WO2024096718A1 - Mobility control based on cell states in wireless communication system - Google Patents

Mobility control based on cell states in wireless communication system Download PDF

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Publication number
WO2024096718A1
WO2024096718A1 PCT/KR2023/017674 KR2023017674W WO2024096718A1 WO 2024096718 A1 WO2024096718 A1 WO 2024096718A1 KR 2023017674 W KR2023017674 W KR 2023017674W WO 2024096718 A1 WO2024096718 A1 WO 2024096718A1
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WO
WIPO (PCT)
Prior art keywords
cell
state
mobility
nes
condition
Prior art date
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PCT/KR2023/017674
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French (fr)
Inventor
Sunghoon Jung
Myoungsoo Kim
Sangwon Kim
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Lg Electronics Inc.
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Publication of WO2024096718A1 publication Critical patent/WO2024096718A1/en

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02Power saving arrangements
    • H04W52/0203Power saving arrangements in the radio access network or backbone network of wireless communication networks
    • H04W52/0206Power saving arrangements in the radio access network or backbone network of wireless communication networks in access points, e.g. base stations
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/14Relay systems
    • H04B7/15Active relay systems
    • H04B7/185Space-based or airborne stations; Stations for satellite systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/24Reselection being triggered by specific parameters
    • H04W36/32Reselection being triggered by specific parameters by location or mobility data, e.g. speed data
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/34Reselection control
    • H04W36/36Reselection control by user or terminal equipment
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W48/00Access restriction; Network selection; Access point selection
    • H04W48/20Selecting an access point
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02Power saving arrangements
    • H04W52/0209Power saving arrangements in terminal devices
    • H04W52/0212Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
    • H04W52/0216Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave using a pre-established activity schedule, e.g. traffic indication frame
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02Power saving arrangements
    • H04W52/0209Power saving arrangements in terminal devices
    • H04W52/0225Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal
    • H04W52/0245Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal according to signal strength
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02Power saving arrangements
    • H04W52/0209Power saving arrangements in terminal devices
    • H04W52/0261Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
    • H04W52/0274Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level by switching on or off the equipment or parts thereof
    • H04W52/028Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level by switching on or off the equipment or parts thereof switching on or off only a part of the equipment circuit blocks
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W76/00Connection management
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W76/00Connection management
    • H04W76/20Manipulation of established connections
    • H04W76/27Transitions between radio resource control [RRC] states
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W76/00Connection management
    • H04W76/20Manipulation of established connections
    • H04W76/28Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Definitions

