WO2020091546A1

WO2020091546A1 - Configuration coordination for power efficient operation for nr

Info

Publication number: WO2020091546A1
Application number: PCT/KR2019/014790
Authority: WO
Inventors: Yunjung Yi; Daesung HWANG
Original assignee: Lg Electronics Inc.
Priority date: 2018-11-02
Filing date: 2019-11-04
Publication date: 2020-05-07

Abstract

A method and apparatus for configuration coordination for power efficient operation for new radio access technology (NR). The wireless device may receive/apply a first configuration of a first parameter, of which a value is selected by the network, from a network. Alternatively or additionally, the wireless device may receive a second configuration of a second parameter, which informs that the wireless device is allowed to select a value of the second parameter, from the network, and select/apply the value of the second parameter.

Description

CONFIGURATION COORDINATION FOR POWER EFFICIENT OPERATION FOR NR

The present disclosure relates to configuration coordination for power efficient operation for new radio access technology (NR).

3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

Work has started in international telecommunication union (ITU) and 3GPP to develop requirements and specifications for new radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU radio communication sector (ITU-R) international mobile telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced mobile broadband (eMBB), massive machine-type-communications (mMTC), ultra-reliable and low latency communications (URLLC), etc. The NR shall be inherently forward compatible.

User equipment (UE) battery life is an important aspect of the user's experience, which will influence the adoption of 5G handsets and/or services. It is critical to study UE power consumption for Rel-16 to ensure that UE power efficiency for 5G NR UEs can be at least not worse than LTE, and techniques and designs for improvements are identified and adopted.

The present disclosure discusses mechanisms to support power efficient operation and effective network operation via network-UE coordination.

In an aspect, a method for a wireless device in a wireless communication system is provided. The method includes receiving/applying a first configuration of a first parameter, of which a value is selected by the network, from a network. The method further includes receiving a second configuration of a second parameter, which informs that the wireless device is allowed to select a value of the second parameter, from the network, and selecting/applying the value of the second parameter.

The present disclosure can have various advantageous effects.

For example, power efficient operation can be achieved.

Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and/or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.

FIG. 1 shows an example of a communication system to which the technical features of the present disclosure can be applied.

FIG. 2 shows an example of wireless devices to which the technical features of the present disclosure can be applied.

FIG. 3 shows an example of a signal processing circuit for a transmission signal to which the technical features of the present disclosure can be applied.

FIG. 4 shows another example of a wireless device to which the technical features of the present disclosure can be applied.

FIG. 5 shows an example of a hand-held device to which the technical features of the present disclosure can be applied.

FIG. 6 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 7 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 8 shows an example of a frame structure to which technical features of the present disclosure can be applied.

FIG. 9 shows another example of a frame structure to which technical features of the present disclosure can be applied.

FIG. 10 shows an example of a subframe structure used to minimize latency of data transmission when TDD is used in NR.

FIG. 11 shows an example of a resource grid to which technical features of the present disclosure can be applied.

FIG. 12 shows an example of a synchronization channel to which technical features of the present disclosure can be applied.

FIG. 13 shows an example of a frequency allocation scheme to which technical features of the present disclosure can be applied.

FIG. 14 shows an example of multiple BWPs to which technical features of the present disclosure can be applied.

FIG. 15 shows an example of SI acquisition procedure to which the technical features of the present disclosure can be applied.

FIG. 16 shows an example of random access procedure to which the technical features of the present disclosure can be applied.

FIG. 17 shows an example of threshold of SS/PBCH block for RACH resource association to which the technical features of the present disclosure can be applied.

FIG. 18 shows an example of power ramping to which the technical features of the present disclosure can be applied.

FIG. 19 shows an example of UE RRC state machine and state transitions in NR to which the technical features of the present disclosure can be applied.

FIG. 20 shows an example of UE state machine and state transitions as well as mobility procedures supported between NR/NGC and E-UTRAN/EPC to which the technical features of the present disclosure can be applied.

FIG. 21 shows an example of DRX cycle to which the technical features of the present disclosure can be applied.

FIG. 22 shows an example of configuration coordination according to an embodiment of the present disclosure.

FIG. 23 shows another example of configuration coordination according to an embodiment of the present disclosure.

FIG. 24 shows an example of a method for a UE according to an embodiment of the present disclosure.

The technical features described below may be used by a communication standard by the 3rd generation partnership project (3GPP) standardization organization, a communication standard by the institute of electrical and electronics engineers (IEEE), etc. For example, the communication standards by the 3GPP standardization organization include long-term evolution (LTE) and/or evolution of LTE systems. The evolution of LTE systems includes LTE-advanced (LTE-A), LTE-A Pro, and/or 5G new radio (NR). The communication standard by the IEEE standardization organization includes a wireless local area network (WLAN) system such as IEEE 802.11a/b/g/n/ac/ax. The above system uses various multiple access technologies such as orthogonal frequency division multiple access (OFDMA) and/or single carrier frequency division multiple access (SC-FDMA) for downlink (DL) and/or uplink (UL). For example, only OFDMA may be used for DL and only SC-FDMA may be used for UL. Alternatively, OFDMA and SC-FDMA may be used for DL and/or UL.

In the present disclosure, the term "/" and "," should be interpreted to indicate "and/or." For instance, the expression "A/B" may mean "A and/or B." Further, "A, B" may mean "A and/or B." Further, "A/B/C" may mean "at least one of A, B, and/or C." Also, "A, B, C" may mean "at least one of A, B, and/or C."

Further, in the present disclosure, the term "or" should be interpreted to indicate "and/or." For instance, the expression "A or B" may comprise 1) only A, 2) only B, and/or 3) both A and B. In other words, the term "or" in the present disclosure should be interpreted to indicate "additionally or alternatively."

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.

An example of a communication system to which the technical features of the present disclosure can be applied is described.

Although not limited thereto, various descriptions, functions, procedures, suggestions, methods and/or operational flowcharts of the present disclosure disclosed herein can be applied to various fields requiring wireless communication and/or connection (e.g., 5G) between devices.

Hereinafter, the present disclosure will be described in more detail with reference to drawings. The same reference numerals in the following drawings and/or descriptions may refer to the same and/or corresponding hardware blocks, software blocks, and/or functional blocks unless otherwise indicated.

Referring to FIG. 1, a communication system 1 to which the technical features of the present disclosure can be applied includes a wireless device, a base station and a network. Here, the wireless device refers to a device that performs communication using a radio access technology (e.g., 5G new radio access technology (NR), long-term evolution (LTE)), and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot 100a, a vehicle 100b-1, 100b-2, an extended reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an internet of things (IoT) device 100f and an artificial intelligence (AI) device / server 400. For example, the vehicle may include a vehicle having a wireless communication function, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices. The XR device may be implemented in the form of head-mounted device (HMD), head-up display (HUD) provided in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. The hand-held device device may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.). The home appliance may include a TV, a refrigerator, a washing machine, etc. The IoT device may include a sensor, a smart meter, etc. For example, the base station and the network may be implemented as a wireless device. A specific wireless device 200a may operate as a base station / network node to other wireless devices.

The wireless devices 100a to 100f may be connected to the network 300 through the base station 200. 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 through the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network and/or a 5G (e.g., NR) network. The wireless devices 100a to 100f may communicate with each other via the base station 200 / network 300, but may also communicate directly (e.g., sidelink communication) without passing through the base station 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). In addition, the IoT device (e.g., sensor) may directly communicate with another IoT device (e.g., sensor) or another wireless device 100a to 100f.

Wireless communication /

connections

150a, 150b, and 150c may be performed between the wireless devices 100a to 100f and the base station 200 and/or between the base stations 200. Here, the wireless communication / connection may be performed by various wireless access technologies (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 device and the base station / wireless device and/or the base stations may transmit / receive wireless signals with each other respectively through the wireless communication /

connection

150a, 150b, and 150c. For example, wireless communications /

connections

150a, 150b, and 150c may transmit / receive signals over various physical channels. To this end, based on various proposals of the present disclosure, at least some of various configuration information setting processes, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / de-mapping, etc.), and resource allocation process for transmitting / receiving a wireless signal may be performed.

Referring to FIG. 2, the first wireless device 100 and the second wireless device 200 may transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device 100 and the second wireless device 200} may correspond to {the wireless device 100x, the base station 200} and/or {the wireless device 100x, the wireless device 100x} in FIG. 1.

The first wireless device 100 may include one or more processors 102 and one or more memories 104. The first wireless device 100 may further include one or more transceivers 106 and/or one or more antennas 108. The processor 102 may control the memory 104 and/or the transceiver 106. The processor 102 may be configured to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. For example, the processor 102 may process information in the memory 104 to generate the first information/signal, and then transmit a wireless signal including the first information/signal through the transceiver 106. In addition, the processor 102 may receive a wireless signal including the second information/signal through the transceiver 106 and then store information obtained from signal processing of the second information/signal in the memory 104. The memory 104 may be coupled to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may include software code that includes instructions for performing some or all of the processes controlled by the processor 102 and/or for carrying out the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 106 may be coupled with the processor 102 and may transmit and/or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and/or a receiver. The transceiver 106 may be mixed with a radio frequency (RF) unit. In the present disclosure, a wireless device may mean a communication modem / circuit / chip.

The second wireless device 200 may include one or more processors 202 and one or more memories 204. The second wireless device 200 may further include one or more transceivers 206 and/or one or more antennas 208. The processor 202 may control the memory 204 and/or the transceiver 206. The processor 202 may be configured to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. For example, the processor 202 may process information in the memory 204 to generate the third information/signal, and then transmit a wireless signal including the third information/signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including the fourth information/signal through the transceiver 206 and then store information obtained from signal processing of the fourth information/signal in the memory 204. The memory 204 may be coupled to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may include software code that includes instructions for performing some or all of the processes controlled by the processor 202 and/or for carrying out the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. Here, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 206 may be coupled with the processor 202 and may transmit and/or receive wireless signals via one or more antennas 208. The transceiver 206 may include a transmitter and/or a receiver. The transceiver 206 may be mixed with an RF unit. In the present disclosure, a wireless device may mean a communication modem / circuit / chip.

Hereinafter, hardware elements of the

wireless devices

100, 200 will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or

more processors

102, 202. For example, one or

more processors

102, 202 may implement one or more layers (e.g., functional layers such as physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), radio resource control (RRC)). One or

more processors

102, 202 may generate one or more protocol data units (PDUs) and/or one or more service data units (SDUs) in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. One or

more processors

102, 202 may generate messages, control information, data, or information in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. One or

more processors

102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, and provide to one or

more transceivers

106, 206. One or

more processors

102, 202 may receive signals (e.g., baseband signals) from one or

more transceivers

106, 206, and obtain PDUs, SDUs, messages, control information, data or information in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein.

