Method and apparatus for on-demand-system information block 1 handling

Abstract

A method performed by a UE for OD-SIB1 handling is provided. The method camps on a first cell. The method receives, from the first cell, an OD-SIB1 request configuration including a first resource configuration, a second resource configuration, and a maximum number. The method transmits, to a second cell, an OD-SIB1 request based on the first resource configuration. The method monitors, from the second cell, a response based on the second resource configuration. The method when the response is received: receives, from the second cell, an SIB1; and camps on the second cell. The method when the response is not received: retransmits the OD-SIB1 request when the number of transmissions of the OD-SIB1 request is less than the maximum number; and determines the second cell as barred when the number of transmissions of the OD-SIB1 request is equal to the maximum number.

Description

METHOD AND APPARATUS FOR ON-DEMAND-SYSTEM INFORMATION BLOCK 1 HANDLING

[0001] The present disclosure is related to wireless communication and, more specifically, to a User Equipment (UE), Base Station (BS), and method for on-demand (OD)-system information block 1 (SIB1) handling in the wireless communication networks.

[0002] Various efforts have been made to improve different aspects of wireless communication for the cellular wireless communication systems, such as the 5thGeneration (5G) New Radio (NR), by improving data rate, latency, reliability, and mobility. The 5G NR system is designed to provide flexibility and configurability to optimize network services and types, accommodating various use cases, such as enhanced Mobile Broadband (eMBB), massive Machine-Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC). As the demand for radio access continues to grow, however, there exists a need for further improvements in the next-generation wireless communication systems.

[0003] The present disclosure is related to a UE, a BS, and a method for OD-SIB1 handling in the wireless communication networks.

[0004] In a first aspect of the present disclosure, a UE for on-demand (OD)-system information block 1 (SIB1) handling is provided. The UE includes at least one processor and at least one non-transitory computer-readable medium that is coupled to the at least one processor and that stores one or more computer-executable instructions. The computer-executable instructions, when executed by the at least one processor, cause the UE to: camp on a first cell; receive, from the first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration comprising a first resource configuration for an OD-SIB1 request, a second resource configuration for a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request; transmit, to a second cell, the OD-SIB1 request based on the first resource configuration; monitor, from the second cell, the response based on the second resource configuration; determine whether the response is received; in response to determining that the response is received: receive, from the second cell, an SIB1; and camp on the second cell; in response to determining that the response is not received: determine whether a number of transmissions of the OD-SIB1 request is less than or equal to the maximum number; retransmit, to the second cell, the OD-SIB1 request in response to determining that the number of transmissions of the OD-SIB1 request is less than the maximum number; and determine the second cell as barred in response to determining that the number of transmissions of the OD-SIB1 request is equal to the maximum number.

[0005] In some implementations of the first aspect, the response includes a random access response (RAR) including a medium access control (MAC) sub-protocol data unit (subPDU) with random access preamble identifier (RAPID) only.

[0006] In a second aspect of the present application, a BS for OD-SIB1 handling is provided. The BS includes at least one processor and at least one non-transitory computer-readable medium that is coupled to the at least one processor and that stores one or more computer-executable instructions. The computer-executable instructions, when executed by the at least one processor, cause the BS to: transmit, to a user equipment (UE) via a first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration comprising a first resource configuration for an OD-SIB1 request, a second resource configuration for a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request; receive, from the UE via a second cell, the OD-SIB1 request based on the first resource configuration; transmit, to the UE via the second cell, the response based on the second resource configuration; and transmit, to the UE via the second cell, an SIB1.

[0007] In some implementations of the second aspect, the response includes a random access response (RAR) including a medium access control (MAC) sub-protocol data unit (subPDU) with random access preamble identifier (RAPID) only.

[0008] In a third aspect of the present disclosure, a method performed by a user equipment (UE) for on-demand (OD)-system information block 1 (SIB1) handling is provided. The method includes: camping on a first cell; receiving, from the first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration comprising a first resource configuration for transmitting an OD-SIB1 request, a second resource configuration for monitoring a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request; transmitting, to a second cell, the OD-SIB1 request based on the first resource configuration; monitoring, from the second cell, the response based on the second resource configuration; determining whether the response is received; in response to determining that the response is received: receiving, from the second cell, an SIB1; and camping on the second cell; and in response to determining that the response is not received: determining whether a number of transmissions of the OD-SIB1 request is less than or equal to the maximum number; retransmitting, to the second cell, the OD-SIB1 request in response to determining that the number of transmissions of the OD-SIB1 request is less than the maximum number; and determining the second cell as barred in response to determining that the number of transmissions of the OD-SIB1 request is equal to the maximum number.

[0009]

[0010] Aspects of the present disclosure are best understood from the following detailed disclosure when read with the accompanying drawings. Various features are not drawn to scale. Dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.

[0011] FIG. 1 is a diagram illustrating the coverage relationships among multiple cells in Scenario 1, according to an example implementation of the present disclosure.

[0012] FIG. 2 is a diagram illustrating the coverage relationships among multiple cells in Scenario 2, according to an example implementation of the present disclosure.

[0013] FIG. 3 is a diagram illustrating the coverage relationships among multiple cells in Scenario 3, according to an example implementation of the present disclosure.

[0014] FIG. 4 is a flowchart illustrating a method / process performed by a UE capable of “on-demand SIB1 request” feature, according to an example implementation of the present disclosure.

[0015] FIG. 5 is a flowchart illustrating a method / process performed by a BS, a network, and / or a cell capable of “Release 19 NES” feature, according to an example implementation of the present disclosure.

[0016] FIG. 6 is a diagram illustrating possible workflows under various assumptions, according to an example implementation of the present disclosure.

[0017] FIG. 7 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0018] FIG. 8 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0019] FIG. 9 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0020] FIG. 10 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0021] FIG. 11 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0022] FIG. 12 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0023] FIG. 13 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0024] FIG. 14 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0025] FIG. 15 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0026] FIG. 16 is a flowchart illustrating a method / process performed by a UE for OD-SIB1 handling, according to an example implementation of the present disclosure.

[0027] FIG. 17 is a flowchart illustrating a method / process performed by a BS for OD-SIB1 handling, according to an example implementation of the present disclosure.

[0028] FIG. 18 is a block diagram illustrating a node for wireless communication, according to an example implementation of the present disclosure.

[0029] Some of the abbreviations used in the present disclosure include: Abbreviation　　　　Full name 3GPP　　　　3rd Generation Partnership Project 5G　　　　5th Generation A-CSI　　　　Aperiodic Channel State Information ACK　　　　Acknowledgment BS　　　　Base Station BWP　　　　Bandwidth Part CA　　　　Carrier Aggregation CE　　　　Control Element CN　　　　Core Network CORESET　　　　Control resource set CSI　　　　Channel State Information CSI-RS　　　　Channel State Information-Reference Signal DC　　　　Dual Connectivity DCI　　　　Downlink Control Information DL　　　　Downlink DL-AOA　　　　Downlink Angle-Of-Arrival DL-TDOA　　　　Downlink Time-Difference-Of-Arrival E-UTRA　　　　Evolved Universal Terrestrial Radio Access FR　　　　Frequency Range FR1　　　　Frequency Range 1 FR2　　　　Frequency Range 2 HARQ　　　　Hybrid Automatic Repeat Request HARQ-ACK　　　　HARQ Acknowledgement ID　　　　Identifier IE　　　　Information Element LTE　　　　Long Term Evolution L1 / L2 / L3　　　　Layer 1 / Layer 2 / Layer 3 MAC　　　　Medium Access Control MAC CE　　　　MAC Control Element MBS　　　　Multicast / Broadcast Service MCG　　　　Master Cell Group MCS　　　　Modulation and Coding Scheme MDT　　　　Minimization of Driven Tests ML　　　　Machine Learning NACK　　　　Negative Acknowledgment NAS　　　　Non-Access Stratum NES　　　　Network Energy Saving NG-RAN　　　　Next Generation RAN NR　　　　New Radio NW　　　　Network OAM　　　　Operations, Administration, and Maintenance OD　　　　On-Demand OFDM　　　　Orthogonal Frequency Division Multiplexing PBCH　　　　Physical Broadcast Channel PCell　　　　Primary Cell PDCCH　　　　Physical Downlink Control Channel PDSCH　　　　Physical Downlink Shared Channel PDU　　　　Protocol Data Unit PHY　　　　Physical (layer) PRACH　　　　Physical Random Access Channel PRS　　　　Positioning Reference Signal PSCell　　　　Primary Secondary Cell PUCCH　　　　Physical Uplink Control Channel PUSCH　　　　Physical Uplink Shared Channel RA　　　　Random Access RACH　　　　Random Access Channel RAN　　　　Radio Access Network RAPID　　　　Random Access Preamble Identifier RAR　　　　Random Access Response Rel　　　　Release RNA　　　　RAN Notification Area RNAU　　　　RAN Notification Area Update RNTI　　　　Radio Network Temporary Identifier RRC　　　　Radio Resource Control RS　　　　Reference Signal RSRP　　　　Reference Signal Received Power RV　　　　Redundancy Version Rx　　　　Reception SCell　　　　Secondary Cell SCG　　　　Secondary Cell Group SCS　　　　Subcarrier Spacing SIB1　　　　System Information Block 1 SpCell　　　　Special Cell SP-CSI　　　　Semi-Persistent Channel State Information SR　　　　Scheduling Request SRS　　　　Sounding Reference Signal SRI　　　　SRS Resource Indicator SSB　　　　Synchronization Signal Block subPDU 　　　　sub-Protocol Data Unit TA　　　　Timing Advance TAG　　　　Timing Advance Group TB　　　　Transport Block TBS　　　　Transport Block Size TCI　　　　Transmission Configuration Indicator TR　　　　Technical Report TS　　　　Technical Specification Tx　　　　Transmission UCI　　　　Uplink Control Information UE　　　　User Equipment UL　　　　Uplink URLLC　　　　Ultra-Reliable and Low-Latency Communication WUS　　　　Wake-Up Signal

[0030] The following contains specific information related to implementations of the present disclosure. The drawings and their accompanying detailed disclosure are merely directed to implementations. However, the present disclosure is not limited to these implementations. Other variations and implementations of the present disclosure will be obvious to those skilled in the art.

[0031] Unless noted otherwise, like or corresponding elements among the drawings may be indicated by like or corresponding reference numerals. Moreover, the drawings and illustrations in the present disclosure are generally not to scale and are not intended to correspond to actual relative dimensions.

[0032] For the purposes of consistency and ease of understanding, like features may be identified (although, in some examples, not illustrated) by the same numerals in the drawings. However, the features in different implementations may be different in other respects and may not be narrowly confined to what is illustrated in the drawings.

