Core network awareness of User Equipment (UE) status

Abstract

According to some embodiments, a method for use in a network node to provide a core network node with a radio resource control (RRC) state of a user equipment (UE) includes: receiving a request from the core network node to receive a notification of a transition of the UE between a first and a second RRC state; determining that the UE has transitioned between the first and second RRC states; and sending a notification of the transition to the core network node. A method for use in a core network node to receive RRC state information of a UE includes: sending a subscription request to the network node to receive notification of a transition of the UE between a first and a second RRC state; and receiving a notification from the network node when the network node determines that the UE has transitioned between the first and the second RRC state.

Description

Technical Field

[0001] Certain embodiments of the present disclosure relate generally to wireless communications and, more particularly, to core network awareness of a user equipment (UE) state, such as the UE state relative to a radio access network (RAN). Background Art

[0002] In a typical wireless, cellular or radio communication network, wireless devices (also referred to as mobile stations, terminals and / or user equipment (UE)) communicate with one or more core networks via a radio access network (RAN). The RAN covers a geographical area that is divided into cells. Each cell is served by a base station (e.g., a radio base station (RBS) or a network node, which in some networks may also be referred to as, for example, a "NodeB," "eNodeB," or "eNB"). A cell is a geographical area in which radio coverage is provided by a radio base station at a base station site or an antenna site (in the case where the antenna and radio base station are not co-located). One radio base station may serve one or more cells.

[0003] The Universal Mobile Telecommunications System (UMTS) is a third-generation (3G) mobile communications system that evolved from the second-generation (2G) Global System for Mobile Communications (GSM). The UMTS Terrestrial Radio Access Network (UTRAN) is essentially a RAN that uses Wideband Code Division Multiple Access (WCDMA) and / or High-Speed ​​Packet Access (HSPA) to communicate with user equipment.

[0004] In a forum known as the 3rd Generation Partnership Project (3GPP), telecommunications vendors specifically propose and agree on standards for third-generation networks and UTRAN, and work on enhanced data rates and radio capacity. In some versions of RAN, such as UMTS, several base stations can be connected (e.g., via landlines or microwave) to a controller node, such as a radio network controller (RNC) or base station controller (BSC), which oversees and coordinates the various activities of the multiple base stations connected to it. The RNC is typically connected to one or more core networks.

[0005] Specifications for the Evolved Packet System (EPS) have been completed within 3GPP, and this work continues in upcoming 3GPP releases. The EPS comprises the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as Long Term Evolution (LTE), the radio access, and the Evolved Packet Core (EPC), also known as the System Architecture Evolution (SAE) core network. E-UTRAN / LTE is a variant of the 3GPP radio access technology in which radio base station nodes are directly connected to the EPC core network rather than being directly connected to the RNC. Generally, in E-UTRAN / LTE, the functionality of the RNC is distributed between the radio base station nodes (e.g., eNodeBs in LTE) and the core network. The RAN of the EPS has a substantially flat architecture, comprising radio base station nodes that do not report to the RNC.

[0006] Radio Resource Control (RRC) can be used in the control plane. The main functions of the control plane include the following: broadcast of system information for non-access stratum (NAS) and access stratum (AS) paging; RRC connection handling; allocation of temporary identifiers for UEs; configuration of (one or more) signaling radio bearers for RRC connections; handling of radio bearers; Quality of Service (QoS) management functions; security functions (including key management); mobility functions (including UE measurement reporting and control of reporting, handover, UE cell selection and reselection, and control of cell selection and reselection); and NAS direct message transfer to / from UEs.

[0007] There is one Packet Data Convergence Protocol (PDCP) entity for each radio bearer of a UE. PDCP is used for both the control plane (i.e., RRC) and the user plane (i.e., user data received via GPRS Tunneling Protocol-User Tunneling (GTP-U) signaling). The main functions of the control plane are encryption / decryption and integrity protection. The main functions of the user plane include encryption / decryption, header compression and decompression using Robust Header Compression (ROHC), in-sequence delivery, duplicate detection, and retransmission.

[0008] The Radio Link Control (RLC) layer provides services for the PDCP layer. There is one RLC entity for each radio bearer of the UE. The main functions of both the control plane and the user plane include: segmentation / splicing, retransmission handling, duplicate detection, and in-sequence delivery to higher layers.

[0009] The Medium Access Control (MAC) provides services to the RLC layer in the form of logical channels and performs mapping between logical channels and transport channels. Key MAC functions include uplink and downlink scheduling, scheduling information reporting, Hybrid Automatic Repeat Request (HARQ) retransmissions, and multiplexing / demultiplexing data across multiple component carriers in carrier aggregation.

[0010] The physical layer (PHY) provides services to the MAC layer in the form of transport channels and handles the mapping of transport channels to physical channels.

[0011] Information related to one or more of these protocol layers and their functionality is hereinafter referred to as RAN context information. In other words, the configuration of these protocol layers for a specific wireless device is the RAN context information for the specific wireless device in the wireless communication network. The configuration of the protocol layers is typically performed at the RRC layer via RRC configuration messages.

[0012] One example of configuration specific information is different identifiers on different protocol layers for a wireless device.The RAN context information may also include additional information such as, for example, the radio access capabilities of the wireless device, previous mobility or traffic history of the wireless device, and so on.

[0013] The above functionality of a network node (e.g., an eNB) can be deployed in different ways. In one example, all protocol layers and related functionality are deployed in the same physical node, including the antenna. An example of this is a micro or femto eNodeB. Another example is a Main-Remote split. In this case, the eNodeB is divided into a main unit and a remote unit. The main unit may also be referred to as a digital unit (DU), and the remote unit is also referred to as a remote radio unit (RRU). In this case, the main unit includes all protocol layers except the lower part of the PHY layer (which is instead placed in the remote unit). In a further example, the remote unit and the antenna are co-located. This may be referred to as an Antenna Integrated Radio (AIR) system.

[0014] The RAN can handle inactive UEs. 3GPP contribution R3-161290 of the 3GPP RAN 3WG meeting in May 2016 (available from www.3gpp.org / ftp / tsg_ran / WG3_Iu / TSGR3_92 / Docs / R3-161290.zip; incorporated herein by reference) includes proposals for a RAN controlled inactive state (as described below).

[0015] If RAN controlled inactive mode is supported, this means that the transition from inactive to active state in the RAN will be transparent to the CN. In the downlink, default downlink packets will be sent to the last node to which the UE was connected (the anchor RAN node). This node is responsible for initiating UE paging within the paging area that the UE is allowed to enter without notifying the network. In the uplink, the UE performs RAN-level procedures to transition to active state to transmit data. If the UE has moved to a different RAN node, the new RAN node will most likely obtain the UE context from another RAN node and, if necessary, notify the CN that the UE has moved to the new node. If the UE moves out of the paging area, the UE can notify the network about the mobility so that the paging area can be updated. This process can trigger a RAN node relocation, or the RAN node can be retained.

[0016] The following RAN functions may be included for inactive mode: (a) paging downlink data; (b) context acquisition to handle mobile UEs (which may be similar to existing LTE procedures); and (c) mobility updates (possibly this may use similar mechanisms as context acquisition). To enable these mechanisms, the UE needs to be assigned a RAN identifier that uniquely identifies the UE context in the RAN. In the event of any failure where it is not possible to retrieve the UE RAN context, it is assumed that the RAN context can be re-established, as it would happen in the case of a new connection establishment. An example is in Figure 1 and 2 is shown in .

[0017] Figure 1 and 2 is a block diagram illustrating signaling between a core network node, a network node, and a wireless device. Figure 1 In FIG, core network node 320 is in communication with three network nodes 120. UE 110 was last connected to network node 120b. UE 110 can move around in the local area without reporting to the network. Core network node 320 maintains a connection to network node 120b.

[0018] When packets arrive for delivery to UE 110, core network node 320 contacts network node 120b. Network node 120b pages UE 110. Network node 120b also instructs network nodes 120a and 120b to page UE 110.

[0019] exist Figure 2In FIG, core network node 320 is in communication with three network nodes 120. UE 110 was last connected to network node 120b. UE 110 can move around in the local area without reporting to the network. Core network node 320 maintains a connection to network node 120b.

[0020] For example, when UE 110 has data to transmit, UE 110 sends a connection request or mobility update to network node 120a. Network node 120a sends a path switch request to core network node 320. Network node 120a also obtains the context of UE 110 from network node 120b.

[0021] Next Generation (NG) core networks should consider the state machines included in the RRC protocol within the new RAT. For example, the mobility state machine for RRC may have an inactive connected state (in addition to the RRC connected state and the RRC idle state). The inactive connected state may also be referred to as the inactive state. Configurability of the RRC inactive connected state may be required to support features that require flexibility, such as the diverse requirements of 5G use cases, future-proofing for new services, and fast time-to-market requirements.

[0022] From the perspective of the Next Generation Core Network, a UE is considered to be in the NG CM-CONNECTED state when it is in the RRC Inactive Connected state at the RRC layer. RRC Inactive Connected is a state in which the UE behaves as if it were in RRC_IDLE at the access stratum (AS) level. However, the UE still enjoys a dedicated active signaling connection and user plane channels between its serving RAN node and the CN. When the UE transitions between the RRC Connected state and the RRC Inactive Connected state, the event is not visible to the core network because no signaling towards the core network is expected based on the transition. Furthermore, the core network does not need to page the UE while it is in the RRC Inactive Connected state because both the control plane and the user plane remain established between the RAN and the core.

