Acquiring synchronization and system information within an energy-saving network associated with a slim synchronization signal.

Abstract

This specification describes systems, methods, and means for acquiring synchronization and system information in energy-saving networks associated with WUS, resulting in slim synchronization and SSB measurements. Synchronization acquisition of a wireless transmit / receive unit (WTRU) can be initiated by detecting a synchronization signal (SS). The WTRU may determine timing and / or resource information for pre-synchronization or DL-WUS type signals based, for example, slim synchronization indications. Pre-synchronization or WUS signaling may provide network energy saving (NES) configuration information for system information and indications for timing.

Description

Technical Field

[0004] , , ,

[0003] , , , , ,

[0005]

[0001] Relates to obtaining synchronization and system information in an energy - saving network associated with a slim synchronization signal.

Background Art

[0002] Cross - reference to related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 526,323, filed Jul. 12, 2023, the content of which is hereby incorporated by reference in its entirety.

[0003] Mobile communications using wireless communication are continuously evolving. The fifth generation of mobile communication radio access technology (RAT) may be referred to as 5G New Radio (NR). Previous (legacy) generations of mobile communication RAT may be, for example, the fourth generation (4G) Long Term Evolution (LTE).

Summary of the Invention

[0004] This specification describes systems, methods, and means for obtaining synchronization and system information in an energy - saving network associated with slim synchronization that results in a WUS and SSB measurements that result in a WUS. Synchronization acquisition of a wireless transmit / receive unit (WTRU) may be initiated by detecting a synchronization signal (SS). The WTRU may determine timing and / or resource information for pre - synchronization or a DL - WUS type signal, for example, based on a slim synchronization indication. Pre - synchronization or WUS signaling may provide network energy savings (NES) configuration information for system information and an indication for timing.

[0005] 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., a wake-up signal (WUS), a 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 selection information). The first signal may indicate a slim sequence that can indicate information associated with the second signal. The first signal may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or both PSS and SSS (e.g., PSS and SSS only). In the example, the first signal may refrain from including a physical broadcast channel (PBCH) block. The WTRU may, for example, determine the resources associated with receiving a second signal (e.g., a pre-synchronization signal, WUS, DL-WUS) based on information associated with the second signal (e.g., indicated by the first signal). The WTRU may receive the second signal via resources determined using the information associated with the second signal. The second signal may include indications associated with receiving the SSB. The SSB may include PBCH blocks. The WTRU may determine the information associated with receiving the SSB based on indications associated with receiving the SSB (e.g., indicated by the second signal). The information associated with receiving the SSB may include one or more of the following: the state of the NES, the SSB period, the presence of all SSBs on all potential SSB transmission opportunities. The WTRU may receive the SSB based on the determined information associated with receiving the SSB. [Brief explanation of the drawing]

[0006] [Figure 1A] This is a system diagram showing an exemplary communication system in which one or more disclosed embodiments may be implemented. [Figure 1B]This is a system diagram showing an exemplary wireless transmit / receive unit (WTRU) that may be used in the communication system shown in Figure 1A, according to one embodiment. [Figure 1C] This is a system diagram showing an exemplary radio access network (RAN) and an exemplary core network (CN) that may be used in the communication system shown in Figure 1A according to one embodiment. [Figure 1D] This is a system diagram showing a further exemplary RAN and a further exemplary CN that may be used in the communication system shown in Figure 1A according to one embodiment. [Figure 2] An exemplary time-frequency structure of SSB is shown. [Figure 3] Further examples of SSB beam sweeps within an SSB burst set are shown. [Figure 4] Examples of slim synchronous signal transmission and SSB transmission are shown. [Figure 5] The left side shows an example of a PSS, SSS, and PBCH limited to 11 PRBs (R-15 PSS / SSS length) with an additional PBCH symbol, having 44 PRBS for PBCH, and the right side shows an example of a PSS, SSS, and PBCH limited to 11 PRBs (R-15 PSS / SSS length) with an additional PBCH symbol, having 55 PRBs for PBCH. [Figure 6] An example of a PSS, SSS, and PBCH limited to 11 PRBs (R-15 PSS / SSS length) with an additional (N) PBCH symbol is shown. [Figure 7] Two exemplary symbolic SSB structures with PBCH and stacked PSS / SSS are shown. [Figure 8] An example of a time-frequency compact structure with only one instance of SS and only one instance of PBCH is shown. [Figure 9] This shows an example of 1SSB-3SS-based transmission. [Figure 10] An example of 1SSB-2SS-based transmission is shown. [Figure 11] This exhibits an exemplary synchronous design with a TDM structure for SSB and PSS / SS. [Figure 12] Exemplary designs for different SS lengths and periods are shown. [Figure 13] An exemplary compact MSI structure with separate coding for PBCH and compact SIB-1 is shown. [Figure 14] This example demonstrates a compact MSI structure with separate coding for a smaller frequency footprint than PBCH and RMSI+. [Figure 15] This shows an exemplary compact MSI structure with co-coding for PBCH and compact SIB-1. [Figure 16] This shows an exemplary compact MSI structure with co-coding for PBCH and compact SIB-1. [Modes for carrying out the invention]

[0007] Figure 1A shows an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, and broadcast to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), quadrature FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT spread OFDM (ZT UW DTS-s OFDM), unique-word OFDM (UW-OFDM), resource block-filtered OFDM, and filter bank multicarrier (FBMC).

[0008] As shown in Figure 1A, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, but it should be understood that the disclosed embodiments intend 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. For example, WTRU102a, 102b, 102c, and 102d, any of which may be called “station” and / or “STA,” may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated processing chain context), consumer electronics devices, and devices operating on commercial and / or industrial wireless networks. Any of WTRU102a, 102b, 102c, and 102d may interchangeably be called UE.

[0009] The communication system 100 may also include base stations 114a and / or base stations 114b. Each of the base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks such as CN 106 / 115, the Internet 110, and / or other networks 112. For example, base stations 114a and 114b may be a transceiver base station (BTS), node B, enode B, home node B, home enode B, gNB, NR node B, site controller, access point (AP), wireless router, etc. Although each of the base stations 114a and 114b is shown as a single element, it should be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0010] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown) such as base station controllers (BSCs), radio network controllers (RNCs), and relay nodes. Base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be called cells (not shown). These frequencies may be in the licensed spectrum, the unlicensed spectrum, or a combination of the licensed and unlicensed spectrum. A cell may provide coverage for wireless service to a particular geographic area that may be relatively fixed or change over time. A cell may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one for each sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers per sector of the cell. For example, beamforming can be used to transmit and / or receive signals in a desired spatial direction.

[0011] Base stations 114a, 114b can communicate with one or more of WTRUs 102a, 102b, 102c, 102d via an air interface 116 which can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 can be established using any suitable radio access technology (RAT).

[0012] More specifically, as described above, the communication system 100 can be a multi-connection system and can employ one or more channel access methods such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base stations 114a in RAN 104 / 113 and WTRUs 102a, 102b, 102c can implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA) that can establish air interfaces 115 / 116 / 117 using Wideband CDMA (WCDMA). WCDMA can include communication protocols such as High Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High Speed Downlink (DL) Packet Access (HSDPA) and / or High Speed UL Packet Access (HSUPA).

[0013] In one embodiment, base stations 114a and WTRUs 102a, 102b, 102c can implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that can establish air interface 116 using Long Term Evolution (LTE) and / or LTE Advanced (LTE-A) and / or LTE-A Pro.

[0014] In one embodiment, base stations 114a and WTRUs 102a, 102b, 102c can implement a radio technology such as NR radio access that can establish air interface 116 using New Radio (NR).

[0015] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement multiple radio access technologies (RATs). For example, base station 114a and WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example, using the dual connectivity (DC) principle. Accordingly, the air interfaces utilized by WTRUs 102a, 102b, 102c may be characterized by transmissions sent between multiple types of RATs and / or multiple types of base stations (e.g., eNBs and gNBs).

[0016] In other embodiments, base station 114a and 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), GSM Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc. [[ID=VII]]

[0017] [[ID=VIII]] In Figure 1A, base station 114b could be, for example, a wireless router, home node B, home enode B, or access point, and may utilize any suitable RAT to facilitate wireless connectivity in localized areas such as workplaces, homes, vehicles, premises, industrial facilities, aerial corridors (for use by drones, for example), and roads. In one embodiment, base station 114b and WTRU 102c, 102d may implement radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, base station 114b and WTRU 102c, 102d may implement radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base station 114b and WTRU 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 Figure 1A, base station 114b may have a direct connection to the internet 110. Therefore, base station 114b may not need to access the internet 110 via CN 106 / 115.

[0018] RAN104 / 113 may communicate with CN106 / 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 WTRU102a, 102b, 102c, and 102d. The data may have varying Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, and mobility requirements. CN106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, internet connectivity, video distribution, and / or implement high-level security features such as user authentication. Although not shown in Figure 1A, it should be understood that RAN104 / 113 and / or CN106 / 115 may communicate directly or indirectly with other RANs employing the same or different RATs as RAN104 / 113. For example, in addition to connecting to RAN104 / 113, which may utilize NR radio technology, CN106 / 115 may also communicate with another RAN (not shown) employing GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0019] CN106 / 115 may also act as a gateway for WTRU102a, 102b, 102c, 102d to access PSTN108, the Internet 110, and / or other networks 112. PSTN108 may include a circuit-switched telephone network providing simple telephone services (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) within the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs that may employ the same RAT as RAN104 / 113 or a different RAT.

[0020] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the communication system 100 may include multimode capability (for example, WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example, WTRU 102c shown in Figure 1A may be configured to communicate with base station 114a which may employ cellular-based radio technology and with base station 114b which may employ IEEE 802 radio technology.

[0021] Figure 1B is a system diagram showing an exemplary WTRU 102. As shown in Figure 1B, the WTRU 102 may include, in particular, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any partial combination of the above elements while remaining consistent with the embodiment.

[0022] The processor 118 may be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. 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. Although Figure 1B shows the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0023] The transmit / receive element 122 may be configured to transmit a signal to a base station (e.g., base station 114a) via the air interface 116 and to receive a signal from there. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and optical signals. It should be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0024] Although the transmit / receive element 122 is shown as a single element in Figure 1B, 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 via the air interface 116.

[0025] The transceiver 120 may be configured to modulate the signal to be transmitted by the transmit / receive element 122 and to demodulate the signal received by the transmit / receive element 122. As described above, the WTRU 102 may have multimode capability. Therefore, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate over multiple RATs, such as NR and IEEE 802.11.

[0026] The processor 118 of the WTRU102 may be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (for example, a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit) and may receive user input data from them. The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Furthermore, the processor 118 may access information from any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132, and store data therein. 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 identification 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 memory not physically located on the WTRU 102, such as on a server or home computer (not shown), and store data therein.

[0027] The processor 118 may receive power from the power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for supplying power to the WTRU 102. For example, the power supply 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.), a solar cell, a fuel cell, etc.

[0028] The processor 118 may also be coupled to a GPS chipset 136 which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be understood that the WTRU 102 may acquire location information by any preferred location determination method while remaining consistent with the embodiment.

[0029] The processor 118 may be further coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functions and / or wired or wireless connectivity. For example, peripherals 138 may include an accelerometer, e-compass, satellite transceiver, digital camera (for photos and / or video), Universal Serial Bus (USB) port, vibration device, television transceiver, hands-free headset, Bluetooth® module, frequency modulation (FM) radio unit, digital music player, media player, video game player module, internet browser, virtual reality and / or augmented reality (VR / AR) device, activity tracker, etc. Peripherals 138 may include one or more sensors, which may be one or more of a gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor, geolocation sensor, altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biosensor, and / or humidity sensor.

[0030] WTRU102 may include a full-duplex radio (for example, one associated with a particular subframe for both UL (for example, transmission) and downlink (for example, reception)) where the transmission and reception of some or all of the signal may be in parallel and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and / or substantially eliminate self-interference through signal processing either through hardware (e.g., chokes) or a processor (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WRTU102 may include a half-duplex radio (for example, one associated with a particular subframe for either UL (for example, transmission) or downlink (for example, reception)).

[0031] Figure 1C is a system diagram showing RAN104 and CN106 according to one embodiment. As described above, RAN104 may employ E-UTRA radio technology to communicate with WTRU102a, 102b, and 102c via the air interface 116. RAN104 may also communicate with CN106.

[0032] RAN104 may include enodes B160a, 160b, and 160c, but it should be understood that RAN104 may include any number of enodes B while remaining consistent with the embodiment. Each of enodes B160a, 160b, and 160c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, enodes B160a, 160b, and 160c may implement MIMO technology. Thus, enode B160a may, for example, use multiple antennas to transmit and / or receive wireless signals from WTRU102a.

[0033] Each of the e-nodes B160a, 160b, and 160c may be associated with a specific cell (not shown) and may be configured to handle wireless resource management decisions, handover decisions, user scheduling in UL and / or DL, etc. As shown in Figure 1C, the e-nodes B160a, 160b, and 160c may communicate with each other via the X2 interface.

[0034] The CN106 shown in Figure 1C may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. Although each of the above elements is shown as part of CN106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0035] The MME162 can be connected to each of the e-nodes B162a, 162b, and 162c in RAN104 via the S1 interface and can function as a control node. For example, the MME162 may be responsible for authenticating users of WTRU102a, 102b, and 102c, activating / deactivating bearers, and selecting a specific serving gateway during the initial attachment of WTRU102a, 102b, and 102c. The MME162 may also provide control plane functionality for switching between RAN104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0036] The SGW164 can be connected to each of the e-nodes B160a, 160b, and 160c in RAN104 via the S1 interface. The SGW164 can generally route and forward user data packets to and from WTRU102a, 102b, and 102c. The SGW164 can perform other functions such as anchoring the user plane during handover between e-nodes B, triggering paging when DL data is available for WTRU102a, 102b, and 102c, and managing and remembering the context of WTRU102a, 102b, and 102c.

[0037] SGW164 may be connected to PGW166, which can provide WTRU102a, 102b, and 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, and 102c and IP-enabled devices.

[0038] CN106 can facilitate communication with other networks. For example, CN106 can provide WTRU102a, 102b, and 102c with access to a circuit-switched network such as PSTN108 to facilitate communication between WTRU102a, 102b, and 102c and conventional fixed communication devices. For example, CN106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN106 and PSTN108. Furthermore, CN106 may provide WTRU102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0039] Although the WTRU is shown as a wireless terminal in Figures 1A to 1D, in some typical embodiments where such a terminal may be used (for example, temporarily or permanently), wired communication is considered to interface with the communication network.

[0040] In a typical embodiment, the other network 112 may be a WLAN.

[0041] A WLAN in Infrastructure Basic Service Set (BSS) mode may have access points (APs) for the BSS and one or more stations (STAs) associated with the APs. APs may have access to or interfaces with a distribution system (DS) or another type of wired / wireless network that carries traffic entering and leaving the BSS. Traffic originating from outside the BSS to an STA may arrive through an AP and be sent to the STA. Traffic originating from an STA to a destination outside the BSS may be sent to an AP to be sent to its respective destination. Traffic between STAs within the BSS may be sent through an AP, for example, here, a source STA may send traffic to an AP, and the AP may send traffic to a destination STA. Traffic between STAs within the BSS is considered and / or sometimes referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between a source STA and a destination STA (e.g., directly between them) using a Direct Link Setup (DLS). In some typical embodiments, the DLS may be an 802.11e DLS or an 802.11z Tunneled DLS (TDLS). A WLAN using Independent BSS (IBSS) mode may not have access points (APs), and STAs within or using IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode is sometimes referred to herein as the “ad-hoc” communication mode.

[0042] When using the 802.11ac infrastructure operating mode or a similar operating mode, an AP may transmit beacons on a fixed channel, such as the primary channel. The primary channel may be of a fixed width (e.g., a 20 MHz bandwidth) or a width dynamically set via signaling. The primary channel may be the operating channel of the BSS and may be used by the STA to establish a connection with the AP. In some typical embodiments, Carrier Sensitivity Multiple Access / Collision Avoidance (CSMA / CA) may be implemented, for example, in an in 802.11 system. In CSMA / CA, an STA, including the AP (e.g., any STA), may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, that particular STA may backoff. One STA (e.g., just one station) may transmit at a given time in a given BSS.

[0043] A high-throughput (HT) STA may use a 40MHz wide channel for communication via a combination of primary 20MHz channels, for example, with adjacent or non-adjacent 20MHz channels, in order to form a 40MHz wide channel.

[0044] Extremely high throughput (VHT) STAs may support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. 40 MHz and / or 80 MHz channels may be formed by combining consecutive 20 MHz channels. 160 MHz channels may be formed by combining eight consecutive 20 MHz channels, or by combining two discontinuous 80 MHz channels, sometimes referred to as an 80+80 configuration. In an 80+80 configuration, data may be passed through a segment parser that can split the data into two streams after channel coding. Inverse fast Fourier transform (IFFT) processing and time-domain processing may be performed separately for each stream. Streams may be mapped onto two 80 MHz channels, and data may be transmitted by a transmitting STA. At the receiver of a receiving STA, the operation described above for the 80+80 configuration may be reversed, and the combined data may be sent to a media access control (MAC).

[0045] Sub-1GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV white space (TVWS) spectrum, while 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using the non-TVWS spectrum. According to a typical embodiment, 802.11ah may support meter-type control / machine-type communications, such as MTC devices in a macro coverage area. The MTC device may have limited capabilities, including support for some and / or limited bandwidths (e.g., only support for that). The MTC device may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0046] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as the primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by the STA that supports the smallest bandwidth operating mode among all STAs operating in the BSS. In the 802.11ah example, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes, the primary channel may be 1MHz wide for an STA (e.g., an MTC type device) that supports (e.g., only) the 1MHz mode. Carrier detection and / or network allocation vector (NAV) settings may depend on the status of the primary channel. For example, if the primary channel is busy because an STA (which only supports 1MHz operating mode) is transmitting to the AP, a large portion of the frequency band remains idle, and the entire available frequency band may be considered busy, even if it could be available elsewhere.

