Enhanced cell (re-) selection prioritization in non-terrestrial networks

Abstract

Systems, methods, and instrumentalities are described herein for enhanced cell (re-) selection prioritization in a non-terrestrial network (NTN). A cell (re-) selection may be determined for a terrestrial network (TN) and an NTN. A cell (re) selection may be determined for a wireless transmit / receive unit (WTRU) location and a coverage area associated with the TN or NTN. For example, a WTRU may connect to a first network and perform a (re) selection of a second network based on being outside of a coverage area associated with the first network. For example, if the WTRU is within a coverage area of multiple networks, the WTRU may prioritize network types.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 395,576, filed on August 5, 2022, the entire contents of which are incorporated herein by reference. Background Art

[0003] Mobile communications using wireless communications continue to evolve. The fifth generation may be referred to as 5G. Previous (legacy) mobile communications may be, for example, fourth generation (4G) Long Term Evolution (LTE). Summary of the invention

[0004] Systems, methods and means for enhanced cell (re)selection prioritization in non-terrestrial networks (NTNs) are described herein. Cell (re)selection may be determined for a terrestrial network (TN) and an NTN. Cell (re)selection may be determined for a wireless transmit / receive unit (WTRU) based on a TN or NTN location and a coverage area associated with the TN or NTN. For example, a WTRU may be connected to a first network and perform (re)selection of a second network based on being outside of a coverage area associated with the first network. For example, if a WTRU is within the coverage area of ​​multiple networks, the WTRU may prioritize network types.

[0005] The WTRU may perform (re)selection of a network based on the location of the WTRU and the coverage area of ​​the network. The WTRU may receive configuration information including location information associated with a TN. The location information associated with the TN may indicate a TN coverage area associated with the TN (e.g., a geographical description of the TN coverage area, such as coordinates and / or radius) and / or frequency information (e.g., frequency, frequency set, frequency range, etc.). The WTRU may determine the distance between the WTRU and a ground reference point associated with the TN coverage area. The WTRU may determine whether the distance between the WTRU and the ground reference point is higher than or equal to a threshold value associated with the location information. For example, if the distance between the WTRU and the ground reference point is lower than the threshold value, the WTRU may be within the TN coverage area. If the distance between the WTRU and the ground reference point is higher than or equal to the threshold value, the WTRU may be outside the TN coverage area. The WTRU may select a network type (e.g., TN or NTN) based on whether the distance between the WTRU and the ground reference point is higher than or equal to the threshold value. For example, if the distance between the WTRU and the ground reference point is higher than or equal to the threshold value (e.g., the WTRU is outside the TN coverage area), the WTRU may select NTN. If the distance between the WTRU and the ground reference point is below a threshold (eg, the WTRU is within the TN coverage area), the WTRU may select a TN. The WTRU may perform measurements on the selected network type (eg, a frequency associated with the selected network type). BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented;

[0007] Figure 1B is an example of an embodiment in which Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within the illustrated communication system;

[0008] Figure 1C is an example of an embodiment in which Figure 1A a system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system;

[0009] Figure 1D is an example of an embodiment in which Figure 1A A system diagram of another example RAN and another example CN used within the illustrated communication system;

[0010] Figure 2 An example of multiple interfaces in a non-terrestrial network is illustrated.

[0011] Figure 3Examples of user plane and control plane protocol stacks for transparent satellite configuration are illustrated.

[0012] Figure 4A and 4B An example of cell selection and reselection procedures in a network is illustrated.

[0013] Figure 5 An example of cell selection based on WTRU location and distance to network coverage area is illustrated.

[0014] Figure 6 An example of grouping one or more frequencies for cell sorting is illustrated, where the one or more frequencies may be associated with different network types.

[0015] Figure 7 An example of prioritizing frequencies according to network type is illustrated.

[0016] Figure 8 An example of prioritizing network types according to frequency is illustrated. DETAILED DESCRIPTION

[0017] 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.

[0018] 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.

[0019] 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 a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, 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.

[0020] 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.

[0021] 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).

[0022] 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).

[0023] 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).

[0024] 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).

[0025] 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).

[0026] 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).

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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).

[0037] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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 an 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.

[0042] 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.

[0043] 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.

[0044] 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 is 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 the CN operator.

[0045] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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 communication interface with a communication network.

[0050] In a representative embodiment, the other network 112 may be a WLAN.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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).

[0055] 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).

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The RAN 113 may include gNBs 180a, 180b, 180c, but it should be understood that the RAN 113 may include any number of gNBs while remaining consistent with the 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, 108b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Therefore, 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).

[0060] 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).

[0061] 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 gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeB 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 eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeB 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0062] 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, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an 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.

[0067] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108 or may communicate therewith. 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] Systems, methods and means for enhanced cell (re)selection prioritization in non-terrestrial networks (NTNs) are described herein. Cell (re)selection may be determined for a terrestrial network (TN) and an NTN. Cell (re)selection may be determined for a wireless transmit / receive unit (WTRU) based on a TN or NTN location and a coverage area associated with the TN or NTN. For example, a WTRU may be connected to a first network and perform (re)selection of a second network based on being outside of a coverage area associated with the first network. For example, if a WTRU is within the coverage area of ​​multiple networks, the WTRU may prioritize network types.

[0072] The WTRU may perform (re)selection of a network based on the location of the WTRU and the coverage area of ​​the network. The WTRU may receive configuration information including location information associated with a TN. The location information associated with the TN may indicate a TN coverage area associated with the TN (e.g., a geographical description of the TN coverage area, such as coordinates and / or radius) and / or frequency information (e.g., frequency, frequency set, frequency range, etc.). The WTRU may determine the distance between the WTRU and a ground reference point associated with the TN coverage area. The WTRU may determine whether the distance between the WTRU and the ground reference point is higher than or equal to a threshold value associated with the location information. For example, if the distance between the WTRU and the ground reference point is lower than the threshold value, the WTRU may be within the TN coverage area. If the distance between the WTRU and the ground reference point is higher than or equal to the threshold value, the WTRU may be outside the TN coverage area. The WTRU may select a network type (e.g., TN or NTN) based on whether the distance between the WTRU and the ground reference point is higher than or equal to the threshold value. For example, if the distance between the WTRU and the ground reference point is higher than or equal to the threshold value (e.g., the WTRU is outside the TN coverage area), the WTRU may select NTN. If the distance between the WTRU and the ground reference point is below a threshold (eg, the WTRU is within the TN coverage area), the WTRU may select a TN. The WTRU may perform measurements on the selected network type (eg, a frequency associated with the selected network type).

[0073] Cell (re)selection may be prioritized between different network types (e.g., terrestrial networks and non-terrestrial networks) and / or between different non-terrestrial network deployment scenarios (e.g., low earth orbit (LEO) or geostationary orbit (GEO)). Cell (re)selection prioritization criteria, cell (re)selection prioritization methods, durations over which cell reselection prioritization may be applied, methods for reporting WTRU cell (re)selection prioritization, and other examples are described herein.

[0074] In an example, the WTRU may prioritize camping on a terrestrial cell or a non-terrestrial cell and / or camping on a non-terrestrial deployment scenario (e.g., LEO or GE), for example, based on the application of a cell (re)selection prioritization configuration. The prioritization configuration and / or activation of the configuration may be provided, for example, via RRC in an RRCRelease or RRCReleasewithSuspend message, via system information (SI), a random access message, and / or paging. The cell (re)selection prioritization may include, for example, grouping frequencies associated with network types and attempting to camp on those cells before attempting to camp on other cells.

