Method and apparatus for prach adaptaion to enhance network energy saving in a wireless communication system

Abstract

A User Equipment (UE) for Physical Random Access Channel (PRACH) adaptation to enhance network energy saving is provided. The UE receives, from a first cell of a serving Radio Access Network (RAN), a configuration for one or more additional PRACH resources; receives, from the first cell, an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated; and considers the first additional PRACH resource is applicable for a random access procedure. In addition, a method and a Base Station (BS) are also provided.

Description

METHOD AND APPARATUS FOR PRACH ADAPTAION TO ENHANCE NETWORK ENERGY SAVING IN A WIRELESS COMMUNICATION SYSTEM

[0001] The present disclosure is related to wireless communication and, more specifically, to a User Equipment (UE), Base Station (BS), and method for physical random access channel (PRACH) adaption to enhance network energy saving in a wireless communication system.

[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, such as improvements in a beam management procedure.Summery of Invention

[0003] The present disclosure is directed to a User Equipment (UE), a Base Station (BS), and a method for physical random access channel (PRACH) adaption to enhance network energy saving in a wireless communication system.

[0004] According to a first aspect of the present disclosure, a UE for PRACH adaptation to enhance network energy saving in a wireless communication system is provided. The UE includes: 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. When executed by the at least one processor, the instructions cause the UE to: receive, from a first cell of a serving Radio Access Network (RAN), a configuration for one or more additional PRACH resources; receive, from the first cell, an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated; and consider the first additional PRACH resource is applicable for a random access procedure.

[0005] In an implementation of the first aspect, the indication is received via Downlink Control Information (DCI) format 1_0 scrambled by a Paging Radio Network Temporary Identifier (P-RNTI). The indication includes at least one bit within an 8-bit short message carried in the DCI format 1_0 scrambled by the P-RNTI.

[0006] In another implementation of the first aspect, the UE further includes: initiate, to the first cell, the random access procedure by using the first additional PRACH resource after considering the first additional PRACH resource is applicable for the random access procedure.

[0007] In another implementation of the first aspect, the random access procedure is a contention-based random access procedure.

[0008] In another implementation of the first aspect, the random access procedure is a contention-free random access procedure triggered via a Physical Downlink Control Channel (PDCCH) order. The PDCCH order is received via a DCI format 1_0 scrambled by a Cell Radio Network Temporary Identifier (C-RNTI) from the first cell.

[0009] In another implementation of the first aspect, the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: consider the first additional PRACH resource is valid for the random access procedure based on a validity period associated with the first additional PRACH resource upon receiving the indication; deactivate the first additional PRACH resource upon the validity period expires; and consider the first additional PRACH resource is not applicable for the random access procedure after the additional PRACH resource is deactivated. The validity period associated with the first additional PRACH resource is included in the indication or is pre-configured to the UE as part of the configuration for the one or more additional PRACH resources before receiving the indication.

[0010] In another implementation of the first aspect, the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: receive, from the first cell, a deactivation indication indicating at least one additional PRACH resource, among the one or more additional PRACH resources, is deactivated; deactivate the at least one additional PRACH resource upon receiving the deactivation indication; and consider the at least one additional PRACH resource is not applicable for the random access procedure after the at least one additional PRACH resource is deactivated.

[0011] In another implementation 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 an operating uplink frequency carrier for the random access procedure, among a Normal Uplink (NUL) frequency carrier and a Supplementary Uplink (SUL) frequency carrier, based on the first additional PRACH resource after receiving the indication; and determine an uplink Bandwidth Part (BWP) based on the first additional PRACH resource. The uplink BWP is one of UL BWP 0, UL BWP 1, UL BWP 2, UL BWP 3, or an Uplink BWP specific to a Reduced Capability (RedCap) UE.

[0012] In another implementation 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 an activation or deactivation status of the one or more additional PRACH resources upon a Radio Resource Control (RRC) state change.

[0013] According to a second aspect of the present disclosure, a BS for PRACH adaptation to enhance network energy saving in a wireless communication system is provided. The BS includes: 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. When executed by the at least one processor, the instructions cause the BS to: transmit, to a UE, a configuration for one or more additional PRACH resources; and transmit, to the UE, an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated. The indication causes the UE to: consider the first additional PRACH resource is applicable for a random access procedure.

[0014] In an implementation of the second aspect, the indication is transmitted via DCI format 1_0 scrambled by a P-RNTI. The indication includes at least one bit within an 8-bit short message carried in the DCI format 1_0 scrambled by the P-RNTI.

[0015] In another implementation of the second aspect, the indication further causes the UE to: consider the first additional PRACH resource is valid for the random access procedure based on a validity period associated with the first additional PRACH resource upon receiving the indication; deactivate the first additional PRACH resource upon the validity period expires; and consider the first additional PRACH resource is not applicable for the random access procedure after the additional PRACH resource is deactivated. The validity period associated with the first additional PRACH resource is included in the indication or is pre-configured to the UE as part of the configuration for the one or more additional PRACH resources before transmitting the indication.

[0016] In another implementation of the second aspect, the one or more computer-executable instructions, when executed by the at least one processor, further cause the BS to: transmit, to the UE, a deactivation indication indicating at least one additional PRACH resource, among the one or more additional PRACH resources, is deactivated. The deactivation indication causes the UE to: deactivate the at least one additional PRACH resource upon receiving the deactivation indication; and consider the at least one additional PRACH resource is not applicable for the random access procedure after the at least one additional PRACH resource is deactivated.

[0017] In another implementation of the second aspect, the indication further causes the UE to: determine an operating uplink frequency carrier for the random access procedure, among a NUL frequency carrier and a SUL frequency carrier, based on the first additional PRACH resource after receiving the indication; and determine an uplink BWP based on the first additional PRACH resource. The uplink BWP is one of UL BWP 0, UL BWP 1, UL BWP 2, UL BWP 3, or an Uplink BWP specific to a RedCap UE.

[0018] According to a third aspect of the present disclosure, a method performed by a UE for PRACH adaptation to enhance network energy saving in a wireless communication system is provided. The method includes: receiving, from a first cell of a serving RAN, a configuration for one or more additional PRACH resources; receiving, from the first cell, an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated; and considering the first additional PRACH resource is applicable for a random access procedure.

[0019] Aspects of the present disclosure are best understood from the following detailed disclosure and the corresponding figures. Various features are not drawn to scale and dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.

[0020] FIG. 1 is a diagram illustrating an uplink bandwidth part (UL-BWP) switching triggered by a downlink control information (DCI)-based physical random access channel (PRACH) adaptation, according to an example implementation of the present disclosure.

[0021] FIG. 2 is a diagram illustrating a validity time period of an activated additional PRACH, according to an example implementation of the present disclosure.

[0022] FIG. 3 is a flowchart illustrating a method / process performed by a user equipment (UE) for PRACH adaptation, according to an example implementation of the present disclosure.

[0023] FIG. 4 is a flowchart illustrating a method / process performed by the UE for PRACH adaptation, according to an example implementation of the present disclosure.

[0024] FIG. 5 is a block diagram illustrating a node for wireless communication, according to an example implementation of the present disclosure.

