Methods on low-power synchronization signal design

Abstract

In accordance with implementations, a WTRU receives from a first serving cell a first signal with a first type of waveform. The first signal carries configuration information for receiving a second signal with a second type of waveform. The configuration information indicates a first threshold and a second threshold less than the first threshold. The WRTU compares a measurement of the second signal to at least one of the first threshold or the second threshold. The WRTU receives a payload in a mode determined based on the comparing.

Description

METHODS ON LOW-POWER SYNCHRONIZATION SIGNAL DESIGN Priority Claim and Cross-Reference

[0001] This patent application claims priority to U.S. Provisional Application No. 63 / 554,674, filed on February 16, 2024, and entitled “Methods on Low-Power Synchronization Signal Design,” application of which is hereby incorporated by reference herein as if reproduced in its entirety. Technical Field

[0002] The present disclosure relates generally to wireless communications, and, in particular embodiments, to systems and methods for low-power synchronization signal design. Background

[0003] A 3rd Generation Partnership Project (3GPP) study on low-power wake-up signal (LP-WUS) and low-power wake-up receiver (LP-WUR) for new radio (NR) was performed. The study covered low-power receiver architectures, signal and protocol design, and evaluation methodology targeting metrics such as power saving gain, latency, coverage availability, coexistence with non-low-power-WUR UEs, and network resource overhead. Several receiver architectures, supporting On-Off Keying (OOK) modulation scheme, were agreed and analyzed including architectures with radio frequency (RF) envelope detection, heterodyne architecture with intermediate frequency (IF) envelope detection, and homodyne / zero-IF architecture with baseband (BB) envelope detection. Another receiver architecture suitable for the reception of orthogonal frequency division multiple access (OFDMA)-based signals / channels with reduced power consumption was also agreed. Different OOK waveform generation options were discussed and evaluated in the 3GPP RAN1 working group. With the conclusion of discussions and evaluations of waveforms, a work item on LP-WUS will start in 3GPP NR Release 19 with focus on harmonized OOK and OFDM waveform generation, i.e., based on orthogonal frequency division multiplexing (OFDM) sequence overlaid over OOK modulated symbols. Further, a periodic low-power synchronization signal (LP-SS) based on OOK is also expected to be specified for LP-WUR architectures that cannot receive existing primary synchronization signal (PSS) / secondary synchronization signal (SSS) to assist in synchronization and radio resource management (RRM) measurements by the LP-WUR. In this document, this disclosure provides technical solutions for an energy efficient design and configuration of LP-SS as well as the procedures for handling LP-SS monitoring forFW 6000682PCT02 1synchronization, measurements, and cell (re-)selection in radio resource control (RRC) Idle / Inactive states. Background

[0004] Technical advantages are generally achieved, by implementations of this disclosure which describe methods, apparatus, and system.

[0005] In accordance with implementations, a WTRU receives from a first serving cell a first signal with a first type of waveform. The first signal carries configuration information for receiving a second signal with a second type of waveform. The configuration information indicates a first threshold and a second threshold less than the first threshold. The WRTU compares a measurement of the second signal to at least one of the first threshold or the second threshold. The WRTU receives a payload in a mode determined based on the comparing.

[0006] In some implementations, the measurement may be above the first threshold. The payload may comprise a low-power wake-up signal (LP-WUS).

[0007] In some implementations, the WRTU may receive the LP-WUS in a first operation mode. The first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU operating with non-coherent detection to monitor the LP- WUS in accordance to the second type of waveform. The non-coherent detection may include envelope detection without using information about at least one overlaid orthogonal frequency division multiplexing (OFDM) sequence.

[0008] In some implementations, the measurement may be below the first threshold and above the second threshold. The WTRU may receive the LP-WUS in the second operation mode.

[0009] In some implementations, the WTRU may receive the LP-WUS in a second operation mode. The second operation mode may correspond to using a LP-WUR of the WTRU operating with coherent detection to monitor the LP-WUS in accordance to the second type of waveform. The coherent detection may include detection using information about at least one overlaid OFDM sequence.

[0010] In some implementations, the measurement may be below the second threshold, and the payload comprises at least one of a short message, a paging message, or a paging downlink control information (DCI).

[0011] In some implementations, the WTRU may receive the payload in the third operation mode. The third operation mode may correspond to using a main radio (MR) of the WTRU to monitor the payload in accordance to the first type of waveform.FW 6000682PCT02 2

[0012] In some implementations, the third operation mode may further correspond to using the MR for serving cell measurements based on at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

[0013] In some implementations, the first type of waveform may be an OFDM waveform or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) waveform. The second type of waveform may be an On-Off Keying (OOK) waveform with pulse shaping based on overlaid OFDM sequences.

[0014] In some implementations, the WTRU in a third operation mode may receive at least one of a paging DCI or a paging message with the first type of waveform in accordance to the LP-WUS. The WTRU in the third operation mode may transmit a physical random access channel (PRACH) preamble in accordance to the first type of waveform.

[0015] In some implementations, the configuration information may further indicate a time window. The second signal may be received in the time window.

[0016] In some implementations, the configuration information may further indicate at least one overlaid OFDM sequence.

[0017] In accordance with implementations, a WTRU receives from a first serving cell a low-power wake-up signal (LP-WUS) configuration and a low-power synchronization signal (LP-SS) configuration. The WTRU in a first operation mode measures one or more LP-SS sequences based on the LP-SS configuration to determine one or more measurements for the one or more LP-SS sequences. The WTRU in the first operation mode receives an LP-WUS based on the LP-WUS configuration and based on that a first measurement of the one or more measurements is above a first threshold. The WTRU in the first operation mode performs serving cell selection based on comparing the one or more measurements to a third threshold.

[0018] In some implementations, at least one of the LP-WUS configuration or the LP-SS configuration may indicate a first set of common LP-WUS area identifiers (IDs).

[0019] In some implementations, the WTRU may receive a payload carrying one or more common LP-WUS area IDs may be associated with each of the one or more LP-SS sequences.

[0020] In some implementations, before receiving the LP-WUS, the WTRU in the first operation mode may determine, a first set of measurements from the one or more measurements above the third threshold. The WTRU in the first operation mode may decode one or more payloads associated with the one or more LP-SS sequences based onFW 6000682PCT02 3the first set of measurements to determine a second set of common LP-WUS area IDs. The WTRU in the first operation mode may determine a third set of common LP-WUS area IDs. The third set may be an intersection of the first set and the second set. The third set is not empty.

[0021] In some implementations, the WTRU in the first operation mode may measure second one or more LP-SS sequences based on the LP-SS configuration to determine second one or more measurements for the second one or more LP-SS sequences. The WTRU in the first operation mode may determine a fourth set of measurements from the second one or more measurements above the third threshold. The WTRU in the first operation mode may decode second one or more payloads associated with the second one or more LP-SS sequences based on the fourth set of measurements to determine a fifth set of common LP-WUS area IDs. The WTRU in the first operation mode may determine a sixth set of common LP-WUS area IDs. The sixth set may be a second intersection of the fourth set and the fifth set. The six set is empty. The WTRU in the second operation mode may perform the serving cell selection. The WTRU in the second operation mode may receive from a second serving cell system information.

[0022] In some implementations, the WTRU in the first operation mode may receive the LP-WUS from the second serving cell.

[0023] In some implementations, the receiving the LP-WU may be based on that the third set includes at least one common LP-WUS area ID.

[0024] In some implementations, the WTRU in the first operation mode may receive the LP-WUS from the first serving cell.

[0025] In some implementations, the WTRU in the first operation mode may receive the LP-WUS from a third serving cell. The at least one common LP-WUS area ID in the third set may include a third common LP-WUS area ID corresponding to the third serving cell.

[0026] In some implementations, the WTRU in the second operation mode may receive the system information from the third serving cell based on the receiving the LP- WUS.

[0027] In some implementations, the WTRU in the second operation mode may receive at least one of a paging DCI or a paging message in accordance to the LP-WUS. The WTRU in the second operation mode may transmit a physical random access channel (PRACH) preamble to at least one of the first serving cell, the second serving cell, or the third serving cell.FW 6000682PCT02 4

[0028] In some implementations, the first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU. The WTRU in the first operation mode may monitor an On-Off Keying (OOK) waveform with or without an overlaid orthogonal frequency division multiplexing (OFDM) sequence.

[0029] In some implementations, the second operation mode may correspond to using a main radio (MR) of the WTRU. The WTRU in the second operation mode may transmit or receive an OFDM signal or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) signal using a transmitter or a receiver of the MR, respectively.

[0030] In accordance with implementations, at least one base station in a first serving cell transmits to a wireless transmit / receive unit (WTRU) a first signal with a first type of waveform. The first signal carries configuration information for receiving a second signal with a second type of waveform. The configuration information indicates a first threshold and a second threshold less than the first threshold. The at least one base station transmits to the WTRU a payload. The payload is received by the WTRU in a mode determined based on comparing a measurement of the second signal to at least one of the first threshold or the second threshold.

[0031] In some implementations, the measurement may be above the first threshold. The payload may comprise a low-power wake-up signal (LP-WUS).

[0032] In some implementations, the payload may be received in a first operation mode of the WTRU. The first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU operating with non-coherent detection to monitor the LP-WUS in accordance to the second type of waveform. The non-coherent detection may include envelope detection without using information about at least one overlaid orthogonal frequency division multiplexing (OFDM) sequence.

[0033] In some implementations, the measurement may be below the first threshold and above the second threshold. The payload may comprise an LP-WUS.

[0034] In some implementations, the payload may be received in a second operation mode of the WTRU. The second operation mode may correspond to using a LP-WUR of the WTRU operating with coherent detection to monitor the LP-WUS in accordance to the second type of waveform. The coherent detection may include detection using information about at least one overlaid OFDM sequence.

[0035] In some implementations, the measurement may be below the second threshold. The payload may comprise at least one of a short message, a paging message, or a paging downlink control information (DCI).FW 6000682PCT02 5

[0036] In some implementations, the payload may be received in a third operation mode of the WTRU. The third operation mode may correspond to using a main radio (MR) of the WTRU to monitor the payload in accordance to the first type of waveform.

[0037] In some implementations, the third operation mode may further correspond to using the MR for serving cell measurements based on at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

[0038] In some implementations, the first type of waveform may be an OFDM waveform or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) waveform. The second type of waveform may be an On-Off Keying (OOK) waveform with pulse shaping based on overlaid OFDM sequences.

[0039] In some implementations, the at least one base station may transmit to the WTRU in a third operation mode at least one of a paging DCI or a paging message with the first type of waveform in accordance to the LP-WUS. The at least one base station may receive from the WTRU in the third operation mode a physical random access channel (PRACH) preamble in accordance to the first type of waveform.

[0040] In some implementations, the configuration information may further indicate a time window. The second signal may be transmitted in the time window.

[0041] In some implementations, the configuration information may further indicate at least one overlaid OFDM sequence.

[0042] In some implementations, the at least one base station may include two or more base stations.

[0043] In accordance with implementations, a base station in a first serving cell of a network system transmits to a wireless transmit / receive unit (WTRU) a low-power wake- up signal (LP-WUS) configuration and a low-power synchronization signal (LP-SS) configuration. The network system transmits to the WTRU in a first operation mode an LP-WUS. The LP WUS is received by the WTRU based on that a first measurement of one or more measurements is above a first threshold. The WTRU in the first operation mode performs serving cell selection based on comparing the one or more measurements to a third threshold.

[0044] In some implementations, at least one of the LP-WUS configuration or the LP-SS configuration may indicate a first set of common LP-WUS area identifiers (IDs).

[0045] In some implementations, the network system may transmit to the WTRU a payload carrying one or more common LP-WUS area IDs associated with each of one or more LP-SS sequences.FW 6000682PCT02 6

[0046] In some implementations, a second base station in a second serving cell of the network system may transmit the LP-WUS to the WTRU in the first operation mode.

[0047] In some implementations, the base station in the first serving cell may transmit the LP-WUS to the WTRU in the first operation mode.

[0048] In some implementations, a third base station in a third serving cell of the network system may transmit system information to the WTRU in a second operation mode.

[0049] In some implementations, the network system may transmit to the WTRU in a second operation mode at least one of a paging DCI or a paging message in accordance to the LP-WUS.

[0050] In some implementations, the network system may receive from the WTRU in the second operation mode a physical random access channel (PRACH) preamble.

[0051] In some implementations, the first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU. The WTRU in the first operation mode may monitor an On-Off Keying (OOK) waveform with or without an overlaid orthogonal frequency division multiplexing (OFDM) sequence.

[0052] In some implementations, a second operation mode may correspond to using a main radio (MR) of the WTRU. The WTRU in the second operation mode may transmit or receive an OFDM signal or a Discrete Fourier Transform-Spread-OFDM (DFT-S- OFDM) signal using a transmitter or a receiver of the MR, respectively.

[0053] In so doing, the disclosed technology provides an energy-efficient design for low-power synchronization signals (LP-SS) and methods for handling LP-SS monitoring in wireless devices. By enabling a low-power wake-up radio (LP-WUR) to perform both serving and neighboring cell measurements, the disclosed technology significantly reduces power consumption compared to conventional systems that require the main radio to frequently wake up. The technical solutions described in this disclosure achieve enhanced mobility support while maintaining ultra-low power consumption, effectively solving the traditional trade-off between power efficiency and mobility management in the wireless network. Brief Description of the Drawings

[0054] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:FW 6000682PCT02 7

[0055] FIG.1 shows an example protocol flow / timeline based on the DRX configuration, in accordance with some implementations;

[0056] FIG.2 shows an example protocol flow / timeline based on the eDRX (T^^^^> 1024 frames) configuration, in accordance with some implementations;

[0057] FIG.3 shows an example protocol flow / timeline based on the LP-WUS configuration with UE addressing, in accordance with some implementations;

[0058] FIG.4 shows an example protocol flow / timeline based on the LP-WUS configuration with UE group addressing, in accordance with some implementations;

[0059] FIG.5 illustrates an example basic block diagram for RF envelope detection receiver architecture, in accordance with some implementations;

[0060] FIG.6 illustrates an example basic block diagram for IF envelope detection receiver architecture, in accordance with some implementations;

[0061] FIG.7 illustrates an example basic block diagram for BB envelope detection receiver architecture, in accordance with some implementations;

[0062] FIG.8 illustrates an example basic block diagram for linear detection receiver architecture, in accordance with some implementations;

[0063] FIG.9 shows an example simplified baseband sequence detector, in accordance with some implementations;

[0064] FIG.10 shows an example deployment with partial LP-WUR cell coverage compared to MR cell coverage, in accordance with some implementations;

[0065] FIG.11 shows an example deployment with LP-WUR cell coverage comparable to MR cell coverage, in accordance with some implementations;

[0066] FIG.12 shows example LP-SS transmission configurations for LP-WUR deployment with LP-WUR cell coverage comparable to MR cell coverage, in accordance with some implementations;

[0067] FIG.13 illustrates an example of common LP-WUS areas and LP-WUS camping concepts, where a UE LP-WUS camped on a gNB does not need to acquire SI of that gNB before LP-WUS detection, in accordance with some implementations;

[0068] FIG.14 shows an example LP-SS transmission configuration considering a set of N1 orthogonal and N2 non-orthogonal OOK-based sequences, and an optional preamble to the first TxO, in accordance with some implementations;FW 6000682PCT02 8

