Method and apparatus for network energy saving

Abstract

A UE for NES 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: receive, via RRC signaling, multiple OD- SSB configurations including a first OD-SSB configuration that configures multiple OD-SSB transmissions associated with an SCell; receive, in a first slot, a first MAC CE for activating the multiple OD-SSB transmissions; determine, based on the first slot and an offset, a starting time of the multiple OD-SSB transmissions; determine, based on a duration or a state of the SCell, whether the multiple OD-SSB transmissions are deactivated. The starting time includes a second slot that follows the first slot after the offset, and the multiple OD-SSB transmissions are performed within the duration.

Description

METHOD AND APPARATUS FOR NETWORK ENERGY SAVING

[0001] The present disclosure is related to wireless communication and, more specifically, to a User Equipment (UE), Base Station (BS), and method for network energy saving (NES) in the wireless communication networks.

[0002] The present disclosure claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 63 / 555,942, filed on February 21, 2024, entitled “ON-DEMAND SSB TRIGGERING UNDER SCELL ACTIVATION,” the content of which is hereby incorporated herein fully by reference into the present disclosure for all purposes.

[0003] Various efforts have been made to improve different aspects of wireless communication for the cellular wireless communication systems, such as the 5th Generation (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 increase, however, there exists a need for further improvements in the next-generation wireless communication systems.

[0004] The present disclosure is related to a UE, a BS, and a method for network energy saving (NES) in the wireless communication networks.

[0005] In a first aspect of the present disclosure, a UE for network energy saving (NES) 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: receive, via radio resource control (RRC) signaling, multiple on-demand (OD)-synchronization signal block (SSB) configurations including a first OD-SSB configuration that configures multiple OD-SSB transmissions associated with a secondary cell (SCell); receive, in a first slot, a first medium access control (MAC) control element (CE) for activating the multiple OD-SSB transmissions; determine, based on the first slot and an offset, a starting time of the multiple OD-SSB transmissions; determine, based on a duration or a state of the SCell, whether the multiple OD-SSB transmissions are deactivated. The starting time includes a second slot that follows the first slot after the offset, and the multiple OD-SSB transmissions are performed within the duration.

[0006] In some implementations of the first aspect, the duration is configured by the first OD-SSB configuration or indicated by the first MAC CE.

[0007] In some implementations of the first aspect, the first MAC CE includes a field that indicates the first OD-SSB configuration.

[0008] In some implementations of the first aspect, the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: determine that the multiple OD-SSB transmissions are deactivated after the duration.

[0009] In some implementations of the first aspect, the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: determine that the multiple OD-SSB transmissions are deactivated in a case that the SCell is determined to be deactivated.

[0010] In some implementations of the first aspect, the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: determine that the SCell is deactivated upon receiving a second MAC CE indicating deactivation of the SCell or upon expiry of a timer associated with the SCell.

[0011] In a second aspect of the present disclosure, a method performed by a UE for network energy saving is provided. The method includes receiving, via radio resource control (RRC) signaling, multiple on-demand (OD)-synchronization signal block (SSB) configurations including a first OD-SSB configuration that configures multiple OD-SSB transmissions associated with a secondary cell (SCell); receiving, in a first slot, a first medium access control (MAC) control element (CE) for activating the multiple OD-SSB transmissions; determining, based on the first slot and an offset, a starting time of the multiple OD-SSB transmissions; determining, based on a duration or a state of the SCell, whether the multiple OD-SSB transmissions are deactivated. The starting time includes a second slot that follows the first slot after the offset, and the multiple OD-SSB transmissions are performed within the duration.

[0012] In a third aspect of the present disclosure, a BS for NES 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, via radio resource control (RRC) signaling, multiple on-demand (OD)-synchronization signal block (SSB) configurations including a first OD-SSB configuration that configures multiple OD-SSB transmissions associated with a secondary cell (SCell); transmit, in a first slot, a first medium access control (MAC) control element (CE) for activating the multiple OD-SSB transmissions; determine, based on the first slot and an offset, a starting time of the multiple OD-SSB transmissions; deactivate, based on a duration or a state of the SCell, the multiple OD-SSB transmissions. The starting time includes a second slot that follows the first slot after the offset, and the multiple OD-SSB transmissions are performed within the duration.

[0013] 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.

[0014] FIG. 1 is a flowchart illustrating a method / process performed by a UE for NES, according to an example implementation of the present disclosure.

[0015] FIG. 2 is a flowchart illustrating a method / process performed by a BS for NES, according to an example implementation of the present disclosure.

[0016] FIG. 3 is a block diagram illustrating a node for wireless communication, according to an example implementation of the present disclosure.