[0025] Some of the abbreviations used in the present disclosure include: Abbreviation　　　　Full name 3GPP　　　　3rd Generation Partnership Project 5G　　　　5th Generation 5GC　　　　5G Core ARFCN　　　　Absolute Radio-Frequency Channel Number AS　　　　Access Stratum BS　　　　Base Station BWP　　　　Bandwidth Part CA　　　　Carrier Aggregation CAG　　　　Closed Access Group CN　　　　Core Network CU　　　　Central Unit DAPS　　　　Dual Active Protocol Stack DC　　　　Dual Connectivity DCI　　　　Downlink Control Information DL　　　　Downlink DU　　　　Distributed Unit E-UTRA(N)　　　　Evolved Universal Terrestrial Radio Access (Network) EN-DC　　　　E-UTRA NR Dual Connectivity EPC　　　　Evolved Packet Core FR　　　　Frequency Range IAB　　　　Integrated Access and Backhaul ID　　　　Identifier IE　　　　Information Element LAN　　　　Local Area Network LTE　　　　Long Term Evolution MAC　　　　Medium Access Control MAC CE　　　　MAC Control Element MCG　　　　Master Cell Group MIB　　　　Master Information Block MN　　　　Master Node MSG　　　　Message MT　　　　Mobile Termination NAS　　　　Non-Access Stratum NE-DC　　　　NR E-UTRA Dual Connectivity NES　　　　Network Energy Saving NPN　　　　Non-Public Network NR　　　　New Radio NR-U　　　　NR Unlicensed NW　　　　Network NSSAI　　　　Network Slice Selection Assistance Information PCell　　　　Primary Cell PCI　　　　Physical Cell Identity PDCCH　　　　Physical Downlink Control Channel PDSCH　　　　Physical Downlink Shared Channel PDU　　　　Protocol Data Unit PHY　　　　Physical (layer) PLMN　　　　Public Land Mobile Network PNI-NPN　　　　Public Network Integrated Non-Public Network PRACH　　　　Physical Random Access Channel PSCell　　　　Primary Secondary Cell PUCCH　　　　Physical Uplink Control Channel PUSCH　　　　Physical Uplink Shared Channel RA　　　　Random Access RAN　　　　Radio Access Network RAR　　　　Random Access Response RAT　　　　Random Access Technology RF　　　　Radio Frequency RNTI　　　　Radio Network Temporary Identifier RRC　　　　Radio Resource Control RS　　　　Reference Signal RSRP　　　　Reference Signal Received Power SCell　　　　Secondary Cell SCG　　　　Secondary Cell Group SI　　　　System Information SIB　　　　System Information Block SL　　　　Sidelink SN　　　　Secondary Node SNPN　　　　Stand-alone Non-Public Network SSB　　　　Synchronization Signal Block TS　　　　Technical Specification UE　　　　User Equipment UL　　　　Uplink V2X　　　　Vehicle-to-Everything WUS　　　　Wake-Up Signal

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] A software implementation may include computer executable instructions and / or Artificial Intelligence (AI) / Machine Learning (ML) module(s) 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), AI / ML module(s), or algorithm(s). The AI / ML module(s) may be implemented with a supervised learning approach, a semi-supervised learning approach, an unsupervised learning approach (e.g., Transductive approach and Inductive approach), a federated learning approach, or a reinforcement learning (RL) approach, but the present disclosure is not limited thereto. The computer-executable instructions associated with the AI module(s) and / or the ML module(s) may include but are not limited to, data management instructions (e.g., collection instructions, validation instructions…etc.), model monitoring and management instructions (e.g., NW KPIs monitoring, model input / output monitoring, model selection / switching / update / upload / download, model (de)activation, model identification, functionality selection, etc.), and / or pre-process input instructions.

[0034] The microprocessors or general-purpose computers may include Application-Specific Integrated Circuits (ASICs), programmable logic arrays, Central Processing Units (CPUs), Tensor Processing Units (TPUs), Graphics Processing Units (GPUs), General-purpose computing on GPUs (GPGPU, / GPGP), and / or using one or more Digital Signal Processors (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 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 (e.g., computer-readable instructions related to AI module(s) and / or the ML module(s)), data structures, program modules or data. The computer-readable medium may include, but is not limited to, Random Access Memory (RAM), Dynamic Random Access Memory (DRAM), High Bandwidth Memory (HBM), Magnetoresistive Random Access Memory (MRAM), Ferroelectric Random Access Memory (FRAM), Resistive Random Access Memory (RRAM), Read-Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory (or other memory technology), Compact Disc Read-Only Memory (CD-ROM) , Digital Versatile Disks (DVD) (or other optical disk storage), magnetic cassettes, magnetic tape, magnetic disk storage (or other magnetic storage devices), or any other equivalent medium capable of storing computer-readable instructions. Computer-storage media may not include a propagated data signal. Communication media may typically embody computer-readable instructions (e.g., computer-readable instructions related to AI module(s) and / or the ML module(s)), 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.

[0035] 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 previously listed components should also be included within the scope of computer-readable media.

[0036] A radio communication network architecture such as a Long-Term Evolution (LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Pro system, a 5G NR Radio Access Network (RAN), 5G-Advanced (5G-A) system, or an open radio access network (O-RAN) may typically include at least one base station (BS), at least one UE, and one or more optional network elements that provide connection within a network. The BS and one or more optional network elements enable the UE to access a radio network. Thus, the UE may communicate with the network, such as a Core Network (CN), an Evolved Packet Core (EPC) network, an Evolved Universal Terrestrial RAN (E-UTRAN), a Next-Generation Core (NGC), a 5G Core (5GC), or an internet via a RAN established by one or more BSs and the network elements / functions.

[0037] 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, a virtual reality (VR) device, an augmented (AR) device, an Internet of Things (IoT) device, an unmanned aerial vehicle (UAV), or a Personal Digital Assistant (PDA) with wireless communication capability. The UE may be configured to receive and transmit signals over an air interface to one or more cells in a RAN. In some implementations, the UE may be an AI / ML-enabled device and / or an AI / ML capable device that is equipped with AI module(s) and / or ML module(s).

[0038] 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.

[0039] 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. In some implementations, the BS may be an AI / ML-enabled device and / or an AI / ML capable device that is equipped with AI module(s) and / or ML module(s). 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.

[0040] 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.

[0041] 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.

[0042] A cell may allocate sidelink (SL) resources for supporting the Proximity Services (ProSe), LTE SL services, LTE / NR sidelink communication services, LTE / NR sidelink discovery services, and / or LTE / NR Vehicle-to-Everything (V2X) services. In addition, a cell may allocate DL and / or UL resources for supporting Multicast / Broadcast Service (MBS) services, Non-Terrestrial Networks (NTN) services, positioning services, power serving services and / or Network Energy Saving (NES) services.

[0043] 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.

[0044] The terms, definitions, and abbreviations as given in this document are either imported from existing documentation (European Telecommunications Standards Institute (ETSI), International Telecommunication Union (ITU), or elsewhere) or newly created by 3GPP experts whenever the need for precise vocabulary is identified.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] In this disclosure, some designs for common Physical Random Access Channel (PRACH) adaptation may be provided to enhance a network energy saving mechanism for wireless communication systems (e.g., Third Generation Partnership Project (3GPP) New Radio (NR) or Evolved Universal Terrestrial Radio Access (E-UTRA)). The provided designs may be based on the Downlink Control Information (DCI)-based PRACH adaptation design (e.g., to support common PRACH adaptation).

[0053] In some implementations, the DCI-based PRACH adaptation may combine with a Bandwidth Part (BWP) switching operation. For example, the DCI which instructs Downlink BWP (DL-BWP) or Uplink BWP (UL-BWP) switching may also activate or deactivate one or more PRACH resource configurations simultaneously. In some implementations, the DCI that activates or deactivates a PRACH configuration may not trigger UL-BWP switching or UL-carrier switching. For example, additional PRACH configuration(s) may be configured only on an initial UL-BWP paired or unpaired with the initial DL-BWP.

