RRM based-entry and exit conditions for LP-WUS monitoring
A dual-receiver architecture with a low-power wake-up receiver in UE devices optimizes power consumption by activating the main radio only when needed, addressing the inefficiencies in power usage in idle modes of 5G NR systems.
Patent Information
- Application Number
- PCT/CN2025/087671
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-04-09
- Filing Date
- 2025-04-08
- Publication Date
- 2025-10-16
AI Technical Summary
Existing wireless communication systems, particularly 5G NR, face challenges in achieving power-efficient operation for user equipment (UE) due to high power consumption by main radios, especially in idle or inactive modes.
Implementing a dual-receiver architecture in UE with a low-power wake-up receiver (LP-WUR) that monitors for low-power wake-up signals (LP-WUS) to activate or deactivate the main radio based on predefined entry and exit conditions, optimizing power consumption while maintaining network connectivity.
The dual-receiver architecture significantly reduces power consumption by allowing the main radio to be deactivated during idle periods, activating only when necessary for data reception, thereby enhancing power efficiency and extending battery life in UE devices.
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Figure CN2025087671_16102025_PF_FP_ABST
Abstract
Description
RRM BASED-ENTRY AND EXIT CONDITIONS FOR LP-WUS MONITORINGCROSS-REFERENCE TO RELATED APPLICATION (S)
[0001] This application claims the benefits of U.S. Provisional Application Serial No. 63 / 631,547, entitled “RRM BASED-ENTRY AND EXIT CONDITIONS FOR LP-WUS MONITORING” and filed on April 9, 2024, which is expressly incorporated by reference herein in its entirety.BACKGROUNDField
[0002] The present disclosure relates generally to wireless communications, and more particularly, to techniques of power-efficient operation of a user equipment (UE) . Background
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.SUMMARY
[0006] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
[0007] In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE determines whether one or more entry conditions for low power wake-up signal (LP-WUS) monitoring are met when a main radio (MR) of the UE is in an activated state and a low power receiver (LR) of the UE is in a deactivated state. The UE activates the LR and deactivates the MR when the one or more entry conditions are met. The UE monitors for an LP-WUS using the activated LR.
[0008] To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.
[0010] FIG. 2 is a diagram illustrating a base station in communication with a UE in an access network.
[0011] FIG. 3 illustrates an example logical architecture of a distributed access network.
[0012] FIG. 4 illustrates an example physical architecture of a distributed access network.
[0013] FIG. 5 is a diagram illustrating a system for power-efficient operation of a user equipment using a low power wake-up receiver architecture.
[0014] FIG. 6 is a diagram illustrating a timing sequence for low power wake-up signal monitoring activation states based on paging cycles.
[0015] FIG. 7 is a flow chart of a method for power-efficient operation using a low power wake-up receiver architecture.DETAILED DESCRIPTION
[0016] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.
[0017] Several aspects of telecommunications systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
[0018] By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.
[0019] Accordingly, in one or more example aspects, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.
[0020] FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and another core network 190 (e.g., a 5G Core (5GC) ) . The base stations 102 may include macrocells (high power cellular base station) and / or small cells (low power cellular base station) . The macrocells include base stations. The small cells include femtocells, picocells, and microcells.
[0021] The base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through backhaul links 132 (e.g., SI interface) . The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN) ) may interface with core network 190 through backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or core network 190) with each other over backhaul links 134 (e.g., X2 interface) . The backhaul links 134 may be wired or wireless.
[0022] The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102’ may have a coverage area 110’ that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and / or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links may be through one or more carriers. The base stations 102 / UEs 104 may use spectrum up to 7 MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .
[0023] Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.
[0024] The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 / AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.
[0025] The small cell 102’ may operate in a licensed and / or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102’ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102’, employing NR in an unlicensed frequency spectrum, may boost coverage to and / or increase capacity of the access network.
[0026] A base station 102, whether a small cell 102’ or a large cell (e.g., macro base station) , may include an eNB, gNodeB (gNB) , or another type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and / or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW / near mmW radio frequency band (e.g., 3 GHz -300 GHz) has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range.
[0027] The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 108a. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 108b. The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 180 / UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 / UE 104. The transmit and receive directions for the base station 180 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.
[0028] The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and / or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start / stop) and for collecting eMBMS related charging information.
[0029] The core network 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 193, a location management function (LMF) 198, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the SMF 194 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and / or other IP services.
[0030] The base station may also be referred to as a gNB, Node B, evolved Node B (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.
[0031] Although the present disclosure may reference 5G New Radio (NR) , the present disclosure may be applicable to other similar areas, such as LTE, LTE-Advanced (LTE-A) , Code Division Multiple Access (CDMA) , Global System for Mobile communications (GSM) , or other wireless / radio access technologies.
[0032] FIG. 2 is a block diagram of a base station 210 in communication with a UE 250 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller / processor 275. The controller / processor 275 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 275 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs) , error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.
[0033] The transmit (TX) processor 216 and the receive (RX) processor 270 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding / decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation / demodulation of physical channels, and MIMO antenna processing. The TX processor 216 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 274 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and / or channel condition feedback transmitted by the UE 250. Each spatial stream may then be provided to a different antenna 220 via a separate transmitter 218TX. Each transmitter 218TX may modulate an RF carrier with a respective spatial stream for transmission.
