System and method for energy efficient operations with adaptive carrier and signaling

Abstract

In accordance with implementations, a UE receives from a first cell a first synchronization signal block (SSB). A transmission of a first system information block 1 (SIB1) carrying a first remaining minimum system information block (RMSI) is disabled. The UE receives from a second cell a second SSB or a second periodic SIB1 carrying a second RMSI and a resource configuration for transmitting an uplink wakeup signal (WUS) requesting the transmission of the first SIB1 carrying the first RMSI for the first cell.

Description

System and Method for Energy Efficient Operations with Adaptive Carrier and SignalingCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 554,799, filed on February 16, 2024 and entitled “System and Method for Energy Efficient Operations with Adaptive Carrier and Signaling,” U.S. Provisional Application No. 63 / 574,534, filed on April 4 and entitled “System and Method for Energy Efficient Operations with Adaptive Carrier and Signaling,” 2024, U.S. Provisional Application No. 63 / 703,037, filed on October 3, 2024 and entitled “System and Method for Energy- Efficient Operations with Adaptive Carrier and Signaling,” and U.S. Provisional Application No. 63 / 717,658, filed on November 7, 2024 and entitled “System and Method for Energy Efficient Operations with Adaptive Carrier and Signaling,” applications of which are incorporated herein by reference in their entireties.BACKGROUND

[0002] Wireless communication systems include long term evolution (LTE), LTE-A, LTE-A-beyond systems, 5G LTE, 5G New Radio (NR), etc. A modern wireless communication system may include a plurality of NodeBs (NBs), which may also be referred to as base stations, network nodes, communications controllers, cells, or enhanced NBs (eNBs), and so on. A NodeB may include one or more network points or network nodes using different radio access technologies (RATs), such as high speed packet access (HSPA) NBs or wireless fidelity (WiFi) access points. A NodeB may be associated with a single network point or multiple network- points. A cell may include a single network point or multiple network points, and each network point may have a single antenna or multiple antennas. A network point may correspond to multiple cells operating in multiple component carriers. Generally, each component carrier in carrier aggregation is a serving cell, either a primary cell (PCell) or a secondary cell (SCell).

[0003] A cell or NodeB may serve a number of users (also commonly referred to as User Equipment (UE), mobile stations, terminals, devices, and so forth) over a period of time. A communication channel from a NB to a UE is generally referred to as a downlink (DL) channel, and a transmission from the NB to the UE is a downlink transmission. A communication channel from a UE to a NB is generally referred to an uplink (UL) channel, and a transmission from the UE to the NB is an uplink transmission.

[0004] It is widely observed that SCell activation in the current new- radio (NR) systems is too slow (the SCell activation latency generally in the range of tens to hundreds of milliseconds). In many cases, the SCell activation latency in the current NRsystems is even longer than that of the LTE systems. So, it is desirable to improve the SCell activation latency for the NR systems and beyond.

[0005] The downlink (DL) waveform in 5G NR is conventional OFDM using a Cyclic Prefix (CP), while the uplink (UL) is conventional OFDM using a CP with a transform precoding function performing Discrete Fourier Transform (DFT) spreading. Downlink and uplink transmissions are organized into frames w ith to ms duration, consisting of ten 1 ms subframes. Each frame is divided into two equally sized half-frames of five subframes each. The slot duration is 14 symbols w ith Normal CP and 12 symbols w ith Extended CP, and scales in time as a function of the used sub-carrier spacing so that there is always an integer number of slots in a subframe.

[0006] For a receiver in the UE to be able to demodulate a DL transmission, it needs to be synchronized with the gNB (transmitter). Therefore, a UE needs to synchronize with the gNB numerology (frame, slots, and symbols). The synchronization is achieved in 5G NR via acquiring by a UE of the Synchronization Signal and PBCH block (SSB).SUMMARY

[0007] Technical advantages are generally achieved, by implementations of this disclosure which describe methods, apparatus, and system.

[0008] In accordance with implementations, a UE receives from a first cell a first synchronization signal block (SSB). A transmission of a first system information block 1 (SI Bl) cariying a first remaining minimum system information block (RMSI) is disabled. The UE receives from a second cell a second SSB or a second periodic SIB1 carrying a second RMSI and a resource configuration for transmitting an uplink wakeup signal (WUS) requesting the transmission of the first SIB1 cariying the first RMSI for the first cell.

[0009] In some implementations, the resource configuration for the uplink WUS may be in the second periodic SIBi or in another system information block (SIB) transmission from the second cell.

[0010] In some implementations, the second cell may indicate that the first cell provides an on-demand SIBi transmission cariying the first RMSI when the first cell receives the uplink WUS in accordance with a WUS resource configuration for transmitting an uplink WUS.

[0011] In some implementations, the second cell may indicate a time duration or time offset of the on-demand SIBi transmission from the first cell after the uplink WUS is received by the first cell.

[0012] In some implementations, resources in the resource configuration for transmitting the uplink WUS may include dedicated resources on a physical random access channel (PRACH) of the first or second cell and a dedicate PRACH preamble.

[0013] In some implementations, the UE may transmit the uplink WUS to the first cell using a PRACH resource in accordance with the resource configuration.

[0014] In some implementations, the UE may receive a random access response (RAR) from the first cell after transmitting the uplink WUS or receiving the transmission of the first SIB1 from the first cell during a RAR window or receiving both RAR and SIB1 during the RAR window.

[0015] In some implementations, the UE may monitor resources for on-demand SIB1 transmission carrying the first RMSI for the first cell. The resources may be indicated by a first master information block (MIB) in a first physical broadcast channel (PBCH) of the first cell for the transmission of the first SIB1 or by the second cell for a system information transmission.

[0016] In some implementations, the UE may camp on the first cell or establishes a radio resource control (RRC) connection to the first cell based on the first RMSI in the first SIB1.

[0017] In some implementations, the UE may receive from the first cell an indication indicating that the first cell receives WUS requests for SIB1 transmission or indicating periodic SIB1 transmissions without requests.

[0018] In some implementations, the UE may receive from the first cell an indication indicating when the first cell may start receiving WUS requests for SIBt transmission or indicating when periodic SI Bl transmissions without requests start.

[0019] In some implementations, the resource configuration may indicate a duration of configuration validity of the resource configuration.

[0020] In some implementations, the resource configuration may indicate an operation mode of the first cell when the configuration validity expires. The operation mode may indicate that the first cell receives WUS requests for SIBt transmission or may indicate periodic SIBt transmissions without requests.

[0021] In some implementations, the resource configuration may indicate a quality threshold of the first cell for which the resource configuration is valid.

[0022] In some implementations, the resource configuration may indicate a threshold of a difference between a quality of the first cell and a second quality of the second cell for which the resource configuration is valid.

[0023] In some implementations, the UE may receive from the first cell an indication of starting SIB1 transmissions on a periodic basis.

[0024] In some implementations, SSB transmission occasions may be indicated in RRC signaling.

[0025] In accordance with implementations, a UE receives system information. The system information indicates transmission parameters including periodicity information. The UE receives a synchronization signal block (SSB) using the transmission parameters.

[0026] In some implementations, the periodicity information may indicate a first periodicity and a second periodicity.

[0027] In some implementations, the periodicity information may indicate that the first periodicity is used for a cell discontinuous transmission (DTX) non-active period and that the second periodicity is used for a cell DTX active period.

[0028] In so doing, the techniques described in this disclosure proUde energyefficient solutions for network operations by introducing an on-demand system information transmission mechanism. Rather than maintaining constant periodic transmissions of SSB and S1B1, which consume significant power, the described techniques allow cells to operate in a power-saving mode where signals are transmitted when requested through an uplink WUS. This approach substantially reduces network energy consumption during low-traffic periods while maintaining system accessibility through coordination between cells. The described solutions significantly improve upon current by enabling faster activation through targeted, on-demand signal transmission while achieving better energy efficiency.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction w ith the accompanying drawings, in which:

[0030] FIG. 1A illustrates an example wireless communication system, in accordance with some implementations;

[0031] FIG. 1B illustrates an example use of carrier aggregation (CA), in accordance with some implementations;

[0032] FIG. 2A illustrates an example of SS bursts multiplexed with PBCH around the SS bursts, in accordance with some implementations;

[0033] FIG. 2B shows examples of signals / channels multiplexed for more than oneUE, in accordance with some implementations;

[0034] FIG-2C shows examples of NZP CSI-RS, in accordance with some implementations;

[0035] FIG. 3A shows QCL assumptions among NR reference signals when wide beams are used for communications, in accordance w ith some implementations;

[0036] FIG. 3B shows QCL assumptions among NR reference signals when narrow beams are used for communications, in accordance with some implementations;

[0037] FIG. 4 illustrates an example time-frequency structure of SSB, in accordance with some implementations;

[0038] FIG. 5 shows an example of SSB time distribution, in accordance with some implementations;

[0039] FIG. 6 shows an example of SSB time distribution, with 20 ms periodicity and SSB burst within 5 ms, in accordance with some implementations;

[0040] FIG. 7 shows the UE behavior in the Legacy Cell DTX, in accordance with some implementations;

[0041] FIG. 8 shows the legacy SCell activation based on e periodic SSB transmission, in accordance with some implementations;

[0042] FIG. 9 shows an example of SCell activation based on TRS, in accordance with some implementations;

[0043] FIGs. 10A and 10B illustrate example flows of SSB / SIB1 on demand, in accordance with some implementations;

[0044] FIG. 11 shows an example flow of SSB / SIB1 on demand, in accordance with some implementations;

[0045] FIG. 12 shows an example of the UE acquiring SIB1 from neighboring cells, in accordance with some implementations;

[0046] FIGs. 13A and 13B illustrate example flows of SIBi on demand, in accordance with some implementations;

[0047] FIG. 14 shows an example of the UE acquiring SSB / SIBt, in accordance with some implementations;

[0048] FIG. 15 shows an example of the UE acquiring SSB / S1B1, in accordance with some implementations;

[0049] FIG. 16 shows operations for an example scenario, in accordance with some implementations;

[0050] FIG. 17 shows operations for an example scenario, in accordance with some implementations;

[0051] FIG. 18 shows operations for an example scenario, in accordance with some implementations;

[0052] FIG. 19A illustrates example distributions of time resources for legacy and additional PRACH resource configurations, in accordance with some implementations;

[0053] FIG. 19B illustrates example distributions of time resources for legacy and additional SSB transmissions, in accordance w ith some implementations;

[0054] FIG. 20 show's an example of additional NES PRACH resources access, in accordance with some implementations;

[0055] FIG. 21 shows an example of specific NES PRACH resources access, in accordance with some implementations;

[0056] FIG. 22 illustrates an example flow' of on-demand SIB1, in accordance with some implementations;

[0057] FIG. 23 shows an example of the UL WUS received at the gNB followed by an RAR and the on-demand SIB1, in accordance with some implementations;

[0058] FIG. 24 shows an example of the reference time for starting time, in accordance with some implementations;

[0059] FIG. 25 illustrates an example of alternative periodic and on-demand SIBi transmissions, in accordance with some implementations;

[0060] FIG. 26 illustrates an example of signaling the UL WUS configuration validity, in accordance with some implementations;

[0061] FIG. 27 illustrates an example of signaling the UL WUS configuration validity, in accordance with some implementations;

[0062] FIG. 28 illustrates an example of a NES Cell providing the UL WUS configuration for a neighboring cell, in accordance with some implementations;

[0063] FIG. 29 illustrates an example of a NES Cell providing the UL WUS configuration for a neighboring cell, in accordance with some implementations;

[0064] FIG. 30A shows a flow chart of a method performed by a UE, in accordance with some implementations;

[0065] FIG. 30B shows a flow chart of a method performed by a UE, in accordance with some implementations;[oo66] FIG. 31 illustrates an example communication system, in accordance with some implementations;

[0067] FIGs. 32 A and 32B illustrate example devices, in accordance with some implementations; and

[0068] FIG. 33 shows a block diagram of a computing system, in accordance with some implementations.

[0069] 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

[0070] FIG. 1A illustrates an example wireless communication system too. Communication system too includes a base station 110 with coverage area 101. The base station 110 senes a plurality of user equipments (UEs), including UEs 120.Transmissions from the base station no to a UE is referred to as a downlink (DL) transmission and occurs over a downlink channel (shown in FIG. 1A as a solid arrowed line 135), while transmissions from a UE to the base station no is referred to as an uplink (UL) transmission and occurs over an uplink channel (shown in FIG. 1A as a dashed arrowed line 130). Data carried over the uplink / downlink connections may include data communicated between the UEs 120, as well as data communicated to / from a remote-end (not shown) by way of a backhaul network 115. Example downlink channels and signals include synchronization signal (SS) blocks, also called SS / physical broadcast channel (PBCH) block SS / PBCH block (SSB), physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), channel state information reference signal (CSI-RS) which includes tracking RS (TRS, aka CSI-RS for tracking), etc. Example uplink channels and signals include physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), an uplink sounding reference signal (SRS), or physical random access channel (PRACH). The transmissions may be periodic, semi- persistent, or aperiodic. For example, P TRS stands for periodic TRS, AP TRS stands for aperiodic TRS, SP CSI-RS stands for semi-persistent CSI-RS, P SSB / SP SSB / AP SSB stand for periodic / semi-persistent / aperiodic SSB, and so on. Sendees may be provided to the plurality of UEs by service providers connected to the base station 110 through the backhaul network 115, such as the Internet. The w reless communication system too may include multiple distributed access nodes 110.

[0071] In a typical communication system, there are several operating modes. In a cellular operating mode, communications to and from the plurality of UEs go through thebase station no, while in device to device communications mode, such as proximity sendees (ProSe) operating mode, for example, direct communication between UEs is possible. As used herein, the term “base station” refers to any component (or collection of components) configured to provide wireless access to a network. Base stations 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, access nodes, access points (APs), transmission points (TPs), transmission-reception points (TRPs), cells, carriers, macro cells, femtocells, pico cells, relays, customer premises equipment (CPE), the network side, the network, and so on. In the present disclosure, the terms “base station” and “TRP” are used interchangeably unless otherwise specified. As used herein, the term “UE” refers to any component (or collection of components) capable of establishing a wireless connection with a base station. UEs may also be commonly referred to as mobile stations, mobile devices, mobiles, terminals, user terminals, users, subscribers, stations, communication devices, CPEs, relays, Integrated Access and Backhaul (IAB) relays, and the like. It is noted that when relaying is used (based on relays, picos, CPEs, and so on), especially multi-hop relaying, the boundary between a controller and a node controlled by the controller may become blurry, and a dual node (e.g., either the controller or the node controlled by the controller) deployment where a first node that provides configuration or control information to a second node is considered to be the controller. Likewise, the concept of UL and DL transmissions can be extended as well.

[0072] A cell may include one or more bandwidth parts (BWPs) for UL or DL allocated for a UE. Each BWP may have its own BWP-specific numerology and configuration, such as the BWP’s bandwidth. It is noted that not all BWPs need to be active at the same time for the UE. A cell may correspond to one carrier, and in some cases, multiple carriers. Typically, one cell (a primary cell (PCell) or a secondary cell (SCell), for example) is a component carrier (a primary component carrier (PCC) or a secondary’ CC (SCO), for example). For some cells, each cell may include multiple carriers in UL, one carrier may be referred to as an UL carrier or non-supplementary UL (non- SUL, or simply UL) carrier w hich has an associated DL, and other carriers are called supplementary UL (SUL) carriers which do not have an associated DL. A cell, or a carrier, may be configured with slot or subframe formats comprising DL and UL symbols, and that cell or carrier may be seen as operating in a time division duplexed (TDD) mode. In general, for unpaired spectrum, the cells or carriers are in TDD mode, and for paired spectrum, the cells or carrier are in a frequency division duplexed (FDD) mode. A transmission time interval (TTI) generally corresponds to a subframe (in LTE) or a slot(in NR). Access nodes may provide w reless access in accordance with one or more wireless communication protocols, e.g., long term evolution (LTE), LTE advanced (LTE- A), 5G, 5G LTE, 5G NR, future 5G NR releases, 6G, High Speed Packet Access (HSPA), Wi-Fi 802.na / b / g / n / ac, etc. While it is understood that communication systems mayemploy multiple access nodes (or base stations) capable of communicating with a number of UEs, only one access node, and two UEs are illustrated in FIG. 1 for simplicity.

[0073] A w ay to increase the network resources is to utilize more usable spectrum resources, which include not only the licensed spectrum resources of the same type as the macro, but also the licensed spectrum resources of different type as the macro (e.g., the macro is an FDD cell but a small cell may use both FDD and TDD carriers), as well as unlicensed spectrum resources and shared-licensed spectrums. Some of the spectrum resources lie in high-frequency bands, such as 6GHz to 60GHz. The unlicensed spectrums may be used by generally any user, subject to regulatoiy- requirements. The shared-licensed spectrums are also not exclusive for an operator to use. Traditionally, the unlicensed spectrums are not used by cellular networks because it is generally difficult to ensure quality of sendee (QoS) requirements. Operating on the unlicensed spectrums mainly includes wireless local area networks (WLAN), e.g., the Wi-Fi networks. Due to the fact that the licensed spectrum is generally scarce and expensive, utilizing the unlicensed spectrum by the cellular operator may be considered. Note that on high- frequency bands and unlicensed / shared-licensed bands, typically TDD is used and hence the channel reciprocity can be exploited for the communications.