[0069] FIG.15 shows an example LP-SS transmission configuration considering a set of N2 non-orthogonal OOK-based sequences, and an optional preamble preceding the first TxO, in accordance with some implementations;

[0070] FIG.16 shows an example LP-SS transmission configuration considering a set of N1(semi-)orthogonal OOK-based sequences, a set of M LP-SS TxOs, and an optional preamble preceding the first TxO, in accordance with some implementations;

[0071] FIG.17 shows an example LP-SS transmission configuration considering a set of N1 orthogonal OOK-based sequences and corresponding payload TxOs with an optional preamble / synchronization, in accordance with some implementations;

[0072] FIG.18 shows an example LP-SS transmission configuration considering a set of N1orthogonal OOK-based sequences and corresponding payload TxOs with an optional preamble / synchronization, in accordance with some implementations;

[0073] FIG.19 shows an example LP-SS transmission configuration considering a set of N1 orthogonal and N2 non-orthogonal OOK-based sequences shared by 2 common LP- WUS areas, and an optional preamble to the first TxO, in accordance with some implementations;

[0074] FIG.20 shows an example LP-SS transmission configuration considering a set of N1 orthogonal OOK-based sequences and corresponding payload TxOs shared by 2 common LP-WUS areas, and an optional preamble to the sequence transmission, in accordance with some implementations;

[0075] FIG.21 illustrates an example flow chart of a UE’s activation / deactivation of LP-WUS monitoring based on LP-SS and PSS strength measurements, in accordance with some implementations;

[0076] FIG.22 illustrates an example flow chart of a UE’s switching between coherent and non-coherent detection of LP-WUS / LP-SS based on the measured received signal strength, in accordance with some implementations;

[0077] FIG.23 illustrates an example flow chart of UE’s activation / deactivation of MR measurements based on LP-SS sequence measurement and payload(s) detection by LP-WUR, in accordance with some implementations;

[0078] FIG.24 shows an example flow chart illustrating neighboring cells measurements and cell selection by a UE with LP-WUR assistance, in accordance with some implementations;FW 6000682PCT02 9

[0079] FIG.25 shows an example flow chart illustrating neighboring cells measurements and cell selection by a UE with LP-WUR assistance and common LP-WUS area configuration, in accordance with some implementations;

[0080] FIG.26 shows an example flow chart illustrating neighboring cells measurements and cell selection by a UE with LP-WUR assistance and common LP-WUS area configuration, in accordance with some implementations;

[0081] FIG.27A shows a flow chart of a method performed by a WTRU, in accordance with some implementations;

[0082] FIG.27B shows a flow chart of a method performed by a WTRU, in accordance with some implementations;

[0083] FIG.27C shows a flow chart of a method performed by a base station, in accordance with some implementations;

[0084] FIG.27D shows a flow chart of a method performed by a network system, in accordance with some implementations;

[0085] FIG.28 illustrates an example wireless communication system, in accordance with some implementations;

[0086] FIG.29 illustrates an example communication system, in accordance with some implementations;

[0087] FIGs.30A and 30B illustrate example devices, in accordance with some implementations; and

[0088] FIG.31 shows a block diagram of a computing system, in accordance with some implementations.

[0089] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale. Detailed Description of Illustrative Embodiments

[0090] In this disclosure, an overview of UE procedures related to power saving in RRC Idle / Inactive states is provided. Then, an overview of LP-WUR architectures and LP-WUS waveform options as discussed in 3GPP RAN1 working group meetings are presented.

[0091] A UE can support three RRC states: RRC_CONNECTED, RRC_IDLE, and RRC_INACTIVE. Further, the UE may have several sleep states including deep sleep and ultra-deep sleep states where the power consumption can be lower in the ultra-deepFW 6000682PCT02 10sleep state. The UE procedures related to power saving in RRC Idle / Inactive as available in existing 3GPP NR specifications and as discussed in Release 18 study item on LP-WUS are discussed in this disclosure.

[0092] In 3GPP, duty-cycled operations in the form of Discontinuous Reception (DRX) and extended Discontinuous Reception (eDRX) are defined for power consumption reduction in NR RRC_IDLE and RRC_INACTIVE states through the reduction of the number of Paging Occasions (POs) monitored by the UE. Further power consumption reduction is achieved through Paging Early Indication (PEI) in NR RRC_IDLE and RRC_INACTIVE states, which is still subject to the duty-cycled operation. Similar power saving techniques are defined for NR RRC_CONNECTED state in the form of connected mode DRX (C-DRX) and Wake-Up Signal (WUS). Both PEI and WUS can be received by UEs as DCIs over the PDCCH.

[0093] For a UE using DRX in the RRC_IDLE or RRC_INACTIVE state, the UE monitors one PEI occasion (PEI-O) and / or one PO per DRX cycle as shown in FIG.1, based on the PEI configuration, where a PEI-O / PO may include a set of PDCCH monitoring occasions (MOs) and can include multiple time slots. The UE initiates RRC Connection Establishment or RRC Connection Resume procedures upon reception of a core network (CN) initiated or a RAN initiated paging, respectively. If PEI is configured, the UE monitors an associated PO in a DRX cycle only if PEI is detected, and the UE’s corresponding subgroup is indicated in the PEI. Each PO is associated with a group of UEs, based on the UEs’ identifiers (IDs), and a PEI is used to further address subgroups of the UEs that belong to that group, where the subgrouping can be based on UEs’ IDs or assigned by the network.

[0094] For a UE using eDRX in the RRC_IDLE or RRC_INACTIVE state, the UE monitors one PEI-O and / or one PO per eDRX cycle, based on the PEI configuration, as shown in FIG.1, if the configured eDRX cycle is no longer than 1024 radio frames, where the DRX cycle in FIG.1 becomes an eDRX cycle. ^^^^in FIG.1 denotes the latency from an arrival of network event at the network to the UE’s monitoring of a PO. Otherwise, the UE monitors one PEI-O and / or one PO per eDRX cycle, based on the PEI configuration, according to a configured DRX cycle during a UE-specific and periodic Paging Time Window (PTW), where the PTW period is determined by the eDRX cycle and the length is configured by upper layers, as shown in FIG.2. ^^^^^in FIG.2 denotes the latency from an arrival of network event at the network to the UE’s monitoring of a PO. The UE initiates RRC Connection Establishment or RRC Connection Resume procedures upon reception of a CN initiated or a RAN initiated paging, respectively. If PEI is configured,FW 6000682PCT02 11the UE monitors an associated PO in a DRX / eDRX cycle only if the PEI is detected and the UE’s corresponding subgroup is indicated in the PEI.

[0095] The DRX, eDRX, and C-DRX can provide more power saving gain by increasing the duty cycle duration at the expense of higher latency. PEI and WUS can provide more power saving gain without an impact on latency, but the gain is limited by the power consumption required to decode a DCI over PDCCH. A new WUS that can be received with significantly lower power consumption than existing PEI / WUS designs could enable new trade-off regions of latency versus power but will require a dedicated low-power wake-up radio / receiver (LP-WUR) with a simple architecture as explained below.

[0096] The benefit for using the LP-WUR is to let the main radio (MR), which can consume a significant amount of power in range of milliwatts (mWs), stay in a sleep power state for as long as possible and have the LP-WUR, which should consume 2-3 orders of magnitude less power than the MR, monitor for a LP-WUS that acts as a trigger for the MR to wake-up. There can be two options for how the LP-WUR may monitor a LP-WUS, and the following terminology may be used interchangeably to identify each option: • Option 1: “Continuous” and “Always-on” monitoring; • Option 2: “Discontinuous”, “Periodic”, and “Duty-Cycled” monitoring.

[0097] Further, there may be three different choices for the behavior of a UE in response to the reception of a LP-WUS depending on the content of the LP-WUS and the network configuration. The three UE behavior choices, which may be applicable to both LP-WUS monitoring “Option 1” and “Option 2” above, are the following. • UE_Behavior (1): The LP-WUS carries a UE ID, and the MR is not required to monitor the POs. • UE_Behavior (2): The LP-WUS carries a UE ID and / or a UE group ID, and the MR is required to monitor legacy POs / paging frames (PFs). • UE_Behavior (3): LP-WUS carries a UE ID and / or a UE group ID, and the MR is required to monitor newly defined POs / PFs.

[0098] UE_Behavior (1), as shown in FIG.3, may result in the best experienced latency under the LP-WUS power saving scheme, especially when the continuous monitoring mode (Option 1) is used. This is due to the fact that the UE / LP-WUR may wake-up the MR to directly initiate RRC Connection Establishment or RRC Connection Resume procedures upon reception of a CN-initiated or a RAN-initiated paging, respectively, as indicated by the LP-WUS. This UE behavior also eliminates the need toFW 6000682PCT02 12align the LP-WUR and MR duty cycles when periodic LP-WUS monitoring is considered. However, this UE behavior may come at the cost of a large LP-WUS payload size and subsequently a potentially high resource overhead requirement.

[0099] UE_Behavior (2), as shown in FIG.4, may result in a LP-WUS latency performance that is limited by the legacy DRX cycle, e.g., {0.32,0.64,1.28,2.56} seconds, and generally underperforms the DRX power saving scheme, with the same DRX cycle configuration, in terms of latency. This is due to the fact that the UE will still have to monitor POs using the MR upon waking up in response to the detection of a LP-WUS. However, the power saving gain is still expected compared to the DRX, i.e., depending on the UE group size, and the managed LP-WUS resource overhead is possible due to the potential of using UE group IDs instead of UE unique IDs.

[0100] UE_Behavior (3) may correspond to the definition of shorter RRC IDLE / INACTIVE state DRX cycles, i.e., < 320 ms, which may result in a better LP-WUS latency performance compared to UE_Behavior (2) without any impact on power consumption due to the use of LP-WUR and at a managed LP-WUS resource overhead due to the use of UE group IDs.

[0101] Two categories of LP-WUR architectures are considered in Release 18 LP- WUS SI (1) Envelope detection based architectures, and (2) linear detection based architectures.

[0102] Envelope detection-based architectures can be used to receive simple modulation schemes such as On-Off Keying (OOK) or Frequency Shift Keying (FSK), i.e., when receive parallel branches are used. The envelope detection-based receiver architectures are divided into RF envelope detection and IF / BB envelope detection architectures.

[0103] A basic block diagram for RF envelope detection is shown in FIG.5. The RF signal is converted directly into baseband using an RF envelope detector 502 and eliminates the need for local oscillators (LOs) or Phase-Locked Loops (PLLs). Signal digitization for digital baseband processing can be performed using a 1-bit or multi-bit analog digital convertor (ADC) 504. The RF Low Noise Amplifier (LNA) 506 and / or BB Amplifier (AMP) 508 can be optionally added. For this architecture, high-Q matching networks and / or RF bandpass filtering (BPF) are considered to suppress adjacent channel interference or interference from legacy NR signal and / or other LP-WUS on adjacent subcarriers.

[0104] Basic block diagrams for IF and BB envelope detection are shown in FIG.6 and FIG.7, respectively. In IF envelope detection (FIG.6), the RF signal is first convertedFW 6000682PCT02 13to an IF signal using an LO 610 and RF mixer 612, and then the IF signal is converted to a BB signal using the IF envelope detector 602. In this architecture, low power consumption is achieved by relaxing the accuracy and stability requirements of the LO. Signal digitization for digital baseband processing can be performed using a 1-bit or multi-bit ADC 604. The RF Low Noise Amplifier (LNA) 606 and / or IF amplifier (AMP) 614 and / or BB AMP 608 can be optionally added. For this architecture, high-Q matching networks and / or RF BPF and / or IF BPF are considered to suppress adjacent channel interference or interference from legacy NR signal and / or other LP-WUS on adjacent subcarriers. Further, an image rejection filter or an image rejection mixer may be used. In contrast, as shown in FIG.7 for the BB envelope detection architecture, the RF signal is directly converted to BB signal using an LO 710 and an RF mixer 712. A high-Q matching networks and / or an RF BPF and / or a BB BPF / LPF are considered to suppress adjacent channel interference or interference from legacy NR signal and / or other LP- WUS on adjacent subcarriers. One benefit of this architecture is that an image rejection filter is not required.

[0105] On the other hand, linear detection based architectures can be used for complex (i.e., phase modulated) signals reception and / or complex sequence detection at the expense of potentially higher power consumption.

[0106] A basic block diagram for linear detection based architectures is shown in FIG.8. The RF signal is converted into baseband using In-phase / Quadrature-phase (I / Q) branches. Potential power consumption reduction compared to a traditional OFDM receiver may come from one or more of the following elements: • lower performance LNA (806) / amplifier (808a and 808b), • Oscillator (810) / PLL with relaxed performance requirements, • ADC (804a and 804b) with lower sampling rate and smaller bit-width • Reduced BB processing (820) complexity

[0107] In R1-2301817, “Summary #2 on LP WUR architecture”, Apple, RAN1#112, February 27th-March 03rd, 2023, a sequence based signal design is considered and the required digital baseband processing is based on the time-domain correlation, as described in FIG.9. At the baseband, the digitized time samples of the received signal are correlated with a locally stored sequence of the correlator 930 in the time-domain and the correlation output is compared by the comparator 934 to a threshold. Using this digital baseband processing can enable the detection of sequences with good correlation properties such as Zadoff-Chu sequences. Different sequences and / or cyclic shifts can then be used to convey information to LP-WURs.FW 6000682PCT02 14

[0108] Four waveform generation options based on OOK and targeting the envelope detection based LP-WUR architectures described above were considered in the LP-WUS study. These are Option OOK-1 (Single-bit per OFDM symbol), Option OOK-2 (Parallel M-bit OOK), Option OOK-3 (Multi-tone single-bit per OFDM symbol), and Option OOK- 4 (Time-domain transformed M-bit OOK). For all options, the LP-WUS can be frequency multiplexed with other NR signals. Two of the options, Option OOK-1 and Option OOK- 4, were selected in the LP-WUS study item conclusion.

[0109] In Option OOK-1, a single OOK pulse / bit is transmitted per one OFDM symbol where all the subcarriers, e.g. N, allocated for LP-WUS are modulated to generate a non-zero power signal at the baseband of the LP-WUR for OOK-bit = 1. Alternatively, all the N subcarriers are allocated zero power (from the LP-WUR’s baseband of view) for OOK-bit = 0.

[0110] In Option OOK-4, M OOK pulses / bits are packed in a single OFDM symbol by time domain multiplexing followed by signal modification and time-to-frequency domain transformation. For example, the M-bits are converted into N' samples by adding ^ ^^ ^^− 1^ zeros for each bit^^^^^or by holding the bit value, i.e., 0 or 1, for ^^− 1^ additional shaping for the pulse of each bit is considered, samples arethrough a signal generation and modification block. either DFT or least square operation is performed to convert the time-domain signal into a frequency-domain signal of length N'. Then, in case N' is selected to be > N subcarriers allocated for LP-WUS, a truncation step with an optional frequency-domain signal modification is performed. Finally, the N frequency-domain samples are allocated to the LP-WUS’s N subcarriers for further OFDM modulation and transmission.

[0111] In addition, two waveform generation options based on FSK and targeting the envelope detection based LP-WUR architectures described above were considered in the study. These are Option FSK-1 (M parallel 1-bit FSK) and Option FSK-2 (Parallel 2MOOK receivers). For the two options, the LP-WUS can be frequency multiplexed with other NR signals. Only Option FSK-2 was selected in the LP-WUS study item conclusion.