One or

more processors

102, 202 may be referred to as a controller, a microcontroller, a microprocessor, and/or a microcomputer. One or

more processors

102, 202 may be implemented by hardware, firmware, software, and/or a combination thereof. For 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), and/or one or more field programmable gate arrays (FPGAs) may be included in one or

more processors

102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein may be implemented using firmware and/or software, and the firmware and/or software may be implemented to include modules, procedures, functions, etc. Firmware and/or software configured to perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein may be included in one or

more processors

102, 202 or stored in one or

more memories

104, 204 and may be driven by one or

more processors

102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein may be implemented using firmware or software in the form of code, instructions and/or a set of instructions.

One or

more memories

104, 204 may be coupled with one or

more processors

102, 202 and may store various forms of data, signals, messages, information, programs, codes, instructions, and/or commands. One or

more memories

104, 204 may be comprised of a read-only memory (ROM), a random access memory (RAM), an erasable programmable read-only memory (EPROM), a flash memory, a hard drive, a register, a cache memory, a computer readable storage medium and/or combinations thereof. One or

more memories

104, 204 may be located inside and/or outside one or

more processors

102, 202. In addition, one or

more memories

104, 204 may be coupled to one or

more processors

102, 202 through various techniques, such as a wired and/or wireless connection.

One or

more transceivers

106, 206 may transmit user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, to one or more other devices. One or

more transceivers

106, 206 may receive user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, from one or more other devices. For example, one or

more transceivers

106, 206 may be coupled with one or

more processors

102, 202 and may transmit and/or receive wireless signals. For example, one or

more processors

102, 202 may control one or

more transceivers

106, 206 to transmit user data, control information, wireless signals/channels, etc., to one or more other devices. In addition, one or

more processors

102, 202 may control one or

more transceivers

106, 206 to receive user data, control information, wireless signals/channels, etc., from one or more other devices. In addition, one or

more transceivers

106, 206 may be coupled to one or

more antennas

108, 208. One or

more transceivers

106, 206 may be configured to transmit and/or receive user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, through one or

more antennas

108, 208. In the present disclosure, one or

more antennas

108, 208 may be a plurality of physical antennas and/or a plurality of logical antennas (e.g., antenna ports). In order to process the received user data, control information, wireless signals/channels, etc., using one or

more processors

102, 202, one or

more transceivers

106, 206 may convert the received user data, control information, wireless signals/channels, etc., from an RF band signal to a baseband signal. One or

more transceivers

106, 206 may convert user data, control information, wireless signals/channels, etc., processed by using one or

more processors

102, 202, from a baseband signal to an RF band signal. To this end, one or

more transceivers

106, 206 may include (analog) oscillators and/or filters.

Referring to FIG. 3, the signal processing circuit 1000 may include a scrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040, a resource mapper 1050, and a signal generator 1060. Although not limited thereto, operations/functions of FIG. 3 may be performed in

processors

102, 202 and/or

transceivers

106, 206 of FIG. 2. The hardware element of FIG. 3 may be implemented in

processors

102, 202 and/or

transceivers

106, 206 of FIG. 2. For example, blocks 1010 to 1060 may be implemented in

processors

102, 202 of FIG. 2. Further, blocks 1010 to 1050 may be implemented in

processors

102, 202 of FIG. 2, and block 1060 may be implemented in

transceivers

106, 206 of FIG. 2.

The codeword may be converted into a wireless signal via the signal processing circuit 1000 of FIG. 3. Here, the codeword is a coded bit sequence of the information block. The information block may include a transport block (e.g., an uplink shared channel (UL-SCH) transport block, a downlink shared channel (DL-SCH) transport block). The wireless signal may be transmitted through various physical channels (e.g., physical uplink shared channel (PUSCH), physical downlink shared channel (PDSCH)).

In detail, the codeword may be converted into a scrambled bit sequence by the scrambler 1010. The scramble bit sequence used for scrambling may be generated based on initialization value, and the initialization value may include ID information of the wireless device, etc. The scrambled bit sequence may be modulated into a modulation symbol sequence by the modulator 1020. The modulation scheme may include pi/2-binary phase shift keying (pi/2-BPSK), m-phase shift keying (m-PSK), m-quadrature amplitude modulation (m-QAM), etc. The complex modulation symbol sequence may be mapped to one or more transport layers by the layer mapper 1030. The modulation symbols of each transport layer may be mapped to the corresponding antenna port(s) by the precoder 1040 (precoding). The output z of the precoder 1040 may be obtained by multiplying the output y of the layer mapper 1030 with the precoding matrix W of N*M. Here, N is the number of antenna ports and M is the number of transport layers. Here, the precoder 1040 may perform precoding after performing transform precoding (e.g., discrete Fourier transform (DFT)) on the complex modulation symbols. Also, the precoder 1040 may perform precoding without performing transform precoding.

The resource mapper 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resource may include a plurality of symbols (e.g., cyclic prefix based OFDMA (CP-OFDMA) symbols, DFT spread OFDMA (DFT-s-OFDMA) symbols) in the time domain, and may include a plurality of subcarriers in the frequency domain. The signal generator 1060 may generate a wireless signal from the mapped modulation symbols, and the generated wireless signal may be transmitted to another device through each antenna. To this end, the signal generator 1060 may include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), a frequency uplink converter, etc.

The signal processing procedure for a reception signal in the wireless device may be configured in the reverse of the signal processing procedure 1010 to 1060 of FIG. 3. For example, a wireless device (e.g., 100, 200 of FIG. 2) may receive a wireless signal from the outside through an antenna port/transceiver. The received wireless signal may be converted into a baseband signal through a signal recoverer. To this end, the signal recoverer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP canceller, and a fast Fourier transform (FFT) module. Thereafter, the baseband signal may be restored to a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scrambling process. The codeword may be restored to the original information block through decoding. Thus, the signal processing circuit for the reception signal (not shown) may include a signal recoverer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler and a decoder.

The wireless device may be implemented in various forms depending on use cases / services (see FIG. 1). Referring to FIG. 4, the

wireless devices

100, 200 may correspond to the

wireless devices

100, 200 of FIG. 2, and may be composed of various elements, components, units, and/or modules. For example, the

wireless device

100, 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional components 140. The communication unit 110 may include a communication circuitry 112 and transceiver(s) 114. For example, the communication circuitry 112 may include one or

more processors

102, 202 and/or one or

more memories

104, 204 of FIG. 2. For example, the transceiver(s) 114 may include one or

more transceivers

106, 206 and/or one or

more antennas

108, 208 of FIG. 2. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional components 140, and controls various operations of the

wireless device

100, 200. For example, the control unit 120 may control the electrical/mechanical operation of the

wireless device

100, 200 based on the program/code/command/information stored in the memory unit 130. In addition, the control unit 120 may transmit the information stored in the memory unit 130 to the outside (e.g., other communication devices) through the communication unit 110 through a wireless/wired interface, or may store the information received from the outside (e.g., other communication devices) through the wireless/wired interface through the communication unit 110 in the memory unit 130.

The additional components 140 may be variously configured according to the type of the

wireless device

100, 200. For example, the additional components 140 may include at least one of a power unit/battery, an input/output (I/O) unit, a driver, or a computing unit. Although not limited thereto, the

wireless devices

100, 200 may be implemented in the form of robots (FIG. 1, 100a), vehicles (FIG. 1, 100b-1, 100b-2), XR devices (FIG. 1, 100c), hand-held devices (FIG. 1, 100d), home appliances (FIG. 1, 100e), IoT devices (FIG. 1, 100f), terminals for digital broadcasting, hologram devices, public safety devices, machine-type communication (MTC) devices, medical devices, fin-tech devices (or financial devices), security devices, climate/environment devices, an AI server/devices (FIG. 1, 400), a base station (FIG. 1, 200), a network node, etc. The

wireless device

100, 200 may be used in a mobile or fixed location depending on use cases / services.

In FIG. 4, various elements, components, units, and/or modules within the

wireless device

100, 200 may be entirely interconnected via a wired interface, or at least a part of the

wireless device

100, 200 may be wirelessly connected through the communication unit 110. For example, in the

wireless device

100, 200, the control unit 120 and the communication unit 110 may be connected by wire, and the control unit 120 and the first unit (e.g., 130, 140) may be wirelessly connected through the communication unit 110. In addition, each element, component, unit, and/or module in the

wireless device

100, 200 may further include one or more elements. For example, the control unit 120 may be composed of one or more processor sets. For example, the control unit 120 may be configured as a set of a communication control processor, an application processor (AP), an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit 130 may include RAM, a dynamic RAM (DRAM), ROM, a flash memory, a volatile memory, a non-volatile memory, and/or combinations thereof.

The hand-held device 100 may include a smart phone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a portable computer (e.g., a notebook, etc.). The hand-held device 100 may be referred to as a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), or a wireless terminal (WT).

Referring to FIG. 5, the hand-held device 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a memory unit 130, a power supply unit 140a, an interface unit 140b, and an I/O unit 140c. The antenna unit 108 may be configured as a part of the communication unit 110. Blocks 110 to 130 / 140a to 140c may correspond to blocks 110 to 130 / 140 of FIG 4, respectively.

The communication unit 110 may transmit and/or receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit 120 may control various components of the hand-held device 100 to perform various operations. The control unit 120 may include an AP. The memory unit 130 may store data, parameters, programs, codes and/or commands necessary for driving the hand-held device 100. In addition, the memory unit 130 may store input/output data/information, etc. The power supply unit 140a may supply power to the hand-held device 100 and may include a wired/wireless charging circuit, a battery, etc. The interface unit 140b may support connection of the hand-held device 100 to another external device. The interface unit 140b may include various ports (e.g., audio input/output ports, video input/output ports, etc.) for connecting to an external device. The I/O unit 140c may receive and/or output image information/signal, audio information/signal, data and/or information input from a user. The I/O unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker and/or a haptic module.

For example, in case of data communication, the I/O unit 140c may obtain information/signals (e.g., touch, text, voice, image, and video) input from the user, and the obtained information/signals may be stored in the memory unit 130. The communication unit 110 may convert the information/signals stored in the memory unit 130 into a wireless signal. The communication unit 110 may directly transmit the converted wireless signal to another wireless device or may transmit the converted wireless signal to a base station. In addition, the communication unit 110 may receive a wireless signal from another wireless device or a base station, and then restore the received wireless signal to original information/signal. The restored information/signal may be stored in the memory unit 130 and then output in various forms (e.g., text, voice, image, video, and haptic) through the I/O unit 140c.

Specifically, FIG. 6 shows a system architecture based on an evolved-UMTS terrestrial radio access network (E-UTRAN). The aforementioned LTE is a part of an evolved-UTMS (e-UMTS) using the E-UTRAN.

Referring to FIG. 6, the wireless communication system includes one or more user equipment (UE) 100, an E-UTRAN and an evolved packet core (EPC). The UE 100 refers to a communication equipment carried by a user. The UE 100 may be fixed or mobile. The UE 100 may be referred to as another terminology, such as MS, UT, SS, a wireless device, etc. The UE 100 may correspond to the wireless device 100x of FIG. 1, the first wireless device 100 of FIG. 2, the wireless device 100 of FIG. 4, or the hand-held device 100 of FIG. 5.