[0074] In a realistic deployment, a gNB may control one or more cells. Multiple remote radio units may be connected to the same base band unit of the gNB by fiber cable, and the latency between base band unit and remote radio unit is quite small. Therefore, the same base band unit can process the coordinated transmission / reception of multiple cells. For example, the gNB may coordinate the transmissions of multiple cells to a UE, w hich is called coordinated multiple point (CoMP) or multi-TRP (mTRP, M-TRP) transmission. The gNB may also coordinate the reception of multiple cells from a UE, which is called CoMP / M-TRP reception. In this case, the backhaul link between these cells with the same gNB is fast backhaul and the scheduling of data transmitted in different cells for the UE can be easily coordinated in the same gNB. The backhaul connections may also be ones with longer latency and lower transmission rates.

[0075] FIG. 1B illustrates the use of carrier aggregation (CA), which is another deployment strategy. As shown in FIG. 1B, system 150 is a typical wireless network configured with carrier aggregation (CA) where communications controller 160 communicates to wireless device 165 using wireless link 170 (solid line) and to wirelessdevice 166 using wireless link 172 (dashed line) and using wireless link 170, respectively. In some example deployments, for wireless device 166, wireless link 170 can be called a primary component carrier (PCC) while wireless link 172 can be called a secondary component carrier (SCC). In some carrier aggregation deployments, the PCC can cariy feedback from a UE device to a communications controller while the SCC can only cariy data traffic. In the 3GPP specifications, a component carrier is called a cell. When multiple cells are controlled by a same eNB, cross scheduling of multiple cells can be implemented because there may be a single scheduler in the same eNB to schedule the multiple cells. With CA, one eNB may operate and control several component carriers forming primary cell (PCell) and secondary cell (SCell).

[0076] Physical layer channels and signals include PSS / SSS, PBCH and its associated demodulation reference signal (DMRS) (see e.g., FIG. 2A, in which the SS bursts are multiplexed with PBCH around the SS bursts), PDSCH and its associated DMRS and phase tracking reference signal (PT-RS), PDCCH and its associated DMRS (see e.g., FIG. 2B for some of these signals / channels w hich are multiplexed for more than one UE), and CSI-RS which further include those used, for CSI acquisition, for beam management, and for tracking (see FIG. 2C for some examples of non-zero powder (NZP) CSI-RS used for channel estimation, interference measurement, and so on, which are multiplexed with PDSCH and for one or more UEs). The CSI-RS for tracking is also called TRS.

[0077] The UE receives timing advance (TA) commands associated with the configured TA group (TAG) to adjust its uplink transmission timing to synchronize w ith the network for uplink transmission so that uplink transmissions from multiple UEs arrive at the base station at about the same time in a transmission time interval (TTI). Likew ise, the UE needs to receive DL reference signals (RS) or synchronization signal (SS) blocks, also called SS / physical broadcast channel (PBCH) block SS / PBCH block (SSB) to acquire and maintain the DL synchronization, such as via maintaining a DL timing tracking loop, based on w hich the UE places the start of its FFT window^ inside the cyclic prefix (CP) for its DL reception. In addition, both UL and DL signals / channels are to be associated with some other signals for deriving the signal / channel properties, such as delay spread, Doppler shift, etc.

[0078] In wireless communications operations, tracking functionalities performed by a UE may include fine time tracking, fine frequency tracking, delay spread estimation, and Doppler spread estimation.

[0079] In fine time tracking, a UE may detect the first arriving path, and based thereon, the UE may generally optimally place its Fast Fourier transform (FFT) window to maximize a data signal to noise plus inter-symbol interference ratio. In a continuousoperation, an FFT window position may drift due to UE mobility and a residual oscillator error between a transmitter and a receiver. The UE may adjust its FFT window position based on a detected change of path arriving (or arrival) time.

[0080] In fine frequency tracking, a UE may detect a frequency offset between a transmitter and a receiver, and adjust its oscillator accordingly. A residual frequency error may be estimated and compensated in the demodulation of data symbols. The residual frequency error compensation may be veiy critical, especially in the case of high signal-to-noise ratio (SNR) and high code rate data transmissions. Uncompensated frequency error may impose phase error on modulated data symbols and result in decoding performance degradation. Because temperature change affects output precision of an oscillator and Doppler shift caused by UE movement, a UE may periodically track the frequency offset and apply corresponding adjustment and compensation.

[0081] Delay spread determines how dispersive a wireless multi-path channel that a UE experiences is. The longer the delay spread, the more frequency selective the channel is. To generally maximize processing gains along the frequency domain in channel estimation based on received pilot signals, the UE may apply linear filtering with a length as long as possible if within the coherent bandwidth of the channel. Coherent bandwidth is inversely proportion to channel selectiveness. Thus, delay spread estimation plays an important role in forming channel estimation filter coefficients and length, hence affecting the performance of channel estimation and data demodulation.

[0082] Doppler spread is usually proportional to UE movement speeds and multipath spatial distribution. Larger Doppler spread corresponds to a faster changing wireless multi-path fading channel. Channel estimation usually applies filtering in the time domain with longer filter length to suppress noise plus interference if within the channel coherent time constraint. Doppler spread estimation is thus another factor along the time domain affecting UE channel estimation performance.

[0083] The quasi co-location (QCL) types corresponding to each DL RS (more specifically, the port(s) or antenna port(s) of the DL RS) are given by the higher layer parameter q cl -Type in QCL-Info and may take one of the following values: 1) 'QCL- TypeA': {Doppler shift, Doppler spread, average delay, delay spread}; 2) 'QCL-TypeB': {Doppler shift, Doppler spread}; 3) 'QCL-TypeC: {Doppler shift, average delay}; and 4) 'QCL-TypeD': {Spatial Rx parameter}. The QCL types maybe configured / indicated in transmission configuration indication (TCI) states for a RS. The QCL assumptions are mainly used for DL RS, but can be generalized for UL RS if the association via pathloss RS and spatial relation are specified. The QCL assumption may be specified as: {RS1: QCL Type C to RS2}, {RS1: QCL Type C to RS2 and QCL Type D to RS3}. Then, RS1(destination RS) derives the properties specified according to the QCL types from the associated (i.e., source) RSs (e.g., RS2). The source RS may be an SSB. Note also that the source RS and destination RS may be on the same carrier or different carriers (i.e., crosscarrier QCL).

[0084] FIG. 3A is a diagram 300 showing QCL assumptions among NR reference signals when w ide beams are used for communications. For example, a TRS, a SS block or a broadcast DMRS may be transmitted using a w ide beam. FIG. 3A shows QCL configurations among a SS block 302, a DMRS 304, a CSI-RS 306, a TRS 308, a CSI-RS 310 and a DMRS 312. The DMRS 304 is for a broadcast channel. That is, the DMRS 304 is a DMRS used for demodulation of a system information block (SIB), radio resource control (RRC) signaling, paging, and etc. before a TRS is configured. The CSI-RS 306 is transmitted for beam forming. The CSI-RS 310 is transmitted for channel estimation. The DMRS 312 is used for demodulation of signals transmitted in a unicast channel. An arrow starting from a first reference signal (e.g., the SS block 302) and ending at a second reference signal (e.g., the DMRS 304) indicates that the second reference signal has a QCL relationship w ith the first reference signal with respect to one or more QCL parameters. The one or more QCL parameters (e.g., an average delay, a Doppler shift, a delay spread, and a spatial RX) are show n on the arrow7, indicating that the one or more QCL parameters required by the second reference signal may be derived using the first reference signal.

[0085] As shown, the DMRS 304 is configured to have a QCL relationship with the SS block 302. The average delay, Doppler shift, delay spread, and spatial RX for the DMRS 304 may be derived based on the SS block 302. Similarly, the CSI-RS 306 and the TRS 308 has a QCL relationship with the SS block 302, respectively. An average delay, a Doppler shift, and a coarse spatial RX required by the CSI-RS 306 may be derived based on the SS block 302. An average delay, a Doppler shift, and a spatial RX required by the TRS 308 may be derived from the SS block 302. The CSI-RS 310 has a QCL relationship with the CSI-RS 306 and the TRS 308, respectively. The CSI-RS 310 may be received using a spatial RX derived based on the CSI-RS 306, and use an average delay, a Doppler shift, and a delay spread from the TRS 308. The DMRS 312 has a QCL relationship with the TRS 308 and the CSI-RS 310, respectively. The DMRS 312 may be received using a spatial RX derived based on the CSI-RS 310. The DMRS 312 may also be received an average delay, a Doppler shift, a Doppler spread and a delay spread derived based on the TRS 308.

[0086] FIG. 3B is a diagram 350 showing QCL assumptions among NR reference signals when narrow beams are used for communications. FIG. 3B shows QCLconfigurations among a SS block 352, a DMRS 354, a CSI-RS 356, a TRS 358, a CSI-RS 360 and a DMRS 362. Similar to FIG. 3A, the DMRS 354 is for demodulation of signals in a broadcast channel, e.g., a physical broadcast channel (PBCH), that is transmitted before a TRS is configured. The CSI-RS 356 is transmitted for beam forming. The CSI-RS 360 is transmitted for channel estimation. The DMRS 362 is used for demodulation of signals transmitted in a unicast channel. An arrow starting from a first reference signal and ending at a second reference signal indicates that the second reference signal has a QCL relationship w ith the first reference signal with respect to one or more QCL parameters. The one or more QCL parameters show n on the arrow indicate that the one or more QCL parameters required by the second reference signal may be derived using the first reference signal. FIG. 3B shows that the reference signals have QCL configurations similar to those illustrated in FIG. 3A, except for TRSs. In FIG. 3B, the TRS 358 has a QCL relationship with the SS block 352 and the CSI-RS 356, respectively. The TRS 358 may be received using a Doppler shift derived based on the SS block 352, and may be received using an average delay and a spatial RX derived based on the CSI- RS 356. Data transmission may employ multiple narrow beams, and multiple narrow TRS beams may be required for tracking. To support both of the scenarios, configuration of TRSs and their QCL assumptions or association should be flexible.

[0087] The SSB consists of primary (PSS) and secondary (SSS) synchronization signals each occupying 1 symbol and 127 subcarriers, and the physical broadcast channel (PBCH) spanning across 3 OFDM symbols and 240 subcarriers, but on one symbol leaving an unused part in the middle for SSS, as shown in FIG. 4. For the 3 MHz channel bandwidth, the PBCH is further equally punctured from both edges to span 144 subcarriers. The possible time locations of SSBs within a half-frame are determined by sub-carrier spacing and the periodicity7of the half-frames where SSBs are transmitted is configured by7the network. During a half-frame, different SSBs may7be transmitted in different spatial directions (i.e., using different beams, spanning the coverage area of a cell).

[0088] When an SSB is associated with a remaining minimum system information (RMSI) signaling, the SSB is referred to as a cell-defining SSB (CD-SSB). A primary cell (PCell)) is always associated to a CD-SSB located on the synchronization raster. When an SSB is not associated with an RMSI, the SSB is referred to as a non-cell defining SSB (NCD-SSB), which can be used to perform radio link monitoring (RLM), bidirectional forwarding detection (BFD), and radio resource management (RRM) measurements and measurements for random access (RA) resource selection inside the active DL BWP w hen the active BWP does not contain the CD-SSB.

[0089] The PBCH carries master information block (MIB) information, which provides the UE with parameters (e.g., control resource set (CORESET) #0 configuration) for monitoring of PDCCH for scheduling PDSCH that carries the system information block 1 (SIBi). PBCH may also indicate that there is no associated SIBi (via ssb- SubcarrierOffset field), in which case the UE may be pointed to another frequency from where to search for an SSB that is associated with a SIBi as well as a frequency range where the UE may assume no SSB associated with SIBi is present. In addition, the MIB carries cellBarred data field, w hich is used by UEs to decide w hether to select this cell or reselect another cell.

[0090] Upon receiving SIBi, a UE obtains some other system information (such as frequencyBandList, tracking AreaCode, trackingAreaList, serving CellConfig Common, etc.). Other information like cellBarredNES indicates that cell is allowed for UE supporting NES Cell DTX / DRX. ServingCellConfigCommon carries information about the physical CelllD, dow nlink configuration common, uplink configuration common, SSB position in a burst, SSB periodicity, etc.).

[0091] SIBi may also include si-Schedulinglnfo containing si-RequestConfig, which may be used to initiate the Random Access procedure on normal uplink in accordance with TS 38.321 using the PRACH preamble(s) and PRACH resource(s) in si- RequestConfig corresponding to the SI message(s) that the UE requires to operate within the cell, and for which si-BroadcastStatus is set to notBroadcasting. Thus, a UE may request the system information corresponding to SIBx, where x=2, 3, ..., 19.

[0092] The gNB may provide the requested SI corresponding to SIB2-SIB19 in multiple ways depending on the UE RRC state.

[0093] For UEs in the RRC CONNECTED state, the gNB may provide SI using downlink control information (DCI) Format i_o with a cyclic redundancy check (CRC) scrambled with the Si-radio network temporary identifier (RNTI) (SI-RNTI). The SI- RNTI is the identification of broadcast and system Information in the downlink. This PDCCH message contains the field system information indicator that indicates whether the system message carried by PDSCH and signaled by this DCI corresponds to SIBi or other SIBx. The DCI i_o scrambled with SI-RNTI also indicates the time, frequency, MCS for the PDSCH that carries SIB information. In addition, it has at least 15 reserved bits.

[0094] For UEs in the RRC INACTIVE or IDLE state, the gNB may provide information via paging. A Short Message (8 bits) may be carried in DCI Format 1_O with a CRC scrambled by the paging RNTI (P-RNTI). P-RNTI is the identification of pagingand system information change notification in the downlink. Repetitions of SI change indication may occur within preceding modification period or within preceding extended discontinuous reception (eDRX) acquisition period. SI change indication is not applicable for SI messages containing posSIBs.

[0095] A cell defining SSB (an SSB with an RMSI associated information) provides or is used for cell (re-)selection and initial access w ith synchronization in time and frequency, frame timing, physical cell identity (PCI), system frame number (SFN), subcarrier spacing (SCS), initial BWP, CORESET# 0 information, SIB1 related information, cell barring status, PRACH occasions, downlink CSI energy per resource element (EPRE) and RRM measurements (including signal strength, QCL related information).

[0096] PSS together with SSS provides cell ID, and symbol synchronization. PBCH via MIB’s associated DMRS provides the least significant bits (LSB) of the SSB index (via DMRS sequence and respectively PBCH payload). The SSB index is used for RRM, CSI- RS measurements to assess link quality, and for the link recovery procedures.

[0097] In the case when SSB is not associated with an RMSI, PBCH indicates that there is no associated SIBi, in which case the UE may be pointed to another frequency from where to search for an SSB that is associated with a SIBi as well as a frequency range where the UE may assume no SSB associated with SIBi is present.

[0098] As specified in TS 38.213, Clause 4.1, for a half frame with SS / PBCH blocks, the first symbol indexes for candidate SS / PBCH blocks are determined according to the SCS of SS / PBCH blocks, where index 0 corresponds to the first symbol of the first slot in a half-frame.

[0099] For instance, for 15kHz SCS there are 4 SSB transmissions in a half-frame for carrier frequencies smaller than or equal to 3 GHz (symbol indexes of {2,8} + 14 • n, n = 0,1), and 8 SSB transmissions (n = 0,1, 2, 3) for carrier frequencies larger than 3GHz, as shown in FIG. 5.

[0100] For the initial cell selection, a UE may assume that half frames with SS / PBCH blocks occur with a periodicity of 2 frames. Thus, the SSB burst is confined in a 5 ms window with a typical periodicity of 20 ms, as shown in FIG. 6, which can be increased up to 160 ms.

[0101] A UE can be provided with a periodicity of the half frames for reception of theSS / PBCH blocks for the serving cell per serving cell by ssb-periodicity Serving Cell as a part of the IE servingCellConfigCommon. The IE contains parameters which a UE wouldtypically acquire from SSB, MIB, or SIBs when accessing the cell from the RRC IDLE state.

[0102] System Information (SI) is the information delivered to the UE, which is necessary' for the UE to operate. SI can be delivered via broadcast and unicast, and SI can be divided into three types of information: MIB, SIB1, and other SI.

[0103] Master Information Block (MIB) contains basic cell configuration and information necessary to acquire SIB1.

[0104] System Information Block r (SIB1) contains information about other SI available in the cell (Remaining Minimum SI - RMSI), information necessary’ for UE to decide whether it may access the cell, and information required to perform mobility procedures in the RRC IDLE mode (cell physical layer configuration, including random access related configuration as well as indication of the transmitted SS / PBCH blocks (SSB)). In order to enable UE to monitor for the PDCCH scheduling PDSCH carrying the SIB1, MIB provides the necessary configuration (jjdcch-ConfigSIB ) and the numerology of the broadcast subCamer SpacingCommon'). Search space defining the time domain for PDCCH monitoring is provided by pdcch-ConfigSIBi.

[0105] The search space configuration for PDCCH monitoring occasions for SIB1 scheduling provided by MIB is called Typeo-PDCCH Common search space (CSS). The CORESET determining the physical resources of the PDCCH scheduling SIBr is called Typeo-PDCCH CORESET.

[0106] There are additional SIBs (from SIB2 onwards) can be delivered through broadcast or “on-demand” manner. The procedure “on-demand” triggers the network to initiate the broadcast of requested System Information messages. The UE is configured with a SI window, where the UE can monitor the PDCCH scheduling the SI message. For each entry of the SI message list scheduling Inf oList), there a time window duration (si- WindowLength) that occurs with a configured periodicity (si-Periodicitij).

[0107] Random access preambles can only be transmitted in the time occasions obtained from Tables 6.3.3.2-2 to 6.3-3.2-4 (TS 38.211) and depend on FRi or FR2 and the spectrum type. The configuration index in these tables is given by the higher layer parameter prach-Configurationlndex, or by msgA-PRACH-Configurationlndex if configured.