[0112] In Option FSK-2, the LP-WUS’s N subcarriers are separated into 2Msegments, with potential guard-bands in-between segments and around the LP-WUS, where each segment may comprise one or multiple contiguous subcarriers and only one segment is modulated at a time, whereas the other segments are allocated zero power (from LP-WUR’s baseband point of view). A variant of this waveform is also defined as Option FSK-2-envelope-IF where the N SCs of LP-WUS can be used to generate 2MFW 6000682PCT02 15segments at the envelope of the LP-WUR’s received signal in baseband where each segment comprises one or more tones.

[0113] Additionally, the LP-WUS study item concluded that knowledge, i.e., specification, of overlaid OFDM sequences that are used to generate the ON waveform of an OOK / FSK signal in the OFDMA transmitter can help a linear detection based receiver, i.e., receiver with I / Q branches, improve its performance.

[0114] A Work Item (WI) on LP-WUS started in 3GPP NR Release 19 with focus on harmonized signal design where an OFDM sequence is overlaid over OOK-1 / OOK-4 waveform options. The harmonized signal design will be used for the generation of LP- WUS which can be received by LP-WUR architectures based on envelope detection only or LP-WUR architectures based on linear detection, i.e., with I / Q branches. A periodic low-power synchronization signal (LP-SS) is expected to be specified as well for LP-WUR architectures that cannot receive existing PSS / SSS, i.e., architectures based on envelope detection only. The periodic LP-SS can be beneficial for the following functionalities: (a) RRM measurements by LP-WUR, (b) at least coarse time synchronization of LP-WUR, and (c) at least coarse frequency synchronization of LP-WUR.

[0115] Among the four waveform generation options for LP-WUS examined, two of them, Option OOK-1 (Single-bit per OFDM symbol) and Option OOK-4 (Time-domain transformed M-bit OOK per OFDM symbol), were selected in the LP-WUS study item conclusion. Further, the significant saving in power consumption by use of LP-WUR in RRC Idle / Inactive state is enabled by sufficiently keeping the main radio (MR) in an ultra-deep sleep (UDS) state. Operations / procedures supporting UE mobility, e.g., RRM measurements and system information monitoring, require the MR to often transition to an active state which would have a negative impact on power saving. Therefore, it was concluded that a new periodic LP-SS, e.g., based on OOK, is desirable for LP-WURs that cannot receive the existing PSS / SSS, for synchronization and RRM measurements by LP- WUR, if specified, at least for serving cell measurements.

[0116] However, restricting the use of LP-SS for serving cell measurements only in RRC Idle / Inactive states will either (1) still require the LP-WUR to wake up the main radio for neighboring cell measurements and cell (re-)selection procedures, especially for UEs with low mobility at cell edge, which can limit or reduce the power saving gain from the utilization of LP-WUS, or (2) limit the use cases to that of low mobility and / or not at cell edge to maximize the power saving gain from the utilization of LP-WUS. Therefore, resource efficient design and configuration of LP-SS that enable LP-WURs to perform low complexity RRM measurements for serving and neighboring cells and corresponding cell (re-)selection evaluations / procedures in RRC Idle / Inactive states can maximize theFW 6000682PCT02 16power saving gain from the utilization of LP-WUS while supporting use cases with varying mobility requirements in RRC Idle and Inactive states.

[0117] The disclosed technique also optimizes a UE’s power consumption via proper design of LP-SS and procedures that enable LP-WUR’s assistance in UE’s mobility, by offloading at least part of serving and / or intra-frequency RRM measurement, and that support limited system information monitoring, by introducing common LP-WUS areas.

[0118] The described solutions in the below include the design of LP-SS that enables low-complexity serving and / or intra-frequency cell measurements and procedures that enables LP-WUR’s assistance in UE’s mobility and that supports limited system information monitoring by introduction of common LP-WUS areas and LP-WUS camping.

[0119] The following set represents some of the parameters / information used for the configuration of LP-WUS and / or LP-SS. The set includes one or more of the following: - a set of one or more physical resource blocks (PRBs) including any required guard bands, - an LP-SS transmission periodicity, - one or more offsets for the transmission occasions of LP-WUS(s), - an LP-SS / LP-WUS transmission data and coding rate.

[0120] The LP-WUR may be used to assist in serving cell measurements only and therefore limited mobility may be supported for UEs equipped with LP-WURs.

[0121] In a first embodiment, cell coverage 1002 for the MR may be expected to be relatively larger than cell coverage 1004 for the LP-WUR, as shown in FIG.10, and therefore it may be sufficient to consider a single OOK sequence for LP-SS, i.e., the same sequence for LP-SS is used by all cells supporting LP-WUS since cell identification may not be needed and / or inter-cell interference is not an issue. The LP-SS can then be used by LP-WUR for serving cell measurements and enable further relaxation or offloading of MR measurements when the UE is not at cell edge. At cell edge, the MR is considered for both serving and neighboring cells measurements as well as cell (re-)selection evaluation.

[0122] In addition to the parameters described above, the LP-SS sequence can be a known preconfigured sequence, e.g., standardized, or one from one or more sequence that are preconfigured and signaled as a parameter to the UE’s MR as part of, for example, a system information (SI) or an RRC message / configuration. Additionally, the transmission occasion of the LP-SS (e.g., slot or subframe number and / or starting OFDM symbol within the slot or subframe of an NR frame) can be determined based on theFW 6000682PCT02 17physical cell ID or signaled as one or more parameters to the UE’s MR as part of, for example, a system information (SI) or an RRC message.

[0123] In a second embodiment, cell coverage (e.g., 1104a / 1104b) for the LP-WUR (e.g., may be expected to be comparable to cell coverage (e.g., 1102) for the MR, as shown in FIG.11, and therefore it may be suitable to consider a single OOK sequence for LP-SS which is also followed by payload that includes an indication of, e.g., a partial or full, cell ID. The LP-SS can then be used by the LP-WUR for serving cell measurements to enable further relaxation or offloading of MR measurements when the UE is not at cell edge. The LP-SS and payload can also be used by LP-WUR for serving cell measurements to enable relaxation of MR measurements when the UE is close to cell edge where payload detection for, e.g., partial or full, cell identification can be used to ensure that the LP-WUR is still within the coverage of the last known serving cell (e.g., in-between MR’s measurements). At the cell edge, the MR may still be considered for both serving and neighboring cells measurements as well as cell (re-)selection evaluation. The payload to carry (e.g., partial or full) cell ID may be used over having a specific sequence for each cell ID to reduce the power consumption that might be associated with multiple sequences correlation / detection.

[0124] The configuration and signaling of the LP-SS sequence may be similar to that of the first embodiment. Additional parameters can be related to the payload and may include any one or more of the following: - a payload length which can be used to determine the extent of partial information on serving cell’s physical cell ID and subsequently the number of cells that can be differentiated in an area; - a payload offset which may be used to enable the time domain multiplexing of neighboring cell transmission to reduce inter-cell interference whereas a single transmission occasion may be considered for the LP-SSs’ sequence from one or more neighboring cells.

[0125] The payload length may be preconfigured, e.g., standardized, whereas the payload offset may be determined based on the physical cell ID or signaled as one or more parameters to the UE’s MR as part of, for example, a system information (SI) or an RRC message. Two example configurations are illustrated in FIG.12 showing multiple LP-SS transmission occasions (TxOs) per a LP-SS transmission periodicity where each TxO may be used by one or more cells based on (e.g., their physical IDs).

[0126] For the above embodiments, a known OFDM sequence may be overlaid over the ON pulses of the LP-SS and / or payload to improve detection / decoding performanceFW 6000682PCT02 18of an I / Q based LP-WUR and subsequently LP-SS coverage for measurement and payload detection for, e.g., partial, identification of serving cell. A single TxO may be used for LP-SS payload transmission and subsequently cell ID detection may correspond only to the cell with the highest signal strength. Alternatively, mitigation of inter-cell interference during payload detection for cell ID determination may be based on the overlaid OFDM sequence which can be cell-specific, i.e., dependent on the transmitting cell’s ID.

[0127] The LP-WUR may be used to assist in both serving and neighboring cell measurements and therefore enhanced, energy-efficient, mobility may be supported for UEs equipped with LP-WURs. The enhanced mobility support may require full cell coverage for LP-WURs where full cell coverage does not necessarily imply coverage similar to that achieved by MRs for, e.g., SSB / PDCCH signals / channels, but rather is corresponding to UL channels as defined in the LP-WUS WI to be PUSCH Msg3.

[0128] Further, there may be different mechanisms of SI acquisition, e.g., full SI acquisition relaxation, for a UE using LP-WUR in RRC Idle / Inactive state depending on, e.g., latency requirements and / or LP-WUS monitoring configurations. For example, a UE equipped with a LP-WUR and operating in RRC Idle / Inactive state may be expected to wake-up the MR for SI acquisition and / or regular communication with the network, i.e., through a serving cell, upon one or more of the following triggers: 1) selection of a new cell using the LP-WUR, i.e., while using the LP-WUR for cell (re- )selection; 2) detection of a LP-WUS addressed to the UE or one of the UE’s (sub-)groups; or 3) failure to use the LP-WUR to evaluate for cell (re-)selection.

[0129] For the first trigger, the LP-WUR may be used to wake-up the MR for SI acquisition directly after the new cell selection due to any of latency requirement (e.g., the UE expects short duration between the detection of a LP-WUS addressed to its UE- Group and a paging occasion), and unknown LP-WUS monitoring configuration in the newly selected cell (e.g., UE expects the LP-WUS monitoring configuration in the newly selected cell to be different than that of the last serving cell). In the case of different LP- WUS configurations, the assumption may be that the LP-SS configuration, which is used for measurements and cell (re-)selection evaluation, for previous and newly selected cell are the same or known by the LP-WUR.

[0130] For the second trigger, the LP-WUR may be used to wake-up the MR to directly communicate with the current serving cell (e.g., monitor paging occasionsFW 6000682PCT02 19and / or establish / resume an RRC connection) without the need for SI acquisition / update if one of the following occurs. • The LP-WUR did not reselect a new cell (i.e., current serving cell is the last serving cell camped on by the MR before operating the LP-WUR), and an SI update indication is not received / detected by the LP-WUR. • The LP-WUR reselected a new cell but the SI for that new cell is received by the MR and stored at the UE (e.g., from another cell).

[0131] Otherwise, the LP-WUR is expected to wake-up the MR for SI acquisition before directly communicating with the current serving cell. In the second alternative, SI for a newly selected cell may be received from a previous (e.g., last) serving cell and stored at the UE for use by the MR upon wake-up (i.e., that is instead of having to receive the SI from the current serving cell). In order to enable the LP-WUR to reselect a new cell without directly waking-up the MR for SI acquisition (e.g., until the detection of a LP- WUS), two new concepts may be defined: (1) a common LP-WUS area, and (2) LP-WUS camping.

[0132] A common LP-WUS area may be defined as an area consisting of one or more cell(s) that share the similar or known configuration (e.g., signaled to the UE equipped with LP-WUR) of any of LP-SS and LP-WUS. A UE equipped with LP-WUR may be expected to receive any of LP-SS and LP-WUS configuration from any of the cells in a common LP-WUS area. Additionally, the UE may not be expected to acquire SI required by the UE’s MR as long as the UE is within a common LP-WUS area with valid configuration and an LP-WUS addressed to the UE or the UE’s UE-Group is not detected. The common LP-WUS area may be a subset of a tracking area (TA) or a RAN notification area (RNA). A UE is expected to perform cell (re-)selection in RRC Idle / Inactive states and camp on a suitable cell within a TA or RNA. If a UE camps on a cell outside (i.e., does not belong to) a TA or an RNA, a location registration procedure or an RNA update (RNAU) procedure may be performed, respectively. One of the purposes of camping is to enable the UE to receive system information and subsequently be capable of receiving paging messages from the network. In contrast to UE camping on a cell within a TA or RNA, a UE equipped with a LP-WUR within a common LP-WUS area may not need the full system information from the network, upon cell reselection, before receiving an LP-WUS as an indication for paging messages and / or Earthquake and Tsunami Warning System (ETWS) / Commercial Mobile Alert System (CMAS) notifications (i.e., the UE may not need to monitor legacy control channel before the detection of an LP-WUS).FW 6000682PCT02 20

[0133] LP-WUS camping may be used to refer to a UE equipped with a LP-WUR where the LP-WUR is used to synchronize with the network and perform measurements based on LP-SS, and monitor for LP-WUS addressed to the UE, a UE-group, or in broadcast. The UE is LP-WUS camped on a cell if the cell belongs to a common LP-WUS area with valid configuration at that UE. An illustrative example is shown in FIG.13 with two common LP-WUS areas 1301 and 1302. The common LP-WUS area 1301 consists of 3 gNBs, and the common LP-WUS area 1302 consists of 2 gNBs, and a UE moving from one cell to another within a common LP-WUS area. The UE 1303 was camped-on a gNB 1301a where SI for the gNB 1301a as well as the common LP-WUS area configuration was acquired. The UE then moves to another gNB 1301b within the common LP-WUS area 1301 where the UE continues using the common LP-WUS area configuration for LP-SS and LP-WUS monitoring without the need to acquire any new SI before the detection of a UE, UE-group, or broadcast addressed LP-WUS.

[0134] A valid configuration of a common LP-WUS area may include one or more of the following, which may be signaled in an RRC message (e.g., system information or RRCRelease message): - one or more identifiers of one or more cells that belong to the common LP-WUS area, - an LP-WUS transmission bandwidth, - one or more LP-WUS transmission occasions defined as one or more offsets from e.g., LP-SS or POs, - an LP-WUS transmission data rate, - an LP-WUS transmission structure, e.g., number of bits for sub-grouping and / or number of POs mapped, - a validity timer for the configuration of the common LP-WUS area.

[0135] The concepts of common LP-WUS area and LP-WUS camping can be helpful when the UE does not need to acquire SI upon cell (re-)selection by the LP-WUR but upon LP-WUS detection (e.g., when latency requirements are relaxed). In contrast to the SRS validity area, the UE does not have to acquire / monitor system information upon cell reselection within the common LP-WUS area. Additionally, the UE may not need to send a request to the network to obtain the common LP-WUS configuration if they are transmitted as part of system information (e.g., SIB1).

[0136] For the third trigger, failure to use the LP-WUR for cell (re-)selection evaluation may be due to unavailability of SI required for proper evaluation (e.g., the LP- WUR is at the edge of a cell close to a common LP-WUS area with a different LP- WUS / LP-SS configuration than the current common LP-WUS area).FW 6000682PCT02 21

[0137] In a set of solutions, an OOK-based design for LP-SS that supports enhanced mobility may be considered without accounting for any additional information in overlaid OFDM sequences. The OOK-based design may still include the case where a fixed overlaid sequence is used to improve coverage (i.e., without carrying any additional information).

[0138] As opposed to the limited mobility scenario, with the single OOK sequence design, described in this disclosure, multiple / different sequences for neighboring cells may be required to enable enhanced mobility support and provide differentiable measurements for the neighboring cells that facilitate the cell (re-)selection evaluation by a LP-WUR.