[0023] The characteristics of the RRC inactive connection state include: (a) The UE is considered to be in NG between the UE and the CN CM-CONNECTED state; (b) configurable to serve service(s) requested by the UE, which means that the RRC Inactive Connected state can be configured based on the characteristics and requirements of the application(s) running in the UE, subscriptions and UE activity (the core network can provide relevant information to the RAN; (c) inspired by the cell reselection procedure with configuration from the network based on UE mobility, network controlled handover is not supported; (d) when the UE moves out of the registration area(s), the UE performs an area registration with the CN; (e) the access stratum (AS) context is stored in the RAN and the UE; (f) the RRC Inactive Connected to RRC Connected state transition is inspired by the suspend and resume procedures defined for LTE in Rel-13 (no signaling to the CN is required to perform the transition, and the AS context can be transferred between RAN nodes); (g) the U-plane and C-plane connections between the RAN and the core remain established; (h) UE reachability will be managed by the RAN with the assistance of the core network; (i) UE paging will be managed by the RAN; (j) the CN will transition to NG-CM upon RAN request IDLE state; (k) Distributed mobility management, where the network follows the UE at the CN level; (l) No Rx / Tx data is performed in this state; (m) In order to support LTE and NR deployments in an efficient manner, the solution for state transition should avoid or minimize UE signaling when the UE switches between Evolved E-UTRA in inactive state and NR.

[0024] Figure 3 This is a state transition diagram showing the RRC state machine within the NG CM / MM state machine model when the RRC INACTIVE CONNECTED state is used. A problem with this particular state machine is that the transition between RRC CONNECTED and RRC CONNECTED INACTIVE is assumed to occur without signaling to the NGCN. This impacts certain functionality supported in the CN (e.g., information about the UE's location after transitioning to RRC CONNECTED INACTIVE can no longer be assumed to be reliable, as the UE has not informed the network of its whereabouts at, for example, a cell-level granularity, as it did when it was RRC CONNECTED). Summary of the Invention

[0025] Specific embodiments include a radio access network (RAN) that provides a core network (CN) with information about whether a user equipment (UE) is or may be in a radio resource control (RRC) connected or RRC connection inactive (or simply inactive) state. The CN can use this information to determine how to manage specific functions, such as functions that depend on granularity or knowledge of the UE's location.

[0026] According to some embodiments, a method for use in a network node to provide an RRC state of a UE to a core network node comprises: receiving a request from the core network node to receive a notification of a transition of the UE between a first RRC state and a second RRC state; determining that the UE has transitioned between the first RRC state and the second RRC state; and sending the notification of the transition of the UE between the first RRC state and the second RRC state to the core network node. The network node may send a subscription response to the core network node indicating that the network node will provide the notification.

[0027] In a specific embodiment, the subscription request includes a request for receiving location information of the UE. The subscription request may include a periodicity for receiving the notification. The periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state.

[0028] In a specific embodiment, the notification includes location information of the UE. The first RRC state may be RRC CONNECTED, and the second RRC state may be RRC CONNECTED INACTIVE (or simply RRC INACTIVE). The subscription request may include an information element (IE) in an INITIAL CONTEXT SETUP REQUEST, and the subscription response may include an IE in an INITIAL CONTEXT SETUP RESPONSE.

[0029] According to some embodiments, a network node capable of providing an RRC state of a UE to a core network node includes processing circuitry. The processing circuitry is operable to: receive a request from the core network node to receive a notification of a transition of the UE between a first RRC state and a second RRC state; determine that the UE has transitioned between the first RRC state and the second RRC state; and send the notification of the transition of the UE between the first RRC state and the second RRC state to the core network node. The processing circuitry is further operable to send a subscription response to the core network node indicating that the network node will provide the notification.

[0030] In a specific embodiment, the subscription request includes a request for receiving location information of the UE. The subscription request may include a periodicity for receiving the notification. The periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state.

[0031] In a specific embodiment, the notification includes location information of the UE. The first RRC state may be RRC CONNECTED, and the second RRC state may be RRC CONNECTED INACTIVE. The subscription request may include an IE in INITIAL CONTEXT SETUP REQUEST, and the subscription response may include an IE in INITIAL CONTEXT SETUP RESPONSE.

[0032] According to some embodiments, a method for use in a core network node to receive RRC state information of a UE includes: sending a subscription request to a network node to receive notification of a transition of the UE between a first RRC state and a second RRC state; and receiving the notification from the network node when the network node determines that the UE has transitioned between the first RRC state and the second RRC state. The core network node may receive a subscription response from the network node indicating that the network node will provide the notification.

[0033] In a specific embodiment, the subscription request includes a request for receiving location information of the UE. The subscription request may include a periodicity for receiving the notification.

[0034] In a specific embodiment, the notification includes location information of the UE. The first RRC state may be RRC CONNECTED, and the second RRC state may be RRC CONNECTED INACTIVE (or simply RRC INACTIVE). The subscription request may include an IE in an INITIAL CONTEXT SETUP REQUEST, and the subscription response may include an IE in an INITIAL CONTEXT SETUP RESPONSE.

[0035] In a particular embodiment, the method further comprises modifying the operation of the core network node with respect to the UE based on the received notification.

[0036] According to some embodiments, a core network node capable of receiving RRC state information of a UE includes processing circuitry. The processing circuitry is operable to: send a subscription request to a network node for receiving notifications of transitions of the UE between a first RRC state and a second RRC state; and, upon the network node determining that the UE has transitioned between the first RRC state and the second RRC state, receive the notification from the network node. The processing circuitry is further operable to receive a subscription response from the network node indicating that the network node will provide the notification.

[0037] In a specific embodiment, the subscription request includes a request for receiving location information of the UE. The subscription request may include a periodicity for receiving the notification.

[0038] In a specific embodiment, the notification includes location information of the UE. The first RRC state may be RRC CONNECTED, and the second RRC state may be RRC CONNECTED INACTIVE. The subscription request may include an IE in INITIAL CONTEXT SETUP REQUEST, and the subscription response may include an IE in INITIAL CONTEXT SETUPRESPONSE.

[0039] In particular embodiments, the processing circuit is further operable to modify operation of the core network node relative to the UE based on the received notification.

[0040] According to some embodiments, a network node capable of providing an RRC state of a UE to a core network node includes a receiving module, a determining module, and a transmitting module. The receiving module is operable to receive a request from the core network node for receiving a notification of a transition of the UE between a first RRC state and a second RRC state. The determining module is operable to determine that the UE has transitioned between the first RRC state and the second RRC state. The transmitting module is operable to send the notification of the transition of the UE between the first RRC state and the second RRC state to the core network node.

[0041] According to some embodiments, a core network node capable of receiving RRC state information of a UE includes a receiving module and a transmitting module. The transmitting module is operable to send a subscription request to a network node for receiving notifications of transitions of the UE between a first RRC state and a second RRC state. The receiving module is operable to receive the notification from the network node when the network node determines that the UE has transitioned between the first RRC state and the second RRC state.

[0042] Also disclosed is a computer program product. The computer program product includes instructions stored on a non-transitory computer-readable medium, which, when executed by a processor, perform the following steps: receiving a request from the core network node to receive a notification of a transition of the UE between a first RRC state and a second RRC state; determining that the UE has transitioned between the first RRC state and the second RRC state; and sending the notification of the transition of the UE between the first RRC state and the second RRC state to the core network node.

[0043] Another computer program product includes instructions stored on a non-transitory computer-readable medium, which, when executed by a processor, perform the following steps: sending a subscription request to the network node for receiving notifications of transitions of the UE between a first RRC state and a second RRC state; and receiving the notification from the network node when the network node determines that the UE has transitioned between the first RRC state and the second RRC state.

[0044] Certain embodiments of the present disclosure may provide one or more technical advantages. For example, some embodiments may advantageously enable the CN to subscribe to certain information available in the RAN (e.g., UE transitions between RRC CONNECTED and RRC CONNECTED INACTIVE). The CN may use the information as input to its functionality (e.g., based on the reliability of knowledge about the UE's location). As an example, when the UE is not connected to the system at the AS level and when it will not necessarily report a change in location (e.g., a change in cell), the CN may adjust its behavior for UE location monitoring during periods of inactive connected state. Other advantages may be readily available to those skilled in the art. Certain embodiments may have none, some, or all of the advantages described. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] For a more complete understanding of the embodiments and their features and advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0046] Figure 1 and 2 is a block diagram illustrating signaling between a core network node, a network node, and a wireless device;

[0047] Figure 3 is a state transition diagram showing the RRC state machine within the NG CM / MM state machine model when the RRC INACTIVE CONNECTED state is used;

[0048] Figure 4 is a block diagram illustrating an example wireless network according to a particular embodiment;

[0049] Figure 5 is a sequence diagram illustrating a core network subscription to a radio access network according to some embodiments;

[0050] Figure 6 is a signaling diagram illustrating an initial context setup procedure according to some embodiments;

[0051] Figure 7 is a signaling diagram illustrating a user equipment context modification indication according to some embodiments;

[0052] Figure 8 is a sequence diagram illustrating autonomous notification from a radio access network to a core network according to some embodiments;

[0053] Figure 9 is a flow chart of an example method in a network node according to some embodiments;

[0054] Figure 10 is a flow chart of an example method in a core network node according to some embodiments;

[0055] Figure 11 is a block diagram illustrating an example embodiment of a wireless device;

[0056] Figure 12A is a block diagram illustrating an example embodiment of a network node;

[0057] Figure 12B is a block diagram illustrating example components of a network node;

[0058] Figure 13A is a block diagram illustrating an example embodiment of a core network node; and

[0059] Figure 13B is a block diagram illustrating example components of a core network node. DETAILED DESCRIPTION

[0060] The next generation (NG) core network should consider the state machines included in the radio resource control (RRC) protocol within 5G New Radio (NR). For example, the mobility state machine for RRC may have an inactive connected state (in addition to the RRC connected state and the RRC idle state). The inactive connected state may also be referred to as the inactive state. Configurability of the RRC inactive connected state may be needed to support features that require flexibility, such as the diverse requirements of 5G use cases, future-proofing for new services, and fast time to market requirements.

