Paging or broadcasting assisting cell

Abstract

Disclosed herein are systems, methods, and instrumentalities associated with the use of an assisting cell for paging and / or broadcasting. A wireless transmit / receive unit (WTRU) as described herein may be configured to camp on a serving cell of a first network. The WTRU may receive paging assistance information from the serving cell. The WTRU may determine that an assisting cell indicated in the paging assistance information satisfies a first condition indicated in the paging assistance information. The assisting cell may be associated with a second network. The WTRU may monitor a paging channel on the assisting cell. The WTRU may perform a measurement on the serving cell. The WTRU may maintain a time synchronization with the assisting cell based on information associated with the serving cell.

Description

I5GSYS_2024P00547WO PATENTSYSTEMS AND METHODS ASSOCIATED WITH A PAGING OR BROADCASTING ASSISTING CELLCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The application claims priority to U.S. Application No. 63 / 679,509 filed August 5, 2024, the contents of which are incorporated by reference in their entirety.BACKGROUND

[0002] Wireless communication networks may include terrestrial networks (TNs) and / or non-terrestrial networks (NTNs). Systems and methods for improving the performance of such TNs and / or NTNs may be desirable.SUMMARY

[0003] Disclosed herein are systems, methods, and instrumentalities associated with the use of an assisting cell for paging and / or broadcasting. A WTRU may be configured to perform (or perform) one or more of the following.

[0004] A wireless transmit / receive unit (WTRU) as described herein may camp on a serving cell of a first network. The WTRU may receive paging assistance information from the serving cell. The WTRU may determine that an assisting cell indicated in the paging assistance information satisfies a first condition indicated in the paging assistance information. The assisting cell may be associated with a second network. The WTRU may monitor a paging channel on the assisting cell. The WTRU may perform a measurement on the serving cell. The WTRU may maintain a time synchronization with the assisting cell based on information associated with the serving cell.

[0005] In examples, the first network may be a terrestrial network (TN) and the second network may be a non-terrestrial network (NTN). The serving cell may be associated with the TN. The assisting cell may be associated with the NTN.

[0006] In examples, the WTRU may measure first reference signals associated with the serving cell at a first periodicity and measure second reference signals associated with the assisting cell at a second periodicity. The first periodicity may be more frequent than the second periodicity. The WTRU may switch to receive a paging or broadcast message in the serving cell based on at least one of: a received signal power, a channel quality, a position of the WTRU, or a location of the serving cell.I5GSYS_2024P00547WO PATENT

[0007] In examples, the WTRU may send a message to a network node associated with reception of a paging or broadcast message in the assisting cell by the WTRU (e.g., the message indicates that the WTRU is monitoring or will monitor the paging channel on the assisting cell, for example, to receive the paging or broadcast message in the assisting cell). The WTRU may periodically check, based on a periodicity configured by the paging assistance information, a system information block (SIB) of the serving cell to determine if a system information update for the assisting cell is required.

[0008] In examples, the WTRU may send a message to a network node associated with switching to monitoring for and / or reception of, by the WTRU, of a paging or broadcast message in the serving cell. For example, the WTRU may switch to monitoring a channel in the serving cell (e.g., to receive a paging or broadcast message in the serving cell).

[0009] In examples, the WTRU may start a paging synchronization timer upon monitoring the paging channel of the assisting cell. The WTRU may, based on an expiration of the paging synchronization timer, reacquire synchronization with the assisting cell by measuring a reference signal.

[0010] Disclosed herein are systems, methods, and instrumentalities associated with the use of an assisting cell for paging and / or broadcasting. A WTRU may be configured to perform (or perform) one or more of the following.

[0011] A wireless transmit / receive unit (WTRU) as described herein may camp on a serving cell of an overlayed network and determine that at least one other cell of the overlayed network is available for receiving a paging or broadcasting message. The WTRU may receive the paging or broadcasting message from the at least one other cell (e.g., instead of the serving cell).

[0012] In examples, the overlayed network may include a terrestrial network (TN) and a non-terrestrial network (NTN). The serving cell may be associated with the TN and the at least one other cell is associated with the NTN.

[0013] In examples, the WTRU may be further configured to measure first reference signals (e.g., for mobility) in the serving cell at a first periodicity and may measure second reference signals (e.g., for synchronization) in the at least one other cell at a second periodicity. The first periodicity may be more frequent than the second periodicity.

[0014] In examples, the WTRU may be further configured to switch to receiving paging or broadcast messages in the serving cell (e.g., instead of the one other cell) based on a condition that may be associatedI5GSYS_2024P00547WO PATENT with at least one of a received signal power, a channel quality, a position of the WTRU, or a location of the serving cell.

[0015] In examples, the WTRU may be further configured to send a message to a network node regarding reception of the paging or broadcast message in the at least one other cell.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments can be implemented.

[0017] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that can be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0018] FIG. 1 C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that can be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0019] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that can be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0020] FIG. 2 is a diagram illustrating examples of network layers.

[0021] FIG. 3 is a diagram illustrating an example of receiving paging in an NTN while camped on a TN.DETAILED DESCRIPTION

[0022] A more detailed understanding can be had from the following description, given by way of example in conjunction with the accompanying drawings.

[0023] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments can be implemented. The communications system 100 can be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 can enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 can 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), singlecarrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.I5GSYS_2024P00547WO PATENT

[0024] As shown in FIG. 1 A, the communications system 100 can include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the I nternet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d can be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which can be referred to as a “station” and / or a “ST A”, can be configured to transmit and / or receive wireless signals and can include a user equipment (WTRU), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d can be interchangeably referred to as a WTRU.