[0047] In the United States, the available frequency band that can be used by 802.11ah ranges from 902 MHz to 928 MHz. In South Korea, the available frequency band ranges from 917.5 MHz to 923.5 MHz. In Japan, the available frequency band ranges from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah ranges from 6 MHz to 26 MHz, depending on the country code.

[0048] Figure 1D is a system diagram showing RAN113 and CN115 according to one embodiment. As described above, RAN113 may employ NR radio technology to communicate with WTRU102a, 102b, and 102c via air interface 116. RAN113 may also communicate with CN115.

[0049] RAN113 may include gNB180a, 180b, and 180c, but it should be understood that RAN113 may include any number of gNBs while remaining consistent with the embodiment. Each of gNB180a, 180b, and 180c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, gNB180a, 180b, and 180c may implement MIMO technology. For example, gNB180a and 108b may utilize beamforming to transmit and / or receive signals from gNB180a, 180b, and 180c. Thus, gNB180a may use multiple antennas to transmit and / or receive wireless signals from, for example, WTRU102a. In one embodiment, gNB180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB180a may transmit multiple component carriers to WTRU102a (not shown). A subset of these component carriers may be on the unlicensed spectrum, while the remaining component carriers may be on the licensed spectrum. In one embodiment, gNB180a, 180b, and 180c may implement coordinated multipoint (CoMP) technology. For example, WTRU102a may receive coordinated transmissions from gNB180a and gNB180b (and / or gNB180c).

[0050] WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using transmissions associated with scalable numerology. For example, OFDM symbol intervals and / or OFDM subcarrier intervals may vary for different transmissions, different cells, and / or different parts of the wireless transmission spectrum. WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or lasting for varying lengths of absolute time).

[0051] gNB180a, 180b, and 180c can be configured to communicate with WTRU102a, 102b, and 102c in standalone and / or non-standalone configurations. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c without accessing other RANs (e.g., e-nodes B160a, 160b, and 160c). In a standalone configuration, WTRU102a, 102b, and 102c can utilize one or more of gNB180a, 180b, and 180c as mobility anchor points. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c using signals in unlicensed bands. In a non-standalone configuration, WTRU102a, 102b, and 102c can communicate with / connect to gNB180a, 180b, and 180c while also communicating with / connecting to other RANs such as enodes B160a, 160b, and 160c. For example, WTRU102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNB180a, 180b, and 180c and one or more enodes B160a, 160b, and 160c. In a non-standalone configuration, enodes B160a, 160b, and 160c can act as mobility anchors for WTRU102a, 102b, and 102c, and gNB180a, 180b, and 180c can provide additional coverage and / or throughput to service WTRU102a, 102b, and 102c.

[0052] Each of the gNB180a, 180b, and 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, support for network slicing, dual connectivity, interaction between NR and E-UTRA, routing of user plane data to user plane functions (UPF) 184a and 184b, and routing of control plane information to access and mobility management functions (AMF) 182a and 182b. As shown in Figure 1D, the gNB180a, 180b, and 180c may communicate with each other via the Xn interface.

[0053] The CN115 shown in Figure 1D may include at least one AMF182a, 182b, at least one UPF184a, 184b, at least one Session Management Function (SMF)183a, 183b, and optionally a Data Network (DN)185a, 185b. While each of the above elements is shown as part of CN115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0054] AMF182a and 182b may be connected to one or more of gNB180a, 180b, and 180c in RAN113 via the N2 interface and may act as control nodes. For example, AMF182a and 182b may be responsible for authenticating users of WTRU102a, 102b, and 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting specific SMF183a and 183b, managing registration areas, terminating NAS signaling, and mobility management. Network slicing may be used by AMF182a and 182b to customize CN support for WTRU102a, 102b, and 102c based on the type of service that is being utilized. For example, different network slices may be established for different use cases, such as services relying on high-reliability, low-latency (URLLC) access, services relying on extended large-scale mobile broadband (eMBB) access, and services using machine-type communications (MTC) access. The AMF162 may provide control plane functionality for switching between RAN113 and other RANs (not shown) employing other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0055] SMF183a and 183b may be connected to AMF182a and 182b in CN115 via the N11 interface. SMF183a and 183b may also be connected to UPF184a and 184b in CN115 via the N4 interface. SMF183a and 183b may select and control UPF184a and 184b and configure traffic routing through UPF184a and 184b. SMF183a and 183b may perform other functions such as managing and allocating IP addresses for UEs, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. PDU session types may include IP-based, non-IP-based, Ethernet-based, etc.

[0056] UPF184a, 184b may be connected to one or more of the gNB180a, 180b, 180c in RAN113 via an N3 interface that can provide WTRU102a, 102b, 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, 102c and IP-enabled devices. UPF184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring.

[0057] CN115 can facilitate communication with other networks. For example, CN115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN115 and PSTN108. Furthermore, CN115 may provide WTRU102a,102b,102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU102a,102b,102c may be connected to the local data network (DN) 185a,185b through UPF184a,184b via an N3 interface to UPF184a,184b and an N6 interface between UPF184a,184b and DN185a,185b.

[0058] In view of Figures 1A to 1D and the corresponding descriptions of Figures 1A to 1D, one or more or all of the functions described herein with respect to one or more of the WTRU102a to d, base stations 114a to b, e-nodes B160a to c, MME162, SGW164, PGW166, gNB180a to c, AMF182a to b, UPF184a to b, SMF183a to b, DN185a to b, and / or any other devices described herein may be implemented by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, an emulation device may be used to test other devices and / or to simulate network and / or WTRU functions.

[0059] Emulation devices may be designed to perform one or more tests on other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices may perform one, several, or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communications network to test other devices in a communications network. One or more emulation devices may perform one, several, or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communications network. Emulation devices may be directly coupled to another device to be tested and / or to perform tests using over-the-air wireless communications.

[0060] One or more emulation devices may perform one or more functions, including all of the above, without being implemented / deployed as part of a wired and / or wireless communication network. For example, an emulation device may be used in a test scenario in a test laboratory and / or an undeployed (e.g., for testing) wired and / or wireless communication network to implement testing of one or more components. One or more emulation devices may be test equipment. To transmit and / or receive data, the emulation device may use direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas).

[0061] This specification describes systems, methods, and means for acquiring synchronization and system information in energy-saving networks associated with WUS, resulting in slim synchronization and SSB measurements. Synchronization acquisition of a wireless transmit / receive unit (WTRU) can be initiated by detecting a synchronization signal (SS). The WTRU may determine timing and / or resource information for pre-synchronization or DL-WUS type signals based, for example, slim synchronization indications. Pre-synchronization or WUS signaling may provide network energy saving (NES) configuration information and timing indications for system information.

[0062] 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., a wake-up signal (WUS), a 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 selection information). The first signal may indicate a slim sequence that can indicate information associated with the second signal. The first signal may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or both PSS and SSS (e.g., PSS and SSS only). In the example, the first signal may refrain from including a physical broadcast channel (PBCH) block. The WTRU may, for example, determine the resources associated with receiving a second signal (e.g., a pre-synchronization signal, WUS, DL-WUS) based on information associated with the second signal (e.g., indicated by the first signal). The WTRU may receive the second signal via resources determined using the information associated with the second signal. The second signal may include indications associated with receiving the SSB. The SSB may include PBCH blocks. The WTRU may determine the information associated with receiving the SSB based on indications associated with receiving the SSB (e.g., indicated by the second signal). The information associated with receiving the SSB may include one or more of the following: the state of the NES, the SSB period, the presence of all SSBs on all potential SSB transmission opportunities. The WTRU may receive the SSB based on the determined information associated with receiving the SSB.

[0063] A WTRU may receive a synchronization signal (SS). The SS may be a slim SS (e.g., a compressed SS). The SS may represent a pre-synchronization signal. The SS may include a primary SS, a secondary SS, or both primary and secondary SS. A WTRU may determine pre-synchronization signal information (e.g., timing and / or resource information) associated with the pre-synchronization signal, for example, based on the characteristics associated with the SS. A WTRU may receive a pre-synchronization signal based on the pre-synchronization signal information. A WTRU may determine SS and physical broadcast channel block (SSB) information based on the pre-synchronization signal. A WTRU may receive an SSB based on the SSB information. A WTRU may determine system information block information. A WTRU may determine random access channel (RACH) parameters based on system information block information.

[0064] Network energy saving (NES) procedures may be used and / or enabled. Extensions may be provided that allow the network to minimize its power consumption from transmitting and receiving. Such minimization may be beneficial in reducing operating costs and environmental sustainability.

[0065] NES design can be (for example, extremely) efficient in terms of minimizing transmissions from the network when there is no data (compared to, for example, older systems). For example, always-on cell-specific reference signals (CRS) can be avoided (for example, not used at all). However, energy consumption can be reduced (for example, there is still potential for reducing energy consumption).

[0066] For example, a network may still consume energy when it refrains from transmitting (e.g., not transmitting) from other activities such as baseband (digital) processing for receiving or beamforming. Such idle power consumption can be significant in high-density networks, even when a WTRU is not being serviced for a given period (e.g., when). Energy consumption could be reduced if the network could switch off these activities when not transmitting to the WTRU.

[0067] The transmission of always-on synchronization signals (e.g., sync or synchronization signals) or reference signals may be discouraged (e.g., they may not be necessary). Adaptive bandwidth and MIMO capabilities may be supported. Adapting network resources may enable greater efficiency.

[0068] The following terms may be used.

[0069] Channel status information (CSI) may include at least one of the following: channel quality index (CQI), rank indicator (RI), precoding matrix index (PMI), L1 channel measurement (e.g., reference signal received power (RSRP) or SINR such as L1-RSRP), CSI-RS resource indicator (CRI), synchronization signal (SS) / physical broadcast channel (PBCH) block resource indicator (SSBRI), layer indicator (LI), and / or any other measurement measured by WTRU from the configured CSI-RS or SS / PBCH block. A WTRU may report a subset of channel status information (CSI) components, where the CSI components may correspond to at least the CSI-RS resource indicator (CRI), SSB resource indicator (SSBRI), panel indications used for reception in the WTRU (such as panel identification information or group identification information), measurements such as L1-RSRP, L1-SINR taken from SSB or CSI-RS (e.g., cri-RSRP, cri-SINR, ssb-Index-RSRP, ssb-Index-SINR), and / or at least other channel status information such as rank indicator (RI), channel quality indicator (CQI), precoding matrix indicator (PMI), and layer index (LI).

[0070] Uplink control information (UCI) may include one or more of the following: CSI, HARQ feedback for one or more HARQ processes, scheduling requests (SR), link recovery requests (LRR), CG-UCI, and / or other control information bits that may be transmitted over PUCCH or PUSCH.

[0071] Channel status may include any conditions relating to the radio / channel status, which may be determined by the WTRU from one or more of the following: WTRU measurements (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), radio link monitoring (RLM) status, and / or channel availability in the unlicensed spectrum (e.g., whether the channel is occupied based on LBT procedure decisions or whether the channel is considered to have experienced a consistent LBT failure).

[0072] A physical random access channel (PRACH) resource (for example, in frequency), a PRACH opportunity (RO) (for example, in time), a preamble format (for example, in terms of total preamble duration, sequence length, guard duration and / or cyclic prefix length), and / or a certain preamble sequence may be used for transmitting a preamble in a random access procedure.

[0073] The properties of scheduling information (e.g., uplink grant or downlink allocation) may include one or more of the following: frequency allocation, time allocation mode such as duration, priority, modulation and coding scheme, transport block size, number of spatial layers, number of transport blocks to be carried, transmit configuration indication (TCI) status or sounding reference signal resource indicator (SRI), number of repetitions, and whether the grant is a configured grant type 1, type 2, or dynamic grant.

[0074] Downlink Control Information (DCI) indications (e.g., or indications) may include one or more of the following: explicit indications by DCI fields (e.g., used to mask cyclic redundancy checks (CRCs) of PDCCHs) or by radio network temporary identifiers (RNTIs); implicit indications by properties (e.g., DCI format, DCI size, core set or search space, aggregation level, identification information for the first control channel resource for DCI (e.g., index of the first control channel element (CCE)), where the mapping between properties and values ​​may be signaled by RRC or MAC); and explicit indications by DL MAC CEs.

[0075] The terms network availability state, cell off-switching, cell DTX mode / configuration, or NES state may be used interchangeably. A WTRU can implicitly determine the cell's DTX / DRX state from its determined active availability state, and vice versa.

[0076] In the following, “a” and “an” and similar phrases should be interpreted as “one or more” and “at least one.” Similarly, words ending in the suffix “one or more” should be interpreted as “one or more” and “at least one.” The term “may” should be interpreted as “for example, may.”

[0077] In this specification, the symbol " / " (for example, a forward slash) may be used to represent "and / or", where, for example, "A / B" may imply "A and / or B".

[0078] A beam can be defined.

[0079] A WTRU may, for example, transmit or receive a physical channel or reference signal according to at least one spatial domain filter. The term "beam" may be used to refer to a spatial domain filter.

[0080] A WTRU may transmit a physical channel or signal using the same spatial domain filter used to receive an RS (e.g., CSI-RS) or SS block. A WTRU transmission is sometimes referred to as a target. The received RS or SS block is sometimes referred to as a reference or source. In such cases, the WTRU may (for example, be said to) transmit a target physical channel or signal according to its spatial relationship with the reference to such an RS or SS block.

[0081] A WTRU may transmit a first physical channel or signal according to the same spatial domain filter used to transmit a second physical channel or signal. The first and second transmissions may be referred to as the target and reference (e.g., source), respectively. In such cases, the WTRU may (for example, be said to) transmit the first (e.g., target) physical channel or signal according to the spatial relationship between the second (e.g., reference) physical channel or signal and the reference.

[0082] Spatial relationships can 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 transmit and a PUSCH DM-RS according to the same spatial domain filter as the SRS indicated in DCI or indicated by an SRI configured by RRC. In the example, the spatial relationship may be configured for an SRS resource indicator (SRI) (e.g., via RRC signaling) or signaled for PUCCH (e.g., by MAC CE). Such spatial relationships are sometimes also called beam indications.

[0083] A WTRU may receive a first (e.g., target) downlink channel or signal according to the same spatial domain filter or spatial receive parameters as a second (e.g., reference) downlink channel or signal. For example, such an association may exist between a physical channel such as a PDCCH or PDSCH and its respective DM-RS. Such an association may exist when the WTRU is configured with a pseudo-collocation (QCL) assumption type D between the corresponding antenna ports, when (e.g., at least) the first and second signals are reference signals. Such an association may be configured as a TCI (Transmit Configuration Indicator) state. A WTRU may receive an indication of the association between a CSI-RS or SS block and a DM-RS by indexing to a set of TCI states (e.g., configured by RRC signaling and / or signaled by MAC CE). Such an indication may also be called a beam indication.

[0084] In this specification, SSB may refer to one or more SSB beams (e.g., spatial relationships) within a collection of SSBs (e.g., an SSB burst). SSB may refer to a beam, and vice versa, or to a CSI-RS resource related to a beam. SSB, multiple SSBs, and / or an SSB burst may refer to one or more beams transmitted from a Transmit / Receive Point (TRP).

[0085] A TRP can be used interchangeably with one or more of the following: transmit point (TP), receive point (RP), radio remote head (RRP), distributed antenna (DA), base station (BS), sector (e.g., of a BS), and / or cell (e.g., a geographic cell area served by a BS). A multi-TRP can be used interchangeably with one or more of the following: MTRP, M-TRP, and multiple TRPs.

[0086] Discontinuous transmission (DTX) and intermittent reception (DRX) of cells may be implemented and / or enabled.

[0087] BS (e.g., gNB) may use reduced downlink transmit / uplink receive activity without a DTX / DRX pattern for a cell limited by, for example, a WTRU DRX configuration and any configured transmit / receive (e.g., a common channel / signal). C-DRX may be configured per WTRU. Alignment of DRX cycles or offsetting for different WTRUs may be done via RRC (e.g., only). During a WTRU's DRX off (inactive) period, the WTRU may not be expected to monitor PDCCH, but the WTRU may initiate UL transmits (e.g., may be allowed to initiate them) according to configured resources (e.g., using PUCCH, RACH, SR, or CG-PUSCH). Alignment / omission of DRX patterns across multiple WTRUs may be achieved, for example, via a gNB implementation.

[0088] Cell DTX / DRX may (or may be intended to) provide a mechanism to inform the WTRU whether the cell remains inactive. This may include extensions to the WTRU DRX configuration for WTRUs in connected mode or idle / inactive mode (e.g., to align / skip DRX cycles or initiate DRX offsets), which may allow for longer opportunities for the cell to remain inactive. During cell DTX / DRX, the cell may have no transmit / receive or only limited transmit / receive (e.g., only). For example, the cell may refrain from transmitting or receiving certain periodic signals / channels (e.g., common channels / signals or WTRU-specific signals / channels) (e.g., they do not need to be transmitted or received).

[0089] Cell DTX / DRX can be applied to WTRUs that are at least in the RRC_CONNECTED state. Periodic cell DTX / DRX (e.g., active and inactive periods) can be configured by gNB via WTRU-specific RRC signaling for each serving cell. Cell DTX / DRX modes can be activated / deactivated via dynamic L1 / L2 signaling and WTRU-specific RRC signaling. WTRU-specific signaling and / or common L1 / L2 signaling can be considered to activate / deactivate cell DTX / DRX modes. 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 parameters such as period, start slot / offset, and duration can be configured for each cell DTX / DRX configuration. In the example, the cell's DTX indication could be part of the SI update or SIB signaling. There may be a common time for (e.g., all) WTRUs to determine the cell's DTX status.