[0075] In an example, the WTRU may start and / or enable cell (re)selection prioritization via an indication (e.g., an explicit indication) and / or implicitly, for example, based on WTRU status, configuration and / or characteristics. The WTRU may (e.g., alternatively) receive and evaluate a set of associated criteria to start cell (re)selection prioritization based on, for example, WTRU speed and / or distance metrics.

[0076] The WTRU may apply a cell (re)selection prioritization configuration for a limited duration, for example based on (e.g., subject to) a timer. The WTRU may start a timer, for example, based on application of the prioritization configuration (e.g., upon application of the prioritization configuration). The WTRU may revert to a different (e.g., default) configuration (e.g., based on / upon expiration of a timer).

[0077] The WTRU may report to the network that the WTRU has applied the cell (re)selection prioritization. For example, the report may be provided via random access signaling such as MsgA / Msg3 / Msg5.

[0078] In an example, the WTRU may prioritize camping on a terrestrial cell or a non-terrestrial cell and / or camping on a non-terrestrial deployment scenario (e.g., LEO or GE), for example, based on the application of a cell (re)selection prioritization configuration. Prioritization configuration information and / or activation of the configuration may be provided, for example, via signaling (e.g., RRC signaling in an RRCRelease or RRCReleasewithSuspend message), via system information (SI), a random access message, and / or paging. Cell (re)selection prioritization may include, for example, grouping frequencies associated with network types and attempting to camp on those cells before attempting to camp on other cells.

[0079] In an example, the WTRU may start and / or enable cell (re)selection prioritization via an indication (e.g., an explicit indication) and / or implicitly, for example, based on WTRU status, configuration and / or characteristics. The WTRU may (e.g., alternatively) receive and evaluate a set of associated criteria to start cell (re)selection prioritization based on, for example, WTRU speed and / or distance metrics.

[0080] The WTRU may apply a cell (re)selection prioritization configuration for a limited duration, for example based on (e.g., subject to) a timer. The WTRU may start tracking time (e.g., via a timer), for example based on application of the prioritization configuration (e.g., upon application of the prioritization configuration). The WTRU may revert to a different (e.g., default) configuration (e.g., based on / upon expiration of a timer).

[0081] The WTRU may report to the network that the WTRU has applied the cell (re)selection prioritization. For example, the report may be provided via random access signaling such as MsgA / Msg3 / Msg5.

[0082] Non-terrestrial networks (NTNs) can facilitate the deployment of wireless networks in areas where land-based antennas cannot be used, for example due to geography or cost. NTNs coupled with TNs can achieve network coverage (e.g., ubiquitous 5G network coverage). NTN deployments can support basic calls and text messaging anywhere in the world. NTNs, TNs, and low-orbit satellites can enable enhanced services such as web browsing with NTNs.

[0083] The NTN may include an airborne or spaceborne platform that may transmit signals from a land-based gNB to a WTRU and vice versa (e.g., via a gateway (GW)). The NTN may support power class 3 WTRUs with omnidirectional antennas and linear polarization and / or (e.g., very) small aperture antenna (VSAT) terminals with directional antennas and circular polarization. The NTN may support support for (e.g., LTE-based) narrowband IoT (NB-IoT) and eMTC type devices. The NTN WTRU may have GNSS capabilities.

[0084] Aerial platforms or spaceborne platforms can be classified according to orbit, for example, low earth orbit (LEO) satellites with an altitude range of 300km to 1500km, geostationary orbit (GEO) satellites with an altitude range of 35,786km, medium earth orbit (MEO) satellites with an altitude range of 7000km to 25000km, and high altitude platform stations (HAP) with an altitude of 8km to 50km. Satellite platforms can (for example, further) be classified as having transparent payloads or regenerative payloads. Transparent satellite payloads can implement frequency conversion and RF amplification in the uplink and / or downlink. Multiple transparent satellites can be connected to a land-based gNB (for example, one land-based gNB). Regenerative satellite payloads can implement a full gNB or gNB DU on a satellite. The regenerative payload can perform digital processing on the signal, for example, including demodulation, decoding, re-encoding, re-modulation and / or filtering.

[0085] One or more of the following radio interfaces may be defined (e.g., configured) in the NTN: a feeder link (e.g., a wireless link between a GW and a satellite); a service link (e.g., a radio link between a satellite and a WTRU); and / or an inter-satellite link (ISL) (e.g., a transmission link between satellites). An ISL may be supported (e.g., only) by a regenerative payload. An ISL may be, for example, a radio (e.g., a 3GPP radio) or an optical interface (e.g., a proprietary optical interface).

[0086] Figure 2 Examples of multiple interfaces in a non-terrestrial network are illustrated. Interfaces (e.g., different 3GPP interfaces) can be used for (e.g., each) radio link, for example, based on the satellite payload configuration. The NR-Uu radio interface can be used for a service link and / or a feeder link, for example, for a transparent payload. The NR-Uu interface can be used on a service link, for example, for a regenerative payload. A satellite radio interface (SRI) can be used for a feeder link, for example, for a regenerative payload. A UP / CP protocol stack can be provided for a payload configuration (e.g., per payload configuration).

[0087] Figure 3 An example of a user plane and control plane protocol stack for a transparent satellite configuration is illustrated. NTN satellites may support multiple cells. 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., like a terrestrial cell). The diameter range of a satellite beam is, for example, 100km to 1000km in a LEO deployment and 200km to 3500km in a GEO deployment. The beam coverage area in a GEO deployment may remain fixed relative to the earth. The area covered by a beam / cell in a LEO deployment may change over time, for example, due to satellite movement. Beam movement may be classified as earth movement, for example, if a LEO beam moves continuously on the earth, or may be classified as earth fixed, for example, if the beam is guided to maintain coverage of a fixed position until a cell (e.g., a new cell) exceeds the coverage area (e.g., in discrete and coordinated changes).

[0088] The round trip time (RTT) and / or maximum differential delay of the NTN platform may be larger (e.g., significantly larger) than that of the terrestrial system, for example, due to the NTN platform altitude and / or due to the beam diameter. In an example of a transparent NTN deployment, the RTT may range from 25.77 ms (e.g., for LEO at 600 km altitude) to 541.46 ms (e.g., for GEO), and the differential delay (e.g., maximum differential delay) may range from 3.12 ms to 10.3 ms. The RTT of the regenerated payload may be approximately half of the RTT of the transparent payload. The transparent configuration information may include the serving link and the feeder link, while the RTT of the regenerated payload may (e.g., only) consider the serving link. The WTRU may perform timing pre-compensation (e.g., before initial access), for example, to reduce / minimize the impact on the existing network (e.g., NR) system (e.g., to avoid preamble ambiguity or to properly time the receive window).

[0089] The pre-compensation process may involve the WTRU obtaining its position (e.g., via GNSS) and / or feeder link (e.g., or common) delay and satellite position (e.g., via satellite ephemeris data). Satellite ephemeris data may be broadcast (e.g., periodically) in system information (SI). Satellite ephemeris data may include satellite speed, direction, and / or velocity. The WTRU may estimate the distance to the satellite (e.g., and therefore estimate the delay). The WTRU may add the feeder link delay component to obtain the complete WTRU-gNB RTT, which may be used to offset timers, receive windows, and / or timing relationships. In some examples, frequency compensation may be performed by the network.

[0090] WTRU mobility and measurement reporting may be provided. The RSRP difference between the cell center and the cell edge may not be as pronounced in the NTN as in terrestrial systems. For example, due to the larger cell overlap area, measurement-based mobility may become less reliable in the NTN environment. The network (e.g., a 3GPP network) may utilize conditional switching and / or measurement report triggers, which may be location and time dependent. Enhanced mobility may be implemented, for example, in LEO deployments, where a fixed WTRU (e.g., due to satellite movement) may perform mobility (e.g., approximately every seven seconds) based on deployment characteristics.