[0025] The communications systems 100 can include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b can be any type of device 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 the other networks 112. By way of example, the base stations 114a, 114b can be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a base station, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b can include any number of interconnected base stations and / or network elements.

[0026] The base station 114a can be part of the RAN 104 / 113, which can also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b can be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which can be referred to as a cell (not shown). These frequencies can be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell can provide coverage for a wireless service to a specific geographical area that can be relatively fixed or that can change over time. The cell can further be divided into cell sectors. For example, the cell associated with the base station 114a can be divided into three sectors. Thus, in oneI5GSYS_2024P00547WO PATENT embodiment, the base station 114a can include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a can employ multiple-input multiple output (MIMO) technology and can utilize multiple transceivers for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in desired spatial directions.

[0027] The base stations 114a, 114b can communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which can 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 can be established using any suitable radio access technology (RAT).

[0028] More specifically, as noted above, the communications system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c can implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA can include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0029] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0030] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as NR Radio Access, which can establish the air interface 116 using New Radio (NR).

[0031] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c can implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., a eNB and a base station).

[0032] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c can 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-I5GSYS_2024P00547WO PATENT2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0033] The base station 114b in FIG. 1 A can be a wireless router, Home Node B, Home eNode B, or access point, for example, and can utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d can 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 can 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 can utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b can have a direct connection to the Internet 110. Thus, the base station 114b can not be required to access the Internet 110 via the CN 106 / 115.

[0034] The RAN 104 / 113 can be in communication with the CN 106 / 115, which can 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 can have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 can provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 can 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 can be utilizing a NR radio technology, the CN 106 / 115 can also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0035] The CN 106 / 115 can also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 can include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 can include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 can include wired and / or wireless communications networksI5GSYS_2024P00547WO PATENT owned and / or operated by other service providers. For example, the networks 112 can include another CN connected to one or more RANs, which can employ the same RAT as the RAN 104 / 113 or a different RAT.

[0036] One or more (e.g., all) of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 can include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d can include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1 A can be configured to communicate with the base station 114a, which can employ a cellularbased radio technology, and with the base station 114b, which can employ an IEEE 802 radio technology.

[0037] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 can include 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, among others. It will be appreciated that the WTRU 102 can include any sub-combination of the foregoing elements while remaining included with an embodiment.

[0038] The processor 118 can 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 in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 can perform signal coding, 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 can be coupled to the transceiver 120, which can be coupled to the transmit / receive element 122. While FIG. 1 B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 can be integrated together in an electronic package or chip.

[0039] The transmit / receive element 122 can be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 can be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 can be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 can be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 can be configured to transmit and / or receive any combination of wireless signals.I5GSYS_2024P00547WO PATENT

[0040] Although the transmit / receive element 122 is depicted in FIG. 1 B as a single element, the WTRU 102 can include any number of transmit / receive elements 122. More specifically, the WTRU 102 can employ MIMO technology. Thus, in one embodiment, the WTRU 102 can include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0041] The transceiver 120 can be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 can have multi-mode capabilities. Thus, the transceiver 120 can include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0042] The processor 118 of the WTRU 102 can be coupled to, and can receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 can also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 can access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 can include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 can include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 can access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0043] The processor 118 can receive power from the power source 134, and can be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 can be any suitable device for powering the WTRU 102. For example, the power source 134 can 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, and the like.

[0044] The processor 118 can also be coupled to the GPS chipset 136, which can 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 can receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated thatI5GSYS_2024P00547WO PATENT the WTRU 102 can acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0045] The processor 118 can further be coupled to other peripherals 138, which can include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 can include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 can include one or more sensors, the sensors can be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0046] The WTRU 102 can include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) can be concurrent and / or simultaneous. The full duplex radio can include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 can include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0047] FIG. 1 C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 can employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 can also be in communication with the CN 106.

[0048] The RAN 104 can include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 can include any number of eNode-Bs while remaining includeent with an embodiment. The eNode-Bs 160a, 160b, 160c can each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c can implement MIMO technology. Thus, the eNode-B 160a, for example, can use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.I5GSYS_2024P00547WO PATENT

[0049] Each of the eNode-Bs 160a, 160b, 160c can be associated with a particular cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c can communicate with one another over an X2 interface.

[0050] The CN 106 shown in FIG. 1 C can include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements can be owned and / or operated by an entity other than the CN operator.

[0051] The MME 162 can be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and can serve as a control node. For example, the MME 162 can be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 can 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.

[0052] The SGW 164 can be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 can generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 can perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0053] The SGW 164 can be connected to the PGW 166, which can 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.

[0054] The CN 106 can facilitate communications with other networks. For example, the CN 106 can 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 can include, or can communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which can include other wired and / or wireless networks that are owned and / or operated by other service providers.I5GSYS_2024P00547WO PATENT

[0055] Although the WTRU is described in FIGS. 1A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal can use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0056] In representative embodiments, the other network 112 can be a WLAN.

[0057] A WLAN in Infrastructure Basic Service Set (BSS) mode can have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP can have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS can arrive through the AP and can be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS can be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS can be sent through the AP, for example, where the source STA can send traffic to the AP and the AP can deliver the traffic to the destination STA. The traffic between STAs within a BSS can be considered and / or referred to as peer-to-peer traffic. The peer-to- peer traffic can be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS can use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (I BSS) mode can not have an AP, and the STAs (e.g., all of the STAs) within or using the I BSS can communicate directly with each other. The IBSS mode of communication can sometimes be referred to herein as an “ad-hoc” mode of communication.

[0058] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP can transmit a beacon on a fixed channel, such as a primary channel. The primary channel can be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel can be the operating channel of the BSS and can be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) can be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, can sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA can back off. One STA (e.g., only one station) can transmit at any given time in a given BSS.