[0054] In some implementations, the DCI-based PRACH adaptation may not combine with a BWP switching operation.

[0055] In some implementations, the DCI-based PRACH adaptation may combine with the Normal Uplink (NUL) carrier or Supplementary Uplink (SUL) carrier switching. For example, the DCI which instructs NUL or SUL switching may also activate or deactivate one or more PRACH resource configurations simultaneously.

[0056] In some implementations, the DCI-based PRACH adaptation may not combine with the Normal Uplink (NUL) carrier or Supplementary Uplink (SUL) carrier switching.

[0057] In some implementations, the DCI-based PRACH adaptation may combine with a Transmission Power Command. For example, the DCI which activates or deactivates one or more PRACH resource configurations may also be associated with one Transmission Power Command simultaneously.

[0058] In some implementations, the DCI-based PRACH adaptation may not combine with a Transmission Power Command.

[0059] In some implementations, the UL-BWP / UL carrier of the activated or deactivated additional PRACH resource configuration(s) (e.g., which may be activated or deactivated by the DCI-PRACH (activation / de-activation) instruction) may not be the same as the current operating UL-BWP / UL carrier of the UE. Therefore, UL frequency carrier information (and / or an UL-BWP index associated with the UL frequency carrier information) may also be configured in a DCI-PRACH instruction that is used to activate or deactivate one or more additional PRACH configurations.

[0060] In some implementations, DCI-PRACH instruction(s) (e.g., for activation or de-activation) may be transmitted only on a search space of an initial DL-BWP. In some implementations, the UE may receive a DCI-PRACH configuration from the serving RAN (e.g., via UE-specific RRC signaling). The DCI-PRACH configuration may configure the search space for DCI-PRACH instruction reception. In addition, the DCI-PRACH configuration may further define specific bit field in a given DCI format to present one or more PRACH configuration indices. Each of the one or more PRACH configuration indices is uniquely associated one pre-configured additional PRACH index associated with one additional PRACH configuration. Then, via DCI-PRACH instruction transmission, the serving RAN would provide / configure / indicate / transmit one or more specific PDCCH configuration indices in the specific bit filed to indicate the additional PRACH configuration(s) be activated / deactivated by the DCI-PRACH activation / deactivation instruction. In addition, the additional PRACH index (or the additional PRACH configuration) may be further associated with an UL carrier (e.g., NUL or SUL) ID or an UL-BWP ID. Therefore, the activation or deactivation of the additional PRACH configuration may support the activation or deactivation of a cross carrier or an UL-BWP.

[0061] In some implementations, a DCI format (e.g., DCI format 1_0) may be used to trigger the additional PRACH resource activation and UL-BWP switching. Therefore, the additional PRACH resource configuration may be associated with a specific UL-BWP. For example, the specific UL-BWP may be the initial UL-BWP to the serving cell. As another example, the specific UL-BWP may not be the initial UL-BWP to the serving cell.

[0062] FIG. 1 is a diagram illustrating a UL-BWP switching triggered by a DCI-based PRACH adaptation, according to an example implementation of the present disclosure.

[0063] Referring to FIG. 1, one or more baseline PRACH resources 111 or one or more additional PRACH resources 112 may be configured on the initial UL-BWP 110. In addition, another additional PRACH configuration 121 is configured on another UL-BWP 120. Additionally, the serving cell may transmit DCI 131 (e.g., which may be also referred to as a DCI-PRACH activation / de-activation instruction, and provided based on DCI format 1_0 / DCI format 0_1 / DCI format 2_7 / DCI format 2_9 or other types of DCI formats). After receiving the DCI 131, the UE may switch to the operating UL-BWP 120. In some implementations, UL-BWP 110 and UL-BWP 120 may be located on the same frequency carrier. In some implementations, UL-BWP 110 and UL-BWP 120 may be located on different frequency carriers.

[0064] In some implementations, a UE may switch its UL operating frequency carrier from a NUL carrier to a SUL carrier (or vice versa) after receiving the DCI-PRACH activation / de-activation instruction (e.g., DCI format 1_0 / 2_7 / 2_9) which activates or deactivates an additional PRACH configuration.

[0065] In some implementations, DCI may be able to activate or deactivate the additional PRACH resource configuration(s) of multiple serving cells. In some implementations, a cell may pre-configure a list of cells where each of the cells is associated with an index.

[0066] In some implementations, DCI may be provided only for either “activation” or “de-activation” of an additional PRACH resource configuration. In other words, DCI may not be able to activate an additional PRACH resource and deactivate an additional PRACH resource jointly in the same DCI. Therefore, a bit field in the DCI may further indicate the functionality of the DCI (e.g., for activation or de-activation of an additional PRACH resource).

[0067] In some implementations, only up to one DCI format 1_0 for additional PRACH configuration activation or de-activation may be provided / encoded / scrambled / multiplexed / transmitted within a PDCCH monitoring occasion. In some implementations, multiple DCI format 1_0 (e.g., 2, 3, or up to N_max, where the value of N_max may be pre-defined or pre-configured by serving RAN) for additional PRACH configuration activation or de-activation may be provided / encoded / scrambled / multiplexed / transmitted within a PDCCH monitoring occasion.

[0068] In some implementations, only one type of DCI (e.g., the DCI format 1_0 provided for either “activation” or “deactivation” of an additional PRACH resource configuration) may be provided / encoded / scrambled / multiplexed / transmitted within a PDCCH monitoring occasion. In other words, different types of DCI format 1_0 (e.g., types for activation and de-activation of additional PRACH resource configuration) may not be provided / encoded / scrambled / multiplexed / transmitted within a PDCCH monitoring occasion.

[0069] In some implementations, both the DCIs for activation and de-activation of additional PRACH resource configuration may be provided / encoded / scrambled / multiplexed / transmitted within a PDCCH monitoring occasion.

[0070] In some implementations, DCI may be provided to “activate” or “de-activate” an additional PRACH resource pre-configured to UEs. In such a case, one or more bit fields may be configured to indicate which parameters in the DCI format 1_0 are provided for activation of the additional PRACH resource configuration, and one or more other bit fields may be configured to indicate which parameters in the DCI format 1_0 are provided for de-activation of the additional PRACH resource configuration.

[0071] FIG. 2 is a diagram illustrating a validity time period of an activated additional PRACH, according to an example implementation of the present disclosure.

[0072] Referring to FIG. 2, one or more baseline PRACH resources 211 or one or more additional PRACH resources 212 may be configured. In some implementations, an additional PRACH resource configuration may be activated for as long as a given time period / timing window 232 once upon or after receiving a DCI format 1_0 231 to activate the additional PRACH resource(s) 212. In some implementations, the UE may start to count a validity timer to zero upon or after receiving a DCI format 1_0 231 to activate the additional PRACH resource configuration. Then, the UE may consider the activated additional PRACH resource(s) 212 (which is activated by the DCI format 1_0 reception or by an RRC signaling / broadcasting system information which configures and activates the additional PRACH resource configuration) becomes invalid after the UE counts the validity timer to zero. In some implementations, the initial value of the validity timer may be pre-defined or pre-configured by the serving RAN via broadcasting control signaling (such as broadcasting system information) or via UE-specific RRC signaling.

[0073] In some implementations, the UE may keep counting the validity timer (e.g., which may be associated with one or more activated additional PRACH resource configurations) without being impacted by an RRC state change (e.g., from an RRC connected state to an RRC idle or inactive state via an RRCRelease message reception; from an RRC inactive state to an RRC connected state via an RRCResume message reception or an RRCResumeComplete message transmission; or from an RRC idle state to an RRC connected state via an RRCSetup message reception or an RRCSetupComplete message transmission).