[0034] At the UE 250, each receiver 254RX receives a signal through its respective antenna 252. Each receiver 254RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 256. The TX processor 268 and the RX processor 256 implement layer 1 functionality associated with various signal processing functions. The RX processor 256 may perform spatial processing on the information to recover any spatial streams destined for the UE 250. If multiple spatial streams are destined for the UE 250, they may be combined by the RX processor 256 into a single OFDM symbol stream. The RX processor 256 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 210. These soft decisions may be based on channel estimates computed by the channel estimator 258. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 210 on the physical channel. The data and control signals are then provided to the controller / processor 259, which implements layer 3 and layer 2 functionality.
[0035] The controller / processor 259 can be associated with a memory 260 that stores program codes and data. The memory 260 may be referred to as a computer-readable medium. In the UL, the controller / processor 259 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 259 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.
[0036] Similar to the functionality described in connection with the DL transmission by the base station 210, the controller / processor 259 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.
[0037] Channel estimates derived by a channel estimator 258 from a reference signal or feedback transmitted by the base station 210 may be used by the TX processor 268 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 268 may be provided to different antenna 252 via separate transmitters 254TX. Each transmitter 254TX may modulate an RF carrier with a respective spatial stream for transmission. The UL transmission is processed at the base station 210 in a manner similar to that described in connection with the receiver function at the UE 250. Each receiver 218RX receives a signal through its respective antenna 220. Each receiver 218RX recovers information modulated onto an RF carrier and provides the information to a RX processor 270.
[0038] The controller / processor 275 can be associated with a memory 276 that stores program codes and data. The memory 276 may be referred to as a computer-readable medium. In the UL, the controller / processor 275 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 250. IP packets from the controller / processor 275 may be provided to the EPC 160. The controller / processor 275 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.
[0039] New radio (NR) may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA) -based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP) ) . NR may utilize OFDM with a cyclic prefix (CP) on the uplink and downlink and may include support for half-duplex operation using time division duplexing (TDD) . NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (e.g. 80 MHz beyond) , millimeter wave (mmW) targeting high carrier frequency (e.g. 60 GHz) , massive MTC (mMTC) targeting non-backward compatible MTC techniques, and / or mission critical targeting ultra-reliable low latency communications (URLLC) service.
[0040] A single component carrier bandwidth of 100 MHz may be supported. In one example, NR resource blocks (RBs) may span 12 sub-carriers with a sub-carrier bandwidth of 60 kHz over a 0.25 ms duration or a bandwidth of 30 kHz over a 0.5 ms duration (similarly, 50MHz BW for 15kHz SCS over a 1 ms duration) . Each radio frame may consist of 10 subframes (10, 20, 40 or 80 NR slots) with a length of 10 ms. Each slot may indicate a link direction (i.e., DL or UL) for data transmission and the link direction for each slot may be dynamically switched. Each slot may include DL / UL data as well as DL / UL control data. UL and DL slots for NR may be as described in more detail below with respect to FIGs. 5 and 6.
[0041] The NR RAN may include a central unit (CU) and distributed units (DUs) . A NR BS (e.g., gNB, 5G Node B, Node B, transmission reception point (TRP) , access point (AP) ) may correspond to one or multiple BSs. NR cells can be configured as access cells (ACells) or data only cells (DCells) . For example, the RAN (e.g., a central unit or distributed unit) can configure the cells. DCells may be cells used for carrier aggregation or dual connectivity and may not be used for initial access, cell selection / reselection, or handover. In some cases DCells may not transmit synchronization signals (SS) in some cases DCells may transmit SS. NR BSs may transmit downlink signals to UEs indicating the cell type. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine NR BSs to consider for cell selection, access, handover, and / or measurement based on the indicated cell type.
[0042] FIG. 3 illustrates an example logical architecture of a distributed RAN 300, according to aspects of the present disclosure. A 5G access node 306 may include an access node controller (ANC) 302. The ANC may be a central unit (CU) of the distributed RAN. The backhaul interface to the next generation core network (NG-CN) 304 may terminate at the ANC. The backhaul interface to neighboring next generation access nodes (NG-ANs) 310 may terminate at the ANC. The ANC may include one or more TRPs 308 (which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs, or some other term) . As described above, a TRP may be used interchangeably with “cell. ”
[0043] The TRPs 308 may be a distributed unit (DU) . The TRPs may be connected to one ANC (ANC 302) or more than one ANC (not illustrated) . For example, for RAN sharing, radio as a service (RaaS) , and service specific ANC deployments, the TRP may be connected to more than one ANC. A TRP may include one or more antenna ports. The TRPs may be configured to individually (e.g., dynamic selection) or jointly (e.g., joint transmission) serve traffic to a UE.
[0044] The local architecture of the distributed RAN 300 may be used to illustrate fronthaul definition. The architecture may be defined that support fronthauling solutions across different deployment types. For example, the architecture may be based on transmit network capabilities (e.g., bandwidth, latency, and / or jitter) . The architecture may share features and / or components with LTE. According to aspects, the next generation AN (NG-AN) 310 may support dual connectivity with NR. The NG-AN may share a common fronthaul for LTE and NR.
[0045] The architecture may enable cooperation between and among TRPs 308. For example, cooperation may be preset within a TRP and / or across TRPs via the ANC 302. According to aspects, no inter-TRP interface may be needed / present.
[0046] According to aspects, a dynamic configuration of split logical functions may be present within the architecture of the distributed RAN 300. The PDCP, RLC, MAC protocol may be adaptably placed at the ANC or TRP.
