Complementary uplink for cell drx

Abstract

A method and wireless device related to Complementary Uplink for Cell DRX is provided. The wireless device receives a configuration related to a first downlink carrier and a second downlink carrier for a serving cell. The wireless device selects an uplink carrier from the first uplink carrier and the second uplink carrier based on a discontinuous reception (DRX) state of the serving cell. The wireless device performs an uplink transmission based on the selected uplink carrier.

Description

COMPLEMENTARY UPLINK FOR CELL DRX

[0001] The present disclosure relates to Complementary Uplink for Cell DRX.

[0002] 3rd Generation Partnership Project (3GPP) New Radio (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. 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.

[0003] 6G is the successor to 5G cellular technology. 6G networks will be able to use higher frequencies than 5G networks and provide substantially higher capacity and much lower latency. The 6G technology market is expected to facilitate large improvements in the areas of imaging, presence technology and location awareness. Working in conjunction with Artificial Intelligence (AI), the 6G computational infrastructure will be able to identify the best place for computing to occur. This includes decisions about data storage, processing and sharing.

[0004] Network energy saving is of great importance for environmental sustainability, to reduce environmental impact (greenhouse gas emissions), and for operational cost savings. As 5G is becoming pervasive across industries and geographical areas, handling more advanced services and applications requiring very high data rates (e.g. XR), networks are being denser, use more antennas, larger bandwidths and more frequency bands. The environmental impact of 5G needs to stay under control, and novel solutions to improve network energy savings need to be developed.

[0005] In wireless communication systems, cell discontinuous reception (DRX) has been introduced as an energy-saving mechanism in which a UE suspends uplink transmissions during predefined inactive periods. While such mechanisms can reduce power consumption, existing systems may still allow certain exceptional uplink transmissions, such as delay-sensitive uplink control signaling, during the cell DRX inactive period, thereby limiting the effectiveness of energy saving. Accordingly, there has been ongoing discussion on introducing a complete cell DRX OFF operation in which no uplink transmission is permitted during the inactive period in order to maximize UE energy efficiency.

[0006] However, in a system supporting complete cell DRX OFF operation, the UE may experience performance degradation in scenarios involving delay-sensitive procedures. For example, when the UE initiates a random access procedure for urgent communication, the UE may need to transmit a random access preamble (MSG1). If the triggering of the random access procedure occurs during the cell DRX inactive period, the UE cannot transmit the random access preamble until the next available transmission opportunity becomes available.

[0007] As a result, the transmission of the random access preamble may be delayed, which may lead to increased latency in the random access procedure. Such delay may degrade user experience, particularly in cases where low-latency communication is required, such as emergency signaling or delay-sensitive services. Therefore, there exists a need for mechanisms that can support complete cell DRX OFF operation for energy saving while mitigating the delay in uplink transmission experienced by the UE.

[0008] Therefore, there may be a need for a mechanism that allows a UE to appropriately perform uplink transmission even when a serving cell operates in a cell DRX inactive period. In particular, when the serving cell is in the cell DRX inactive period, the UE may select a complementary uplink carrier for uplink transmission based on a state of the serving cell or a remaining time until a next active period of a normal uplink carrier. Such a mechanism may enable the UE to refrain from transmitting on the normal uplink carrier during the cell DRX inactive period while allowing the UE to transmit delay-sensitive or urgent uplink data via the complementary uplink carrier, thereby reducing latency in uplink transmission and improving energy efficiency.

[0009] In an aspect, a method performed by a wireless device is provided. The method comprises receiving a configuration related to a first downlink carrier and a second downlink carrier for a serving cell. The method comprises selecting an uplink carrier from the first uplink carrier and the second uplink carrier based on a discontinuous reception (DRX) state of the serving cell. The method comprises performing an uplink transmission based on the selected uplink carrier.

[0010] The present disclosure may have various advantageous effects.

[0011] For example, the network may achieve improved energy saving performance by enabling a complete cell DRX OFF operation for uplink transmissions, where no uplink transmission is performed during the cell DRX inactive period. In conventional approaches, even during the inactive period, the UE may still attempt uplink transmissions for delay-sensitive data, thereby reducing energy saving efficiency. In contrast, by restricting such transmissions, unnecessary power consumption can be reduced.

[0012] For example, by separating the transmission of urgent or delay-sensitive uplink data from the normal uplink carrier operating under cell DRX, the UE may maintain strict DRX inactivity while still supporting necessary uplink communication.

[0013] For example, from the UE perspective, urgent or delay-sensitive uplink data can be transmitted through a complementary uplink carrier even when the serving cell is in the cell DRX inactive period. Accordingly, the UE may transmit critical data without waiting for the next active period of the normal uplink carrier, thereby avoiding unnecessary transmission delay.

[0014] For example, by allowing the UE to perform uplink transmissions via a complementary uplink carrier during the cell DRX inactive period, the system can simultaneously achieve reduced power consumption and low-latency uplink data transmission. This enables a balanced operation in which energy efficiency is improved without degrading uplink transmission performance.

[0015] 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 various additional 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.

[0016] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0017] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0018] FIG. 3 shows an example of a UE to which implementations of the present disclosure are applied.