[0074] In some implementations, the UE may release or remove the validity timer upon the UE initiating an inter-RAT cell reselection procedure or inter-RAT mobility event (e.g., conditional handover / Dual Active Protocol Stack (DAPS) or Lower-layer Triggered Mobility (LTM)). In some implementations, the valid period of an additional PRACH configuration may be interrupted upon or after the UE initiates an inter-RAT cell reselection procedure or inter-RAT mobility event (e.g., conditional handover). In some implementations, the inter-RAT may include the scenario where the UE changes its serving RAN from a New Radio (NR) RAN to E-UTRAN (or vice versa).

[0075] In some implementations, the UE may release or remove the validity timer upon the UE initiating an intra-RAT cell reselection procedure or intra-RAT mobility event (e.g., conditional handover / DAPS or LTM). In some implementations, the valid period of an additional PRACH configuration may be interrupted upon or after the UE initiates an intra-RAT cell reselection procedure or intra-RAT mobility event (e.g., conditional handover). In some implementations, intra-RAT may include the scenario where the UE is moving within the NR RAN or E-UTRAN.

[0076] In some implementations, the valid period of an additional PRACH resource configuration may be defined by a timing window. The timing window of an additional PRACH resource configuration may be started upon reception of a DCI format 1_0 to activate the additional PRACH resource configuration, a specific number of symbols / slots / msec after the reception of the DCI-PRACH activation / de-activation instruction (e.g., via DCI format 1_0 transmission), or upon receiving the RRC configuration which activates the additional PRACH resource configuration.

[0077] In some implementations, to prevent a large group of UEs from starting to access an additional PRACH resource configuration (e.g., after receiving a DCI format 1_0 to activate the additional PRACH resource configuration), one additional offset time or backoff indicator may be pre-defined or pre-configured to the UE. Therefore, each UE may start to activate an additional PRACH resource configuration at different times.

[0078] In some implementations, different additional offset times may be decided by different UEs and each may be based on a random value derivation from a given range (e.g., a random value decided between [0,1]). The given range may be pre-defined or may be configured by the serving RAN via broadcasting control signaling.

[0079] In some implementations, the serving RAN may repeat the transmission of the DCI-PRACH activation / de-activation instruction multiple times in one PDCCH occasion or across multiple (e.g., continuous) PDCCH occasions.

[0080] In some implementations, the stop time of the validity time period / window / counter of an activated additional PRACH configuration may be the first symbol after the PDCCH occasion which conveys the DCI-PRACH de-activation instruction(s). In some implementations, the stop time of the validity time period / window / counter of an activated additional PRACH configuration may be the first symbol after the System Information window (SI-window) which configures / deactivates / modifies the additional PRACH configuration(s).

[0081] In some implementations, the start time of the validity time period / window / counter of an activated additional PRACH configuration may be the first symbol after the PDCCH occasion which conveys the DCI-PRACH activation instruction(s). In some implementations, the start time of the validity time period / window / counter of an activated additional PRACH configuration may be the first symbol after the SI-window which configures / activates / modifies the additional PRACH configuration(s).

[0082] In some implementations, some of the bit fields in the DCI format 1_0 may indicate that the DCI is transmitted to activate or deactivate one or more additional PRACH resource configurations (e.g., the additional PRACH configuration specific for Network Energy Saving (NES) functionality in Release 19). In some implementations, the DCI format 1_0 may be with CRC scrambled by P-RNTI.

[0083] In some implementations, paging DCI or a short message may be used to indicate the activation or deactivation of additional PRACH adaptation. For example, one or more bits (e.g., reserved bits) in the short message may be used to activate or deactivate the additional PRACH resource configuration. One bit may be set to “1” to activate all of the additional PRACH resource configuration, and the same bit may be set to “0” to de-activate all of the additional PRACH resource configuration.

[0084] In some implementations, the DCI-PRACH activation or deactivation instruction may not be assembled with other DCI which is also scrambled with P-RNTI (e.g., the paging DCI). In other words, the serving RAN may not be allowed to assemble both the paging DCI and the additional PRACH activation or deactivation instruction in one PDCCH occasion (e.g., in one common search space). Additionally, the UE may also not expect both the paging DCI and the additional PRACH activation or deactivation instruction to be assembled jointly in one PDCCH occasion. Therefore, during the blind decoding procedure, the UE may stop decoding or descrambling a DCI with P-RNTI if the UE already decodes DCI scrambled with P-RNTI successfully. For example, a UE may stop monitoring the additional PRACH activation or deactivation instruction in one PDCCH occasion if the UE already decodes a paging DCI successfully in the same PDCCH occasion. In contrast, a UE may stop monitoring a paging DCI in one PDCCH occasion if the UE already decodes an additional PRACH activation or deactivation instruction successfully in the same PDCCH occasion.

[0085] In some implementations, both the additional PRACH activation or deactivation instruction and the paging DCI may be assembled or transmitted in the same PDCCH occasion, and the UE may need to try to decode or descramble both the additional PRACH activation or deactivation instruction and the paging DCI in one PDCCH occasion during the blind decoding procedure.

[0086] In some implementations, the additional PRACH activation or deactivation instruction may be applicable only to the NES-capable UE defined in R-19 and so a legacy UE which does not support the NES functionality defined in R-19 may still implement the blind decoding approach based on a conventional approach (e.g., the blind decoding procedure defined in Release 18).

[0087] In some implementations, the PRACH configuration index of the additional PRACH configuration (e.g., associated with the PRACH configuration table defined in 3GPP TS 38.211, as shown in Table 1) may be configured directly within the DCI for additional PRACH activation or deactivation. In some implementations, a list of additional PRACH configuration may be pre-configured to the UE (e.g., via broadcasting system information or UE-specific RRC control signaling), and each additional PRACH configuration in the list may also be pre-configured with one Additional_PRACH_index (e.g., via explicit signaling or based on the ascending / descending sequence in the list of additional PRACH configuration). Therefore, the serving RAN may activate or deactivate one additional PRACH configuration by including the Additional_PRACH_index in the DCI.

[0088] In some implementations, DCI may further indicate which type of index (e.g., by configuring one PRACH configuration index defined in the 3GPP technical specification or by configuring one Additional_PRACH_index) is configured to the UE.

[0089] In some implementations, the serving RAN may configure the frequency location of the additional PRACH configuration (e.g., msg1-FrequencyStart or msgA-RO-FrequencyStart) into the DCI.