[0090] A WTRU may consist of DRX and / or DTX configuration information for multiple cells (for example, simultaneously within a given serving cell). A WTRU may consist of a primary or default cell DTX and / or DRX configuration that the WTRU can apply by default. Based on the reception of a signaling that activates one cell's DTX and / or DRX configuration, the WTRU may deactivate another (for example, or all others). Based on the reception of a signaling that deactivates one cell's DTX and / or DRX configuration, the WTRU may activate another or activate the default cell DTX / DRX configuration. Based on the determination that the duration has elapsed (for example, timer expiration), the WTRU may fall back to the default cell DRX and / or DTX configuration. The WTRU may reset such duration (e.g., via a timer) based on the reception of DL signaling or data or indication from the NW to remain in a given non-default DTX or DRX state of the cell.

[0091] Network availability status, cell DTX mode, and / or NES status may be considered and / or used.

[0092] An NES state or availability state may refer to a cell state in which a cell or TRP has activated at least one NES technique. NES techniques may include one or more of the following: DTX of the cell, DRX of the cell, spatial domain adaptation (e.g., antenna ports and / or a subset of elements are turned off), power domain adaptation (e.g., a subset of channels are transmitted at reduced power or muted), and / or the cell or TRP is turned off.

[0093] A WTRU may determine whether it can transmit or receive on certain resources depending on the network availability state (which may imply, for example, the power saving status of a gNB). Availability states may correspond to the network energy saving state, the cell's DTX mode, the cell's DRX mode, and / or the gNB activity level. Availability states may be specific to uplinks or downlinks and may change per symbol, per slot, per frame, or at a longer duration granularity. Availability states may be determined by the WTRU or indicated by the network. Availability states may be one or more of the following: "On," "DL and UL Active," "UL Only Active," "Off," "Reduced Tx Power," "Hibernate," "Microsleep," "Light Sleep," or "Deep Sleep." Such states may be abstracted by NW configuration parameters and / or values. Dynamic indications may point to active availability states (for example, by DCI or MAC CE signaling). An "Off" availability state may imply that the gNB's baseband hardware is completely turned off. A “sleep” availability state may imply that the gNB periodically wakes up to transmit certain signals (e.g., presence signals, synchronization, or reference signals) or to receive certain UL signals. In certain availability states, certain DL or UL resources may be unavailable for a certain period of time, which may allow the network to turn off baseband processing and other activities. For example, a WTRU may consist of periodic active and inactive periods for each availability (e.g., by RRC signaling). Certain measurement resources (e.g., SSB or CSI-RS) may be made available (e.g., only) in certain availability states, such as RLM, BFD, RRM measurements, CSI-RS feedback configurations, and / or different power offsets for CSI feedback.

[0094] The WTRU may send a request (e.g., a startup request) to the network (for example, based on conditions that have been met) to modify, for example, the availability state to a state in which resources that can satisfy the WTRU's requirements are available.

[0095] WTRU may determine its availability state from receiving availability state indications (e.g., via L1 / L2 signaling, e.g., group-common DCI or indications), or implicitly from receiving or not receiving periodic DL signaling.

[0096] A WTRU may determine whether a resource is available for transmission / reception and / or measurement for a determined network availability state (e.g., whether the resource is applicable in an active availability state). A WTRU may adapt its active C-DRX cycle, active spatial elements (e.g., antennas or logical ports), active TRPs, and paging occasions depending on the signaled or determined availability state. A WTRU may consist of one or more sets of NES transmit and / or receive parameters for each availability state, for example, by broadcasted or dedicated configuration signaling. A WTRU may apply a set of NES parameters according to the determined or signaled availability state. A 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: several antenna ports, C-DRX configurations, measurement configurations (e.g., for RRM, RLM, and / or BFD), CSI feedback, CSI-RS configurations, SSB configurations, CHO or mobility candidates, and a set of active TRPs.

[0097] An availability state may be applicable to at least one transmit, receive, or measure resource. An availability state may be applicable to at least one time period, such as a time slot or time symbol. An availability state may be applicable to a serving cell, cell group, frequency band, bandwidth portion, TRP, set of spatial elements, or frequency range within a bandwidth portion. For example, if the NES state changes within a cell (e.g., when), the WTRU may receive an availability state change indication that this change is for that cell only, for all cells at the same frequency, and / or for all cells at the same RAT.

[0098] A WTRU may consider that, for example, after receiving DL signaling that modifies the availability state of a cell or TRP, the active availability state associated with the cell, carrier, TRP, or frequency band should be “off,” “deep sleep,” or “micro sleep.” For example, a WTRU may receive a turn-off command for broadcast signaling, RRC signaling, DCI (e.g., a group-common DCI), or DL ​​MAC CE (e.g., the indication portion of a PDSCH). A WTRU may determine the availability state based on (for example, from) the reception of availability state indications from L1 / L2 signaling (e.g., a group-common DCI or indication) or broadcast signaling associated with the availability state.

[0099] For example, availability state change indications could be part of SI updates or SIB signaling (e.g., in a separate SIB not read by WTRUs). There may be a common time for WTRUs in a cell (e.g., all WTRUs) to determine the availability state status.

[0100] The WTRU may determine a change in NES state from the reception of group-common command L1 signaling (e.g., group-common DCI, multi-stage DCI, a specific DCI format, or DCI scrambled by a configured or specified NES-specific RNTI). The L1 signaling may indicate one of the configured NES parameter sets to apply, or, upon determining a change in NES state, may determine a delta configuration from the current set of parameters. The WTRU may, for example, send feedback / acknowledgment to the gNB (e.g., multiplexed with UL data, possibly MAC CE or a portion of the UL TB as a subheader indication) following the reception of the NES state change indication.

[0101] A WTRU may determine a change in the NES state from the reception of broadcast signaling associated with an indication or change in the NES state (e.g., signaling in a portion of an SIB or broadcast or multicast PDSCH). A WTRU may indicate the NES state in an SIB (e.g., explicitly indicate the NES state). A WTRU may receive configuration information that includes one or more SIBs exclusively associated with the configuration of the NES parameters (e.g., may be composed of that SIB). A WTRU may receive configuration information to periodically receive such broadcast or multicast indications (e.g., may be configured to receive them). A WTRU may determine that an indication is a false positive if, for example, it is not received at an expected periodic opportunity, if several false positives are counted, and / or if time (e.g., via a timer) has elapsed since the last reception of the indication of the NES state. The WTRU may initiate inter-cell, inter-frequency, and / or inter-RAT measurements, initiate mobility procedures, and / or evaluate CHO candidates configured based on (for example, subsequently) a decision on false positives of NES state indications.

[0102] A WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., "off", "deep sleep", "microsleep", or "hibernate") based on one or more of the following: reception of commands or signals indicating a change in availability state, reception of paging messages, paging DCI, paging PDSCH, or paging-related signals, gNB DTX status, lack of detection of presence indications, detection of PSS signals (e.g., PSS limited signals) or simplified / separated down SSB signals, detection of RS signals or their absence, RRC status of the WTRU, whether paging was received (e.g., within a configured time window), whether system information was received (e.g., within a configured time window), measured channel state below or above a threshold, etc.

[0103] A WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., "off," "deep sleep," "microsleep," or "hibernate") based on the reception of a command or signal indicating a change in availability state (e.g., a group-common DCI or RRC signaling or presence signal for a connection mode). A WTRU may implicitly determine an availability state from the reception of periodic DL signaling. A WTRU may be configured (e.g., it may receive configuration information indicating this) or specified to associate an availability state with one or more DL signal types (e.g., SSB, partial SSB, and / or one or more periods).

[0104] A WTRU may implicitly assume an availability state (e.g., "off," "deep sleep," "microsleep," or "hibernate") associated with a cell, carrier, TRP, or frequency band, for example, based on the reception of a paging message, paging DCI, paging PDSCH, or paging-related signal (e.g., PEI) on a subset of POs (e.g., one aligned with NES DRX cycles or a configured subset of PDCCH resources). A WTRU may assume an availability state after receiving an indication portion of a DCI or PDCCH that schedules paging (e.g., depending on P-RNTI, NES-RNTI, or receiving an explicit indication, e.g., based on reserved bits). A WTRU may assume an availability state after receiving a paging message with a P-RNTI, a separately configured NES P-RNTI, or an NES group RNTI. A WTRU may assume an availability state after receiving a paging message with a P-RNTI. A WTRU may consist of one or more PEI subgroups for an NES, where the subgroups may be associated with one or more availability states. For example, if the subgroup consists of and / or is associated with an availability state, the WTRU may assume an availability state in which the PEI has the NES subgroup. Indications of availability states or availability state transitions may be shown in the paging payload, for example, as a flag portion of a paging message or short message. Such paging indications may further indicate alternative cells to monitor for paging while the cell from which the signaling was received is off, sleep, or in an NES state. Such paging indications may further indicate or signal applicable reconfiguration parameters (for example, initial access, applicable PRACH resources, applicable SSB / RS opportunities, applicable SI cycles, and / or applicable cells and associated availability states).

[0105] WTRU may implicitly assume availability states (e.g., "off", "deep sleep", "micro sleep", or "hibernate") associated with cells, carriers, TRPs, or frequency bands based, for example, on the gNB DTX status (e.g., whether the gNB is in active time or whether the associated activity timer is running).

[0106] A WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band based on the lack of presence indication detection, such as one or more of the following:

[0107] WTRU may, for example, determine the availability state associated with a cell (e.g., "off" or "deep sleep") if presence indications are not detected on one or more presence indication opportunities.

[0108] The WTRU may assume or change the availability state of a cell after several consecutive false positives or after a duration following the failure to detect an presence signal (e.g., after the timer expires). The WTRU may determine that the availability state is active or inactive (e.g., inactive) after a duration associated with the availability state (e.g., after the timer expires). Such durations (e.g., via a timer) can be configured and / or maintained in connected mode (e.g., only) or in other states (e.g., idle and inactive states).

[0109] A WTRU may implicitly determine an availability state from, for example, the absence of receiving periodic DL signaling (e.g., during duration). For example, a WTRU may receive configuration information indicating a signal quality threshold (e.g., an RSRP threshold) (e.g., it may consist of a signal quality threshold). If a WTRU does not detect a signal associated with an availability state with a signal intensity above the threshold (e.g., a presence signal or SSB), the WTRU may assume that this availability state is inactive and may assume a different availability state. This criterion can also be coupled to the absence of detection of the presence signal identification sequence (e.g., detection of a PSS sequence).

[0110] A WTRU may implicitly assume availability states (e.g., “off”, “deep sleep”, “microsleep”, or “hibernate”) associated with cells, carriers, TRPs, or frequency bands based on the time of day. A WTRU may receive configuration information indicating that it (e.g., automatically) assumes a certain availability state (e.g., off, sleep, or hibernate) for a configured subset of cells (e.g., capacity boost cells) depending on the time of day (e.g., it may be configured to assume such a state). For example, a WTRU may determine that a capacity boost cell has an availability state as “on” during certain hours of the day, as “deep sleep” during other configured hours, and as “off” during a third set of configured hours, either daytime or nighttime.

[0111] WTRU may implicitly assume availability states (e.g., "off", "deep sleep", "micro sleep", or "hibernate") associated with cells, carriers, TRPs, or frequency bands based on the availability states of related cells (e.g., another carrier in 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 related cell or capacity boost cell).

[0112] WTRU may implicitly assume availability states (e.g., "off", "deep sleep", "micro sleep", or "hibernation") associated with cells, carriers, TRPs, or frequency bands based, for example, on the detection of PSS-limited signals or simplified / separated down-SSB signals.

[0113] WTRU may implicitly assume availability states (e.g., "off", "deep sleep", "microsleep", or "hibernate") associated with cells, carriers, TRPs, or frequency bands based, for example, on the detection of RS signals (e.g., CSI-RS, PRS, TRS) or their absence.

[0114] A WTRU may implicitly assume an availability state (e.g., "off", "deep sleep", "micro sleep", or "hibernate") associated with a cell, carrier, TRP, or frequency band based on the WTRU's RRC state (e.g., idle, inactive, or connected mode).

[0115] WTRU may implicitly assume availability states (e.g., "off," "deep sleep," "microsleep," or "hibernate") associated with cells, carriers, TRPs, or frequency bands based on whether paging was received (e.g., within a configured time window, if applicable).

[0116] A WTRU may implicitly assume an availability state (e.g., "off," "deep sleep," "microsleep," or "hibernate") associated with a cell, carrier, TRP, or frequency band, based on whether system information (e.g., a subset of periodic SI or SIB) has been received (e.g., possibly within a configured time window).

[0117] A WTRU may implicitly assume an availability state associated with a cell, carrier, TRP, or frequency band (e.g., "off," "deep sleep," "microsleep," or "hibernate") based on a measured channel state that is below or above a threshold. A WTRU may assume a change in the NES state based on a change in the measured channel state or causing the channel measurement to fall below or above a threshold. For example, a WTRU may use a degradation of an SSB or CSI-RS measurement (e.g., possibly in combination with other signaling) to determine the NES state. For example, a configured window following the reception of a DCI may be used to measure the SSB and / or CSI-RS for degradation. If a delta of SSB-RSRP degradation is measured, the WTRU may determine that the NES state has changed and assume an associated action for such an NES state (e.g., a trigger for group scheduling for CHO candidate selection or mobility commands).

[0118] A WTRU may receive (or be configured to receive) configuration information to monitor indications that may characterize a level of network activity (e.g., availability state). Network activity may be associated with gNBs and / or cells. A WTRU may assume the same availability state for all cell portions of the same gNB, e.g., cells of the same MAC entity. Network activity indications (e.g., presence indications) may include channels (e.g., PDCCHs) and / or signals (e.g., sequences). Activity indications or NES state change indications / commands may indicate a level of activity that the WTRU can expect from the associated gNB and / or cell, e.g., reduced activity. Activity indications may include activity information from other gNBs / cells. Activity indications may be PDCCHs that include group-common signaling. For example, a network may send a group-common DCI to a group of WTRUs (e.g., WTRUs in a serving cell) indicating a change in activity state or activity level during UL and / or DL. The CRC of the PDCCH may be scrambled using a dedicated activity indication RNTI or NES-RNTI. The WTRU may consist of at least one search space associated with the monitoring opportunity of the activity indication PDCCH. The indication may include a sleep transition signal, e.g., a predefined sequence. When the WTRU detects this sequence (e.g., when), the WTRU may anticipate a reduced activity level over a specific duration. The WTRU may activate the C-DRX for the indicated time period. Multiple (e.g., two) sequences may be used to indicate normal and reduced activity.

[0119] Signaling within a PDCCH or activity indication may include (for example, may include):

[0120] Signaling within PDCCH or activity indication may include (or may include) the expected activity level (e.g., availability state) of the relevant gNB / cell over a specific time interval. Activity levels may be predetermined and / or configured, and may include, for example, normal and reduced activity. Signaling may indicate activity levels. For example, bit "1" may indicate normal activity, and bit "0" may indicate reduced activity.

[0121] Signaling within a PDCCH or activity indication may include (e.g., may include) transmit and / or receive attributes per activity level (e.g., availability state) (e.g., transmit and receive attributes may be defined). For example, during reduced activity, a WTRU may refrain from monitoring certain PDCCH search spaces (e.g., including all SS) (e.g., may not be expected to monitor), and / or may receive certain types of PDSCH transmits (e.g., including all PDSCH transmits), and / or may transmit PUCCH / PUSCH transmits, and / or may perform certain measurements. A WTRU may start or stop monitoring PDCCH and / or TCI states associated with determined NES states, including PDCCH resources or TCI states associated with (de)activated TRPs or spatial elements.

[0122] Signaling within PDCCH or activity indications may include (for example, may include) a set of configurations that can be associated with an activity level, and can be used / applied when that activity level (e.g., NES parameter set) is indicated, such as SS configuration, CSI reporting configuration, and index of transmitted SSBs. Each set of configurations may have attributes associated with the activity level, such as a tag that can be set to "reduced activity".

[0123] Time intervals in which activity levels can be assumed may be signaled within a PDCCH transmission or portion of an activity indication. Time intervals may be represented using a bitmap, for example, where each bit in the bitmap may be associated with a specific duration, e.g., a slot or frame. For example, bit "1" may indicate normal activity on the associated frame, and bit "0" may indicate reduced activity. Time intervals may be represented by a start time and an interval length. 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 interval length may be configured or signaled within an indication PDCCH transmission.

[0124] The time intervals over which the activity level is assumed can be predetermined. WTRU may assume an interruption delay (e.g., the time until the NES state changes) after receiving an NES state change command (e.g., after the last symbol or slot in which the command was received). The interruption time can be in units of absolute time, symbols, or slots.

[0125] A WTRU may determine whether an uplink or downlink resource or signal is available for transmission / reception and / or measurement for a determined network availability state, for example, whether a resource is applicable in an active availability state. A WTRU may determine that a subset of measurement resources and / or signals (e.g., SSB, CSI-RS, TRS, PRS) are not applicable in some availability states. A WTRU may determine that a subset of uplink or downlink resources (e.g., PRACH, PUSCH, PUCCH) are not applicable in some availability states. A WTRU may transmit some uplink signals (e.g., only) in a subset of NW availability states (e.g., SRS, pSRS, PRACH, UCI).

[0126] Synchronization signals and procedures may be made available and / or provided.

[0127] Downlink synchronization may be performed.

[0128] Downlink synchronization may involve the WTRU detecting radio frame boundaries (e.g., the exact timing of when a radio frame begins) and OFDM symbol boundaries (e.g., the exact timing of when an OFDM symbol begins). This can be done by detecting and analyzing synchronization signal blocks (SSBs).

