Non-terrestrial network-terrestrial network interworking

Abstract

A wireless transmit-receive unit (WTRU) may reside on a non-terrestrial network (NTN) cell and evaluate one or more terrestrial network (TN) cells to, for example, determine whether to change a radio access network (RAN) based notification area (RNA). In an example, the WTRU may receive an indication to change from a first TN cell to the NTN cell. The WTRU may perform a cell reselection to the NTN cell based on the indication. The first TN cell may be associated with a first RNA. The WTRU may evaluate a second TN cell associated with the second RNA. The WTRU may determine that a cell reselection condition associated with the second TN cell is satisfied. The WTRU may perform cell reselection to the second TN cell based on a determination that the cell reselection condition is satisfied.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 395,387, filed on August 5, 2022, the disclosure of which is incorporated herein by reference in its entirety. Background Art

[0003] Mobile communications using wireless communications continue to evolve. The fifth generation of mobile communications radio access technology (RAT) may be referred to as 5G New Radio (NR). The previous generation (legacy) mobile communications RAT may be, for example, fourth generation (4G) long term evolution (LTE). Wireless communication devices may establish communications with other devices and data networks, for example, via access networks such as radio access networks (RAN). Summary of the invention

[0004] Disclosed herein are systems, methods, and tools for non-terrestrial network (NTN)-terrestrial network (TN) interworking.

[0005] A wireless transmit-receive unit (WTRU) may reside on an NTN cell and evaluate, for example, one or more TN cells to determine whether to change a notification area (RNA) based on a radio access network (RAN). In an example, the WTRU may receive an indication of a change from a first TN cell to the NTN cell. The WTRU may perform a cell reselection to the NTN cell based on the indication. The first TN cell may be associated with a first RNA. The WTRU may evaluate a second TN cell associated with a second RNA. The WTRU may determine that a cell reselection condition associated with the second TN cell is satisfied. The WTRU may perform a cell reselection to the second TN cell based on determining that the cell reselection condition is satisfied. For example, the evaluation of the second TN cell associated with the second RNA may include measurements of the second TN cell associated with the second RNA and / or determining that the cell reselection condition associated with the second TN cell is satisfied.

[0006] The WTRU may evaluate the second TN cell during a time period associated with the WTRU being configured to monitor paging messages from the NTN cell, for example, in the RRC_INACTIVE state. In an example, the WTRU may receive an indication that the state of the WTRU is changed from the RRC_CONNECTED state to the RRC_INACTIVE state. The WTRU may initiate the change from the RRC_CONNECTED state to the RRC_INACTIVE state based on the indication. The WTRU may monitor the paging message from the NTN cell in the RRC_INACTIVE state (for example, during a time period associated with the WTRU being configured to operate in the RRC_INACTIVE state). When the WTRU monitors the paging message from the NTN cell, the WTRU may evaluate the second TN cell. If the cell reselection condition associated with the second TN cell is met, the WTRU may perform the cell reselection to the second TN cell associated with the second RNA. The WTRU may receive the paging message from the NTN cell in the RRC_INACTIVE state. The WTRU may initiate a change of the state of the WTRU from the RRC_INACTIVE state to the RRC_CONNECTED state based on the reception of the paging message. The WTRU may receive data transmission from the second TN cell associated with the second RNA in the RRC_CONNECTED state (e.g., during a time period associated with the WTRU being configured to operate in the RRC_CONNECTED state).

[0007] In an example, the WTRU may send an indication of a change from the first RNA to the second RNA to the NTN cell. The WTRU may receive an indication from the NTN cell to change the state of the WTRU from the RRC_INACTIVE state to the RRC_IDLE state. The WTRU may initiate a change from the RRC_INACTIVE state to the RRC_IDLE state based on the indication, for example, before performing the cell reselection to the second TN cell.

[0008] The WTRU may, for example, evaluate one or more TN cells based on identification information associated with the one or more TN cells. The WTRU may receive the identification information associated with the one or more TN cells, and the one or more TN cells may include the first TN cell associated with the first RNA and / or the second TN cell associated with the second RNA. The WTRU may evaluate the one or more TN cells for cell reselection based on the identification information. The WTRU may evaluate the one or more TN cells during a time period associated with the WTRU being configured to monitor the paging message from the NTN cell. In an example, the WTRU may limit the evaluation to the one or more TN cells (e.g., not evaluating the NTN cell for the cell reselection).

[0009] The WTRU may determine the satisfaction of the cell reselection condition associated with the second TN cell based on a reference signal received power (RSRP) associated with the second TN cell. The WTRU may receive a cell reselection threshold in a radio resource control (RRC) message. The WTRU may determine the RSRP associated with the second TN cell associated with the second RNA. To determine the satisfaction of the cell reselection condition associated with the second TN cell, the WTRU may determine that the RSRP associated with the second TN cell is equal to or greater than the cell reselection threshold.

[0010] The WTRU may determine the satisfaction of the cell reselection condition associated with the second TN cell based on the cell reselection priority associated with the second TN cell. The WTRU may receive cell reselection priority information in an RRC message. The WTRU may determine the cell reselection priority associated with the second TN cell associated with the second RNA. The WTRU may determine the satisfaction of the cell reselection condition associated with the second TN cell based on the cell reselection priority associated with the second TN cell and the cell reselection priority information received in the RRC message. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0012] Figure 1B is an example of a method that can be used according to an embodiment of the present invention. Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system.

[0013] Figure 1C is an example of a method that can be used according to an embodiment of the present invention. Figure 1ASystem diagram of an example Radio Access Network (RAN) and an example Core Network (CN) for use within the illustrated communication system.

[0014] Figure 1D is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of another example RAN and another example CN for use within the illustrated communication system.

[0015] Figure 2 is an example of a depiction of different interfaces in a non-terrestrial network.

[0016] Figure 3 is an example of a WTRU triggered transition from RRC_IDLE to RRC_CONNECTED.

[0017] Figure 4 is an example of a WTRU triggered rejection of the transition from RRC_IDLE.

[0018] Figure 5 is an example of a WTRU triggered transition from RRC_INACTIVE to RRC_CONNECTED (WTRU context retrieval successful).

[0019] Figure 6 is an example of a WTRU triggered transition from RRC_INACTIVE to RRC_CONNECTED (WTRU context retrieval failure).

[0020] Figure 7 is an example of a rejection from the network when the WTRU attempts to restore the connection.

[0021] Figure 8 is an example of a network triggered transition from RRC_INACTIVE to RRC_CONNECTED.

[0022] Fig. 9 is an example of an RNA update procedure with WTRU context relocation.

[0023] Fig.10 is an example of a periodic RNA update procedure without WTRU context relocation.

[0024] Fig.11 is an example of the RNA update procedure for transitioning to RRC_IDLE.

[0025] Fig.12 is an example of a resume request responded with a release with redirection, WTRU context relocation.

[0026] Fig.13 is an example process of a CN controlled subgroup.

[0027] Fig.14 is an example procedure for sub-grouping based on WTRU ID.

[0028] Fig.15 It is an example of the NTN-TN network layer.

[0029] Fig.16 is an example of releasing to RRC_IDLE to reside on the NTN.

[0030] Fig.17 is an example of RNA changes based on TN measurements.

[0031] Fig.18 is an example of RNA changes based on TN measurements.

[0032] Fig.19 is an example 1900 for evaluating one or more TN cells to determine RNA updates. DETAILED DESCRIPTION

[0033] Figure 1A 1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word DFT spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multi-carrier (FBMC), etc.

[0034] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the UE 102a, 102b, 102c, 102d (any of which may be referred to as a "station" and / or "STA") may be configured to send and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0035] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device that is configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be base transceiver stations (BTS), Node Bs, Code Bs, Home Node Bs, Home eNode Bs, gNBs, NR Node Bs, site controllers, access points (APs), wireless routers, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0036] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSC), radio network controllers (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies (which may be referred to as cells (not shown)). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0037] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0038] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0039] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro).

[0040] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0041] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0042] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), and GSM EDGE (GERAN).

[0043] Figure 1AThe base station 114b in may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial venues, homes, vehicles, campuses, industrial facilities, sky corridors (e.g., for use by drones), and roads. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.11) to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.15) to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0044] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the text and video, the CN 106 / 115 may be configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Figure 1A Although not shown in the figure, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0045] The CN 106 / 115 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0046] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0047] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0048] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC) and state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0049] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from a base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV, or visible light signal. In another embodiment, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0050] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0051] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0052] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, and a secure digital (SD) memory card, among others. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0053] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0054] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0055] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device and activity tracker, etc. Peripheral device 138 may include one or more sensors, which may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geolocation sensor; altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor and / or humidity sensor.

[0056] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0057] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0058] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0059] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, and scheduling of users in the UL and / or DL, among other things. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0060] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as being part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0061] The MME 162 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, and selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0062] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0063] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0064] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0065] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0066] In a representative embodiment, the other network 112 may be a WLAN.

[0067] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or out of the BSS. Traffic originating from outside the BSS and destined for the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and destined for a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the target STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the target STA (e.g., directly between them) using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0068] When using the 802.11ac infrastructure operation mode or a similar operation mode, the AP may send beacons on a fixed channel (such as a primary channel). The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0069] High throughput (HT) STAs may communicate using a 40 MHz wide channel (eg, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels) to form a 40 MHz wide channel.

[0070] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0071] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support instrument type control / machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0072] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting only a 1MHz operating mode) is sending to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0073] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0074] Figure 1D 1 is a system diagram illustrating the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0075] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0076] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or varying absolute time lengths over time).

[0077] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNBs 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNode-Bs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0078] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b and routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNB180a, 180b, and 180c can communicate with each other via the Xn interface.

[0079] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0080] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, and / or services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0081] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0082] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring, etc.

[0083] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0084] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a-d, base station 114a-b, evolved Node B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b and / or any other device described herein. The simulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0085] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0086] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0087] A WTRU on a TN (e.g., a WTRU in RRC_INACTIVE state or RRC_CONNECTED state) may transmit to the TN, for example, an indication of a preference to camp on a non-terrestrial network (NTN). The TN may release the WTRU to an RRC_IDLE state. The WTRU may perform cell reselection to camp on the NTN and / or monitor for paging from the NTN.

[0088] For example, the WTRU may send an indication of the availability of the NTN, for example, in a message. The WTRU may receive an RRC release message from the TN. The WTRU may transition from an RRC inactive operating condition to an RRC idle operating condition based on the RRC release message received from the TN. The WTRU may camp on the NTN and attempt to decode a paging message from the NTN. The message including the indication of the availability of the NTN may include WTRU assistance information (e.g., UE assistance information) and / or an RRC release request.

[0089] The WTRU may reside on the NTN in RRC_INACTIVE state and monitor changes in RNA on the TN using, for example, neighbor cell measurements and / or cell reselection evaluation. If a change in TN RNA is detected, for example via the current NTN or by triggering a cell reselection to the TN, the WTRU may perform a RAN notification area update.

[0090] For example, the WTRU may operate under RRC inactive operating conditions. For example, when operating under RRC inactive operating conditions, the WTRU may reside on the NTN. The WTRU may detect changes in the RNA associated with the TN and perform RNA updates based on the detected changes in the RNA associated with the TN. The WTRU may detect changes in the RNA associated with the TN based on cell selection criteria. When residing on the NTN, the WTRU may measure multiple TN cells that are neighbors of the TN cell associated with the RNA. The WTRU may determine that the cell reselection criteria are met based on the measurement of multiple TN cells, and detect changes in the RNA associated with the TN based on determining that the cell selection criteria are met. The WTRU may perform RNA updates via the NTN network or by triggering a cell reselection to the TN.