[0061] From the perspective of the Next Generation Core Network, when a user equipment (UE) is in the RRC Inactive Connected state at the RRC layer, the UE is considered to be in the NG CM-CONNECTED state. RRC Inactive Connected is a state in which the UE behaves as if it were in RRC_IDLE at the access stratum (AS) level. However, the UE still enjoys a dedicated active signaling connection and user plane channels between its serving RAN node and the core network (CN). When the UE transitions between the RRC Connected state and the RRC Inactive Connected state, the events are not visible to the core network because no signaling towards the core network is expected based on the transition. Furthermore, when the UE is in the RRC Inactive Connected state, the core network does not have to page the UE because both the control plane and the user plane remain established between the RAN and the core.

[0062] The problem with the specific state machine is that the transition between RRC CONNECTED and RRC CONNECTED INACTIVE is assumed to take place without signaling to the Next Generation Core Network (NGCN). This affects certain functionalities supported in the CN (e.g., information about the UE's location after the transition to RRC CONNECTED INACTIVE can no longer be assumed to be reliable, since the UE has not informed the network about its whereabouts at a granularity of, for example, cell level, as it did when it was in RRC CONNECTED).

[0063] Specific embodiments described herein eliminate the problems described above and include embodiments that include the RAN providing information to the core network regarding whether a UE is or may be in an RRC connected or RRC connected inactive (or simply inactive) state. This information can be used by the core network to determine how to manage specific functions, such as functions that depend on granularity or knowledge of the UE's location.

[0064] The following description sets forth numerous specific details. However, it is understood that embodiments can be practiced without these specific details. In other instances, well-known circuits, structures, and techniques are not shown in detail to avoid obscuring the understanding of this description. With the included description, one of ordinary skill in the art will be able to implement appropriate functionality without undue experimentation.

[0065] References in the specification to "one embodiment," "an embodiment," "an example embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment may include the particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is intended that it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0066] With reference to the accompanying drawings Figure 4-13B Specific embodiments are described, with like reference numerals used for like and corresponding parts of the various drawings. LTE and NR are used throughout this disclosure as example cellular systems, but the concepts presented herein may also be applied to other wireless communication systems.

[0067] Figure 4 1 is a block diagram illustrating an example wireless network according to a specific embodiment. The wireless network 100 includes one or more wireless devices 110 (e.g., mobile phones, smartphones, laptops, tablets, MTC devices, or any other device that can provide wireless communication) and a plurality of network nodes 120 (e.g., base stations or eNodeBs). The network nodes 120 serve a coverage area 115 (also referred to as a cell 115).

[0068] Generally, a wireless device 110 within the coverage of a radio network node 120 (e.g., within a cell 115 served by the network node 120) communicates with the radio network node 120 by transmitting and receiving wireless signals 130. For example, the wireless device 110 and the radio network node 120 may communicate wireless signals 130 containing voice traffic, data traffic, and / or control signals. A network node 120 that communicates voice traffic, data traffic, and / or control signals to the wireless device 110 may be referred to as a serving network node 120 for the wireless device 110.

[0069] In some embodiments, the wireless device 110 may be referred to by the non-limiting term "UE". A UE may include any type of wireless device capable of communicating with a network node or another UE via radio signals. A UE may include a radio communication device, a target device, a device-to-device (D2D) UE, a machine-type UE, or a UE capable of machine-to-machine communication (M2M), a sensor equipped with a UE, an iPAD, a tablet computer, a mobile terminal, a smartphone, a laptop embedded device (LEE), a laptop mounted device (LME), a USB dongle, a customer premises equipment (CPE), etc.

[0070] In some embodiments, the network node 120 may include any type of network node, such as a base station, a radio base station, a base transceiver station, a base station controller, a network controller, an evolved Node B (eNB), a Node B, a multi-RAT base station, a multi-cell / multicast coordination entity (MCE), a relay node, an access point, a radio access point, a remote radio unit (RRU), a remote radio head (RRH), a core network node (e.g., an MME, a SON node, a coordination node, etc.) or even an external node (e.g., a third-party node, a node outside the current network), etc.

[0071] The wireless signals 130 may include downlink transmissions (from the radio network node 120 to the wireless device 110 ) and uplink transmissions (from the wireless device 110 to the radio network node 120 ).

[0072] Each network node 120 may have a single transmitter or multiple transmitters for transmitting wireless signals 130 to wireless devices 110. In some embodiments, network node 120 may include a multiple-input multiple-output (MIMO) system. Similarly, each wireless device 110 may have a single receiver or multiple receivers for receiving signals 130 from network node 120.

[0073] Network 100 may include carrier aggregation.For example, wireless device 110 may be served by both network nodes 120a and 120b and communicate wireless signals 130 with both network nodes 120a and 120b.

[0074] In some embodiments, the network node 125 may be interfaced with a radio network controller (RNC). The radio network controller may control the network node 120 and may provide certain radio resource management functions, mobility management functions, and / or other suitable functions. In some embodiments, the functions of the radio network controller may be included in the network node 120. The radio network controller may be interfaced with a core network node (CN) (e.g., core network node 320).

[0075] In some embodiments, the radio network controller can be connected to the core network node 320 via an interconnected wired or wireless network. The interconnected network can refer to any interconnected system capable of transmitting audio, video, signals, data, messages, or any combination thereof. The interconnected network can include all or part of the following: a public switched telephone network (PSTN), a public or private data network, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a local, regional, or global communication or computer network (e.g., the Internet), a wired or wireless network, an intranet, or any other suitable communication link including a combination thereof.

[0076] In some embodiments, core network node 320 may manage the establishment of communication sessions and various other functionalities for wireless device 110. Wireless device 110 may exchange certain signals with core network node 320 using a non-access stratum layer. In non-access stratum signaling, signals between wireless device 110 and core network node 320 may pass transparently through the radio access network. In some embodiments, network node 120 may interface with one or more network nodes 120 via an inter-node interface, such as, for example, an X2 interface.

[0077] The wireless device 110 may include state information, such as radio resource control (RRC) state information. For example, the wireless device 110 may be in one of the IDLE, CONNECTED, or CONNECTED INACTIVE RRC states. The network node 120 (or radio node controller) may control the state of the wireless device 110. In some embodiments, the network node 120 may send notifications about the state or state transitions of the wireless device 110 to the core network node 320. For example, the core network node 320 may register or subscribe to state change notifications of the wireless device 110. Upon determining a state change, the network node 120 may notify the core network node 320 of the state change. The notification may include location information. Figure 5-10 Describes status notifications in more detail.

[0078] In the wireless network 100, each radio network node 120 may use any suitable radio access technology, such as Long Term Evolution (LTE), LTE-Advanced, NR, UMTS, HSPA, GSM, cdma2000, WiMax, WiFi, and / or other suitable radio access technologies. The wireless network 100 may include any suitable combination of one or more radio access technologies. For purposes of example, various embodiments may be described within the context of certain radio access technologies. However, the scope of the present disclosure is not limited to the examples described, and other embodiments may use different radio access technologies.

[0079] As described above, embodiments of a wireless network may include one or more wireless devices and one or more different types of radio network nodes capable of communicating with the wireless devices. The network may also include any additional components suitable for supporting communications between wireless devices or between a wireless device and another communication device (e.g., a landline telephone). A wireless device may include any suitable combination of hardware and / or software. For example, in a particular embodiment, a wireless device such as wireless device 110 may include the following with respect to: Figure 11Similarly, a network node may include any suitable combination of hardware and / or software. For example, in a specific embodiment, a network node (e.g., network node 120) may include the following components with respect to Figure 12A The core network node may include any suitable combination of hardware and / or software. For example, in a specific embodiment, a core network node (e.g., core network node 320) may include the following components with respect to Figure 13A The components described.

[0080] The embodiments disclosed herein are based on the principle that the core network becomes aware of whether the UE is in RRC CONNECTED INACTIVE or is likely to become RRC CONNECTED INACTIVE. Two groups of embodiments are disclosed - subscription-based notification and autonomous RAN-initiated notification. These main embodiments, including their variations, are described in more detail below.

[0081] Specific embodiments include subscription-based notifications. According to certain embodiments, the CN subscribes to the RAN, so that the RAN provides the CN with information about the UE, including whether the UE is RRC CONNECTED or RRC CONNECTED INACTIVE. This information can be used by the CN to determine how to manage certain functions, for example, with respect to granular knowledge of the UE's location.

[0082] Specific embodiments include a standalone subscription process, which includes a process on the CN / RAN interface. Figure 4 An example is shown in .

[0083] Figure 5 is a sequence diagram illustrating a core network subscription to a radio access network according to some embodiments. In step 1, the UE is connected to the network and can receive and transfer user plane data and control plane data. In step 2, the core network sends a request to the RAN to subscribe to the UE transitioning between RRC CONNECTED and RRC CONNECTED INACTIVE. The request may include parameters describing the specific data requested (e.g., current location request) and / or details of the subscription.