[0108] PRACH slots have periodicities from 10 ms up to 160 ms from Table 6.3.3.2-3 (FRi) and Table 6.3-3.2-4 (FR2), (TS 38.211).[01091 The PRACH slots are in the index frame given by the formula nfmod x = y, (TS 38.212, Clause 6.3.3.21, where x is the configuration period {1,2,4,8,16}. The PRACH slots are in a subframe (indicated by the Subframe number) while the number of slots is indicated by the Number of PRACH slots within a subframe (none, one or two). For instance, in Table 6.3.3.2-3, if PRACH configuration 76 is selected, the period x=2, i.e. 20 ms, thus in the odd frames, one PRACH slot will be in each of the subframes 2, 3, 4, 7, 8, 9.

[0110] In the above tables for FR2, the column of the subframe number is replaced with the column of slot number, w here a slot duration corresponds to 60 kHz SCS.

[0111] The UE can monitor the Paging Occasions (POs) as described in clause 7.1 ofTS 38.304 to receive System Information change notifications in the RRC_IDLE state and the RRC_ INACTIVE. The changes in the system information are notified by the network using a Short Message as specified in TS 38.331. When the Short Message notifies system information changes, the UE can acquire or re-acquire the concerned system information as specified in TS 38.331.

[0112] The paging procedure is used to transmit information to a UE in the RRC_IDLE or RRC_INACTIVE state (TS 38.331, Clause 5.3.2). The UE may use Discontinuous Reception (DRX) in RRC_IDLE and RRC_INACTIVE state to reduce power consumption. The UE monitors one paging occasion (PO) per DRX cycle.

[0113] The network initiates the paging procedure by transmitting the Paging message at the UE's paging occasion as specified in TS 38.304. The network may address multiple UEs within a Paging message by including one PagingRecord for each UE. The network may also include one or multiple temporary mobile group identities (TMGIs) in the Paging message to page UEs for specific MBS multicast session(s).

[0114] For each SSB there are several paging occasions nrofPDCCH- MonitormgOccasionPerSSB-InPO').

[0115] The number of PDCCH monitoring occasions corresponding to an SSB within a Paging Occasion (PO) is specified in TS 38.304, clause 7.1.

[0116] The maximum number of paging occasions per paging frame is 4. One Paging Frame (PF) is one Radio Frame and may contain one or multiple POs or the starting point of a PO.

[0117] The PF and PO for paging are determined by the following formulae:

[0118] SFN for the PF is determined by:(SFN + PF_offset) mod T = (T div N)*(UE_ID mod N)

[0119] Index (i_s), indicating the index of the PO, is determined by:i_s = floor (UE_ID / N) mod Ns

[0120] where T = DRX cycle of UE. If UE does not operate in the DRX (eDRX) mode, T is determined by the shortest of the UE specific DRX value (s), if configured by RRC and / or upper layers, and a default DRX value broadcast in the system information.

[0121] N : number of total paging frames in T

[0122] Ns: number of paging occasions for a PF

[0123] PF_offset: offset used for PF determination

[0124] UE_ID:

[0125] If the UE operates in eDRX as specified in clause 7.4 :5G-S-TMSI mod 4096

[0126] else:5G-S-TMSI mod 1024

[0127] Parameters Ns, nAndPagingFrameOffset, nrofPDCCH- MonitoringOccasionPerSSB-InPO, and the length of default DRX Cycle are signaled in SIBt. The values of N and PF_offset are derived from the parameter nAndPagingFrameOffset as defined in TS 38.331. The parameter firstPDCCH- MonitoringOccasionOfPO is signaled in SIBt for paging in the BWP configured by initialDownlinkBWP. For paging in a DL BWP other than the BWP configured by initialDownlinkBWP, the parameter first-PDCCH-MonitoringOccasionOJPO is signaled in the corresponding BWP configuration.

[0128] The values for paging cycle period (T) are defined in TS 38.331:

[0129] PagingCycle ::= ENUMERATED {rf32, rf64, rfi28, rf256}

[0130] In Rel-17, more values were added:

[0131] ExtendedPagingCycle-ri7 ::= ENUMERATED {rf256, rf5i2, rfiO24, spare }, which allows extending the period up to 1024 frames =10.240 s duration

[0132] As described in TS 38.300, to facilitate reducing gNB downlink transmission / uplink reception active time, a UE can be configured with a periodic cell DTX / DRX pattern (i.e. active and non-active periods).

[0133] The pattern configuration for cell DTX / DRX is common for the UEs configured with this feature in the cell. The cell DTX and cell DRX patterns can be configured and activated separately. A maximum of two cell DTX / DRX patterns can be configured per MAC entity for different serving cells. When the cell DTX is configuredand activated for the concerned cell, the UE may not monitor PDCCH in selected cases or does not monitor SPS occasions during cell DTX non-active duration.

[0134] When the cell DRX is configured and activated for the concerned cell, the UE does not transmit on configured grant (CG) resources or does not transmit a scheduling request (SR) during cell DRX non-active duration. This feature is only applicable to UEs in the RRC_CONNECTED state, and this feature does not impact Random Access procedure, SSB transmission, paging, and system information broadcasting. Cell DTX / DRX can be activated / deactivated by RRC signaling or Li group common signaling. Cell DTX / DRX is characterized by the following:

[0135] active duration: duration that the UE waits for to receive PDCCHs or semi- persistent scheduling (SPS) occasions, and transmit SR or CG. In this duration, the gNB transmission / reception of PDCCH, SPS, SR, CG, periodic and semi-persistent CS1 report are not impacted for the purpose of network energy saving;

[0136] cycle: specifies the periodic repetition of the active-duration followed by a period of non-active duration.

[0137] Active duration and cycle parameters are common between cell DTX and cell DRX, when both are configured,

[0138] Once the gNB recognizes there is an emergency call or public safety related service (e.g., multimedia priority service (MPS) or mission critical service (MCS)), the network should ensure that there is no impact to that service (e.g. it may release or deactivate cell DTX / DRX configuration). The network should also ensure that there is at least partial overlapping between UE's connected mode DRX on-duration and cell DTX / DRX active duration, i.e. the UE’s connected mode DRX periodicity is a multiple of cell DTX / DRX periodicity or vice versa. The active duration is also known as the active period or active time. These terms are used interchangeably.

[0139] FIG. 7 shows the UE behavior in the Legacy Cell DTX, in accordance with some implementations.

[0140] Network adaptation, or adaptive transmission, has been studied in 3GPP, such as cell on / off, fast SCell activation / deactivation, SCell layer-i dormancy, etc., to achieve efficient network adaptation for various purposes, such as network / UE power saving, interference management, network / UE complexity7reduction, and so on. It is observed that NR Rel-15 SCell activation latency is generally in the range of tens to hundreds of milliseconds, which is even longer than LTE for many cases. The large latency in activating an SCell is primarily dominated by the time gap associated with the SSB measurement timing configuration (SMTC), which configures the UE to monitor andprocess SSB ty pically once every tens of milliseconds. Based on SSB, the UE can gain necessary7information to set its automatic gain control (AGC), acquire timing, and perform frequency synchronization. In contrast, in LTE SCell activation, these operations are based on the always-on cell -specific reference signal (CRS) (e.g., periodic CRSs with short intervals in between) and hence may be completed faster.

[0141] FIG. 8 shows the legacy SCell activation based on e periodic SSB transmission, in accordance with some implementations;

[0142] When the SCell is deactivated, its periodic (P) SSB may be turned off for long. However, this leads to slow activation.

[0143] FIG. 9 shows an example of SCell activation based on aperiodic tracking reference signal (TRS), in accordance with some implementations;

[0144] For Rel-17 SCell activation, the P SSB may' be turned off after deactivation. However, to enable fast activation via aperiodic (AP) tracking reference signal (TRS), the SCell has to be remain known to the UE, i.e., it can only be turned off for a short period.

[0145] The Work Item for Network Energy Savings was completed in RAN1#114 fulfilling its stated objectives. These completed objectives were a subset of the recommendations (TR 38.864) from the Study Item that were presented in December 2022 at RAN#98. In RAN#ioi, companies were quite unanimous in their support for a new WI in Rel-19 for further enhancements of network energy savings. In RAN#1O2, a new Work Item Description (WID) was agreed for NES Rel-19. The objectives of the work item are the following:

[0146] 1. Specify procedures and signaling method(s) to support on-demand SSBSCell operation for UEs in connected mode configured with CA, for both intra- / interband CA. (RAN1 / 2 / 3 / 4):- Specify triggering method(s) (select from the UE uplink wake-up-signal using an existing signal / channel, cell on / off indication via backhaul, SCell activation / deactivation signaling)- Notei: On-demand SSB transmission can be used by UE for at least SCell time / frequency synchronization, L1 / L3 measurements and SCell activation, and is supported for FR1 and FR2 in non-shared spectrum.

[0147] 2. Study' procedures and signaling method(s) to support on-demand SIBi forUEs in idle / inactive mode, including: (RAN1 / 2 / 3)- Triggering method by uplink wake-up-signal using an existing signal / channel.- Wake-up-signal configuration provisioning to UE- - Note: No modification of SSB will be discussed under this objective- Information exchange between gNBs at least for the configuration of wakeup signal, if necessary.- Checkpoint for normative work in RAN# 105

[0148] 3. Specify adaptation of common signal / channel transmissions.(RANl / 2 / 3 / 4)- Adaptation of SSB in the time domain, e.g. adapting periodicity- Adaptation of PRACH in the time domain- Study adaptation of PRACH in the spatial domain, e.g. non-uniform PRACH resources per SSB, and specify if found beneficial- Adaptation of paging occasions including confining the paging occasions in the time domain- - Note: there shall be no paging latency increase- Note: there shall be no negative impact to legacy UEs, unless significant benefits are shown.

[0149] The technical problem addressed in this disclosure is cell energy reduction. A cell may spend a lot of energy for its periodic broadcasts such as SSB or SIB1. There is overhead associated with transmitting SIB1 periodically including the transmission of PDCCH in the same slot as the PDSCH carrying SIB1. Especially at a low or zero load, such broadcasts may be potentially transmitted w ith larger periodicities to achieve energy savings. As an extreme case of power saving, a cell may stop the broadcast either for a finite period or indefinitely^ until a request to restart the broadcast is received. When the periodicity of SIB1 is changed, a UE that needs the information contained in SIBt may not obtain it as it normally would. It is desirable to provide means for a UE to obtain SI Bi as needed.

[0150] Such changes, in either periodicity or tuning off / on transmissions can be communicated to UEs, which can adapt their own sleeping patterns accordingly. Therefore, the used signaling to either request information or request transmissions of the broadcasts can be specified.

[0151] The similar technical problem exists for the UL RACH occasions (RO) when the gNB must monitor the channel for potential transmissions from UEs. A way to save the receive energy for reception is to adapt the RO periodicity and signal these changes.

[0152] This disclosure provides solutions for network energy saving for various scenarios when the time distribution of some gNB signals and channels changes based on gNB and UE sleep patterns. This disclosure offers solutions for signaling of these changes to the UE, and for the UE to request information regarding changes. Moreover, the UE may request starting (on-demand) transmission of some of these signals to accommodate the UE sleeping patterns and capabilities.

[0153] This disclosure provides solutions for several scenarios. This disclosure uses the term “request” to indicate that the UE requests an update about the system information, and to indicate that a cell receiving a request may start / stop / change scheduling of a signal transmission or reception. The request may be signaled via random access dedicated resources. Sometimes the term “wakeup signal” may be used to indicate such request. The terms may be used interchangeably.

[0154] In this disclosure, the scheduling and the transmission patterns changes of SSB and / or SIB1 are considered as examples of ways to achieve energy savings at the gNB. The transmission patterns may be defined in time as periodicity of the transmission, or a grouping in time of subsequent transmissions or even stopping a transmission until a request is received.

[0155] The transmission patterns may also be defined in space, as transmissions in specific directions or a subset of directions, which for instance may be specified via a mask applied on a set of directions.

[0156] Therefore, the terms “request”, “demand,” or “wakeup signals” may apply for a specific signal, specific temporal patterns, a specific spatial pattern, or a combination of the above. Thus, a cell responding to such request may decide to respond to the specific request, or to a wider set including the specific request. Moreover, when a cell responds to a request to transmit a signal (such as SSB or SIBi), it may decide to transmit a set of aperiodic transmissions, or a set of periodic transmissions.

[0157] Some of the embodiments below may be described for one of idle, inactive, and connected mode for a UE. However, they can be applicable to a mode not directly described.

[0158] Scenario 1: A standalone cell (PCell) broadcasts SSB and SIBi. The cell decides to switch to a Discontinuous Transmission (DTX) mode and / or Discontinuous Receiving mode (DRX) non-active mode.

[0159] The cell DTX operation affects UE's monitoring activity of PDCCH and configured dow nlink assignments in the RRC_CONNECTED state. For all activatedServing Cells with cell DTX configured and activated, the MAC entity may monitor PDCCH and configure dow nlink assignments using the cell DTX operation.

[0160] Each Serving Cell may be configured by RRC with a periodic cell DTX pattern (i.e., Active and Non-Active Periods). During a Non_Active period of a cell DTX pattern, a UE does not monitor PDCCH nor does not instruct the physical layer to receive transport block on the DL-SCH of this Serving Cell.

[0161] In this scenario, the cell still broadcasts the SI (such SSB, SIBt) or other signals. However, the periodicity and patterns of the broadcast may change. For instance, during the non-active duration of DTX, the cell is broadcasting SSB and / or SIBt, paging at much larger periods, to conserve energy. Similarly, entering in a non-active period of DRX, the gNB may limit its receiving occasions such PRACH occasions.

[0162] In one embodiment, prior to starting a new configuration of broadcast / receive during the non-active period DTX / DRX, the cell informs UEs about the change of the system information i.e., the new schedule (e.g., time pattern), and / or PHY (e.g., frequency) resources for the transmissions of SSB and / or SIBt. The cell also may inform UEs via SIBt or RRC configuration that the cell may receive requests for the “on-demand” SSB or SIBt when a UE needs it or just requests about schedule validity.

[0163] The indication of the SSB transmission occasions may be achieved via RRC signaling in SIBt for instance or via a modified DCI Format 2-9, which now is used for activating or de-activating the cell DTX and / or DRX configuration of one or multiple serving cells for one or more UEs, and / or for providing NES-mode indication of the primary cell for one or more UEs. Another possibility may be to use a modified DCI Format i_o w ith CRC scrambled by SI-RNTI.

[0164] The new schedule may include, among others, information on the PHY resources, the new period, offset in time, and duration of the transmissions. The new pattern of transmissions may be provided via a bit mask that indicates which of the potential transmissions will be executed. In a different embodiment, the new' schedule has an associated time duration. After the duration of the new schedule expires, the broadcast signals (such as SSB, SIBt, or paging) or the receiving occasions (such as PRACH occasion) may fall back to a previously known schedule or to a default schedule and pattern (see FIG. 11 described below for additional descriptions).

[0165] Alternatively, the UEs may be provided with a list of such schedules, where each entry of the list includes necessary information for UE to acquire a signal, such as SSB, SIBt, paging transmissions, or for cell receiving occasions, in the new cell NES DTX / DRX state.

[0166] The UEs in the RRC CONNECTED state may be informed via the PDSCH, which carries information about the new schedule or transmission pattern for SSB, SIB1, or paging. The DCI scheduling the PDSCH carrying the new scheduling information, may have a CRC scrambled with a SI-RNTI sequence. This DCI can have fields that identify whether system information is about to changes, what are the changes, and what are the new schedules related the SI broadcast.

[0167] The UEs in the RRC INACTIVE or IDLE state may be informed about the new schedule or pattern of transmissions via ongoing SSB and SIB1 transmissions, or via paging.

[0168] The incoming schedule(s) for SSB and / or SIB1 transmissions may be broadcast to all UEs in the cell, groups of UEs in the cell or subgroup of UEs that belong to a specific group. The broadcast may be done via current S1B1, via another existing or new SIB, or via paging.

[0169] When the UEs are informed via paging operation, the DCI scheduling the PDSCH carrying the information about new schedule may' be scrambled with a P-RNTI sequence.

[0170] FIGs. 10A and 10B show example flows of SSB / SIB1 on demand, in accordance with some implementations. In FIG. 10A, Cell A 1002 broadcasts SSB / SIBt for large periods, or stops temporarily the broadcast. A UE 1004 that was in a sleeping state may wake up and need resynchronization. The UE 1004 places a request (demand) to Cell A 1002 to transmit an SSB / SIBt broadcast. The gNB of Cell A 1002 broadcasts the requested signal.

[0171] In FIG. 10B, in a different implementation example, the UE 1054 rather than requesting an SSB / SIBt transmission, the UE 1054 requests the SSB / SIBt related information (for instance, the new transmission time, periodicity, or information on other SIB transmission). The gNB of Cell A 1052 replies to UE with the requested information.