[0019] FIGS. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0020] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0021] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0022] FIG. 8 shows an example of cell Discontinuous Reception (drx) inactive period to which implementations of the present disclosure are applied.

[0023] FIG. 9 shows an example of a method performed by a wireless device to which implementations of the present disclosure are applied.

[0024] FIG. 10 shows an example of a method performed by a base station to which implementations of the present disclosure are applied.

[0025] FIG. 11 shows an example of a random access procedure to which implementations of the present disclosure are applied.

[0026] FIG. 12 shows another example of a random access procedure to which implementations of the present disclosure are applied.

[0027] FIG. 13 shows another example of random access procedure to which implementations of the present disclosure are applied.

[0028] 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).

[0029] 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.

[0030] 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.

[0031] 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".

[0032] 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".

[0033] 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".

[0034] 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".

[0035] 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".

[0036] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0037] 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.

[0038] 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.

[0039] FIG. 1 shows an example of a communication system to which implementations of the present disclosure are applied.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] The wireless devices 100a to 100f represent devices performing communication using radio access technology (RAT) (e.g., 5G new RAT (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 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 AR / 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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).

[0050] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0051] 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).

[0052] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0053] Here, the radio communication technologies implemented in the wireless devices in the present disclosure may include narrowband internet-of-things (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 machine type communication (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.

[0054] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure are applied.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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).

[0071] 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.

[0072] 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.

[0073] In the implementations of the present disclosure, a UE may operate as a transmitting device in UL and as a receiving device in 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.

[0074] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0075] FIG. 3 shows an example of a UE to which implementations of the present disclosure are applied.

[0076] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0077] 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.

[0078] 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 SNAPDRAGONTMseries of processors made by QUALCOMM®, EXYNOSTMseries of processors made by SAMSUNG®, A series of processors made by APPLE®, HELIOTMseries of processors made by MEDIATEK®, ATOMTMseries of processors made by INTEL® or a corresponding next generation processor.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] FIGS. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0086] 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).

[0087] 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.

[0088] 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.

[0089] 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.

[0090] The RLC sublayer supports three transmission modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (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).

[0091] 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.

[0092] 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.

[0093] 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 5G Core network (5GC) or Next-Generation Radio Access Network (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.

[0094] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure are applied.

[0095] 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., 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 Cyclic Prefix (CP)-OFDM symbols), SC-FDMA symbols (or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbols).

[0096] 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 Tsfper 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 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 △f = 2u*15 kHz.

[0097] Table 3 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frame Nframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the normal CP, according to the subcarrier spacing Δf= 2u*15 kHz.

[0098] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0099] Table 4 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frame Nframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the extended CP, according to the subcarrier spacing △f = 2u*15 kHz.

[0100] uNslotsymbNframe,uslotNsubframe,uslot212404

[0101] 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,ugrid,x*NRBscsubcarriers and Nsubframe,usymbOFDM symbols is defined, starting at Common Resource Block (CRB) Nstart,ugridindicated by higher-layer signaling (e.g., RRC signaling), where Nsize,ugrid,xis the number of Resource Blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink. NRBscis the number of subcarriers per RB. In the 3GPP based wireless communication system, NRBscis 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,ugridfor 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.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 NsizeBWP,i-1, where i is the number of the bandwidth part. The relation between the physical resource block nPRBin the bandwidth part i and the common resource block nCRBis as follows: nPRB= nCRB+ NsizeBWP,i, where NsizeBWP,iis 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. The 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 Physical Uplink Control Channel (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.

[0102] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure are applied.

[0103] 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.

[0104] In the PHY layer, the uplink transport channels UL-SCH and Random Access Channel (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 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.

[0105] Hereinafter, technical features related to support for energy saving are described. Section 15.4.1 of 3GPP TS 38.300 V18.5.0 may be referred.

[0106] The aim of this function is to reduce operational expenses through energy savings.

[0107] The 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, or to support various adaptation techniques in time, frequency, spatial and power domains.

[0108] Hereinafter, technical features related to Cell DTX / DRX are described. Section 15.4.2.3 of 3GPP TS 38.300 V18.5.0 may be referred.

[0109] To facilitate reducing gNB downlink transmission / uplink reception active time, UE can be configured with a periodic cell DTX / 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. A maximum of two cell DTX / DRX patterns can be configured per MAC entity for different serving cells. When cell DTX is configured and activated for the concerned cell, the UE may not monitor PDCCH in selected cases or does not monitor 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 does not 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 operation is only supported for single TRP scenario. Cell DTX / DRX can be activated / deactivated by RRC signalling or L1 group common signalling. Cell DTX / DRX is characterized by the following:

[0110] - 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, CG, periodic and semi-persistent CSI report are not impacted for the purpose of network energy saving;

[0111] - cycle:specifies the periodic repetition of the active-duration followed by a period of non-active duration.

[0112] Active duration and cycle parameters are common between cell DTX and cell DRX, when both are configured;

[0113] Once the gNB recognizes there is an emergency call or public safety related service, 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.

[0114] Hereinafter, technical features related to Cell-Level Energy Saving are described. Section 5.34.1 of 3GPP TS 38.321 V18.5.0 may be referred.