  • the present disclosure relates to mobility control based on cell states in wireless communications.
  • 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity.
  • the 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.
  • ITU International Telecommunication Union
  • 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU Radio communication sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process.
  • ITU-R ITU Radio communication sector
  • IMT International Mobile Telecommunications
  • the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.
  • the NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), Ultra-Reliable and Low Latency Communications (URLLC), etc.
  • eMBB enhanced Mobile BroadBand
  • mMTC massive Machine Type Communications
  • URLLC Ultra-Reliable and Low Latency Communications
  • the NR shall be inherently forward compatible.
  • UE may perform a mobility to be provided with service from a better cell. For example, UE may perform a cell reselection in an idle/inactive mode, and perform a handover in a connected mode. To perform a mobility to a better cell, cell state may be considered.
  • An aspect of the present disclosure is to provide method and apparatus for prioritization for mobility control based on cell states in a wireless communication system.
  • a method performed by a user equipment (UE) in a wireless communication system comprises: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  • UE user equipment
  • UE user equipment
  • a method performed by a network node configured to operate in a wireless communication system comprises: transmitting, to a user equipment (UE), information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; and transmitting, to the UE, information for at least one cell state among the multiple cell states, wherein at least one mobility condition related to the at least one cell state is evaluated among the multiple mobility conditions, and wherein a mobility to the target cell is performed based on a mobility condition among the at least one mobility condition being satisfied.
  • UE user equipment
  • an apparatus adapted to operate in a wireless communication system comprises: at least processor; and at least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  • a non-transitory computer readable medium has stored thereon a program code implementing instructions that, based on being executed by at least one processor, perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  • CCM computer readable medium
  • the present disclosure may have various advantageous effects.
  • UE can evaluate mobility condition(s) associated with the NES state the cell enters to achieve optimal mobility.
  • FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.
  • FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.
  • FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.
  • FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
  • FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
  • FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.
  • FIG. 8 shows an example of a conditional handover procedure to which technical features of the present disclosure can be applied.
  • FIG. 9 shows an example of a method performed by a UE according to an embodiment of the present disclosure.
  • FIG. 10 shows an example of a method performed by a network node according to an embodiment of the present disclosure.
  • FIG. 11 shows an example of adjusting reselection parameters depending on cell states according to an embodiment of the present disclosure.
  • FIG. 12 shows an example of adjusting execution conditions for conditional mobility depending on cell states according to an embodiment of the present disclosure.
  • CDMA Code Division Multiple Access
  • FDMA Frequency Division Multiple Access
  • TDMA Time Division Multiple Access
  • OFDMA Orthogonal Frequency Division Multiple Access
  • SC-FDMA Single Carrier Frequency Division Multiple Access
  • MC-FDMA Multi Carrier Frequency Division Multiple Access
  • CDMA may be embodied through radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000.
  • TDMA may be embodied through radio technology such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE).
  • OFDMA may be embodied through radio technology such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA).
  • UTRA is a part of a Universal Mobile Telecommunications System (UMTS).
  • 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA.
  • 3GPP LTE employs OFDMA in downlink (DL) and SC-FDMA in uplink (UL).
  • Evolution of 3GPP LTE includes LTE-Advanced (LTE-A), LTE-A Pro, and/or 5G New Radio (NR).
  • LTE-A LTE-Advanced
  • implementations of the present disclosure are mainly described in regards to a 3GPP based wireless communication system.
  • the technical features of the present disclosure are not limited thereto.
  • the following detailed description is given based on a mobile communication system corresponding to a 3GPP based wireless communication system, aspects of the present disclosure that are not limited to 3GPP based wireless communication system are applicable to other mobile communication systems.
  • a or B may mean “only A”, “only B”, or “both A and B”.
  • a or B in the present disclosure may be interpreted as “A and/or B”.
  • A, B or C in the present disclosure may mean “only A”, “only B”, “only C”, or "any combination of A, B and C”.
  • slash (/) or comma (,) may mean “and/or”.
  • A/B may mean “A and/or B”.
  • A/B may mean "only A”, “only B”, or “both A and B”.
  • A, B, C may mean "A, B or C”.
  • At least one of A and B may mean “only A”, “only B” or “both A and B”.
  • the expression “at least one of A or B” or “at least one of A and/or B” in the present disclosure may be interpreted as same as “at least one of A and B”.
  • At least one of A, B and C may mean “only A”, “only B”, “only C”, or “any combination of A, B and C”.
  • at least one of A, B or C or “at least one of A, B and/or C” may mean “at least one of A, B and C”.
  • parentheses used in the present disclosure may mean “for example”.
  • control information PDCCH
  • PDCCH control information
  • PDCCH control information
  • PDCCH control information
  • FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.
  • the 5G usage scenarios shown in FIG. 1 are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in FIG. 1.
  • Three main requirement categories for 5G include (1) a category of enhanced Mobile BroadBand (eMBB), (2) a category of massive Machine Type Communication (mMTC), and (3) a category of Ultra-Reliable and Low Latency Communications (URLLC).
  • eMBB enhanced Mobile BroadBand
  • mMTC massive Machine Type Communication
  • URLLC Ultra-Reliable and Low Latency Communications
  • the communication system 1 includes wireless devices 100a to 100f, Base Stations (BSs) 200, and a network 300.
  • FIG. 1 illustrates a 5G network as an example of the network of the communication system 1, the implementations of the present disclosure are not limited to the 5G system, and can be applied to the future communication system beyond the 5G system.
  • the BSs 200 and the network 300 may be implemented as wireless devices and a specific wireless device may operate as a BS/network node with respect to other wireless devices.
  • the wireless devices 100a to 100f represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G NR or LTE) and may be referred to as communication/radio/5G devices.
  • RAT Radio Access Technology
  • the wireless devices 100a to 100f may include, without being limited to, a robot 100a, vehicles 100b-1 and 100b-2, an eXtended Reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an Internet-of-Things (IoT) device 100f, and an Artificial Intelligence (AI) device/server 400.
  • the vehicles may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles.
  • the vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone).
  • UAV Unmanned Aerial Vehicle
  • the XR device may include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) device and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc.
  • the hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook).
  • the home appliance may include a TV, a refrigerator, and a washing machine.
  • the IoT device may include a sensor and a smartmeter.
  • the wireless devices 100a to 100f may be called User Equipments (UEs).
  • a UE may include, for example, a cellular phone, a smartphone, a laptop computer, a digital broadcast terminal, a Personal Digital Assistant (PDA), a Portable Multimedia Player (PMP), a navigation system, a slate Personal Computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle having an autonomous traveling function, a connected car, an UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a FinTech device (or a financial device), a security device, a weather/environment device, a device related to a 5G service, or a device related to a fourth industrial revolution field.
  • PDA Personal Digital Assistant
  • PMP Portable Multimedia Player
  • PC slate Personal Computer
  • tablet PC a tablet PC
  • ultrabook a vehicle, a vehicle having
  • the wireless devices 100a to 100f may be connected to the network 300 via the BSs 200.
  • An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300.
  • the network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a beyond-5G network.
  • the wireless devices 100a to 100f may communicate with each other through the BSs 200/network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs 200/network 300.
  • the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X) communication).
  • the IoT device e.g., a sensor
  • the IoT device may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.
  • Wireless communication/connections 150a, 150b and 150c may be established between the wireless devices 100a to 100f and/or between wireless device 100a to 100f and BS 200 and/or between BSs 200.
  • the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication 150a, sidelink communication (or Device-to-Device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, Integrated Access and Backhaul (IAB)), etc.
  • the wireless devices 100a to 100f and the BSs 200/the wireless devices 100a to 100f may transmit/receive radio signals to/from each other through the wireless communication/connections 150a, 150b and 150c.
  • the wireless communication/connections 150a, 150b and 150c may transmit/receive signals through various physical channels.
  • various configuration information configuring processes e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/de-mapping
  • resource allocating processes for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.
  • NR supports multiples numerologies (and/or multiple Sub-Carrier Spacings (SCS)) to support various 5G services. For example, if SCS is 15 kHz, wide area can be supported in traditional cellular bands, and if SCS is 30 kHz/60 kHz, dense-urban, lower latency, and wider carrier bandwidth can be supported. If SCS is 60 kHz or higher, bandwidths greater than 24.25 GHz can be supported to overcome phase noise.
  • numerologies and/or multiple Sub-Carrier Spacings (SCS)
  • the NR frequency band may be defined as two types of frequency range, i.e., Frequency Range 1 (FR1) and Frequency Range 2 (FR2).
  • the numerical value of the frequency range may be changed.
  • the frequency ranges of the two types may be as shown in Table 1 below.
  • FR1 may mean "sub 6 GHz range”
  • FR2 may mean "above 6 GHz range”
  • mmW millimeter Wave
  • FR1 may include a frequency band of 410MHz to 7125MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving).
  • the radio communication technologies implemented in the wireless devices in the present disclosure may include NarrowBand IoT (NB-IoT) technology for low-power communication as well as LTE, NR and 6G.
  • NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology, may be implemented in specifications such as LTE Cat NB1 and/or LTE Cat NB2, and may not be limited to the above-mentioned names.
  • LPWAN Low Power Wide Area Network
  • the radio communication technologies implemented in the wireless devices in the present disclosure may communicate based on LTE-M technology.
  • LTE-M technology may be an example of LPWAN technology and be called by various names such as enhanced MTC (eMTC).
  • eMTC enhanced MTC
  • LTE-M technology may be implemented in at least one of the various specifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and may not be limited to the above-mentioned names.
  • the radio communication technologies implemented in the wireless devices in the present disclosure may include at least one of ZigBee, Bluetooth, and/or LPWAN which take into account low-power communication, and may not be limited to the above-mentioned names.
  • ZigBee technology may generate Personal Area Networks (PANs) associated with small/low-power digital communication based on various specifications such as IEEE 802.15.4 and may be called various names.
  • PANs Personal Area Networks
  • FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.
  • the first wireless device 100 and/or the second wireless device 200 may be implemented in various forms according to use cases/services.
  • ⁇ the first wireless device 100 and the second wireless device 200 ⁇ may correspond to at least one of ⁇ the wireless device 100a to 100f and the BS 200 ⁇ , ⁇ the wireless device 100a to 100f and the wireless device 100a to 100f ⁇ and/or ⁇ the BS 200 and the BS 200 ⁇ of FIG. 1.
  • the first wireless device 100 and/or the second wireless device 200 may be configured by various elements, devices/parts, and/or modules.
  • the first wireless device 100 may include at least one transceiver, such as a transceiver 106, at least one processing chip, such as a processing chip 101, and/or one or more antennas 108.
  • a transceiver such as a transceiver 106
  • a processing chip such as a processing chip 101
  • antennas 108 one or more antennas 108.
  • the processing chip 101 may include at least one processor, such a processor 102, and at least one memory, such as a memory 104. Additional and/or alternatively, the memory 104 may be placed outside of the processing chip 101.
  • the processor 102 may control the memory 104 and/or the transceiver 106 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. For example, the processor 102 may process information within the memory 104 to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver 106. The processor 102 may receive radio signals including second information/signals through the transceiver 106 and then store information obtained by processing the second information/signals in the memory 104.
  • the memory 104 may be operably connectable to the processor 102.
  • the memory 104 may store various types of information and/or instructions.
  • the memory 104 may store a firmware and/or a software code 105 which implements codes, commands, and/or a set of commands that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • the firmware and/or the software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • the firmware and/or the software code 105 may control the processor 102 to perform one or more protocols.
  • the firmware and/or the software code 105 may control the processor 102 to perform one or more layers of the radio interface protocol.
  • the processor 102 and the memory 104 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR).
  • the transceiver 106 may be connected to the processor 102 and transmit and/or receive radio signals through one or more antennas 108.
  • Each of the transceiver 106 may include a transmitter and/or a receiver.
  • the transceiver 106 may be interchangeably used with Radio Frequency (RF) unit(s).
  • the first wireless device 100 may represent a communication modem/circuit/chip.
  • the second wireless device 200 may include at least one transceiver, such as a transceiver 206, at least one processing chip, such as a processing chip 201, and/or one or more antennas 208.
  • the processing chip 201 may include at least one processor, such a processor 202, and at least one memory, such as a memory 204. Additional and/or alternatively, the memory 204 may be placed outside of the processing chip 201.
  • the processor 202 may control the memory 204 and/or the transceiver 206 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. For example, the processor 202 may process information within the memory 204 to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver 206. The processor 202 may receive radio signals including fourth information/signals through the transceiver 106 and then store information obtained by processing the fourth information/signals in the memory 204.
  • the memory 204 may be operably connectable to the processor 202.
  • the memory 204 may store various types of information and/or instructions.
  • the memory 204 may store a firmware and/or a software code 205 which implements codes, commands, and/or a set of commands that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • the firmware and/or the software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • the firmware and/or the software code 205 may control the processor 202 to perform one or more protocols.
  • the firmware and/or the software code 205 may control the processor 202 to perform one or more layers of the radio interface protocol.
  • the processor 202 and the memory 204 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR).
  • the transceiver 206 may be connected to the processor 202 and transmit and/or receive radio signals through one or more antennas 208.
  • Each of the transceiver 206 may include a transmitter and/or a receiver.
  • the transceiver 206 may be interchangeably used with RF unit.
  • the second wireless device 200 may represent a communication modem/circuit/chip.
  • One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202.
  • the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as Physical (PHY) layer, Media Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and Service Data Adaptation Protocol (SDAP) layer).
  • layers e.g., functional layers such as Physical (PHY) layer, Media Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and Service Data Adaptation Protocol (SDAP) layer).
  • PHY Physical
  • MAC Media Access Control
  • RLC Radio Link Control
  • PDCP Packet Data Convergence Protocol
  • RRC Radio Resource Control
  • SDAP Service Data Adaptation Protocol
  • the one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs), one or more Service Data Unit (SDUs), messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • the one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure and provide the generated signals to the one or more transceivers 106 and 206.
  • signals e.g., baseband signals
  • the one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • signals e.g., baseband signals
  • the one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers.
  • the one or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof.
  • ASICs Application Specific Integrated Circuits
  • DSPs Digital Signal Processors
  • DSPDs Digital Signal Processing Devices
  • PLDs Programmable Logic Devices
  • FPGAs Field Programmable Gate Arrays
  • the one or more processors 102 and 202 may be configured by a set of a communication control processor, an Application Processor (AP), an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), and a memory control processor.
  • AP Application Processor
  • ECU Electronic Control Unit
  • CPU Central Processing Unit
  • GPU Graphic Processing Unit
  • memory control processor a memory control processor
  • the one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and/or commands.
  • the one or more memories 104 and 204 may be configured by Random Access Memory (RAM), Dynamic RAM (DRAM), Read-Only Memory (ROM), electrically Erasable Programmable Read-Only Memory (EPROM), flash memory, volatile memory, non-volatile memory, hard drive, register, cash memory, computer-readable storage medium, and/or combinations thereof.
  • the one or more memories 104 and 204 may be located at the interior and/or exterior of the one or more processors 102 and 202.
  • the one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.
  • the one or more transceivers 106 and 206 may transmit user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, to one or more other devices.
  • the one or more transceivers 106 and 206 may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, from one or more other devices.
  • the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals.
  • the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices.
  • the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices.
  • the one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208. Additionally and/or alternatively, the one or more transceivers 106 and 206 may include one or more antennas 108 and 208. The one or more transceivers 106 and 206 may be adapted to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, through the one or more antennas 108 and 208. In the present disclosure, the one or more antennas 108 and 208 may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports).
  • the one or more transceivers 106 and 206 may convert received user data, control information, radio signals/channels, etc., from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc., using the one or more processors 102 and 202.
  • the one or more transceivers 106 and 206 may convert the user data, control information, radio signals/channels, etc., processed using the one or more processors 102 and 202 from the base band signals into the RF band signals.
  • the one or more transceivers 106 and 206 may include (analog) oscillators and/or filters.
  • the one or more transceivers 106 and 206 can up-convert OFDM baseband signals to OFDM signals by their (analog) oscillators and/or filters under the control of the one or more processors 102 and 202 and transmit the up-converted OFDM signals at the carrier frequency.
  • the one or more transceivers 106 and 206 may receive OFDM signals at a carrier frequency and down-convert the OFDM signals into OFDM baseband signals by their (analog) oscillators and/or filters under the control of the one or more processors 102 and 202.
  • the wireless devices 100 and 200 may further include additional components.
  • the additional components 140 may be variously configured according to types of the wireless devices 100 and 200.
  • the additional components 140 may include at least one of a power unit/battery, an Input/Output (I/O) device (e.g., audio I/O port, video I/O port), a driving device, and a computing device.
  • the additional components 140 may be coupled to the one or more processors 102 and 202 via various technologies, such as a wired or wireless connection.
  • a UE may operate as a transmitting device in Uplink (UL) and as a receiving device in Downlink (DL).
  • a BS may operate as a receiving device in UL and as a transmitting device in DL.
  • the first wireless device 100 acts as the UE
  • the second wireless device 200 acts as the BS.
  • the processor(s) 102 connected to, mounted on or launched in the first wireless device 100 may be adapted to perform the UE behavior according to an implementation of the present disclosure or control the transceiver(s) 106 to perform the UE behavior according to an implementation of the present disclosure.
  • the processor(s) 202 connected to, mounted on or launched in the second wireless device 200 may be adapted to perform the BS behavior according to an implementation of the present disclosure or control the transceiver(s) 206 to perform the BS behavior according to an implementation of the present disclosure.
  • a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.
  • NB node B
  • eNB eNode B
  • gNB gNode B
  • FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.
  • a UE 100 may correspond to the first wireless device 100 of FIG. 2.
  • a UE 100 includes a processor 102, a memory 104, a transceiver 106, one or more antennas 108, a power management module 141, a battery 142, a display 143, a keypad 144, a Subscriber Identification Module (SIM) card 145, a speaker 146, and a microphone 147.
  • SIM Subscriber Identification Module
  • the processor 102 may be adapted to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • the processor 102 may be adapted to control one or more other components of the UE 100 to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
  • Layers of the radio interface protocol may be implemented in the processor 102.
  • the processor 102 may include ASIC, other chipset, logic circuit and/or data processing device.
  • the processor 102 may be an application processor.
  • the processor 102 may include at least one of DSP, CPU, GPU, a modem (modulator and demodulator).
  • processor 102 may be found in SNAPDRAGON TM series of processors made by Qualcomm ® , EXYNOS TM series of processors made by Samsung ® , A series of processors made by Apple ® , HELIO TM series of processors made by MediaTek ® , ATOM TM series of processors made by Intel ® or a corresponding next generation processor.
  • the memory 104 is operatively coupled with the processor 102 and stores a variety of information to operate the processor 102.
  • the memory 104 may include ROM, RAM, flash memory, memory card, storage medium and/or other storage device.
  • modules e.g., procedures, functions, etc.
  • the modules can be stored in the memory 104 and executed by the processor 102.
  • the memory 104 can be implemented within the processor 102 or external to the processor 102 in which case those can be communicatively coupled to the processor 102 via various means as is known in the art.
  • the transceiver 106 is operatively coupled with the processor 102, and transmits and/or receives a radio signal.
  • the transceiver 106 includes a transmitter and a receiver.
  • the transceiver 106 may include baseband circuitry to process radio frequency signals.
  • the transceiver 106 controls the one or more antennas 108 to transmit and/or receive a radio signal.
  • the power management module 141 manages power for the processor 102 and/or the transceiver 106.
  • the battery 142 supplies power to the power management module 141.
  • the display 143 outputs results processed by the processor 102.
  • the keypad 144 receives inputs to be used by the processor 102.
  • the keypad 144 may be shown on the display 143.
  • the SIM card 145 is an integrated circuit that is intended to securely store the International Mobile Subscriber Identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). It is also possible to store contact information on many SIM cards.
  • IMSI International Mobile Subscriber Identity
  • the speaker 146 outputs sound-related results processed by the processor 102.
  • the microphone 147 receives sound-related inputs to be used by the processor 102.
  • FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
  • FIG. 4 illustrates an example of a radio interface user plane protocol stack between a UE and a BS
  • FIG. 5 illustrates an example of a radio interface control plane protocol stack between a UE and a BS.
  • the control plane refers to a path through which control messages used to manage call by a UE and a network are transported.
  • the user plane refers to a path through which data generated in an application layer, for example, voice data or Internet packet data are transported.
  • the user plane protocol stack may be divided into Layer 1 (i.e., a PHY layer) and Layer 2.
  • the control plane protocol stack may be divided into Layer 1 (i.e., a PHY layer), Layer 2, Layer 3 (e.g., an RRC layer), and a non-access stratum (NAS) layer.
  • Layer 1 i.e., a PHY layer
  • Layer 2 e.g., an RRC layer
  • NAS non-access stratum
  • Layer 1 Layer 2 and Layer 3 are referred to as an access stratum (AS).
  • the Layer 2 is split into the following sublayers: MAC, RLC, and PDCP.
  • the Layer 2 is split into the following sublayers: MAC, RLC, PDCP and SDAP.
  • the PHY layer offers to the MAC sublayer transport channels, the MAC sublayer offers to the RLC sublayer logical channels, the RLC sublayer offers to the PDCP sublayer RLC channels, the PDCP sublayer offers to the SDAP sublayer radio bearers.
  • the SDAP sublayer offers to 5G core network quality of service (QoS) flows.
  • QoS quality of service
  • the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing/de-multiplexing of MAC SDUs belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in case of carrier aggregation (CA)); priority handling between UEs by means of dynamic scheduling; priority handling between logical channels of one UE by means of logical channel prioritization; padding.
  • HARQ hybrid automatic repeat request
  • a single MAC entity may support multiple numerologies, transmission timings and cells. Mapping restrictions in logical channel prioritization control which numerology(ies), cell(s), and transmission timing(s) a logical channel can use.
  • MAC Different kinds of data transfer services are offered by MAC.
  • multiple types of logical channels are defined, i.e., each supporting transfer of a particular type of information.
  • Each logical channel type is defined by what type of information is transferred.
  • Logical channels are classified into two groups: control channels and traffic channels. Control channels are used for the transfer of control plane information only, and traffic channels are used for the transfer of user plane information only.
  • Broadcast control channel is a downlink logical channel for broadcasting system control information
  • PCCH paging control channel
  • PCCH is a downlink logical channel that transfers paging information
  • common control channel CCCH
  • DCCH dedicated control channel
  • DTCH Dedicated traffic channel
  • a DTCH can exist in both uplink and downlink.
  • BCCH can be mapped to broadcast channel (BCH); BCCH can be mapped to downlink shared channel (DL-SCH); PCCH can be mapped to paging channel (PCH); CCCH can be mapped to DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped to DL-SCH.
  • PCCH downlink shared channel
  • CCCH can be mapped to DL-SCH
  • DCCH can be mapped to DL-SCH
  • DTCH can be mapped to DL-SCH.
  • the RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged node (AM).
  • the RLC configuration is per logical channel with no dependency on numerologies and/or transmission durations.
  • the main services and functions of the RLC sublayer depend on the transmission mode and include: transfer of upper layer PDUs; sequence numbering independent of the one in PDCP (UM and AM); error correction through ARQ (AM only); segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs; reassembly of SDU (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC re-establishment; protocol error detection (AM only).
  • the main services and functions of the PDCP sublayer for the user plane include: sequence numbering; header compression and decompression using robust header compression (ROHC); transfer of user data; reordering and duplicate detection; in-order delivery; PDCP PDU routing (in case of split bearers); retransmission of PDCP SDUs; ciphering, deciphering and integrity protection; PDCP SDU discard; PDCP re-establishment and data recovery for RLC AM; PDCP status reporting for RLC AM; duplication of PDCP PDUs and duplicate discard indication to lower layers.
  • ROIHC robust header compression
  • the main services and functions of the PDCP sublayer for the control plane include: sequence numbering; ciphering, deciphering and integrity protection; transfer of control plane data; reordering and duplicate detection; in-order delivery; duplication of PDCP PDUs and duplicate discard indication to lower layers.
  • the main services and functions of SDAP include: mapping between a QoS flow and a data radio bearer; marking QoS flow ID (QFI) in both DL and UL packets.
  • QFI QoS flow ID
  • a single protocol entity of SDAP is configured for each individual PDU session.
  • the main services and functions of the RRC sublayer include: broadcast of system information related to AS and NAS; paging initiated by 5GC or NG-RAN; establishment, maintenance and release of an RRC connection between the UE and NG-RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including: handover and context transfer, UE cell selection and reselection and control of cell selection and reselection, inter-RAT mobility); QoS management functions; UE measurement reporting and control of the reporting; detection of and recovery from radio link failure; NAS message transfer to/from NAS from/to UE.
  • SRBs signaling radio bearers
  • DRBs data radio bearers
  • mobility functions including: handover and context transfer, UE cell selection and reselection and control of cell selection and reselection, inter-RAT mobility
