Acquiring synchronization and system information in energy saving networks associated with a slim synchronization signal

Abstract

Systems, methods, and instrumentalities are described herein for acquiring synchronization and system information in energy saving networks associated with slim sync leading to WUS and WUS leading to SSB measurements. A wireless transmit / receive unit (WTRU) sync acquisition may start by detecting a synchronization signal (SS). The WTRU may determine timing and / or resource information for pre-sync or DL-WUS style signal(s), for example, based on the slim sync indication. Pre-sync or WUS signaling may provide an indication for network energy savings (NES) configuration information and timing for system information.

Description

ACQUIRING SYNCHRONIZATION AND SYSTEM INFORMATION IN ENERGY SAVING NETWORKS ASSOCIATED WITH A SLIM SYNCHRONIZATION SIGNALCROSS-REFERENCE TO RELATED APPLICATOINS

[0001] The application claims the benefit of U.S. Provisional Application 63 / 526,323, filed July 12, 2023, the contents of which are incorporated by reference in their entirety herein.BACKGROUND

[0002] Mobile communications using wireless communication continue to evolve. A fifth generation of mobile communication radio access technology (RAT) may be referred to as 5G new radio (NR). A previous (legacy) generation of mobile communication RAT may be, for example, fourth generation (4G) long term evolution (LTE).SUMMARY

[0003] Systems, methods, and instrumentalities are described herein for acquiring synchronization and system information in energy saving networks associated with slim sync leading to WUS and WUS leading to SSB measurements. A wireless transmit / receive unit (WTRU) sync acquisition may start by detecting a synchronization signal (SS). The WTRU may determine timing and / or resource information for pre-sync or DL-WUS style signal(s), for example, based on the slim sync indication. Pre-sync or WUS signaling may provide an indication for network energy savings (NES) configuration information and timing for system information.

[0004] The WTRU may receive a first signal. The first signal may include a slim SS. The slim SS may be a compressed SS. The first signal may indicate information associated with a second signal. The second signal may include a pre-synchronization signal (e.g., wake-up signal (WUS), downlink WUS (DL-WUS)). The information associated with the second signal may be indicated based on one or more properties or characteristics associated with the slim SS (e.g., timing information, frequency information, phase information, sequence choice information). The first signal may indicate a slim sequence that may indicate information associated with the second signal. The first signal may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or a PSS and an SSS (e.g., only a PSS and an SSS). In examples, the first signal may refrain from including a physical broadcast channel (PBCH) block. TheWTRU may determine a resource associated with reception of the second signal (e.g., pre-synchronization signal; WUS; DL-WUS), for example, based on the information associated with the second signal (e.g., indicated by the first signal). The WTRU may receive the second signal, for example, via the resource determined using the information associated with the second signal. The second signal may include an indication associated with reception of an SSB. The SSB may include a PBCH block. The WTRU may determine information associated with reception of the SSB, for example, based on the indication associated with the reception of the SSB (e.g., indicated by the second signal). The information associated with receiving the SSB may include one or more of the following: an NES state, an SSB periodicity, a presence of a full SSB on a potential full SSB transmission occasion, etc. The WTRU may receive the SSB, for example, based on the determined information associated with reception of the SSB.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0006] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A according to an embodiment.

[0007] FIG. 1 C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0008] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1A according to an embodiment.

[0009] FIG. 2 illustrates an example time-frequency structure of a SSB.

[0010] FIG. 3 further illustrates an example of SSB Beam Sweeping within SSB Burst Sets.

[0011] FIG. 4 illustrates examples of slim synchronization signal transmission and SSB transmission.

[0012] FIG. 5 illustrates an example of PSS, SSS and PBCH confined to 11 PRBs (R-15 PSS / SSS length) with additional PBCH symbols where the left hand side has 44 PRBS for PBCH and the right hand side has 55 PRBs for PBCH.

[0013] FIG. 6 illustrates an example of PSS, SSS and PBCH confined to 11 PRBs (R-15 PSS / SSS length) with additional (N) PBCH symbols.

[0014] FIG. 7 illustrates an example 2 Symbol SSB structure with PSS / SSS stacked with PBCH.

[0015] FIG. 8 illustrates an example of Time-Frequency Compact Structure with 1 Instance only SS, 1 instance only PBCH.

[0016] FIG. 9 illustrate example 1 SSB-3SS based transmissions.

[0017] FIG. 10 illustrates example 1 SSB-2SS based transmissions.

[0018] FIG. 11 illustrates an example Sync Design with TDM structure for SSB and PSS / SS.

[0019] FIG. 12 illustrates example designs for different SS lengths and periodicities.

[0020] FIG. 13 illustrates an example compact MSI Structure with separate encoding for PBCH and compact SIB-1.

[0021] FIG. 14 illustrates an example compact MSI Structure with separate encoding for PBCH and RMSI plus Smaller Freq Footprint.

[0022] FIG. 15 illustrates an example compact MSI Structure with Joint encoding for PBCH and compact SIB-1 .

[0023] FIG. 16 illustrates an example compact MSI Structure with Joint encoding for PBCH and compact SIB-1DETAILED DESCRIPTION

[0024] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 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, filter bank multicarrier (FBMC), and the like.

[0025] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a ON 106 / 115, a public switched telephone network (PSTN) 108, the Internet 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 may 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 may be referred to as a “station” and / or a “ST A”, may be configured to transmit 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 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 may be interchangeably referred to as a UE.

[0026] The communications systems 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 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 may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, 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 may include any number of interconnected base stations and / or network elements.

[0027] The base station 114a may be part of the RAN 104 / 113, which may 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 may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the 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 transmit and / or receive signals in desired spatial directions.

[0028] 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).

[0029] More specifically, as noted above, the communications system 100 may be a multiple access system and may 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 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). 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).

[0030] 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), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0031] 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).

[0032] 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 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 may 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 gNB).

[0033] 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), GSM EDGE (GERAN), and the like.

[0034] The base station 114b in FIG. 1 A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may 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 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 mayimplement 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 femtocell. As shown in FIG. 1 A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0035] 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 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 may 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 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 be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0036] The CN 106 / 115 may 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 may include circuit- switched telephone networks that provide 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), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications 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.

[0037] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications 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 over different wireless links). For example, the WTRU 102c shown in FIG. 1A 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.

[0038] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may 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 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0039] 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 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 may 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 may be coupled to the transceiver 120, which may 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 may be integrated together in an electronic package or chip.

[0040] The transmit / receive element 122 may 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 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may 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 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0041] Although the transmit / receive element 122 is depicted in FIG. 1 B as a single element, 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.

[0042] The transceiver 120 may 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 may have multi-mode capabilities. Thus, the transceiver120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11 , for example.

[0043] The processor 118 of the WTRU 102 may be coupled to, and may 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 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 the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), 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, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may 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).

[0044] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the 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, and the like.

[0045] 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 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 that the WTRU 102 may acquire location information by way of any suitable locationdetermination method while remaining consistent with an embodiment.

[0046] The processor 118 may further be coupled to other peripherals 138, which may 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 may 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 may include one or more sensors, the sensors may be one or more of a gyroscope, anaccelerometer, 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.

[0047] The WTRU 102 may 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) may be concurrent and / or simultaneous. The full duplex radio may 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 WRTU 102 may 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)).

[0048] 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 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.

[0049] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-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 eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0050] Each of the eNode-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, scheduling of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0051] The CN 106 shown in FIG. 1 C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0052] The MME 162 may be connected to each of the eNode-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, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 mayprovide 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.

[0053] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the 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 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.

[0054] 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.

[0055] 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 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 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0056] Although the WTRU is described in FIGS. 1 A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0057] In representative embodiments, the other network 112 may be a WLAN.

[0058] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may 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 may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11 z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) modemay not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad-hoc” mode of communication.

[0059] When using the 802.11 ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may 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) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every 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.

[0060] High Throughput (HT) STAs may 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.

[0061] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0062] Sub 1 GHz modes of operation are supported by 802.11 af 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, and 802.11 ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah 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 may support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for)certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0063] WLAN systems, which may 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 may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest 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, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may 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 may 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 may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0064] In the United States, the available frequency bands, which may 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, the 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.

[0065] 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 may employ an 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.

[0066] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit 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, the gNB 180a may transmit multiple component carriers to the 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, the 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).

[0067] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the 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 gNBs 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).

[0068] 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 the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 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 may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0069] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may 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 gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0070] The CN 115 shown in FIG. 1 D may 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 may be owned and / or operated by an entity other than the CN operator.

[0071] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may 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 may 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 may 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 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.

[0072] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernetbased, and the like.

[0073] 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, providing mobility anchoring, and the like.

[0074] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may 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 may 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.

[0075] In view of Figures 1A-1 D, 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, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0076] The emulation devices may 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 may 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 may 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 may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0077] The one or more emulation devices may 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 may 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 may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0078] Systems, methods, and instrumentalities are described herein for acquiring synchronization and system information in energy saving networks associated with slim sync leading to WUS and WUS leading to SSB measurements. A wireless transmit / receive unit (WTRU) sync acquisition may start by detecting a synchronization signal (SS). The WTRU may determine timing and / or resource information for pre-sync or DL-WUS style signal(s), for example, based on the slim sync indication. Pre-sync or WUS signaling may provide an indication for network energy savings (NES) configuration information and timing for system information.

[0079] The WTRU may receive a first signal. The first signal may include a slim SS. The slim SS may be a compressed SS. The first signal may indicate information associated with a second signal. The second signal may include a pre-synchronization signal (e.g., wake-up signal (WUS), downlink WUS (DL-WUS)). The information associated with the second signal may be indicated based on one or more properties orcharacteristics associated with the slim SS (e.g., timing information, frequency information, phase information, sequence choice information). The first signal may indicate a slim sequence that may indicate information associated with the second signal. The first signal may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or a PSS and an SSS (e.g., only a PSS and an SSS). In examples, the first signal may refrain from including a physical broadcast channel (PBCH) block. The WTRU may determine a resource associated with reception of the second signal (e.g., pre-synchronization signal; WUS; DL-WUS), for example, based on the information associated with the second signal (e.g., indicated by the first signal). The WTRU may receive the second signal, for example, via the resource determined using the information associated with the second signal. The second signal may include an indication associated with reception of an SSB. The SSB may include a PBCH block. The WTRU may determine information associated with reception of the SSB, for example, based on the indication associated with the reception of the SSB (e.g., indicated by the second signal). The information associated with receiving the SSB may include one or more of the following: an NES state, an SSB periodicity, a presence of a full SSB on a potential full SSB transmission occasion, etc. The WTRU may receive the SSB, for example, based on the determined information associated with reception of the SSB.

[0080] The WTRU may receive a synchronization signal (SS). The SS may be a slim SS (e.g., a compressed SS). The SS may indicate a pre-synchronization signal. The SS may include a primary SS or a secondary SS or a primary SS and a secondary SS. The WTRU may determine pre-synchronization signal information (e.g., timing and / or resource information) associated with the pre-synchronization signal, for example, based on a characteristic associated with the SS. The WTRU may receive the presynchronization signal based on the pre-synchronization signal information. The WTRU may determine SS and physical broadcast channel block (SSB) information, for example, based on the pre-synchronization signal. The WTRU may receive an SSB based on the SSB information. The WTRU may determine system information block information. The WTRU may determine random access channel (RACH) parameters, for example, based on the system information block information.

[0081] Network energy savings (NES) procedures may be used and / or enabled. Enhancements enabling the network to minimize its power consumption from transmission and reception may be provided. Such minimization may be beneficial for reducing operational costs and environmental sustainability.

[0082] An NES design may be (e.g., very) efficient from the perspective of minimizing transmissions from the network when there is no data (e.g., compared to earlier systems). For example, an always-on cell-specific reference signal (CRS) may be refrained from being used (e.g., not used). However, energy consumption may be reduced (e.g., there may be still potential for energy consumption reduction).

[0083] For example, the network may still consume energy when refraining from transmitting (e.g., not transmitting) from other activities such as baseband (e.g., digital) processing for reception or beamforming. Such idle power consumption may not be negligible in dense networks, for example, even if (e.g., when no WTRU is served during a given period. If the network could turn off these activities when not transmitting to a WTRU, energy consumption could be reduced.

[0084] Transmission of always-on synch signals (e.g., sync signals or synchronization signals) or reference signals may be refrained from being used (e.g., may not be needed). Adaptable bandwidth and MIMO capabilities may be supported. Adaptation of network resources may enable greater efficiency.

[0085] The following terminology may be used.

[0086] Channel state information (CSI) may include at least one of the following: channel quality index (CQI), rank indicator (Rl), precoding matrix index (PMI), an L1 channel measurement (e.g., reference signal received power (RSRP) such as L1-RSRP, or SINR), CSI-RS resource indicator (CRI), synchronization signal (SS)Zphysical broadcast channel (PBCH) block resource indicator (SSBRI), layer indicator (LI), and / or any other measurement quantity measured by the WTRU from the configured CSI-RS or SS / PBCH block. A WTRU may report a subset of channel state information (CSI) components, where CSI components may correspond to at least a CSI-RS resource indicator (CRI), a SSB resource indicator (SSBRI), an indication of a panel used for reception at the WTRU (such as a panel identity or group identity), measurements such as L1 -RSRP, L1-SINR taken from SSB or CSI-RS (e.g. cri-RSRP, cri-SINR, ssb-lndex-RSRP, ssb-lndex-SINR), and / or other channel state information such as at least rank indicator (Rl), channel quality indicator (CQI), precoding matrix indicator (PMI), Layer Index (LI), and / or the like.

[0087] Uplink control information (UCI) may include one or more of CSI, HARQ feedback for one or more HARQ processes, a scheduling request (SR), a link recovery request (LRR), CG-UCI and / or other control information bits that may be transmitted on the PUCCH or PUSCH.

[0088] Channel conditions may include (e.g., any) conditions relating to the state of the radio / channel, which may be determined by the WTRU from one or more of a WTRU measurement (e.g., L1 / SINR / RSRP, CQI / MCS, channel occupancy, received signal strength indicator (RSSI), power headroom, exposure headroom), L3 / mobility-based measurements (e.g. RSRP, RSRQ, s-measure), an radio link monitoring (RLM) state, and / or channel availability in unlicensed spectrum (e.g., whether the channel is occupied based on determination of an LBT procedure or whether the channel is deemed to have experienced a consistent LBT failure).

[0089] A physical random access channel (PRACH) resource (e.g., in frequency), a PRACH occasion (RO) (e.g., in time), a preamble format (e.g., in terms of total preamble duration, sequence length, guardtime duration and / or in terms of length of cyclic prefix) and / or a certain preamble sequence may be used for the transmission of a preamble in a random access procedure.

[0090] A property of scheduling information (e.g., an uplink grant or a downlink assignment) may include one or more of the following: a frequency allocation; an aspect of time allocation, such as a duration; a priority; a modulation and coding scheme; a transport block size; a number of spatial layers; a number of transport blocks to be carried; a transmission configuration indication (TCI) state or sounding reference signal resource indicator (SRI); a number of repetitions; whether the grant is a configured grant type 1 , type 2 or a dynamic grant; etc.

[0091] An indication by downlink control information (DCI) (e.g., or an indication) may include one or more of the following: an explicit indication by a DCI field or by a radio network temporary identifier (RNTI) (e.g., used to mask cyclic redundancy check (CRC) of the PDCCH); an implicit indication by a property (e.g., such as DCI format, DCI size, Coreset or search space, aggregation level, identity of first control channel resource (e.g., index of first control channel element (CCE)) for a DCI, where the mapping between the property and the value may be signaled by RRC or MAC); an explicit indication by a DL MAC CE; etc.

[0092] The terms network availability state, cell turned off, cell DTX mode / configuration, or NES state may be used interchangeably. The WTRU may determine a cell DTX / DRX state implicitly from a determined active availability state, and visa-versa.

[0093] Hereinafter, ‘a’ and ‘an’ and similar phrases are to be interpreted as ‘one or more’ and ‘at least one’. Similarly, any term which ends with the suffix ‘(s)’ is to be interpreted as ‘one or more’ and ‘at least one’. The term ‘may’ is to be interpreted as ‘may, for example’.