[0172] FIG. 11 shows an example flow of SSB / SIBt on demand, in accordance with some implementations. After the Cell A 1102 informs the UE 1104 about the change of the system information i.e., the new schedule (e.g., time pattern 1), and / or PHY (e.g., frequency) resources for the transmissions of SSB / SIBt, as described above, the UE 1104 may start a timer and monitor the SSB / SIBt based on the new schedule (e.g., time pattern 1) before the timer expires. After the timer expiration, the UE 1104 may monitor the SSB / SIBt based on the default schedule (e.g., time pattern 2).[01731 Scenario 2: A standalone cell (PCell) broadcasts SSB but stops broadcasting SIBi or have veiy long periods between broadcasts of SIBt, for instance during the nonactive period of DTX. The cell may resume broadcasting SIBi if there is a request for it. The SIBi related information may be initially acquired by a UE from neighboring cells. In this scenario, as shown in FIG. 12, the UE 1204 searching for a cell acquires the SSB from that cell (e.g., Cell A 1202), which indicates via MIB (SSB) that the SIBi is not transmitted, and the Cell A 1202 indicates the neighboring cells (e.g., Cell N 1212) and resources where SIBi is transmitted. The UE 1204 may acquire SIBi from the neighboring Cell N 1212.

[0174] In one embodiment, the neighboring Cell N 1212 belongs to the same group or validity area as the Cell A 1202. Such validity areas, for instance, may be provided to the UE 1204 through configuration as a list of group ID and cell IDs. In such a validity area, the cells are synchronized; therefore, synchronization information from one cell (numerology, start of a frame, subframe, symbol, etc.) may be used to access another cell. In this case, after receiving Cell A 1202 for SSB, the UE 1204 may monitor a Cell N 1212 for SIBi transmission in the Cell N 1212, and acquire SIBi of the Cell N 1212 directly or first acquire the Cell N 1212 SSB and then the Cell N 1212 SIBi. The Cell N 1212 SIBi carries information about schedule of Cell A 1202 SIBi, and / or information about when the UE 1202 may either place a request for SI or an earlier transmission of the Cell A 1202 SIBi. Such a request may be transmitted by the UE 1204 in the Cell A 1202. In an alternative embodiment, the PRACH occasions in the Cell A 1202 are also reduced; therefore, the Cell N 1212 SIBi configures the UE that a request may be placed in the Cell N 1212, that is dedicated PRACH occasions and frequency resources in the Cell N 1212, which may forward the request to the Cell A 1202 via backhaul for instance.

[0175] When the Cell A 1202 receives such a request or demand, the Cell A 1202 may restart transmission of SIBi, as shown in FIG. 13A, or the Cell A 1202 may provide the UE 1204 with the last SIBi schedule via paging, for instance, as shown in FIG. 13B.

[0176] Scenario : As shown in FIG. 14, a standalone Cell A 1402 either stops broadcasting in-cell SSB and stops broadcasting in-cell SIBi or has these broadcasts at very long periods during the non-active period of DTX. A UE 1404 searching for a cell may receive the SSB and SIBi transmissions from a neighboring Cell N 1412 at a lower power level. SIBi from the Cell N 1412 may indicate that in the area there are dormant / silent cells which may be woken up. SIBi from the Cell N 1412 provides information about the PHY resources to place a request to wake up the cells in the area. SIBi from the Cell N 1412 also may indicate that such request (or demand) may be placed in some conditions, for instance, when the SSB from the Cell N 1412 is received by the UE1404 at a power level below a threshold. In one embodiment, the UE 1404 compares the received power of SSB from the Cell N 1412 with the threshold and places a wakeup request in the Cell A 1412. The request is either received by the Cell A 1402, which allocates PHY resources to receive over the air such demands, or if the Cell A 1402 does not have such resources and is turned off. The request may be received by the Cell N 1412, which, may wait for any indication from the Cell A 1402 that restarted the in-cell SSB / SIB1 transmission, and, if no indication is received after a timer expiration, the Cell N 1412 wakes up the Cell A 1402 via the backhaul connection. When the Cell A 1402 receives the request / wakeup signal, the Cell A 1402 may turn on the transmission of incell SSB and SIB1 and start operating. The UE 1404 compares the received SSBs strengths from the Cell A 1402 and Cell N 1412 and (re)-selects one as the PCell.

[0177] As shown in FIG, 15, in this embodiment, Release 19 cells support a new initial channel access. A Rel-18 NES UE 1504 is a UE capable of supporting Rel-18 Cell NES features. Similarly, a Rel-19 NES UE 1514 is a UE capable of supporting Rel-19 Cell NES features. In the legacy specs (e.g., Rel-18), w hen the MIB indicates Cell Barred:- Rel-17 and previous release UEs reselect the cell.- Rel-18 NES UE 1504 expects SIB1 to be transmitted and receives SIB1 from the Cell N 1512.- - If the field cellBarredNES is absent in SIB1, the Rel-18 NES UE 1504 considers this cell barred.- - If the cellBarredNES is present in SIB1, the Rel-18 NES UE 1504 consider this cell as available.

[0178] In this disclosure, the above behavior with an additional signaling dedicated to Rel 19 only UE 1514 capable of NES Cell DTX / DRX is provided:- Relig NES UE 1514 expects SIB1 to be transmitted and receives SIB1 from the Cell A 1502. If the field cellBarredNES is present in SIB1 and if cellBarredNES_Rig is present, the Rel-19 UE 1514 is not barred; else, the Rel-19 UE 1514 is barred from this cell.

[0179] Moreover, if the MIB indicates that SIB1 is not transmitted (ssb-SubcarrierOffsef), an R19 NES UE 1514 may acquire a neighboring SIB1, which may indicate that this cell support SIBi on request and it is available for Rel 19 NES, as in a previous embodiment. In a different embodiment the cellBarredNES_Ri9 can be validity area specific rather than cell specific, where the validity area comprises multiple cells.[O18o] For this purpose, a SIB1 of a neighboring cell may cariy a list of neighboring cells SSB, and a field indicated cellBarredNES_Reli9 on / off, and if it is not barred the resources for SIB1 on demand.

[0181] Further embodiments for Scenarios 4, 5, and 6 are provided below.

[0182] Consider at least two cells in the network, called Cell A and Cell B (also known as NES Cell).

[0183] - Cell A- Cell A periodically transmits at least its own legacy SSB and SIBs (including SIB1), and operates according to legacy specifications without the NES feature of turning off its SSB and / or SIBs. Therefore, Cell A can be used for initial access for legacy / new UEs.- Cell A may provide wakeup signal (WUS) configuration or assistance (such as timing) to UEs for accessing other cells (e.g., Cell B).

[0184] - Cell B- - Cell B may transmit SIB1 transmission in response to the UL WUS from a UE. It does not transmit at least the legacy periodic SIBs, including SIB1. In other words, Cell B can turn off at least its SIBs, for, e.g., NES purposes. Cell B cannot be used for initial access for legacy UEs.

[0185] - Relationship between Cell A and Cell B- - Cell A and Cell B can be co-located and share certain components, and they may be intra-band CA carriers or inter-band CA carriers or they can be non-co-located as neighbor cells.- - They may share certain properties, such as the same timing, same large-scale fading, etc., or not share common properties.- - The potential enhancements can be different based on different relationships between Cell A and Cell B.

[0186] To address is whether / how SSB is transmitted on Cell B, there are a couple of possible cases, and if there is any backward compatibility issue is described below.- Cell B SSB is still transmitted periodically when its SI Bl is turned off. Cell B SSB is always-on, regardless of Cell B SIBi on / off status.- - For legacy UE in idle / in active mode, if it monitors Cell B SSB but it will not be able to find associated SIBi, to avoid backward compatibility issue, Cell B has to be properly configured.- For most legacy UEs, when finding that the cell is “barred,” they will perform cell reselection.- For legacy RedCap UEs, when finding that the cell is :barred,” they will check the field ssb-SubcarrierOffset. If the field indicates no SIBi, they will continue to read the field pdcch-ConfigSIBi, based on which they may find information for a cell defining (CD) SSB, implying that the current SSB is a non-cell defining (NCD) SSB, or it may not find information for CD SSB, implying that the current frequency range does not provide SIBi for the SSB. No backward compatibility issue will be encountered.- For Rel-18 UEs capable of NES Cell DTX / DRX, when finding that the cell is “barred,” they will apply the information from the fields ssb-SubcarrierOffset and pdcch- ConfigSIBi to acquire SIBi. If the fields indicate the presence of SIBi but they cannot find SIBi, this could be a backward compatibility issue. To prevent the backward compatibility issue, the field ssb-SubcarrierOffset can indicate the absence of SIBi.- - Thus, Cell B can be configured as a barred cell with the field ssb-SubcarrierOffset indicating the absence of SIBi, so that legacy UEs will not experience issues due to the missing SIB for the SSB. There could be other configurations to prevent backward compatibility issue, and more study can be carried out.- - For UE supporting on-demand SIBi feature in idle / inactive / connected mode, they can ignore the field cellBarred and the absence of SIBi indication from the field ssb- SubcarrierOffset. There would be no backward compatibility issue w ith only receiving SSB, and new designs can be provided for on-demand SIB transmission.- Cell B SSB is not transmitted when its SIBi is turned off- Cell B SSB is turned on or off at the same time and in the same way as Cell B SIBi is turned on or off. In other words, Cell B SSB and SIBi are not always on, and they can be transmitted in an on-demand fashion.- It is possible that Cell B may not be configured w ith always-on SSB, and that affects not only connected UEs but also inactive / idle UEs, unless such a cell allows no UEs to camp under it or perform initial access with it, w h ich is a bit too restrictive from network operation perspective. An embodiment that a UE expects always-on SSB during inactive / idle state from a NES Cell but may not have always-on SSB during connected state is a non-preferred embodiment.- - The turning-off can be done when the network determines all connected UEs (if any) are compatible with this feature. There will not be backward compatibility issue for such UEs.- - Inactive UEs and idle UEs not supporting this feature may wake up to look for the SSB for synchronization and subsequent operations such as paging, but they could not find the SSB. This prevents them from paging or performing RACH. These UEs will perform a cell reselection which is an existing behavior. This may cause some delay and complexity, but there would not be critical backward compatibility issues for such UEs.- - Inactive UEs and idle UEs camped under this cell and supporting this feature may be relying on Cell B SSB for its synchronization, paging, etc. These UEs know that Cell B SSB can be turned off, and they can use the new designs from this WI (e.g., using WUS to request on-demand SSB and SIB from Cell B) to ensure proper operations.- - Though legacy UEs may camp under Cell B and may also be connected to Cell B when the SSB / SIB are transmitted, it may limit Cell B’s flexibility to turn off its SSB / SIB. For this reason, Cell B may prevent legacy UEs from camping or connecting to it, via its MIB by configuring the cell as barred or S1B1 absent using MIB fields cellBarred and / or ssb- SubcarrierOffset. However, this may not be strictly necessary and can be left for network implementation.

[0187] Thus, both cases can be feasible and will not lead to backward compatibility' issues with proper configuration / enhancements.

[0188] To summarize, for potential enhancements of on-demand SIB1 of a cell for UEs in idle / inactive mode, at least the following two cases for the cell’s SSB are considered:- The cell’s SSB is always on (transmitted periodically regardless of its SIB1 on / off status).- - The cell’s MIB may be configured to indicate the cell as barred and / or SIBi absent to avoid backward compatibility issue.- The cell does not transmit always-on SSB, and the cell transmits only on-demand SSB and SIBi, and one of SSB / SIB1 is transmitted only when the other is transmitted.

[0189] To address which cell, Cell A or Cell B, provides the WUS configuration for Cell B, the following two cases are analyzed.- 1. WUS configuration is provided by Cell B- - If the UE is inactive and stores information received from Cell B w hen it w as connected to Cell B, the WUS configuration information for Cell B may be included in some configuration information, and Cell B may or may not need to use its SIB (when SIB is transmitted) to broadcast the WUS configuration information for Cell B.- - Otherw ise, the UE is inactive or idle. The UE may read Cell B’s SIB when it is transmitted (which can be intermittent). The SIB may include the WUS configuration information for Cell B. However, the WUS configuration information transmission cannot be purely on-demand based; otherwise the UE may not be able to receive the WUS configuration information and hence cannot be camped under this cell at all. Thus, the WUS configuration information transmission should be at least periodic. To enable more energy saving, Cell B can configure long periodicity for SIB as well as on-demand SIB, and SIB carries WUS configuration information.- 2. WUS configuration is provided by Cell A- - If the UE is idle and camped under Cell A, it may read Cell A’s SIB broadcast to all UEs which may include WUS configuration information for Cell B.- - If the UE is inactive and stores information received from Cell A when it w as connected to Cell A, the WUS configuration information for Cell B may be included in some configuration information, and in this case, the UE does not have to (though it may be beneficial to do so at certain times) monitor Cell A SIB for the WUS configuration information for Cell B.- - If the UE is inactive and does not store WUS configuration information for Cell B, it may read Cell A’s SIB broadcast to all UEs which may include WUS configuration information for Cell B.- - Consequently, Cell B does not have to periodically broadcast WUS configuration information for itself. Hence, Cell B SIB can operate on a purely on-demand basis, and when Cell B SIB is transmitted, it can also carry WUS configuration information for itself. Cell B can also send / update its connected UEs with WUS configuration information for itself.

[0190] To summarize, for potential enhancements of on-demand SIBi of a cell for UEs in idle / inactive mode, the following two scenarios for the WUS configuration for the cell are considered:- WUS configuration for the cell may be provided by an assisting cell:- - In the assisting cell’s broadcast SIB or other configuration signaling when the UE was connected to the assisting cell.- WUS configuration for the cell may be provided by the same cell:- - In this cell’s broadcast SIB (with long periodicity) or other configuration signaling when the UE was connected to the cell.

[0191] Aspects of WUS transmission are discussed below.

[0192] 1. WUS transmission reference: by WUS transmission reference, this disclosure refers to the DL synchronization, time / frequency reference points for WUS resources, DL RS for PL estimate used in WUS power control, etc. Generally, the reference is based on SSB, at least for idle / inactive UEs. Which cell’s SSB, Cell B’s or Cell A’s SSB, can be used as the WUS transmission reference is described below.

[0193] 2. WUS transmission target cell: which cell, Cell A or Cell B, the WUS from the UE for Cell B is transmitted is described below.

[0194] Which cell’s SSB, Cell B’s or Cell A’s SSB, can be used as the WUS transmission reference, is described below.- The WUS transmission reference is Cell B SSB, and target is also Cell B: If the WUS is transmitted to Cell B and Cell B SSB is always on, the UE can acquire DL synchronization and PL estimate from Cell B SSB, and the WUS transmission opportunities are relative to Cell B SSB location in time-frequency domain. It is infeasible to use Cell B SSB as WUS transmission reference if Cell B SSB operates only as on-demand SSB. The UE may not be able to find the on-demand SSB and may not be able to acquire sufficiently accurate synchronization for its WUS transmission. Thus, Cell B SSB can be always on to be the WUS transmission reference. The WUS transmission to Cell B is only needed when Cell B SIB is not being transmitted. So, if Cell B SIB operates purely as on-demand SIB, or Cell B SIB transmission is configured with long periodicity, WUS transmission can be allowed.- The WUS transmission reference is Cell A SSB, and target is also Cell A: Cell A SSB is alw ays on, so if needed, it can act as WUS transmission reference. If the WUS is to be transmitted to Cell A, the UE can acquire DL synchronization and PL estimate from Cell A SSB, and the WUS transmission opportunities are relative to Cell A SSB location in time-frequency domain. In this case, Cell B SSB should not be always on (to save energy, as it is not used in WUS transmission); otherwise it makes more sense to utilize Cell B SSB. Cell B SSB should be transmitted only in an on-demand fashion to reduce energy consumption.- The WUS transmission reference is Cell A SSB, and target is Cell B: If the WUS is to be transmitted to Cell B and Cell B SSB is not always on (i.e., supporting only on-demand transmission), the UE cannot acquire DL synchronization and PL estimate directly from Cell B. It may acquire DL synchronization and time / frequency reference points from Cell A SSB, if both cells are synchronized / coordinated. The PL estimate based on Cell A SSB may not be exact for WUS transmission toward Cell B. However, this can still be overcome through network implementation or some standards support, such as startingthe WUS transmission w ith relatively low power but ramping up the power if needed, by configured Po leading to low transmission power, and / or configuring a smaller alpha in open-loop power control. In this case, WUS transmission toward Cell B may still be feasible, though it is more involved than other cases.

[0195] To summarize, for potential enhancements of on-demand SIB1 for UEs in idle / inactive mode, at least the following scenarios for the WUS transmission reference and target cell are considered:- WUS transmission target cell is the cell supporting on-demand SIB1.- - The WUS transmission reference is this cell’s SSB, if this cell’s SSB is always on.- - The WUS transmission reference is an assisting cell’s SSB, if the cells are synchronized and the target cell SSB is only on-demand and not always on.- WUS transmission target cell is an assisting cell.- - The WUS transmission reference is the assisting cell’s SSB.- The SSB of the cell supporting on-demand SIB1 is not always on.

[0196] There can be a variety of scenarios for potential on-demand SIB1 enhancements. Some scenarios and associated operations are summarized in Table 1 below.Table 1 Some scenarios with on-demand SIB1

[0198] - Scenario 4: Single-cell scenario (standalone; without an assisting cell, or optionally with an assisting cell): Cell B is a standalone cell for Rel-19 UEs and can provide all essential functions, including transmitting WUS configuration and receiving WUS transmission. Cell B always transmits SSB, i.e., SSB is always on, such as with the legacy periodicity of 20 ms. Cell B does not always transmit SIB1 when SSB is transmitted; instead, SIB1 can be transmitted with much longer periodicity than SSB andcan also be triggered by WUS. For example, SIBi and WUS configuration are broadcast w ith 1280 ms periodicity to reduce energy consumption, and in addition, SIBi can be sent on-demand per request from UE WUS.- - When SIBi and other SIBs are transmitted, WUS configuration for Cell B is included. Cell B always monitors potential WUS transmissions on its configured WUS transmission opportunities. WUS transmission opportunity is only configured on the time-domain resources when Cell B SIB is not transmitting, e.g., within a duration between consecutive periodic SIBi bursts occurring with long periodicity.- - UE receives and stores Cell B’s SI and WUS configuration information acquired from SIBs (for idle / inactive / connected UEs), and optionally from other RRC configuration signaling (only for connected UEs). When needed, the UE transmits WUS to this cell based on this cell’s SSB. Cell B receives the WUS and then performs on-demand SIBi transmission. In general, the WUS configuration validity duration should be (much) longer than SIBi validity duration.- - Optionally, an assisting cell, Cell A, provides WUS configuration information for Cell B, in Cell A’s SIBs or other configuration information.- - Cell B is configured as inaccessible by legacy UE, by configuring the cell’s MIB as barred and / or SIBi absent, at least when SIBi is not periodically transmitted according to legacy period.