[0090] In some implementations, the UE may be pre-configured with one or more the following additional PRACH resources: 　　　　1) N1 additional (x, y) set configuration. Each additional (x, y) set in the N1 additional (x, y) set configuration may be associated with an explicit (e.g., by explicit signaling) or implicit (e.g., by referring to the ascending / descending order shown in the N1 additional (x, y) set configuration) index. Up to N1 (x, y) sets may be included in the N1 additional (x, y) set configuration, and the value of N1 may be pre-defined (e.g., by 3GPP technical specification) or may be configured by the serving RAN via common system information or UE-specific RRC signaling. 　　　　2) N2 additional y value list. Each additional y value in the N2 additional y value list configuration may be associated with an explicit (e.g., by explicit signaling) or implicit (e.g., by referring to the ascending / descending order shown in the N2 additional y value list) index. Up to N2 y values may be included in the N2 additional y value configuration, and the value of N2 may be pre-defined (e.g., by 3GPP technical specification) or may be configured by the serving RAN via common system information or UE-specific RRC signaling. 　　　　3) Nx additional frame-level timing offset list for PRACH resource at frame-level. Each additional frame-level timing offset in the Nx additional frame-level timing offset list configuration may be associated with an explicit (e.g., by explicit signaling) or implicit (e.g., by referring to the ascending / descending order shown in the Nx additional frame-level timing offset list) index. Up to Nx additional frame-level timing offsets may be included in the Nx additional frame-level timing offset list, and the value of Nx may be pre-defined (e.g., by 3GPP technical specification) or may be configured by the serving RAN via common system information or UE-specific RRC signaling. 　　　　4) Ny additional slot-level timing offset list for PRACH resource at slot-level. Each additional slot-level timing offset in the Ny additional slot-level timing offset list configuration may be associated with an explicit (e.g., by explicit signaling) or implicit (e.g., by referring to the ascending / descending order shown in the Ny additional slot-level timing offset list) index. Up to Ny additional slot-level timing offsets may be included in the Ny additional slot-level timing offset list, and the value of Ny may be pre-defined (e.g., by 3GPP technical specification) or may be configured by the serving RAN via common system information or UE-specific RRC signaling.

[0091] In some implementations, the serving RAN may indicate the adaptation of additional PRACH resource configuration in the time-domain by transmitting one or more of the timing information into the DCI (e.g., the DCI which activates or deactivates one or more additional PRACH resource configurations): 　　　　1) One additional (x, y) value or an index of the additional (x, y) set corresponding to the N1 additional (x, y) set configuration. 　　　　2) One additional y value or an index of the additional y value corresponding to the N2 additional y value list. 　　　　3) One additional frame-level timing offset or an index of the additional frame-level timing offset corresponding to the Nx additional frame-level timing offset list. 　　　　4) One additional slot-level timing offset or an index of the additional slot-level timing offset corresponding to the Ny additional slot-level timing offset list.

[0092] It should be noted that, the timing offset may also be applicable to sub-frame, symbol, or super-frame level timing offset.

[0093] In some implementations, the UE may receive DCI, which instructs the UE to initiate a (e.g., 2-step or 4-step) random access (RA) procedure (e.g., which may be referred to as a PDCCH-order RA procedure).

[0094] In some implementations, the DCI that instructs the UE to implement a random access procedure may also activate or deactivate an additional PRACH resource (e.g., which is configured to support network energy saving).

[0095] In some implementations, while the PDCCH-order RA procedure is embedded with the dynamic activation instruction of one additional PRACH resource, the UE may implement the triggered RA procedure on the activated additional PRACH resources.

[0096] In some implementations, DCI may be used to activate multiple additional PRACH configurations (e.g., by providing a PRACH configuration index or Additional_PRACH_index directly) and / or deactivate multiple additional PRACH configurations (e.g., by providing a PRACH configuration index or Additional_PRACH_index directly).

[0097] In some implementations, the serving RAN may configure multiple additional PRACH configurations. Each additional PRACH configuration in the list may also be pre-configured with an Additional_PRACH_index (e.g., via explicit signaling or based on the ascending / descending sequence in the list of additional PRACH configuration). Therefore, the serving RAN may activate or deactivate one or more additional PRACH configurations by including the Additional_PRACH_index in DCI.

[0098] In some implementations, the serving RAN may be able to activate as many as “Max_additional” additional PRACH configurations to UEs. The value of Max_additional may be pre-defined (e.g., by 3GPP technical specification) or pre-configured by the serving RAN via broadcasting system information or UE-specific control signaling. In some implementations, the serving RAN may not be able to activate more additional PRACH configurations once the serving RAN or cell has already activated up to “Max_additional” additional PRACH configurations. In some implementations, one activated PRACH configuration may be deactivated explicitly (e.g., by DCI 1_0 reception) or implicitly (e.g., based on the expiry of the validity time period or validity timer expiration). Therefore, a serving cell may be able to activate one additional PRACH resource configuration only while the total number of additional PRACH configurations is smaller than or equal to Max_additional. The UE may not expect more than “Max_additional” additional PRACH resource configurations to be activated simultaneously.

[0099] In some implementations, while Max_additional equals to 1, a serving cell may be able to activate one additional PRACH resource configuration upon or after an activated or ongoing additional PRACH configuration becomes deactivated (e.g., via explicit or implicit approach).

[0100] In some implementations, the serving cell / UE may record / estimate the activated period of one activated additional PRACH configuration upon / when the additional PRACH configuration is activated (e.g., via RRC signaling or DCI approach). For example, a first activated period timer (e.g., Tact#1) associated with a first additional PRACH configuration may be triggered to count (e.g., with initial value = 0) while the first additional PRACH configuration is activated. Additionally, the value of Tact#1 may increase continuously when the first additional PRACH configuration is still activated and valid. Then, with more additional PRACH configurations being activated, multiple timers (e.g., Tact#1, Tact#2, Tact#3, Tact#4) may also be triggered or counted by the UE. Additionally, Max_additional may be configured as four, and so the serving cell has already activated four additional PRACH configurations, which is the maximum number of additional PRACH configurations that the serving cell can activate. Then, after activating up to the maximum number of additional PRACH configurations, when the serving cell activates another additional PRACH configuration (e.g., via DCI approach), the serving RAN / UE may deactivate one active additional PRACH configuration which has the longest activated period timer value (e.g., Tact#1). In other words, the eldest activated additional PRACH resource configuration may be deactivated automatically after the serving cell has activated up to the maximum number of additional PRACH configurations, and another new activation DCI is transmitted by the serving RAN and received by the UE.

[0101] In some implementations, the serving RAN may be able to activate up to one additional PRACH configuration to the UE, but the serving RAN may still be able to configure multiple additional PRACH configurations. While a UE receives DCI which activates the additional PRACH resource configuration (e.g., activates a first PRACH), the UE may receive another DCI which activates another PRACH resource configuration (e.g., activates a second PRACH). In such a case, the first PRACH may be deactivated automatically by the UE and serving RAN, and the second PRACH may become the only activated additional PRACH resource configuration.

[0102] In some implementations, the additional PRACH resource activation triggered by a DCI transmitted on an operating DL-BWP may be limited by the additional PRACH resource configuration configured for the activated UL-BWP or UL carrier (e.g., NUL or SUL) associated with the operating DL-BWP.

[0103] In some implementations, the RAN / cell may configure different additional PRACH resource configurations on different uplink carriers / UL-BWPs. Additionally, the activated additional PRACH resource configuration may be considered deactivated when the UL-BWP becomes inactivated (e.g., after UL-BWP switching).

[0104] In some implementations, additional PRACH configurations may be applicable / configurable only to the initial BWP or the UL-BWP configured for a specific feature (e.g., UEs of reduced capability (RedCap UE)).

[0105] In some implementations, the serving cell may use DCI to modify the parameters of an additional PRACH configuration. In some implementations, two bits in DCI may be provided to indicate the DCI type. For example, “00” may indicate a DCI type that activates one or more additional PRACH configurations, “10” or “01” may indicate a DCI type that modifies one or more activated PRACH configurations, and “11” may be indicate a DCI type that deactivates one or more additional PRACH configurations. In some implementations, DCI or DCI format may only be associated with one DCI type. In some implementations, DCI or DCI format may be able to be associated with two or more DCI types in the DCI or DCI format.