[0115] Each Serving Cell may be configured by RRC with a periodic cell DTX pattern (i.e., Active and Non-Active Periods). The cell DTX operation controls UE's monitoring activity of PDCCH and configured downlink assignments in RRC_CONNECTED. For all activated Serving Cells with cell DTX configured and activated, the MAC entity may monitor PDCCH and configured downlink assignments using the cell DTX operation.

[0116] Each Serving Cell may be configured by RRC with a periodic cell DRX pattern (i.e., Active and Non-Active Periods). The cell DRX operation controls Scheduling Request and configured uplink grant transmission activity in RRC_CONNECTED. For all activated Serving Cells with cell DRX configured and activated, the MAC entity may transmit configured uplink grant transmissions and Scheduling Request using the cell DRX operation.

[0117] RRC controls cell DTX and cell DRX operation by configuring the following parameters incellDTX-DRX-Configper Serving Cell:

[0118] -cellDTX-DRX-ConfigType: defines whether only cell DTX is configured, only cell DRX is configured, or both are configured;

[0119] -cellDTX-DRX-onDurationTimer: the active duration at the beginning of a cell DTX / DRX cycle;

[0120] -cellDTX-DRX-StartOffset: defines the subframe where the cell DTX / DRX cycle starts;

[0121] -cellDTX-DRX-SlotOffset: the delay before starting thecellDTX-DRX-onDurationTimer;

[0122] -cellDTX-DRX-Cycle: the cell DTX / DRX cycle period.

[0123] -cellDTX-DRX-ActivationStatus: the initial activation status of cell DTX and cell DRX operation.

[0124] Hereinafter, technical features related to Cell Discontinuous Transmission are described. Section 5.34 of 3GPP TS 38.321 V18.5.0 may be referred.

[0125] Each Serving Cell may be configured by RRC with a periodic cell DTX pattern (i.e., Active and Non-Active Periods). The cell DTX operation controls UE's monitoring activity of PDCCH and configured downlink assignments in RRC_CONNECTED. For all activated Serving Cells with cell DTX configured and activated, the MAC entity may monitor PDCCH and configured downlink assignments using the cell DTX operation.

[0126] Each Serving Cell may be configured by RRC with a periodic cell DRX pattern (i.e., Active and Non-Active Periods). The cell DRX operation controls Scheduling Request and configured uplink grant transmission activity in RRC_CONNECTED. For all activated Serving Cells with cell DRX configured and activated, the MAC entity may transmit configured uplink grant transmissions and Scheduling Request using the cell DRX operation.

[0127] RRC controls cell DTX and cell DRX operation by configuring the following parameters in cellDTX-DRX-Config per Serving Cell:

[0128] - cellDTX-DRX-ConfigType: defines whether only cell DTX is configured, only cell DRX is configured, or both are configured;

[0129] - cellDTX-DRX-onDurationTimer: the active duration at the beginning of a cell DTX / DRX cycle;

[0130] - cellDTX-DRX-StartOffset: defines the subframe where the cell DTX / DRX cycle starts;

[0131] - cellDTX-DRX-SlotOffset: the delay before starting the cellDTX-DRX-onDurationTimer;

[0132] - cellDTX-DRX-Cycle: the cell DTX / DRX cycle period.

[0133] - cellDTX-DRX-ActivationStatus: the initial activation status of cell DTX and cell DRX operation.

[0134] Cell DRX is configured ifcellDTX-DRX-ConfigTypeis set todrxordtxdrx. Cell DRX operation is activated and deactivated for each Serving Cell by:

[0135] - receiving a cell DRX indication from lower layers indicatingactivationordeactivationof cell DRX operation;

[0136] - configuringcellDTX-DRX-Configby upper layers: if cell DRX is configured andcellDTX-DRX-ActivationStatusis set toactivated, cell DRX operation is activated upon cell DRX configuration; if cell DRX is configured andcellDTX-DRX-ActivationStatusis set todeactivated, cell DRX operation is deactivated upon cell DRX configuration; ifcellDTX-DRX-Configisreleased, cell DRX operation is deactivated and all the corresponding configurations are released.

[0137] When cell DRXis configured and activated for a Serving Cell, the cell DRX Active Period includes the time while:

[0138] -cellDTX-DRX-onDurationTimeris running for the associated Serving Cell.

[0139] For each Serving Cell configured with cell DRX, the MAC entity shall:

[0140] 1> if cell DRX is activated for this Serving Cell:

[0141] 2> if [(SFN Х 10) + subframe number] modulo (cellDTX-DRX-Cycle) = (cellDTX-DRX-StartOffset):

[0142] 3> startcellDTX-DRX-onDurationTimerfor this serving cell aftercellDTX-DRX-SlotOffsetfrom the beginning of the subframe.

[0143] NOTE 1: In case of unaligned SFN across carriers in a cell group, the SFN of the SpCell is used to calculate the cell DRX duration.