[0084] In step 3, the RAN provides a response to the core network indicating whether the RAN accepts the subscription request from step 2 and provides details related to the accepted subscription and / or the requested data (e.g., current location response). In step 4, upon the UE transition (e.g., from RRC CONNECTED to RRC CONNECTED INACTIVE), the RAN sends a notification to the core network. The notification may include parameters describing the UE behavior configured by the network. These parameters may have been requested in step 2.

[0085] Another option is to do this during the connection setup process (i.e. already Figure 4 13) includes a subscription mechanism. Alternative embodiments are detailed below based on the initial UE context setup procedure in LTE. New functionality is illustrated relative to currently standardized procedures. For example, embodiments may be described relative to the connection setup procedure described in Section 8.3.1 of 3GPP TS 36.413 v13.3.0 (which is incorporated herein by reference in its entirety). According to certain embodiments, the subscription procedure is embedded within the UE context setup procedure on the CN / RAN interface.

[0086] The purpose of the Initial Context Setup procedure is to establish the necessary overall initial UE context (including E-RAB context, security keys, handover constraint list, UE radio capabilities and UE security capabilities, etc.). The procedure uses UE associated signaling. Figure 6 An example is shown in .

[0087] Figure 6 is a signaling diagram illustrating the initial context setup procedure according to some embodiments. The signaling diagram is from 3GPP TS 36.413 v13.3.0 Figure 8 .Reproduction of 3.1.2-1.

[0088] In case of establishing an E-RAB, the EPC must be ready to receive user data before the INITIAL CONTEXT SETUP REQUEST message has been received by the MME. If no UE-associated logical S1 connection exists, a UE-associated logical S1 connection shall be established upon receipt of the INITIAL CONTEXT SETUP REQUEST message.

[0089] The INITIAL CONTEXT SETUP REQUEST message shall contain the information required by the eNB to build a new E-RAB configuration consisting of at least one additional E-RAB within the E-RAB to be set up list IE.

[0090] The E-RAB to be used as an IE for establishing a project may include:

[0091] NAS-PDU IE,

[0092] Correlation ID IE in case of LIPA operation,

[0093] SIPTO correlation ID IE in case of SIPTO@LN operation,

[0094] Bearer Type IE.

[0095] The INITIAL CONTEXT SETUP REQUEST message can contain

[0096] Tracking activated IE.

[0097] • Handover Constraint List IE, which may contain roaming or access constraints.

[0098] UE Radio Capability IE.

[0099] • Subscriber Profile ID for RAT / Frequency Priority IE.

[0100] ·CS Fallback Indicator IE.

[0101] SRVCC operation may IE.

[0102] CSG Membership Status IE.

[0103] Registered LAI IE.

[0104] • GUMMEI IE, which indicates the MME serving the UE and shall only be present according to subclauses 4.6.2 and 4.7.6.6 of TS 36.300.

[0105] • MME UE S1AP ID 2 IE, which indicates the MME UE S1AP ID assigned by the MME and shall only be present according to subclause 4.6.2 of TS 36.300.

[0106] Management-based MDT allows IE.

[0107] Management-based MDT PLMN List IE.

[0108] • Additional CS Fallback Indicator IE.

[0109] Masked IMEISV IE.

[0110] Expected UE Behavior IE.

[0111] ProSe Authorization IE

[0112] UE User Plane CIoT Support Indicator IE.

[0113] • Subscription request IE, e.g., subscribing to UE transitions between RRC CONNECTED and RRC CONNECTED INACTIVE.

[0114] The INITIAL CONTEXT SETUP REQUEST message shall contain the Subscriber Profile ID for the RAT / Frequency Priority IE (if available in the MME).

[0115] If the Correlation ID IE is included in the INITIALCONTEXT SETUP REQUEST message towards the eNB with L-GW functionality for LIPA operation, the eNB shall use this information for LIPA operation for the concerned E-RABs.

[0116] If the SIPTO Correlation ID IE is included in the INITIAL CONTEXT SETUP REQUEST message towards the eNB with L-GW functionality for SIPTO@LN operation, the eNB shall use this information for SIPTO@LN operation for the concerned E-RABs.

[0117] If the Bearer Type IE is included in the INITIAL CONTEXT SETUP REQUEST message and is set to "Non-IP", the eNB shall not perform header compression for the concerned E-RAB.

[0118] If the masked IMEISV IE is included in the INITIAL CONTEXT SETUP REQUEST, the target eNB shall (if supported) use it to determine the characteristics of the UE for subsequent processing.

[0119] If the Expected UE Behavior IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) store this information and may use it to determine the RRC connection time.

[0120] Upon receiving the INITIAL CONTEXT SETUP REQUEST message, the eNB shall

[0121] Attempt to perform the requested E-RAB configuration.

[0122] • Store the UE aggregate maximum bit rate in the UE context and use the received UE aggregate maximum bit rate for non-GBR bearers for the concerned UE.

[0123] • Pass the values ​​contained in the NAS-PDU IE and E-RAB ID IE received by the E-RAB for each established data radio bearer to the radio interface protocol. The eNB shall not send NAS PDUs associated with failed data radio bearers to the UE.

[0124] • Store the received handover restriction list in the UE context.

[0125] • Store the received UE radio capabilities in the UE context.

[0126] • Store the received Subscriber Profile ID for RAT / Frequency priority in the UE context and use it as defined in TS 36.300.

[0127] • The received SRVCC operation may be stored in the UE context and used as defined in TS 23.216.

[0128] • Store the received UE security capabilities in the UE context.

[0129] • Store the received security keys in the UE context, use them and associate them with the initial value of the NCC (as defined in TS 33.401).

[0130] • Store the received CSG membership status (if supported) in the UE context.

[0131] • Store the received management-based MDT allow information (if supported) in the UE context.

[0132] • Store the received management-based MDT PLMN list information (if supported) in the UE context.

[0133] • Store the received ProSe authorization information (if supported) in the UE context.

[0134] - Evaluate the Subscription Request IE and the included associated parameters, which describe the information the CN requests to be notified of and the manner in which it requests this information to be provided (e.g., periodicity, etc.).

[0135] For initial context setup, an initial value for the next hop link count is stored in the UE context.

[0136] The allocation of resources based on the value of the Allocation and Retention Priority IE shall follow the principles described for the E-RAB establishment procedure.

[0137] The eNB shall use the information in the Handover Constraint List IE (if present in the INITIAL CONTEXT SETUP REQUEST message) to

[0138] Determine the target of subsequent mobility actions, for which the eNB provides information about the target of the mobility action towards the UE, unless the CS Fallback Indicator IE is set to "CS Fallback High Priority" and the Additional CS Fallback Indicator IE is not present, in which case the eNB may use the information in the Handover Constraint List IE;

[0139] • Selecting the appropriate SCG during dual connectivity operations.

[0140] If the Handover Constraint List IE is not included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall assume that there is no roaming and no access restrictions apply to the UE. The eNB shall also assume that there is no roaming and no access restrictions apply to the UE in the following cases:

[0141] Establishing one of the E-RABs with a specific ARP value (TS 23.401);

[0142] CS Fallback Indicator IE is set to "CS Fallback High Priority" and Additional CS Fallback Indicator IE is not present, and in case of Applying Handover Constraint List IE, no suitable target is found, in which case it shall be processed according to TS 23.272;

[0143] • CS Fallback Indicator IE is set to "CS Fallback High Priority" and Additional CS Fallback Indicator IE is set to "Unconstrained", in which case it shall be handled according to TS 23.272.

[0144] If the Trace Activation IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) initiate the requested trace functionality (as described in TS 32.422). Specifically, the eNB shall (if supported):

[0145] If the Trace Activation IE does not include an MDT Configuration IE, initiate the requested trace session (as described in TS 32.422);

[0146] If the Trace Activation IE includes an MDT Activation IE set to "MDT and Trace Immediately" within the MDT Configuration IE, initiate the requested trace session and MDT session (as described in TS 32.422);

[0147] If the Trace Activation IE includes an MDT Activation IE set to "Immediate MDT Only", "Logged MDT Only" or "Logged MBSFN MDT" within the MDT Configuration IE, the requested MDT session is initiated (as described in TS 32.422) and the eNB shall ignore the interface to the Trace IE and Trace Depth IE.

[0148] • If the Trace Activation IE includes the MDT Location Information IE within the MDT Configuration IE, this information is stored and considered in the requested MDT session.

[0149] • If the Trace Activation IE includes the Signaling-based MDT PLMN List IE within the MDT Configuration IE, the eNB may use it to propagate the MDT configuration (as described in TS 37.320).

[0150] • If the Trace Activation IE includes the MBSFN-ResultToLog IE within the MDT Configuration IE, it is considered for MDT configuration (as described in TS 37.320).

[0151] • If the Trace Activation IE includes the MBSFN-AreaId IE in the MBSFN-ResultToLog IE within the MDT Configuration IE, then it is considered for MDT configuration (as described in TS 37.320).

[0152] If the CS Fallback Indicator IE is included in the INITIAL CONTEXT SETUP REQUEST message, it indicates that the UE context to be set up is subject to CS fallback. The eNB shall reply with an INITIAL CONTEXT SETUP RESPONSE message and then act as defined in TS 23.272.

[0153] If the Registered LAI IE is included in the INITIAL CONTEXT SETUP REQUEST message, it indicates that the eNB may consider the Registered LAI IE when selecting a target cell or frequency, and then act as defined in TS 23.272.