[0139] In a first embodiment, a LP-WUR may be used to measure signal strengths of serving and neighboring cells to perform cell (re-)selection and an MR may be used to acquire SI of newly selected cells to obtain / confirm LP-WUS monitoring configuration and maintain up-to-date SI for the MR. An ordered set ^ of OOK sequences may consist of ^^(semi-)orthogonal sequences and ^^non-orthogonal sequences (e.g., may not provide reliable measurements if transmitted concurrently) and a BS may then select a sequence index^^^∈^0, 1, … ,|^|− 1!"based on its physical cell ID (PID) and|^|as ^^= $%& ()*|^|,|^|= ^^+ ^^

[0140] Subsequently, multiple TxOs may be configured such that the ^^sequences may share the same TxO and the ^^sequences are assigned non-overlapping TxOs. An LP-SS TxO index ^,^∈ ^1, 2, … , ^^+ 1!" may then be selected, regardless of the configured LP-SS periodicity for the serving and neighboring cells, as ,^ = .1, ^^−^ < ^^^^^ + ^^ ≥ ^ ^^ <

[0141] A frame withto carry LP-SS TxOs based on any of the LP-SS periodicity ^2" defined in number of frames, an offset (3455, which may be cell-specific), number of TxOs per subframe^^6", and total number of TxOs per LP-SS transmission period ^^7". The cell-specific offset may be used to align the LP-SS TxOs across multiple cells. The following example formula may be used to determine whether a frame of number^2"is used to carry an LP-SS TxO ^+ = 1 * ^ … ^ − 1! ^ = : 7where ^9Each LP-SS TxO may consist of one or more transmission repetition(s) corresponding to one or more gNB transmission beam(s). Further, a single (e.g., short) preamble may be transmittedFW 6000682PCT02 22before the first LP-SS TxO by every gNB to provide timing synchronization for the LP- WURs that are aware of the preamble. An example LP-SS transmission configuration is illustrated in FIG.14.

[0142] In a different technical realization, the overall set of OOK-based sequences may contain only a set of non-orthogonal sequences, i.e., the total number of OOK sequences in the set |^| = ^^, and the BS may then select the sequence index ^^^∈ ^0, 1, … , |^| − 1!" based on its PID and |^| as ^^= $%& ()* |^|, |^| = ^^

[0143] The base station may subsequently select an LP-SS TxO with index ^,^∈ ^1, 2, … , |^| = ^^!" from a set of occasions such that sequences are assigned non- overlapping TxOs. For example, the LP-SS TxO index is selected according to ,^= ^^+ 1. A preamble may still be used to precede the first LP-SS TxO and a frame may be determined to carry an LP-SS TxO according to above embodiment. An example LP-SS transmission configuration is illustrated in FIG.15.

[0144] In another technical realization, the overall set of OOK-based sequences may contain only a set of (semi-)orthogonal sequences (i.e., the total number of OOK sequences in the set |^| = ^^, and the BS may then select the sequence index^^^∈^0, 1, … ,|^|− 1!"based on its PID and|^|as the following. ^^= $%& ()*|^|,|^|= ^^

[0145] The baseLP-SS TxO and a frame may be determined, in an example, to carry an LP-SS TxO according to the following. ,455= 1 ()* 2

[0146] Alternatively, a set^<"of LP-SS TxOs may be considered where the set^^"of OOK-based sequences may be reused in every TxO and a common preamble may precede the first TxO to provide timing reference. The base station may then, in an example, select an LP-SS TxO with index ^,^∈ ^1, 2, … , |<| = =!" from the set of occasions according to the following. ,^= >$%&|^|? ()* |<|

[0147] The alternative of the set of LP-SS TxOs where a set of OOK-based sequences may be reused can be applied to any of the technical realizations described above. An example LP-SS transmission configuration with ^^OOK-based (semi-)orthogonal sequences and = LP-SS TxOs is illustrated in FIG.16.FW 6000682PCT02 23

[0148] In some embodiments, a payload may follow the LP-SS sequence, e.g., directly or at an offset considering any of the technical realizations of the above embodiments. The payload may contain information about one or more common LP-WUS area(s) (e.g., one or more identifier(s), supported by a gNB). For example, a UE equipped with a LP- WUR may be configured (e.g., associated or registered) with a common LP-WUS area (e.g., identifier), and as long as the LP-WUR receives / detects the same information (e.g., identifier), on common LP-WUS area(s) in the LP-SS payload as configured, the UE may not be required to acquire new SI upon cell switching and until, e.g., detection of a UE, UE-Group, or broadcast addressed LP-WUS.

[0149] In one technical realization shown in FIG.17, a set of ^^payload TxOs are considered where each TxO corresponds to one from the set of ^^(semi-)orthogonal OOK-based sequences in^^". Subsequently, a UE detecting an OOK-based sequence of index ^^∈ ^0, 1, … , |^| − 1! considers the payload TxO ,^= ^^+ 1 for of the common LP-WUS areas’ identifiers served by the gNBdetected OOK-based sequence. The relationship between a gNB’s PID and the OOK-based sequence index may be determined, in an example, according to the following formula. ^^= $%& ()*|^|,|^|= ^^

[0150] A fixed offset between LP-SS sequence transmission or payload TxO and subsequent payload TxO may be present and known by UEs equipped with LP-WURs.

[0151] In another technical realization as shown in FIG.18, a set of ^^payload TxOs are considered where each payload may follow the transmission of one from the set of ^^non-orthogonal OOK-based sequences in ^^". Subsequently, a UE detecting an OOK- based sequence of index ^^∈^0, 1, … ,|^|− 1!considers the following payload to determine / decode the common LP-WUS areas’ identifiers served by the gNB corresponding to the detected OOK-based sequence. The relationship between a gNB’s PID and the OOK-based sequence index may be determined, in an example, according to the formula of the previous technical realization. Further, a common (e.g., short) preamble / sync sequence may precede the transmission of the LP-SS sequence to minimize the power consumption associated with concurrent detection and / or measurement of the multiple sequences in the set.

[0152] Other technical realizations may correspond to a combination of the technical realizations described above.

[0153] In an alternative embodiment to the first and second embodiments above, the set of (semi-)orthogonal and / or non-orthogonal OOK sequences may be used to indicateFW 6000682PCT02 24different common WUS areas’ identifiers, i.e., the LP-WUR uses the detected sequence(s) corresponding to one or more common LP-WUS area(s) to determine whether LP-SS and / or LP-WUR monitoring configuration are valid based on configured one or more common LP-WUS area(s)’ identifier(s). Additionally, one or more payload transmission(s) / TxO(s) may follow, and correspond to, each of the transmitted OOK- based sequence for LP-SS where each payload may contain information (e.g., partial or full identification using PID) about different cells within a common WUS area. The one or more payload transmission(s) / TxO(s) (i.e., corresponding to a common LP-WUS area) from different cells may still need to be staggered in time domain to facilitate detection by LP-WURs especially at the cell edge. Alternatively, the one or more payload transmission(s) from different cells are transmitted on the same TxO following the LP-SS sequence transmission (i.e., corresponding to a common LP-WUS area) at the expense of lower detection performance and lower capability to differentiate between cells within a common LP-WUS area at cell edge.

[0154] In another embodiment, a set ^ of OOK sequences, which may consist of, for example, ^^(semi-)orthogonal sequences and ^^non-orthogonal sequences, are shared by one or more, for example, ^, common LP-WUS areas where each common LP-WUS area is assigned a subset of sequences ^@, A ∈ ^0, 1, … , ^ − 1!, and the subset of sequences in ^@are selected from the set ^ based on sequences’ indices satisfying the following relationship, ^^()* ^ = B@, A ∈ ^0, 1 , … , ^ − 1! where ^^∈ ^0, 1, … , |^| − 1! is the index of a sequence in ^ and B@is an offset specific to the ACDcommon LP-WUS area.

[0155] A gNB / base station that belongs to, e.g., within, the ACDcommon LP-WUS area, A ∈^0, 1 , … , ^ − 1!, may select a sequence index EF@∈ G0, 1, … , H^@H − 1IJ from the subset E^@J based on its PID and the common LP-WUS area corresponding subset size H^@H according to the following. F@= $%& ()* H^@H, H^@H =|^| / ^

[0156] Similar tomay be configured such that the ^^sequences may share the same TxO and the ^^sequences are assigned non- overlapping TxOs. An LP-SS TxO index ^,^∈ ^1, 2, … , ^^+ 1!" may then be selected, in an example, as ,^ = .1, ^ < ^^^^ ^FW 6000682PCT02

[0157] where ^^may be defined / selected as ^^= $%& ()* |^|, |^| = ^^+ ^^. An example LP-SS transmission configuration is shown in FIG.19, considering a set of OOK sequences ^ shared by two example common LP-WUS areas.

[0158] In one technical realization, the set ^ may consist of ^^(e.g., sequences ^0, 1, … , ^^− 1! in FIG.19) (semi-)orthogonal sequences only and single TxO (e.g., TxO (1) as shown in FIG.19). In a second technical realization, the set ^ may consist of ^^, e.g., sequences ^^^, ^^+ 1, … , ^^+ ^^− 1! in FIG.19), non-orthogonal sequences only and a set of non-overlapping TxOs (e.g., TxO^2"to TxO ^^^+ 1" as shown in FIG.19. In a third technical realization, the set of OOK sequences ^ that are shared between one or more common LP-WUS area(s) may be reused over one or more sets of TxOs as illustrated in FIG.16, i.e., for the special case of (semi-)orthogonal sequences only. In an alternative to the third realization, the whole set ^ of OOK sequences may be used by a single common LP-WUS area and only the TxOs are shared by one or more (e.g., ^) common LP-WUS area(s). In this alternative, the LP-SS preamble may be specific to a common LP-WUS area and may be used to indicate the beginning of a TxO specific to a certain common LP-WUS area.

[0159] In a fourth technical realization, a payload with TxO configuration similar to, for example, the two example configurations illustrated in FIG.17 for (semi-)orthogonal sequences only configuration and FIG.18 for non-orthogonal sequences only configuration, may follow the LP-SS sequence transmission and may include additional information about the corresponding one or more common LP-WUS area(s) and / or associated gNB identifier(s). An example configuration for a set of ^^(semi-)orthogonal sequences followed by ^^payload TxOs which are shared by two common LP-WUS areas is illustrated in FIG.20.

[0160] A transmission configuration that includes a combination of (semi- )orthogonal and non-orthogonal sequences may also be supported. Further, a configuration where the set of OOK sequences and corresponding payloads may be reused over one or more sets of TxOs may be supported.

[0161] In an example flow illustrated in FIG.21, a UE may be equipped with an envelope detection-based LP-WUR that performs serving cell measurements only as described above. At the operation 2102, the UE transmits its LP-WUR capability and receives LP-WUS / LP-WUR configuration using any of RRC and system information signaling. The LP-WUS / LP-WUR configuration may include any of: • a duty cycle configured as an indication to one of a set of preconfigured values or as a number of, e.g., slots, subframes, frames;FW 6000682PCT02 26• a periodic low-power reference signal (LP-SS) configuration including any of set of allocated frequency resources, transmission periodicity, transmission duration, sequence length, and data rate, • an LP-WUS transmission configuration including any of data rate, coding scheme, coding rate, synchronizing / triggering preamble, payload size, and CRC length, • one or more received signal strength measurement thresholds.

[0162] At the operation 2104, the UE determines an LP-SS sequence based on any of the pre-configuration, a received indication from the serving cell, and a serving cell’s physical cell ID (PID / PCI).

[0163] At the operation 2106, the UE, e.g., using the LP-WUR, measures the serving cell’s received signal strength ^Laccording to the determined LP-SS sequence and compares the signal strength ^Lagainst a first configured threshold ,^.

[0164] At the operation 2110, on the condition that thesignal strength ^Lis above or equal to a first configured threshold ,^, the UE may utilize a LP-WUR to monitor for LP-WUS according to received configuration.

[0165] Otherwise, at the operation 2108, if the measured signal strength ^Lis below the first configured threshold ,^the UE may utilize the MR or LP-WUR for serving cell measurements, i.e., based on any of PSS and SSS, and compare the measured signal strength ^Magainst a second configured threshold ,^. If ^Mis above or equal to ,^, the UE may utilize a LP-WUR to monitor for LP-WUS according to received configuration at the operation 2110. Otherwise, if ^Mis below ,^, at the operation 2112, the UE may utilize the MR for monitoring / decoding any of short messages, paging DCIs, and paging messages, and the UE may, subsequently, skip the operation 2110.

[0166] At the operation 2112, the UE, e.g., using LP-WUR, detects a LP-WUS and may then utilize the MR to monitor for any of short messages, paging DCIs, and paging messages. Alternatively, the UE, e.g., using LP-WUR, continues serving cell measurements, i.e., based on LP-SS, and LP-WUS monitoring until an LP-WUS is detected.

[0167] At the operation 2114, the UE initiates the RRC connection establishment or resume procedure or continues operating in the RRC Idle / Inactive state based on the received any of short messages, paging DCIs, and paging messages.

[0168] In an alternative technical realization to the operation 2108 above, the UE may switch between coherent and non-coherent detection of LP-WUS / LP-SS based on measured received signal strength from serving cell.FW 6000682PCT02 27

[0169] On a first condition that the measured signal strength ^Lfalls below a third configured threshold ,N, the UE, e.g., using LP-WUR, evaluates the second condition.

[0170] Otherwise, at the operation 2206, the UE, e.g., using LP-WUR, monitors for LP-WUS non-coherently, i.e., utilizing conventional envelope detection without information on the overlaid OFDM sequence, according to received configuration.

[0171] On the second condition that the measured signal strength ^Lis above the first configured threshold ,^(,^< ^L< ,N), at the operation 2204, the UE, e.g., using LP- WUR, monitors for LP-WUS coherently, i.e., utilizing information on an overlaid OFDM sequence, according to received configuration.

[0172] Otherwise, if the measured signal strength ^Lis below the first configured threshold ,^, at the operation 2202, the UE may utilize the MR for serving cell measurements, i.e., based on any of PSS and SSS, and for monitoring / decoding any of short messages, paging DCIs, and paging messages.

[0173] In the above technical realization, the first threshold (,^) and third threshold (,N) may be signaled explicitly from the network to the UE or implicitly. For example, the two thresholds may be related by an offset signifying the difference in detection performance between coherent and non-coherent LP-WUS detection. The order of the conditions illustrated in FIG.22 may be switched.

[0174] The serving cell measurements (e.g., using LP-WUR) may be based on any of LP-SS with or without coherent detection (i.e., information on an overlaid OFDM sequence) and the existing NR synchronization signals (e.g., PSS and / or SSS). Embodiments do not preclude a LP-WUR performing one or more serving cell measurements before monitoring an LP-WUS, e.g., monitoring period for LP-WUS is longer than that of any of LP-SS and PSS / SSS.

[0175] In another embodiment illustrated in FIG.23, a UE may be equipped with an envelope detection-based LP-WUR that performs serving cell measurements only as described above. At the operation 2302, the UE transmits its LP-WUR (or LP-WUS monitoring) capability and receives the LP-WUS / LP-WUR configuration using any of RRC and system information signaling. The LP-WUS / LP-WUR configuration may include any of: • a duty cycle configured as an indication to one of a set of preconfigured values or as a number of, e.g., slots, subframes, frames; • an LP-SS configuration including any of set of allocated frequency resources, transmission periodicity, transmission duration, sequence length, payload size, payload offset, and data rate.FW 6000682PCT02 28• LP-WUS transmission configuration including any of data rate, coding scheme, coding rate, synchronizing / triggering preamble, payload size, and CRC length; • one or more received signal strength measurement thresholds.