[0144] 1> if cell DRX is activated and the Serving Cell is not in the cell DRX Active Period:

[0145] 2> not instruct the physical layer to signal a SR on a PUCCH resource for SR;

[0146] 2> not increment theSR_COUNTERfor a SR;

[0147] 2> not start thesr-ProhibitTimerfor a SR;

[0148] 2> not deliver any configured uplink grant and the associated HARQ information to the HARQ entity;

[0149] 2> not instruct a HARQ process associated with a configured uplink grant to trigger a new transmission or a retransmission;

[0150] 2> not report CSI on PUCCH and semi-persistent CSI configured on PUSCH;

[0151] 2> if an emergency service is initiated by upper layers and this Serving Cell is the SpCell:

[0152] 3> initiate a Random Access procedure.

[0153] NOTE 2: How the MAC layer in the UE is aware of an ongoing emergency service is up to UE implementation.

[0154] 2> if upper layers provide Access Identity 1 or Access Identity 2 and this Serving Cell is the SpCell:

[0155] 3> initiate a Random Access procedure.

[0156] The cell DrX operation was introduced in Rel-18 for the purpose of the network energy saving, but network may still need to monitor the MSG1 transmission from UEs during the cell DrX Inactive period. That is, the network may not save energy from the cell DRX operation depending the frequency of the delay sensitive data.

[0157] For example, if all uplink transmission is completely prohibited during the cell DRX Inactive period to achieve complete cell DRX operation for network energy saving, the transmission requirement of the delay sensitive data will not be met and UE may experience the severe performance degradation.

[0158] FIG. 8 shows an example of cell Discontinuous Reception (drx) inactive period to which implementations of the present disclosure are applied.

[0159] cell DRX inactive period may refer to a state in which uplink transmission is not performed, and a UE is unable to transmit uplink data from the corresponding carrier.

[0160] the wireless device may wait to transmit uplink control channels in the cell DRX active period. the uplink control channels are not transmitted in the cell DRX inactive period.

[0161] For example, if a random access (RA) preamble is triggered during Cell DRX inactive period as shown in fig. 8, the transmission of random access preamble will be delayed by X ms. This is because the wireless device does not perform uplink transmission during the DRX inactive period, and thus the transmission of the random access preamble is deferred until the DRX state transitions to an active period.

[0162] The following drawings are created to explain specific embodiments of the present disclosure. The names of the specific devices or the names of the specific signals / messages / fields shown in the drawings are provided by way of example, and thus the technical features of the present disclosure are not limited to the specific names used in the following drawings.

[0163] An embodiment of the present disclosure related to a specific drawing described below may be combined with various embodiments of the present disclosure related to other drawings, and some descriptions, functions, procedures, proposals, methods and / or operations of the embodiment may be omitted.

[0164] FIG. 9 shows an example of a method performed by a wireless device to which implementations of the present disclosure are applied.

[0165] In step S901, the method comprises receiving a configuration related to a first uplink carrier and a second uplink carrier for a serving cell.

[0166] In step S902, the method comprises selecting an uplink carrier from the first uplink carrier and the second uplink carrier based on a discontinuous reception (DRX) state of the serving cell.

[0167] In step S903, the method comprises performing an uplink transmission based on the selected uplink carrier.

[0168] In some implementations, based on the DrX period of the serving cell being a drx active period, the first uplink carrier may be selected as the uplink carrier.

[0169] In some implementations, based on the drx period of the serving cell being a drx inactive period, the second uplink carrier may be selected as the uplink carrier.

[0170] In some implementations, based on the first uplink carrier being in an active period, the first uplink carrier may be selected as the uplink carrier.

[0171] In some implementations, based on the first uplink carrier being in an inactive period, the second uplink carrier may be selected as the uplink carrier.

[0172] In some implementations, based on a remaining time until next available transmission opportunity on the first uplink carrier exceeding a threshold, the second uplink carrier may be selected as the uplink carrier.

[0173] In some implementations, based on a remaining time until next available transmission opportunity on the first uplink carrier not exceeding a threshold, the first uplink carrier may be selected as the uplink carrier.

[0174] In some implementations, based on a remaining time until next active period of the first uplink carrier exceeding a threshold, the second uplink carrier may be selected as the uplink carrier.

[0175] In some implementations, based on a remaining time until next active period of the first uplink carrier not exceeding a threshold, the first uplink carrier may be selected as the uplink carrier.

[0176] In some implementations, the second uplink carrier may be related to more than one serving cell.

[0177] In some implementations, the uplink reception over the second uplink carrier may be restricted to a specific type of uplink data or a specific procedure or a specific logical channel which is allowed to be transmitted over the second uplink carrier.

[0178] In some implementations, an activation or a deactivation of the first uplink carrier may be indicated by network.

[0179] In some implementations, the first uplink carrier may be selected as the uplink carrier based on: (i) a remaining time of an inactive period of the first uplink carrier being shorter than a remaining time of an inactive period of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in the inactive period.

[0180] In some implementations, the second uplink carrier may be selected as the uplink carrier based on: (i) a remaining time of an inactive period of the first uplink carrier being longer than a remaining time of an inactive period of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in the inactive period.

[0181] In some implementations, the first uplink carrier may be selected as the uplink carrier based on: (i) a remaining time until a first transmission opportunity of the first uplink carrier being shorter than a remaining time until a first transmission opportunity of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in an inactive period.

[0182] In some implementations, the second uplink carrier may be selected as the uplink carrier based on: (i) a remaining time until a first transmission opportunity of the first uplink carrier being longer than a remaining time until a first transmission opportunity of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in an inactive period.