[0129] A synchronization signal block and / or PBCH block may include primary and secondary synchronization signals (PSS, SSS) that may occupy, for example, one symbol and 127 subcarriers (for example, they may each occupy), and the PBCH may span three OFDM symbols and 240 subcarriers, leaving an unused portion in the middle for the SSS on one symbol as shown in Figure 2. The possible time locations of an SSB within a half-frame may be determined by the subcarrier spacing, and the period of the half-frame in which the SSB is transmitted may be indicated by the network (for example, it may be configured). Within a half-frame, different SSBs may be transmitted in different spatial directions (for example, across the cell's coverage area using different beams).

[0130] Multiple SSBs can be transmitted within a carrier frequency span. The physical cell identification information (PCI) of SSBs transmitted in different frequency locations may not be unique (for example, they do not need to be unique), and different SSBs in the frequency domain may have different PCIs. However, when an SSB is associated with an RMSI (for example, when), the SSB may be called a cell-defined SSB (CD-SSB). A PCell may be associated with a CD-SSB located on a synchronous raster.

[0131] Figure 2 shows an exemplary time-frequency structure of SSB.

[0132] Polar coding can be used for PBCH.

[0133] For example, a WTRU may assume a bandwidth-specific subcarrier spacing for SSB unless it is configured to assume a different subcarrier spacing for the network.

[0134] PBCH transmission symbols can carry their own frequency-multiplexed DMRS.

[0135] 4-phase shift keying (QPSK) modulation can be used for PBCH transmission.

[0136] A cell search is performed and / or it may be made available.

[0137] Cell discovery may involve the WTRU obtaining time and frequency synchronization with the cell and detecting its cell ID. Cell discovery may be based on primary and secondary synchronization signals and PBCH DMRS located on the synchronization raster. System information (SI) can be divided into a master information block (MIB) and several system information blocks (SIB). The MIB may contain parameters that can be transmitted (e.g., always) over the BCH (e.g., with a period of 80ms and repetitions occurring within 80ms) and used (e.g., may be required) to retrieve SIB1 from a cell. SIB1 can be transmitted over the DL-SCH (e.g., with a period of 160ms and variable transmission repetitions). The default transmission repetition period for SIB1 may be 20ms. The actual transmission repetition period may be determined by the network (e.g., depending on the network implementation).

[0138] MIB and / or SIB1 may constitute the minimum system information (MSI) used (for example, required) to operate on the cell.

[0139] In SSB and CORESET multiplexing pattern 1, the recurring transmission period of SIB1 may be 20 ms. In SSB and CORESET multiplexing patterns 2 / 3, the transmission recurring period of SIB1 may be the same as the SSB period. SIB1 may contain information about the availability and scheduling of other SIBs (e.g., mapping of SIBs to SI messages, period, SI window size) with an indication of whether one or more SIBs are provided only on demand (and, for example, the configuration used by the WTRU to enforce SI requests in that case). SIB1 may be a cell-specific SIB.

[0140] SIB1 can be received.

[0141] The Master Information Block (MIB) on a PBCH transmission may provide the WTRU with parameters (e.g., CORESET#0 configuration information) for monitoring the PDCCH to schedule a PDSCH transmission carrying System Information Block 1 (SIB1). The PBCH transmission may also indicate that there is no associated SIB1, in which case the WTRU may point to another frequency on which to search for an SSB associated with SIB1, as well as a frequency range in which the WTRU can assume that no SSB associated with SIB1 exists. The indicated frequency range may be limited to consecutive spectral allocations of the same operator in which the SSB was detected.

[0142] SSB indexing and SSB bursting may be performed and / or enabled.

[0143] Each SSB within an SSB burst set (e.g., all SSBs within a 5ms period of SSB transmission) may be assigned a unique number (e.g., starting from 0 and increasing by 1). This number may be reset to 0 for the next SSB burst set (e.g., the next 5ms span) after an SSB transmission cycle (e.g., after a default 20ms cycle). This unique number (e.g., SSB index) may be communicated (e.g., notified) to the WTRU via PBCH DMRS and PBCH payload. Candidate SSBs in a half-frame may be indexed in ascending chronological order (e.g., from 0 to L-1). The WTRU may determine the SSB index for each half-frame from a one-to-one mapping with the index of the DMRS sequence transmitted in the PBCH, with 2 LSB bits if L=4 or 3 LSB bits if L>4. If L=64, the WTRU may determine 3 MSB bits of the SS / PBCH block index for each half-frame by the PBCH payload bits.

[0144] Figure 3 shows an exemplary SSB burst with a period of 20 ms. Figure 3 further shows an example of an SSB beam sweep within the SSB burst set.

[0145] Network energy consumption can occur during SSB transmission.

[0146] A network may consume energy in transmitted SSB (e.g., unnecessary energy) when it is not necessary (e.g., when it does not transmit SSB according to a fixed pattern and period). This can worsen when the network employs a large number of beams (e.g., when it does not. For example, when the network employs a large number of beams, the SSB may be swept across all beams (e.g., all of them) along with the necessary system information.

[0147] SSB's periodic broadcast requirement may limit gNBs from sleeping for longer intervals (for example, by not allowing them to sleep at all).

[0148] For example, if a cell / TRP transmits SSB using a fixed pattern and period (for example, it must transmit it), the gNB may refrain from using longer sleep cycles for its Tx and power amplifier (for example, which can consume considerable energy) (for example, it may not use them at all). This situation can worsen if network traffic allows for longer sleep cycles, but Tx and PA must be started and kept running to conform to the SSB pattern and period (for example, when).

[0149] For example, even when there is no / minimal traffic (for instance, when), fixed broadcast-period transmissions of SSB and SIB-1 may (for instance, may require) use a longer startup time for gNB.

[0150] The transmission and retrieval of system information may follow fixed, deterministic patterns for SSB and SIB-1. These patterns may simplify the retrieval of system information for WTRUs (e.g., after power-up). The patterns may create hurdles such as a burden on network energy consumption (e.g., a significant burden) and / or having a sufficiently long DTx for gNBs.

[0151] System information can be obtained using WTRU power consumption.

[0152] Due to the SSB and SIB-1 transmission patterns, WTRUs may have more time (for example, they may need more time) to obtain minimal system information. In some cases, WTRUs may have (for example, partial) information already provided by other cells, but they may (for example, they may need to) obtain system information from the cells.

[0153] Longer cell search times for broadband carriers may be made available and / or provided.

[0154] A network can transmit SSB on any frequency span of the carrier (e.g., any frequency span). This flexibility can be beneficial for network scheduling and operation. The broadband carrier and flexible SSB transmission locations in the frequency domain can make the initial cell search for the WTRU very long. Because the carrier bandwidth can be extremely large in the FR2 and sub-GHz bands, the time to locate / detect the SSB (e.g., this can be a small fraction of the carrier bandwidth in the frequency domain) can be considerable, which can add a negative aspect to the user experience.

[0155] Receiving a slim sync signal may result in monitoring and / or receiving a pre-sync signal (e.g., a wake signal (WUS)). Receiving a pre-sync signal (e.g., a WUS) may result in measuring SSB (e.g., receiving SSB).

[0156] Figure 4 shows examples of transmitting slim sync signals (e.g., PSS and / or SSS) and SSB.

[0157] Acquiring WTRU synchronization may involve (for example, initiating) detecting (for example, receiving) a slim SS (for example, a first signal which may include a PSS or PSS and SSS) (for example, lines 2-4 are shown in Figure 4 which shows an example of PSS / SSS transmission, compared to line 1 which shows an exemplary SSB design (for example, a legacy SSB design) in which SSB may be transmitted at a given period).

[0158] The WTRU may determine information about pre-synchronization or DL-WUS type signals (e.g., information about the reception of a second signal such as a pre-synchronization or DL-WUS type signal), such as timing and / or resource information, e.g., resources. This information may be determined based on slim synchronization (SS) indications (e.g., implicit indications, explicit indications).

[0159] Pre-synchronization or WUS signaling (e.g., a second signal) may provide indication for the reception of a synchronization signal block (SSB), such as NES configuration information and / or complete system information timing.

[0160] Networks that transmit slim sync / pre-sync using low-power Tx / PA can save power (e.g., additional power).

[0161] The WTRU may receive a slim version of the SS (e.g., a compressed SS). The slim version of the SS may include a PSS (e.g., alone) or a PSS and an SSS (as shown in Figure 4, for example, line 2 shows an example where two slim SSs (e.g., PSS / SSS) may be transmitted during an SSB period, each slim SS may be associated with a WUS signal; line 3 shows an example where a slim SS and associated WUS transmission follow an SSB transmission; and line 4 shows an exemplary slim SS transmission during an extended SSB period).

[0162] WTRU can decode a slim sync signal (e.g., the first signal). Slim SS can indicate a second signal (e.g., a pre-sync signal, e.g., the DL-WUS signal) (e.g., a slim sequence associated with slim SS, such as PSS and / or SSS, can indicate it (e.g., through properties associated with the slim sequence)).

[0163] The WTRU may, for example, determine information associated with a second signal based on slim SS indications (e.g., timing and / or resources of a pre-synchronization signal, e.g., a DL-WUS signal). (For example, it may determine resources associated with receiving a second signal based on information associated with a second signal indicated by a first signal.) The WTRU may determine to receive a second signal on the same frequency or a different frequency based on indications received through a first signal. For example, the selection of time, frequency, phase, or sequence associated with a slim sync signal may explicitly or implicitly provide information related to a second signal (e.g., a pre-synchronization or DL-WUS signal). In an example (e.g., using explicit information provisioning), the properties of the slim sync signal (e.g., preferred properties) may include and / or indicate a mapping to physical resources or properties of a second signal. For example, a first sequence used in a slim sequence may indicate (e.g., to the WTRU) a first period and a first offset for transmitting a second signal. A second sequence (if used, for example) may indicate a second period and a second offset. In an exemplary design using implicit information provisioning, properties (e.g., slim sequence time resources, frequency resources, phase, or sequence selection) may indicate the active NES state of the cell. The WTRU may have knowledge of the period and offset for the second signal transmission (e.g., through (pre)configuration or specification) and therefore may determine the information necessary to receive the DL-WUS (e.g., resources and configuration) based on the indicated NES state.

[0164] The WTRU may receive (e.g., detect) a pre-synchronization signal (e.g., DL-WUS) based on information associated with a second signal (e.g., timing information, resource information, frequency information, sequence information), for example, as shown in rows 2-4 of Figure 4, indicated by a first signal (e.g., according to determined timing and / or frequency resources, for example, via determined resources). The WTRU may decode the pre-synchronization (e.g., DL-WUS) signal, which may indicate (e.g., provide the WTRU with indication of that information), for example, information associated with the reception of SSB (e.g., the cell's NES status, the SSB period, and / or the presence of all SSBs on potential all-SSB transmission opportunities).

[0165] The WTRU may discover and / or receive the SSB based on indications shown by a second signal (e.g., pre-synchronization signal indications, e.g., DL-WUS signal indications). The WTRU may decode the PBCH transmission associated with the SSB based on information determined from the indications shown by the second signal.

[0166] The WTRU may, for example, determine the timing and resources (e.g., information) of an SIB-1 transmission based on PBCH information (e.g., information revealed by a decoded PBCH transmission).

[0167] The WTRU may decode the SIB-1 (e.g., an additional system information block) on the determined resource (based on the information shown in the SSB, for example, as shown in Figure 4). The WTRU may determine the RACH parameters (e.g., for RACH transmission). The WTRU may, for example, send a RACH preamble (to a network node, for example) according to the RACH parameters determined as part of the initial access procedure.

[0168] The WUS signal may provide information and transmission patterns for slim synchronization signals and / or SSB transmissions.

[0169] WTRU synchronization can be initiated by receiving a WUS signal from the network (for example, initially).

[0170] Based on the properties of the received DL-WUS, the WTRU may determine the SSB structure (e.g., structure type, e.g., slim SSB or full SSB) during the network's NES state (e.g., inactive state) based on the reception of a pre-synchronization sequence (e.g., DL-WUS) indication.

[0171] After detection / decoding of a pre-synchronization signal (e.g., detection / decoding of a successful pre-synchronization signal (e.g., WUS)), the WTRU may determine (e.g., know) the timing, period, transmit power, frequency allocation, number of SSB beams per burst, and / or SSB content (e.g., PSS, SSS, PBCH, SIB1) of the SSB, for at least one NES sleep cycle and / or during the NES state of the cell.

[0172] Pre-synchronization (WUS) can be transmitted across multiple frequency spans within a carrier (for example, for a broadband carrier), which can speed up the search for the first cell.

[0173] WTRU can monitor and receive DL signals (e.g., DL-WUS) from the network.

[0174] The WTRU may, for example, determine based on the reception of DL-WUS that one or more SSBs (e.g., slim SSB or full SSB) have been transmitted and / or may be received during the next SSB transmission opportunity in the first SSB cycle (e.g., the NES cycle).

[0175] The WTRU may, for example, determine the type of SSB structure to monitor and / or receive during the first SSB cycle (e.g., slim SSB structure or full SSB structure) based on at least one property of the received or decoded DL-WUS.

[0176] The properties of DL-WUS may include one or more of the following: modulation type (e.g., OOK vs. OFDM), time or frequency opportunity when DL-WUS is received, sequence type (e.g., ZC or M), sequence index, channel coding type, or content of the embedded message.

[0177] The SSB structural types may include at least one of the following: time-compressed SSB (e.g., PBCH / SIB1 multiplexed in the frequency domain), power-reduced SSB, narrowband SSB, SSB bursts with a reduced number of SSB beams per burst, SSB without PBCH, or SSB using a second period for the attached SIB-1 compared to a first SIB-1 period.

[0178] The WTRU may, for example, receive an SSB during the transmission opportunity of the first SSB cycle based on the determined SSB structure.

[0179] A WTRU may, for example, receive a PBCH transmission and / or one or more SIBs (e.g., at least one of these) based on the reception of an SSB.

[0180] The WTRU may transmit a preamble (for example, based on information received in at least one of the received SSB and PBCH and / or SIB).

[0181] The WTRU may assume the same SSB structure during the first cycle until another DL-WUS is received.

[0182] The first SSB cycle is nondeterministic and / or can be used while the cell is in the NES state.

[0183] The second SSB cycle is deterministic and / or can be used when the cell is not in the NES state.

[0184] Compact, minimal system information can be received, signaled, provided, and / or used.

[0185] The network may transmit minimal system information (e.g., compact minimal system information), which may include at least SSB (e.g., PSS+SSS+MIB(PBCH block / transmit)) or a digest of SI.

[0186] The SI digest may include {MSI digest (MIB + SIB - 1), and digests of other SIs}.

[0187] An SI digest may contain a value or a set of values.

[0188] A WTRU may be connected to a serving cell. The serving cell may provide the WTRU with system information of the neighbor cell Cx and a digest of SIs corresponding to the system information provided to the WTRU (for example, the WTRU may receive a digest of the SI and / or first SI associated with the neighbor cell). The digest of SIs may contain values ​​or sets of values.

[0189] WTRU can perform cell reselection to cell Cx (e.g., neighbor cell).

[0190] The WTRU may receive and / or decode transmissions from cell Cx. Transmissions associated with cell Cx may include the C-MSI of cell Cx. The WTRU may determine a digest of the SI from the C-MSI (e.g., a digest of the second SI).

[0191] C-MSI may include digests of SSB (e.g., PSS, SSS, PBCH block / transmit) and / or SI.

[0192] CMSI may include a digest of SI and at least one of the PSS, SSS, or PBCH blocks.

[0193] The WTRU can compare the SI digests to verify whether they match the stored SI digests for cell Cx (for example, it can determine whether the digest of a first SI received from the serving cell matches the digest of a second SI indicated by a transmission received from a neighbor cell (for example, cell Cx)) (for example, it can determine whether it requires a new SIB-1 and / or another SIB (for example, based on the determination that the digest of the first SI does not match the digest of the second SI)).

[0194] For example, if the SI digest does not match the stored SI digest for cell Cx, the WTRU may receive / decode an SIB-1 from cell Cx (e.g., a neighbor cell) to obtain the RACH parameters for cell Cx.

[0195] If the SI digests match, the WTRU may already have RACH parameters for cell Cx (for example, the WTRU may determine RACH parameters based on the digests of a first SI and a second SI (for example, if they match each other)).

[0196] A WTRU may, for example, be transmitted on cell Cx using RACH based on the RACH parameter. A WTRU may indicate a digest of other stored SIs, for example, so the network knows what system information the WTRU has (for example, in Msg1 / 3 / MsgA).

[0197] The network can provide delta system information to WTRUs that show a "digest of other SIs".

[0198] C-MSI reception may be based on a first SSB cycle that is non-deterministic or an NES cycle.

[0199] Reception of SIB-1 may be based on a second SSB cycle that is deterministic, total, or a non-NES SSB cycle.

[0200] The DTX active period of a cell may include the duration during which the configured cell's DTX pattern is active (e.g., the duration of the cell's DTX pattern's on-duration period). The WTRU may receive configuration information indicating the cell's DTX active period and may monitor the PDCCH and other DL signals and channels during such time. This may be applicable after the cell's DTX configuration has been indicated by the NW to be activated (e.g., only).

[0201] The DTX inactivity period for a cell may include the duration during which the configured cell's DTX pattern is inactive / inactive (e.g., a period of time outside the periodic on-duration period of the cell's DTX pattern). This may be applicable only after the cell's DTX configuration has been indicated by the network to be activated (e.g., only).

[0202] The DRX active period of a cell may include the duration during which the configured cell's DRX pattern is active (e.g., the duration of the cell's DRX pattern's on-duration period). The WTRU may receive configuration information indicating that it will transmit UL signals on the UL channel during such a time (e.g., it may be predefined to be permitted to transmit). This may be applicable only after the NW has indicated that the cell's DRX configuration is to be activated (e.g., only).

[0203] The DRX inactivity period for a cell may include the duration during which the configured cell's DRX pattern is inactive / inactive (e.g., a period of time outside the periodic on-duration period of the cell's DRX pattern). This may be applicable only after the cell's DRX configuration has been indicated by the network to be activated (e.g., only).

