference may be made herein to quantitative measures, values, geometric relationships or the like, unless otherwise stated, any one or more if not all of these may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances or the like.

[0041] As used herein, unless specified otherwise or clear from context, the “or” of a set of operands is the “inclusive or” and thereby true if and only if one or more of the operands is true, as opposed to the “exclusive or” which is false when all of the operands are true. Thus, for example, “[A] or [B]” is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Further, the articles “a” and “an” mean “one or more,” unless specified otherwise or clear fromcontext to be directed to a singular form. Furthermore, it should be understood that unless otherwise specified, the terms “data,” “content,” “digital content,” “information,” and similar terms may be at times used interchangeably. The term “network” may refer to a group of interconnected computers including clients and servers; and within a network, these computers may be interconnected directly or indirectly by various means including via one or more switches, routers, gateways, access points or the like.

[0042] Reference may be made herein to terms specific to a particular system, architecture or the like, but it should be understood that example implementations of the present disclosure may be equally applicable to any of a number of systems, architectures and the like. For example, reference may be made to 3 GPP technologies such as Global System for Mobile Communications (GSM), UMTS, LTE, LTE Advanced, 5GNR, 5G Advanced and 6G; however, it should be understood that example implementations of the present disclosure may be equally applicable to non-3GPP technologies such as IEEE 802, Bluetooth and Bluetooth Low Energy.

[0043] Further, as used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry); (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions); or (c) hardware circuit(s) and / or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0044] The above definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0045] FIG. 1 illustrates a telecommunications system 100 according to various example implementations of the present disclosure. The telecommunications system generally includesone or more telecommunications networks. As shown, for example, the system includes one or more public land mobile networks (PLMNs) 102 coupled to one or more other external data networks 104 - notably including a wide area network (WAN) such as the Internet. Each of the PLMNs includes a core network (CN) 106 backbone such as the Evolved Packet Core (EPC) of LTE, the 5G core network (5GC) or the like; and each of the core networks and the Internet are coupled to one or more radio access networks (RANs) 108, air interfaces or the like that implement one or more radio access technologies (RATs). As used herein, a “network device” refers to any suitable device at a network side of a telecommunications network. Examples of suitable network devices are described in greater detail below.

[0046] In addition, the system includes one or more radio units that may be varyingly known as user equipment (UE) 110, terminal device, terminal equipment, mobile station or the like. The UE is generally a device configured to communicate with a network device or a further UE in a telecommunications network. The UE may be a portable computer (e.g., laptop, notebook, tablet computer), mobile phone (e.g., cell phone, smartphone), wearable computer (e.g., smartwatch), or the like. In other examples, the UE may be an Internet of things (loT) device, an industrial loT (IIoT device), a vehicle equipped with a vehicle-to-everything (V2X) communication technology, or the like. In some examples, as referenced by 3 GPP, the UE may be a narrowband loT (NB- loT) device, an enhanced machine-type communication (eMTC) device, a reduced capability (RedCap) device, an ambient loT device, or the like.

[0047] In operation, these UEs 110 may be configured to connect to one or more of the RANs 108 according to their particular radio access technologies to thereby access a particular CN 106 of a PLMN 102, or to access one or more of the external data networks 104 (e.g., the Internet). The external data network may be configured to provide Internet access, operator services, 3rd party services, etc. For example, the International Telecommunication Union (ITU) has classified 5G mobile network services into three categories: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine type communications (mMTC) or massive internet of things (MIoT).

[0048] Examples of radio access technologies include 3 GPP radio access technologies such as GSM, UMTS, LTE, LTE Advanced, 5G NR, 5G Advanced, and 6G. Other examples of radio access technologies include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee) and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), ultra wideband (UWB), and the like. Generally, a radio access technology may refer to any 2G, 3G, 4G, 5G, 6G or higher generation mobile communicationtechnology and their different versions, as well as to any other wireless radio access technology that may be arranged to interwork with such a mobile communication technology to provide access to the CN 106 of a mobile network operator (MNO).

[0049] In various examples, a RAN 108 may be configured as one or more macrocells, microcells, picocells, femtocells or the like. The RAN may generally include one or more radio access nodes that are configured to interact with UEs 110. In various examples, a radio access node may be referred to as a base station (BS), access point (AP), base transceiver station (BTS), Node B (NB), evolved NB (eNB), macro BS, NB (MNB) or eNB (MeNB), home BS, NB (HNB) or eNB (HeNB), next generation NB (gNB), enhanced gNB (en-gNB), next generation eNB (ng- eNB), or the like. The RAN may include some type of network controlling / governing entity responsible for control of the radio access nodes. The network controlling / governing entity and radio access node may be separate or integrated into a single apparatus. The network controlling / governing entity may include processing circuity configured to carry out various management functions, etc. The processing circuity may be associated with a memory, computer- readable storage medium or database for maintaining information required in the management functions.

[0050] ARAN 108 may be centralized or distributed. In various examples, components of a RAN may be interconnected by Ethernet, Gigabit Ethernet, Asynchronous Transfer Mode (ATM), optical fiber, dark fiber, passive wavelength division multiplexing (WDM), WDM passive optical network (WDM-PON), optical transport network (OTN), time sensitive networking (TSN) and / or any other data link layer network, possibly including radio links. The RAN may be connected to a CN 106 through one or more gateways, network functions or the like.

[0051] As will be appreciated, a PLMN 102 may be deployed in a number of different manners. In a 4GLTE deployment, the EPC is the CN 106, and the evolved UMTS terrestrial radio access network (E-UTRAN) is the RAN 108; and the E-UTRAN includes one or more eNBs (radio access nodes) configured to connect UEs 110 to the E-UTRAN to thereby access the EPC. FIG. 2 illustrates a deployment 200, such as a 5G or 6G deployment. As shown, the 5GC 202 is the CN, and the next generation (NG) radio access network (NG-RAN) 204 is the RAN; and the NG-RAN includes one or more NG-RAN nodes 206 (radio access nodes) configured to connect UEs 208 to the NG-RAN to thereby access the 5GC (at times referred to as the NGC). In this context, a NG-RAN node may be a gNB or a ng-eNB. The term ‘gNB’ in 5G may correspond to the eNB in 4G LTE.

[0052] Some deployments of 4G LTE and 5G in particular are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5 G technologies, and are referred to as non-standalone (NSA) deployments. In some deployments, the E-UTRAN includes one or more ng-eNBs that are configured to communicate with the 5GC, and that may also be configured to communicate with one or more gNBs. Similarly, in another deployment, the NG-RAN may include one or more en-gNBs that are configured to communicate with the EPC, and that may also be configured to communicate with one or more eNBs. In various instances, a single UE 208, a dual-mode or multimode UE, may support multiple (two or more) RANs — thereby being configured to connect to multiple RANs, such as 4G LTE and 5G.

[0053] In some deployments, operations of a radio access node (e.g., NG-RAN node 206) may be distributed or functionally split into components including one or more remote radio head (RRHs) or radio units (RUs), and a baseband unit (BBU); and in some architectures, the BBU may be split into a distributed unit (DU) and a central / centralized unit (CU), such as a server, host or node. In some architectures, the RRH / RU and DU may be collocated. It is also possible that node operations may be distributed among a plurality of servers, hosts or nodes.

[0054] It should also be understood that the distribution of work between core network operations and radio access node operations may vary depending on implementation. Thus, a 5G network architecture may be based on a so-called CU-DU split. One gNB-CU (central node) may control one or more gNB-DUs. The gNB-CU may control a plurality of spatially separated gNB- DUs, acting at least as transmit / receive (Tx / Rx) nodes. In some example implementations, however, the gNB-DUs (also called DU) may include, for example, a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU (also called a CU) may include the layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC), and an internet protocol (IP) layer. Other functional splits are also possible. It is considered that skilled person is familiar with the OSI model and the functionalities within each layer.

[0055] In some example implementations, the server or CU may generate a virtual network through which the server communicates with the radio node. In general, virtual networking may involve a process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Such virtual network may provide flexible distribution of operations between the server and the radio head / node. In practice, any digital signal processing task may be performed in either the CU orthe DU, and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation.

[0056] Although only one NG-RAN node 206 is shown in FIG. 2, the deployment may include multiple NG-RAN nodes. FIG. 3 illustrates an example including multiple NG-RAN nodes 206 connected to one another by a network interface, such as an Xn interface. The Xn interface may be used for various purposes such as in UE context retrieval, handover procedures, interference co-ordination, load balancing / management, and the like. Similarly, the NG-RAN nodes may be connected to the 5GC 202 by a network interface. As also shown, in 5GNR, the network interface between a NG-RAN node and the CN is referred to as the NG interface, which is a network interface between the NG-RAN node and network functions of the 5GC, including an access and mobility management function (AMF) / user plane function (UPF) 302.

[0057] The network interface between the NG-RAN node 206 and the 5GC 202 may support the exchange of signaling messages between the NG-RAN 204 and the 5GC. The signaling messages may be formatted according to an application layer protocol, such as the NG application protocol (NGAP) for the NG interface. The NGAP supports a number of procedures, comprising elementary procedures, such as to establish, maintain or release the RAN part of a communication session between a UE 208 and external data network 104 (referred to in 5GNR as a packet data unit (PDU) session), perform handover of a UE, and the like.

[0058] As specified by 3 GPP, the RRC layer of the 5G radio protocol stack is responsible for various control functions such as synchronization, connection establishment and its management, facilitating security and reliable messaging, radio resource management, signaling handling, dedicated and broadcast network configuration management, mobility procedures paging notification.

[0059] The operation of the RRC is guided by a state machine which defines certain specific states that a UE 208 may be present in. The different states in the RRC state machine have different amounts of radio resources associated with them and these are the resources that the UE may use when the UE is present in each state. Since different amounts of resources are available at different states, the quality of the service that the user experiences and the energy consumption of the UE are influenced by this state machine. Relative to previous generations, 5GNR supplemented RRC IDLE and RRC CONNECTED states by an RRC INACTIVE state, which offers light connectivity with major power saving methods integrated into the state.

[0060] A UE 208 may at times be in an RRC IDLE state with respect to a NG-RAN node 208, and a connection management (CM)-IDLE state with respect to an AMF in the 5GC 202.The UE may carry out procedures with the NG-RAN node to setup and reconfigure an RRC connection, during which the UE may transition from RRC IDLE to RRC CONNECTED. The UE may also establish a control plane signaling connection with the AMF, and transition from CM-IDLE to CM-CONNECTED. These procedures may include a configuration of radio bearers (e.g., SRB2), lower layer configurations (e.g., PHY, MAC, RLC, PDCP configuration parameters) and any RRC specific configuration for a given feature (with a list of related parameters). AUE context at the serving NG-RAN node may also be established.

[0061] The UE context generally includes context information associated with the UE 208 (at times referred to as “UE context information” or more simply “UE context”), which may be used by the serving NG-RAN node 206 to maintain a radio network service provided by the serving NG-RAN node towards the UE. The UE context may include, for example, PDU session context, security key(s), mobility restriction list, UE radio capability, UE security capabilities, and the like. The UE context may also include other information that supports the UE in RRC INACTIVE. This other information may include, for example, the UE access stratum (AS) security context, at least one resume MAC identifier (ResumeMAC-I)) / short resume MAC identifier (shortResumeMAC-I), associated security keys (e.g., KNG-RAN*, Kg\i>>), and the like.

[0062] After a certain data activity (which may be timer-based), the RRC connection may be released to transition the UE 208 from the RRC CONNECTED state to the RRC IDLE state. Alternatively, the serving NG-RAN node 206 may send the UE to the RRC INACTIVE state in which the UE may move freely across different cells within its RAN notification area (RNA) without needing an RRC connection.

[0063] The serving NG-RAN node 206 may send the UE 208 to RRC INACTIVE by an RRC release message. The UE receiving an RRC release message may ‘suspend’ some selected configurations to re-activate them during an RRC resume procedure. The RRC release message received by the UE may also include an inactive radio network temporary identifier (I-RNTI) assigned to the UE by the serving NG-RAN node 206. In some examples, the I-RNU is partitioned into a NG-RAN specific part that identifies the serving NG-RAN node, and a UE- specific part identifies the UE context stored by the serving NG-RAN node. In some examples, the I-RNU is partitioned in three parts, further including a part that indicates a length of the NG- RAN specific part identifying the serving NG-RAN node.