[0094] A symbol ‘I’ (e.g., forward slash) may be used herein to represent ‘and / or’, where for example, ‘A / B’ may imply ‘A and / or B’.

[0095] A beam may be defined.

[0096] A WTRU may transmit or receive a physical channel or reference signal, for example, according to at least one spatial domain filter. The term beam may be used to refer to a spatial domain filter.

[0097] The WTRU may transmit a physical channel or signal using the same spatial domain filter as the spatial domain filter used for receiving an RS (e.g., such as CSI-RS) or an SS block. The WTRU transmission may be referred to as a target. The received RS or SS block may be referred to as reference or source. In such case, the WTRU may (e.g., be said to) transmit the target physical channel or signal according to a spatial relation with a reference to such RS or SS block.

[0098] The WTRU may transmit a first physical channel or signal according to the same spatial domain filter as the spatial domain filter used for transmitting a second physical channel or signal. The first and second transmissions may be referred to as target and reference (e.g., source), respectively. In such case, the WTRU may (e.g., be said to) transmit the first (e.g., target) physical channel or signal according to a spatial relation with a reference to the second (e.g., reference) physical channel or signal.

[0099] A spatial relation may be implicit or signaled (e.g., configured by RRC signaling, or signaled by MAC CE or DCI). For example, a WTRU may implicitly transmit a PUSCH transmission and DM-RS of a PUSCH according to the same spatial domain filter as an SRS indicated by an SRI indicated in DCI or configured by RRC. In examples, a spatial relation may be configured (e.g., via RRC signaling) for an SRS resource indicator (SRI) or signaled (e.g., by MAC CE) for a PUCCH. Such spatial relation may also be referred to as a beam indication.

[0100] The WTRU may receive a first (e.g., target) downlink channel or signal according to the same spatial domain filter or spatial reception parameter as a second (e.g., reference) downlink channel or signal. For example, such association may exist between a physical channel such as PDCCH or PDSCH and its respective DM-RS. If (e.g., at least when) the first and second signals are reference signals, such association may exist if (e.g., when) the WTRU is configured with a quasi-colocation (QCL) assumption type D between corresponding antenna ports. Such association may be configured as a TCI (transmission configuration indicator) state. A WTRU may receive an indication (e.g., be indicated) an association between a CSI-RS or SS block and a DM-RS by an index to a set of TCI states (e.g., configured by RRC signaling and / or signaled by MAC CE). Such indication may also be referred to as a beam indication.

[0101] Herein, an SSB may refer to one or more SSB beam (e.g., spatial relation) within a collection of SSBs (e.g., SSB burst). An SSB may refer to a beam and visa-versa or a CSI-RS resource related to the beam. SSB, SSBs, and / or SSB burst may refer to one or more beams transmitted from a transmission and reception point (TRP).

[0102] A TRP may be interchangeably used with one or more of a transmission point (TP), a reception point (RP), a radio remote head (RRP), a distributed antenna (DA), a base station (BS), a sector (e.g., of a BS), and / or a cell (e.g., a geographical cell area served by a BS). Multi-TRP may be interchangeably used with one or more of MTRP, M-TRP, and multiple TRPs.

[0103] Cell discontinuous transmission (DTX) and cell discontinuous reception (DRX) may be performed and / or enabled.

[0104] The BS (e.g., gNB) may use reduced downlink transmission / uplink reception activity without a cell DTX / DRX pattern (e.g., an explicit cell DTX / DRX pattern) with restrictions, for example, due to WTRU DRX configurations and any configured transmission / reception (e.g., common channels / signals). C-DRXmay be configured per WTRU. The alignment of the DRX cycles or offsets for different WTRUs may be be done (e.g., only done) via RRC. During an WTRU DRX off (e.g., inactive) period, the WTRU may not expect to monitor a PDCCH, but the WTRU may (e.g., be allowed to) initiate UL transmission according to the configured resources (e.g., using PUCCH, RACH, SR, or CG-PUSCH). Aligning / Omitting of DRX patterns across multiple WTRUs can be achieved, for example, via gNB implementation.

[0105] Cell DTX / DRX may provide (e.g., aim at providing) mechanisms informing the WTRU whether the cell stays inactive. This may include enhancements to WTRU DRX configuration (e.g., to align / omit DRX cycles or start offsets of DRX) for WTRUs in connected mode or idle / inactive mode, which may allow longer opportunities for cell inactivity. During a cell DTX / DRX, the cell may have no transmission / reception or (e.g., only) keep limited transmission / reception. For example, the cell may refrain from transmitting or receiving (e.g., does not need to transmit or receive) some periodic signals / channels (e.g., such as common channels / signals or WTRU specific signals / channels).

[0106] Cell DTX / DRX may be applied to at least WTRUs in an RRC_CONNECTED state. A periodic Cell DTX / DRX (e.g., active and non-active periods) can be configured by gNB via WTRU-specific RRC signaling per serving cell. Cell DTX / DRX mode can be activated / de-activated via dynamic L1 / L2 signalling and WTRU-specific RRC signaling. WTRU specific and / or common L1 / L2 signalling can be considered for activating / deactivating the Cell DTX / DRX mode. Cell DTX and Cell DRX modes can be configured and operated separately (e.g., one RRC configuration set for DL and another for UL). Cell DTX / DRX can also be configured and operated together. One or more of the following parameters can be configured per Cell DTX / DRX configuration: periodicity, start slot / offset, on duration; etc. In examples, Cell DTX indication may be part of SI update or SIB signaling. There may be a common time for (e.g., all) WTRUs to determine cell DTX status.

[0107] The WTRU may be configured with multiple cell DRX and / or cell DTX configuration information (e.g., simultaneously in a given serving cell). The WTRU may be configured with a primary or a default cell DTX and / or cell DRX configuration, which the WTRU may apply by default. Based on reception of signaling activating one cell DTX and / or cell DRX configuration, the WTRU may deactivate another one (e.g., or all other ones). Based on reception of signaling deactivating one cell DTX and / or cell DRX configuration, the WTRU may activate another one or activate a default cell DTX / DRX configuration. Based on a determination that a duration has elapsed (e.g., expiry of a timer), the WTRU may fallback to the default cell DRX and / or cell DTX configuration. The WTRU may reset such duration (e.g., via a timer), for example, based on reception of DL signaling or data or an indication from the NW to remain in a given non-default cell DTX or cell DRX state.

[0108] Network Availability States, Cell DTX mode, and / or NES states may be considered and / or used.

[0109] An NES state or an availability state may refer to a cell state in which the cell or TRP has activated at least one NES technique. An NES technique may include one or more of the following: cell DTX, cell DRX, spatial domain adaptation (e.g., where a subset of antenna ports and / or elements are turned off), power domain adaptation (e.g., where a subset of channels are transmitted with reduced power or muted), and / or the cell or TRP has turned off.

[0110] The WTRU may determine whether it can transmit or receive on certain resources, for example, depending on a network availability state (e.g., which may imply the gNB’s power savings status). An availability state may correspond to a network energy savings state, a cell DTX mode, a cell DRX mode, and / or a gNB activity level. An availability state can be uplink or downlink specific, and may change from symbol to symbol, slot to slot, frame to frame, or on longer duration granularity. The availability state may be determined by the WTRU or indicated by the network. An availability state can be, for example, one or more of the following: “On”, “DL and UL active”, “UL only active”, “off”, “reduced Tx power”, “dormant”, “micro sleep”, “light sleep”, or “deep sleep”. Such states can be abstracted by NW configuration parameters and / or values. A dynamic indication may point to the active availability state (e.g., by DCI or MAC CE signaling). The “Off” availability state may imply that the gNB’s baseband hardware is completely turned off. The “sleep” availability state may imply that the gNB wakes up periodically to transmit certain signals (e.g., presence signals, synchronization, or reference signals) or receive certain UL signals. In some availability states, some DL or UL resources may not be available during certain periods of time, and this may enable the network to turn off baseband processing and other activities. For example, the WTRU may be configured (e.g., by RRC signaling) with periodic Active and Inactive periods per availability. Some measurement resources (e.g., SSBs or CSI-RS) may (e.g., only) be made available in certain availability states, such as, for example, RLM, BFD, RRM measurements, CSI-RS feedback configuration, and / or a different power offset for CSI feedback.

[0111] The WTRU may transmit (e.g., based on a fulfilled condition) a request to the network (e.g., wake-up request), for example, to modify the availability state to a state for which resources that may satisfy WTRU requirements are available.

[0112] The WTRU may determine an availability state from reception of an availability state indication (e.g., by L1 / L2 signaling (e.g., a group common DCI or indication)) or implicitly determine it from the reception of periodic DL signaling or lack thereof.

[0113] The WTRU may determine if a resource is available for transmission / reception and / or measurements for the determined network availability state (e.g., if it is applicable in the active availability state). The WTRU may adapt its active C-DRX cycle, active spatial elements (e.g., antenna or logical ports), active TRPs, paging occasions as a function of the signaled, or determined availability state. TheWTRU may be configured with one or more sets of NES transmission and / or reception parameters per availability state, e.g., by broadcast or dedicated configuration signaling. The WTRU may apply the NES parameter set according to the determined or signaled availability state. The WTRU may apply one or more applicable configurations depending on the determined NES state. A set of NES parameters may include one or more of the following: a number of antenna ports, a C-DRX configuration, a measurement configuration (e.g. for RRM, RLM, and / or BFD), CSI feedback, a CSI-RS configuration, an SSB configuration, CHO or mobility candidates, a set of active TRPs, etc.

[0114] An availability state may be applicable to at least one transmission, reception, or measurement resource. An availability state may be applicable to at least one time period, for example, such as a time slot or time symbol. An availability state may be applicable to a serving cell, a cell group, a frequency band, a bandwidth part, a TRP, a set of spatial elements, or a range of frequencies within a bandwidth part. For example, if (e.g., when) an NES state changes in a cell, the WTRU may receive an availability state change indication that may indicate that this change is just for that cell, for all cells at the same frequency, and / or same RAT.

[0115] The WTRU may consider the active availability state associated with a cell, carrier, TRP, or frequency band to be “Off’, “Deep sleep”, or “Micro sleep”, for example, after reception of a DL signaling that changes the cell’s or TRP’s availability state. For example, the WTRU may receive a turn off command on broadcast signaling, RRC signaling, DCI (e.g., a group common DCI), or a DL MAC CE (e.g. indication part of PDSCH). The WTRU may determine an availability state based on (e.g., from) reception of availability state indication from e.g., by L1 / L2 signaling (e.g., a group common DCI or indication) or broadcast signaling associated with an availability state.

[0116] For example, an availability state change indication may be part of an SI update or an SIB signaling (e.g., in a separate SIB that is not read by WTRUs). There may be a common time for WTRUs (e.g., all WTRUs) in the cell to determine availability state status.

[0117] The WTRU may determine a change of NES state change from the reception of a group common command L1 signaling (e.g., a group common DCI, a multi-stage DCI, a specific DCI format, or a DCI scrambled by a configured or specified NES-specific RNTI). L1 signaling may indicate one of the configured NES parameters sets to apply or may determine a delta configuration from the current set of parameters upon determining an NES state change. The WTRU may transmit feedback / acknowledgment to a gNB (e.g., possibly multiplexed with UL data (e.g., part of an UL TB as a MAC CE or a subheader indication)), for example, following the reception of NES state change indication.

[0118] The WTRU may determine a change of NES state from the reception of broadcast signaling associated with NES state indication or change (e.g., including signaling in SIB(s) or part of a broadcast ormulticast PDSCH). The WTRU may be indicated the NES state (e.g., indicated explicitly the NES state) in the SIB. The WTRU may receive configuration information including (e.g., be configured with) one or more SIBs exclusively associated with configuration of NES parameters. The WTRU may receive configuration information (e.g., be configured) to receive such broadcast or multicast indication periodically. The WTRU may determine an indication is mis-detected, for example, if not received on expected periodic occasions, if a number of misdetections is counted, and / or if a time (e.g., via a timer) has elapsed since the last reception of the NES state indication. The WTRU may start inter-cell, inter-frequency, and / or inter-RAT measurements, start a mobility procedure, and / or start evaluating configured CHO candidates, for example, based on (e.g., following) the determination of a misdetection of the NES state indication.

[0119] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) from one or more of the following: reception of a command or signal indicating a change in availability state; reception of a paging message, paging DCI, paging PDSCH, or a paging related signal; the gNB DTX status; lack of detection of a presence indication; based on time in the day; based on the availability state of an associated cell; detection of a PSS (e.g., PSS only) signal or a simplified / stripped down SSB signal; detection of an RS signal or the lack thereof; the WTRU’s RRC state; whether paging has been received (e.g., within a configured time window); whether system information has been received (e.g., within a configured time window); measured channel condition(s) being below or above a threshold; etc.

[0120] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, reception of a command or signal indicating a change in availability state (e.g., a group common DCI in connected mode or RRC signaling or a presence signal). The WTRU may determine an availability state implicitly form the reception of periodic DL signaling. The WTRU may be configured (e.g., receive configuration information indicating) or specified to associate an availability state with one or more DL signal type (e.g., SSB, partial SSB, and / or one or more periodicity).

[0121] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, reception of a paging message, paging DCI, paging PDSCH, or a paging related signal (e.g., PEI), e.g., possibly on a subset of POs (e.g., those aligned with NES DRX cycle or a configured subset of PDCCH resources). The WTRU may assume a certain availability state after reception of an indication part of the DCI or PDCCH scheduling paging (e.g., as a function of the P-RNTI, NES-RNTI or based on receiving an explicit indication, e.g., on a reserved bit). The WTRU may assume a certain availability state after the reception of a paging message with a certain P-RNTI, a separately configured NES P-RNTI, or the NES group RNTI.The WTRU may assume a certain availability state after the reception of a paging message with a certain P-RNTI. The WTRU may be configured with one more PEI subgroup for NES, where a subgroup may be associated with one or more availability state. The WTRU may assume a certain availability state after reception of a PEI with an NES subgroup, for example, if that subgroup is configured and / or associated with the availability state. The indication of the availability state or the availability state switch may be indicated in the paging payload, e.g., as a flag part of the paging message or the short message. Such paging indication may further indicate an alternative cell to monitor paging on while the cell from which the signaling was received is off, sleep, or in NES state. Such paging indication may further indicate or signal applicable reconfiguration parameters (e.g., for initial access, applicable PRACH resources, applicable SSB / RS occasions, applicable SI cycle, and / or the applicable cell(s) and associated availability states).

[0122] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, the gNB DTX status (e.g., whether the gNB is in active time or an associated activity timer is running).

[0123] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, lack of detection of a presence indication, such as, for example, one or more of the following.

[0124] The WTRU may determine an availability state associated with the cell (e.g., “off” or “deep sleep”), for example, if presence indication was not detected on one or more presence indication occasion.

[0125] The WTRU may assume or change the cell’s availability state after a number of consecutive misdetections or after a duration (e.g., timer expires) following no detection of a presence signal. The WTRU may determine an availability state is active or not active (e.g., de-active) after a duration (e.g., expiry of a timer) associated with the availability state. Such duration (e.g., via a timer) can be configured and / or maintained in connected mode (e.g., only), or also in other states (e.g., idle and inactive states).

[0126] The WTRU may determine an availability state implicitly, for example, from the lack of reception of periodic DL signaling (e.g., during a duration). For example, the WTRU may receive configuration information indicating (e.g., be configured with) a signal quality threshold (e.g., an RSRP threshold). If the WTRU does not detect a signal associated with an availability state (e.g., a presence signal or an SSB) with a signal strength above the threshold, the WTRU may assume that this availability state is not active and may assume a different availability state. This criterion can be also coupled with lack of detection of an identifying sequence of the presence signal (e.g., detection of the PSS sequence for example).

[0127] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, based on time in the day. The WTRU may receive configuration information indicating (e.g., be configured) to (e.g.,automatically) assume a certain availability state (e.g., off, sleep, or dormant) for a configured subset of cells (e.g., capacity boosting cells) depending on the time in the day. For example, the WTRU may determine that a capacity boosting cell has an availability state as “On” in certain hours of the day, “Deep sleep” in other configured hours, and “Off” in a third set of configured hours of the day or night.