[0091] Disclosed herein are systems, methods, and tools for NTN-TN intercommunication. A WTRU may reside on an NTN cell and evaluate, for example, one or more TN cells to determine whether to change an RNA. In an example, the WTRU may reside on an NTN cell and evaluate, for example, one or more TN cells to determine whether to change an RNA. In an example, the WTRU may receive an indication of a change from a first TN cell to the NTN cell. The WTRU may perform a cell reselection to the NTN cell based on the indication. The first TN cell may be associated with a first RNA. The WTRU may evaluate a second TN cell associated with a second RNA. The WTRU may determine that a cell reselection condition associated with the second TN cell is satisfied. The WTRU may perform a cell reselection to the second TN cell based on determining that the cell reselection condition is satisfied. For example, the evaluation of the second TN cell associated with the second RNA may include measurements of the second TN cell associated with the second RNA and / or determining that the cell reselection condition associated with the second TN cell is satisfied.

[0092] The WTRU may evaluate the second TN cell during a time period associated with the WTRU being configured to monitor paging messages from the NTN cell, for example, in the RRC_INACTIVE state. In an example, the WTRU may receive an indication that the state of the WTRU is changed from the RRC_CONNECTED state to the RRC_INACTIVE state. The WTRU may initiate the change from the RRC_CONNECTED state to the RRC_INACTIVE state based on the indication. The WTRU may monitor the paging message from the NTN cell in the RRC_INACTIVE state (for example, during a time period associated with the WTRU being configured to operate in the RRC_INACTIVE state). When the WTRU monitors the paging message from the NTN cell, the WTRU may evaluate the second TN cell. If the cell reselection condition associated with the second TN cell is met, the WTRU may perform the cell reselection to the second TN cell associated with the second RNA. The WTRU may receive the paging message from the NTN cell in the RRC_INACTIVE state. The WTRU may initiate a change of the state of the WTRU from the RRC_INACTIVE state to the RRC_CONNECTED state based on the reception of the paging message. The WTRU may receive data transmission from the second TN cell associated with the second RNA in the RRC_CONNECTED state (e.g., during a time period associated with the WTRU being configured to operate in the RRC_CONNECTED state).

[0093] In an example, the WTRU may send an indication of a change from the first RNA to the second RNA to the NTN cell. The WTRU may receive an indication from the NTN cell to change the state of the WTRU from the RRC_INACTIVE state to the RRC_IDLE state. The WTRU may initiate a change from the RRC_INACTIVE state to the RRC_IDLE state based on the indication, for example, before performing the cell reselection to the second TN cell.

[0094] The WTRU may, for example, evaluate one or more TN cells based on identification information associated with the one or more TN cells. The WTRU may receive the identification information associated with the one or more TN cells, and the one or more TN cells may include the first TN cell associated with the first RNA and / or the second TN cell associated with the second RNA. The WTRU may evaluate the one or more TN cells for cell reselection based on the identification information. The WTRU may evaluate the one or more TN cells during a time period associated with the WTRU being configured to monitor the paging message from the NTN cell. In an example, the WTRU may limit the evaluation to the one or more TN cells (e.g., not evaluating the NTN cell for the cell reselection).

[0095] The WTRU may determine the satisfaction of the cell reselection condition associated with the second TN cell based on a reference signal received power (RSRP) associated with the second TN cell. The WTRU may receive a cell reselection threshold in a radio resource control (RRC) message. The WTRU may determine the RSRP associated with the second TN cell associated with the second RNA. To determine the satisfaction of the cell reselection condition associated with the second TN cell, the WTRU may determine that the RSRP associated with the second TN cell is equal to or greater than the cell reselection threshold.

[0096] The WTRU may determine the satisfaction of the cell reselection condition associated with the second TN cell based on the cell reselection priority associated with the second TN cell. The WTRU may receive cell reselection priority information in an RRC message. The WTRU may determine the cell reselection priority associated with the second TN cell associated with the second RNA. The WTRU may determine the satisfaction of the cell reselection condition associated with the second TN cell based on the cell reselection priority associated with the second TN cell and the cell reselection priority information received in the RRC message.

[0097] NTN may be implemented in one or more examples herein.

[0098] NTN can facilitate the deployment of wireless networks in areas where ground-based antennas may not be available, for example, due to geographic and / or cost reasons. It is envisioned that, in conjunction with terrestrial networks, NTN can enable ubiquitous coverage of 5G networks. NTN deployments can support basic calls and / or texts anywhere in the world, and if combined with the proliferation of next-generation low-orbit satellites, enhanced services (e.g., web browsing) can be enabled.

[0099] A basic NTN may include a platform (e.g., an airborne platform and / or a space platform) that transmits signals from a land-based base station (e.g., a gNB) to a WTRU via a gateway (GW), and vice versa. The NTN may support power class 3 WTRUs with omnidirectional antennas and linear polarization, or very small aperture antenna (VSAT) terminals with directional antennas and circular polarization. Support for narrowband Internet of Things (NB-IoT) and enhanced MTC (eMTC) type devices may be provided. Regardless of the device type, it may be assumed that one or more (e.g., all) NTN WTRUs may have global navigation satellite system (GNSS) capabilities.

[0100] Platforms (e.g., airborne and / or space platforms) may be classified according to orbit, e.g., focusing on low earth orbit (LEO) satellites with an altitude range of 300km to 1500km and geosynchronous orbit (GEO) satellites with an altitude of 35786km). Other platform classifications may be assumed to be implicitly supported (e.g., medium earth orbit (MEO) satellites with an altitude range of 7000km to 25000km and high altitude platform stations (HAPS) with an altitude of 8km to 50km). Satellite platforms may be further classified as having "transparent" payloads or "regenerative" payloads. Transparent satellite payloads may, for example, utilize multiple transparent satellites that may be connected to a land-based gNB to implement frequency conversion and RF amplification in the uplink and downlink. Regenerative satellite payloads may implement a full gNB or gNB distributed unit (DU) on a satellite. The regenerative payload may perform digital processing on the signal, including, for example, one or more of the following: demodulation; decoding; re-encoding; remodulation; filtering. References herein to gNB may refer to an exemplary base station, and the gNB may be replaced with any other suitable base station.

[0101] The following radio interfaces may be defined in the NTN: feeder link (e.g., wireless link between GW and satellite); service link (e.g., radio link between satellite and WTRU); inter-satellite link (ISL) (e.g., transmission link between satellites). The ISL may be supported by (e.g., only by) regenerative payloads and may be a 3GPP radio interface or a proprietary optical interface. Figure 2 is an example depicting different interfaces in a non-terrestrial network. In one or more examples (eg, the examples shown in one or more figures herein), a WTRU may be interchangeably referred to as a UE.

[0102] Depending on the satellite payload configuration, different interfaces (e.g., different 3GPP interfaces) may be used for the radio links (e.g., for each radio link). In a transparent payload, the NR Uu radio interface may be used for the service link and / or the feeder link. For a regenerative payload, the NR-Uu interface may be used for the service link and the satellite radio interface (SRI) may be used for the feeder link. A user plane (UP) and / or control plane (CP) protocol stack may be used for the payload configuration (e.g., for each payload configuration).

[0103] NTN satellites may support multiple cells, and a cell (e.g., each cell) may include one or more satellite beams. One or more satellite beams may cover a coverage area on the earth (e.g., in the same way that a terrestrial cell covers a coverage area on the earth), and may range in diameter from 100km to 1000km in a LEO deployment, and from 200km to 3500km in a GEO deployment. The beam coverage area in a GEO deployment may remain fixed relative to the earth, and in a LEO deployment, the area covered by the beam / cell may change over time, for example, due to satellite movement. Beam movement may be classified as "earth mobile," where a LEO beam moves continuously across the earth, or may be classified as "earth fixed," where a beam may be manipulated to maintain coverage of a fixed location until a different cell (e.g., a new cell) (e.g., in discrete and coordinated changes) exceeds the coverage area.

[0104] Due to the altitude and / or beam diameter of the NTN platform, the round trip time (RTT) and maximum differential delay associated with the NTN may be higher (e.g., significantly larger) than that of terrestrial systems. In a transparent NTN deployment, the RTT may range from 25.77ms (e.g., LEO at 600km altitude) to 541.46ms (e.g., for GEO), and the maximum differential delay may be 3.12ms to 10.3ms. The RTT of the regenerated payload may be approximately half of the RTT of the transparent payload because, in some examples, the transparent configuration may include both the serving link and the feeder link, while the RTT of the regenerated payload may take into account the serving link (e.g., only the serving link). To minimize the impact on some NR systems (e.g., to avoid preamble ambiguity or to properly time the receive window), the WTRU may perform timing precompensation before initial access.

[0105] The pre-compensation process may require the WTRU to obtain one or more of: the WTRU's position (e.g., via GNSS); feeder link delay and / or common delay (e.g., via satellite ephemeris data); satellite position (e.g., via satellite ephemeris data). Satellite ephemeris data may be broadcast (e.g., periodically) in system information and may include one or more of: satellite velocity; direction; velocity. The WTRU may estimate the distance and / or delay to the satellite and / or may add a feeder link delay component to obtain a complete WTRU-gNB RTT (e.g., UE-gNB RTT) that may be used to offset one or more of: a timer; a receive window; or a timing relationship. It may be assumed that frequency compensation may be performed, for example, by the network.

[0106] WTRU mobility and / or measurement reporting may be provided in the NTN. In the NTN, the difference in RSRP between the cell center and the cell edge may not be as significant as in terrestrial systems. In some examples, this combined with the relatively large cell overlap area may result in reduced reliability of some measurement-based mobility (e.g., traditional measurement-based mobility) in the NTN environment. Different conditional switching and measurement report triggers associated with location and / or time may be provided (e.g., different triggers that depend on location and / or time). In some examples (e.g., LEO deployments), enhanced mobility may be used, where a stationary WTRU may be expected to perform mobility periodically (e.g., approximately every 7 seconds depending on the deployment characteristics) due to satellite movement.

[0107] This document may describe mobility, state transitions, and paging. This document may describe mobility in RRC_IDLE. This document may describe cell selection.

[0108] The principles of public land mobile network (PLMN) selection in NR may be based on the principles of PLMN selection. Cell selection may be required at the transition from RM-DEREGISTERED to RM-REGISTERED, from CM-IDLE to CM-CONNECTED, and from CM-CONNECTED to CM-IDLE, and may be based on one or more of the following principles: the WTRU non-access stratum (NAS) layer may identify the selected PLMN and equivalent PLMNs; the cell selection may be based on the cell definition synchronization signal block (CD-SSB) located on the synchronization raster (see clause 5.2.4) (for example, the WTRU may search NR frequency bands and for a carrier frequency (for example, each carrier frequency) may identify the strongest cell according to the CD-SSB. The WTRU may then read the cell system information broadcast to identify its PLMN (for example, the WTRU may search the carriers (for example, each carrier) in turn ("initial cell selection") or use stored information to shorten the search ("stored information cell selection")); the WTRU may seek to identify a suitable cell (if the WTRU cannot identify a suitable cell, then W The WTRU may seek to identify a qualified cell. When a suitable cell can be found, or if a qualified cell is found (e.g., only a qualified cell is found), the WTRU may camp on the cell and begin a cell reselection process (e.g., a suitable cell may be a cell for which measured cell attributes satisfy the cell selection criteria; the cell PLMN may be a selected PLMN, a registered PLMN, or an equivalent PLMN; the cell may not be barred or reserved, and the cell may not be part of a tracking area, which may be in a list of "roaming prohibited tracking areas"; a qualified cell may be a cell for which measured cell attributes satisfy the cell selection criteria and the cell may not be barred; the IAB-MT may apply a cell selection process as described for the WTRU with the following differences (e.g., the IAB-MT may ignore a cell barring or cell reservation indication included in a cell system information broadcast; the IAB-MT may consider (e.g., only consider) a cell as a candidate for cell selection if the cell system information broadcast indicates that the IAB supports the selected PLMN or the selected SNPN).