[0064] The UE 208 in the RRC INACTIVE state may carry out an RRC connection resume procedure to resume a connection with its last serving NG-RAN node 206 or another NG-RAN node, and thereby transition back to RRC CONNECTED. During this procedure, the UE maysend an RRC resume request message to a new serving NG-RAN node, and include the I-RNTI assigned by the UE’s last serving NG-RAN node. The I-RNU may be used by the new serving NG-RAN node to identify both the UE and the last serving NG-RAN node storing the UE context. If the new serving NG-RAN node is able to resolve the identity of the last serving NG- RAN node contained in the I-RNU, the new serving NG-RAN node may retrieve the UE context from the last serving gNB, such as over an Xn interface connection between the NG-RAN nodes. Notably, the UE in the INACTIVE state may remain CM-CONNECTED with the AMF.

[0065] One area of further development of the 5G topology is wireless access backhaul (WAB). In deployments with WAB, there is usually a NG-RAN node serving WAB node, also known as donor NG-RAN node 206, connected to the 5GC 202 (e.g., AMF / UPF 302), and that can connect UEs 208 to the network. In a WAB scenario, the donor NG-RAN node also connects wirelessly via a NR backhaul (BH) link to one or more WAB nodes, which are typically mobile and referred to at times as mobile WAB (MWAB) nodes. The MWAB node includes a mobile termination (MT) function (at times referred to as a (M)WAB-MT or (M)WAB-UE) to support the NR BH link to the donor NG-RAN node. The MWAB node also includes a full gNB (gNB- DU and gNB-CU) to provide radio network service to one or more UEs. The MWAB node may therefore operate as a relay to UE(s). In one contemplated scenario, a MWAB node may be a vehicle-mounted relay that provides access for UEs onboard a vehicle (e.g., aircraft, cruise ship).

[0066] FIG. 4 illustrates a deployment 400 of WAB in relation to a serving network, according to some example implementations. As shown, a MWAB node 402 includes a full gNB 404 (at times referred to as a (M)WAB-gNB) configured to provide radio network service (NR access) to one or more UEs 208. The MWAB node also includes a MT 406 configured to provide the radio connection for a NR BH link to a donor NG-RAN node, shown for example as a donor gNB 408. The donor gNB in turn connects to a an AMF 410 and UPF 412 in the 5GC 202. A BH connection for the MWAB-gNB may be provided by a BH PDU session 414 established for the WAB-MT to the serving network. The WAB-gNB NG interfaces (for both control and user plane) may be transparently forwarded through the serving network. AUE connected to the MWAB node may see a cell provided by the MWAB node as a normal cell, and for UE-to-UE communication, the UE may establish its own UE PDU session 416 to another UE across its UPF 418 in the 5GC. The WAB deployment may therefore be transparent to UEs without a need for enhancements to legacy UEs.

[0067] The WAB deployment 400 is similar to integrated access and backhaul (IAB), except that while a IAB node is typically stationary, a MWAB node may be mobile. An IAB node alsoonly has gNB-DU functionality, with gNB-CU functionality provided by the donor. The MWAB mode includes a full gNB 404 with both gNB-DU and gNB-CU functionality. This means that a MWAB-gNB may send UEs 208 to RRC INACTIVE independent of the donor. In cases in which a MWAB node moves away or is otherwise becomes unavailable, a new serving NG-RAN node 206 with which the UE resumes an RRC connection may be unable to reach the MWAB node to retrieve the UE context. This may be because the Xn interface between the MWAB-gNB and new serving NG-RAN node is lost or has been released, or that the MWAB node is in a coverage hole or facing failure. It may also mean that the MWAB node is at the border of the UE’s RNA. In these cases in which the UE context cannot be retrieved from the MWAB to resume the RRC connection, the RRC connection must be setup again similar to the UE in RRC IDLE, defeating the purpose of RRC INACTIVE.

[0068] Example implementations of the present disclosure provide solutions for resuming a RRC connection of a UE 208 released to RRC INACTIVE by a MWAB node 402. According to some example implementations, the MWAB node may be configured to send an RRC release message to one or more UEs to trigger the UE(s) to transition to an inactive state. The MWAB node may determine to forward the UE context information associated with the UE(s) triggered to transition to the inactive state to one or more NG-RAN nodes 206 or a shared database at which the UE context information may be stored to enable a continued radio network service to the UE(s). These NG-RAN nodes(s) may include the donor gNB 408 and / or other NG-RAN nod(s) 206 in an RNA of the UE(s) 208. In some examples, the UE context information may be forwarded based on a determination by the MWAB node to release an Xn interface connection with the NG-RAN node(s).

[0069] In some examples, the UE context information may be forwarded with information that indicates at least one condition on which the UE context information may be releasable by the one or more NG-RAN node(s) 206 or the shared database. The NG-RAN node(s) or shared database may then release the UE context information when the condition(s) is satisfied.

[0070] In some examples, the UE context information may be forwarded to the NG-RAN nodes(s) 206 to enable the NG-RAN nodes(s) to provide the continued radio network service. In other some examples, the UE context information may be forwarded to the NG-RAN nodes(s) including an anchor NG-RAN node (e.g., donor gNB 408) from which the UE context information may be retrievable by another NG-RAN node to enable the other NG-RAN node to provide the continued radio network service to the UE(s). Similarly, the UE context informationmay be forwarded to the shared database from which the UE context information may be retrievable by the other NG-RAN node 206.

[0071] As indicated above, the MWAB node 402 may be configured to assign an I-RNTI to the UE(s) 208, and the RRC release message to the UE(s) may include the I-RNU for the UE(s) to use in a request for the continued radio network service with another NG-RAN node 206.

[0072] In some example implementations, the I-RNU identifies the UE context information and the MWAB node. The MWAB node has a second Xn interface connection with the other NG- RAN node 206. In some of these examples, the MWAB node 402 may be configured to send a Xn interface connection release message to the other NG-RAN node 206 with which the MWAB node has an Xn interface connection. And in this message, the MWAB node may include identifiers (IDs) of the MWAB node (MWAB ID) and the anchor NG-RAN node (e.g., donor gNB ID) to enable the other NG-RAN node to retrieve the UE context information based on the I-RNU and the IDs.

[0073] In other examples, the UE context information may be forwarded to the anchor NG- RAN node (e.g., donor gNB 408) from which the MWAB ID and the anchor NG-RAN node ID (e.g., donor gNB ID) are sent to the other NG-RAN node 206 to enable the other NG-RAN node 206 to retrieve the UE context information based on the I-RNU and the IDs.

[0074] In other examples, the release message sent to the UE(s) 208, and the request sent from the UE(s) to the other NG-RAN node 206, may include both the I-RNU and the anchor NG-RAN node ID (e.g., donor gNB ID). This may enable the other NG-RAN node 206 to retrieve the UE context information based on the I-RNTI and the anchor NG-RAN node ID.

[0075] In yet other examples, the MWAB node 402 may assign an I-RNU to the UE(s) 208 that identifies the UE context information and the anchor NG-RAN node (e.g., donor gNB 408) or the shared database from which the UE context information may be retrievable. In particular, for example, the NG-RAN specific part of the I-RNU may identify the anchor NG-RAN node or the shared database by its respective ID.

[0076] According to some other example implementations, the MWAB node 402 may be configured to make a determination to send the UE(s) to RRC INACTIVE. Based on this determination, the MWAB node may be configured to carry out a handover procedure to hand over each UE from the MWAB node to the donor gNB 408 or another NG-RAN node 206. This may include the MWAB node configured to forward the context information to the donor gNB / other NG-RAN node from which an RRC release message may be sent to the UE(s) to trigger the UE(s) to transition to RRC INACTIVE. In this regard, during the handover, the MWAB nodemay be configured to send a cause for the handover to the donor gNB / other NG-RAN node, and the cause may include a request for the donor gNB / other NG-RAN node to send the UE(s) to RRC INACTIVE.

[0077] To further illustrate the above and other example implementations of the present disclosure, FIGS. 5 A and 5B illustrate a signaling chart 500 of procedures of a UE 208 sent to RRC INACTIVE by a MWAB node 402 that forwards UE context information to a NG-RAN node at which the UE returns to a connected state, according to some example implementations. In the illustrated signaling chart, a donor gNB 408 may be made an anchor node for UE context stored at an MWAB node 402. It should be understood, however, another NG-RAN node 206 may instead be made the anchor node for the UE context. In some examples, then, the anchor node may be selected based on a number of different factors, such as measurements from the UE 206, Xn interface availability, or the like.

[0078] As shown in FIG. 5A, a MWAB-MT 406 of a MWAB node 402 is connected to a donor gNB 408 and being served by a cell of the donor gNB, and a UE 208 is at step 501 in RRC CONNECTED state and being served by the MWAB-gNB 404. The MWAB node is being served over a NR BH by the donor gNB. An Xn interface is also established between the MWAB-gNB and the donor gNB.

[0079] The MWAB node 402 at step 502 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE. One or more cell provided by the donor gNB 408 are in the RNA of UE. The MWAB-gNB 404 assigns an I-RNTI, and provides the I-RNTI to the UE while releasing to inactive. The MWAB node may also inform the core network to stop delivery of data to the MWAB node for the UE by providing a transport network layer (TNL) identifier (ID) just before or after sending the UE to inactive. Upon receiving RRC release message, the UE at step 503 switches its RRC state from RRC CONNECTED to RRC INACTIVE.

[0080] The MWAB node 402 at step 504 decides to release its Xn interface connection with the donor gNB 408. The MWAB node may decide to release this Xn interface connection for a number of reasons, including that the MWAB node is moving away. In some example implementations, the donor gNB may instead decide to release the Xn interface connection with the MWAB node.

[0081] As the UE 208 had been released to RRC INACTIVE and the RNA of the UE includes the donor gNB cell(s), the MWAB node 402 at step 505 proactively makes the UE context and other relevant information available at the donor gNB 408 via a Xn release request,which may instead be made available via a Xn release response when initiated by the donor gNB 408. In particular, for example, the information made available may include UE context information (also including UE 5G AS security context) and associated I-RNTI. The information may also include the TNL ID used by the MWAB node 402 for the UE.

[0082] In some examples, the information made available by the MWAB node 402 may include at least one ResumeMAC-I / shortResumeMAC-I for at least one cell of the donor gNB 408 (considering the cell(s) as targets(s)). In other examples, the information may include parameters to enable calculation of at least one ResumeMAC-I / shortResumeMAC-I at the donor gNB. These parameters may include, for example, a key KRRCint, source (herein MWAB) physical cell identity (PCI), source (herein MWAB) cell radio network temporary identifier (C-RNTI), and / or an integrity algorithm in the stored UE AS security context.

[0083] The information made available by the MWAB node 402 may also include a key KNG- RAN* for at least one cell of the donor gNB 408 (considering the cell(s) as targets(s)), or parameters to enable calculation of KNG-RAN* at the donor gNB. These parameters may include, for example, KgNB (for horizontal key derivation) of the MWAB node 402. In case vertical key derivation is to be used for generating the KNG-RAN*, the next hop (NH) parameter may be provided to the donor gNB by the AMF 410.

[0084] Even further, in some examples, the information made available by the MWAB node 402 may include one or more parameters that enable RAN paging by the donor gNB 408. These parameters may include, for example, a MWAB cell configuration and one or more parameters to calculate one or more paging occasions for the UE 208.

[0085] As shown in FIG. 5B, the MWAB-gNB 404 of the MWAB node 402 at step 506 sends UE context and other relevant information (for the UE 208 sent to RRC INACTIVE) to the donor gNB 408 in a Xn release request. Upon receipt of the information, the donor gNB may perform a number of tasks. In some examples, the donor gNB may use the TNL ID to send a request to the core network on behalf of the MWAB node to stop delivery of user data for the UE at the MWAB node (alternative to action of the MWAB node in step 501). This may avoid a waste of data sent to the MWAB node, release of the Xn interface connection may prevent the data being forwarded. The donor gNB may also use the TNL ID in a path switch request to change the user data path with the AMF 410.

[0086] As another task, when the Xn interface connection (between the MWAB node 402 and the donor gNB 408) is released, the donor gNB may distribute its gNB ID and associated I-RNTI of the UE 208 sent to inactive, to any one or more if not all NG-RAN nodes 206 of the RNA asthe UE may resume the connection in any cell of the RNA at any time. This may enable retrieval of the UE context from the donor gNB.