[0128] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, based on the availability state of an associated cell (e.g., another carrier of the same MAC entity, another carrier in the same cell group, another carrier in the same gNB, another sector in the same gNB, or a configured associated cell or capacity boosting cell).

[0129] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, etection of a PSS only signal or a simplified / stripped down SSB signal.

[0130] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, detection of an RS signal (e.g., CSI-RS, PRS, TRS) or the lack thereof.

[0131] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, the WTRU’s RRC state (e.g., Idle, inactive, or connected mode).

[0132] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, whether paging has been received (e.g., possibly within a configured time window).

[0133] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, whether system information (e.g., periodic SI or a subset of SIBs) have been received (e.g., possibly within a configured time window).

[0134] The WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., “Off, “deep sleep”, “micro sleep” or dormant”) based on, for example, measured channel condition(s) being below or a above a threshold. The WTRU may assume a change of NES state based on a change of measured channel conditions or making a channel measurement below or above a threshold. For example, the WTRU may use degradation in measurements of SSBs or CSI-RS (e.g., possibly in combination with other signaling) to determine the NES state. For example, a configured window following the DCI reception can be used to measure SSBs and / or CSI-RS for degradation. If a delta of SSB-RSRP drop is measured the WTRU may determine that the NES state has changed andassume associated actions for such NES state (e.g., trigger for CHO candidate selection or for group scheduling for a mobility command).

[0135] The WTRU may receive configuration information (e.g., be configured) to monitor an indication that may characterize the level of network activity (e.g., an availability state). The network activity may be associated with a gNB and / or a cell. The WTRU may assume the same availability state for all cells part of the same gNB, e.g., cells of the same MAC entity. The network activity indication (e.g., the presence indication) may include a channel (e.g., a PDCCH) and / or a signal (e.g., a sequence). The activity indication or the NES state change indication / command may indicate the level of activity the WTRU may expect from the associated gNB and / or cell, e.g., reduced activity. The activity indication may contain activity information of other gNBs / cells. The activity indication may be a PDCCH containing group common signaling. For example, the NW may transmit a group common DCI to a group of WTRUs (e.g. WTRUs in the serving cell) indicating a change of an activity state or activity level in UL and / or DL. The CRC of the PDCCH may be scrambled with a dedicated activity indication RNTI or an NES-RNTI. A WTRU may be configured with at least one search space associated with the monitoring occasions of the activity indication PDCCH. The indication may include a go-to-sleep signal, e.g., a predefined sequence. If (e.g., when) the WTRU detects this sequence, the WTRU may expect a reduced activity level over a specific time duration. The WTRU may activate C-DRX for the period of time indicated. Multiple (e.g., two) sequences may be used to indicate regular activity and reduced activity.

[0136] The signaling within the PDCCH or the activity indication may include (e.g., contain) one or more of the following.

[0137] The signaling within the PDCCH or the activity indication may include (e.g., contain) an expected activity level of the associated gNBs / cells over a specific time interval (e.g., an availability state). The activity levels may be predetermined and / or configured and may, for example, include regular and reduced activity. The signaling may indicate the activity level. For example, bit “1” may indicate regular activity and bit "0" may indicate reduced activity.

[0138] The signaling within the PDCCH or the activity indication may include (e.g., contain) transmission and / or reception attributes for each activity level (e.g. availability state) (e.g., transmission and reception attributes may be defined). For example, during reduced activity, WTRU may refrain from monitoring (e.g., not be expected to monitor) certain PDCCH search spaces (e.g., including all SSs), and / or receive a certain type of PDSCH transmission (e.g., including all PDSCH transmission), and / or transmit PUCCH / PUSCH transmissions, and / or perform certain measurements. The WTRU may start or stop monitoring PDCCH and / or TCI states associated with determined NES state, including PDCCH resources or TCI states associated with (de)activated TRPs or spatial elements.

[0139] The signaling within the PDCCH or the activity indication may include (e.g., contain) a set of configurations that may be associated with an activity level and may be used / applied when that activity level is indicated (e.g., an NES parameter set), such as, for example, SS configurations, CSI reporting configurations, indices of transmitted SSBs, etc. Each set of configurations may have an attribute associated with an activity level, such as, for example, a tag that can be set to “reduced activity”.

[0140] The time interval over which an activity level may be assumed may be signaled in the PDCCH transmission or part of the activity indication. The time interval may be indicated using a bitmap, for example, where each bit in the bitmap may be associated with a specific duration, e.g., a slot or a frame. For example, bit “1” may indicate regular activity and bit “0” may indicate reduced activity on an associated frame. The time interval may be indicated with a start time and length of interval. The start time may be defined. For example, it may be determined by adding a fixed offset to the time the indication is received. The length of the interval may be configured or signaled in the indication PDCCH transmission.

[0141] The time interval over which an activity level is assumed may be predetermined. The WTRU may assume an interruption delay (e.g., a time until the NES state changes) after the NES state change command reception (e.g., after the last symbol or slot on which the command was received). The interruption time can be in absolute time, a number of symbols, or a number of slots.

[0142] The WTRU may determine that an uplink or downlink resource or signal is available for transmission / reception and / or measurements for the determined network availability state, for example, if it is applicable in the active availability state. The WTRU may determine that a subset of measurement resources and / or signals (e.g., SSBs, CSI-RS, TRS, PRS) are not applicable in certain availability states. The WTRU may determine that a subset of uplink or downlink resources (e.g., PRACH, PUSCH, PUCCH) are not applicable in certain availability states. The WTRU may transmit some uplink signals (e.g., only) in a subset of NW availability states (e.g., SRS, pSRS, PRACH, UCI).

[0143] Synchronization signals and procedures may be enabled and / or provided.

[0144] Downlink synchronization may be performed.

[0145] Downlink synchronization may include a WTRU detecting the radio frame boundary (e.g.,, the exact timing when a radio frame starts) and OFDM symbol boundary (e.g., the exact timing when an OFDM symbol starts). This process may be done by detecting and analyzing synchronization signal block (SSB).

[0146] The synchronization signal block and / or PBCH block may include primary and secondary synchronization signals (PSS, SSS), for example, that may occupy (e.g., each occupy) 1 symbol and 127 subcarriers, and the PBCH may span across 3 OFDM symbols and 240 subcarriers, but on one symbol leaving an unused part in the middle for SSS as shown in FIG. 2. The possible time locations of SSBs within a half-frame may be determined by sub-carrier spacing and the periodicity of the half-frames whereSSBs are transmitted may be indicated (e.g., configured) by the network. During a half-frame, different SSBs may be transmitted in different spatial directions (e.g., using different beams, spanning the coverage area of a cell).

[0147] Within the frequency span of a carrier, multiple SSBs may be transmitted. The physical cell identities (PCIs) of SSBs transmitted in different frequency locations may not be unique (e.g., do not have to be unique), for example, different SSBs in the frequency domain can have different PCIs. However, if (e.g., when) an SSB is associated with an RMSI, the SSB may be referred to as a Cell-Defining SSB (CD- SSB). A PCell may be associated to a CD-SSB located on the synchronization raster.

[0148] FIG. 2 illustrates an example time-frequency structure of a SSB.

[0149] Polar coding may be used for a PBCH.

[0150] The WTRU may assume a band-specific sub-carrier spacing for the SSB, for example, unless a network has configured the WTRU to assume a different sub-carrier spacing.

[0151] PBCH transmission symbols may carry their own frequency multiplexed DMRS.

[0152] Quadrature phase shift keying (QPSK) modulation may be used for a PBCH transmission.

[0153] Cell search may be performed and / or enabled.

[0154] Cell search may include where a WTRU acquires time and frequency synchronization with a cell and detects the Cell ID of that cell. Cell search may be based on the primary and secondary synchronization signals, and PBCH DMRS, located on the synchronization raster.System Information (SI) may be divided into the master information block (MIB) and a number of system information blocks (SIBs). The MIB may be (e.g., always) transmitted on the BCH (e.g., with a periodicity of 80 ms and repetitions made within 80 ms) and may include parameters that may be used (e.g., needed) to acquire SIB1 from the cell. The SIB1 may be transmitted on the DL-SCH (e.g., with a periodicity of 160 ms and variable transmission repetition). The default transmission repetition periodicity of SIB1 may be 20 ms. The (e.g., actual) transmission repetition periodicity may be determined by the network (e.g., up to network implementation).

[0155] A MIB and / or a SIB1 may make up the minimum system information (MSI) used (e.g., required) to operate on a cell.

[0156] For SSB and CORESET multiplexing pattern 1, SIB1 repetition transmission period may be 20 ms. For SSB and CORESET multiplexing pattern 2 / 3, SIB1 transmission repetition period may be the same as the SSB period. SIB1 may include information regarding the availability and scheduling (e.g., mapping of SIBs to SI message, periodicity, Sl-window size) of other SIBs with an indication whether one or more SIBsare only provided on demand (e.g., and, in that case, the configuration used by the WTRU to perform the SI request). SIB1 may be a cell-specific SIB.

[0157] SI B1 may be received.

[0158] The Master Information Block (MIB) on a PBCH transmission may provide the WTRU with parameters (e.g. CORESET#0 configuration information) for monitoring of a PDCCH for scheduling PDSCH transmission(s) that carry the System Information Block 1 (SIB1). A PBCH transmission may also indicate that there is no associated SIB1 , for example, in which case the WTRU may be pointed to another frequency from where to search for an SSB that is associated with a SIB1 as well as a frequency range where the WTRU may assume no SSB associated with SIB1 is present. The indicated frequency range may be confined within a contiguous spectrum allocation of the same operator in which SSB is detected.

[0159] SSB indexing and SSB Burst may be performed and / or enabled.

[0160] A (e.g., each) SSB within an SSB burst set (e.g., all of the SSBs within the 5 ms period of the SSB transmission) may be assigned with a unique number (e.g., starting from 0 and increasing by 1). This number may reset to 0 in the next SSB burst set (e.g., next 5 ms span after SSB transmission cycle (e.g., after the default cycle of 20 ms). This unique number (e.g., SSB Index) may be indicated (e.g., informed) to the WTRU via PBCH DMRS and via a PBCH payload. The candidate SSBs in a half frame may be indexed in an ascending order in time (e.g., from 0 to L-1). A WTRU may determine the 2 LSB bits, for L = 4, or the 3 LSB bits, for L > 4 , of a SSB index per half frame from a one-to-one mapping with an index of the DMRS sequence transmitted in the PBCH. For L = 64 . The WTRU may determine the 3 MSB bits of the SS / PBCH block index per half frame by PBCH payload bits.

[0161] FIG. 3 illustrates an example SSB burst with a periodicity of 20 ms. FIG. 3 further illustrates an example of SSB Beam Sweeping within SSB Burst Sets.

[0162] Network energy consumption may occur with SSB transmissions.

[0163] Networks may consume (e.g., be consuming) energy (e.g., unnecessary energy) in transmitting SSBs, for example, if (e.g., when) it may not be necessary (e.g., particularly in low load scenarios where the network may be able to save some energy if it does not transmit SSBs according to fixed patterns and periodicities). This may be aggravated if (e.g., when) the network is employing a large number of beams. SSBs may be (e.g., need to be) sweeped in (e.g., all) beams along with necessary system information, for example, if the network is employing a large number of beams.

[0164] SSB periodic broadcast requirements may limit (e.g., may not allow) the gNBs to sleep for longer intervals.

[0165] The gNB may refrain from using (e.g., not use) longer sleep cycles for its Tx and power amplifier (e.g., which may consume considerable energy), for example, if the cells / TRPs transmit (e.g., have to transmit) SSBs with fixed patterns and periodicities. This situation may be bad if (e.g., when) the network traffic may allow longer sleep cycles but the network has to keep the Tx and PA up and running to comply with the SSB patterns and periodicities.

[0166] SSB and SIB-1 fixed broadcast periodic transmissions may use (e.g., require) gNBs longer wakeup, for example, even if (e.g., when) there is no / minimal traffic.

[0167] System information transmission and acquisition may follow fixed deterministic pattern(s) for SSB and SIB-1 . These patterns may simplify the system information acquisition for the WTRUs (e.g., after the power up). The patterns may result in a burden (e.g., significant burden) in network energy consumption and / or a hurdle to have sufficiently long DTx for the gNBs.

[0168] System information acquisition may use WTRU power consumption.

[0169] SSB and SIB-1 transmission patterns may use (e.g., require) WTRUs longer time to get the minimum system information. In some cases, the WTRUs may have (e.g., partial) information already probably provided by other cells but they may (e.g., need to) acquire the system information from the cell.

[0170] Longer cell Search Time for Wideband Carriers may be enabled and / or provided.

[0171] The network may (e.g., be allowed to) transmit SSB on a (e.g., any) frequency span of the carrier. This flexibility may be beneficial for network scheduling and operation. Wideband carriers and the flexible SSB transmission location in frequency domain may make the initial cell search very long for a WTRU. As the carrier bandwidths can be extremely large in FR2 and sub-GHz bands, the time to locate / detect SSB (e.g., which may be a small fraction of the carrier bandwidth in the frequency domain) can take considerable time which may add negatively to the user experience.

[0172] Slim sync signal reception may lead to monitoring for and / or reception of a pre-synchronization signal (e.g., wake up signal (WUS). The pre-synchronization signal (e.g., WUS) reception may lead to SSB measurement(s) (e.g., reception of an SSB).

[0173] FIG. 4 illustrates examples of slim synchronization signal (e.g., PSS and / or SSS) transmission and SSB transmission.

[0174] WTRU synchronization acquisition may include (e.g., start by) detecting (e.g., receiving) a slim SS (e.g., a first signal, for example, that may include a PSS or a PSS and an SSS), for example, (e.g., as shown in FIG. 4, for example, where rows 2-4 show examples of PSS / SSS transmissions as compared to row 1 that illustrates an example SSB design (e.g., legacy SSB design) where SSB(s) may be transmitted with a given periodicity).

[0175] The WTRU may determine information (e.g., the timing and / or resource information, for example, a resource) for a pre-sync or DL-WUS style signal (e.g., for reception of a second signal, such as a presynchronization signal or DL-WUS style signal). The information may be determined based on the slim sync (SS) indication (e.g., implicit indication, explicit indication).

[0176] Pre-sync or WUS signaling (e.g., the second signal) may provide an indication for reception of a synchronization signal block (SSB), for example, NES configuration information and / or the timing for complete system information.

[0177] A network transmitting slim-sync / pre-sync with a lower power Tx / PA may save power (e.g., additional power).

[0178] A WTRU may receive a slim version of a SS (e.g., a compressed SS). The slim version of the SS may include a PSS (e.g., alone) or a PSS and a SSS (e.g., as shown in FIG. 4, where row 2 illustrates an example where two slim SS (e.g., PSS / SSS) may be transmitted in an SSB period and each slim SS may be associated with a WUS signal, where row 3 illustrates an example where an SSB transmission is followed by a slim SS and associated WUS transmission, and where row 4 illustrates an example slim SS transmission in an extended SSB period).

[0179] The WTRU may decode the slim sync signal (e.g., a first signal). The slim SS may indicate (e.g., a slim sequence associated with the slim SS, such as a PSS and / or an SSS may indicate (e.g., via properties associated with the slim sequence)) a second signal (e.g., a pre-sync signal, for example, a DL- WUS signal).

[0180] The WTRU may determine information associated with the second signal (e.g., a timing and / or a resource for the pre-sync signal, e.g., DL-WUS signal), for example, based on the slim SS indication (e.g., determine a resource associated with reception of the second signal based on the information associated with the second signal indicated by the first signal). The WTRU may determine to receive the second signal on the same frequency or a different frequency based upon the indication received through the first signal. For example, a time, a frequency, a phase, or a sequence choice associated with the slim sync signal may provide the information associated to the second signal (e.g., a pre-sync or DL-WUS signal) explicitly or implicitly. In examples (e.g., with explicit information provisioning), a property (e.g., suitable property) of the slim sync signal may include and / or indicate a mapping to the physical resource or properties of the second signal. For example, a first sequence used in the slim sequence may indicate (e.g., to the WTRU) a first periodicity and a first offset for the second signal transmission. A second sequence (e.g., if used) may indicate a second periodicity and a second offset. In an example design with implicit information provisioning, a property (e.g., slim sequence time resource, a frequency resource, a phase, or a sequence choice) may indicate the active NES state for the cell. The WTRU may have the knowledge of theperiodicities and offsets for the second signal transmission (e.g., through (pre-)configuration or specification) and thus based upon the indicated NES state may determine the information necessary to receive DL-WUS (e.g., resource and configuration etc.).