[0017] 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 CHO　　　　Conditional Handover CORESET　　　　Control resource set CPE　　　　Customer Premises Equipment CPU　　　　Channel State Information Processing Unit CQI　　　　Channel Quality Indicator CR　　　　Change Request CSI　　　　Channel State Information CSI-RS　　　　Channel State Information-Reference Signal DC　　　　Dual Connectivity DCI　　　　Downlink Control Information DL　　　　Downlink DMRS　　　　Demodulation Reference Signal DRX　　　　Discontinuous Reception DTX　　　　Discontinuous Transmission e-LCID　　　　Enhanced Logical Channel Identifier E-UTRA　　　　Evolved Universal Terrestrial Radio Access FR　　　　Frequency Range FR1　　　　Frequency Range 1 FR2　　　　Frequency Range 2 FWA　　　　Fixed Wireless Access HARQ　　　　Hybrid Automatic Repeat Request HARQ-ACK　　　　HARQ Acknowledgement HO　　　　Handover ID　　　　Identifier IE　　　　Information Element IIoT　　　　Industrial Internet of Things LCID　　　　Logical Channel Identifier LTE　　　　Long Term Evolution L1 / L2 / L3　　　　Layer 1 / Layer 2 / Layer 3 MAC　　　　Medium Access Control MAC CE　　　　MAC Control Element MCG　　　　Master Cell Group MCS　　　　Modulation and Coding Scheme NACK　　　　Negative Acknowledgment NAS　　　　Non-Access Stratum NES　　　　Network Energy Saving NG-RAN　　　　Next Generation RAN NR　　　　New Radio NW　　　　Network NZP CSI-RS　　　　Non-Zero Power CSI-RS OD-SSB　　　　On-Demand Synchronization Signal Block 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 PH　　　　Power Headroom PHR　　　　Power Headroom Report PHY　　　　Physical (layer) PRACH　　　　Physical Random Access Channel PSCell　　　　Primary Secondary Cell PTRS　　　　Phase Tracking Reference Signal PUCCH　　　　Physical Uplink Control Channel PUSCH　　　　Physical Uplink Shared Channel QCL　　　　Quasi Co-Location RA　　　　Random Access RACH　　　　Random Access Channel RAN　　　　Radio Access Network RAR　　　　Random Access Response Rel　　　　Release RFM　　　　Radio Frequency Management RI　　　　Rank Indicator RMSI　　　　Remaining Minimum System Information RNTI　　　　Radio Network Temporary Identifier RRC　　　　Radio Resource Control RRM　　　　Radio Resource Management RS　　　　Reference Signal RV　　　　Redundancy Version SCell　　　　Secondary Cell SCG　　　　Secondary Cell Group SCS　　　　Subcarrier Spacing SDM　　　　Spatial Division Multiplexing SFN　　　　System Frame Number SMTC1　　　　Synchronization Signal Measurement Timing Configuration 1 SMTC2　　　　Synchronization Signal Measurement Timing Configuration 2 SSB-MTC ID　　　　Synchronization Signal Block Measurement Timing Configuration Identifier SSB-MTC IE　　　　Synchronization Signal Block Measurement Timing Configuration Information Element 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 TA　　　　Timing Advance TAG　　　　Timing Advance Group TB　　　　Transport Block TBS　　　　Transport Block Size TCI　　　　Transmission Configuration Indicator TDM　　　　Time Division Multiplexing TDRA　　　　Time Domain Resource Assignment TPC　　　　Transmission Power Control TPMI　　　　Transmit Precoder Matrix Indication TR　　　　Technical Report TRI　　　　Transmit Rank Indication TS　　　　Technical Specification UE　　　　User Equipment UL　　　　Uplink URLLC　　　　Ultra-Reliable and Low-Latency Communication USS　　　　UE-Specific Search Space WCDMA　　　　Wideband Code Division Multiple Access WG　　　　Working Group WI　　　　Working Item WUS　　　　Wake-Up Signal ZP-CSI-RS　　　　Zero power CSI-RS

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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).

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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”.

[0043] Network energy saving is of great importance for achieving environmental sustainability, as it may help to reduce environmental impact, such as greenhouse gas emissions, and may contribute to operational cost savings. As 5G networks are becoming pervasive across industries and geographical areas, they may handle more advanced services and applications that require very high data rates, such as XR. These networks may become denser, use a greater number of antennas, operate with larger bandwidths, and utilize more frequency bands. The environmental impact of 5G networks needs to remain under control, and novel solutions may need to be developed to improve network energy savings.

[0044] The 3GPP Rel-18 work on network energy savings for NR may have led to the specification of some techniques that were found to be beneficial, primarily for the RRC_CONNECTED mode, user-specific signals and channels, and low-load scenarios. The techniques specified in the 3GPP Rel-18 may include: (a) the SSB-less SCell operation for the inter-band CA in the FR1 and co-located cells, (b) the enhancements to the cell DTX / DRX mechanism, including the alignment of the cell DTX / DRX and the UE DRX in the RRC_CONNECTED mode, (c) the inter-node information exchange on the cell DTX / DRX mechanism, (d) the techniques in the spatial and power domains to enable the efficient adaptation of the spatial elements, as well as the efficient adaptation of the power offset values between the PDSCH and the CSI-RS, (e) the mechanisms to prevent legacy UEs from camping on cells adopting the 3GPP Rel-18 NES techniques, (f) the CHO procedure enhancements, (g) the inter-node beam activation and enhancements for restricting paging within a limited area, and (h) the corresponding RRM / RF core requirements.

[0045] In the upcoming 3GPP Rel-19 work, one of the objectives may be to specify procedures and signaling method(s) to support on-demand SSB SCell operation for UEs in the connected mode configured with CA, for both intra-band and inter-band CA. More specifically, triggering method(s) may be further studied, including: (a) a UE uplink wake-up signal using an existing signal or channel, (b) a cell on / off indication via the backhaul, and (c) the SCell activation or deactivation signaling.

[0046] In 5G NR, there may be three types of Carrier Aggregation (CA): the intra-band contiguous CA, the intra-band non-contiguous CA, and the inter-band CA. Moreover, the intra-band and the inter-band CA may be feasible within the FR1, within the FR2, and across the FR1 and the FR2. In 3GPP Rel-15, the SSB-less SCell, which does not have to transmit the SSB, may be supported for the intra-band (contiguous / non-contiguous) CA within the FR1 or the FR2. Specifically, for the SSB-less SCell in the same frequency band as the PCell, the UE may obtain time / frequency synchronization from the PCell.