[0087] The donor gNB 408 at step 507 sends an Xn release response to the MWAB-gNB 404 of the MWAB node 402. The Xn release response may in some examples include acknowledgement of receipt of the UE context and other relevant information for the UE 208 sent in step 506. After a certain time, then, the MWAB node at step 508 moves away, at which point the Xn interface connection with the donor gNB is either released or lost.

[0088] Also after a certain time, the UE 208 at step 509 camps in a cell provided by the donor gNB 408. In some examples, UE resumes may be due to some uplink data arrival. As shown at step 510, then, resuming of the suspended RRC connection may be initiated at the cell of donor gNB. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC-I / shortResumeMAC-I in a RRC resume request. The donor gNB may then map the UE context to the UE using provided I-RNTI.

[0089] In examples in which a ResumeMAC-I / shortResumeMAC-I is shared in steps 505 and 506, the donor gNB 408 may also verify authenticity of the UE 208 by comparing it to one provided by the UE. In other examples in which parameters to calculate ResumeMAC-I / shortResumeMAC-I are instead shared, the donor gNB may first calculate the ResumeMAC-I / shortResumeMAC-I and then verify the authenticity of the UE. This verification is oftentimes done by the source node that sent the UE to RRC INACTIVE, but here performed by the target node.

[0090] Since the UE context and other relevant information for the UE 208 are already available at the donor gNB 408 (made available at steps 505 and 506), so further fetching of the UE context from the MWAB node 402 is not required.

[0091] The cell of the donor gNB 408 at step 511 sends a RRC resume request to the UE 208. The key KNG-RAN* (made available in steps 505 and 506) may be used for protection of RRC messages after the RRC resume request.

[0092] Upon receipt of RRC resume request, the UE 208 at step 512 transitions from RRCINACTIVE to RRC CONNECTED. The donor gNB 408 and the UE 208 at step 513 complete the resumption of the RRC connection. And the donor gNB at steps 514 and 515 performs a path switch with the AMF 410 (if not done in step 506).

[0093] FIGS. 6A and 6B illustrate a signaling chart 600 of procedures of a UE 208 sent to an inactive state by a MWAB node 402 that forwards UE context information to one or more NG- RAN nodes having an Xn network interface connection with the MWAB node, and at one ofwhich the UE returns to a connected state, according to some example implementations. As shown in FIG. 6A, a MWAB-MT 406 of a MWAB node is connected to a donor gNB 408 and being served by a cell of the donor gNB, and a UE is at step 601 in RRC CONNECTED state and being served by the MWAB-gNB 404. The MWAB node is being served over a NR BH by the donor gNB. An Xn interface is also established between the MWAB-gNB and the donor gNB, as well as between the MWAB-gNB and one or more other NG-RAN nodes including a first NG- RAN node (NG-RAN 1) 206A, and perhaps also a second NG-RAN node (NG-RAN 2) 206B.

[0094] The MWAB node 402 at step 602 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE. One or more cell provided by the donor gNB 408 are in the RNA of UE. The MWAB-gNB 404 assigns an I-RNTI, and provides the I-RNTI to the UE while releasing to inactive. The MWAB node may also inform the core network to stop delivery of data to the MWAB node for the UE by providing a TNL ID just before or after sending the UE to inactive. Upon receiving RRC release message, the UE at step 603 switches its RRC state from RRC CONNECTED to RRC INACTIVE.

[0095] The MWAB node 402 at step 604 decides to release its Xn interface connection with the donor gNB 408 / other NG-RAN node(s) 206A, 206B. The MWAB node may decide to release its Xn interface connection(s) for a number of reasons, including that the MWAB node is moving away. In some example implementations, the donor gNB or other NG-RAN node(s) may instead decide to release its Xn interface connection with the MWAB node.

[0096] As the UE 208 had been released to RRC INACTIVE, and the MWAB node 402 has Xn interface connections with the donor gNB 408 and other NG-RAN node(s) 206A, 206B, the MWAB node 402 at step 605 proactively makes the UE context and other relevant information available at one or more if not all of the NG-RAN nodes with which the MWAB node has an Xn interface connection. This information may be made available via a Xn release request, or a Xn release response when initiated by the donor gNB / other NG-RAN node. In particular, for example, the information made available may include UE context information (also including UE 5G AS security context) and associated I-RNTI. As explained above, the information may also include the TNL ID used by the MWAB node for the UE, at least one ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), KNG-RAN* (or parameters to calculate), parameter(s) that enable RAN paging by the donor gNB / other NG-RAN node(s), and the like.

[0097] The MWAB-gNB 404 of the MWAB node 402 at step 606 sends UE context and other relevant information (for the UE 208 sent to RRC INACTIVE) to the donor gNB 408 and other NG-RAN node(s) 206A, 206B, such as in a Xn release request. The donor gNB and other NG-RAN node(s) send an Xn release response to the MWAB-gNB. The Xn release response may in some examples include acknowledgement of receipt of the UE context and other relevant information for the UE 208 sent in step 606.

[0098] In some examples, the UE context and other relevant information may only be sent by the MWAB-gNB 404 to those of the other NG-RAN node(s) 206A, 206B that do not have an Xn interface connection with the donor gNB 408, which may be determined by filtering by the donor gNB. This may save resources at NG-RAN nodes where the UE 208 is less likely to resume its suspended RRC connection; and those NG-RAN node(s) with an Xn interface connection with the donor gNB may retrieve the UE context and other relevant information from the donor gNB as an anchor for that information.

[0099] As shown in FIG. 6B, after a certain time, the MWAB node at step 607 moves away, at which point its Xn interface connections with the donor gNB and other NG-RAN node(s) 206A, 206B are either released or lost.

[0100] Also after a certain time, the UE 208 at step 608 camps in a cell provided by the first NG-RAN node 206A. In some examples, UE resumes may be due to some uplink data arrival. As shown at step 609, then, resuming of the suspended RRC connection may be initiated at the cell of first NG-RAN node. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC-I / shortResumeMAC-I in a RRC resume request. The first NG-RAN node may then map the UE context to the UE using provided I-RNTI.

[0101] In examples in which a ResumeMAC-I / shortResumeMAC-I is shared in steps 605 and 606, the first NG-RAN node 206A may also verify authenticity of the UE 208 by comparing it to one provided by the UE. In other examples in which parameters to calculate ResumeMAC-I / shortResumeMAC-I are instead shared, the first NG-RAN node may first calculate the ResumeMAC-I / shortResumeMAC-I and then verify the authenticity of the UE. Again, this verification is oftentimes done by the source node that sent the UE to RRC INACTIVE, but here performed by the target node.

[0102] As shown at step 610, since the UE context and other relevant information for the UE 208 are already available at the first NG-RAN node 206A (made available at steps 605 and 606), so further fetching of the UE context from the MWAB node 402 is not required.

[0103] The cell of the first NG-RAN node 206A at step 611 sends a RRC resume request to the UE 208. The key KNG-RAN* (made available in steps 605 and 606) may be used for protection of RRC messages after the RRC resume request.

[0104] Upon receipt of RRC resume request, the UE 208 at step 612 transitions from RRC INACTIVE to RRC CONNECTED. The first NG-RAN node 206A and the UE 208 at step 613 compl ete the resumption of the RRC connection. And the first NG-RAN node at steps 614 and 615 performs a path switch with the AMF 410, such as using the TNL ID provided by the MWAB-gNB 404 at steps 605 and 606.

[0105] FIGS. 7 A and 7B illustrate a signaling chart 700 of procedures of a UE 208 sent to an inactive state by a MW AB node 402 that forwards UE context information to NG-RAN nodes in an RNA of the UE, and at one of which the UE returns to a connected state, according to some example implementations. As shown in FIG. 7A, a M AB-MT 406 of a MW AB node is connected to a donor gNB 408 and being served by a cell of the donor gNB, and a UE is at step 701 in RRC CONNECTED state and being served by the MWAB-gNB 404. The MW AB node is being served over a NR BH by the donor gNB. An Xn interface is also established between the MWAB-gNB and the donor gNB, as well as between the MWAB-gNB and other NG-RAN nodes including a first NG-RAN node (NG-RAN 1) 206A and a second NG-RAN node (NG-RAN 2) 206B. One or more (or perhaps all) cells of the other NG-RAN nodes are in the RNA of the UE.

[0106] The MW AB node 402 at step 702 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE. The MW AB node may also inform the core network to stop delivery of data to the MW AB node for the UE by providing a TNL ID just before or after sending the UE to inactive. Upon receiving RRC release message, the UE at step 703 switches its RRC state from RRC CONNECTED to RRC INACTIVE.

[0107] The MW AB node 402 at step 704 decides to release its Xn interface connection with the donor gNB 408 / other NG-RAN node(s) 206A, 206B. The MWAB node may decide to release its Xn interface connection(s) for a number of reasons, including that the MWAB node is moving away. In some example implementations, the donor gNB or other NG-RAN node(s) may instead decide to release its Xn interface connection with the MWAB node.

[0108] As the UE 208 had been released to RRC INACTIVE, and the MWAB node 402 has Xn interface connections with the donor gNB 408 and other NG-RAN node(s) 206A, 206B, the MWAB node 402 at step 705 proactively makes the UE context and other relevant information available at all of the NG-RAN nodes in the RNA of the UE. In examples in which the MWAB lacks an established Xn interface connection with any of the NG-RAN nodes in the RNA, the MWAB may first establish an Xn interface connection before the information is made available. This information may be made available via a Xn release request, or a Xn release response wheninitiated by the donor gNB / other NG-RAN node. In particular, for example, the information made available may include UE context information (also including HE 5G AS security context) and associated I-RNTI. As explained above, the information may also include the TNL ID used by the MW AB node for the UE, at least one ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), KNG-RAN* (or parameters to calculate), parameter(s) that enable RAN paging by the donor gNB / other NG-RAN node(s), and the like.

[0109] The MWAB-gNB 404 of the MW AB node 402 at step 706 sends UE context and other relevant information (for the UE 208 sent to RRC INACTIVE) to the donor gNB 408 and other NG-RAN node(s) 206A, 206B, such as in a Xn release request. The donor gNB and other NG-RAN node(s) send an Xn release response to the MWAB-gNB. The Xn release response may in some examples include acknowledgement of receipt of the UE context and other relevant information for the UE 208 sent in step 706.

[0110] In some examples, the UE context and other relevant information may only be sent by the MWAB-gNB 404 to those of the other NG-RAN node(s) 206A, 206B that do not have an Xn interface connection with the donor gNB 408, which may be determined by filtering by the donor gNB. This may save resources at NG-RAN nodes where the UE 208 is less likely to resume its suspended RRC connection; and those NG-RAN node(s) with an Xn interface connection with the donor gNB may retrieve the UE context and other relevant information from the donor gNB as an anchor for that information.

[0111] As shown in FIG. 7B, after a certain time, the MW AB node at step 707 moves away, at which point its Xn interface connections with the donor gNB and other NG-RAN node(s) 206A, 206B are either released or lost.

[0112] Also after a certain time, the UE 208 at step 708 camps in a cell provided by the first NG-RAN node 206A. In some examples, UE resumes may be due to some uplink data arrival. As shown at step 709, then, resuming of the suspended RRC connection may be initiated at the cell of first NG-RAN node. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC-I / shortResumeMAC-I in a RRC resume request. The first NG-RAN node may then map the UE context to the UE using provided I-RNTI.

[0113] In examples in which a ResumeMAC-I / shortResumeMAC-I is shared in steps 705 and 706, the first NG-RAN node 206A may also verify authenticity of the UE 208 by comparing it to one provided by the UE. In other examples in which parameters to calculate ResumeMAC-I / shortResumeMAC-I are instead shared, the first NG-RAN node may first calculate theResumeMAC-I / shortResumeMAC-I and then verify the authenticity of the UE. Again, this verification is oftentimes done by the source node that sent the UE to RRC INACTIVE, but here performed by the target node.

[0114] As shown at step 710, since the UE context and other relevant information for the UE 208 are already available at the first NG-RAN node 206A (made available at steps 705 and 706), so further fetching of the UE context from the MW AB node 402 is not required.