[0059] High Throughput (HT) STAs can use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0060] Very High Throughput (VHT) STAs can support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels can be formed by combining contiguous 20 MHz channels. AI5GSYS_2024P00547WO PATENT160 MHz channel can be formed by combining 8 contiguous 20 MHz channels, or by combining two noncontiguous 80 MHz channels, which can be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, can be passed through a segment parser that can divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, can be done on each stream separately. The streams can be mapped on to the two 80 MHz channels, and the data can be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration can be reversed, and the combined data can be sent to the Medium Access Control (MAC).

[0061] Sub 1 GHz modes of operation are supported by 802.11af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and802.11 ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah can support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices can have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices can include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0062] WLAN systems, which can support multiple channels, and channel bandwidths, such as 802.11 n,802.11 ac, 802.11 af, and 802.11 ah, include a channel which can be designated as the primary channel. The primary channel can have a bandwidth equal to the largest common operating bandwidth supported by all ST As in the BSS. The bandwidth of the primary channel can be set and / or limited by a STA, from among all ST As in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of802.11 ah, the primary channel can be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands can be considered busy even though a majority of the frequency bands remains idle and can be available.

[0063] In the United States, the available frequency bands, which can be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, theI5GSYS_2024P00547WO PATENT available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0064] FIG. 1 D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 can employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 can also be in communication with the CN 115.

[0065] The RAN 113 can include base stations 180a, 180b, 180c, though it will be appreciated that the RAN 113 can include any number of base stations while remaining includeent with an embodiment. The base stations 180a, 180b, 180c can each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the base stations 180a, 180b, 180c can implement MIMO technology. For example, base stations 180a, 108b can utilize beamforming to transmit signals to and / or receive signals from the base stations 180a, 180b, 180c. Thus, the base station 180a, for example, can use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the base stations 180a, 180b, 180c can implement carrier aggregation technology. For example, the base station 180a can transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers can be on unlicensed spectrum while the remaining component carriers can be on licensed spectrum. In an embodiment, the base stations 180a, 180b, 180c can implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from base station 180a and base station 180b (and / or base station 180c).

[0066] The WTRUs 102a, 102b, 102c can communicate with base stations 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing can vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c can communicate with base stations 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0067] The base stations 180a, 180b, 180c can be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c can communicate with base stations 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c can utilize one or more of base stations 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c can communicate with base stations 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c can communicateI5GSYS_2024P00547WO PATENT with / connect to base stations 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c can implement DC principles to communicate with one or more base stations 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c can serve as a mobility anchor for WTRUs 102a, 102b, 102c and base stations 180a, 180b, 180c can provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0068] Each of the base stations 180a, 180b, 180c can be associated with a particular cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the base stations 180a, 180b, 180c can communicate with one another over an Xn interface.

[0069] The CN 115 shown in FIG. 1 D can include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements can be owned and / or operated by an entity other than the CN operator.

[0070] The AMF 182a, 182b can be connected to one or more of the base stations 180a, 180b, 180c in the RAN 113 via an N2 interface and can serve as a control node. For example, the AMF 182a, 182b can be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing can be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices can be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 can 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.

[0071] The SMF 183a, 183b can be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b can also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b can select and control the UPF 184a, 184b and configure the routing of traffic through the UPFI5GSYS_2024P00547WO PATENT184a, 184b. The SMF 183a, 183b can perform other functions, such as managing and allocating WTRU IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type can be IP-based, non-IP based, Ethernet-based, and the like.

[0072] The UPF 184a, 184b can be connected to one or more of the base stations 180a, 180b, 180c in the RAN 113 via an N3 interface, which can 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 can 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, providing mobility anchoring, and the like.

[0073] The CN 115 can facilitate communications with other networks. For example, the CN 115 can include, or can communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 can provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which can include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c can be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0074] In view of Figures 1A-1D, and the corresponding description of Figures 1A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, base station 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, can be performed by one or more emulation devices (not shown). The emulation devices can be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices can be used to test other devices and / or to simulate network and / or WTRU functions.

[0075] The emulation devices can be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices can perform the one or more, 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. The one or more emulation devices can perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device can be directly coupled to another device for purposes of testing and / or can perform testing using over-the-air wireless communications.I5GSYS_2024P00547WO PATENT

[0076] The one or more emulation devices can perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices can be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices can be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which can include one or more antennas) can be used by the emulation devices to transmit and / or receive data.

[0077] Disclosed herein are systems, methods, and instrumentalities associated with the use of an assisting cell for paging and / or broadcasting. A wireless transmit / receive unit (WTRU) as described herein may be configured to camp on a serving cell of a first network. The WTRU may receive paging assistance information from the serving cell. The WTRU may determine that an assisting cell indicated in the paging assistance information satisfies a first condition indicated in the paging assistance information. The assisting cell may be associated with a second network. The WTRU may monitor a paging channel on the assisting cell. The WTRU may perform a measurement on the serving cell. The WTRU may maintain a time synchronization with the assisting cell based on information associated with the serving cell.

[0078] In examples, the first network may be a terrestrial network (TN) and the second network may be a non-terrestrial network (NTN). The serving cell may be associated with the TN. The assisting cell may be associated with the NTN.

[0079] In examples, the device may measure first reference signals associated with the serving cell at a first periodicity and measure second reference signals associated with the assisting cell at a second periodicity, the first periodicity being more frequent than the second periodicity. The device may switch to receive a paging or broadcast message in the serving cell based on at least one of: a received signal power, a channel quality, a position of the WTRU, or a location of the serving cell.