  • QoS management functions UE measurement reporting and control of the reporting; detection of and recovery from radio link failure; NAS
  • FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
  • OFDM numerologies e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration
  • SCCS subcarrier spacing
  • TTI transmission time interval
  • symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols).
  • Each frame is divided into two half-frames, where each of the half-frames has 5ms duration.
  • Each half-frame consists of 5 subframes, where the duration T sf per subframe is 1ms.
  • Each subframe is divided into slots and the number of slots in a subframe depends on a subcarrier spacing.
  • Each slot includes 14 or 12 OFDM symbols based on a cyclic prefix (CP). In a normal CP, each slot includes 14 OFDM symbols and, in an extended CP, each slot includes 12 OFDM symbols.
  • a slot includes plural symbols (e.g., 14 or 12 symbols) in the time domain.
  • a resource grid of N size,u grid,x *N RB sc subcarriers and N subframe,u symb OFDM symbols is defined, starting at common resource block (CRB) N start,u grid indicated by higher-layer signaling (e.g., RRC signaling), where N size,u grid,x is the number of resource blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink.
  • N RB sc is the number of subcarriers per RB. In the 3GPP based wireless communication system, N RB sc is 12 generally.
  • Each element in the resource grid for the antenna port p and the subcarrier spacing configuration u is referred to as a resource element (RE) and one complex symbol may be mapped to each RE.
  • Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l representing a symbol location relative to a reference point in the time domain.
  • an RB is defined by 12 consecutive subcarriers in the frequency domain.
  • the slot length and symbol length are halved.
  • the slot length is 1ms, which is the same as the subframe length.
  • SCS is 120kHz
  • the symbol length is half of that when the SCS is 60kHz.
  • SCS is 240kHz
  • RBs are classified into CRBs and physical resource blocks (PRBs).
  • CRBs are numbered from 0 and upwards in the frequency domain for subcarrier spacing configuration u.
  • the center of subcarrier 0 of CRB 0 for subcarrier spacing configuration u coincides with 'point A' which serves as a common reference point for resource block grids.
  • PRBs are defined within a bandwidth part (BWP) and numbered from 0 to N size BWP,i -1, where i is the number of the bandwidth part.
  • BWP bandwidth part
  • n PRB n CRB + N size BWP,i , where N size BWP,i is the common resource block where bandwidth part starts relative to CRB 0.
  • the BWP includes a plurality of consecutive RBs.
  • a carrier may include a maximum of N (e.g., 5) BWPs.
  • a UE may be configured with one or more BWPs on a given component carrier. Only one BWP among BWPs configured to the UE can active at a time. The active BWP defines the UE's operating bandwidth within the cell's operating bandwidth.
  • the term "cell” may refer to a geographic area to which one or more nodes provide a communication system, or refer to radio resources.
  • a “cell” as a geographic area may be understood as coverage within which a node can provide service using a carrier and a "cell” as radio resources (e.g., time-frequency resources) is associated with bandwidth which is a frequency range configured by the carrier.
  • the "cell” associated with the radio resources is defined by a combination of downlink resources and uplink resources, for example, a combination of a DL component carrier (CC) and a UL CC.
  • the cell may be configured by downlink resources only, or may be configured by downlink resources and uplink resources.
  • the coverage of the node may be associated with coverage of the "cell" of radio resources used by the node. Accordingly, the term "cell" may be used to represent service coverage of the node sometimes, radio resources at other times, or a range that signals using the radio resources can reach with valid strength at other times.
  • CA two or more CCs are aggregated.
  • a UE may simultaneously receive or transmit on one or multiple CCs depending on its capabilities.
  • CA is supported for both contiguous and non-contiguous CCs.
  • the UE When CA is configured, the UE only has one RRC connection with the network.
  • one serving cell At RRC connection establishment/re-establishment/handover, one serving cell provides the NAS mobility information, and at RRC connection re-establishment/handover, one serving cell provides the security input.
  • This cell is referred to as the primary cell (PCell).
  • the PCell is a cell, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure.
  • secondary cells can be configured to form together with the PCell a set of serving cells.
  • An SCell is a cell providing additional radio resources on top of special cell (SpCell).
  • the configured set of serving cells for a UE therefore always consists of one PCell and one or more SCells.
  • the term SpCell refers to the PCell of the master cell group (MCG) or the primary SCell (PSCell) of the secondary cell group (SCG).
  • MCG master cell group
  • PSCell primary SCell
  • SCG secondary cell group
  • An SpCell supports PUCCH transmission and contention-based random access, and is always activated.
  • the MCG is a group of serving cells associated with a master node, comprised of the SpCell (PCell) and optionally one or more SCells.
  • the SCG is the subset of serving cells associated with a secondary node, comprised of the PSCell and zero or more SCells, for a UE configured with DC.
  • a UE in RRC_CONNECTED not configured with CA/DC there is only one serving cell comprised of the PCell.
  • serving cells is used to denote the set of cells comprised of the SpCell(s) and all SCells.
  • two MAC entities are configured in a UE: one for the MCG and one for the SCG.
  • FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.
  • Radio bearers are categorized into two groups: DRBs for user plane data and SRBs for control plane data.
  • the MAC PDU is transmitted/received using radio resources through the PHY layer to/from an external device.
  • the MAC PDU arrives to the PHY layer in the form of a transport block.
  • the uplink transport channels UL-SCH and RACH are mapped to their physical channels physical uplink shared channel (PUSCH) and physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to physical downlink shared channel (PDSCH), physical broadcast channel (PBCH) and PDSCH, respectively.
  • uplink control information (UCI) is mapped to physical uplink control channel (PUCCH)
  • DCI downlink control information
  • PDCCH physical downlink control channel
  • a MAC PDU related to UL-SCH is transmitted by a UE via a PUSCH based on an UL grant, and a MAC PDU related to DL-SCH is transmitted by a BS via a PDSCH based on a DL assignment.
  • UE may perform a mobility from a source cell to a target cell, in a connected state (i.e., RRC_CONNECTED) or a non-connected state (i.e., RRC_IDLE/RRC_INACTIVE).
  • Mobility in a connected state may comprise a network-controlled mobility and/or a UE-based mobility (i.e., conditional mobility).
  • the network-controlled mobility may comprise a handover (i.e., PCell change), secondary node (SN) addition (i.e., PSCell addition) and/or SN change (i.e., PSCell change).
  • the conditional mobility may comprise a conditional handover (CHO) (i.e., conditional PCell change), a conditional SN addition (i.e., conditional PSCell addition, CPA) and/or a conditional SN change (i.e., conditional PSCell change, CPC).
  • CHO conditional handover
  • CPA conditional PSCell addition
  • CPC conditional SN change
  • Mobility in a non-connected state may comprise cell selection and/or cell reselection.
  • Srxlev Q rxlevmeas - (Q rxlevmin + Q rxlevminoffset )- P compensation - Qoffset temp
  • Squal Q qualmeas - (Q qualmin + Q qualminoffset ) - Qoffset temp .
  • Srxlev Cell selection RX level value (dB) Squal Cell selection quality value (dB) Qoffset temp Offset temporarily applied to a cell as specified in TS 38.331 [3]
  • Q rxlevmin is obtained from q-RxLevMinSUL, if present, in SIB1, SIB2 and SIB4, additionally, if Q rxlevminoffsetcellSUL is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell; else Q rxlevmin is obtained from q-RxLevMin in SIB1, SIB2 and SIB4, additionally, if Q rxlevminoffsetcell is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell.
  • Q qualmin Minimum required quality level in the cell (dB). Additionally, if Q qualminoffsetcell is signalled for the concerned cell, this cell specific offset is added to achieve the required minimum quality level in the concerned cell.
  • P compensation For FR1, if the UE supports the additionalPmax in the NR-NS-PmaxList, if present, in SIB1, SIB2 and SIB4: max(P EMAX1 -P PowerClass , 0) - (min(P EMAX2 , P PowerClass ) - min(P EMAX1 , P PowerClass )) (dB); else: max(P EMAX1 -P PowerClass , 0) (dB) For FR2, P compensation is set to 0. For IAB-MT, P compensation is set to 0.
  • P EMAX1 , P EMAX2 Maximum TX power level of a UE may use when transmitting on the uplink in the cell (dBm) defined as P EMAX in TS 38.101 [15]. If UE supports SUL frequency for this cell, P EMAX1 and P EMAX2 are obtained from the p-Max for SUL in SIB1 and NR-NS-PmaxList for SUL respectively in SIB1, SIB2 and SIB4 as specified in TS 38.331 [3], else P EMAX1 and P EMAX2 are obtained from the p-Max and NR-NS-PmaxList respectively in SIB1, SIB2 and SIB4 for normal UL as specified in TS 38.331 [3]. P PowerClass Maximum RF output power of the UE (dBm) according to the UE power class as defined in TS 38.101-1 [15].
  • the signalled values Q rxlevminoffset and Q qualminoffset are only applied when a cell is evaluated for cell selection as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN.
  • the UE may check the S criteria of a cell using parameter values stored from a different cell of this higher priority PLMN.
  • Absolute priorities of different NR frequencies or inter-RAT frequencies may be provided to the UE in the system information, in the RRCRelease message, or by inheriting from another RAT at inter-RAT cell (re)selection.
  • an NR frequency or inter-RAT frequency may be listed without providing a priority (i.e., the field cellReselectionPriority is absent for that frequency). If any fields with cellReselectionPriority are provided in dedicated signalling, the UE shall ignore any fields with cellReselectionPriority and any slice reselection information provided in system information. If slice reselection information is provided in dedicated signaling, the UE shall ignore slice reselection information provided in system information.
  • information provided in RRCRelease may override information provided in SIB. This may include slice-specific re-selection information, existing/legacy cellResleectionPriority.
  • PCI-lists may be provided in RRCRelease.
  • UE shall derive re-selection priorities.
  • UE shall only apply the priorities provided by system information from current cell, and the UE preserves priorities provided by dedicated signalling and deprioritisationReq received in RRCRelease unless specified otherwise.
  • the UE When the UE in camped normally state, has only dedicated priorities other than for the current frequency, the UE shall consider the current frequency to be the lowest priority frequency (i.e. lower than any of the network configured values).
  • the UE When the HSDN capable UE is in High-mobility state, the UE shall always consider the HSDN cells to be the highest priority (i.e., higher than any other network configured priorities).
  • the UE When the HSDN capable UE is not in High-mobility state, the UE shall always consider HSDN cells to be the lowest priority (i.e., lower than any other network configured priorities). If the UE is configured to perform both NR sidelink communication and V2X sidelink communication, the UE may consider the frequency providing both NR sidelink communication configuration and V2X sidelink communication configuration to be the highest priority. If the UE is configured to perform NR sidelink communication and not perform V2X communication, the UE may consider the frequency providing NR sidelink communication configuration to be the highest priority. If the UE is configured to perform V2X sidelink communication and not perform NR sidelink communication, the UE may consider the frequency providing V2X sidelink communication configuration to be the highest priority.
  • the frequency only providing the anchor frequency configuration should not be prioritized for V2X service during cell reselection.
  • UE When UE is configured to perform NR sidelink communication or V2X sidelink communication performs cell reselection, it may consider the frequencies providing the intra-carrier and inter-carrier configuration have equal priority in cell reselection.
  • the prioritization among the frequencies which UE considers to be the highest priority frequency is left to UE implementation.
  • the UE is configured to perform V2X sidelink communication or NR sidelink communication, if it has the capability and is authorized for the corresponding sidelink operation.
  • UE When UE is configured to perform both NR sidelink communication and V2X sidelink communication, but cannot find a frequency which can provide both NR sidelink communication configuration and V2X sidelink communication configuration, UE may consider the frequency providing either NR sidelink communication configuration or V2X sidelink communication configuration to be the highest priority.
  • the UE is configured with either dedicated cell reselection priorities or slice or slice group specific frequency priorities in the RRCRelease message.
  • the UE shall only perform cell reselection evaluation for NR frequencies and inter-RAT frequencies that are given in system information and for which the UE has a priority provided.
  • the MBS broadcast capable UE may consider that frequency to be the highest priority during the MBS broadcast session as long as the two following conditions are fulfilled:
  • the cell reselected by the UE due to frequency prioritization for MBS is providing SIB20;
  • MBS FSAI(s) of that frequency is indicated in SIB21 of the serving cell and the same MBS FSAI(s) is also indicated for this MBS broadcast service in MBS User Service Description (USD), or
  • - SIB21 is not provided in the serving cell and that frequency is included in the USD of this service, or
  • - SIB21 is provided in the serving cell but does not provide the frequency mapping for the concerned service, and that frequency is included in the USD of this service.
  • the UE may consider cell reselection candidate frequencies at which it can not receive the MBS broadcast service to be of the lowest priority during the MBS broadcast session as specified in TS 38.300 [2], as long as the SIB20 is provided by the cell on the MBS frequency which the UE monitors and as long as the condition 2) above is fulfilled for the serving cell.
  • UE In case UE receives RRCRelease with deprioritisationReq, UE shall consider current frequency and stored frequencies due to the previously received RRCRelease with deprioritisationReq or all the frequencies of NR to be the lowest priority frequency (i.e. lower than any of the network configured values) while T325 is running irrespective of camped RAT. The UE shall delete the stored deprioritisation request(s) when a PLMN selection or SNPN selection is performed on request by NAS.
  • UE should search for a higher priority layer for cell reselection as soon as possible after the change of priority.
  • the minimum related performance requirements are still applicable.
  • the UE shall delete priorities provided by dedicated signalling when:
  • T320 the optional validity time of dedicated priorities
  • the UE receives an RRCRelease message with the field cellReselectionPriorities absent;
  • a PLMN selection or SNPN selection is performed on request by NAS.
  • the UE shall not consider any exclude-listed cells as candidate for cell reselection.
  • the UE shall consider only the allow-listed cells, if configured, as candidates for cell reselection.
  • the UE in RRC_IDLE state shall inherit the priorities provided by dedicated signalling and the remaining validity time (i.e. T320 in NR and E-UTRA), if configured, at inter-RAT cell (re)selection.
  • the network may assign dedicated cell reselection priorities for frequencies not configured by system information.
  • cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if a cell of a higher priority NR or EUTRAN RAT/frequency fulfils Squal > Thresh X, HighQ during a time interval Treselection RAT .
  • cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if i) a cell of a higher priority RAT/ frequency fulfils Srxlev > Thresh X, HighP during a time interval Treselection RAT ; and ii) more than 1 second has elapsed since the UE camped on the current serving cell.
  • Cell reselection to a cell on an equal priority NR frequency shall be based on ranking for intra-frequency cell reselection.
  • cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if the serving cell fulfils Squal ⁇ Thresh Serving, LowQ and a cell of a lower priority NR or E-UTRAN RAT/ frequency fulfils Squal > Thresh X, LowQ during a time interval Treselection RAT .
  • cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if i) the serving cell fulfils Srxlev ⁇ Thresh Serving, LowP and a cell of a lower priority RAT/ frequency fulfils Srxlev > Thresh X, LowP during a time interval Treselection RAT ; and ii) more than 1 second has elapsed since the UE camped on the current serving cell.
  • the UE For a UE performing slice-based cell reselection if a cell fulfils the above criteria for cell reselection based on re-selection priority for the frequency and slice group, but this cell does not support the slice group, the UE shall re-derive a re-selection priority for the frequency by considering the slice group(s) supported by this cell (rather than those of the corresponding NR frequency). This reselection priority shall be used until the highest ranked cell changes on the frequency, or new slice or slice group priorities are received from NAS. UE shall ensure the cell reselection criteria above are fulfilled based on the newly derived priorities.
  • Cell reselection to a higher priority RAT/frequency shall take precedence over a lower priority RAT/frequency if multiple cells of different priorities fulfil the cell reselection criteria.
  • the UE shall reselect a cell if the highest-priority frequency is an NR frequency, the highest ranked cell among the cells on the highest priority frequency(ies) meeting the criteria according to clause; and/or if the highest-priority frequency is from another RAT, the strongest cell among the cells on the highest priority frequency(ies) meeting the criteria of that RAT.
  • Qoffset For intra-frequency Equals to Qoffset s,n , if Qoffset s,n is valid, otherwise this equals to zero.
  • Qoffset temp Offset temporarily applied to a cell.
  • the UE shall perform ranking of all cells that fulfil the cell selection criterion S.
  • the cells shall be ranked according to the R criteria specified above by deriving Q meas,n and Q meas,s and calculating the R values using averaged RSRP results.
  • rangeToBestCell the UE shall perform cell reselection to the highest ranked cell. If this cell is found to be not-suitable, the UE shall not consider this cell and, for operation in licensed spectrum, other cells on the same frequency as candidates for reselection for a maximum of 300 seconds.
  • the UE shall perform cell reselection to the cell with the highest number of beams above the threshold (i.e. absThreshSS-BlocksConsolidation) among the cells whose R value is within rangeToBestCell of the R value of the highest ranked cell.
  • threshold i.e. absThreshSS-BlocksConsolidation
  • "beam above threshold” may be referred to as good beam. If there are multiple such cells, the UE shall perform cell reselection to the highest ranked cell among them. If this cell is found to be not-suitable, the UE shall not consider this cell and, for operation in licensed spectrum, other cells on the same frequency as candidates for reselection for a maximum of 300 seconds.
  • the UE shall reselect the new cell, only if i) the new cell is better than the serving cell according to the cell reselection criteria specified above during a time interval Treselection RAT ; and/or ii) more than 1 second has elapsed since the UE camped on the current serving cell.
  • the UE considers that there is one beam above the threshold for each cell on that frequency.
  • FIG. 8 shows an example of a conditional handover procedure to which technical features of the present disclosure can be applied.
  • the conditional handover procedure as shown in FIG. 8 may also be applied to other conditional mobility procedures i.e., CPA procedure and/or CPC procedure.
  • the source cell may transmit measurement control message to the UE.
  • the measurement control message may comprise a measurement configuration including a list of measurement configurations, and each measurement configuration in the list includes a measurement identity (ID), the corresponding measurement object and the corresponding report configuration.
  • ID measurement identity
  • the UE may transmit a measurement report message to the source cell.
  • the measurement report message may comprise a result of measurement on neighbor cell(s) around the UE which can be detected by the UE.
  • the UE may generate the measurement report message according to a measurement configuration and/or measurement control information in the measurement control message received in step S801.
  • the source cell may make a handover decision based on the measurement report. For example, the source cell may make a handover decision and determine candidate target cells (e.g., target cell 1 and target cell 2) for handover among neighbor cells around the UE based on a result of measurement (e.g., signal quality, reference signal received power (RSRP), reference signal received quality (RSRP)) on the neighbor cells.
  • candidate target cells e.g., target cell 1 and target cell 2
  • RSRP reference signal received power
  • RSRP reference signal received quality
  • the source cell may transmit handover request messages to the target cell 1 and the target cell 2 which are determined in step S805. That is, the source cell may perform handover preparation with the target cell 1 and the target cell 2.
  • the handover request message may comprise necessary information to prepare the handover at the target side (e.g., target cell 1 and target cell 2).
  • each of the target cell 1 and the target cell 2 may perform an admission control based on information included in the handover request message.
  • the target cell may configure and reserve the required resources (e.g., C-RNTI and/or RACH preamble).
  • the AS-configuration to be used in the target cell can either be specified independently (i.e. an "establishment") or as a delta compared to the AS-configuration used in the source cell (i.e. a "reconfiguration").
  • the target cell and the target cell 2 may transmit a handover request acknowledge (ACK) message to the source cell.
  • the handover request ACK message may comprise cell configuration (i.e., RRCReconfiguration message including ReconfigurationWithSync) including information on resources reserved and prepared for a handover.
  • the handover request ACK message may comprise a transparent container to be sent to the UE as an RRC message (i.e., RRCReconfiguration message/cell configuration) to perform the handover.
  • the container/cell configuration/RRCReconfiguration message may include information required to access the target cell (i.e., access configuration) comprising at least one of a physical cell ID of the target cell, identifier of the UE (i.e., C-RNTI), HO validity timer (i.e., T304 timer), the target gNB security algorithm identifiers for the selected security algorithms, a set of dedicated RACH resources for contention-free random access (e.g., dedicated random access preamble), the association between RACH resources and SSB(s), the association between RACH resources and UE-specific CSI-RS configuration(s), common RACH resources, or system information of the target cell.
  • access configuration comprising at least one of a physical cell ID of the target cell, identifier of the UE (i.e., C-RNTI), HO validity timer (i.e., T304 timer), the target gNB security algorithm identifiers for the selected security algorithms, a set of dedicated RACH resources for contention-free random access
  • the container may include timing adjustment indication and optionally a pre-allocated uplink grant.
  • the handover request ACK message may also include RNL/TNL information for forwarding tunnels, if necessary. As soon as the source cell receives the handover request ACK message, or as soon as the transmission of the conditional handover command is initiated in the downlink, data forwarding may be initiated.
  • the source cell may transmit a RRCReconfiguration message including a conditional reconfiguration to the UE.
  • the conditional reconfiguration may be also referred to as (or, may comprise) conditional handover (CHO) configuration and/or a conditional handover command (e.g., CHO command).
  • the conditional reconfiguration may comprise a list of conditional reconfigurations/conditional handover commands, including a conditional reconfiguration/conditional handover command for each of the candidate target cells (e.g., target cell 1, target cell 2).
  • the conditional reconfiguration may comprise a conditional reconfiguration/conditional handover command for the target cell 1, and a conditional reconfiguration/conditional handover command for the target cell 2.
  • the conditional reconfiguration for a target cell may comprise an index/identifier identifying the corresponding conditional reconfiguration, a handover condition (or, execution condition for conditional mobility/handover) for the target cell, and/or a cell configuration (i.e., RRCReconfiguration message including the reconfigurationWithSync) for the target cell.
  • the RRCReconfiguration message and/or reconfigurationWithSync for the target cell may comprise information required to access the target cell comprising at least one of a physical cell ID of the target cell, identifier of the UE (i.e., C-RNTI), HO validity timer (i.e., T304 timer), the target gNB security algorithm identifiers for the selected security algorithms, a set of dedicated RACH resources for contention-free random access (e.g., dedicated random access preamble), the association between RACH resources and SSB(s), the association between RACH resources and UE-specific CSI-RS configuration(s), common RACH resources, or system information of the target cell.
  • a physical cell ID of the target cell identifier of the UE (i.e., C-RNTI), HO validity timer (i.e., T304 timer), the target gNB security algorithm identifiers for the selected security algorithms, a set of dedicated RACH resources for contention-free random access (e.g., dedicated random access preamble
  • the UE may perform an evaluation of the handover condition for the candidate target cells (e.g., target cell 1, target cell 2) and select a target cell for a handover among the candidate target cells. For example, the UE may perform measurements on the candidate target cells, and determine whether a candidate target cell fulfils a handover condition for the candidate target cell among the candidate target cells based on a result of the measurements on the candidate target cells. Or, the UE may determine whether the target cell/measurement result for the target cell fulfils the handover condition of the target cell. If the UE identifies that the target cell 1 fulfils a handover condition for the target cell 1, the UE may select the target cell 1 as a target cell for the handover.
  • the candidate target cells e.g., target cell 1, target cell 2
  • the UE may perform measurements on the candidate target cells, and determine whether a candidate target cell fulfils a handover condition for the candidate target cell among the candidate target cells based on a result of the measurements on the candidate target cells. Or, the UE may determine whether
  • the UE may detach from the old cell i.e., the source cell and synchronize to a new cell i.e., the selected target cell.
  • the UE may perform a handover from the source cell to the target cell based on applying the cell configuration. For example, upon receiving the handover command, the UE may start the T304 timer, and perform a contention-free random access towards the target cell based on the set of dedicated RACH resources.
  • step S819 upon successful completion of the random access procedure, the UE may stop the T304 timer, and transmit a handover complete message (i.e., RRCReconfigurationComplete message) to the target cell.
  • the UE may send the RRCReconfigurationComplete message comprising the C-RNTI to confirm the handover, to the target cell to indicate that the handover procedure is completed for the UE.
  • the target RAN node may verify the C-RNTI sent in the RRCReconfigurationComplete message.
  • the target RAN node can now begin sending data to the UE.
  • the UE may retry random access towards the target cell.
  • the UE may declare handover failure (HOF) and perform an RRC re-establishment procedure.
  • HAF handover failure
  • the aim of NES function is to reduce operational expenses through energy savings.
  • the NES function allows, for example in a deployment where capacity boosters can be distinguished from cells providing basic coverage, to optimize energy consumption enabling the possibility for an E-UTRA or NR cell providing additional capacity via single or dual connectivity, to be switched off when its capacity is no longer needed and to be re-activated on a need basis, and other various techniques in time, frequency, spatial and power domains.
  • the intra-system energy saving solution builds upon the possibility for the NG-RAN node owning a capacity booster cell to autonomously decide to switch-off such cell to lower energy consumption (inactive state).
  • the decision is typically based on cell load information, consistently with configured information.
  • the switch-off decision may also be taken by operation and maintenance (O&M).
  • the NG-RAN node may initiate handover actions in order to off-load the cell being switched off and may indicate the reason for handover with an appropriate cause value to support the target node in taking subsequent actions, e.g. when selecting the target cell for subsequent handovers.
  • All neighbour NG-RAN nodes are informed by the NG-RAN node owning the concerned cell about the switch-off actions over the Xn interface, by means of the NG-RAN node Configuration Update procedure.
  • All informed nodes maintain the cell configuration data, e.g., neighbour relationship configuration, also when a certain cell is inactive. If basic coverage is ensured by NG-RAN node cells, NG-RAN node owning non-capacity boosting cells may request a re-activation over the Xn interface if capacity needs in such cells demand to do so. This is achieved via the Cell Activation procedure. During switch off time period of the boost cell, the NG-RAN node may prevent idle mode UEs from camping on this cell and may prevent incoming handovers to the same cell.
  • the NG-RAN node receiving a request should act accordingly.
  • the switch-on decision may also be taken by O&M. All peer NG-RAN nodes are informed by the NG-RAN node owning the concerned cell about the re-activation by an indication on the Xn interface.
  • the inter-system energy saving solution builds upon the possibility for the NG-RAN node owning a capacity booster cell to autonomously decide to switch-off such cell to dormant state.
  • the decision is typically based on cell load information, consistently with configured information.
  • the switch-off decision may also be taken by O&M.
  • the NG-RAN node indicates the switch-off action to the eNB over NG interface and S1 interface.
  • the NG-RAN node could also indicate the switch-on action to the eNB over NG interface and S1 interface.
  • the eNB providing basic coverage may request a NG-RAN node's cell re-activation based on its own cell load information or neighbour cell load information, the switch-on decision may also be taken by O&M.
  • the eNB requests a NG-RAN node's cell re-activation and receives the NG-RAN node's cell re-activation reply from the NG-RAN node over the S1 interface and NG interface.
  • the NG-RAN node's cell should remain switched on at least until expiration of the minimum activation time.