[0115] The cell of the first NG-RAN node 206A at step 711 sends a RRC resume request to the UE 208. The key KNG-RAN* (made available in steps 705 and 706) may be used for protection of RRC messages after the RRC resume request.

[0116] Upon receipt of RRC resume request, the UE 208 at step 712 transitions from RRCINACTIVE to RRC CONNECTED. The first NG-RAN node 206A and the UE 208 at step 713 complete the resumption of the RRC connection. And the first NG-RAN node at steps 714 and 715 performs a path switch with the AMF 410, such as using the TNL ID provided by the MWAB-gNB 404 at steps 705 and 706.

[0117] FIGS. 8A-8C illustrate a signaling chart 800 of procedures of a UE 208 sent to an inactive state by a MW AB node 402 that forwards UE context information to an anchor node from which the UE context is retrieved by a NG-RAN node at which the UE returns to a connected state, according to some example implementations. As described below, the donor gNB 408 is made the anchor node for the UE context, although it should be understood that another NG-RAN node may instead be made the anchor node. In some examples, the anchor node may be selected based on a number of different factors, such as measurements from the UE 206, Xn interface availability, or the like. As described below, in examples in which the UE context is unavailable at the NG-RAN node where the UE is resuming the RRC connection, the NG-RAN node may retrieve the UE context from the anchor node.

[0118] As shown in FIG. 8 A, a MWAB-MT 406 of a MW AB node is connected to a donor gNB 408 and being served by a cell of the donor gNB, and a UE is at step 801 in RRC CONNECTED state and being served by the MWAB-gNB 404. The MW AB node is being served over a NR BH by the donor gNB. An Xn interface is also established between the MWAB-gNB and the donor gNB, as well as between the MWAB-gNB and a first NG-RAN node (NG-RAN 1) 206A.

[0119] The MW AB node 402 at step 802 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE. The MWAB-gNB 404 assigns an I-RNTI, and provides the I-RNU to the UE while releasing to inactive. The NG-RAN specific part of the I-RNTT identifies the MW AB node by its own ID (MW AB ID). The MW AB node may also inform the core network to stop delivery of data to the MW AB node for the UE by providing a TNL ID just before or after sending the UE to inactive. Upon receiving RRC release message, the UE at step 803 switches its RRC state from RRC CONNECTED to RRC INACTIVE.

[0120] The MW AB node 402 at step 804 decides to release its Xn interface connection with the first NG-RAN node 206A. The MW AB node may decide to release this Xn interface connection for a number of reasons, including that the MWAB node is moving away. In some example implementations, the first NG-RAN node may instead decide to release the Xn interface connection with the MWAB node.

[0121] The MWAB-gNB 404 of the MWAB node 402 at step 805 sends a Xn release request to the first NG-RAN node 206A. In the Xn release request, the MWAB-gNB provides indication that the Xn release request is from an MWAB, and the MWAB-gNB includes its MWAB ID, and the ID of the donor gNB 408 (donor gNB ID). In case Xn release is initiated by the first NG- RAN node 206A then this information is provided by MWAB node in the Xn release response.

[0122] As shown in FIG. 8B at step 806, the MWAB node 402 makes the donor gNB 408 an anchor node for UE context retrieval. In some examples, as shown at step 806A, the MWAB node proactively makes the UE context and other relevant information available at the donor gNB, and sends the UE context and other relevant information to the donor gNB, such as in an Xn release request. In particular, for example, the information made available may include UE context information (also including UE 5G AS security context) and associated I-RNTI. As explained above, the information may also include the TNL ID used by the MWAB node for the UE, at least one ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), KNG- RAN* (or parameters to calculate), parameter(s) that enable RAN paging by the donor gNB, and the like.

[0123] Upon receipt of the UE context and other relevant information, the donor gNB 408 may perform a number of tasks. In some examples, the donor gNB may use the TNL ID to send a request to the core network on behalf of the MWAB node 402 to stop delivery of user data for the UE 208 at the MWAB node. This may avoid a waste of data sent to the MWAB node, release of the Xn interface connection may prevent the data being forwarded. The donor gNB may also use the TNL ID in a path switch request to change the user data path with the AMF 410.

[0124] The donor gNB 408 may send an Xn release response to the MWAB-gNB 404 of the MW AB node 402. The Xn release response may in some examples include acknowledgement of receipt of the UE context and other relevant information for the UE 208.

[0125] In other examples, as shown at step 806B and described in greater detail below, the MWAB-gNB 404 may hand over the UE 208 to the donor gNB 408, before releasing the UE to RRC INACTIVE.

[0126] Information to resume RRC connection of the UE 208 is therefore made available at the donor gNB 408 at step 807. As shown in FIG. 8C, after a certain time, the MW AB node 402 at step 808 moves away, at which point the Xn interface connection with the donor gNB is either released or lost.

[0127] Also after a certain time, the UE 208 at step 809 camps in a cell provided by the first NG-RAN node 206A. As shown at step 810, then, resuming of the suspended RRC connection may be initiated at the cell of first NG-RAN node. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC- I / shortResumeMAC-I in a RRC resume request.

[0128] As shown at step 811, the UE context is not available at the new NG-RAN node, namely, first NG-RAN node 206A. The first NG-RAN node determines the NG-RAN node ID in the NG-RAN specific part of the I-RNU sent by the UE 208 to the first NG-RAN node, and compares the NG-RAN node ID with the MW AB ID provided in step 805. If the identifiers match, the first NG-RAN node knows the MW AB node 402 sent the UE 208 to RRC INACTIVE. The first NG-RAN node now starts UE context retrieval from the donor gNB 408, using the donor gNB ID provided in step 805.

[0129] The first NG-RAN node 206A at step 812 sends a retrieve UE context request message to the donor gNB 408. The first NG-RAN node provides I-RNTI, as well as the ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), and / or KNG-RAN* (or parameters to calculate). The donor gNB may map the UE context to the UE using the I-RNTI provided by the first NG-RAN node. In examples in which a ResumeMAC-I / shortResumeMAC-I is shared in step 806A, the donor gNB may also verify authenticity of the UE 208 by comparing it to one provided by the UE. In other examples in which parameters to calculate ResumeMAC-I / shortResumeMAC-I are instead shared, the donor gNB may first calculate the ResumeMAC-I / shortResumeMAC-I and then verify the authenticity of the UE. Again, this verification is oftentimes done by the source node that sent the UE to RRC INACTIVE, but here performed by the donor gNB.

[0130] As shown at step 813, the donor gNB sends a retrieve UE context response message to the first NG-RAN node 206A; and in the retrieve UE context response message, the donor gNB provides the UE context information (also including UE 5G AS security context).

[0131] The cell of the first NG-RAN node 206A at step 814 sends a RRC resume request to the UE 208. Upon receipt of RRC resume request, the UE at step 815 transitions from RRC INACTIVE to RRC CONNECTED. The first NG-RAN node and the UE at step 816 complete the resumption of the RRC connection. And the first NG-RAN node at steps 817 and 818 performs a path switch with the AMF 410 (if not done at step 806).

[0132] In the procedures described in FIGS. 8A-8C, an NG-RAN node having an Xn interface connection to the MW AB node 402 may directly approach the donor gNB. For other NG-RANs that do not have an Xn interface connection with the MW AB node, procedures described below may be used. In this regard, FIGS. 9A-9D illustrate a signaling chart 900 of procedures of a UE 208 sent to an inactive state by a MW AB node 402 that forwards UE context information to an anchor node from which the UE context is retrieved by a NG-RAN node at which the UE returns to a connected state, according to other example implementations. In these examples, information regarding the donor gNB or other anchor node may be provided to the new NG-RAN node (shown as the first NG-RAN node 206A) by the UE via a UE resume procedure, or by the donor gNB via an Xn interface connection between the donor gNB and new NG-RAN node. An Xn interface connection between the MW AB node 402 and new NG RAN is therefore not needed.

[0133] As shown in FIG. 9A, a MWAB-MT 406 of a MW AB node is connected to a donor gNB 408 and being served by a cell of the donor gNB, and a UE is at step 901 in RRC CONNECTED state and being served by the MWAB-gNB 404. The MW AB node is being served over a NR BH by the donor gNB. An Xn interface is also established between the MWAB-gNB and the donor gNB. To make the new NG RAN, namely the first NG-RAN node 206A, aware of the anchor node (herein donor gNB), a number of options may be used.

[0134] In a first option (Option A), the MW AB node 402 at step 902 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE. The MWAB-gNB 404 assigns an I-RNTI, and provides the I-RNU to the UE while releasing to inactive. The NG-RAN specific part of the I-RNTI identifies the donor gNB 408 (donor gNB ID), instead of the MWAB node by its own ID (MW AB ID). This allows the donor gNB to be contacted for UE context retrieval. The MWAB node may also inform the core network to stop delivery of data to the MWAB node for the UE by providing a TNL ID justbefore or after sending the UE to inactive. Upon receiving RRC release message, the UE at step 903 switches its RRC state from RRC CONNECTED to RRC INACTIVE.

[0135] The MW AB node 402 makes the donor gNB 408 an anchor node for UE context retrieval. The MW AB node proactively makes the UE context and other relevant information available at the donor gNB, and at step 904 sends the UE context and other relevant information to the donor gNB, such as in an Xn release request sent immediately after sending the UE to RRC INACTIVE. As before, for example, the information made available may include UE context information (also including UE 5G AS security context) and associated I-RNTI. As explained above, the information may also include the TNL ID used by the MW AB node for the UE, at least one ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), KNG-RAN* (or parameters to calculate), parameter(s) that enable RAN paging by the donor gNB, and the like.

[0136] After a certain time, the MW AB node 402 at step 905 moves away, at which point theXn interface connection with the donor gNB 408 is either released or lost. Also after a certain time, the UE 208 at step 906 camps in a cell provided by the first NG-RAN node 206A. As shown at step 907, then, resuming of the suspended RRC connection may be initiated at the cell of first NG-RAN node. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC-I / shortResumeMAC-I in a RRC resume request.

[0137] As shown at step 908, the UE context is not available at the new NG-RAN node, namely, first NG-RAN node 206A. The first NG-RAN node determines that the NG-RAN node ID in the NG-RAN specific part of the I-RNTI (sent by the UE 208 to the first NG-RAN node) is the donor gNB ID, and starts UE context retrieval from the donor gNB 408 using the donor gNB ID.

[0138] As shown in FIG. 9B, in a second option (Option B), the MW AB node 402 at step 909 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE. The MWAB-gNB 404 assigns an I-RNTI (including a NG-RAN specific part with the MW AB ID), and provides the I-RNTI to the UE while releasing to inactive. The MWAB-gNB also provides the donor gNB ID, and may provide an indication that the MW AB released the UE to RRC INACTIVE (a MW AB released UE indicator). In another example, the donor gNB ID and MW AB released UE indicator may be encoded in the I- RNTI itself. The MW AB node may inform the core network to stop delivery of data to the MW AB node for the UE by providing a TNL ID just before or after sending the UE to inactive.Upon receiving RRC release message, the UE at step 910 switches its RRC state from RRC CONNECTED to RRC INACTIVE.

[0139] The MW AB node 402 makes the donor gNB 408 an anchor node for UE context retrieval. The M AB node proactively makes the UE context and other relevant information available at the donor gNB, and at step 911 sends the UE context and other relevant information to the donor gNB, such as in an Xn release request sent immediately after sending the UE to RRC INACTIVE. As before, for example, the information made available may include UE context information (also including UE 5G AS security context) and associated I-RNTI. As explained above, the information may also include the TNL ID used by the MW AB node for the UE, at least one ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), KNG-RAN* (or parameters to calculate), parameter(s) that enable RAN paging by the donor gNB, and the like.

[0140] After a certain time, the MW AB node 402 at step 912 moves away, at which point theXn interface connection with the donor gNB 408 is either released or lost. Also after a certain time, the UE 208 at step 913 camps in a cell provided by the first NG-RAN node 206A. As shown at step 914, then, resuming of the suspended RRC connection may be initiated at the cell of first NG-RAN node. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC-I / shortResumeMAC-I in a RRC resume request. The UE may also provide the donor gNB ID, and perhaps also the MW AB released UE indicator.