[0091] The network (e.g., NR) cell selection / reselection process may be complex, e.g., Figure 4A and Figure 4B The examples described herein can focus on Figure 4A The box in highlights the portion of the network cell selection / reselection process, which may cover aspects related to going from RRC_CONNECTED to RRC_IDLE / RRC_INACTIVE (e.g., upon receipt of an RRC release message or upon a transient cell selection completed during RRC reestablishment), for example, if the WTRU is able to find a suitable cell to camp on (e.g., when the WTRU is able to find a suitable cell to camp on).

[0092] Figure 4A and Figure 4BAn example of a cell selection and reselection process in a network (e.g., an NR network) is illustrated. Cell selection may include a WTRU searching a network (e.g., NR) frequency band. For example, a strong cell (e.g., the strongest cell) may be identified for a carrier frequency (e.g., each carrier frequency) based on the CD-SSB. The WTRU may read the broadcasted cell system information to identify the PLMN to find a suitable cell to reside in. A suitable cell may be a cell where the measured cell attributes meet the cell selection criteria. The cell PLMN may be a selected PLMN, a registered PLMN, or an equivalent PLMN. The cell may not be prohibited or reserved. The cell may not be part of a tracking area in a prohibited roaming tracking area list.

[0093] The WTRU may camp on a cell when transitioning from a connected state (e.g., such as RRC_CONNECTED or RRC_INACTIVE) to an idle state (e.g., such as RRC_IDLE). For example, the WTRU may camp on a cell as a result of cell selection, based on the frequency assigned by the RRC in the state transition message (if any).

[0094] For example, a cell selection criterion (e.g., referred to as criterion S) may be satisfied if (e.g., when) the following conditions are satisfied:

[0095] Srxlev>0 and Squal>0

[0096] in:

[0097] Srxlev=Q rxlevmeas –(Q rxlevmin +Q rxlevminoffset )–P compensation -Qoffset temp

[0098] Squal=Q qualmeas –(Q qualmin +Q qualminoffset )-Qoffset temp

[0099] Table 1 describes examples of parameters used for cell selection criteria:

[0100]

[0101]

[0102] Table 1 - Examples of parameters for cell selection criteria

[0103] For example, if (e.g., when) camping (e.g., normally) in a visited public land mobile network (VPLMN), cells are evaluated for cell selection as a result of a periodic search for higher priority public land mobile networks (PLMNs), the signaled value Q may (e.g., only) be applied. rxlevminoffset and Q qualminoffset The WTRU may check the S criteria of a cell using parameter values ​​stored from a different cell of a higher priority PLMN (eg, during a periodic search for a higher priority PLMN).

[0104] Cell reselection may be performed, for example, by a WTRU in RRC_IDLE / RRC_INACTIVE.A WTRU may perform intra-frequency, inter-frequency and / or inter-RAT cell reselection.

[0105] The WTRU may receive configuration information indicating (e.g., being configured with) a priority among one or more RATs (e.g., camping on NR over LTE whenever an NR cell is available) and / or a priority among frequencies within a RAT (e.g., fa may have a high priority, fb may have a medium priority, fc may have a low priority, etc.). A neighbor cell list (NCL) may be provided to the WTRU. The NCL may indicate which neighbor cells (e.g., intra-frequency, inter-frequency, inter-RAT) may be considered for cell reselection. An allowed list may be provided to the WTRU. The allowed list may indicate neighbor cells that may be considered for reselection. An excluded list may be provided to the WTRU. The excluded list may indicate neighbor cells that are not suitable for reselection.

[0106] The WTRU may (eg, attempt to) camp on a cell operating with a high priority RAT (eg, the highest priority RAT) and with a high priority frequency (eg, the highest priority frequency).

[0107] For example, if the serving cell satisfies Srxlev>S IntraSearchP and Squal>S IntraSearchQ , the WTRU may choose not to perform intra-frequency measurements. The WTRU may perform intra-frequency measurements (e.g., in other ways).

[0108] For example, if the serving cell satisfies Srxlev>S nonIntraSearchP and Squal>S nonIntraSearchQ, the WTRU may choose not to perform measurements of NR inter-frequency cells of equal or lower priority or RAT inter-frequency cells of lower priority. The WTRU may (e.g., in other ways) perform measurements of network (e.g., NR) inter-frequency cells of equal or lower priority and / or RAT inter-frequency cells of lower priority. Table 2 provides a description of parameters that may be used for the measurement criteria.

[0109] <![CDATA[S IntraSearchP ]]> Srxlev threshold in dB for intra-frequency measurements. <![CDATA[S IntraSearchQ ]]> Squal threshold in dB for intra-frequency measurements. <![CDATA[S nonIntraSearchP ]]> Srxlev threshold in dB for NR inter-frequency and inter-RAT measurements. <![CDATA[S nonIntraSearchQ ]]> Squal threshold in dB for NR inter-frequency and inter-RAT measurements.

[0110] Table 2 - Examples of parameters in measurement standards

[0111] For example, if (e.g., when) the WTRU decides based on criteria to perform intra-frequency measurements for cell reselection, the WTRU may perform cell ranking on the cells. Inter-frequency and / or inter-RAT reselection may be based on (e.g., absolute) priority, where the WTRU may attempt to camp on an available high priority frequency (e.g., the highest priority frequency available).

[0112] For serving cells (R s ) and for neighboring cells (R n ) can be defined by the following formula:

[0113] R s =Q meas,s +Q hyst -Qoffset temp

[0114] R n =Q meas,n -Qoffset-Qoffset temp

[0115] Table 3 provides a description of the parameters in the cell ranking criteria:

[0116]

[0117] Table 3 - Examples of parameters in cell ranking criteria

[0118] The WTRU may perform a ranking of (eg, all) cells that satisfy a cell selection criterion S (eg, as described herein).

[0119] The cells may be ranked according to the R criterion (e.g., as described herein). For example, Q meas,n and Q meas,sAnd the average RSRP result is used to calculate the R value to rank the cells. For example, if rangeToBestCell is not (e.g., may not be) configured, the WTRU may perform cell reselection on a high-ranking cell (e.g., the highest-ranking cell). For example, if rangeToBestCell is configured (e.g., may be configured), the WTRU may perform cell reselection on a cell with the highest number of beams above a threshold (e.g., absThreshSS-BlocksConsolidation) among cells whose R values ​​may be within the rangeToBestCell range of the R values ​​of the high-ranking cells (e.g., the highest-ranking cells). The WTRU may perform cell reselection on the highest-ranking cell among multiple cells.

[0120] For example, the WTRU may reselect a cell (e.g., a new cell) if one or more of the following conditions are met: during the time interval TreselectionRAT, the cell (e.g., the new cell) is (e.g., may be) superior to the serving cell according to the cell reselection criteria (e.g., as described herein); and / or a threshold time (e.g., a duration, such as 1 second) has (e.g., may have) been exceeded since the WTRU was camped on the serving cell (e.g., the current serving cell).

[0121] The network (e.g., NR and LTE) may support non-terrestrial networks. Coverage (e.g., TN and NTN coverage, which may include, for example, coverage areas, coordinates associated with the coverage areas (e.g., reference coordinates), and / or radius associated with the coverage (e.g., relative to the coordinates)) may be provided (e.g., via configuration information) by a satellite that relays transmissions to a gNB (e.g., via a gateway). For example, based on the cell diameter of the non-terrestrial cell (e.g., a large cell diameter), there may be areas (e.g., coverage areas) where terrestrial and non-terrestrial coverage overlap. NTN cell (re)selection and terrestrial to non-terrestrial cell (re)selection as well as cell (re)selection between different NTN deployment scenarios (e.g., LEO or GEO) may be implemented.