[0047] FIG. 4 illustrates an example physical architecture of a distributed RAN 400, according to aspects of the present disclosure. A centralized core network unit (C-CU) 402 may host core network functions. The C-CU may be centrally deployed. C-CU functionality may be offloaded (e.g., to advanced wireless services (AWS) ) , in an effort to handle peak capacity. A centralized RAN unit (C-RU) 404 may host one or more ANC functions. Optionally, the C-RU may host core network functions locally. The C-RU may have distributed deployment. The C-RU may be closer to the network edge. A distributed unit (DU) 406 may host one or more TRPs. The DU may be located at edges of the network with radio frequency (RF) functionality.
[0048] FIG. 5 illustrates a system for power-efficient operation of a user equipment (UE) using a low power wake-up receiver architecture. The figure includes three parts: FIG. 5 (A) , FIG. 5 (B) , and FIG. 5 (C) , which together demonstrate the operation of the low power wake-up signal (LP-WUS) monitoring system. The system implements a power-efficient operation scheme utilizing a dual-receiver architecture within a UE 504. This architecture includes a main radio (MR) 510 and a low power receiver (LR) 520, where the LR 520 serves as a wake-up mechanism for the power-intensive MR 510. The LR 520, also referred to as a low-power wake-up receiver (LP-WUR) , operates with significantly lower power consumption compared to the MR 510, thereby enabling substantial power savings in the UE 504.
[0049] FIG. 5 (A) is a diagram 500 illustrating a power-saving state of a UE 504 where no data is to be received. In this state, a main radio (MR) 510 is deactivated (Off) to conserve power, while a low power receiver (LR) 520 is activated (On) . The LR 520 continuously monitors for incoming LP-WUS signals while consuming significantly less power than would be required if the MR 510 were active. This configuration represents the entry condition for LP-WUS monitoring, where the UE 504 has determined that it can safely deactivate its power-intensive main radio while maintaining network connectivity through the low-power receiver.
[0050] FIG. 5 (B) is a diagram 540 illustrating a low power wake-up signal (LP-WUS) 550. The LP-WUS 550 serves as a wake-up signal transmitted by the network to the UE 504 when there is data pending for the UE 504. The signal includes a specific pattern that can be detected by the low-power receiver. The waveform shown represents the time-domain representation of the LP-WUS 550, which follows a predefined pattern that the LR 520 is configured to recognize.
[0051] FIG. 5 (C) is a diagram 580 illustrating the UE 504 after receiving the LP-WUS 550, transitioning to a state where the UE 504 has data to receive. In this state, the MR 510 is activated (On) to process the incoming data, while the LR 520 is deactivated (Off) . The transition from the state shown in FIG. 5 (A) to the state shown in FIG. 5 (C) is triggered by the LP-WUS 550 detected by the LR 520, which signals the UE 504 to wake up the MR 510. This represents the exit condition from LP-WUS monitoring.
[0052] In certain implementations, the system operates as follows: when no data is expected for the UE 504, the UE 504 conserves power by keeping only the LR 520 active to monitor for potential incoming LP-WUS 550 signals (FIG. 5 (A) ) . When the network has data to transmit to the UE 504, it sends the LP-WUS 550 (FIG. 5 (B) ) . Upon detecting the LP-WUS 550, the LR 520 triggers the activation of the MR 510 and deactivates itself, enabling the UE 504 to receive the pending data using the more capable but power-intensive MR 510 (FIG. 5 (C) ) .
[0053] As shown, the LR 520 monitors for LP-WUSs 550, which serve as triggers for activating the MR 510 when necessary. These triggers are particularly important for paging monitoring in IDLE / INACTIVE modes and for physical downlink control channel (PDCCH) monitoring in CONNECTED mode. Further, the LR 520 monitors low-power synchronization signals (LP-SS) or existing primary / secondary synchronization signals (PSS / SSS) , depending on the specific LP-WUR architecture implemented. This monitoring enables the UE 504 to maintain synchronization and perform radio resource management (RRM) measurements of the serving cell while in IDLE / INACTIVE modes.
[0054] The power-saving mechanism operates through a coordinated activation and deactivation scheme between the LR 520 and MR 510. When the LR 520 is activated for LP-WUS monitoring, the MR 510 enters a deactivated state, substantially reducing the overall power consumption of the UE 504. This state transition is illustrated in FIG. 5 (A) , where the LR 520 remains active while the MR 510 is deactivated during periods when no data reception is expected.
[0055] Upon detection of an LP-WUS 550, as shown in FIG. 5 (B) , the system initiates a state transition. The LP-WUS 550 contains a specific signal pattern that the LR 520 is designed to recognize, indicating pending data transmission for the UE 504. Following this detection, the system transitions to the state depicted in FIG. 5 (C) , where the MR 510 is activated to handle the incoming data transmission while the LR 520 is deactivated. This coordinated switching mechanism optimizes power consumption by maintaining network connectivity through the low-power LR 520 during idle periods while enabling full functionality through the MR 510 only when necessary for data reception.
[0056] The power-efficient operation of the UE 504 relies on well-defined conditions that govern the transitions between different operational states of the dual-receiver architecture. These conditions, known as entry and exit conditions, determine when the LR 520 should be activated for LP-WUS monitoring while the MR 510 is deactivated, and vice versa.
[0057] The entry conditions specify the criteria that must be satisfied for the UE 504 to enter a power-saving state where the LR 520 is activated and the MR 510 is deactivated, as illustrated in FIG. 5 (A) . This state represents the power-efficient monitoring mode where the LR 520 maintains network connectivity while consuming minimal power. The transition to this state occurs when the UE 504 determines that immediate data reception is unlikely and that operating conditions are suitable for low-power monitoring.