[0176] At the operation 2304, the UE determines an LP-SS sequence based on any of pre-configuration and a received indication from the serving cell.

[0177] At the operation 2306, the UE, e.g., using LP-WUR, performs synchronization, measures a received signal strength ^Lusing the determined LP-SS sequence, and compares the signal strength ^Lagainst a configured threshold ,.

[0178] At the operation 2308, on the condition that the measured signal strength ^Lis below the configured threshold ,, the UE, e.g., using LP-WUR, monitors one or more payload TxO(s) according to the received configuration.

[0179] In a technical realization, one or more TxO are configured and shared by the serving cell and one or more neighboring cells whereas payload detection in a TxO may be dictated by the cell with the strongest received signal strength within the set of cells sharing the TxO. In one example, a single TxO is configured and used by the serving cell and one or more neighboring cell whereas the cell with the strongest received signal strength may dictate the detected payload, e.g., signals from other cells may be treated as noise. In another example, each payload TxO is used by one of a serving cell or a neighbor cell reducing inter-cell interference during payload detection / decoding. The payload TxO contains, e.g., partial or full, information on the transmitting cell identifier as discussed in Section 4.1.1.

[0180] Otherwise, the UE continues at the operation 2306, e.g., utilizing the LP- WUR, performing received signal strength measurement and determination of serving cell coverage, e.g., received signal strength above a configured threshold or serving cell ID detected in a payload TxO.

[0181] At the operation 2310, the UE determines whether the serving cell identifier is detected. If the UE, e.g., using LP-WUR detects, the serving cell identifier in, e.g., one of, the payload TxO(s), and the UE continues at the operation 2306, e.g., utilizing the LP- WUR, performing received signal strength measurement and determination of serving cell coverage.

[0182] Otherwise (e.g., the UE, e.g., using LP-WUR, detects one or more cell identifier(s), i.e., in the one or more payload TxO(s), different than the serving cell identifier), at the operation 2312, the UE, e.g., via the MR, is utilized for serving and / or neighboring cell(s) measurement, i.e., based on existing synchronization signalsFW 6000682PCT02 29PSS / SSS. The detected one or more cell identifier(s) by the LP-WUR may be used by the MR to reduce the power consumption associated with cell search upon wakeup.

[0183] In an embodiment illustrated in FIG.24, a UE may be equipped with an envelope detection-based LP-WUR that can perform serving and neighboring cell measurements as described above. At the operation 2402, the UE transmits its LP-WUR (or LP-WUS monitoring) capability and receives a LP-WUS / LP-WUR configuration using any of RRC and system information signaling. The LP-WUS / LP-WUR configuration may include any of: • a duty cycle configured as an indication to one of a set of preconfigured values or as a number of, e.g., slots, subframes, frames; • an LP-SS configuration including any of: o a set of allocated frequency resources, o a transmission periodicity, one or more transmission occasions, one or more offsets between the one or more transmission occasions, o a preamble preceding, e.g., the first, transmission occasion, o a set of ^^(semi-)orthogonal sequences, o a set of ^^non-orthogonal sequences, o transmission occasion duration, sequence length, and data rate; • an LP-WUS transmission configuration including any of data rate, coding scheme, coding rate, synchronizing / triggering preamble, payload size, and CRC length. • one or more received signal strength measurement thresholds.

[0184] At the operation 2404, the UE determines a first LP-SS sequence and a first transmission occasion based on any of a received indication from a first serving cell and the first serving cell’s physical cell ID (e.g., PID / PCI).

[0185] At the operation 2406, the UE, e.g., using LP-WUR, measures one or more first received signal strength(s) ^L,^∀P using one or more (semi-)orthogonal LP-SS sequence(s) transmitted in a second transmission occasion, wherein the second transmission occasion may be an initial transmission occasion from a set of one or more transmission occasion(s). In a technical realization, the second transmission occasion is preceded by a known preamble, and the UE, e.g., using LP-WUR, measures the one or more received signal strength(s) in the second transmission occasion only upon the detection of and / or synchronization using the preamble. In another technical realization, the measurement of the one or more first received signal strength(s) are subject to a measured received signal strength of the first LP-SS in the first transmission occasion below a first configured threshold.FW 6000682PCT02 30

[0186] At the operation 2408, the UE, e.g., using LP-WUR, measures one or more second received signal strength(s) ^L,@∀A using one or more non-orthogonal LP-SS sequence(s) transmitted in one or more third transmission occasion(s), wherein the one or more third transmission occasion(s) may be determined based on one or more configured offsets. In a technical realization, a transmission occasion from the one or more third transmission occasion is an initial transmission occasion which may be preceded by a known preamble. In another technical realization, the measurement of the one or more second received signal strength(s) are subject to a measured received signal strength of the first LP-SS in the first transmission occasion below a first configured threshold.

[0187] At the operation 2410, the UE, e.g., using LP-WUR, determines one or more third received signal strength(s), measurements, ^L,Q∀R from any of the one or more first and second received signal strength(s) above a second configured threshold.

[0188] At the operation 2412, the UE determines the received signal strength of the first LP-SS sequence in the first transmission occasion. On the condition that the received signal strength of the first LP-SS sequence in the first transmission occasion is determined below the second configured threshold, at the operation 2414, the UE, e.g., via MR, utilizes the one or more third received signal strength(s) to assist in RRM measurements, i.e., based on any of PSS and SSS, and cell selection, i.e., selection of a second serving cell. In a technical realization, the one or more third received signal strength(s) may be used to determine a sub-set of physical cell identifiers to be considered for RRM measurements which can reduce the power consumption associated with cell search, e.g., PSS / SSS monitoring, measurements, and MIB acquisition.

[0189] Otherwise, the UE continues with the operation 2406 (e.g., the UE using LP- WUR, performs received signal strength measurements and monitors for LP-WUS according to the received configuration).

[0190] At the operation 2416, the UE, e.g., via MR, acquires system information of the second serving cell.

[0191] Similar to previous embodiments, the UE may initiate RRC connection establishment or resume procedure or continue operating in RRC Idle / Inactive state based on a received any of short messages, paging DCIs, and paging messages wherein the reception may be triggered by a detected LP-WUS. In a technical realization, only a set of (semi-)orthogonal sequences and one or more transmission occasion(s) may be configured for LP-SS. In another technical realization, only a set of non-orthogonal sequences and one or more transmission occasion(s) may be configured for LP-SS. InFW 6000682PCT02 31another technical realization the set of (semi-)orthogonal and / or non-orthogonal sequences may be reused over one or more transmission occasion(s).

[0192] In an alternative technical realization of the above embodiment, illustrated in FIG.25, the LP-SS configuration may further include payload configuration succeeding sequence transmission. The payload may include information on one or more common LP-WUS area(s) wherein a common LP-WUS area may contain one or more cell(s) / gNB(s) with similar LP-SS and / or LP-WUS configuration. Further, the UE may be configured with one or more first common LP-WUS area(s) identifier(s). The operation 2502 may be otherwise similar to the operation 2402 in FIG.24. Further, the operation 2506 is similar to the operation 2406 in FIG.24, and the operation 2510 is similar to the operation 2410 in FIG.24.

[0193] A UE may then, in the operation 2512 subsequent to the operation 2510, e.g., utilizing LP-WUR, decode the one or more payload succeeding one or more LP-SS sequence(s) corresponding to the one or more third received signal strength(s) and determine one or more second common LP-WUS area(s) identifier(s).

[0194] At the operation 2514, the UE, e.g., using LP-WUR, identifies one or more third common LP-WUS area(s) identifier(s) which are included in both the one or more first and second common LP-WUS area(s) identifier(s).

[0195] If the set of one or more third common LP-WUS area(s) identifier(s) is not empty, at the operation 2516, the UE, e.g., using LP-WUR, performs received signal strength measurements and monitors for LP-WUS according to any of the identified one or more third common LP-WUS area(s) identifier(s).

[0196] If the UE, e.g., using LP-WUR, detects an LP-WUS, the UE performs, e.g., using MR, any of system information acquisition, paging DCI monitoring, paging message monitoring, and short message monitoring at the operation 2520. In a technical realization, the UE’s acquisition of system information, e.g., using the MR, may be subject to UE’s detection of an LP-WUS in a cell different than the initial serving cell wherein the initial serving cell is the cell where the UE first started, e.g., utilizing LP- WUR, LP-SS based measurements and LP-WUS monitoring.

[0197] If the UE, e.g., using the LP-WUR, determines the set of common LP-WUS area(s) identifier(s) that are common to both the one or more first and second common LP-WUS area(s) identifier(s) is empty, the UE, e.g., using the MR, at the operation 2518, utilizes the one or more third received signal strength(s) to assist in RRM measurements, i.e., based on any of PSS and SSS, and cell selection, i.e., selection of a second servingFW 6000682PCT02 32cell. Subsequently, at the operation 2520, the UE, e.g., using MR, acquires system information of the second serving cell.

[0198] Referring back to the operation 2516, the LP-WUS is not detected or there is no LP-WUS monitoring occasion, the UE continues with the operation 2506.

[0199] In an embodiment illustrated in FIG.26, a UE may be equipped with an envelope detection-based LP-WUR that can perform common LP-WUS area(s) measurements as described above. At the operation 2602, the UE transmits its LP-WUR (or LP-WUS monitoring) capability and receives the LP-WUS / LP-WUR configuration using any of RRC and system information signaling. The LP-WUS / LP-WUR configuration may include any of: • a duty cycle configured as an indication to one of a set of preconfigured values or as a number of, e.g., slots, subframes, frames; • one or more LP-SS and LP-WUS configuration(s) as part of one or more common LP- WUS area(s) configuration in a first set of common LP-WUS area(s); • an LP-SS configuration including any of: o a set of allocated frequency resources, o a transmission periodicity, one or more transmission occasions, one or more offsets between the one or more transmission occasions, o a preamble preceding, e.g., the first, transmission occasion, o a set of ^^(semi-)orthogonal sequences, o a set of ^^non-orthogonal sequences, o transmission occasion duration, sequence length, and data rate, o mapping between the LP-SS sequences and / or the TxOs and common LP-WUS areas identifiers; • an LP-WUS transmission configuration including any of data rate, coding scheme, coding rate, synchronizing / triggering preamble, payload size, and CRC length; • one or more received signal strength measurement thresholds.

[0200] At the operation 2604, the UE determines a second set of LP-SS sequence(s) and corresponding transmission occasion(s) based on any of a received indication from a first serving cell and one or more common LP-WUS area(s) identifier(s) of the first set.

[0201] At the operation 2606, the UE, e.g., using the LP-WUR, measures one or more received signal strength(s) ^L,^∀P using one or more (semi-)orthogonal and / or non- orthogonal LP-SS sequence(s) transmitted in corresponding one or more transmission occasion(s) according to the second set. In a technical realization, at least one of the one or more transmission occasion(s) in the second set may be preceded by a knownFW 6000682PCT02 33preamble and the UE, e.g., using the LP-WUR, measures the one or more received signal strength(s) only upon the detection of and / or synchronization using the preamble.

[0202] At the operation 2608, the UE, e.g., using the LP-WUR, determines a third set of common LP-WUS area(s), i.e., as a subset of the first set of common LP-WUS area(s), wherein each common LP-WUS area can be identified by an identifier. The third set is determined based on the one or more received signal strength(s) measurement(s), wherein only common LP-WUS area(s) with corresponding received signal strength(s) measurement(s) above a configured threshold are included in the third set.

[0203] On the condition that the third set is empty, at the operation 2612, the UE, e.g., using MR performs RRM measurements, i.e., based on any of PSS and SSS, and cell selection, i.e., selection of a second serving cell.

[0204] Otherwise (the third set is not empty), at the operation 2610, the UE, e.g., using the LP-WUR, monitors for LP-WUS according to configuration of one of the common LP-WUS area(s) in the third set. The one of the common LP-WUS area(s) in the third set may be selected based on the corresponding received signal strength measurement, e.g., the one with the highest signal strength. In a technical realization, the UE, e.g., using the LP-WUR, may detect an LP-WUS and subsequently, e.g., using the MR, may perform RRM measurements and cell selection. Alternatively, if an LP-WUS is not detected or an LP-WUS monitoring occasion is not available for the operation 2610, the UE, e.g., using the LP-WUR, continues performing received signal strength measurements at the operation 2606.

[0205] At the operation 2614, the UE, e.g., using the MR, performs any of system information acquisition, paging DCI monitoring, paging message monitoring, and short message monitoring. In a technical realization, the UE’s acquisition of system information, e.g., using the MR, may be subject to UE’s detection of an LP-WUS in a cell different than the initial serving cell wherein the initial serving cell is the cell where the UE first started, e.g., via LP-WUR, LP-SS based measurements and LP-WUS monitoring. In another technical realization, the UE’s acquisition of system information may be due to the second serving cell being different than the initial serving cell.

[0206] In a technical realization, there can be one-to-one mapping from a common LP-WUS area identifier to an LP-SS sequence. In this technical realization, the one or more cell(s) constituting the common LP-WUS area may not be differentiable, and the MR may not have assistance from the LP-WUR during RRM measurements upon wake- up based on an LP-WUS detection.FW 6000682PCT02 34

[0207] In another technical realization, there can be a one-to-many mapping from a common LP-WUS area identifier to LP-SS sequences, wherein the one or more LP-SS sequences may correspond to one or more cell identifier(s), e.g., multiple cells are part of a single common LP-WUS area and the cells can be differentiated by different LP-SS sequences. In this technical realization, the knowledge of cell identifiers may be used for UE, e.g., the MR, assistance during RRM measurements upon wake-up based on an LP- WUS detection.

[0208] In another technical realization, there can be one-to-one mapping from a common LP-WUS area identifier to an LP-SS sequence, however, each LP-SS sequence may be associated with one or more payload(s) conveying, e.g., partial or full, information on the one or more cell(s) constituting the common LP-WUS area. In this technical realization, the knowledge of cell identifiers may be used for UE, e.g., the MR, assistance during RRM measurements upon wake-up based on an LP-WUS detection.

[0209] Similar to the previous embodiments, the UE may initiate RRC connection establishment or resume procedure or continue operating in RRC Idle / Inactive state based on a received any of short messages, paging DCIs, and paging messages, wherein the reception may be triggered by a detected LP-WUS. In a technical realization, only a set of (semi-)orthogonal sequences and one or more transmission occasion(s) may be configured for LP-SS. In another technical realization, only a set of non-orthogonal sequences and one or more transmission occasion(s) may be configured for LP-SS. In another technical realization the set of (semi-)orthogonal and / or non-orthogonal sequences may be reused over one or more transmission occasion(s).

[0210] In some embodiments, a wireless transmit / receive unit (WTRU) receives, from a first serving cell, a configuration for low-power wake-up signals (LP-WUSs) and low-power synchronization signal (LP-SSs). The configuration may be used for a LP- WUS, a LP-WUS transmitted multiple times, or different LP-WUSs. The configuration can be sent in multiple sections. The WTRU determines one or more measurements for one or more sequences based on the configuration. One measurement of the one or more measurements corresponds to one sequence of the one or more sequences. The WTRU receives an LP-WUS according to the configuration in response to that a first measurement from the one or more measurements is above a first threshold. The WTRU receives a physical random access channel (PRACH) preamble in response to the receiving the LP-WUS or in response to a paging downlink control information (DCI).