[0141] As shown at step 915, the UE context is not available at the new NG-RAN node, namely, first NG-RAN node 206A. The first NG-RAN node may determine the MW AB node 402 released the UE 208 to RRC INACTIVE by the MW AB released UE indicator (if provided), and start UE context retrieval from the donor gNB 408 using the donor gNB ID received from the UE (at step 914). In examples without the MW AB released UE indicator, the first NG-RAN node may start UE context retrieval from the donor gNB 408 using only the donor gNB ID received from the UE.

[0142] As shown in FIG. 9C, in a third option (Option C), the MW AB node 402 at step 916 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE. The MWAB-gNB 404 assigns an I-RNTI (including a NG-RAN specific part with the MW AB ID), and provides the I-RNTI to the UE while releasing to inactive. The MW AB node may also inform the core network to stop delivery of data to the MW AB node for the UE by providing a TNL ID just before or after sending the UE to inactive.Upon receiving RRC release message, the UE at step 917 switches its RRC state from RRC CONNECTED to RRC INACTIVE.

[0143] The MW AB node 402 makes the donor gNB 408 an anchor node for UE context retrieval. The M AB node proactively makes the UE context and other relevant information available at the donor gNB, and at step 918 sends the UE context and other relevant information to the donor gNB, such as in an Xn release request sent immediately after sending the UE to RRC INACTIVE. As before, for example, the information made available may include UE context information (also including UE 5G AS security context) and associated I-RNTI. As explained above, the information may also include the TNL ID used by the MW AB node for the UE, at least one ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), KNG-RAN* (or parameters to calculate), parameter(s) that enable RAN paging by the donor gNB, and the like.

[0144] After a certain time, the MW AB node 402 at step 919 moves away, at which point the Xn interface connection with the donor gNB 408 is either released or lost. The donor gNB at step 920 indicates to other NG-RAN nodes (might or might not be in RNA) that it is an anchor node for the UE 208, and provides the I-RNTI, the MW AB node ID, and perhaps also its own ID (i.e. donor’s own gNB ID). As shown, these other NG-RAN node(s) may include a first NG-RAN node (NG-RAN 1) 206A, and perhaps also a second NG-RAN node (NG-RAN 2) 206B.

[0145] Also after a certain time, the UE 208 at step 921 camps in a cell provided by the first NG-RAN node 206A. As shown at step 922, then, resuming of the suspended RRC connection may be initiated at the cell of first NG-RAN node. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC- I / shortResumeMAC-I in a RRC resume request.

[0146] As shown at step 923, the UE context is not available at the new NG-RAN node, namely, first NG-RAN node 206A. The first NG-RAN node determines that the MW AB node 402 released the UE 208 to RRC INACTIVE, such as by comparing the NG-RAN node ID in the NG-RAN specific part of the I-RNTI (sent by the UE 208 to the first NG-RAN node) and the MW AB ID (received from the donor gNB - the anchor node). The first NG-RAN node then starts UE context retrieval from the donor gNB 408 using the donor gNB ID received from the donor gNB (at step 920).

[0147] Regardless of the option used, as shown in FIG. 9D, after determining the donor gNB 408 is the anchor node for the UE 208, the first NG-RAN node 206A at step 924 sends a retrieve UE context request message to the donor gNB using the donor gNB ID. The first NG-RAN nodeprovides I-RNTI, as well as the ResumeMAC-I / shortResumeMAC-I (or parameters to enable calculation), and / or KNG-RAN* (or parameters to calculate). The donor gNB may map the UE context to the UE using the I-RNTI provided by the first NG-RAN node. In examples in which a ResumeMAC-I / shortResumeMAC-I is shared, the donor gNB may also verify authenticity of the UE by comparing it to one provided by the UE. In other examples in which parameters to calculate ResumeMAC-I / shortResumeMAC-I are instead shared, the donor gNB may first calculate the ResumeMAC-I / shortResumeMAC-I and then verify the authenticity of the UE. Again, this verification is oftentimes done by the source node that sent the UE to RRC INACTIVE, but here performed by the donor gNB.

[0148] As shown at step 925, the donor gNB 408 sends a retrieve UE context response message to the first NG-RAN node 206A; and in the retrieve UE context response message, the donor gNB provides the UE context information (also including UE 5G AS security context).

[0149] The cell of the first NG-RAN node 206A at step 926 sends a RRC resume request to the UE 208. Upon receipt of RRC resume request, the UE at step 927 transitions from RRC INACTIVE to RRC CONNECTED. The first NG-RAN node and the UE at step 928 complete the resumption of the RRC connection. And the first NG-RAN node at steps 929 and 930 performs a path switch with the AMF 410 (if not done earlier).

[0150] FIGS. 10A-10C illustrate a signaling chart 1000 of procedures for a MW AB node 402 sending a UE 208 to an inactive state, and forwarding the UE context to an anchor node e.g., donor gNB 408) with at least one condition on which the UE context may be discarded or otherwise released, according to other example implementations. In this example, the anchor node may use the condition(s) to determine a validity period of the UE context, and discard the context if the UE 208 has not resumed at the anchor node or the context has not been retrieved by another NG-RAN node.

[0151] As shown in FIG. 10A, in an example with UE context discard, a UE 208 is at step 1001 in RRC CONNECTED state and being served by the M AB node 402. The M AB node is being served over a NR BH by the donor gNB. An Xn interface is also established between the MWAB node and the donor gNB, and perhaps also between the MWAB node and other NG- RAN node(s). The MWAB node 402 at step 1002 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE.

[0152] The MWAB node 402 decides to release its Xn interface connection with the donor gNB 408, and perhaps also the other NG-RAN node(s) (including a first NG-RAN node 206A), such as due to the MWAB node moving away. The MWAB node makes the donor gNB 408 (orother NG-RAN node) an anchor node for UE context retrieval. The MW AB node proactively makes the UE context and other relevant information available at the donor gNB, and at step 1003 sends the UE context and other relevant information to the donor gNB, such as in an Xn release request. The M AB node also provides at least one condition, such as a context validity timer, other MWAB assistance information (e.g., static / moving indication, MW AB node trajectory / velocity), or the like.

[0153] The donor gNB 408 (or other anchor node) at step 1004 determines that the UE context has expired based on the validity timer and / or other MWAB assistance information received at step 1003. In response, the donor gNB discards the UE context, since it no longer considers the UE context valid.

[0154] FIG. 10B illustrates an example in which the UE context is retrieved before being discarded. In this example, steps 1001, 1002 and 1003 are as described above with respect to FIG. 10A. Steps 1004-1008, then, follow steps 808-812 in FIG. 8C. In this regard, after a certain time, the MWAB node 402 at step 1004 moves away, at which point the Xn interface connection with the donor gNB is either released or lost.

[0155] Also after a certain time, the UE 208 at step 1005 camps in a cell provided by the first NG-RAN node 206A. As shown at step 1006, then, resuming of the suspended RRC connection may be initiated at the cell of first NG-RAN node. In case the UE triggered its transition from RRC INACTIVE to RRC CONNECTED, the UE may provide the I-RNTI and ResumeMAC- I / shortResumeMAC-I in a RRC resume request.

[0156] As shown at step 1007, the UE context is not available at the new NG-RAN node, namely, first NG-RAN node 206A. The I-RNTI indicates or by any other example implementations as mentioned in this disclosure indicate to contact the donor gNB 408 for UE context retrieval, and the first NG-RAN node at step 1008 sends a retrieve UE context request message to the donor gNB 408. The donor gNB at step 1009 determines the UE context has not yet been discarded. The donor gNB then at step 1010 sends a retrieve UE context response message to the first NG-RAN node 206A; and in the retrieve UE context response message, the donor gNB provides the UE context information (also including UE 5G AS security context). The procedure may then follow steps 814-818 described above to complete a successful UE resume, as shown at step 1011.

[0157] FIG. 10C illustrates an example similar to FIG. 10A, but with an additional notification about the UE context discard. In this example, steps 1001, 1002, 1003 and 1004 are as described above with respect to FIG. 10A, including the donor gNB discarding the UE context.In step 1005, the donor gNB determines that it has an active Xn interface connection with the MW AB node 402 (active from before, or relased and setup again). The donor gNB then at step 1006 notifies or otherwise informs the MW AB node that the donor gNB has discarded the UE context.

[0158] FIGS. 11 A and 1 IB illustrate a signaling chart 1100 of procedures for a MW AB node 402 handing off a UE 208 to a NG-RAN node before the UE is sent to an inactive state, and the UE returning to a connected state with the NG-RAN node, according to other example implementations. In this example, the UE being sent to RRC INACTIVE is first handed off from the MW AB node to another NG-RAN node that then sends the UE to RRC INACTIVE. In some examples, a handover (HO) request from the MW AB node may indicate one or more causes for the HO, such as “make NG-RAN node an anchor,” “send UE to inactive,” or the like.

[0159] As shown in FIG. 5A, a MWAB-MT 406 of a MWAB node 402 is connected to a donor gNB 408 and being served by a cell of the donor gNB, and a UE 208 is at step 501 in RRC CONNECTED state and being served by the MWAB-gNB 404. The MWAB node is being served over a NR BH by the donor gNB. An Xn interface is also established between the MWAB-gNB and the donor gNB. The MWAB-gNB 404 at step 1102 decides to send the UE 208 to RRC INACTIVE, such as based on an inactive timer for unicast services, temporary lack of data for a multi cast / broadcast (MBS) session, or the like. The MWAB node may also decide to release its Xn interface connection with the donor gNB, such as due to the MWAB node moving away.

[0160] The MWAB-gNB 404 at step 1103 decides to HO the UE 208 to a target cell provided by the donor gNB 408. The target cell may be selected based on a number of different factors, such as measurements from the UE 206, Xn interface availability, or the like. The MWAB-gNB sends a handover request message, giving a cause of the HO such as “make NG-RAN node an anchor” and / or “send UE to inactive”. By this, the donor gNB knows to send the UE 208 to RRC INACTIVE. And due to the HO procedure, the UE context is shifted to the donor gNB.

[0161] As shown in FIG. 1 IB, the donor gNB 408 at step 1105 sends the UE 208 to RRC INACTIVE with a RRC release message with a configuration (suspendConfig) for RRC INACTIVE, based on the indication / cause the donor gNB received in step 1103. Upon receiving RRC release message, the UE at step 1106 switches its RRC state from RRC CONNECTED to RRC INACTIVE. After a certain time, the MWAB node 402 at step 1107 moves away, at which point the Xn interface connection with the donor gNB is either released or lost.

[0162] Also after a certain time, the UE 208 at step 1108 camps in a cell provided by the donor gNB 408. As shown at step 1109, then, resuming of the suspended RRC connection may be initiated at the cell of donor gNB, such as in a manner described above. And since the UE context for the UE 208 is already available at the donor gNB 408 (made available at step 1103 and 1104), further fetching of the UE context is not required.

[0163] The cell of the donor gNB 408 at step 1110 sends a RRC resume request to the UE 208. Upon receipt of RRC resume request, the UE 208 at step 1111 transitions from RRC INACTIVE to RRC CONNECTED. The donor gNB 408 and the UE 208 at step 1112 complete the resumption of the RRC connection. And the donor gNB at steps 1113 and 1114 performs a path switch with the AMF 410.

[0164] FIG. 12 is a flowchart illustrating various steps in a method 1200 according to various example implementations. The method includes providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node, as shown at block 1202 of FIG. 12. The method includes sending a release message from the MW AB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state, as shown at block 1204. The method includes making at block 1206 a determination at the MW AB node to release a network interface connection with one or more radio access nodes; and based on the determination, forwarding at block 1208 the context information associated with the at least one user equipment triggered to transition to the inactive state by the MW AB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0165] In some examples, the context information is forwarded at block 1208 with information that indicates at least one condition on which the context information is releasable by the one or more radio access nodes or the shared database.

[0166] In some examples, the one or more radio access nodes to which the context information is forwarded at block 1208 include at least one of the radio access node by which the MW AB node is served over the wireless backhaul, or at least one other radio access node in a notification area of the at least one user equipment.

[0167] In some examples, the context information is forwarded at block 1208 by the MW AB node to the one or more radio access nodes to enable the one or more radio access nodes to provide the continued radio network service.

[0168] In some examples, the context information is forwarded at block 1208 by the MW AB node to the one or more radio access nodes including an anchor radio access node from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service to the at least one user equipment.