[0058] Conversely, the exit conditions define the circumstances under which the UE 504 must transition from the power-saving state to an active state where the MR 510 is activated and the LR 520 is deactivated, as shown in FIG. 5 (C) . This transition is typically triggered by the reception of an LP-WUS 550, as depicted in FIG. 5 (B) , indicating that the network has pending data for the UE 504.
[0059] The state transitions between these operational modes are bidirectional. When the UE 504 is in an idle or inactive mode with the LR 520 activated, the reception of an LP-WUS 550 triggers the exit condition, leading to the activation of the MR 510. Subsequently, when the data reception is complete and no further immediate transmissions are expected, the entry conditions may be satisfied again, allowing the UE 504 to return to the power-saving state with the LR 520 active and the MR 510 deactivated.
[0060] Referring to FIGs. 5 (A) - (C) , the power-efficient operation of the UE 504 implements specific entry conditions that govern when the LP-WUS monitoring should be activated. When these entry conditions are met, the LR 520 is activated while the MR 510 is deactivated, as illustrated in FIG. 5 (A) . These entry conditions serve two distinct purposes: maintaining the power-saving state and initiating transitions from active to power-saving states.
[0061] The first two entry conditions relate to maintaining the UE 504 in its power-saving state as illustrated in FIG. 5 (A) . When no LP-WUS 550 indicating a wake-up command is received by the LR 520, the UE 504 maintains its power-saving configuration with the LR 520 activated and the MR 510 deactivated. Similarly, when no uplink transmission is scheduled or needed by the UE 504, the power-saving state is maintained. These conditions help the UE 504 remain in its low-power state when there is no immediate need for full radio capabilities.
[0062] The third entry condition specifically governs the transition from an active state (FIG. 5 (C) ) to the power-saving state (FIG. 5 (A) ) . This condition requires that the serving cell’s quality, as determined through RRM measurements, exceeds a predetermined threshold. The LR 520, being a low-power receiver, requires sufficient signal quality to maintain reliable monitoring of LP-WUS 550 signals. When the serving cell quality rises above this threshold while the MR 510 is active, the UE 504 can transition to the power-saving state by activating the LR 520 and deactivating the MR 510.
[0063] FIG. 6 is a diagram 600 illustrating a timing sequence for LP-WUS monitoring activation states based on paging cycles. The diagram shows alternating periods of LR activated states 610 and LR deactivated states 620. Initially, the LR 520 is in an activated state where it monitors for LP-WUS signals. When an LP-WUS 550 is received, the LR 520 transitions to a deactivated state 620, during which the MR 510 is activated to handle data reception.
[0064] In this example, a paging cycle 640 is a predetermined time duration for monitoring potential wake-up signals. A conditional re-activation of the LR 520 is based on the absence of LP-WUS 550 reception within the paging cycle 640. After the last received LP-WUS 550, if no new LP-WUS is detected during the subsequent paging cycle 640, the LR 520 returns to its activated state 610. This mechanism provides a time-based criterion for transitioning back to the power-saving state where the LR 520 is active and the MR 510 is deactivated.
[0065] FIG. 6 demonstrates a timing-based entry condition for LP-WUS monitoring activation, specifically related to the timing of LP-WUS reception relative to paging cycles. The timing-based entry condition establishes that LP-WUS monitoring is activated (i.e., the LR 520 is turned on and the MR 510 is turned off) when no LP-WUS 550 indicating the UE 504 to wake up is received after a certain paging cycle 640 (e.g., the first paging cycle) since the last received LP-WUS 550. This condition provides a temporal mechanism for the UE 504 to return to its power-saving state after a period of activity triggered by a previous LP-WUS 550.
[0066] In the initial state shown in FIG. 6, the LR 520 is in an activated state 610 where it monitors for incoming LP-WUS 550 signals. Upon receiving an LP-WUS 550, the UE 504 transitions to a state where the LR 520 is deactivated 620 and the MR 510 is activated to handle the incoming data transmission. This transition represents the exit from LP-WUS monitoring based on the reception of a wake-up signal.
[0067] The paging cycle 640 represents a predetermined time duration during which the UE 504 may receive paging messages or other downlink transmissions. After the completion of this paging cycle 640 following the last received LP-WUS 550, if no new LP-WUS 550 is detected, the UE 504 satisfies the entry condition to return to the power-saving state with the LR 520 activated 610 and the MR 510 deactivated.
[0068] This timing-based entry condition complements the other entry conditions for LP-WUS monitoring. While the condition related to the absence of LP-WUS 550 reception (without a timing constraint) maintains the UE 504 in its power-saving state, this paging cycle-based condition specifically governs the transition back to the power-saving state after a period of activity. Accordingly, the UE 504 does not prematurely return to its power-saving state when additional transmissions might be imminent, while also preventing the UE 504 from unnecessarily remaining in a high-power state when no further transmissions are expected within the paging cycle 640.
[0069] As described supra, satisfying any one of the entry conditions is sufficient for the UE 504 to enter or maintain the LP-WUS monitoring state where the LR 520 is activated and the MR 510 is deactivated. Conversely, if none of the entry conditions are met, the UE 504 will not enter or remain in this power-saving state.