[0199] - Scenario 5: Multi-cell scenario with limited essential assistance from an assisting cell: Cell B is a non-standalone cell for Rel-19 UEs and relies on Cell A to broadcast WUS configuration for Cell B. Cell B transmits always-on SSB, and also transmits SIBi / SIBs / WUS configuration on an on-demand basis, but does not configure periodic SIBi / SIBs / WUS configuration transmission. Cell B monitors WUS, and when detected, it transmits SIBi / SIBs / WUS configuration.- - When SIBi and other SIBs are transmitted, WUS configuration for Cell B is included, but since the transmission is on-demand, most UEs may not receive it. Hence an assisting cell, Cell A is needed to periodically broadcast WUS configuration information for Cell B. WUS is configured to be based on Cell B SSB and is monitored by Cell B.- - UE receives and stores WUS configuration information for Cell B from Cell A. The UE monitors Cell B SSB. When needed, the UE transmits WUS to Cell B based on Cell B SSB. Cell B then performs on-demand SIBi and other SIBs transmissions and UE receives the transmissions.- - Cell B is configured as inaccessible by legacy UE, by configuring the cell’s MIB as barred or SIB1 absent, at least when SIB1 is not periodically transmitted. If SIB1 is resumed, the barring status can change accordingly.

[0200] - Scenario 6: Multi-cell scenario with full assistance from an assisting cell: Cell B is a non-standalone cell for Rel-19 UEs and its SSB / SIB1 transmissions are only on an on-demand basis. It relies on Cell A for (almost) all WUS-related operations. Cell B can save more energy in this scenario than in the other scenarios.- - When SSB, SIB1, and other SIBs are transmitted by Cell B, WUS configuration for Cell B is included; however, as these transmissions are only on an on-demand basis, most UEs cannot receive them. For this reason, Cell B SSB cannot be used as WUS reference.- - WUS configuration for Cell B is broadcast by an assisting cell, Cell A, which does not turn off its SSB / SIB1 / SIBs transmission, and the WUS configuration can be included in SIB1 or other SIBs. WUS transmission reference and target are also Cell A. Cell A monitors potential WUS transmissions for Cell B on the configured WUS transmission opportunities.- - UE receives and stores SI and WUS configuration information for Cell B from Cell A. When needed, the UE transmits WUS based on Cell A SSB.- Cell A then receives the WUS for Cell B and informs Cell B. Cell B then performs on- demand SSB and SIB1 transmission.- Alternatively, if Cell A and Cell B are synchronized and coordinated, Cell B can monitor and receive WUS transmission. This way, Cell B can start on-demand SSB and SI Bl transmission without waiting for backhaul signaling from Cell A.- - The cell may be configured as inaccessible by legacy UE.

[0201] To summarize, the following scenarios and enhancements of a cell with on- demand SIB1 for UEs in idle / inactive mode are provided.- Scenario 4: The cell can be standalone, by transmitting always-on SSB and long- periodicity SIB1 / WUS configuration and monitoring the configured WUS transmission opportunities. WUS transmission is based on this cell’s SSB. This cell transmits on- demand SIB1 if it detects WUS.- Scenario 5: The cell transmits always-on SSB and transmits on-demand SIB1 if it detects WUS. WUS transmission is based on this cell’s SSB. WUS configuration is transmitted by an assisting cell in the assisting cell’s SIBs.- Scenario 6: The cell transmits on-demand SSB / SIB1 if a UE transmits WUS for this cell. WUS configuration is transmitted by an assisting cell in the assisting cell’s SIBs, andWUS transmission is based on the assisting cell’s SSB. WUS is monitored by the assisting cell only or by both cells if both cells are synchronized.

[0202] FIG. 16 shows example operations for Scenario 4, in accordance with some implementations. The SSB is configured with regular period, e.g., 80 ms. SIB1, other SIBs, and WUS configuration for Cell B 1602 are configured with longer period, e.g., 1280 ms (not rawn to scale). Thus, starting at SFN o, 128, 256, ..., 896, a SIB1 burst of 160 ms is transmitted, if no SFN offset is configured for SIB1. One radio frame lasts 10 ms, and its number (i.e., index) ranges from 0 to 1024. The WUS opportunities (WO) are monitored only when SIB1 is not transmitted. The UE 1604 receives WUS configuration and performs WUS transmission when needed, according to the WUS configuration and towards Cell B 1602. After that, Cell B starts on-demand SIB1 transmission. In an embodiment, the on-demand SIB1 transmission may be relative to the WUS transmission occasion and the time offset is pre-configured (e.g., in WUS configuration) to the UE 1604 in terms of number of slots or milliseconds. In an embodiment, the on- demand SIB1 transmission may start from the next SSB transmission. In an embodiment, the MIB for Cell B 1602 is modified to provide SIB1 scheduling information. For example, PDCCH-ConfigSIBt indicates a much longer periodicity for CORESET#o and search space#o monitoring occasions. One of the reserved indexes in CORESET#o and / or search space#o can be used to indicate the periodicity and offset from SFN#o for the UE 1604 to find SIB1. In an embodiment, SIB1 content can be modified to include WUS configuration for Cell B 1602, or alternatively, a new SIB can be added to include WUS configuration for Cell B 1602. In an embodiment, WUS transmission is only allowed outside the SIB1 burst and at least x ms (e.g., 160 ms) later than the last transmission of a SIB1 burst. In an embodiment, the UE 1604 is connected to Cell B 1602, and it is not expected to transmit WUS to Cell B 1602 if Cell B 1602 is not in dormancy or not in Cell DTX / DRX.

[0203] FIG. 17 shows example operations for Scenario 5, in accordance with some implementations. The Cell B 1702 SSB is configured w ith regular period (e.g., 80 ms). Cell B 1702 SIB1, other SIBs, and WUS configuration for Cell B 1702 are configured only for on-demand transmission by Cell B 1702. The WUS configuration information for Cell B 1702 is instead delivered by Cell A 1712, such as in one of its SIBs. The UE 1704 will need to first receive Cell A 1712 SSB, SIB1, WUS configuration for Cell B 1702 , and then possibly transmit a WUS to Cell B 1702. The WUS opportunities (WO) are monitored by Cell B 1702 w ith a configured time offset from Cell B 1702 SSB transmission. The UE 1704 performs WUS transmission when needed, according to the WUS configuration and towards Cell B 1702 based on Cell B 1702 SSB. After that, Cell B 1702 starts on-demandSIB1 transmission. In an embodiment, the MIB for Cell B 1702 is modified to provide SIB1 scheduling information. For example, PDCCH-ConfigSIBi indicates that CORESET#o and search space#o monitoring occasions are on-demand, i.e., no configured period. One of the reserved indexes in CORESET# o and / or search space# 0 can be used to indicate the on-demand SIBi so that the UE 1704 will not search for SIBi. In an embodiment, the MIB for Cell B 1702, such as the field PDCCH-ConfigSIBi, can include information for the UE 1704 to search for the assisting cell, such as the frequency for Cell A 1712 (if the cells are on different frequencies), or WUS validity area index so that the UE 1704 can attempt to find any cell in the WUS validity area for the WUS configuration information. In an embodiment, Cell A 1702 SIBi content can be modified to include WUS configuration for Cell B 1702, or alternatively, a new SIB can be added to include WUS configuration for Cell B 1702. In an embodiment, the UE 1704 expects / assumes the WUS configuration information received from Cell B 1702 SIB when Cell B 1702 is transmitting Cell B 1702 non-SIB RRC configuration when the UE 1704 enters connected mode with Cell B 1702 as a serving cell and receives the RRC configuration from Cell B 1702 , Cell A 1712 SIB, or Cell A 1712 non-SIB RRC configuration if the UE 1704 enters connected mode with Cell A 1712 as a (primary or secondary) serving cell and receives RRC configuration from Cell A 1712, are all consistent, and latest received from any configuration of either cell is the most up to date one. In an embodiment, the UE 1704 is connected to Cell B 1702, and it is not expected to transmit WUS to Cell B 1702 if Cell B 1702 is not in dormancy or not in Cell DTX / DRX.

[0204] FIG. 18 shows example operations for Scenario 6, in accordance with some implementations. The Cell B 1802 SSB, SIBi, other SIBs, and WUS configuration for Cell B 1802 are only for on-demand transmission by Cell B 1802. The WUS configuration information for Cell B 1802 is instead delivered by Cell A 1812, such as in one of its SIBs. The UE 1804 will need to first receive Cell A 1812 SSB, SIBi, WUS configuration for Cell B 1802, and then possibly transmit the WUS to Cell A 1812 or Cell B 1802 (if the cells are synchronized). The WUS opportunities (WO) are monitored by Cell A 1812 and / or Cell B 1802 with a configured time offset from Cell A 1812 SSB transmission. The UE performs WUS transmission when needed, according to the WUS configuration and based on Cell A 1812 SSB. After that, Cell B 1802 starts on-demand SSB / SIB1 transmission. In an embodiment, the MIB for Cell B 1802 is modified to inform the UE 1804 that the cell SSB and SIBi support on-demand transmission. For example, PDCCH-ConfigSIBi indicates that SSB, CORESET#o and search space#o monitoring occasions are on-demand (i.e., no configured period). In an embodiment for the connected UE 1804, Cell B 1802 is an SCell for the UE 1804, and the UE 1804 can assume that SSB / SIB1 are not periodically transmitted. The SSB / SIBi may be stopped if the SCell is deactivated, or activated but indormancy / cell DTX. In an embodiment for the connected UE 1804, Cell B 1802 is the PCell for the UE 1804, and the UE 1804 can assume that SSB / SIB1 are not periodically transmitted. When the PCell is in cell DTX, the UE does not expect SSB / SIB1 transmission except during the active periods. When the PCell is not in cell DTX, the UE 1804 can expect SSB / SIB1 transmissions according to configured periodicities, and the periodicity for SSB can be different (generally shorter) than that of SIB1. In an embodiment, the UE 1804 expects / assumes the WUS configuration information received from Cell B 1802 SIB when Cell B 1802 is transmitting Cell B 1802 non-SIB RRC configuration when the UE 1804 enters connected mode with Cell B 1802 as a serving cell and receives RRC configuration from Cell B 1802, Cell A 1812 SIB, or Cell A 1812 non-SIB RRC configuration if the UE 1804 enters the connected mode with Cell A 1812 as a (primary or secondary) serving cell and receives RRC configuration from Cell A 1812, are all consistent, and latest received from any configuration of either cell is the most up to date one. In an embodiment, the UE 1804 is connected to Cell B 1802, and it is not expected to transmit WUS to Cell B 1802 if Cell B 1802 is not in dormancy or not in Cell DTX / DRX. The UE 1804 may transmit WUS to Cell B 1802 if Cell B 1802 is the PCell and in Cell DTX / DRX, in which case an active period starts following the WUS with certain time offset, and SSB will be transmitted during the active period.

[0205] Regarding UL WUS design, since the UE is in idle / inactive mode, at least an embodiment is to use PRACH preamble as the starting point, and WUS should be allowed only on specific time / frequency-domain resources and with specific sequences, since the network has to monitor all possible WUS transmission occasions (i.e., all possible WUS time / frequency-domain resources and sequences).

[0206] Next, whether and / or how the WUS resources are multiplexed with other resources, especially with regular PRACH resources used for initial access and other activities, are described in this disclosure. There can be different options for solving whether a WUS transmission can be distinguished from a non-WUS, regular PRACH transmission.- WUS is indistinguishable from non-WUS PRACH transmissions.- In this case, generally the network will reply with the RAR (i.e., Message 2) to allocate UL assignments for follow-up transmissions by the UE. However, this option may not be unnecessaiy for WUS to trigger the SIB1 transmission, and the UE may not be able to receive RAR since it has not received all necessary system information.- WUS is distinguishable from non-WUS PRACH transmissions.- In this case, rather than the network replying with the RAR, the network responds w ith either an on-demand SIB1 or a confirmation plus the on-demand SIB1. The UE may not have to monitor the RAR or send another UL, and the entire WUS-based procedure can be done after the UE receives SIBi. Therefore, this option can reduce latency and UE / network complexity.

[0207] To separate WUS from non-WUS PRACH transmissions, WUS can be assigned with dedicated time-domain resources, frequency-domain resources, and / or w ith specific sequences.

[0208] In an embodiment, WUS design can be based on PRACH preamble with dedicated time, frequency, and / or sequence resources (such as based on a partition of PRACH preambles, which can reuse Rel-17 feature combination mechanism on PRACH preamble partitioning, priority, etc.), and any combination thereof.

[0209] WUS triggering conditions

[0210] Many of idle / inactive UE behaviors are generally specified by higher layers, such as cell reselection, camping, establishing RRC connections, etc. For this reason, RAN1 may not have to specify the details of WUS triggering conditions other than setting a criterion to prevent a UE from sending WUS too often to keep waking up the NES Cell. Thus, in an embodiment, WUS can be triggered only once during the process to camp under the NES Cell, or to establish RRC connection to the NES Cell, or to monitor the NES Cell as a neighbor cell / candidate cell, or to complete the cell selection, or reselecting, involving NES Cell. A timer may also be introduced so that no more than N WUSs can be sent during a time period of M seconds.

[0211] In some embodiments, WUS transmission can be triggered only once during each of the following:- to camp under the NES Cell;- to establish an RRC connection to the NES Cell;- to monitor the NES Cell as a neighbor cell / candidate cell; and / or- to complete the cell (re-)selection involving the NES Cell; and / or- a certain time duration.

[0212] For example, within each t second(s), there can be at most 1 WUS transmission for a NES Cell. More generally, within each t second(s), there can be at most n (> 1) WUS transmissions for a NES Cell. For another example, within M periods of the SSB transmissions of a NES Cell, there can be at most n (> 1) WUS transmissions for the NES Cell. In an embodiment, the time duration restriction may take precedence overother restrictions, which has the pro of higher network energy saving but has the con of degraded latency performance, and hence more suitable for latency-insensitive UEs or traffic. In an embodiment, the other restrictions take precedence over the time duration restriction. For example, within t second(s), the UE first sends WUS and then adds the NES Cell as a candidate cell, and shortly after that, it needs to camp under the NES Cell or needs to connect to the NES Cell, which may (or may not) need another WUS transmission to the NES Cell. If this UE is latency-sensitive or the traffic is latencysensitive, it can send WUS for each of the procedures while not considering the time duration restrictions.

[0213] After the gNB receives a WUS transmission from a UE, there are several options that the gNB may respond to the WUS transmission. For one, the gNB may send a feedback message to confirm that SIBi will be transmitted, and some information about the SIBi resources can be provided, such as information about PDCCH and PDSCH carrying the SIBi, based on which the UE can find the SIBi. Alternatively, the gNB may not send a feedback message for confirmation, but just starts to transmit SIBi according to a predetermined schedule, such as sending the PDCCH for SIBi within a certain time window7starting from the WUS transmission, or turning on the SIBi transmission based on existing legacy SIBi transmission schedule based on the NES Cell’s SSB. In some contexts, the WUS response is not strictly necessary or useful. If the WUS transmission does not get through and the UE does not receive either the WUS response or the SIBi, the UE will perform a retransmission of WUS anyway. In some embodiments, the gNB may not send any WUS response other than the requested SIBi transmission.

[0214] In an embodiment, the NES Cell responds to a WUS transmission with one of the following.- SIBi transmission according to legacy SIBi transmission schedule based on the NES Cell SSB.- SIBi transmission within a time window of the WUS transmission.

[0215] Several options can be utilized for the WUS configuration validity area, with different pros and cons.

[0216] Option 1 is the pre-defined UL WUS configuration. This option would reduce the signaling overhead and latency, but it may lack flexibility.

[0217] Option 2 is the UL WUS configuration that applies to multiple NES Cells. This option can provide a tradeoff between signaling overhead, latency, complexity, and flexibility. Cell A can carry one WUS configuration applicable to multiple NES Cells in aWUS configuration validity area, and different areas can have different WUS configurations.

[0218] Option 3 is UL WUS configuration that applies to a single NES Cell. This option may result in higher complexity than other options. For example, if in an area there are several NES Cells, then each Cell A in this area may have to provide several different WUS configurations associated with the several NES Cells. UE will need to receive several WUS configurations and then select one, or will need to send more specific request for a particular NES Cell’s WUS configuration.

[0219] Therefore, in at least one embodiment, it is to specify UL WUS configuration that applies to multiple NES Cells.

[0220] This disclosure provides solutions for SSB adaptation signaling, PRACH adaptation signaling, and Paging adaptation signaling. When the gNB changes the time configuration for SSB, PRACH or Paging, the gNB may inform UEs about a change in the SSB / PRACH / Paging transmission via Paging. Such Paging signaling is suitable for UEs in CONNECTED, INACTIVE or IDLE RRC state.