[0211] FIG.27A shows a flow chart of a method 2700 performed by a wireless transmit / receive unit (WTRU), in accordance with some implementations. The WTRU may include computer-readable code or instructions executing on one or moreFW 6000682PCT02 35processors of the WTRU. Coding of the software for carrying out or performing the method 2700 is well within the scope of a person of ordinary skill in the art having regard to the present disclosure. The method 2700 may include additional or fewer operations than those shown and described and may be carried out or performed in a different order. Computer-readable code or instructions of the software executable by the one or more processors may be stored on at least one non-transitory computer-readable medium, such as for example, at least one memory of the WTRU. In some embodiments, the method 2700 may be performed by one or more of units or modules (e.g., an integrated circuit) of the WTRU, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0212] The method 2700 starts at the operation 2702, where the WTRU receives from a first serving cell a first signal with a first type of waveform (for example, similar to the first type of waveform described elsewhere herein). The first signal carries configuration information for receiving a second signal with a second type of waveform (for example, similar to the second type of waveform described elsewhere herein). The configuration information indicates a first threshold and a second threshold less than the first threshold. At the operation 2704, the WRTU compares a measurement of the second signal to at least one of the first threshold or the second threshold. At the operation 2706, the WRTU receives a payload in a mode determined based on the comparing.

[0213] In some implementations, the measurement may be above the first threshold. The payload may comprise a low-power wake-up signal (LP-WUS).

[0214] In some implementations, the WRTU may receive the LP-WUS in a first operation mode. The first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU operating with non-coherent detection to monitor the LP- WUS in accordance to the second type of waveform. The non-coherent detection may include envelope detection without using information about at least one overlaid orthogonal frequency division multiplexing (OFDM) sequence.

[0215] In some implementations, the measurement may be below the first threshold and above the second threshold. The WTRU may receive the LP-WUS in the second operation mode.

[0216] In some implementations, the WTRU may receive the LP-WUS in a second operation mode. The second operation mode may correspond to using a LP-WUR of the WTRU operating with coherent detection to monitor the LP-WUS in accordance to the second type of waveform. The coherent detection may include detection using information about at least one overlaid OFDM sequence.FW 6000682PCT02 36

[0217] In some implementations, the measurement may be below the second threshold, and the payload comprises at least one of a short message, a paging message, or a paging downlink control information (DCI).

[0218] In some implementations, the WTRU may receive the payload in the third operation mode. The third operation mode may correspond to using a main radio (MR) of the WTRU to monitor the payload in accordance to the first type of waveform.

[0219] In some implementations, the third operation mode may further correspond to using the MR for serving cell measurements based on at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

[0220] In some implementations, the first type of waveform may be an OFDM waveform or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) waveform. The second type of waveform may be an On-Off Keying (OOK) waveform with pulse shaping based on overlaid OFDM sequences.

[0221] In some implementations, the WTRU in a third operation mode may receive at least one of a paging DCI or a paging message with the first type of waveform in accordance to the LP-WUS. The WTRU in the third operation mode may transmit a physical random access channel (PRACH) preamble in accordance to the first type of waveform.

[0222] In some implementations, the configuration information may further indicate a time window. The second signal may be received in the time window.

[0223] In some implementations, the configuration information may further indicate at least one overlaid OFDM sequence.

[0224] FIG.27B shows a flow chart of a method 2750 performed by a wireless transmit / receive unit (WTRU), in accordance with some implementations. The WTRU may include computer-readable code or instructions executing on one or more processors of the WTRU. Coding of the software for carrying out or performing the method 2750 is well within the scope of a person of ordinary skill in the art having regard to the present disclosure. The method 2750 may include additional or fewer operations than those shown and described and may be carried out or performed in a different order. Computer-readable code or instructions of the software executable by the one or more processors may be stored on at least one non-transitory computer-readable medium, such as for example, at least one memory of the WTRU. In some embodiments, the method 2750 may be performed by one or more of units or modules (e.g., an integrated circuit) of the WTRU, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).FW 6000682PCT02 37

[0225] The method 2750 starts at the operation 2752, where the WTRU receives from a first serving cell a low-power wake-up signal (LP-WUS) configuration and a low-power synchronization signal (LP-SS) configuration. At the operation 2754, the WTRU in a first operation mode measures one or more LP-SS sequences based on the LP-SS configuration to determine one or more measurements for the one or more LP-SS sequences. At the operation 2756, the WTRU in the first operation mode receives an LP- WUS based on the LP-WUS configuration and based on that a first measurement of the one or more measurements is above a first threshold. At the operation 2758, the WTRU in the first operation mode performs serving cell selection based on comparing the one or more measurements to a third threshold.

[0226] In some implementations, at least one of the LP-WUS configuration or the LP-SS configuration may indicate a first set of common LP-WUS area identifiers (IDs).

[0227] In some implementations, the WTRU may receive a payload carrying one or more common LP-WUS area IDs may be associated with each of the one or more LP-SS sequences.

[0228] In some implementations, before receiving the LP-WUS, the WTRU in the first operation mode may determine, a first set of measurements from the one or more measurements above the third threshold. The WTRU in the first operation mode may decode one or more payloads associated with the one or more LP-SS sequences based on the first set of measurements to determine a second set of common LP-WUS area IDs. The WTRU in the first operation mode may determine a third set of common LP-WUS area IDs. The third set may be an intersection of the first set and the second set. The third set is not empty.

[0229] In some implementations, the WTRU in the first operation mode may measure second one or more LP-SS sequences based on the LP-SS configuration to determine second one or more measurements for the second one or more LP-SS sequences. The WTRU in the first operation mode may determine a fourth set of measurements from the second one or more measurements above the third threshold. The WTRU in the first operation mode may decode second one or more payloads associated with the second one or more LP-SS sequences based on the fourth set of measurements to determine a fifth set of common LP-WUS area IDs. The WTRU in the first operation mode may determine a sixth set of common LP-WUS area IDs. The sixth set may be a second intersection of the fourth set and the fifth set. The six set is empty. The WTRU in the second operation mode may perform the serving cell selection. The WTRU in the second operation mode may receive from a second serving cell system information.FW 6000682PCT02 38

[0230] In some implementations, the WTRU in the first operation mode may receive the LP-WUS from the second serving cell.

[0231] In some implementations, the receiving the LP-WU may be based on that the third set includes at least one common LP-WUS area ID.

[0232] In some implementations, the WTRU in the first operation mode may receive the LP-WUS from the first serving cell.

[0233] In some implementations, the WTRU in the first operation mode may receive the LP-WUS from a third serving cell. The at least one common LP-WUS area ID in the third set may include a third common LP-WUS area ID corresponding to the third serving cell.

[0234] In some implementations, the WTRU in the second operation mode may receive the system information from the third serving cell based on the receiving the LP- WUS.

[0235] In some implementations, the WTRU in the second operation mode may receive at least one of a paging DCI or a paging message in accordance to the LP-WUS. The WTRU in the second operation mode may transmit a physical random access channel (PRACH) preamble to at least one of the first serving cell, the second serving cell, or the third serving cell.

[0236] In some implementations, the first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU. The WTRU in the first operation mode may monitor an On-Off Keying (OOK) waveform with or without an overlaid orthogonal frequency division multiplexing (OFDM) sequence.

[0237] In some implementations, the second operation mode may correspond to using a main radio (MR) of the WTRU. The WTRU in the second operation mode may transmit or receive an OFDM signal or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) signal using a transmitter or a receiver of the MR, respectively.

[0238] FIG.27C shows a flow chart of a method 2760 performed by a network system, in accordance with some implementations. The network may include at least one base station. The operations performed by the at least one base station as described below may all be performed by one base station of the network system, or any different two operations performed by the at least one base station may be performed by different base stations of the network system, respectively. In addition, any operation performed by the at least one base station may be jointly performed by multiple base stations of the at least one base station. The at least one base station of the network system may includeFW 6000682PCT02 39computer-readable code or instructions executing on one or more processors of the at least one base station. Coding of the software for carrying out or performing the method 2760 is well within the scope of a person of ordinary skill in the art having regard to the present disclosure. The method 2760 may include additional or fewer operations than those shown and described and may be carried out or performed in a different order. Computer-readable code or instructions of the software executable by the one or more processors may be stored on at least one non-transitory computer-readable medium, such as for example, at least one memory of the at least one base station of the network system. In some embodiments, the method 2760 may be performed by one or more of units or modules (e.g., an integrated circuit) of the at least one base station, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0239] The method 2760 starts at the operation 2762, where the at least one base station of the network system in a first serving cell transmits to a wireless transmit / receive unit (WTRU) a first signal with a first type of waveform (for example, similar to the first type of waveform described elsewhere herein). The first signal carries configuration information for receiving a second signal with a second type of waveform (for example, similar to the second type of waveform described elsewhere herein). The configuration information indicates a first threshold and a second threshold less than the first threshold. At the operation 2764, the at least one base station transmits to the WTRU a payload. The payload is received by the WTRU in a mode determined based on comparing a measurement of the second signal to at least one of the first threshold or the second threshold.

[0240] In some implementations, the measurement may be above the first threshold. The payload may comprise a low-power wake-up signal (LP-WUS).

[0241] In some implementations, the payload may be received in a first operation mode of the WTRU. The first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU operating with non-coherent detection to monitor the LP-WUS in accordance to the second type of waveform. The non-coherent detection may include envelope detection without using information about at least one overlaid orthogonal frequency division multiplexing (OFDM) sequence.

[0242] In some implementations, the measurement may be below the first threshold and above the second threshold. The payload may comprise an LP-WUS.

[0243] In some implementations, the payload may be received in a second operation mode of the WTRU. The second operation mode may correspond to using a LP-WUR of the WTRU operating with coherent detection to monitor the LP-WUS in accordance toFW 6000682PCT02 40the second type of waveform. The coherent detection may include detection using information about at least one overlaid OFDM sequence.

[0244] In some implementations, the measurement may be below the second threshold. The payload may comprise at least one of a short message, a paging message, or a paging downlink control information (DCI).

[0245] In some implementations, the payload may be received in a third operation mode of the WTRU. The third operation mode may correspond to using a main radio (MR) of the WTRU to monitor the payload in accordance to the first type of waveform.

[0246] In some implementations, the third operation mode may further correspond to using the MR for serving cell measurements based on at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

[0247] In some implementations, the first type of waveform may be an OFDM waveform or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) waveform. The second type of waveform may be an On-Off Keying (OOK) waveform with pulse shaping based on overlaid OFDM sequences.

[0248] In some implementations, the at least one base station may transmit to the WTRU in a third operation mode at least one of a paging DCI or a paging message with the first type of waveform in accordance to the LP-WUS. The at least one base station may receive from the WTRU in the third operation mode a physical random access channel (PRACH) preamble in accordance to the first type of waveform.

[0249] In some implementations, the configuration information may further indicate a time window. The second signal may be transmitted in the time window.

[0250] In some implementations, the configuration information may further indicate at least one overlaid OFDM sequence.

[0251] In some implementations, the at least one base station may include two or more base stations.

[0252] FIG.27D shows a flow chart of a method 2770 performed by a network system, in accordance with some implementations. The network system may include computer-readable code or instructions executing on one or more processors of the network system. Coding of the software for carrying out or performing the method 2770 is well within the scope of a person of ordinary skill in the art having regard to the present disclosure. The method 2770 may include additional or fewer operations than those shown and described and may be carried out or performed in a different order. Computer-readable code or instructions of the software executable by the one or moreFW 6000682PCT02 41processors may be stored on at least one non-transitory computer-readable medium, such as for example, at least one memory of the network system. In some embodiments, the method 2770 may be performed by one or more of units or modules (e.g., an integrated circuit) of the network system, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0253] The method 2770 starts at the operation 2772, where a base station in a first serving cell of the network system transmits to a wireless transmit / receive unit (WTRU) a low-power wake-up signal (LP-WUS) configuration and a low-power synchronization signal (LP-SS) configuration. At the 0perations 2774, the network system transmits to the WTRU in a first operation mode an LP-WUS. The LP WUS is received by the WTRU based on that a first measurement of one or more measurements is above a first threshold. The WTRU in the first operation mode performs serving cell selection based on comparing the one or more measurements to a third threshold.

[0254] In some implementations, at least one of the LP-WUS configuration or the LP-SS configuration may indicate a first set of common LP-WUS area identifiers (IDs).

[0255] In some implementations, the network system may transmit to the WTRU a payload carrying one or more common LP-WUS area IDs associated with each of one or more LP-SS sequences.

[0256] In some implementations, a second base station in a second serving cell of the network system may transmit the LP-WUS to the WTRU in the first operation mode.

[0257] In some implementations, the base station in the first serving cell may transmit the LP-WUS to the WTRU in the first operation mode.

[0258] In some implementations, a third base station in a third serving cell of the network system may transmit system information to the WTRU in a second operation mode.

[0259] In some implementations, the network system may transmit to the WTRU in a second operation mode at least one of a paging DCI or a paging message in accordance to the LP-WUS.

[0260] In some implementations, the network system may receive from the WTRU in the second operation mode a physical random access channel (PRACH) preamble.

[0261] In some implementations, the first operation mode may correspond to using a low-power wake-up radio (LP-WUR) of the WTRU. The WTRU in the first operation mode may monitor an On-Off Keying (OOK) waveform with or without an overlaid orthogonal frequency division multiplexing (OFDM) sequence.FW 6000682PCT02 42

[0262] In some implementations, a second operation mode may correspond to using a main radio (MR) of the WTRU. The WTRU in the second operation mode may transmit or receive an OFDM signal or a Discrete Fourier Transform-Spread-OFDM (DFT-S- OFDM) signal using a transmitter or a receiver of the MR, respectively.

[0263] In accordance with implementations, a WTRU receives from a first serving cell a low-power wake-up signal (LP-WUS) configuration and a low-power synchronization signal (LP-SS) configuration. At least one of the LP-WUS configuration or the LP-SS configuration indicates a set of common LP-WUS area identifiers (IDs). The WTRU in a first operation mode measures one or more LP-SS sequences based on the LP-SS configuration to determine one or more measurements for the one or more LP-SS sequences. The WTRU in the first operation mode receives an LP-WUS based on the LP- WUS configuration and based on that a first measurement of the one or more measurements is above a first threshold. The WTRU performs serving cell selection based on comparing the one or more measurements to a third threshold and based on the set of common LP-WUS area IDs.