  • the minimum activation time may be configured by O&M or be left to the NG-RAN node's implementation.
  • UE can be configured with a periodic cell discontinuous transmission (DTX)/discontinuous reception (DRX) pattern (i.e., active and non-active periods).
  • DTX periodic cell discontinuous transmission
  • DRX discontinuous reception
  • the pattern configuration for cell DTX/DRX is common for the UEs configured with this feature in the cell.
  • the cell DTX and cell DRX patterns can be configured and activated separately.
  • the UE does not monitor PDCCH in selected cases or SPS occasions during cell DTX non-active duration.
  • cell DRX is configured and activated for the concerned cell, the UE does not transmit on CG resources or transmit a SR during cell DRX non-active duration.
  • Cell DTX/DRX can be activated/deactivated by RRC signalling or L1 group common signalling.
  • Cell DTX/DRX is characterized by the following:
  • - active duration duration that the UE waits for to receive PDCCHs or SPS occasions, and transmit SR or CG. In this duration, the gNB transmission/reception of PDCCH, SPS, SR and CG, are not impacted for the purpose of network energy saving;
  • Active duration and cycle parameters are common between cell DTX and cell DRX, when both are configured.
  • the network should ensure that there is no impact to that service (e.g. it may release or deactivate cell DTX/DRX configuration).
  • the network should also ensure that there is at least partial overlapping between UE's connected mode DRX on-duration and cell DTX/DRX active duration, i.e. the UE's connected mode DRX periodicity is a multiple of cell DTX/DRX periodicity or vice versa.
  • NES capable UEs to a cell is controlled by a single bit in SIB1 (if present), otherwise the barring mechanisms apply.
  • non-NES state or, NES_off state
  • cell DTX/DRX state a sub-state of NES state
  • cell turning-off or, switch-off
  • the non-NES state is a state in which i) UE is not configured with a cell DTX/DRX configuration, or ii) UE is configured with the cell DTX/DRX configuration, but cell DTX/DRX is not activated. In the non-NES state, all duration is an active duration.
  • the cell DTX/DRX state is a state in which UE is configured with a cell DTX/DRX configuration, and cell DTX/DRX is activated. In the cell DTX/DRX state, a cycle of the active duration and a non-active duration is periodically repeated.
  • the cell turning-off state is a state in which all duration is the non-active duration. While a cell is in the cell turning-off state, UE in an idle mode is not allowed to camp on the cell, and UE is not allowed to perform a mobility to the cell.
  • - UE may monitor PDCCH and/or semi-persistent scheduling (SPS) occasions (i.e., cell DTX active duration); and/or
  • PS semi-persistent scheduling
  • - UE may transmit on configured grant (CG) resources, and/or transmit a scheduling request (SR) (i.e., cell DRX active duration).
  • CG configured grant
  • SR scheduling request
  • - UE does not monitor PDCCH and/or SPS occasions (i.e., cell DTX non-active duration); and/or
  • - UE does not transmit on CG resources, and/or does not transmit SR (i.e., cell DRX non-active duration).
  • a cell may enter its operation state to save its energy consumption.
  • a cell may enter NES state.
  • NES state There may be various cell states including non-NES state and NES states that are sub-states in NES state.
  • network may want to randomize cell reselection adjustments/execution conditions based on cell's (sub-)state.
  • UE should be able to determine when/in which condition the cell state information becomes invalid.
  • FIG. 9 shows an example of a method performed by a UE according to an embodiment of the present disclosure. The method may also be performed by a wireless device.
  • UE may receive information for multiple mobility conditions for a target cell.
  • Each of the multiple mobility conditions may be related to a corresponding cell state among multiple cell states.
  • step S903 UE may receive information for at least one cell state among the multiple cell states.
  • step S905 UE may evaluate at least one mobility condition related to the at least one cell state among the multiple mobility conditions.
  • step S907 based on a mobility condition among the at least one mobility condition being satisfied, UE may perform a mobility to the target cell.
  • the information for the multiple mobility conditions may be received via a radio resource control (RRC) signalling.
  • the information for the at least one cell state may be received via a media access control (MAC) control element (CE) signalling or downlink control information (DCI).
  • RRC radio resource control
  • MAC media access control
  • CE control element
  • DCI downlink control information
  • the mobility may comprise a cell reselection.
  • the multiple mobility conditions may comprise a cell reselection condition that: a cell ranking value for the target cell is highest among a cell ranking value for a serving cell and one or more cell ranking values for one or more neighbor cells; or based on the cell ranking value for the target cell belonging to one or more cell ranking values for cells within a threshold range from a highest cell ranking value, a number of good beams of the target cell is highest among the cells.
  • the mobility may comprise a conditional mobility.
  • the multiple mobility conditions may comprise execution conditions for the conditional mobility.
  • the execution conditions may be related to at least one of a measurement value for the target cell, a measurement value for a serving cell, one or more thresholds, or a time-to-trigger (TTT).
  • TTT time-to-trigger
  • the execution conditions may comprise at least one of: an event A2 condition that a measurement value for the serving cell is lower than a source cell threshold; an event A3 condition that a measurement value for the target cell is higher than a measurement value for the serving cell plus offset threshold for at least TTT; an event A4 condition that a measurement value for the target cell is higher than a target cell threshold; or an event A5 condition that a state in which a measurement value for the target cell is higher than a target cell threshold and a measurement value for the serving cell is lower than a source cell threshold lasts for at least TTT.
  • the information for the multiple mobility conditions may comprises: the multiple mobility conditions; and multiple cell state identifiers (IDs) each of which is related to a corresponding mobility condition.
  • UE may identify the at least one mobility condition related to the at least one cell state based on at least one matching cell state ID.
  • the information for the multiple mobility conditions may comprise: multiple offsets; and multiple cell state identifiers (IDs) each of which is related to a corresponding offset.
  • UE may identify at least one offset related to the at least one cell state based on at least one matching cell state ID.
  • UE may determine the at least one mobility condition based on applying the at least one offset to one or more parameters of a reference mobility condition.
  • the at least one mobility condition may be relaxed with respect to the reference mobility condition based on the at least one offset being applied to the one or more parameters.
  • the one or more parameters may comprise at least one of a cell ranking value for the target cell, a cell ranking value for a serving cell, a cell ranking value for at least one neighbor cell other than the target cell, a measurement value for the target cell, a measurement value for the serving cell, an offset threshold, a source cell threshold, a target cell threshold, or a time-to-trigger (TTT).
  • TTTT time-to-trigger
  • the multiple cell states may comprise a non-network energy saving (NES) state, a first NES state and a second NES state.
  • the first NES state and the second NES state may be sub-states of a NES state.
  • the non-NES state may be a state in which all duration is an active duration.
  • the first NES state may be a state in which a cycle of the active duration and a non-active duration is periodically repeated.
  • the second NES state may be a state in which all duration is the non-active duration.
  • the UE monitors at least one of physical downlink control channel (PDCCH) or semi-persistent scheduling (SPS) occasions; or the UE performs a transmission on configured grant (CG) resources, or transmits a scheduling request (SR).
  • the UE does not monitor at least one of PDCCH or SPS occasions; or the UE does not perform a transmission on CG resources, or does not transmit an SR.
  • the at least one cell state may comprise at least one of the first NES state or the second NES state.
  • a mobility condition related to the first NES state may be more relaxed than a reference mobility condition related to the non-NES state.
  • a mobility condition related to the second NES state may be more relaxed than the mobility condition related to the first NES state.
  • the non-NES state may be a non-cell discontinuous transmission (DTX)/discontinuous reception (DRX) state.
  • the first NES state may be a cell DTX/DRX state.
  • the second NES state may be a cell turning-off state.
  • UE may receive configuration including association between cell states and mobility adjustment values.
  • UE may receive state of one or multiple cells. The validity of the received cell state may be related to a timer.
  • UE may measure quality of serving cell and one or more neighbour cells.
  • UE may determine mobility adjustment values for the serving cell and the neighbour cells. The mobility adjustment may be applied only if the cell state is considered valid.
  • UE may perform evaluation of the measured cells by applying the determined mobility adjustment values.
  • UE may access one of the measured cell chosen by the evaluation.
  • UE may receive configuration including association between cell states and mobility adjustment values.
  • UE may receive state of one or multiple cells. The validity of the received cell state may be related to a timer.
  • UE may measure quality of serving cell and one or more neighbour cells.
  • UE may determine mobility adjustment values for the serving cell and the neighbour cells. The mobility adjustment may be applied only if the cell state is considered valid.
  • UE may evaluate ranking of the measured cells by applying the determined reselection adjustment values.
  • UE may perform cell reselection to the best ranked cell.
  • UE may receive a configuration including one or more target cell configurations and mobility conditions associated with at least one of the target cell(s).
  • the execution conditions may be associated with cell states for one of the serving cells or the target cells.
  • UE may receive a lower layer indication including at least one cell state.
  • UE may determine at least one applicable mobility execution condition based on the lower layer indication and validity of the cell state.
  • UE may evaluate the applicable mobility condition. Based on the determined mobility condition being met, UE may access the target cell associated with the mobility condition.
  • FIG. 10 shows an example of a method performed by a network node according to an embodiment of the present disclosure.
  • the network node may be a source node associated with a serving cell for mobility, and comprise a base station (BS).
  • BS base station
  • the network node may transmit, to a UE, information for multiple mobility conditions for a target cell.
  • Each of the multiple mobility conditions may be related to a corresponding cell state among multiple cell states.
  • the information for the multiple mobility conditions may be transmitted via RRC signalling.
  • the network node may transmit, to the UE, information for at least one cell state among the multiple cell states.
  • the information for the at least one cell state may be transmitted via MAC CE signalling and/or DCI.
  • step S1005 UE may evaluate at least one mobility condition related to the at least one cell state among the multiple mobility conditions.
  • step S1007 based on a mobility condition among the at least one mobility condition being satisfied, UE may perform a mobility to the target cell.
  • FIG. 11 shows an example of adjusting reselection parameters depending on cell states according to an embodiment of the present disclosure.
  • UE may receive information for multiple cell reselection conditions for a target cell.
  • the information for the multiple cell reselection conditions may be received via RRC signalling and/or system information block (SIB) broadcast.
  • SIB system information block
  • the information for the multiple cell reselection conditions may comprise the multiple cell reselection conditions, and multiple cell state IDs each of which is related to a corresponding cell reselection condition. If cell state information comprising the information for the multiple cell reselection conditions is configured to UE via RRC signalling and/or SIB broadcast, this step may be omitted.
  • UE may receive cell state information for a serving cell and/or one or more neighbour cells.
  • the cell state information may be provided to UE via RRC signalling and/or SIB broadcast.
  • the cell state information may be defined for a list of cells, and comprise the following information elements (IEs) as shown in table 7:
  • Qoffset j is cell and/or state specific offset. Instead of Qoffset j , state specific Qoffset j can be configured for a group of neighbour cells.
  • the cell state ID may indicate a cell state among non-NES state and NES states.
  • the cell state information may be provided to UE via MAC CE and/or DCI.
  • the MAC CE and/or DCI may comprise at least one of:
  • UE may be (pre-)configured with the following association information via dedicated RRC signalling and/or SIB broadcast:
  • short cell ID e.g., PCI
  • the association information may be received via RRC signalling and/or SIB broadcast before step S1103.
  • the association information may be included in the information for the multiple cell reselection conditions received in step S1101.
  • the UE may determine whether the cell state information is valid or not. For example, the cell state information is valid within a certain duration, where the duration can be configurable, until it is overridden by a new information for the same cell. For another example, the cell state information is valid until it is overridden by a new information for the same cell.
  • UE may determine at least one cell reselection condition for the target cell based on the cell state information.
  • UE may identify at least one cell state/cell state ID informed by the cell state information, and determine the at least one cell reselection condition related to the at least one cell state/cell state ID. For example, UE may determine at least one cell state specific offset (e.g., Qoffset) related to the at least one cell state/cell state ID based on the association information in the information for the multiple cell reselection conditions.
  • the at least one cell state specific offset may comprise a cell state specific offset for a serving cell, and/or one or more cell state specific offsets for one or more neighbour cells.
  • UE may determine the at least one cell reselection condition for the target cell based on applying the at least one cell state specific offset to one or more parameters of a reference cell reselection condition.
  • a cell reselection condition for the target cell may be a condition that:
  • R n value for the target cell is highest among R s value for a serving cell (e.g., cell ranking value for the serving cell) and/or one or more R n' values for one or more neighbour cells (e.g., cell ranking value for neighbour cell); or
  • R n value for the target cell belongs to one or more R values for cells within a threshold range from the highest R value, the number of good beams which the target cell has is highest among the cells.
  • R s and R n may be expressed as:
  • R s Q meas,s +Q hyst - Qoffset temp + Qs,j;
  • R n Q meas,n -Qoffset - Qoffset temp + Qn,j, where
  • Qx,j may be zero.
  • R s and R n may be expressed as:
  • R s Q meas,s +Q hyst - Qoffset temp + Qs,j*I s,j ;
  • R n Q meas,n -Qoffset - Qoffset temp + Qn,j*I n,j , where
  • I s,j indicator function (0 or 1) for applying Qs,j;
  • I n,j indicator function (0 or 1) for applying Qn,j.
  • UE needs to be preconfigured with P s,j: and P n,j via RRC signalling or dynamic signalling.
  • P s,j and P n,j via RRC signalling or dynamic signalling.
  • state specific P n,j can be configured for a group of neighbour cells.
  • R s and R n may be expressed as:
  • R s Q meas,s +Q hyst - Qoffset temp + Qs,j*P s,j ;
  • R n Q meas,n -Qoffset - Qoffset temp + Qn,j*P n,j , where
  • UE when UE performs cell reselection evaluation, UE draws a random value between 0 and 1 with uniform distribution and applies the random value as P s,j and P n,j .
  • P s,j the random value
  • P n,j the random value between 0 and 1 with uniform distribution
  • state specific P n,j can be configured for a group of neighbour cells.
  • the cell state specific offset Qs,j is construed as being applied to R s , Q meas,s , Q hyst and/or Qoffset temp .
  • the cell state specific offset Qn,j is construed as being applied to R n , Q meas,n , Qoffset and/or Qoffset temp .
  • the at least one cell state specific offset may be set to zero when the at least one cell state specific offset is related to a non-NES state (i.e., NES_off state).
  • NES state ⁇ NES_1, NES_2 ⁇ , and UE may be configured with the following Qoffsets in the association information included in the information for the multiple cell reselection conditions:
  • UE may be notified via MAC CE/DCI about cell (sub)states as follows:
  • the following table 8 shows R values (i.e., combination of (R s , R- n ) values) that UE uses for cell reselection:
  • the at least one cell state may comprise one or more NES states including cell DTX/DRX state and/or cell turning-off state.
  • a cell reselection condition related to the cell DTX/DRX state is more relaxed than a reference cell reselection condition related to the non-NES state
  • a cell reselection condition related to the cell turning-off state is more relaxed than the cell reselection condition related to the cell DTX/DRX state.
  • the at least one cell state specific offset related to the at least one cell state may be applied to one or more parameters of the reference cell reselection condition.
  • the at least one cell state specific offset may be applied to:
  • - a measurement value for a cell other than the target cell to decrease a cell ranking of the cell by an amount with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state.
  • step S1107 UE may perform a cell reselection to the target cell based on a cell reselection condition for the target cell being satisfied.
  • FIG. 12 shows an example of adjusting execution conditions for conditional mobility depending on cell states according to an embodiment of the present disclosure.
  • UE may receive a configuration for one or more candidate target cells for conditional mobility.
  • the configuration may be a conditional mobility command.
  • the configuration may comprise a cell configuration for a target cell, and information for multiple execution conditions for the target cell.
  • the information for the multiple execution conditions may be received via RRC signalling and/or SIB broadcast.
  • the information for the multiple execution conditions may comprise the multiple execution conditions, and multiple cell state IDs each of which is related to a corresponding execution condition, as shown in table 9:
  • condExecutionCond1 SEQUENCE ⁇ cellstateID cellstateID / cell state ID related to at least one execution condition / measIDlist SEQUENCE (SIZE (1...2)) OF MeasID / at least one execution condition determined by CondTriggerConfig in ReportConfig of the corresponding MeasID / ⁇ condExecutionCond2
  • SEQUENCE ⁇ cellstateID cellstateID measIDlist SEQUENCE (SIZE (1...2)) OF MeasID ⁇ condExecutionCond3
  • SIZE (1...2) OF MeasID ⁇
  • step S1203 UE may receive cell state information for a serving cell and/or one or more neighbour cells.
  • the cell state information may be provided to UE via RRC signalling and/or SIB broadcast.
  • the cell state information may be defined for a list of cells, and comprise the following information elements (IEs) as shown in table 10:
  • Qoffset j is cell and/or state specific offset. Instead of Qoffset j , state specific Qoffset j can be configured for a group of neighbour cells.
  • the cell state ID may indicate a cell state among non-NES state and NES states.
  • the cell state information may be provided to UE via MAC CE and/or DCI.
  • the MAC CE and/or DCI may comprise at least one of:
  • UE may be (pre-)configured with the following association information via dedicated RRC signalling and/or SIB broadcast:
  • short cell ID e.g., PCI
  • the association information may be received via RRC signalling and/or SIB broadcast before step S1203.
  • the association information may be included in the information for the multiple execution conditions received in step S1201.
  • the UE may determine whether the cell state information is valid or not. For example, the cell state information is valid within a certain duration, where the duration can be configurable, until it is overridden by a new information for the same cell. For another example, the cell state information is valid until it is overridden by a new information for the same cell.
  • UE may evaluate mobility execution condition(s) for candidate cell(s).
  • UE may evaluate at least one execution condition related to at least one cell state/cell state ID informed by the cell state information. For example, UE may determine at least one cell state specific offset (e.g., Qoffset) related to the at least one cell state/cell state ID based on the association information in the information for the multiple execution conditions.
  • the at least one cell state specific offset may comprise a cell state specific offset for a serving cell, and/or one or more cell state specific offsets for one or more neighbour cells.
  • UE may determine the at least one execution condition for a target cell based on applying the at least one cell state specific offset to one or more parameters of at least one reference execution condition.
  • the UE may determine measurement metrics comprising execution condition metric for serving cell (i.e., serving cell execution condition metric, R s ) and/or one or more execution condition metrics for one or more neighbour cells (i.e., neighbour cell execution condition metric, R n ) as follows:
  • R s Q meas,s +Q hyst - Qoffset temp ;
  • R n Q meas,n -Qoffset - Qoffset temp .
  • an execution condition for the target cell may be an event A3 condition that R n for the target cell is higher than R s plus offset threshold for at least time-to-trigger (TTT).
  • TTT time-to-trigger
  • R s and R n may be expressed as:
  • R s Q meas,s +Q hyst - Qoffset temp + Qs,j;
  • R n Q meas,n -Qoffset - Qoffset temp + Qn,j, where
  • the cell state specific offset Qs,j is construed as being applied to R s , Q meas,s , Q hyst and/or Qoffset temp .
  • the cell state specific offset Qn,j is construed as being applied to R n , Q meas,n , Qoffset and/or Qoffset temp . If the cell state is unknown or considered invalid, Qx,j is zero;
  • At least one cell state specific offset may be applied to the offset threshold
  • At least one cell state specific offset may be applied to the TTT.
  • an execution condition for the target cell may be an event A5 condition that a state in which i) R n for the target cell is higher than a target cell threshold, and ii) R s is lower than a source cell threshold lasts for at least TTT.
  • R s and R n may be expressed as:
  • R s Q meas,s +Q hyst - Qoffset temp + Qs,j;
  • R n Q meas,n -Qoffset - Qoffset temp + Qn,j, where
  • the cell state specific offset Qs,j is construed as being applied to R s , Q meas,s , Q hyst and/or Qoffset temp .
  • the cell state specific offset Qn,j is construed as being applied to R n , Q meas,n , Qoffset and/or Qoffset temp . If the cell state is unknown or considered invalid, Qx,j is zero;
  • At least one cell state specific offset may be applied to the target cell threshold
  • At least one cell state specific offset may be applied to the source cell threshold
  • At least one cell state specific offset may be applied to the TTT.
  • the at least one cell state specific offset may be set to zero when the at least one cell state specific offset is related to a non-NES state (i.e., NES_off state).
  • the at least one cell state may comprise one or more NES states including cell DTX/DRX state and/or cell turning-off state.
  • an execution condition related to the cell DTX/DRX state is more relaxed than a reference execution condition related to the non-NES state
  • an execution condition related to the cell turning-off state is more relaxed than the execution condition related to the cell DTX/DRX state.
  • the at least one cell state specific offset related to the at least one cell state may be applied to one or more parameters of the reference execution condition.
  • the at least one cell state specific offset may be applied to:
  • a measurement value for a source cell to decrease the measurement value for the source cell by a decrement with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state;
  • a target cell threshold to decrease the target cell threshold by a decrement with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state;
  • UE may perform a mobility to a target cell based on an execution condition for the target cell being satisfied.
  • UE may apply the cell configuration for the target cell based on the execution condition for the target cell being satisfied.
  • xxxExcludedCellList should be configured to include NES cells so that legacy UEs excludes the NES cells from cell reselection candidates.
  • NES capable UEs should ignore the ExcludedCellList so that they can consider the NES cells as cell reselection candidate cells.
  • ExcludedCellListNES ExcludedCellList only applicable to NES capable UEs
  • Option A can prevent legacy UEs from reselecting NES cells but this option cannot prevent legacy UEs from selecting and camping NES cells.
  • cellBarred in MIB of NES cell should be set to barred.
  • NES capable UEs should ignore the cellBarred.
  • NES capable UEs should be supported based on 1-bit barring mechanism. Then, another cellBarred field only applicable to NES capable UEs (e.g., cellBarredNES) may be introduced in SIB1.
  • cellBarredNES another cellBarred field only applicable to NES capable UEs
  • This solution can effectively prevent legacy UEs from camping in NES cells.
  • This kind of mechanism is used to control access for NTN UEs and access from RedCap UEs.
  • This solution cannot avoid legacy UEs from reselecting NES cells in the first place.
  • Legacy UEs will attempt to camp on the NES cell by acquiring MIB and then leave the NES cell only after identifying the cellBarred set to barred.
  • option A can be further considered, but such optimization is not considered essential. That is, option B is sufficient.
  • cellReservationForOtherUse To bar legacy UEs that is not capable of NPN from NES cell, cellReservationForOtherUse should be set to true in NES cell. To bar NPN capable UEs from NES cell, cellReservationForFutureUse should be set to true in NES cell. NES capable UEs should ignore both cellReservationForOtherUse and cellReservationForFutureUse in NES cell.
  • a new cell reservation field e.g., cellReservationForFutureUse2 may be introduced. If this field is absent, the UE should consider that the cell is not reserved. Otherwise the UE should consider the cell as barred.
  • Access restriction based on cell reservation in NES cell should be built on top of existing access control handling used for access control in NPN cells, which slightly complicates access control mechanism in NES cell.
  • Option C can work but this option is not preferred given that other like option B is simple and sufficient.
  • option B alone is sufficient to prevent legacy UEs from accessing NES cells. If option B is taken, a new cell barring field needs to be introduced in SIB1 that is only applicable to NES capable UEs.
  • - NES cell can set cellBarred in MIB to barred in order to prevent legacy UEs from accessing NES cells.
  • NES capable UEs ignores cellBarred.
  • a new cell barring field is introduced in SIB1 only applicable to NES capable UEs. If this field is set to barred, NES capable UEs shall consider this cell as barred.
  • the network should be able to configure NES capable UEs to (de)prioritize NES cells.
  • Mechanism can be considered for both frequency and cell levels cell selection/reselection (de)prioritization.
  • Intra-NR cell reselection is limited to frequencies listed in SIB3 and SIB4.
  • Currently network can configure Qoffset to prioritize or deprioritize certain cell(s) in SIB3/4 for cell reselection.
  • Qoffset can be configured for each neighbour cell included in the intra-frequency neighbour cell information in SIB3 and equal priority inter-frequency neighbour cell info in SIB4, and Qoffset ranges from -24 dB to +24 dB, which is sufficient to enable relative (de)prioritization by using smaller value of
  • Qoffset can be applicable to prioritize or deprioritize NES cells for cell reselection.
  • Qoffset does not work well, since the Qoffset is a broadcast parameter.
  • Qoffset is useful if network wants to apply common prioritization policy for legacy UEs and NES capable UEs.
  • Existing Qoffset is not useful if network wants to apply different prioritization policy for legacy UEs and NES capable UEs.
  • QoffsetNES QoffsetNES
  • Network configures existing Qoffset to control reselection for legacy UEs and new Offset (OffsetNES) to control reselection for NES capable UEs. Then, NES capable UEs should ignore existing Qoffset but apply QoffsetNES instead.
  • - Differentiated prioritization policy for NES cells may apply for legacy UEs and for NES capable UEs respectively (e.g., de-prioritization of NES cells by legacy UEs and prioritization of NES cells by NES capable UEs, or vice versa)
  • a new Qoffset (e.g., QoffsetNES) dedicated to NES capable UEs is introduced.
  • NES capable UEs ignore existing Qoffset but apply QoffsetNES instead.
  • the method in perspective of the UE described in the present disclosure may be performed by the first wireless device 100 shown in FIG. 2 and/or the UE 100 shown in FIG. 3.
  • the UE comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.
  • the operations comprise: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  • the method in perspective of the UE described in the present disclosure may be performed by a software code 105 stored in the memory 104 included in the first wireless device 100 shown in FIG. 2.
  • At least one computer readable medium stores instructions that, based on being executed by at least one processor, perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  • CCM computer readable medium
  • the method in perspective of the UE described in the present disclosure may be performed by control of the processor 102 included in the first wireless device 100 shown in FIG. 2 and/or by control of the processor 102 included in the UE 100 shown in FIG. 3.
  • an apparatus configured to/adapted to operate in a wireless communication system (e.g., wireless device/UE) comprises at least processor, and at least one computer memory operably connectable to the at least one processor.
  • the at least one processor is configured to/adapted to perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  • the method in perspective of a network node described in the present disclosure may be performed by the second wireless device 200 shown in FIG. 2.
  • the network node comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.
  • the operations comprise: transmitting, to a user equipment (UE), information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; and transmitting, to the UE, information for at least one cell state among the multiple cell states, wherein at least one mobility condition related to the at least one cell state is evaluated among the multiple mobility conditions, and wherein a mobility to the target cell is performed based on a mobility condition among the at least one mobility condition being satisfied.
  • UE user equipment
  • the present disclosure may have various advantageous effects.
  • UE can evaluate mobility condition(s) associated with the NES state the cell enters to achieve optimal mobility.