[0047] In addition, the SSB-less SCell for the inter-band CA within the FR1 may be supported in the 3GPP Rel-18. In the current specification, the network may configure a cell that is co-located with the SSB-less SCell as a reference cell so that the UE may obtain time / frequency synchronization for such SSB-less SCell from the reference cell. It is observed that the UE may obtain time / frequency synchronization for the SSB-less SCell using legacy mechanisms for the scenarios discussed above, and the on-demand SSB transmission for these scenarios may not be needed.

[0048] With this regard, the target scenarios for on-demand SSB transmission in the 3GPP Rel-19 may include the inter-band CA without the co-located cell(s) and the inter-band CA where the SSB-less SCell and the PCell are across the FR1 and the FR2. Table 1 below illustrates the SSB-less SCell scenarios, according to an example implementation of the present disclosure.

[0049] In some implementations, upon the successful reception of the PDSCH carrying an SCell activation MAC CE, the UE may send an HARQ feedback to the network. Afterward, the UE may obtain time and frequency synchronization based on the reference signal(s) (e.g., the SSB(s)) from the target SCell. Subsequently, the UE may perform the CSI-RS measurements and the CQI reporting, after which the UE may be scheduled for reception or transmission at the SCell.

[0050] Considering a configured SSB-less SCell, the network may send an SCell activation MAC CE to activate the SSB-less SCell. However, since no SSB(s) is transmitted in the corresponding SSB-less SCell, this may lead to the failure of SCell activation because the synchronization may not be completed, and the UE may fail to perform the subsequent measurements needed to support data transmission. Therefore, a trigger mechanism to enforce the SSB-less SCell to transmit its SSB(s) while the gNB is sending the activation MAC CE may be required.

[0051] The proposed mechanism may not be limited to the SSB-less SCell but may also be applicable to the SCells transmitting the SSB set periodically based on the existing 3GPP New Radio protocols. This mechanism may also support scenarios where the SSB is transmitted with a longer periodicity compared to the periodicity defined in the existing 3GPP NR protocols.

[0052] The on-demand SSB transmission may be triggered by either the UE or the network. If the on-demand SSB transmission is triggered by the UE, upon the reception of the SCell activation MAC CE, the UE may send a request to the network via the uplink (UL) signaling (e.g., the WUS) to request the SSB transmission in order to perform the time and frequency synchronizations. However, this approach may cause additional UL signaling overhead and may introduce additional SCell activation delay.

[0053] In some implementations, the on-demand SSB transmission may be triggered by the network. Since the network may clearly know and control the timing of activation, it may decide when to transmit the SSB for the SSB-less SCell. To support network-triggered on-demand SSB transmission, three options may be considered. Table 2 below illustrates the options to support network-triggered on-demand SSB transmission, according to an example implementation of the present disclosure.

[0054] Option 1: Implicitly triggered by legacy activation MAC CE

[0055] Upon the UE MAC entity being configured with one or more SCells, the gNB may activate the configured SCell via an SCell Activation / Deactivation MAC CE or an enhanced SCell Activation / Deactivation MAC CE. The SCell Activation / Deactivation MAC CE may include a one-octet or a four-octet format, which may be distinguished by the corresponding LCID. The Ci field may be used to indicate the activation (e.g., when set to 1) for the SCell with SCellIndex i. Similarly, an Enhanced SCell Activation / Deactivation MAC CE, which may also include a one-octet or a four-octet format and may be distinguished by the e-LCID, may be used to enable the activation and TRS transmission together.

[0056] Under Option 1, if the gNB sends the above MAC CE, the SSB-less SCell may resume the SSB transmission to facilitate the activation (e.g., the SSB may primarily be used for the time and frequency synchronizations). The resumption of the SSB transmission means that the SSB-less SCell may perform periodic SSB transmissions using the legacy format (e.g., the cell may temporarily act as a normal SCell). In some implementations, the cell (or base station) may fall back to the SSB-less SCell based on the network implementation. In some implementations, the cell (or base station) may fall back to the SSB-less SCell if at least one of the following conditions (a)-(c) is met: (a) The cell / BS receives the acknowledgment from the UE. (b) The cell / BS sends the SCell Activation / Deactivation MAC CE or the enhanced SCell Activation / Deactivation MAC CE to deactivate the corresponding SCell. (c) After a configured period or a default period. The time unit of the configured period or the default period may be in slots, milliseconds (ms), or system frame numbers (SFN). The time unit may vary based on the SCell’s subcarrier spacing (SCS) or operating frequency range (e.g., the FR1 or FR2).

[0057] In some implementations, the cell or base station may resume or fall back to normal SSB delivery based on 3GPP NR mechanisms for a non-NES cell after at least one of the conditions (a)-(c) described above is met.

[0058] When the UE receives the SCell Activation / Deactivation MAC CE or the enhanced SCell Activation / Deactivation MAC CE to activate the SSB-less SCell, the UE may assume that the SSB-less SCell will resume the SSB transmission. The UE may then activate the SCell (or determine the SCell to be activated) based on the timing as specified in the 3GPP TS 38.213 for the MAC CE activation. Specifically, the UE may apply the normal SCell operation, which may include: (a) the SRS transmission, (b) the CSI reporting, (c) the PDCCH monitoring, and (d) the PUCCH transmission, if configured, after the SSB synchronization is completed. In some implementations, the UE may remain unaware of whether the activated SCell is a normal SCell or an SSB-less SCell but is only required to perform the behavior as described above.

[0059] In some implementations, the UE may send the HARQ feedback for the MAC PDU containing the SCell Activation / Deactivation MAC CE or the Enhanced SCell Activation / Deactivation MAC CE. There may be following three alternatives (i)-(iii) to decide when to send the feedback.