[0070] The coordination between these entry conditions enables the UE 504 to optimize its power consumption while maintaining network connectivity. When in the power-saving state depicted in FIG. 5 (A) , the LR 520 continuously monitors for any incoming LP-WUS 550 signals. Upon detecting an LP-WUS 550, the UE 504 exits this power-saving state and transitions to the active state shown in FIG. 5 (C) , where the MR 510 is activated to handle the incoming data transmission. This transition mechanism allows the UE 504 to minimize power consumption during periods of inactivity while maintaining the ability to quickly respond to network communications when needed.
[0071] The transition from power-saving state to active state occurs through specific exit conditions that govern when the main radio (MR) 510 should be activated. The MR 510 activation represents a state where the low power receiver (LR) 520 is deactivated while the MR 510 is turned on, as illustrated in FIG. 5 (C) . This transition is defined by the absence of conditions that maintain the power-saving state shown in FIG. 5 (A) .
[0072] The exit conditions for activating the MR 510 are effectively the inverse of the entry conditions that maintain LP-WUS monitoring. When any of the entry conditions cease to be valid, the UE 504 must exit its power-saving state and activate its MR 510. Specifically, the MR 510 becomes activated when the UE 504 receives an LP-WUS 550 indicating a wake-up command, when the UE 504 needs to perform uplink transmission, or when the serving cell’s quality falls below the specified threshold based on RRM measurements.
[0073] The temporal aspect of these exit conditions is demonstrated in FIG. 6, where the transition from an LR activated state 610 to an LR deactivated state 620 occurs upon the reception of an LP-WUS 550. During the LR deactivated state 620, the MR 510 remains active to handle data reception and transmission. This state persists until the entry conditions for returning to the power-saving mode are met again, such as the completion of a paging cycle 640 without receiving additional LP-WUS 550 signals.
[0074] The activation of the MR 510 serves as a response mechanism to network demands or degraded radio conditions that require the full capabilities of the main receiver. This transition enables the UE 504 to maintain reliable communication when circumstances necessitate the use of the more capable but power-intensive main radio.
[0075] The entry and exit conditions for LP-WUS monitoring can be additionally controlled through network signaling mechanisms or determined by the UE 504 implementation. This flexibility in condition determination provides an additional layer of control over the power-efficient operation of the dual-receiver architecture.
[0076] When network signaling indication is employed, the network can explicitly configure the UE 504 to transition between different operational modes. Through dedicated signaling, the network can direct the UE 504 to enter the low-power WUR mode where the LR 520 is activated and the MR 510 is deactivated, as shown in FIG. 5 (A) . Conversely, the network can signal the UE 504 to return to the legacy mode of operation where the MR 510 remains active, as depicted in FIG. 5 (C) .
[0077] The network signaling approach enables dynamic control over the UE’s power-saving mechanisms based on network conditions and requirements. This configuration can be particularly beneficial in scenarios where the network needs to manage multiple UEs with different power-saving capabilities or when network conditions necessitate specific operational modes for certain UEs.
[0078] Alternatively, the entry and exit conditions can be determined by the UE implementation itself. In this autonomous approach, the UE 504 can make decisions about transitioning between operational states based on its internal algorithms and measurements. This implementation-specific determination allows the UE 504 to optimize its power consumption according to its unique characteristics and requirements while maintaining compatibility with the network’s LP-WUS framework.
[0079] In certain implementations, the power-efficient operation of the UE 504 with dual-receiver architecture may rely on Radio Resource Management (RRM) based conditions that govern the transitions between different operational states.
[0080] When the LR 520 is capable of receiving LP-SS and / or PSS / SSS for synchronization and RRM measurements, it can monitor the downlink radio link quality of the serving cell based on the detected reference signal. The UE 504 estimates this downlink radio link quality and compares it to two threshold values: Xin and Xout.
[0081] The threshold Xout is defined as the level at which the downlink radio link cannot be reliably received and corresponds to an out-of-sync threshold. When the measured radio link quality falls below this threshold, the LR 520 cannot reliably monitor for LP-WUS 550 signals, necessitating a transition to the MR 510 for maintaining network connectivity.
[0082] Conversely, the threshold Xin is defined as the level at which the downlink radio link quality can be received with significantly higher reliability than at Xout and corresponds to an in-sync threshold. When the measured radio link quality exceeds this threshold, the UE 504 can confidently rely on the LR 520 for monitoring LP-WUS 550 signals, allowing the power-intensive MR 510 to be deactivated.
[0083] The threshold levels Xin and Xout can be determined through two mechanisms. First, they can be configured by the network using signaling indication, where the network transmits specific threshold values to the UE 504 through system information blocks (SIBs) or other signaling mechanisms. Alternatively, these thresholds can be determined by the UE 504 implementation, allowing the UE 504 to autonomously decide appropriate threshold values based on its capabilities and operating conditions.
[0084] The radio link quality assessment for entry and exit conditions can be based on various metrics, providing flexibility in implementation and optimization for different scenarios. In one embodiment, the estimated downlink radio link quality and the defined threshold levels (Xinand Xout) can be based on Reference Signal Received Power (RSRP) levels. This approach utilizes the power of the received reference signal as an indicator of link quality, with higher RSRP values generally indicating better link conditions.
[0085] In another embodiment, the radio link quality assessment can be based on Signal-to-Noise Ratio (SNR) levels. This metric considers not only the strength of the received signal but also the noise level, providing a more comprehensive evaluation of the link quality. Higher SNR values indicate a cleaner signal with less noise interference, potentially allowing for more reliable LP-WUS 550 detection by the LR 520.