[0221] This disclosure uses the term “resources” to refer to the time transmission or receiving occasions for SSB, PRACH or Paging. However, the resources may have a more general meaning, such as frequency resources or preamble resources (e.g., when different preambles used are used to distinguish between transmissions).

[0222] This disclosure presents solutions for the adaptive resource allocation, wherein resources may be allocated uniformly to all users (for instance for all legacy users), or differentiated by the UE’s capability, for instance, different resources for the legacy devices versus resources for NES capable UEs.

[0223] In one embodiment, the Paging message has the PDCCH scrambled by a new R19-SI-RNTI sequence. When a NES capable UE is receiving a PDSCH scheduled with PDCCH scrambled with SSB-SI-RNTI, the UE assumes that PDSCH is QCL with the last acquired SS / PBCH block.

[0224] In a different embodiment, there is a specific and distinct Paging from the gNB (and therefore specific RNTI sequence) for paging informing NES capable UES about SSB time adaptation, another Paging informing the NES capable UEs about PRACH adaptation and another Paging about Paging time adaptation respectively.

[0225] A NES capable UE monitors for SSB updates in its own paging occasions for RRC_IDLE and for RRC_INACTIVE while no SDT procedure is ongoing.

[0226] A NES capable UE monitors for possible SSB configurations updates in any paging occasion for RRC_CONNECTED and during the SDT procedure in RRC_INACTIVE.

[0227] Similarly, for the other Paging transmission informing on PRACH or Paging adaptation, when the Paging changes the gNB uses the previous Paging occasions and formats to inform about the new Paging occasions.

[0228] For this purpose, the information transmitted by the gNB to NES capable UEs may comprise the following.• A new field to indicate a change / addition of signals SSB transmission or time pattern. The indication may comprise, for instance, offset with respect to frame #0, duration of the transmissions burst, the period of burst repetition, and the number of transmissions in the transmission burst, the period of transmissions inside the transmission burst.• A new field to indicate a change / addition of the SIB1 transmission period or time pattern.• A new field to indicate the change / addition of PRACH configuration.• A new field to indicate the change / addition of Paging configuration.

[0229] If any of these fields are not present, the information related to that channel / signal did not change and it is assumed to be the same as the last valid configuration.

[0230] The follow ing embodiments can be used for cell w ith DTX / DRX or without DTX / DRX configuration.

[0231] In an embodiment, the gNB configures a set of PHY resources for PRACH that is accessible for both legacy and NES capable UEs based on the legacy resource configurations, and one or more sets of resources for PRACH that are accessible only to the NES UEs.

[0232] For instance, for cell DRX, a legacy PRACH configuration is configured for DRX non-active and active periods, while additional PRACH resources are configured only for NES capable UEs during the active period.

[0233] In a different embodiment, NES capable UEs may access only additional PRACH resources and not legacy resources.

[0234] In a different embodiment, the NES capable UEs are signaled or configured with whether they can access the legacy PRACH resources. The signaling or configurationmay give access to all or a subset of the legacy configured PRACH resources, or to all or a subset of the additional resources possibly for a limited time duration.

[0235] The access of legacy UEs to legacy PRACH configured resources would not be impacted by the DTX / DRX operation.

[0236] In one embodiment, the additional PRACH resources available only to NES capable UEs are added only for the DRX active periods, when the gNB is committed to monitor more PRACH resources.

[0237] The additional PRACH resources may be configured at the time UEs are configured with cell DTX / DRX, or afterwards via RRC configurations.

[0238] The additional PRACH resources for NES capable UEs may be enabled or disabled dynamically or semi-statically via DCI, MAC CE, and / or configured via RRC configurations. They also may be indicated via new SIB (system information block) broadcast message, or via a Paging message, with a DCI scrambled by a new RNTI named, for instance, PRACH-SI-RNTI.

[0239] Thus, the NES capable UEs may use the information for their RACH access and for their own energy saving modes.

[0240] In a different embodiment, the additional resources may be indicated via association w ith SSB indices, where the association may be uniform (e.g., the same) for all SSB indices or specific (e.g., different) for one or more SSB indices. In other words, SSB with different indices may be followed by different numbers and different distribution of the corresponding PRACH resources.

[0241] For instance, SSB index 1 has associated PRACH resources set 1 for the NES capable UEs, SSB index 2 has associated PRACH resources set 2 for the NES capable UEs, and so on.

[0242] One way to implement the non-uniform distribution is using a mask for anSSB index, which may enable / disable the PRACH occasions that may be already configured for the SSB index.

[0243] Another way to signal the SSB to PRACH resources mapping is by adding specific codebooks that map each SSB or group of SSB indices to a set of PRACH resources.

[0244] In a different embodiment, the additional resources for NES capable UEs are added for the active and not active cell DRX periods, with the same or different configurations.

[0245] In a different embodiment, the DTX configuration may have two configurations of SSB transmission for active and non-active periods, and the DRX configuration may have two PRACH occasions configurations for active and non-active periods. In this embodiment, for SSB (same as for PRACH), there is a basic configuration compatible with legacy specification and additional configurations specific to the active and respectively non-active periods that can be announce to the NES capable UEs.

[0246] Thus, four possible configurations can be identified for SSB and PRACH additional occasions corresponding to {DTX active, DRX active}, {DTX non-active, DRX active}, {DTX active, DRX non-active}, and {DTX non-active, DRX non-active}.

[0247] In one embodiment, the additional PRACH occasions are located close in time, for instance in consecutive PRACH slots. The reason to allocate the additional PRACH occasions closer to each other is to allow the gNB more contiguous time to save energy.

[0248] A NES capable UE may request information from the gNB onSSB / PRACH / Paging transmission schedule via either of the following mechanisms:• dedicated PUCCH in RRC_CONNECTED for specific information on either of SSB, PRACH or Paging transmissions; and / or• dedicated SIB request, when the schedule for the above signaling / channels is provided by a dedicated SIB.

[0249] FIGs. 19A and 19B illustrate possible distributions of time resources (e.g., PRACH or SSB occasions), in accordance with some implementations. In FIGs. 19A and 19 B, the bars 1902 indicate the switching time between the active and the non-active configurations of DRX and DTX modes, respectively. The bars 1904 indicate the legacy configuration of resources. The bars 1906 indicate additional resources dedicated to NES capable UEs.

[0250] FIG. 20 shows an example flowchart for accessing additional PRACH resources (NES PRACH resources) by a NES capable UE, in accordance with some implementations. At the operation 2002, the NES capable UE receives a NES PRACH resource configuration. At the operation 2004, the NES capable UE determines whether the NES PRACH resource is enabled based on the NES PRACH resource configuration. If the determination is NO, the NES capable UE may access the legacy PRACH resources at the operation 2006. If the determination is YES, the NES capable UE may access the legacy and NES PRACH resources.

[0251] FIG-21shows an example flowchart for accessing additional PRACH resources (NES PRACH resources) by a NES capable UE, where the additional NES PRACH resources (e.g., all or subsets of them) can be enabled or disabled dynamically or via configuration, in accordance with some implementations. At the operation 2102, the NES capable UE receives a NES PRACH resource configuration. At the operation 2104, the NES capable UE determines whether the NES PRACH resources are enabled based on the NES PRACH resource configuration. If the determination at the operation 2104 indicates that the NES PRACH resources are enabled (YES), the process proceeds to the operation 2108, where the NES capable UE determines whether the NES UE is allowed to access legacy PRACH resources. If the determination at the operation 2108 indicates that access to legacy PRACH resources is not allowed (NO), the NES capable UE accesses only NES PRACH resources at the operation 2110. If the determination at the operation 2108 indicates that access to legacy PRACH resources is allowed (YES), the NES capable UE accesses both the legacy and NES PRACH resources at the operation 2112. Returning to the operation 2104, if the determination indicates that the NES PRACH resources are not enabled (NO), the NES capable UE accesses both the legacy PRACH resources at the operation 2106.

[0252] For SIBt on demand, several scenarios are described above. In Case #2 shown in FIG. 22, a UE 2204 may obtain the UL WUS configuration from the Cell A 2212, which implies that a UE that can receive the SSB from a NES Cell 2202 always receives the SSB and SIB1 from the neighboring Cell A 2212. In other words, the NES Cell 2202 is always covered by one or multiple neighboring cells (e.g., Cell A 2212). In addition, the reported energy savings for the NES Cell 2202 is substantial only for empty or low load of the NES Cell 2202. For this reason, it is expected that once the load increases, the NES Cell 2202 would start transmitting SIB1 periodically to avoid additional signaling related to the on-demand SIB1. Thus, for a low number of SIB1 requests, the NES Cell 2202 may use on-demand SIBt feature and use regular SIBt transmission when the number of on-demand SIBt requests increases. In one embodiment, the NES Cell 2202 may sw itch from on-demand SIBt to periodic (regular) SIBt transmission and from periodic SIBt transmission to per request SIBt transmission. When the NES Cell 2202 starts transmitting periodically SIBt, the Cell A 2212 can stop transmission of UL WUS configuration if it is only dedicated to that NES Cell 2202 (i.e. no valid for other NES Cells).

[0253] Thus, when the per request of a signaling status changes (i.e., from per request to periodic and vice versa), the Cell A 2212 updates the necessary’ information inits ow n signaling. The same may hold for the NES Cell 2202, which may remove the barred status in the MIB as soon as the periodic SIBi starts.

[0254] The WID notes emphasize that the impact on the legacy UEs as well as the specs impact should be minimized. As described in TS 38.300, a legacy UE “that cannot determine the full contents of the minimum SI of a cell by receiving from that cell, shall consider that cell as barred.” Thus, for legacy UEs, the NES Cell implementing on- demand SIBi is de facto barred.

[0255] Because, in Case #2, a NES Cell is always in the coverage of one or more Cells A, it is expected that the legacy UEs would camp on one of the Cells A. To avoid a legacy UE continuously trying to monitor and decode SIBi (and spending additional energy) when SIBi is not periodically transmitted, the barred bit of the NES Cell (e.g., NES Cell 2202) should be set to one.

[0256] In one embodiment, a NES Cell implementing on-demand SIBi is barred for legacy devices. In other words, the MIB barred bit is set to one. Thus, the legacy devices would not extend the monitoring of SIBi from the NES Cell and would camp on one of Cells A.

[0257] Some other legacy devices, such as RedCap or release 18 NES capable UEs, if detecting that the MIB indicates a cell barred, may be required to monitor SIBi to further decide w hether the cell is barred for them or not. For this reason, if they continue monitoring for a possible SIBi and after a while w hen they do not find a SIBi transmission, they will consider the NES Cell barred and camp on another cell.

[0258] An R19 NES capable UE camped on Cell A determines that NES Cell provides SIBi on-demand and uses the UL WUS configuration provided by Cell A to request on- demand SIBi via UL WUS transmission.

[0259] In one embodiment, an R19 NES capable UE may also support legacy features such as RedCap or legacy NES features. In this case, in one embodiment, Cell A together with the UL WUS configuration for the SIBi request may indicate whether NES Cell is barred to redcap devices or legacy NES capable devices.

[0260] Whether an R19 NES capable UE, that support SIBi on demand and RedCap feature, could access or not the NES feature is described below.

[0261] In one embodiment, if the Cell A 2212 indicates that the NES Cell 2202 is barred for RedCap devices, the R19 NES capable UE may still access the NES Cell 2202 as a UE that does not support RedCap (i.e. a regular legacy UE).

[0262] Using this approach, the NES Cell 2202 that supports SIB1 on demand can be accessible to R19 NES capable devices as legacy devices and not R19 NES capable devices as RedCap devices or legacy NES capable devices.

[0263] The Cell A 2212 may also indicate for instance that the NES Cell 2202 is accessible to R19 NES capable devices that support RedCap features.

[0264] In another embodiment, the UL WUS configuration and cell barred indication can be provided using different system information transmissions in the Cell A 2212. For instance, the barred information may be provided in the SIB1 of the Cell A 2212 and the UL WUS configuration may be provided in another (new) dedicated SIB in the Cell A 2212, which can be periodically transmitted or per request transmitted. In this case, SIB1 in the Cell A 2212 may also indicate the transmission of the new SIB (carrying the UL WUS configuration) and its characteristics, for instance whether is periodic or on demand, and its periodicity.

[0265] The UL WUS configuration for the NES Cell 2202 may be provided for instance by SIB1 of the Cell A 2212 or a (new) dedicated SIB from Cell A 2212.

[0266] As defined in the specs, the “MIB is always transmitted on the BCH with a periodicity of 80 ms and repetitions made within 80 ms (TS 38.212 clause 7.1) and it includes parameters that are needed to acquire SIBi from the cell.... The SIBt is transmitted on the DL-SCH w ith a periodicity of 160 ms and variable transmission repetition periodicity within 160 ms as specified in TS 38.213, clause 13. The default transmission repetition periodicity of SIBi is 20 ms but the actual transmission repetition periodicity is up to network implementation.”

[0267] Therefore, using SIBi of the Cell A 2212 to provide UL WUS configuration may be wasteful as SIBi is by default broadcast every 20 ms. If a new SIB is dedicated for the UL WUS configuration, it may be transmitted at different (lower) periodicity, which may save overhead and avoid legacy devices to buffer unnecessary information. In addition, changing the UL WUS configuration would not require reconfiguration of RMSI (SIBi). In some scenario, an UE 2204 may need to monitor for new SIB to acquire the necessary7UL WUS configuration thus increasing latency of SIBi request. However, as described above, it is expected that the number of UEs requesting on-demand SIBi is relatively reduced, and therefore the Cell A 2212 energy gain is more advantageous than the potentially UE latency. In addition, if the latency compatibility is an issue, the new SIB periodicity7may be increased as needed. If a new SIB is defined for this purpose, following the legacy approach, the SIB may be obtained by a SIB request w hen necessary7.

[0268] In some embodiments, the Cell A 2212 supports a new SIB for UL WUS provisioning. In other different embodiments, the Cell A 2212 could provide UL WUS configuration either in SIB1 or in a new’ SIB. For instance, SIB1 can indicate that the UL WUS is provided in a new’ SIB and the periodicity of the new’ SIB. The Cell A 2212 can dynamically switch between SIB1 and a new SIB to provide the UL WUS configuration. When the UL WUS configuration is provided in a new’ SIB, the UE 2204 camped on the Cell A 2212 can request the UL WUS configuration by requesting new’ SIB transmission or information about new SIB.

[0269] One of the remaining determinations for RAN1 is whether the UL WUS resources are in the same PRACH resource pool as for PRACH other usage.

[0270] As described above, once the NES Cell 2202 load increases, the NES is diminished, and therefore it is expected that a cell with medium or high load will switch to always on S1B1 (periodic) broadcast / transmissions. For empty or low NES Cell load, the number of UEs initiating random access (for instance for initial access) is expected to be small, thus the allocated PRACH resources for other usage would be sufficient to accommodate infrequent requests for on-demand SIBi.

[0271] Therefore, it is advantageous if the dedicated WUS resource shares the same PRACH resource pool with PRACH resource for other usages.

[0272] The concurrent transmissions of UL-WUS may be more successful than the initial access random access transmissions because the UE identification is not needed since the request is a broadcast message. As long as multiple UL-WUS transmissions carry’ the same preamble at the same time / frequency resource, no further apart in time than the OFDM symbol cyclic prefix, the network will successfully receive the request. This contrasts with the contention based random access where the UL transmissions interfere with each other.

[0273] In one embodiment, there is a dedicated PRACH preamble for UL WUS SIBi request, which means that all NES capable UEs would send a SIBi request to the NES Cell 2202 using the same preamble.

[0274] In a different embodiment, the PRACH resources (in time and / or in frequency) for UL WUS (SIBi request) are different from the PRACH resources for other usages.

[0275] RAN1 agreed that after transmission of UL WUS on a dedicated PRACH, the UE 2304 expects a RAR message from the gNB (e.g., NES Cell 2302), as showo in FIG. 23-

[0276] In the legacy design (TS 38.213, Clause 8.2), in response to a PRACH transmission, a UE attempts to detect a DCI format 1_O w ith CRC scrambled by a corresponding RA-RNTI during a window controlled by higher layers. Using a similar approach, a UE after sending a UL WUS may attempt to detect a DCI format 1_O w ith CRC scrambled by a new corresponding RNTI.

[0277] In some embodiments, there is a new SIB1-RNTI that scrambles the CRC for DCI format i_o RAR in response to UL WUS. The UE 2304, as soon as sent a UL WUS may start monitoring for the RAR, in other words the DCI with a CRC scrambled by SIB1-RNTI. The UE 2304 is a NES capable UE, supporting NES features defined by 3GPP standard releases, for example R19 release and later on release.

[0278] If the UE 2304 detects the DCI format i_o with the CRC scrambled by the corresponding S1B1-RNT1 and LSBs of an SFN field in the DCI format t_o, if included and applicable, are same as corresponding LSBs of the SFN where the UE transmitted PRACH, and the UE 2304 receives a transport block in a corresponding PDSCH within the window, the UE 2304 passes the transport block to higher layers.

[0279] The starting time and the duration time for SIB1 monitoring can be provided to the UE 2304 together with the UL WUS or separately, for instance, in the RAR message.

[0280] Because the RAR message is not acknowledged, while the UL WUS configuration is prerequisite for the on-demand SIB1 implementation, providing the information together with the UL WUS configuration is more robust to transmission failure of RAR message. Another possible solution is to provide the values in the RAR with additional default values that can be used if the UE 2304 fails to receive a RAR message.