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Abstract

The present disclosure relates to mobility control based on cell states in wireless communications. According to an embodiment of the present disclosure, a method performed by a user equipment (UE) in a wireless communication system comprises: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.

Description

MOBILITY CONTROL BASED ON CELL STATES IN WIRELESS COMMUNICATION SYSTEM
The present disclosure relates to mobility control based on cell states in wireless communications.
3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.
Work has started in International Telecommunication Union (ITU) and 3GPP to develop requirements and specifications for New Radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU Radio communication sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.
The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), Ultra-Reliable and Low Latency Communications (URLLC), etc. The NR shall be inherently forward compatible.
In wireless communications, UE may perform a mobility to be provided with service from a better cell. For example, UE may perform a cell reselection in an idle/inactive mode, and perform a handover in a connected mode. To perform a mobility to a better cell, cell state may be considered.
An aspect of the present disclosure is to provide method and apparatus for prioritization for mobility control based on cell states in a wireless communication system.
According to an embodiment of the present disclosure, a method performed by a user equipment (UE) in a wireless communication system comprises: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
According to an embodiment of the present disclosure, a user equipment (UE) configured to operate in a wireless communication system comprises: at least one transceiver; at least one processor; and at least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
According to an embodiment of the present disclosure, a network node configured to operate in a wireless communication system comprises: at least one transceiver; at least one processor; and at least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising: transmitting, to a user equipment (UE), information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; and transmitting, to the UE, information for at least one cell state among the multiple cell states, wherein at least one mobility condition related to the at least one cell state is evaluated among the multiple mobility conditions, and wherein a mobility to the target cell is performed based on a mobility condition among the at least one mobility condition being satisfied.
According to an embodiment of the present disclosure, a method performed by a network node configured to operate in a wireless communication system comprises: transmitting, to a user equipment (UE), information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; and transmitting, to the UE, information for at least one cell state among the multiple cell states, wherein at least one mobility condition related to the at least one cell state is evaluated among the multiple mobility conditions, and wherein a mobility to the target cell is performed based on a mobility condition among the at least one mobility condition being satisfied.
According to an embodiment of the present disclosure, an apparatus adapted to operate in a wireless communication system comprises: at least processor; and at least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
According to an embodiment of the present disclosure, a non-transitory computer readable medium (CRM) has stored thereon a program code implementing instructions that, based on being executed by at least one processor, perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
The present disclosure may have various advantageous effects.
For example, when a base station associated with a cell operates multiple NES states, UE can evaluate mobility condition(s) associated with the NES state the cell enters to achieve optimal mobility.
Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and/or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.
FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.
FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.
FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.
FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.
FIG. 8 shows an example of a conditional handover procedure to which technical features of the present disclosure can be applied.
FIG. 9 shows an example of a method performed by a UE according to an embodiment of the present disclosure.
FIG. 10 shows an example of a method performed by a network node according to an embodiment of the present disclosure.
FIG. 11 shows an example of adjusting reselection parameters depending on cell states according to an embodiment of the present disclosure.
FIG. 12 shows an example of adjusting execution conditions for conditional mobility depending on cell states according to an embodiment of the present disclosure.
The following techniques, apparatuses, and systems may be applied to a variety of wireless multiple access systems. Examples of the multiple access systems include a Code Division Multiple Access (CDMA) system, a Frequency Division Multiple Access (FDMA) system, a Time Division Multiple Access (TDMA) system, an Orthogonal Frequency Division Multiple Access (OFDMA) system, a Single Carrier Frequency Division Multiple Access (SC-FDMA) system, and a Multi Carrier Frequency Division Multiple Access (MC-FDMA) system. CDMA may be embodied through radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be embodied through radio technology such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE). OFDMA may be embodied through radio technology such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is a part of a Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE employs OFDMA in downlink (DL) and SC-FDMA in uplink (UL). Evolution of 3GPP LTE includes LTE-Advanced (LTE-A), LTE-A Pro, and/or 5G New Radio (NR).
For convenience of description, implementations of the present disclosure are mainly described in regards to a 3GPP based wireless communication system. However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is given based on a mobile communication system corresponding to a 3GPP based wireless communication system, aspects of the present disclosure that are not limited to 3GPP based wireless communication system are applicable to other mobile communication systems.
For terms and technologies which are not specifically described among the terms of and technologies employed in the present disclosure, the wireless communication standard documents published before the present disclosure may be referenced.
In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, "A or B" in the present disclosure may be interpreted as "A and/or B". For example, "A, B or C" in the present disclosure may mean "only A", "only B", "only C", or "any combination of A, B and C".
In the present disclosure, slash (/) or comma (,) may mean "and/or". For example, "A/B" may mean "A and/or B". Accordingly, "A/B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B or C".
In the present disclosure, "at least one of A and B" may mean "only A", "only B" or "both A and B". In addition, the expression "at least one of A or B" or "at least one of A and/or B" in the present disclosure may be interpreted as same as "at least one of A and B".
In addition, in the present disclosure, "at least one of A, B and C" may mean "only A", "only B", "only C", or "any combination of A, B and C". In addition, "at least one of A, B or C" or "at least one of A, B and/or C" may mean "at least one of A, B and C".
Also, parentheses used in the present disclosure may mean "for example". In detail, when it is shown as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, "control information" in the present disclosure is not limited to "PDCCH", and "PDCCH" may be proposed as an example of "control information". In addition, even when shown as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information".
Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.
Although not limited thereto, various descriptions, functions, procedures, suggestions, methods and/or operational flowcharts of the present disclosure disclosed herein can be applied to various fields requiring wireless communication and/or connection (e.g., 5G) between devices.
Hereinafter, the present disclosure will be described in more detail with reference to drawings. The same reference numerals in the following drawings and/or descriptions may refer to the same and/or corresponding hardware blocks, software blocks, and/or functional blocks unless otherwise indicated.
FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.
The 5G usage scenarios shown in FIG. 1 are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in FIG. 1.
Three main requirement categories for 5G include (1) a category of enhanced Mobile BroadBand (eMBB), (2) a category of massive Machine Type Communication (mMTC), and (3) a category of Ultra-Reliable and Low Latency Communications (URLLC).
Referring to FIG. 1, the communication system 1 includes wireless devices 100a to 100f, Base Stations (BSs) 200, and a network 300. Although FIG. 1 illustrates a 5G network as an example of the network of the communication system 1, the implementations of the present disclosure are not limited to the 5G system, and can be applied to the future communication system beyond the 5G system.
The BSs 200 and the network 300 may be implemented as wireless devices and a specific wireless device may operate as a BS/network node with respect to other wireless devices.
The wireless devices 100a to 100f represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G NR or LTE) and may be referred to as communication/radio/5G devices. The wireless devices 100a to 100f may include, without being limited to, a robot 100a, vehicles 100b-1 and 100b-2, an eXtended Reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an Internet-of-Things (IoT) device 100f, and an Artificial Intelligence (AI) device/server 400. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. The vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) device and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter.
In the present disclosure, the wireless devices 100a to 100f may be called User Equipments (UEs). A UE may include, for example, a cellular phone, a smartphone, a laptop computer, a digital broadcast terminal, a Personal Digital Assistant (PDA), a Portable Multimedia Player (PMP), a navigation system, a slate Personal Computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle having an autonomous traveling function, a connected car, an UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a FinTech device (or a financial device), a security device, a weather/environment device, a device related to a 5G service, or a device related to a fourth industrial revolution field.
The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a beyond-5G network. Although the wireless devices 100a to 100f may communicate with each other through the BSs 200/network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs 200/network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.
Wireless communication/ connections 150a, 150b and 150c may be established between the wireless devices 100a to 100f and/or between wireless device 100a to 100f and BS 200 and/or between BSs 200. Herein, the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication 150a, sidelink communication (or Device-to-Device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, Integrated Access and Backhaul (IAB)), etc. The wireless devices 100a to 100f and the BSs 200/the wireless devices 100a to 100f may transmit/receive radio signals to/from each other through the wireless communication/ connections 150a, 150b and 150c. For example, the wireless communication/ connections 150a, 150b and 150c may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/de-mapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.
NR supports multiples numerologies (and/or multiple Sub-Carrier Spacings (SCS)) to support various 5G services. For example, if SCS is 15 kHz, wide area can be supported in traditional cellular bands, and if SCS is 30 kHz/60 kHz, dense-urban, lower latency, and wider carrier bandwidth can be supported. If SCS is 60 kHz or higher, bandwidths greater than 24.25 GHz can be supported to overcome phase noise.
The NR frequency band may be defined as two types of frequency range, i.e., Frequency Range 1 (FR1) and Frequency Range 2 (FR2). The numerical value of the frequency range may be changed. For example, the frequency ranges of the two types (FR1 and FR2) may be as shown in Table 1 below. For ease of explanation, in the frequency ranges used in the NR system, FR1 may mean "sub 6 GHz range", FR2 may mean "above 6 GHz range," and may be referred to as millimeter Wave (mmW).
Frequency Range designation Corresponding frequency range Subcarrier Spacing
FR1 450MHz - 6000MHz 15, 30, 60kHz
FR2 24250MHz - 52600MHz 60, 120, 240kHz
As mentioned above, the numerical value of the frequency range of the NR system may be changed. For example, FR1 may include a frequency band of 410MHz to 7125MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving).
Frequency Range designation Corresponding frequency range Subcarrier Spacing
FR1 410MHz - 7125MHz 15, 30, 60kHz
FR2 24250MHz - 52600MHz 60, 120, 240kHz
Here, the radio communication technologies implemented in the wireless devices in the present disclosure may include NarrowBand IoT (NB-IoT) technology for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology, may be implemented in specifications such as LTE Cat NB1 and/or LTE Cat NB2, and may not be limited to the above-mentioned names. Additionally and/or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and be called by various names such as enhanced MTC (eMTC). For example, LTE-M technology may be implemented in at least one of the various specifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and may not be limited to the above-mentioned names. Additionally and/or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may include at least one of ZigBee, Bluetooth, and/or LPWAN which take into account low-power communication, and may not be limited to the above-mentioned names. For example, ZigBee technology may generate Personal Area Networks (PANs) associated with small/low-power digital communication based on various specifications such as IEEE 802.15.4 and may be called various names.FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.
In FIG. 2, The first wireless device 100 and/or the second wireless device 200 may be implemented in various forms according to use cases/services. For example, {the first wireless device 100 and the second wireless device 200} may correspond to at least one of {the wireless device 100a to 100f and the BS 200}, {the wireless device 100a to 100f and the wireless device 100a to 100f} and/or {the BS 200 and the BS 200} of FIG. 1. The first wireless device 100 and/or the second wireless device 200 may be configured by various elements, devices/parts, and/or modules.
The first wireless device 100 may include at least one transceiver, such as a transceiver 106, at least one processing chip, such as a processing chip 101, and/or one or more antennas 108.
The processing chip 101 may include at least one processor, such a processor 102, and at least one memory, such as a memory 104. Additional and/or alternatively, the memory 104 may be placed outside of the processing chip 101.
The processor 102 may control the memory 104 and/or the transceiver 106 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. For example, the processor 102 may process information within the memory 104 to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver 106. The processor 102 may receive radio signals including second information/signals through the transceiver 106 and then store information obtained by processing the second information/signals in the memory 104.
The memory 104 may be operably connectable to the processor 102. The memory 104 may store various types of information and/or instructions. The memory 104 may store a firmware and/or a software code 105 which implements codes, commands, and/or a set of commands that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the firmware and/or the software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the firmware and/or the software code 105 may control the processor 102 to perform one or more protocols. For example, the firmware and/or the software code 105 may control the processor 102 to perform one or more layers of the radio interface protocol.
Herein, the processor 102 and the memory 104 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and/or receive radio signals through one or more antennas 108. Each of the transceiver 106 may include a transmitter and/or a receiver. The transceiver 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the first wireless device 100 may represent a communication modem/circuit/chip.
The second wireless device 200 may include at least one transceiver, such as a transceiver 206, at least one processing chip, such as a processing chip 201, and/or one or more antennas 208.
The processing chip 201 may include at least one processor, such a processor 202, and at least one memory, such as a memory 204. Additional and/or alternatively, the memory 204 may be placed outside of the processing chip 201.
The processor 202 may control the memory 204 and/or the transceiver 206 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. For example, the processor 202 may process information within the memory 204 to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver 206. The processor 202 may receive radio signals including fourth information/signals through the transceiver 106 and then store information obtained by processing the fourth information/signals in the memory 204.
The memory 204 may be operably connectable to the processor 202. The memory 204 may store various types of information and/or instructions. The memory 204 may store a firmware and/or a software code 205 which implements codes, commands, and/or a set of commands that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the firmware and/or the software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the firmware and/or the software code 205 may control the processor 202 to perform one or more protocols. For example, the firmware and/or the software code 205 may control the processor 202 to perform one or more layers of the radio interface protocol.
Herein, the processor 202 and the memory 204 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and/or receive radio signals through one or more antennas 208. Each of the transceiver 206 may include a transmitter and/or a receiver. The transceiver 206 may be interchangeably used with RF unit. In the present disclosure, the second wireless device 200 may represent a communication modem/circuit/chip.
Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as Physical (PHY) layer, Media Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and Service Data Adaptation Protocol (SDAP) layer). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs), one or more Service Data Unit (SDUs), messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure.
The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors 102 and 202. For example, the one or more processors 102 and 202 may be configured by a set of a communication control processor, an Application Processor (AP), an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), and a memory control processor.
The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and/or commands. The one or more memories 104 and 204 may be configured by Random Access Memory (RAM), Dynamic RAM (DRAM), Read-Only Memory (ROM), electrically Erasable Programmable Read-Only Memory (EPROM), flash memory, volatile memory, non-volatile memory, hard drive, register, cash memory, computer-readable storage medium, and/or combinations thereof. The one or more memories 104 and 204 may be located at the interior and/or exterior of the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.
The one or more transceivers 106 and 206 may transmit user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, to one or more other devices. The one or more transceivers 106 and 206 may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, from one or more other devices. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices.
The one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208. Additionally and/or alternatively, the one or more transceivers 106 and 206 may include one or more antennas 108 and 208. The one or more transceivers 106 and 206 may be adapted to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, through the one or more antennas 108 and 208. In the present disclosure, the one or more antennas 108 and 208 may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports).
The one or more transceivers 106 and 206 may convert received user data, control information, radio signals/channels, etc., from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc., using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals/channels, etc., processed using the one or more processors 102 and 202 from the base band signals into the RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and/or filters. For example, the one or more transceivers 106 and 206 can up-convert OFDM baseband signals to OFDM signals by their (analog) oscillators and/or filters under the control of the one or more processors 102 and 202 and transmit the up-converted OFDM signals at the carrier frequency. The one or more transceivers 106 and 206 may receive OFDM signals at a carrier frequency and down-convert the OFDM signals into OFDM baseband signals by their (analog) oscillators and/or filters under the control of the one or more processors 102 and 202.
Although not shown in FIG. 2, the wireless devices 100 and 200 may further include additional components. The additional components 140 may be variously configured according to types of the wireless devices 100 and 200. For example, the additional components 140 may include at least one of a power unit/battery, an Input/Output (I/O) device (e.g., audio I/O port, video I/O port), a driving device, and a computing device. The additional components 140 may be coupled to the one or more processors 102 and 202 via various technologies, such as a wired or wireless connection.
In the implementations of the present disclosure, a UE may operate as a transmitting device in Uplink (UL) and as a receiving device in Downlink (DL). In the implementations of the present disclosure, a BS may operate as a receiving device in UL and as a transmitting device in DL. Hereinafter, for convenience of description, it is mainly assumed that the first wireless device 100 acts as the UE, and the second wireless device 200 acts as the BS. For example, the processor(s) 102 connected to, mounted on or launched in the first wireless device 100 may be adapted to perform the UE behavior according to an implementation of the present disclosure or control the transceiver(s) 106 to perform the UE behavior according to an implementation of the present disclosure. The processor(s) 202 connected to, mounted on or launched in the second wireless device 200 may be adapted to perform the BS behavior according to an implementation of the present disclosure or control the transceiver(s) 206 to perform the BS behavior according to an implementation of the present disclosure.
In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.
FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.
Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.
A UE 100 includes a processor 102, a memory 104, a transceiver 106, one or more antennas 108, a power management module 141, a battery 142, a display 143, a keypad 144, a Subscriber Identification Module (SIM) card 145, a speaker 146, and a microphone 147.
The processor 102 may be adapted to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. The processor 102 may be adapted to control one or more other components of the UE 100 to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. Layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include ASIC, other chipset, logic circuit and/or data processing device. The processor 102 may be an application processor. The processor 102 may include at least one of DSP, CPU, GPU, a modem (modulator and demodulator). An example of the processor 102 may be found in SNAPDRAGONTM series of processors made by Qualcomm®, EXYNOSTM series of processors made by Samsung®, A series of processors made by Apple®, HELIOTM series of processors made by MediaTek®, ATOMTM series of processors made by Intel® or a corresponding next generation processor.
The memory 104 is operatively coupled with the processor 102 and stores a variety of information to operate the processor 102. The memory 104 may include ROM, RAM, flash memory, memory card, storage medium and/or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. The modules can be stored in the memory 104 and executed by the processor 102. The memory 104 can be implemented within the processor 102 or external to the processor 102 in which case those can be communicatively coupled to the processor 102 via various means as is known in the art.
The transceiver 106 is operatively coupled with the processor 102, and transmits and/or receives a radio signal. The transceiver 106 includes a transmitter and a receiver. The transceiver 106 may include baseband circuitry to process radio frequency signals. The transceiver 106 controls the one or more antennas 108 to transmit and/or receive a radio signal.
The power management module 141 manages power for the processor 102 and/or the transceiver 106. The battery 142 supplies power to the power management module 141.
The display 143 outputs results processed by the processor 102. The keypad 144 receives inputs to be used by the processor 102. The keypad 144 may be shown on the display 143.
The SIM card 145 is an integrated circuit that is intended to securely store the International Mobile Subscriber Identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). It is also possible to store contact information on many SIM cards.
The speaker 146 outputs sound-related results processed by the processor 102. The microphone 147 receives sound-related inputs to be used by the processor 102.
FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
In particular, FIG. 4 illustrates an example of a radio interface user plane protocol stack between a UE and a BS and FIG. 5 illustrates an example of a radio interface control plane protocol stack between a UE and a BS. The control plane refers to a path through which control messages used to manage call by a UE and a network are transported. The user plane refers to a path through which data generated in an application layer, for example, voice data or Internet packet data are transported. Referring to FIG. 4, the user plane protocol stack may be divided into Layer 1 (i.e., a PHY layer) and Layer 2. Referring to FIG. 5, the control plane protocol stack may be divided into Layer 1 (i.e., a PHY layer), Layer 2, Layer 3 (e.g., an RRC layer), and a non-access stratum (NAS) layer. Layer 1, Layer 2 and Layer 3 are referred to as an access stratum (AS).
In the 3GPP LTE system, the Layer 2 is split into the following sublayers: MAC, RLC, and PDCP. In the 3GPP NR system, the Layer 2 is split into the following sublayers: MAC, RLC, PDCP and SDAP. The PHY layer offers to the MAC sublayer transport channels, the MAC sublayer offers to the RLC sublayer logical channels, the RLC sublayer offers to the PDCP sublayer RLC channels, the PDCP sublayer offers to the SDAP sublayer radio bearers. The SDAP sublayer offers to 5G core network quality of service (QoS) flows.
In the 3GPP NR system, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing/de-multiplexing of MAC SDUs belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in case of carrier aggregation (CA)); priority handling between UEs by means of dynamic scheduling; priority handling between logical channels of one UE by means of logical channel prioritization; padding. A single MAC entity may support multiple numerologies, transmission timings and cells. Mapping restrictions in logical channel prioritization control which numerology(ies), cell(s), and transmission timing(s) a logical channel can use.
Different kinds of data transfer services are offered by MAC. To accommodate different kinds of data transfer services, multiple types of logical channels are defined, i.e., each supporting transfer of a particular type of information. Each logical channel type is defined by what type of information is transferred. Logical channels are classified into two groups: control channels and traffic channels. Control channels are used for the transfer of control plane information only, and traffic channels are used for the transfer of user plane information only. Broadcast control channel (BCCH) is a downlink logical channel for broadcasting system control information, paging control channel (PCCH) is a downlink logical channel that transfers paging information, system information change notifications and indications of ongoing public warning service (PWS) broadcasts, common control channel (CCCH) is a logical channel for transmitting control information between UEs and network and used for UEs having no RRC connection with the network, and dedicated control channel (DCCH) is a point-to-point bi-directional logical channel that transmits dedicated control information between a UE and the network and used by UEs having an RRC connection. Dedicated traffic channel (DTCH) is a point-to-point logical channel, dedicated to one UE, for the transfer of user information. A DTCH can exist in both uplink and downlink. In downlink, the following connections between logical channels and transport channels exist: BCCH can be mapped to broadcast channel (BCH); BCCH can be mapped to downlink shared channel (DL-SCH); PCCH can be mapped to paging channel (PCH); CCCH can be mapped to DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped to DL-SCH. In uplink, the following connections between logical channels and transport channels exist: CCCH can be mapped to uplink shared channel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mapped to UL-SCH.
The RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged node (AM). The RLC configuration is per logical channel with no dependency on numerologies and/or transmission durations. In the 3GPP NR system, the main services and functions of the RLC sublayer depend on the transmission mode and include: transfer of upper layer PDUs; sequence numbering independent of the one in PDCP (UM and AM); error correction through ARQ (AM only); segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs; reassembly of SDU (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC re-establishment; protocol error detection (AM only).
In the 3GPP NR system, the main services and functions of the PDCP sublayer for the user plane include: sequence numbering; header compression and decompression using robust header compression (ROHC); transfer of user data; reordering and duplicate detection; in-order delivery; PDCP PDU routing (in case of split bearers); retransmission of PDCP SDUs; ciphering, deciphering and integrity protection; PDCP SDU discard; PDCP re-establishment and data recovery for RLC AM; PDCP status reporting for RLC AM; duplication of PDCP PDUs and duplicate discard indication to lower layers. The main services and functions of the PDCP sublayer for the control plane include: sequence numbering; ciphering, deciphering and integrity protection; transfer of control plane data; reordering and duplicate detection; in-order delivery; duplication of PDCP PDUs and duplicate discard indication to lower layers.
In the 3GPP NR system, the main services and functions of SDAP include: mapping between a QoS flow and a data radio bearer; marking QoS flow ID (QFI) in both DL and UL packets. A single protocol entity of SDAP is configured for each individual PDU session.
In the 3GPP NR system, the main services and functions of the RRC sublayer include: broadcast of system information related to AS and NAS; paging initiated by 5GC or NG-RAN; establishment, maintenance and release of an RRC connection between the UE and NG-RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including: handover and context transfer, UE cell selection and reselection and control of cell selection and reselection, inter-RAT mobility); QoS management functions; UE measurement reporting and control of the reporting; detection of and recovery from radio link failure; NAS message transfer to/from NAS from/to UE.
FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.
The frame structure shown in FIG. 6 is purely exemplary and the number of subframes, the number of slots, and/or the number of symbols in a frame may be variously changed. In the 3GPP based wireless communication system, OFDM numerologies (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) may be differently configured between a plurality of cells aggregated for one UE. For example, if a UE is configured with different SCSs for cells aggregated for the cell, an (absolute time) duration of a time resource (e.g., a subframe, a slot, or a TTI) including the same number of symbols may be different among the aggregated cells. Herein, symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols).
Referring to FIG. 6, downlink and uplink transmissions are organized into frames. Each frame has Tf = 10ms duration. Each frame is divided into two half-frames, where each of the half-frames has 5ms duration. Each half-frame consists of 5 subframes, where the duration Tsf per subframe is 1ms. Each subframe is divided into slots and the number of slots in a subframe depends on a subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on a cyclic prefix (CP). In a normal CP, each slot includes 14 OFDM symbols and, in an extended CP, each slot includes 12 OFDM symbols. The numerology is based on exponentially scalable subcarrier spacing βf = 2u*15 kHz.
Table 3 shows the number of OFDM symbols per slot Nslot symb, the number of slots per frame Nframe,u slot, and the number of slots per subframe Nsubframe,u slot for the normal CP, according to the subcarrier spacing βf = 2u*15 kHz.
u Nslot symb Nframe,u slot Nsubframe,u slot
0 14 10 1
1 14 20 2
2 14 40 4
3 14 80 8
4 14 160 16
Table 4 shows the number of OFDM symbols per slot Nslot symb, the number of slots per frame Nframe,u slot, and the number of slots per subframe Nsubframe,u slot for the extended CP, according to the subcarrier spacing βf = 2u*15 kHz.
u Nslot symb Nframe,u slot Nsubframe,u slot
2 12 40 4
A slot includes plural symbols (e.g., 14 or 12 symbols) in the time domain. For each numerology (e.g., subcarrier spacing) and carrier, a resource grid of Nsize,u grid,x*NRB sc subcarriers and Nsubframe,u symb OFDM symbols is defined, starting at common resource block (CRB) Nstart,u grid indicated by higher-layer signaling (e.g., RRC signaling), where Nsize,u grid,x is the number of resource blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink. NRB sc is the number of subcarriers per RB. In the 3GPP based wireless communication system, NRB sc is 12 generally. There is one resource grid for a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL). The carrier bandwidth Nsize,u grid for subcarrier spacing configuration u is given by the higher-layer parameter (e.g., RRC parameter). Each element in the resource grid for the antenna port p and the subcarrier spacing configuration u is referred to as a resource element (RE) and one complex symbol may be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l representing a symbol location relative to a reference point in the time domain. In the 3GPP based wireless communication system, an RB is defined by 12 consecutive subcarriers in the frequency domain. As shown in FIG. 6, as SCS doubles, the slot length and symbol length are halved. For example, when SCS is 15kHz, the slot length is 1ms, which is the same as the subframe length. When SCS is 30kHz, the slot length is 0.5ms (=500us), and the symbol length is half of that when the SCS is 15kHz. When SCS is 60kHz, the slot length is 0.25ms (=250us), and the symbol length is half of that when the SCS is 30kHz. When SCS is 120kHz, the slot length is 0.125ms (=125us), and the symbol length is half of that when the SCS is 60kHz. When SCS is 240kHz, the slot length is 0.0625ms (=62.5us), and the symbol length is half of that when the SCS is 120kHz.
In the 3GPP NR system, RBs are classified into CRBs and physical resource blocks (PRBs). CRBs are numbered from 0 and upwards in the frequency domain for subcarrier spacing configuration u. The center of subcarrier 0 of CRB 0 for subcarrier spacing configuration u coincides with 'point A' which serves as a common reference point for resource block grids. In the 3GPP NR system, PRBs are defined within a bandwidth part (BWP) and numbered from 0 to Nsize BWP,i-1, where i is the number of the bandwidth part. The relation between the physical resource block nPRB in the bandwidth part i and the common resource block nCRB is as follows: nPRB = nCRB + Nsize BWP,i, where Nsize BWP,i is the common resource block where bandwidth part starts relative to CRB 0. The BWP includes a plurality of consecutive RBs. A carrier may include a maximum of N (e.g., 5) BWPs. A UE may be configured with one or more BWPs on a given component carrier. Only one BWP among BWPs configured to the UE can active at a time. The active BWP defines the UE's operating bandwidth within the cell's operating bandwidth.
In the present disclosure, the term "cell" may refer to a geographic area to which one or more nodes provide a communication system, or refer to radio resources. A "cell" as a geographic area may be understood as coverage within which a node can provide service using a carrier and a "cell" as radio resources (e.g., time-frequency resources) is associated with bandwidth which is a frequency range configured by the carrier. The "cell" associated with the radio resources is defined by a combination of downlink resources and uplink resources, for example, a combination of a DL component carrier (CC) and a UL CC. The cell may be configured by downlink resources only, or may be configured by downlink resources and uplink resources. Since DL coverage, which is a range within which the node is capable of transmitting a valid signal, and UL coverage, which is a range within which the node is capable of receiving the valid signal from the UE, depends upon a carrier carrying the signal, the coverage of the node may be associated with coverage of the "cell" of radio resources used by the node. Accordingly, the term "cell" may be used to represent service coverage of the node sometimes, radio resources at other times, or a range that signals using the radio resources can reach with valid strength at other times.
In CA, two or more CCs are aggregated. A UE may simultaneously receive or transmit on one or multiple CCs depending on its capabilities. CA is supported for both contiguous and non-contiguous CCs. When CA is configured, the UE only has one RRC connection with the network. At RRC connection establishment/re-establishment/handover, one serving cell provides the NAS mobility information, and at RRC connection re-establishment/handover, one serving cell provides the security input. This cell is referred to as the primary cell (PCell). The PCell is a cell, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure. Depending on UE capabilities, secondary cells (SCells) can be configured to form together with the PCell a set of serving cells. An SCell is a cell providing additional radio resources on top of special cell (SpCell). The configured set of serving cells for a UE therefore always consists of one PCell and one or more SCells. For dual connectivity (DC) operation, the term SpCell refers to the PCell of the master cell group (MCG) or the primary SCell (PSCell) of the secondary cell group (SCG). An SpCell supports PUCCH transmission and contention-based random access, and is always activated. The MCG is a group of serving cells associated with a master node, comprised of the SpCell (PCell) and optionally one or more SCells. The SCG is the subset of serving cells associated with a secondary node, comprised of the PSCell and zero or more SCells, for a UE configured with DC. For a UE in RRC_CONNECTED not configured with CA/DC, there is only one serving cell comprised of the PCell. For a UE in RRC_CONNECTED configured with CA/DC, the term "serving cells" is used to denote the set of cells comprised of the SpCell(s) and all SCells. In DC, two MAC entities are configured in a UE: one for the MCG and one for the SCG.
FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.
Referring to FIG. 7, "RB" denotes a radio bearer, and "H" denotes a header. Radio bearers are categorized into two groups: DRBs for user plane data and SRBs for control plane data. The MAC PDU is transmitted/received using radio resources through the PHY layer to/from an external device. The MAC PDU arrives to the PHY layer in the form of a transport block.
In the PHY layer, the uplink transport channels UL-SCH and RACH are mapped to their physical channels physical uplink shared channel (PUSCH) and physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to physical downlink shared channel (PDSCH), physical broadcast channel (PBCH) and PDSCH, respectively. In the PHY layer, uplink control information (UCI) is mapped to physical uplink control channel (PUCCH), and downlink control information (DCI) is mapped to physical downlink control channel (PDCCH). A MAC PDU related to UL-SCH is transmitted by a UE via a PUSCH based on an UL grant, and a MAC PDU related to DL-SCH is transmitted by a BS via a PDSCH based on a DL assignment.
In wireless communications, UE may perform a mobility from a source cell to a target cell, in a connected state (i.e., RRC_CONNECTED) or a non-connected state (i.e., RRC_IDLE/RRC_INACTIVE). Mobility in a connected state may comprise a network-controlled mobility and/or a UE-based mobility (i.e., conditional mobility). The network-controlled mobility may comprise a handover (i.e., PCell change), secondary node (SN) addition (i.e., PSCell addition) and/or SN change (i.e., PSCell change). The conditional mobility may comprise a conditional handover (CHO) (i.e., conditional PCell change), a conditional SN addition (i.e., conditional PSCell addition, CPA) and/or a conditional SN change (i.e., conditional PSCell change, CPC). Mobility in a non-connected state may comprise cell selection and/or cell reselection.
Hereinafter, cell selection/reselection is described.
I. Cell selection criterion
The cell selection criterion S is fulfilled when Srxlev > 0 and Squal > 0. Herein, Srxlev = Qrxlevmeas - (Qrxlevmin + Qrxlevminoffset )- Pcompensation - Qoffsettemp, and Squal = Qqualmeas - (Qqualmin + Qqualminoffset) - Qoffsettemp. Parameters are defined as table 5:
Srxlev Cell selection RX level value (dB)
Squal Cell selection quality value (dB)
Qoffsettemp Offset temporarily applied to a cell as specified in TS 38.331 [3] (dB)
Qrxlevmeas Measured cell RX level value (RSRP)
Qqualmeas Measured cell quality value (RSRQ)
Qrxlevmin Minimum required RX level in the cell (dBm). If the UE supports SUL frequency for this cell, Qrxlevmin is obtained from q-RxLevMinSUL, if present, in SIB1, SIB2 and SIB4, additionally, if QrxlevminoffsetcellSUL is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell;
else Qrxlevmin is obtained from q-RxLevMin in SIB1, SIB2 and SIB4, additionally, if Qrxlevminoffsetcell is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell.
Qqualmin Minimum required quality level in the cell (dB). Additionally, if Qqualminoffsetcell is signalled for the concerned cell, this cell specific offset is added to achieve the required minimum quality level in the concerned cell.
Qrxlevminoffset Offset to the signalled Qrxlevmin taken into account in the Srxlev evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN, as specified in TS 23.122 [9].
Qqualminoffset Offset to the signalled Qqualmin taken into account in the Squal evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN, as specified in TS 23.122 [9].
Pcompensation For FR1, if the UE supports the additionalPmax in the NR-NS-PmaxList, if present, in SIB1, SIB2 and SIB4:
max(PEMAX1 -PPowerClass, 0) - (min(PEMAX2, PPowerClass) - min(PEMAX1, PPowerClass)) (dB);
else:
max(PEMAX1 -PPowerClass, 0) (dB)