[0169] In some examples, the method 1200 further includes assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MWAB node. In some of these examples, the MW AB node has a second network interface connection with the other radio access node. Also in some of these examples, the method further includes sending a network interface connection release message from the MWAB node to the other radio access node, the network interface connection release message including identifiers of the MWAB node and the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0170] In some examples, the method 1200 further includes assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MWAB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MWAB node. In some of these examples, the context information is forwarded at block 1208 to the anchor radio access node from which identifiers of the MWAB node and the anchor radio access node are sent to the other radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0171] In some examples, the method 1200 further includes assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MWAB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MWAB node. In some of these examples, the release message sent at block 1204 to the at least one user equipment, and the request sent from the at least one user equipment to the other radio access node, further includes an identifier of the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifier of the anchor radio access node.

[0172] In some examples, the method 1200 further includes assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the anchor radio access node from which the context information is retrievable.

[0173] In some examples, the context information is forwarded at block 1208 by the MW AB node to the shared database from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service.

[0174] In some examples, the method 1200 further includes assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the shared database.

[0175] FIG. 13 is a flowchart illustrating various steps in a method 1300 according to various example implementations. The method includes providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node, as shown at block 1302. The method includes making at block 1304 a determination at the MW AB node to send the at least one user equipment to an inactive state; and based on the determination, carrying at block 1306 out a handover procedure to hand over each user equipment of the at least one user equipment from the MW AB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0176] In some examples, carrying out the handover procedure at block 1306 also includes sending a cause for the handover from the MW AB node to the radio access node or the other radio access node, the cause including a request for the radio access node or the other radio access node to send the at least one user equipment to the inactive state.

[0177] FIG. 14 is a flowchart illustrating various steps in a method 1400 according to various example implementations. The method includes receiving context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MW AB) node served over a wireless backhaul by a radio access node, as shown at block 1402.The method includes receiving a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state, as shown at block 1404. The method includes determining the context information is available without retrieving the context information from the MW AB node, as shown at block 1406. And the method includes providing the continued radio network service to the user equipment based on the context information, as shown at block 1408.

[0178] In some examples, the method 1400 further includes carrying out a path switch procedure for the user equipment with an access and mobility management function.

[0179] FIG. 15 is a flowchart illustrating various steps in a method 1500 according to various example implementations. The method includes receiving a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNTI) assigned to the user equipment by a mobile wireless access backhaul (MW AB) node that sent the user equipment to the inactive mode, as shown at block 1502. The method includes determining a network node other than the MW AB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNTI, as shown at block 1504. The method includes retrieving the context information from the network node based on the I-RNTI, as shown at block 1506. And the method includes providing the continued radio network service to the user equipment based on the context information, as shown at block 1508.

[0180] In some examples, the method 1500 further includes carrying out a path switch procedure for the user equipment with an access and mobility management function.

[0181] In some examples, determining the network node storing the context information at block 1504 includes determining an anchor radio access node storing the context information.

[0182] In some examples, the method 1500 further includes receiving identifiers of the MW AB node and the anchor radio access node from the MW AB node. In some of these examples, the I-RNU identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNU and the identifiers.

[0183] In some examples, the method 1500 further includes receiving identifiers of the MW AB node and the anchor radio access node from the anchor radio access node. In some of these examples, the I-RNU identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

[0184] In some examples, the request to provide the continued radio network service includes an identifier of the anchor radio access node. In some of these examples, the I-RNU identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNU and the identifier of the anchor radio access node.

[0185] In some examples, the I-RNU identifies the context information and the anchor radio access node storing the context information.

[0186] In some examples, determining the network node storing the context information at block 1504 includes determining a shared database storing the context information. In some of these examples, the I-RNU identifies the context information and the shared database storing the context information.

[0187] According to example implementations of the present disclosure, a telecommunications system 100 or PLMN 102, and its components such as a CN 106, RAN 108, UE 110, 5GC 202, NG-RAN 204, NG-RAN node 206, UE 208, AMF / UPF 302, MW AB node 402, MWAB-gNB 404, MWAB-MT 406, donor gNB 408, AMF 410, UPF 412, and / or NG-RAN node(s) 206A, 206B, may be implemented by various means. Means for implementing the system and its components may include hardware, firmware, software, or combinations thereof. In some examples, one or more apparatuses may be configured to function as or otherwise implement the system and its components shown and described herein. In examples involving more than one apparatus, the respective apparatuses may be connected to or otherwise in communication with one another in a number of different manners, such as directly or indirectly via a wired or wireless network or the like.

[0188] According to some example implementations, at least some of the method 1200 described with respect to FIG. 12 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Similarly, at least some of the method 1300 described with respect to FIG. 13 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. At least some of the method 1400 described with respect to FIG. 14 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method; and at least some of the method 1500 described with respect to FIG. 15 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Examples of a suitable apparatus may include a NG-RAN node, gNB (e.g., gNB-DU, gNB-CU), ng-eNB, MW AB node, MWAB-gNB, or any suitable apparatus, such as a server, host or node.

[0189] FIG. 16 illustrates an apparatus 1600 in which means for performing various functions includes hardware, alone or under direction of one or more computer programs from a computer- readable storage medium or other memory, such as computer memory, according to some example implementations of the present disclosure. The apparatus may include one or more of each of a number of components such as, for example, processing circuitry 1602 connected to computer-readable storage medium or other memory 1604.

[0190] The processing circuitry 1602 may be composed of one or more processors alone or in combination with one or more computer-readable storage media. The processing circuitry is generally any piece of computer hardware that is capable of processing information such as, for example, data, computer programs and / or other suitable electronic information. The processing circuitry is composed of a collection of electronic circuits some of which may be packaged as an integrated circuit or multiple interconnected integrated circuits (an integrated circuit at times more commonly referred to as a “chip”). The processing circuitry may be configured to execute computer programs, which may be stored onboard the processing circuitry or otherwise stored in the memory 1604 (of the same or another apparatus).

[0191] The processing circuitry 1602 may be a number of processors, a multi-core processor or some other type of processor, depending on the particular implementation. Further, the processing circuitry may be implemented using a number of heterogeneous processor systems in which a main processor is present with one or more secondary processors on a single chip. As another illustrative example, the processing circuitry may be a symmetric multi-processor system containing multiple processors of the same type. In yet another example, the processing circuitry may be embodied as or otherwise include one or more ASICs, FPGAs or the like. Thus, although the processing circuitry may be capable of executing a computer program to perform one or more functions, the processing circuitry of various examples may be capable of performing one or more functions without the aid of a computer program. In either instance, the processing circuitry may be appropriately programmed to perform functions or operations according to example implementations of the present disclosure.

[0192] The memory 1604 is generally any piece of computer hardware that is capable of storing information such as, for example, data, computer programs, instructions 1606 (e.g., computer-readable program code) and / or other suitable information either on a temporary basis and / or a permanent basis. The memory may include volatile and / or non-volatile memory, and may be fixed or removable. Examples of suitable memory include recording media, randomaccess memory (RAM), read-only memory (ROM), a hard drive, a flash memory, a thumb drive, a removable computer diskette, an optical disk or some combination thereof.

[0193] The memory 1604 is a non-transitory device capable of storing information. One example of a suitable memory is a computer-readable storage medium, which is distinguishable from a computer-readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media comprise electronic carrier signals, telecommunications signals, software distribution packages, or some combination thereof. As used herein, the term “non-transitory” is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM versus ROM). A computer-readable medium as described herein generally refers to a computer-readable storage medium or computer-readable transmission medium. A computer- readable medium is any entity or device capable in which information, such as one or more computer programs or portions thereof, may be stored and carried.

[0194] In addition to the memory 1604 (e.g., computer-readable storage medium), the processing circuitry 1602 may also be connected to one or more interfaces for displaying, transmitting and / or receiving information. The interfaces may include a communications interface 1608 and / or one or more user interfaces (e.g., display, user input interface). The communications interface may be configured to transmit and / or receive information, such as to and / or from other apparatus(es), network(s) or the like. The communications interface may be configured to transmit and / or receive information by physical (wired) and / or wireless communications links. Examples of suitable communication interfaces include a network interface controller (NIC), wireless NIC (WNIC) or the like.

[0195] Execution of the instructions 1606 by the processing circuitry 1602, or storage of the instructions in the memory 1604, supports combinations of operations for implementing example implementations of the present disclosure. In this manner, an apparatus 1600 may comprise at least one processing circuitry and at least one memory coupled to the at least one processing circuitry, where the at least one processing circuitry is configured to execute instructions stored in the at least one memory. It will also be understood that one or more functions, and combinations of functions, may be implemented by special purpose hardware-based computer systems and / or processing circuitry which perform the specified functions, or combinations of special purpose hardware and program code instructions.

[0196] Some example implementations of the present disclosure may also be carried out in the form of a computer process defined by one or more computer programs or portions thereof.Example implementations of the present disclosure may be carried out by executing at least one portion of a computer program comprising instructions. The computer program may be in source code form, object code form, or in some intermediate form. The computer program may be stored in a computer-readable medium that is readable by a computer, processing circuitry or other suitable apparatus. As indicated above, for example, the computer program may be stored in a memory, such as a computer-readable storage medium. Additionally or alternatively, for example, the computer program may be stored in a computer-readable transmission medium. The coding of software for carrying out example implementations of the present disclosure is well within the scope of a person of ordinary skill in the art.

[0197] As will be appreciated, any suitable instructions may be loaded onto a computer, a processing circuitry or other programmable apparatus from a memory or a computer-readable medium (e.g., computer-readable storage medium, computer-readable transmission medium) to produce a particular machine, such that the particular machine becomes a means for implementing the functions specified herein. The instructions may also be stored in a computer- readable medium that can direct a computer, a processing circuitry or other programmable apparatus to function in a particular manner to thereby generate a particular machine or particular article of manufacture. In some examples, the instructions stored in the computer-readable medium may produce an article of manufacture, where the article of manufacture becomes a means for implementing functions described herein. The instructions may be retrieved from a computer-readable medium and loaded into a computer, processing circuitry or other programmable apparatus to configure the computer, processing circuitry or other programmable apparatus to execute operations to be performed on or by the computer, processing circuitry or other programmable apparatus.

[0198] Retrieval, loading and execution of instructions comprising program code instructions may be performed sequentially such that one instruction is retrieved, loaded and executed at a time. In some example implementations, retrieval, loading and / or execution may be performed in parallel such that multiple instructions are retrieved, loaded, and / or executed together. Execution of the program code instructions may produce a computer-implemented process such that the instructions executed by the computer, processing circuitry or other programmable apparatus provide operations for implementing functions described herein.

[0199] As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.

[0200] Clause 1. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node; send a release message from the MW AB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; make a determination at the MW AB node to release a network interface connection with one or more radio access nodes; and based on the determination, forward the context information associated with the at least one user equipment triggered to transition to the inactive state by the MW AB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0201] Clause 2. The apparatus of clause 1, wherein the context information is forwarded with information that indicates at least one condition on which the context information is releasable by the one or more radio access nodes or the shared database.

[0202] Clause 3. The apparatus of clause 1 or clause 2, wherein the one or more radio access nodes to which the context information is forwarded include at least one of the radio access node by which the MW AB node is served over the wireless backhaul, or at least one other radio access node in a notification area of the at least one user equipment.

[0203] Clause 4. The apparatus of any of clauses 1 to 3, wherein the context information is forwarded by the MW AB node to the one or more radio access nodes to enable the one or more radio access nodes to provide the continued radio network service.

[0204] Clause 5. The apparatus of any of clauses 1 to 4, wherein the context information is forwarded by the MW AB node to the one or more radio access nodes including an anchor radio access node from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service to the at least one user equipment.

[0205] Clause 6. The apparatus of clause 5, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further assign an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifiesthe context information and the MWAB node, and wherein the MW AB node has a second network interface connection with the other radio access node, and the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send a network interface connection release message from the MWAB node to the other radio access node, the network interface connection release message including identifiers of the MWAB node and the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNH and the identifiers.

[0206] Clause 7. The apparatus of clause 5 or clause 6, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further assign an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MWAB node, the release message includes the I-RNH for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the MWAB node, wherein the context information is forwarded to the anchor radio access node from which identifiers of the MWAB node and the anchor radio access node are sent to the other radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0207] Clause 8. The apparatus of any of clauses 5 to 7, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further assign an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MWAB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNH identifies the context information and the MWAB node, and wherein the release message sent to the at least one user equipment, and the request sent from the at least one user equipment to the other radio access node, further includes an identifier of the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifier of the anchor radio access node.