[0060] (i) The UE may send the HARQ feedback after receiving the MAC CE. In some implementations, the UE may send an ACK if the MAC CE is successfully decoded, and the gNB may assume the activation of the SCell is successful, ensuring alignment between the UE and the gNB on the SCell state (e.g., whether the SCell is activated or deactivated). However, the UE may still fail to perform the SSB synchronization, and the UE may perform the failure handling in such cases. In some implementations, the UE may send a NACK if the MAC CE cannot be successfully decoded, and the gNB may treat the SCell as still deactivated. The SSB-less SCell may stop the SSB transmission upon receiving the NACK to save power. In some implementations, the SSB-less SCell may continue the SSB transmission, as the gNB may send another MAC CE.

[0061] (ii) The UE may send the HARQ feedback after the successful completion of the SSB synchronization. In some implementations, the UE may send an ACK if the SSB synchronization is successfully completed. Both the UE and the gNB may then achieve alignment on the SCell state, and the SSB-less SCell may stop the SSB transmission upon receiving the ACK to save power. In some implementations, the UE may send a NACK if the SSB synchronization cannot be successfully completed. Upon receiving the NACK, the gNB may modify the CA configuration or send another MAC CE. The UE may also send a failure report to the gNB (e.g., via the PCell) and indicate the corresponding failure cause. The failure cause may include failure of decoding the MAC CE and failure of decoding the SSB.

[0062] In some implementations, the gNB may activate multiple SSB-less SCells via one MAC CE, and the UE may send one ACK if all SSB synchronizations are successful or if at least one SSB synchronization is successful. In some implementations, an implicit ACK may be applied, where the UE only sends a NACK if the SSB synchronization cannot be successfully completed. In some implementations, for legacy UEs (not capable of the 3GPP Rel-19 NES features), the HARQ feedback may be sent after receiving the MAC CE. In some implementations, to the serving RAN, the serving cell / base station may have knowledge about whether the UE is an NES-capable UE, an NES UE, or an NES-configured UE, and may determine the expected range or timing of the feedback message transmitted by the UE.

[0063] (iii) The UE may send the HARQ feedback separately after receiving the MAC CE and the SSB (set) for the DL / UL synchronization. In some implementations, the UE may send two separate HARQ feedback messages. The first HARQ feedback may acknowledge the reception of the MAC CE. The second HARQ feedback may provide an ACK / NACK for successful or unsuccessful SSB synchronization, respectively. The UE may send the second HARQ feedback only when sending a positive acknowledgement subject to the reception of MAC CE. The SSB-less SCell may start the SSB transmission after receiving the first ACK and may stop the SSB transmission after receiving the second ACK. If the second ACK is not received, the SSB-less SCell may continue the SSB transmission.

[0064] In some implementations, the SCell may be recognized as activated (e.g., by the serving RAN, serving base station, serving (special) cell, or concerned UE) only when both ACKs are received by the gNB. Otherwise, the serving RAN, serving base station, or serving (special) cell may not determine / consider / recognize the SCell to be activated if neither of the feedback messages, or just one of the two feedback messages, is received, or if a NACK message is received on one or all of the feedback messages. Under certain conditions, the UE may only need to transmit a single NACK message to inform the serving RAN that the SCell activation was not successful. Regarding the second HARQ feedback, an alternative approach may allow the UE to send an RRC message to indicate whether the SSB synchronization is successful for each respective SSB-less SCell, in cases where multiple SSB-less SCells are activated via one MAC CE.

[0065] In some implementations, for legacy UEs (not capable of the 3GPP Rel-19 NES features), only the first HARQ feedback may be sent after receiving the MAC CE. The serving RAN may have sufficient knowledge / information / configuration to determine whether the concerned UE is a legacy UE, an NES UE, an NES-capable UE, or a UE operating on NES functionality. In some implementations, a NACK message (either the first or the second NACK message) may act as the wake-up signaling to trigger the serving RAN to deliver additional SSBs.

[0066] Option 2: RRC configuration plus implicitly triggered by legacy activation MAC CE

[0067] The gNB may configure the UE with a configuration of a specific on-demand SSB transmission pattern. The configured pattern may specify how an SSB-less SCell resumes its SSB transmission pattern when the UE receives an SCell Activation / Deactivation MAC CE or an enhanced SCell Activation / Deactivation MAC CE. Accordingly, the UE may attempt to perform the SSB synchronization and provide the corresponding acknowledgment to the serving RAN. The configuration may include the following information (a)-(c):

[0068] (a) Indicate whether the on-demand SSB is a periodic / semi-periodic / aperiodic transmission after the gNB sends the MAC CE for the corresponding SSB-less SCell.

[0069] In some implementations, if the transmission is aperiodic, the gNB may provide a transmission offset. The time unit of the transmission offset may be in milliseconds (ms), slots, frames, or system frame numbers (SFN). For example, if the gNB sends an activation MAC CE in slot n, the on-demand SSB may be transmitted in slot n + offset. The offset may vary based on the subcarrier spacing (SCS) of the active bandwidth part (BWP) in the activated SCell. The gNB may also configure a transmission duration during which the on-demand SSB may be transmitted after slot n + offset. Such a combination may be achieved by configuring a separate SMTC that is independent of the existing measurement configuration (e.g., the SMTC1 or SMTC2).