For FR2, Pcompensation is set to 0.
For IAB-MT, Pcompensation is set to 0.
PEMAX1, PEMAX2 Maximum TX power level of a UE may use when transmitting on the uplink in the cell (dBm) defined as PEMAX in TS 38.101 [15]. If UE supports SUL frequency for this cell, PEMAX1 and PEMAX2 are obtained from the p-Max for SUL in SIB1 and NR-NS-PmaxList for SUL respectively in SIB1, SIB2 and SIB4 as specified in TS 38.331 [3], else PEMAX1 and PEMAX2 are obtained from the p-Max and NR-NS-PmaxList respectively in SIB1, SIB2 and SIB4 for normal UL as specified in TS 38.331 [3].
PPowerClass Maximum RF output power of the UE (dBm) according to the UE power class as defined in TS 38.101-1 [15].
The signalled values Qrxlevminoffset and Qqualminoffset are only applied when a cell is evaluated for cell selection as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN. During this periodic search for higher priority PLMN, the UE may check the S criteria of a cell using parameter values stored from a different cell of this higher priority PLMN.
II. Reselection priorities handling
Absolute priorities of different NR frequencies or inter-RAT frequencies may be provided to the UE in the system information, in the RRCRelease message, or by inheriting from another RAT at inter-RAT cell (re)selection. In the case of system information, an NR frequency or inter-RAT frequency may be listed without providing a priority (i.e., the field cellReselectionPriority is absent for that frequency). If any fields with cellReselectionPriority are provided in dedicated signalling, the UE shall ignore any fields with cellReselectionPriority and any slice reselection information provided in system information. If slice reselection information is provided in dedicated signaling, the UE shall ignore slice reselection information provided in system information.
In some implementations, information provided in RRCRelease may override information provided in SIB. This may include slice-specific re-selection information, existing/legacy cellResleectionPriority.
In some implementations, "PCI-lists" may be provided in RRCRelease.
If UE is in camped normally state and UE supports slice-based cell reselection, UE shall derive re-selection priorities.
If UE is in camped on any cell state, UE shall only apply the priorities provided by system information from current cell, and the UE preserves priorities provided by dedicated signalling and deprioritisationReq received in RRCRelease unless specified otherwise. When the UE in camped normally state, has only dedicated priorities other than for the current frequency, the UE shall consider the current frequency to be the lowest priority frequency (i.e. lower than any of the network configured values). When the HSDN capable UE is in High-mobility state, the UE shall always consider the HSDN cells to be the highest priority (i.e., higher than any other network configured priorities). When the HSDN capable UE is not in High-mobility state, the UE shall always consider HSDN cells to be the lowest priority (i.e., lower than any other network configured priorities). If the UE is configured to perform both NR sidelink communication and V2X sidelink communication, the UE may consider the frequency providing both NR sidelink communication configuration and V2X sidelink communication configuration to be the highest priority. If the UE is configured to perform NR sidelink communication and not perform V2X communication, the UE may consider the frequency providing NR sidelink communication configuration to be the highest priority. If the UE is configured to perform V2X sidelink communication and not perform NR sidelink communication, the UE may consider the frequency providing V2X sidelink communication configuration to be the highest priority.
The frequency only providing the anchor frequency configuration should not be prioritized for V2X service during cell reselection.
When UE is configured to perform NR sidelink communication or V2X sidelink communication performs cell reselection, it may consider the frequencies providing the intra-carrier and inter-carrier configuration have equal priority in cell reselection.
The prioritization among the frequencies which UE considers to be the highest priority frequency is left to UE implementation.
The UE is configured to perform V2X sidelink communication or NR sidelink communication, if it has the capability and is authorized for the corresponding sidelink operation.
When UE is configured to perform both NR sidelink communication and V2X sidelink communication, but cannot find a frequency which can provide both NR sidelink communication configuration and V2X sidelink communication configuration, UE may consider the frequency providing either NR sidelink communication configuration or V2X sidelink communication configuration to be the highest priority.
The UE is configured with either dedicated cell reselection priorities or slice or slice group specific frequency priorities in the RRCRelease message.
The UE shall only perform cell reselection evaluation for NR frequencies and inter-RAT frequencies that are given in system information and for which the UE has a priority provided.
If the MBS broadcast capable UE is receiving or interested to receive an MBS broadcast service(s) and can only receive this MBS broadcast service(s) by camping on a frequency on which it is provided, the UE may consider that frequency to be the highest priority during the MBS broadcast session as long as the two following conditions are fulfilled:
1) The cell reselected by the UE due to frequency prioritization for MBS is providing SIB20;
2) Either:
- One or more MBS FSAI(s) of that frequency is indicated in SIB21 of the serving cell and the same MBS FSAI(s) is also indicated for this MBS broadcast service in MBS User Service Description (USD), or
- SIB21 is not provided in the serving cell and that frequency is included in the USD of this service, or
- SIB21 is provided in the serving cell but does not provide the frequency mapping for the concerned service, and that frequency is included in the USD of this service.
It is up to UE implementation how to use information in USD to determine whether/how to do the frequency prioritization for specific frequency/frequencies included in USD.
If the MBS broadcast capable UE is receiving or interested to receive an MBS broadcast service(s), the UE may consider cell reselection candidate frequencies at which it can not receive the MBS broadcast service to be of the lowest priority during the MBS broadcast session as specified in TS 38.300 [2], as long as the SIB20 is provided by the cell on the MBS frequency which the UE monitors and as long as the condition 2) above is fulfilled for the serving cell.
In case UE receives RRCRelease with deprioritisationReq, UE shall consider current frequency and stored frequencies due to the previously received RRCRelease with deprioritisationReq or all the frequencies of NR to be the lowest priority frequency (i.e. lower than any of the network configured values) while T325 is running irrespective of camped RAT. The UE shall delete the stored deprioritisation request(s) when a PLMN selection or SNPN selection is performed on request by NAS.
UE should search for a higher priority layer for cell reselection as soon as possible after the change of priority. The minimum related performance requirements are still applicable.
The UE shall delete priorities provided by dedicated signalling when:
- the UE enters a different RRC state; or
- the optional validity time of dedicated priorities (T320) expires; or
- the UE receives an RRCRelease message with the field cellReselectionPriorities absent; or
- a PLMN selection or SNPN selection is performed on request by NAS.
The UE shall not consider any exclude-listed cells as candidate for cell reselection.
The UE shall consider only the allow-listed cells, if configured, as candidates for cell reselection.
The UE in RRC_IDLE state shall inherit the priorities provided by dedicated signalling and the remaining validity time (i.e. T320 in NR and E-UTRA), if configured, at inter-RAT cell (re)selection.
The network may assign dedicated cell reselection priorities for frequencies not configured by system information.
III. Inter-frequency and inter-RAT Cell Reselection criteria
If threshServingLowQ is broadcast in system information and more than 1 second has elapsed since the UE camped on the current serving cell, cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if a cell of a higher priority NR or EUTRAN RAT/frequency fulfils Squal > ThreshX, HighQ during a time interval TreselectionRAT.
Otherwise, cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if i) a cell of a higher priority RAT/ frequency fulfils Srxlev > ThreshX, HighP during a time interval TreselectionRAT; and ii) more than 1 second has elapsed since the UE camped on the current serving cell.
Cell reselection to a cell on an equal priority NR frequency shall be based on ranking for intra-frequency cell reselection.
If threshServingLowQ is broadcast in system information and more than 1 second has elapsed since the UE camped on the current serving cell, cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if the serving cell fulfils Squal < ThreshServing, LowQ and a cell of a lower priority NR or E-UTRAN RAT/ frequency fulfils Squal > ThreshX, LowQ during a time interval TreselectionRAT.
Otherwise, cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if i) the serving cell fulfils Srxlev < ThreshServing, LowP and a cell of a lower priority RAT/ frequency fulfils Srxlev > ThreshX, LowP during a time interval TreselectionRAT; and ii) more than 1 second has elapsed since the UE camped on the current serving cell.
For a UE performing slice-based cell reselection if a cell fulfils the above criteria for cell reselection based on re-selection priority for the frequency and slice group, but this cell does not support the slice group, the UE shall re-derive a re-selection priority for the frequency by considering the slice group(s) supported by this cell (rather than those of the corresponding NR frequency). This reselection priority shall be used until the highest ranked cell changes on the frequency, or new slice or slice group priorities are received from NAS. UE shall ensure the cell reselection criteria above are fulfilled based on the newly derived priorities.
Cell reselection to a higher priority RAT/frequency shall take precedence over a lower priority RAT/frequency if multiple cells of different priorities fulfil the cell reselection criteria.
If more than one cell meets the above criteria, the UE shall reselect a cell if the highest-priority frequency is an NR frequency, the highest ranked cell among the cells on the highest priority frequency(ies) meeting the criteria according to clause; and/or if the highest-priority frequency is from another RAT, the strongest cell among the cells on the highest priority frequency(ies) meeting the criteria of that RAT.
IV. Intra-frequency and equal priority inter-frequency Cell Reselection criteria
The cell-ranking criterion Rs for serving cell and Rn for neighbouring cells is defined by: Rs = Qmeas,s +Qhyst - Qoffsettemp; and Rn = Qmeas,n -Qoffset - Qoffsettemp. Parameters are defined as table 6:
Qmeas RSRP measurement quantity used in cell reselections.
Qoffset For intra-frequency: Equals to Qoffsets,n, if Qoffsets,n is valid, otherwise this equals to zero.For inter-frequency: Equals to Qoffsets,n plus Qoffsetfrequency, if Qoffsets,n is valid, otherwise this equals to Qoffsetfrequency.
Qoffsettemp Offset temporarily applied to a cell.
The UE shall perform ranking of all cells that fulfil the cell selection criterion S.The cells shall be ranked according to the R criteria specified above by deriving Qmeas,n and Qmeas,s and calculating the R values using averaged RSRP results.
If rangeToBestCell is not configured, the UE shall perform cell reselection to the highest ranked cell. If this cell is found to be not-suitable, the UE shall not consider this cell and, for operation in licensed spectrum, other cells on the same frequency as candidates for reselection for a maximum of 300 seconds.
If rangeToBestCell is configured, then the UE shall perform cell reselection to the cell with the highest number of beams above the threshold (i.e. absThreshSS-BlocksConsolidation) among the cells whose R value is within rangeToBestCell of the R value of the highest ranked cell. In the present disclosure, "beam above threshold" may be referred to as good beam. If there are multiple such cells, the UE shall perform cell reselection to the highest ranked cell among them. If this cell is found to be not-suitable, the UE shall not consider this cell and, for operation in licensed spectrum, other cells on the same frequency as candidates for reselection for a maximum of 300 seconds.
In all cases, the UE shall reselect the new cell, only if i) the new cell is better than the serving cell according to the cell reselection criteria specified above during a time interval TreselectionRAT; and/or ii) more than 1 second has elapsed since the UE camped on the current serving cell.
If rangeToBestCell is configured but absThreshSS-BlocksConsolidation is not configured on an NR frequency, the UE considers that there is one beam above the threshold for each cell on that frequency.
FIG. 8 shows an example of a conditional handover procedure to which technical features of the present disclosure can be applied. In the present disclosure, the conditional handover procedure as shown in FIG. 8 may also be applied to other conditional mobility procedures i.e., CPA procedure and/or CPC procedure.
Referring to FIG. 8, in step S801, the source cell may transmit measurement control message to the UE. The measurement control message may comprise a measurement configuration including a list of measurement configurations, and each measurement configuration in the list includes a measurement identity (ID), the corresponding measurement object and the corresponding report configuration.
In step S803, the UE may transmit a measurement report message to the source cell. The measurement report message may comprise a result of measurement on neighbor cell(s) around the UE which can be detected by the UE. The UE may generate the measurement report message according to a measurement configuration and/or measurement control information in the measurement control message received in step S801.
In step S805, the source cell may make a handover decision based on the measurement report. For example, the source cell may make a handover decision and determine candidate target cells (e.g., target cell 1 and target cell 2) for handover among neighbor cells around the UE based on a result of measurement (e.g., signal quality, reference signal received power (RSRP), reference signal received quality (RSRP)) on the neighbor cells.
In step S807, the source cell may transmit handover request messages to the target cell 1 and the target cell 2 which are determined in step S805. That is, the source cell may perform handover preparation with the target cell 1 and the target cell 2. The handover request message may comprise necessary information to prepare the handover at the target side (e.g., target cell 1 and target cell 2).
In step S809, each of the target cell 1 and the target cell 2 may perform an admission control based on information included in the handover request message. The target cell may configure and reserve the required resources (e.g., C-RNTI and/or RACH preamble). The AS-configuration to be used in the target cell can either be specified independently (i.e. an "establishment") or as a delta compared to the AS-configuration used in the source cell (i.e. a "reconfiguration").
In step S811, the target cell and the target cell 2 may transmit a handover request acknowledge (ACK) message to the source cell. The handover request ACK message may comprise cell configuration (i.e., RRCReconfiguration message including ReconfigurationWithSync) including information on resources reserved and prepared for a handover. For example, the handover request ACK message may comprise a transparent container to be sent to the UE as an RRC message (i.e., RRCReconfiguration message/cell configuration) to perform the handover. The container/cell configuration/RRCReconfiguration message may include information required to access the target cell (i.e., access configuration) comprising at least one of a physical cell ID of the target cell, identifier of the UE (i.e., C-RNTI), HO validity timer (i.e., T304 timer), the target gNB security algorithm identifiers for the selected security algorithms, a set of dedicated RACH resources for contention-free random access (e.g., dedicated random access preamble), the association between RACH resources and SSB(s), the association between RACH resources and UE-specific CSI-RS configuration(s), common RACH resources, or system information of the target cell. If RACH-less handover is configured, the container may include timing adjustment indication and optionally a pre-allocated uplink grant. The handover request ACK message may also include RNL/TNL information for forwarding tunnels, if necessary. As soon as the source cell receives the handover request ACK message, or as soon as the transmission of the conditional handover command is initiated in the downlink, data forwarding may be initiated.
In step S813, the source cell may transmit a RRCReconfiguration message including a conditional reconfiguration to the UE. The conditional reconfiguration may be also referred to as (or, may comprise) conditional handover (CHO) configuration and/or a conditional handover command (e.g., CHO command). The conditional reconfiguration may comprise a list of conditional reconfigurations/conditional handover commands, including a conditional reconfiguration/conditional handover command for each of the candidate target cells (e.g., target cell 1, target cell 2). For example, the conditional reconfiguration may comprise a conditional reconfiguration/conditional handover command for the target cell 1, and a conditional reconfiguration/conditional handover command for the target cell 2. The conditional reconfiguration for a target cell may comprise an index/identifier identifying the corresponding conditional reconfiguration, a handover condition (or, execution condition for conditional mobility/handover) for the target cell, and/or a cell configuration (i.e., RRCReconfiguration message including the reconfigurationWithSync) for the target cell. The RRCReconfiguration message and/or reconfigurationWithSync for the target cell may comprise information required to access the target cell comprising at least one of a physical cell ID of the target cell, identifier of the UE (i.e., C-RNTI), HO validity timer (i.e., T304 timer), the target gNB security algorithm identifiers for the selected security algorithms, a set of dedicated RACH resources for contention-free random access (e.g., dedicated random access preamble), the association between RACH resources and SSB(s), the association between RACH resources and UE-specific CSI-RS configuration(s), common RACH resources, or system information of the target cell.
In step S815, the UE may perform an evaluation of the handover condition for the candidate target cells (e.g., target cell 1, target cell 2) and select a target cell for a handover among the candidate target cells. For example, the UE may perform measurements on the candidate target cells, and determine whether a candidate target cell fulfils a handover condition for the candidate target cell among the candidate target cells based on a result of the measurements on the candidate target cells. Or, the UE may determine whether the target cell/measurement result for the target cell fulfils the handover condition of the target cell. If the UE identifies that the target cell 1 fulfils a handover condition for the target cell 1, the UE may select the target cell 1 as a target cell for the handover.
In step S817, the UE may detach from the old cell i.e., the source cell and synchronize to a new cell i.e., the selected target cell. The UE may perform a handover from the source cell to the target cell based on applying the cell configuration. For example, upon receiving the handover command, the UE may start the T304 timer, and perform a contention-free random access towards the target cell based on the set of dedicated RACH resources.
In step S819, upon successful completion of the random access procedure, the UE may stop the T304 timer, and transmit a handover complete message (i.e., RRCReconfigurationComplete message) to the target cell. The UE may send the RRCReconfigurationComplete message comprising the C-RNTI to confirm the handover, to the target cell to indicate that the handover procedure is completed for the UE. The target RAN node may verify the C-RNTI sent in the RRCReconfigurationComplete message. The target RAN node can now begin sending data to the UE. When the random access fails and the T304 timer is still running, the UE may retry random access towards the target cell. Upon expiry of the T304 timer, the UE may declare handover failure (HOF) and perform an RRC re-establishment procedure.
Hereinafter, contents regarding network energy saving (NES) are described.
The aim of NES function is to reduce operational expenses through energy savings.
The NES function allows, for example in a deployment where capacity boosters can be distinguished from cells providing basic coverage, to optimize energy consumption enabling the possibility for an E-UTRA or NR cell providing additional capacity via single or dual connectivity, to be switched off when its capacity is no longer needed and to be re-activated on a need basis, and other various techniques in time, frequency, spatial and power domains.
The intra-system energy saving solution builds upon the possibility for the NG-RAN node owning a capacity booster cell to autonomously decide to switch-off such cell to lower energy consumption (inactive state). The decision is typically based on cell load information, consistently with configured information. The switch-off decision may also be taken by operation and maintenance (O&M).
The NG-RAN node may initiate handover actions in order to off-load the cell being switched off and may indicate the reason for handover with an appropriate cause value to support the target node in taking subsequent actions, e.g. when selecting the target cell for subsequent handovers.
All neighbour NG-RAN nodes are informed by the NG-RAN node owning the concerned cell about the switch-off actions over the Xn interface, by means of the NG-RAN node Configuration Update procedure.
All informed nodes maintain the cell configuration data, e.g., neighbour relationship configuration, also when a certain cell is inactive. If basic coverage is ensured by NG-RAN node cells, NG-RAN node owning non-capacity boosting cells may request a re-activation over the Xn interface if capacity needs in such cells demand to do so. This is achieved via the Cell Activation procedure. During switch off time period of the boost cell, the NG-RAN node may prevent idle mode UEs from camping on this cell and may prevent incoming handovers to the same cell.
The NG-RAN node receiving a request should act accordingly. The switch-on decision may also be taken by O&M. All peer NG-RAN nodes are informed by the NG-RAN node owning the concerned cell about the re-activation by an indication on the Xn interface.
The inter-system energy saving solution builds upon the possibility for the NG-RAN node owning a capacity booster cell to autonomously decide to switch-off such cell to dormant state. The decision is typically based on cell load information, consistently with configured information. The switch-off decision may also be taken by O&M. The NG-RAN node indicates the switch-off action to the eNB over NG interface and S1 interface. The NG-RAN node could also indicate the switch-on action to the eNB over NG interface and S1 interface.