[0033] References to “one implementation,” “an implementation,” “example implementation,” “various implementations,” “some implementations,” “implementations of the present application,” etc., may indicate that the implementation(s) of the present application so described may include a particular feature, structure, or characteristic, but not every possible implementation of the present application necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase “In some implementations,” or “in an example implementation,” “an implementation,” do not necessarily refer to the same implementation, although they may. Moreover, any use of phrases like “implementations” in connection with “the present application” are never meant to characterize that all implementations of the present application must include the particular feature, structure, or characteristic, and should instead be understood to mean “at least some implementations of the present application” includes the stated particular feature, structure, or characteristic. The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the equivalent.

[0034] The expression “at least one of A, B and C” or “at least one of the following: A, B and C” means “only A, or only B, or only C, or any combination of A, B and C.” The terms “system” and “network” may be used interchangeably. The term “and / or” is only an association relationship for describing associated objects and represents that three relationships may exist such that A and / or B may indicate that A exists alone, A and B exist at the same time, or B exists alone. The character “ / ” generally represents that the associated objects are in an “or” relationship.

[0035] For the purposes of explanation and non-limitation, specific details, such as functional entities, techniques, protocols, and standards, are set forth for providing an understanding of the disclosed technology. In other examples, detailed disclosure of well-known methods, technologies, systems, and architectures are omitted so as not to obscure the present disclosure with unnecessary details.

[0036] Persons skilled in the art will immediately recognize that any network function(s) or algorithm(s) disclosed may be implemented by hardware, software, or a combination of software and hardware. Disclosed functions may correspond to modules which may be software, hardware, firmware, or any combination thereof.

[0037] A software implementation may include computer executable instructions stored on a computer-readable medium, such as memory or other type of storage devices. One or more microprocessors or general-purpose computers with communication processing capability may be programmed with corresponding executable instructions and perform the disclosed network function(s) or algorithm(s).

[0038] The microprocessors or general-purpose computers may include Application-Specific Integrated Circuits (ASICs), programmable logic arrays, and / or one or more Digital Signal Processor (DSPs). Although some of the disclosed implementations are oriented to software installed and executing on computer hardware, alternative implementations implemented as firmware, as hardware, or as a combination of hardware and software are well within the scope of the present disclosure. The computer-readable medium includes but is not limited to Random Access Memory (RAM), Read Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM), magnetic cassettes, magnetic tape, magnetic disk storage, or any other equivalent medium capable of storing computer-readable instructions.

[0039] A radio communication network architecture such as a Long-Term Evolution (LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Pro system, or a 5G NR Radio Access Network (RAN) typically includes at least one base station (BS), at least one UE, and one or more optional network elements that provide connection within a network. The UE communicates with the network such as a Core Network (CN), an Evolved Packet Core (EPC) network, an Evolved Universal Terrestrial RAN (E-UTRAN), a 5G Core (5GC), or an internet via a RAN established by one or more BSs.

[0040] A UE may include, but is not limited to, a mobile station, a mobile terminal or device, or a user communication radio terminal. The UE may be a portable radio equipment that includes, but is not limited to, a mobile phone, a tablet, a wearable device, a sensor, a vehicle, or a Personal Digital Assistant (PDA) with wireless communication capability. The UE is configured to receive and transmit signals over an air interface to one or more cells in a RAN.

[0041] The BS may be configured to provide communication services according to at least a Radio Access Technology (RAT) such as Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM) that is often referred to as 2G, GSM Enhanced Data rates for GSM Evolution (EDGE) RAN (GERAN), General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS) that is often referred to as 3G based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), LTE, LTE-A, evolved LTE (eLTE) that is LTE connected to 5GC, NR (often referred to as 5G), and / or LTE-A Pro. However, the scope of the present disclosure is not limited to these protocols.

[0042] The BS may include, but is not limited to, a node B (NB) in the UMTS, an evolved node B (eNB) in LTE or LTE-A, a radio network controller (RNC) in UMTS, a BS controller (BSC) in the GSM / GERAN, an ng-eNB in an Evolved Universal Terrestrial Radio Access (E-UTRA) BS in connection with 5GC, a next generation Node B (gNB) in the 5G-RAN, or any other apparatus capable of controlling radio communication and managing radio resources within a cell. The BS may serve one or more UEs via a radio interface. Although the gNB is used as an example in some implementations within the present disclosure, it should be noted that the disclosed implementations may also be applied to other types of base stations.

[0043] The BS may be operable to provide radio coverage to a specific geographical area using multiple cells forming the RAN. The BS may support the operations of the cells. Each cell may be operable to provide services to at least one UE within its radio coverage.

[0044] Each cell (may often referred to as a serving cell) may provide services to one or more UEs within the cell’s radio coverage, such that each cell schedules the DL (and optionally UL resources) to at least one UE within its radio coverage for DL (and optionally UL packet transmissions from the UE). The BS may communicate with one or more UEs in the radio communication system via the cells.

[0045] A cell may allocate sidelink (SL) resources for supporting the Proximity Services (ProSe) or Vehicle to Everything (V2X) services. Each cell may have overlapped coverage areas with other cells.

[0046] In Multi-RAT Dual Connectivity (MR-DC) cases, the primary cell of a Master Cell Group (MCG) or a Secondary Cell Group (SCG) may be referred to as a Special Cell (SpCell). A Primary Cell (PCell) may include the SpCell of an MCG. A Primary SCG Cell (PSCell) may include the SpCell of an SCG. MCG may include a group of serving cells associated with the Master Node (MN), including the SpCell and optionally one or more Secondary Cells (SCells). An SCG may include a group of serving cells associated with the Secondary Node (SN), including the SpCell and optionally one or more SCells.

[0047] As discussed above, the frame structure for NR may support flexible configurations for accommodating various next generation (e.g., 5G) communication requirements, such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC), while fulfilling high reliability, high data rate, and low latency requirements. The Orthogonal Frequency-Division Multiplexing (OFDM) technology in the 3GPP may serve as a baseline for an NR waveform. The scalable OFDM numerology, such as adaptive sub-carrier spacing, channel bandwidth, and Cyclic Prefix (CP), may also be used.

[0048] Two coding schemes may be considered for NR, specifically, Low-Density Parity-Check (LDPC) code and Polar Code. The coding scheme adaption may be configured based on channel conditions and / or service applications.

[0049] At least the DL transmission data, a guard period, and UL transmission data should be included in a transmission time interval (TTI) of a single NR frame. The respective portions of the DL transmission data, the guard period, and the UL transmission data should also be configurable based on, for example, the network dynamics of NR. SL resources may also be provided in an NR frame to support ProSe services or V2X services.

[0050] Any two or more than two of the following paragraphs, (sub)-bullets, points, actions, behaviors, terms, or claims described in the present disclosure may be combined logically, reasonably, and properly to form a specific method.

[0051] Any sentence, paragraph, (sub)-bullet, point, action, behaviors, terms, or claims described in the present disclosure may be implemented independently and separately to form a specific method.

[0052] Dependency, e.g., “based on”, “more specifically”, “preferably”, “in one embodiment”, “in some implementations”, etc., in the present disclosure is just one possible example which would not restrict the specific method.

[0053] In some implementations, all the designs / embodiment / implementations introduced within this disclosure are not limited to be applied for dealing with the problems discussed within this disclosure. For example, the described embodiments may be applied to solve other problems that exist in the RAN of wireless communication systems. In some implementations, all of the numbers listed within the designs / embodiment / implementations introduced within this disclosure are just examples and for illustration, for example, of how the described methods are executed.

[0054] The term “A and / or B” within the present disclosure means “A”, “B”, or “A and B”. The term “A and / or B and / or C” within the present disclosure means “A”, “B”, “C”, “A and B”, “A and C”, “B and C”, or “A and B and C”. The term “A / B” within the present disclosure means “A” or “B”.

[0055] Network Energy Saving (NES) is of great importance for environmental sustainability, for reducing environmental impact (e.g., greenhouse gas emissions), and for achieving operational cost savings. As 5G becomes pervasive across industries and geographical areas and supports more advanced services and applications requiring very high data rates (e.g., Extended Reality (XR)), networks may become denser and may utilize more antennas, larger bandwidths, and additional frequency bands. The environmental impact of 5G needs to remain under control, and novel solutions to enhance network energy savings may need to be developed.

[0056] The 3rdGeneration Partnership Project (3GPP) Release 18 work on network energy savings for New Radio (NR) may lead to the specification of some techniques that may be found beneficial, primarily for Radio Resource Control (RRC) Connected mode, user-specific signals and channels, and low load scenarios. The techniques specified in Release 18 may include: (a) SSB-less Secondary Cell (SCell) operation for inter-band Carrier Aggregation (CA) for Frequency Range 1 (FR1) and co-located cells, (b) enhancement on a cell Discontinuous Transmission / Discontinuous Reception (DTX / DRX) mechanism, including the alignment of cell DTX / DRX and UE DRX in RRC_CONNECTED mode, (c) inter-node information exchange on cell DTX / DRX, (d) techniques in spatial and power domains to enable efficient adaptation of spatial elements as well as efficient adaptation of power offset values between the Physical Downlink Shared Channel (PDSCH) and the Channel State Information-Reference Signal (CSI-RS), (e) mechanisms to prevent legacy UEs from camping on cells adopting the Release 18 NES techniques, (f) enhancement(s) on a Conditional Handover (CHO) procedure, (g) inter-node beam activation and enhancements on restricting paging in a limited area, and (h) the corresponding Radio Resource Management (RRM) / Radio Frequency (RF) core requirements.

[0057] In upcoming Release 19 work, one of the objectives may be to specify procedures and signaling method(s) to support on-demand System Information Block 1 (SIB1) for UEs in idle / inactive mode. This may include: (a) a triggering method by an uplink Wake-Up Signal (WUS) using an existing signal / channel, (b) Wake-Up-Signal configuration provisioning to a UE, and (c) information exchange between gNBs, at least for the configuration of a wake-up signal.

[0058] Three scenarios under Release 19 Network Energy Saving (NES) objective 2 (e.g., a cell broadcasts the Synchronization Signal / PBCH (SSB) but does not broadcast the System Information Block 1 (SIB1)) are discussed in the present disclosure.

[0059] Scenario 1

[0060] FIG. 1 is a diagram illustrating the coverage relationships among multiple cells in Scenario 1, according to an example implementation of the present disclosure. In FIG. 1, the cell#1 may be operated at the first frequency, and the cell#1 may broadcast the SSB and the SIB1. The cell#2 and the cell#4 may be operated at the second frequency, which may be different from the first frequency, and both broadcast the SSB only (e.g., both the cell#2 and the cell#4 broadcast the SSB but do not broadcast the SIB1). The coverage of the cell#2 and the coverage of the cell#4 may be fully overlapped with the coverage of the cell#1. The cell#3 may be operated at the third frequency, which may be different from the first frequency and the second frequency. The cell#3 may broadcast the SSB only (e.g., the cell#3 broadcasts the SSB but does not broadcast the SIB1), and the coverage of the cell#3 may be fully overlapped with the coverage of the cell#1.