[0070] In some implementations, if the transmission is semi-periodic, the gNB may provide a duration during which the on-demand SSB may be transmitted using the existing SMTC configuration. The time unit of the duration may be in milliseconds (ms), slots, frames, or system frame numbers (SFN), and it may vary based on the subcarrier spacing (SCS) of the active bandwidth part (BWP) in the activated SCell. In some implementations, if no duration is provided, the UE may assume that the on-demand SSB will be transmitted only within the timing as specified in the 3GPP TS 38.213 for MAC CE activation or within another default period.

[0071] In some implementations, if the transmission is periodic, the UE may assume that it can adopt the legacy behavior to acquire the on-demand SSB after receiving the activation MAC CE.

[0072] (b) Indicate whether the SIB1 will be broadcast (e.g., by the serving RAN via a special cell and / or a secondary cell). The gNB may resume the SSB transmission (e.g., based on a normal SSB transmission pattern or an NES-specific SSB pattern designed / indicated / configured for the 3GPP Rel-19 NES feature) without the SIB1 transmission. Specifically, one bit may be used for this indication. The UE may assume that the SIB1 will be transmitted together with the SSB if the indication is not present.

[0073] (c) Provide assistance information, such as a DMRS type, to speed up the decoding and synchronization of the SSB. The assistance information may be an information field appended to the PSS, SSS, or PBCH. In addition to the existing information appended to the SSB, a bitmap indicating the availability of the on-demand SSB for the corresponding beam may also be provided.

[0074] The on-demand SSB transmission pattern may be provided by a new RRC message, a new information element (IE) incorporated into the RRC configuration (e.g., the CA / Dual Connectivity, such as MCG / SCG), or a new information IE incorporated into the serving cell common configuration. Different SSB-less SCells may apply different on-demand SSB transmission patterns, or a common transmission pattern may be applied to all SSB-less SCells. The gNB may configure the pattern even when the current CA configuration belongs to the intra-band CA or the inter-band co-located cell scenarios, where the UE can complete the time and frequency synchronization without the SSB transmission. In such cases, the pattern may become valid when the CA configuration is changed to the inter-band CA scenario. Otherwise, the UE may follow the same behavior after receiving the MAC CE. The configuration may not be provided for the PCell and PSCell. The configuration may be suspended when the SCell is deactivated, such as deactivation triggered by a timer or by a MAC CE.

[0075] When a relative SSB transmission pattern configuration is provided, the UE may follow the configuration to perform a new behavior after receiving the legacy activation MAC CE. Otherwise, the UE may perform the legacy behavior after receiving the legacy activation MAC CE. The new behavior represents that the UE may assume that the SSB will be transmitted according to the provided configuration and aim to complete synchronization within the defined timing. Consequently, the UE may send an acknowledgment based on the completion of the SSB synchronization (or the DL synchronization) rather than upon the reception of the MAC CE. The acknowledgment behavior defined in Option 1 may also be applied to Option 2. Alternative behavior represents that when receiving the SSB transmission pattern configuration, the UE may follow the new behavior to detect and synchronize the SSB. However, the UE may still be specified to send the HARQ feedback based on the reception of the MAC CE.

[0076] Option 3: Explicitly triggered by a new enhanced activation MAC CE

[0077] As discussed in Option 2, the network may configure the UE with a specific on-demand SSB transmission pattern for an SSB-less SCell. This pattern may be periodic, semi-periodic, or aperiodic. If the on-demand SSB transmission pattern is aperiodic, the network may configure the UE with an SSB transmission offset, an SSB transmission duration, and / or an on-demand SSB configuration (e.g., the SSB-MTC IE / SSB-MTC ID associated with one specific SSB-MTC IE, based on the 3GPP NR protocol; the numerology IE or a numerology ID associated with one specific numerology IE, based on the 3GPP protocol) including an SSB transmission offset and / or an SSB transmission duration.

[0078] In some implementations, after the UE is configured with the configuration(s) for the aperiodic on-demand SSB transmission for the SSB-less SCell, the network may indicate to the UE to activate the SCell which triggers the aperiodic or semi-persistent on-demand SSB transmission through a new enhanced SCell Activation / Deactivation MAC CE. When the UE receives the new enhanced SCell Activation / Deactivation MAC CE, the UE may assume that the SSB transmission will be resumed in an aperiodic manner for the SSB-less SCell. Accordingly, the UE may perform the time and frequency synchronizations based on the aperiodic on-demand SSB. As legacy behavior, the network may indicate to the UE to activate the SCell without triggering the aperiodic or semi-persistent on-demand SSB transmission by using a legacy SCell Activation / Deactivation MAC CE.

[0079] To activate SCells and trigger the aperiodic on-demand SSB transmission for one or more SCells, the new enhanced SCell Activation / Deactivation MAC CE may include at least one of the following fields (a)-(d):

[0080] (a) Ci field: The Ci field may include one or more octets. If an SCell with SCellIndex i is configured for the MAC entity, the Ci field may indicate the activation or deactivation status of the SCell with the SCellIndex i. Otherwise, the MAC entity may ignore the Ci field. The Ci field may be set to 1 to indicate that the SCell with SCellIndex i is to be activated. If the Ci field is set to 1 to indicate that the SCell with SCellIndex i is to be activated, an on-demand SSB configuration ID field, an offset field, and / or a duration field may be included in the new enhanced SCell Activation / Deactivation MAC CE for the SCell. The Ci field may be set to 0 to indicate that the SCell with SCellIndex i is to be deactivated. If the Ci field is set to 0 to indicate that the SCell with SCellIndex i is to be deactivated, the on-demand SSB configuration ID field, the offset field, and the duration field may not be included in the new enhanced SCell Activation / Deactivation MAC CE for the SCell.