[0208] Clause 9. The apparatus of any of clauses 5 to 8, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further assign an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MWAB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the anchor radio access node from which the context information is retrievable.

[0209] Clause 10. The apparatus of any of clauses 1 to 9, wherein the context information is forwarded by the MW AB node to the shared database from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service.

[0210] Clause 11. The apparatus of clause 10, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further assign an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the M AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the shared database.

[0211] Clause 12. An apparatus comprising: means for providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node; means for sending a release message from the MW AB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; means for making a determination at the MW AB node to release a network interface connection with one or more radio access nodes; and based on the determination, means for forwarding the context information associated with the at least one user equipment triggered to transition to the inactive state by the MW AB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0212] Clause 13. The apparatus of clause 12, wherein the context information is forwarded with information that indicates at least one condition on which the context information is releasable by the one or more radio access nodes or the shared database.

[0213] Clause 14. The apparatus of clause 12 or clause 13, wherein the one or more radio access nodes to which the context information is forwarded include at least one of the radio access node by which the MW AB node is served over the wireless backhaul, or at least one other radio access node in a notification area of the at least one user equipment.

[0214] Clause 15. The apparatus of any of clauses 12 to 14, wherein the context information is forwarded by the MWAB node to the radio access nodes to enable the one or more radio access nodes to provide the continued radio network service.

[0215] Clause 16. The apparatus of any of clauses 12 to 15, wherein the context information is forwarded by the MWAB node to the one or more radio access nodes including an anchor radioaccess node from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service to the at least one user equipment.

[0216] Clause 17. The apparatus of clause 16, wherein the apparatus further comprises means for assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MW AB node, and wherein the MW AB node has a second network interface connection with the other radio access node, and the apparatus further comprises means for sending a network interface connection release message from the MW AB node to the other radio access node, the network interface connection release message including identifiers of the MW AB node and the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0217] Clause 18. The apparatus of clause 16 or clause 17, wherein the apparatus further comprises means for assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MW AB node, wherein the context information is forwarded to the anchor radio access node from which identifiers of the MW AB node and the anchor radio access node are sent to the other radio access node to enable the other radio access node to retrieve the context information based on the I- RNTI and the identifiers.

[0218] Clause 19. The apparatus of any of clauses 16 to 18, wherein the apparatus further comprises means for assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MW AB node, and wherein the release message sent to the at least one user equipment, and the request sent from the at least one user equipment to the other radio access node, further includes an identifier of the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifier of the anchor radio access node.

[0219] Clause 20. The apparatus of any of clauses 16 to 19, wherein the apparatus further comprises means for assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MW AB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNU identifies the context information and the anchor radio access node from which the context information is retrievable.

[0220] Clause 21. The apparatus of any of clauses 12 to 20, wherein the context information is forwarded by the M AB node to the shared database from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service.

[0221] Clause 22. The apparatus of clause 21, wherein the apparatus further comprises means for assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MWAB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNU identifies the context information and the shared database.

[0222] Clause 23. A method comprising: providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; sending a release message from the MWAB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; making a determination at the MWAB node to release a network interface connection with one or more radio access nodes; and based on the determination, forwarding the context information associated with the at least one user equipment triggered to transition to the inactive state by the MWAB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0223] Clause 24. The method of clause 23, wherein the context information is forwarded with information that indicates at least one condition on which the context information is releasable by the one or more radio access nodes or the shared database.

[0224] Clause 25. The method of clause 23 or clause 24, wherein the one or more radio access nodes to which the context information is forwarded include at least one of the radio access node by which the MWAB node is served over the wireless backhaul, or at least one other radio access node in a notification area of the at least one user equipment.

[0225] Clause 26. The method of any of clauses 23 to 25, wherein the context information is forwarded by the MW AB node to the radio access nodes to enable the one or more radio access nodes to provide the continued radio network service.

[0226] Clause 27. The method of any of clauses 23 to 26, wherein the context information is forwarded by the MW AB node to the one or more radio access nodes including an anchor radio access node from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service to the at least one user equipment.

[0227] Clause 28. The method of clause 27, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the MW AB node, and wherein the MW AB node has a second network interface connection with the other radio access node, and the method further comprises sending a network interface connection release message from the MW AB node to the other radio access node, the network interface connection release message including identifiers of the MW AB node and the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0228] Clause 29. The method of clause 27 or clause 28, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MW AB node, wherein the context information is forwarded to the anchor radio access node from which identifiers of the MW AB node and the anchor radio access node are sent to the other radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0229] Clause 30. The method of any of clauses 27 to 29, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the MW AB node, and wherein the release message sent to the at least one user equipment, and the request sent from theat least one user equipment to the other radio access node, further includes an identifier of the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNU and the identifier of the anchor radio access node.

[0230] Clause 31. The method of any of clauses 27 to 30, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNTI identifies the context information and the anchor radio access node from which the context information is retrievable.

[0231] Clause 32. The method of any of clauses 23 to 31, wherein the context information is forwarded by the MW AB node to the shared database from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service.

[0232] Clause 33. The method of clause 32, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the shared database.

[0233] Clause 34. A computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node; send a release message from the MW AB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; make a determination at the MW AB node to release a network interface connection with one or more radio access nodes; and based on the determination, forward the context information associated with the at least one user equipment triggered to transition to the inactive state by the MWAB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

[0234] Clause 35. The computer-readable storage medium of clause 34, wherein the context information is forwarded with information that indicates at least one condition on which the context information is releasable by the one or more radio access nodes or the shared database.

[0235] Clause 36. The computer-readable storage medium of clause 34 or clause 35, wherein the one or more radio access nodes to which the context information is forwarded include at least one of the radio access node by which the MW AB node is served over the wireless backhaul, or at least one other radio access node in a notification area of the at least one user equipment.

[0236] Clause 37. The computer-readable storage medium of any of clauses 34 to 36, wherein the context information is forwarded by the M AB node to the one or more radio access nodes to enable the one or more radio access nodes to provide the continued radio network service.

[0237] Clause 38. The computer-readable storage medium of any of clauses 34 to 37, wherein the context information is forwarded by the MWAB node to the one or more radio access nodes including an anchor radio access node from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service to the at least one user equipment.

[0238] Clause 39. The computer-readable storage medium of clause 38, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further assign an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MWAB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the MWAB node, and wherein the MWAB node has a second network interface connection with the other radio access node, and the computer- readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further send a network interface connection release message from the MWAB node to the other radio access node, the network interface connection release message including identifiers of the MWAB node and the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0239] Clause 40. The computer-readable storage medium of clause 38 or clause 39, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further assign an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MWAB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the MWAB node, wherein the context information isforwarded to the anchor radio access node from which identifiers of the MW AB node and the anchor radio access node are sent to the other radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifiers.

[0240] Clause 41. The computer-readable storage medium of any of clauses 38 to 40, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further assign an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the MW AB node, and wherein the release message sent to the at least one user equipment, and the request sent from the at least one user equipment to the other radio access node, further includes an identifier of the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNTI and the identifier of the anchor radio access node.

[0241] Clause 42. The computer-readable storage medium of any of clauses 38 to 41, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further assign an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNH identifies the context information and the anchor radio access node from which the context information is retrievable.

[0242] Clause 43. The computer-readable storage medium of any of clauses 34 to 42, wherein the context information is forwarded by the MW AB node to the shared database from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service.

[0243] Clause 44. The computer-readable storage medium of clause 43, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further assign an inactive radio network temporary identifier (I-RNTI) to the at least one user equipment by the MW AB node, the release message includes the I-RNTI for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNH identifies the context information and the shared database.

[0244] Clause 45. An apparatus comprising means for performing the method of any of clauses 23 to 33.

[0245] Clause 46. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 23 to 33.

[0246] Clause 47. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 23 to 33.

[0247] Clause 48. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 23 to 33.

[0248] Clause 49. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node; make a determination at the MW AB node to send the at least one user equipment to an inactive state; and based on the determination, carry out a handover procedure to hand over each user equipment of the at least one user equipment from the MW AB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0249] Clause 50. The apparatus of clause 49, wherein the apparatus caused to carry out the handover procedure also includes the apparatus caused to send a cause for the handover from the MW AB node to the radio access node or the other radio access node, the cause including a request for the radio access node or the other radio access node to send the at least one user equipment to the inactive state.

[0250] Clause 51. An apparatus comprising: means for providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node; means for making a determination at the MW AB node to send the at least one user equipment to an inactive state; and based on the determination,means for carrying out a handover procedure to hand over each user equipment of the at least one user equipment from the MW AB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0251] Clause 52. The apparatus of clause 51, wherein the means for carrying out the handover procedure includes means for sending a cause for the handover from the M AB node to the radio access node or the other radio access node, the cause including a request for the radio access node or the other radio access node to send the at least one user equipment to the inactive state.

[0252] Clause 53. A method comprising: providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; making a determination at the MWAB node to send the at least one user equipment to an inactive state; and based on the determination, carrying out a handover procedure to hand over each user equipment of the at least one user equipment from the MWAB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0253] Clause 54. The method of clause 53, wherein carrying out the handover procedure also includes sending a cause for the handover from the MWAB node to the radio access node or the other radio access node, the cause including a request for the radio access node or the other radio access node to send the at least one user equipment to the inactive state.

[0254] Clause 55. A computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: provide a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; make a determination at the MWAB node to send the at least one user equipment to an inactive state; and based on the determination, carry out a handover procedure to hand over each user equipment of the at least one user equipment from the MWAB node to the radio access node or another radio access node, including forwarding the context information to the radio accessnode or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

[0255] Clause 56. The computer-readable storage medium of clause 55, wherein the apparatus caused to carry out the handover procedure also includes the apparatus caused to send a cause for the handover from the MW AB node to the radio access node or the other radio access node, the cause including a request for the radio access node or the other radio access node to send the at least one user equipment to the inactive state.

[0256] Clause 57. An apparatus comprising means for performing the method of clause 53 or clause 54.

[0257] Clause 58. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of clause 53 or clause 54.

[0258] Clause 59. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of clause 53 or clause 54.

[0259] Clause 60. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of clause 53 or clause 54.

[0260] Clause 61. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: receive context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (M AB) node served over a wireless backhaul by a radio access node; receive a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state; determine the context information is available without retrieving the context information from the MW AB node; and provide the continued radio network service to the user equipment based on the context information.

[0261] Clause 62. The apparatus of clause 61, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further at least: carry out a path switch procedure for the user equipment with an access and mobility management function.

[0262] Clause 63. An apparatus comprising: means for receiving context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MW AB) node served over a wireless backhaul by a radio access node; meansfor receiving a request to provide a continued radio network service to an user equipment of the at least one user equipment in the inactive state; means for determining the context information is available without retrieving the context information from the MWAB node; and means for providing the continued radio network service to the user equipment based on the context information.

[0263] Clause 64. The apparatus of clause 63, wherein the apparatus further comprises: means for carrying out a path switch procedure for the user equipment with an access and mobility management function.

[0264] Clause 65. A method comprising: receiving context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MWAB) node served over a wireless backhaul by a radio access node; receiving a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state; determining the context information is available without retrieving the context information from the MWAB node; and providing the continued radio network service to the user equipment based on the context information.

[0265] Clause 66. The method of clause 65, wherein the method further comprises: carrying out a path switch procedure for the user equipment with an access and mobility management function.

[0266] Clause 67. A computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: receive context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MWAB) node served over a wireless backhaul by a radio access node; receive a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state; determine the context information is available without retrieving the context information from the MWAB node; and provide the continued radio network service to the user equipment based on the context information.

[0267] Clause 68. The computer-readable storage medium of clause 67, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further at least: carry out a path switch procedure for the user equipment with an access and mobility management function.

[0268] Clause 69. An apparatus comprising means for performing the method of clause 65 or clause 66.

[0269] Clause 70. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of clause 65 or clause 66.

[0270] Clause 71. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of clause 65 or clause 66.

[0271] Clause 72. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of clause 65 or clause 66.

[0272] Clause 73. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: receive a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNH) assigned to the user equipment by a mobile wireless access backhaul (MWAB) node that sent the user equipment to the inactive mode; determine a network node other than the MWAB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNTI; retrieve the context information from the network node based on the I-RNU; and provide the continued radio network service to the user equipment based on the context information.