[0109] The WTRU may transition to RRC_IDLE. Upon transitioning from RRC_CONNECTED or RRC_INACTIVE to RRC_IDLE, the WTRU may camp on a cell as a result of cell selection based on frequency (eg, the frequency assigned by the RRC in the state transition message, if any).

[0110] The WTRU may recover from out of coverage. The WTRU may attempt to find a suitable cell in the manner described herein for stored information or initial cell selection. In some examples, if no suitable cell is found on any frequency or RAT, the WTRU may attempt to find a qualified cell.

[0111] In multi-beam operation, cell quality may be derived between beams corresponding to the same cell.

[0112] Cell reselection may be described herein. A WTRU in RRC_IDLE may perform cell reselection. The principles of the process may be one or more of the following: cell reselection may be based on a CD-SSB located on a synchronization raster; the WTRU may measure properties of the serving cell and neighboring cells to implement the reselection process (e.g., for inter-frequency neighbor cell search and measurement, the carrier frequency (e.g., only the carrier frequency) may be indicated); cell reselection may identify a cell on which the WTRU may camp. Cell reselection may be based on cell reselection criteria involving measurements of the serving cell and neighboring cells (e.g., intra-frequency reselection may be based on a ranking of cells; inter-frequency reselection may be based on an absolute priority, where the WTRU attempts to camp on the highest priority frequency available; a neighbor cell list (NCL) may be provided by the serving cell to handle specific cases of intra-frequency and inter-frequency neighboring cells; an exclusion list may be provided to prevent the WTRU from reselecting to specific intra-frequency and inter-frequency neighboring cells; an allow list may be provided to request the WTRU to reselect to specific intra-frequency and inter-frequency neighboring cells (e.g., only specific intra-frequency and inter-frequency neighboring cells); cell reselection may be speed dependent; service specific priorities; slice specific cell reselection information may be provided to facilitate the WTRU to reselect a cell supporting a specific slice. In multi-beam operation, cell quality may be derived between beams corresponding to the same cell.

[0113] The WTRU may perform state transitions. Figure 3 is an example of a WTRU triggered transition from RRC_IDLE to RRC_CONNECTED. Figure 3A WTRU-triggered transition from RRC_IDLE to RRC_CONNECTED is described (e.g., a NAS portion may also be provided). At 1, the WTRU may request to establish a connection different from RRC_IDLE (e.g., a new connection). At 2 / 2a, the gNB may complete the RRC setup procedure. A scenario in which the gNB rejects the request may be described herein. At 3, the first NAS message from the WTRU piggybacked in the RRCSetupComplete may be transmitted to the AMF. At 4 / 4a / 5 / 5a, additional NAS messages may be exchanged between the WTRU and the AMF. At 6, the AMF may prepare WTRU context data (including protocol data unit (PDU) session context, security keys, WTRU radio capabilities, and WTRU security capabilities, etc.) and may transmit the WTRU context data to the gNB. At 7 / 7a, the gNB may activate AS security with the WTRU. At 8 / 8a, the gNB may perform reconfiguration to establish a signaling radio bearer (SRB) 2 and a data radio bearer (DRB) for the WTRU, or establish SRB2 and (optionally) DRB for an integrated access and backhaul (IAB)-mobile terminal (MT). At 9, the gNB may inform the AMF that the establishment process may be completed. The RRC messages at 1 and 2 may use SRB0, and some or all subsequent messages may use SRB1. The messages at 7 / 7a may be integrity protected. Starting from 8, some or all messages may be integrity protected and encrypted. For signaling-only connections, 8 may be skipped as SRB2 and DRB may not be established.

[0114] Figure 4 is an example of a WTRU triggered rejection of the transition from RRC_IDLE. Figure 4 Describes a rejection from the network when the WTRU attempts to establish a connection from RRC_IDLE. At 1, the WTRU may attempt to establish a connection different from RRC_IDLE (e.g., a new connection). At 2, the gNB may not be able to handle the process, for example due to congestion. At 3, the gNB may transmit an RRC reject (with a wait time) to keep the WTRU in RRC_IDLE.

[0115] This document may describe mobility in RRC_INACTIVE.

[0116] RRC_INACTIVE may be a state in which the WTRU remains in CM-CONNECTED and can move within the area configured by the Next Generation (NG)-RAN (RNA) without notifying the NG-RAN. In RRC_INACTIVE, the last serving gNB node may maintain the WTRU context and the WTRU-associated NG connection with the serving AMF and UPF.

[0117] If the last serving gNB may receive DL data from the UPF or DL ​​WTRU associated signaling from the AMF (except the WTRU context release command message (e.g., UE context release as defined in 3GPP)) while the WTRU may be in RRC_INACTIVE, then the last serving gNB may perform paging in the cell corresponding to the RNA, and if the RNA includes cells of neighboring gNBs, then the last serving gNB may transmit an Xn Application Protocol (XnAP) RAN page to the neighboring gNB.

[0118] When a WTRU CONTEXT RELEASE COMMAND message is received while the WTRU may be in RRC_INACTIVE, the last serving gNB may page in the cell corresponding to the RNA, and if the RNA includes cells of neighboring gNBs, the last serving gNB may transmit an XnAP RAN paging to the neighboring gNBs to explicitly release the WTRU.

[0119] When an NG RESET message is received while the WTRU may be in RRC_INACTIVE, the last serving gNB may page the WTRU involved in the cell corresponding to the RNA, and if the RNA includes cells of neighboring gNBs, an XnAP RAN paging may be transmitted to the neighboring gNB to explicitly release the WTRU involved.

[0120] In case of RAN paging failure, the gNB may behave accordingly.

[0121] The AMF may provide core network assistance information to the NG-RAN node to assist the NG-RAN node in deciding whether the WTRU may be transferred to RRC_INACTIVE and assist the WTRU in configuring and paging in RRC_INACTIVE. The core network assistance information may include the registration area configured for the WTRU, the periodic registration update timer and the WTRU identity index value, and may include WTRU specific discontinuous reception (DRX), an indication of whether the WTRU may be configured with mobile initiated connection only (MICO) mode by the AMF, the desired WTRU behavior, the WTRU radio capabilities for paging, the paging early indication (PEI) with paging subpacket assistance information, and the NR paging eDRX information and the paging cause indication for voice services. The NG-RAN node may consider the WTRU registration area when configuring RNA. The WTRU specific DRX and WTRU identity index value may be used by the NG-RAN node for RAN paging. The periodic registration update timer may be considered by the NG-RAN node to configure the periodic RNA update timer. The NG-RAN node may consider the desired WTRU behavior to assist the WTRU RRC state transition decision. The NG-RAN node may use the WTRU radio capabilities for paging during RAN paging. The NG-RAN node may take into account the PEI with paging sub-group assistance information for sub-group paging in RRC_INACTIVE. When transmitting XnAP RAN paging to a neighboring NG-RAN node, the PEI with paging sub-group assistance information may be included. When the NR WTRU may be in RRC_INACTIVE, the NG-RAN node may consider the NR paging eDRX information to configure RAN paging. When transmitting XnAP RAN paging to a neighboring NG-RAN node, NR paging eDRX information for RRC_IDLE and for RRC_INACTIVE may be included. The NG-RAN node may consider the paging cause indication for voice services to include the paging cause in the RAN paging for the WTRU in the RRC_INACTIVE state. When transmitting XnAP RAN paging to a neighboring NG-RAN node, the paging cause may be included.

[0122] Upon transition to RRC_INACTIVE, the NG-RAN node may configure the periodic RNA update timer value for the WTRU. When the periodic RNA update timer expires without notification from the WTRU, the gNB may behave accordingly.

[0123] If the WTRU accesses a gNB other than the last serving gNB, the receiving gNB may trigger the XnAP Retrieve UE Context procedure to obtain the WTRU context from the last serving gNB and may also trigger the Xn-U Address Indication procedure which includes tunnel information for potential recovery of data from the last serving gNB. Upon successful retrieval of the WTRU context, the receiving gNB may perform slice-aware admission control with the slice information received and may become the serving gNB and it further triggers an NGAP Path Switch Request and applicable RRC procedures. After the path switch procedure, the serving gNB may trigger the release of the WTRU context at the last serving gNB via the XnAP WTRU Context Release procedure.

[0124] In the case that the WTRU may not be reachable at the last serving gNB, the gNB may fail (e.g. any) AMF initiated WTRU associated Type 1 procedure which allows the unsuccessful operation to be signaled in the corresponding response message. It may trigger the NAS Non-Delivery Indication procedure to report the non-delivery of any non-PDU session related NAS PDUs received from the AMF.

[0125] If the WTRU accesses a gNB other than the last serving gNB and the receiving gNB does not find a valid WTRU context, the receiving gNB may perform establishment of a different RRC connection (e.g., a new RRC connection), for example, instead of resuming the previous RRC connection. The WTRU context retrieval may also fail, so if the serving AMF changes, a different RRC connection (e.g., a new RRC connection) may be established.

[0126] When a WTRU in RRC_INACTIVE state moves out of the configured RNA, the WTRU may need to initiate an RNA update procedure. Upon receiving an RNA update request from the WTRU, the receiving gNB may trigger the XnAP Retrieve WTRU Context procedure to obtain the WTRU context from the last serving gNB and may decide to transfer the WTRU back to the RRC_INACTIVE state, move the WTRU to the RRC_CONNECTED state, or transfer the WTRU to RRC_IDLE. In case of periodic RNA updates, if the last serving gNB decides not to relocate the WTRU context, the last serving gNB fails the Retrieve WTRU Context procedure and may transfer the WTRU back to RRC_INACTIVE or directly transfer the WTRU to RRC_IDLE via an encapsulated RRC Release message.

[0127] A cell reselection may be performed. A WTRU in RRC_INACTIVE may perform a cell reselection. The principle of this process is probably the same as for the RRC_IDLE state.

[0128] RAN-based Notification Area may be used. A WTRU in RRC_INACTIVE state may be configured with an RNA by the last serving NG-RAN node, where: the RNA may cover a single or multiple cells and may be contained within a CN registration area; Xn connectivity may be available within the RNA; RAN-based Notification Area Updates (RNAU) may be transmitted by the WTRU periodically and may also be transmitted in the event that the WTRU's cell reselection procedure selects a cell that does not belong to the configured RNA.

[0129] There may be several alternatives as to how the RNA may be configured: a cell list (e.g., an explicit list of one or more cells constituting the RNA may be provided to the WTRU); a RAN area list (e.g., one or more RAN area IDs may be provided to the WTRU, where a RAN area may be a subset of or equal to a CN tracking area; a RAN area may be specified by a RAN area ID which may include a TAC and (optionally) a RAN area code; a cell may broadcast one or more RAN area IDs in system information.

[0130] The NG-RAN may provide different RNA definitions to different WTRUs (e.g., the NG-RAN may not mix different definitions to the same WTRU at the same time). The WTRU may support some or all of the RNA configuration options listed above.

[0131] A state transition may occur. A WTRU triggered transition from RRC_INACTIVE to RRC_CONNECTED may occur.