The E-UTRAN consists of one or more evolved NodeB (eNB) 200. The eNB 200 provides the E-UTRA user plane and control plane protocol terminations towards the UE 100. The eNB 200 is generally a fixed station that communicates with the UE 100. The eNB 200 hosts the functions, such as inter-cell radio resource management (RRM), radio bearer (RB) control, connection mobility control, radio admission control, measurement configuration/provision, dynamic resource allocation (scheduler), etc. The eNB 200 may be referred to as another terminology, such as a base station (BS), a base transceiver system (BTS), an access point (AP), etc. The eNB 200 may correspond to the base station 200 of FIG. 1, the second wireless device 200 of FIG. 2, or the wireless device 200 of FIG. 4.

A downlink (DL) denotes communication from the eNB 200 to the UE 100. An uplink (UL) denotes communication from the UE 100 to the eNB 200. A sidelink (SL) denotes communication between the UEs 100. In the DL, a transmitter may be a part of the eNB 200, and a receiver may be a part of the UE 100. In the UL, the transmitter may be a part of the UE 100, and the receiver may be a part of the eNB 200. In the SL, the transmitter and receiver may be a part of the UEs 100.

The EPC includes a mobility management entity (MME), a serving gateway (S-GW) and a packet data network (PDN) gateway (P-GW). The MME hosts the functions, such as non-access stratum (NAS) security, idle state mobility handling, evolved packet system (EPS) bearer control, etc. The S-GW hosts the functions, such as mobility anchoring, etc. The S-GW is a gateway having an E-UTRAN as an endpoint. For convenience, MME/S-GW 300 will be referred to herein simply as a "gateway," but it is understood that this entity includes both the MME and S-GW. The P-GW hosts the functions, such as UE Internet protocol (IP) address allocation, packet filtering, etc. The P-GW is a gateway having a PDN as an endpoint. The P-GW is connected to an external network. The MME/S-GW 300 may correspond to the network 300 of FIG. 1.

The UE 100 is connected to the eNB 200 by means of the Uu interface. The UEs 100 are interconnected with each other by means of the PC5 interface. The eNBs 200 are interconnected with each other by means of the X2 interface. The eNBs 200 are also connected by means of the S1 interface to the EPC, more specifically to the MME by means of the S1-MME interface and to the S-GW by means of the S1-U interface. The S1 interface supports a many-to-many relation between MMEs / S-GWs and eNBs.

Specifically, FIG. 7 shows a system architecture based on a 5G NR. The entity used in the 5G NR (hereinafter, simply referred to as "NR") may absorb some or all of the functions of the entities introduced in FIG. 6 (e.g., eNB, MME, S-GW). The entity used in the NR may be identified by the name "NG" for distinction from the LTE/LTE-A.

Referring to FIG. 7, the wireless communication system includes one or more UE 100, a next-generation RAN (NG-RAN) and a 5th generation core network (5GC). The NG-RAN consists of at least one NG-RAN node. The NG-RAN node is an entity corresponding to the eNB 200 shown in FIG. 6. The NG-RAN node consists of at least one gNB 200 and/or at least one ng-eNB 200. The gNB 200 provides NR user plane and control plane protocol terminations towards the UE 100. The ng-eNB 200 provides E-UTRA user plane and control plane protocol terminations towards the UE 100. The gNB 200 and/or ng-eNB 200 may correspond to the base station 200 of FIG. 1, the second wireless device 200 of FIG. 2, or the wireless device 200 of FIG. 4.

The 5GC includes an access and mobility management function (AMF), a user plane function (UPF) and a session management function (SMF). The AMF hosts the functions, such as NAS security, idle state mobility handling, etc. The AMF is an entity including the functions of the conventional MME. The UPF hosts the functions, such as mobility anchoring, PDU handling. The UPF an entity including the functions of the conventional S-GW. The SMF hosts the functions, such as UE IP address allocation, PDU session control.

The gNBs 200 and ng-eNBs 200 are interconnected with each other by means of the Xn interface. The gNBs 200 and ng-eNBs 200 are also connected by means of the NG interfaces to the 5GC, more specifically to the AMF by means of the NG-C interface and to the UPF by means of the NG-U interface.

Hereinafter, frame structure/physical resources in NR is described.

In LTE/LTE-A, one radio frame consists of 10 subframes, and one subframe consists of 2 slots. A length of one subframe may be 1ms, and a length of one slot may be 0.5ms. Time for transmitting one transport block by higher layer to physical layer (generally over one subframe) is defined as a transmission time interval (TTI). A TTI may be the minimum unit of scheduling.

In NR, DL and UL transmissions are performed over a radio frame with a duration of 10ms. Each radio frame includes 10 subframes. Thus, one subframe corresponds to 1ms. Each radio frame is divided into two half-frames.

Unlike LTE/LTE-A, NR supports various numerologies, and accordingly, the structure of the radio frame may be varied. NR supports multiple subcarrier spacings in frequency domain. Table 1 shows multiple numerologies supported in NR. Each numerology may be identified by index μ.

μ	Subcarrier spacing (kHz)	Cyclic prefix	Supported for data	Supported for synchronization
0	15	Normal	Yes	Yes
1	30	Normal	Yes	Yes
2	60	Normal, Extended	Yes	No
3	120	Normal	Yes	Yes
4	240	Normal	No	Yes

Referring to Table 1, a subcarrier spacing may be set to any one of 15, 30, 60, 120, and 240 kHz, which is identified by index μ. However, subcarrier spacings shown in Table 1 are merely exemplary, and specific subcarrier spacings may be changed. Therefore, each subcarrier spacing (e.g., μ=0,1...4) may be represented as a first subcarrier spacing, a second subcarrier spacing...Nth subcarrier spacing.

Referring to Table 1, transmission of user data (e.g., PUSCH, PDSCH) may not be supported depending on the subcarrier spacing. That is, transmission of user data may not be supported only in at least one specific subcarrier spacing (e.g., 240 kHz).

In addition, referring to Table 1, a synchronization channel (e.g., a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH)) may not be supported depending on the subcarrier spacing. That is, the synchronization channel may not be supported only in at least one specific subcarrier spacing (e.g., 60 kHz).

One subframe includes N_symb ^subframe,μ = N_symb ^slot * N_slot ^subframe,μ consecutive OFDM symbols. In NR, a number of slots and a number of symbols included in one radio frame/subframe may be different according to various numerologies, i.e., various subcarrier spacings.

Table 2 shows an example of a number of OFDM symbols per slot (N_symb ^slot), a number of slots per radio frame (N_symb ^frame,μ), and a number of slots per subframe (N_symb ^subframe,μ) for each numerology in normal cyclic prefix (CP).

μ	Number of OFDM symbols per slot(N_symb ^slot)	Number of slots per radio frame (N_symb ^frame,μ)	Number of slots per subframe(N_symb ^subframe,μ)
0	14	10	1
1	14	20	2
2	14	40	4
3	14	80	8
4	14	160	16

Referring to Table 2, when a first numerology corresponding to μ=0 is applied, one radio frame includes 10 subframes, one subframe includes to one slot, and one slot consists of 14 symbols.

Table 3 shows an example of a number of OFDM symbols per slot (N_symb ^slot), a number of slots per radio frame (N_symb ^frame,μ), and a number of slots per subframe (N_symb ^subframe,μ) for each numerology in extended CP.

μ	Number of OFDM symbols per slot(N_symb ^slot)	Number of slots per radio frame (N_symb ^frame,μ)	Number of slots per subframe(N_symb ^subframe,μ)
2	12	40	4

Referring to Table 3, μ=2 is only supported in extended CP. One radio frame includes 10 subframes, one subframe includes to 4 slots, and one slot consists of 12 symbols.

In the present disclosure, a symbol refers to a signal transmitted during a specific time interval. For example, a symbol may refer to a signal generated by OFDM processing. That is, a symbol in the present disclosure may refer to an OFDM/OFDMA symbol, or SC-FDMA symbol, etc. A CP may be located between each symbol.

FIG. 8 shows an example of a frame structure to which technical features of the present disclosure can be applied. FIG. 9 shows another example of a frame structure to which technical features of the present disclosure can be applied.

In FIG. 8, a subcarrier spacing is 15 kHz, which corresponds to μ=0. In FIG. 9, a subcarrier spacing is 30 kHz, which corresponds to μ=1.

Meanwhile, a frequency division duplex (FDD) and/or a time division duplex (TDD) may be applied to a wireless communication system to which an embodiment of the present disclosure is applied. When TDD is applied, in LTE/LTE-A, UL subframes and DL subframes are allocated in units of subframes.

In NR, symbols in a slot may be classified as a DL symbol (denoted by D), a flexible symbol (denoted by X), and a UL symbol (denoted by U). In a slot in a DL frame, the UE shall assume that DL transmissions only occur in DL symbols or flexible symbols. In a slot in an UL frame, the UE shall only transmit in UL symbols or flexible symbols. The flexible symbol may be referred to as another terminology, such as reserved symbol, other symbol, unknown symbol, etc.

Table 4 shows an example of a slot format which is identified by a corresponding format index. The contents of the Table 4 may be commonly applied to a specific cell, or may be commonly applied to adjacent cells, or may be applied individually or differently to each UE.

Format

Symbol number in a slot

0

1

2

3

4

5

6

7

8

9

10

11

12

13

0

D

1

U

2

X

3

D

X

...

For convenience of explanation, Table 4 shows only a part of the slot format actually defined in NR. The specific allocation scheme may be changed or added.

The UE may receive a slot format configuration via a higher layer signaling (i.e., RRC signaling). Or, the UE may receive a slot format configuration via downlink control information (DCI) which is received on PDCCH. Or, the UE may receive a slot format configuration via combination of higher layer signaling and DCI.

The subframe structure shown in FIG. 10 may be called a self-contained subframe structure. Referring to FIG. 10, the subframe includes DL control channel in the first symbol, and UL control channel in the last symbol. The remaining symbols may be used for DL data transmission and/or for UL data transmission. According to this subframe structure, DL transmission and UL transmission may sequentially proceed in one subframe. Accordingly, the UE may both receive DL data and transmit UL acknowledgement/non-acknowledgement (ACK/NACK) in the subframe. As a result, it may take less time to retransmit data when a data transmission error occurs, thereby minimizing the latency of final data transmission.

In the self-contained subframe structure, a time gap may be required for the transition process from the transmission mode to the reception mode or from the reception mode to the transmission mode. For this purpose, some symbols at the time of switching from DL to UL in the subframe structure may be set to the guard period (GP).

An example shown in FIG. 11 is a time-frequency resource grid used in NR. An example shown in FIG. 11 may be applied to UL and/or DL.

Referring to FIG. 11, multiple slots are included within one subframe on the time domain. Specifically, when expressed according to the value of "μ", "14·2μ" symbols may be expressed in the resource grid. Also, one resource block (RB) may occupy 12 consecutive subcarriers. One RB may be referred to as a physical resource block (PRB), and 12 resource elements (REs) may be included in each PRB. The number of allocatable RBs may be determined based on a minimum value and a maximum value. The number of allocatable RBs may be configured individually according to the numerology ("μ"). The number of allocatable RBs may be configured to the same value for UL and DL, or may be configured to different values for UL and DL.