[0122] In some examples, both types of network coverage may be available to the WTRU. A WTRU in IDLE / INACTIVE mode (e.g., RRC IDLE / INACTIVE) may camp on one or the other network type, which may provide different advantages. For example, from a WTRU power saving perspective, camping on a non-terrestrial cell may provide better power saving, for example, because the non-terrestrial cell provides much wider coverage. Camping on a non-terrestrial cell may reduce the number of cell measurements, system information (SI) readings, and cell reselections. For example, camping on a terrestrial cell may provide advantages from a latency perspective due to greater (e.g., much greater) propagation delays in non-terrestrial networks. For example, if (e.g., when) a connection is established, the signaling exchange used to perform the RRC establishment or RRC recovery process may introduce delays (e.g., significant delays) to the connection establishment and / or a reduction in overall signaling throughput.

[0123] The TN-NTN cell (re)selection process may utilize measurement-based criteria without taking into account the different characteristics (e.g., very different characteristics) of terrestrial and non-terrestrial networks or the different characteristics between different NTN deployment scenarios. Enhancements to the cell (re)selection process may support overlapping TN-NTN coverage, e.g., to utilize the power saving benefits of NTN without longer latency, without longer session establishment time, and without limited throughput.

[0124] In some examples, the WTRU may prioritize camping on a terrestrial cell over camping on a non-terrestrial cell (e.g., if the WTRU is within the coverage of a TN) or camping on a non-terrestrial deployment scenario (e.g., LEO or GEO), which may be referred to as cell (re)selection prioritization.

[0125] The WTRU may distinguish between terrestrial cells and non-terrestrial cells, for example, based on (e.g., via) dedicated frequencies (e.g., frequencies) assigned to network types (e.g., each network type). For example, terrestrial networks may be associated with frequencies f1 to fN, while non-terrestrial cells may be associated with frequencies fN+1 to fk. The WTRU may receive configuration information (e.g., assistance information, network type prioritization assistance information) indicating frequency information associated with a TN or NTN (e.g., a frequency, a set of frequencies, or a frequency range associated with a TN or NTN).

[0126] In some examples (e.g., deployments), terrestrial cells and non-terrestrial cells may share and / or overlap in frequency. The WTRU may determine that a cell may be a terrestrial cell or a non-terrestrial cell, for example, based on one or more of the following: a set of one or more cell IDs associated with a network type (e.g., per network type); a set of one or more PLMN IDs associated with a network type (e.g., per network type); an indication (e.g., an explicit indication) such as within system information (SI) (e.g., the indication may be a flag bit indicating that the cell may be an NTN cell); an implicit indication (e.g., via the presence of an information field such as the presence of SI (SIB19), including NTN-specific information or satellite ephemeris information); access or barring information (e.g., the presence of a barring bit or an NTN-specific barring bit); and / or a frequency band indicator indicating a frequency band defined (e.g., exclusively) for a certain type of network (e.g., provided in a serving cell for cells or carriers indicated in a neighbor list).

[0127] Although the examples (e.g., as described herein) use prioritization of terrestrial networks versus non-terrestrial networks, the examples may be applicable (e.g., equally applicable) if (e.g., when) prioritization is performed between different non-terrestrial network types, or vice versa. For example, the WTRU may (e.g., similarly) differentiate between different non-terrestrial deployments (e.g., between LEO deployments or GEO deployments) via one or more differentiation methods (e.g., as described herein). The WTRU may (e.g., additionally) differentiate between LEO or GEO satellites, for example, via ephemeris format (e.g., orbital characteristics or PVT) or other satellite characteristics (e.g., as found in satellite ephemeris data, such as altitude or velocity).

[0128] Cell (re)selection prioritization criteria may be provided. In some examples (e.g., as described herein), the WTRU may enable / disable cell (re)selection prioritization, select among cell (re)selection prioritization methods, determine the duration for which cell (re)selection prioritization is applied, report cell (re)selection prioritization characteristics, or prioritize between cells belonging to a specific network type (e.g., terrestrial or non-terrestrial) or NTN deployment scenario (e.g., LEO or GEO), all of which may be collectively referred to as "cell (re)selection prioritization actions". Cell (re)selection prioritization actions may be based on one or more criteria (e.g., as described herein).

[0129] The cell (re)selection prioritization criteria may include a network indication / configuration (e.g., an explicit network indication / configuration). In some examples, the WTRU may be configured (e.g., explicitly configured) to perform a cell (re)selection prioritization action. For example, the WTRU may receive an RRCRelease message (e.g., an action performed by the WTRU in the RRC IDLE state) or an RRCReleasewithSuspend message (e.g., an action performed by the WTRU in the RRC INACTIVE state). The message may include, for example, one or more of the following: an indication to enable / disable cell (re)selection prioritization; a method for prioritizing cell (re)selection and / or associated configuration information (e.g., deviations and associated criteria as described herein); a network type (e.g., terrestrial network or non-terrestrial network) or NTN deployment scenario (e.g., LEO or GEO) to be prioritized; a duration for performing cell (re)selection prioritization (e.g., as described herein); and / or reporting criteria and / or associated reporting configuration (e.g., as described herein).

[0130] In some examples, the WTRU may receive an indication for performing a cell (re)selection prioritization action and / or may receive one or more information items (e.g., as described herein, such as a geographical description of a TN coverage area (e.g., TN reference coordinates, TN radius), a geographical description of an NTN coverage area (e.g., NTN reference coordinates, NTN radius), and / or corresponding frequency information associated with the TN and NTN, such as via one or more of the following methods: Figure 5 as shown): within paging (e.g., via a paging short message); via DCI; and / or via random access signaling (e.g., msg2, msg4, msgB).

[0131] The cell (re)selection prioritization criteria may include WTRU speed. In some examples, the WTRU performs a cell (re)selection prioritization action based on the WTRU speed. For example, a fixed or low mobility WTRU may be prioritized to camp on a terrestrial cell, while a mobile or high mobility WTRU may be prioritized to camp on a non-terrestrial network. In another example, a fixed or low mobility WTRU may be prioritized to camp on a LEO cell, while a mobile or high mobility cell may be prioritized to camp on a GEO cell.

[0132] The WTRU may detect WTRU speed / mobility via one or more of: measurement changes; relaxed monitoring state; WTRU positioning information; satellite positioning information; frequency compensation information; cell (re)selection times; mobility state estimation state; mobility history records; and / or relative speed between the WTRU and the satellite.

[0133] The WTRU can detect its speed / mobility via a measurement change (e.g., based on an RSRP change). For example, if (e.g., when): (SrxlevRef – Srxlev) < SSearchDeltaP, the measurement criteria for a WTRU with low mobility can be met, where Srxlev can be equal to the current Srxlev value of the serving cell (dB) or a neighboring cell (dB), and SrxlevRef can be equal to the reference Srxlev value of the serving cell (dB) or a neighboring cell (dB). The conditions for setting Srxlevref can be based on a time criterion, e.g., if the low mobility criteria have not been met for TSearchDeltaP.

[0134] The WTRU can detect its speed / mobility based on (e.g., via) a relaxed monitoring state. For example, the WTRU can determine that it is in a low mobility state based on the activation of relaxed monitoring. For example, the low mobility state can be indicated by one or more low mobility criteria (e.g., in combination) (e.g., as described herein) and / or based on the criterion that the WTRU is not at the cell edge. For example, if / when: Srxlev > SSearchThresholdP, and / or if / when SSearchThresholdQ (e.g., if SSearchThresholdQ can be configured), the measurement criteria for a WTRU that may not be at the cell edge can be met.

[0135] The WTRU can detect its speed / mobility via WTRU location information. For example, the WTRU can use WTRU location information (e.g., in two or more acquisitions, measurements, or obtainments) to determine the WTRU speed.