[0154] If the UE Security Capability IE included in the INITIAL CONTEXT SETUP REQUEST message contains only the EIA0 algorithm (as defined in TS 33.401), and if this EIA0 algorithm is defined in the configured list of allowed integrity protection algorithms in the eNB (TS 33.401), the eNB shall use it and ignore the key received in the Security Key IE.

[0155] If the GUMMEI IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) store this information in the UE context and use it for subsequent X2 handovers.

[0156] If the MME UE S1AP ID 2 IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) store this information in the UE context and use it for subsequent X2 handovers.

[0157] If the Management-based MDT Allowed IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall use it (if supported) together with the information in the Management-based MDT PLMN List IE (if available in the UE context) to allow subsequent selection of the UE for Management-based MDT as defined in TS 32.422.

[0158] If the UE User Plane CIoT Support Indicator IE is included in the INITIAL CONTEXT SETUP REQUEST message and is set to "Supported", the eNB shall (if supported) consider that User Plane CIoT EPS optimization as specified in TS 23.401 is supported for the UE.

[0159] The eNB shall report the successful establishment of security procedures with the UE and the results of all requested E-RABs to the MME in the INITIAL CONTEXT SETUP RESPONSE message in the following manner:

[0160] The list of successfully established E-RABs should be included in the E-RAB Establishment List IE

[0161] The list of E-RABs for which establishment failed shall be included in the E-RAB Establishment Failure List IE.

[0162] When the eNB reports an unsuccessful establishment of an E-RAB, the cause value should be precise enough to enable the MME to know the reason for the unsuccessful establishment, such as "radio resources not available", "failure in radio interface procedures".

[0163] After sending the INITIAL CONTEXT SETUP RESPONSE message, the procedure is terminated in the eNB.

[0164] If the Subscription Request IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB evaluates its content and replies to the CN in the INITIAL CONTEXT SETUP RESPONSE message with the result of the subscription request, i.e. whether the eNB will provide the subscribed information from the CN and about the way in which the information (or a subset thereof) will be provided.

[0165] With respect to the table descriptions of INITIAL CONTEXT SETUP REQUEST and INITIAL CONTEXT SETUP RESPONSE, additional IEs may be encoded according to the following example changes to current TS 36.413 starting at section 9.1.4.1:

[0166] 9.1.4.1 INITIAL CONTEXT SETUP REQUEST This message is sent by the MME to request the establishment of a UE context.

[0167] Direction: MME → eNB

[0168]

[0169]

[0170]

[0171] 9.1.4.3 INITIAL CONTEXT SETUP RESPONSE This message is sent by the eNB to confirm the establishment of the UE context.

[0172] Direction: eNB→MME

[0173]

[0174] In the IEs described in the table description above, the CN may send a subscription request to the RAN to provide different information. Examples include, but are not limited to, subscriptions for reporting transitions between active states (i.e., RRC_CONNECTED) and connected inactive states. Another example is reporting location information (e.g., reporting changes in location at the cell level, at the registration area level, or at the tracking area level). Another example is reporting both types of information together (i.e., an indication of state transitions and location information).

[0175] The RAN can respond by confirming the subscription to the requested information (which will trigger future reporting via new or existing procedures in both confirmed (category 1) and unconfirmed (category 2) modes) or by rejecting the subscription. Another way to encode IEs in the request and response messages would be to list the multiple information elements that the RAN is requesting subscription for reporting. The RAN replies with an equivalent list that includes information for which subscription is accepted and excludes information for which subscription is unconfirmed. In the above embodiment, the CN includes a request for a certain type of information to be supplied when a specific event occurs during UE context creation. Upon a positive response from the eNB to the CN (i.e., the information will be provided according to the configured rules), the RAN will signal the CN with the requested information when the configured event occurs.

[0176] Such signaling may occur in various forms. Signaling may occur via a new Category 2 procedure that includes the requested information. Signaling may occur via, for example, a UE Context Modification Indication / Confirm (which is in the Figure 7 The existing process (shown in ) occurs.

[0177] Figure 7 is a signaling diagram illustrating a user equipment context modification indication according to some embodiments. In the illustrated process, the eNB indicates the information configured for reporting by the CN in the UE context modification indication. The CN confirms the correct receipt of such information in the UE context modification confirmation.

[0178] In additional embodiments, information exchange between the RAN and CN may be supported via a procedure for transmitting NAS PDUs. For example, a request from the CN to subscribe to UE transitions between RRC CONNECTED and RRC CONNECTED INACTIVE may be provided via a DL NAS TRANSPORT procedure. This procedure may include potential parameters describing optional requests for specific data (e.g., current location request) and details of the subscription.

[0179] The RAN may reply to this request via UL NAS TRANSPORT or other procedures for transmitting NAS PDUs in the uplink. This procedure may indicate whether the RAN accepts the subscription request and provide details related to the accepted subscription and data if requested (e.g., current location response). Alternatively, the procedure may only include the requested data if an event triggering data reporting has occurred.

[0180] The latter use of the NAS transmission procedure may be advantageous in cases when there is no UE context setup (eg, when user data is transferred via the CP channel and when the UE transitions between connected and connected inactive states).

[0181] A second group of embodiments includes autonomous RAN initiated core network notification. According to certain embodiments, the core network notification procedure may be autonomous, initiated by the RAN without core network subscription.

[0182] Specific embodiments include an independent autonomous RAN initiated core network notification procedure, which may include procedures on the CN / RAN interface. The RAN notifies the core network any time it believes that the UE has potentially become subject to the RRC CONNECTED INACTIVE state. Figure 8 An example is shown in .

[0183] Figure 8 This is a sequence diagram illustrating autonomous notification from the radio access network to the core network according to some embodiments. In step 1, the UE is connected to the network and can receive and transfer user plane and control plane data. In step 2, the RAN concludes that the UE may potentially be experiencing RRC CONNECTED INACTIVE. This determination can be based on various factors, including, but not limited to, activity mode.

[0184] In step 3, the RAN indicates to the core network that the UE may potentially (e.g., based on its activity pattern) experience RRC CONNECTED INACTIVE. In step 4, the CN acknowledges receipt of the notification from step 3. In step 5, the CN uses the indication received from the RAN in step 3, for example, when managing features that rely on knowledge of the UE's location.

[0185] Another alternative to the above is during the connection establishment process (i.e. already Figure 6 The mechanism is included in step 1 of the UE context setup procedure. This is described in detail below based on the initial UE context setup procedure in LTE. Specific embodiments include an embedded autonomous RAN-initiated core network notification procedure. According to certain embodiments, the subscription procedure is embedded in the UE context setup procedure on the CN / RAN interface.

[0186] The new functionality is shown with respect to current standardization procedures.For example, the embodiments may be described with respect to the connection setup procedure described in section 8.3.1 of 3GPP TS 36.413 v13.3.0.

[0187] The purpose of the Initial Context Setup procedure is to establish the necessary overall initial UE context (including E-RAB context, security keys, handover constraint list, UE radio capabilities and UE security capabilities, etc.) The procedure uses UE associated signaling.

[0188] exist Figure 6 (From 3GPP TS 36.413v13.3.0 Figure 8 An example is shown in .3.1.2-1 Reproduced). When establishing an E-RAB, the EPC must be ready to receive user data before the INITIAL CONTEXT SETUP RESPONSE message has been received by the MME. If no UE-associated logical S1 connection exists, a UE-associated logical S1 connection should be established upon receipt of the INITIAL CONTEXT SETUP REQUEST message.

[0189] The INITIAL CONTEXT SETUP REQUEST message shall contain the information required by the eNB to build a new E-RAB configuration consisting of at least one additional E-RAB within the E-RAB to be set up list IE.

[0190] The E-RAB to be used as an IE for establishing a project may include:

[0191] NAS-PDU IE,

[0192] Correlation ID IE in case of LIPA operation,

[0193] SIPTO correlation ID IE in case of SIPTO@LN operation,

[0194] Bearer Type IE.

[0195] The INITIAL CONTEXT SETUP REQUEST message can contain

[0196] Tracking activated IE.

[0197] • Handover Constraint List IE, which may contain roaming or access constraints.

[0198] UE Radio Capability IE.

[0199] • Subscriber Profile ID for RAT / Frequency Priority IE.

[0200] ·CS Fallback Indicator IE.

[0201] SRVCC operation may IE.

[0202] CSG Membership Status IE.

[0203] Registered LAI IE.

[0204] • GUMMEI IE, which indicates the MME serving the UE and shall only be present according to subclauses 4.6.2 and 4.7.6.6 of TS 36.300.

[0205] • MME UE S1AP ID 2 IE, which indicates the MME UE S1AP ID assigned by the MME and shall only be present according to subclause 4.6.2 of TS 36.300.

[0206] Management-based MDT allows IE.

[0207] Management-based MDT PLMN List IE.

[0208] • Additional CS Fallback Indicator IE.

[0209] Masked IMEISV IE.

[0210] Expected UE Behavior IE.

[0211] ProSe Authorization IE

[0212] UE User Plane CIoT Support Indicator IE.

[0213] ·RRC CONNECTED INACTIVE IE.

[0214] The INITIAL CONTEXT SETUP REQUEST message shall contain the Subscriber Profile ID for the RAT / Frequency Priority IE (if available in the MME).

[0215] If the Correlation ID IE is included in the INITIALCONTEXT SETUP REQUEST message towards the eNB with L-GW functionality for LIPA operation, the eNB shall use this information for LIPA operation for the concerned E-RABs.