[0080] In examples, the device may send a message to a network node regarding reception of a paging or broadcast message in the assisting cell. The device may periodically check, based on a periodicity configured by the paging assistance information, a system information block (SIB) of the serving cell to determine if a system information update for the assisting cell is required.

[0081] In examples, the device may start a paging synchronization timer upon monitoring the paging channel of the assisting cell. The device may, based on an expiration of the paging synchronization timer, reacquire synchronization with the assisting cell by measuring a reference signal.I5GSYS_2024P00547WO PATENT

[0082] Disclosed herein are systems, methods, and instrumentalities associated with the use of an assisting cell for paging and / or broadcasting. A wireless transmit / receive unit (WTRU) as described herein may be configured to camp on a serving cell of an overlayed network and determine that at least one other cell of the overlayed network is available for receiving a paging or broadcasting message. The WTRU may receive the paging or broadcasting message from the at least one other cell (e.g, instead of the serving cell).

[0083] Paging and / or mobility procedures may be performed in a wireless communication system (e.g., if a WTRU is in an RRCJDLE or RRCJNACTIVE state). Discontinuous receptions (DRX) may be performed in the wireless communication system. The wireless communication system may include a terrestrial network (TN) and / or a non-terrestrial network (NTN), either or both of which may support coverage enhancements and / or broadcast services.

[0084] An NTN may be enhanced to support a TN-NTN deployment. An NTN capable WTRU may operate in the coverages of multiple (e.g, two) network layers, one of which may be based on an NTN and another one of which may be based on a TN. In examples, a network layer may mean a single frequency layer, on which a communication network system may operate. The communication network system may be a TN, an NTN or any radio access technology (e.g, E-UTRA, NR, etc.).

[0085] A wireless communication network as described herein may include multiple layers. For example, terrestrial networks, low earth orbit (LEO) satellite networks, medium earth orbit (MEO) satellite networks and / or geostationary earth orbit (GEO) satellite networks may operate with different cell sizes and / or different over-the-air propagation delays. The GEO networks may have the largest cell coverage, with the longest propagation delay, followed by the MEO networks and the LEO networks (e.g, which may have smaller cell coverage and shorter propagation delays), and finally the terrestrial networks (e.g, which may have the smallest cell coverage but the shortest propagation delays).

[0086] FIG. 2 illustrates examples of network layers (e.g, NTN and / or TN layers). The examples provided herein may refer to TN+NTN coverage, but those skilled in the art would appreciate that the principles disclosed herein may be applicable to any combination of network layers such as LEO- 3EO, TN+MEO-A3EO, TN lower frequency (e.g, FR1 or a frequency <= 1 GHz) + TN higher frequency (e.g, FR2 or a frequency > 1GHz), and so on.

[0087] From a WTRU power saving point of view, with available TN and NTN coverages, the WTRU may be configured to camp on the NTN. This may be because NTN cells may provide wider coverage than TN cells, and therefore neighbor cell measurements, cell reselection, system information (SI) reading may be reduced (e.g, minimized), for example, for a moving WTRU.I5GSYS_2024P00547WO PATENT

[0088] From a network (NW) paging load point of view, the WTRU may be configured to camp on an NTN cell. This may be because the NTN cell may provide wider coverage than a TN cell, and / or the cell location may be known, so paging across multiple cells within a RAN notification area (RNA), a tracking area (TA) or a registration area (RA) may not need to be escalated.

[0089] In an NTN network such as a GEO network, it may be unlikely for a WTRU to reselect another cell. In other scenarios such as in an LEO network, with the earth moving, a cell location may be known. For example, even in the case of cell reselection within a TA / RNA, the cell location may be known as the WTRU may be unlikely to have moved significantly within the geographical area.

[0090] From a latency point of view, the WTRU may be configured to camp on a TN cell. This may be because RRC connection establishment procedures, RRC resume procedures, and / or data transfers may be subject to long propagation delays in an NTN cell and therefore the TN cell may be a better choice, for example, in terms of signaling delay and / or data throughput. Another reason for camping on the TN cell may be that the notification and / or delivery of a paging message and a Multicast-Broadcast Service (MBS) message (e.g., including a Public Warning System (PWS) message) may be subject to long latency, but when considering potential paging escalation, the overall performance may not be worse than an NTN cell.

[0091] Systems and methods described herein may take advantage of overlapping network layers (e.g., in an RRCJDLE or RRCJNACTIVE state), such as overlapping TN-NTN coverage, to achieve power saving and / or paging and broadcast load benefits of the NTN (e.g., while a WTRU is in the RRCJDLE or RRCJNACTIVE state), while still achieve fast connection set-up, high throughput and / or low latency via the TN (e.g. while a WTRU is performing RRC connection establishment / resumption procedures, or while a WTRU is in the RRC_CONNECTED state). When described herein, overlapping network coverage or an overlay network may mean having different networks (e.g., different systems, different radio access technologies (RATs), different frequencies, etc.) covering the same geographical area.

[0092] In some examples, a WTRU may receive paging or broadcast signals over channels configured on a current serving cell, and the WTRU may not be able to receive those signals via another cell (e.g., while the WTRU is in an RRCJDLE state or an RRCJNACTIVE state). The system in these examples may be enhanced to allow the WTRU to receive the paging and / or broadcast signals over a cell other than (e.g., in addition to) a current serving cell while the WTRU is camped on that serving cell.

[0093] In some examples, a WTRU may not be able to take advantage of an overlayed mobile communication system to receive paging and / or broadcast signals while the WTRU is camped on a single serving cell. In these example, even if the WTRU is in the coverage of a wide-coverage cell, such as an NTNI5GSYS_2024P00547WO PATENT cell or a lower frequency (e.g., less than 1 GHz or FR1) cell while the WTRU is camped on a high frequency (e.g., greater than 1 GHz or FR2) cell, the WTRU may not be able to receive paging and / or broadcast services over the wide-coverage cell for rapid connection establishment and / or better user plane performance while the WTRU is camped on the smaller-coverage cell.