[0204] The DRX / DTX of an activated cell may include the state of the configured cell's DRX or the cell's DTX pattern, for example, where such a state is activated by L1 / L2 DL signaling, RRC (re)configuration, and / or cell-common configuration, as well as not deactivated.

[0205] The DRX / DTX of a deactivated cell may include the state of the DRX or DTX pattern of a configured cell, where such a state is deactivated by L1 / L2 DL signaling, RRC(re)configuration, and / or cell-common configuration.

[0206] For example, there may be a link between the availability state, the NES state, and the cell's DTX / DRX, and therefore the terms can be used interchangeably. A WTRU can implicitly determine the cell's DTX state from its determined active availability state, and vice versa. A WTRU can implicitly determine the cell's RTX state from its determined active availability state, and vice versa.

[0207] The terms alternate cell and stable cell may be used interchangeably (for example, as described herein). The WTRU may receive configuration information indicating a list of stable cells (for example, alternate cells that may not turn off, e.g., several macrocells) (for example, it may consist of such a list). The list may be a list of alternate cells per serving / camped cell or a general list of PCIs for the entire network, tracking area, etc. (for example, either of these). The WTRU may receive configuration information with a measurable configuration for the alternate cells (for example, it may consist of such a configuration).

[0208] System information may be transmitted and retrieved, and / or made available.

[0209] Synchronization signal transmission may use a low-power Tx and / or power amplifier. The gNB may be equipped with a low-power transmitter and / or power amplifier (PA). Synchronization sequences (including, for example, SSB or sequences as described herein) may be transmitted by the gNB using, for example, a low-power Tx and / or PA.

[0210] The gNB transmission of the synchronization signal may use a low-power Tx, and the PA may be associated with the cell's NES state. For example, if the relevant cell is in an inactive state of the NES (e.g., when), the synchronization signal may be transmitted using a low-power Tx and PA. For example, if the relevant cell is in an active state of the NES (e.g., when), the synchronization signal may be transmitted using a normal Tx and PA.

[0211] Slim synchronous structures for NES (e.g., Tx and PA of low-power gNBs) may be used and / or provided.

[0212] An SSB design for narrowband carriers (for example, suitable for FR1) may be used.

[0213] WTRUs can be predefined or preconfigured in an SSB structure that includes, for example, PSS, SSS, and / or PBCH blocks. These signals in the structure may occupy the same frequency footprint, for example, they may span the same number of physical resource blocks (PRBs). A network may use the same structure for (for example, all) SSBs in the SSB burst set it uses.

[0214] The synchronization sequences for PSS and SSS (for example, respectively) may occupy 11 PRBs in the frequency domain and (for example, one) OFDM symbol. The frequency span of the 11 PRBs can be used (for example, it may help) to reuse the same PSS / SSS sequence. To enable the use of MIB / PBCH (for example, if PBCH is mapped over 48 PRBs), the updated SSB structure may use 4 OFDM symbols, resulting in 44 PRBs available for PBCH (for example, as shown on the left side (LHS) of Figure 5). For SSB transmissions of the same power, a PBCH with 44 PRBs may have little coverage reduction (for example, because it may have less redundancy for PBCH in the case of the same number of PBCH information bits and PBCH DMRS).

[0215] For example, to avoid coverage loss in the PBCH (compared to legacy designs, for example), five OFDM symbols can be allocated to the PBCH. This SSB structure (using five OFDM symbols, for example) can result in 55 PRBs available for the PBCH (as shown on the right side of Figure 5, for example). The availability of 55 PRBs for the PBCH can result in improved coverage over legacy designs for the same number of PBCH information bits and PBCH DMRS.

[0216] Figure 5 shows an example of PSS, SSS, and PBCH (e.g., PSS / SSS length) in 11 PRBs (e.g., PSS / SSS length) with additional PBCH symbols, with 44 PRBS for PBCH on the left and 55 PRBs for PBCH on the right.

[0217] The proposed design (for example, the one described herein) may leverage the reuse of PBCH processing from other (e.g., legacy) designs. Mapping adjustments for different numbers of PRBs can be easily achieved by limiting updates to the rate matching block for PBCH processing. The polar coding of the PBCH may result in 512 bits (which may be, for example, inputs for the rate matching block). The rate matching block may increase these bits to 864 bits (e.g., 432 QPSK symbols).

[0218] 48 PRBs × 12 × 3 / 4 (1 / 4 DMRS) can be equal to 432 resource elements.

[0219] The rate matching block can be updated to provide PBCH bits for mapping, for example, four symbols (e.g., left side of Figure 5) or five symbols (e.g., right side of Figure 5).

[0220] The frequency occupancy for SSB can be selected differently from that of 11 PRBs. This design may allow for the selection of PSS and SSS sequences with different lengths than other (e.g., legacy) SSB designs. For systems operating over narrowband carriers, the frequency span can be reduced, and suitable PSS and SSS sequences can be selected. The number of symbols for PBCH transmission can be further increased to achieve a certain coverage level.

[0221] In complementary designs (for example, more suitable for wideband carriers), the frequency occupancy for SSB can be increased to a preferred value greater than 11 PRBs. Longer PSS and SSS sequences can be used with such SSB. In the example, the PSS / SSS sequence can be repeated in the frequency domain to an appropriate length. PBCH can use the same or different number of OFDM symbols in such SSB designs.

[0222] In the example, the network may transmit updated structures using the low-power Tx and PA of a gNB. This can be beneficial for network energy saving purposes, for example, as the gNB may turn off its normal / high-power Tx and PA for longer time intervals.

[0223] In the example, the WTRU can be predefined or preconfigured to receive SSB transmitted from a normal Tx / PA or a low-power Tx / PA.

[0224] In the example, the WTRU can be predefined or preconfigured to receive both the legacy SSB structure and the proposed SSB structure (for example, simultaneously). The use of the SSB structure can be linked to the cell's NES state. When the cell is in the active state of the NES, the SSB can be transmitted using the legacy structure. When the cell is in the inactive state of the NES, the SSB can be transmitted using the proposed structure.

[0225] If a WTRU knows the NES state of a cell (e.g., determines the NES state of the cell), it may use an appropriate SSB structure to receive the synchronization signal. If a WTRU does not know the NES state for the cell from which it is attempting to decode the SSB, it may attempt to decode the SSB from legacy and proposed structures (e.g., blind decoding). A WTRU may derive whether the cell's NES state is active or inactive by decoding the SSB structure in use, for example. Depending on the predefined or network configuration, the detection of a structure may indicate that the network is not applying the NES state or is not in an active NES state. The detection of a proposed structure may indicate that the cell is in an inactive NES state.

[0226] In the example, the WTRU can be predefined or preconfigured to receive different SSB structures for different frequency ranges or frequency bands. In the example, different SSB designs can be defined for FR1 and FR2.

[0227] For example, FR1 may maintain a longer footprint (for instance, more OFDM symbols because it will generally have fewer beams to sweep within FR1). The proposed design could be used for FR1 with a potential update to an SSB burst structure.

[0228] The proposed SSB structure can be used with SSB-SSB burst mapping by, for example, restricting it to (for example, only) one SSB transmission within a subframe / slot. For this purpose, the start symbol of the first legacy SSB mapping can be used as the first start symbol of the proposed SSB structure. In the example, the (for example, new) mapping of SSBs in an SSB burst set can be designed for the proposed SSB structure.

[0229] The proposed design can be used for narrowband carriers and / or reinforced frequencies. These carriers / frequencies may be (for example) medium to low bandwidths. The proposed design, using smaller frequency spans (for example compared to other (e.g., legacy) designs), may (for example) address SSB during such carriers / frequencies. The (e.g., default) SSB structure can be defined in each (e.g.) band where the WTRU may (e.g., at least) assume initial access. The network may override the (e.g., default) SSB structure by indicating it in system information or configuration information, for example. This may be useful for cells that may not be intended to provide initial access to the WTRU or when the WTRU is configured to (e.g., blindly) detect and decode the SSB structure.

[0230] The SSB design can be used for narrowband carriers and may be suitable for FR1.

[0231] A WTRU can be predefined or preconfigured in an SSB structure that may include, for example, a PSS, an SSS, and a PBCH. Signals in a structure may occupy the same frequency footprint, for example, they may span the same number of physical resource blocks (PRBs). A network may use the same structure for (for example, all) SSBs in the SSB burst set it uses.

[0232] The synchronization sequences for PSS and SSS (for example, respectively) may occupy 11 PRBs in the frequency domain and within a single OFDM symbol. To reuse PSS / SSS sequences (for example, from other (e.g., legacy) designs), the frequency span may (for example, be maintained) consist of 11 PRBs.

[0233] The proposed SSB design can be used by a network for cells in an NES state with reduced transmit power. The design may, for example, use repetitions of PSS and SSS as parts of the SSB structure to overcome coverage loss. Figure 6 shows an exemplary SSB design. As shown in Figure 6, the SSB may include (for example, consist of) multiple (e.g., two) repetitions of PSS, (e.g., two) repetitions of SSS, and six OFDM symbols for PBCH transmission.

[0234] Figure 6 shows an example of a PSS, SSS, and PBCH limited to 11 PRBs (R-15 PSS / SSS length) with an additional (N) PBCH symbols.

[0235] Figure 6 shows examples of several PSS / SSS repetitions and symbols for PBCH transmission. A (preferred) number of PSS / SSS repetitions can be selected for the proposed SSB design. The number of repetitions may depend on the allowed power level for the gNB's Tx and the preferred coverage area that the network attempts to cover for the cell's SSB transmission. The number of repetitions may also depend on the frequency occupancy of the SSB.

[0236] Motivation for the proposed design may include reusing PBCH processing from other (e.g., legacy) designs. Mapping adjustments for a different number of PRBs (e.g., compared to other (e.g., legacy) designs) can be achieved (e.g., easily) by limiting updates to the rate-matching block for PBCH processing. The rate-matching block can be updated, for example, to provide PBCH bits to a selected target number of symbols and PRBs.

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

[0238] In example designs (for instance, designs more suitable for wideband carriers), the frequency occupancy for SSB can be increased to a preferred value greater than 11 PRBs. Longer PSS and SSS sequences can be used with such SSB. In exemplary designs, legacy PSS / SSS sequences can be repeated in the frequency domain to an appropriate length. PBCH can use the same or different number of OFDM symbols in such SSB designs.

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

[0240] In the example, the WTRU may receive configuration information indicating that it will receive SSB transmitted from a Tx / PA (e.g., a regular Tx / PA or a low-power Tx / PA) (for example, it may be predefined or preconfigured to do so).

[0241] In the example, the WTRU may receive configuration information indicating that it will receive another (e.g., legacy) SSB structure and the proposed SSB structure (e.g., simultaneously) (e.g., it may be predefined or preconfigured to do so). The use of the SSB structure may be linked to the cell's NES state. For example, when the cell is in an active state of the NES (e.g., when), the SSB may be sent using the other (e.g., legacy) structure. For example, when the cell is in an inactive state of the NES (e.g., when), the SSB may be sent using the proposed structure.

[0242] For example, if a WTRU knows the cell's NES state (for example, based on the determination of the cell's NES state), the WTRU may use an appropriate SSB structure to receive the synchronization signal. For example, if a WTRU does not know the NES state of the cell from which it is attempting to decode the SSB, the WTRU may decode (for example, attempt to do so) the SSB from other structures (for example, legacy structures) and the proposed structure (for example, blind decoding). The WTRU may deduce, for example, that the cell's NES state is active or inactive by decoding the SSB structure in use. Detection of other (for example, legacy) structures may indicate that the network is refraining from applying (for example, not applying) the NES state or the active state of the NES (for example, according to predefined or network configuration). Detection of the proposed structure may indicate that the cell is in an inactive state of the NES.

[0243] The proposed structure (for example, as described herein) may be used (for example, may be very suitable for) scenarios in which a network may employ other (e.g., legacy) or proposed SSB structures, and a WTRU may (e.g., may need to) blindly detect and decode the SSB for either structure. This may be based on the similarity of the design in which the first symbol of the SSB carries the PSS and the third symbol carries the SSS. Thus, the commonality in the transmission of these two signals may improve (e.g., help to improve) the blind detection / decoding process for legacy and proposed SSB structures.

[0244] In the example, the WTRU may be predefined or preconfigured to receive different SSB structures for different frequency ranges or frequency bands. In the example, different SSB designs may be defined for FR1 and FR2.

[0245] For example, FR1 can generally maintain a longer footprint, e.g., more OFDM symbols, because it may have fewer beams to sweep within FR1. The proposed design could be used for FR1 with (potential) updates to an SSB burst structure.

[0246] The proposed SSB structure can be used with (e.g., legacy) SSB-SSB burst mapping by, for example, limiting it to (e.g., only) (e.g., one) SSB transmissions within a subframe / slot. For this purpose, the start symbol of the first (e.g., legacy) SSB mapping can be used as the first start symbol of the proposed SSB structure. In different designs, the (e.g., new) mapping of SSBs in an SSB burst set can be designed for the proposed SSB structure.

[0247] The proposed design can be used for narrowband carriers and / or reformatted or reused spectral / frequency carriers. These carriers / frequencies may be (for example, generally) of medium to low bandwidth. The proposed design, using smaller frequency spans (for example, compared to legacy designs), can be used to address SSBs during such carriers / frequencies. The (for example, default) SSB structure can be defined in each (for example) band, which the WTRU may (for example, at least) assume to have initial access to. The network may override the SSB structure (for example, the default SSB structure) by indicating it, for example, in system information or configuration information. This may be useful for cells that may not (for example, may not be intended to) provide initial access to the WTRU, or when the WTRU is configured to blindly detect and decode the SSB structure (for example, sometimes).

[0248] A slim sync structure for NES (e.g., FR2) may be used and / or provided.

[0249] In the example, the network may transmit a compressed synchronous signal structure. This compressed synchronous signal structure is sometimes called slim synchronous. A slim synchronous signal may include a time-compressed version of (e.g., legacy) SSB. Figure 7 shows a proposed design for slim synchronous. The design may span multiple (e.g., two) OFDM symbols. A PSS may be transmitted in the first OFDM symbol, and then an SSS may be transmitted in the second OFDM symbol. A PBCH transmission may be transmitted on both OFDM symbols on the lower and upper frequency portions. A suitable number of PRBS on the lower and upper portions of the PSS / SSS sequence may be employed to transmit the PBCH transmission.

[0250] To keep the design for PSS / SSS sequences and PBCH processing / decoding as close as possible to other designs (e.g., legacy designs), PSS and SSS can span 11 PRBs (e.g., where the lengths of PSS and SSS can be 127, as in the legacy case). The upper and lower 12 PRBs (e.g., respectively) can be dedicated to PBCH transmission. This could result in 12*4=48 PRBs for PBCH transmission (e.g., as in the legacy SSB case). This could allow for (e.g., complete) reuse of the transmit / receive chain for PSS / SSS and PBCH transmission, except for minor changes to the mapping to different PRBS in the proposed design. This could result in a slim synchronous design for multiple (e.g., two) symbols with a frequency span of 35 PRBs.

[0251] 12(PBCH) + 11(SS) + 12(PBCH) can be equal to 35 PRBs.

[0252] In the example, the frequency span of slim synchronization can be adjusted to the number of PRBs in the frequency domain (e.g., a desired number) by increasing or decreasing the number of PRBs for PBCH transmission, for example. This may involve updates to the PBCH processing (e.g., some updates may be required), and may be handled in conjunction with updates to the "rate matching" block of the PBCH processing (e.g., easily handled).

[0253] Figure 7 shows two exemplary symbolic SSB structures with PBCH and stacked PSS / SSS.

[0254] Reusing (e.g., legacy) PSS / SSS sequences during slim synchronization may be possible, for example, based on maintaining 11 PRBs for PSS / SSS.

[0255] In the example, the number of PRBs used for PSS / SSS may be less than 11. In such cases, the (e.g., legacy) sequence may be truncated to fit the selected number of PRBs. The PSS / SSS sequence (e.g., the new PSS / SSS sequence) may be designed for the (e.g., newly) selected number of PRBs for the PSS / SSS.

[0256] In the example, the number of PRBs used for PSS / SSS can be more than 11. In such cases, the (e.g., legacy) sequence can be transmitted in a predefined repeating order (which may be known to the WTRU, for example). Longer (e.g., new) PSS / SSS sequences can be designed to be transmitted in a slim synchronous structure, for example.

[0257] A slim synchronous design (for example, one spanning only two OFDM symbols) may be useful for one or more of the following:

[0258] gNB can complete the synchronization signal in two OFDM symbols instead of four OFDM symbols, which can result in a longer sleep time (for example, from the perspective of NES).

[0259] Time-compressed slim sync can provide a compact SSB burst structure (e.g., resulting in more efficient synchronous transmission) in FR2 or systems employing a larger number of beams (e.g., future systems). The mapping of SSBs in slots for SSB burst sets can be modified, for example, with a slim sync design of two symbols. In contrast to other (e.g., legacy) SSB burst designs (e.g., limiting transmissions of a maximum of two SSBs in a single slot), slim sync can be used to accommodate four slim syncs per slot while still making available, for example, the first symbol in the slot for PDCCH and a later symbol for potential PUCCH transmissions.

[0260] Figure 8 shows an example of a time-frequency compact structure with only one instance of SS and only one instance of PBCH.

[0261] In an example (for example, for a design for slim synchronization), a time-compressed structure can be achieved by splitting the transmission of a PSS / SSS sequence from a PBCH transmission (e.g., slim SS may refrain from including a PBCH transmission / block (e.g., may not include one)). In this split design for slim synchronization, the network may transmit PSS / SSS over two symbol transmissions. In subsequent transmission intervals, PBCH transmissions of two symbols may be transmitted over the same resource. PSS / SSS may use a frequency span of 11 PRBs to reuse a design (e.g., a legacy design) for the sequence. PBCH transmissions may use the same frequency span of 11 PRBs (e.g., resulting in 22 PRBs for the PBCH transmission). For example, if the PBCH carries the same number of information bits, this may (e.g., require) a higher code rate PBCH compared to other designs (e.g., a legacy design). This, in turn, may result in lower coverage for the PBCH.