[0264] This disclosure incorporates the following by reference in their entireties. [1] RP-234056, “New WID: Low-power Wake-up Signal and Receiver for NR (LP- WUS / WUR)”, CMCC, RAN#102, Dec.11-15, 2023. [2] R1-2208379, “Low Power WUS Receiver Architectures Considerations and Modeling”, Futurewei, RAN1#110-bis-e, October 10-19, 2022. [3] 3GPP TS 38.304, “NR; User Equipment (UE) procedures in Idle mode and RRC Inactive state (Release 17)” V17.1.0 (2022-06). [4] RP-213645, “New SID: Study on low-power Wake-up Signal and Receiver for NR”, Vivo, RAN#94e, Dec.6-17, 2021. [5] RP-222644, “Revised SID: Study on low-power Wake-up Signal and Receiver for NR”, Vivo, RAN#97e, Sept.12-16, 2022. [6] RWS-210169, “New SID: Study on ultra-low power wake up signal in Rel-18”, Vivo, RAN Rel-18 workshop, June 28 – July 2, 2021. [7] 3GPP TR 38.869, “Study on low-power wake up signal and receiver for NR (Release 18)” V1.0.0 (2023-09). [8] David D. Wentzloff, “Low Power Radio Survey,” [Online]. www.eecs.umich.edu / wics / low_power_radio_survey.html. [9] R1-2210666, “Summary #3 on [110bis-e-R18-LP_WUS-02] LP WUR architecture”, Apple, RAN1#110bis-e, October 10th-19th, 2022.

[0010] C. Bryant, et.al, “A 2.45GHz 50uw wake-up receiver front-end with -88dBm sensitivity and 250kbps data rate”, ESSCIRC, 2014.FW 6000682PCT02 43

[0011] X. Huang, S. Rampu, X. Wang, G. Dolmans and H. de Groot, "A 2.4GHz / 915MHz 51µW wake-up receiver with offset and noise suppression," 2010 IEEE International Solid-State Circuits Conference - (ISSCC), 2010, pp.222-223, doi: 10.1109 / ISSCC.2010.5433958.

[0012] X. Huang, P. Harpe, G. Dolmans, H. de Groot and J. R. Long, "A 780–950 MHz, 64–146 µW Power-Scalable Synchronized-Switching OOK Receiver for Wireless Event- Driven Applications," in IEEE Journal of Solid-State Circuits, vol.49, no.5, pp.1135- 1147, May 2014, doi: 10.1109 / JSSC.2014.2307056.

[0013] S. Moazzeni, M. Sawan and G. E. R. Cowan, "An Ultra-Low-Power Energy- Efficient Dual-Mode Wake-Up Receiver," in IEEE Transactions on Circuits and Systems I: Regular Papers, vol.62, no.2, pp.517-526, Feb.2015, doi: 10.1109 / TCSI.2014.2360336.

[0014] X. Huang, A. Ba, P. Harpe, G. Dolmans, H. de Groot and J. R. Long, "A 915 MHz, Ultra-Low Power 2-Tone Transceiver with Enhanced Interference Resilience," in IEEE Journal of Solid-State Circuits, vol.47, no.12, pp.3197-3207, Dec.2012, doi: 10.1109 / JSSC.2012.2216706.

[0015] C. Salazar, A. Cathelin, A. Kaiser and J. Rabaey, "A 2.4 GHz Interferer-Resilient Wake-Up Receiver Using A Dual-IF Multi-Stage N-Path Architecture," in IEEE Journal of Solid-State Circuits, vol.51, no.9, pp.2091-2105, Sept.2016, doi: 10.1109 / JSSC.2016.2582509.

[0016] Chairs notes RAN1_110bis-e v17.

[0017] R1-2212676, “Summary #3 on LP WUR architecture”, Apple.

[0018] R1-2210909, “Discussion on architecture of LP-WUS receiver”, Huawei, HiSilicon

[0019] R1-2301817, “Summary #2 on LP WUR architecture”, Apple, RAN1#112, February 27th-March 03rd, 2023.

[0020] R1-2300101, “Discussion on architecture of LP-WUS receiver”, Huawei, HiSilicon, RAN1#112, February 27th-March 03rd, 2023.

[0021] R1-2301373, “On the L1 signal design and procedures for low power wake-up signal”, Apple, RAN1#112, February 27th-March 03rd, 2023.

[0265] The WTRU in this disclosure may include a main radio and a low power wake- up radio. The main radio of the WTRU is used for transmitting or receiving regular communication signal(s) such as system information, paging messages, and data transmissions using higher-order modulation schemes. The low power wake-up radio (e.g., low-power wake-up receiver (LP-WUR)) of the WTRU is used to support the sleep mode operation(s) of the WTRU (e.g., especially if the WTRU is an IoT UE and can operate with power consumption 2-3 orders of magnitude lower than the main radio).FW 6000682PCT02 44The WTRU in the sleep mode has its main radio shut down to reduce power consumption and may enter different levels of sleep states including deep sleep and ultra-deep sleep states. The low power wake-up radio of the WTRU monitors the over-the-air signal for low-power wake-up signals (LP-WUSs) from the base station and can also monitor low- power synchronization signals (LP-SSs) for cell measurements and selection. Once the low power wake-up radio detects an LP-WUS, it may send a control signal to wake up the main radio for regular communication.

[0266] For the illustration purpose, this disclosure uses the OFDM waveform or the DFT-S-OFDM waveform as the examples of the first type of waveform which support high spectral efficiency and are commonly used in cellular systems. The first type of waveform is not limited to OFDM waveforms or DFT-S-OFDM waveforms and may comprise any waveform type (carrying, for example, a regular communication signal) that can be received and decoded by the main radio of the WTRU known in the art such as single-carrier waveforms or other multi-carrier waveforms. Further for the illustration purpose, this disclosure uses the OOK waveform as an example of the second type of waveform due to its simplicity and compatibility with envelope detection. The second type of waveform is not limited to OOK waveforms and may comprise any waveform type (carrying, for example, an LP-WUS) that can be received and decoded by the LP-WUR know in the art (e.g., according to, but not limited to, the receiver architecture described with respect to any of FIGs.6-9 of this disclosure) while achieving the low power result (e.g., without waking up the main radio for signal detection / processing) such as FSK waveforms or other energy-efficient modulation schemes.

[0267] According to implementations of this disclosure, the low power wake-up radio does not have to always send the control signal to wake up the main radio every time the low power wake-up radio receives an LP-WUS to further preserving energy , but rather makes this decision based on various factors including signal strength measurements, common LP-WUS area identifiers, and configured thresholds. The LP-WUR can operate in different detection modes including non-coherent detection using envelope detection and coherent detection using information about overlaid OFDM sequences, depending on the received signal strength and power efficiency requirements.

[0268] FIG.28 illustrates an example communications system 2800. Communications system 2800 includes an access node 2810 serving user equipments (UEs) with coverage 2801, such as UEs 2820. In a first operating mode, communications to and from a UE passes through access node 2810 with a coverage area 2801. The access node 2810 is connected to a backhaul network 2815 for connecting to the internet, operations and management, and so forth. In a second operating mode, communicationsFW 6000682PCT02 45to and from a UE do not pass through access node 2810, however, access node 2810 typically allocates resources used by the UE to communicate when specific conditions are met. Communications between a pair of UEs 2820 can use a sidelink connection (shown as two separate one-way connections 2825). In FIG.28, the sidelink communication is occurring between two UEs operating inside of coverage area 2801. However, sidelink communications, in general, can occur when UEs 2820 are both outside coverage area 2801, both inside coverage area 2801, or one inside and the other outside coverage area 2801. Communication between a UE and access node pair occur over uni-directional communication links, where the communication links between the UE and the access node are referred to as uplinks 2830, and the communication links between the access node and UE is referred to as downlinks 2835.

[0269] Access nodes may also be commonly referred to as Node Bs, evolved Node Bs (eNBs), next generation (NG) Node Bs (gNBs), master eNBs (MeNBs), secondary eNBs (SeNBs), master gNBs (MgNBs), secondary gNBs (SgNBs), network controllers, control nodes, base stations, access points, transmission points (TPs), transmission-reception points (TRPs), cells, carriers, macro cells, femtocells, pico cells, and so on, while UEs may also be commonly referred to as mobile stations, mobiles, terminals, users, subscribers, stations, and the like. Access nodes may provide wireless access in accordance with one or more wireless communication protocols, e.g., the Third Generation Partnership Project (3GPP) long term evolution (LTE), LTE advanced (LTE- A), 5G, 5G LTE, 5G NR, sixth generation (6G), High Speed Packet Access (HSPA), the IEEE 802.11 family of standards, such as 802.11a / b / g / n / ac / ad / ax / ay / be, etc. While it is understood that communications systems may employ multiple access nodes capable of communicating with a number of UEs, only one access node and two UEs are illustrated for simplicity.

[0270] FIG.29 illustrates an example communication system 2900. In general, the system 2900 enables multiple wireless or wired users to transmit and receive data and other content. The system 2900 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

[0271] In this example, the communication system 2900 includes electronic devices (ED) 2910a-2910c, radio access networks (RANs) 2920a-2920b, a core network 2930, a public switched telephone network (PSTN) 2940, the Internet 2950, and other networks 2960. While certain numbers of these components or elements are shown in FIG.29, any number of these components or elements may be included in the system 2900.FW 6000682PCT02 46

[0272] The EDs 2910a-2910c are configured to operate or communicate in the system 2900. For example, the EDs 2910a-2910c are configured to transmit or receive via wireless or wired communication channels. Each ED 2910a-2910c represents any suitable end user device and may include such devices (or may be referred to) as a user equipment or device (UE), wireless transmit or receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular telephone, personal digital assistant (PDA), smartphone, laptop, computer, touchpad, wireless sensor, or consumer electronics device.

[0273] The RANs 2920a-2920b here include base stations 2970a-2970b, respectively. Each base station 2970a-2970b is configured to wirelessly interface with one or more of the EDs 2910a-2910c to enable access to the core network 2930, the PSTN 2940, the Internet 2950, or the other networks 2960. For example, the base stations 2970a-2970b may include (or be) one or more of several well-known devices, such as a base transceiver station (BTS), a Node-B (NodeB), an evolved NodeB (eNB), a Next Generation (NG) NodeB (gNB), a gNB centralized unit (gNB-CU), a gNB distributed unit (gNB-DU), a Home NodeB, a Home eNodeB, a site controller, an access point (AP), or a wireless router. The EDs 2910a-2910c are configured to interface and communicate with the Internet 2950 and may access the core network 2930, the PSTN 2940, or the other networks 2960.

[0274] In the embodiment shown in FIG.29, the base station 2970a forms part of the RAN 2920a, which may include other base stations, elements, or devices. Also, the base station 2970b forms part of the RAN 2920b, which may include other base stations, elements, or devices. Each base station 2970a-2970b operates to transmit or receive wireless signals within a particular geographic region or area, sometimes referred to as a “cell.” In some embodiments, multiple-input multiple-output (MIMO) technology may be employed having multiple transceivers for each cell.

[0275] The base stations 2970a-2970b communicate with one or more of the EDs 2910a-2910c over one or more air interfaces 2990 using wireless communication links. The air interfaces 2990 may utilize any suitable radio access technology.

[0276] It is contemplated that the system 2900 may use multiple channel access functionality, including such schemes as described above. In particular embodiments, the base stations and EDs implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and wireless protocols may be utilized.

[0277] The RANs 2920a-2920b are in communication with the core network 2930 to provide the EDs 2910a-2910c with voice, data, application, Voice over Internet ProtocolFW 6000682PCT02 47(VoIP), or other services. Understandably, the RANs 2920a-2920b or the core network 2930 may be in direct or indirect communication with one or more other RANs (not shown). The core network 2930 may also serve as a gateway access for other networks (such as the PSTN 2940, the Internet 2950, and the other networks 2960). In addition, some or all of the EDs 2910a-2910c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies or protocols. Instead of wireless communication (or in addition thereto), the EDs may communicate via wired communication channels to a service provider or switch (not shown), and to the Internet 2950.

[0278] Although FIG.29 illustrates one example of a communication system, various changes may be made to FIG.29. For example, the communication system 2900 could include any number of EDs, base stations, networks, or other components in any suitable configuration.

[0279] FIGs.30A and 30B illustrate example devices that may implement the methods and teachings according to this disclosure. In particular, FIG.30A illustrates an example ED 3010, and FIG.30B illustrates an example base station 3070. These components could be used in the system 2900 or in any other suitable system.

[0280] As shown in FIG.30A, the ED 3010 includes at least one processing unit 3000. The processing unit 3000 implements various processing operations of the ED 3010. For example, the processing unit 3000 could perform signal coding, data processing, power control, input / output processing, or any other functionality enabling the ED 3010 to operate in the system 2900. The processing unit 3000 also supports the methods and teachings described in more detail above. Each processing unit 3000 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 3000 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0281] The ED 3010 also includes at least one transceiver 3002. The transceiver 3002 is configured to modulate data or other content for transmission by at least one antenna or NIC (Network Interface Controller) 3004. The transceiver 3002 is also configured to demodulate data or other content received by the at least one antenna 3004. Each transceiver 3002 includes any suitable structure for generating signals for wireless or wired transmission or processing signals received wirelessly or by wire. Each antenna 3004 includes any suitable structure for transmitting or receiving wireless or wired signals. One or multiple transceivers 3002 could be used in the ED 3010, and one or multiple antennas 3004 could be used in the ED 3010. Although shown as a singleFW 6000682PCT02 48functional unit, a transceiver 3002 could also be implemented using at least one transmitter and at least one separate receiver.

[0282] The ED 3010 further includes one or more input / output devices 3006 or interfaces (such as a wired interface to the Internet 2950). The input / output devices 3006 facilitate interaction with a user or other devices (network communications) in the network. Each input / output device 3006 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

[0283] In addition, the ED 3010 includes at least one memory 3008. The memory 3008 stores instructions and data used, generated, or collected by the ED 3010. For example, the memory 3008 could store software or firmware instructions executed by the processing unit(s) 3000 and data used to reduce or eliminate interference in incoming signals. Each memory 3008 includes any suitable volatile or non-volatile storage and retrieval device(s). Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, and the like.

[0284] As shown in FIG.30B, the base station 3070 includes at least one processing unit 3050, at least one transceiver 3052, which includes functionality for a transmitter and a receiver, one or more antennas 3056, at least one memory 3058, and one or more input / output devices or interfaces 3066. A scheduler, which would be understood by one skilled in the art, is coupled to the processing unit 3050. The scheduler could be included within or operated separately from the base station 3070. The processing unit 3050 implements various processing operations of the base station 3070, such as signal coding, data processing, power control, input / output processing, or any other functionality. The processing unit 3050 can also support the methods and teachings described in more detail above. Each processing unit 3050 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 3050 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0285] Each transceiver 3052 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 3052 further includes any suitable structure for processing signals received wirelessly or by wire from one or more EDs or other devices. Although shown combined as a transceiver 3052, a transmitter and a receiver could be separate components. EachFW 6000682PCT02 49antenna 3056 includes any suitable structure for transmitting or receiving wireless or wired signals. While a common antenna 3056 is shown here as being coupled to the transceiver 3052, one or more antennas 3056 could be coupled to the transceiver(s) 3052, allowing separate antennas 3056 to be coupled to the transmitter and the receiver if equipped as separate components. Each memory 3058 includes any suitable volatile or non-volatile storage and retrieval device(s). Each input / output device 3066 facilitates interaction with a user or other devices (network communications) in the network. Each input / output device 3066 includes any suitable structure for providing information to or receiving / providing information from a user, including network interface communications.

[0286] FIG.31 is a block diagram of a computing system 3100 that may be used for implementing the devices and methods disclosed herein. For example, the computing system can be any entity of UE, access network (AN), mobility management (MM), session management (SM), user plane gateway (UPGW), or access stratum (AS). Specific devices may utilize all of the components shown or only a subset of the components, and levels of integration may vary from device to device. Furthermore, a device may contain multiple instances of a component, such as multiple processing units, processors, memories, transmitters, receivers, etc. The computing system 3100 includes a processing unit 3102. The processing unit includes a central processing unit (CPU) 3114, memory 3108, and may further include a mass storage device 3104, a video adapter 3110, and an I / O interface 3112 connected to a bus 3120.