[0136] The WTRU can detect its speed / mobility via satellite location information. For example, the WTRU can use satellite location information acquired (e.g., measured or obtained) two or more times (e.g., obtained via satellite assistance information such as ephemeris data) to determine the relative distance from the satellite to the WTRU (e.g., and by extension, to determine the WTRU speed).

[0137] The WTRU can detect its speed / mobility via frequency compensation information. For example, the WTRU can use Doppler information to approximate the WTRU speed.

[0138] The WTRU can detect its speed / mobility via multiple cell (re)selections. For example, the WTRU can count the number of cell reselections (e.g., to cells from a terrestrial network and / or cells from a non-terrestrial network) within a given time period.

[0139] The WTRU may detect the WTRU speed / mobility via the relative speed between the WTRU and the satellite. For example, the WTRU may calculate the relative speed / distance between itself and the satellite, for example, via satellite ephemeris data.

[0140] In some examples, a WTRU camped on a TN network may evaluate a low mobility criterion based on measurements of a serving cell (e.g., according to the methods described herein). A WTRU camped on an NTN network may evaluate a low mobility criterion based on measurements performed on a neighboring cell (e.g., a TN neighboring cell). For example, the low mobility criterion may be evaluated based on the Srxlev value (dB) of the neighboring cell. The WTRU may use one or more parameters provided by a cell (e.g., a current NTN cell).

[0141] In some examples, the WTRU may maintain / store information about speed, direction, or velocity. In some examples, the WTRU may maintain a mobility state, such as stationary, low mobility, medium mobility, or high mobility. The state (e.g., each state) may be associated with a (e.g., determined, indicated, configured) set of criteria (e.g., speed threshold, number of cell (re)selections per hour). The WTRU may enter an associated mobility state based on (e.g., when) the criteria are met.

[0142] The WTRU may maintain different mobility states for terrestrial networks and / or non-terrestrial networks. For example, the WTRU may maintain multiple (e.g., two) separate mobility states associated with a terrestrial network and a non-terrestrial network, for example, TNMobilityState and NTNMobilityState, respectively. The WTRU may use different metrics to evaluate terrestrial mobility states (e.g., measurement changes, cell (re)selection frequency) and non-terrestrial mobility states (e.g., satellite positioning information, WTRU-satellite relative speed). The WTRU may maintain mobility states, for example, based on a virtual cell reselection count of cell changes on a TN. The WTRU may evaluate cell reselection, for example, based on cell measurements of neighboring cells on neighboring TNs, for example, when the WTRU resides on an NTN and does not perform reselection.

[0143] The cell (re)selection prioritization criteria may include WTRU distance (eg, determining whether the WTRU is within the coverage of a TN or NTN). Figure 5An example of cell selection based on the WTRU location and the distance to the network coverage area is illustrated. In some examples, the WTRU may perform a cell (re)selection prioritization action based on the distance between the WTRU and a reference point (e.g., the WTRU may determine the distance between the WTRU and a terrestrial reference point associated with a TN coverage area). For example, if the distance meets, exceeds, and / or falls below a threshold criterion (e.g., the WTRU may determine whether the distance between the WTRU and the terrestrial reference point is above or equal to a threshold associated with the location information (e.g., the radius of the TN or NTN coverage), such as Figure 5 ), the WTRU may monitor one or more distances and / or may perform one or more actions (e.g., select a network type and / or perform reselection for a TN or NTN). The distance thresholds may be based on, for example, one or more of: WTRU-satellite distance; distance between WTRU-satellite cell centers; distance between WTRU and satellite coverage area; distance between WTRU and ground-based gNB; distance between WTRU and ground coverage edge; and / or distance between WTRU and reference point. For example, if the distance between the WTRU and a reference point (e.g., the center of the coverage area) is less than a threshold (e.g., the radius of the coverage area), the WTRU may be within the coverage area (e.g., TN or NTN), as shown. Figure 5 If the distance between the WTRU and a reference point (e.g., the center of the coverage area) is higher than or equal to a threshold (e.g., the radius of the coverage area), the WTRU may be outside the coverage area (e.g., TN or NTN), as shown in FIG. Figure 5 For example, if the WTRU is within the coverage area of ​​a TN, the WTRU may determine to select (e.g., prioritize) a TN (e.g., as shown in FIG. Figure 5 The WTRU may perform measurements based on the cell selection (e.g., performing measurements on frequencies associated with the selected network, e.g., if the WTRU is within a TN coverage area, performing measurements on frequencies associated with the TN), as shown. Figure 5 shown.

[0144] The cell (re)selection prioritization criteria may include WTRU configuration information, status and / or characteristics.

[0145] In some examples, the WTRU may perform a cell (re)selection prioritization action based on WTRU configuration information (e.g., current WTRU configuration), WTRU state, and / or one or more WTRU characteristics. Examples of WTRU aspects that may affect cell (re)selection prioritization may be, for example, one or more of the following: network type of the cell on which the WTRU may camp (e.g., currently camp); network type of the cell on which the WTRU may have been released (e.g., the network type that provided the WTRU with an RRCRelease or RRCReleasewithSuspend message); QoS characteristics or historical traffic profile of the WTRU data; WTRU device type (e.g., the WTRU may be a VSAT device and the WTRU may prioritize cells from non-terrestrial networks); WTRU capabilities (e.g., whether the WTRU is able to connect to an NTN cell); whether the network type or NTN deployment scenario frequency overlaps; RRC state (e.g., the WTRU may be able to connect to an NTN cell based on / upon receipt of an RRCRelease message such as an RRC IDLE WTRU or based on an RRCReleasewithSuspend message such as an RRC INACTIVE WTRU). WTRU / applies different cell (re)selection prioritization methods when receiving; and / or the number of detected cells belonging to a network type (for example, if the WTRU may not detect cells of a network type on one or more frequencies, the WTRU may prioritize another network type, or if the WTRU detects that the number of cells belonging to a network type exceeds X, the WTRU may prioritize that network type during cell (re)selection).

[0146] The cell (re)selection prioritization may be based on the DRX configuration, the paging cycle and / or the RACH configuration. In some examples, the WTRU may perform a cell (re)selection prioritization action based on one or more WTRU configurations, which may include, for example, one or more of: DRX length, paging cycle length, and / or RACH configuration.

[0147] The WTRU may perform cell (re)selection prioritization actions based on the DRX length. For example, a WTRU configured with long DRX (e.g., eDRX) may prioritize cell (re)selection over cells originating from non-terrestrial networks or GEO NTN deployment scenarios. A WTRU configured with a short (shorter) DRX cycle may prioritize cell (re)selection over cells originating from terrestrial cells or LEONTN deployment scenarios.

[0148] The WTRU may perform a cell (re)selection prioritization action based on the paging cycle length. For example, a WTRU configured with a long paging cycle may prioritize cell (re)selection over cells originating from non-terrestrial networks or GEO NTN deployment scenarios. A WTRU configured with a short (shorter) paging cycle may prioritize cell (re)selection over cells originating from terrestrial cells or LEONTN deployment scenarios. For example, if the WTRU may not have been paged for a certain amount of time or for a duration (e.g., may not have been paged for X time units), the WTRU may prioritize staying on a cell originating from a non-terrestrial network. For example, if the WTRU last received a page or was released from a connected state by a terrestrial cell (e.g., the WTRU received an RRCRelease or RRCReleasewithSuspend message from a terrestrial cell), the WTRU may prioritize connecting to a terrestrial network.

[0149] The WTRU may perform cell (re)selection prioritization actions based on the RACH configuration. For example, the WTRU may prioritize the network type with the RACH occasion closest to the paging occasion (eg, to respond to the paging quickly).