[0216] If the SIPTO Correlation ID IE is included in the INITIAL CONTEXT SETUP REQUEST message towards the eNB with L-GW functionality for SIPTO@LN operation, the eNB shall use this information for SIPTO@LN operation for the concerned E-RABs.

[0217] If the Bearer Type IE is included in the INITIAL CONTEXT SETUP REQUEST message and is set to "Non-IP", the eNB shall not perform header compression for the concerned E-RAB.

[0218] If the masked IMEISV IE is included in the INITIAL CONTEXT SETUP REQUEST, the target eNB shall (if supported) use it to determine the characteristics of the UE for subsequent processing.

[0219] If the Expected UE Behavior IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) store this information and may use it to determine the RRC connection time.

[0220] Upon receiving the INITIAL CONTEXT SETUP REQUEST message, the eNB shall

[0221] Attempt to perform the requested E-RAB configuration.

[0222] • Store the UE aggregate maximum bit rate in the UE context and use the received UE aggregate maximum bit rate for non-GBR bearers for the concerned UE.

[0223] • Pass the values ​​contained in the NAS-PDU IE and E-RAB ID IE received by the E-RAB for each established data radio bearer to the radio interface protocol. The eNB shall not send NAS PDUs associated with failed data radio bearers to the UE.

[0224] • Store the received handover restriction list in the UE context.

[0225] • Store the received UE radio capabilities in the UE context.

[0226] • Store the received Subscriber Profile ID for RAT / Frequency priority in the UE context and use it as defined in TS 36.300.

[0227] • The received SRVCC operation may be stored in the UE context and used as defined in TS 23.216.

[0228] • Store the received UE security capabilities in the UE context.

[0229] • Store the received security keys in the UE context, use them and associate them with the initial value of the NCC (as defined in TS 33.401).

[0230] • Store the received CSG membership status (if supported) in the UE context.

[0231] • Store the received management-based MDT allow information (if supported) in the UE context.

[0232] • Store the received management-based MDT PLMN list information (if supported) in the UE context.

[0233] • Store the received ProSe authorization information (if supported) in the UE context.

[0234] For initial context setup, an initial value for the next hop link count is stored in the UE context.

[0235] The allocation of resources based on the value of the Allocation and Retention Priority IE shall follow the principles described for the E-RAB establishment procedure.

[0236] The eNB shall use the information in the Handover Constraint List IE (if present in the INITIAL CONTEXT SETUP REQUEST message) to

[0237] Determine the target of subsequent mobility actions, for which the eNB provides information about the target of the mobility action towards the UE, unless the CS Fallback Indicator IE is set to "CS Fallback High Priority" and the Additional CS Fallback Indicator IE is not present, in which case the eNB may use the information in the Handover Constraint List IE;

[0238] • Selecting the appropriate SCG during dual connectivity operations.

[0239] If the Handover Constraint List IE is not included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall assume that there is no roaming and no access restrictions apply to the UE. The eNB shall also assume that there is no roaming and no access restrictions apply to the UE in the following cases:

[0240] Establishing one of the E-RABs with a specific ARP value (TS 23.401);

[0241] • CS Fallback Indicator IE is set to "CS Fallback High Priority" and Additional CS Fallback Indicator IE is not present, and in case of Applying Handover Constraint List IE, no suitable target is found, in which case it shall be processed according to TS 23.272.

[0242] • CS Fallback Indicator IE is set to "CS Fallback High Priority" and Additional CS Fallback Indicator IE is set to "Unconstrained", in which case it shall be handled according to TS 23.272.

[0243] If the Trace Activation IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) initiate the requested trace functionality (as described in TS 32.422). Specifically, the eNB shall (if supported):

[0244] If the Trace Activation IE does not include an MDT Configuration IE, initiate the requested trace session (as described in TS 32.422);

[0245] If the Trace Activation IE includes an MDT Activation IE set to "MDT and Trace Immediately" within the MDT Configuration IE, initiate the requested trace session and MDT session (as described in TS 32.422);

[0246] If the Trace Activation IE includes an MDT Activation IE set to "Immediate MDT Only", "Logged MDT Only" or "Logged MBSFN MDT" within the MDT Configuration IE, the requested MDT session is initiated (as described in TS 32.422) and the eNB shall ignore the interface to the Trace IE and Trace Depth IE.

[0247] • If the Trace Activation IE includes the MDT Location Information IE within the MDT Configuration IE, this information is stored and considered in the requested MDT session.

[0248] • If the Trace Activation IE includes the Signaling-based MDT PLMN List IE within the MDT Configuration IE, the eNB may use it to propagate the MDT configuration (as described in TS 37.320).

[0249] • If the Trace Activation IE includes the MBSFN-ResultToLog IE within the MDT Configuration IE, it is considered for MDT configuration (as described in TS 37.320).

[0250] • If the Trace Activation IE includes the MBSFN-AreaId IE in the MBSFN-ResultToLog IE within the MDT Configuration IE, then it is considered for MDT configuration (as described in TS 37.320).

[0251] If the CS Fallback Indicator IE is included in the INITIAL CONTEXT SETUP REQUEST message, it indicates that the UE context to be set up is subject to CS fallback. The eNB shall reply with an INITIAL CONTEXT SETUP RESPONSE message and then act as defined in TS 23.272.

[0252] If the Registered LAI IE is included in the INITIAL CONTEXT SETUP REQUEST message, it indicates that the eNB may consider the Registered LAI IE when selecting a target cell or frequency, and then act as defined in TS 23.272.

[0253] If the UE Security Capability IE included in the INITIAL CONTEXT SETUP REQUEST message contains only the EIA0 algorithm (as defined in TS 33.401), and if this EIA0 algorithm is defined in the configured list of allowed integrity protection algorithms in the eNB (TS 33.401), the eNB shall use it and ignore the key received in the Security Key IE.

[0254] If the GUMMEI IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) store this information in the UE context and use it for subsequent X2 handovers.

[0255] If the MME UE S1AP ID 2 IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall (if supported) store this information in the UE context and use it for subsequent X2 handovers.

[0256] If the Management-based MDT Allowed IE is included in the INITIAL CONTEXT SETUP REQUEST message, the eNB shall use it (if supported) together with the information in the Management-based MDT PLMN List IE (if available in the UE context) to allow subsequent selection of the UE for Management-based MDT as defined in TS 32.422.

[0257] If the UE User Plane CIoT Support Indicator IE is included in the INITIAL CONTEXT SETUP REQUEST message and is set to "Supported", the eNB shall (if supported) consider that User Plane CIoT EPS optimization as specified in TS 23.401 is supported for the UE.

[0258] The eNB shall report the successful establishment of security procedures with the UE and the results of all requested E-RABs to the MME in the INITIAL CONTEXT SETUP RESPONSE message in the following manner:

[0259] The list of successfully established E-RABs should be included in the E-RAB Establishment List IE

[0260] The list of E-RABs for which establishment failed shall be included in the E-RAB Establishment Failure List IE.

[0261] When the eNB reports an unsuccessful establishment of an E-RAB, the cause value should be precise enough to enable the MME to know the reason for the unsuccessful establishment, such as "radio resources not available", "failure in radio interface procedures".

[0262] After sending the INITIAL CONTEXT SETUP RESPONSE message, the procedure is terminated in the eNB.

[0263] The RAN may indicate to the CN that the UE may become subject to RRC CONNECTED INACTIVE.

[0264] Specific embodiments executed in a network node may be Figure 9 In summary, a specific embodiment executed in a core network node may be Figure 10 Summary.

[0265] Figure 9 is a flow chart illustrating an example method in a network node according to some embodiments. In a specific embodiment, Figure 9 One or more steps may be performed by Figure 4 The described wireless network 100 is performed by the network node 120.

[0266] The method begins at step 912, where the network node receives a subscription request for receiving notifications of UE transitions between a first RRC state and a second RRC state. For example, the network node 120 may receive a subscription request from the core network node 320 to be notified of a transition of the wireless device 110 from an RRC CONNECTED STATE to an RRC CONNECTED INACTIVE state (or vice versa). The subscription request may include a request for receiving location information of the UE. The subscription request may include a periodicity for receiving notifications. The periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state. In some embodiments, the request may include additional information. The network node may select a subscription request based on the information above with respect to the RRC CONNECTED STATE. Figure 6-8Any of the embodiments or examples described may be used to receive a subscription request.

[0267] At step 914, the network node may optionally send a subscription response indicating that the network node will provide notifications. For example, network node 120 may provide a response to core network node 320 indicating that network node 120 accepts the subscription and will provide all or some of the requested information to core network node 320. The network node may provide a subscription response according to the above with respect to Figure 6-8 In some embodiments, the network node 120 may not provide a confirmation at all, and the method may proceed directly to step 916.

[0268] At step 916, the network node determines whether the UE has transitioned between the first RRC state and the second RRC state. For example, the network node 120 may determine that the wireless device 110 has transitioned from the RRC CONNECTED STATE to the RRC CONNECTED INACTIVE state or is about to transition from the RRC CONNECTED STATE to the RRC CONNECTED INACTIVE state (or vice versa). If a state transition has occurred, the method continues to step 918.

[0269] At step 918, the network node sends a notification of the transition of the UE between the first RRC state and the second RRC state to the core network node. For example, network node 120 sends the notification to core network node 320. The notification may include information about the state change (e.g., from state and / or to state), location information, or any other suitable information.

[0270] In a specific embodiment, the network node may send the notification in close temporal proximity to the occurrence of a state transition. In some embodiments, the network node may send the notification at a scheduled interval. The notification may comprise a one-time notification, or the notification may continue for each state transition until the network node receives an unsubscribe request. The network node may determine the subscription status of the subscriber according to the above with respect to the subscription status. Figure 6-8 Any embodiment or example described may be used to send notifications.