[0094] A WTRU may be configured to perform (or perform) one or more of the following.

[0095] A WTRU may be configured to use an assisting cell in an overlayed network (e.g., a network with multiple overlapping layers such as a TN-based layer and an NTN-based layer, see e.g., FIG. 2) for paging and / or broadcast message reception while the WTRU is camped on a regular serving cell (e.g., on a primary layer of a network).

[0096] The WTRU may be configured to perform mobility measurements on (e.g., only on) a primary network layer while maintaining timing synchronization with an assisting cell (e.g., the WTRU may acquire and / or maintain timing synchronization with the assisting cell based on less-frequent reference signal acquisitions than regular measurements associated with the serving cell, such as mobility measurements). The assisting cell may be referred to as an assisting network layer or a secondary network layer.

[0097] The WTRU may switch a paging cell based on certain condition(s) including, for example, one or more of: radio quality (e.g., reference signal received quality or RSRQ), time, radio received power (e.g., reference signal received power or RSRP), WTRU position, serving cell location (e.g., ephemeris), etc. In some examples, “ephemeris” may mean an indication provided by a network (e.g., an NTN system) to a WTRU that indicates a trajectory of a satellite (e.g., the WTRU may predict a satellite location based on a given ephemeris (e.g., and an epoch time) and the current time).

[0098] A WTRU may be configured to perform (or perform) one or more of the following.

[0099] A WTRU may detect and / or acquire assistance configuration information. For example, the WTRU may camp on a serving cell (e.g., a primary layer of a network). The WTRU may check system information (SI) (e.g., from the serving cell) to determine whether the SI includes paging assistance configuration information. The WTRU may (e.g., based on the determination that the SI includes the paging assistance configuration information) evaluate an assisting cell. For example, if paging assistance configuration information is present, the WTRU may evaluate a candidate assisting cell indicated by the paging assistance configuration. The WTRU may acquire synchronization with a designated assisting cell (e.g., the candidate assisting cell), for example, by acquiring one or more synchronization signal block (SSBs) of that cell. The WTRU may determine if a radio received power and / or quality is good enough to receive a paging message from the assisting cell.I5GSYS_2024P00547WO PATENTThe evaluation condition(s) may be provided via the paging assistance configuration information. The WTRU may evaluate (e.g., periodically or continuously evaluate) the condition(s) on the paging assisting cell. If the assisting cell no longer fulfills the condition(s), the WTRU may start using the serving cell for paging. The WTRU may receive a paging message (e.g., from the assisting cell). For example, if a candidate assisting cell fulfills the condition(s), the WTRU may consider the candidate cell to be a paging assisting cell (e.g., an assisting network layer) and may start monitoring a paging channel in the paging assisting cell. The WTRU may perform mobility measurements on the primary layer and maintain timing synchronization with the paging assisting cell (e.g., by re-acquiring one or more SSBs of the assisting cell before timing synchronization is lost).

[0100] As a result of one or more technique(s) described herein, a network may not need to identify a TN cell for NTN paging capable WTRUs in a TA covered by one or more NTN cells, while the WTRU may speed up call setups using a TN cell. Since an NTN may support PWS messaging, a network may be able to provide PWS information to NTN paging capable WTRUs via fewer PWS delivery operations (e.g., performing one PWS delivery operation instead of sending multiple PWS messages corresponding to the number of available TN cells). The delivery of PWS messages may become faster.

[0101] A primary serving cell of a WTRU may provide wireless access for the WTRU (e.g., the cell may be referred to as a “PCell” in some examples). The primary serving cell may be associated with a coverage area, which may be small (e.g., a TN cell or a higher-frequency cell such as a >1GHz cell or an FR2 cell).

[0102] A paging assisting cell may provide paging services for a WTRU. In examples, the paging cell may be different from a primary serving cell. The paging cell may be associated with a coverage area, which may be wide (e.g., an NTN cell or a lower frequency cell such as a < 1 GHz cell or an FR1 cell).

[0103] A broadcast assisting cell may provide broadcast services for a WTRU. In examples, such a cell may be different from a primary serving cell and may be associated with a wide coverage area (e.g., an NTN cell or a lower frequency cell such as a < 1 GHz cell or an FR1 cell).

[0104] In examples, paging may be performed via a wider coverage cell (e.g., a paging assisting cell) while a WTRU is camped on a smaller coverage cell (e.g., a primary serving cell). For example, the WTRU may be in an RRCJDLE or RRCJNACTIVE state and may be camped on a primary serving cell. The WTRU may be provided with (e.g., via RRC signaling, system information or another suitable signaling mechanism) paging configuration information associated with a paging assisting cell. The WTRU and the network may take advantage of the wider-coverage cell for paging and / or broadcast services.I5GSYS_2024P00547WO PATENT

[0105] FIG. 3 illustrates an example scenario involving a TN cell and a paging / broadcast assisting NTN cell. In this example, a WTRU may receive system information (e.g., from a TN base station (TNgNB)), which may include paging configuration information. The paging configuration information may indicate more than one paging configuration such as a paging configuration associated with a primary serving cell and one or more additional paging configurations associated with other cells (e.g., neighboring cells such as paging assisting cells, which may be NTN cells or cells on FR1 frequencies). The system information may be provided by the primary serving cell. The system information may include the paging configuration information associated with the one or more paging assisting cells. The system information may include respective identifiers of the one or more paging assisting cells (e.g., identities associated with neighboring cells, the frequencies and / or physical cell identities (PCIs) of the paging assisting cells). The WTRU may acquire system information from one or more of the paging assisting cells to obtain that cell’s paging configuration information, or the WTRU may obtain the paging configuration of the paging assisting cell by the paging configuration for the paging assisting cell provided by the primary serving cell.