[0150] The cell (re)selection prioritization may be based on a power saving metric. In some examples, the WTRU may perform a cell (re)selection prioritization action based on the WTRU power. For example, if the WTRU may have entered a WTRU power saving state or power saving mode (PSM), the WTRU may change the cell (re)selection prioritization (e.g., the WTRU may prioritize non-terrestrial cells over terrestrial cells, or prioritize cells from a GEO NTN deployment over a LEO NTN deployment).

[0151] In some examples, the WTRU may perform a cell (re)selection prioritization action based on a power saving preference. For example, the WTRU may perform a cell (re)selection prioritization action based on an application layer based preference (e.g., a selected power saving preference). In some examples, the WTRU may indicate a preference to the network, for example, in a WTRU assistance information message. If / when a cell reselection evaluation is performed, the network may (e.g., in response) provide the WTRU with an updated cell reselection priority for application.

[0152] The cell (re)selection prioritization may be implemented in one or more methods, which may be selected, determined, configured, indicated, etc.

[0153] The WTRU may perform cell reselection prioritization, for example, based on the configuration, indication or satisfaction (e.g., when the one or more criteria are configured, indicated or satisfied) of one or more criteria (e.g., such as whether the WTRU is within a TN or NTN coverage area, as described herein). The WTRU may determine which cell (re)selection prioritization method to select and / or which network type or NTN deployment scenario may be prioritized based on, for example, received configuration information, the content of the indication and / or the criteria that have been satisfied.

[0154] Network type prioritization may be implemented based on (e.g., via) measurement biases. In some examples, the WTRU may receive and / or be configured with one or more cell (re)selection biases to apply to cell ranking measurements, e.g., to prioritize residing on network types or NTN deployment scenarios. The bias may be positive or negative. The bias may have one or more associated criteria to apply the bias. The criteria may include, for example, one or more of the following: a network type (e.g., a terrestrial network or a non-terrestrial network), for example, where the WTRU may apply a deviation to one or more (e.g., all) cells / frequencies belonging to the network type; an NTN deployment scenario (e.g., LEO or GEO), for example, where the WTRU may apply a deviation to one or more (e.g., all) cells / frequencies belonging to the deployment scenario; a PLMN ID, for example, where the WTRU may apply a deviation to one or more (e.g., all) cells / frequencies associated with the PLMN; a cell ID, for example, where the WTRU may apply a deviation to a cell; a frequency or frequency range, for example, where the WTRU may apply a deviation to one or more (e.g., all) frequencies at an indicated frequency or within an indicated frequency range; a threshold, where, for example, the WTRU may apply a deviation if a prioritization criterion (e.g., as described herein) meets, exceeds, or falls below a threshold; and / or a state, where, for example, the WTRU may apply a deviation if a prioritization criterion (e.g., as described herein) or a configuration may be equivalent to an indicated state.

[0155] The WTRU may be configured with multiple deviations. The WTRU may apply one or more (e.g., all) deviations that have met the relevant criteria. In some examples, the WTRU may select and apply a deviation by selecting the deviation with the largest absolute value among multiple (e.g., all) deviations that apply to the network type, NTN deployment scenario, PLMN and / or frequency range. In some examples, the WTRU may select and apply one or more deviations, for example, by selecting the maximum positive and negative deviations that apply to the network type, NTN deployment scenario, PLMN and / or frequency range. The WTRU may apply the sum of multiple deviations.

[0156] Network type prioritization may be independent of measurements. In some examples, the WTRU may prioritize network types independent of measurements (e.g., whether or not the best frequency / cell belongs to a preferred network type). For example, the WTRU may (e.g., only) evaluate candidate cells from that network type, or may (e.g., alternatively) evaluate candidate cells from a second network type after all frequencies / candidate cells from a first network type have been evaluated (e.g., only).

[0157] Candidate cells / frequencies may be eliminated based on network type. In some examples, the WTRU may prioritize network types or deployment scenarios by down-selecting or eliminating candidate cells for cell (re)selection based on network type. For example, the WTRU may eliminate candidate cells for (re)selection originating from network types (e.g., terrestrial networks vs. non-terrestrial networks) or NTN deployment scenarios (e.g., LEO vs. GEO). The WTRU may eliminate candidate cells and / or frequencies, for example, based on (e.g., via) one or more of the following methods: prohibiting cells associated with a network type or deployment scenario; prohibiting / not performing measurements on frequencies associated with a network type or deployment scenario; and / or prohibiting PLMNs associated with a network type or deployment scenario.

[0158] Network type prioritization may be based on non-overlapping frequencies. In some example deployments, terrestrial networks and / or non-terrestrial networks may be associated with unique frequencies. The WTRU may group frequencies associated with a particular network type. The WTRU may (e.g., then) determine which network type may be prioritized. The WTRU may, for example, perform cell ranking based on an associated set of frequencies. The WTRU may (e.g., if no suitable cell is found) attempt to perform cell ranking on a set of frequencies belonging to a network type of reduced priority.

[0159] In deployments where terrestrial networks and non-terrestrial networks may be associated with one or more frequencies (e.g., unique frequencies), the WTRU may group the frequencies associated with the network types. The WTRU may determine which network type may be prioritized and may perform cell ranking based on the associated frequency set. If no suitable cell is found, the WTRU may attempt to perform cell ranking on a frequency set belonging to a network type of reduced priority. This may be done in Figure 6TN-NTN prioritization is exemplarily illustrated in , where during prioritization A, the WTRU may camp (e.g., attempt to camp) on one or more terrestrial frequencies (e.g., all terrestrial frequencies), and during prioritization B, the WTRU may camp (e.g., attempt to camp) on non-terrestrial frequencies (e.g., all non-terrestrial frequencies). This process may similarly be used to prioritize between different NTN deployment scenarios (e.g., if associated with different frequencies).

[0160] Figure 6 An example of TN-NTN priority sorting is shown. Figure 6 As shown, when camping priority is A, the WTRU may attempt to camp on one or more (e.g., all) terrestrial frequencies before attempting to camp on the NTN frequency. Figure 6 As shown, when camping on priority order B, the WTRU may attempt to camp on one or more (e.g., all) non-terrestrial frequencies before camping on a TN frequency. This process may similarly be used to prioritize between different NTN deployment scenarios (e.g., if associated with different frequencies).

[0161] Figure 6 An example of grouping frequencies associated with different network types is illustrated. For example, Figure 6 An example of grouping frequencies associated with different network types prior to cell sorting may be shown. Network type prioritization may be based on overlapping frequencies. In some example deployments, terrestrial networks and non-terrestrial networks may have overlapping frequencies. For example, if a frequency has suitable cells available from both terrestrial networks and non-terrestrial networks, the WTRU may (e.g., always) select a particular network type.

[0162] Prioritization of network types with overlapping frequencies can be provided. Figure 7 An example of network type prioritization based on overlapping frequencies is shown. In a deployment where terrestrial networks and non-terrestrial networks have overlapping frequencies, the WTRU may select a network type (e.g., a specific network type) if the frequency has suitable cells available from both the terrestrial network and the non-terrestrial network. Figure 7 In priority order A, if the priority frequency f1 (eg, the highest priority frequency f1) has both suitable terrestrial cells and non-terrestrial cells, the WTRU may select a terrestrial cell. In priority order B, the WTRU may select a non-terrestrial cell.

[0163] If the high ranking frequency (e.g., the highest ranking frequency) contains cells from both terrestrial networks and non-terrestrial networks and cells from one network type (e.g., only cells) are suitable, the WTRU may select that cell regardless of whether the cell is from a preferred network type. Figure 7 In the priority order A, if frequency f1 (eg, the highest priority frequency f1) has suitable cells (eg, only suitable cells) from the non-terrestrial network, the WTRU may select the non-terrestrial cell.