[0281] Related to starting time and duration, a time reference is necessary to be defined.

[0282] In FIG. 24, three possible reference time options are presented: (1) the UL WUS transmission, (2) the RAR reception, and the (3) RAR window.

[0283] The starting time and the duration indicate to the UE 2404 when the on- demand SIB1 transmissions are expected. This information is used by the gNB (e.g., the NES Cell 2402) to transmit on-demand SIBt and by the UE 2404 to monitor the SIB1 transmissions. However, during the UL WUS and RAR messages exchange, it may happen that one of the transmissions fails to be received (decoded) by the other side. To select one of the options, this disclosure describes w hat the UE behavior is in different scenarios. The UE 2404 is expected to monitor the RAR message during the RARw indow and monitor for SIB1 transmission at least for specified duration from the starting time. In some embodiments, the UE 2404 is a NES capable UE, supporting NES features defined by 3GPP standard releases, for example R19 release and later on release.

[0284] All scenarios assume that the UE received previously the UL WUS configuration (e.g., from the Cell A 2412).

[0285] The UE 2404 transmits the UL WUS and waits for the duration of the RAR window to receive RAR message.

[0286] Scenario 1: the gNB (e.g., NES Cell 2402) receives a UL WUS message and transmit a RAR message.

[0287] Scenario la: the UE 2404 receives the RAR message during the RAR window and uses the starting time for SIB1 monitoring. In this scenario, the UL WUS transmission, the RAR reception (same as RAR transmission time), or the RAR window may be used as the time reference. In other words, the time reference at the UE 2404 coincides with time reference at the gNB (e.g., NES Cell 2402).

[0288] Scenario lb: the UE 2404 does not receive the RAR message during the RAR window. In this scenario, the gNB (e.g., NES Cell 2402) assumes that UE 2404 received RAR, the time reference at the gNB (e.g., NES Cell 2402) coincides with the time reference at the UE 2404 when the time reference is either the UL WUS transmission or the RAR transmission window.

[0289] Scenario 2: the gNB (e.g., NES Cell 2402) does not receive the UL WUS that UE 2404 sent, therefore does not send an RAR message.

[0290] In this scenario, the reference time is unknown at the gNB (e.g., NES Cell 2402). At the UE 2404, the reference time of the UL WUS transmission or the reference time based on RAR window are known.

[0291] In the legacy specs, a UE may monitor SIB1 transmission at any time after receiving an SSB that carries necessary SIB1 configuration. As described above, multiple UEs may request on-demand SIB1 in some time window. Therefore, it is expected that UE may monitor for both RAR message and SIB1 messages after the UL WUS transmission.

[0292] If the starting time is beyond the RAR window and the UE 2404 monitors only RAR messages during the RAR window-, the UE 2404 may miss a SIBi transmission requested by another UE.

[0293] If the starting time is before the end of the RAR window and the UE 2404 monitors only the RAR message, the UE 2404 may miss SIB1 transmission during RAR window in the case of RAR message failure.

[0294] In some embodiments, the UE 2404 monitors during the RAR window for both RAR message and SIB1 transmissions from the NES Cell 2402.

[0295] What is UE behavior if the does not receive a RAR message during the RAR window (Scenarios lb and 2) and when UE may or may not receive a SI Bl requested by another UE. Several possibilities are described below.

[0296] Scenario A: the UE receives neither a RAR nor a SIB1 during the RAR window.

[0297] Option 1: the UE stops monitoring for SIBt and may retransmit the UL WUS. The UE can interpret the absence of RAR message as stop to monitor SIBt beyond the RAR window.

[0298] Option 2: the UE continues monitoring for SIBt despite not receiving the RAR message using starting time and duration (from the UL WUS configuration). If no SIB1 is received, the UE may retransmit the UL WUS.

[0299] Scenario B: the UE does not receive a RAR message but receives SIBt transmission,

[0300] Option 1: the UE continues monitoring for RAR message until the RAR window ends.

[0301] Option 2: the UE may stop monitoring for the RAR message.

[0302] The reception of SIBt message may be considered as an acknowledgement to the UL WUS (like a RAR) despite the fact a RAR message is not received, thus a UE may not need to retransmit another SIBt request.

[0303] For Scenario A, Option 2 may be more robust than Option 1 at the expense of extra time monitoring of SIBt transmissions. For this case (Scenario A, Option 2), a more appropriate reference time for starting time is based on the RAR window-. Otherwise (if the reference time is the UL WUS), the starting time may need to be larger than the RAR window.

[0304] In general, the starting point plus the duration is expected to extend beyond the RAR window end; otherwise, the RAR window would be sufficient for SIBt monitoring. Thus, assuming that during the RAR window the UE monitors for both RAR and SIBt, the reference time for the starting time may be based on the RAR window.

[0305] The reference time point is defined based on the RAR w indow of the UL-WUS transmission.

[0306] One of the requirements stated in the WID is that “RAN1 specification impact to support this feature should be minimized.” Therefore, reusing the existing solutions with minimum changes is preferred.

[0307] As described above, the NES Cell providing on-demand SIB1 is barred for the legacy devices. A barred UE may proceed to cell re-selection to other cells on the same frequency as the barred cell as specified in TS 38.304. However, a simple indication of cell barred in the MIB cellBarred field is not sufficient.

[0308] Some legacy devices such as RedCap or 2RX XR UEs, if the MIB (ssb- SubcarrierOffset) indicates that SIB1 is present, will acquire SIB1 to determine whether that cell is barred or not (TS 38.331, Clause 5.2.2.41). Thus, to minimize the impact on the legacy devices, the ssb-SubcarrierOffset can indicate the absence of SIBi. If there is no such indication, these devices may spend extra energy by unnecessary monitoring of SIBi.

[0309] In one embodiment, a NES Cells supporting on-demand SIBi, has ssb- SubcarrierOffset indicating the absence of SIBi.

[0310] Reusing the existing design for type 0 PDCCH monitoring occasions for SIBi, on how the search space zero (searchSpaceZero) configuration is provided in MIB can be utilized. In the legacy specs, pdcch-ConfigSIBi may point to another frequency from where to search for an SSB that is associated with a SIBi as well as a frequency range, where the UE may assume no SSB associated with SIBi is present. Thus, if the frequency of SSB of Cell A is indicated, the discovery latency of Cell A is reduced.

[0311] In one embodiment, the SSB of a NES Cell supporting on-demand SIBi indicates the frequency7of SSB of Cell A. If the SSB of the NES Cell supporting on- demand SIBi indicates the frequency of SSB of Cell A, how searchSpaceZero for on- demand SIBi is provided is described in this disclosure.

[0312] Because the RAR message may not be reliable, and because the MIB of the NES Cell may provide searchSpaceZero for Cell A, Option2 may be utilized.

[0313] For type 0 PDCCH monitoring occasions for on-demand SIBi support Option2, searchSpaceZero for on-demand SIBi is provided from UL WUS configuration.

[0314] Note 1 in the WID requires that “No modification of SSB will be discussed under this objective,” which implies that there will be no changes to PBCH payload of NES Cell.

[0315] Moreover, the combination of barred status with ssb-SubcarrierOffset indicating no SIB1 is present, and the frequency provided for Cell A SSB is a reliable way to redirect a NES capable UE in a timely manner to Cell A where WUS configuration may indicate whether a cell is supporting on-demand SIB1 or not. This approach may require minimum changes to the existing specs

[0316] The WUS configuration can inform the UE that one or multiple cells in the neighborhood are NES Cells supporting on-demand SIB1. The detailed configuration can be discussed jointly with the discussion of WUS configuration validity area.

[0317] In one embodiment, the UE identification of NES Cell with on-demand SIB1 is based on WUS configuration.

[0318] In a different embodiment, the PRACH resources in the NES Cell may adapt in time. For instance, the R19 NES capable UE may access a different set of PRACH resources than any other legacy devices.

[0319] The set of resources for R19 NES capable UEs may be used for the initial access as well as the SIB1 request. The amount of PRACH resources may vary in time.

[0320] In a different embodiment, the R19 NES capable UEs may use a subset of their allocated PRACH resources for initial access and another subset of PRACH resources for on-demand signaling requests.

[0321] Yet, in a different embodiment, the R19 NES capable UE may access their PRACH dedicated resources as well as the legacy PRACH resources. In order to minimize the impact to the legacy UEs, the R19 NES capable UEs can try first to use their dedicated resources and then the legacy resources. For instance, after a number of failures of accessing the PRACH of dedicate resources, an R19 NES capable UE can try accessing some of the legacy PRACH resources.

[0322] In one embodiment, the partition of the PRACH resources and their access may be provided in SIB1 of Cell A or UL WUS configuration provided by Cell A.

[0323] In a different embodiment, the partition and the rule of access may be provided even in NES Cell. For instance, the on-demand SIB1 can specify a set of resources for initial access and another set for other purposes such as further signaling requests.

[0324] Moreover, when the NES Cell switches to regular (periodically) transmitted SIBi, SIBi may indicate one set of PRACH resources for legacy UEs, another (dedicated) set of PRACH resources for R19 NES capable UEs, and yet another (common) subset of the PRACH for legacy UEs that can be accessed by the R19 NES capable UEs.

[0325] An R19 NES capable UE may be indicated rules of accessing the common PRACH resources for legacy UEs and for R19 NES capable UEs. For instance, some priority’ by implementing a higher probability to access the dedicated resources than the common resources, or the common resources after failing to access dedicated resources, etc. may be used.

[0326] In a different embodiment, the R19 NES capable UE may be indicated a DTX operation of the NES Cell.

[0327] In one embodiment, the indication may be provided by Cell A.

[0328] In one embodiment, the NES Cell may have two different configurations for the DTX active period and respectively’ the non-active period. In the active period, the UE may’ expect that SIB1 (or SSB) is transmitted. While in the non-active period, SIB1 (or SSB) is not transmitted.

[0329] In one embodiment, after the R19 NES capable UE transmits a UL WUS, the RAR window that starts at the UL WUS transmission may be continued during the non- active DTX period. Yet in a different embodiment, the RAR window stops when the non- active DTX period starts and restarts when the DTX active period starts.

[0330] In a different embodiment, the SIB1 may be delivered with different starting and respectively duration times, or respectively two periodicities (two different configurations) when NES Cell is in DTX active and respectively non-active period.

[0331] In one embodiment, as shown in FIG. 25, a NES Cell may have a special DTX mode, where during the active mode it broadcasts SIB1 (and / or SSB). While in non- active period, it accepts requests for on-demand SIB1 (and / or SSB) transmissions.

[0332] This mode of operation indication and associated configurations may be indicated in the NES Cell, or provided be a Cell A. Such configuration may also be valid for a validity area that may cover multiple NES Cells.

[0333] For NES indication, SSB or SIB1 transmissions during the active periods may be used, for instance.[°334] A NES Cell may switch back and forth between NES mode of operation and legacy mode of operation. The present embodiments are examples for on-demand SIBi NES operations; however, these operations can be extended directly for on-demand SSB NES mode of operation or for adaptive signaling mode of operation of NES Cells.

[0335] For instance, if a NES Cell operates in the on-demand SIBi mode of operation to save energy^ at zero or low’ load, the NES Cell may decide to switch to a normal (legacy) SIBi transmission when the number of UEs is increasing. This switching would reduceunnecessary requests and signaling between the NES Cell (e.g., gNB) and the UEs. To this end, a Cell A may provide timing information when such a transition occurs. This information coming from the network (e.g., gNB) may be provided at any time.

[0336] For instance, the information can include a countdown value of the frame number to the switching, or an absolute value of the system frame number (SFN) when this happens. In a different embodiment, this can be considered as the lifetime (duration) of a UL WUS configuration. A Cell A can provide different UL WUS configurations for different NES Cells, where each UL WUS configuration has different lifetimes. When the lifetime of WUS configuration expires, the UE may not place SIB1 request using UL WUS provided by that configuration. The lifetime of the UL WUS configuration or the time until the transition of NES Cell to legacy cell operation, or vice versa may be provided at any time. If such information is missing, the implicit duration of configuration is infinite time or a large number of frames. However, the gNB may overwrite the lifetime either in the UL WUS configuration or using other means of signaling such as MAC CE, RRC or DO. There may be different UE assumptions when a LP WUS configuration expires per network signaling. For one, the UE assumes the NES Cell is to operate in legacy mode, i.e., it wil 1 transmit SIB1 periodically according to the configuration information in the NES Cell SSB, so no UL WUS is needed to acquire or reacquire SIB1, and the UE can monitor the periodic SIB1 transmission. For another, the UE assumes the NES Cell is to enter an even deeper sleep / energy saving mode, such as turned-off mode, and the UE may leave the NES Cell and camp under another cell, such as Cell A. In an embodiment, information about which of above assumptions is valid may be sent to the UE. In another embodiment, information about the next operation mode of the NES Cell is sent, and when the information indicates a transition to a normal mode or turned-off mode, the current UL WUS configuration will expire. In other w ords, a transition signaling may se e as an indicator of expiry’ of the UL WUS configuration.

[0337] In an embodiment, the UL WUS configuration indicates the direction of NES Cell mode of operation switching, for instance from NES on-demand SIB1 to legacy cell. The indication may be associated with a specific NES Cell ID in a list of NES Cells, together with validity timers for each NES Cell. As shown in FIG. 26, at the operation 2602, the UE receives an UL WUS configuration. At the operation 2604, the UE determines whether the UL WUS valid limited time condition is satisfied. If the determination at the operation 2604 indicates NO, the process proceeds to the operation 2606, where the UE uses UL WUS as necessaiy. If the determination at the operation 2604 indicates YES, the process proceeds to the operation 2608, where the UE determines whether the UL WUS time has expired. If the determination at the operation2606 indicates NO, the process returns to the operation 2606 to use UL WUS as necessary. If the determination at the operation 2608 indicates YES, the process proceeds to the operation 2610, where the UE determines whether the NES cell is switching to legacy SIB1. If the determination at the operation 2610 indicates YES, the UE monitors legacy SIB1 at the operation 2612. If the determination at the operation 2610 indicates NO, the UE does not use UL WUS at the operation 2614

[0338] In a different embodiment, a Cell A may provide multiple UL WUS configurations, where the validity of the configuration may be associated with other criteria such as the NES SSB strength (e.g., SSB RSRP). For instance, a UE may be allowed to use a specific UL WUS configuration only when the SSB strength is between specific limits. As shown in FIG. 27, at the operation 2702, the UE receives an UL WUS configuration. At the operation 2704, the UE determines whether the UL WUS is valid based on NES SSB RSRP. If the determination at the operation 2704 indicates NO, the process proceeds to the operation 2706, w here the UE uses UL WUS as necessary. If the determination at the operation 2704 indicates YES, the process proceeds to the operation 2708, w here the UE determines whether NES SSB RSRP satisfies UL WUS condition. If the determination at the operation 2708 indicates YES, the process returns to the operation 2706 to use UL WUS as necessary7. If the determination at the operation 2708 indicates NO, the UE does not use UL WUS at the operation 2710.

[0339] Yet, in a different embodiment, UL WUS configuration validity may depend on a combination of time and NES SSB strength.

[0340] In a different embodiment, another condition associated with UL WUS validity or usage may be the RSRP difference between the Cell A SSB and NES SSB. Thus, only those UEs that are receiving a weak SSB from Cell A but a strong SSB from NES Cell may use the on-demand SIBt and later camp on NES Cell.

[0341] In a different embodiment, a NES Cell may provide information about switching mode of operation to a legacy' mode using paging messages, or group DO or RRC configuration. The information signals the switch between NES mode of operation to a different mode, such as a legacy SIBt periodic transmission or vice-versa. When a cell transitions from legacy mode to SIBt on-demand, the legacy UEs may be affected and obliged to do a reselection to a legacy cell.

[0342] Cell A and NES Cells both may provide UL WUS configurations. A NES Cell may provide UL WUS configurations (or reconfiguration) for its own UEs (camped on NES Cell) or for UEs from other NES Cells. Normally, the configuration of UL WUS in Cell A and in a NES Cell are in sync. However, this disclosure also considers the casewhen one of these configurations expires and the other is still valid. In this case, a UE would be allowed to use only the valid configuration. In a different embodiment, when the two configurations of UL WUS for the same NES Cell are not coordinated, the UE may be required to suspend on any SIB1 request until the configurations are in sync again. If this case is not desirable, to avoid those conflicts, a UE may also be required to consider as a valid UL WUS configuration only if received from the cell it camped on. Thus, a UE camped in a NES Cell wi 11 consider a UL WUS configuration valid only when the UL WUS configuration provided in SIBx. Or a UE camped in a Cell A considers valid only the UL WUS configuration provided by Cell A.[°343] A technical issue to solve is when a NES Cell provides the UL WUS configuration for itself and other neighboring cells. In this case, if the NES Cell is an on- demand SIB1 cell, a UE may camp on that cell only if it receives a UL WUS configuration and after placing an SIBi request, receives a SIBi.

[0344] One possibility for NES Cells to provide a UL WUS configuration for themselves and neighboring cells is to use a dedicated SIB (SIBx). In this case, a UE that camped (or in connected mode) in the NES Cell can receive the dedicated SIBx to get the updated UL WUS configuration. A UE from neighboring cells in this case can first camp on the NES Cell and then receive SIBx w ith UL WUS configuration for the NES Cell neighboring cell. Then, the UE can place a SIBi request in the neighboring cell of the NES Cell.

[0345] In this scenario, the NES Cell plays the role of a pseudo Cell A without having a periodic SIBi transmission (a legacy SIBi transmission).