[0132] Figure 5 is an example of a WTRU triggered transition from RRC_INACTIVE to RRC_CONNECTED (WTRU context retrieval successful). Figure 5A WTRU-triggered transition from RRC_INACTIVE to RRC_CONNECTED is described in case of a successful WTRU context retrieval. At 1, the WTRU may recover from RRC_INACTIVE, providing an Inactive Radio Network Temporary Identifier (I-RNTI) allocated by the last serving gNB. At 2, if the gNB is able to resolve the gNB identity contained in the I-RNTI, the gNB may request the last serving gNB to provide the WTRU context data. At 3, the last serving gNB may provide the WTRU context data. At 4 / 5, the gNB and WTRU may complete the recovery of the RRC connection. If authorization allows, user data may also be transmitted at 5. At 6, the gNB may provide a forwarding address if it is possible to prevent the loss of DL user data buffered in the last serving gNB. At 7 / 8, the gNB may perform a path switch. At 9, the gNB may trigger the release of WTRU resources at the last serving gNB. After 1 above, when the gNB decides to reject the recovery request (e.g., immediately) using a single RRC message and keep the WTRU in RRC_INACTIVE (e.g., without any reconfiguration) (e.g., as described in the two examples below), or when the gNB decides to establish a different RRC connection (e.g., a new RRC connection), SRB0 (without security) may be used. Conversely, when the gNB decides to reconfigure the WTRU (e.g., with a new DRX cycle or RNA) or when the gNB decides to push the WTRU to RRC_IDLE, SRB1 (with integrity protection and ciphering as previously configured for that SRB) may be used. Once the WTRU context can be retrieved (e.g., after 3), SRB1 may be used (e.g., only).

[0133] Figure 6 is an example of a WTRU triggered transition from RRC_INACTIVE to RRC_CONNECTED (WTRU context retrieval failure). Figure 6A WTRU-triggered transition from RRC_INACTIVE to RRC_CONNECTED is described in the event of a WTRU context retrieval failure. At 1, the WTRU may recover from RRC_INACTIVE, providing the I-RNTI allocated by the last serving gNB. At 2, if the gNB is able to resolve the gNB identity contained in the I-RNTI, the gNB may request the last serving gNB to provide the WTRU context data. At 3, the last serving gNB may not retrieve or verify the WTRU context data. At 4, the last serving gNB may indicate a failure to the gNB. At 5, the gNB may perform a fallback to establish a different RRC connection (e.g., a new RRC connection) by transmitting an RRCSetup. At 6, a different connection (e.g., a new connection) may be established.

[0134] Figure 7 is an example of a rejection from the network when the WTRU attempts to restore the connection. Figure 7 Describes rejections from the network when the WTRU attempts to recover a connection from RRC_INACTIVE. At 1, the WTRU may attempt to recover a connection from RRC_INACTIVE. At 2, the gNB may not be able to handle the process, for example due to congestion. At 3, the gNB may transmit an RRC reject (with a wait time) to keep the WTRU in RRC_INACTIVE.

[0135] A network triggered transition from RRC_INACTIVE to RRC_CONNECTED may occur. Figure 8 is an example of a network triggered transition from RRC_INACTIVE to RRC_CONNECTED. Figure 8 A network-triggered transition from RRC_INACTIVE to RRC_CONNECTED is described. At 1, a RAN paging triggering event may occur (incoming DL user plane, DL signaling from 5GC, etc.). At 2, RAN paging may be triggered (e.g., only in cells controlled by the last serving gNB, or also by means of Xn RAN paging in cells controlled by other gNBs that are configured for the WTRU in the RAN-based Notification Area (RNA). At 3, the WTRU may be paged with the I-RNTI. At 4, if the WTRU has been successfully reached, it may attempt to recover from RRC_INACTIVE.

[0136] RNA updates can be performed. Fig. 9 is an example of an RNA update procedure with WTRU context relocation. Fig. 9A WTRU triggered RNA update procedure involving context retrieval on Xn is described. The procedure may be triggered when the WTRU moves out of the configured RNA, or periodically. At 1, the WTRU may recover from RRC_INACTIVE, providing the I-RNTI allocated by the last serving gNB and an appropriate cause value (e.g., RAN Notification Area Update). At 2, if the gNB is able to resolve the gNB identity contained in the I-RNTI, the gNB may request the last serving gNB to provide the WTRU context data, thereby providing the cause value received at 1. At 3, the last serving gNB may provide the WTRU context (as assumed below). Alternatively, the last serving gNB may decide to move the WTRU to RRC_IDLE (and the procedure follows Fig.11 3 and later), or if the WTRU is still in the previously configured RNA, the last serving gNB keeps the WTRU context in the last serving gNB and keeps the WTRU in RRC_INACTIVE (and the procedure follows Fig.10 3 and following procedures). At 4, the gNB may move the WTRU to RRC_CONNECTED (and the procedure follows Figure 5 At 4) the WTRU may either transfer the WTRU back to RRC_IDLE (in which case an RRC Release message may be sent by the gNB) or transfer the WTRU back to RRC_INACTIVE as assumed below. At 5, the gNB may provide a forwarding address if this may prevent the loss of DL user data buffered in the last serving gNB. At 6 / 7, the gNB may perform a path switch. At 8, the gNB may keep the WTRU in RRC_INACTIVE state by transmitting an RRC Release with a suspend indication. At 9, the gNB may trigger the release of the WTRU resources at the last serving gNB.

[0137] Fig.10 is an example of a periodic RNA update procedure without WTRU context relocation. Fig.10The RNA update procedure is described for a situation where the WTRU may still be within a configured RNA and the last serving gNB decides not to relocate the WTRU context and keep the WTRU in RRC_INACTIVE. At 1, the WTRU may recover from RRC_INACTIVE, providing the I-RNTI assigned by the last serving gNB and an appropriate cause value (e.g., RAN Notification Area Update). At 2, if the gNB is able to resolve the gNB identity contained in the I-RNTI, the gNB may request the last serving gNB to provide the WTRU context data, providing the cause value received at 1. At 3, the last serving gNB may store the received information for use in the next recovery attempt (e.g., the cell RNTI and physical cell ID (PCI) associated with the recovery cell), and may respond to the gNB with a RETRIEVE UE CONTEXTFAILURE message including an encapsulated RRC release message. The RRC release message may include a suspend indication. At 4, the gNB may forward the RRC release message to the WTRU.

[0138] Fig.11 is an example of the RNA update procedure for transitioning to RRC_IDLE. Fig.11 The RNA update process is described for the case where the last serving gNB decides to move the WTRU to RRC_IDLE. At 1, the WTRU may recover from RRC_INACTIVE, providing the I-RNTI allocated by the last serving gNB and an appropriate cause value (e.g., RAN Notification Area Update). At 2, if the gNB is able to resolve the gNB identity contained in the I-RNTI, the gNB may request the last serving gNB to provide the WTRU context data, providing the cause value received at 1. At 3, the last serving gNB may provide an RRC Release message to move the WTRU to RRC_IDLE instead of providing the WTRU context. At 4, the last serving gNB may delete the WTRU context. At 5, the gNB may transmit an RRC Release that triggers the WTRU to move to RRC_IDLE.

[0139] A resume request responded with a release with redirection, WTRU context relocation may be used. Fig.12 is an example of a resume request responded with a release with redirection, WTRU context relocation. Fig.12Describes WTRU triggered NAS procedures to which the network responds with a Release with Redirection, WTRU Context Relocation. At 1, the WTRU may recover from RRC_INACTIVE, providing the I-RNTI allocated by the last serving gNB. At 2, if the gNB is able to resolve the gNB identity contained in the I-RNTI, the gNB may request the last serving gNB to provide the WTRU context data. At 3, the last serving gNB may provide the WTRU context. At 4, the gNB may move the WTRU to RRC_CONNECTED (and the procedure follows Figure 5 4) either transmits the WTRU back to RRC_IDLE (in which case an RRC Release message may be transmitted by the gNB), or transmits the WTRU back to RRC_INACTIVE, including a Release with a redirection indication (as assumed below). At 5, the gNB may provide a forwarding address if it is possible to prevent the loss of DL user data buffered in the last serving gNB. At 6. / 7, the gNB may perform a path switch. At 8, the gNB may keep the WTRU in the RRC_INACTIVE state by transmitting an RRC Release with a Suspend indication that includes the redirection information (the frequency layer where the WTRU performed cell selection when entering RRC_INACTIVE). At 9, the gNB may trigger the release of the WTRU resources at the last serving gNB. Upon receiving a Release with a redirection, higher layers may trigger pending procedures so that the WTRU may attempt to resume again after cell selection.

[0140] Paging may be used. Paging may allow the network to reach WTRUs in RRC_IDLE and in RRC_INACTIVE states with paging messages, and to notify WTRUs in RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states of system information changes and Earthquake and Tsunami Warning System (ETWS) / Commercial Mobile Alert System (CMAS) indications with short messages. Both paging messages and short messages may be addressed using a paging (P)-RNTI on a physical downlink control channel (PDCCH) (e.g., but the former may be transmitted on the PCCH and the latter may be transmitted directly on the PDCCH).

[0141] When in RRC_IDLE, the WTRU may monitor the Paging Channel for CN initiated paging. When in RRC_INACTIVE and there is no SDT process in progress, the WTRU may monitor the Paging Channel for RAN initiated paging and CN initiated paging. The WTRU may not need to monitor the Paging Channel continuously; Paging DRX may be a situation where a WTRU in RRC_IDLE or RRC_INACTIVE may (e.g., only) monitor the Paging Channel during one Paging Occasion (PO) of each DRX cycle. The Paging DRX cycle may be configurable by the network: for CN initiated paging, a default cycle may be broadcast in the system information; for CN initiated paging, a WTRU specific cycle may be configured via NAS signaling; for RAN initiated paging, a WTRU specific cycle may be configured via RRC signaling (e.g., the WTRU may use the shortest of the applicable DRX cycles; for example, a WTRU in RRC_IDLE may use the shortest of the first two cycles described above, while a WTRU in RRC_INACTIVE may use the shortest of the three cycles).

[0142] The PO of the WTRU for CN initiated paging and RAN initiated paging may be based on the same WTRU ID, resulting in overlapping POs for both. The number of different POs in a DRX cycle may be configured via system information, and the network may assign WTRUs to these POs based on the WTRU's ID.

[0143] When in RRC_CONNECTED and when in RRC_INACTIVE and a small data transmission (SDT) procedure is in progress, the WTRU may monitor the paging channel in the PO (e.g., any PO) signaled in the system information for SI change indication and public warning system (PWS) notification. In the case of bandwidth adaptation (BA), the WTRU in RRC_CONNECTED may monitor (e.g., only monitor) the paging channel on the active BWP if the common search space is configured.

[0144] In order to operate with shared spectrum channel access, the WTRU may be configured with an additional number of PDCCH monitoring occasions in its PO to monitor for paging. When a WTRU detects a PDCCH transmission within a PO of a WTRU addressed with a P-RNTI, then there may be no need for the WTRU to monitor subsequent PDCCH monitoring occasions within that PO.

[0145] If a paging cause may be included in the paging message, a WTRU in RRC_IDLE or RRC_INACTIVE state may use the paging cause.

[0146] Paging optimization for WTRU in CM_IDLE may be performed: Upon WTRU context release, the NG-RAN node may provide the AMF with a list of recommended cells and NG-RAN nodes as assistance information for subsequent paging. The AMF may also provide paging attempt information including a paging attempt count and an expected number of paging attempts, and may include a next paging area range. If the paging attempt information may be included in the paging message, the paged NG-RAN node (e.g., each paged NG-RAN node) may receive the same information during the paging attempt. The paging attempt count may be increased by 1 at a new paging attempt (e.g., each new paging attempt). The next paging area range (when present) may indicate whether the AMF plans to modify the paging area currently selected at the next paging attempt. If the WTRU has changed its state to CM CONNECTED, the paging attempt count may be reset.

[0147] Paging optimization for a WTRU in RRC_INACTIVE may be performed: Upon RAN paging, the serving NG-RAN node may provide RAN paging area information. The serving NG-RAN node may also provide RAN paging attempt information. The paged NG-RAN node (e.g., each paged NG-RAN node) may receive the same RAN paging attempt information during the paging attempt, which has the following content: paging attempt count, expected number of paging attempts, and next paging area range. The paging attempt count may be increased by 1 at a new paging attempt (e.g., each new paging attempt). The next paging area range (when present) may indicate whether the serving NG_RAN node plans to modify the RAN paging area currently selected at the next paging attempt. If the WTRU leaves the RRC_INACTIVE state, the paging attempt count may be reset.