[0164] like Figure 7 As shown, when camping on priority order A, if frequency f1 (e.g., the highest priority frequency f1) has suitable terrestrial cells and non-terrestrial cells, the WTRU may (e.g., always) select the terrestrial cell. Figure 7 As shown, when camping on priority order B, if frequency f1 (eg, the highest priority frequency f1) has suitable terrestrial cells and non-terrestrial cells, the WTRU may (eg, always) select the non-terrestrial cell.

[0165] For example, if the highest ranked frequencies include cells from both terrestrial networks and non-terrestrial networks and a cell from (e.g., only) one network type is suitable, the WTRU may select that cell regardless of whether the cell is from a preferred network type. Figure 7 As shown, while camping on priority order A, the WTRU may select a non-terrestrial cell if frequency f1 (eg, the highest priority frequency f1) has (eg, only) suitable cells from the non-terrestrial network.

[0166] Figure 8 An example of prioritizing network types based on frequency is illustrated. In one example, if a high ranking frequency (e.g., the highest ranking frequency) contains cells from both terrestrial networks and non-terrestrial networks and cells from non-preferred network types (e.g., only cells) may be suitable, the WTRU may move to the next highest priority frequency until a suitable cell from a preferred network type can be found. For example, in Figure 8 In the example of FIG. 1 , under priority order A, if frequency f1 (e.g., which is the highest priority frequency f1) has a suitable cell (e.g., only suitable cells) from a non-terrestrial network, the WTRU may attempt to connect to a terrestrial cell on frequency f2. If no suitable cell is found on any frequency, the WTRU may connect to a suitable NTN cell on the highest priority frequency. Under priority order B, the WTRU may prefer non-terrestrial cells.

[0167] In some examples, for example, if the high-ranked frequencies (e.g., the highest-ranked frequencies) include cells from both terrestrial networks and non-terrestrial networks, and cells from (e.g., only from) non-preferred network types are suitable, the WTRU may move to the next highest priority frequency until a suitable cell from the preferred network type is found. Figure 8As shown, when camping on priority order A, if the highest priority frequency f1 has (e.g., only) suitable cells from non-terrestrial networks, the WTRU may (e.g., attempt to) connect to a terrestrial cell on frequency f2. For example, if no suitable cell is found on any frequency, the WTRU may connect to a suitable NTN cell on a high priority frequency (e.g., the highest priority frequency). Figure 8 As shown, while camping on priority order B, if the highest priority frequency f1 has suitable cells (eg, only) from the terrestrial network, the WTRU may attempt to connect to a non-terrestrial cell on frequency f2.

[0168] Prioritization may have a duration (e.g., in terms of time or count). In some examples, the WTRU may apply cell (re)selection prioritization semi-statically (e.g., based on configuration). In some examples, the WTRU may apply cell (re)selection prioritization based on satisfying criteria (e.g., as described herein).

[0169] The WTRU may apply a time-based switch between prioritizations. In some examples, the WTRU may temporarily (e.g., subject to a timing condition) apply a cell (re)selection prioritization. The timing conditions for prioritization may include, for example, one or more of the following or may be indicated by one or more of the following: when time runs, when a time period elapses, subject to a counter, until an indicated time and / or duration period.

[0170] The timing condition for prioritization may be indicated by a timer (e.g., when the timer runs) and / or a time period that may elapse. For example, the WTRU may start a timer (e.g., based on application of / upon application of cell (re)selection prioritization), may determine a duration, etc. The WTRU may stop cell (re)selection prioritization upon expiration of a timer, upon elapse of a duration, etc.

[0171] The timing condition for prioritization may include or may be indicated by a counter (eg, the prioritization is subject to the counter).For example, the WTRU may apply cell (re)selection prioritization for the next X resources (eg, frames, subframes, symbols).

[0172] The timing condition for prioritization may include or may be indicated by (eg, prioritization until) the indicated time. For example, the WTRU may apply cell (re)selection prioritization until 10:00:35 UTC.

[0173] The timing condition for prioritization may include or may be indicated by a time period (e.g., general or specific). For example, the WTRU may apply cell (re)selection prioritization for five minutes, which may be specific, such as between 10:00:35 UTC and 10:00:40 UTC.

[0174] In some examples, the WTRU may track time (e.g., start a timer) based on releasing to RRC IDLE / INACTIVE mode (e.g., receiving an RRCRelease or RRCReleasewithSuspend message) (e.g., upon release to this mode). The WTRU may apply cell (re)selection prioritization (e.g., only) for the indicated or configured duration. In some examples, the WTRU may start tracking time (e.g., via a timer or counter) based on starting cell (re)selection prioritization (e.g., when starting cell (re)selection prioritization). In some examples, the WTRU may start tracking time (e.g., via a timer or counter) after the WTRU last resided on a cell belonging to a network type (e.g., a terrestrial cell or a non-terrestrial cell). In some examples, an offset may (e.g., optionally) be applied to time (e.g., the start of a timer or counter).

[0175] The WTRU may stop tracking time (e.g., via a timer), for example, based on one or more of the following (e.g., when they occur): successful connection establishment (e.g., sending of an RRCSetupComplete or RRCREsumeComplete message); attempted connection establishment (e.g., sending of an RRCSetupRequest or RRCResumeRequest message); sending of a random access message (e.g., msgA, msg1, msg3, or msg5); receipt of a random access message (e.g., msgB, msg2, msg4) and / or application of different priority sorting configurations.

[0176] The WTRU may (e.g., based on / upon expiration of a timing condition) perform one or more of the following actions: stop applying cell (re)selection priority sorting; revert to a default or alternative cell (re)selection priority sorting configuration / method; discard the associated cell (re)selection priority sorting configuration; perform cell (re)selection; and / or perform random access (e.g., sending a preamble).

[0177] Prioritization may be periodic. In some examples, the WTRU may periodically apply cell (re)selection prioritization. For example, a series of times at which the cell (re)selection prioritization may be applied may be provided to the WTRU.

[0178] In some examples, the WTRU may be provided / configured with a time (e.g., UTC 10:00:32) and / or an offset (e.g., 5 minutes or X frames). For example, the WTRU / WTRU side may apply the cell (re)selection prioritization at every original time + X*offset. The offset multiplier X may be a configurable number (e.g., an integer).

[0179] In some examples, a plurality of times (e.g., timers) may be provided to the WTRU, such as a cycle duration and an on-duration. As described herein, a timer may refer to a period of time that may elapse. The WTRU may apply cell (re)selection prioritization while the on-duration (e.g., timer) is running, when a period of time has elapsed, and / or when within a period of time. The WTRU may wait (e.g., based on the expiration of the on-duration timer / when it expires and / or when a period of time has elapsed) until the cycle duration (e.g., timer) restarts and then starts the on-duration (e.g., timer) again (e.g., the WTRU may reapply the cell (re)selection prioritization).

[0180] WTRU-based TN / NTN prioritization may be reported (e.g., by the WTRU to the network). In some examples, the WTRU may report that it has applied cell (re)selection prioritization and / or information / characteristics about cell (re)selection prioritization. The WTRU may report, for example, one or more of: whether the WTRU is applying a cell (e.g., currently applying cell (re)selection prioritization); the network type and / or NTN deployment scenario of the current prioritization; the prioritization method; which cell (re)selection criteria have been met and / or the current status of the cell (re)selection prioritization criteria (e.g., each cell); and / or the remaining duration for which the WTRU may apply cell (re)selection prioritization (e.g., remaining duration).