[0183] In some implementations, the configuration related to the first uplink carrier and the second uplink carrier for the serving cell may include information related to at least one of i) a state of the serving cell, ii) a state of the first uplink carrier, iii) a remaining time until a first transmission opportunity of the first uplink carrier, iv) a remaining time until a next active period of the normal uplink carrier.

[0184] Furthermore, the wireless device may be implemented by the first wireless device 100 shown in FIG. 2, and / or the UE 100 shown in FIG. 3.

[0185] More specifically, the wireless device comprises at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions. Operations performed based on the instructions being executed by the at least one processor are as follows.

[0186] The wireless device receives a configuration related to a first downlink carrier and a second downlink carrier for a serving cell. The wireless device selects an uplink carrier from the first uplink carrier and the second uplink carrier based on a discontinuous reception (DRX) state of the serving cell. The wireless device performs an uplink transmission based on the selected uplink carrier.

[0187] In some implementations, based on the DrX period of the serving cell being a drx active period, the first uplink carrier may be selected as the uplink carrier.

[0188] In some implementations, based on the drx period of the serving cell being a drx inactive period, the second uplink carrier may be selected as the uplink carrier.

[0189] In some implementations, based on the first uplink carrier being in an active period, the first uplink carrier may be selected as the uplink carrier.

[0190] In some implementations, based on the first uplink carrier being in an inactive period, the second uplink carrier may be selected as the uplink carrier.

[0191] In some implementations, based on a remaining time until next available transmission opportunity on the first uplink carrier exceeding a threshold, the second uplink carrier may be selected as the uplink carrier.

[0192] In some implementations, based on a remaining time until next available transmission opportunity on the first uplink carrier not exceeding a threshold, the first uplink carrier may be selected as the uplink carrier.

[0193] In some implementations, based on a remaining time until next active period of the first uplink carrier exceeding a threshold, the second uplink carrier may be selected as the uplink carrier.

[0194] In some implementations, based on a remaining time until next active period of the first uplink carrier not exceeding a threshold, the first uplink carrier may be selected as the uplink carrier.

[0195] In some implementations, the second uplink carrier may be related to more than one serving cell.

[0196] In some implementations, the uplink reception over the second uplink carrier may be restricted to a specific type of uplink data or a specific procedure or a specific logical channel which is allowed to be transmitted over the second uplink carrier.

[0197] In some implementations, an activation or a deactivation of the first uplink carrier may be indicated by network.

[0198] In some implementations, the first uplink carrier may be selected as the uplink carrier based on: (i) a remaining time of an inactive period of the first uplink carrier being shorter than a remaining time of an inactive period of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in the inactive period.

[0199] In some implementations, the second uplink carrier may be selected as the uplink carrier based on: (i) a remaining time of an inactive period of the first uplink carrier being longer than a remaining time of an inactive period of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in the inactive period.

[0200] In some implementations, the first uplink carrier may be selected as the uplink carrier based on: (i) a remaining time until a first transmission opportunity of the first uplink carrier being shorter than a remaining time until a first transmission opportunity of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in an inactive period.

[0201] In some implementations, the second uplink carrier may be selected as the uplink carrier based on: (i) a remaining time until a first transmission opportunity of the first uplink carrier being longer than a remaining time until a first transmission opportunity of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in an inactive period.

[0202] In some implementations, the configuration related to the first uplink carrier and the second uplink carrier for the serving cell may include information related to at least one of i) a state of the serving cell, ii) a state of the first uplink carrier, iii) a remaining time until a first transmission opportunity of the first uplink carrier, iv) a remaining time until a next active period of the normal uplink carrier.

[0203] Furthermore, the method described above in FIG. 8 may be performed by control of a processing apparatus. The processing apparatus may be implemented by the processor 102 included in the first wireless device 100 shown in FIG. 2 and / or the processor 102 included in the UE 100 shown in FIG. 3.

[0204] More specifically, the processing apparatus comprises at least one processor that is integrated with a wireless device, and at least one memory comprising processor-executable instructions stored thereon that are configured to cause the at least one processor to perform the method described in FIG. 9.

[0205] Furthermore, the method described above 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.

[0206] The technical features of the present disclosure may be embodied directly in hardware, in a software executed by a processor, or in a combination of the two. For example, a method performed by a wireless device in a wireless communication may be implemented in hardware, software, firmware, or any combination thereof. For example, a software may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, a removable disk, a CD-ROM, or any other storage medium.

[0207] Some example of storage medium may be coupled to the processor such that the processor can read information from the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. For other example, the processor and the storage medium may reside as discrete components.

[0208] The computer-readable medium may include a tangible and non-transitory computer-readable storage medium.

[0209] For example, non-transitory computer-readable media may include RAM such as Synchronous DRAM (SDRAM), ROM, Non-Volatile RAM (NVRAM), EEPROM, flash memory, magnetic or optical data storage media, or any other medium that can be used to store instructions or data structures. Non-transitory computer-readable media may also include combinations of the above.

[0210] In addition, the method described herein may be realized at least in part by a computer-readable communication medium that carries or communicates code in the form of instructions or data structures and that can be accessed, read, and / or executed by a computer.