[0346] In a different embodiment, as shown in FIG. 28, Cell A 2812 may proidde in addition to the UL WUS configuration for the NES Cell 2802, the configuration of SIBx transmitted by the NES Cell 2802, where SIBx contains the UL WUS configuration for NES Cell 2802 and UL WUS configuration for some neighboring cells (e.g., neighboring cell 2822)of the NES Cell 2802. In that case, a UE 2804 receiving SSB from Cell A 2812, the NES Cell 2802, and a neighbor of NES Cell 2822, may receive the SIBx configuration for the NES Cell 2802 from Cell A 2812, and then monitor SIBx from the NES Cell 2802, and use the UL WUS configuration provided by the SIBx to place a SIBi request in the neighboring cell 2822 of NES Cell 2802.

[0347] In a different embodiment, as shown in FIG. 29, a UE 2904 may camp on the NES Cell 2902 after obtaining an on-demand SIBi from the NES Cell 2902. The on- demand SIBi transmitted by the NES Cell 2902 may be in response the UL WUS transmitted by the UE 2904 based on the UL WUS configuration for NES Cell from CellA 2912. The on-demand SIB1 may contain information about SIBx transmission, where SIBx contains UL WUS configuration for the NES Cell 2902 and neighboring cells (e.g., neighboring cell 2922). After receiving SIBx, the UE 2904 may place a SIB1 request in one of the neighboring cells (e.g., neighboring cell 2922) provided that cell operates as NES with on-demand SIB1.

[0348] In one embodiment, the gNB may signal to the UE the duration of particular mode of operation such as on-demand-SSB and on-demand SIBi.

[0349] In the above embodiments, a neighbor cell to a first cell may be a cell non-co- located with the first cell and having the same or different carrier frequency, or a cell colocated with the first cell but on a different carrier frequency.

[0350] FIG- 3OA shows a flow chart of a method 3000 performed by a UE, in accordance w ith some implementations. The UE may include computer-readable code or instructions executing on one or more processors of the UE. Coding of the software for carrying out or performing the method 3000 is well w ithin the scope of a person of ordinary skill in the art having regard to the present disclosure. The method 3000 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 UE. In some embodiments, the method 3000 may be performed by one or more of units or modules (e.g., an integrated circuit) of the UE, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0351] The method 3000 starts at the operation 3002, where the UE receives from a first cell a first synchronization signal block (SSB). A transmission of a first system information block 1 (SIBi) carrying a first remaining minimum system information block (RMSI) is disabled. At the operation 3004, the UE receives from a second cell a second SSB or a second periodic SIBi carrying a second RMSI and a resource configuration for transmitting an uplink wakeup signal (WUS) requesting the transmission of the first SIBi carrying the first RMSI for the first cell.

[0352] In some implementations, the resource configuration for the uplink WUS may be in the second periodic SIBi or in another system information block (SIB) transmission from the second cell.

[0353] In some implementations, the second cell may indicate that the first cell provides an on-demand SIBi transmission carrying the first RMSI when the first cellreceives the uplink WUS in accordance with a WUS resource configuration for transmitting an uplink WUS.

[0354] In some implementations, the second cell may indicate a time duration or time offset of the on-demand SIB1 transmission from the first cell after the uplink WUS is received by the first cell.

[0355] In some implementations, resources in the resource configuration for transmitting the uplink WUS may include dedicated resources on a physical random access channel (PRACH) of the first or second cell and a dedicate PRACH preamble.

[0356] In some implementations, the UE may transmit the uplink WUS to the first cell using a PRACH resource in accordance with the resource configuration.

[0357] In some implementations, the UE may receive a random access response (RAR) from the first cell after transmitting the uplink WUS or receiving the transmission of the first SIB1 from the first cell during a RAR window or receiving both RAR and SIB1 during the RAR window.

[0358] In some implementations, the UE may monitor resources for on-demand SIB1 transmission carrying the first RMSI for the first cell. The resources may be indicated by a first master information block (MIB) in a first physical broadcast channel (PBCH) of the first cell for the transmission of the first SIB1 or by the second cell for a system information transmission.[°3591 In some implementations, the UE may camp on the first cell or establishes a radio resource control (RRC) connection to the first cell based on the first RMSI in the first SIBt.

[0360] In some implementations, the UE may receive from the first cell an indication indicating that the first cell receives WUS requests for SIBt transmission or indicating periodic SIBt transmissions without requests.

[0361] In some implementations, the UE may receive from the first cell an indication indicating when the first cell may start receiving WUS requests for SIBt transmission or indicating when periodic SIBt transmissions without requests start.

[0362] In some implementations, the resource configuration may indicate a duration of configuration validity of the resource configuration.

[0363] In some implementations, the resource configuration may indicate an operation mode of the first cell w hen the configuration validity expires. The operation mode may indicate that the first cell receives WUS requests for SIBt transmission or may indicate periodic SIBt transmissions without requests.

[0364] In some implementations, the resource configuration may indicate a quality threshold of the first cell for which the resource configuration is valid.

[0365] In some implementations, the resource configuration may indicate a threshold of a difference between a quality of the first cell and a second quality of the second cell for which the resource configuration is valid.

[0366] In some implementations, the UE may receive from the first cell an indication of starting SIB1 transmissions on a periodic basis.

[0367] In some implementations, SSB transmission occasions may be indicated in RRC signaling.

[0368] FIG. 30B shows a flow chart of a method 3050 performed by a UE, in accordance w ith some implementations. The UE may include computer-readable code or instructions executing on one or more processors of the UE. Coding of the software for carrying out or performing the method 3050 is well within the scope of a person of ordinary skill in the art having regard to the present disclosure. The method 3050 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 softw are 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 UE. In some embodiments, the method 3050 may be performed by one or more of units or modules (e.g., an integrated circuit) of the UE, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0369] The method 3050 starts at the operation 3052, where the UE receives system information. The system information indicates transmission parameters including periodicity information. At the operation 3054, the UE receives a synchronization signal block (SSB) using the transmission parameters.

[0370] In some implementations, the periodicity information may indicate a first periodicity and a second periodicity.

[0371] In some implementations, the periodicity information may indicate that the first periodicity is used for a cell discontinuous transmission (DTX) non-active period and that the second periodicity is used for a cell DTX active period.

[0372] This disclosure incorporates the following by reference in their entireties.[1] RP-234065, New WID: Enhancements of network energy savings for NR, Ericsson (Moderator).[2] TS 38.133, 5G NR Requirements for support of radio resource management.[3] Rl-21io697> Summary of agreements for Rel-17 feMR-DC WI, Rapporteur (Huawei).

[0373] FIG- 31illustrates an example communication system 3100. In general, the system 3100 enables multiple wireless or wired users to transmit and receive data and other content. The system 3100 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).

[0374] In this example, the communication system 3100 includes electronic devices (ED) 3iioa-3tioc, radio access networks (RANs) 3i2oa-3t2ob, a core network 3130, a public switched telephone network (PSTN) 3140, the Internet 3150, and other networks 3160. While certain numbers of these components or elements are shown in FIG. 31, any number of these components or elements may be included in the system 3100.

[0375] The EDs 31103-31100 are configured to operate or communicate in the system 3100. For example, the EDs 31103-31100 are configured to transmit or receive via wireless or wired communication channels. Each ED 31103-31100 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.

[0376] The RANs 3i2oa-3i2ob here include base stations 31703-3170^ respectively. Each base station 3i70a-3i70b is configured to wirelessly interface with one or more of the EDs 3iioa-3iioc to enable access to the core network 3130, the PSTN 3140, the Internet 3150, or the other networks 3160. For example, the base stations 3i70a-3i70b may include (or be) one or more of several well-know n 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 31103-31100 are configured to interface and communicate with the Internet 3150 and may access the core network 3130, the PSTN 3140, or the other networks 3160.

[0377] In the embodiment show n in FIG. 31, the base station 3170a forms part of the RAN 3120a, which may include other base stations, elements, or devices. Also, the base station 3170b forms part of the RAN 3120b, w-hich may include other base stations, elements, or devices. Each base station 3i7oa-3i7ob operates to transmit or receivew ireless signals w ithin 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.

[0378] The base stations 3i70a-3i70b communicate with one or more of the EDs 3iioa-3iioc over one or more air interfaces 3190 using wireless communication links. The air interfaces 3190 may utilize any suitable radio access technology.

[0379] It is contemplated that the system 3100 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.

[0380] The RANs 3i2oa-3i2ob are in communication with the core network 3130 to provide the EDs 31103-3110c with voice, data, application, Voice over Internet Protocol (VoIP), or other services. Understandably, the RANs 3i2oa-3i2ob or the core network 3130 may be in direct or indirect communication with one or more other RANs (not shown). The core network 3130 may also serve as a gateway access for other networks (such as the PSTN 3140, the Internet 3150, and the other networks 3160). In addition, some or all of the EDs 31103-31100 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 sen ice provider or switch (not shown), and to the Internet 3150.

[0381] Although FIG. 31 illustrates one example of a communication system, various changes may be made to FIG. 31. For example, the communication system 3100 could include any number of EDs, base stations, networks, or other components in any suitable configuration.

[0382] FIGs. 32A and 32B illustrate example devices that may implement the methods and teachings according to this disclosure. In particular, FIG. 32A illustrates an example ED 3210, and FIG. 32B illustrates an example base station 3270. These components could be used in the system 3100 or in any other suitable system.

[0383] As shown in FIG. 32A, the ED 3210 includes at least one processing unit 3200. The processing unit 3200 implements various processing operations of the ED 3210. For example, the processing unit 3200 could perform signal coding, data processing, power control, input / output processing, or any other functionality enabling the ED 3210 to operate in the system 3100. The processing unit 3200 also supports the methods and teachings described in more detail above. Each processing unit 3200includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 3200 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0384] The ED 3210 also includes at least one transceiver 3202. The transceiver 3202 is configured to modulate data or other content for transmission by at least one antenna or NIC (Network Interface Controller) 3204. The transceiver 3202 is also configured to demodulate data or other content received by the at least one antenna 3204. Each transceiver 3202 includes any suitable structure for generating signals for wireless or wired transmission or processing signals received w irelessly or by wire. Each antenna 3204 includes any suitable structure for transmitting or receiving wireless or wired signals. One or multiple transceivers 3202 could be used in the ED 3210, and one or multiple antennas 3204 could be used in the ED 3210. Although shown as a single functional unit, a transceiver 3202 could also be implemented using at least one transmitter and at least one separate receiver.

[0385] The ED 3210 further includes one or more input / output devices 3206 or interfaces (such as a wired interface to the Internet 3150). The input / output devices 3206 facilitate interaction with a user or other devices (network communications) in the network. Each input / output device 3206 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.

[0386] In addition, the ED 3210 includes at least one memory73208. The memory 3208 stores instructions and data used, generated, or collected by the ED 3210. For example, the memory 3208 could store software or firmware instructions executed by the processing unit(s) 3200 and data used to reduce or eliminate interference in incoming signals. Each memory 3208 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.

[0387] As shown in FIG. 32B, the base station 3270 includes at least one processing unit 3250, at least one transceiver 3252, which includes functionality for a transmitter and a receiver, one or more antennas 3256, at least one memory73258, and one or more input / output devices or interfaces 3266. A scheduler, which would be understood by one skilled in the art, is coupled to the processing unit 3250. The scheduler could be included within or operated separately from the base station 3270. The processing unit 3250 implements various processing operations of the base station 3270, such as signalcoding, data processing, power control, input / output processing, or any other functionality. The processing unit 3250 can also support the methods and teachings described in more detail above. Each processing unit 3250 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 3250 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0388] Each transceiver 3252 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 3252 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 3252, a transmitter and a receiver could be separate components. Each antenna 3256 includes any suitable structure for transmitting or receiving w ireless or w ired signals. While a common antenna 3256 is shown here as being coupled to the transceiver 3252, one or more antennas 3256 could be coupled to the transceiver(s) 3252, allowing separate antennas 3256 to be coupled to the transmitter and the receiver if equipped as separate components. Each memoiy 3258 includes any suitable volatile or non-volatile storage and retrieval device(s). Each input / output device 3266 facilitates interaction with a user or other devices (network communications) in the network. Each input / output device 3266 includes any suitable structure for providing information to or receiving / rovi ing information from a user, including network interface communications.

[0389] FIG. 33 is a block diagram of a computing system 3300 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 3300 includes a processing unit 3302. The processing unit includes a central processing unit (CPU) 3314, memory 3308, and may further include a mass storage device 3304, a video adapter 3310, and an I / O interface 3312 connected to a bus 3320.

[0390] The bus 3320 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 3314 may comprise any type of electronic data processor. The memoiy 3308 maycomprise any type of non-transitory system memory such as static random access memoiy (SRAM), dynamic random access memory’ (DRAM), synchronous DRAM (SDRAM), read-only memory’ (ROM), or a combination thereof. In an embodiment, the memoiy’ 3308 may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs.

[0391] The mass storage 3304 may comprise any ty pe 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 3320. The mass storage 3304 may comprise, for example, one or more of a solid state drive, hard disk drive, a magnetic disk drive, or an optical disk drive.

[0392] The video adapter 3310 and the I / O interface 3312 provide interfaces to couple external input and output devices to the processing unit 3302. As illustrated, examples of input and output devices include a display 3318 coupled to the video adapter 3310 and a mouse, keyboard, or printer 3316 coupled to the I / O interface 3312. Other devices may be coupled to the processing unit 3302, 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.

[0393] The processing unit 3302 also includes one or more network interfaces 3306, which may comprise wired links, such as an Ethernet cable, or wireless links to access nodes or different networks. The network interfaces 3306 allow the processing unit 3302 to communicate with remote units via the networks. For example, the network interfaces 3306 may provide wireless communication via one or more transmitters / transmit antennas and one or more receivers / receive antennas. In an embodiment, the processing unit 3302 is coupled to a local-area network 3322 or a wide-area network for data processing and communications with remote devices, such as other processing units, the Internet, or remote storage facilities.

[0394] 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 hardw are, softw are, or a combination thereof. For instance, one or moreof the units or modules may be an integrated circuit, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0395] 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 to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

WHAT IS CLAIMED IS:

1. A method comprising: receiving, by a user equipment (UE) from a first cell, a first synchronization signal block (SSB), wherein a transmission of a first system information block 1 (SIBt) carrying a first remaining minimum system information block (RMSI) is disabled; and receiving, by the UE from a second cell, a second SSB or a second periodic SIB1 carrying a second RMSI and a resource configuration for transmitting an uplink wakeup signal (WUS) requesting the transmission of the first SIBt carrying the first RMSI for the first cell.

2. The method of claim 1, wherein the resource configuration for the uplink WUS is in the second periodic SIBt or in another system information block (SIB) transmission from the second cell.

3. The method of any of claims 1-2, wherein the second cell indicates that the first cell provides an on-demand SIBt transmission earning the first RMSI when the first cell receives the uplink WUS in accordance with a WUS resource configuration for transmitting an uplink WUS.

4. The method of claim 3, wherein the second cell indicates a time duration or time offset of the on-demand SIBt transmission from the first cell after the uplink WUS is received by the first cell.

5. The method of any of claims 1-4, wherein resources in the resource configuration for transmitting the uplink WUS include dedicated resources on a physical random access channel (PRACH) of the first or second cell and a dedicate PRACH preamble.

6. The method of any of claims 1-5, wherein the UE transmits the uplink WUS to the first cell using a PRACH resource in accordance with the resource configuration.

7. The method of claim 6, wherein the UE receives a random access response (RAR) from the first cell after transmitting the uplink WUS or receiving the transmission of the first SIBt from the first cell during a RAR window or receiving both RAR and SIBt during the RAR window.

8. The method of claim 6, wherein the UE monitors resources for on-demand SIBt transmission cariying the first RMSI for the first cell, and wherein the resources are indicated by a first master information block (MIB) in a first physical broadcast channel(PBCH) of the first cell for the transmission of the first SIB1 or by the resource configuration from the second cell for a system information transmission.

9. The method of any of claims 1-8, wherein the UE camps on the first cell or establishes a radio resource control (RRC) connection to the first cell based on the first RMSI in the first SIB1.

10. The method of any of claims 1-9, wherein the UE receives from the first cell an indication indicating that the first cell receives WUS requests for SIB1 transmission or indicating periodic SIB1 transmissions without requests.

11. The method of any of claims 1-10, wherein the UE receives from the first cell an indication indicating when the first cell may start receiving WUS requests for SIB1 transmission or indicating when periodic SIB1 transmissions w ithout requests start.

12. The method of any of claims 1-11, wherein the resource configuration indicates a duration of configuration validity of the resource configuration.

13. The method of claim 12, wherein the resource configuration indicates an operation mode of the first cell when the configuration validity expires, and wherein the operation mode indicates that the first cell receives WUS requests for SIB1 transmission or indicates periodic SIB1 transmissions without requests.

14. The method of any of claims 1-13, wherein the resource configuration indicates a quality threshold of the first cell for which the resource configuration is valid.

15. The method of any of claims 1-14, wherein the resource configuration indicates a threshold of a difference between a quality of the first cell and a second quality of the second cell for which the resource configuration is valid.

16. The method of any of claims 1-15, wherein the UE receives from the first cell an indication of starting SIB1 transmissions on a periodic basis.

17. The method of claim 16, wherein SSB transmission occasions are indicated in RRC signaling.

18. The method of any of claims 1-17, the second periodic SIBi further indicating a second resource configuration for transmitting uplink WUSs for the second cell.19- A user equipment (UE), 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 UE to perform a method according to any of claims 1-18.

20. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a user equipment (UE), cause the UE to perform a method according to any of claims 1-18.

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