[0086] A third embodiment bases the radio link quality assessment on Block Error Rate (BLER) targets. This approach directly measures the error performance of the link, with lower BLER values indicating better link quality. By setting appropriate BLER thresholds, the UE 504 can determine when the link quality is sufficient for reliable LP-WUS 550 detection by the LR 520.
[0087] The entry conditions for LP-WUS monitoring define the criteria under which the UE 504 transitions to a state where the LR 520 is activated and the MR 510 is deactivated, as illustrated in FIG. 5 (A) . These conditions are primarily based on RRM measurements of the serving cell’s quality, which must exceed specific thresholds to enable reliable operation of the LR 520.
[0088] When the UE 504 is in a state where the MR 510 is active and the LR 520 is inactive, as shown in FIG. 5 (C) , the transition to the power-saving state with active LR 520 can occur based on RRM measurements performed by either the MR 510 or the LR 520, depending on the specific implementation and configuration.
[0089] In the case of MR-based entry conditions, the UE 504 activates the LR 520 and deactivates the MR 510 when the MR RRM measurement for downlink radio link quality is greater than or equal to a threshold Xin. This threshold represents the minimum signal quality level at which the LR 520 can reliably monitor for LP-WUS 550 signals. The MR 510, with its superior reception capabilities, performs these measurements to determine if the radio conditions are suitable for transitioning to the power-saving state with the LR 520 active.
[0090] Alternatively, in implementations where the LR 520 can perform measurements while the MR 510 is active, the entry condition can also be based on LR RRM measurements. In this scenario, the UE 504 activates the LR 520 and deactivates the MR 510 when the LR RRM measurement for downlink radio link quality is greater than or equal to the threshold Xin. This approach provides an additional verification that the LR 520 can indeed receive signals with sufficient quality before the UE 504 commits to the power-saving state.
[0091] When both MR and LR measurements are available and thresholds are configured for both, the entry condition may require that both measurements exceed their respective thresholds, providing a high confidence level in the LR’s ability to reliably monitor for LP-WUS 550 signals.
[0092] The exit conditions for LP-WUS monitoring specify when the UE 504 should transition from the power-saving state with active LR 520 to a state where the MR 510 is activated and the LR 520 is deactivated. Unlike the entry conditions, which can be based on measurements from either the MR 510 or the LR 520, the exit conditions are primarily determined by measurements performed by the LR 520, as it is the only active receiver in the power-saving state.
[0093] The primary RRM-based exit condition is triggered when the LR RRM measurement for downlink radio link quality falls below or equals a threshold Xout. This threshold represents the minimum signal quality required for the LR 520 to reliably detect LP-WUS 550 signals. When the measured signal quality drops below this threshold, the LR 520 can no longer guarantee reliable detection of wake-up signals, necessitating the activation of the MR 510 to maintain network connectivity.
[0094] Upon meeting this exit condition, the UE 504 activates the MR 510 and can deactivate the LR 520, transitioning to the state illustrated in FIG. 5 (C) . The UE 504 maintains reliable communication with the network even when radio conditions deteriorate beyond the capabilities of the low-power receiver.
[0095] The exit condition based on RRM measurements complements other exit conditions, such as the reception of an LP-WUS 550 or the need for uplink transmission. Together, these conditions form a comprehensive framework for managing the operational states of the dual-receiver architecture to optimize power consumption while maintaining reliable network connectivity. The thresholds Xin and Xout can be determined through two primary mechanisms: network configuration or UE implementation.
[0096] When determined by network configuration, the thresholds are signaled to the UE 504 through appropriate signaling mechanisms. This approach allows the network to adapt the thresholds based on network conditions, deployment scenarios, or specific requirements for different UE categories. The network may configure separate thresholds for different types of low power receivers, such as those based on OFDM or OOK modulation schemes, to accommodate various LP-WUR architectures.
[0097] Alternatively, the thresholds can be determined by the UE implementation itself. In this approach, the UE 504 autonomously sets appropriate threshold values based on its specific capabilities, power consumption characteristics, and performance requirements. This implementation-specific determination provides flexibility for UE manufacturers to optimize the power-saving mechanisms according to their unique designs.
[0098] The relationship between the thresholds Xin and Xout typically follows a hysteresis pattern, where Xin is greater than Xout. This hysteresis prevents rapid oscillations between operational states when the measured signal quality fluctuates around a threshold value. By requiring a higher quality level for entry into the power-saving state than for exit, the UE 504 can maintain stable operation even in varying radio conditions.
[0099] The radio link quality assessment for RRM-based entry and exit conditions can utilize various metrics, providing flexibility in implementation and optimization for different scenarios. The primary metric agreed upon for serving cell quality measurement is the Reference Signal Received Power (RSRP) level of the low power signal.
[0100] When using RSRP as the metric, the UE 504 compares the measured RSRP of the serving cell’s reference signal against the configured thresholds Xin and Xout. Higher RSRP values generally indicate better link conditions, with values above Xin enabling the transition to the power-saving state with active LR 520, and values below Xout triggering the activation of the MR 510.
[0101] In addition to RSRP, the Reference Signal Received Quality (RSRQ) may optionally be used as a supplementary metric for assessing the serving cell’s quality. While RSRP provides information about the signal strength, RSRQ offers insights into the signal quality by considering interference and noise levels. The combination of these metrics can provide a more comprehensive evaluation of the radio link conditions.
[0102] Alternative metrics that may be considered in certain implementations include Signal-to-Noise Ratio (SNR) levels and Block Error Rate (BLER) targets. SNR considers both the signal strength and the noise level, providing a measure of how clearly the signal can be distinguished from background noise. BLER directly measures the error performance of the link, with lower values indicating better transmission reliability. These metrics offer different perspectives on the radio link quality and may be suitable for specific deployment scenarios or UE capabilities.