[0211] More specifically, a non-transitory Computer-Readable Medium (CRM) stores instructions that, based on being executed by at least one processor, perform the method described in FIG. 9.

[0212] FIG. 10 shows an example of a method performed by a base station to which implementations of the present disclosure are applied.

[0213] In step S1001, the method comprises transmitting to a wireless device a configuration related to a first uplink carrier and a second uplink carrier for a serving cell. an uplink carrier from the first uplink carrier and the second uplink carrier is selected based on a discontinuous reception (DRX) state of the serving cell. the uplink transmission is performed based on the selected uplink carrier

[0214] Furthermore, the base station may be implemented by the second wireless device 200 shown in FIG. 2.

[0215] More specifically, the base station comprises at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions. Operations performed based on the instructions being executed by the at least one processor are as follows.

[0216] The base station transmits to a wireless device a configuration related to a first uplink carrier and a second uplink carrier for a serving cell. an uplink carrier from the first uplink carrier and the second uplink carrier is selected based on a discontinuous reception (DRX) state of the serving cell. the uplink transmission is performed based on the selected uplink carrier

[0217] Hereinafter, various aspects for performing an uplink transmission based on the selected uplink carrier are described according to implementations of the present disclosure.

[0218] Uplink carrier selection

[0219] The UE may select an uplink carrier to monitor for uplink transmission between a normal uplink carrier and a complementary uplink carrier based on whether the serving cell is in the cell drx active period or in the cell drx inactive period.

[0220] (1) For example, if the serving cell is in the cell drx active period, the UE may perform uplink transmission using the normal downlink carrier.

[0221] (2) For example, if the serving cell is in the cell drx inactive period, the UE may perform uplink transmission using the complementary uplink carrier.

[0222] The UE may select an uplink carrier for performing uplink transmission between a normal downlink carrier and a complementary downlink carrier based on whether the normal uplink carrier is in the active period or in the inactive period.

[0223] (1) For example, if the normal uplink carrier is in the active period, the UE may perform uplink transmission using the normal uplink carrier.

[0224] (2) For example, if the normal uplink carrier is in the inactive period, the UE may perform uplink transmission using the complementary uplink carrier.

[0225] The UE may select an uplink carrier to monitor for performing uplink transmission between a normal uplink carrier and a complementary uplink carrier based on the remaining time until the next available transmission opportunity on the normal uplink carrier.

[0226] When an uplink transmission is triggered,

[0227] (1) For example, if the remaining time until the next available transmission opportunity on the normal uplink carrier exceeds a threshold, the UE may perform uplink transmission using the complementary uplink carrier.

[0228] (2) For example, if not, the UE may perform uplink transmission using the normal uplink carrier.

[0229] The transmission opportunity may be different depending on the data which triggers the uplink transmission. For example, the transmission opportunity for random access preamble may be PRACH occasion, while the transmission opportunity for Scheduling Request is PUCCH resource.

[0230] FIG. 11 shows an example of a random access procedure to which implementations of the present disclosure are applied.

[0231] As shown in FIG. 11, random access procedure may be triggered during the cell DRX inactive period. the remaining time until the next available PRACH occasion on the normal carrier may be M ms.

[0232] For example, if the threshold N (ms) is shorter than M, the UE may perform the RA preamble transmission using the complementary uplink carrier as shown in fig. 11.

[0233] In this case, since the remaining time exceeds the threshold, the delay related to waiting for the next PRACH occasion on the normal uplink carrier may be reduced by utilizing the complementary uplink carrier. Accordingly, the random access procedure may be performed with reduced latency, thereby improving uplink transmission efficiency.

[0234] FIG. 12 shows another example of a random access procedure to which implementations of the present disclosure are applied.

[0235] For example, if the threshold N (ms) is larger than M, the UE may perform the random access (RA) preamble transmission using the normal uplink carrier as shown in fig. 12.

[0236] In this case, since the remaining time until the next available PRACH occasion does not exceed the threshold, the delay related to waiting for the transmission opportunity on the normal uplink carrier may be acceptable. Accordingly, the UE may perform the random access preamble transmission on the normal uplink carrier without switching to the complementary uplink carrier.

[0237] The UE may select an uplink carrier for performing uplink transmission between a normal downlink carrier and a complementary downlink carrier based on the remaining time until the next active period of the normal uplink carrier.

[0238] When an uplink transmission is triggered,

[0239] (1) For example, if the remaining time until the next active period of the normal uplink carrier exceeds a threshold, the UE may perform uplink transmission using the complementary uplink carrier.

[0240] (2) For example, if not, the UE may perform uplink transmission using the normal uplink carrier.

[0241] Complementary uplink carrier

[0242] For a serving cell, a normal uplink carrier and a complementary uplink carrier may be configured.

[0243] A complementary uplink carrier may be related to more than one serving cell, e.g. associated with a serving cell group.

[0244] Configured grant for complementary uplink

[0245] For example, if a configured grant is configured for the complementary uplink carrier, the UE may consider the configured grant is deactivated during the cell DRX active period, and the UE may consider the configured grant is activated during the cell DRX inactive period.