[0287] The bus 3120 may be one or more of any type of several bus architectures including a memory bus or memory controller, a peripheral bus, or a video bus. The CPU 3114 may comprise any type of electronic data processor. The memory 3108 may comprise any type of non-transitory system memory such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or a combination thereof. In an embodiment, the memory 3108 may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs.

[0288] The mass storage 3104 may comprise any type of non-transitory storage device configured to store data, programs, and other information and to make the data, programs, and other information accessible via the bus 3120. The mass storage 3104 may comprise, for example, one or more of a solid state drive, hard disk drive, a magnetic disk drive, or an optical disk drive.

[0289] The video adapter 3110 and the I / O interface 3112 provide interfaces to couple external input and output devices to the processing unit 3102. As illustrated, examples ofFW 6000682PCT02 50input and output devices include a display 3118 coupled to the video adapter 3110 and a mouse, keyboard, or printer 3116 coupled to the I / O interface 3112. Other devices may be coupled to the processing unit 3102, and additional or fewer interface cards may be utilized. For example, a serial interface such as Universal Serial Bus (USB) (not shown) may be used to provide an interface for an external device.

[0290] The processing unit 3102 also includes one or more network interfaces 3106, which may comprise wired links, such as an Ethernet cable, or wireless links to access nodes or different networks. The network interfaces 3106 allow the processing unit 3102 to communicate with remote units via the networks. For example, the network interfaces 3106 may provide wireless communication via one or more transmitters / transmit antennas and one or more receivers / receive antennas. In an embodiment, the processing unit 3102 is coupled to a local-area network 3122 or a wide-area network for data processing and communications with remote devices, such as other processing units, the Internet, or remote storage facilities.

[0291] It should be appreciated that one or more steps of the embodiment methods provided herein may be performed by corresponding units or modules. For example, a signal may be transmitted by a transmitting unit or a transmitting module. A signal may be received by a receiving unit or a receiving module. A signal may be processed by a processing unit or a processing module. Other steps may be performed by a performing unit or module, a generating unit or module, an obtaining unit or module, a setting unit or module, an adjusting unit or module, an increasing unit or module, a decreasing unit or module, a determining unit or module, a modifying unit or module, a reducing unit or module, a removing unit or module, or a selecting unit or module. The respective units or modules may be hardware, software, or a combination thereof. For instance, one or more of the units or modules may be an integrated circuit, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0292] Although the description has been described in detail, it should be understood that various changes, substitutions and alterations can be made without departing from the spirit and scope of this disclosure as defined by the appended claims. Moreover, the scope of the disclosure is not intended to be limited to the particular embodiments described herein, as one of ordinary skill in the art will readily appreciate from this disclosure that processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, may perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein. Accordingly, the appended claims are intended toFW 6000682PCT02 51include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.FW 6000682PCT02 52

Claims

What is Claimed Is:

1. A method, comprising: receiving, by a wireless transmit / receive unit (WTRU) from a first serving cell, a first signal with a first type of waveform, the first signal carrying configuration information for receiving a second signal with a second type of waveform, wherein the configuration information indicates a first threshold and a second threshold less than the first threshold; comparing, by the WTRU, a measurement of the second signal to at least one of the first threshold or the second threshold; and receiving, by the WTRU, a payload in a mode determined based on the comparing.

2. The method of claim 1, wherein the measurement is above the first threshold, and the payload comprises a low-power wake-up signal (LP-WUS).

3. The method of claim 2, wherein the receiving the payload is in a first operation mode, wherein the first operation mode corresponds to using a low-power wake-up radio (LP-WUR) of the WTRU operating with non-coherent detection to monitor the LP-WUS in accordance to the second type of waveform, and wherein the non-coherent detection includes envelope detection without using information about at least one overlaid orthogonal frequency division multiplexing (OFDM) sequence.

4. The method of claim 1, wherein the measurement is below the first threshold and above the second threshold, and the payload comprises an LP-WUS.

5. The method of claim 4, wherein the receiving the payload is in a second operation mode, and the second operation mode corresponds to using a LP-WUR of the WTRU operating with coherent detection to monitor the LP-WUS in accordance to the second type of waveform, and wherein the coherent detection includes detection using information about at least one overlaid OFDM sequence.

6. The method of claim 1, wherein the measurement is below the second threshold, and the payload comprises at least one of a short message, a paging message, or a paging downlink control information (DCI).

7. The method of claim 6, wherein the receiving the payload is in a third operation mode, and the third operation mode corresponds to using a main radio (MR) of the WTRU to monitor the payload in accordance to the first type of waveform.FW 6000682PCT02 538. The method of claim 7, wherein the third operation mode further corresponds to using the MR for serving cell measurements based on at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

9. The method of any of claims 1-8, wherein the first type of waveform is an OFDM waveform or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) waveform, and the second type of waveform is an On-Off Keying (OOK) waveform with pulse shaping based on overlaid OFDM sequences.

10. The method of any of claims 2 and 4, further comprising: receiving, by the WTRU in a third operation mode, at least one of a paging DCI or a paging message with the first type of waveform in accordance to the LP-WUS; and transmitting, by the WTRU in the third operation mode, a physical random access channel (PRACH) preamble in accordance to the first type of waveform.

11. The method of claim 1, wherein the configuration information further indicates a time window, and the second signal is received in the time window.

12. The method of claim 1, wherein the configuration information further indicates at least one overlaid OFDM sequence.

13. A method, comprising: receiving, by a wireless transmit / receive unit (WTRU) from a first serving cell, a low-power wake-up signal (LP-WUS) configuration and a low-power synchronization signal (LP-SS) configuration; measuring, by the WTRU in a first operation mode, one or more LP-SS sequences based on the LP-SS configuration to determine one or more measurements for the one or more LP-SS sequences; and receiving, by the WTRU in the first operation mode, an LP-WUS based on the LP- WUS configuration and based on that a first measurement of the one or more measurements is above a first threshold; and performing, by the WTRU in the first operation mode, serving cell selection based on comparing the one or more measurements to a third threshold.

14. The method of claim 13, wherein at least one of the LP-WUS configuration or the LP-SS configuration indicates a set of common LP-WUS area identifiers (IDs).

15. The method of claim 14, further comprising: receiving, by the WTRU, a payload carrying one or more common LP-WUS area IDs associated with each of the one or more LP-SS sequences.FW 6000682PCT02 5416. The method of claim 15, further comprising: before the receiving the LP-WUS, determining, by the WTRU in the first operation mode, a first set of measurements from the one or more measurements above the third threshold; decoding, by the WTRU in the first operation mode, one or more payloads associated with the one or more LP-SS sequences based on the first set of measurements to determine a second set of common LP-WUS area IDs; and determining, by the WTRU in the first operation mode, a third set of common LP- WUS area IDs, the third set being an intersection of the first set and the second set, wherein the third set is not empty.

17. The method of claim 16, further comprising: measuring, by the WTRU in the first operation mode, second one or more LP-SS sequences based on the LP-SS configuration to determine second one or more measurements for the second one or more LP-SS sequences; determining, by the WTRU in the first operation mode, a fourth set of measurements from the second one or more measurements above the third threshold; decoding, by the WTRU in the first operation mode, second one or more payloads associated with the second one or more LP-SS sequences based on the fourth set of measurements to determine a fifth set of common LP-WUS area IDs; determining, by the WTRU in the first operation mode, a sixth set of common LP- WUS area IDs, the sixth set being a second intersection of the fourth set and the fifth set, wherein the sixth set is empty; performing, by the WTRU in a second operation mode, second serving cell selection; and receiving, by the WTRU in the second operation mode, system information from a second serving cell.

18. The method of claim 17, further comprising: receiving, by the WTRU in the first operation mode, the LP-WUS from the second serving cell.

19. The method of claim 17, wherein the receiving the LP-WUS is based on that the third set includes at least one common LP-WUS area ID.

20. The method of claim 19, the receiving the LP-WUS comprising: receiving, by the WTRU in the first operation mode, the LP-WUS from the first serving cell.

21. The method of claim 19, the receiving the LP-WUS further comprising: receiving, by the WTRU in the first operation mode, the LP-WUS from a thirdFW 6000682PCT02 55serving cell, wherein the at least one common LP-WUS area ID in the third set includes a third common LP-WUS area ID corresponding to the third serving cell.

22. The method of claim 21, further comprising: receiving, by the WTRU in the second operation mode, the system information from the third serving cell based on the receiving the LP-WUS.

23. The method of any of claims 18-22, further comprising: receiving, by the WTRU in the second operation mode, at least one of a paging DCI or a paging message in accordance to the LP-WUS; and transmitting, by the WTRU in the second operation mode to at least one of the first serving cell, the second serving cell, or the third serving cell, a physical random access channel (PRACH) preamble.

24. The method of claim 13, wherein the first operation mode corresponds to using a low-power wake-up radio (LP-WUR) of the WTRU, and wherein the WTRU in the first operation mode monitors an On-Off Keying (OOK) waveform with or without an overlaid orthogonal frequency division multiplexing (OFDM) sequence.

25. The method of claim 13, wherein a second operation mode corresponds to using a main radio (MR) of the WTRU, and wherein the WTRU in the second operation mode transmits or receives an OFDM signal or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) signal using a transmitter or a receiver of the MR, respectively.

26. A wireless transmit / receive unit (WTRU), comprising: at least one processor; and a non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the WTRU to perform a method according to any of claims 1-12.

27. A wireless transmit / receive unit (WTRU), comprising: at least one processor; and a non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the WTRU to perform a method according to any of claims 13-25.

28. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a wireless transmit / receive unit (WTRU), cause the WTRU to perform a method according to any of claims 1-12.FW 6000682PCT02 5629. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a wireless transmit / receive unit (WTRU), cause the WTRU to perform a method according to any of claims 13-25.

30. A method, comprising: transmitting, by at least one base station in a first serving cell to a wireless transmit / receive unit (WTRU), a first signal with a first type of waveform, the first signal carrying configuration information for receiving a second signal with a second type of waveform, wherein the configuration information indicates a first threshold and a second threshold less than the first threshold; and transmitting, by the at least one base station to the WTRU, a payload, the payload received by the WTRU in a mode determined based on comparing a measurement of the second signal to at least one of the first threshold or the second threshold.

31. The method of claim 30, wherein the measurement is above the first threshold, and the payload comprises a low-power wake-up signal (LP-WUS).

32. The method of claim 31, wherein the payload is received in a first operation mode of the WTRU, and the first operation mode corresponds to using a low-power wake-up radio (LP-WUR) of the WTRU operating with non-coherent detection to monitor the LP- WUS in accordance to the second type of waveform, and wherein the non-coherent detection includes envelope detection without using information about at least one overlaid orthogonal frequency division multiplexing (OFDM) sequence.

33. The method of claim 30, wherein the measurement is below the first threshold and above the second threshold, and the payload comprises an LP-WUS.

34. The method of claim 33, wherein the payload is received in a second operation mode of the WTRU, wherein the second operation mode corresponds to using a LP-WUR of the WTRU operating with coherent detection to monitor the LP-WUS in accordance to the second type of waveform, and wherein the coherent detection includes detection using information about at least one overlaid OFDM sequence.

35. The method of claim 30, wherein the measurement is below the second threshold, and the payload comprises at least one of a short message, a paging message, or a paging downlink control information (DCI).FW 6000682PCT02 5736. The method of claim 35, wherein the payload is received in a third operation mode of the WTRU, and the third operation mode corresponds to using a main radio (MR) of the WTRU to monitor the payload in accordance to the first type of waveform.

37. The method of claim 36, wherein the third operation mode further corresponds to using the MR for serving cell measurements based on at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

38. The method of any of claims 30-37, wherein the first type of waveform is an OFDM waveform or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) waveform, and the second type of waveform is an On-Off Keying (OOK) waveform with pulse shaping based on overlaid OFDM sequences.

39. The method of any of claims 31 and 33, further comprising: transmitting, by the at least one base station to the WTRU in a third operation mode, at least one of a paging DCI or a paging message with the first type of waveform in accordance to the LP-WUS; and receiving, by the at least one base station from the WTRU in the third operation mode, a physical random access channel (PRACH) preamble in accordance to the first type of waveform.

40. The method of claim 30, wherein the configuration information further indicates a time window, and the second signal is transmitted in the time window.

41. The method of claim 30, wherein the configuration information further indicates at least one overlaid OFDM sequence.

42. The method of claim 30, wherein the at least one base station includes two or more base stations.

43. A method, comprising: transmitting, by a base station in a first serving cell of a network system to a wireless transmit / receive unit (WTRU), a low-power wake-up signal (LP-WUS) configuration and a low-power synchronization signal (LP-SS) configuration; and transmitting, by the network system to the WTRU in a first operation mode, an LP-WUS, wherein the LP WUS is received by the WTRU based on that a first measurement of one or more measurements is above a first threshold, and wherein the WTRU in the first operation mode performs serving cell selection based on comparing the one or more measurements to a third threshold.FW 6000682PCT02 5844. The method of claim 43, wherein at least one of the LP-WUS configuration or the LP-SS configuration indicates a first set of common LP-WUS area identifiers (IDs).

45. The method of claim 44, further comprising: transmitting, by the network system to the WTRU, a payload carrying one or more common LP-WUS area IDs associated with each of one or more LP-SS sequences.

46. The method of claim 43, wherein a second base station in a second serving cell of the network system transmits the LP-WUS to the WTRU in the first operation mode.

47. The method of claim 43, wherein the base station in the first serving cell transmits the LP-WUS to the WTRU in the first operation mode.

48. The method of claim 43, wherein a third base station in a third serving cell of the network system transmits the LP-WUS to the WTRU in the first operation mode.

49. The method of claim 43, wherein a third base station in a third serving cell of the network system transmits system information to the WTRU in a second operation mode.

50. The method of claim 43, further comprising: transmitting, by the network system to the WTRU in a second operation mode, at least one of a paging DCI or a paging message in accordance to the LP-WUS; and receiving, by the network system from the WTRU in the second operation mode, a physical random access channel (PRACH) preamble.

51. The method of claim 43, wherein the first operation mode corresponds to using a low-power wake-up radio (LP-WUR) of the WTRU, and wherein the WTRU in the first operation mode monitors an On-Off Keying (OOK) waveform with or without an overlaid orthogonal frequency division multiplexing (OFDM) sequence.

52. The method of claim 43, wherein a second operation mode corresponds to using a main radio (MR) of the WTRU, and wherein the WTRU in the second operation mode transmits or receives an OFDM signal or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) signal using a transmitter or a receiver of the MR, respectively.

53. At at least one base station, comprising: at least one processor; and at least one non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the atFW 6000682PCT02 59least one processor, cause the at least one base station to perform a method according to any of claims 30-42.

54. A network system, comprising: at least one processor; and at least one non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the network system to perform a method according to any of claims 43-52.

55. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a base station, cause the base station to perform a method according to any of claims 30-42.

56. At least one non-transitory computer-readable medium having instructions stored thereon that, when executed by a network system, cause the network system to perform a method according to any of claims 43-52.FW 6000682PCT02 60

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