[0181] The WTRU may receive (e.g., detect) the pre-sync signal (e.g., DL-WUS), for example, based on the information (e.g., timing information, resource information, frequency information, sequency information) associated with the second signal (e.g., as shown in FIG. 4 in rows 2-4) indicated by the first signal (e.g., according to the determined timing and / or frequency resource (e.g., via the determined resource)). The WTRU may decode the pre-sync (e.g., DL-WUS) signal, for example, which may indicate (e.g., provide the WTRU with an indication of) information associated with reception of an SSB (e.g., Cell NES status, the SSB periodicity, and / or the presence of a full SSB on a potential full SSB transmission occasion).

[0182] The WTRU may find and / or receive a SSB, for example, based on the indication indicated by the second signal (e.g., pre-sync signal indication, e.g., DL-WUS signal indication). The WTRU may decode a PBCH transmission associated with the SSB, for example, based on the information determined from the indication indicated by the second signal.

[0183] The WTRU may determine the timing and resource (e.g., information) for a SIB-1 transmission, for example, based on PBCH information (e.g., indicated by the decoded PBCH transmission).

[0184] The WTRU may decode a SIB-1 (e.g., additional system information block(s)) over the determined resource (e.g., based on information indicated in the SSB as shown in FIG. 4). The WTRU may determine RACH parameters (e.g., for a RACH transmission).The WTRU may transmit a RACH preamble (e.g., to a network node) according to the determined RACH parameters, for example, as part of an initial access procedure.

[0185] A WUS signal may provide information and transmission patterns for slim sync signals and / or SSB transmission.

[0186] WTRU sync acquisition may start by receiving WUS signal from the network (e.g., first).

[0187] The WTRU may determine the SSB structure (e.g., structure type, for example, a slim SSB or a full SSB) during a network NES state (e.g., inactive state) based on a property of the received DL-WUS, for example, based on reception of pre-sync sequence (e.g., DL-WUS) indication.

[0188] After detecting / decoding a pre-sync signal (e.g., successful pre-sync signal (e.g., WUS) detection / decoding), the WTRU may determine (e.g., know) the SSB timing, periodicity, transmit power, frequency allocation, the number of SSB beams per burst, and / or the content of the SSB (e.g., PSS, SSS, PBCH, SIB1), for example, at least during the NES sleep cycles, and / or the NES state of the cell.

[0189] Pre-sync (WUS) can be transmitted over multiple frequency spans within a carrier (e.g., for wideband carriers), for example, which may speed up the initial cell search.

[0190] The WTRU may monitor for and receive a DL-signal (e.g., DL-WUS) from the network.

[0191] The WTRU may determine that one or more SSBs (e.g., slim SSBs or full SSBs) are transmitted and / or may be received during an upcoming SSB transmission occasion in a first SSB cycle (e.g., NES cycle), for example, based on reception of the DL-WUS.

[0192] The WTRU may determine an SSB structure type (e.g., slim SSB structure or full SSB structure) to monitor and / or receive during the first SSB cycle, for example, based on at least one property of the received or decoded DL-WUS.

[0193] A property of the DL WUS may include one or more of the following: a modulation type (e.g., OOK vs OFDM), the time or frequency occasion on which the DL-WUS is received, a sequence type (e.g., ZC or M), a sequence index, a channel coding type, or contents of an embedded message.

[0194] SSB structure type may include at least one of the following: time-compressed SSB (e.g., with PBCH / SIB1 multiplexed in frequency domain), power reduced SSB, Narrow-band SSB, an SSB burst with a reduced number of SSB beams per burst, PBCH-less SSB, or an SSB with a 2nd periodicity for the accompanying SIB-1 compared to the 1st SIB-1 periodicity.

[0195] The WTRU may receive an SSB in a transmission occasion of the first SSB cycle, for example, based on the determined SSB structure.

[0196] The WTRU may receive a (e.g., at least one of a) PBCH transmission and / or one or more SIBs, for example, based on reception of the SSB.

[0197] The WTRU may transmit a preamble (e.g., based on the received SSB and information received in the PBCH and / or at least one of the SIBs).

[0198] The WTRU may assume the same SSB structure during the first cycle until another DL-WUS is received.

[0199] The first SSB cycle may be non-deterministic and / or used while the cell is in a NES state.

[0200] A second SSB cycle may be deterministic and / or used when the cell is not in an NES state.

[0201] Compact minimum system Information may be received, signaled, provided, and / or used.

[0202] The network may transmit minimum system information (e.g., compact minimum system information), for example, which may include at least a SSB (e.g., PSS + SSS -HVII B (PBCH block / transmission)) or SI digest.

[0203] SI digest may include {MSI digest (MIB+SIB-1), Other SI digest}.

[0204] SI digest may include a value or a set of values.

[0205] The WTRU may be connected to a serving cell. The serving cell may provide the WTRU with system information of a neighbour Cell Cx and SI digest corresponding to the system information provided to the WTRU (e.g., WTRU may receive SI and / or a first SI digest associated with the neighbor cell). The SI digest may include a value or a set of values.

[0206] The WTRU may perform cell re-selection to the cell Cx (e.g., neighbour cell).

[0207] The WTRU may receive and / or decode a transmission of cell Cx. The transmission associated with cell Cx may include a C-MSI of the cell Cx. The WTRU may determine a SI digest (e.g., second SI digest) from the C-MSI.

[0208] The C-MSI may include an SSB (e.g., PSS, SSS, PBCH block / transmission) and / or an SI digest.

[0209] CMSI may include SI digest and at least one of a PSS, a SSS, a PBCH block.

[0210] The WTRU may compare the SI digest to validate if it matches the stored SI digest (e.g., determine whether the first SI digest received from the serving cell matches the second SI digest indicated by the transmission received from the neighbour cell (e.g., Cx cell)) for the cell Cx (e.g., to determine whether it needs fresh SIB-1 and / or other SIBs (e.g., based on a determination that the first SI digest does not match the second SI digest)).

[0211] The WTRU may receive / decode a SIB-1 from cell Cx (e.g., neighbour cell) to obtain RACH parameters for cell Cx, for example, if the SI digest does not match the stored SI digest for cell Cx.

[0212] If SI digest matches, the WTRU may already have the RACH parameters for cell Cx (e.g., the WTRU may determine the RACH parameters based on the first SI digest and the second SI digest (e.g., that match each other)).

[0213] The WTRU may transmit using RACH on cell Cx, for example, based on the RACH parameters. The WTRU may indicate the stored other SI digest, for example, so the network knows what system information WTRU has (e.g., in Msg1 / 3 / MsgA).

[0214] The network can provide delta system information with respect to WTRU indicated “other SI digest”.

[0215] C-MSI reception may be based on a first SSB cycle that may be a non-deterministic or NES cycle.

[0216] Reception of SIB-1 may be based on a second SSB cycle which may be a deterministic, full or non-NES SSB cycle.

[0217] A Cell DTX active period may include a duration of time over which a configured cell DTX pattern is active (e.g., periods of time during an On Duration periods of a Cell DTX pattern). A WTRU may receive configuration information indicating the cell DTX active period and may monitor a PDCCH and other DLsignals and channels during such time. This may be applicable (e.g., only) after a cell DTX configuration has been indicated by the NW to be activated.

[0218] Cell DTX inactive period may include a duration of time over which a configured cell DTX pattern is not active / inactive (e.g., periods of time outside periodic On Duration periods of a Cell DTX pattern). This may be applicable (e.g., only) after a cell DTX configuration has been indicated by the NW to be activated.

[0219] Cell DRX active period may include a duration of time over which a configured cell DRX pattern is active (e.g., periods of time during an On Duration periods of a Cell DRX pattern). A WTRU may receive configuration information indicating (e.g., predefined to be allowed) to transmit UL signals and on UL channels during such time. This may be applicable (e.g., only) after a cell DRX configuration has been indicated by the NW to be activated.

[0220] Cell DRX inactive period may include a duration of time over which a configured cell DRX pattern is not active / inactive (e.g., periods of time outside periodic On Duration periods of a Cell DRX pattern). This may be applicable (e.g., only) after a cell DRX configuration has been indicated by the NW to be activated.

[0221] Activated Cell DRX / DTX may include a state of a configured cell DRX or Cell DTX pattern, for example, where such state has been activated by L1 / L2 DL signaling, RRC (re)-configuration, and / or cell common configurations, and has not been de-activated.

[0222] De-activated Cell DRX / DTX may include a state of a configured cell DRX or Cell DTX pattern, where such state has been deactivated by L1 / L2 DL signaling, RRC (re)-configuration, and / or cell common configurations.

[0223] There may be a link between availability state, NES state, and Cell DTX / DRX, for example, such that the terms may be used interchangeably. The WTRU may determine a cell DTX state implicitly from a determined active availability state, and visa-versa. The WTRU may determine a cell RTX state implicitly from a determined active availability state, and visa-versa.

[0224] The terms alternative cell and stable cell may be used interchangeably (e.g., as described herein). The WTRU may receive configuration information indicating (e.g., be configured) with a list of stable cells (e.g., alternative cells that may not turn off, e.g., some macro cells). The list may be (e.g., either) a list of alternative cells per serving / camped cell or a general list of PCIs for the whole NW, tracking area, etc. The WTRU may receive configuration information (e.g., be configured) with measurement object configuration for the alternative cells.

[0225] System Information Transmission and Acquisition may be performed and / or enabled.

[0226] Synchronization Signal Transmission may use low power Tx and / or a power amplifier: The gNB may be equipped with a low power transmitter and / or power amplifier (PA). The synchronization sequences(e.g., including SSB or sequences as described herein) may be transmitted by the gNB, for example, using the lower power Tx and / or PA.

[0227] The gNB transmission of sync signals may use low power Tx and PA may be associated to the cell NES state. In examples, the sync signals may be transmitted using low power Tx and PA, for example if (e.g., when) the associated cell is in NES Inactive state. The sync signals may be transmitted using normal Tx and PA, for example, if (e.g., when) the associated cell is in NES Active state.

[0228] Slim Sync Structures for NES (e.g., Low power gNB Tx and PA) may be used and / or provided.

[0229] An SSB Design for Narrow band Carriers may be used (e.g., suitable for FR1).

[0230] The WTRU may be pre-defined or pre-configured with an SSB structure, for example, comprising of a PSS, a SSS and / or a PBCH block. These signals in the structure may occupy the same frequency footprint, e.g., they may span the same number of physical resource blocks (PRBs). The network may use the same structure for (e.g., all) the SSBs in the SSB burst set that it uses.

[0231] The synchronization sequences of PSS and SSS may (e.g., each) occupy 11 PRBs in frequency domain and a (e.g., one) OFDM symbol. The frequency span of 11 PRBs may be used (e.g., helpful), for example, to re-use the same PSS / SSS sequences. To allow the use of MIB / PBCH (e.g., similar to where PBCH is mapped over 48 PRBs) the updated SSB structure may use 4 OFDM symbols resulting in 44 PRBs available for PBCH (e.g., as shown in the left-hand side (LHS) of FIG. 5. For the same power SSB transmission, the PBCH with 44 PRBs may have little coverage reduction (e.g., as it may have lower redundancy for PBCH for the same number of PBCH information bits and PBCH DMRS).

[0232] Five (5) OFDM symbols can be allocated to the PBCH, for example, to avoid the PBCH coverage loss (e.g., compared to the legacy design). This SSB structure (e.g., using 5 OFDM symbols) may result in 55 PRBs available for PBCH (e.g., as shown in the right-hand side of FIG. 5). The availability of 55 PRBs for PBCH may result in improved coverage over the legacy design for the same number of PBCH information bits and PBCH DMRS.

[0233] FIG. 5 illustrates an example of PSS, SSS and PBCH in (e.g., confined to) 11 PRBs (e.g., PSS / SSS length) with additional PBCH symbols where the left hand side has 44 PRBS for PBCH and the right hand side has 55 PRBs for PBCH.

[0234] The proposed design (e.g., as described herein) may leverage re-using the PBCH processing from other (e.g., legacy) designs. The mapping adjustment to different number of PRBs can be easily achieved by limiting the update to rate matching block for PBCH processing. The polar coding of PBCH may result in 512 bits (e.g., which may be the input for rate matching block). The rate matching block may increase these bits to 864 bits (e.g., 432 QPSK symbols).

[0235] 48 PRB * 12 * % (1 / 4 DMRS) may equal 432 resource elements.

[0236] The rate matching block can be updated, for example, so as to provide the PBCH bits for 4 symbol (e.g., left hand side of FIG. 5) or 5 symbol (e.g., right hand side of FIG. 5) mapping.

[0237] The frequency occupancy for the SSB can be chosen different from 11 PRBs. This design may allow PSS and SSS selection with lengths different from other (e.g., legacy) SSB designs. For the systems operating over narrow band carriers, the frequency span can be reduced and suitable PSS and SSS sequences can be selected. The number of symbols for the transmission of PBCH can be increased further to achieve a certain coverage level.

[0238] In examples, a complementary design (e.g., more suitable for wide band carriers) the frequency occupancy for SSB can be increased to a suitable value larger than 11 PRBs. Longer PSS and SSS sequences can be used with such SSBs. In examples, PSS / SSS sequences can be repeated in frequency domain to the appropriate length. PBCH can use same or different number of OFDM symbols in such SSB designs.

[0239] In examples, the network may transmit the updated structure with a low power gNB Tx and PA. This can be beneficial for network energy saving purpose, for example, as the gNB may turn off its normal / high-power Tx and PA for longer intervals of time.

[0240] In examples, the WTRU can be pre-defined or pre-configured to receive SSB transmitted from normal Tx / PA or low power Tx / PA.

[0241] In examples, the WTRU can be pre-defined or pre-configured to receive legacy SSB structure and the proposed SSB structure (e.g., at the same time). The usage of the SSB structure can be linked to the cell NES state. When the cell is in an NES active state, the SSBs can be transmitted using the legacy structure. When the cell is in an NES inactive state, the SSB can be transmitted using the proposed structure.

[0242] If the WTRU knows the cell NES state (e.g., determines the cell NES state), the WTRU may use the appropriate SSB structure to receive the sync signals. If the WTRU does not know the NES state for the cell that it is trying to decode the SSB, the WTRU may try to decode (e.g., blindly decode) the SSB from the legacy and the proposed structures. The WTRU can derive whether the cell NES state is active or inactive, for example, by decoding the SSB structure in use. According to the pre-defi nition or network configuration, the detection of structure may indicate that the network is not applying NES state or in NES active state. The detection of the proposed structure may indicate the cell being in NES inactive state.

[0243] In examples, the WTRUs can be pre-defined or pe-configured to receive different SSB structures for different frequency ranges or frequency bands. In examples, different SSB designs can be defined for FR1 and FR2.

[0244] For example, FR1 could keep a longer time footprint (e.g., more OFDM symbols as typically it will have fewer beams to sweep with in FR1). The proposed design may be used for FR1 with a potential update to the SSB burst structure.

[0245] The proposed SSB structure may be used with the SSB-SSB burst mapping, for example, by limiting (e.g., only) a (e.g., one) SSB transmission in a (e.g., one) sub-frame / slot. For this purpose, the start symbol of the first legacy SSB mapping may be used as the first start symbol of the proposed SSB structure. In examples, the (e.g., new) mapping of SSBs in the SSB burst set can be designed for the proposed SSB structures.