[0103] The selection of appropriate metrics and thresholds for RRM-based entry and exit conditions enables the UE 504 to make informed decisions about transitioning between operational states, optimizing power consumption while maintaining reliable network connectivity through the dual-receiver architecture.
[0104] The low power wake-up receiver (LR) 520 can be implemented using different receiver architectures, specifically through Orthogonal Frequency Division Multiplexing (OFDM) -based or On-Off Keying (OOK) -based wake-up receivers. When a cell supports both types of LRs, the network can configure separate entry and exit thresholds for each receiver type. This configuration flexibility enables optimization of the power-saving mechanism for different LR implementations while maintaining reliable LP-WUS 550 detection capabilities.
[0105] The serving cell quality measurements utilize specific metrics for both entry and exit conditions. For the entry condition, the measurements performed by both the main radio (MR) 510 and the LR 520 primarily rely on the Reference Signal Received Power (RSRP) of the low power signal. Additionally, Reference Signal Received Quality (RSRQ) may be optionally included as a supplementary metric. These measurements provide comprehensive assessment of the radio conditions before transitioning to the power-saving state illustrated in FIG. 5 (A) .
[0106] When the network configures thresholds for both MR 510 and LR 520 measurements, the entry condition becomes more stringent. The UE 504 may verify that all measured results exceed their respective configured thresholds before activating the LR 520 and deactivating the MR 510. This dual-verification approach provides enhanced reliability in determining suitable conditions for power-efficient operation.
[0107] The exit conditions, however, follow a simplified approach. When the UE 504 operates in the power-saving state with active LR 520, as shown in FIG. 5 (A) , the exit condition relies solely on measurements performed by the LR 520. The MR 510, being deactivated in this state, does not contribute to the exit condition determination. The LR 520 monitors the serving cell quality using the same metrics -RSRP as the primary metric and RSRQ as an optional supplementary measurement.
[0108] Separate thresholds for different LR architectures may be implemented. This framework enables adaptation to different receiver implementations while maintaining consistent power-saving objectives. This flexibility in configuration allows network operators to optimize the entry and exit conditions based on the deployed LR technologies and network conditions.
[0109] FIG. 7 is a flow chart 700 of a method for power-efficient operation using a low power wake-up receiver architecture. The method may be performed by a UE, such as the UE 504 shown in FIG. 5.
[0110] In operation 702, the UE determines, when a main radio (MR) of the UE is in an activated state and a low power receiver (LR) of the UE is in a deactivated state, whether one or more entry conditions for low power wake-up signal (LP-WUS) monitoring are met. In operation 704, the UE activates the LR and deactivates the MR when the one or more entry conditions are met. In operation 706, the UE monitors, using the activated LR, for an LP-WUS.
[0111] Meeting the one or more entry conditions requires at least one of: determining that no uplink transmission occurs at the UE; determining that no LP-WUS indicating the UE to wake up is received; determining that a serving cell quality is greater than or equal to one or more thresholds based on radio resource management (RRM) measurements; and determining that no LP-WUS indicating the UE to wake up is received after a paging cycle since a last received LP-WUS.
[0112] In certain configurations, meeting the one or more entry conditions requires determining that the serving cell quality is greater than or equal to the one or more thresholds based on the RRM measurements. To determine that the serving cell quality is greater than or equal to the one or more thresholds, the UE measures a downlink radio link quality of a serving cell and compares the measured downlink radio link quality to the one or more thresholds.
[0113] In certain configurations, the downlink radio link quality is measured based on at least one of: reference signal received power (RSRP) levels; signal-to-noise ratio (SNR) levels; or block error rate (BLER) targets.
[0114] In certain configurations, the one or more thresholds is configured by a network for both the MR and the LR using signaling indication.
[0115] In certain configurations, to determine that the serving cell quality is greater than or equal to the one or more thresholds, the UE determines that an MR RRM measurement for the downlink radio link quality is greater than or equal to the first threshold.
[0116] In certain configurations, to determine that the serving cell quality is greater than or equal to the one or more thresholds, the UE further determines that an LR RRM measurement for the downlink radio link quality is greater than or equal to the second threshold.
[0117] In certain configurations, the UE determines, when the LR is in the activated state and the MR is in the deactivated state, whether one or more exit conditions for the LP-WUS monitoring are met. The UE activates the MR and deactivates the LR when the one or more exit conditions are met.
[0118] Meeting the one or more exit conditions requires at least one of: receiving an LP-WUS indicating the UE to wake up; determining that an uplink transmission is to occur at the UE; or determining that a serving cell quality is less than or equal to a second threshold based on RRM measurements.
[0119] In certain configurations, to determine that the serving cell quality is less than or equal to the second threshold, the UE determines that an LR RRM measurement for the downlink radio link quality is less than or equal to the second threshold.
[0120] In certain configurations, the second threshold is defined as a level at which the downlink radio link cannot be reliably received by LR.
[0121] In certain configurations, the UE monitors, using the activated LR, low-power synchronization signals (LP-SS) or primary / secondary synchronization signals (PSS / SSS) for synchronization and RRM measurements of a serving cell while the UE is in an idle mode or an inactive mode.
[0122] In certain configurations, the LP-WUS is used to trigger the UE to wake up for paging monitoring in IDLE or INACTIVE modes, or for physical downlink control channel (PDCCH) monitoring in CONNECTED mode.