[0148] WTRU power savings for paging monitoring may be used: To reduce WTRU power consumption due to false paging alerts, the group of WTRUs monitoring the same PO may be further divided into multiple sub-groups. Using sub-grouping, if the sub-group to which the WTRU belongs can be paged as indicated via the associated PEI, the WTRU may monitor the PDCCH in its PO for paging. If the WTRU cannot find its sub-group ID with PEI configuration in the cell, or if the WTRU may not be able to monitor the associated PEI opportunity corresponding to its PO, the WTRU may monitor paging in its PO. These subgroups may have the following characteristics: they may be formed based on CN-controlled subgroups or WTRUID-based subgroups; if the CN-controlled subgroup ID cannot be provided from the AMF, the WTRU ID-based subgroup may be used if supported by the WTRU and the network; the RRC state (e.g., RRC_IDLE or RRC_INACTIVE state) may not affect which subgroup the WTRU belongs to; subgroup support for the cell may be broadcast in system information as one of the following (e.g., only CN-controlled subgroups, only WTRU ID-based subgroups, or both CN-controlled subgroups and WTRU ID-based subgroups); the total number of subgroups allowed in the cell may be up to 8 and may represent the sum of CN-controlled subgroups and WTRU ID-based subgroups configured by the network; if the cell supports CN-controlled subgroups, the WTRU configured with the CN-controlled subgroup ID may apply the CN-controlled subgroup ID; otherwise, the WTRU may derive the WTRUID-based subgroup ID (e.g., if the cell only supports WTRU ID-based subgroups).

[0149] The PEI associated with a subgroup may have the following characteristics: if the WTRU can support PEI, the WTRU may support at least a subgrouping method based on the WTRU ID; PEI monitoring may be limited to the cell whose last connection was released via system information (for example, unless the network indicates that the WTRU will not update its last used cell information); a WTRU with PEI capability may store its last used cell information; a gNB that supports PEI monitoring of the last used cell function may provide the WTRU's last used cell information to the AMF in the NG-AP UE context release complete message of the WTRU with PEI capability; a WTRU that expects multicast and broadcast service (MBS) group notification may ignore PEI and may monitor paging in its PO.

[0150] CN controlled subgrouping may be used: For CN controlled subgrouping, the AMF may be responsible for assigning a subgroup ID to the WTRU. The total number of subgroups of CN controlled subgrouping, which may be configured, for example, by operations, administration and maintenance (OAM), may be up to a certain number (e.g., 8). It may be assumed that CN controlled subgrouping support may be uniform within the RNA.

[0151] Fig.13 is an example process of a CN controlled subgroup. Fig.13 The process of CN controlled subgrouping is described. At 1, the WTRU may indicate its support for CN controlled subgrouping via NAS signaling. At 2, if the WTRU supports CN controlled subgrouping, the AMF may determine the subgroup ID allocation for the WTRU. At 3, the AMF may transmit the subgroup ID to the WTRU via NAS signaling. At 4, the AMF may notify the gNB of the CN allocated subgroup ID for paging the WTRU in RRC_IDLE / RRC_INACTIVE state. At 5, when a paging message for the WTRU may be received from the CN or may be generated by the gNB, the gNB may determine the PO and associated PEI timing for the WTRU. At 6, before the WTRU may be paged in the PO, the gNB may send the associated PEI and indicate the corresponding CN controlled subgroup of the WTRU to be paged in the PEI.

[0152] WTRU ID based subgrouping may be used. For WTRU ID based subgrouping, the gNB and the WTRU may determine the subgroup ID based on the WTRU ID and the total number of subgroups in the cell for WTRU ID based subgrouping. The total number of subgroups for WTRU ID based subgrouping may be determined by the gNB for a cell (e.g., per cell) and may be different in different cells. Fig.14 is an example procedure for sub-grouping based on WTRU ID. Fig.14 A process for WTRU ID-based subgrouping is described. At 1, the gNB may determine the total number of subgroups of WTRU ID-based subgrouping in the cell. At 2, the gNB may broadcast the total number of subgroups of WTRU ID-based subgrouping in the cell. At 3, when a paging message for a WTRU with PEI capability may be received at the gNB from the CN or may be generated by the gNB, the gNB may determine the PO and associated PEI timing for the WTRU. At 4, before the WTRU may be paged in the PO, the gNB may send the associated PEI and indicate the corresponding subgroup derived based on the WTRU ID of the WTRU that may be paged in the PEI.

[0153] Extended DRX for RRC_IDLE and RRC_INACTIVE may be used. When extended DRX (eDRX) may be used, the following may apply. For RRC_INACTIVE, the eDRX configuration for RAN paging may be decided and configured by the NG-RAN. In RRC_INACTIVE, the WTRU may monitor both RAN and CN paging. For RRC_IDLE, eDRX for CN paging may be configured by upper layers. In RRC_IDLE, the WTRU may monitor CN paging (e.g., only CN paging). Information on whether a WTRU in RRC_IDLE and RRC_INACTIVE may be allowed eDRX on a cell may be provided in system information for RRC_IDLE and RRC_INACTIVE, respectively. The maximum value of the eDRX cycle may be 10485.76 seconds (2.91 hours) for RRC_IDLE and 10.24 seconds for RRC_INACTIVE, while the minimum value of the eDRX cycle may be 2.56 seconds for both RRC_IDLE and RRC_INACTIVE. The hyper system frame number (H-SFN) may be broadcast by the cell and incremented by one when the SFN wraps around; the paging superframe (PH) may refer to the H-SFN where the WTRU starts monitoring paging DRX during the paging time window (PTW) used in RRC_IDLE. The PH and PTW may be determined based on formulas that may be known to the AMF, WTRU and NG-RAN. If the eDRX cycle may be greater than 10.24 seconds, the H-SFN, PH and PTW may be used. When the eDRX cycle may be longer than the system information modification period, the WTRU may verify that the stored system information is still valid before establishing an RRC connection.

[0154] NR NTN (non-terrestrial network) enhancements (e.g., NTN-TN and NTN-NTN mobility and service continuity enhancements) may include one or more of the following. NTN-TN and NTN-NTN measurement / mobility and service continuity enhancements may be specified. For NTN-NTN mobility, cell reselection for earth mobile cells (e.g., cell reselection enhancements), timing-based and / or location-based cell reselection for quasi-earth fixed cells may be considered. NTN-NTN handover for RRC_CONNECTED WTRUs in quasi-earth fixed cells and / or earth mobile cells (e.g., NTN-NTN handover enhancements) may be specified to reduce signaling overhead. Cell reselection for RRC_IDLE / INACTIVE WTRUs (e.g., cell reselection enhancements) may be specified to reduce WTRU power consumption (NTN-TN mobility may be prioritized). Enhancements to Xn[ / NG] signaling may be specified to support feeder link handover CHO, such as information exchange of necessary information such as between gNBs.

[0155] The network may include several layers (e.g., TN and one or more of LEO satellites, MEO satellites, and GEO satellites) that may operate with different cell sizes and different air propagation delays (e.g., each layer may operate with a different cell size and / or different air propagation delay). Fig.15 is an example of the NTN-TN network layer. In the example (for example, Fig.15 ), GEO (e.g., satellite or cell) may have the largest cell coverage (e.g., has the longest propagation delay) among the TN, LEO, MEO, and GEO, followed by MEO, then LEO (which may have smaller cell coverage and / or shorter propagation delay than GEO and MEO), and TN, which has the smallest cell coverage and shortest propagation delay among the TN, LEO, MEO, and GEO.

[0156] Although one or more examples herein may involve TN to NTN coverage, the principles, processes, tools, and systems may be applied to any combination of network layers (eg, LEO to GEO, TN to MEO to GEO, etc.).

[0157] If both TN coverage and NTN coverage are available to the WTRU, the WTRU may camp on the NTN cell, for example, even when the WTRU is in the RRC_INACTIVE state (e.g., mode / operating condition), which may advantageously provide benefits from a WTRU power saving perspective. In an example, the NTN cell may have wider coverage than a TN cell (or a combination of multiple TN cells) (e.g., as shown in FIG. Fig.15 ), which may minimize (eg, particularly for a mobile WTRU) one or more of: neighbor cell measurements; cell reselection; system information (SI) readings.

[0158] The WTRU may camp on an NTN cell, which may additionally advantageously provide benefits, for example, from a NW paging load perspective. For example, if TN coverage and NTN coverage are available to the WTRU, the WTRU may camp on an NTN cell, for example, when the WTRU is in an RRC inactive state. One or more cell reselection methods described in one or more examples for a WTRU in an RRC_INACTIVE state may be used for a WTRU in an RRC_IDLE state (e.g., the same or similar cell reselection methods may be used for both RRC_IDLE and RRC_INACTIVE, for example, different parameters may be configured (e.g., cell reselection priorities, thresholds), but the process may be the same or similar). In an example, when an NTN cell has wider coverage than a TN cell or a combination of multiple TN cells (e.g., such as Fig.15, the WTRU cell location (e.g., the cell in which the WTRU resides) may be known and / or more readily available. For example, when the WTRU cell location is known or known with greater confidence (e.g., based on a higher likelihood, a higher statistical likelihood, or an increased reliability of a related indication), there may be no need to escalate paging across multiple cells within an RNA. In an example, in a TN cell, the WTRU may perform cell reselection, for example, in an RRC_INACTIVE state within an RNA, without notifying the network. For example, the network may page in multiple cells to find the location of the WTRU. In some examples, in an NTN cell with relatively wide coverage (e.g., a GEO satellite), the cell location associated with the WTRU may be or is more likely to be known, for example because the WTRU may not need to reselect to another cell. In an NTN cell with medium coverage (e.g., another NTN cell such as LEO, Earth Mobile), the cell location may be known with greater confidence (e.g., the number of potential cells in which the WTRU may reside may be limited compared to, for example, a TN). For example, in an NTN cell with medium coverage, the cell location may be known with greater confidence even in the case of cell reselection within the TA / RNA (e.g., because the WTRU may not have moved significantly within the geographic area). In one or more examples herein, the WTRU cell location may refer to the cell, carrier, band, subband, and / or BWP in which the WTRU resides.

[0159] If TN coverage and NTN coverage are available to the WTRU, the WTRU may camp on the TN cell, which may advantageously provide benefits, for example from a latency perspective. In some examples, for example, in terms of signaling latency and / or data throughput, the TN cell may be a better choice than the NTN cell (e.g., the RRC recovery process and / or data transmission may experience long propagation delays in the NTN cell). Notification and / or delivery of paging messages may be subject to latency in the NTN cell (e.g., it may be long or longer than when using a TN cell). The NTN cell may still be used for paging message delivery (e.g., considering potential paging upgrades, the latency on the NTN cell may not always be worse).

[0160] There may be differences between the RRC_INACTIVE state and the RRC_IDLE state (e.g., differences that result in a query compared to the RRC_IDLE state), for example, because the WTRU is in CM-CONNECTED (e.g., connected to the core network). A base station (e.g., such as the last serving base station of a gNB) may maintain a WTRU context and / or a WTRU-associated connection (e.g., a WTRU-associated NG connection with a serving AMF and / or UPF). Paging (e.g., RAN paging) may be initiated. For example, when the WTRU is in the RRC_INACTIVE state, if the last serving gNB receives DL information from the UPF or DL ​​WTRU-associated signaling from the AMF (e.g., if the last serving gNB receives DL information or DL ​​WTRU-associated signaling, other than a WTRU CONTEXT RELEASE COMMAND message), the last serving gNB may page in one or more cells corresponding to the RNA and / or may transmit an XnAP RAN page to neighboring gNBs (e.g., if the RNA includes cells of neighboring gNBs, the last serving gNB may also page in these cells of the neighboring gNBs).