NR supports multiple numerology (or, subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, wide area in traditional cellular bands may be supported. When the SCS is 30 kHz/60 kHz, dense-urban, lower latency and wider carrier bandwidth may be supported. When the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz may be supported to overcome phase noise.

The NR frequency band may be defined as two types of frequency range, i.e., FR1 and 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 5 below. For ease of explanation, in the frequency ranges used in the NR system, FR1 may mean "sub 6 GHz range", FR2 may mean "above 6 GHz range," and may be referred to as millimeter wave (mmW).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	450MHz - 6000MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

As mentioned above, the numerical value of the frequency range of the NR system may be changed. For example, FR1 may include a frequency band of 410MHz to 7125MHz as shown in Table 6 below. That is, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	410MHz - 7125MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

Hereinafter, a cell search in NR is described.

The UE may perform cell search in order to acquire time and/or frequency synchronization with a cell and to acquire a cell identifier (ID). Synchronization channels such as PSS, SSS, and PBCH may be used for cell search.

Referring to FIG. 12, the PSS and SSS may include one symbol and 127 subcarriers. The PBCH may include 3 symbols and 240 subcarriers.

The PSS is used for SS/PBCH block symbol timing acquisition. The PSS indicates 3 hypotheses for cell ID identification. The SSS is used for cell ID identification. The SSS indicates 336 hypotheses. Consequently, 1008 physical layer cell IDs may be configured by the PSS and the SSS.

The SS/PBCH block may be repeatedly transmitted according to a predetermined pattern within the 5ms window. For example, when L SS/PBCH blocks are transmitted, all of SS/PBCH block #1 through SS/PBCH block #L may contain the same information, but may be transmitted through beams in different directions. That is, quasi co-located (QCL) relationship may not be applied to the SS/PBCH blocks within the 5ms window. The beams used to receive the SS/PBCH block may be used in subsequent operations between the UE and the network (e.g., random access operations). The SS/PBCH block may be repeated by a specific period. The repetition period may be configured individually according to the numerology.

Referring to FIG. 12, the PBCH has a bandwidth of 20 RBs for the 2nd/4th symbols and 8 RBs for the 3rd symbol. The PBCH includes a demodulation reference signal (DM-RS) for decoding the PBCH. The frequency domain for the DM-RS is determined according to the cell ID. Unlike LTE/LTE-A, since a cell-specific reference signal (CRS) is not defined in NR, a special DM-RS is defined for decoding the PBCH (i.e., PBCH-DMRS). The PBCH-DMRS may contain information indicating an SS/PBCH block index.

The PBCH performs various functions. For example, the PBCH may perform a function of broadcasting a master information block (MIB). System information (SI) is divided into a minimum SI and other SI. The minimum SI may be divided into MIB and system information block type-1 (SIB1). The minimum SI excluding the MIB may be referred to as a remaining minimum SI (RMSI). That is, the RMSI may refer to the SIB1.

The MIB includes information necessary for decoding SIB1. For example, the MIB may include information on a subcarrier spacing applied to SIB1 (and MSG 2/4 used in the random access procedure, other SI), information on a frequency offset between the SS/PBCH block and the subsequently transmitted RB, information on a bandwidth of the PDCCH/SIB, and information for decoding the PDCCH (e.g., information on search-space/control resource set (CORESET)/DM-RS, etc., which will be described later). The MIB may be periodically transmitted, and the same information may be repeatedly transmitted during 80ms time interval. The SIB1 may be repeatedly transmitted through the PDSCH. The SIB1 includes control information for initial access of the UE and information for decoding another SIB.

Hereinafter, DL control channel in NR is described.

The search space for the PDCCH corresponds to aggregation of control channel candidates on which the UE performs blind decoding. In LTE/LTE-A, the search space for the PDCCH is divided into a common search space (CSS) and a UE-specific search space (USS). The size of each search space and/or the size of a control channel element (CCE) included in the PDCCH are determined according to the PDCCH format.

In NR, a resource-element group (REG) and a CCE for the PDCCH are defined. In NR, the concept of CORESET is defined. Specifically, one REG corresponds to 12 REs, i.e., one RB transmitted through one OFDM symbol. Each REG includes a DM-RS. One CCE includes a plurality of REGs (e.g., 6 REGs). The PDCCH may be transmitted through a resource consisting of 1, 2, 4, 8, or 16 CCEs. The number of CCEs may be determined according to the aggregation level. That is, one CCE when the aggregation level is 1, 2 CCEs when the aggregation level is 2, 4 CCEs when the aggregation level is 4, 8 CCEs when the aggregation level is 8, 16 CCEs when the aggregation level is 16, may be included in the PDCCH for a specific UE.

The CORESET is a set of resources for control signal transmission. The CORESET may be defined on 1/2/3 OFDM symbols and multiple RBs. In LTE/LTE-A, the number of symbols used for the PDCCH is defined by a physical control format indicator channel (PCFICH). However, the PCFICH is not used in NR. Instead, the number of symbols used for the CORESET may be defined by the RRC message (and/or PBCH/SIB1). Also, in LTE/LTE-A, since the frequency bandwidth of the PDCCH is the same as the entire system bandwidth, so there is no signaling regarding the frequency bandwidth of the PDCCH. In NR, the frequency domain of the CORESET may be defined by the RRC message (and/or PBCH/SIB1) in a unit of RB.

The base station may transmit information on the CORESET to the UE. For example, information on the CORESET configuration may be transmitted for each CORESET. Via the information on the CORESET configuration, at least one of a time duration of the corresponding CORESET (e.g., 1/2/3 symbol), frequency domain resources (e.g., RB set), REG-to-CCE mapping type (e.g., whether interleaving is applied or not), precoding granularity, a REG bundling size (when the REG-to-CCE mapping type is interleaving), an interleaver size (when the REG-to-CCE mapping type is interleaving) and a DMRS configuration (e.g., scrambling ID) may be transmitted. When interleaving to distribute the CCE to 1-symbol CORESET is applied, bundling of two or six REGs may be performed. Bundling of two or six REGs may be performed on the two symbols CORESET, and time first mapping may be applied. Bundling of three or six REGs may be performed on the three symbols CORESET, and a time first mapping may be applied. When REG bundling is performed, the UE may assume the same precoding for the corresponding bundling unit.

In NR, the search space for the PDCCH is divided into CSS and USS. The search space may be configured in CORESET. As an example, one search space may be defined in one CORESET. In this case, CORESET for CSS and CORESET for USS may be configured, respectively. As another example, a plurality of search spaces may be defined in one CORESET. That is, CSS and USS may be configured in the same CORESET. In the following example, CSS means CORESET in which CSS is configured, and USS means CORESET in which USS is configured. Since the USS may be indicated by the RRC message, an RRC connection may be required for the UE to decode the USS. The USS may include control information for PDSCH decoding assigned to the UE.

Since the PDCCH needs to be decoded even when the RRC configuration is not completed, CSS should also be defined. For example, CSS may be defined when a PDCCH for decoding a PDSCH that conveys SIB1 is configured or when a PDCCH for receiving MSG 2/4 is configured in a random access procedure. Like LTE/LTE-A, in NR, the PDCCH may be scrambled by a radio network temporary identifier (RNTI) for a specific purpose.

A resource allocation in NR is described.

In NR, a specific number (e.g., up to 4) of bandwidth parts (BWPs) may be defined. A BWP (or carrier BWP) is a set of consecutive PRBs, and may be represented by a consecutive subsets of common RBs (CRBs). Each RB in the CRB may be represented by CRB1, CRB2, etc., beginning with CRB0.

Referring to FIG. 13, multiple BWPs may be defined in the CRB grid. A reference point of the CRB grid (which may be referred to as a common reference point, a starting point, etc.) is referred to as so-called "point A" in NR. The point A is indicated by the RMSI (i.e., SIB1). Specifically, the frequency offset between the frequency band in which the SS/PBCH block is transmitted and the point A may be indicated through the RMSI. The point A corresponds to the center frequency of the CRB0. Further, the point A may be a point at which the variable "k" indicating the frequency band of the RE is set to zero in NR. The multiple BWPs shown in FIG. 13 is configured to one cell (e.g., primary cell (PCell)). A plurality of BWPs may be configured for each cell individually or commonly.

Referring to FIG. 13, each BWP may be defined by a size and starting point from CRB0. For example, the first BWP, i.e., BWP #0, may be defined by a starting point through an offset from CRB0, and a size of the BWP #0 may be determined through the size for BWP #0.

A specific number (e.g., up to four) of BWPs may be configured for the UE. Even if a plurality of BWPs are configured, only a specific number (e.g., one) of BWPs may be activated per cell for a given time period. However, when the UE is configured with a supplementary uplink (SUL) carrier, maximum of four BWPs may be additionally configured on the SUL carrier and one BWP may be activated for a given time. The number of configurable BWPs and/or the number of activated BWPs may be configured commonly or individually for UL and DL. Also, the numerology and/or CP for the DL BWP and/or the numerology and/or CP for the UL BWP may be configured to the UE via DL signaling. The UE can receive PDSCH, PDCCH, channel state information (CSI) RS and/or tracking RS (TRS) only on the active DL BWP. Also, the UE can transmit PUSCH and/or physical uplink control channel (PUCCH) only on the active UL BWP.

Referring to FIG. 14, 3 BWPs may be configured. The first BWP may span 40 MHz band, and a subcarrier spacing of 15 kHz may be applied. The second BWP may span 10 MHz band, and a subcarrier spacing of 15 kHz may be applied. The third BWP may span 20 MHz band and a subcarrier spacing of 60 kHz may be applied. The UE may configure at least one BWP among the 3 BWPs as an active BWP, and may perform UL and/or DL data communication via the active BWP.

A time resource may be indicated in a manner that indicates a time difference/offset based on a transmission time point of a PDCCH allocating DL or UL resources. For example, the start point of the PDSCH/PUSCH corresponding to the PDCCH and the number of symbols occupied by the PDSCH / PUSCH may be indicated.

Carrier aggregation (CA) is described. Like LTE/LTE-A, CA can be supported in NR. That is, it is possible to aggregate continuous or discontinuous component carriers (CCs) to increase the bandwidth and consequently increase the bit rate. Each CC may correspond to a (serving) cell, and each CC/cell may be divided into a primary serving cell (PSC)/primary CC (PCC) or a secondary serving cell (SSC)/secondary CC (SCC).

Hereinafter, system information (SI) acquisition is described.

System Information (SI) is divided into the MasterInformationBlock (MIB) and a number of SystemInformationBlocks (SIBs).

- The MIB is always transmitted on the broadcast channel (BCH) with a periodicity of 80ms and repetitions made within 80ms and it includes parameters that are needed to acquire SIB1 from the cell.