[0262] For example, increasing the frequency span of the slim sync signal can increase PBCH coverage. In the example, PBCH transmission can span more PRBs. In the example, PBCH transmission can span 24 PRBs, which could provide 48 PRBs for PBCH transmission (e.g., the same as in the legacy design). This could allow for complete reuse of PBCH transmission and reception. The PSS / SSS span can be kept to 11 PRBs. Sync coverage can be improved, for example, by allowing PSS / SSS transmissions to span more PRBs. Both PSS / SSS can use several (e.g., the same number) PRBs with respect to PBCH, e.g., 24 PRBs. The PSS / SSS sequence can be repeated (e.g., twice) in the frequency domain (e.g., 127*2=254 resource elements) while leaving (24*12=)34 resource elements (e.g., 24*12=254 resource elements) (e.g., 127*2=254 resource elements). Some of these resource elements (e.g., half) can be left at the top and bottom ends of the PSS / SSS iteration (e.g., at the top and bottom ends, respectively). In the example, longer PSS / SSS sequences (e.g., new ones) can be designed, which may provide a more efficient design for these sequences.

[0263] In the example, the PSS / SSS sequence may indicate a time or frequency span of PBCH transmission from among a number of configurable time-frequency spans (for example, it may carry information about it). The WTRU may determine a suitable time-frequency footprint for the PBCH (for example, based on detecting the PSS / SSS sequence) and decode the PBCH (for example, according to indications received in the PSS / SSS sequence).

[0264] In the example, the relative periods of PSS / SSS and PBCH may differ. The relative periods of PSS / SSS and PBCH may have a mapping from the cell's NES state. The WTRU may derive the relative periods of PSS / SSS and PBCH transmissions based on knowledge of the cell's NES state, which may be provided to the WTRU, for example, through explicit or implicit signaling.

[0265] In this example, the WTRU may detect the relative periods of PSS / SSS and PBCH. The WTRU may, for example, determine the NES status and state of a cell based on the detected relative periods of PSS / SSS and PBCH.

[0266] In the example, a network may provide PSS / SSS and PBCH period or time-frequency footprint through the transmission of sequences (e.g., special sequences). A WTRU may receive configuration information with the time-frequency arrangement of the special sequences that the network uses to indicate the PSS / SS and PBCH period or time-frequency footprint (e.g., it may be predefined or preconfigured in that arrangement). A WTRU may detect (e.g., special) sequences on known time-frequency resources. Properties of (e.g., special) sequences (e.g., one of the following, such as sequence selection, phase, cyclic shift, power, etc.) may indicate the PSS / SSS and PBCH period and / or time-frequency footprint. A WTRU may detect (e.g., special) sequences and determine information about PSS / SSS and PBCH transmissions.

[0267] The network can provide indications of the cell's NES state and slim synchronization throughout the same sequence. In the example, the NES state may have a direct mapping to the slim synchronization period and time-frequency footprint.

[0268] The determination of the WTRU for a slim sync format / pattern (e.g., whether it is transmitted using legacy SSB or one of the newly proposed formats / patterns) may be based on one or more of the following: sync raster location, frequency band (e.g., FR1 / 2 may use legacy SSB, and FR3 / 4 band may use slim sync or one of the types of slim sync), physical cell ID (e.g., this may be determined based on PSS and / or SSS reception, which can indicate which format / type of slim sync is used for transmitting / retrieving sync and system information), subcarrier spacing (e.g., different subcarrier spacings may be associated with different formats / types of slim sync), and cell operating mode (e.g., NES mode or otherwise).

[0269] The characteristics possessed by each FR SSB structure may include one or more of the following:

[0270] Different frequency ranges may be assigned different SSB structures (e.g., the default SSB structure). In the example, FR1 may be assigned an SSB structure (e.g., a single SSB structure) with more OFDM symbols (e.g., fewer beams). FR2 may have a different SSB structure (e.g., the default SSB structure) with fewer OFDM symbols (e.g., to handle more beams and provide NES benefits).

[0271] Whether a cell applies or does not apply NES techniques can affect the structure of the SSB that the cell employs to transmit synchronization information. For example, one structure may be used (e.g., defined) for cells that do not apply NES procedures, and a different SSB structure may be used (e.g., defined) for cells that do apply NES procedures. This may have some decoding impact on WTRUs, but can be kept low by a sensible selection of the two SSB structures. On the other hand, the network may benefit from NES, and WTRUs may connect regardless of whether the cell is in NES or not (e.g., they may still be connectable).

[0272] Dynamic power updates for synchronous / SSB transmission may be implemented and / or enabled.

[0273] Power settings for each SSB may be used, enabled, and / or configured. The WTRU may receive configuration information with multiple "SSB tx assumptions" for each frequency band, carrier, TRP, BWP, NES state, and / or SSB structure (for example, these may be configured or predefined by the "SSB tx assumptions"). The tx assumptions for an SSB may include at least one of the following: transmit power level, QCL / TCI assumption, spatial relationship / beam configuration information (including, for example, beamwidth and / or azimuth angle of the transmitted SSB), association from RACH to SSB, PSS / SS sequence, path loss criterion, number of transmitted SSBs, whether the SSB is associated with auxiliary carriers (SUL) (for example, for the purpose of determining the path loss criterion or measuring channel condition (e.g., RSRP)), associated measurement configuration (including gap, applicable L1 / L3 measurement opportunities and types), associated SSBs to be measured for the purposes of BFD, BFR, RRM, and / or RLM, associated SRI per SSB or beam, associated CSI-RS resources to be measured per SSB or beam, tx power or power offset of the CSI-RS associated with the SSB, associated power control parameters, SSB structure (as described herein), maximum power reduction (MPR) value for PHR, etc. The WTRU may, for example, determine the parameters associated with the SSB's tx assumption (for example, any of these parameters) based on the reception of the SSB transmitted along with one of the relevant parameters.

[0274] The WTRU may consist of SSB bursts with indications relating to whether such an SSB (which may be referred to as an "unstable SSB" in this specification) can be muted or transmitted at reduced power (for example, configuration information indicating this may be received). The WTRU may then determine other SSBs as "stable SSBs".

[0275] This may indicate that SSB has been muted or its power has been changed.

[0276] The WTRU may determine that (for example, at least one or more) SSBs within an SSB burst are muted or transmitted at reduced power. The WTRU may make such a determination based on one or more of the following, or on the tx assumptions of the SSBs associated with the SSBs:

[0277] A WTRU may determine, for example, based on the reception of dynamic L1 / L2 signaling (e.g., indications by MAC CE or DCI), that (e.g., at least one or more) SSBs within an SSB burst will be muted or transmitted at reduced power. The signaling (e.g., MAC CE) may indicate (e.g., at least) one of the following: BWP, SSB index, cell ID, BWP ID, resource ID, spatial relationship, power change, or predefined or preconfigured power level, which will result in the SSB being muted or its power changed.

[0278] The WTRU may, for example, determine, based on the reception of broadcast signaling, that (e.g., at least one or more) SSBs within an SSB burst will be muted or transmitted at reduced power. For example, the WTRU may determine, from the reception of broadcast information, the transmit power of the SSBs to be transmitted, and thereby the SI may indicate such an assumption (e.g., as part of the SIB, MIB, or PBCH).

[0279] The WTRU may determine, for example, that (e.g., at least one or more) SSBs within an SSB burst are muted or transmitted at reduced power based on the reception of a DL WUS signal. The WTRU may determine the SSB's tx assumption from the properties associated with the received DL WUS. The DL WUS properties may include at least one of the following: modulation type (e.g., OOK vs OFDM), time or frequency opportunity when the WUS is received, continuity type (e.g., ZC or M), sequence index, channel coding type, etc. The WTRU may determine the SSB's tx assumption from explicit information indicated / signaled in the content of the DL-WUS's embedded message.

[0280] The WTRU may determine, for example, that SSBs within an SSB burst (e.g., at least one or more) will be muted or transmitted at reduced power based on the reception of SSBs having specific physical layer properties or structures. SSB structures or physical layer properties may include at least one of the following: time-compressed SSB (e.g., with multiplexed PBCH / SIB1 in the frequency domain), reduced-power SSB, narrowband SSB, SSB with reduced SSB beams per burst, SSB without PBCH, SSB without SIB, etc. In the example, the WTRU may determine the SSB transmit power and / or which SSBs will be muted from the received PSS and / or SSS sequences.

[0281] The WTRU may determine, for example, based on the reception of an indication portion of the PDSCH payload, such as indicated in msg4 or msgB, that (for example, at least one or more) SSBs within an SSB burst will be muted or transmitted at reduced power.

[0282] The WTRU may determine that (e.g., at least one or more) SSBs within an SSB burst are muted or transmitted at a reduced power based on, for example, the reception of an indication of RRC signaling (e.g., a DCCH message or a CCCH message). The WTRU may receive the SSB tx assumptions applicable as part of the RRC signaling and / or changes (e.g., delta reconfigurations) to an (e.g., existing) configuration.

[0283] The WTRU may determine that (e.g., at least one or more) SSBs within an SSB burst are muted or transmitted at a reduced power based on, for example, the reception of a PDCCH order (e.g., for CFRA) or a mobility command. The WTRU may assume the SSB tx assumptions associated with the SSB indicated as part of the PDCCH order.

[0284] The WTRU may determine that (e.g., at least one or more) SSBs within an SSB burst are muted or transmitted at a reduced power from a determined active NES state. The WTRU may determine the SSB tx assumptions applicable from the determined or indicated NES state. The WTRU may be configured or pre - defined with the SSB tx power or assumptions or the power setting of the SSB for each NES state. The WTRU may assume, for example, that a subset of SSBs are muted or transmitted at different power levels or different spatial relationships based on the activation of the NES state.

[0285] The muting of the SSB or the power reduction of the SSB may affect the WTRU procedure.

[0286] The path loss may be estimated.

[0287] The WTRU may, for example, modify its path loss criteria (e.g., parts of the RACH or PHR procedure) based on a decision that an SSB is muted or transmitted at reduced power (e.g., based on the activation of an NES state). The WTRU may receive configuration information (e.g., it may be configured therewith) that shows a list of SSBs to be measured for use (e.g., from which the L1 SS-RSRP should be measured) based on the activation of the relevant NES state.

[0288] WTRU may use parameters associated with the SSB tx assumption (e.g., transmit power, spatial relationships) to calculate / estimate path loss based on, for example, the decision that SSB is transmitted at reduced power or under the SSB tx assumption. WTRU may exclude previous measurements taken when SSB was transmitted at full power.

[0289] Random access procedures may be affected.

[0290] The WTRU may receive (or be configured with) configuration information indicating thresholds (e.g., rsrp-ThresholdSSB) per NES state, per SSB tx assumption, or per SSB transmit power. The WTRU may use the relevant thresholds (e.g., rsrp-ThresholdSSB) in the RA procedure to select an SSB and / or associated preamble, for example, based on a decision that the SSB is transmitted with a given SSB tx assumption or a decision that a given NES state is active.

[0291] The WTRU may receive (or be configured with) configuration information that shows mappings per NES state or per SSB tx assumption (e.g., SSB-to-RO mapping). The WTRU may use the relevant configured SSB-to-RO mapping in the RA procedure to select an SSB and associated preamble, for example, based on a decision that an SSB is transmitted with a given SSB tx assumption or a decision that a given NES state is active. The WTRU may use the alternative SSB-to-RO mapping associated with an SSB tx assumption based, for example, on a decision that a subset of an SSB or TRP is muted. In the example, the WTRU may reallocate preambles, ROs, and / or PRACH resources mapped to a muted SSB or an SSB with reduced power to other SSBs that are transmitted (e.g., an unmuted SSB, a stable SSB, an unmuted TRP, or an SSB transmitted at full power). In the example, the WTRU may reallocate PRACH resources mapped to muted SSBs equally to the remaining stable SSBs (for example, in a consecutive order, with a preference for the time domain or the frequency domain).

[0292] The WTRU may receive configuration information indicating a list of SSBs (e.g., SSBs in an SSB burst) or TRPs that it can select in a random access procedure (e.g., it may be configured therein) if, for example, an SSB is transmitted with a given SSB tx assumption (e.g., when) or if the WTRU determines that a cell is in a given NES state (e.g., when). The WTRU may refrain from measuring other SSBs that are not transmitted at full power as part of a random access procedure (e.g., it may ignore / not measure them). If the WTRU is in connected mode (e.g., when / and), the WTRU may consider other SSBs (e.g., unstable SSBs). The WTRU may assume a QCL assumption for an SSB once during a random access procedure and again after its completion, which may be configured for each SSB tx assumption. The WTRU may be indicated by a list of additional unstable SSBs as part of msg4 or msgB.

[0293] WTRUs can be configured per NES state or per SSB tx assumption with separate thresholds for selecting between NUL and SUL, between SULs, between different PRACH segments with different characteristics, and between 2-step PRACH resources and 4-step PRACH resources. WTRUs may apply thresholds related to the RA procedure based, for example, on whether a given NES state is active or whether the SSB is determined to be transmitted with a given SSB tx assumption.

[0294] The WTRU may receive (or be composed of) configuration information indicating RO masks (e.g., ra-ssb-OccasionMaskIndex) per NES state or per SSB tx assumption. The WTRU may use the relevant RO masks in the RA procedure to select the RO and / or associated SSB based on the decision that the SSB is being transmitted with a given SSB tx assumption or that a given NES state is active.

[0295] The WTRU may reset the power ramping counter based, for example, on determining that the SSB is transmitting with different SSB tx assumptions (e.g., compared to a previous preamble transmit attempt), or based on the activation of a given NES state. The WTRU may reset the power ramping counter if, for example, the SSB changes, or the SSB's power changes, or if it keeps it but adjusts the counter to account for the power difference (e.g., incrementing it by more than one to reach the same power level as if the SSB's power had not changed). For example, the WTRU may increment the preamble transmit counter by a value (e.g., >1) such that the increment multiplied by the power ramping step is close to (or equal to) the SSB's transmit power difference or estimated path loss difference compared to a previous preamble transmit attempt.

[0296] The WTRU may restart the RA procedure or reset the preamble transmit counter, for example, based on determining that the SSB is transmitting with a different SSB tx assumption (for example, compared to a previous preamble transmission attempt), or based on the activation of a given NES state.

[0297] The WTRU may select an SDT RA or CG resource corresponding to a stable SSB, an unmuted SSB, or a full-power SSB (for example, as part of the SDT procedure). For example, if the SSB is transmitted at reduced power or the cell is in a given NES state, the WTRU may add or subtract an offset to the measured SS-RSRP threshold for selecting a given SSB (for example, selecting the relevant RO or CG resource), where such an offset may be configured or determined as a power reduction offset for the SSB (for example, for each SSB tx assumption).

[0298] A WTRU may apply backoff for each SSB, for example, based on the receipt of a backoff indication. A backoff indication may indicate a given SSB. A WTRU may, for example, refrain from selecting such an SSB while the backoff time is progressing. A WTRU may receive an indication in the RAR / MsgB prohibiting the selection of a given SSB (e.g., the associated RO) during the RA procedure or for a period of time.

[0299] Mobility and cell (re)selection may be made available and / or implemented.

[0300] The WTRU may begin performing (e.g., several) measurements (e.g., regarding the measurement configuration / gap associated with the SSB's tx assumption, for example) based on receiving indications of different SSB tx assumptions, receiving SSB power reduction indications, and / or determining different SSB tx assumptions. The WTRU may measure one or more target cells (e.g., configured CHO candidates, CHO candidates configured for when the source cell enters the NES state).

[0301] The WTRU may initiate a measurement session (e.g., a new one) if it determines, for example, that a cell is transmitting an SSB with different SSB tx assumptions (e.g., when) or when the cell is in a given NES state. The WTRU may discard previous measurement samples performed using different SSB tx assumptions if it is performing filtering / averaging of measurements (e.g., when).

[0302] Power control may be used, implemented, and / or enabled.

[0303] The WTRU may receive (or be composed of) configuration information indicating parameters (e.g., separate power control parameters) that will apply / are associated with a given NES state or when an SSB is transmitted under the SSB tx assumption. The parameters may include one or more of the following: PCMAX (e.g., maximum permissible transmit power per carrier), P0 (e.g., nominal target receive power), α (e.g., partial path loss compensation parameter), and / or δ (e.g., power adjustment by closed-loop power control). For example, if the WTRU determines that a serving cell is transmitting an SSB at reduced power or is in an NES state, the WTRU may use an alternative α to compensate for path loss. The WTRU may apply an alternative power adjustment delta (δ) based, for example, on the reception of signaling from the network (e.g., as part of L1 / L2 signaling) or on the reception of TPC commands associated with a cell transmitting an SSB under a non-default SSB tx assumption or a cell in an NES state.

[0304] For example, the WTRU may apply alternative power control parameters if an adjacent cell is in an NES state to apply alternative power control parameters, if an adjacent cell is transmitting SSB at reduced power, or when receiving signaling from a serving cell (e.g., L1 / L2 signaling).