[0161] If the WTRU resides on an NTN cell but has moved (e.g., such that the RNA of the TN may change), the DL data may have been delivered to the last serving base station (e.g., a gNB in ​​the TN cell), and in some examples, if the WTRU is paged via the NTN cell, the WTRU may not be able to reach and / or may not be able to deliver data in a gNB (e.g., any gNB) within the RNA, for example, unless the NTN gNB may be part of the same RNA as the last connected TN gNB (e.g., this may or may not be possible due to the relatively large size of the NTN cell). Although one or more examples herein may use the term gNB, they may apply to any base station. The coverage of an NTN cell may cover multiple TN RNAs. The NTN cells in one or more examples herein may be interchangeably referred to as NTN satellites.

[0162] In some examples, if the WTRU performs RNAU to the RNA of the NTN cell and / or remains in the RRC_INACTIVE state, data delivery on the NTN cell may experience long delays (eg, due to long propagation times on the NTN radio links).

[0163] If the WTRU is in the RRC_INACTIVE state (e.g., when the WTRU is in TN and / or NTN), then overlapping network layers (e.g., overlapping TN-NTN coverage) may be used, for example, to achieve power savings and / or paging load benefits for the NTN cell, and / or may be used to deliver data through the TN cell, for example to achieve better throughput and / or latency.

[0164] In an example, a WTRU in an RRC_INACTIVE state (e.g., when the WTRU is camped on a TN cell and / or registered to a TNRNA) may be released to an RRC_IDLE state to perform a cell reselection to an NTN cell (e.g., to save power). The WTRU may be paged by the CN (e.g., only by the CN), and, for example, based on a redirection command or a handover command from the NTN cell, or based on an indication in a paging message to respond on a TN cell, a different RRC connection (e.g., a new RRC connection) may be established on the NTN cell, or a different RRC connection may be established when the WTRU returns to the TN cell. The WTRU may save power by camping on an NTN cell (e.g., by camping on an NTN cell, the WTRU may not always benefit from the latency advantage of being in the RRC_INACTIVE state). The examples herein may be applicable to devices where power savings are valuable (e.g., devices that may require the latency advantage of the RRC_INACTIVE state at certain instances or times and may require power savings at other instances or times). In an example, the devices may include wearable devices or portable devices that may be in use at certain instances or times and in a standby mode at other instances or times.

[0165] Fig.16 is an example of releasing to RRC_IDLE to reside on the NTN. At 1650, the WTRU (e.g., WTRU 1610) may transmit WTRU assistance information (e.g., UE assistance information) or an RRC release request to, for example, a base station (e.g., TN gNB 1620).

[0166] The WTRU may transmit WTRU assistance information (e.g., to release the WTRU to idle to camp on an NTN cell). In an example, a WTRU (e.g., a WTRU in an RRC_CONNECTED state) may initiate the sending of WTRU assistance information including, for example, an indication that the WTRU prefers to camp on an NTN cell (e.g., to save power). In some examples, a WTRU (e.g., a WTRU in an RRC_INACTIVE state) may first perform an RRC connection recovery procedure, for example, to send the WTRU assistance information.

[0167] The WTRU may transmit an RRC release request (e.g., to release the WTRU to idle to camp on an NTN cell). In some examples, transmitting an RRC release request to move from an RRC_INACTIVE state to an RRC_IDLE state may be more efficient than, for example, transmitting WTRU assistance information. For example, when the WTRU is in an RRC_INACTIVE state, the WTRU may send a message (e.g., Msg3, Msg5, or MsgA) or a request. The message may include an RRC release request (e.g., Msg3, Msg5, or MsgA may include a new RRC message, such as an RRC release request). The RRC release request may indicate or include an indication that the WTRU prefers to camp on an NTN cell.

[0168] The RRC release request or WTRU assistance information may indicate or include an indication of the availability of the NTN cell. For example, the WTRU may include one or more of the following in the RRC release request or WTRU assistance information: available measurement results of the NTN cell (e.g., measured via TN); location information (e.g., coarse WTRU location); indications (e.g., 1 bit) of detected NTN cells that may be suitable (e.g., any detected NTN cell associated with a measurement above a threshold or any detected NTN cell that meets a suitability criterion or condition); information about satellites and / or NTN cells (e.g., including one or more of satellite ephemeris data, NTN deployment scenarios, NTN cell reference points, satellite coverage area information, neighboring satellite assistance information, detected NTN cell IDs); information about time / frequency precompensation for the NTN cell (e.g., timing advance of the WTRU via a timing advance MAC CE).

[0169] In response to receiving the RRC release request or WTRU assistance information, at 1660, the network (e.g., TN gNB 1620) may send a message indicating a change from the RRC_INACTIVE state to the RRC_IDLE state (e.g., an RRC release message). The RRC release message may include cell reselection priority information (e.g., transmission priority information). The cell reselection priority information may indicate a priority associated with one or more frequency layers associated with the NTN (e.g., the cell reselection priority information may indicate a higher priority assigned to the NTN frequency layer). The RRC release message may include a de-prioritization indication (e.g., a de-prioritization indication indicating de-prioritization for the current frequency layer or RAT such that the current frequency layer or RAT may be considered to have a lower priority than other frequency layers or RATs). The RRC release message may include information indicating one or more of the following that the WTRU may use to perform the redirection (e.g., the WTRU may attempt to camp on): a specific target frequency; a specific target band; a specific target cell; a specific target network. The information provided in the RRC release message may include a time value (e.g., a timer value during which one or more parameters apply; for example, these parameters may include parameters in the RRC release, such as a cell reselection priority validity timer and / or a de-prioritization timer). For example, the information provided in the RRC release message may include a timer that specifies how long the WTRU may camp on / prioritize the NTN frequency layer before resetting to use the broadcast priority value.

[0170] At 1670, the WTRU may perform reselection to the NTN (e.g., cell reselection to an NTN cell having NTN gNB 1640), for example, based on information provided in the RRC release message. The WTRU may monitor paging in the NTN (e.g., monitor paging messages from the NTN cell having NTN gNB 1640). At 1680, the WTRU may receive a paging message from the NTN (e.g., from NTN gNB 1640).

[0171] In an example, the WTRU may perform reselection to the NTN cell and remain in the RRC_INACTIVE state. In this case, the request (e.g., in one or more examples herein (such as Fig.16 The RRC release request or WTRU assistance information described in the example shown in Figure 1) may be used to request a change of network (e.g., a change from TN to NTN or from NTN to TN). In the example, before changing from the RRC_CONNECTED state to the RRC_INACTIVE state, the WTRU may perform measurements associated with one or more NTN cells and may transmit a request for cell reselection to the NTN cell based on the measurements. After the request is transmitted, the WTRU may receive an indication of the change from the TN cell to the NTN cell.

[0172] For example, after the request is transmitted, the WTRU may receive a suspend indication (e.g., SuspendConfig) with an indication of a change from a TN cell to an NTN cell. In an example, configuration information (e.g., configuration information associated with an RRC release) may include, for example, SuspendConfig, instead of information indicating a release to an RRC_IDLE state. In some examples, the WTRU may be configured to perform reselection to an NTN cell (e.g., during an RRC connection and before the connection may be suspended), and / or maintain RNA tracking on a TN cell while camped on an NTN cell, such as described in one or more examples herein.

[0173] TN-NTN interworking may be used. TN-NTN interworking may provide and / or enable one or more of the following: paging the WTRU via an NTN cell (e.g., through an NTN platform); responding to a TN cell or being redirected to the TN cell (e.g., so that the WTRU may remain CM-CONNECTED and DL data received at the last used TN base station (e.g., gNB) may be delivered to the WTRU via the TN cell).

[0174] Fig.17 is an example of RNA changes based on TN measurements. Fig.17 In the embodiment, when WTRU 1710 resides on the NTN, WTRU 1710 may determine whether to perform an RNA update (eg, RNA maintenance) of the TN.

[0175] RNA may include multiple regions. Fig.17 As shown, RNA 2 may include multiple cells, including cell 1750 and cell 1720. Cell 1750 and cell 1720 may be TN cells. WTRU 1710 may be in an area where cell 1720, cell 1730, and cell 1760 have coverage, such as Fig.17 Cell 1720 may be associated with RNA 2. Cell 1730 may be associated with RNA 3. Cell 1760 may be associated with RNA 3. The WTRU may perform cell measurements for cell selection or reselection.

[0176] For example, the WTRU 1710 may initially select the cell 1730 associated with RNA 3. The WTRU 1710 may perform a cell reselection to the NTN cell 1746, for example as shown in one or more examples herein. The WTRU may camp on the NTN cell 1746 (e.g., using the NTN cell 1746 to monitor paging from the NTN platform 1740, etc.). For example, the WTRU may receive an indication of a change from a TN (e.g., a cell 1730 associated with RNA 3) to an NTN (e.g., an NTN cell 1746). The WTRU may perform a cell reselection to the NTN cell 1746 based on the received indication. For example, the WTRU may receive an indication of a change from the RRC_CONNECTED state to the RRC_INACTIVE state in conjunction with or separately from an indication of a change from a TN cell to an NTN. When the WTRU camps on the NTN cell, the WTRU may be released to the RRC_INACTIVE state. The WTRU may, for example, perform measurements to determine whether to perform a cell reselection. Measurements can be associated with different cells and / or RNAs. Fig.17 As shown, for example, when the WTRU is camped on the NTN cell 1746, the WTRU may perform TN measurements. The WTRU 1710 may, for example, evaluate one or more TN cells based on the TN measurements. For example, when the WTRU is camped on the NTN cell 1746, the WTRU 1710 may perform measurements associated with RNA 2 (e.g., measurements of the cell 1720 associated with RNA 2) and measurements associated with RNA 3 (e.g., measurements of the cell 1730 associated with RNA 3 and / or measurements of the cell 1760 associated with RNA 3). The WTRU 1710 may determine that a cell reselection condition has been met (e.g., the cell reselection condition has been met or fulfilled). The cell reselection condition may be a TN cell reselection condition. The cell reselection condition may be associated with the cell 1720 associated with RNA 2. For example, the WTRU 1710 may move to a location that is better covered by RNA 2 than RNA 3, and / or the measurement associated with the cell 1720 associated with RNA 2 may be greater than a predetermined value. The WTRU 1710 may perform cell reselection to the cell 1720 associated with RNA 2.

[0177] The WTRU may register with one or more RNAs. In an example, the WTRU may register with at least 2 RNAs (e.g., a first RNA associated with the TN and a second RNA associated with the NTN). In some examples, the WTRU may register to use a first RNA associated with the TN and a second RNA associated with the NTN. Before the WTRU performs a cell reselection to an NTN cell and / or a transition from the RRC_CONNECTED state to the RRC_INACTIVE state, the WTRU may register with the first RNA associated with the TN and the second RNA associated with the NTN (e.g., simultaneously).

[0178] In some examples, a first RNA associated with a TN and an NTN cell, or a first RNA associated with a TN and a second RNA associated with an NTN may be associated. In this way, the WTRU may be paged (e.g., by receiving a paging message) via the NTN cell associated with the first RNA, and / or the WTRU may respond to paging (e.g., in response to receipt of a paging message) via the TN cell associated with the first RNA. For example, the network may associate a TN RNA with an NTN cell (or with an NTN RNA) so that when DL data arrives at a TN gNB last used by the WTRU, the network may page the WTRU via the NTN cell so that the WTRU responds via the TN cell (e.g., the TN cell associated with the TN RNA). From the perspective of the CN, the WTRU may be in a TN cell (e.g., even if the WTRU is paged via an NTN cell). If the TN base station has data to be transmitted to the WTRU, the TN base station may notify the NTN cell (e.g., the NTN cell associated with the TN cell). For example, when data arrives, the TN gNB may notify the associated NTN gNB, for example, via X2 / Xn. The WTRU may be paged in the NTN RNA or NTN cell (eg, "RAN" paging). The WTRU may respond in the TN cell (eg, upon receipt of a paging message).