- The SIB1 is transmitted on the downlink shared channel (DL-SCH) with a periodicity and repetitions. SIB1 includes information regarding the availability and scheduling (e.g., periodicity, SI-window size) of other SIBs. It also indicates whether they (i.e., other SIBs) are provided via periodic broadcast basis or only on-demand basis. If other SIBs are provided on-demand then SIB1 includes information for the UE to perform SI request.

- SIBs other than SIB1 are carried in SI messages, which are transmitted on the DL-SCH. Each SI message is transmitted within periodically occurring time domain windows (referred to as SI-windows);

- For PSCell and SCells, RAN provides the required SI by dedicated signalling. Nevertheless, the UE shall acquire MIB of the PSCell to get system frame number (SFN) timing of the secondary cell group (SCG) (which may be different from master cell group (MCG)). Upon change of relevant SI for SCell, RAN releases and adds the concerned SCell. For PSCell, SI can only be changed with Reconfiguration with Sync.

The UE applies the SI acquisition procedure to acquire the access stratum (AS)- and non-access stratum (NAS) information. The procedure applies to UEs in RRC_IDLE, in RRC_INACTIVE and in RRC_CONNECTED.

The UE in RRC_IDLE and RRC_INACTIVE shall ensure having a valid version of (at least) the MIB, SIB1 as well as SystemInformationBlockTypeX through SystemInformationBlockTypeY (depending on support of the concerned RATs for UE controlled mobility).

The UE in RRC_CONNECTED shall ensure having a valid version of (at least) the MIB, SIB1 as well as SystemInformationBlockTypeX (depending on support of mobility towards the concerned RATs).

The UE shall store relevant SI acquired from the currently camped/serving cell. A version of the SI that the UE acquires and stores remains valid only for a certain time. The UE may use such a stored version of the SI e.g. after cell re-selection, upon return from out of coverage or after SI change indication.

Hereinafter, a random access procedure is described.

The random access procedure of the UE can be summarized in Table 7.

	Type of Signals	Operations/Information acquired
1st step	Physical random access channel (PRACH) preamble in UL	* Initial beam acquisition* Random election of RA-preamble ID
2nd Step	Random access response on DL-SCH	* Timing alignment information* RA-preamble ID* Initial UL grant, Temporary cell radio network temporary identifier (C-RNTI)
3rd Step	UL transmission on uplink shared channel (UL-SCH)	* RRC connection request* UE identifier
4th Step	Contention Resolution on DL	* Temporary C-RNTI on PDCCH for initial access* C-RNTI on PDCCH for UE in RRC_CONNECTED

Firstly, the UE may transmit PRACH preamble in UL as Msg1 of the random access procedure.

Random access preamble sequences, of two different lengths are supported. Long sequence length 839 is applied with subcarrier spacings of 1.25 and 5 kHz and short sequence length 139 is applied with

sub-carrier spacings

15, 30, 60 and 120 kHz. Long sequences support unrestricted sets and restricted sets of Type A and Type B, while short sequences support unrestricted sets only.

Multiple RACH preamble formats are defined with one or more RACH OFDM symbols, and different cyclic prefix and guard time. The PRACH preamble configuration to use is provided to the UE in the system information.

When there is no response to the Msg1, the UE may retransmit the PRACH preamble with power ramping within the prescribed number of times. The UE calculates the PRACH transmit power for the retransmission of the preamble based on the most recent estimate pathloss and power ramping counter. If the UE conducts beam switching, the counter of power ramping remains unchanged.

The system information informs the UE of the association between the SS blocks and the RACH resources. The threshold of the SS block for RACH resource association is based on the reference signal received power (RSRP) and network configurable. Transmission or retransmission of RACH preamble is based on the SS blocks that satisfy the threshold.

Referring to FIG. 16 again, when the UE receives random access response (RAR) on DL-SCH, the DL-SCH may provide timing alignment information, RA-preamble ID, initial UL grant and Temporary C-RNTI.

Based on this information, the UE may transmit UL transmission on UL-SCH as Msg3 of the random access procedure. Msg3 can include RRC connection request and UE identifier.

In response, the network may transmit Msg4, which can be treated as contention resolution message on DL. By receiving this, the UE may enter into RRC connected state.

Specific explanation for each of the steps is as follows.

Prior to initiation of the physical random access procedure, Layer 1 shall receive from higher layers a set of SS/PBCH block indexes and shall provide to higher layers a corresponding set of RSRP measurements.

Prior to initiation of the physical random access procedure, Layer 1 shall receive the following information from the higher layers:

- Configuration of PRACH transmission parameters (PRACH preamble format, time resources, and frequency resources for PRACH transmission)

- Parameters for determining the root sequences and their cyclic shifts in the PRACH preamble sequence set (index to logical root sequence table, cyclic shift (N_CS), and set type (unrestricted, restricted set A, or restricted set B)).

From the physical layer perspective, the L1 random access procedure encompasses the transmission of random access preamble (Msg1) in a PRACH, random access response (RAR) message with a PDCCH/PDSCH (Msg2), and when applicable, the transmission of Msg3 PUSCH, and PDSCH for contention resolution.

If a random access procedure is initiated by a PDCCH order to the UE, a random access preamble transmission is with a same subcarrier spacing as a random access preamble transmission initiated by higher layers.

If a UE is configured with two UL carriers (i.e., UL carrier and supplemental UL (SUL) carrier) for a serving cell and the UE detects a PDCCH order, the UE uses the UL/SUL indicator field value from the detected "PDCCH order" to determine the UL carrier for the corresponding random access preamble transmission.

Regarding the random access preamble transmission step, physical random access procedure is triggered upon request of a PRACH transmission by higher layers or by a PDCCH order. A configuration by higher layers for a PRACH transmission includes the following.

- A configuration for PRACH transmission.

- A preamble index, a preamble subcarrier spacing, P_PRACH,target, a corresponding random access RNTI (RA-RNTI), and a PRACH resource.

A preamble is transmitted using the selected PRACH format with transmission power P_PRACH,b,f,c(i), on the indicated PRACH resource.

A UE is provided a number of SS/PBCH blocks associated with one PRACH occasion by the value of higher layer parameter SSB - perRACH -Occasion. If the value of SSB - perRACH -Occasion is smaller than one, one SS/PBCH block is mapped to 1/SSB -per- rach -occasion consecutive PRACH occasions. The UE is provided a number of preambles per SS/PBCH block by the value of higher layer parameter cb- preamblePerSSB and the UE determines a total number of preambles per SSB per PRACH occasion as the multiple of the value of SSB - perRACH -Occasion and the value of cb- preamblePerSSB .

SS/PBCH block indexes are mapped to PRACH occasions in the following order.

- First, in increasing order of preamble indexes within a single PRACH occasion.

- Second, in increasing order of frequency resource indexes for frequency multiplexed PRACH occasions.

- Third, in increasing order of time resource indexes for time multiplexed PRACH occasions within a PRACH slot.

- Fourth, in increasing order of indexes for PRACH slots.

In response to a PRACH transmission, a UE attempts to detect a PDCCH with a corresponding RA-RNTI during a window controlled by higher layers. The window starts at the first symbol of the earliest control resource set the UE is configured for Type1-PDCCH common search space that is at least ceil (Δ * N_slot ^{subframe, u} * N_symb ^slot) / T_sf) symbols after the last symbol of the preamble sequence transmission. The length of the window in number of slots, based on the subcarrier spacing for Type0-PDCCH common search space is provided by higher layer parameter rar - WindowLength.

If a UE detects the PDCCH with the corresponding RA-RNTI and a corresponding PDSCH that includes a DL-SCH transport block within the window, the UE passes the transport block to higher layers. The higher layers parse the transport block for a random access preamble identity (RAPID) associated with the PRACH transmission. If the higher layers identify the RAPID in RAR message(s) of the DL-SCH transport block, the higher layers indicate an uplink grant to the physical layer. This is referred to as random access response (RAR) UL grant in the physical layer. If the higher layers do not identify the RAPID associated with the PRACH transmission, the higher layers can indicate to the physical layer to transmit a PRACH. A minimum time between the last symbol of the PDSCH reception and the first symbol of the PRACH transmission is equal to N_T,1 + Δ_new + 0.5 msec where N_T,1 is a time duration of N₁ symbols corresponding to a PDSCH reception time for PDSCH processing capability 1 when additional PDSCH DM-RS is configured and Δ_new ≥0.

A UE shall receive the PDCCH with the corresponding RA-RNTI and the corresponding PDSCH that includes the DL-SCH transport block with the same DM-RS antenna port quasi co-location properties, as for a detected SS/PBCH block or a received channel state information reference signal (CSI-RS). If the UE attempts to detect the PDCCH with the corresponding RA-RNTI in response to a PRACH transmission initiated by a PDCCH order, the UE assumes that the PDCCH and the PDCCH order have same DM-RS antenna port quasi co-location properties.

A RAR UL grant schedules a PUSCH transmission from the UE (Msg3 PUSCH). The contents of the RAR UL grant, starting with the most significant bit (MSB) and ending with the least significant bit (LSB), are given in Table 8. Table 8 shows random access response grant content field size.

RAR Grant field	Number of bits
Frequency hopping flag	1
Msg3 PUSCH frequency resource allocation	12
Msg3 PUSCH time resource allocation	4
Modulation and coding scheme (MCS)	4
Transmit power control (TPC) command for Msg3 PUSCH	3
CSI request	1
Reserved bits	3

The Msg3 PUSCH frequency resource allocation is for uplink resource allocation type 1. In case of frequency hopping, based on the indication of the frequency hopping flag field, the first one or two bits, N_UL,hop bits, of the Msg3 PUSCH frequency resource allocation field are used as hopping information bits.

The MCS is determined from the first sixteen indices of the applicable MCS index table for PUSCH.

The TPC command δ_msg2,b,f,c is used for setting the power of the Msg3 PUSCH.

In non-contention based random access procedure, the CSI request field is interpreted to determine whether an aperiodic CSI report is included in the corresponding PUSCH transmission. In contention based random access procedure, the CSI request field is reserved.

Unless a UE is configured a subcarrier spacing, the UE receives subsequent PDSCH using same subcarrier spacing as for the PDSCH reception providing the RAR message.

If a UE does not detect the PDCCH with a corresponding RA-RNTI and a corresponding DL-SCH transport block within the window, the UE performs the procedure for random access response reception failure.

For example, the UE may perform power ramping for retransmission of the Random Access Preamble based on a power ramping counter. However, the power ramping counter remains unchanged if a UE conducts beam switching in the PRACH retransmissions.

Referring to FIG. 18, the UE may increase the power ramping counter by 1, when the UE retransmit the random access preamble for the same beam. However, when the beam had been changed, the power ramping counter remains unchanged.

Regarding Msg3 PUSCH transmission, higher layer parameter msg3 - tp indicates to a UE whether or not the UE shall apply transform precoding, for an Msg3 PUSCH transmission.