[0061] The UE#1 may not be capable of “on-demand SIB1 request” or “Release 19 Network Energy Saving” feature, which may mean that the UE#1 cannot request the SIB1 while the UE#1 identifies a cell not broadcasting the SIB1 during its idle / inactive state (e.g., RRC_IDLE state or RRC_INACTIVE state). Under scenario 1, the UE#1 may detect the cell#1 (e.g., under its coverage) and may camp on the cell#1 only. If the cell#1 is not suitable, the UE#1 may perform the cell (re)selection based on the 3GPP specifications. The UE#2 may be capable of “on-demand SIB1 request” feature, which may mean that the UE#2 may request SIB1’s transmission while the UE#2 is in the RRC idle / inactive state and identifies a cell not broadcasting the SIB1. Under scenario 1, the UE#2 may detect the cell#1 and the cell#2, and may try to camp on the cell#1 or try to request the SIB1 associated with the cell#2.

[0062] Certain criteria may determine why the UE#2 camps on one of the other cells rather than the cell#1. For example, the UE#2 may be configured to camp on a specific frequency, or the UE#2 may be barred by the cell#1 since the cell#1 is overloaded. The UE#2 may be able to trigger “on-demand SIB1 request” associated with at least one SSB, at least one cell, or at least one frequency via one or more requests. After receiving the on-demand SIB1 request, the cell(s) (e.g., cell#1, cell#2) may provide the SIB1 to fulfill the UE#2’s needs. The mechanism to provide the SIB1 may include broadcast, multicast, or unicast transmission approaches. When broadcast or multicast transmission is used, the cell may stop broadcasting the SIB1 once the demand is fulfilled. Moreover, the “on-demand SIB1 request” behavior may not be guaranteed to succeed, and the UE#2 may repeat the request, try to camp on other cells, or remain in the idle / inactive state.

[0063] Potential Issues under Scenario 1

[0064] As described above in the present disclosure, the UE#2 may prefer to camp on one of other cells rather than the cell#1, and the UE#2 may trigger “on-demand SIB1 request” to acquire the SIB1 of the concerned cells. The potential issues at the UE-side may include the following (a)-(f).

[0065] (a) Issue#1-1: How does the UE determine that the SIB1 is not broadcasted? The UE may fail to detect the SIB1 even though the cell broadcasts the SIB1, and the UE may fail to decode the SIB1 due to insufficient channel quality. Avoiding miss-detection situations may be the critical first step under this scenario. In addition, the SIB1 may only be skipped at a particular SSB, and how the UE recognizes the skipping of the SIB1 is per cell or per SSB.

[0066] (b) Issue#1-2: How does the UE determine that the cell not broadcasting the SIB1 should be its camping target? Specifically, if more than one cell meets the condition (e.g., not broadcasting the SIB1), how does the UE determine which cell to camp on, and what is the impact on different frequency criteria, such as intra-frequency and / or inter-frequency scenarios?

[0067] (c) Issue#1-3: Under which cell does the UE trigger the “on-demand SIB1 request” behavior? How does the UE know and obtain the corresponding configuration that indicates the associated radio resources and the applied parameters for performing the request behavior? In addition, how does the UE identify the validity of the configuration, and how does the UE determine whether to suspend, release, or modify the configuration under different specified conditions?

[0068] (d) Issue#1-4: How does the UE perform the request with the relative transmission power control, the payload of the request, the use of time / frequency domain resources, and the possible retransmission / repetition? Whether the request is executed in a contention-based or conte

[0069] (e) Issue#1-5: How does the UE determine that the “on-demand SIB1 request” is successful or that the demand is fulfilled, and what are the upcoming behaviors while the request succeeds or fails?

[0070] (f) Issue#1-6: What are the consequences if the idle / inactive UE identifies the cell not broadcasting the SIB1 and then the UE is unable to perform camping? For example, shall the UE record / store the relative situation if the UE is configured to perform Minimization of Driven Tests (MDT) or Multicast / Broadcast Service (MBS)?

[0071] The potential issues at the cell-side may include the following (a)-(c). (a) Issue#1-a: Shall the cell provide explicit or implicit signaling to the UE to let the UE know that the cell does not broadcast the SIB1? Could the signaling be adaptive with the broadcast state (e.g., broadcast / non-broadcast) of the SIB1? It is possible that the cell does not broadcast the SIB1 but resumes broadcasting the SIB1 during the UE’s camp (e.g., the on-demand SIB1 request may be triggered by another UE). This may confuse the UE. For example, the camped UE may be required to periodically check the SIB1’s content in every modification period, and it may be unclear whether the UE is still required to follow this rule if the UE recognizes that the cell does not broadcast its SIB1. Thus, how to design the signaling should be discussed.

[0072] (b) Issue#1-b: While the cell decides not to broadcast the SIB1, does the decision apply to every SSB? Similarly, if the cell decides to broadcast the SIB1, does such changes apply to every SSB? It also requires clarification whether the change / adaptation in SIB1 broadcasting behavior has some restrictions, such as an application delay or a prohibition mechanism within a period.

[0073] (c) Issue#1-c: In case a cell decides not to broadcast the SIB1, the cell may be required to notify the decision to neighboring cells, a cell with broadcasting the SIB1, or the core network. Moreover, what information should be provided during the negotiation is for further discussed.

[0074] Scenario 2

[0075] FIG. 2 is a diagram illustrating the coverage relationships among multiple cells in Scenario 2, according to an example implementation of the present disclosure. In FIG. 2, the cell#1 may be operated at the first frequency, and the cell#1 may broadcast the SSB and the SIB1. The cell#2 and the cell#4 may be operated at the second frequency, which may be different from the first frequency, and both broadcast the SSB only (e.g., both the cell#2 and the cell#4 broadcast the SSB but do not broadcast the SIB1). The coverage of the cell#2 and the coverage of the cell#4 may be partially overlapped with the coverage of the cell#1. The cell#3 may be operated at the third frequency#3, which may be different from the first frequency and the second frequency. The cell#3 may broadcast the SSB only (e.g., the cell#3 broadcasts the SSB but does not broadcast the SIB1), and the coverage of the cell#3 may be partially overlapped with the coverage of the cell#1.

[0076] The UE#1 may not be capable of “on-demand SIB1 request” or “Release 19 Network Energy Saving” feature, which may mean that the UE#1 cannot request the SIB1 while the UE#1 is in the RRC idle / inactive state and identifies a cell not broadcasting the SIB1. Under scenario 2, the UE#1 may detect the cell#1 and the cell#3, and only the cell#1 may be accessible. If the cell#1 is not suitable, the UE#1 may perform the cell (re)selection based on the 3GPP specifications, even though the cell#3’s quality is sufficient (e.g., the SSB-RSRP between the cell#3 and the UE#1 is higher than a threshold, but no SIB1 could be acquired, so the UE#1 may try to search for cells other than the cell#1 and the cell#3). The UE#2 may be capable of “on-demand SIB1 request” feature, which may mean that the UE#2 may request the SIB1 while the UE#2 is in the RRC idle / inactive state and identifies a cell not broadcasting the SIB1. Under scenario 2, the UE#2 may detect the cell#2 and try to request the SIB1 associated with the cell#2. Otherwise, the UE#2 may perform the cell (re)selection or may be forced to be out of service. In addition, the UE#2 may not obtain other assistance from the cell#1 because the UE#2 is not within the coverage of cell#1. The UE#3 may be capable of “on-demand SIB1 request” feature, which may mean that the UE#3 may detect the cell#1 and the cell#4 and may decide whether to camp on the cell#1 or try to request the SIB1 associated with the cell#4. In some implementations, the UE#3 may obtain certain assistance from the cell#1 and then camp on cell#4.

[0077] If the UE#2 fails to camp on the cell#2 even though the UE#2 has performed the “on-demand SIB1 request,” the UE#2 may record such condition to reflect the existence of a coverage hole (e.g., since there are no suitable / acceptable cells for the UE#2 to camp on). When the UE#2 enters the RRC connected state, the UE#2 may report the condition, and a network vendor may try to optimize the network. Otherwise, it may be wasteful for a cell to broadcast the SSB without the SIB1.

[0078] Certain criteria may determine why the UE#3 camps on the cell#4 rather than the cell#1. For example, the UE#3 may be configured to camp on a specific frequency, or the cell#1 may be overloaded. The UE#3 may be able to trigger “on-demand SIB1 request” associated with at least one cell or at least one frequency via one request. After receiving the demand request, the cell(s) may provide the SIB1 to fulfill the UE#3’s needs. The mechanism to provide the SIB1 may include broadcast, multicast, or unicast transmission approaches. When broadcast transmission is used, the cell may stop broadcasting the SIB1 once the UE#3’s demand is fulfilled. Moreover, the “on-demand SIB1 request” behavior may not be guaranteed to succeed, and the UE#3 may repeat the same request, try to camp on other cells, or remain in the idle / inactive state.

[0079] Potential Issues under Scenario 2

[0080] As described above in the present disclosure, the UE#2 may prefer to camp on the cell#2, and the UE#2 may trigger “on-demand SIB1” behavior to acquire the cell#2’s SIB1. For the UE#3, multiple choices may be available (e.g., subject to the UE#3 being in partially overlapped coverage). The potential issues at the UE-side may include the following (a)-(f).

[0081] (a) Issue#2-1: How does the UE determine that the SIB1 is not broadcasted? The UE may fail to detect the SIB1 even though the cell broadcasts it, but the channel quality between the UE and the cell is not sufficiently good.

[0082] (b) Issue#2-2: How does the UE determine that it is required to camp on the cell not broadcasting the SIB1? Specifically, if more than one cell meets the condition (e.g., not broadcasting the SIB1), how does the UE determine which cell to camp on, and what is the impact on different frequency criteria, such as intra-frequency and / or inter-frequency scenarios? Additionally, how does the UE determine that camping on a cell not broadcasting the SIB1 is the only feasible option and further recognize itself to be out of service (e.g., with no available / suitable / acceptable cell)? This will be further considered in this scenario.

[0083] (c) Issue#2-3: Under which cell does the UE trigger the “on-demand SIB1 request” behavior? How does the UE know and obtain the corresponding configuration that includes the associated radio resources and the applied parameters for performing the behavior? In addition, how does the UE identify the validity of the configuration, and how does the UE determine whether to suspend, release, or modify the configuration? For the UE#2, the cell#2 may be the only cell to receive such request, and the cell#2 may be able to provide the relative configuration in some way.

[0084] (d) Issue#2-4: How does the UE perform the request with the relative transmission power control, the payload of the request, the use of time / frequency domain resources, and possible retransmission / repetition? More specifically, the design of the request sequence may need to be determined, which may include the signaling sequence generation method.