[0271] Can Figure 9 The method 900 shown in the embodiment may be modified, added or omitted. In addition, one or more steps in the method 900 may be performed in parallel or in any suitable order.

[0272] Figure 10 is a flow chart illustrating an example method in a core network node according to some embodiments. In a specific embodiment, Figure 10 One or more steps may be performed by Figure 4The described wireless network 100 is performed by the core network node 320.

[0273] The method begins at step 1012, where the core network node sends a subscription request for receiving notifications of UE transitions between a first RRC state and a second RRC state. For example, the core network node 320 may send a subscription request to the network node 120 to be notified of a transition of the wireless device 110 from an RRC CONNECTED STATE to an RRC CONNECTED INACTIVE state (or vice versa). The subscription request may include a request for receiving location information of the UE. The subscription request may include a periodicity for receiving notifications. The periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state. In some embodiments, the request may include additional information. The core network node may select a subscription request based on the information above with respect to the RRC CONNECTED STATE. Figure 6-8 Any embodiment or example described to send a subscription request.

[0274] At step 1014, the core network node may optionally receive a subscription response indicating that the network node will provide notifications. For example, core network node 320 may receive a response from network node 120 indicating that network node 120 accepts the subscription and will provide all or some of the requested information to core network node 320. The core network node may receive a subscription response according to the above with respect to Figure 6-8 In some embodiments, the network node 120 may not provide a confirmation at all, and the method may proceed directly to step 1016.

[0275] At step 1016, the core network node receives a notification from the network node. For example, when the network node 120 determines that the wireless device 110 has transitioned from the RRC CONNECTED STATE to the RRC CONNECTED INACTIVE state or is about to transition from the RRC CONNECTED STATE to the RRC CONNECTED INACTIVE state (or vice versa), the core network node 320 may receive a notification from the network node 120. The core network node may receive a notification based on the above information relative to the wireless device 110. Figure 6-8 Any of the embodiments or examples described may be used to receive notifications.

[0276] At step 1018, the core network node modifies the operation of the core network node relative to the UE based on the received notification. For example, the core network node 320 may perform operations depending on the location of the wireless device 110. The core network node 320 may use the location information received in the notification to perform operations. The core network node 320 may modify the operation of the core network node relative to the UE based on the received notification. Figure 6-8Any embodiment or example described may be modified to operate.

[0277] Can Figure 10 The method 1000 shown in the embodiment may be modified, added or omitted. In addition, one or more steps in the method 1000 may be performed in parallel or in any suitable order.

[0278] Figure 11 is a block diagram illustrating an example embodiment of a wireless device. The wireless device is Figure 4 An example of a wireless device 110 is shown in FIG. In a particular embodiment, the wireless device is capable of transitioning between RRC states.

[0279] Specific examples of wireless devices include mobile phones, smartphones, PDAs (personal digital assistants), portable computers (e.g., laptops, tablets), sensors, modems, machine type (MTC) devices / machine to machine (M2M) devices, laptop embedded equipment (LEEs), laptop mounted equipment (LMEs), USB dongles, devices with device-to-device capabilities, vehicle-to-vehicle devices, or any other device that can provide wireless communication. The wireless device includes a transceiver 1110, processing circuitry 1120, memory 1130, and a power source 1140. In some embodiments, the transceiver 1110 facilitates (e.g., via an antenna) transmitting and receiving wireless signals to and from the wireless network node 120, the processing circuitry 1120 executes instructions to provide some or all of the functionality described herein as provided by the wireless device, and the memory 1130 stores the instructions executed by the processing circuitry 1120. The power source 1140 supplies electrical power to one or more of the components of the wireless device 110 (eg, the transceiver 1110 , the processing circuit 1120 , and / or the memory 1130 ).

[0280] The processing circuitry 1120 includes any suitable combination of hardware and software implemented in one or more integrated circuits or modules for executing instructions and manipulating data to perform some or all of the described functions of the wireless device. In some embodiments, the processing circuitry 1120 may include, for example, one or more computers, one or more programmable logic devices, one or more central processing units (CPUs), one or more microprocessors, one or more applications, and / or other logic, and / or any suitable combination of the foregoing. The processing circuitry 1120 may include analog and / or digital circuitry configured to perform some or all of the described functions of the wireless device 110. For example, the processing circuitry 1120 may include resistors, capacitors, inductors, transistors, diodes, and / or any other suitable circuit components.

[0281] The memory 1130 is generally operable to store computer-executable code and data. Examples of the memory 1130 include computer memory (e.g., random access memory (RAM) or read-only memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a compact disk (CD) or digital video disk (DVD)), and / or any other volatile or non-volatile, non-transitory computer-readable and / or computer-executable memory device that stores information.

[0282] The power source 1140 is generally operable to supply electrical power to the components of the wireless device 110. The power source 1140 may include any suitable type of battery, such as lithium-ion, lithium-air, lithium polymer, nickel-cadmium, nickel-metal hydride, or any other suitable type of battery for supplying power to a wireless device.

[0283] Other embodiments of the wireless device may include additional components (beyond Figure 11 ), which is responsible for providing certain aspects of the functionality of the wireless device, including any functionality described above and / or any additional functionality (including any functionality necessary to support the solutions described above).

[0284] Figure 12A is a block diagram illustrating an example embodiment of a network node. The network node is Figure 4 . In a particular embodiment, the network node can receive a request to receive a notification of a transition of a UE between a first RRC state and a second RRC state; determine that the UE has transitioned between the first RRC state and the second RRC state; and send a notification of the transition of the UE between the first RRC state and the second RRC state to a core network node. The network node can send a subscription response to the core network node indicating that the network node will provide notifications.

[0285] The network node 120 may be an eNodeB, a nodeB, a base station, a wireless access point (e.g., a Wi-Fi access point), a low-power node, a base transceiver station (BTS), a transmission point or node, a remote RF unit (RRU), a remote radio head (RRH), or other radio access node. The network node includes at least one transceiver 1210, at least one processing circuit 1220, at least one memory 1230, and at least one network interface 1240. The transceiver 1210 facilitates (e.g., via an antenna) transmitting and receiving wireless signals to and from wireless devices (e.g., wireless device 110); the processing circuit 1220 executes instructions to provide some or all of the functionality described above as provided by the network node 120; the memory 1230 stores instructions executed by the processing circuit 1220; and the network interface 1240 communicates signals to backend network components (e.g., gateways, switches, routers, the Internet, public switched telephone networks (PSTNs), controllers, and / or other network nodes 120). The processing circuit 1220 and the memory 1230 may be the same as above. Figure 11 The processing circuitry 1320 and memory 1330 are of the same type as described.

[0286] In some embodiments, the network interface 1240 is communicatively coupled to the processing circuitry 1220 and refers to any suitable device operable to receive input from the network node 120, send output from the network node 120, perform suitable processing of the input or output or both, communicate to other devices, or any combination of the foregoing. The network interface 1240 includes appropriate hardware (e.g., a port, a modem, a network interface card, etc.) and software for communicating over a network, including protocol conversion and data processing capabilities.

[0287] Other embodiments of network node 120 include additional components (beyond Figure 12A ), which is responsible for providing certain aspects of the functionality of the network node, including any functionality described above and / or any additional functionality (including any functionality necessary to support the solutions described above). Various different types of network nodes may include components having the same physical hardware but configured (e.g., via programming) to support different radio access technologies, or may represent partial or completely different physical components.

[0288] Figure 12B is a block diagram illustrating example components of a network node 120. The components may include a receiving module 1250, a determining module 1252, and a transmitting module 1254.

[0289] The receiving module 1250 may perform the receiving function of the network node 120. For example, the receiving module 1250 may receive a request from the core network node to receive a notification of a transition of the UE between the first RRC state and the second RRC state, as described in any of the above embodiments or examples. In certain embodiments, the receiving module 1250 may include or be included in the processing circuit 1220. In specific embodiments, the receiving module 1250 may communicate with the determining module 1252 and the transmitting module 1254.

[0290] The determination module 1252 may perform the determination function of the network node 120. For example, the determination module 1252 may determine that the UE has transitioned between the first RRC state and the second RRC state according to any of the examples described above. In certain embodiments, the determination module 1252 may include or be included in the processing circuit 1220. In specific embodiments, the determination module 1252 may communicate with the receiving module 1250 and the transmitting module 1254.

[0291] The transmission module 1254 can perform transmission functions of the network node 120. For example, the transmission module 1254 can transmit subscription responses and / or state transition notifications to the core network node according to any of the examples described above. In some embodiments, the transmission module 1254 can include or be included in the processing circuit 1220. In specific embodiments, the transmission module 1254 can communicate with the receiving module 1250 and the determining module 1252.

[0292] Figure 13A 3 is a block diagram of an example core network node 320 according to certain embodiments. In certain embodiments, the core network node can send a subscription request to a network node to receive notifications of transitions of a UE between a first RRC state and a second RRC state; and receive a notification from the network node when the network node determines that the UE has transitioned between the first RRC state and the second RRC state. The core network node can receive a subscription response from the network node indicating that the network node will provide notifications.