[0106] The system information described herein may include paging configuration selection condition(s). The WTRU may determine which paging configuration to use based on the condition(s). For example, if one of the paging assisting cells fulfills the condition(s), the WTRU may monitor (e.g., start monitoring) that paging assisting cell’s paging channel. The selection condition(s) may include, for example, whether the RSRP of a paging assisting cell is equal to or greater than a threshold for a certain time duration, whether a paging assisting cell’s coverage (e.g., which may be predicted based on known information such as time, WTRU position, and / or NTN ephemeris information, or based on the fact that the WTRU is camped on a primary serving cell) satisfies a condition, and / or the like. The WTRU may determine that it is under the coverage of a paging assisting cell if the WTRU is camped on a primary serving cell whose coverage area is part of the paging assisting cell’s coverage area (e.g., for this case, the WTRU may not need to check additional condition(s) to ensure that the WTRU is under the coverage of the paging assisting cell). If a selected paging assisting cell no longer fulfills the condition(s) (e.g., the RSRP of the paging assisting cell is less than the threshold for a time duration, or the WTRU is leaving the cell’s coverage area based on prediction made from time, WTRU position and / or NTN ephemeris information), the WTRU may stop monitoring the paging assisting cell’s paging channel (e.g., the WTRU may start monitoring the primary serving cell’s paging channel instead). The selection condition(s) may be provided (e.g., explicitly) by the network (e.g., via RRC configuration or system information) or they may be preconfigured for the WTRU (e.g., hardcoded according to specifications).I5GSYS_2024P00547WO PATENT

[0107] A paging cell type may be provided via uplink notifications. For example, a network node (e.g., which may be interchangeably referred to as a network device in this disclosure) such as a base station may not know which cell(s) are being monitored (e.g., for paging) by a WTRU in an RRCJDLE or RRCJNACTIVE mode unless the WTRU notifies the network node about those cell(s). In examples, an uplink message may be used to notify the network node about which cell (s) and / or network layer(s) (e.g., frequencies and / or systems for a TN cell / layer or an NTN cell / layer) are being monitored by the WTRU. For example, such an uplink message may be sent upon a change of cell for paging receptions. In examples, the network node may use a trial-and-error approach to determine the cell(s) that the WTRU may be monitoring for paging. In examples, the network node may send a paging message over a first cell (e.g., an NTN cell) and if that attempt fails (e.g., the network node does not receive any paging response from the WTRU for a certain time period), the network node may try another cell (e.g., a TN cell).

[0108] In some examples, a primary serving cell may update its system information by sending a system information (SI) update indication to WTRUs via paging. In these examples, an SI update may fail if the WTRUs are only monitoring paging messages from an assisting cell.

[0109] One or more of the following may be implemented, for example, to avoid missing an SI update indication event.

[0110] A paging assisting cell may send a paging message indicating that a primary serving cell may be expecting a WTRU to perform a system information update procedure. The paging message may indicate which cell on the primary serving cell’s frequency that the WTRU may use for the SI update procedure.

[0111] A primary serving cell may provide configuration information associated with monitoring paging messages for SI update indications, for example, if a paging assisting cell’s paging configuration is configured by the primary serving cell. A WTRU may monitor the primary serving cell’s paging channel to receive an SI update notification from the primary serving cell. The configuration information provided by the primary serving cell may include, for example, paging cycles associated with SI updates.

[0112] A WTRU may (e.g., periodically) check if a stored system information block (SIB) for a primary serving cell is up-to-date. Since SI updates may not occur frequently, the periodicity of SI update checks may be long and the periodicity may be configured (e.g., explicitly) by the network (e.g., as part of the configuration of a paging assisting cell) or be preconfigured for the WTRU (e.g., hardcoded according to specifications). The WTRU may check the value tags of SIBs, which may be provided by a primary serving cell. If one or more SIBs have a different value tag from the SIB value tag(s) stored in the WTRU, the WTRU may acquire the corresponding SIB(s) (e.g., SIB(s) with a changed value tag) from the primary serving cell.I5GSYS_2024P00547WO PATENT

[0113] In examples, measurement requirements associated with a paging assisting cell may be relaxed. For example, if a WTRU is camped on a primary serving cell, the WTRU may be expected to monitor for one or more SSBs sent from the primary serving cell and / or one of more neighboring cells (e.g., to support mobility of the WTRU related to the primary serving cell). If the WTRU performs cell measurements of both the primary serving cell (e.g., for mobility related to the primary network layer) and the paging assisting cell (e.g., for mobility related to the assisting network layer), extra power (e.g., battery power) of the WTRU may be consumed (e.g., compared to performing measurements related to only the primary serving cell). Measurement requirements for the WTRU (e.g., while the WTRU is monitoring a paging assisting cell) may be relaxed based on one or more of the following to avoid battery drain.

[0114] The WTRU may measure a paging assisting cell’s reference signal(s) (e.g., SSB(s)) to ensure that the paging assisting cell is strong enough for paging reception. The WRU may acquire synchronization with the paging assisting cell (e.g., by reading the SSB(s) of the paging assisting cell) prior to using the paging assisting cell for paging receptions. If the paging assisting cell’s quality is not good enough or if the WTRU fails to synchronize with the paging assisting cell, the WTRU may decide not to use the paging assisting cell for paging receptions (e.g., the WTRU may start using a primary serving cell for the paging receptions). Based on a determination to use the paging assisting cell, the WTRU may perform measurements in the primary serving cell and / or the neighboring cell(s) if necessary (e.g., the WTRU may decide not to perform reference signal measurements for neighboring cell(s) when the serving cell is strong enough) and while the WTRU may maintain synchronization with the paging assisting cell. If the WTRU determines that timing synchronization with the paging assisting cell may be lost soon, the WTRU may re-acquire synchronization with the paging assisting cell by reading the SSB(s) of that cell.