[0085] (e) Issue#2-5: How does the UE determine that the “on-demand SIB1 request” is successful or fulfilled, and what are the upcoming behaviors while the request succeeds or fails?

[0086] (f) Issue#2-6: What are the consequences if the RRC idle / inactive UE identifies a cell not broadcasting the SIB1 while the UE is not required to perform camping on that cell at that time? Specifically, shall the UE record / store the relative situation if the UE is configured to perform MDT or MBS?

[0087] The potential issues at the cell-side may include the following (a)-(c). (a) Issue#2-a: Shall the cell provide explicit or implicit signaling to let the UE know that the cell does not broadcast the SIB1? The signaling may be adaptive with the broadcast of the SIB1. The cell may not broadcast the SIB1 but may resume the broadcast during the UE’s camp (e.g., the on-demand SIB1 request may be triggered by another UE).

[0088] (b) Issue#2-b: While the cell decides not to broadcast the SIB1, does the decision apply to every SSB? Similarly, if the cell decides to broadcast the SIB1, do the changes apply to every SSB? It also requires clarification whether the change / adaptation in SIB1 broadcasting behavior has some restrictions, such as an application delay or a prohibition mechanism within a period.

[0089] (c) Issue#2-c: In case the cell decides not to broadcast the SIB1, the cell may be required to notify the decision to neighboring cells or the cell with broadcasting the SIB1. Moreover, what information should be provided during the negotiation may need to be clarified.

[0090] Scenario 3

[0091] FIG. 3 is a diagram illustrating the coverage relationships among multiple cells in Scenario 3, according to an example implementation of the present disclosure. In FIG. 3, the cell#1 may be operated at the first frequency, and the cell#1 may broadcast the SSB and the SIB1. The cell#2 and the cell#4 may be operated at the second frequency, which may be different from the first frequency, and both broadcast the SSB only (e.g., both the cell#2 and the cell#4 broadcast the SSB but do not broadcast the SIB1). The coverage of the cell#2 and the coverage of the cell#4 may be not overlapped with the coverage of the cell#1. The cell#3 may be operated at the third frequency, which may be different from the first frequency and the second frequency. The cell#3 may broadcast the SSB only (e.g., the cell#3 broadcasts the SSB but does not broadcast the SIB1), and the coverage of the cell#3 may not be overlapped with the coverage of the cell#1.

[0092] The UE#1 may not be capable of “on-demand SIB1 request” feature, which may mean that the UE#1 cannot request the SIB1 while the UE#1 is in the RRC idle / inactive state and identifies the cell not broadcasting the SIB1. Under scenario 3, the UE#1 may detect the cell#1 and may perform the legacy operation. The UE#2 may be capable of “on-demand SIB1 request” feature, which may mean that the UE#2 may request the SIB1 while the UE#2 is in the RRC idle / inactive state and identifies a cell not broadcasting the SIB1. Under scenario 3, the UE#2 may detect the cell#2 and try to request the SIB1 associated with the cell#2. Otherwise, the UE#2 may perform the cell (re)selection or may be forced to be out of service. In addition, the UE#2 may not obtain other assistance from the cell#1 because the UE#2 is not within the coverage of cell#1. The UE#3 may not be capable of “on-demand SIB1 request” feature, which may mean that the UE#3 may detect the cell#3 but cannot request the SIB1 transmission. As a result, the UE#3 may be recognized as out of service.

[0093] If UE#2 fails to camp on the cell#2 even though the UE#2 has performed the “on-demand SIB1 request,” the UE#2 may record such condition to reflect the existence of a coverage hole (e.g., since there are no available / suitable / acceptable cells). When the UE#2 enters the RRC connected state, the UE#2 may report the condition, and a network vendor may try to optimize the network. Otherwise, it may be wasteful for the cell to broadcast the SSB without the SIB1.

[0094] Potential Issues under Scenario 3

[0095] In some implementations, the potential issues under scenario 3 may be the same as the potential issues under scenario 2.

[0096] To resolve the enumerated issues for different scenarios, the following principles (a)-(d) may be considered. (a) The existing system frame structure and channel may be reused to support the “on-demand SIB1 request” behavior. The original limitation of the system may be maintained, such as the size budget of the DCI and blind decoding. (b) The unnecessary behaviors on the cell side may be eliminated to enable the cell to save network energy. (c) The legacy UEs and cells may not be impacted. For example, the on-demand SIB1 sequence shall not confuse legacy systems or generate error cases. (d) The common solutions that can be applied across various scenarios may be developed.

[0097] FIG. 4 is a flowchart illustrating a method / process 400 performed by a UE capable of “on-demand SIB1 request” feature, according to an example implementation of the present disclosure.

[0098] In action 402, the process 400 may start by determining whether the SIB 1 is broadcasted. The UE may try to synchronize with the SSB of the cell. By decoding the SSB, the UE may obtain PSS and SSS information to derive the PCI for the corresponding cell (e.g., the cell where the UE receives the SSB) and may be able to identify the symbol boundary. With further decoding of the PBCH on the SSB, the UE may synchronize with the frame and may obtain associated time and frequency resources to acquire the SIB1 broadcast by the corresponding cell. Under legacy behavior, the UE may select the appropriate SSB (e.g., beam) to obtain the SIB1. If all information is provided but the UE fails to obtain the SIB1, the UE may try to synchronize with other SSBs or may perform cell search again. This means that the UE may waste significant effort to confirm whether the SIB1 is received or whether the channel quality between the UE and the corresponding cell is not sufficiently good. Hereafter, action 402 may be designed to guide the UE’s process to check the availability / validity of the SIB1 and / or apply an earlier determination method to improve efficiency. The availability may include whether the SIB1 is present or is broadcast on demand. The UE may obtain other assistance information and may determine the availability of the SIB1, where the assistance information may be provided from another cell, a core network, an Operations, Administration, and Maintenance (OAM) system, etc.

[0099] In action 404, the process 400 may determine whether to camp on a cell without broadcasting the SIB1. After confirming there is no available SIB1 for the corresponding cell, the UE may try cell search with another cell at the same or a different frequency. Alternatively, the UE may try to request the SIB1 on the cell. It is feasible that action 404 may be determined before action 402 if the UE is configured to skip the cell not broadcasting the SIB1 or skip a particular frequency, even though the UE is capable of “on-demand SIB1 request” feature. If the UE decides to camp on a cell not broadcasting the SIB1, the UE may perform action 406. Otherwise, the UE may perform cell search. In some implementations, it is a UE implementation to perform action 404, but the NW or the gNB may override the decisions. For example, an access control may be used to prohibit the UE from accessing the cell not broadcasting the SIB1. The control approach may work together with Access Control Barring (ACB) / Unified Access Control (UAC) or may operate independently.

[0100] In action 406, the process 400 may acquire the on-demand SIB1 request configuration. Once the UE decides the availability of the SIB1 request and would like to camp on the cell accordingly, the UE may be provided with relative configuration(s) to enable the request. If no configuration is applied, the process 400 may return to action 404 to determine the target cell to camp on again, or the UE may apply a default or a stored configuration. The acquisition of the SIB1 configuration may be performed on the same cell (e.g., the one that does not broadcast the SIB1) or a different cell. The configuration for the on-demand SIB1 request may facilitate the generation of the request sequence, the appropriate setting for the request behavior, the associated resource(s) and channel, and the relative control mechanisms. In action 406, the UE may also check the validity of the configuration. In some implementations, the UE may acquire at least one configuration. In some implementations, the UE may obtain multiple configurations subject to respective cells.

[0101] In action 408, the process 400 may perform the on-demand SIB1 request. The UE may follow the configuration or follow certain procedures to perform action 408. The UE may send request signaling to the cell (e.g., the cell not broadcasting the SIB1, the cell where the UE receives the SSB(s) in action 402, or another cell). The signaling may be coded with a specific format and may be transmitted in a contention-based manner (e.g., other UEs may transmit the same sequence via the same resource) or in a contention-free manner (e.g., the sequence may be transmitted via a reserved resource, where only the UE can use it). To guarantee the reliability and success of the request, the UE may transmit the sequence using a diversity approach, where the repetition / retransmission of the sequence with the same and / or different transmitting power may be adopted. The content of a request sequence may include a simple ON / OFF request, a request for specific portions of the SIB1, or an indication of an identification of the UE.

[0102] In action 410, the process 400 may determine whether the on-demand SIB1 request is completed. Upon completion of action 408, the UE may try to perform cell search again to check whether the SIB1 is broadcast by the cell (e.g., the cell where the UE receives the SSB(s) in action 402). The broadcast of the SIB1 may be an implicit acknowledgment that the UE may recognize as the request being successfully completed if the SIB1 is broadcast. The gNB (e.g., or the cell where the UE receives the SSB(s) in action 402) may successfully receive the request but still decide not to broadcast the SIB1. In this regard, the UE may still recognize the failure of the request. Another option is that the gNB (e.g., or the cell where the UE receives the SSB(s) in action 402) may provide an explicit acknowledgment if the gNB (or the cell where the UE receives the SSB(s) in action 402) receives the request.

[0103] When the UE receives the acknowledgment from the gNB (e.g., or the cell where the UE receives the SSB(s) in action 402) but still fails to receive the SIB1, the UE may identify itself as barred from the cell. The barring may last for a long period, and the UE may not try to request the SIB1. The barring duration may be configured by barring parameters provided in the SIB1. The UE may, by default, bar itself from requesting the SIB1 for a default value (e.g., 300 seconds). In some implementations, when the UE is barred but the cell broadcasts the SIB1 (e.g., requested by another UE), the UE may still be prohibited from camping on the cell, or the barring may expire / terminate implicitly (e.g., if the SIB1 is broadcast, or if the UE receives the SIB1 from the barred cell).

[0104] In action 412, the process 400 may perform cell camp on the target cell. In action 412, if the UE can receive the SIB1 after the request behavior, the UE may try to camp on the target cell. The UE may store the corresponding SIB1 information and may associate the corresponding SIB1 information with the PCI of the cell. The UE may perform paging monitoring on the cell and may stay in the RRC idle / inactive state. The UE may perform the RRC resume operation to transition from the inactive state to the connected state. The UE may perform the RRC connection establishment (e.g., or the RRC connection setup) and may enter the RRC connected state. The process 400 may then end. The steps / actions shown in FIG. 4 should not be construed as necessarily order dependent. The order in which the process is described is not intended to be construed as a limitation. Moreover, some of the actions shown in FIG. 4 may be omitted in some implementations and one or more actions shown in FIG. 4 may be combined. For example, action 406 may be performed before action 404 if there is a pre-configured approach for determining camp priority.

[0105] FIG. 5 is a flowchart illustrating a method / process 500 performed by a BS (e.g., gNB), a network, and / or a cell capable of “Release 19 NES” feature, according to an example implementation of the present disclosure.