[0081] (b) [Alt. 1] on-demand SSB configuration ID (ODSSB_ID) field: The number of the ODSSB_ID field may be zero, one, or greater than one. The ODSSB_ID field may be used to trigger the on-demand SSB. If the ODSSB_ID field(s) is included in the new enhanced SCell Activation / Deactivation MAC CE, the ODSSB_ID field(s) may be placed in ascending order based on the SCellIndex of the SCells to be activated as indicated by the Ci field(s). If ODSSB_ID j is set to a non-zero value, it may indicate the corresponding on-demand SSB configuration with the index ODSSB_ID j. If ODSSB_ID j is set to zero, it may indicate that no on-demand SSB configuration is used for the corresponding SCell. In this case, the UE may assume that legacy SSB synchronization for the corresponding SCell shall be performed. In some implementations, the ODSSB_ID field(s) may be included in the new enhanced SCell Activation / Deactivation MAC CE only when at least one on-demand SSB configuration is configured for the SCell with the Ci field set to 1.

[0082] In some implementations, if the UE receives the new enhanced SCell Activation / Deactivation MAC CE where the Ci field indicates the same SCell state as the previous status (e.g., SCell#2 is already activated and the Ci field is set to 1), but the corresponding ODSSB_ID j is set to a non-zero value, the UE may assume that this signaling is used to notify the SSB-less SCell to transmit the on-demand SSB based on the configuration with the index ODSSB_ID j.

[0083] (c) offset field: The number of the offset field may be zero, one, or greater than 1. If the offset field(s) is included in the new enhanced SCell Activation / Deactivation MAC CE, the offset field(s) may be placed in ascending order based on the SCellIndex of the SCells to be activated as indicated by the Ci field(s).

[0084] [Alt. 2] In some implementations, the offset field may be included in the new enhanced SCell Activation / Deactivation MAC CE only when the corresponding ODSSB_ID field(s) is also included in the new enhanced SCell Activation / Deactivation MAC CE and set to a non-zero value. If the offset field is set to a non-zero value, the offset field may further indicate that the field value overrides the on-demand SSB transmission offset configured in the configuration with the corresponding ODSSB_ID. If the offset field is set to zero, the UE may ignore the offset field.

[0085] [Alt. 3] In some implementations, for all SCells to be activated (e.g., Ci field is set to 1), the offset field(s) may be included in the new enhanced SCell Activation / Deactivation MAC CE while no corresponding ODSSB_ID field(s) is included in the new enhanced SCell Activation / Deactivation MAC CE. If the offset field for Ci field is set to a non-zero value, and the UE receives the new enhanced SCell Activation / Deactivation MAC CE in slot n, it may indicate that the SCell may resume the legacy SSB transmission at slot n + offset. If the offset field is set to zero, it may indicate that the UE shall perform the legacy SSB synchronization for the corresponding SCell.

[0086] (d) duration field: The number of the duration field may be zero, one, or greater than one. If the duration field(s) is included in the new enhanced SCell Activation / Deactivation MAC CE, the duration field(s) may be placed in ascending order based on the SCellIndex of the SCells to be activated as indicated by the Ci field(s).

[0087] [Alt. 4] In some implementations, the duration field may be included in the new enhanced SCell Activation / Deactivation MAC CE only when the corresponding ODSSB_ID field(s) is also included in the new enhanced SCell Activation / Deactivation MAC CE and set to a non-zero value. If the duration field is set to a non-zero value, the duration field may further indicate that the field value overrides the on-demand SSB transmission duration configured in the configuration with the corresponding ODSSB_ID. If the duration field is set to zero, the UE may ignore the duration field.

[0088] [Alt. 5] In some implementations, for all SCells to be activated (e.g., Ci field is set to 1), the duration field(s) may be included in the new enhanced SCell Activation / Deactivation MAC CE while no corresponding ODSSB_ID field(s) is included in the new enhanced SCell Activation / Deactivation MAC CE. In this case, the duration field may be included in the new enhanced SCell Activation / Deactivation MAC CE only when the corresponding offset field is included in the new enhanced SCell Activation / Deactivation MAC CE. For example, the duration field for the SCell with SCellIndex i may be included in the new enhanced SCell Activation / Deactivation MAC CE only when the offset field for the SCell with SCellIndex i is included in the new enhanced SCell Activation / Deactivation MAC CE. If the duration field for the SCell with SCellIndex i is set to a non-zero value, and the UE receives the new enhanced SCell Activation / Deactivation MAC CE in slot n, it may indicate that the SCell with SCellIndex i will resume the legacy SSB transmission at slot n + offset within the duration.

[0089] In some implementations, the proposed mechanism may also be applied to the activation or deactivation of one or more SCells. The proposed mechanism may be applied only when one or more activated SCells are operating in the NES mode (e.g., the concerned SCell acts as an NES Cell). In contrast, the legacy HARQ ACK / NACK message transmission may be applied if none of the activated SCells (activated by the concerned MAC CE) are operating in the NES mode. In some implementations, the UE may reply with the proposed NACK message if the UE fails to achieve the DL synchronization for at least one SCell (e.g., operating in the NES mode) which is labeled as “activated” by the concerned MAC CE.

[0090] Alternatives for the new enhanced SCell Activation / Deactivation MAC CE design are summarized in Table 3. It may be possible for different SSB-less SCells to apply different alternatives, allowing for greater flexibility. However, it may be simpler to apply a common alternative for all SSB-less SCells or for all SCells. Table 3 below illustrates alternatives for the format of the new enhanced SCell Activation / Deactivation MAC CE, according to an example implementation of the present disclosure.