[0179] The WTRU may measure and / or evaluate one or more TN cells, for example, for cell reselection. When the WTRU resides on an NTN cell, for example, after cell reselection of the NTN cell has been performed, measurements and / or evaluations of one or more TN cells may be performed. The WTRU may determine that a cell reselection condition (e.g., a cell reselection criterion for a TN cell) has been met. For example, an RNA change in the TN may be performed based on measurements and / or evaluations of one or more TN cells. In an example, when the WTRU resides on an NTN cell, the WTRU may, for example, measure and / or evaluate cell reselection criteria associated with the TN so that one or more suitable base stations (e.g., a correct gNB or a gNB within a TN RNA in which the WTRU may be geographically located) are used to receive data from the WTRU and / or transmit data to the WTRU.

[0180] The WTRU may receive identification information associated with one or more RNAs (e.g., a TN RNA). The WTRU may receive cell identification information associated with an RNA. For example, the WTRU may receive a list of cell identifications belonging to a TN RNA, a list of cell identifications belonging to multiple TN RNAs, or multiple lists of cell identifications belonging to multiple TN RNAs (e.g., a respective list of cell identifications for each TN RNA).

[0181] The WTRU may receive information about a cell reselection condition associated with a TN cell associated with an RNA, a cell reselection condition associated with a TN cell associated with an RNA, or a cell reselection condition associated with a TN cell associated with multiple RNAs. For example, the WTRU may receive cell reselection criteria corresponding to a cell. In an example, the cell reselection criteria may include thresholds and / or priorities associated with cells on a frequency (e.g., some or all cells on a frequency). The cell reselection condition may include a cell reselection threshold (e.g., a predetermined cell measurement value). The cell reselection condition may include cell reselection priority information (e.g., a predetermined priority level associated with a cell or frequency). In an example, the cell reselection criteria may include cell-specific information for a corresponding cell (e.g., each corresponding cell).

[0182] Identification information associated with one or more RNAs and / or cells may be received, for example, via RRC signaling. One or more cell reselection conditions may be received, for example, via RRC signaling. Identification information associated with one or more RNAs and / or cells may be received in a TN or NTN. One or more cell reselection conditions may be received in a TN or NTN. In an example, a cell identification list associated with one or more TN RNAs (e.g., belonging to one or more TN RNAs) and / or a cell reselection criterion (e.g., a cell reselection threshold and / or priority) corresponding to a cell may be received in broadcast signaling or dedicated signaling (e.g., dedicated RRC signaling). A cell identification list associated with one or more TN RNAs and / or a cell reselection criterion corresponding to a cell may be received via a TN cell or via an NTN cell. In some examples, a cell identification list associated with one or more TN RNAs and / or a cell reselection criterion corresponding to a cell may be received and / or stored from a TN cell via broadcast system information.

[0183] For example, when the WTRU is camped on the second network, the WTRU may evaluate one or more cells of the first network. The WTRU may evaluate the virtual cell reselection state of the first network. For example, when the WTRU is camped on the second network, the WTRU may evaluate the cell reselection state of the first network as if it were camped on the first network. For example, when camped on an NTN cell, the WTRU may determine the virtual cell reselection state of the TN based on one or more of the following: TN cell reselection information (e.g., stored TN cell reselection information); RNA and / or cell information; measurement results. The TN cell reselection information may include, for example, cell reselection conditions. The RNA and / or cell information may include, for example, identification information associated with one or more RNAs and / or cells. The WTRU may perform one or more of the following as if the WTRU were camped on a TN cell (e.g., even though the WTRU may be camped on an NTN cell): measurements of one or more TN cells; evaluation of cell reselection criteria for TN cells; determination of whether to perform cell reselection to one or more TN cells.

[0184] For example, if the RNA associated with the WTRU has not changed, the WTRU may not perform cell reselection (e.g., any cell reselection). In some examples, the WTRU may evaluate the cell reselection criteria without triggering cell reselection (e.g., the WTRU may only evaluate the cell reselection criteria).

[0185] If the WTRU determines that the cell reselection to a TN cell may result in a change in RNA, the WTRU may notify the base station (e.g., NTN gNB) of the change in RNA (e.g., a message indicating "RNA change in TN"). The WTRU may transmit an indication of the change from the first RNA to the second RNA to the base station. The WTRU may be released to the RRC_IDLE state (e.g., before the cell is reselected to a TN cell associated with a different RNA or without cell reselection to a TN cell associated with a different RNA). For example, in response to an indication of the RNA change transmitted by the WTRU, the base station may transmit an indication of a change from the RRC_INACTIVE state to the RRC_IDLE state to the WTRU. The WTRU may receive, for example, an indication of a change from the RRC_INACTIVE state to the RRC_IDLE state from the base station. In some examples, when the WTRU operates in the RRC_IDLE state, DL data may no longer be delivered to the WTRU in the TN (e.g., because the WTRU may no longer be in the same RNA).

[0186] In an example, if the WTRU determines that a cell reselection to a TN cell may result in a change in RNA, the WTRU may initiate and / or perform an RNA update, for example, via the NTN. In an example, the WTRU may initiate an RNA update procedure (e.g., an RNA update procedure as described in one or more examples herein), performing signaling via the NTN cell.

[0187] In some examples, if the WTRU determines that cell reselection to a TN cell may result in a change of RNA, the WTRU may perform cell reselection to a cell associated with a different RNA. In an example, the WTRU may initiate cell reselection to a TN cell associated with a different RNA and / or trigger an RNA update on the TN itself. For example, after the WTRU receives a data transmission from a TN cell associated with a different RNA, the WTRU may return to camping on the NTN again.

[0188] Using one or more examples herein, the WTRU may camp on an NTN cell to avoid cell reselection within the TN RNA and / or may perform cell reselection if the TN RNA changes (e.g., performing cell reselection only when necessary) to update the TN RNA. If a service is to be initiated, the WTRU may be paged on the NTN cell (e.g., by receiving a paging message) and / or respond to the paging via the TN cell. One or more examples herein enjoy the power saving benefits of reduced cell reselection (e.g., the benefits of camping on the NTN) and the benefits of improved latency (e.g., by performing data delivery and / or most signaling on the TN cell to reduce latency).

[0189] For example, some measurement conditions may be used to perform measurements on the TN while residing on the NTN. In an example, if the NTN is associated with a frequency layer with a higher priority than the TN, and the NTN cell has suitable quality, the WTRU may not need to perform measurements on the TN cell. In some examples, the WTRU may perform measurements on one or more TN cells (e.g., TN cells associated with a lower priority than the NTN cell) even if the NTN is associated with a frequency layer with a higher priority than the TN, and the NTN cell has suitable quality. As an example, a condition may be to perform measurements on one or more TN cells or carriers according to a higher priority frequency requirement (e.g., a higher priority frequency requirement associated with the NTN) even if the TN cell or carrier is assigned a lower priority. The WTRU may perform measurements at a specific rate (e.g., a rate higher than high priority frequency measurements and lower than coverage-based measurements, such as a requirement that applies when the coverage of the serving cell is below a threshold).

[0190] Fig.18 is an example of RNA changes based on TN measurements. Fig.18 , when the WTRU 1810 is camped on the NTN, the WTRU 1810 may determine whether to perform an RNA update (e.g., RNA maintenance) of the TN. At 1850, the WTRU 1810 may be released to an RRC_INACTIVE state with an indication to move to the NTN (e.g., to the NTN gNB 1840). At 1850, the network (e.g., the TN gNB 1820) may send a message indicating a change to the RRC_INACTIVE state (e.g., an indication associated with an RRC release, such as a suspension indication). The WTRU 1810 may receive an indication of a change to the RRC_INACTIVE state. The WTRU 1810 may initiate a change to the RRC_INACTIVE state (e.g., a change from an RRC_CONNECTED state to an RRC_INACTIVE state), for example, based on the indication of a change to the RRC_INACTIVE state.

[0191] The message may include an indication to move to NTN. The WTRU may initially select (e.g., perform cell selection) a TN cell associated with RNA 1, such as TN gNB 1820. The indication to move to NTN may include an indication to change from a TN cell to an NTN cell. For example, the WTRU may transmit a request to TN gNB 1820 to change from a TN cell to an NTN cell. In response to the request, TN gNB 1820 may transmit an indication to WTRU 1810 to change from a TN cell to an NTN cell.

[0192] In an example, the WTRU 1810 may receive separate indications (e.g., a first indication indicating a change from a TN cell to an NTN cell and a second indication indicating a change from an RRC_CONNECTED state to an RRC_INACTIVE state) at different times. The WTRU 1810 may receive separate indications simultaneously. The WTRU 1810 may receive an indication indicating a change from a TN cell to an NTN cell and an indication indicating a change from an RRC_CONNECTED state to an RRC_INACTIVE state. In some examples, an indication of a change to an RRC_INACTIVE state may be used as an indication of a change from a TN cell to an NTN cell. For example, the WTRU 1810 may initiate a change from a TN cell to an NTN cell based on receipt of an indication of a change to an RRC_INACTIVE state.

[0193] At 1870, the WTRU 1810 may perform cell reselection to an NTN cell (e.g., NTN gNB 1840) and / or monitor paging on the NTN cell. The WTRU 1810 may perform cell reselection to the NTN cell, for example, based on an indication indicating a change from a TN cell to an NTN cell. For example, after the WTRU 1810 performs cell reselection to the NTN cell, the WTRU 1810 may monitor paging messages on the NTN cell.

[0194] For example, when the WTRU is operating in the RRC_INACTIVE state, the WTRU 1810 may receive a paging message from an NTN cell. The WTRU 1810 may initiate a change from the RRC_INACTIVE state to the RRC_CONNECTED state based on the receipt of the paging message. In the RRC_CONNECTED state, the WTRU 1810 may receive data transmission from a second TN cell.

[0195] At 1880, the WTRU 1810 may evaluate one or more cells, for example, during a time period associated with the WTRU 1810 being configured to monitor for paging messages from NTN cells. For example, at 1880, the WTRU 1810 may perform measurements of TN cells in RNA1 and RNA2, which may include a TN gNB 1820 associated with RNA 1 and a TN gNB 1830 associated with RNA 2, while the WTRU 1810 monitors for paging messages from the NTN cells. The WTRU 1810 may evaluate the one or more cells at a time before the WTRU 1810 receives a paging message from the NTN cell and after the WTRU 1810 performs a cell reselection to the NTN cell. For example, after the WTRU 1810 receives a paging message from the NTN cell, the WTRU 1810 may stop monitoring for paging. When WTRU1810 performs cell selection / reselection to an NTN cell, for example, after WTRU 1810 receives a data transmission from TN gNB 1830 associated with RNA2, WTRU 1810 may resume monitoring paging in NTN.

[0196] For example, during a time period associated with the WTRU 1810 being configured to monitor paging messages from an NTN cell, the WTRU 1810 may determine a virtual cell reselection state for the TN. The determination of the virtual cell reselection state for the TN may include an evaluation of one or more TN cells and / or limiting the evaluation to one or more TN cells. For example, the evaluation of one or more TN cells may include an evaluation of a TN gNB 1820 associated with RNA 1 and / or an evaluation of a TN gNB 1830 associated with RNA 2, and may be limited to TN cells (e.g., only TN cells). In some examples, the WTRU 1810 may evaluate cell reselection criteria without considering the current NTN cell (e.g., performing virtual cell reselection as if the WTRU were camped on a TN cell).