[0181] The WTRU may report information about cell (re)selection priority ranking based on, for example: whether the reporting is configured to be enabled; in response to a network request (e.g., the WTRU may receive an indication in a paging or system information); based on the application of cell (re)selection priority ranking (e.g., when applying cell (re)selection priority ranking); based on a change in cell (re)selection priority ranking (e.g., when changing cell (re)selection priority ranking) (e.g., if the WTRU has changed its preference for network type); based on WTRU connection establishment (e.g., when the WTRU connection is established) (e.g., during random access).

[0182] The WTRU may report information about cell (re)selection prioritization, for example, via RRC signaling or MAC CE. The report may be transmitted, for example: during the random access procedure (e.g., via msgA, msg3, or msg5); via dedicated resources (e.g., stored grants, configured grant occasions, or resources periodically reserved for WTRU reporting) and / or using previously provided resources (e.g., provided in RRCRelease or RRCReleasewithSuspend).

[0183] In some examples, the WTRU may receive an RRCRelease message from a non-terrestrial network that includes one or more of: a prioritization configuration, criteria for applying the prioritization, and / or a duration for applying the configuration. The WTRU may detect (e.g., when performing cell (re)selection) that one or more prioritization criteria have been met (e.g., the RSRP of a terrestrial cell has increased by a threshold). The WTRU may apply (e.g., based on / when the prioritization criteria are met) a cell (re)selection priority configuration that may prioritize terrestrial networks, for example, by grouping (e.g., all) terrestrial frequencies and attempting to select suitable cells on (e.g., all) terrestrial frequencies before attempting to select suitable cells on non-terrestrial frequencies. The WTRU may start a timer and / or determine a time period that may be allowed to elapse (e.g., based on / when applying the prioritization configuration). The WTRU may continue to perform cell reselection via the prioritized configuration (e.g., while a timer is running, while within a period of time, and / or when a period of time has elapsed), for example, until a connection is established (e.g., via random access) or upon expiration of a timer (e.g., when a period of time has elapsed). The WTRU may revert to a different (e.g., default) cell reselection priority (e.g., based on / upon expiration of a timer) and / or may re-attempt cell (re)selection.

[0184] In some examples, the WTRU may receive an RRCRelease message from a terrestrial network. The message may include one or more of the following: a prioritization configuration, criteria for applying the prioritization, and / or a duration for applying the configuration. The WTRU may detect (e.g., when performing cell (re)selection) that one or more prioritization criteria have been met (e.g., the RSRP of the terrestrial cell has dropped below a threshold). The WTRU may (e.g., based on meeting the prioritization criteria / when meeting the prioritization criteria) apply a cell (re)selection priority configuration, which prioritizes non-terrestrial networks, for example, by (e.g., via) grouping (e.g., all) non-terrestrial frequencies and attempting to select suitable cells on (e.g., all) non-terrestrial frequencies before attempting to select suitable cells on terrestrial frequencies. The WTRU may (e.g., based on the application of the prioritization configuration / when applying the prioritization configuration) start a timer. The WTRU may (e.g., while the timer is running) continue to perform cell reselection via the prioritized configuration, for example, until a connection is established (e.g., via random access) or until the timer expires. The WTRU may revert to a different (eg, default) cell reselection priority (eg, based on / upon expiration of a timer) and / or may reattempt cell (re)selection.

[0185] 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.

[0186] Although the implementation described herein may consider 3GPP specific protocols, it should be understood that the implementation described herein is not limited to such scenarios 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 such scenarios and is also applicable to other wireless systems.

[0187] The processes described above 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 disk (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, terminal, base station, RNC, and / or any host computer.

Claims

1. A wireless transmit / receive unit (WTRU), the wireless transmit / receive unit (WTRU) comprising: A processor, the processor being configured to: receiving configuration information, the configuration information comprising location information associated with a terrestrial network (TN) coverage area and frequency information associated with the TN coverage area; determining a distance between the WTRU and a ground reference point associated with the TN coverage area; selecting a network type based on the distance between the WTRU and the terrestrial reference point associated with the TN coverage area; and Measurements are performed on a reference signal sent from the selected network type.

2. The WTRU of claim 1 , wherein if the distance between the WTRU and the terrestrial reference point is higher than or equal to a threshold, then the selected network type is a non-terrestrial network (NTN).

3. The WTRU of claim 1 , wherein if the distance between the WTRU and the ground reference point is below a threshold, the selected network type is a TN network.

4. The WTRU of claim 1 , wherein the location information indicates a geographic description associated with the TN coverage area, wherein the geographic description associated with the TN coverage area indicates one or more of coordinates or a radius.

5. The WTRU of claim 4, wherein the processor is further configured to: determining a threshold based on the location information associated with the TN coverage area, wherein the threshold is the radius associated with the TN coverage area; and determining whether the distance between the WTRU and the terrestrial reference point is higher than or equal to the threshold, wherein the threshold is associated with the location information, wherein the network type is selected based on whether the distance between the WTRU and the terrestrial reference point is higher than or equal to the threshold associated with the TN coverage area.

6. The WTRU of claim 5, wherein if the distance between the WTRU and the ground reference point is higher than or equal to the threshold, the WTRU is outside the TN coverage area, and wherein if the distance between the WTRU and the ground reference point is lower than the threshold, the WTRU is within the TN coverage area.

7. The WTRU of claim 1 , wherein the measurements performed are performed based on frequency information associated with the selected network type, and wherein the measurements performed are performed at a frequency indicated by the frequency information associated with the selected network type.

8. The WTRU of claim 1 , wherein the measurement performed is a first measurement, wherein the first measurement is performed based on frequency information associated with the selected network type, wherein the first measurement is performed on a first frequency indicated by the frequency information associated with the selected network type, and wherein the processor is further configured to: A second measurement is performed on the reference signal sent from the selected network type, wherein the second measurement is performed based on the frequency information associated with the selected network type, wherein the second measurement is performed on a second frequency indicated by the frequency information associated with the selected network type.

9. The WTRU of claim 1, wherein the configuration information is received via reception of system information.

10. A method comprising: receiving configuration information, the configuration information comprising location information associated with a terrestrial network (TN) coverage area and frequency information associated with the TN coverage area; determining a distance between a wireless transmit / receive unit (WTRU) and a ground reference point associated with the TN coverage area; selecting a network type based on the distance between the WTRU and the terrestrial reference point associated with the TN coverage area; and Measurements are performed on a reference signal sent from the selected network type.

11. The method of claim 10, wherein if the distance between the WTRU and the terrestrial reference point is higher than or equal to a threshold, the selected network type is a non-terrestrial network (NTN), and wherein if the distance between the WTRU and the terrestrial reference point is lower than the threshold, the selected network type is a TN network.

12. The method of claim 10, wherein the configuration information is received via reception of system information, and wherein the location information indicates a geographic description associated with the TN coverage area, wherein the geographic description associated with the TN coverage area indicates one or more of coordinates or a radius.

13. The method according to claim 12, further comprising: determining a threshold based on the location information associated with the TN coverage area, wherein the threshold is the radius associated with the TN coverage area; as well as determining whether the distance between the WTRU and the terrestrial reference point is higher than or equal to the threshold, wherein the threshold is associated with the location information, wherein the network type is selected based on whether the distance between the WTRU and the terrestrial reference point is higher than or equal to the threshold associated with the TN coverage area.

14. The method of claim 13, wherein if the distance between the WTRU and the ground reference point is higher than or equal to the threshold, the WTRU is outside the TN coverage area, and wherein if the distance between the WTRU and the ground reference point is lower than the threshold, the WTRU is within the TN coverage area.

15. The method of claim 10, wherein the performed measurements are performed based on the frequency information associated with the selected network type, and wherein the performed measurements are performed at a frequency indicated by the frequency information associated with the selected network type.

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