[0091] In some implementations, if there is no requirement to trigger on-demand SSB for any SCell to be activated, the network may use the legacy SCell Activation / Deactivation MAC CE. If at least one SCell to be activated must trigger the on-demand SSB, the network may use the new enhanced SCell Activation / Deactivation MAC CE. For example, when the network intends to activate the SCell 1 that triggers the on-demand SSB and the SCell 2 that does not trigger the on-demand SSB, the network may set the ODSSB_ID field for the SCell 1 to a non-zero value and the ODSSB_ID field for the SCell 2 to zero, such that the UE may perform the synchronization based on the on-demand SSB for the SCell 1 and perform the synchronization based on the legacy behavior for the SCell 2.

[0092] The new enhanced SCell Activation / Deactivation MAC CE may be transmitted on the PCell or the SCell. The new enhanced SCell Activation / Deactivation MAC CE may be identified by a MAC subheader with the eLCID. When the UE receives a legacy SCell Activation / Deactivation MAC CE or the new enhanced SCell Activation / Deactivation MAC CE, the acknowledgment behavior defined in Option 1 or Option 2 may also be applied to Option 3.

[0093] FIG. 1 is a flowchart illustrating a method / process 100 performed by a UE for network energy saving, according to an example implementation of the present disclosure.

[0094] In action 102, the process 100 may start by receiving, via radio resource control (RRC) signaling, multiple on-demand (OD)-synchronization signal block (SSB) configurations including a first OD-SSB configuration that configures multiple OD-SSB transmissions associated with a secondary cell (SCell).

[0095] In action 104, the process 100 may receive, in a first slot, a first medium access control (MAC) control element (CE) for activating the multiple OD-SSB transmissions. In some implementations, the first MAC CE may include a field that indicates the first OD-SSB configuration.

[0096] In action 106, the process 100 may determine, based on the first slot and an offset, a starting time of the multiple OD-SSB transmissions. The starting time may include a second slot that follows the first slot after the offset.

[0097] In action 108, the process 100 may determine, based on a duration or a state of the SCell, whether the multiple OD-SSB transmissions are deactivated. The multiple OD-SSB transmissions may be performed within the duration. The process 100 may then end. In some implementations, the duration may be configured by the first OD-SSB configuration or indicated by the first MAC CE. In some implementations, the process 100 may determine that the multiple OD-SSB transmissions are deactivated after the duration. In some implementations, the process 100 may determine that the multiple OD-SSB transmissions are deactivated in a case that the SCell is determined to be deactivated. In some implementations, the process 100 may determine that the SCell is deactivated upon receiving a second MAC CE indicating deactivation of the SCell or upon expiry of a timer associated with the SCell.

[0098] The steps / actions shown in FIG. 1 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. 1 may be omitted in some implementations and one or more actions shown in FIG. 1 may be combined.

[0099] The technical problem addressed by the method illustrated in FIG. 1 is how to efficiently manage and control on-demand synchronization signal block (OD-SSB) transmissions for secondary cells (SCells) in a manner that reduces unnecessary resource usage and improves network energy efficiency while maintaining synchronization capabilities. Specifically, the problem includes determining appropriate timings and durations for OD-SSB transmissions to optimize activation and deactivation of SCells under varying network and user conditions. The method improves the efficiency and flexibility of OD-SSB transmissions for SCells, which contributes to reducing network energy consumption and optimizing resource allocation. By configuring the starting time of OD-SSB transmissions based on a first slot and an offset, and managing deactivation based on a duration or the SCell state, the method reduces unnecessary transmissions and signaling.

[0100] FIG. 2 is a flowchart illustrating a method / process 200 performed by a BS for network energy saving, according to an example implementation of the present disclosure.

[0101] In action 202, the process 200 may start by transmitting, via radio resource control (RRC) signaling, multiple on-demand (OD)-synchronization signal block (SSB) configurations including a first OD-SSB configuration that configures multiple OD-SSB transmissions associated with a secondary cell (SCell).

[0102] In action 204, the process 200 may transmit, in a first slot, a first medium access control (MAC) control element (CE) for activating the multiple OD-SSB transmissions. In some implementations, the first MAC CE may include a field that indicates the first OD-SSB configuration.

[0103] In action 206, the process 200 may determine, based on the first slot and an offset, a starting time of the multiple OD-SSB transmissions. The starting time may include a second slot that follows the first slot after the offset.

[0104] In action 208, the process 200 may deactivate, based on a duration or a state of the SCell, the multiple OD-SSB transmissions. The multiple OD-SSB transmissions may be performed within the duration. The process 200 may then end. In some implementations, the duration may be configured by the first OD-SSB configuration or indicated by the first MAC CE. In some implementations, the process 200 may deactivate the multiple OD-SSB transmissions after the duration. In some implementations, the process 200 may deactivate the multiple OD-SSB transmissions in a case that the SCell is deactivated. In some implementations, the process 200 may deactivate the SCell after transmitting a second MAC CE indicating deactivation of the SCell or upon expiry of a timer associated with the SCell.

[0105] The method illustrated in FIG. 2 is similar to that in FIG. 1, except that it is described from the perspective of the BS (instead of the UE).

[0106] The steps / actions shown in FIG. 2 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. 2 may be omitted in some implementations and one or more actions shown in FIG. 2 may be combined.

[0107] FIG. 3 is a block diagram illustrating a node 300 for wireless communication, according to an example implementation of the present disclosure. As illustrated in FIG. 3, a node 300 may include a transceiver 320, a processor 328, a memory 334, one or more presentation components 338, and at least one antenna 336. The node 300 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. 3). FIG. 3 is a block diagram illustrating a node for wireless communication, according to an example implementation of the present disclosure.