[0293] Examples of core network nodes may include a mobile switching center (MSC), a serving GPRS support node (SGSN), a mobility management entity (MME), a radio network controller (RNC), a base station controller (BSC), an access and mobility management function (AMF), etc. The core network node includes processing circuitry 620, memory 630, and a network interface 640. In some embodiments, the processing circuitry 620 executes instructions to provide some or all of the functionality described above as provided by the network node, the memory 630 stores instructions executed by the processing circuitry 620, and the network interface 640 communicates signals to any suitable node (e.g., a gateway, a switch, a router, the Internet, a public switched telephone network (PSTN), a network node 120, a radio network controller, or a core network node 320, etc.).

[0294] The processing circuitry 620 may include any suitable combination of hardware and software implemented in one or more modules to execute instructions and manipulate data to perform some or all of the described functions of the core network node. In some embodiments, the processing circuitry 620 may include, for example, one or more computers, one or more central processing units (CPUs), one or more microprocessors, one or more applications, and / or other logic.

[0295] The memory 630 is generally operable to store instructions (e.g., computer programs), software, applications including one or more of logic, rules, algorithms, codes, tables, etc., and / or other instructions that can be executed by the processor. Examples of the memory 630 include computer memory (e.g., random access memory (RAM) or read-only memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a compact disk (CD) or a digital video disk (DVD)), and / or any other volatile or non-volatile, non-transitory computer-readable and / or computer-executable memory device that stores information.

[0296] In some embodiments, the network interface 640 is communicatively coupled to the processing circuit 620 and may refer to any suitable device operable to receive input from a network node, send output from a network node, perform suitable processing of the input or output or both, communicate to other devices, or any combination of the foregoing. The network interface 640 may include appropriate hardware (e.g., a port, a modem, a network interface card, etc.) and software for communicating over a network, including protocol conversion and data processing capabilities.

[0297] Other embodiments of the network node may include beyond Figure 6, which may be responsible for providing certain aspects of the functionality of the network node, including any functionality described above and / or any additional functionality (including any functionality necessary to support the solutions described above).

[0298] Figure 13B is a block diagram illustrating example components of a core network node 320. The components may include a receiving module 1350 and a transmitting module 1352.

[0299] The receiving module 1350 may perform the receiving functionality of the core network node 320. For example, the receiving module 1350 may receive a notification of a transition of a UE between a first RRC state and a second RRC state and / or a response to a notification subscription from the network node, as described in any of the above embodiments or examples. In certain embodiments, the receiving module 1350 may include or be included in the processing circuit 620. In specific embodiments, the receiving module 1350 may communicate with the transmitting module 1352.

[0300] The transmission module 1352 can perform transmission functions for the core network node 320. For example, the transmission module 1352 can transmit a subscription request to a network node according to any of the examples described above. In some embodiments, the transmission module 1352 can include or be included in the processing circuit 620. In particular embodiments, the transmission module 1352 can communicate with the receiving module 1250.

[0301] Some embodiments of the present disclosure may provide one or more technical advantages. Some embodiments may benefit from some, none, or all of these advantages. Other technical advantages may be readily ascertained by one of ordinary skill in the art. For example, some embodiments may advantageously enable the CN to subscribe to certain information available in the RAN (e.g., UE transitions between RRC CONNECTED and RRC CONNECTED INACTIVE). The CN may use the information as input to its functionality (e.g., based on the reliability of knowledge about the UE's location). As an example, when the UE is not connected to the system at the AS level and when it will not necessarily report a change in location (e.g., a change of cell), the CN may adjust its behavior for UE location monitoring during periods of inactive connected state.

[0302] Although the present disclosure has been described in terms of certain embodiments, variations and permutations of the embodiments will be apparent to those skilled in the art. Although some embodiments have been described with reference to certain radio access technologies, any suitable radio access technology (RAT) or combination of radio access technologies may be used, such as Long Term Evolution (LTE), LTE-Advanced, NR, UMTS, HSPA, GSM, cdma2000, WiMax, WiFi, etc. Accordingly, the above description of the embodiments does not constrain the present disclosure. Other variations, permutations, and modifications are possible without departing from the spirit and scope of the present disclosure.

[0303] Abbreviations:

[0304] 3GPP Third Generation Partnership Project

[0305] Carrier Aggregation (CA)

[0306] CC component carrier

[0307] eNB evolved Node B.

[0308] eNodeB Evolved Node B.

[0309] FDD Frequency Division Duplex

[0310] LTE Long Term Evolution

[0311] NR New Radio

[0312] PCC Primary Component Carrier

[0313] PCell Primary Cell

[0314] RAT Radio Access Technology

[0315] RRC Radio Resource Control

[0316] RSRP Reference Signal Received Power

[0317] RSRQ Reference Signal Received Quality

[0318] SCC Secondary Component Carrier

[0319] SCell Secondary Cell

[0320] TDD Time Division Duplex

[0321] UE User Equipment

[0322] UMTS Universal Mobile Telecommunications System

Claims

1. A method for providing a radio resource control (RRC) state of a user equipment (UE) to a core network node for use in a network node, the method comprising: receiving, from the core network node, a subscription request for receiving notifications of transitions of the UE between a first RRC state and a second RRC state, wherein the subscription request includes a periodicity for receiving the notifications, wherein the periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state; determining that the UE has transitioned between the first RRC state and the second RRC state; as well as The notification of the transition of the UE between the first RRC state and the second RRC state is sent to the core network node. 2 . The method of claim 1 , further comprising sending a subscription response to the core network node indicating that the network node will provide the notification.

3. The method of claim 1 or 2, wherein the subscription request comprises a request for receiving location information of the UE. The method according to claim 1 , wherein the notification includes location information of the UE.

5. The method of claim 1 or 2, wherein the first RRC state is RRC CONNECTED and the second RRC state is RRC CONNECTED INACTIVE.

6. The method of claim 2, wherein the subscription request comprises an information element (IE) in an INITIAL CONTEXT SETUP REQUEST, and the subscription response comprises an IE in an INITIAL CONTEXT SETUP RESPONSE.

7. A network node capable of providing a radio resource control (RRC) state of a user equipment (UE) to a core network node, the network node comprising processing circuitry operable to: receiving, from the core network node, a subscription request for receiving notifications of transitions of the UE between a first RRC state and a second RRC state, wherein the subscription request includes a periodicity for receiving the notifications, wherein the periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state; determining that the UE has transitioned between the first RRC state and the second RRC state; and The notification of the transition of the UE between the first RRC state and the second RRC state is sent to the core network node.

8. The network node of claim 7, the processing circuit further operable to send a subscription response to the core network node indicating that the network node will provide the notification.

9. The network node according to claim 7 or 8, wherein the subscription request comprises a request to receive location information of the UE.

10. The network node according to claim 7 or 8, wherein the notification includes location information of the UE.

11. The network node of claim 7 or 8, wherein the first RRC state is RRC CONNECTED and the second RRC state is RRC CONNECTED INACTIVE.

12. The network node of claim 8, wherein the subscription request comprises an information element (IE) in an INITIAL CONTEXT SETUP REQUEST, and the subscription response comprises an IE in an INITIAL CONTEXT SETUP RESPONSE.

13. A method for receiving Radio Resource Control (RRC) status information of a user equipment (UE) for use in a core network node, the method comprising: sending a subscription request to a network node for receiving notifications of transitions of the UE between a first RRC state and a second RRC state, wherein the subscription request includes a periodicity for receiving the notifications, wherein the periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state; as well as The notification is received from the network node when the network node determines that the UE has transitioned between the first RRC state and the second RRC state.

14. The method of claim 13, further comprising receiving a subscription response from the network node indicating that the network node will provide the notification.

15. The method of claim 13 or 14, wherein the subscription request comprises a request for receiving location information of the UE.

16. The method of claim 13 or 14, wherein the subscription request includes a periodicity for receiving the notifications.

17. The method of claim 13 or 14, wherein the notification includes location information of the UE.

18. The method of claim 13 or 14, wherein the first RRC state is RRC CONNECTED and the second RRC state is RRC CONNECTED INACTIVE.

19. The method of claim 14, wherein the subscription request includes an information element (IE) in an INITIAL CONTEXT SETUP REQUEST, and the subscription response includes an IE in an INITIAL CONTEXT SETUP RESPONSE.

20. The method of claim 13, 14 or 19, further comprising modifying operation of the core network node relative to the UE based on the received notification.

21. A core network node capable of receiving radio resource control (RRC) status information of a user equipment (UE), the core network node comprising a processing circuit operable to: sending a subscription request to a network node for receiving notifications of transitions of the UE between a first RRC state and a second RRC state, wherein the subscription request includes a periodicity for receiving the notifications, wherein the periodicity specifies whether the notification is a one-time notification or a notification for each subsequent transition of the UE between the first RRC state and the second RRC state; and The notification is received from the network node when the network node determines that the UE has transitioned between the first RRC state and the second RRC state.

22. The core network node of claim 21, the processing circuit further operable to receive a subscription response from the network node indicating that the network node will provide the notification.

23. The core network node of claim 21 or 22, wherein the subscription request comprises a request to receive location information of the UE.

24. The core network node of claim 21 or 22, wherein the subscription request includes a periodicity for receiving the notification.

25. The core network node of claim 21 or 22, wherein the notification includes location information of the UE.

26. The core network node of claim 21 or 22, wherein the first RRC state is RRC CONNECTED and the second RRC state is RRC CONNECTED INACTIVE.

27. The core network node of claim 22, wherein the subscription request includes an information element (IE) in an INITIAL CONTEXT SETUP REQUEST, and the subscription response includes an IE in an INITIAL CONTEXT SETUPRESPONSE.

28. The core network node of any one of claims 21, 22 or 27, the processing circuit further operable to modify operation of the core network node relative to the UE based on the received notification.

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