[0106] In some implementations, only an activated PRACH configuration can be modified by the serving cell (e.g., by using DCI approach). In some implementations, only one activated PRACH configuration can be activated by the serving RAN / cell, and so all of the modifications of PRACH resource configuration (e.g., based on one or more DCIs) are applied to the activated PRACH resource configuration.

[0107] In some implementations, the baseline PRACH resource configuration and additional PRACH resource configuration may be configured to be associated with different events / features / feature combinations. Therefore, while a UE (or the MAC entity of the UE) is initiating an RA procedure, the UE may evaluate / decide / select one appropriate PRACH resource for the initiated RA procedure. In some implementations, the UE may trigger a UL-BWP switching (e.g., from UL-BWP#0 to UL-BWP#1) based on the result of PRACH resource selection.

[0108] In some implementations, the UE may re-evaluate the selected additional PRACH resource, which is activated by a DCI (e.g., a DCI specific for the activation or deactivation of dynamic PRACH adaptation).

[0109] In some implementations, the events / features / feature combinations used by the UE for baseline, additional, or DCI (de)activated PRACH resource selection may include 2-step RA, 4-step RA, SI request, small data transmission (SDT) procedure (e.g., RA-SDT procedure), Contention-based RA procedure.

[0110] In some implementations, a UE which is applicable to implement PRACH adaptation may receive the DCI, which is for additional PRACH resource adaptation, while the UE is implementing an RA procedure (e.g., an RRC establishment / re-establishment / resume procedure or a RA-SDT procedure). Then, after receiving the DCI-PRACH (activation / de-activation) instruction, the UE may switch its operating UL-BWP or operating uplink frequency carrier (e.g., NUL / SUL carrier) while the UE is implementing the initial transmission or re-transmission of a preamble.

[0111] In some implementations, the UE may further re-select PRACH resources to the additional PRACH resources if one or more additional PRACH resources are activated by the DCI-PRACH instruction (e.g., because the UE may be pre-configured to treat / consider those additional PRACH resources with a higher priority than the conventional / baseline PRACH resource).

[0112] In some implementations, the UE may further re-select PRACH resources to the baseline PRACH resources if one or more additional PRACH resources are deactivated by the DCI-PRACH (e.g., because the original PRACH resource selected by the UE may be deactivated by the DCI-PRACH instruction).

[0113] In some implementations, the UE may stick to baseline PRACH resources during an RA procedure, and the UE may be limited or restricted from re-selecting PRACH resources even after receiving one or more DCI-PRACH instructions from the serving RAN.

[0114] In some implementations, while the UE initializes an RA procedure and selects a Random Access Opportunity (RO) occasion to transmit the preamble, even though receiving the DCI to provide additional RO resources, the UE may continue using the same RACH at a certain number of re-attempts and may fall back to use the additional RO afterwards.

[0115] In some implementations, while the UE initializes an RA procedure and / or performs a re-attempt, the UE may independently select the RO resource based on the up-to-date RACH configuration. If receiving the DCI and activating or deactivating the additional RO resource, the UE may select the additional RO resource accordingly in a following re-attempt(s).

[0116] In some implementations, additional PRACH resource configuration(s) for a 2-step RA procedure may also be optionally configured for network energy saving.

[0117] In some implementations, one additional signaling threshold (e.g., DL-RSRP threshold) may be configured to UEs. The UE may decide whether to initiate a 2-step RA procedure (e.g., if the DL-RSRP monitored by the UE is higher than or equal to the DL-RSRP threshold) or a 4-step RA procedure (e.g., if the DL-RSRP monitored by the UE is lower than or equivalent to the DL-RSRP threshold). In some implementations, the DL-RSRP threshold used by additional PRACH resource configuration for 2-step / 4-step RA procedure determination may be different from the DL-RSRP threshold used by the legacy or baseline PRACH resource configuration for 2-step / 4-step RA procedure determination. In some implementations, the DL-RSRP threshold used by additional PRACH resource configuration for 2-step / 4-step RA procedure determination may be the same as the DL-RSRP threshold used by the legacy or baseline PRACH resource configuration for 2-step / 4-step RA procedure determination.

[0118] In some implementations of a first design, the UE may store the activated or deactivated status upon RRC state change. Therefore, the activated or deactivated status of one additional PRACH resource configuration may not be impacted by the RRC state transitions of the UE side.

[0119] In some implementations, a UE may receive a DCI-PRACH (activation / de-activation) instruction while the UE is staying in an RRC idle state to activate / deactivate one or more additional PRACH resource configurations. Then, the UE may store the activated / deactivated status of the additional PRACH configuration upon or after the UE moves to an RRC connected state (e.g., upon or after a UE transmits the RRCSetupComplete message from the serving RAN or upon or after the UE receives the RRCSetup message from the serving RAN).

[0120] In some implementations, a UE may receive a DCI-PRACH (activation / de-activation) instruction while the UE is staying in an RRC inactive state to activate / deactivate one or more additional PRACH resource configurations. Then, the UE may store the activated / deactivated status of the additional PRACH configuration upon or after the UE moves to an RRC connected state (e.g., upon or after a UE transmits the RRCResumeComplete message from the serving RAN or upon or after the UE receives the RRCResume message from the serving RAN). In some implementations, a UE may receive the DCI-PRACH (activation / de-activation) instruction during an SDT procedure (e.g., a configured-grant SDT procedure or a random access SDT procedure).

[0121] In some implementations, the activated or deactivated status of one additional PRACH resource configuration may be still valid after a UE resumes from RRC connected state to RRC idle state.

[0122] In some implementations, the activated / deactivated status of one additional PRACH resource configuration may be still valid after a UE switches from an RRC inactive state to an RRC idle state.

[0123] In some implementations, a UE may receive a DCI-PRACH (activation / de-activation) instruction while the UE is staying in an RRC connected state to activate / deactivate one or more additional PRACH resource configurations. Then, the UE may store the activated / deactivated status of the additional PRACH configuration upon or after the UE moves to an RRC idle or inactive state (e.g., upon or after the UE receives the RRCRelease message from the serving RAN).

[0124] In some implementations, the UE may store the activated / deactivated status of the additional PRACH resource configuration into the suspend configuration (e.g., automatically, without further indication from the serving RAN or based on additional configuration (e.g., one indication in the RRCRelease or RRCReconfiguration message) from the serving RAN to instruct the UE to move to an RRC inactive state). In some implementations, the activated / deactivated status of the additional PRACH resource configuration may not be stored in the suspend configuration.

[0125] In some implementations, a UE may be enabled to initiate an SDT procedure (e.g., RA-SDT procedure) on the activated PRACH resource configuration only while the status of the additional PRACH resource configuration is activated. In some implementations, a UE may not (or may be disabled to) initiate an SDT procedure (e.g., RA-SDT procedure) on the PRACH resource configuration if the status of the additional PRACH resource configuration is deactivated.

[0126] In some implementations of a second design, the UE may release / remove the activated / deactivated status upon an RRC state change. Therefore, the activated / deactivated status of one additional PRACH resource configuration may be reset (e.g., reset to “deactivated” state) by the RRC state transitions of the UE side. The activated / deactivated status of one additional PRACH configuration may be reset to “deactivated” state upon or after the UE moves from an RRC idle / inactive state to an RRC connected state (and vice versa). The activated / deactivated status of one additional PRACH configuration may be reset to “deactivated” state upon or after the UE moves from an RRC connected state to an RRC inactive / idle state (and vice versa). The activated / deactivated status of one additional PRACH configuration may be reset to “deactivated” state upon or after the UE moves from an RRC inactive state to an RRC idle state (and vice versa).