[0108] Each of the components may directly or indirectly communicate with each other over one or more buses 340. The node 300 may be a UE or a BS that performs various functions disclosed with reference to FIGS. 1 and 2.

[0109] The transceiver 320 has a transmitter 322 (e.g., transmitting / transmission circuitry) and a receiver 324 (e.g., receiving / reception circuitry) and may be configured to transmit and / or receive time and / or frequency resource partitioning information. The transceiver 320 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 320 may be configured to receive data and control channels.

[0110] The node 300 may include a variety of computer-readable media. Computer-readable media may be any available media that may be accessed by the node 300 and include volatile (and / or non-volatile) media and removable (and / or non-removable) media.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] The memory 334 may include computer-storage media in the form of volatile and / or non-volatile memory. The memory 334 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. 3, the memory 334 may store a computer-readable and / or computer-executable instructions 332 (e.g., software codes) that are configured to, when executed, cause the processor 328 to perform various functions disclosed herein, for example, with reference to FIGS. 1 and 2. Alternatively, the instructions 332 may not be directly executable by the processor 328 but may be configured to cause the node 300 (e.g., when compiled and executed) to perform various functions disclosed herein.

[0115] The processor 328 (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 328 may include memory. The processor 328 may process the data 330 and the instructions 332 received from the memory 334, and information transmitted and received via the transceiver 320, the baseband communications module, and / or the network communications module. The processor 328 may also process information to send to the transceiver 320 for transmission via the antenna 336 to the network communications module for transmission to a CN.

[0116] One or more presentation components 338 may present data indications to a person or another device. Examples of presentation components 338 may include a display device, a speaker, a printing component, a vibrating component, etc.

[0117] 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 network energy saving, the UE comprising: 　　　　at least one processor; and 　　　　at least one non-transitory computer-readable medium coupled to 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: 　　　　　　　　receive, via radio resource control (RRC) signaling, a plurality of on-demand (OD)-synchronization signal block (SSB) configurations comprising a first OD-SSB configuration that configures a plurality of OD-SSB transmissions associated with a secondary cell (SCell); 　　　　　　　　receive, in a first slot, a first medium access control (MAC) control element (CE) for activating the plurality of OD-SSB transmissions; 　　　　　　　　determine, based on the first slot and an offset, a starting time of the plurality of OD-SSB transmissions; 　　　　　　　　determine, based on a duration or a state of the SCell, whether the plurality of OD-SSB transmissions are deactivated, wherein: 　　　　the starting time comprises a second slot that follows the first slot after the offset, and 　　　　the plurality of OD-SSB transmissions are performed within the duration.

2. The UE of claim 1, wherein the duration is configured by the first OD-SSB configuration or indicated by the first MAC CE.

3. The UE of claim 1, wherein the first MAC CE comprises a field that indicates the first OD-SSB configuration.

4. The UE of claim 1, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: 　　　　determine that the plurality of OD-SSB transmissions are deactivated after the duration.

5. The UE of claim 1, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: 　　　　determine that the plurality of OD-SSB transmissions are deactivated in a case that the SCell is determined to be deactivated.

6. The UE of claim 5, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: 　　　　determine that the SCell is deactivated upon receiving a second MAC CE indicating deactivation of the SCell or upon expiry of a timer associated with the SCell.

7. A method performed by a user equipment (UE) for network energy saving, the method comprising: 　　　　receiving, via radio resource control (RRC) signaling, a plurality of on-demand (OD)-synchronization signal block (SSB) configurations comprising a first OD-SSB configuration that configures a plurality of OD-SSB transmissions associated with a secondary cell (SCell); 　　　　receiving, in a first slot, a first medium access control (MAC) control element (CE) for activating the plurality of OD-SSB transmissions; 　　　　determining, based on the first slot and an offset, a starting time of the plurality of OD-SSB transmissions; 　　　　determining, based on a duration or a state of the SCell, whether the plurality of OD-SSB transmissions are deactivated, wherein: 　　　　the starting time comprises a second slot that follows the first slot after the offset, and 　　　　the plurality of OD-SSB transmissions are performed within the duration.

8. A base station (BS) for network energy saving, the BS comprising: 　　　　at least one processor; and 　　　　at least one non-transitory computer-readable medium coupled to 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, via radio resource control (RRC) signaling, a plurality of on-demand (OD)-synchronization signal block (SSB) configurations comprising a first OD-SSB configuration that configures a plurality of OD-SSB transmissions associated with a secondary cell (SCell); 　　　　　　　　transmit, in a first slot, a first medium access control (MAC) control element (CE) for activating the plurality of OD-SSB transmissions; 　　　　　　　　determine, based on the first slot and an offset, a starting time of the plurality of OD-SSB transmissions; 　　　　　　　　deactivate, based on a duration or a state of the SCell, the plurality of OD-SSB transmissions, wherein: 　　　　the starting time comprises a second slot that follows the first slot after the offset, and 　　　　the plurality of OD-SSB transmissions are performed within the duration.

9. The BS of claim 8, wherein the duration is configured by the first OD-SSB configuration or indicated by the first MAC CE.

10. The BS of claim 8, wherein the first MAC CE comprises a field that indicates the first OD-SSB configuration.

11. The BS of claim 8, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the BS to: 　　　　deactivate the plurality of OD-SSB transmissions after the duration.

12. The BS of claim 8, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the BS to: 　　　　deactivate the plurality of OD-SSB transmissions in a case that the SCell is deactivated.

13. The BS of claim 12, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the BS to: 　　　　deactivate the SCell after transmitting a second MAC CE indicating deactivation of the SCell or upon expiry of a timer associated with the SCell.

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