[0106] In action 502, the process 500 may start by determining not to broadcast the SIB1. To enable power / energy saving, the network in action 502 may determine not to broadcast the SIB1, and the behavior may apply to all SSBs (e.g., all beams) or at least one SSB. The network may perform analysis on the loading of each direction and may turn on / off the SIB1 transmission on corresponding directions. The broadcasting periodicity may be adaptive with a longer periodicity if the network would like to achieve greater power / energy saving gain. Specifically, the cell may broadcast a “compact” SIB1, where only specific information may be provided in comparison with a conventional SIB1 as specified in the 3GPP technical specifications. In some implementations, the network may decide not to broadcast the SIB1 on a higher frequency band (e.g., because of the smaller coverage).

[0107] In action 504, the process 500 may provide assistance information / configuration. While the gNB / NW decides not to broadcast the SIB1 on the associated cell, the cell may require negotiating such changes with other cells. The other cells may include a neighboring cell (e.g., whose coverage is fully, partially, or not overlapped with the cell) not broadcasting the SIB1. The negotiation may further include a frequency, an SSB (e.g., SSB index) for not broadcasting SIB1, the periodicity of broadcasting SIB1, the configuration to support “on-demand SIB1 request,” and other information about the cell loading and cell barring control. The negotiated cell may provide corresponding assistance information for its serving UE or the requested UE. The cell may provide assistance information independently rather than negotiating with a neighbor cell. The assistance information may be appended by a special design in the PSS / SSS / PBCH or may be provided via an Operations, Administration, and Maintenance (OAM) system or pre-configuration.

[0108] In action 506, the process 500 may monitor the SIB1 request signaling. The cell may monitor a specific resource or a configured resource to identify whether any UE transmits the on-demand SIB1 request signaling. The monitoring may take place at any SSB, any frequency, at least one SSB, or at least one frequency. If multiple requests are detected in respective SSBs and / or frequencies, the cell may recognize that the request is aimed at an associated SSB / frequency. On the contrary, the request may be agnostic to SSB / frequency, and the cell may recognize that the request is to enable the broadcasting of the SIB1 on any SSB / frequency. The cell may adopt “energy-efficient monitoring,” where the monitoring may only be triggered when specific conditions are met. Otherwise, the cell may not monitor a request sequence. In some implementations, the cell may only monitor a request on a specific SSB, resource, and / or frequency to avoid power / energy consumption.

[0109] In action 508, the process 500 may determine whether the SIB1 request is received. The cell may detect multiple requests from different sources (e.g., even though the requests are transmitted on the same resource), and action 508 may be required to distinguish the requests from different sources. In some implementations, action 508 may not be required to distinguish the requests from different sources. The distinction may be accomplished by checking the sequence, checking the received power on the associated uplink physical resource, checking the Received Signal Strength Indicator, or checking the received resources, where different UEs may generate different sequences (e.g., with the same request content). The cell may treat the request sequence as successfully received when the received strength is sufficiently large or when the received sequence can be decoded. The cell may adapt the configuration for transmitting the request sequence based on the reception results / performance of the request.

[0110] In action 510, the process 500 may determine whether to broadcast the SIB1. After obtaining the on-demand SIB1 request, the cell may respond to the request, and the cell may transmit an ACK / NAK to the UE. The cell may then start broadcasting the SIB1. The broadcast of the SIB1 may be performed using all SSBs on all frequencies, all SSBs on particular frequencies, particular SSBs on all frequencies, or particular SSBs on particular frequencies The process 500 may then end.

[0111] In the present disclosure, the Cell A may be referred to as a normal cell, which periodically transmits at least its own SIB1 (e.g., like the cell#1 as illustrated in FIGs.1-3). The NES Cell (e.g., like the cell#2, cell#3, and cell#4 as illustrated in FIGs.1-3) may be a cell that may not transmit the SIB1 without the UE’s request but may transmit the SIB1 in response to a UL WUS (e.g., an on-demand SIB1 request) from the UE.

[0112] In some implementations, the UE may obtain the UL WUS configuration from either an NES Cell or a Cell A. The UE may transmit the UL WUS to the NES Cell or the Cell A as a target cell for UL WUS transmission, and the PRACH may be a starting point for UL WUS signaling. The conditions to trigger the UL WUS may include that a UE would like to establish an RRC connection with a particular cell, or a UE would like to camp on a particular cell for its RRC idle / inactive mode operation, such as receiving / monitoring paging. The entire possible workflows under various assumptions are provided in FIG. 6. The designs are provided below for a UE trying to perform the RRC connection establishment. FIG. 6 is a diagram illustrating possible workflows under various assumptions, according to an example implementation of the present disclosure. In FIG. 6, the UE may conduct a cell search to identify two cells and may perform either an RRC connection establishment or an idle / inactive operation for one of the two cells. Among the two cells, one cell may be a Cell A, and the other may be an NES cell. The UE may select a cell from the two cell. The selected cell may provide the UE with a UL WUS configuration. The UL WUS configuration may include parameters necessary for the UE to transmit a UL WUS and monitor a NW’s response to the UL WUS. Then, when a condition for transmitting the UL WUS is satisfied, the UE may transmit the UL WUS to one of the two cells. The cell that provide the UL WUS configuration and the cell to which the UE transmits the UL WUS may be different. After acquiring an OD-SIB1, the UE may camp on the NES cell. In some implementations, the UE may perform the RRC connection establishment for the NES cell.

[0113] Case 1: An RRC Idle / Inactive UE would like to perform an RRC establishment and detect a Cell A during an initial cell search. The WUS configuration may be provided by the Cell A and the WUS may be transmitted to the Cell A. FIG. 7 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0114] In action 701, the UE may try to detect Cell A’s SSB and may identify that the Cell A is not barred based on MIB information (e.g., the CellBarred IE is not set to ‘barred,’ and the CellBarred IE is set to ‘notBarred’). The UE may be able to acquire the SIB1 of the Cell A. With SIB1, the UE may determine whether the Cell A is reserved for other use (e.g., the flag cellReservedForOperatorUse may be broadcast with a value of ‘reserved’ or ‘not reserved’).

[0115] If the cell status is indicated as “not barred” and “reserved” for operator use for any PLMN / SNPN, and not “true” for other use and not “true” for future use, the UE with an Access Identity of 11 (e.g., PLMN Use) or an Access Identity of 15 (e.g., PLMN Staff) may be allowed to use the cell for camping on (e.g., the UE may treat the cell as a candidate during the cell (re)selection procedure). If the cell is reserved, the UE with Access Identity 0, 1, 2, 12, 13, or 14 may treat the cell as ‘barred’ and may not be allowed to camp on it. Another flag cellReservedForOtherUse in the SIB1 may be broadcast with a value of ‘true’ or may be absent. When this flag is broadcast by the SIB1, and when the cell does not broadcast any CAG-IDs or NIDs or the cell does not broadcast any CAG-IDs and the UE is not operating in SNPN Access Mode, all UEs may treat the cell as ‘barred’.

[0116] More specifically, the IE uac-BarringInfo within the SIB1 may provide the parameters to determine when a unified access barring check is required. The unified access barring check may involve the UE generating a uniformly distributed random number between 0 and 1. If the random number is less than the value of the IE uac-BarringFactor, the access attempt may be permitted. Otherwise, the access attempt may be barred. If an access attempt is barred, the UE may wait for a time period and may try the access attempt again. The UE may check which access category and / or access identity it belongs to and may apply corresponding parameters to verify whether it can try the access attempt.

[0117] In action 702, while the UE is barred due to either the reserved setting or the UE fails to attempt access subject to UAC, the UE may further check whether an SIBx is broadcast. The SIBx may be system information providing the WUS configuration. The SIBx may be new system information other than an existing one, or it may be incorporated with other existing ones. If the state of the SIBx is “broadcasting,” the UE may receive the SIBx based on configurations upon the SIB1 reception, and no UE demand request may be needed. If the state of the SIBx is “notBroadcasting,” the UE may be able to trigger the on-demand SI request. If the Cell A is specified to provision the WUS configuration, the UE may trigger the on-demand SI request regardless of UAC checking results.

[0118] In action 703, the UE may use either an Msg1-based or an Msg3-based approach to request the SIBx. In action 704, the Cell A may then broadcast the SIBx (e.g., no dedicated signaling may be applied under case 1). The WUS configuration in the SIBx may include the following information (a)-(d).

[0119] (a) WUS signaling configuration: A dedicated preamble or a dedicated PRACH resource may be provided. The Cell A may also configure an RA type and associated RA parameters (e.g., which may be separated from SI-RequestConfig or RACH-ConfigCommon). For example, the RA parameter may include the maximum attempt number for WUS signaling, the transmission power setting (e.g., initial power value and power ramping value), an RAR window, etc.

[0120] In some implementation, the WUS configuration may be common for all NES Cells (e.g., supported by the serving RAN / PLMN / SNPN), such that, while the UE uses this configuration to send the WUS, the Cell A may notify all its neighboring NES Cells to resume their SIB1 transmission(s). In some implementations, the WUS configuration may be cell-specific for different NES Cells, and an association between the WUS configuration and the NES Cell may be needed. The association may be supported by using a PCI or a partial PCI, and the Cell A may configure multiple preambles and / or multiple ROs, and different preambles / ROs may be mapped to a specific NES cell. When the UE sends the WUS, the Cell A may recognize the demand and may notify the corresponding NES Cells (e.g., via the Xn interface, via XnAP messages, or via inter-node RRC messages). In some implementations, the RA configuration of the WUS signaling configuration may be provided within the RACH-ConfigCommon or SI-RequestConfig in the SIB1 of the Cell A. The WUS configuration in the SIBx may contain other configurations. If no SIBx is provided for the WUS configuration, the Cell A may provide it only via an existing SIB1.

[0121] (b) NES Cell’s SIB1 validity information and other system information IDs: The validity information, such as one or more value tags (e.g., associated with different SIBs) may be presented with the configuration of the SIB1, and an area ID (e.g., the systeminformationAreaID) may be provided to let the UE know whether the stored SIB1 of the NES Cell and its configuration can be reused or a new SIB1 acquisition may be needed. If the stored SIB1 and / or other SIBs are valid, the UE may skip the transmission of the WUS and may perform the RRC connection establishment or may camp on the associated NES Cell directly. Otherwise, the UE may trigger the WUS transmission. Moreover, a tracking area ID and a RNA ID (e.g., RAN Notification Area ID) may be appended together, such that the information may facilitate the UE to determine whether it could stay in the Cell A for the RRC idle / inactive mode operation if the ID (e.g., the tracking area ID or RNA ID) is the same as what Cell A broadcasts).