[0115] The WTRU may be configured with multiple synchronization configurations (e.g., for a relaxed mode and a normal mode), which may be used by the WTRU to synchronize or resynchronize with a paging assisting cell. Each configuration may be associated with a set of conditions (e.g., monitoring for paging on a paging assisting cell while camped on a primary serving cell, monitoring for paging on the primary serving cell, etc.), and the WTRU may apply the configuration based on the conditions.

[0116] In an example implementation of a relaxed synchronization configuration, a WTRU may be configured to monitor (e.g., only) a subset of synchronization signals (e.g., SSBs with a long periodicity, SSBs of a paging assisting cell, etc.).

[0117] A WTRU may be configured with a time period (e.g., a paging-sync-timer) associated with synchronization. The WTRU may start to monitor a time period (e.g., by starting the paging-sync-timer) ifI5GSYS_2024P00547WO PATENT monitoring (e.g, beginning to monitor) for paging in a paging assisting cell. If the time period elapses, the WTRU may re-acquire synchronization with the paging assisting cell (e.g., by reading the reference signals of the cell). The WTRU may monitor (e.g., start to monitor) the time period again. During the time period (e.g., while the paging-sync-timer is running), the WTRU may not need to acquire synchronization with the paging assisting cell. The WTRU may measure reference signals (e.g., for synchronization) after the time period elapses (e.g., upon expiration of the paging-sync-timer).

[0118] Measurement requirements may be defined for a paging assisting cell. A WTRU may be configured to measure one or more reference signals of a serving cell based on a first periodicity (e.g., every X seconds) while measure one or more reference signals of a paging assisting cell based on a second periodicity (e.g., every Y seconds, where Y may be bigger than X).

[0119] In examples, a WTRU may primarily perform serving cell measurements (e.g., the WTRU may measure one or more neighboring cells for mobility) with relaxed paging assisting cell measurements (e.g., while the WTRU is monitoring a paging channel of the paging assisting cell). The chances of battery drain due to the use of two cells serving may be reduced.

[0120] Broadcasting messages may be transmitted over an assisting cell. As described herein, a paging assisting cell may be used for paging receptions. The same or similar techniques may be applied for receiving broadcasting message. In examples, the term “paging assisting cell” may be replaced with “broadcasting assisting cell,” and a WTRU may monitor for an MBS broadcasting channel and / or receive a broadcasting message (e.g., a PWS system information block) while monitoring a paging channel. The WTRU may receive broadcast messages as well as paging messages in an assisting cell. In the broadcasting assisting cell case, the techniques described herein for a paging assisting cell may be similarly applied (e.g., except for uplink notifications).

[0121] In examples, a paging (or broadcasting) assisting cell may be used for an overlayed area. A WTRU may use the assisting cell (e.g, in an overlayed network) for paging receptions, for example, when the WTRU is camped on a regular serving cell (e.g, a primary network layer). The WTRU may perform measurements (e.g, mobility measurements) on the primary layer (e.g, only on the primary layer) while maintaining timing synchronization with the assisting cell (e.g, by acquiring the synchronization with the assisting cell based on less-frequent reference signal acquisitions than regular measurements). The WTRU may switch the paging assisting cell based on certain condition(s) (e.g, based on radio quality, radio received power, timing, WTRU position, and / or assisting cell location or assisting cell’s ephemeris). The WTRU may notify the network which cell / layer (e.g, the frequency, the system associated with a TN or an NTN, or a RAT with an NR or an E-I5GSYS_2024P00547WO PATENTUTRA / LTE network) may be used for paging receptions (e.g, so that the network may page the WTRU in the right cell / layer).

[0122] A WTRU may acquire assisting cell configuration information. The WTRU may camp on a serving cell (e.g., a primary network layer) and may check whether received system information includes any paging assisting configuration. The WTRU may evaluate an assisting cell. For example, if a paging assisting configuration is present in the system information, the WTRU may evaluate a candidate assisting cell indicated by the paging assisting configuration (e.g., the WTRU may acquire synchronization with the designated assisting cell by acquiring SSBs of the cell). The WTRU may determine whether a radio received power and / or quality is good enough for paging receptions. The evaluation condition(s) may be provided via the paging assisting configuration or provided in specifications (e.g., hard-coded in the WTRU). The WTRU may evaluate (e.g., periodically or continuously evaluate) the paging assisting cell based on the condition(s). If the assisting cell no longer fulfills the condition(s), the WTRU may stop using the assisting cell and start using the serving cell for paging.

[0123] If a candidate assisting cell fulfills the condition(s), the WTRU may use that candidate cell as a paging assisting cell (e.g., as an assisting network layer) and may start monitoring a paging channel on the paging assisting cell. The WTRU may perform mobility measurements on the primary network layer while maintaining timing synchronization with the paging assisting cell (e.g., by re-acquiring the SSB(s) of the assisting cell before timing synchronization is lost).

[0124] The WTRU may send an uplink message to a network to indicate which cell / layer / system is being used for paging (e.g., so that the network may use the right cell / layer / system / RAT for paging to the WTRU). In examples, the WTRU may send the uplink notification message when the WTRU changes the cell / layer / system / RAT for paging (e.g., between the serving cell and the paging assisting cell / layer / system).