[0305] To estimate the uplink path loss for a given beam, the WTRU may use a downlink path loss reference (e.g., generally, where SSB or CSI-RS may be involved). If the SSB or CSI-RS is muted or transmitted at low power, the WTRU may add the power difference (e.g., compared to the total SSB power) to the path loss estimate. For example, if the SSB or CSI-RS is transmitted with different SSB tx assumptions, the WTRU may take the associated QCL / TCI assumptions to estimate the path loss. The WTRU may use (e.g., any of) the parameters associated with the SSB tx assumption determined to estimate the path loss. The WTRU may calculate estimates of multiple path losses for different beams / SSBs. For example, when the serving cell is in the NES state (e.g., sometimes) or when some SSBs are transmitted with non-default SSB assumptions (e.g., estimating the path loss only for stable SSBs), the WTRU may estimate the path loss for a subset of beams (e.g., only for a subset of beams). The WTRU may be composed of SRI values corresponding to each SSB or SSB tx assumption that can be used for the uplink transmission corresponding to the selected SSB. In the case of a scheduled PUSCH transmission, the DCI may further indicate the applicable SSB tx assumptions that can be used by the WTRU to estimate the path loss. The WTRU may assume a configured or pre-defined value of the SRI for a scheduled PUSCH that may be associated with the NES state or the SSB tx assumption.

[0306] CSI reporting may be performed.

[0307] The CSI-RS tx power may be indicated, for example, relative to the SSB power, and therefore the WTRU may use (e.g., require) some form of indication regarding what tx power the gNB is using for SSB transmission. The WTRU may receive dynamic indications (e.g., absolute or delta change values) regarding the CSI-RS transmit power assumption. The WTRU may receive (e.g., configured with) configuration information indicating the CSI-RS power assumption for each SSB tx assumption, and may implicitly determine this from receiving an SSB with a non-default SSB tx assumption. For example, if a received SSB is transmitted with a different SSB tx assumption, the WTRU may determine that the CSI-RS is being transmitted with a different QCL or spatial relation.

[0308] For example, if SSB is transmitted with a non-default SSB tx assumption, the WTRU may report a CSI about the difference between the SSB tx assumption used and the SSB tx assumption for full power. The WTRU may report multiple (e.g., two) CSI reports, such as 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 a tuned CSI measurement corresponding to the active SSB tx assumption to decode the received PDSCH.

[0309] Power headroom reporting (PHR) may be used and / or implemented.

[0310] A WTRU may trigger a PHR if, for example, it determines that an SSB is being transmitted under different SSB tx assumptions, or if a service cell activates a given NES state. For example, if an SSB is being transmitted at low power, a WTRU may trigger a PHR. A WTRU may adjust the estimate of path loss for a PHR. If an SSB or CSI-RS is muted or transmitted at low power, a WTRU may add the power difference (e.g., compared to full SSB power) to the estimate of path loss. For example, if the network is in an NES state (e.g., until the active period of a cell DRX), a WTRU may postpone triggering or transmitting a PHR (e.g., a PHR MAC CE). If the network is in a given NES state (e.g., when), a WTRU may consist of an alternative PHR prohibition time to be applied (e.g., via a timer).

[0311] In the example, the WTRU may contain multiple (e.g., two) PHR values ​​in a single report, for example, where one PHR may correspond to the tx assumption of the active SSB and another PHR may correspond to the tx assumption of a different SSB (e.g., the SSB at full power or the SSB at reduced power). The WTRU may indicate the SSB used to calculate the path loss estimate and PHR as part of the signaling (e.g., via MAC CE).

[0312] For example, if a service cell is in an NES state, or if the corresponding SSB is transmitted with a non-default SSB tx assumption (e.g., when), the WTRU may determine a different PCMAX value to use for calculating the PHR, where the PCMAX value may be a value configured for the determined SSB tx assumption. The WTRU may subtract an NES-specific MPR value from the PCMAX, where the NES-specific MPR may be determined based on the power difference between the current SSB tx assumption and the full-power SSB. If the SSB is transmitted at low power (e.g., with a non-default SSB tx assumption), or if the serving cell is in an NES state, the WTRU may take such an MPR value into consideration in calculating the PHR.

[0313] Beam fault detection and recovery can be performed.

[0314] The WTRU may receive configuration information indicating alternative BFD or RLM candidate beamlists to measure when the current cell is in a given NES state (e.g., when) or when the SSB is transmitted with a non-default SSB tx assumption. In the example, 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 the BFD or RLM, where the offset may correspond to the power difference of the CSI or SSB resources with reduced measured power relative to the total power setting. When the serving cell is in an NES state or when the SSB is transmitted with a non-default SSB tx assumption, the WTRU may consist of alternative thresholds for declaring a BFI instance.

[0315] The WTRU may receive (for example, comprise) configuration information indicating a list of alternative BFR candidate beams to measure when the current cell is in a given NES state or when the SSB is transmitted with a non-default SSB tx assumption. The WTRU may, for example, measure, select, and / or indicate a stable SSB (e.g., only stable SSBs) during the restoration procedure based on beam fault detection. The WTRU may receive (for example, comprise) configuration information indicating alternative thresholds for selecting a suitable restored SSB or CSI-RS when the serving cell is in an NES state or when the SSB is transmitted with a non-default SSB tx assumption.

[0316] NES adaptive cycles for slim sync and SSB may be used and / or made available.

[0317] The WTRU may receive (for example, may be predefined or configured) configuration information having a first cycle (e.g., an NES cycle) for all potential SSB transmission opportunities and a second cycle for all stable SSB transmission opportunities. The first SSB (e.g., unstable) cycle may correspond to opportunities where non-deterministic SSB transmissions, e.g., backward-incompatible SSB structures are transmitted (e.g., as described herein with respect to slim synchronous structures for NES and dynamic power updates for synchronous / SSB transmissions), and / or used while the cell is in an NES state. The second SSB (e.g., stable) cycle may be deterministic and / or used, e.g., when the cell is not in an NES state (e.g., when). The duration of a stable cycle may be longer than the duration of an unstable cycle. The presence of SSB transmissions on an unstable cycle may be limited to a subset of NES states (e.g., only when the NES state is active). SS may refer to slim synchronous opportunities transmitted on an unstable cycle (e.g., such cycles are shown in Figures 8 and 9). Figures 8 and 9 illustrate slim synchronization consisting of PSS / SSS (e.g., PSS / SSS only) as an example. In the example, it could consist of PSS (e.g., only), SSS (e.g., only), (e.g., PSS and SSS only), or different synchronization sequences. Figures 8 and 9 show synchronization signals from a given beam with different periods. For cells / TRPs / networks employing multiple beams, the synchronization signal may be swept / transmitted in each beam direction according to a synchronization burst pattern.

[0318] Figure 9 shows an exemplary 1SSB-3SS-based transmission.

[0319] Figure 10 shows an example of 1SSB-2SS-based transmission.

[0320] A WTRU may use a stable SSB cycle for inter-cell measurements, cell (re)selection measurements, some initial access procedures, and / or in idle mode. A WTRU may monitor and measure SSB on an unstable cycle, for example, based on receiving all system information. Configuration information related to the unstable cycle may be provided by broadcast signaling (e.g., as part of system information, SIB1, or other SI). The period of a stable cycle may be predefined and may depend on the carrier on which the SSB is transmitted, the BWP, the subcarrier interval, and / or the frequency bandwidth.

[0321] The period and occurrence of unstable cycles (for example, along with other relevant configurations) may be determined by the WTRU from system information, reading RRC release messages, or properties of the received SSB during a stable cycle. Properties of the received SSB may include the sequence used for the PSS or SSS, the structure type of the SSB (for example, as described herein), or the tx assumptions of the SSB (for example, as described herein). System information or RRC release message configuration information may provide one or more configuration pieces of information, such as the period for the expected SSB during an unstable cycle, the start offset, the SSB structure, the tx assumptions of the SSB, whether the PBCH is multiplexed with the SSB, the period of the relevant SIB1, and whether it is multiplexed.

[0322] During an unstable cycle SSB opportunity, the WTRU may assume that SSB is transmitted using low-power transmissions and / or received at the WTRU using low-power receivers / PAs (e.g., apart from the main radio). During an unstable cycle SSB opportunity, the WTRU may receive a subset of {PSS, SSS, PBCH, DL WUS}. For example, the WTRU may assume that PSS (e.g., only) is received, PSS and SSS (e.g., PSS and SSS only) is received, PSS, SSS and PBCH (e.g., only) is received, or PSS, SSS, PBCH and DL WUS are received. The received SS or SSB may provide indication of the SSB period / next occurrence or period for both SS and SSB. During an unstable cycle SSB opportunity, PSS / SSS may be transmitted with DL-WUS rather than PBCH, or DL-WUS may be transmitted over some fixed TF resource / opportunity. The PSS( / SSS) sequence can carry indications for the timing of the next full SSB block or on-demand SSB.

[0323] A WTRU may receive configuration information indicating the time and frequency opportunities for the WTRU to monitor DL ​​activation signals (e.g., signals defining low-power WUS or SSB). This configuration may be provided within a portion of system information / broadcast signaling or an RRC release message. DL WUS opportunities may be determined to be aligned (before or after) SSB transmission opportunities in stable and / or unstable cycles.

[0324] A WTRU may monitor and / or receive DL signals (DL-WUS) from the network. Based on the reception of DL-WUS, for example, a WTRU may determine that one or more SSBs are to be transmitted and received during the next SSB transmission opportunity in a first SSB cycle (e.g., a stable cycle / NES cycle). Based on at least one property of the received or decoded DL-WUS, a WTRU may determine the type of SSB structure to monitor and / or receive during the first SSB cycle. The properties of the DL-WUS may include one or more of the following: modulation type (e.g., OOK vs OFDM), time or frequency opportunity when the DL-WUS is received, sequence type (e.g., ZC or M), sequence index, channel coding type, or content of the embedded message. The SSB structure type can be any structure (for example, one of the structures described herein) and can be one or more of the following: time-compressed SSB (for example, with PBCH / SIB1 multiplexed in the frequency domain), reduced-power SSB, narrowband SSB, SSB burst with a reduced number of SSB beams per burst, SSB without PBCH, or SSB transmission without SIB. A WTRU may, for example, receive an SSB during a transmission opportunity of a first SSB cycle based on the determined SSB structure. Based on the reception of the SSB, a WTRU may receive a PBCH and / or one or more SIBs (for example, at least one of the SIBs). For example, in the case of a portion of the initiation access procedure, a WTRU may transmit a preamble (for example, using the determined RACH parameters) (for example, based on the received SSB and information received in at least one of the PBCH and / or SIBs).

[0325] The WTRU may assume the same SSB structure during the first cycle until another DL-WUS is received. The WTRU may combine the received SSBs from stable and unstable cycles into the cumulative energy for the received signal.

[0326] In the example, the WTRU may determine the active NES state from the reception of the DL WUS, for example, based on the properties of the received or decoded DL-WUS (e.g., at least one property). The NES state may be encoded as part of the content of the DL WUS message. The DL WUS may provide indications of the NES status and relative period for SSBs and SSs (e.g., slim SSs). The WTRU may determine the NES state of a cell from the period or relative period for stable and unstable SSB cycles, for example, based on a predefined period or a relative period defined in the specification. The WTRU may determine the SSB structure or the tx assumption of an SSB (e.g., TDM between one SSB and N PSS / SSS with repetitions) from the reception of the PBCH or its contents or from the properties of the received PSS / SSS sequence. For dynamically switching the NES state, the gNB may indicate an update to the NES state via the DL WUS. The DL WUS may further indicate an update to the SSB period or a switch to a different SSB's tx assumption. WTRU can determine the state of the NES cell from the determined SSB tx assumptions (e.g., SSB type or period) (for example, alternatively).

[0327] Changes to the SSB cycle or on-demand SSB can be requested (for example, via UL WUS).

[0328] WTRU may receive configuration information indicating that it will send a request in one or more NES states (for example, an uplink start request "UL WUS" or a cell start request "Cell WUS") (for example, it may be predefined or configured to do so). WTRU transmits a WUS of a cell to change the tx assumption of an active SSB (e.g., as described herein), change the transmission period of an active SSB (e.g., in a stable cycle or an unstable cycle or both), activate SSB transmission (e.g., on an unstable cycle), change the structure / type of the transmitted SSB (e.g., as described herein), transmit all SSBs (e.g., SSBs with PBCH and SSBs transmitted at full power, or on-demand SSBs), activate or deactivate a given NES state, request for slim SSB and / or PBCH transmission, request for reception of system information (e.g., SIB1 transmission, other SIs, and / or MSIs), indicate an active NES state, activate a given data or control channel (e.g., PDSCH, SPS, CG, PUCCH), DL Configuration of WUS resources, for example, configuration of system access resources for a given cell (e.g., a cell in NES state) including a PRACH resource configuration and / or a subset of system information for a given cell, one or more of the above required for a given carrier, BWP, frequency band, or TRP.

[0329] A WTRU may include information (for example, any of the information described herein) requested as part of a cell WUS request (for example, part of an RA payload (for example, in msgA or msg3) triggered for cell WUS in attached support data). For example, a WTRU may include indications regarding the SSB's tx assumptions, SSB's tx power, SSB's structure, and / or SSB's period requested in a message sent as part of a message or procedure with cell WUS (for example, on a PUSCH resource as part of an RA triggered by cell WUS).

[0330] The WTRU may monitor the PDCCH after the cell's WUS transmission to receive, for example, requested signals, channels, and / or information. The WTRU may monitor the reception of requested time-domain cycles (e.g., unstable cycles), carriers, BWP, or TRPs, SSB, PBCH, and / or SI. The WTRU may monitor the DL WUS after the UL WUS signal transmission. The WTRU may assume predefined changes in the SSB structure after the cell's WUS transmission or after receiving a response to the cell's WUS.

[0331] A WTRU may trigger the transmission of a cell's WUS signal based on satisfying at least one of the following conditions, for example: detection of a cell discovery signal; channel measurements exceeding or falling below a configured threshold; arrival of new data, if the data arrives from a subset of DRB, SRB, LCH, LCG or is associated with a certain priority level or index; the amount of buffered data exceeding a threshold; triggering a BSR and / or SR; detection of a beam fault or RLM event (e.g., RLF); triggering an L3 or mobility event; detection of an SCG or MCG failure; or, in some cases, based on the elapsed duration (e.g., timer expiration), combined with the absence of SSB or DRS during such a period.

[0332] A WTRU may transmit a WUS of a cell on the same cell, TRP, or BWP from which the requested signal / channel / information was produced, or on a different serving cell, TRP, or BWP. For example, a WTRU may detect that an Scell ​​has not transmitted any SSB within a time period and then request on-demand SSB transmission or activation of SSB on such a cell by transmitting a WUS of the cell on a different serving cell (e.g., SpCell). A WTRU may transmit a WUS of a cell solely for the purpose of transmitting SSB on a secondary cell. A WTRU may transmit a WUS of a cell on a secondary cell (e.g., only on secondary cells) or on an unstable cell (e.g., only on unstable cells). A WTRU may assume the activation of an additional SSB transmission cycle (e.g., an unstable SSB cycle) after transmitting a WUS of a cell or after receiving a DL response to it.

[0333] Periodicity and repetition for slim synchronization and SSB may be used, implemented, and / or provided.

[0334] In an example (for example, for designing the acquisition of system information), the WTRU may receive configuration information indicating that it will receive one of the legacy or proposed SSB structures (as described herein, for example) and different relative periods for all SSBs or slim synchronization (for example, it may be predefined or preconfigured to do so). Different synchronization structures, the number of repetitions for PSS / SSS symbols in all SSBs or standalones, and relative periods may have a mapping to the cell's NES state. The WTRU may determine the expected SSB structure, repetitions, and relative periods based on the cell's NES state.

[0335] Figure 11 shows an exemplary synchronization design in which the full synchronization includes (e.g., features) two symbols for PSS / SSS (e.g., two symbols for each of PSS / SSS) and six symbols for PBCH. In this full synchronization, the frequency occupation of the PSS / SSS and PBCH transmissions may be the same. For each beam, after (e.g., one) full synchronization, multiple (e.g., two) slim synchronizations may follow during the next several transmission periods (e.g., two transmission periods). Each (e.g., each) slim synchronization may include (e.g., features) two symbols for PSS and two symbols for SSS.

[0336] Figure 11 shows an exemplary synchronous design with a TDM structure for SSB and PSS / SS.

[0337] The network can transmit full sync and / or slim sync (e.g., PSS / SSS) through low-power Tx and PA. This can allow for longer sleep times for the gNB's normal (high-power) Tx and PA, which adds a significant energy-saving benefit to network operation.

[0338] Figure 11 shows an example of using two OFDM symbols for PSS and SSS transmission during each synchronization period. The number of PSS / SSS symbols per period may be increased to compensate for the synchronization coverage loss associated with the use of low-power Tx and PA.

[0339] In the example, the period of PSS / SSS transmission may be increased. In the example, full synchronization (e.g., PSS / SSS / PBCH) may use period T1. PSS / SSS transmission without PBCH may use a much shorter period T2, which provides more PSS / SSS opportunities that WTRU can average out to increase performance and compensate for coverage loss.

[0340] A WTRU can be predefined or preconfigured with two sets of configuration information. One set of configuration information may be for fully synchronous (e.g., PSS / SSS / PBCH) transmissions, and the other may be for PSS / SSS transmissions without PBCH. In the example, there may be a single configuration with additional parameters. These additional parameters may provide, for example, the relative time and relative period of a slim PSS / SSS transmission compared to a full PSS / SSS / PBCH transmission.

[0341] Figure 12 shows two examples of slim synchronization with different numbers of symbols and different transmission periods for each transmission interval.

[0342] As shown at the top of Figure 12, a design with two PSS / SSS symbols repeating every 2 milliseconds can be used.

[0343] As shown at the bottom of Figure 12, a design with one PSS / SSS symbol having a period of 1 millisecond can be used.

[0344] Figure 12 shows exemplary designs for different SS lengths and periods.

[0345] A slim SSB design may consist of a (preferred) number of PSS and SSS symbols (e.g., PSS / SSS symbols only). Other designs for slim SSB may consist of transmitting PSS (e.g., only), transmitting SSS (e.g., only), transmitting PSS and SSS (e.g., transmitting PSS and SSS only), or an NES-based (e.g., new) sequence for PSS, SSS, or both.