[0127] In some implementations, part of the first design and part of the second design may be merged / configured / combined as predefined or by the serving RAN via explicit signaling to define how a UE stores / updates the activated / deactivated status of additional PRACH configurations.

[0128] In some implementations, the serving RAN / UE may implement / treat the activated / deactivated status of each of the additional PRACH resource configurations respectively / independently (e.g., based on any combinations of the first design or the second design for the storage / update of the activated / deactivated status of each of the additional PRACH configurations). In some implementations, the activated / deactivated status may be generally applied to all of the additional PRACH configurations.

[0129] In some implementations, the validity timer / window / period of one additional PRACH configuration may be interrupted / released upon the activated / deactivated status of the additional PRACH resource configuration changes (e.g., from an activated status to a deactivated status due to an RRC state change). In some implementations, the validity timer / window / period of one additional PRACH configuration may be interrupted / released upon the release / activation / deactivation from the serving RAN (e.g., by broadcasting system information or UE-specific control signaling which activates / deactivates / modifies the additional PRACH resource configuration).

[0130] In some implementations, the serving RAN may configure both the baseline PRACH configuration (e.g., the PRACH resource which legacy UE and R-19 NES-capable UE can access) and additional PRACH configuration (e.g., the PRACH resource which legacy UE or UE which does not support R-19 NES cannot access) to a UE during an LTM operation (e.g., the serving RAN may configure both legacy PRACH resource configuration and additional PRACH resource configuration of one candidate cell in the LTM-config).

[0131] In some implementations, the UE may be enabled to trigger LTM operation one time while the T311 timer is counting by the UE (e.g., the UE is implementing an RRC re-establishment procedure by trying to select a suitable cell). In some implementations, the UE may be able to trigger LTM operation by accessing the additional PRACH resource configuration if the status of the additional PRACH resource configuration is activated (e.g., by RRC signaling in the LTM-config or by receiving a DCI-PRACH activation / de-activation instruction after receiving the LTM-config for LTM operation) while the T311 timer is counting. The T311 counting activity in the UE side may be referred to 3GPP TS 38.331.

[0132] In some implementations, one cell may only configure additional PRACH configuration in the cell coverage to support UEs. In other words, it may be possible that a UE may camp on the cell but the UE may not be able to access the cell if the additional PRACH resource configuration is deactivated by the cell (e.g., the additional PRACH resource configuration is configured and deactivated by broadcasting system information, such as SIB1). In such a case, the UE may consider that the cell is barred, and the UE may try to camp on other cells if the UE is triggered by an upper layer to initiate an RA procedure. In some implementations, the UE may also consider that the frequency on which the “additional PRACH resource configuration-only” cell is operating may be (temporarily) ruled out during the cell (re)selection procedure because the cells operating on the concerned frequency carrier are also additional PRACH resource configuration-only cell(s).

[0133] It should be noted that, the additional PRACH configuration may also be applicable to initialUplinkBWP-RedCap.

[0134] Based on the above, several implementations for common PRACH adaptation are provided to enhance the network energy saving mechanism for wireless communication systems (e.g., NR or E-UTRA). The implementations may be based on the DCI-based PRACH adaptation design, supporting common PRACH adaptation.

[0135] FIG. 3 is a flowchart illustrating a method / process 300 performed by a UE for PRACH adaptation, according to an example implementation of the present disclosure.

[0136] Referring to FIG. 3, in action 302, the process 300 may start by receive, from a first cell of a serving RAN (e.g., a base station), a configuration for one or more additional PRACH resources. In action 304, the process 300 may receive, from the first cell (e.g., from the base station), an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated.

[0137] In some implementations, the indication is transmitted / received via DCI\ format 1_0 scrambled by a Paging Radio Network Temporary Identifier (P-RNTI). For example, the indication may include at least one bit within an 8-bit short message carried in the DCI format 1_0 scrambled by the P-RNTI.

[0138] In some implementations, upon the reception of the indication, the UE may consider the first additional PRACH resource is activated / valid.

[0139] In some implementations, the indication may indicate more than one additional PRACH resources, among the configured addition PRACH resources, are activated. Therefore, the UE may consider that the indicated additional PRACH resources are activated / valid.

[0140] Referring to FIG. 3, in action 306, the process 300 may consider the first additional PRACH resource is applicable for a random access (RA) procedure.

[0141] In some implementations, the RA procedure may be a contention-based RA procedure. In some implementations, the RA procedure may be a contention-free RA procedure triggered via a PDCCH order, and the PDCCH order may be received via a DCI format 1_0 scrambled by a Cell Radio Network Temporary Identifier (C-RNTI) from the first cell.

[0142] In some implementations, the UE may first evaluate whether the first addition PRACH resource is applicable for the RA procedure, then consider the first addition PRACH resource is applicable for the RA procedure when the evaluation result is positive. Otherwise, the UE may consider the first addition PRACH resource is inapplicable for the RA procedure.

[0143] FIG. 4 is a flowchart illustrating a method / process 400 performed by a UE for PRACH adaptation, according to an example implementation of the present disclosure.

[0144] In some implementations, before entering action 306, the process 300 may first perform process 400. Referring to FIG. 4, in action 402, the process 400 may evaluate whether the first addition PRACH resource is applicable for the RA procedure. In a case that the evaluation result is positive, action 306 of process 300 is entered; otherwise, action 404 is entered.

[0145] In some implementations, the UE may consider the first additional PRACH resource is valid / applicable for the RA procedure based on a validity period associated with the first additional PRACH resource upon receiving the indication, and deactivate the first additional PRACH resource upon the validity period expires. If the validity period has not expired, action 306 may be entered, such that the UE may consider the first additional PRACH resource is valid / applicable for the RA procedure. Otherwise, once the validity period expires, the UE may consider the first additional PRACH resource is not applicable for the RA procedure and action 404 may be entered.

[0146] In some implementations, the validity period associated with the first additional PRACH resource may be included in the indication (e.g., received in action 304) or is pre-configured to the UE as part of the configuration for the one or more additional PRACH resources before receiving the indication.

[0147] In some implementations, the UE may further receive, from the first cell (e.g., the base station), a deactivation indication indicating at least one additional PRACH resource, among the one or more additional PRACH resources, is deactivated. Upon the reception of the deactivation indication, the UE may deactivate the at least one additional PRACH resource indicated in the deactivation indication. If no deactivation indication is received, action 306 may be entered, such that the UE may consider the first additional PRACH resource is valid / applicable for the RA procedure. Otherwise, once the deactivation indication is received, the UE may consider the at least one additional PRACH resource is not applicable for the RA procedure after the at least one additional PRACH resource is deactivated. In a case that the at least one additional PRACH resource includes the first additional PRACH resource, action 404 may be entered.

[0148] Referring to FIG. 4, in action 404, the process 400 may consider the first additional PRACH resource is inapplicable for the RA procedure. The process 400 may then end.

[0149] In some implementations, the UE may determine an operating UL frequency carrier for the RA procedure, among a NUL frequency carrier and a SUL frequency carrier, based on the first additional PRACH resource after receiving the indication. In some implementations, the UE may further determine an UL-BWP for the RA procedure based on the first additional PRACH resource. The UL-BWP may be one of UL BWP 0, UL BWP 1, UL BWP 2, UL BWP 3, or an Uplink BWP specific to a Reduced Capability (RedCap) UE.

[0150] Referring back to FIG. 3, in action 308, the process 300 may initiate, to the first cell, the RA procedure by using the first additional PRACH resource after considering the first additional PRACH resource is applicable for the RA procedure. The process 300 may then end.