[0246] The proposed design may be used for narrow band carriers and / or re-farmed frequencies. These carriers / frequencies may be (e.g., typically of) medium to low bandwidths. The proposed design with a smaller frequency span (e.g., compared to the other (e.g., legacy) designs) may (e.g., could be of interest to) accommodate SSB in such carriers / frequencies. A (e.g., default) SSB structure can be defined with a (e.g., each) band which the WTRUs may assume for initial access (e.g., at least). The network may override the (e.g., default) SSB structure, for example, by indicating in the system information or configuration information. This may work for the cells which may not be destined to provide initial access to the WTRUs, or if (e.g., when) the WTRUs are configured to (e.g., blindly) detect and decode the SSB structure.

[0247] SSB design may be used for narrow band carriers and may be suitable for FR1 .

[0248] The WTRU may be pre-defined or pre-configured with an SSB structure, for example, that may include PSS, SSS, and a PBCH. The signals in the structure may occupy the same frequency footprint, e.g., they may span the same number of physical resource blocks (PRBs). The network may use the same structure for (e.g., all) the SSBs in the SSB burst set that it uses.

[0249] The synchronization sequences of PSS and SSS may (e.g., each) occupy 11 PRBs in frequency domain and one OFDM symbol. To re-use PSS / SSS sequences (e.g., from other (e.g., legacy) designs), the frequency span may be (e.g., kept being) 11 PRBs.

[0250] The proposed SSB design may be used by the network for the cells in NES state with reduced transmission power. The design may use repetitions of PSS and SSS as part of the SSB structure, for example, to overcome the coverage loss,. FIG. 6 illustrates an example SSB design. As shown in FIG. 6, the SSB may include (e.g., be comprised of) multiple (e.g., two) repetitions of PSS, (e.g., two) repetitions of SSS, and 6 OFDM symbols for PBCH transmission.

[0251] FIG. 6 illustrates an example of PSS, SSS and PBCH confined to 11 PRBs (R-15 PSS / SSS length) with additional (N) PBCH symbols.

[0252] FIG. 6 shows an example of number of PSS / SSS repetitions and the number of symbols for PBCH transmission. A (e.g., suitable) number of PSS / SSS repetitions can be selected for the proposed SSB design. The number of repetitions may depend upon the permissible power levels for the gNB Tx and the suitable coverage area that the network intends to cover for cells’ SSB transmissions. The number of repetitions may depend upon the frequency occupancy of the SSB.

[0253] A motivation for the proposed design may include to re-use the PBCH processing from other (e.g., legacy) designs. The mapping adjustment to different number of PRBs (e.g., compared to other (e.g., legacy) designs) may be (e.g., easily) achieved by limiting the update to rate matching block for PBCH processing. The rate matching block may be updated, for example, to provide the PBCH bits for the selected target number of symbols and PRBs.

[0254] In examples, the frequency occupancy for the SSB can be chosen different from 11 PRBs. This design may allow PSS and SSS selection with lengths different from other (e.g., legacy) SSB designs. For the systems operating over narrow band carriers, the frequency span may be reduced and suitable PSS and SSS sequences can be selected. The number of symbols for the transmission of a PBCH block can be increased further to achieve a certain coverage level.

[0255] In examples (e.g., a design more suitable for wide band carriers), the frequency occupancy for SSB may be increased to a suitable value larger than 11 PRBs. Longer PSS and SSS sequences may be used with such SSBs. In example designs, the legacy PSS / SSS sequences may be repeated in the frequency domain to the appropriate length. The PBCH may use same or different number of OFDM symbols in such SSB designs.

[0256] In examples, the network may transmit the updated structure with a low power gNB Tx and PA. This may be beneficial for network energy saving purpose, for example, as the gNB may turn off its normal / high-power Tx and PA for longer intervals of time.

[0257] In examples, the WTRU may receive configuration information indicating (e.g., be pre-defined or pre-configured) to receive SSB transmitted from Tx / PA (e.g., normal Tx / PA or low power Tx / PA).

[0258] In examples, the WTRU may receive configuration information indicating (e.g., be pre-defined or pre-configured) to receive another (e.g., legacy) SSB structure and the proposed SSB structure (e.g., at the same time). The usage of the SSB structure can be linked to the cell NES state. The SSBs may be transmitted using the other (e.g., legacy) structure, for example, if (e.g., when) the cell is in NES active state,. The SSB can be transmitted using the proposed structure, for example, if (e.g., when) the cell is in NES inactive state.

[0259] The WTRU may use an appropriate SSB structure to receive a sync signal(s), for example, if the WTRU knows the cell NES state (e.g., based on a determination of the cell NES state). The WTRU may(e.g., try to) decode (e.g., blindly decode) the SSB from the other structure (e.g., legacy structure) and the proposed structures, for example, if the WTRU does not know the NES state for the cell that it is trying to decode the SSB. The WTRU may derive the cell NES state being active or inactive, for example, by decoding the SSB structure in use. The detection of other (e.g., legacy) structure may indicate that the network is refraining from applying (e.g., not applying) NES state or in NES active state (e.g., according to the pre-defi nition or network configuration). The detection of the proposed structure may indicate the cell being in NES inactive state.

[0260] The proposed structure (e.g., as described herein) may be used (e.g., very suitable) for the scenarios where the network may employ other (e.g., legacy) or proposed SSB structure and WTRUs may (e.g., need to) blindly detect and decode SSB for any of the structures. This may be based on the design similarity that the first symbol of SSB is carrying PSS and the third symbol is carrying SSS. Thus, the commonality in the transmission of these two signals may (e.g., help) improve the blind detection / decoding processing for the legacy and the proposed SSB structures.

[0261] In examples, the WTRUs may be pre-defined or pre-configured to receive different SSB structures for different frequency ranges or frequency bands. In examples, different SSB designs may be defined for FR1 and FR2.

[0262] For example, FR1 may keep a longer time footprint, e.g., more OFDM symbols as typically it may have fewer beams to sweep with in FR1 . The proposed design may be used for FR1 with a (e.g., potential) update to the SSB burst structure.

[0263] The proposed SSB structure may be used with the (e.g., legacy) SSB-SSB burst mapping, for example, by limiting (e.g., only) a (e.g., one) SSB transmission in a (e.g., one) sub-frame / slot. For this purpose, the start symbol of the first (e.g., legacy) SSB mapping may be used as the first start symbol of the proposed SSB structure. In a different design, the (e.g., new) mapping of SSBs in the SSB burst set may be designed for the proposed SSB structures.

[0264] The proposed design can be used for narrow band carriers and / or re-farmed or re-purposed spectrum / frequency carriers. These carriers / frequencies may be (e.g., typically) of medium to low bandwidths. The proposed design with a smaller frequency span (e.g., compared to the legacy design) may be used to accommodate SSB in such carriers / frequencies. A (e.g., default) SSB structure may be defined with a (e.g., each) band which the WTRUs may assume for initial access (e.g., at least). The network may override the SSB structure (e.g., default SSB structure), for example, by indicating in the system information or configuration information. This may work for the cells which may not provide (e.g., not be destined to provide) initial access to the WTRUs, or if (e.g., when) the WTRUs are configured to blindly detect and decode the SSB structure.

[0265] Slim Sync Structures for NES (e.g., FR2) may be used and / or provided.

[0266] In examples, the network may transmit a compressed sync signal structure. The compressed sync signal structure may be termed as slim sync. The slim sync signal may include a time compressed version of (e.g., legacy) SSB. FIG. 7 shows a proposed design for slim sync. The design may span multiple (e.g., two) OFDM symbols. PSS may be transmitted in the first OFDM symbol, followed by the SSS in the 2nd OFDM symbol. PBCH transmission may be transmitted on both OFDM symbols, on lower and upper frequency portions. A suitable number of PRBS on lower and upper sides of the PSS / SSS sequences may be employed to transmit PBCH transmission(s).

[0267] To keep the design for PSS / SSS sequences and PBCH processing / decoding as close as possible to other designs (e.g., legacy designs), the PSS and SSS may span 11 PRBs (e.g., where the length of the PSS and SSS may be 127 (e.g., as in legacy)). 12 PRBs (e.g., each) on the upper and lower sides may be dedicated for PBCH transmission. This may result in 12*4 = 48 PRBs for PBCH transmission (e.g., as in legacy SSB). This may allow the (e.g., complete) re-use of transmission / receive chain for PSS / SSS and PBCH transmission, for example, except for the minor change of the mapping to different PRBS in the proposed design. This may result in a multiple (e.g., 2) symbol slim sync design with frequency span of 35 PRBs.

[0268] 12 (PBCH) + 11 (SS) + 12 (PBCH) may equal 35 PRBs.

[0269] In examples, the frequency span of the slim sync can be adjusted to a number (e.g., desired number) of PRBs in the frequency domain, e.g., by increasing or decreasing the number of PRBs for PBCH transmission. This may use an (e.g., require some) update to the PBCH processing, for example, which may be handled (e.g., easily handled) with the update to the “rate matching” block of the PBCH processing.

[0270] FIG. 7 illustrates an example 2 Symbol SSB structure with PSS / SSS stacked with PBCH.

[0271] Reuse of (e.g., legacy) PSS / SSS sequences in the slim sync may be allowed, for example, based on keeping the 11 PRBs for PSS / SSS.

[0272] In examples, the number of PRBs used for PSS / SSS may be less than 11 . In such a case, the (e.g., legacy) sequences may be truncated to fit in the selected number of PRBs. PSS / SSS sequences (e.g., new PSS / SSS sequences) may be designed, for example, for the (e.g., newly) selected number of PRBs of PSS / SSS.

[0273] In examples, the number of PRBs used for PSS / SSS can be larger than 11 . In such a case, the (e.g., legacy) sequences can be transmitted in a pre-defined repetition order (e.g., which may be known to WTRUs. The (e.g., new) PSS / SSS sequences of larger length may be designed, for example, to be transmitted in the slim sync structure.

[0274] A slim sync design (e.g., spanning only 2 OFDM symbols) may be useful for one or more of the following.

[0275] The gNB may finish sync signals in 2 OFDM symbols rather than 4 OFDM symbols and can have more sleep time (e.g., from an NES perspective).

[0276] The time compressed slim sync may provide a compact SSB burst structure(s) (e.g., leading to more efficient sync transmissions), for example, in FR2 or systems (e.g., future systems) employing larger number of beams. The mapping of SSBs in the slots for SSB burst set may be revised, for example, with a 2 symbol slim sync design. Contrary to the other (e.g., legacy) SSB burst design (e.g., which limits the transmission of at most 2 SSBs in one slot), the slim sync can be used to accommodate 4 slim sync per slot, for example, while still allowing the initial symbols in the slot for PDCCH and the later symbols for potential PUCCH transmissions.

[0277] FIG. 8 illustrates an example of Time-Frequency Compact Structure with 1 Instance only SS, 1 instance only PBCH.

[0278] In examples (e.g., for a design for slim sync), a time compressed structure may be obtained by splitting the transmission of PSS / SSS sequences from PBCH transmission (e.g., the slim SS may refrain from including (e.g., not include) a PBCH transmission / block). In this split design of slim sync, the network may transmit PSS / SSS on a two-symbol transmission. In the subsequent transmission interval, the two symbol PBCH transmission may be transmitted on the same resource. A PSS / SSS may use a frequency span of 11 PRBs, for example, to reuse the design (e.g., legacy design) for sequences. PBCH transmission(s) may use the same frequency span of 11 PRBs (e.g., resulting in 22 PRBs for PBCH transmission). This may use (e.g., require) a higher code rate of PBCH compared to other designs (e.g., legacy design), for example, if the PBCH carries same number of information bits. This may then result in low coverage for PBCH.

[0279] The frequency span of a slim sync signal may be increased, for example, to increase the coverage of PBCH. In examples, the PBCH transmission may span a larger number of PRBs. In examples, a PBCH transmission may span 24 PRBs, which may provide 48 PRBs for PBCH transmission (e.g., same as in a legacy design). This may allow full re-use of PBCH transmission and reception. PSS / SSS span can be kept to 11 PRBs. The coverage for sync may be improved, for example, by allowing PSS / SSS transmission over larger number of PRBs. Both PSS / SSS may use a number (e.g., same number) of PRBs as of PBCH, e.g., 24 PRBs. The PSS / SSS sequences (e.g., each) may be repeated (e.g., twice) in the frequency domain (e.g., 127*2 = 254 resource elements) while leaving (24*12 - 254 =) 34 resource elements (e.g., which can be left blank). A number (e.g., half) of these resource elements may be left on an upper and lower end (e.g., each upper and lower end) of the PSS / SSS repetition. In examples, (e.g., new)longer PSS / SSS sequences can be designed which may provide a more efficient design for these sequences.

[0280] In examples, the PSS / SSS sequences may indicate (e.g., carry the information about) the time or frequency span of the PBCH transmission among a configurable number of time frequency spans. A WTRU (e.g., based on detecting PSS / SSS sequences) may determine the suitable time frequency footprint for PBCH and may decode PBCH (e.g., according to the indication received in PSS / SSS sequences).

[0281] In examples, the relative periodicities of PSS / SSS and PBCH can be different. The relative periodicities of PSS / SSS and PBCH may have mapping from the cell NES state. The WTRU may derive the relative periodicities of PSS / SSS and PBCH transmission, for example, based upon the knowledge of cell NES state which can be provided to the WTRU through explicit or implicit signaling.

[0282] In examples, the WTRU may detect the relative periodicities of PSS / SSS and PBCH. The WTRU may determine the cell NES status and state, for example, based on the detected relative periodicities of PSS / SSS and PBCH.

[0283] In examples, the network may provide the PSS / SSS and PBCH periodicities or time frequency footprint through the transmission of a sequence (e.g., special sequences). The WTRU may receive configuration information (e.g., may be pre-defined or pre-configured) with the time frequency placement of the special sequence that the network uses to indicate PSS / SS and PBCH periodicities or time frequency footprint. The WTRU may detect the sequence (e.g., special) sequence on the known time frequency resource. A (e.g., one of the) properties of the (e.g., special) sequence (e.g., such as sequence selection, phase, cyclic shift, power, etc.) may indicate the periodicities and / or time frequency footprint of PSS / SSS and PBCH. The WTRU may detect the sequence (e.g., special) sequence and may determine the information for PSS / SSS and PBCH transmission.

[0284] The network may provide the indication of cell NES state and slim sync through the same sequence. In examples, the NES states may have direct mapping to slim sync periodicities and time frequency footprint.

[0285] The WTRU determination of the slim sync format / pattern (e.g., whether it is transmitted using legacy SSB or one of the newly proposed formats / patterns) may be based upon one or more of the following: a Sync-raster location; a frequency band (e.g., FR1 / 2 may use legacy SSB, FR3 / 4 bands may use slim sync or one of the types of slim sync); Physical cell ID (e.g., which may be determined based on the reception of PSS and / or SSS which can indicate which format / type of slim sync be used for synchronization and system information transmission / acquisition); Subcarrier spacing (e.g., different subcarrier spacings can be associated to different formats / types of slim sync); mode of operation for the cell (e.g., NES mode or not); etc.

[0286] A feature of having per FR SSB Structure may include one or more of the following.

[0287] Different frequency ranges may be assigned different SSB structures (e.g., default SSB structures). In examples, FR1 can be assigned an SSB structure (e.g., one SSB structure) with a larger number of OFDM symbols (e.g., as number of beams is small). FR2 can have a different SSB structure (e.g., default SSB structure) with smaller number of OFDM symbols (e.g., to accommodate larger number of beams and provide NES benefit).

[0288] The cell applying NES techniques or not may impact the structure of SSB that cell employs to transmit sync information. A (e.g., one) structure may be used (e.g., defined) for cells not applying NES procedure, and a different SSB structure may be used (e.g., defined) for the cells which are applying NES procedure. This may have some decoding impact for WTRUs but can be kept low by judicious choice of two SSB structures. On the other hand, the network may get the NES benefit and WTRUs may connect (e.g., still able to connect) independent of a cell being in NES or not.

[0289] Dynamic Power Updates for Sync / SSB Transmissions may be performed and / or enabled.