[0125] A serving cell (e.g., a TN serving cell) may configure a WTRU to monitor a paging channel of another cell (e.g, a neighboring NTN cell) while the WTRU is camped on the serving cell. The WTRU may perform cell selection / reselection based on one or more SSBs of the serving cell and the neighboring cell(s) so that the WTRU may establish a connection after (e.g, immediately after) paging while the WTRU is synchronized with another cell (e.g, a paging assisting cell) for paging receptions. The WTRU may do so by checking the timing of the paging assisting cell less-frequently than the serving system’s SSB measurements.

[0126] If the paging assisting cell becomes unavailable (e.g, becoming too weak for the WTRU), the WTRU may switch back to the serving cell for paging reception. If the paging assisting cell becomes available for the WTRU (e.g, when the WTRU moves into a coverage area of the paging assisting cell), the WTRU may switchI5GSYS_2024P00547WO PATENT to performing paging via the paging assisting cell. The WTRU may notify the network about the switch, for example, via an uplink message (e.g., a UE Assistance Information (UAI) message).

[0127] Although 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 other features and elements.

[0128] Although the implementations described herein may consider 3GPP specific protocols, it is understood that the implementations described herein are not restricted to this scenario and may be applicable to other wireless systems. For example, although the solutions described herein consider LTE, LTE-A, New Radio (NR) or 5G specific protocols, it is understood that the solutions described herein are not restricted to this scenario and are applicable to other wireless systems as well.

[0129] 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 (transmitted over wired and / or wireless connections) and / or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a solid state drive, register, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as compact disc (CD)-ROM disks, and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, a terminal, a base station (e.g., a gNB), a control unit, a data unit, an RNC, and / or any host computer.

Claims

I5GSYS_2024P00547WO PATENTCLAIMS1 . A wireless transmit / receive unit (WTRU), comprising: a processor configured to: camp on a serving cell of a first network; receive paging assistance information from the serving cell; determine that an assisting cell indicated in the paging assistance information satisfies a first condition indicated in the paging assistance information, wherein the assisting cell is associated with a second network; monitor a paging channel on the assisting cell; perform a measurement on the serving cell; and maintain a time synchronization with the assisting cell based on information associated with the serving cell.

2. The WTRU of claim 1 , wherein the first network is a terrestrial network (TN) and the second network is a non-terrestrial network (NTN).

3. The WTRU of claim 2, wherein the serving cell is associated with the TN and wherein the assisting cell is associated with the NTN.

4. The WTRU of claim 1 , wherein the processor is further configured to: measure first reference signals associated with the serving cell at a first periodicity and measure second reference signals associated with the assisting cell at a second periodicity, the first periodicity being more frequent than the second periodicity.

5. The WTRU of claim 1 , wherein the processor is further configured to: switch to monitor for a paging or broadcast message in the serving cell based on at least one of: a received signal power, a channel quality, a position of the WTRU, or a location of the serving cell; and receive the paging or broadcast message on the serving cell.

6. The WTRU of claim 5, wherein the processor is further configured to: send a message to a network node, wherein the message indicates the switch to monitor for the paging or broadcast message in the serving cell.I5GSYS_2024P00547WO PATENT7. The WTRU of claim 1 , wherein the processor is further configured to: send a message to a network node that indicates the WTRU being configured to monitor the paging channel on the assisting cell.

8. The WTRU of claim 1 , wherein the processor is further configured to: periodically check, based on a periodicity configured by the paging assistance information, a system information block (SIB) of the serving cell to determine if a system information update for the assisting cell is required.

9. The WTRU of claim 1 , wherein the processor is further configured to: start a paging synchronization timer upon monitoring the paging channel of the assisting cell; and based on an expiration of the paging synchronization timer, reacquire synchronization with the assisting cell by measuring a reference signal.

10. A method associated with a wireless transmit / receive unit (WTRU), the method comprising: camping on a serving cell of a first network; receiving paging assistance information from the serving cell; determining that an assisting cell indicated in the paging assistance information satisfies a first condition indicated in the paging assistance information, wherein the assisting cell is associated with a second network; monitoring a paging channel on the assisting cell; performing a measurement on the serving cell; and maintaining a time synchronization with the assisting cell based on information associated with the serving cell.11 . The method of claim 10, wherein the first network is a terrestrial network (TN) and the second network is a non-terrestrial network (NTN).

12. The method of claim 11 , wherein the serving cell is associated with the TN and wherein the assisting cell is associated with the NTN.I5GSYS_2024P00547WO PATENT13. The method of claim 10, further comprising: measuring first reference signals associated with the serving cell at a first periodicity and measuring second reference signals associated with the assisting cell at a second periodicity, the first periodicity being more frequent than the second periodicity.

14. The method of claim 10, further comprising: switching to monitor for a paging or broadcast message in the serving cell based on at least one of: a received signal power, a channel quality, a position of the WTRU, or a location of the serving cell; and receive the paging or broadcast message on the serving cell.

15. The method of claim 14, further comprising: sending a message to a network node, wherein the message indicates the switch to monitor for the paging or broadcast message in the serving cell.

16. The method of claim 10, further comprising: sending a message to a network node that indicates the WTRU being configured to monitor the paging channel on the assisting cell.

17. The method of claim 10, further comprising: periodically checking, based on a periodicity configured by the paging assistance information, a system information block (SIB) of the serving cell to determine if a system information update for the assisting cell is required.

18. The method of claim 10, further comprising: starting a paging synchronization timer upon monitoring the paging channel of the assisting cell; and based on an expiration of the paging synchronization timer, reacquiring synchronization with the assisting cell by measuring a reference signal.

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