[0151] In some implementations, in response to an RRC state change, the UE may determine / record / store an activation or deactivation status of the one or more additional PRACH resources.

[0152] FIG. 5 is a block diagram illustrating a node 500 for wireless communication in accordance with various aspects of the present disclosure. As illustrated in FIG. 5, a node 500 may include a transceiver 520, a processor 528, a memory 534, one or more presentation components 538, and at least one antenna 536. The node 500 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. 5).

[0153] Each of the components may directly or indirectly communicate with each other over one or more buses 540. The node 500 may be a UE or a BS that performs various functions disclosed with reference to FIGS. 1 to 4.

[0154] The transceiver 520 has a transmitter 522 (e.g., transmitting / transmission circuitry) and a receiver 524 (e.g., receiving / reception circuitry) and may be configured to transmit and / or receive time and / or frequency resource partitioning information. The transceiver 520 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 520 may be configured to receive data and control channels.

[0155] The node 500 may include a variety of computer-readable media. Computer-readable media may be any available media that may be accessed by the node 500 and include volatile (and / or non-volatile) media and removable (and / or non-removable) media.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] The memory 534 may include computer-storage media in the form of volatile and / or non-volatile memory. The memory 534 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. 5, the memory 534 may store a computer-readable and / or computer-executable instructions 532 (e.g., software codes) that are configured to, when executed, cause the processor 528 to perform various functions disclosed herein, for example, with reference to FIGS. 1 to 4. Alternatively, the instructions 532 may not be directly executable by the processor 528 but may be configured to cause the node 500 (e.g., when compiled and executed) to perform various functions disclosed herein.

[0160] The processor 528 (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 528 may include memory. The processor 528 may process the data 530 and the instructions 532 received from the memory 534, and information transmitted and received via the transceiver 520, the baseband communications module, and / or the network communications module. The processor 528 may also process information to send to the transceiver 520 for transmission via the antenna 536 to the network communications module for transmission to a CN.

[0161] One or more presentation components 538 may present data indications to a person or another device. Examples of presentation components 538 may include a display device, a speaker, a printing component, a vibrating component, etc.

[0162] 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 Physical Random Access Channel (PRACH) adaptation to enhance network energy saving in a wireless communication system, 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: 　　　　　　　　receive, from a first cell of a serving Radio Access Network (RAN), a configuration for one or more additional PRACH resources; 　　　　　　　　receive, from the first cell, an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated; and 　　　　　　　　consider the first additional PRACH resource is applicable for a random access procedure.

2. The UE of claim 1, wherein the indication is received via Downlink Control Information (DCI) format 1_0 scrambled by a Paging Radio Network Temporary Identifier (P-RNTI), and the indication comprises at least one bit within an 8-bit short message carried in the DCI format 1_0 scrambled by the P-RNTI.

3. The UE of claim 1, further comprises: 　　　　initiate, to the first cell, the random access procedure by using the first additional PRACH resource after considering the first additional PRACH resource is applicable for the random access procedure.

4. The UE of claim 1, wherein the random access procedure is a contention-based random access procedure.

5. The UE of claim 1, wherein the random access procedure is a contention-free random access procedure triggered via a Physical Downlink Control Channel (PDCCH) order, and the PDCCH order is received via a Downlink Control Information (DCI) format 1_0 scrambled by a Cell Radio Network Temporary Identifier (C-RNTI) from the first cell.

6. 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: 　　　　consider the first additional PRACH resource is valid for the random access procedure based on a validity period associated with the first additional PRACH resource upon receiving the indication; 　　　　deactivate the first additional PRACH resource upon the validity period expires; and 　　　　consider the first additional PRACH resource is not applicable for the random access procedure after the additional PRACH resource is deactivated, 　　　　wherein the validity period associated with the first additional PRACH resource is included in the indication or is pre-configured to the UE as part of the configuration for the one or more additional PRACH resources before receiving the indication.

7. 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: 　　　　receive, from the first cell, a deactivation indication indicating at least one additional PRACH resource, among the one or more additional PRACH resources, is deactivated; 　　　　deactivate the at least one additional PRACH resource upon receiving the deactivation indication; and 　　　　consider the at least one additional PRACH resource is not applicable for the random access procedure after the at least one additional PRACH resource is deactivated.

8. 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 an operating uplink frequency carrier for the random access procedure, among a Normal Uplink (NUL) frequency carrier and a Supplementary Uplink (SUL) frequency carrier, based on the first additional PRACH resource after receiving the indication; and 　　　　determine an uplink Bandwidth Part (BWP) based on the first additional PRACH resource, 　　　　wherein the uplink BWP is one of UL BWP 0, UL BWP 1, UL BWP 2, UL BWP 3, or an Uplink BWP specific to a Reduced Capability (RedCap) UE.

9. 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 an activation or deactivation status of the one or more additional PRACH resources upon a Radio Resource Control (RRC) state change.

10. A Base Station (BS) for physical random access channel (PRACH) adaptation to enhance network energy saving in a wireless communication system, 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), a configuration for one or more additional PRACH resources; and 　　　　　　　　transmit, to the UE, an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated, 　　　　wherein the indication causes the UE to: 　　　　　　　　consider the first additional PRACH resource is applicable for a random access procedure.

11. The BS of claim 10, wherein the indication is transmitted via Downlink Control Information (DCI) format 1_0 scrambled by a Paging Radio Network Temporary Identifier (P-RNTI), and the indication comprises at least one bit within an 8-bit short message carried in the DCI format 1_0 scrambled by the P-RNTI.

12. The BS of claim 10, wherein the indication further causes the UE to: 　　　　consider the first additional PRACH resource is valid for the random access procedure based on a validity period associated with the first additional PRACH resource upon receiving the indication; 　　　　deactivate the first additional PRACH resource upon the validity period expires; and 　　　　consider the first additional PRACH resource is not applicable for the random access procedure after the additional PRACH resource is deactivated, 　　　　wherein the validity period associated with the first additional PRACH resource is included in the indication or is pre-configured to the UE as part of the configuration for the one or more additional PRACH resources before transmitting the indication.

13. The BS of claim 10, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the BS to: 　　　　transmit, to the UE, a deactivation indication indicating at least one additional PRACH resource, among the one or more additional PRACH resources, is deactivated, 　　　　wherein the deactivation indication causes the UE to: 　　　　　　　　deactivate the at least one additional PRACH resource upon receiving the deactivation indication; and 　　　　　　　　consider the at least one additional PRACH resource is not applicable for the random access procedure after the at least one additional PRACH resource is deactivated.

14. The BS of claim 10, wherein the indication further cause the UE to: 　　　　determine an operating uplink frequency carrier for the random access procedure, among a Normal Uplink (NUL) frequency carrier and a Supplementary Uplink (SUL) frequency carrier, based on the first additional PRACH resource after receiving the indication; and 　　　　determine an uplink Bandwidth Part (BWP) based on the first additional PRACH resource, wherein the uplink BWP is one of UL BWP 0, UL BWP 1, UL BWP 2, UL BWP 3, or an Uplink BWP specific to a Reduced Capability (RedCap) UE.

15. A method performed by a User Equipment (UE) for physical random access channel (PRACH) adaptation to enhance network energy saving in a wireless communication system, the method comprising: 　　　　receiving, from a first cell of a serving Radio Access Network (RAN), a configuration for one or more additional PRACH resources; 　　　　receiving, from the first cell, an indication which indicates a first additional PRACH resource, among the one or more additional PRACH resources, is activated; and 　　　　considering the first additional PRACH resource is applicable for a random access procedure.

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