[0122] In some implementations, the IE areaScope may be applied. When the IE areaScope (e.g., the areaScope associated with the SIBx) is set to “false” or is not present or is absent, the NES Cell’s SIB1 may be cell-specific, and the UE may be unable to use any stored SIB1 information, which leads to the request for the NES Cell’s SIB1 being mandated. When the IE areaScope (e.g., the areaScope associated with the SIBx) is set to “true” or is present, the NES Cell’s SIB1 may be area-specific. The UE may be able to use the stored SIB1 information and / or SIBx information associated with the IE areaScope to acquire the NES Cell’s SIB1 (e.g., by determining whether the valueTag associated with the stored SIB1 information and / or SIBx information associated with the areaScope is the same as the received valueTag). In some implementations, a Boolean indication (e.g., the NESspecific) may be associated with each NES Cell, such that the Cell A may provide the corresponding configurations for the UE to acquire the corresponding NES Cell’s SIB1 information. The Cell A may provide separate configurations for respective NES Cells. For example, if NESspecific is set to “true” or is present, the SIBx may be associated with the configuration for a particular NES Cell. If NESspecific is set to “false” or is absent, the SIBx may be cell-specific.

[0123] (c) WUS trigger condition(s): The Cell A may configure the UE with specific conditions to send the WUS. The WUS trigger conditions may include at least one of the following (i)-(iv). (i) An NES Cell’s SSB SSB RSRP exceeds a threshold (e.g., the threshold may be different based on an SIB2’s configuration). The threshold may be a fixed value, may be preconfigured, or may be provided to the UE in the WUS configuration or in the SIB1 of the Cell A. (ii) Allowed Access Categories, which are the only limited Access Categories (ACs) (e.g., high-priority services) that may trigger the SIB1’s transmission of the NES Cell. (iii) Allowed NSSAI, which indicates the only specific (network) slice that is allowed to wake up the NES Cell for (RRC) connection purposes. (iv) An SIB1 transmission check flag: If the flag is set to “true,” the UE may be required to perform the cell search on the NES Cell and may determine whether the SIB1 is transmitted or not. The determination may rely on the MIB information of the NES Cell. The UE may be permitted to send the WUS when the UE determines there is no SIB1 transmission on the detected NES Cell. If the flag is set to “false,” the UE may trigger the WUS regardless of the check results. If the flag is not present (or is absent), the UE may assume that checking the SIB1 state of the NES Cell is always required before sending the WUS.

[0124] (d) SIB1 transmission pattern: The Cell A may indicate a transmission pattern (e.g., time / frequency pattern) of the SIB1 of the NES Cell once the NES Cell decides to transmit it. The pattern may include aperiodic, semi-periodic (e.g., with a configured duration and periodicity), and periodic (e.g., with a periodicity). More specifically, the IE SubCarrierSpacingCommon, the IE PDCCH-ConfigSIB1, and relative information, which are present in the MIB of the NES Cell, may be provided together with the transmission pattern to enable the UE to acquire the SIB1 without detecting the MIB of the NES Cell. If the transmission pattern is not present in the WUS configuration, the UE may follow the legacy operation to acquire the SIB1 of the NES Cell.

[0125] The Cell A may update the WUS configuration (e.g., the SIBx), and the update may follow modification period specifications. In addition, the validity of the WUS configuration may be checked by the Cell A’s value tag and / or an area ID.

[0126] In action 705, when receiving the WUS configuration and satisfying the trigger conditions, the UE may send the WUS to the Cell A based on the configuration. The Cell A may provide an acknowledgment, and the acknowledgment may be an RAR scrambled by a corresponding RA-RNTI, with the RAR content not appending a TA value or a grant. In action 706, the Cell A may notify the corresponding NES Cell (e.g., following the receipt of the associated WUS) to transmit the SIB1 via a backhaul, an Xn interface, or an S1 interface. In action 707, in response to receiving the notification from the Cell A, the NES Cell may transmit the SIB1 to the UE. The NES Cell may also send a confirmation message back to the Cell A. The Cell A may send the RAR after receiving the confirmation message from the NES Cell. The UE may repeat the WUS transmission if the UE does not receive the acknowledgment, and the UE may identify it as an access failure if the repetition exceeds the configured maximum number. The configuration of the maximum number may take place together with the WUS configuration or may be given by a default value.

[0127] After receiving the acknowledgment, the UE may either follow legacy operation to acquire the MIB / SIB1 of the NES Cell or may monitor a configured CORESET#0 and SS#0 to receive the SIB1 based on corresponding configurations provided by the WUS configuration. The NES Cell may terminate the SIB1 transmission based on its implementation or a configured SIB1 transmission pattern in the WUS configuration. If the WUS configuration already contains part of the NES Cell’s SIB1 information, the NES Cell may not append / include that part of information into the SIB1, or the NES Cell may not transmit that part of information. The UE may send an acknowledgment (e.g., transmit another WUS using different dedicated preambles) to notify the Cell A of the successful reception of the SIB1 from the NES Cell.

[0128] Case 2: An RRC idle / inactive UE would like to perform an RRC connection establishment and detect a Cell A during an initial cell search. The WUS configuration may be provided by the Cell A, but the WUS may be transmitted to the NES Cell. FIG. 8 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0129] In FIG. 8, the actions 801-804 may be similar to the actions 701-704 as illustrated in FIG. 7, except that the WUS configuration may further include additional RA settings for the UE to enable the transmission of the WUS to the NES Cell and the monitoring of the SIB1 under the NES Cell. The UE may optionally transmit a particular acknowledgment if the SIB1 is acquired after the WUS transmission. For example, the WUS configuration may include a RACH configuration of the NES Cell (e.g., RACH-ConfigCommon of the NES Cell).

[0130] In action 805, the UE may try to perform the SSB (or DL) synchronization with the NES Cell and then may send the WUS to the NES Cell. Since there is no valid SIB1 yet, it may be problematic to proceed with the reception of an RAR or other acknowledgment. Therefore, the WUS configuration may indicate the corresponding acknowledgment monitoring configuration. The UE may transmit the WUS to the Cell A. The UE may wait for an acknowledgment for the WUS transmission from the NES Cell. In some implementations, the UE may not receive an explicit acknowledgment. The UE may recognize the successful reception of the SIB1 of the NES Cell as a positive acknowledgment. If the UE does not receive the SIB1 within the configured duration (e.g., as signaled in the WUS configuration) or a default time, the UE may treat the WUS transmission as a failure case and may repeat the WUS transmission until reaching the maximum attempt number. The maximum attempt number may be configured in the WUS configuration or may be a default value. In action 806, in response to receiving the WUS from the UE, the NES Cell may transmit the SIB1 to the UE.

[0131] The NES Cell may notify the Cell A to stop broadcasting the SIBx if the NES Cell transmits its SIB1 after receiving the WUS. The NES Cell may also report the traffic load of the WUS reception (e.g., the number of preambles received within a duration) to the Cell A and may suggest a preferred WUS configuration setting to the Cell A. Subsequently, the Cell A may adjust the WUS configuration and may perform the SIBx modification accordingly. In case 2, the UE may not send any acknowledgments to the Cell A once the UE is able to acquire the SIB1 of the NES Cell.

[0132] Case 3: An RRC idle / inactive UE would like to perform an RRC connection establishment and detect a Cell A during an initial cell search. The WUS configuration may be provided by the NES Cell, but the WUS may be transmitted to the Cell A. The NES Cell may provide a minimum WUS configuration, and the Cell A may additionally provide other WUS configuration(s). The minimum WUS configuration may be used to indicate that the NES Cell supports the WUS transmission / reception to trigger the SIB1 transmission and further provides the validity check. The other WUS configuration(s) may be used to configure other parameters (e.g., the preamble ID and / or the maximum number of preamble retransmissions). FIG. 9 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0133] In action 901, the UE may receive the SIB1 from the Cell A. In action 902, the UE may be barred by the Cell A. When the UE is barred by the Cell A in action 902, the UE may not try to request other SIB(s) from the Cell A, regardless of whether the state of other SIB(s) is broadcasting or not broadcasting. The UE may perform cell search to identify whether other cells could be detected. If no cells are identified, the UE may follow legacy barring mechanisms and may try again for camping on the Cell A. If the UE detects another Cell A (e.g., the SIB1 is broadcast by another Cell A) and / or the NES Cell, this other Cell A may still be prioritized for camping unless (1) no other Cell A is available for camping on, or (2) the NES Cell’s SSB RSRP is better than Cell A with a configured threshold. The configuration may take place together with the WUS configuration, or the UE may acquire it via the SIB2 (e.g., cell reselection criteria and parameters).

[0134] In action 903, the UE may decode the SSB and the corresponding MIB, and the MIB may indicate there is no SIB1 transmission (e.g., by setting kSSBto 30 in FR1). The UE may re-interpret the MIB information to acquire the minimum WUS configuration. The minimum WUS configuration may include the following (a)-(c).

[0135] (a) WUS transmission flag: The WUS transmission flag may indicate the UE to transmit the WUS to the Cell A or the NES Cell (e.g., if the WUS transmission flag is set to “0,” it indicates the UE to transmit the WUS to the Cell A, and if the WUS transmission flag is set to “1,” it indicates the UE to transmit the WUS to the NES Cell).

[0136] (b) SIB1’s validity information and other system information IDs: The validity information, such as a value tag and an area ID (e.g., systeminformationAreaID), may be provided in the SIB1 to let the UE know whether the stored SIB1 of the NES Cell can be reused or a new SIB1 acquisition may be needed. If the stored SIB1 is valid, the UE may skip the transmission of the WUS and may perform the RRC connection establishment or may camp on the associated NES Cell directly. If the stored SIB1 is invalid, the UE may trigger the WUS transmission. Moreover, a tracking area ID and / or a RNA ID may be appended together, such that the information may facilitate the UE to determine whether it could stay in the Cell A for the RRC idle / inactive mode operation (e.g., if the tracking area ID is the same as the Cell A’s tracking area ID, and / or if the RNA ID is the same as the Cell A’s RNA ID).

[0137] (c) Basic RA configuration: An entry in a pre-defined RA configuration may be used together with the detected PCI to identify the applied preamble and resource. For example, the minimum WUS configuration may provide a parameter K, and the UE may perform a MOD function with the detected PCI by parameter K to know the corresponding entry of the WUS signaling configuration. This configuration may only be present if the WUS transmission flag is set to “1” (e.g., the WUS transmission flag indicates the UE to transmit the WUS to the NES Cell).

[0138] When receiving the minimum WUS configuration and the UE is configured to transmit the WUS to the Cell A, the UE may try to acquire the SIBx to obtain other WUS configuration(s) through action 904 and action 905. The other WUS configuration(s) may be a full configuration of all WUS-related configurations or a delta configuration other than a minimum configuration. The information content (e.g., the preamble ID and / or the maximum number of preamble retransmissions) may be appended in the other WUS configuration(s).