[0346] For each of these designs, the number of symbols / repetitions can be optimized to achieve a trade-off between network energy savings, effective coverage, and WTRU synchronization performance. These designs can be further combined with different relative periods for full synchronization and slim synchronization.

[0347] The NES status or SSB location may be indicated through sequence transmission.

[0348] The WTRU may determine the time-frequency location of the SSB by detecting a sequence transmitted by the network (e.g., a pre-synchronization signal such as a WUS). This sequence is sometimes referred to as a pre-synchronization sequence (as described herein, for example).

[0349] In the example, the WTRU might anticipate a pre-synchronization sequence that will be transmitted by the network at a known period. The known period can be a fixed value or one of a known set of values.

[0350] A WTRU may decide to decode a pre-synchronization sequence across a group of N consecutive physical resource blocks (PRBs). N can be a known value among several PRBs. N can be a value from a set of known values ​​for PRBs. The network may transmit a sequence within each group of N PRBs. The length of the sequence can be a known value or from a set of known values.

[0351] For example, the WTRU may determine the timing and placement of the pre-synchronization sequence based on information received (e.g., indicated) in a slim synchronization signal (e.g., as described herein).

[0352] In the example, the WTRU might anticipate a pre-synchronized sequence that will be sent from a known sequence type, such as a Zadoff-Chu or M sequence.

[0353] In the example, the pre-synchronization sequence can be the transmission of a PSS sequence with a given period at a configured time-frequency location.

[0354] The WTRU determination of the type / format / pattern of the pre-synchronization sequence may be based on one or more of the following: synchronization raster location, frequency band (e.g., FR1 / 2 may use one type of pre-synchronization sequence, and (e.g., new) band FR3 / 4 band may use a different type of pre-synchronization sequence), physical cell ID which can indicate which format / type of pre-synchronization sequence will be used by the network (e.g., may be determined based on PSS and / or SSS reception), subcarrier interval (e.g., different subcarrier intervals may be associated with different formats / types / periods for pre-synchronization sequences), and cell operating mode (e.g., NES mode or otherwise).

[0355] The WTRU may detect DL pre-synchronization sequences transmitted by the network. The WTRU may determine one or more of the following (for example, based on at least one of the properties of the received or detected pre-synchronization sequence): the time location of the SSB, the frequency location of the SSB (for example, in a broadband carrier with a suitable granularity), the structure of the SSB, the presence or absence of slim sync, the structure of slim sync (for example, as described herein), the presence or absence of transmission of compact minimal system information, the period of the SSB or slim sync, the relative period of the SSB and slim sync, and the NES indication of the cell.

[0356] A pre-synchronized sequence can carry information in one of its physical properties, such as time location, frequency location, sequence type, sequence selection, sequence phase, initialization parameters, etc. (for example, it can be shown).

[0357] Compact, minimal system information can be transmitted / retrieved.

[0358] A WTRU may receive configuration information indicating a compact format SSB (e.g., PSS, SSS, and PBCH) as well as SIB-1 or RMSI (for example, it may be predefined or preconfigured to receive it). The entire compact form of PSS, SSS, and minimal system information (PBCH and SIB-1) is sometimes referred to as SSM.

[0359] SSM may include PSS + SSS + compact minimal system information (PBCH, SIB-1).

[0360] In SSM, the PBCH may not provide time, frequency resources / parameters to discover SIB-1 (for example, it may not need to). The PBCH content within SSM may differ from the (e.g., legacy) PBCH transmitted as part of the (e.g., legacy) SSB.

[0361] A subset of parameters from SIB-1 may be sent as part of an SSM, for example, according to predefined or preconfigured information provided to the WTRU. This set of parameters is sometimes referred to as a compact SIB-1 or compact RMSI.

[0362] The WTRU may receive configuration information indicating that it will detect and decode one or a combination of the following: different types of SSMs, e.g., different subsets of PBCH, SIB-1 (RMSI), different subsets of PBCH, SIB-1 and below SIB information (e.g., several elements taken from SIB-2, SIB-3, SIB-4, SIB-5, etc.), time / frequency resources for different MSIs (e.g., offsets from PSS / SSS), and channel codings that may differ among different types of SSMs (for example, it may be configured to do so).

[0363] In the example, the WTRU may decode SSB and / or compact SIB-1 (e.g., RMSI), where the compact SIB-1 may be transmitted over the same frequency resources as the PBCH on subsequent OFDM symbols (e.g., as shown in Figure 12). As shown in Figure 12, the WTRU may decode compact SIB-1 across four OFDM symbols after the last OFDM symbol of the PBCH, according to the previous configuration. The WTRU may decode compact SIB-1 over two, three, four or more OFDM symbols (e.g., it may be configured to do so).

[0364] In the example, PBCH transmission and compact SIB-1 can be coded (for example, independently). PBCH may use polar coding. Compact SIB-1 can be coded using LDPC according to parameters known to or pre-configured in the WTRU, for example. In the example, compact SIB-1 can be polar coded.

[0365] The design of the reference symbol for compact SIB-1 transmission can use the same sequence generation and comb structure as for PBCH. Therefore, DMRS for SIB-1 can follow the same comb 4 design as used for PBCH.

[0366] The DMRS frequency offset for a compact SIB-1 can be the same as that for a PBCH, depending on the cell identification information of the cell transmitting the PBCH. For example, a compact SIB-1 transmit can use a comb 2 DMRS structure in the first OFDM symbol of the SIB-1 transmit. This first symbol can be accompanied by additional DMRS symbols within the compact SIB-1 transmit. DMRS indications for a compact SIB-1 transmit can be shown in the PBCH. Thus, a WTRU can decode a PBCH transmit, which may provide one or more of the following: the comb structure for DMRS related to the DMRS structure of the compact SIB-1, the number / location of additional DMRS symbols, the resource element offset for DMRS Res, etc.

[0367] Figure 13 shows an exemplary compact MSI structure with separate coding for PBCH and compact SIB-1.

[0368] In the example, the WTRU may have knowledge of multiple subsets / formats of legacy SIB-1 information elements through preconfiguration that the network can transmit as compact SIB-1. The WTRU may decode the PBCH and determine the format (e.g., a specific subset of SIB-1) that the network may indicate through the PBCH transmission. The WTRU may decode and / or interpret the information elements of the compact SIB-1 transmission according to indications received in the PBCH transmission.

[0369] In the example (for example, for SSM transmission), PBCH transmission and compact SIB-1 can use the same frequency span as PSS / SSS (as shown, for example, in Figure 14).

[0370] Figure 14 shows an exemplary compact MSI structure with separate coding for a smaller frequency footprint than PBCH and RMSI+.

[0371] PBCH transmissions can be transmitted with the same information content as in the current design, with some minor modifications. PBCH transmissions can provide indications regarding the transmission attributes of SIB-1 (e.g., DMRS, some symbols for SIB-1 transmissions, etc.).

[0372] The compact SIB-1 can follow PBCH transmission according to the indication provided by PBCH transmission.

[0373] In the example, the PBCH transmission and compact SIB-1 can be encoded (e.g., joint encoded) and transmitted (e.g., joint transmitted) together with the PSS / SSS sequence (e.g., as shown in Figure 15). The PBCH transmission and compact SIB-1 (e.g., providing a compact MSI) can be mapped over a larger number of PRBs (e.g., compared to PSS / SSS). In the example, the compact MSI can span 20 PRBs that are traversed by the PBCH during legacy SSB. The modulation, coding, and DMRS for the MSI can follow predefined / preconfigured values, or one of a set of predefined / preconfigured values ​​can be used.

[0374] In the example, the WTRU may provide indication of the compact MSI transmission parameters through one of the physical properties of the PSS / SSS (for example, it may receive them). In the example, the indication may be provided through a DL-WUS signal transmitted by the network over a known time-frequency resource.

[0375] In this example, the WTRU may determine the format and period of the compact MSI through NES indications transmitted over the network (e.g., along with PSS / SSS sequences).

[0376] In this example, the WTRU may determine the format and period of a compact MSI for a cell (for example, along with a PSS / SSS sequence) through indications received from another cell. The other cell providing indications to the WTRU could be the serving cell of the UE.

[0377] Figure 15 shows an exemplary compact MSI structure with co-coding for PBCH and compact SIB-1.

[0378] Figure 16 shows an exemplary design for compact MSI transmission with a PSS / SSS sequence, where the jointly coded compact MSI can be transmitted over the same frequency span as the PSS / SSS.

[0379] Figure 16 shows an exemplary compact MSI structure with co-coding for PBCH and compact SIB-1.

[0380] In the example, a compact MSI may contain (for example, may contain) a digest of the PBCH and SI. The digest of the SI may contain a single value or a set of values ​​(for example, may contain). In the example, the digest of the SI may contain (for example, may contain) two values, for example, here, one value is the digest of the MSI relating to the MIB and SIB-1. The second value in the digest of the SI may correspond to other system information. A WTRU may receive system information and a digest of the SI for its neighbor cell Cx through its serving cell. For example, if the WTRU re-selects cell Cx, the WTRU may (for example, later) retrieve a compact MSI. The WTRU may compare the digest of the SI to verify for cell Cx whether it matches its stored digest of the SI (for example, it may determine whether it requires a new SIB-1 and / or other SIBs). For example, if the SI digest does not match the stored SI digest for cell Cx, the WTRU may receive / decode an SIB-1 from cell Cx to obtain the RACH parameters for cell Cx. For example, if the SI digests match, the WTRU may already have the RACH parameters for cell Cx (for example, based on previously received SI digests). Based on the RACH parameters, the WTRU may transmit a RACH on cell Cx. The WTRU may indicate a stored "digest of other SIs," and thus the network knows what system information the WTRU has (for example, in Msg1 / 3 / MsgA as part of the UE's RACH transmission). The network can provide delta system information to a WTRU in which a "digest of other SIs" has been indicated. Reception of the C-MSI may be based on a first SSB cycle, which may be non-deterministic or an NES cycle. Reception of SIB-1 may be based on a second SSB cycle that is deterministic, total, or a non-NES SSB cycle.

[0381] In the example, the time-frequency span of (e.g., legacy) SSB (e.g., 20 PRBs - 4 OFDM symbols) may be used to transmit SSMs (e.g., PSS, SSS, and compact MSI). In the example, the PBCH parameters related to CORESET-0 may be replaced by a digest of the SI. This design may be advantageous in maintaining the same SSB burst pattern as other (e.g., legacy) burst designs.

[0382] In the example, the network may represent two sets of cycles (e.g., periods), for example, here, one set may refer to the cycles / periods transmitted in all / legacy SSB and SIB-1, and the second set may refer to the cycles / periods transmitted in compact MSI transmit structures (e.g., according to other designs described herein).

[0383] In the example, the cycle / period of the second set may have one of the compact MSI transmit structures depending on the entire SSB / SIB-1 transmit or the cell's NES state. The WTRU receives the cell's NES state and may determine the compact MSI transmit structure / period according to the cell's NES state. The indication may be the NES state itself, which may have a mapping to one of the structures, or the NES indication may have additional indications that the WTRU uses to determine the compact MSI structure / period.

[0384] A WTRU may receive (or decide to receive) system information transmitted from the network through one of the patterns / formats, such as (e.g., legacy) SSB, SIB-1 and additional SIBs, (e.g., as described herein) SSM, (e.g., as described herein) one or more SSM types, or a combination of (e.g., legacy) SSB / SIB-1 and one or more of the (e.g., as described herein) SSM types.

[0385] The determination of the WTRU format / pattern of system information, whether it is transmitted using legacy SSB / SIB-1 or the newer SSM format, may be based on one or more of the following: synchronous raster location, frequency band (e.g., FR1 / 2 may use (e.g., legacy) SSB, and (e.g., newer) band FR3 / 4 may use SSM or one of the SSM types), physical cell ID which can indicate which format / type of SSB / SSM is used for transmitting / receiving system information (e.g., this may be determined based on PSS and / or SSS reception), subcarrier spacing (e.g., different subcarrier spacings which may be associated with different formats / types of SSB / SSM), and cell operating mode (e.g., NES mode or otherwise).

[0386] The determination of the WTRU format / pattern of system information from one of the SSM types / formats / patterns may be based on one or more of the following: synchronous raster location, frequency band (e.g., FR1 / 2 may use (e.g., legacy) SSB, and (e.g., newer) band FR3 / 4 may use SSM or one of the SSM types), physical cell ID which can indicate which format / type of SSB / SSM is used for transmitting / receiving system information (e.g., this may be determined based on PSS and / or SSS reception), subcarrier spacing (e.g., different subcarrier spacings which may be associated with different formats / types of SSB / SSM), and cell operating mode (e.g., NES mode or otherwise).

[0387] The WTRU may (for example, decide to) perform one or more of the following actions (for example, if the WTRU determines the presence of one of the SSM formats / types or a combination with legacy SSB / SIB-1):

[0388] A WTRU may decide to perform RACH according to the type / format of the system information it receives. For example, if it receives a legacy SSB / SIB-1, a WTRU may use a four-step RACH procedure to perform RACH. If it receives one of the SSB types, a WTRU may use a two-step RACH procedure to perform RACH.

[0389] The WTRU may, for example, perform a RAC power update in one configuration / defined manner if it detects SSB / SIB-1, or it may decide to perform a RAC power update in a second configuration / defined manner if it detects one of the SSM types / formats.

[0390] A WTRU may, for example, select a RACH sequence from one set if it detects a legacy SSB / SIB-1 (for example, it may decide to select one set). A WTRU may, for example, select a RACH sequence from a second set if it detects one of the SSM types / formats (for example, the first set of RACH sequences is associated with the detection of legacy SSB / SIB-1, and the second set of RACH sequences is associated with SSMs). There may be two or more defined SSM types and their associated RACH sequences.

[0391] A WTRU may decide to monitor (e.g., listen to) RACH responses in one of the search spaces according to the SSM format / type. For example, a WTRU might listen to one type 1 search space associated with legacy SSB / SIB-1, while simultaneously listening to another type 1 search space associated with one of the SSM types to receive RACH responses. There may be two or more type 1 search spaces associated with different types / formats of SSMs.

[0392] A WTRU may monitor (e.g., listen to) (e.g., decide to do so) paging in one of the search spaces according to the SSM format / type, thereby allowing these search spaces to be associated with the same or different sets of control resources. The sets of search spaces may have different periods, different PDCCH candidates, etc. For example, a WTRU may monitor / decode (e.g., listen to) (e.g., decide to do so) a paging search space associated with an SSB / SIB-1 if (e.g., when) the WTRU detects an SSB / SIB-1. A WTRU may decode (e.g., decide to decode) another paging search space associated with an SSM if (e.g., when) it detects an SSM. Two or more paging search spaces may be associated with different SSM types / formats.

[0393] While the features and elements described above are described in specific combinations, each feature or element can be used alone or in various combinations with or without other features and elements in preferred embodiments.

[0394] While the implementations described herein may consider protocols specific to 3GPP, it should be understood that the embodiments described herein are not limited to this scenario and may be applicable to other wireless systems. For example, while the solutions described herein consider protocols specific to LTE, LTE-A, New Radio (NR), or 5G, it should be understood that the solutions described herein are not limited to this scenario and may be applicable to other wireless systems.

[0395] The processes described above may be implemented in computer programs, software, and / or firmware embedded in computer-readable media for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted via wired and / or wireless connections) and / or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and / or optical media such as compact disc (CD)-ROM discs and / or digital multi-purpose discs (DVDs). Processors related to software may be used to implement radio frequency transceivers for use in WTRUs, terminals, base stations, RNCs, and / or any host computer.

Claims

1. A wireless transmitter / receiver unit (WTRU), A first signal is received, the first signal is a slim sync signal (SS), and the first signal indicates information associated with a second signal. Determine the resource associated with the reception of the second signal, and the resource is determined using the information associated with the second signal. The second signal is received via the resource determined using the information associated with the second signal, and the indication that the second signal is associated with the reception of a synchronization signal block (SSB), Based on the indication in the second signal, information associated with the reception of the SSB is determined. The SSB is received based on the information associated with the reception of the SSB that has been determined. A WTRU equipped with a processor configured as such.

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

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

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

5. The WTRU according to claim 1, wherein the SSB includes a physical broadcast channel (PBCH) block.

6. The WTRU according to claim 1, wherein the second signal is a pre-synchronization start signal.

7. The WTRU according to claim 1, wherein the second signal is at least one of the time associated with the slim SS, the frequency associated with the slim SS, the phase associated with the slim SS, or the sequence selection associated with the slim SS, as determined by the first signal.

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

9. The WTRU according to claim 1, wherein the information associated with the reception of the SSB indicates one or more of the following: network energy saving (NES) status, SSB period, or the presence of all SSBs on a potential all-SSB transmission opportunity.

10. Receiving a first signal, wherein the first signal is a slim sync signal (SS), and the first signal indicates information associated with a second signal. Determining the resource associated with the 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 includes an indication associated with the reception of a synchronization signal block (SSB), Based on the indication in the second signal, determine the information associated with the reception of the SSB, Receiving the SSB based on the information associated with the reception of the SSB determined above, Methods that include...

11. The method according to claim 10, wherein the slim SS is a compressed SS.

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

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

14. The method according to claim 10, wherein the SSB includes a physical broadcast channel (PBCH) block.

15. The method according to claim 10, wherein the second signal is a pre-synchronization start signal.

16. The method according to claim 10, wherein the second signal is at least one of the time associated with the slim SS, the frequency associated with the slim SS, the phase associated with the slim SS, or the sequence selection associated with the slim SS, as determined by the first signal.

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

18. The method according to claim 10, wherein the information associated with the reception of the SSB indicates one or more of the following: network energy saving (NES) status, SSB period, or the presence of all SSBs on a potential all-SSB transmission opportunity.

Images