[0123] It is understood that the specific order or hierarchy of blocks in the processes / flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes / flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
[0124] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and / or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”
Claims
1.A method of wireless communication performed by a user equipment (UE) , comprising:determining, when a main radio (MR) of the UE is in an activated state and a low power receiver (LR) of the UE is in a deactivated state, whether one or more entry conditions for low power wake-up signal (LP-WUS) monitoring are met;activating the LR and deactivating the MR when the one or more entry conditions are met; andmonitoring, using the activated LR, for an LP-WUS.2.The method of claim 1, wherein meeting the one or more entry conditions requires at least one of:determining that no uplink transmission occurs at the UE;determining that no LP-WUS indicating the UE to wake up is received;determining that a serving cell quality is greater than or equal to one or more thresholds based on radio resource management (RRM) measurements; anddetermining that no LP-WUS indicating the UE to wake up is received after a paging cycle since a last received LP-WUS.3.The method of claim 2, wherein meeting the one or more entry conditions requires determining that the serving cell quality is greater than or equal to the one or more thresholds based on the RRM measurements, and wherein determining that the serving cell quality is greater than or equal to the one or more thresholds comprises:measuring a downlink radio link quality of a serving cell; andcomparing the measured downlink radio link quality to the one or more thresholds.4.The method of claim 3, wherein the downlink radio link quality is measured based on at least one of:reference signal received power (RSRP) levels;signal-to-noise ratio (SNR) levels; orblock error rate (BLER) targets.5.The method of claim 3, wherein the one or more thresholds is configured by a network for both the MR and the LR using signaling indication.6.The method of claim 3, wherein determining that the serving cell quality is greater than or equal to the one or more thresholds comprises:determining that an MR RRM measurement for the downlink radio link quality is greater than or equal to the first threshold.7.The method of claim 6, wherein determining that the serving cell quality is greater than or equal to the one or more thresholds further comprises:determining that an LR RRM measurement for the downlink radio link quality is greater than or equal to the second threshold.8.The method of claim 1, further comprising:determining, when the LR is in the activated state and the MR is in the deactivated state, whether one or more exit conditions for the LP-WUS monitoring are met; andactivating the MR and deactivating the LR when the one or more exit conditions are met.9.The method of claim 8, wherein meeting the one or more exit conditions requires at least one of:receiving an LP-WUS indicating the UE to wake up;determining that an uplink transmission is to occur at the UE; ordetermining that a serving cell quality is less than or equal to a second threshold based on RRM measurements.10.The method of claim 9, wherein determining that the serving cell quality is less than or equal to the second threshold comprises:determining that an LR RRM measurement for the downlink radio link quality is less than or equal to the second threshold.11.The method of claim 10, wherein the second threshold is defined as a level at which the downlink radio link cannot be reliably received by LR.12.The method of claim 1, further comprising:monitoring, using the activated LR, low-power synchronization signals (LP-SS) or primary / secondary synchronization signals (PSS / SSS) for synchronization and RRM measurements of a serving cell while the UE is in an idle mode or an inactive mode.13.The method of claim 1, wherein the LP-WUS is used to trigger the UE to wake up for paging monitoring in IDLE or INACTIVE modes, or for physical downlink control channel (PDCCH) monitoring in CONNECTED mode.14.An apparatus for wireless communication, the apparatus being a user equipment (UE) , comprising:a memory; andat least one processor coupled to the memory and configured to:determine, when a main radio (MR) of the UE is in an activated state and a low power receiver (LR) of the UE is in a deactivated state, whether one or more entry conditions for low power wake-up signal (LP-WUS) monitoring are met;activate the LR and deactivate the MR when the one or more entry conditions are met; andmonitor, using the activated LR, for an LP-WUS.15.The apparatus of claim 14, wherein meeting the one or more entry conditions requires at least one of:determining that no uplink transmission occurs at the UE;determining that no LP-WUS indicating the UE to wake up is received;determining that a serving cell quality is greater than or equal to one or more thresholds based on radio resource management (RRM) measurements; anddetermining that no LP-WUS indicating the UE to wake up is received after a paging cycle since a last received LP-WUS.16.The apparatus of claim 15, wherein meeting the one or more entry conditions requires determining that the serving cell quality is greater than or equal to the one or more thresholds based on the RRM measurements, and wherein determining that the serving cell quality is greater than or equal to the one or more thresholds comprises:measuring a downlink radio link quality of a serving cell; andcomparing the measured downlink radio link quality to the one or more thresholds.17.The apparatus of claim 16, wherein the downlink radio link quality is measured based on at least one of:reference signal received power (RSRP) levels;signal-to-noise ratio (SNR) levels; orblock error rate (BLER) targets.18.The apparatus of claim 16, wherein the one or more thresholds is configured by a network for both the MR and the LR using signaling indication.19.The apparatus of claim 16, wherein determining that the serving cell quality is greater than or equal to the one or more thresholds comprises:determining that an MR RRM measurement for the downlink radio link quality is greater than or equal to the first threshold.20.A computer-readable medium storing computer executable code for wireless communication of a user equipment (UE) , comprising code to:determine, when a main radio (MR) of the UE is in an activated state and a low power receiver (LR) of the UE is in a deactivated state, whether one or more entry conditions for low power wake-up signal (LP-WUS) monitoring are met;activate the LR and deactivate the MR when the one or more entry conditions are met; andmonitor, using the activated LR, for an LP-WUS.
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