The subcarrier spacing for Msg3 PUSCH transmission is provided by higher layer parameter msg3 - scs. A UE shall transmit PRACH and Msg3 PUSCH on a same uplink carrier of the same serving cell. An UL BWP for Msg3 PUSCH transmission is indicated by SIB1.

A minimum time between the last symbol of a PDSCH reception conveying a RAR and the first symbol of a corresponding Msg3 PUSCH transmission scheduled by the RAR in the PDSCH for a UE when the PDSCH and the PUSCH have a same subcarrier spacing is equal to N_T,1 + N_T,2 + N_TA,max + 0.5 msec. N_T,1 is a time duration of N₁ symbols corresponding to a PDSCH reception time for PDSCH processing capability 1 when additional PDSCH DM-RS is configured, N_T,2 is a time duration of N₂ symbols corresponding to a PUSCH preparation time for PUSCH processing capability 1, and N_TA,max is the maximum timing adjustment value that can be provided by the timing advance (TA) command field in the RAR.

In response to an Msg3 PUSCH transmission when a UE has not been provided with a C-RNTI, the UE attempts to detect a PDCCH with a corresponding temporary C-RNTI (TC-RNTI) scheduling a PDSCH that includes a UE contention resolution identity. In response to the PDSCH reception with the UE contention resolution identity, the UE transmits hybrid automatic repeat request acknowledgement (HARQ-ACK) information in a PUCCH. A minimum time between the last symbol of the PDSCH reception and the first symbol of the corresponding HARQ-ACK transmission is equal to N_T,1 + 0.5 msec. N_T,1 is a time duration of N₁ symbols corresponding to a PDSCH reception time for PDSCH processing capability 1 when additional PDSCH DM-RS is configured.

Hereinafter, RRC_IDLE/RRC_INACTIVE state and discontinuous reception (DRX) is described.

A UE has only one RRC state at one time. The RRC state indicates whether an RRC layer of the UE is logically connected to an RRC layer of an NG RAN.

The UE is either in RRC_CONNECTED state or in RRC_INACTIVE state when an RRC connection has been established. If this is not the case, i.e. no RRC connection is established, the UE is in RRC_IDLE state.

When in the RRC_CONNECTED state or RRC_INACTIVE state, the UE has an RRC connection and thus the NG RAN can recognize a presence of the UE in a cell unit. Accordingly, the UE can be effectively controlled. On the other hand, when in the RRC_IDLE state, the UE cannot be recognized by the NG RAN, and is managed by a core network in a tracking area unit which is a unit of a wider area than a cell. That is, regarding the UE in the RRC_IDLE state, only a presence or absence of the UE is recognized in a wide area unit. To get a typical mobile communication service such as voice or data, a transition to the RRC_CONNECTED state is necessary.

WWhen a user initially powers on the UE, the UE first searches for a proper cell and thereafter stays in the RRC_IDLE state in the cell. Only when there is a need to establish an RRC connection, the UE staying in the RRC_IDLE state establishes the RRC connection with the NG RAN through an RRC connection procedure and then transitions to the RRC_CONNECTED state or RRC_INACTIVE state. Examples of a case where the UE in the RRC_IDLE state needs to establish the RRC connection are various, such as a case where uplink data transmission is necessary due to telephony attempt of the user or the like or a case where a response message is transmitted in response to a paging message received from the NG RAN.

Referring to FIG. 19, UE may transit to NR RRC_CONNECTED through connection establishment in NR RRC_IDLE. The UE may transit to NR RRC_IDLE through connection release in NR RRC_CONNECTED. The UE may transit to NR RRC_IDLE through connection inactivation in NR RRC_CONNECTED.

Referring to FIG. 20, in addition to the UE RRC state transition in NR shown in FIG. 19, handover or cell reselection between NR and E-UTRAN may be supported. More specifically, the UE may transit to E-UTRAN RRC_CONNECTED through connection establishment in E-UTRA RRC_IDLE. The UE may transit to E-UTRAN RRC_IDLE through connection release in E-UTRAN RRC_CONNECTED. The UE may transit between E-UTRA RRC_CONNECTED and NR RRC_CONNECTED through handover. The UE may transition between E-UTRAN RRC_IDLE, NR RRC_IDLE and NR RRC_INACTIVE through cell reselection.

The procedure of the UE related to the DRX can be summarized as Table 9.

	Type of signals	UE procedure
1st step	RRC siganling(MAC-CellGroupConfig)	Receive DRX configuration information
2nd step	MAC CE(control element)((Long) DRX command MAC CE)	Receive DRX command
3rd step	-	Monitor a PDCCH during an on-duration of a DRX cycle

The UE uses DRX in RRC_IDLE and RRC_INACTIVE in order to reduce power consumption. When the DRX is configured, the UE performs a DRX operation according to DRX configuration information. For example, when the DRX is configured, the UE tries to receive the PDCCH only in a predetermined time interval, and does not attempt to receive the PDCCH in the remaining time period. At this time, a time period during which the UE should attempt to receive the PDCCH is referred to as an On-duration, and this on-duration is defined once per DRX cycle.

The UE can receive DRX configuration information from a gNB through a RRC signaling and operate as the DRX through a reception of the (Long) DRX command MAC CE. The DRX configuration information may be included in the MAC-CellGroupConfig. The IE MAC-CellGroupConfig is used to configure MAC parameters for a cell group, including DRX. The DRX command MAC CE or the Long DRX command MAC CE is identified by a MAC PDU subheader with LCID.

DRX is characterized by the following.

- On-duration: duration that the UE waits for, after waking up, to receive PDCCHs. If the UE successfully decodes a PDCCH, the UE stays awake and starts the inactivity timer;

- Inactivity-timer: duration that the UE waits to successfully decode a PDCCH, from the last successful decoding of a PDCCH, failing which it can go back to sleep. The UE shall restart the inactivity timer following a single successful decoding of a PDCCH for a first transmission only (i.e., not for retransmissions);

- Retransmission-timer: duration until a retransmission can be expected

- Cycle: specifies the periodic repetition of the on-duration followed by a possible period of inactivity.

The UE monitors one paging occasion (PO) per DRX cycle and one PO can consist of multiple time slots (e.g., subframe or OFDM symbol) where paging DCI can be sent. In multi-beam operations, the length of one PO is one period of beam sweeping and the UE can assume that the same paging message is repeated in all beams of the sweeping pattern. The paging message is same for both RAN initiated paging and CN initiated paging.

One paging frame (PF) is one radio frame, which may contain one or multiple PO(s).

The UE initiates RRC Connection Resume procedure upon receiving RAN paging. If the UE receives a CN initiated paging in RRC_INACTIVE, the UE moves to RRC_IDLE and informs NAS.

Hereinafter, power saving in NR is described.

Because NR system may be capable of supporting high speed data transport, it is expected that user data tends to be bursty and served in very short durations. One efficient UE power saving mechanism is to trigger UE for network access from power efficient mode. UE would stay in the power efficient mode, such as micro sleep or OFF period in the long DRX cycle, unless it is informed of network access through UE power saving framework. Alternatively, network can assist the UE to switch from the network access mode to the power efficient mode when there is no traffic to deliver, e.g., dynamic UE transition to sleep with network assistance signal.

In addition to minimizing the power consumption with the new wake up/go-to-sleep mechanism, it is equally importance to reduce the power consumption during the network access in RRC_CONNECTED. More than half of the power consumption in LTE is UE in RRC_CONNECTED. The power saving scheme should focus on minimizing the dominate factor of power consumption during the network access, which includes the processing of aggregated bandwidth, active RF chain number and active reception/transmission time, and dynamic transition to power efficient mode. Since the majority cases of LTE field TTIs are with no data or small data, the power saving scheme for the dynamic adaptation to the different data arrival should be studied in RRC_CONNECTED. Dynamic adaptation to traffic in different dimensions, such as carrier, antenna, beamforming, and bandwidth, can also be studied for Rel-16. Furthermore, methods to enhance the transitions between network access mode and power saving mode should be considered. Both network-assisted and UE-assisted approaches should be considered for UE power saving mechanism.

UE also consumes a lot of power for RRM measurements. In particular, UE would need to power up before the DRX ON period to track the channel in preparation for the RRM measurement. Some of the RRM measurements are not necessary but consumes a lot of UE power. For example, the low mobility UEs does not have to measure as frequent as high mobility UEs. Network would provide the signalling to assist UE to reduce the power consumption on unnecessary RRM measurements. Additional UE assistance, e.g., the UE status information, etc., is also useful for the network to enable the UE power consumption reduction on RRM measurements.

Detailed UE Power saving schemes are as follows.

(1) UE adaptation to the traffic and power consumption characteristic

(2) Adaptation to the variation in frequency

(3) Adaptation to the variation in time

(4) Adaptation to antenna

(5) Adaptation to DRX configuration

i) DL-SCH characterised by support for UE DRX to enable UE power saving

ii) Paging channel (PCH) characterised by support for UE DRX to enable UE power saving (DRX cycle is indicated by the network to the UE).

(6) Adaptation to UE processing capability

The UE reports its UE radio access capabilities which are static at least when the network requests. The gNB can request what capabilities for the UE to report based on band information. When allowed by the network, a temporary capability restriction request may be sent by the UE to signal the limited availability of some capabilities (e.g., due to hardware sharing, interference or overheating) to the gNB. The gNB can then confirm or reject the request. The temporary capability restriction should be transparent to 5GC. Namely, only static capabilities are stored in 5GC.

(7) Adaptation to achieve reducing PDCCH monitoring/decoding

A UE monitors a set of PDCCH candidates in the configured monitoring occasions in one or more configured CORESETs according to the corresponding search space configurations. A CORESET consists of a set of PRBs with a time duration of 1 to 3 OFDM symbols. The resource units REGs and CCEs are defined within a CORESET with each CCE consisting a set of REGs. Control channels are formed by aggregation of CCE. Different code rates for the control channels are realized by aggregating different number of CCE. Interleaved and non-interleaved CCE-to-REG mapping are supported in a CORESET.

(8) Power saving signal/channel/procedure for triggering adaptation to UE power Consumption

To enable reasonable UE battery consumption when CA is configured, an activation/deactivation mechanism of cells is supported. When a cell is deactivated, the UE does not need to receive the corresponding PDCCH or PDSCH, cannot transmit in the corresponding uplink, nor is it required to perform channel quality indicator (CQI) measurements. Conversely, when a cell is active, the UE shall receive PDSCH and PDCCH (if the UE is configured to monitor PDCCH from this SCell) and is expected to be able to perform CQI measurements. NG-RAN ensures that while PUCCH SCell (a SCell configured with PUCCH) is deactivated, SCells of secondary PUCCH group (a group of SCells whose PUCCH signalling is associated with the PUCCH on the PUCCH SCell) should not be activated. NG-RAN ensures that SCells mapped to PUCCH SCell are deactivated before the PUCCH SCell is changed or removed.

At reconfiguration without mobility control information:

- SCells added to the set of serving cells are initially deactivated;

- SCells which remain in the set of serving cells (either unchanged or reconfigured) do not change their activation status (activated or deactivated).