[0290] Power settings per SSB may be used, enabled, and / or configured.The WTRU may receive configuration information (e.g., be configured or predefined) with or multiple “SSB tx assumptions” per frequency band, carrier, TRP, BWP, NES state, and / or SSB structure. An SSB tx assumption may include at least one of the following: a transmission power level; a QCL / TCI assumption; spatial relation / beam configuration information (e.g., including the beamwidths and / or azimuths of the transmitted SSB); RACH to SSB association; PSS / SS sequence; a pathloss reference; a number of transmitted SSBs; whether the SSB is associated with a supplementary carrier (SUL) (e.g., for the purpose of determining a pathloss reference or measuring channel conditions (e.g., RSRP)); an associated measurement configuration (including gaps, applicable L1 / L3 measurements occasions and types); associated SSBs to measure for the purpose of BFD, BFR, RRM, and / or RLM; an associated SRI per SSB or beam; an associated CSI-RS resource to measure per SSB or beam; a CSI-RS tx power or power offset associated with the SSB; associated power control parameters; an SSB structure (as described herein); a maximum power reduction (MPR) value for PHR; etc. The WTRU may determine a parameter (e.g., any of these parameters) associated with an SSB tx assumption, for example, based on (e.g., from) the reception of an SSB transmitted with one of the associated parameters.

[0291] The WTRU may be configured (e.g., receive configuration information indicating) per SSB with an SSB burst with an indication, for example, relating to whether such SSB can be muted or transmitted with a reduced power (e.g., which may be referred to as a “non-stable SSB” herein). The WTRU may thus determine other SSBs as “stable SSBs”.

[0292] SSB muting or power change may be indicated.

[0293] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power. The WTRU may make such determination or determine the SSB tx assumption associated with the SSB based on one or more of the following:

[0294] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power, for example, based on reception of dynamic L1 / L2 signaling (e.g., a MAC CE or an indication by DCI). The signaling (e.g., MAC CE) may indicate (e.g., at least) one of the following: the BWP on which the SSB is muted or power changed, SSB index, Cell ID, bwp ID, resource id, spatial relation, power change, indication to a predefined or preconfigured power level.

[0295] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power, for example, based on reception of broadcast signaling. For example, the WTRU may determine the SSB transmit power and other which SSBs are transmitted from reception of broadcast information, whereby the SI may indicate such assumptions (e.g., part of SIB, MIB, or PBCH).

[0296] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power, for example, based on reception of a DL WUS signal. The WTRU may determine the SSB tx assumption from a property associated with the received DL WUS. A property of the DL WUS may include at least one of the following: modulation type (e.g., OOK vs OFDM), the time or frequency occasions on which WUS is received, sequency type (e.g., ZC or M), sequence index, a channel coding type, etc. The WTRU may determine the SSB tx assumption from explicit information indicated / signaled in the contents of an embedded message of the DL-WUS.

[0297] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power, for example, based on reception of an SSB with a particular physical layer property or structure. The SSB structure or physical layer property may include at least one of the following: a time-compressed SSB (e.g., with PBCH / SIB1 multiplexed in frequency domain), power reduced SSB, Narrow-band SSB, an SSB with reduced SSB beams per burst, PBCH-less SSB, SIB-less SSB, etc. In examples, the WTRU may determine the SSB transmit power and / or which SSBs are muted from the received PSS and / or SSS sequence.

[0298] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power, for example, based on reception of an indication part of a PDSCH payload, e.g., indicated in msg4 or msgB.

[0299] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power, for example, based on reception of an indication of RRC signaling (e.g., DCCH message or a CCCH message). The WTRU may receive the applicable SSB txassumption part of RRC signaling, and / or a change (e.g., delta re-configuration) with regards to an (e.g., existing) configuration.

[0300] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power, for example, based on reception of a PDCCH order (e.g., for CFRA) or a mobility command. The WTRU may assume a SSB tx assumption associated with an SSB indicated part of the PDCCH order.

[0301] The WTRU may determine that a (e.g., at least one or multiple) SSBs within an SSB burst are muted or transmitted with reduced power from the determined active NES state. The WTRU may determine the applicable SSB tx assumption from the determined or indicated NES state. The WTRU may be configured or predefined with an SSB tx power or an assumption or an SSB power setting per NES state. The WTRU may assume that a subset of SSBs is muted or transmitted with a different power level or with a different spatial relation, for example, based on activation of a NES state.

[0302] SSB muting or SSB power reduction may impact WTRU procedures.

[0303] Pathloss may be estimated.

[0304] The WTRU may change its pathloss reference (e.g., part of a RACH or a PHR procedure), for example, based on a determination that an SSB has been muted or an SSB is transmitted with reduced power (e.g., based on activation of a NES state). The WTRU may receive configuration information indicating (e.g., be configured) per NES state with a list of SSBs to measure (e.g., measure L1 SS-RSRP from) to use based on activation of the associated NES state.

[0305] The WTRU may use the parameters associated with the SSB tx assumption (e.g., transmit power, spatial relation) to compute / estimate the pathloss, for example, based on a determination that an SSB is transmitted with reduced power or a SSB tx assumption. The WTRU may exclude previously made measurements taken when the SSB was transmitted in full power.

[0306] The random-access procedure may be impacted.

[0307] The WTRU may receive configuration information indicating (e.g., be configured) with a threshold (e.g., rsrp-ThresholdSSB) per NES state, per SSB tx assumption, or per SSB transmission power. The WTRU may use the associated threshold (e.g., rsrp-ThresholdSSB) in the RA procedure to select an SSB and / or associated preamble, for example, based on a determination that SSBs are transmitted with a given SSB tx assumption or determination that a given NES state is active,.

[0308] The WTRU may receive configuration information indicating (e.g., be configured with) a mapping (e.g., SSB-to-RO mapping) per NES state or per SSB tx assumption. The WTRU may use the associated configured SSB-to-RO mapping in the RA procedure to select an SSB and associated preamble, forexample, based on determination that SSBs are transmitted with a given SSB tx assumption or determination that a given NES state is active. The WTRU may use an alternative SSB-to-RO mapping associated with the SSB tx assumption, for example, based on determining that a subset of SSBs or TRPs are muted. In examples, the WTRU may re-allocated preambles, ROs, and / or PRACH resources mapped to muted SSBs or SSBs with reduced power to other SSBs transmitted (e.g., non muted SSBs, stable SSBs, non-muted TRPs, or SSBs transmitted with full power). In examples, the WTRU may reallocate PRACH resources mapped to a muted SSB equally to remaining stable SSBs (e.g., in consecutive order, by time domain first or frequency domain first).

[0309] The WTRU may receive configuration information indicating (e.g., be configured with) a list of SSBs (e.g., SSBs within an SSB burst) or TRPs that the WTRU can select in a random access procedure, for example if (e.g., when) SSBs are transmitted with a given SSB tx assumption or if (e.g., when) the WTRU determines that the cell is in a given NES state. The WTRU may refrain from measuring (e.g., ignore / not measure) other SSB not transmitted with a full power part of a random-access procedure. The WTRU may consider other SSB (e.g., non-stable SSBs) if (e.g., when / once) the WTRU is in connected mode. The WTRU may assume once QCL assumption for an SSB during the random-access procedure and another after its completion, which can be configured per SSB tx assumption. The WTRU may be indicated with the list of additional non-stable SSBs part of msg4 or msgB.

[0310] The WTRU may be configured per NES state or per SSB tx assumption with separate thresholds for selecting between NUL and SUL, selecting between SULs, selection between different PRACH partitions of different features, selecting between 2-step and 4-step PRACH resources. The WTRU may apply the associated thresholds in the RA procedure, for example, based on determining that a given NES state is active or SSBs are transmitted with a given SSB tx assumption.

[0311] The WTRU may receive configuration information indicating (e.g., be configured with) an RO mask (e.g., ra-ssb-OccasionMasklndex) per NES state or per SSB tx assumption. The WTRU may use the associated RO mask in the RA procedure to select an RO and / or an associated SSB, based on determination that SSBs are transmitted with a given SSB tx assumption or determination that a given NES state is active.

[0312] The WTRU may reset the power ramping counter, for example, on determining that the SSB is transmitting with a different SSB tx assumption (e.g., compared to previous preamble transmission attempts) or based on activation of a given NES state. The WTRU may reset the power ramping counter, for example, if the SSB changed or SSB power changed or keep it but adjust the counter to account for the power difference (e.g., increase it by more than one to arrive the same power level if SSB power was not changed). The WTRU may increase the preamble transmission counter by a value (e.g., >1), for example,such that increase value multiplied by the power ramping step is closes (or equal to) to the SSB transmission power difference or the pathloss estimation difference compared to the prior preamble transmission attempt.

[0313] The WTRU may restart the RA procedure or reset the preamble transmission counter, for example, based on determining that the SSB is transmitting with a different SSB tx assumption (e.g., compared to previous preamble transmission attempts) or based on activation of a given NES state.

[0314] The WTRU may select SDT RA or CG resources that correspond to stable SSBs, non-muted SSBs or full power SSBs (e.g., as part of an SDT procedure). The WTRU may be adding or subtracting an offset to the measured SS-RSRP threshold for selecting a given SSB (e.g., which therefore selects the associated RO or CG resource), for example, if the SSB is transmitted with reduced power or if the cell is in a given NES state, where such offset may be configured or determined as the power reduction offset of the SSB (e.g., per the SSB tx assumption).

[0315] The WTRU may apply backoff on a per SSB-basis, for example, based on reception of a backoff indication. The backoff indication may indicate a given SSB. The WTRU may refrain from selecting such SSB, for example, while the backoff time is running. The WTRU may receive an indication in RAR / MsgB barring the selection of a given SSB (e.g., and thus the associated RO) during the RA procedure or for a period of time.

[0316] Mobility and cell (re)-selection may be enabled and / or performed.

[0317] The WTRU may start performing a (e.g., some) measurement(s) (e.g., possibly on the measurement configuration / gaps associated with the SSB tx assumption), for example, based on receiving an indication of a different SSB tx assumption, an SSB power reduction indication, and / or determining a different SSB tx assumption. The WTRU may measure one or more target cell (e.g., CHO candidates configured, CHO candidates configured for when the source cell enters NES state).

[0318] The WTRU may start a (e.g., new) measurement session, for example, if (e.g., when) it determines that the cell is transmitting SSB with a different SSB tx assumption or when the cell is in a given NES state. The WTRU may discard prior measurement samples performed using a different SSB tx assumption, for example, if (e.g., when) performing measurement filtering / averaging.

[0319] Power control may be used, performed, and / or enabled.

[0320] The WTRU may receive configuration information indicating (e.g., be configured with) parameters (e.g., separate power control parameters) to be applied / associated with a given NES state or when SSBs are transmitted with a certain SSB tx assumption. Parameters may include one or more of the following: PCMAX (e.g., the maximum allowed transmit power per carrier); P0 (e.g., a nominal target received power); a (e.g., the fractional path-loss compensation parameter); and / or 5 (e.g., the power adjustment dueto the closed-loop power control). The WTRU may use an alternative a for compensating for the pathloss, for example, if the WTRU determines that the serving cell is transmitting SSB with reduce power or is in a NES state. The WTRU may apply an alternative power adjustment delta (5), for example, based on reception of signaling from the network (e.g., part of L1 / L2 signaling) or reception of a TPC command associated with a cell transmitting SSB with a non-default SSB tx assumption or in NES state.

[0321] The WTRU may apply alternative power control parameter(s), for example, if a neighboring cell is in a NES state, a neighboring cell is transmitting SSB with reduced power, or upon reception of signaling (e.g. L1 / L2 signaling) from the serving cell to apply such alternative power control parameters.

[0322] To estimate uplink pathloss for a given beam, the WTRU may use a downlink pathloss reference (e.g., where typically an SSB or CSI-RS may be involved). If an SSB or CSI-RS is muted or transmitted with lower power, the WTRU may add the power difference (e.g., compared to full SSB power) to the pathloss estimate. The WTRU may take the QCL / TCI assumption associated to estimate the pathloss, for example, if an SSB or CSI-RS is transmitted with a different SSB tx assumption,. The WTRU may use (e.g., any of) the parameters associated with the determined SSB tx assumption to estimate the pathloss. The WTRU may compute multiple pathloss estimates for different beams / SSBs. The WTRU may estimate pathloss for a subset of beams (e.g., only for a subset of beams), for example, if (e.g., when) the serving cell is in NES state or when some SSBs are transmitted with a non-default SSB assumption (e.g. estimate pathloss only for stable SSBs). The WTRU may be configured with an SRI value corresponding to each SSB or SSB tx assumption, which may be used for uplink transmissions corresponding to the selected SSB. For a scheduled PUSCH transmission, the DCI may further indicate an applicable SSB tx assumption, which may be used by the WTRU to estimate pathloss. The WTRU may assume a configured or predefined value for SRI for a scheduled PUSCH, which may be associated with a NES state or an SSB tx assumption.

[0323] CSI reporting may be performed.

[0324] CSI-RS tx power may be indicated relative to SSB power, for example, so the WTRUs use (e.g., need) an indication in some form about what tx power the gNB is using for SSB transmissions. The WTRU may receive a dynamic indication about the CSI-RS transmit power assumption (e.g. an absolute value or a delta change value). The WTRU may receive configuration information indicating (e.g., be configured with) the CSI-RS power assumption per SSB tx assumption, and may determine it implicitly from receiving the SSB with a non-default SSB tx assumption. The WTRU may determine that the CSI-RS is transmitted with a different QCL or spatial relation, for example, if the received SSB is transmitted with a different SSB tx assumption.

[0325] The WTRU may report CSI for the difference between a used SSB tx assumption and a full power SSB tx assumption, for example, if an SSB is transmitted with a non-default SSB tx assumption. The WTRU may report multiple (e.g., two) CSI reports, for example, such as a (e.g., one) report for the active SSB tx assumption and another report for a hypothetical SSB tx assumption (e.g. full power transmission or reduced power transmission). The WTRU may use the adjusted CSI measurement corresponding to the active SSB tx assumption to decode and received PDSCH.

[0326] A power headroom report (PHR) may be used and / or performed.

[0327] The WTRU may trigger a PHR, for example, if it determines that an SSB is transmitted with a different SSB tx assumption or if the service cell has activated a given NES state. For example, the WTRU may trigger a PHR if the SSB is transmitted with lower power. The WTRU may adjust the pathloss estimate for PHR. If an SSB or CSI-RS is muted or transmitted with lower power, the WTRU may add the power difference (e.g., compared to full SSB power) to the pathloss estimate. The WTRU may postpone the triggering or transmission of a PHR (e.g., PHR MAC CE), for example, if the network is in a NES state (e.g. until the active period of cell DRX). The WTRU may be configured with an alternative PHR prohibit time (e.g., via a timer) to apply if (e.g., when) the network is in a given NES state.

[0328] In examples, the WTRU may include multiple (e.g., two) PHR values in a single report, for example, where one PHR may correspond to the active SSB tx assumption and another PHR may correspond to a different SSB tx assumption (e.g., full power SSB or reduced power SSB). The WTRU may indicate the SSB(s) that was used to compute the pathloss estimate and PHR part of a signaling (e.g., via the MAC CE).

[0329] The WTRU may determine a different PCMAX value to use for the PHR computation, for example, if (e.g., when) the service cell is in a NES state or the corresponding SSB is transmitted with a non-default SSB tx assumption, where the PCMAX value may be the value configured for the determined SSB tx assumption. The WTRU may subtract an NES specific MPR value from PCMAX, where NES specific MPR may be determined based on the power difference between the current SSB tx assumption and full power SSB. The WTRU may consider such MPR value in the PHR computation if the SSB is transmitted with low power (e.g. a non-default SSB tx assumption) or the serving cell is in a NES state.

[0330] Beam failure detection and recovery may be performed.

[0331] The WTRU may receive configuration information indicating (e.g., be configured with) an alternative BFD or RLM candidate beam list to measure, for example, if (e.g., when) the current cell is in a given NES state or when SSBs are transmitted with a non-default SSB tx assumption. In examples, the set may correspond to stable SSBs (e.g., only). The WTRU may add an offset to the measured BFD CSI-RS or SSB samples for BFD or RLM, where the offset can correspond to the power difference to the measuredpower reduced CSI or SSB resources to the full power setting. The WTRU may be configured with an alternative threshold for declaring a BFI instance when the serving cell is in a NES state or when SSB(s) are transmitted with a non-default SSB tx assumption.