The eNB providing basic coverage may request a NG-RAN node's cell re-activation based on its own cell load information or neighbour cell load information, the switch-on decision may also be taken by O&M. The eNB requests a NG-RAN node's cell re-activation and receives the NG-RAN node's cell re-activation reply from the NG-RAN node over the S1 interface and NG interface. Upon reception of the re-activation request, the NG-RAN node's cell should remain switched on at least until expiration of the minimum activation time. The minimum activation time may be configured by O&M or be left to the NG-RAN node's implementation.
To facilitate reducing gNB downlink transmission/uplink reception activity time, UE can be configured with a periodic cell discontinuous transmission (DTX)/discontinuous reception (DRX) pattern (i.e., active and non-active periods). The pattern configuration for cell DTX/DRX is common for the UEs configured with this feature in the cell. The cell DTX and cell DRX patterns can be configured and activated separately. When cell DTX is configured and activated for the concerned cell, the UE does not monitor PDCCH in selected cases or SPS occasions during cell DTX non-active duration. When cell DRX is configured and activated for the concerned cell, the UE does not transmit on CG resources or transmit a SR during cell DRX non-active duration. This feature is only applicable to UEs in RRC_CONNECTED state and it does not impact Random Access procedure, SSB transmission, paging, and system information broadcasting. Cell DTX/DRX can be activated/deactivated by RRC signalling or L1 group common signalling. Cell DTX/DRX is characterized by the following:
- active duration: duration that the UE waits for to receive PDCCHs or SPS occasions, and transmit SR or CG. In this duration, the gNB transmission/reception of PDCCH, SPS, SR and CG, are not impacted for the purpose of network energy saving;
- cycle: specifies the periodic repetition of the active-duration followed by a period of non-active duration;
Active duration and cycle parameters are common between cell DTX and cell DRX, when both are configured.
Once the gNB recognizes there is an emergency call or public safety related service (e.g. MPS or MCS), the network should ensure that there is no impact to that service (e.g. it may release or deactivate cell DTX/DRX configuration). The network should also ensure that there is at least partial overlapping between UE's connected mode DRX on-duration and cell DTX/DRX active duration, i.e. the UE's connected mode DRX periodicity is a multiple of cell DTX/DRX periodicity or vice versa.
The access of NES capable UEs to a cell is controlled by a single bit in SIB1 (if present), otherwise the barring mechanisms apply.
In the present disclosure, there may be various cell states including non-NES state (or, NES_off state), cell DTX/DRX state (a sub-state of NES state), and/or a cell turning-off (or, switch-off) state (a sub-state of NES state).
The non-NES state is a state in which i) UE is not configured with a cell DTX/DRX configuration, or ii) UE is configured with the cell DTX/DRX configuration, but cell DTX/DRX is not activated. In the non-NES state, all duration is an active duration.
The cell DTX/DRX state is a state in which UE is configured with a cell DTX/DRX configuration, and cell DTX/DRX is activated. In the cell DTX/DRX state, a cycle of the active duration and a non-active duration is periodically repeated.
The cell turning-off state is a state in which all duration is the non-active duration. While a cell is in the cell turning-off state, UE in an idle mode is not allowed to camp on the cell, and UE is not allowed to perform a mobility to the cell.
In the active duration:
- UE may monitor PDCCH and/or semi-persistent scheduling (SPS) occasions (i.e., cell DTX active duration); and/or
- UE may transmit on configured grant (CG) resources, and/or transmit a scheduling request (SR) (i.e., cell DRX active duration).
In the non-active duration:
- UE does not monitor PDCCH and/or SPS occasions (i.e., cell DTX non-active duration); and/or
- UE does not transmit on CG resources, and/or does not transmit SR (i.e., cell DRX non-active duration).
Meanwhile, a cell may enter its operation state to save its energy consumption. For example, a cell may enter NES state. There may be various cell states including non-NES state and NES states that are sub-states in NES state. When a cell changes its sub-state, its acceptance level of UEs' camping may be different. So, it is desirable to adjust reselection parameters/execution conditions for conditional mobility depending on cell's (sub-)state. Furthermore, network may want to randomize cell reselection adjustments/execution conditions based on cell's (sub-)state.
In addition, once UE receives cell state information, UE should be able to determine when/in which condition the cell state information becomes invalid.
FIG. 9 shows an example of a method performed by a UE according to an embodiment of the present disclosure. The method may also be performed by a wireless device.
Referring to FIG. 9, in step S901, UE may receive information for multiple mobility conditions for a target cell. Each of the multiple mobility conditions may be related to a corresponding cell state among multiple cell states.
In step S903, UE may receive information for at least one cell state among the multiple cell states.
In step S905, UE may evaluate at least one mobility condition related to the at least one cell state among the multiple mobility conditions.
In step S907, based on a mobility condition among the at least one mobility condition being satisfied, UE may perform a mobility to the target cell.
According to various embodiments, the information for the multiple mobility conditions may be received via a radio resource control (RRC) signalling. The information for the at least one cell state may be received via a media access control (MAC) control element (CE) signalling or downlink control information (DCI).
According to various embodiments, the mobility may comprise a cell reselection. The multiple mobility conditions may comprise a cell reselection condition that: a cell ranking value for the target cell is highest among a cell ranking value for a serving cell and one or more cell ranking values for one or more neighbor cells; or based on the cell ranking value for the target cell belonging to one or more cell ranking values for cells within a threshold range from a highest cell ranking value, a number of good beams of the target cell is highest among the cells.
According to various embodiments, the mobility may comprise a conditional mobility. The multiple mobility conditions may comprise execution conditions for the conditional mobility. The execution conditions may be related to at least one of a measurement value for the target cell, a measurement value for a serving cell, one or more thresholds, or a time-to-trigger (TTT).
According to various embodiments, the execution conditions may comprise at least one of: an event A2 condition that a measurement value for the serving cell is lower than a source cell threshold; an event A3 condition that a measurement value for the target cell is higher than a measurement value for the serving cell plus offset threshold for at least TTT; an event A4 condition that a measurement value for the target cell is higher than a target cell threshold; or an event A5 condition that a state in which a measurement value for the target cell is higher than a target cell threshold and a measurement value for the serving cell is lower than a source cell threshold lasts for at least TTT.
According to various embodiments, the information for the multiple mobility conditions may comprises: the multiple mobility conditions; and multiple cell state identifiers (IDs) each of which is related to a corresponding mobility condition. UE may identify the at least one mobility condition related to the at least one cell state based on at least one matching cell state ID.
According to various embodiments, the information for the multiple mobility conditions may comprise: multiple offsets; and multiple cell state identifiers (IDs) each of which is related to a corresponding offset. UE may identify at least one offset related to the at least one cell state based on at least one matching cell state ID. UE may determine the at least one mobility condition based on applying the at least one offset to one or more parameters of a reference mobility condition.
According to various embodiments, the at least one mobility condition may be relaxed with respect to the reference mobility condition based on the at least one offset being applied to the one or more parameters. The one or more parameters may comprise at least one of a cell ranking value for the target cell, a cell ranking value for a serving cell, a cell ranking value for at least one neighbor cell other than the target cell, a measurement value for the target cell, a measurement value for the serving cell, an offset threshold, a source cell threshold, a target cell threshold, or a time-to-trigger (TTT).
According to various embodiments, the multiple cell states may comprise a non-network energy saving (NES) state, a first NES state and a second NES state. The first NES state and the second NES state may be sub-states of a NES state.
According to various embodiments, the non-NES state may be a state in which all duration is an active duration. The first NES state may be a state in which a cycle of the active duration and a non-active duration is periodically repeated. The second NES state may be a state in which all duration is the non-active duration.
According to various embodiments, in the active duration: the UE monitors at least one of physical downlink control channel (PDCCH) or semi-persistent scheduling (SPS) occasions; or the UE performs a transmission on configured grant (CG) resources, or transmits a scheduling request (SR). In the non-active duration: the UE does not monitor at least one of PDCCH or SPS occasions; or the UE does not perform a transmission on CG resources, or does not transmit an SR.
According to various embodiments, the at least one cell state may comprise at least one of the first NES state or the second NES state. A mobility condition related to the first NES state may be more relaxed than a reference mobility condition related to the non-NES state. A mobility condition related to the second NES state may be more relaxed than the mobility condition related to the first NES state.
According to various embodiments, the non-NES state may be a non-cell discontinuous transmission (DTX)/discontinuous reception (DRX) state. The first NES state may be a cell DTX/DRX state. The second NES state may be a cell turning-off state.
According to various embodiments, UE may receive configuration including association between cell states and mobility adjustment values. UE may receive state of one or multiple cells. The validity of the received cell state may be related to a timer. UE may measure quality of serving cell and one or more neighbour cells. UE may determine mobility adjustment values for the serving cell and the neighbour cells. The mobility adjustment may be applied only if the cell state is considered valid. UE may perform evaluation of the measured cells by applying the determined mobility adjustment values. UE may access one of the measured cell chosen by the evaluation.
According to various embodiments, UE may receive configuration including association between cell states and mobility adjustment values. UE may receive state of one or multiple cells. The validity of the received cell state may be related to a timer. UE may measure quality of serving cell and one or more neighbour cells. UE may determine mobility adjustment values for the serving cell and the neighbour cells. The mobility adjustment may be applied only if the cell state is considered valid. UE may evaluate ranking of the measured cells by applying the determined reselection adjustment values. UE may perform cell reselection to the best ranked cell.
According to various embodiments, UE may receive a configuration including one or more target cell configurations and mobility conditions associated with at least one of the target cell(s). The execution conditions may be associated with cell states for one of the serving cells or the target cells. UE may receive a lower layer indication including at least one cell state. UE may determine at least one applicable mobility execution condition based on the lower layer indication and validity of the cell state. UE may evaluate the applicable mobility condition. Based on the determined mobility condition being met, UE may access the target cell associated with the mobility condition.
FIG. 10 shows an example of a method performed by a network node according to an embodiment of the present disclosure. The network node may be a source node associated with a serving cell for mobility, and comprise a base station (BS).
Referring to FIG. 10, in step S1001, the network node may transmit, to a UE, information for multiple mobility conditions for a target cell. Each of the multiple mobility conditions may be related to a corresponding cell state among multiple cell states. The information for the multiple mobility conditions may be transmitted via RRC signalling.
In step S1003, the network node may transmit, to the UE, information for at least one cell state among the multiple cell states. The information for the at least one cell state may be transmitted via MAC CE signalling and/or DCI.
In step S1005, UE may evaluate at least one mobility condition related to the at least one cell state among the multiple mobility conditions.
In step S1007, based on a mobility condition among the at least one mobility condition being satisfied, UE may perform a mobility to the target cell.
FIG. 11 shows an example of adjusting reselection parameters depending on cell states according to an embodiment of the present disclosure.
Referring to FIG. 11, in step S1101, UE may receive information for multiple cell reselection conditions for a target cell. The information for the multiple cell reselection conditions may be received via RRC signalling and/or system information block (SIB) broadcast. The information for the multiple cell reselection conditions may comprise the multiple cell reselection conditions, and multiple cell state IDs each of which is related to a corresponding cell reselection condition. If cell state information comprising the information for the multiple cell reselection conditions is configured to UE via RRC signalling and/or SIB broadcast, this step may be omitted.
In step S1103, UE may receive cell state information for a serving cell and/or one or more neighbour cells.
For example, the cell state information may be provided to UE via RRC signalling and/or SIB broadcast. For each frequency, the cell state information may be defined for a list of cells, and comprise the following information elements (IEs) as shown in table 7:
- For serving cell:
(1)Cell state ID
(2)State-specific Qoffset {
1) Qoffset for cell state 1
2) Qoffset for state 2
3) Qoffset for state 3
...}
- For each neighbour cell:
(1)Cell ID (PCI, frequency)
(2)Cell state ID
(3)State-specific Qoffset {
1) Qoffset for cell state 1
2) Qoffset for state 2
3) Qoffset for state 3
...}
In table 7, Qoffsetj is cell and/or state specific offset. Instead of Qoffsetj, state specific Qoffsetj can be configured for a group of neighbour cells. The cell state ID may indicate a cell state among non-NES state and NES states.
For example, the cell state information may be provided to UE via MAC CE and/or DCI. The MAC CE and/or DCI may comprise at least one of:
- Field1: short frequency ID (can be omitted for intra-frequency cells);
- Field2: short cell ID; or
- Field3: cell state ID.
Since MAC CE/DCI can carry limited information, UE may be (pre-)configured with the following association information via dedicated RRC signalling and/or SIB broadcast:
- association between short frequency ID and actual frequency identifier (ARFCN);
- association between short cell ID and actual cell ID (e.g., PCI);
- association between cell state ID and Qffset;
- association between {cell ID, cell state ID} and Qffset; or
- IEs as shown in table 7 above.
That is, when the MAC CE/DCI carrying the cell state information is received in step S1103, the association information may be received via RRC signalling and/or SIB broadcast before step S1103. For example, the association information may be included in the information for the multiple cell reselection conditions received in step S1101.
Once the UE receives the cell state information, the UE may determine whether the cell state information is valid or not. For example, the cell state information is valid within a certain duration, where the duration can be configurable, until it is overridden by a new information for the same cell. For another example, the cell state information is valid until it is overridden by a new information for the same cell.
In step S1105, UE may determine at least one cell reselection condition for the target cell based on the cell state information.
UE may identify at least one cell state/cell state ID informed by the cell state information, and determine the at least one cell reselection condition related to the at least one cell state/cell state ID. For example, UE may determine at least one cell state specific offset (e.g., Qoffset) related to the at least one cell state/cell state ID based on the association information in the information for the multiple cell reselection conditions. The at least one cell state specific offset may comprise a cell state specific offset for a serving cell, and/or one or more cell state specific offsets for one or more neighbour cells. Then, UE may determine the at least one cell reselection condition for the target cell based on applying the at least one cell state specific offset to one or more parameters of a reference cell reselection condition.
For example, a cell reselection condition for the target cell may be a condition that:
i) Rn value for the target cell (e.g., cell ranking value for the target cell) is highest among Rs value for a serving cell (e.g., cell ranking value for the serving cell) and/or one or more Rn' values for one or more neighbour cells (e.g., cell ranking value for neighbour cell); or
ii) when Rn value for the target cell belongs to one or more R values for cells within a threshold range from the highest R value, the number of good beams which the target cell has is highest among the cells.
For example, Rs and Rn may be expressed as:
Rs = Qmeas,s +Qhyst - Qoffsettemp + Qs,j; and
Rn = Qmeas,n -Qoffset - Qoffsettemp+ Qn,j, where
Qs,j: Qoffset for serving cell in NES state j; and
Qn,j : Qoffset for neighbour cell n in NES state j.
If the cell state is unknown or considered invalid, Qx,j may be zero.
For example, Rs and Rn may be expressed as:
Rs = Qmeas,s +Qhyst - Qoffsettemp + Qs,j*Is,j; and
Rn = Qmeas,n -Qoffset - Qoffsettemp+ Qn,j*In,j, where
Qs,j: Qoffset for serving cell in NES state j
Qn,j : Qoffset for neighbour cell n in NES state j
Is,j: indicator function (0 or 1) for applying Qs,j; and
In,j: indicator function (0 or 1) for applying Qn,j.
To determine the indicator function value, UE needs to be preconfigured with Ps,j: and Pn,j via RRC signalling or dynamic signalling. When UE performs cell reselection evaluation, UE draws a random value between 0 and 1 with uniform distribution. If the random value is smaller than Ps,j, Is,j=1, and otherwise 0. If the random value is smaller than Pn,j, In,j=1, and otherwise 0. Instead of cell and state specific Pn,j , state specific Pn,j can be configured for a group of neighbour cells.
For example, Rs and Rn may be expressed as:
Rs = Qmeas,s +Qhyst - Qoffsettemp + Qs,j*Ps,j; and
Rn = Qmeas,n -Qoffset - Qoffsettemp+ Qn,j*Pn,j, where
Qs,j: Qoffset for serving cell in NES state j; and
Qn,j : Qoffset for neighbour cell n in NES state j.
To determine the indicator function value, when UE performs cell reselection evaluation, UE draws a random value between 0 and 1 with uniform distribution and applies the random value as Ps,j and Pn,j. Instead of cell and state specific Pn,j , state specific Pn,j can be configured for a group of neighbour cells.
In the above examples, the cell state specific offset Qs,j is construed as being applied to Rs, Qmeas,s, Qhyst and/or Qoffsettemp. The cell state specific offset Qn,j is construed as being applied to Rn, Qmeas,n, Qoffset and/or Qoffsettemp.
The at least one cell state specific offset may be set to zero when the at least one cell state specific offset is related to a non-NES state (i.e., NES_off state).
For example, NES state = {NES_1, NES_2}, and UE may be configured with the following Qoffsets in the association information included in the information for the multiple cell reselection conditions:
- When serving cell is in NES_1, Qs,1 is +4dB;
- When serving cell is in NES_2, Qs,2 is -4dB;
- When neighbour cell n1 is in NES_1, Qn1,1 is -5 dB;
- When neighbour cell n1 is in NES_2, Qn1,2 is +3 dB;
- When neighbour cell n2 is in NES_1, Qn1,1 is +3 dB; and
- When neighbour cell n2 is NES_2, Qn1,2 is -4 dB.
For example, UE may be notified via MAC CE/DCI about cell (sub)states as follows:
- Field1 = freq1 (intra-frequency);
- Field2 = PCI_n1; and
- Field3 = NES_1.
The following table 8 shows R values (i.e., combination of (Rs, R-n) values) that UE uses for cell reselection:
n1 = NES_1 n1 = NES_2 N2 = NES_1 N2 = NES_2
Serving cell = NES_off Rs = Qmeas,s
Rn1 = Qmeas,n1-5
Rs = Qmeas,s
Rn1 = Qmeas,n1 + 3
Rs = Qmeas,s
Rn2 = Qmeas,n2 + 3
Rs = Qmeas,s
Rn2 = Qmeas,n2 - 4
Serving cell = NES_1 Rs = Qmeas,s + 4 Rn1 = Qmeas,n1-5 Rs = Qmeas,s + 4
Rn1 = Qmeas,n1 + 3
Rs = Qmeas,s + 4
Rn2 = Qmeas,n2 + 3
Rs = Qmeas,s + 4
Rn2 = Qmeas,n2 - 4
Serving cell = NES_2 Rs = Qmeas,s -4 Rn1 = Qmeas,n1-5 Rs = Qmeas,s - 4
Rn1 = Qmeas,n1 + 3
Rs = Qmeas,s - 4
Rn2 = Qmeas,n2 + 3
Rs = Qmeas,s - 4
Rn2 = Qmeas,n2 - 4
For example, the at least one cell state may comprise one or more NES states including cell DTX/DRX state and/or cell turning-off state. In this case, i) a cell reselection condition related to the cell DTX/DRX state is more relaxed than a reference cell reselection condition related to the non-NES state, and ii) a cell reselection condition related to the cell turning-off state is more relaxed than the cell reselection condition related to the cell DTX/DRX state.To relax the at least one cell reselection condition, the at least one cell state specific offset related to the at least one cell state may be applied to one or more parameters of the reference cell reselection condition. For example, the at least one cell state specific offset may be applied to:
- a measurement value for a target cell to increase a cell ranking of the target cell by an increment with respect to a non-NES state, where the increment is higher in the cell-turning off state than in the cell DTX/DRX state; and/or
- a measurement value for a cell other than the target cell to decrease a cell ranking of the cell by an amount with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state.
In step S1107, UE may perform a cell reselection to the target cell based on a cell reselection condition for the target cell being satisfied.
FIG. 12 shows an example of adjusting execution conditions for conditional mobility depending on cell states according to an embodiment of the present disclosure.
Referring to FIG. 12, in step S1201, UE may receive a configuration for one or more candidate target cells for conditional mobility. The configuration may be a conditional mobility command. The configuration may comprise a cell configuration for a target cell, and information for multiple execution conditions for the target cell. The information for the multiple execution conditions may be received via RRC signalling and/or SIB broadcast.
The information for the multiple execution conditions may comprise the multiple execution conditions, and multiple cell state IDs each of which is related to a corresponding execution condition, as shown in table 9:
condExecutionCond1 SEQUENCE {
cellstateID cellstateID / cell state ID related to at least one execution condition /
measIDlist SEQUENCE (SIZE (1...2)) OF MeasID / at least one execution condition determined by CondTriggerConfig in ReportConfig of the corresponding MeasID /
}