[0246] For example, if a configured grant is configured for the normal uplink carrier, the UE may consider the configured grant is activated during the cell DRX active period, and the UE may consider the configured grant is deactivated during the cell DRX inactive period.

[0247] For example, if a configured grant is configured for the complementary uplink carrier, the UE may consider the configured grant is deactivated when the normal uplink is in active period, and the UE may consider the configured grant is activated when the normal uplink is in inactive period.

[0248] For example, if a configured grant is configured for the normal uplink carrier, the UE may consider the configured grant is activated when the normal uplink is in active period, and the UE may consider the configured grant is deactivated when the normal uplink is in inactive period.

[0249] Restriction on CUL usage

[0250] The uplink transmission over the complementary uplink carrier may be restricted to specific types of uplink data, e.g. only for a specific procedure, such as random access, or only for specific logical channel data. The specific uplink data that can be transmitted over the complementary uplink carrier may be configured by the network or predefined.

[0251] For example, if uplink transmission is triggered by data which is not allowed to be transmitted over the complementary uplink carrier, the UE may not transmit the date during the cell DRX inactive period.

[0252] For example, if uplink transmission is triggered by data which is not allowed to be transmitted over the complementary uplink carrier, the UE may not transmit the date while the normal uplink is in inactive period.

[0253] For example, if the uplink transmission is triggered by data which is allowed to be transmitted over the complementary uplink carrier, the UE may transmit the data over the complementary uplink carrier during the cell DRX inactive period.

[0254] For example, if the uplink transmission is triggered by data which is allowed to be transmitted over the complementary uplink carrier, the UE may transmit the data over the complementary uplink carrier while the normal uplink is in inactive period.

[0255] Activation / de-activation of the normal uplink

[0256] The activation or de-activation of the normal uplink carrier may be indicated by the network, e.g. via RRC signal, MAC CE, or physical layer signal.

[0257] The active or inactive state of the normal uplink may change according to the active / inactive pattern configured by the network.

[0258] Activation / de-activation of the complementary uplink

[0259] The activation or de-activation of the complementary uplink carrier may be indicated by the network, e.g. via RRC signal, MAC CE, or physical layer signal.

[0260] The active or inactive state of the complementary uplink may change according to the active / inactive pattern configured by the network.

[0261] The UE may receive the active or inactive period configuration for the normal uplink carrier and for the complementary uplink carrier from the network, e.g. via system information in RRC_ILDE / INACTIVE or via dedicated configuration in RRC_CONNECTED.

[0262] For example, when the uplink transmission is triggered, if both the normal uplink carrier and the complementary uplink carrier are in the inactive period, the UE may select an uplink carrier between the normal uplink carrier and the complementary uplink carrier based on the remaining time of the current inactive period, i.e. the remaining time until the next active period, of each uplink carrier.

[0263] (1) For example, if the remaining time of the inactive period of the normal uplink carrier is shorter than the remaining time of the inactive period of the complementary uplink carrier, the UE may select the normal uplink carrier.

[0264] (2) For example, if the remaining time of inactive period of the normal uplink carrier is longer than the remaining time of inactive period of the complementary uplink carrier, the UE may select the complementary uplink carrier.

[0265] (3) The UE may perform uplink transmission using the selected uplink carrier after the selected uplink carrier enters the active period.

[0266] When the uplink transmission is triggered, if both the normal uplink carrier and the complementary uplink carrier are in the inactive period, the UE may select an uplink carrier between the normal uplink carrier and the complementary uplink carrier based on the remaining time until the first transmission opportunity of each downlink carrier.

[0267] (1) For example, if the remaining time until the first transmission opportunity of the normal uplink carrier is shorter than the remaining time until the first opportunity of the complementary uplink carrier, the UE may select the normal uplink carrier.

[0268] (2) For example, if the remaining time until the first transmission opportunity of the normal uplink carrier is longer than remaining time until the first transmission opportunity of the complementary uplink carrier, the UE may select the complementary uplink carrier.

[0269] (3) The UE may perform uplink transmission using the selected uplink carrier.

[0270] FIG. 13 shows another example of random access procedure to which implementations of the present disclosure are applied.

[0271] when a random access (RA) procedure is triggered, if cell DRX is configured for a serving cell, the UE may select an uplink carrier based on a remaining time until a next active period of each uplink carrier. As shown in FIG. 13, the remaining time until the next active period of a normal uplink carrier (T1) is longer than remaining time until the next active period of a complementary uplink carrier (T2). Accordingly, the UE may transmit MSG1 using the complementary uplink carrier. In this case, since the complementary uplink carrier becomes available earlier, the delay in initiating the random access procedure may be reduced.

[0272] The present disclosure may have various advantageous effects.

[0273] For example, the network may achieve improved energy saving performance by enabling a complete cell DRX OFF operation for uplink transmissions, where no uplink transmission is performed during the cell DRX inactive period. In conventional approaches, even during the inactive period, the UE may still attempt uplink transmissions for delay-sensitive data, thereby reducing energy saving efficiency. In contrast, by restricting such transmissions, unnecessary power consumption can be reduced.

[0274] For example, by separating the transmission of urgent or delay-sensitive uplink data from the normal uplink carrier operating under cell DRX, the UE may maintain strict DRX inactivity while still supporting necessary uplink communication.