[0332] The WTRU may receive configuration information indicating (e.g., be configured with) an alternative BFR candidate beam list, for example, to measure when the current cell is in a given NES state or when SSBs are transmitted with a non-default SSB tx assumption. The WTRU may measure, select, and / or indicate stable SSBs (e.g., only stable SSBs) during the recovery procedure, for example, based on detection of a beam failure. The WTRU may receive configuration information indicating (e.g., be configured with) an alternative threshold for selecting an appropriate recovery SSB or CSI-RS, for example, when the serving cell is in a NES state or when SSB(s) are transmitted with a non-default SSB tx assumption.

[0333] NES Adaptive Periodicities for Slim sync and SSB may be used and / or enabled.

[0334] The WTRU may receive configuration information (e.g., be predefined or configured) with a first cycle for potential full SSB transmission occasions (e.g. a NES cycle) and a second cycle for stable full SSB transmission occasions. The first SSB (e.g., non-stable) cycle may correspond to non-deterministic SSB transmissions, e.g., occasions during which non-backwards compatible SSB structures are transmitted (e.g., as described herein with respect to slim sync structures for NES and dynamic power updates for sync / SSB transmissions) and / or used while the cell is in a NES state. The second SSB (e.g., stable) cycle may be deterministic and / or used, for example, if (e.g., when) the cell is not in an NES state. The period of the stable cycle may be larger than the non-stable cycle period, for example. Presence of SSB transmissions on the non-stable cycle may be limited to a subset of NES states (e.g. only when a NES state is active). SS may refer to a slim sync occasion transmitted on the non-stable cycle (e.g., as such cycles are illustrated in FIGs. 8 and 9). FIGs. 8 and 9 show slim sync comprising of PSS / SSS (e.g., only PSS / SSS) as examples. In examples, it may comprise of (e.g., only) PSS, (e.g., only) SSS (e.g., only PSS and SSS) or a different sync sequence. FIGs. 8 and 9 show the sync signals from a given beam with different periodicities. For a cell / TRP / network employing multiple beams, sync signals may be sweeped / transmitted in each beam direction according to the sync burst pattern.

[0335] FIG. 9 illustrate example 1 SSB-3SS based transmissions.

[0336] FIG. 10 illustrates example 1 SSB-2SS based transmissions.

[0337] The WTRU may use the stable SSB cycle for the purpose of inter-cell measurements, cell (re)- selection measurements, some initial access procedures, and / or in Idle mode. The WTRU may monitor and measure SSBs on the non-stable cycle, for example, based on receiving full system information. Configuration information related to the non-stable cycle may be provided by broadcast signaling (e.g. partof system information, SIB1, or other SI). The periodicity of the stable cycle may be predefined, and may depend on the carrier, BWP, subcarrier spacing, and / or the frequency band on which the SSB is transmitted.

[0338] The periodicity and occurrence of the non-stable cycle (e.g., along with other related configurations) may be determined by the WTRU from reading system information, RRC release message, or from a property of the received SSBs in the stable cycle. A property of the received SSB may include the sequence used for PSS or SSS, the SSB structure type (e.g., as described herein), or the SSB tx assumption (e.g., as described herein). System information or RRC release message configuration information may provide one or more of the following configuration information for the expected SSB in the non-stable cycle: periodicity, start offset, SSB structure, SSB tx assumption, whether PBCH is multiplexed with the SSB, an associated SIB1 periodicity and whether it’s multiplexed, etc.

[0339] During SSB occasions of the non-stable cycle, the WTRU may assume SSBs are transmitted using a low power transmitted, and / or received at the WTRU using a low power receiver / PA (e.g., apart from the main radio). During SSB occasions of the non-stable cycle, the WTRU may receive a subset of {PSS, SSS, PBCH, DL WUS}. For example, the WTRU may assume that PSS is received (e.g., only), PSS and SSS are received (e.g., only PSS and SSS), PSS and SSS and PBCH are received (e.g., only), or PSS and SSS and PBCH and DL WUS are received. The received SS or SSB may provide an indication of SSB periodicity / next occurrence or periodicities for both SS and SSB. During SSB occasions of the non- stable cycle, PSS / SSS may be transmitted with DL-WUS which instead PBCH, or DL-WUS may be transmitted on some fixed T-F resource / occasion. PSS( / SSS) sequence may carry an indication to the timing of an upcoming full SSB block or an on-demand SSB.

[0340] The WTRU may receive configuration information indicating (e.g., be predefined or configured with) time and frequency occasions for which the WTRU monitors a DL wake up signal (e.g. a low power WUS or an SSB defining signal). The configuration may be provided in system information / broadcast signaling, or part of an RRC release message. DL WUS occasions may be determined to be aligned with (before or after) SSB transmission occasions of the stable cycle and / or the non-stable cycle.

[0341] The WTRU may monitor for and / or receive a DL-signal (DL-WUS) from the network. The WTRU may determine that one or more SSBs are transmitted and may be received during an upcoming SSB transmission occasion in a first SSB cycle (e.g., the stable cycle / NES cycle), for example, based on reception of the DL-WUS. The WTRU may determine an SSB structure type to monitor and / or receive during the first SSB cycle based on at least one property of the received or decoded DL-WUS. A property of the DL WUS may include one or more of the following: modulation type (e.g., OOK vs OFDM), the time or frequency occasion on which the DL-WUS is received, sequence type (e.g., ZC or M), sequence index, achannel coding type, or contents of an embedded message. The SSB structure type may be a (e.g., any of the) structures (e.g., as described herein), and may be one or more of the following: a time-compressed SSB (e.g., with PBCH / SIB1 multiplexed in frequency domain), power reduced SSB, narrow-band SSB, an SSB burst with a reduced number of SSB beams per burst, PBCH-less SSB, or SIB-less SSB transmission. The WTRU may receive an SSB in a transmission occasion of the first SSB cycle, for example, based on the determined SSB structure. Based on reception of the SSB, the WTRU may receive a (e.g., at least one) of PBCH and / or one or more SIBs. The WTRU may transmit (e.g., using a determined RACH parameter) a preamble (e.g., based on the received SSB and information received in the PBCH and / or at least one of the SIBs), e.g., if part of an initial access procedure.

[0342] The WTRU may assume the same SSB structure during the first cycle until another DL-WUS is received. The WTRU may combine SSB receptions from the stable and non-stable cycles to accumulate energy for the received signal.

[0343] In examples, the WTRU may determine the active NES state from the reception of a DL WUS, e.g., based on a property (e.g., at least one property) of the received or decoded DL-WUS. The NES state may be encoded part of the DL WUS message contents. DL WUS may provide an indication of NES status & relative periodicities for SSB and SS (e.g., slim SS). The WTRU may determine the cell’s NES state from the periodicities for stable and non-stable SSB cycles or relative periodicities, for example, based on predefined periodicities or relative periodicities defined in the specifications. The WTRU may determine the SSB structure or the SSB tx assumption (e.g., TDM between one SSB and N PSS / SSS with repetitions) from the reception of the PBCH or its contents or from a property of the received PSS / SSS sequences. For dynamic switching the NES states, the gNB may indicate an update to the NES state via the DL WUS. The DL WUS may further indicate an update to SSB periodicity or a switch to a different SSB tx assumption. The WTRU may (e.g., alternatively) determine the NES cell state from the determined SSB tx assumption (e.g., the SSB type or periodicity).

[0344] SSB periodicity change or on demand SSB may be requested (e.g., via UL WUS).

[0345] The WTRU may receive configuration information indicating (e.g., be predefined or configured) to transmit a request (e.g., an uplink wake-up request “UL WUS” or a cell wake up request “Cell WUS”) in one or more NES states. The WTRU may transmit a Cell WUS to request one or more of the following: a change to the active SSB tx assumption (e.g., as described herein); a change to the active SSB transmission periodicity (e.g., either on the stable cycle or the non-stable cycle or both); activation of SSB transmission (e.g., on the non-stable cycle); a change to the transmitted SSB structure / type (e.g., as described herein); a transmission of a full SSB (e.g., an SSB with PBCH, and SSB transmitted at full power, or an on-demand SSB); activation of a given NES state or deactivation of the active NES state; arequest for a slim SSB and / or a PBCH transmission; a request for reception of system information (e.g., SIB1 transmission, other SI, and / or MSI); an indication of the active NES state; activation of a given data or control channel (e.g., PDSCH, SPS, CG, PUCCH); configuration of DL WUS resources; configuration of system access resources for a given cell (e.g., the cell in NES state), for example, including PRACH resource configurations and / or a subset of system information for a given cell; any of the above requested for a given carrier, BWP, frequency band, or TRP; etc.

[0346] The WTRU may include (e.g., any of) the requested information (e.g., as described herein) part of the Cell WUS request (e.g., in accompanying assistance data, part of a RA payload (e.g., in msgA or msg3) triggered for the cell WUS). For example, the WTRU may include an indication on the requested SSB tx assumption, SSB tx power, SSB structure, and / or SSB periodicity in a message accompanying the cell WUS or transmitted part of a procedure (e.g. on a PUSCH resource part of a RA triggered by the cell WUS).

[0347] The WTRU may monitor the PDCCH after the transmission of the cell WUS, for example, to receive the requested signals, channels, and / or information. The WTRU may monitor for SSB, PBCH, and / or SI reception on the requested time domain cycle (e.g., non-stable cycle), carrier, BWP, or TRP. The WTRU may monitor DL WUS after the transmission of the UL WUS signal. The WTRU may assume a predefined change in SSB structure after transmitting the cell WUS, or after receiving a response to the cell WUS.

[0348] The WTRU may trigger the transmission of a Cell WUS signal, for example, based on satisfying at least one of the following conditions: detection of a cell discovery signal; making a channel measurement based above or below a configured threshold; arrival of new data, possibly if data arrived form a subset of DRBs, SRBs, LCHs, LCGs, or associated with a certain priority level or index; amount of buffered data is above a threshold; triggering a BSR and / or SR; detection of a beam failure or an RLM event (e.g. RLF); triggering a of L3 or mobility event; detecting an SCG or MCG failure; based on a duration elapsing (e.g., expiry of a timer), possibly combined with not receiving an SSB or DRS during such period; etc.

[0349] The WTRU may transmit the Cell WUS on the same cell, TRP or BWP for which the requested signal / channel / information is made for, or on a different serving cell, TRP, or BWP. For example, the WTRU may detect that an Scell is not transmitting any SSBs within a period of time then may request an on demand SSB transmission or activation of SSBs on such cell by transmitting a cell WUS on a different serving cell (e.g., the SpCell). The WTRU may transmit the cell WUS only for transmission of SSBs on a secondary cell. The WTRU may transmit a cell WUS on a secondary cell (e.g., only on a secondary cell) or a non-stable cell (e.g., only a non-stable cell). The WTRU may assume the activation of an additional SSBtransmission cycle (e.g. the SSB non-stable cycle) after transmission of the cell WUS or receiving a DL response to it.

[0350] Periodicities and Repetitions for Slim sync and SSB may be used, performed, and / or provided.

[0351] In examples (e.g., for a design for system information acquisition), the WTRUs may receive configuration information indicating (e.g., be pre-defined or pre-configured) to receive one of the legacy or proposed SSB structures (e.g., as described herein) and different relative periodicities for full SSB or slim sync. Different sync structures, number of repetitions for PSS / SSS symbols within the full SSB or standalone, relative periodicities may have a mapping to the NES state of the cell. The WTRU may determine the expected SSB structure, repetitions and relative periodicities based upon the cell NES state.

[0352] FIG. 11 shows an example sync design where a full sync includes (e.g..comprises) 2 symbols for PSS / SSS (e.g., 2 symbols for PSS / SSS each), and 6 symbols for PBCH. In this full sync, the frequency occupancy of the PSS / SSS and PBCH transmission may be the same. For each beam, a (e.g., one) full sync may be followed by multiple (e.g., two) slim syncs in the next number of transmission periods (e.g., two transmission periods). A (e.g., each) slim sync may include (e.g., comprise ) two symbols for PSS and two symbols for SSS.

[0353] FIG. 11 illustrates an example Sync Design with TDM structure for SSB and PSS / SS.

[0354] The network can transmit the full sync and / or slim sync (e.g., PSS / SSS) through a low power Tx and PA. This may allow larger sleep time for the gNB normal (high power) Tx and PA which adds a significant energy saving advantage for the network operation.

[0355] FIG. 11 shows an example of using two OFDM symbols for the transmission of PSS and SSS in each sync period. To compensate the sync coverage loss associated with the use of low power Tx and PA, the number of PSS / SSS symbols in one period may be increased.

[0356] In examples, the periodicity of PSS / SSS transmission may be increased. In examples, the full sync (e.g., PSS / SSS / PBCH) may use a periodicity of T1. The PSS / SSS transmissions without PBCH may use a much shorter periodicity T2 providing more PSS / SSS occasions which WTRUs can average out to increase the performance and compensate the coverage loss.

[0357] The WTRUs may be pre-defined or pre-configured with two sets of configuration information. One configuration information may be for the full sync (e.g., PSS / SSS / PBCH) transmission, and one configuration information may be for PSS / SSS transmissions without PBCH. In examples, there may be a single configuration with additional parameters. The additional parameters can provide the relative time and the relative periodicities of the slim PSS / SSS transmissions, for example, compared to the full PSS / SSS / PBCH transmissions.

[0358] FIG. 12 illustrates two examples of slim sync with different number of symbols per transmission interval and different transmission periodicities.

[0359] As shown at the top of FIG. 12, a design with 2 PSS / SSS symbols, repeating every 2m-sec may be used.

[0360] As shown at the bottom of FIG. 12, a design with 1 PSS / SSS symbol, with a periodicity of 1 m- sec may be used.

[0361] FIG. 12 illustrates example designs for different SS lengths and periodicities

[0362] Slim SSB design may comprise of a (e.g., suitable) number of PSS and SSS symbols (e.g., only PSS / SSS symbols). The other designs for slim SSB could comprise of: PSS (e.g., only) transmission; SSS (e.g., only) transmission; PSS and SSS transmission (e.g., only PSS and SSS transmission); NES based (e.g, new) sequences for PSS, SSS or both; etc.

[0363] For each of these designs, the number of symbols / repetitions can be optimized to achieve a trade-off of network energy saving, effective coverage and WTRU sync performance. These designs can further be combined with different relative periodicities of full sync and slim sync.

[0364] NES state or SSB location may be indicated through a sequence transmission.

[0365] A WTRU may determine the time frequency location of SSB by detecting a sequence transmitted by the network (e.g., pre-synchronization signal, for example, such as a WUS). This sequence may be referred to as pre-sync sequence (e.g., as described herein).

[0366] In examples, the WTRU may expect the pre-sync sequence to be transmitted by the network with a known periodicity. The known periodicity can be a fixed value or one of the values among a known set of values.

[0367] The WTRU may determine to decode the pre-sync sequence over a group of N contiguous physical resource blocks (PRBs). N may be a known value in number of PRBs. N may be a value from a set of known values of PRBs. The network may transmit the sequence within each group of N PRBs. The length of the sequence can be a known value, or from a known set of values.

[0368] In examples, the WTRU may determine the timing and placement of the pre-sync sequence, for example, based on the information received in (e.g., indicated by) a slim-sync signal (e.g., as described herein).

[0369] In examples, the WTRU may expect the pre-sync sequence to be transmitted from a known sequence type, e.g., Zadoff-Chu or M sequence.

[0370] In examples, the pre-sync sequence can be the transmission of PSS sequence on a configured time frequency location and with a given periodicity.

[0371] The WTRU determination of the type / format / pattern of pre-sync sequence may be based on one or more of the following: Sync-raster location; frequency band (e.g., FR1 / 2 may use one type of pre-sync sequence, (e.g., new) bands FR3 / 4 bands may use a different type of pre-sync sequence); physical cell ID (e.g., which may be determined based on the reception of PSS and / or SSS) can indicate which format / type of pre-sync sequence will be used by the network; subcarrier spacing (e.g., different sub-carrier spacings can be associated to different formats / types / periodicities for pre-sync sequences); mode of operation for the cell (e.g., NES mode or not); etc.