[0139] Upon obtaining other WUS configuration(s), the UE and the Cell A may perform actions 906-908, which may be the same as the actions 705-707 as illustrated in FIG. 7. The NES Cell may terminate the SIB1 transmission based on its implementation or a configured pattern. The NES Cell may use dedicated signaling to indicate the SIB1 change and its transmission pattern for connected UEs.

[0140] Case 4: An RRC idle / inactive UE would like to perform an RRC connection establishment and detect a Cell A during an initial cell search. The WUS configuration may be provided by the NES cell, and the WUS may be transmitted to the NES Cell. The WUS configuration provided by the NES Cell may further include two operations: (a) the NES Cell may provide a minimum WUS configuration only, and (b) the NES Cell may provide a minimum WUS configuration, and the Cell A may optionally provide other WUS configuration(s). FIG. 10 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure. FIG. 11 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0141] The actions 1001-1003 as illustrated in FIG. 10 and actions 1101-1103 as illustrated in FIG. 11 may be similar to actions 901-903 as illustrated in FIG. 9, except that a minimum WUS configuration may indicate the necessity to acquire other WUS configuration(s). A 1-bit indication may be used to indicate the necessity to acquire other WUS configuration(s). If the bit is set to “1,” it indicates that the Cell A may assist with the provision of other WUS configuration(s) (e.g., as illustrated in FIG. 10), and the UE may perform actions 1004-1005 accordingly. In action 1006, the UE may send the WUS to the NES cell. In action 1007, the UE may receive the SSB and SIB1 from the NES cell. If the bit is set to “0,” it indicates that no other WUS configuration(s) are provided from other Cell A(s) (e.g., as illustrated in FIG. 11), and the UE may need to transmit the WUS to the NES Cell using the available information in the minimum WUS configuration. Subsequently, the UE may send the WUS to the NES cell directly (e.g. as illustrated in action 1104 of FIG. 11). In action 1105, the UE may receive the SSB and SIB1 from the NES cell.

[0142] In some implementations, the 1-bit indication may not be needed, and a default behavior may be applied directly (e.g., without needing to signal the 1-bit indication). For example, by the default setting, the UE may assume it should transmit the WUS to the NES Cell directly based on the information broadcast by the NES Cell. The UE may fall back to the Cell A to acquire other WUS configuration(s) via an SIBx-request procedure (e.g., as illustrated in action 1004 and action 1005 of FIG. 10), if the NES Cell does not perform the SIB1 transmission even though the WUS was received from the UE. With obtaining other WUS configuration(s), the UE may try to perform the WUS transmission again, based on the other WUS configuration(s).

[0143] Case 5: An RRC idle / inactive UE would like to perform an RRC connection establishment and detect an NES Cell during an initial cell search. The WUS configuration may be provided by the Cell A, and the WUS may be transmitted to the Cell A. Case 5 may not be valid if the UE cannot detect another Cell A, which may mean that the UE cannot camp on any cells and may follow legacy procedures to continuously perform the cell search (e.g., the UE also treats the NES Cell as a barred cell). If another Cell A is detected, the process may be performed as illustrated in FIG. 12. FIG. 12 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0144] In action 1201, the UE may recognize that the SIB1 is not broadcast based on the information appended in the MIB, and the UE may fail to camp on the NES Cell for its RRC connection establishment. The UE may perform the cell search and may detect the Cell A. In action 1202, the UE may be barred by the Cell A due to the cell is reserved for other use or subject to UAC barring control.

[0145] Actions 1204-1208 may be similar to actions 703-707 as illustrated in FIG. 7, the UE may trigger the SI request to acquire the WUS configuration and may transmit the WUS signaling to the Cell A. Subsequently, the UE may return to the NES Cell and may perform the SIB1 acquisition.

[0146] Case 6: An RRC idle / inactive UE would like to perform an RRC connection establishment and detect an NES Cell during an initial cell search. The WUS configuration may be provided by the Cell A, but the WUS may be transmitted to the NES Cell. Case 6 may be invalid if no Cell A is detected. The intention of supporting this case is that the Cell A may have more channel resources (e.g., channel bandwidth) to provide other WUS configurations via the SIBx compared to what the NES cell may offer. FIG. 13 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0147] The actions 1301-1305 may be the similar to actions 1201-1205 as illustrated in FIG. 12, except that the WUS configuration may include additional RA settings for the UE to enable the monitoring of the NES Cell and to transmit a specific acknowledgment. For example, the WUS configuration may include the RACH-ConfigCommon of the NES Cell. If the UE is not barred by the Cell A, the UE may try to camp on the Cell A rather than triggering the on-demand SIB1 request for camping on the NES Cell. If the UE is barred by the Cell A, the UE may perform the actions 1306 and 1307, and the actions 1306 and 1307 may be similar to actions 805 and 806 as illustrated in FIG. 8, respectively.

[0148] Case 7: An RRC idle / inactive UE would like to perform an RRC connection establishment and detect an NES Cell during an initial cell search and receive the WUS configuration. The UE may transmit the WUS to the Cell A to trigger the transmission of the SIB1 from the NES Cell. The WUS configuration transmitted from the NES Cell may be a minimum WUS configuration to indicate support for an on-demand SIB1 request. The WUS configuration may instruct the UE to send the WUS to the Cell A (if detected) to trigger the WUS transmission to the Cell A. If Cell A is not detected, the UE may treat this attempt on the NES Cell as a failure of entry (e.g., unable to acquire the SIB1), or the UE may fall back to transmit the WUS to the NES Cell directly. FIG. 14 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0149] With the provision of the minimum WUS configuration, the UE may know that the WUS should be transmitted to the Cell A and may perform the cell search procedure accordingly. After detecting the Cell A, the UE may skip the UAC barring check (e.g., the UE may not intend to camp on the Cell A but may be required to acquire SIB1 information to understand the potential resource allocation for the WUS transmission). With the SIB1 information, the UE may be able to transmit the WUS and may skip the SI request procedure, even though the SIBx is indicated as “not broadcasting.” The NES Cell may provide a parameter K for a basic RA configuration in its minimum WUS configuration, and such RA configuration may be associated with the Cell A. The UE may use that information and the received SIB1 information to identify the WUS occasion and may transmit the WUS in action 1406.

[0150] In some implementations, the Cell A may provide other WUS configuration(s) (e.g., this may imply that the NES Cell does not need to provide the WUS details in the minimum WUS configuration). The UE may perform the SI request procedure in action 1404 if the Cell A indicates that the SIBx is not broadcasting in action 1402. With a full WUS configuration, the UE may be able to transmit the WUS to the Cell A and acquire the SIB1 from the NES Cell based on the configuration. The minimum WUS configuration may indicate whether other WUS configuration(s) are needed from the Cell A (e.g., using a 1-bit flag) and whether the other WUS configuration(s) are broadcast (e.g., using a 1-bit flag). With these indications, the UE may accelerate the WUS transmission (e.g., by skipping certain procedures).

[0151] Case 8: An RRC idle / inactive UE would like to perform an RRC connection establishment and detect an NES Cell during an initial cell search and receive the WUS configuration from the NES Cell. The UE may transmit the WUS to the NES Cell directly to trigger the transmission of the SIB1 from the NES Cell. In some implementations, all signaling may be exchanged between the UE and the NES Cell, which may mean that case 8 may be applied to standalone NES Cell deployments. FIG. 15 is a diagram illustrating a process of on-demand SIB acquisition, according to an example implementation of the present disclosure.

[0152] Depending on the available space of the MIB, the minimum WUS configuration may include at least one of: (a) a flag to support the WUS and an optional indication of the target cell, (b) validity information of the SIB1, and (c) a basic RA configuration, such as a parameter K. The UE may transmit the WUS based on the configuration after determining that the trigger conditions are fulfilled. The trigger conditions may include at least one of a WUS support check, a validity check, and / or an SSB quality check. After transmitting the WUS, the UE may monitor the SSB and related MIB information after a time offset. The time offset may be a default value. The UE may identify the success of the WUS transmission if the MIB indicates the presence of the SIB1. The UE may treat the NES Cell as a barred cell if the UE cannot acquire the SIB1 after transmitting the WUS but no response is received within a duration. The duration may be a default value. Subsequently, the UE may try to perform the cell search based on the legacy operations.

[0153] Specifically, to support the configuration of the WUS to enable the on-demand SIB1 request among different scenarios, the content of the WUS configuration may be separated into individual portions, and different portions may be transmitted by the Cell A, the NES Cell, or both. The corresponding indication may be used to let the UE know which cell to complete the provision of the WUS configuration and the associated provisioning method. The content of the WUS configuration may include validity information on the NES Cell’s SIBx (e.g., including the SIB1 and other SIBs), trigger conditions, and relevant settings to guide when the WUS is permitted to be sent.

[0154] In some implementations, the SSB may include the PSS, the SSS, and the PBCH payload. The PSS and the SSS may be pseudo-random sequences with a length equal to 127. The PBCH payload may include the MIB (e.g., 24 bits in total) and an 8-bit payload. The information in the MIB may include the SFN, the SCS, the DMRS configuration, access control, and mainly a configuration for SIB1 acquisition. By decoding the PSS and the SSS, the UE may identify the PCI for the corresponding cell and may determine the symbol boundary. With decoding of the PBCH, the UE may determine the frame boundary and may try to decode the PDCCH.

[0155] In NR, to enable beamforming, the SSB patterns may be introduced, with respective SSBs (e.g., each with a corresponding space direction) transmitted in the time domain (e.g., as a transmission pattern). The SSB index may be used to distinguish the SSB and help the UE determine the frame boundary. The gNB may perform beam sweeping across different SSBs, and the UE may choose the best SSB (e.g., with the best RSRP) to acquire SI, receive paging, and perform the RACH procedure in case the UE would like to perform the RRC connection establishment.

[0156] When decoding the MIB, the UE may know the configuration of the PDCCH, which may include the CORESET#0 and the SS#0. The UE may then derive an entry from a default table to identify the time / frequency resources where the SIB1 is transmitted. Upon reception of the SIB1, the UE may obtain cell (re)selection information, the PLMN ID, the Cell ID, and common serving cell information for upcoming operations.

[0157] FIG. 16 is a flowchart illustrating a method / process 1600 performed by a UE for OD-SIB1 handling, according to an example implementation of the present disclosure.

[0158] In action 1602, the process 1600 may start by camping on a first cell.

[0159] In action 1604, the process 1600 may receive, from the first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration including a first resource configuration for transmitting an OD-SIB1 request, a second resource configuration for monitoring a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request.

[0160] In action 1606, the process 1600 may transmit, to a second cell, the OD-SIB1 request based on the first resource configuration.

[0161] In action 1608, the process 1600 may monitor, from the second cell, the response based on the second resource configuration. In some implementations, the response may include a random access response (RAR) including a medium access control (MAC) sub-protocol data unit (subPDU) with random access preamble identifier (RAPID) only.