[0197] At 1890, the WTRU 1810 may determine that a condition is satisfied (e.g., a cell reselection condition that results in cell reselection from a cell in RNA1 to a cell in RNA2). The WTRU 1810 may determine that the cell reselection condition associated with the TN gNB 1830 is satisfied, for example, based on an evaluation of one or more TN cells including the TN gNB 1830. For example, the WTRU 1810 may determine that the RSRP associated with the TN gNB 1830 is equal to or greater than a cell reselection threshold. The WTRU 1810 may determine that the cell reselection priority associated with the TN gNB 1830 is appropriate based on cell reselection priority information (e.g., transmit priority information) received in an RRC message. The WTRU may perform cell reselection to the TN gNB 1830 in RNA2 (e.g., cell reselection from an NTN cell to the TN gNB 1830 in RNA2).

[0198] At 1896, the WTRU may initiate an RNA update process (eg, an RNA update process from RNA1 to RNA2).

[0199] Fig.19 An example 1900 for evaluating one or more TN cells to determine RNA updates is illustrated. At 1920, the WTRU may be released from the TN gNB in ​​RNA1 to the RRC_INACTIVE state (with an indication to move to NTN), e.g. Fig.18 At 1930, the WTRU may perform cell reselection to the NTN cell and may monitor paging on the NTN cell, such as Fig.18 At 1940, the WTRU may perform measurements of the TN cells in RNA1 and RNA2 and may evaluate cell reselection criteria that do not consider the current NTN cell (e.g., using virtual cell reselection as if the WTRU were camped on the TN), such as Fig.18 At 1950, the WTRU may determine that criteria are met that may result in cell reselection from a cell in RNA1 to a cell in RNA2, such as Fig.18 The WTRU may perform reselection from NTN to TN RNA2 (eg, cell reselection from an NTN cell to a TN cell associated with RNA 2), for example, as shown in FIG. Fig.18 At 1960, the WTRU may initiate an RNA update process for RNA2, such as Fig.18 As shown in 1890.

[0200] Although the features and elements described above are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without the other features and elements.

[0201] Although the specific implementation described herein may consider 3GPP specific protocols, it should be understood that the specific implementation described herein is not limited to this scenario and is applicable to other wireless systems. For example, although the solution described herein considers LTE, LTE-A, new radio (NR) or 5G specific protocols, it should be understood that the solution described herein is not limited to this scenario and is also applicable to other wireless systems. For example, although the system has been described with reference to 3GPP, 5G and / or NR network layers, the envisioned implementation extends to specific implementations beyond the use of specific network layer technologies. Similarly, potential specific implementations extend to some or all types of service layer architectures, systems and implementations. The techniques described herein can be applied independently and / or used in combination with other resource configuration techniques.

[0202] The processes described herein may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (sent via wired and / or wireless connections) and / or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as, but not limited to, built-in hard disks and removable disks), magneto-optical media, and / or optical media (such as compact disks (CD)-ROM disks and / or digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, a terminal, a base station, an RNC, and / or any host computer.

[0203] It should be understood that the entity that performs the processes described herein can be a logical entity that can be implemented in the form of software (e.g., computer executable instructions) that is stored in the memory of a mobile device, network node, or computer system and executed on its processor. That is, these processes can be implemented in the form of software (e.g., computer executable instructions) stored in the memory of a mobile device and / or a network node (such as a node or a computer system) that, when executed by the processor of the node, performs the process in question. It should also be understood that any sending and receiving processes shown in the figure can be performed by the communication circuit of the node under the control of the processor of the node and the computer executable instructions (e.g., software) executed by it.

[0204] The various techniques described herein can be implemented in combination with hardware or software, or in a combination of the two where appropriate. Therefore, the specific implementation and device of the subject matter described herein or some aspects or parts thereof may take the form of program code (e.g., instructions), which is embodied in a tangible medium, which includes any other machine-readable storage medium, wherein when the program code is loaded into a machine (such as a computer) and executed by the machine, the machine becomes a device for practicing the subject matter described herein. In the case where the program code is stored on a medium, it is possible that the program code under consideration is stored on one or more media that jointly perform the action under consideration, that is, the one or more media together contain the code for performing the action, but in the case where there is more than one single medium, it is not required that any particular part of the code be stored on any particular medium. In the case of program code execution on a programmable device, the computing device generally includes a processor, a storage medium (including volatile and non-volatile memory and / or storage elements) readable by the processor, at least one input device, and at least one output device. One or more programs may implement or utilize the process described in conjunction with the subject matter described herein, for example, by using an API, a reusable control, etc. Such programs are preferably implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language and combined with a hardware implementation.

[0205] Although example embodiments may involve utilizing aspects of the subject matter described herein in the context of one or more stand-alone computing systems, the subject matter described herein is not so limited, but may be implemented in conjunction with any computing environment, such as a network or distributed computing environment. Still further, aspects of the subject matter described herein may be implemented in or across multiple processing chips or devices, and storage may similarly be affected across multiple devices. Such devices may include personal computers, network servers, handheld devices, supercomputers, or computers integrated into other systems, such as automobiles and airplanes.

[0206] In describing the preferred embodiments of the subject matter of the present disclosure as shown in the accompanying drawings, specific terminology is employed for the sake of clarity. However, the claimed subject matter is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to achieve a similar purpose.

Claims

1. A wireless transmit / receive unit (WTRU), the wireless transmit / receive unit (WTRU) comprising: A processor, the processor being configured to: receiving an indication of a change from a first terrestrial network (TN) cell to a non-terrestrial network (NTN) cell, wherein the first TN cell is associated with a notification area (RNA) based on a first radio access network (RAN); performing cell reselection to the NTN cell based on the indication; determining that a cell reselection condition associated with a second TN cell is satisfied, wherein the second TN cell is associated with a second RNA; as well as Based on determining that the cell reselection condition is satisfied, cell reselection to the second TN cell associated with the second RNA is performed.

2. The WTRU of claim 1 , wherein the processor is further configured to: receiving an indication to change the state of the WTRU from an RRC_CONNECTED state to an RRC_INACTIVE state; initiating the change of the state of the WTRU from the RRC_CONNECTED state to the RRC_INACTIVE state; and During a time period associated with the WTRU being configured to operate in the RRC_INACTIVE state, a paging message is received from the NTN cell.

3. The WTRU of claim 2, wherein the processor is further configured to: evaluating the second TN cell associated with the second RNA during a time period associated with the WTRU being configured to monitor the paging message from the NTN cell, wherein the evaluation of the second TN cell includes measurement of the second TN cell and determining that the cell reselection condition associated with the second TN cell is satisfied; initiating a change of the state of the WTRU from the RRC_INACTIVE state to the RRC_CONNECTED state based on the receipt of the paging message; as well as During a time period associated with the WTRU being configured to operate in the RRC_CONNECTED state, a data transmission is received from the second TN cell.

4. The WTRU of claim 2, wherein the processor is further configured to: performing measurements associated with the NTN cell; and, Prior to the change of the state of the WTRU from the RRC_CONNECTED state to the RRC_INACTIVE state, a request for the cell reselection to the NTN cell based on the measurements associated with the NTN cell is transmitted, wherein the indication of changing from the first TN cell to the NTN cell is received after transmitting the request.

5. The WTRU of claim 2, wherein the processor is further configured to: receiving identification information associated with a plurality of TN cells, the plurality of TN cells including the first TN cell associated with the first RNA and the second TN cell associated with the second RNA; monitoring the paging message from the NTN cell; as well as During a time period associated with the WTRU being configured to monitor the paging message from the NTN cell, the plurality of TN cells are evaluated based on the identification information, wherein the evaluation of the plurality of TN cells is limited to the plurality of TN cells.

6. The WTRU of claim 1 , wherein the processor is further configured to: receiving a cell reselection threshold in a radio resource control (RRC) message; and and determining a reference signal received power (RSRP) associated with the second TN cell associated with the second RNA, wherein the determination of the satisfaction of the cell reselection condition associated with the second TN cell comprises determining that the RSRP associated with the second TN cell is equal to or greater than the cell reselection threshold.

7. The WTRU of claim 1 , wherein the processor is further configured to: receiving cell reselection priority information in a radio resource control (RRC) message; and determining a cell reselection priority associated with the second TN cell associated with the second RNA, wherein the determination of the satisfaction of the cell reselection condition associated with the second TN cell is based on the cell reselection priority associated with the second TN cell and the cell reselection priority information received in the RRC message.

8. The WTRU of claim 1 , wherein the processor is further configured to: transmitting an indication of a change from the first RNA to the second RNA to the NTN cell; receiving an indication from the NTN cell to change the state of the WTRU from an RRC_INACTIVE state to an RRC_IDLE state; and Based on the indication, a change of the state of the WTRU from the RRC_INACTIVE state to the RRC_IDLE state is initiated before performing the cell reselection to the second TN cell.

9. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: receiving an indication of a change from a first terrestrial network (TN) cell to a non-terrestrial network (NTN) cell, wherein the first TN cell is associated with a notification area (RNA) based on a first radio access network (RAN); performing cell reselection to the NTN cell based on the indication; determining that a cell reselection condition associated with a second TN cell is satisfied, wherein the second TN cell is associated with a second RNA; as well as Based on determining that the cell reselection condition is satisfied, cell reselection to the second TN cell associated with the second RNA is performed.

10. The method according to claim 9, further comprising: receiving an indication to change the state of the WTRU from an RRC_CONNECTED state to an RRC_INACTIVE state; initiating the change of the state of the WTRU from the RRC_CONNECTED state to the RRC_INACTIVE state; as well as During a time period associated with the WTRU being configured to operate in the RRC_INACTIVE state, a paging message is received from the NTN cell.

11. The method according to claim 10, further comprising: evaluating the second TN cell associated with the second RNA during a time period associated with the WTRU being configured to monitor the paging message from the NTN cell, wherein the evaluation of the second TN cell includes measurement of the second TN cell and determining that the cell reselection condition associated with the second TN cell is satisfied; initiating a change of the state of the WTRU from the RRC_INACTIVE state to the RRC_CONNECTED state based on the receipt of the paging message; as well as During a time period associated with the WTRU being configured to operate in the RRC_CONNECTED state, a data transmission is received from the second TN cell.

12. The method according to claim 10, further comprising: performing measurements associated with the NTN cell; as well as, Prior to the change of the state of the WTRU from the RRC_CONNECTED state to the RRC_INACTIVE state, a request for the cell reselection to the NTN cell based on the measurements associated with the NTN cell is transmitted, wherein the indication of changing from the first TN cell to the NTN cell is received after transmitting the request.

13. The method according to claim 9, further comprising: receiving identification information associated with a plurality of TN cells, the plurality of TN cells including the first TN cell associated with the first RNA and the second TN cell associated with the second RNA; monitoring the paging message from the NTN cell; as well as During a time period associated with the WTRU being configured to monitor the paging message from the NTN cell, the plurality of TN cells are evaluated based on the identification information, wherein the evaluation of the plurality of TN cells is limited to the plurality of TN cells.

14. The method according to claim 9, further comprising: receiving a cell reselection threshold in a radio resource control (RRC) message; as well as and determining a reference signal received power (RSRP) associated with the second TN cell associated with the second RNA, wherein the determination of the satisfaction of the cell reselection condition associated with the second TN cell comprises determining that the RSRP associated with the second TN cell is equal to or greater than the cell reselection threshold.

15. The method according to claim 9, further comprising: receiving cell reselection priority information in a radio resource control (RRC) message; as well as determining a cell reselection priority associated with the second TN cell associated with the second RNA, wherein the determination of the satisfaction of the cell reselection condition associated with the second TN cell is based on the cell reselection priority associated with the second TN cell and the cell reselection priority information received in the RRC message.

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