[0372] The WTRU may detect the DL pre-sync sequence transmitted by the network.The WTRU may determine (e.g., based on at least one of the properties of the received or detected pre-sync sequence) one or more of the following: SSB time location; SSB frequency location (e.g., in a wideband carrier with suitable granularity); SSB structure; Slim Sync presence / absence; the structure of the slim Sync (e.g., as described herein); presence / absence of transmission of compact Minimum System Information; periodicity of SSB or Slim Sync; relative Periodicities of SSB and Slim Sync; NES indication of the cell; etc.

[0373] The pre-sync sequence can carry the information (e.g., indicate) in one of the physical properties, for example: time location; frequency location; sequence Type; sequence selection; phase of the sequence; initialization parameters; etc.

[0374] Compact minimum system information transmission / acquisition may be performed.

[0375] The WTRU may receive configuration information indicating (e.g., be pre-defined or preconfigured to receive) SSB (e.g., PSS, SSS and PBCH) and SIB-1 or RMSI in a compact format. The compact form of PSS, SSS and whole minimum system information (PBCH and SIB-1) may be termed as SSM.

[0376] SSM may inclue PSS + SSS + Compact Minimum System Information (PBCH, SIB-1).

[0377] In SSM, PBCH may not (e.g., need to) indicate the time, frequency resource / parameters to find SIB-1 . The PBCH contents within SSM may be different from the (e.g., legacy) PBCH transmitted as part of (e.g., legacy) SSBs.

[0378] A subset of parameters from SIB-1 may be transmitted as part of SSM, for example, according to the pre-defi nition or pre-configuration information provided the WTRUs. This set of parameters may be referred to as a compact SIB-1 or a compact RMSI.

[0379] The WTRU may receive configuration information indicating (e.g., be configured) to detect and decode different types of SSM, e.g., one or a combination of the following: a different subset of PBCH, SIB- 1 (RMSI); different subsets of PBCH, SIB-1 and the following SIBs information (e.g., some elements taken from SIB-2, SIB-3, SIB-4, SIB-5 and so on); time / frequency resources for MSI could be different (e.g., offset from PSS / SSS); channel coding could be different among different types of SSM; etc.

[0380] In examples, the WTRU may decode the SSB and / or compact SIB-1 (e.g., RMSI) where compact SIB-1 may be transmitted on the same frequency resource as PBCH on the subsequent OFDM symbols (e.g., as shown in FIG. 12). As shown in FIG. 12, the WTRU may decode the compact SIB-1 spanning 4 OFDM symbols subsequent to last OFDM symbol of PBCH, according to the prior configuration. The WTRU may (e.g., be configured to) decode compact SIB-1 on 2, 3, 4 or more number of OFDM symbols.

[0381] In examples, the PBCH transmission and the compact SIB-1 may be encoded (e.g., independently encoded). The PBCH may use polar coding. The compact SIB-1 may be LDPC encoded, for example, according to the parameters known or pre-configured to the WTRUs. In examples, the compact SIB-1 may be polar encoded.

[0382] The design of reference symbols for compact SIB-1 transmission can use the same sequence generation and comb structure as for PBCH. Thus, the DMRS for SIB-1 can follow the same comb-4 design as used for PBCH.

[0383] The frequency offset of the DMRS for compact SIB-1 can be the same as for PBCH according the cell identity of the cell transmitting PBCH. In examples, the compact SIB-1 transmission can use comb- 2 DMRS structure in the first OFDM symbol of SIB-1 transmission. This first symbol can be accompanied by an additional DMRS symbol within compact SIB-1 transmission. The DMRS indication for compact SIB- 1 transmission can be indicated in the PBCH. Thus, WTRU may decode PBCH transmission(s), and the PBCH transmission may provide one or more of the following related to the DMRS structure of compact SIB-1 : comb structure for DMRS; number / location of additional DMRS symbols; resource element offset for DMRS Res; etc.

[0384] FIG. 13 illustrates an example compact MSI Structure with separate encoding for PBCH and compact SIB-1.

[0385] In examples, the WTRU may have knowledge of multiple subsets / formats of information elements of legacy SIB-1 through pre-configuration which the network can transmit as compact SIB-1 . The WTRU may decode PBCH and may determine a format (e.g., a specific subset of SIB-1) that the network may indicate through PBCH transmission. The WTRU may decode and / or interpret the information elements of the compact SIB-1 transmission according to the indication received in PBCH transmission.

[0386] In examples (e.g., for SSM transmission), PBCH transmission and compact SIB-1 may use the same frequency span as of PSS / SSS (e.g., as shown in FIG. 14).

[0387] FIG. 14 illustrates an example compact MSI Structure with separate encoding for PBCH and RMSI plus Smaller Freq Footprint.

[0388] PBCH transmission(s) may be transmitted with the same information content as in current design with some minor modification. PBCH transmissions can provide indication on the transmission attributes of SIB-1 (e.g., DMRS, number of symbols for SIB-1 transmission, etc.).

[0389] A compact SIB-1 may follow a PBCH transmission according to the indication provided by PBCH transmission.

[0390] In examples, the PBCH transmission and compact SIB-1 may be encoded (e.g., jointly encoded) and transmitted (e.g., jointly transmitted) along with PSS / SSS sequences (e.g., as shown in FIG. 15). The PBCH transmission and compact SIB-1 (e.g., providing compact MSI) may be mapped on a larger number of PRBs (e.g., compared to PSS / SSS). In examples, the compact MSI can span 20 PRBs as spanned by PBCH in legacy SSBs. The modulation, coding and DMRS for MSI can follow the pre-defined / pre- configured values or can use one of the set of values pre-defined / pre-configured.

[0391] In examples, the WTRU may be provided (e.g., receive) the indication of the transmission parameters of compact MSI through one of the physical properties of PSS / SSS. In examples, the indication can be provided through DL-WUS signal transmitted by the network over known time frequency resource.

[0392] In examples, the WTRU may determine the format and periodicity of the compact MSI (e. , g . , along with PSS / SSS sequences) through the NES indication transmitted by the network.

[0393] In examples, the WTRU may determine the format and periodicity of the compact MSI (e.g., along with PSS / SSS sequences) for a cell through an indication received from another cell. The other cell providing the indication to the WTRU could be UE’s serving cell.

[0394] FIG. 15 illustrates an example compact MSI Structure with Joint encoding for PBCH and compact SIB-1 .

[0395] FIG. 16 shows an example design for compact MSI transmission along with PSS / SSS sequences where the jointly encoded compact MSI may be transmitted over the same frequency span as of PSS / SSS.

[0396] FIG. 16 illustrates an example compact MSI Structure with Joint encoding for PBCH and compact SIB-1

[0397] In examples, the compact MSI can include (e.g., comprise) PBCH and SI digest. The SI digest may include (e.g., comprise) a single value or a set of values. In examples, SI digest may include (e.g., comprise) two values, for example, where one value is MSI digest related to MIB and SIB-1 . The second value in SI digest may correspond to other system information. The WTRU may receive the system information and SI digest for a neighbor cell Cx through its serving cell. The WTRU may acquire compact MSI (e.g, later), for example, if the WTRU reselects to the cell Cx. The WTRU may compare the SI digest to validate if it matches its stored SI digest for the cell Cx (e.g., to determine whether it needs fresh SIB-1and / or other SIBs). The WTRU may receive / decode SIB-1 from cell Cx to obtain RACH parameters for cell Cx, for example, if the SI digest does not match the stored SI digest for cell Cx. The WTRU may already have the RACH parameters for cell Cx (e.g., based on the previously received SI digest), for example, if the SI digest matches,. Based on the RACH parameters, the WTRU may transmit RACH on cell Cx. The WTRU may indicate the stored “other SI digest” so the network knows what system information WTRU has (e.g., in Msg1 / 3 / MsgA as part of the UE’s RACH transmission). The network can provide delta system information with respect to WTRU indicated “other SI digest”. C-MSI reception may be based on a first SSB cycle that may be a non-deterministic or NES cycle. Reception of SIB-1 may be based on a second SSB cycle which may be a deterministic, full or non-NES SSB cycle.

[0398] In examples, a (e.g., legacy) SSB time-frequency span (e.g., 20 PRBs - 4 OFDM symbols) may be used to transmit SSM (e.g., PSS, SSS and compact MSI). In examples, the PBCH parameters related to CORESET-O may be replaced by the SI digest. This design could be advantageous to keep the same SSB burst patterns as in other (e.g., legacy) burst design.

[0399] In examples, the network can indicate two set of cycles (e.g., periodicities), for example, where one set may refer to the cycles / periodicities transmitted with full / legacy SSB and SIB-1 , and the second set may refer to the cycles / periodicities where compact MSI transmission structures are transmitted (e.g., according to other designs as described herein).

[0400] In examples, the second set of cycles / periodicities may have full SSB / SIB-1 transmissions or one of the compact MSI transmission structures according to the cell NES state. The WTRUs may receive the cell NES state and determine the compact MSI transmission structures / periodicities according to the cell NES state. The indication can be NES state itself which may have mapping to one of the structures, or the NES indication may have additional indication through which WTRU determines the compact MSI structure / periodicity.

[0401] The WTRU may (e.g., determine to) receive the system information transmitted from the network through one of the following patterns / formats: (e.g., legacy) SSB, SIB-1 and additional SIBs; SSM (e.g., as described herein); one or more the SSM types (e.g., as described herein); a combination of (e.g., legacy) SSB / SIB-1 and one or more of the SSM types (e.g., as described herein); etc.

[0402] The WTRU determination of the format / pattern of system information whether it is transmitted using legacy SSB / SIB-1 or new SSM format may be based on one or more of the following: Sync-raster location; frequency band (e.g., FR1 / 2 may use (e.g., legacy) SSB, (e.g., new) bands FR3 / 4 bands may use SSM or one of the types of SSM); physical cell ID (e.g., which may be determined based on the reception of PSS and / or SSS) can indicate which format / type of SSB / SSM be used for system informationtransmission / acquisition; subcarrier spacing (e.g., different sub-carrier spacings can be associated to different formats / types of SSB / SSM); mode of operation for the cell (e.g., NES mode or not); etc.

[0403] The WTRU determination of the format / pattern of system information from one of the types / formats / patterns of SSM may be based upon one or more of the following: Sync-raster location; frequency band (e.g., FR1 / 2 may use (e.g., legacy) SSB, (e.g., new) bands FR3 / 4 bands may use SSM or one of the types of SSM); physical cell ID (e.g., which may be determined based on the reception of PSS and / or SSS) can indicate which format / type of SSB / SSM be used for system information transmission / acquisition; subcarrier spacing (e.g., different sub-carrier spacings can be associated to different formats / types of SSB / SSM); mode of operation for the cell (e.g., NES mode or not); etc.

[0404] The WTRU may (e.g., determine to) perform one or more of the following (e.g., if / when a WTRU determines the presence of one of the SSM formats / types, or a combination with legacy SSB / SIB-1).

[0405] The WTRU may determine to perform RACH according to the type / format of system information it received. The WTRU may use 4-step RACH procedure to perform RACH, for example, if it received legacy SSB / SIB-1 . The WTRU may perform 2-step RACH procedure to perform RACH, for example, if it receives one of the SSM types.

[0406] The WTRU may (e.g., determine to) perform RACH power updates in one configured / defined manner, for example, if it detects SSB / SIB-1 and it may determine to perform RAC power updates in a 2nd configured / defined manner if it detects one of the SSM types / formats.

[0407] The WTRU may (e.g., determine to) select a RACH sequence selection from one set, for example, if it detects legacy SSB / SIB-1 . The WTRU may determine to select a RACH sequence from a second set, for example, if it detects one of the SSM types / formats (e.g., where the first set of RACH sequences is associated to the detection of legacy SSB / SIB-1 and the second set of RACH sequences is associated to the SSM). There could be more than one SSM types and their associated RACH sequences defined.

[0408] The WTRU may determine to monitor (e.g., listen) for a RACH response in one of the search spaces according to the SSM formats / types. In examples, the WTRU may listen to one Type 1 search space associated to legacy SSB / SIB-1 , whereas another Type 1 search space associated to one of the SSM types to receive RACH response. There could be more than one Type 1 search spaces associated to different types / formats of SSM.

[0409] The WTRU may (e.g., determine to) monitor for (e.g., listen to) paging in one of the search spaces according to the SSM formats / types whereby these search spaces may be associated to the same or different control resource sets. The set of search spaces may have different periodicities, different PDCCH candidates etc. In examples, the WTRU may (e.g., determine to) monitor / decode (e.g., Iisten_ a(e.g., one) paging search space associated to SSB / SIB-1, e.g., if (e.g., when) the WTRU detects SSB / SIB- I .The WTRU may (e.g., determine to) decode another paging search space associated to SSM (e.g., if / when it detects SSM). More than one paging search spaces may be associated to different SSM types / formats.

[0410] 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.

[0411] 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.

[0412] 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 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, terminal, base station, RNC, and / or any host computer.

Claims

CLAIMSWhat Is Claimed Is:1 . A wireless transmit / receive unit (WTRU) comprising, a processor configured to: receive a first signal, wherein the first signal is a slim synchronization signal (SS), and wherein the first signal indicates information associated with a second signal; determine a resource associated with reception of the second signal, wherein the resource is determined using the information associated with the second signal; receive the second signal via the resource determined using the information associated with the second signal, wherein the second signal comprises an indication associated with reception of a synchronization signal block (SSB); determine, based on the indication in the second signal, information associated with reception of the SSB; and receive the SSB based on the determined information associated with reception of the SSB.

2. The WTRU of claim 1 , wherein the slim SS is a compressed SS.

3. The WTRU of claim 2, wherein the slim SS is associated with one of a first primary synchronization signal (PSS) or the first PSS and a first secondary synchronization signal (SSS).

4. The WTRU of claim 3, wherein the slim SS does not include a physical broadcast channel (PBCH) block.

5. The WTRU of claim 1 , wherein the SSB comprises a physical broadcast channel (PBCH) block.

6. The WTRU of claim 1 , wherein the second signal is a pre-synchronization wake up signal.

7. The WTRU of claim 1 , wherein the second signal is indicated by the first signal by at least one of a time associated with the slim SS, a frequency associated with the slim SS, a phase associated with the slim SS, or a sequence choice associated with the slim SS.

8. The WTRU of claim 1 , wherein information associated with the second signal includes one or more of timing information associated with the second signal or resource information associated with the second signal.

9. The WTRU of claim 1 , wherein the information associated with receiving the SSB indicates one or more of a network energy savings (NES) state, a SSB periodicity, or a presence of a full SSB on a potential full SSB transmission occasion.

10. A method, the method comprising: receiving a first signal, wherein the first signal is a slim synchronization signal (SS), and wherein the first signal indicates information associated with a second signal; determining a resource associated with reception of the second signal, wherein the resource is determined using the information associated with the second signal; receiving the second signal via the resource determined using the information associated with the second signal, wherein the second signal comprises an indication associated with reception of a synchronization signal block (SSB); determining, based on the indication in the second signal, information associated with reception of the SSB; and receiving the SSB based on the determined information associated with reception of the SSB.11 . The method of claim 10, wherein the slim SS is a compressed SS.

12. The method of claim 11 , wherein the slim SS is associated with one of a first primary synchronization signal (PSS) or the first PSS and a first secondary synchronization signal (SSS).

13. The method of claim 12, wherein the slim SS does not include a physical broadcast channel (PBCH) block.

14. The method of claim 10, wherein the SSB comprises a physical broadcast channel (PBCH) block.

15. The method of claim 10, wherein the second signal is a pre-synchronization wake up signal.

16. The method of claim 10, wherein the second signal is indicated by the first signal by at least one of a time associated with the slim SS, a frequency associated with the slim SS, a phase associated with the slim SS, or a sequence choice associated with the slim SS.

17. The method of claim 10, wherein information associated with the second signal includes one or more of timing information associated with the second signal or resource information associated with the second signal.

18. The method of claim 10, wherein the information associated with receiving the SSB indicates one or more of a network energy savings (NES) state, a SSB periodicity, or a presence of a full SSB on a potential full SSB transmission occasion.

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