At reconfiguration with mobility control information (i.e., handover):

- SCells are deactivated.

To enable reasonable UE battery consumption when bandwidth adaptation (BA) is configured, only one UL BWP for each uplink carrier and one DL BWP or only one DL/UL BWP pair can be active at a time in an active serving cell, all other BWPs that the UE is configured with being deactivated. On deactivated BWPs, the UE does not monitor the PDCCH, does not transmit on PUCCH, PRACH and UL-SCH.

With BA, the receive and transmit bandwidth of a UE need not be as large as the bandwidth of the cell and can be adjusted. The width can be ordered to change (e.g., to shrink during period of low activity to save power). The location can move in the frequency domain (e.g., to increase scheduling flexibility). And the subcarrier spacing can be ordered to change (e.g., to allow different services). A subset of the total cell bandwidth of a cell is referred to as a BWP and BA is achieved by configuring the UE with BWP(s) and telling the UE which of the configured BWPs is currently the active one. When BA is configured, the UE only has to monitor PDCCH on the one active BWP, i.e., it does not have to monitor PDCCH on the entire DL frequency of the cell. A BWP inactivity timer (independent from the DRX inactivity-timer described above) is used to switch the active BWP to the default one. The timer is restarted upon successful PDCCH decoding and the switch to the default BWP takes place when it expires.

(9) Power consumption reduction in RRM measurements

The RRM configuration can include both beam measurement information (for layer 3 mobility) associated to SS/PBCH block(s) and CSI-RS(s) for the reported cell(s) if both types of measurements are available. Also, if CA is configured, the RRM configuration can include the list of best cells on each frequency for which measurement information is available. And the RRM measurement information can also include the beam measurement for the listed cells that belong to the target gNB.

In current network operation, it is typically operated such that a UE reports its capability upon an initial setup, then the network configures the UE in different operating modes including the number of CAs, MIMO layers, power configurations, etc., regardless of UE situation. For example, if a UE is in indoor, it is not likely that the UE needs very active measurement as the mobility is very limited. Furthermore, if the UE connects via Wi-Fi in indoor, it is not desirable to operate very short DRX cycles in LTE/NR or no DRX in LTE/NR. On the other hand, if the UE uses LTE/NR actively as the quality of Wi-Fi signals is not good, even in indoor case, DRX configuration needs to be adjusted. Also, when the UE watches video, it is likely that the UE's requested traffic is relatively static. In that case, configured grant based periodic transmission can be effective with rather state number of active carriers. On the other hand, if the UE performs active online games, the traffic may be more fluctuated and the latency becomes very important. In that case, adopting carrier aggregation with high bandwidth/data rate seem more beneficial.

As such information is UE-internal information, it is desirable that a UE is also in the control-loop to determine a set of behaviors/configurations which impact power consumption considerably. For example, the number of active carriers, the number of measurement frequencies, bandwidth to monitor, control monitoring periodicity, etc., may cause impact considerably on the total UE power consumption. With internal information in a UE, the UE may recommend a certain set of configurations and/or operating modes to the network.

The present disclosure provides assistant information in order for UE to efficiently use power and/or a process for transmitting the assistant information to the network. The present disclosure proposes to a mechanism to change the operating paradigm of LTE/NR where a UE can be more involved in determining UE's operating mode.

Specifically, the present disclosure discusses a few mechanisms to send UE-assistant information to reduce overall power consumption without impacting performance at the UE side (also targeting to minimize impact on network side as well). Namely, the present disclosure discusses a few parameters which the UE can indicate to the network and configuration mechanisms to allow flexible negotiation between the network and UEs for better operation. This may be required as the network and UE may know different things and also need to consider various network operation environments where recommended values by the UE may not be appropriate in some cases from the network perspective.

In NR, a UE reports its capability upon a connection. Based on its reported capabilities, the network configures different set of carriers/MIMO configurations, etc. The followings are parameters/operating modes which could have considerable impact on UE overall power consumption. The UE may transmit at least one of the followings to the network as assistant information.

(1) MIMO/antenna related parameters

To handle MIMO related operation, a UE may report dynamic capabilities for MIMO/antenna related parameters (i.e., MIMO/antenna related parameters can be updated instead of sending once at setup procedure). A UE may report its recommended values for MIMO/antenna related parameters. Or, the network may indicate multiple MIMO/antenna related parameters and then the UE may select the final MIMO/antenna related parameter.

The MIMO/antenna related parameters may include the number of panels active. In addition to UE's panel numbers, the UE may also report its currently active panel number (including panel indices potentially) which can be used for configuring RSs/resources/layers/etc. Alternatively, the network may configure required active panels (or the required number of active panels) per BWP configuration. Intra-band CA may require the same number/set of active panels in each BWP in each carrier.

(2) (Maximum) number of CCs and/or number of active CCs and/or total BW

A UE may report the recommended values of maximum number of CCs to be aggregated and/or number of configured/active CCs, and/or the total BW required for the UE.

(3) Total number of blind decodings (BDs) and/or maximum transport block size (TBS) per numerology or per carrier or per UE:

The number of BDs/maximum TBS is currently UE capability. Based on UE capability, the network may configure the number of BDs. In terms of TBS, the overall processing limit is expected to be the supported maximum TBS. TBS is computed based on maximum supported modulation, support bandwidth, scaling factor, etc. Though a UE can be configured with BWP which then defines maximum bandwidth, as the UE can always be reconfigured with larger BW for the BWP, it is not guaranteed to reduce UE processing to handle only limited TBS. Another approach is to restrict UE's maximum TBS by the system bandwidth which is reported in SIB1. The UE may reduce its capability based on maximum system bandwidth reported in SIB1. Yet, when a UE is configured with multiple carriers, the overall maximum TBS can be considerable though currently active carriers are not requiring high computation power. It is therefore beneficial to consider restricting a UE's total required maximum TBS and/or active carriers and/or maximum BDs.

A UE may report its recommended values for total number of BDs and/or maximum TBS. Or, the network may indicate total number of BDs and/or maximum TBS and then the UE may select the final total number of BDs and/or maximum TBS.

Alternatively, as the network knows overall carrier's load condition, it is also considerable to restrict bandwidth per each carrier for each UE. A UE can be configured with maximum bandwidth schedulable by the network in each carrier, then the UE can compute maximum required TBS in that carrier and adjust its processing capability/power to handle that maximum.

(4) Total number of processing capability #1 vs capability #2

In addition to UE capability supporting capability #1 and/or capability #2, the UE may also recommend the values of maximum carriers with capability #2 (may be per frequency range or per band grouping (e.g., number of capability #2 supported in a set of band combinations reported by the UE)). Based on the recommended maximum which is expected to be smaller or equal to the number of carriers supported with capability #2 signalled in UE capability signalling, the network may configure capability #2 to carriers. This requires configuration of capability #1 or #2 in each carrier. If a new processing capability is introduced, this can be further extended to cover the new processing capability(s).

(5) Suggested numerologies (number and/or numerology)

Though a UE may support multiple numerologies in different set of bands, it may not be so desirable that a UE need to run many different numerologies. Thus, a UE may report set of numerologies recommended as follows.

- Report a set of recommended numerologies per band (or per CC)

- Report a set of recommended numerologies per frequency range (e.g., FR1 vs FR2)

- Report a set of recommended numerologies for NR with or without LTE (i.e., dual connectivity (DC) with LTE or not)

(6) DRX parameters

Period, on-duration, recommended PDCCH monitoring and/or related quality of service (QoS) requirements from a UE perspective may be reported.

(7) Default timer

(8) Multi-RAT DC (MR-DC)

Based on UE information, recommendation on DC may be reported.

(9) Outdoor/indoor

The location information, particularly about indoor or outdoor scenario, can be indicated by the UE for better management. Alternatively, this information may be carried by other means such as power saving mode recommended by the UE.

(10) Wi-Fi zone/out-of-Wi-Fi

The connectivity including quality (e.g., signal quality, busy status, security, etc.) of Wi-Fi can be informed. This information can be carried by other means such as power saving mode and/or operating mode recommend by the UE.

(11) Inter-RAT measurement related assistance information

A UE may maintain a list of cell IDs and/or RATs detected at the current location (how to manage the current location and how to group the locations to maintain this list can be UE-implementation), then the UE can indicate a set of RATs for inter-RAT measurement. For example, if a UE experiences that the quality of Wi-Fi is very poor, it is likely that the UE will be connected to LTE/NR. In that case, the UE can ask full scale inter-RAT measurement for LTE/NR. On the other hand, if the quality of Wi-Fi is very good with static mobility, the UE may request very limited inter-RAT measurements on LTE/NR. Similarly, in case of roaming possible situation (e.g., at the airport or during the flight or after flight), inter-RAT mobility is requested full-blown, whereas inter-RAT measurement at home is requested to be reduced. In other words, based on UE mobility, location, traffic pattern, quality of Wi-Fi, unlicensed spectrum and/or basic RAT (e.g., LTE), inter-RAT measurement can be performed in different levels.

This measurement can also be based on the measurement results on a certain RAT and/or based on other module such as Wi-Fi. For example, if the UE is connected to Wi-Fi network, the UE can report the inter-RAT measurement to be very restrictive (such as only NR) or only slow network such as GSM for message reception and limited voice. Further, depending on the indoor/outdoor or UE mobility, the UE can also recommend a set of RATs for measurement. It is also possible to recommend various threshold values for measurement related threshold such as RRM events, s-measure threshold, a threshold of RRM reports, etc. When a UE is not required to perform measurement on a certain set of RATs, the time expected for the regular measurement for such RATs can be skipped from the measurement. By this way, a UE can save power for the measurement. Necessary synchronization and tracking may be still performed.

In terms of applying this behaviour, the following approaches can be considered.

- A UE may autonomously perform inter-RAT measurement based on its profiling. It is up to UE what RATs to measure and report. This requires UE implementation techniques to be supported by the specification.

- A UE may recommend a set of inter-RAT measurements including potentially frequency layers/numbers, then selection from the set of inter-RAT measurements may be made by the network. The network may reconfigure the UE measurement requirements based on the recommended values.

(12) Power efficient mode indication

As the UE may know whether there will be a lot of data packets going in or not by application, recommendation on power efficient modes can be considered in the following cases. In terms of power efficient mode, the followings are examples, at least in case of scheduling request (SR) transmission. It can also be applied to RACH-based indication.

- Example 1

In terms of traffic in each DL and UL, traffic type (low, medium, high) can be indicated. If three states are indicated, totally 9 states can be indicated. If two states are indicated per each DL or UL, total 4 states can be indicated.

- Example 2

Number of recommended active carriers per each DL and UL can be indicated. The information may be determined based on the expected traffic load per each DL and UL and power for UL. In terms of number of active carriers, it is also possible to indicate how many per frequency range (e.g., 1 for FR1 and 3 for FR2, and so on). In terms of recommending FR2 CA, a UE may also utilize its mobility information, and if there is high mobility, FR2 may not be proposed. Or, based on environments. it may recommend desirable frequency range (e.g., in indoor mmW frequency, in emergency situation, very low frequency, etc.).