[0273] Clause 74. The apparatus of clause 73, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further at least: carry out a path switch procedure for the user equipment with an access and mobility management function.

[0274] Clause 75. The apparatus of clause 73 or clause 74, wherein the apparatus caused to determine the network node storing the context information includes the apparatus caused to determine an anchor radio access node storing the context information.

[0275] Clause 76. The apparatus of clause 75, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further receive identifiers of the MWAB node and the anchor radio access node from the MWAB node, and wherein the I-RNTI identifies the context information and the MWAB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

[0276] Clause 77. The apparatus of clause 75 or clause 76, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further receive identifiers of the MW AB node and the anchor radio access node from the anchor radio access node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I- RNTI and the identifiers.

[0277] Clause 78. The apparatus of any of clauses 75 to 77, wherein the request to provide the continued radio network service includes an identifier of the anchor radio access node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifier of the anchor radio access node.

[0278] Clause 79. The apparatus of any of clauses 75 to 78, wherein the I-RNTI identifies the context information and the anchor radio access node storing the context information.

[0279] Clause 80. The apparatus of any of clauses 73 to 79, wherein the apparatus caused to determine the network node storing the context information includes the apparatus caused to determine a shared database storing the context information, and wherein the I-RNTI identifies the context information and the shared database storing the context information.

[0280] Clause 81. An apparatus comprising: means for receiving a request to provide a continued radio network service to an user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNTI) assigned to the user equipment by a mobile wireless access backhaul (MW AB) node that sent the user equipment to the inactive mode; means for determining a network node other than the MW AB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNTI; means for retrieving the context information from the network node based on the I-RNTI; and means for providing the continued radio network service to the user equipment based on the context information.

[0281] Clause 82. The apparatus of clause 81, wherein the apparatus further comprises: means for carrying out a path switch procedure for the user equipment with an access and mobility management function.

[0282] Clause 83. The apparatus of clause 81 or clause 82, wherein the means for determining the network node storing the context information includes means for determining an anchor radio access node storing the context information.

[0283] Clause 84. The apparatus of clause 83, wherein the apparatus further comprises means for receiving identifiers of the MWAB node and the anchor radio access node from the MW AB node, and wherein the I-RNTI identifies the context information and the MWAB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

[0284] Clause 85. The apparatus of clause 83 or clause 84, wherein the apparatus further comprises means for receiving identifiers of the MWAB node and the anchor radio access node from the anchor radio access node, and wherein the I-RNTI identifies the context information and the MWAB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

[0285] Clause 86. The apparatus of any of clauses 83 to 85, wherein the request to provide the continued radio network service includes an identifier of the anchor radio access node, and wherein the I-RNTI identifies the context information and the MWAB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifier of the anchor radio access node.

[0286] Clause 87. The apparatus of any of clauses 83 to 86, wherein the I-RNTI identifies the context information and the anchor radio access node storing the context information.

[0287] Clause 88. The apparatus of any of clauses 81 to 87, wherein the means for determining the network node storing the context information includes means for determining a shared database storing the context information, and wherein the I-RNTI identifies the context information and the shared database storing the context information.

[0288] Clause 89. A method comprising: receiving a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNTI) assigned to the user equipment by a mobile wireless access backhaul (MWAB) node that sent the user equipment to the inactive mode; determining a network node other than the MWAB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNTI; retrieving the context information from the network node based on the I-RNTI; and providing the continued radio network service to the user equipment based on the context information.

[0289] Clause 90. The method of clause 89, wherein the method further comprises: carrying out a path switch procedure for the user equipment with an access and mobility management function.

[0290] Clause 91. The method of clause 89 or clause 90, wherein determining the network node storing the context information includes determining an anchor radio access node storing the context information.

[0291] Clause 92. The method of clause 91, wherein the method further comprises receiving identifiers of the MW AB node and the anchor radio access node from the MW AB node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

[0292] Clause 93. The method of clause 91 or clause 92, wherein the method further comprises receiving identifiers of the MW AB node and the anchor radio access node from the anchor radio access node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

[0293] Clause 94. The method of any of clauses 91 to 93, wherein the request to provide the continued radio network service includes an identifier of the anchor radio access node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifier of the anchor radio access node.

[0294] Clause 95. The method of any of clauses 91 to 94, wherein the I-RNTI identifies the context information and the anchor radio access node storing the context information.

[0295] Clause 96. The method of any of clauses 89 to 95, wherein determining the network node storing the context information includes determining a shared database storing the context information, and wherein the I-RNTI identifies the context information and the shared database storing the context information.

[0296] Clause 97. A computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: receive a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNTI) assigned to the user equipment by a mobile wireless access backhaul (MW AB) node that sent the user equipment to the inactive mode; determine a network node other than the MW AB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNTI; retrievethe context information from the network node based on the I-RNTI; and provide the continued radio network service to the user equipment based on the context information.

[0297] Clause 98. The computer-readable storage medium of clause 97, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further at least: carry out a path switch procedure for the user equipment with an access and mobility management function.

[0298] Clause 99. The computer-readable storage medium of clause 97 or clause 98, wherein the apparatus caused to determine the network node storing the context information includes the apparatus caused to determine an anchor radio access node storing the context information.

[0299] Clause 100. The computer-readable storage medium of clause 99, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further receive identifiers of the MW AB node and the anchor radio access node from the MW AB node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

[0300] Clause 101. The computer-readable storage medium of clause 99 or clause 100, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the apparatus to further receive identifiers of the MW AB node and the anchor radio access node from the anchor radio access node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I- RNTI and the identifiers.

[0301] Clause 102. The computer-readable storage medium of any of clauses 99 to 101, wherein the request to provide the continued radio network service includes an identifier of the anchor radio access node, and wherein the I-RNTI identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifier of the anchor radio access node.

[0302] Clause 103. The computer-readable storage medium of any of clauses 99 to 102, wherein the I-RNH identifies the context information and the anchor radio access node storing the context information.

[0303] Clause 104. The computer-readable storage medium of any of clauses 99 to 103, wherein the apparatus caused to determine the network node storing the context information includes the apparatus caused to determine a shared database storing the context information, and wherein the I-RNTI identifies the context information and the shared database storing the context information.

[0304] Clause 105. An apparatus comprising means for performing the method of any of clauses 89 to 96.

[0305] Clause 106. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 89 to 96.

[0306] Clause 107. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 89 to 96.

[0307] Clause 108. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 89 to 96.

[0308] Many modifications and other implementations of the disclosure set forth herein will come to mind to one skilled in the art to which the disclosure pertains having the benefit of the teachings presented in the foregoing description and the associated figures. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated figures describe example implementations in the context of certain example combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

We Claim:

1. A method comprising: providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MW AB) node having context information associated with the at least one user equipment, the MW AB node served over a wireless backhaul by a radio access node; sending a release message from the MW AB node to the at least one user equipment to trigger the at least one user equipment to transition to an inactive state; making a determination at the MW AB node to release a network interface connection with one or more radio access nodes; and based on the determination, forwarding the context information associated with the at least one user equipment triggered to transition to the inactive state by the MW AB node to the one or more radio access nodes or a shared database at which the context information is stored to enable a continued radio network service to the at least one user equipment.

2. The method of claim 1 , wherein the context information is forwarded with information that indicates at least one condition on which the context information is releasable by the one or more radio access nodes or the shared database.

3. The method of claim 1 or claim 2, wherein the one or more radio access nodes to which the context information is forwarded include at least one of the radio access node by which the MW AB node is served over the wireless backhaul, or at least one other radio access node in a notification area of the at least one user equipment.

4. The method of any of claims 1 to 3, wherein the context information is forwarded by the MW AB node to the one or more radio access nodes to enable the one or more radio access nodes to provide the continued radio network service.

5. The method of any of claims 1 to 4, wherein the context information is forwarded by the MW AB node to the one or more radio access nodes including an anchor radio access node from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service to the at least one user equipment.

6. The method of claim 5, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MW AB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the MW AB node, and wherein the MW AB node has a second network interface connection with the other radio access node, and the method further comprises sending a network interface connection release message from the MW AB node to the other radio access node, the network interface connection release message including identifiers of the MW AB node and the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNU and the identifiers.

7. The method of claim 5 or claim 6, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MW AB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the MW AB node, wherein the context information is forwarded to the anchor radio access node from which identifiers of the MW AB node and the anchor radio access node are sent to the other radio access node to enable the other radio access node to retrieve the context information based on the I- RNTI and the identifiers.

8. The method of any of claims 5 to 7, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MWAB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNU identifies the context information and the MWAB node, and wherein the release message sent to the at least one user equipment, and the request sent from the at least one user equipment to the other radio access node, further includes an identifier of the anchor radio access node to enable the other radio access node to retrieve the context information based on the I-RNU and the identifier of the anchor radio access node.

9. The method of any of claims 5 to 8, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MWAB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I-RNU identifies the context information and the anchor radio access node from which the context information is retrievable.

10. The method of any of claims 1 to 9, wherein the context information is forwarded by the MWAB node to the shared database from which the context information is retrievable by another radio access node to enable the other radio access node to provide the continued radio network service.

11. The method of claim 10, wherein the method further comprises assigning an inactive radio network temporary identifier (I-RNU) to the at least one user equipment by the MWAB node, the release message includes the I-RNU for the at least one user equipment to use in a request for the continued radio network service with the other radio access node, and the I- RNTI identifies the context information and the shared database.

12. A method comprising: providing a radio network service to at least one user equipment by a mobile wireless access backhaul (MWAB) node having context information associated with the at least one user equipment, the MWAB node served over a wireless backhaul by a radio access node; making a determination at the MWAB node to send the at least one user equipment to an inactive state; and based on the determination, carrying out a handover procedure to hand over each user equipment of the at least one user equipment from the MWAB node to the radio access node or another radio access node, including forwarding the context information to the radio access node or the other radio access node from which a release message is sent to the at least one user equipment to trigger the at least one user equipment to transition to the inactive state.

13. The method of claim 12, wherein carrying out the handover procedure also includes sending a cause for the handover from the MWAB node to the radio access node or theother radio access node, the cause including a request for the radio access node or the other radio access node to send the at least one user equipment to the inactive state.

14. A method comprising: receiving context information associated with at least one user equipment being sent to an inactive state by a mobile wireless access backhaul (MW AB) node served over a wireless backhaul by a radio access node; receiving a request to provide a continued radio network service to a user equipment of the at least one user equipment in the inactive state; determining the context information is available without retrieving the context information from the MW AB node; and providing the continued radio network service to the user equipment based on the context information.

15. The method of claim 14, wherein the method further comprises: carrying out a path switch procedure for the user equipment with an access and mobility management function.

16. A method comprising: receiving a request to provide a continued radio network service to a user equipment in an inactive state, the request including an inactive radio network temporary identifier (I-RNTI) assigned to the user equipment by a mobile wireless access backhaul (MW AB) node that sent the user equipment to the inactive mode; determining a network node other than the MW AB node storing context information associated with the user equipment to enable the continued radio network service, the network node determined based on the I-RNTI; retrieving the context information from the network node based on the I-RNTI; and providing the continued radio network service to the user equipment based on the context information.

17. The method of claim 16, wherein the method further comprises: carrying out a path switch procedure for the user equipment with an access and mobility management function.

18. The method of claim 16 or claim 17, wherein determining the network node storing the context information includes determining an anchor radio access node storing the context information.

19. The method of claim 18, wherein the method further comprises receiving identifiers of the MW AB node and the anchor radio access node from the MW AB node, and wherein the I-RNU identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

20. The method of claim 18 or claim 19, wherein the method further comprises receiving identifiers of the MW AB node and the anchor radio access node from the anchor radio access node, and wherein the I-RNU identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifiers.

21. The method of any of claims 18 to 20, wherein the request to provide the continued radio network service includes an identifier of the anchor radio access node, and wherein the I-RNU identifies the context information and the MW AB node, and the anchor radio access node storing the context information is determined based on the I-RNTI and the identifier of the anchor radio access node.

22. The method of any of claims 18 to 21, wherein the I-RNU identifies the context information and the anchor radio access node storing the context information.

23. The method of any of claims 16 to 22, wherein determining the network node storing the context information includes determining a shared database storing the context information, and wherein the I-RNU identifies the context information and the shared database storing the context information.

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