[0275] For example, from the UE perspective, urgent or delay-sensitive uplink data can be transmitted through a complementary uplink carrier even when the serving cell is in the cell DRX inactive period. Accordingly, the UE may transmit critical data without waiting for the next active period of the normal uplink carrier, thereby avoiding unnecessary transmission delay.

[0276] For example, by allowing the UE to perform uplink transmissions via a complementary uplink carrier during the cell DRX inactive period, the system can simultaneously achieve reduced power consumption and low-latency uplink data transmission. This enables a balanced operation in which energy efficiency is improved without degrading uplink transmission performance.

[0277] 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.

[0278] 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

A method comprising:receiving, by a wireless device, a configuration related to a first uplink carrier and a second uplink carrier for a serving cell;selecting, by the wireless device, an uplink carrier from the first uplink carrier and the second uplink carrier based on a discontinuous reception (DRX) state of the serving cell; andperforming, by the wireless device, an uplink transmission based on the selected uplink carrier.The method of claim 1, wherein, based on the DrX period of the serving cell being a drx active period, the first uplink carrier is selected as the uplink carrier.The method of claim 1, wherein, based on the drx period of the serving cell being a drx inactive period, the second uplink carrier is selected as the uplink carrier.The method of claim 1, wherein, based on the first uplink carrier being in an active period, the first uplink carrier is selected as the uplink carrier.The method of claim 1, wherein, based on the first uplink carrier being in an inactive period, the second uplink carrier is selected as the uplink carrier.The method of claim 1, wherein, based on a remaining time until next available transmission opportunity on the first uplink carrier exceeding a threshold, the second uplink carrier is selected as the uplink carrier.The method of claim 1, wherein, based on a remaining time until next available transmission opportunity on the first uplink carrier not exceeding a threshold, the first uplink carrier is selected as the uplink carrier.The method of claim 1, wherein, based on a remaining time until next active period of the first uplink carrier exceeding a threshold, the second uplink carrier is selected as the uplink carrier.The method of claim 1, wherein, based on a remaining time until next active period of the first uplink carrier not exceeding a threshold, the first uplink carrier is selected as the uplink carrier.The method of claim 1, wherein the second uplink carrier is related to more than one serving cell.The method of claim 1, wherein the uplink reception over the second uplink carrier is restricted to a specific type of uplink data or a specific procedure or a specific logical channel which is allowed to be transmitted over the second uplink carrier.The method of claim 1, wherein an activation or a deactivation of the first uplink carrier is indicated by network.The method of claim 1, wherein the first uplink carrier is selected as the uplink carrier based on:(i) a remaining time of an inactive period of the first uplink carrier being shorter than a remaining time of an inactive period of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in the inactive period.The method of claim 1, wherein the second uplink carrier is selected as the uplink carrier based on:(i) a remaining time of an inactive period of the first uplink carrier being longer than a remaining time of an inactive period of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in the inactive period.The method of claim 1, wherein the first uplink carrier is selected as the uplink carrier based on:(i) a remaining time until a first transmission opportunity of the first uplink carrier being shorter than a remaining time until a first transmission opportunity of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in an inactive period.The method of claim 1, wherein the second uplink carrier is selected as the uplink carrier based on:(i) a remaining time until a first transmission opportunity of the first uplink carrier being longer than a remaining time until a first transmission opportunity of the second uplink carrier, and (ii) both the first uplink carrier and the second uplink carrier being in an inactive period.The method of claim 1, wherein the configuration related to the first uplink carrier and the second uplink carrier for the serving cell includes information related to at least one of i) a state of the serving cell, ii) a state of the first uplink carrier, iii) a remaining time until a first transmission opportunity of the first uplink carrier, iv) a remaining time until a next active period of the first uplink carrier.A wireless device comprising:at least one processor; andat least one 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 comprising:receiving a configuration related to a first uplink carrier and a second uplink carrier for a serving cell;selecting an uplink carrier from the first uplink carrier and the second uplink carrier based on a discontinuous transmission (DRX) state of the serving cell; andperforming an uplink transmission based on the selected uplink carrier.A non-transitory computer-readable medium having stored thereon a plurality of instructions, which, when executed by a processor of a wireless device, cause the wireless device to perform operations, the operations comprising:receiving a configuration related to a first uplink carrier and a second uplink carrier for a serving cell;selecting an uplink carrier from the first uplink carrier and the second uplink carrier based on a discontinuous reception (DRX) state of the serving cell; andperforming an uplink transmission based on the selected uplink carrier.A method comprising:receiving, by a wireless device, a configuration related to a first uplink carrier and a second uplink carrier for a serving cell;wherein an uplink carrier from the first uplink carrier and the second uplink carrier is selected based on a discontinuous reception (DRX) state of the serving cell, andwherein the uplink transmission is performed based on the selected uplink carrier.A base station comprising:at least one processor; andat least one 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 comprising:transmitting, to a wireless device, a configuration related to a first uplink carrier and a second uplink carrier for a serving cell,wherein an uplink carrier from the first uplink carrier and the second uplink carrier is selected based on a discontinuous reception (DRX) state of the serving cell, andwherein the uplink transmission is performed based on the selected uplink carrier.

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