condExecutionCond2 SEQUENCE {
cellstateID cellstateID
measIDlist SEQUENCE (SIZE (1...2)) OF MeasID
}

condExecutionCond3 SEQUENCE {
cellstateID cellstateID
measIDlist SEQUENCE (SIZE (1...2)) OF MeasID
}
If cell state information comprising the information for the multiple execution conditions is configured to UE via RRC signalling and/or SIB broadcast, this step may be omitted.In step S1203, UE may receive cell state information for a serving cell and/or one or more neighbour cells.
For example, the cell state information may be provided to UE via RRC signalling and/or SIB broadcast. For each frequency, the cell state information may be defined for a list of cells, and comprise the following information elements (IEs) as shown in table 10:
- For serving cell:
(1)Cell state ID
(2)State-specific Qoffset {
1) Qoffset for cell state 1
2) Qoffset for state 2
3) Qoffset for state 3
...}
- For each neighbour cell:
(1)Cell ID (PCI, frequency)
(2)Cell state ID
(3)State-specific Qoffset {
1) Qoffset for cell state 1
2) Qoffset for state 2
3) Qoffset for state 3
...}
In table 10, Qoffsetj is cell and/or state specific offset. Instead of Qoffsetj, state specific Qoffsetj can be configured for a group of neighbour cells.The cell state ID may indicate a cell state among non-NES state and NES states.
For example, the cell state information may be provided to UE via MAC CE and/or DCI. The MAC CE and/or DCI may comprise at least one of:
- Field1: short frequency ID (can be omitted for intra-frequency cells);
- Field2: short cell ID; or
- Field3: cell state ID.
Since MAC CE/DCI can carry limited information, UE may be (pre-)configured with the following association information via dedicated RRC signalling and/or SIB broadcast:
- association between short frequency ID and actual frequency identifier (ARFCN);
- association between short cell ID and actual cell ID (e.g., PCI);
- association between cell state ID and Qffset;
- association between {cell ID, cell state ID} and Qffset; or
- IEs as shown in table 10 above.
That is, when the MAC CE/DCI carrying the cell state information is received in step S1203, the association information may be received via RRC signalling and/or SIB broadcast before step S1203. For example, the association information may be included in the information for the multiple execution conditions received in step S1201.
Once the UE receives the cell state information, the UE may determine whether the cell state information is valid or not. For example, the cell state information is valid within a certain duration, where the duration can be configurable, until it is overridden by a new information for the same cell. For another example, the cell state information is valid until it is overridden by a new information for the same cell.
In step S1205, UE may evaluate mobility execution condition(s) for candidate cell(s). UE may evaluate at least one execution condition related to at least one cell state/cell state ID informed by the cell state information. For example, UE may determine at least one cell state specific offset (e.g., Qoffset) related to the at least one cell state/cell state ID based on the association information in the information for the multiple execution conditions. The at least one cell state specific offset may comprise a cell state specific offset for a serving cell, and/or one or more cell state specific offsets for one or more neighbour cells. Then, UE may determine the at least one execution condition for a target cell based on applying the at least one cell state specific offset to one or more parameters of at least one reference execution condition.
For the evaluation, the UE may determine measurement metrics comprising execution condition metric for serving cell (i.e., serving cell execution condition metric, Rs) and/or one or more execution condition metrics for one or more neighbour cells (i.e., neighbour cell execution condition metric, Rn) as follows:
Rs= Qmeas,s +Qhyst - Qoffsettemp; and
Rn = Qmeas,n -Qoffset - Qoffsettemp.
For example, an execution condition for the target cell may be an event A3 condition that Rn for the target cell is higher than Rs plus offset threshold for at least time-to-trigger (TTT). In this case:
1) Rs and Rn may be expressed as:
Rs= Qmeas,s +Qhyst - Qoffsettemp + Qs,j; and
Rn = Qmeas,n -Qoffset - Qoffsettemp+ Qn,j, where
Qs,j: Qoffset for serving cell in NES state j; and
Qn,j : Qoffset for neighbour cell n in NES state j.
The cell state specific offset Qs,j is construed as being applied to Rs, Qmeas,s, Qhyst and/or Qoffsettemp. The cell state specific offset Qn,j is construed as being applied to Rn, Qmeas,n, Qoffset and/or Qoffsettemp. If the cell state is unknown or considered invalid, Qx,j is zero;
2) at least one cell state specific offset may be applied to the offset threshold; and/or
3) at least one cell state specific offset may be applied to the TTT.
For example, an execution condition for the target cell may be an event A5 condition that a state in which i) Rn for the target cell is higher than a target cell threshold, and ii) Rs is lower than a source cell threshold lasts for at least TTT. In this case:
1) Rs and Rn may be expressed as:
Rs= Qmeas,s +Qhyst - Qoffsettemp + Qs,j; and
Rn = Qmeas,n -Qoffset - Qoffsettemp+ Qn,j, where
Qs,j: Qoffset for serving cell in NES state j; and
Qn,j : Qoffset for neighbour cell n in NES state j.
The cell state specific offset Qs,j is construed as being applied to Rs, Qmeas,s, Qhyst and/or Qoffsettemp. The cell state specific offset Qn,j is construed as being applied to Rn, Qmeas,n, Qoffset and/or Qoffsettemp. If the cell state is unknown or considered invalid, Qx,j is zero;
2) at least one cell state specific offset may be applied to the target cell threshold;
3) at least one cell state specific offset may be applied to the source cell threshold; and/or
4) at least one cell state specific offset may be applied to the TTT.
The at least one cell state specific offset may be set to zero when the at least one cell state specific offset is related to a non-NES state (i.e., NES_off state).
For example, the at least one cell state may comprise one or more NES states including cell DTX/DRX state and/or cell turning-off state. In this case, i) an execution condition related to the cell DTX/DRX state is more relaxed than a reference execution condition related to the non-NES state, and ii) an execution condition related to the cell turning-off state is more relaxed than the execution condition related to the cell DTX/DRX state.
To relax the at least one execution condition, the at least one cell state specific offset related to the at least one cell state may be applied to one or more parameters of the reference execution condition. For example, the at least one cell state specific offset may be applied to:
- a measurement value for a target cell to increase the measurement value for the target cell by an increment with respect to a non-NES state, where the increment is higher in the cell-turning off state than in the cell DTX/DRX state;
- a measurement value for a source cell to decrease the measurement value for the source cell by a decrement with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state;
- an offset threshold to decrease the offset threshold by a decrement with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state;
- a source cell threshold to increase the source cell threshold by an increment with respect to a non-NES state, where the increment is higher in the cell-turning off state than in the cell DTX/DRX state;
- a target cell threshold to decrease the target cell threshold by a decrement with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state; and/or
- a TTT to decrease the TTT by a decrement with respect to a non-NES state, where the decrement is higher in the cell-turning off state than in the cell DTX/DRX state.
In step S1207, UE may perform a mobility to a target cell based on an execution condition for the target cell being satisfied. UE may apply the cell configuration for the target cell based on the execution condition for the target cell being satisfied.
In some implementations, to support network to bar legacy UEs from accessing NES the following options may be considered:
Option A) Intra/InterFreqExcludedCellList;
Option B) cellBarred; and/or
Option C) Cell reservation fields in MIB/SIB.
1. Option A
xxxExcludedCellList should be configured to include NES cells so that legacy UEs excludes the NES cells from cell reselection candidates.
NES capable UEs should ignore the ExcludedCellList so that they can consider the NES cells as cell reselection candidate cells.
Using xxxexcludedCellList should be supported for NES capable UEs as well. So, another ExcludedCellList only applicable to NES capable UEs (e.g., ExcludedCellListNES) may be introduced in SIB/4.
Option A can prevent legacy UEs from reselecting NES cells but this option cannot prevent legacy UEs from selecting and camping NES cells.
2. Option B
cellBarred in MIB of NES cell should be set to barred. NES capable UEs should ignore the cellBarred.
access control for NES capable UEs should be supported based on 1-bit barring mechanism. Then, another cellBarred field only applicable to NES capable UEs (e.g., cellBarredNES) may be introduced in SIB1.
This solution can effectively prevent legacy UEs from camping in NES cells. This kind of mechanism is used to control access for NTN UEs and access from RedCap UEs. This solution cannot avoid legacy UEs from reselecting NES cells in the first place. Legacy UEs will attempt to camp on the NES cell by acquiring MIB and then leave the NES cell only after identifying the cellBarred set to barred.
If further optimization to avoid legacy UEs from reselecting NES cells in the first place, option A can be further considered, but such optimization is not considered essential. That is, option B is sufficient.
3. Option C
To bar legacy UEs that is not capable of NPN from NES cell, cellReservationForOtherUse should be set to true in NES cell. To bar NPN capable UEs from NES cell, cellReservationForFutureUse should be set to true in NES cell. NES capable UEs should ignore both cellReservationForOtherUse and cellReservationForFutureUse in NES cell.
To control access from UEs that are joint-capable of NPN and NES from NPN+NES cell, a new cell reservation field, e.g., cellReservationForFutureUse2 may be introduced. If this field is absent, the UE should consider that the cell is not reserved. Otherwise the UE should consider the cell as barred.
This option can prevent legacy UEs from camping in NES cell. Access restriction based on cell reservation in NES cell should be built on top of existing access control handling used for access control in NPN cells, which slightly complicates access control mechanism in NES cell.
Option C can work but this option is not preferred given that other like option B is simple and sufficient.
Comparing the options, option B alone is sufficient to prevent legacy UEs from accessing NES cells. If option B is taken, a new cell barring field needs to be introduced in SIB1 that is only applicable to NES capable UEs.
In conclusion:
- NES cell can set cellBarred in MIB to barred in order to prevent legacy UEs from accessing NES cells. NES capable UEs ignores cellBarred.
- a new cell barring field is introduced in SIB1 only applicable to NES capable UEs. If this field is set to barred, NES capable UEs shall consider this cell as barred.
- configuring xxxExcludedCellList including NES cells to help legacy UEs avoid reselecting NES cells is not essential.
In some implementations, the network should be able to configure NES capable UEs to (de)prioritize NES cells. Mechanism can be considered for both frequency and cell levels cell selection/reselection (de)prioritization.
In some implementations, whether any new cell reselection mechanism for prioritizing or deprioritizing NES cells is needed or not may be an issue. Intra-NR cell reselection is limited to frequencies listed in SIB3 and SIB4. Currently network can configure Qoffset to prioritize or deprioritize certain cell(s) in SIB3/4 for cell reselection. Qoffset can be configured for each neighbour cell included in the intra-frequency neighbour cell information in SIB3 and equal priority inter-frequency neighbour cell info in SIB4, and Qoffset ranges from -24 dB to +24 dB, which is sufficient to enable relative (de)prioritization by using smaller value of |Qoffset|or even virtually absolute (de)prioritization by using larger value of |Offset|. So, Qoffset is applicable to prioritize or deprioritize NES cells for cell reselection. Qoffset can be applicable to legacy UEs as well.
That is, Qoffset can be applicable to prioritize or deprioritize NES cells for cell reselection.
If network wants to apply different prioritization policy for legacy UEs and NES capable UEs, e.g., prioritizing NES cells by NES capable UEs while deprioritizing NES cells by legacy UEs, Qoffset does not work well, since the Qoffset is a broadcast parameter.
That is, Qoffset is useful if network wants to apply common prioritization policy for legacy UEs and NES capable UEs. Existing Qoffset is not useful if network wants to apply different prioritization policy for legacy UEs and NES capable UEs.
To enable differentiated prioritization policy, the easiest way is to introduce another Qoffset (e.g., QoffsetNES) applicable only to NES capable UEs. Network configures existing Qoffset to control reselection for legacy UEs and new Offset (OffsetNES) to control reselection for NES capable UEs. Then, NES capable UEs should ignore existing Qoffset but apply QoffsetNES instead.
In conclusion:
- Offset works fine if network wants to apply a common prioritization policy for legacy UEs and NES capable UEs.
- Differentiated prioritization policy for NES cells may apply for legacy UEs and for NES capable UEs respectively (e.g., de-prioritization of NES cells by legacy UEs and prioritization of NES cells by NES capable UEs, or vice versa)
- If differentiated cell reselection prioritization policy for legacy UEs and for NES capable UEs respectively is supported, a new Qoffset (e.g., QoffsetNES) dedicated to NES capable UEs is introduced. NES capable UEs ignore existing Qoffset but apply QoffsetNES instead.
Furthermore, the method in perspective of the UE described in the present disclosure (e.g., in FIG. 9) may be performed by the first wireless device 100 shown in FIG. 2 and/or the UE 100 shown in FIG. 3.
More specifically, the UE comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.
The operations comprise: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
Furthermore, the method in perspective of the UE described in the present disclosure (e.g., in FIG. 9) may be performed by a software code 105 stored in the memory 104 included in the first wireless device 100 shown in FIG. 2.
More specifically, at least one computer readable medium (CRM) stores instructions that, based on being executed by at least one processor, perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
Furthermore, the method in perspective of the UE described in the present disclosure (e.g., in FIG. 9) may be performed by control of the processor 102 included in the first wireless device 100 shown in FIG. 2 and/or by control of the processor 102 included in the UE 100 shown in FIG. 3.
More specifically, an apparatus configured to/adapted to operate in a wireless communication system (e.g., wireless device/UE) comprises at least processor, and at least one computer memory operably connectable to the at least one processor. The at least one processor is configured to/adapted to perform operations comprising: receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; receiving information for at least one cell state among the multiple cell states; evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
Furthermore, the method in perspective of a network node described in the present disclosure (e.g., in FIG. 10) may be performed by the second wireless device 200 shown in FIG. 2.
More specifically, the network node comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.
The operations comprise: transmitting, to a user equipment (UE), information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; and transmitting, to the UE, information for at least one cell state among the multiple cell states, wherein at least one mobility condition related to the at least one cell state is evaluated among the multiple mobility conditions, and wherein a mobility to the target cell is performed based on a mobility condition among the at least one mobility condition being satisfied.
The present disclosure may have various advantageous effects.
For example, when a base station associated with a cell operates multiple NES states, UE can evaluate mobility condition(s) associated with the NES state the cell enters to achieve optimal mobility.
Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and/or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.
Claims in the present disclosure can be combined in a various way. For instance, technical features in method claims of the present disclosure can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.

Claims (21)

  1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising:
    receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states;
    receiving information for at least one cell state among the multiple cell states;
    evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and
    based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  2. The method of claim 1, wherein the information for the multiple mobility conditions is received via a radio resource control (RRC) signalling, and
    wherein the information for the at least one cell state is received via a media access control (MAC) control element (CE) signalling or downlink control information (DCI).
  3. The method of claim 1, wherein the mobility comprises a cell reselection, and
    wherein the multiple mobility conditions comprise a cell reselection condition that:
    a cell ranking value for the target cell is highest among a cell ranking value for a serving cell and one or more cell ranking values for one or more neighbor cells; or
    based on the cell ranking value for the target cell belonging to one or more cell ranking values for cells within a threshold range from a highest cell ranking value, a number of good beams of the target cell is highest among the cells.
  4. The method of claim 1, wherein the mobility comprises a conditional mobility,
    wherein the multiple mobility conditions comprise execution conditions for the conditional mobility, and
    wherein the execution conditions are related to at least one of a measurement value for the target cell, a measurement value for a serving cell, one or more thresholds, or a time-to-trigger (TTT).
  5. The method of claim 1, wherein the execution conditions comprise at least one of:
    an event A2 condition that a measurement value for the serving cell is lower than a source cell threshold;
    an event A3 condition that a measurement value for the target cell is higher than a measurement value for the serving cell plus offset threshold for at least TTT;
    an event A4 condition that a measurement value for the target cell is higher than a target cell threshold; or
    an event A5 condition that a state in which a measurement value for the target cell is higher than a target cell threshold and a measurement value for the serving cell is lower than a source cell threshold lasts for at least TTT.
  6. The method of claim 1, wherein the information for the multiple mobility conditions comprises:
    the multiple mobility conditions; and
    multiple cell state identifiers (IDs) each of which is related to a corresponding mobility condition, and
    wherein the method further comprises identifying the at least one mobility condition related to the at least one cell state based on at least one matching cell state ID.
  7. The method of claim 1, wherein the information for the multiple mobility conditions comprises:
    multiple offsets; and
    multiple cell state identifiers (IDs) each of which is related to a corresponding offset, and
    wherein the method further comprises:
    identifying at least one offset related to the at least one cell state based on at least one matching cell state ID; and
    determining the at least one mobility condition based on applying the at least one offset to one or more parameters of a reference mobility condition.
  8. The method of claim 7, wherein the at least one mobility condition is relaxed with respect to the reference mobility condition based on the at least one offset being applied to the one or more parameters, and
    wherein the one or more parameters comprise at least one of a cell ranking value for the target cell, a cell ranking value for a serving cell, a cell ranking value for at least one neighbor cell other than the target cell, a measurement value for the target cell, a measurement value for the serving cell, an offset threshold, a source cell threshold, a target cell threshold, or a time-to-trigger (TTT).
  9. The method of claim 1, wherein the multiple cell states comprise a non-network energy saving (NES) state, a first NES state and a second NES state, and
    wherein the first NES state and the second NES state are sub-states of a NES state.
  10. The method of claim 9, wherein the non-NES state is a state in which all duration is an active duration,
    wherein the first NES state is a state in which a cycle of the active duration and a non-active duration is periodically repeated, and
    wherein the second NES state is a state in which all duration is the non-active duration.
  11. The method of claim 10, wherein, in the active duration:
    the UE monitors at least one of physical downlink control channel (PDCCH) or semi-persistent scheduling (SPS) occasions; or
    the UE performs a transmission on configured grant (CG) resources, or transmits a scheduling request (SR); and
    wherein, in the non-active duration:
    the UE does not monitor at least one of PDCCH or SPS occasions; or
    the UE does not perform a transmission on CG resources, or does not transmit an SR.
  12. The method of claim 9, wherein the at least one cell state comprises at least one of the first NES state or the second NES state,
    wherein a mobility condition related to the first NES state is more relaxed than a reference mobility condition related to the non-NES state, and
    wherein a mobility condition related to the second NES state is more relaxed than the mobility condition related to the first NES state.
  13. The method of claim 9, wherein the non-NES state is a non-cell discontinuous transmission (DTX)/discontinuous reception (DRX) state,
    wherein the first NES state is a cell DTX/DRX state, and
    wherein the second NES state is a cell turning-off state.
  14. The method of claims 1 to 13, wherein the UE is in communication with at least one of a mobile device, a network, or autonomous vehicles.
  15. A user equipment (UE) configured to operate in a wireless communication system, the UE comprising:
    at least one transceiver;
    at least one processor; and
    at least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:
    receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states;
    receiving information for at least one cell state among the multiple cell states;
    evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and
    based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  16. The UE of claim 15, wherein the UE is arranged to implement a method of one of claims 2 to 14.
  17. A network node configured to operate in a wireless communication system, the network node comprising:
    at least one transceiver;
    at least one processor; and
    at least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:
    transmitting, to a user equipment (UE), information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; and
    transmitting, to the UE, information for at least one cell state among the multiple cell states,
    wherein at least one mobility condition related to the at least one cell state is evaluated among the multiple mobility conditions, and
    wherein a mobility to the target cell is performed based on a mobility condition among the at least one mobility condition being satisfied.
  18. A method performed by a network node configured to operate in a wireless communication system, the method comprising:
    transmitting, to a user equipment (UE), information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states; and
    transmitting, to the UE, information for at least one cell state among the multiple cell states,
    wherein at least one mobility condition related to the at least one cell state is evaluated among the multiple mobility conditions, and
    wherein a mobility to the target cell is performed based on a mobility condition among the at least one mobility condition being satisfied.
  19. The method of claim 18, wherein the UE is arranged to implement a method of one of claims 1 to 14.
  20. An apparatus adapted to operate in a wireless communication system, the apparatus comprising:
    at least processor; and
    at least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:
    receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states;
    receiving information for at least one cell state among the multiple cell states;
    evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and
    based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
  21. A non-transitory computer readable medium (CRM) having stored thereon a program code implementing instructions that, based on being executed by at least one processor, perform operations comprising:
    receiving information for multiple mobility conditions for a target cell, wherein each of the multiple mobility conditions is related to a corresponding cell state among multiple cell states;
    receiving information for at least one cell state among the multiple cell states;
    evaluating at least one mobility condition related to the at least one cell state among the multiple mobility conditions; and
    based on a mobility condition among the at least one mobility condition being satisfied, performing a mobility to the target cell.
PCT/KR2023/017674 2022-11-04 2023-11-06 Mobility control based on cell states in wireless communication system WO2024096718A1 (en)

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Citations (1)

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ERICSSON: "Handling of Legacy UEs on a NES Capable Cell", 3GPP DRAFT; R2-2210255, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, vol. RAN WG2, no. Electronic meeting; 20221010 - 20221019, 30 September 2022 (2022-09-30), Mobile Competence Centre ; 650, route des Lucioles ; F-06921 Sophia-Antipolis Cedex ; France, XP052263577 *
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