[0162] In action 1610, the process 1600 may determine whether the response is received.

[0163] In action 1612, the process 1600 may in response to determining that the response is received: receive, from the second cell, an SIB1; and camp on the second cell.

[0164] In action 1614, the process 1600 may in response to determining that the response is not received: determine whether a number of transmissions of the OD-SIB1 request is less than or equal to the maximum number; retransmit, to the second cell, the OD-SIB1 request in response to determining that the number of transmissions of the OD-SIB1 request is less than the maximum number; and determine the second cell as barred in response to determining that the number of transmissions of the OD-SIB1 request is equal to the maximum number.

[0165] The steps / actions shown in FIG. 16 should not be construed as necessarily order dependent. The order in which the process is described is not intended to be construed as a limitation. Moreover, some of the actions shown in FIG. 16 may be omitted in some implementations and one or more actions shown in FIG. 16 may be combined.

[0166] The technical problem addressed by the method illustrated in FIG. 16 is how to enhance the efficiency and reliability of OD-SIB1 acquisition in a wireless communication network. The method illustrated in FIG. 16 introduces a systematic mechanism for requesting and receiving OD-SIB1 with controlled resource allocation and retransmission handling. By defining specific resource configurations for transmitting the OD-SIB1 request and monitoring the response, the method ensures efficient utilization of network resources. Additionally, the inclusion of a maximum transmission limit prevents excessive retransmissions, enabling the UE to make an informed decision about whether to retry or mark the second cell as barred. These enhancements improve the reliability of system information acquisition, reduce power consumption, and optimize network resource usage, leading to a more efficient and robust connectivity process.

[0167] FIG. 17 is a flowchart illustrating a method / process 1700 performed by a BS for OD-SIB1 handling, according to an example implementation of the present disclosure.

[0168] In action 1702, the process 1700 may start by transmitting, to a UE via a first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration including a first resource configuration for an OD-SIB1 request, a second resource configuration for a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request.

[0169] In action 1704, the process 1700 may receive, from the UE via a second cell, the OD-SIB1 request based on the first resource configuration.

[0170] In action 1706, the process 1700 may transmit, to the UE via the second cell, the response based on the second resource configuration. In some implementations, the response may include a random access response (RAR) including a medium access control (MAC) sub-protocol data unit (subPDU) with random access preamble identifier (RAPID) only.

[0171] In action 1708, the process 1700 may transmit, to the UE via the second cell, an SIB1.

[0172] The UE may transmit, to the second cell, the OD-SIB1 request based on the first resource configuration. The UE may monitor, from the second cell, the response based on the second resource configuration. The UE may determine whether the response is received. The UE may in response to determining that the response is received: receive, from the second cell, an SIB1; and camp on the second cell. The UE may in response to determining that the response is not received: determine whether a number of transmissions of the OD-SIB1 request is less than or equal to the maximum number; retransmit, to the second cell, the OD-SIB1 request in response to determining that the number of transmissions of the OD-SIB1 request is less than the maximum number; and determine the second cell as barred in response to determining that the number of transmissions of the OD-SIB1 request is equal to the maximum number. The method illustrated in FIG. 17 is similar to that in FIG. 16, except that it is described from the perspective of the BS (instead of the UE).

[0173] The steps / actions shown in FIG. 17 should not be construed as necessarily order dependent. The order in which the process is described is not intended to be construed as a limitation. Moreover, some of the actions shown in FIG. 17 may be omitted in some implementations and one or more actions shown in FIG. 17 may be combined.

[0174] FIG. 18 is a block diagram illustrating a node 1800 for wireless communication, according to an example implementation of the present disclosure. As illustrated in FIG. 18, a node 1800 may include a transceiver 1820, a processor 1828, a memory 1834, one or more presentation components 1838, and at least one antenna 1836. The node 1800 may also include a radio frequency (RF) spectrum band module, a BS communications module, a network communications module, and a system communications management module, Input / Output (I / O) ports, I / O components, and a power supply (not illustrated in FIG. 18).

[0175] Each of the components may directly or indirectly communicate with each other over one or more buses 1840. The node 1800 may be a UE or a BS that performs various functions disclosed with reference to FIGS. 16 and 17.

[0176] The transceiver 1820 has a transmitter 1822 (e.g., transmitting / transmission circuitry) and a receiver 1824 (e.g., receiving / reception circuitry) and may be configured to transmit and / or receive time and / or frequency resource partitioning information. The transceiver 1820 may be configured to transmit in different types of subframes and slots including, but not limited to, usable, non-usable, and flexibly usable subframes and slot formats. The transceiver 1820 may be configured to receive data and control channels.

[0177] The node 1800 may include a variety of computer-readable media. Computer-readable media may be any available media that may be accessed by the node 1800 and include volatile (and / or non-volatile) media and removable (and / or non-removable) media.

[0178] The computer-readable media may include computer-storage media and communication media. Computer-storage media may include both volatile (and / or non-volatile media), and removable (and / or non-removable) media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or data.

[0179] Computer-storage media may include RAM, ROM, EPROM, EEPROM, flash memory (or other memory technology), CD-ROM, Digital Versatile Disks (DVD) (or other optical disk storage), magnetic cassettes, magnetic tape, magnetic disk storage (or other magnetic storage devices), etc. Computer-storage media may not include a propagated data signal. Communication media may typically embody computer-readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave, or other transport mechanisms and include any information delivery media.

[0180] The term “modulated data signal” may mean a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. Communication media may include wired media, such as a wired network or direct-wired connection, and wireless media, such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above listed components should also be included within the scope of computer-readable media.

[0181] The memory 1834 may include computer-storage media in the form of volatile and / or non-volatile memory. The memory 1834 may be removable, non-removable, or a combination thereof. Example memory may include solid-state memory, hard drives, optical-disc drives, etc. As illustrated in FIG. 18, the memory 1834 may store a computer-readable and / or computer-executable instructions 1832 (e.g., software codes) that are configured to, when executed, cause the processor 1828 to perform various functions disclosed herein, for example, with reference to FIGS. 16 and 17. Alternatively, the instructions 1832 may not be directly executable by the processor 1828 but may be configured to cause the node 1800 (e.g., when compiled and executed) to perform various functions disclosed herein.

[0182] The processor 1828 (e.g., having processing circuitry) may include an intelligent hardware device, e.g., a Central Processing Unit (CPU), a microcontroller, an ASIC, etc. The processor 1828 may include memory. The processor 1828 may process the data 1830 and the instructions 1832 received from the memory 1834, and information transmitted and received via the transceiver 1820, the baseband communications module, and / or the network communications module. The processor 1828 may also process information to send to the transceiver 1820 for transmission via the antenna 1836 to the network communications module for transmission to a CN.

[0183] One or more presentation components 1838 may present data indications to a person or another device. Examples of presentation components 1838 may include a display device, a speaker, a printing component, a vibrating component, etc.

[0184] In view of the present disclosure, it is obvious that various techniques may be used for implementing the disclosed concepts without departing from the scope of those concepts. Moreover, while the concepts have been disclosed with specific reference to certain implementations, a person of ordinary skill in the art may recognize that changes may be made in form and detail without departing from the scope of those concepts. As such, the disclosed implementations are to be considered in all respects as illustrative and not restrictive. It should also be understood that the present disclosure is not limited to the particular implementations disclosed and many rearrangements, modifications, and substitutions are possible without departing from the scope of the present disclosure.

Claims

1. A user equipment (UE) for on-demand (OD)-system information block 1 (SIB1) handling, the UE comprising: 　　　　at least one processor; and 　　　　at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the UE to: 　　　　　　　　camp on a first cell; 　　　　　　　　receive, from the first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration comprising a first resource configuration for an OD-SIB1 request, a second resource configuration for a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request; 　　　　　　　　transmit, to a second cell, the OD-SIB1 request based on the first resource configuration; 　　　　　　　　monitor, from the second cell, the response based on the second resource configuration; 　　　　　　　　determine whether the response is received; 　　　　　　　　in response to determining that the response is received: 　　　　　　　　　　　　receive, from the second cell, an SIB1; and 　　　　　　　　　　　　camp on the second cell; 　　　　　　　　in response to determining that the response is not received: 　　　　　　　　　　　　determine whether a number of transmissions of the OD-SIB1 request is less than or equal to the maximum number; 　　　　　　　　　　　　retransmit, to the second cell, the OD-SIB1 request in response to determining that the number of transmissions of the OD-SIB1 request is less than the maximum number; and 　　　　　　　　　　　　determine the second cell as barred in response to determining that the number of transmissions of the OD-SIB1 request is equal to the maximum number.

2. The UE of claim 1, wherein the response comprises a random access response (RAR) including a medium access control (MAC) sub-protocol data unit (subPDU) with random access preamble identifier (RAPID) only.

3. A base station (BS) for on-demand (OD)-system information block 1 (SIB1) handling, the BS comprising: 　　　　at least one processor; and 　　　　at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the BS to: 　　　　　　　　transmit, to a user equipment (UE) via a first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration comprising a first resource configuration for an OD-SIB1 request, a second resource configuration for a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request; 　　　　　　　　receive, from the UE via a second cell, the OD-SIB1 request based on the first resource configuration; 　　　　　　　　transmit, to the UE via the second cell, the response based on the second resource configuration; and 　　　　　　　　transmit, to the UE via the second cell, an SIB1.

4. The BS of claim 3, wherein the response comprises a random access response (RAR) including a medium access control (MAC) sub-protocol data unit (subPDU) with random access preamble identifier (RAPID) only.

5. A method performed by a user equipment (UE) for on-demand (OD)-system information block 1 (SIB1) handling, the method comprising: 　　　　camping on a first cell; 　　　　receiving, from the first cell, an on-demand (OD)-system information block 1 (SIB1) request configuration, the OD-SIB1 request configuration comprising a first resource configuration for transmitting an OD-SIB1 request, a second resource configuration for monitoring a response to the OD-SIB1 request, and a maximum number of transmissions of the OD-SIB1 request; 　　　　transmitting, to a second cell, the OD-SIB1 request based on the first resource configuration; 　　　　monitoring, from the second cell, the response based on the second resource configuration; 　　　　determining whether the response is received; 　　　　in response to determining that the response is received: 　　　　　　　　receiving, from the second cell, an SIB1; and 　　　　　　　　camping on the second cell; and 　　　　in response to determining that the response is not received: 　　　　　　　　determining whether a number of transmissions of the OD-SIB1 request is less than or equal to the maximum number; 　　　　　　　　retransmitting, to the second cell, the OD-SIB1 request in response to determining that the number of transmissions of the OD-SIB1 request is less than the maximum number; and 　　　　　　　　determining the second cell as barred in response to determining that the number of transmissions of the OD-SIB1 request is equal to the maximum number.

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