- Example 3: Location profiling

Another approach is to maintain a set of profiles which can be saved locally at the UE and/or remotely at the network. The UE may indicate one of profile matched among the stored profiles. The profile can include a set of frequencies (and/or RATs) with more than K detected cells with at least a certain threshold of RSRP, mobility, recommended configuration/parameters, etc. For example, a UE may maintain multiple profiles (e.g., home main room, home living room, office, outside, favourite place 1, favourite place 2, etc.). The main information stored under each profile is the set of frequencies (and/or RATs) which have high probability of good quality and mobility information. This can be used for determining beam and mobility related configurations.

Such mode can be indicated via RACH and/or SR, and the network may utilize the indicated information to configure a set of parameters. For example, if traffic amount for each DL and UL is indicated, it can be indicated via multi-bit SR or carried over buffer status reporting (BSR). Profiling can be carried in Msg3 or via PRACH using different PRACH resources to indicate different state.

When the network receives this information, this can be considered as either hard recommendation (i.e., request) or soft recommendation (i.e., recommendation) depending on the mechanism and parameters. For example, in terms of power saving mode or operating mode, it can be considered that a UE switches autonomously to the recommended values and the network may reconfigure a certain set of parameters accordingly. When the UE autonomously switches the mode, it may be also possible to reload a set of associated parameters which are pre-configured by the network. This behaviour can be seen similarly as BWP switching where a set of parameters are configured for each operating mode/power saving mode in prior, and those will be activated upon activating the operation/power saving mode.

(13) Reject the configured carriers

When the network configures a set of carriers or a carrier, the UE may indicate reject message if the UE may not consider the configured carrier should be activated. Upon receiving the reject message, the network may know that the carrier is not desirable to be activated. Extending this idea, the UE may indicate MAC control element (CE) based indication and/or RRC based indication indicating which carriers should be activated or deactivated for the configured carriers. For example, if a UE is configured with 10 carriers, the UE may indicate bitmap of 10 bits for each configured carrier to indicate whether the carrier should be activated or deactivated regularly or aperiodically. Based on the information, the network may activate or deactivate a certain set of carriers among the configured carriers. In terms of indication, it can also be indicated that PCell should be deactivated. In such a case, the network may handover the UE to different cell to switch PCell. In addition, a UE may reject when the network configures a carrier as the configured carrier can be activated anytime.

In terms of carrier configuration, the network may also indicate different configuration type to-be-activated carrier, backup-carrier. The to-be-activated carrier is referred to a configured carrier which can be activated in a near future and active measurement is needed as if the serving cell. The backup-carrier is a carrier referred as backup and is not likely to be activated in a near future. Thus, a UE is not required to prepare RF to support backup-carrier unless the configured carrier switches from backup-carrier to to-be-activated carrier. This is similar to dormant SCell where the UE may wake-up RF to prepare activation in a near future. For each carrier type, activation delay can be considered differently. For to-be-activated carrier, the activation delay is expected to be small whereas backup-carrier is expected to be very large. A UE may reject to-be-activated carrier configuration. Alternatively, the UE may recommend carrier type between two (to-be-activated or backup-carrier) based on its current conditions for each carrier. Thus, instead of active/deactive proposed in above, carrier type can be recommended for each configured but not activated carriers.

(14) By UE choice

A UE may select different power saving mode. For example, the network provide multiple different data rate services (e.g., 3G only, 3G + 4G single carrier, 3G + 4G CA, 4G only, 4G single carrier + 5G single carrier, 4G + 5G full service). Different rate may correspond to a set of RATs and/or a set of possible active carriers that the UE can expect. When the UE selects higher data rate, it means that the UE can be serviced with high data rate to reduce the overall latency of file transfer or support real-time applications. Different pricing may be associated with different data rate, and the UE may pay more by allowing more data in a short time. As this will estimate the necessary carriers, by selecting a certain service in advance, necessary measurement configurations and MIMO/BWP/CA/DC related parameters can be configured accordingly.

The proposal is to provide multiple data rate which at least include a set of possible RATs and number of potential carriers or maximum data rate per RAT, which can be selected by the UE (by human or by application or by the phone itself based on internal information). In terms of selection, similar mechanism of selecting on/off Wi-Fi/Cellular in current smart phone can be considered. A device can be equipped with on/off for each RAT, and OFF-RAT measurement can be deactivated autonomously or by network configuration. Alternatively, a combination of RAT + data rate + the number of measurement configurations can be tied with UE power saving or charging model. For example, a UE may pay base rate in every day (e.g., 0.1$ per day) where basic feature includes messaging/voice via 3G. For example, there are three different charging (e.g., 0.1 cent/1 min, 0.2 cent/1 min, 1 cent/min), and different charging is associated with different QoS (e.g., 0.1 cent/1min means LTE + single carrier, 0.2 cent/1min means LTE and/or NR + limited CA/DC or limited BW/TBS, 1 cent/min means LTE + NR CA/DC full scale). Paying the same price, there can be different maximum data rate supported by the UE, thus, this may promote human to switch higher data rate equipped devices as well. With multiple charging models, a UE can select the best charging based on the current needs. Furthermore, a UE does not need to perform unnecessary measurement/processing which is not required currently. By this, the UE can also save its power consumption. Moreover, this charging may be selected by the device or recommended by the device itself based on the active applications, history of current UE, location, etc.

(15) The operative RAT can be set differently/independently according to the power consumption mode (and/or power saving mode). In this case, in the power saving mode, the UE may operate based on the corresponding RAT for all/some applications. The operative RAT can be set differently/independently according to context-based (location-based and/or when a specific Wi-Fi AP is acknowledge and/or upon charging). As the situation changes, the UE may operate based on corresponding RAT for all/some applications. Operative RAT can be set differently/independently by application. In this case, the UE may operate based on the RAT depending on the operation or active application. The RAT may operate differently according to the plurality of combinations. According to the operative RAT, RRM measurement, higher layer configuration, and/or transmission/reception methods may be applied/used differently. Currently, the UE can select RAT. Based on this, all applications may operate based on the single or multiple RATs.

Hereinafter, reporting the above-described assistant information and configuring/selecting final parameter is described according to an embodiment of the present disclosure.

1. A set of possible configurations by network + UE selection

In step S2200, instead of indicating exact parameters, a network configures sets of values for each configuration parameter. Each set may be a set of sets of parameters and/or range of parameters and/or multiple values of parameters.

In step S2210, a UE selects a set/value among the configured sets of values for each configuration.

In step S2220, the UE reports the selected set/value via RRC message or MAC CE or multi-bit SR or via UCI transmission.

The UE may reselect the set/value if conditions (e.g., power saving level or traffic pattern changes) change, and inform the reselected set/value to the network. If the UE does not report the selected set/value, the first set/value or the last set/value may be selected. It can be also considered to include recommended set/value in the configuration by the network, and the recommended set/value may be assumed to be selected by the UE unless otherwise indicated by the UE.

Set/value/parameter may be indicated and a reserved value can be added such as flexible. If 'flexible' is indicated, the UE may be allowed to select a set/value among the possible candidates. In terms of candidates, the followings may be considered.

- A set of values possible in the specification

- A set of values possible by network configurations

- A set of values possible in each BWP configured by the network or by the specification

- A set of values possible in each numerology configured by the network or by the specification

A UE may select the set/value and informs the network via the above mentioned signaling mechanisms.

Another approach to utilize flexible resource is to confirm the parameter are configured per UE's recommendation through random access procedure or via SR transmission or by RRC signaling. In other words, if some parameters are configured as flexible, the UE can assume that the parameters are set per UE's recommendation.

Another approach is to allow reject of the configured parameters such that the network may reconfigure with different parameter. For example, for every RRC reconfiguration message, a UE may send feedback which is either confirm or reject on the configured parameters. The feedback may also include a bit more information on power saving mode increase or decrease. Power saving mode increase means more power saving is desired, whereas power saving mode decrease may imply more active operating mode is desired. Instead of reject, it is also considerable to send one of confirm, increase power saving mode, or decrease power saving mode.

The following shows a few examples.

- Codebook: Based on learning, a UE may report best set of codebooks recommended. At least, base matrix or related parameters can be recommended.

- Configured grant configuration: How many configurations are needed, and recommended periodicity and TBS/MCS can be recommended.

- CORESET configuration: The interval of control monitoring can be recommended which are decided based on the tolerable latency.

- Measurement report related configuration such as threshold values for event triggered RRM

- Measurement objects related configuration such as the number of frequencies to monitor, number of cells to monitor per each frequency, etc.

2. A set of recommendations by the UE + network configuration

In step S2300, a UE provides a recommended value or a set of recommended values to the network. The recommended set of values can be indicated as RRC messages and/or MAC CE and/or UCI transmission including SR.

In step S2310, the network determines whether or not to value/set of values recommended by the UE. The network may select the values/set of values based on the recommendation by the UE.

In step S2320, the network configures the value/set of values.

The set of indicatable values can be different depending on various conditions even though the same index is indicated. For example, a set of values may be different per each parameter depending on an operating mode. For example, in power efficient mode, MIMO layers of {1, 2} are used whereas in active mode, MIMO layers of {4, 8} are used where index 1 refers 1 and 4 respectively.

The recommended values by the UE may be respected by the network or not. In terms of UE behaviour on the recommended values and corresponding configuration, the followings approaches can be considered.

- The values may be recommended only. The configuration can be based on UE capability signalling. Thus, as long as the UE supports the configured setup/parameters, it is considered as valid configuration.

- The values may be requested. The configuration which exceeds the recommended values are considered as invalid and the UE may ignore the configurations or resend the recommended values or reject the configurations. The UE can reduce its capability to the recommended values. To support this approach, the UE may also utilize reporting UE capabilities differently in different time/operating modes/situations/conditions.

3. Dynamic UE capability Indication

Another approach to reduce UE power consumption is to signal different UE capabilities depending on its desire on power consumption and expected QoS. For example, a UE may report different number of carriers/band combinations based on the required number of carriers in current situation. In terms of signaling, each capability may be updated via RRC/MAC CE or a set of capabilities can be updated via RRC/MAC CE as a set or a set of modes where a UE ties different set of capabilities can be also indicated where the set is reported by the UE.

In step S2400, the wireless device receives a first configuration of a first parameter from a network. A value of the first parameter is selected by the network. The first parameter may be selected by the network from multiple sets of the first parameter recommended by the wireless device.

In step S2410, the wireless device receives a second configuration of a second parameter from the network. The second parameter informs that the wirelss device is allowed to select a value of the second parameter.

At least one of the first parameter or the second parameter includes MIMO or antenna related parameters. At least one of the first parameter or the second parameter may include information on a number of CCs or a number of active CCs or a total bandwidth required for the wireless device. At least one of the first parameter or the second parameter may include information on a total number of blind decodings or a maximum TBS. At least one of the first parameter or the second parameter may include information on a numerology. At least one of the first parameter or the second parameter includes information on DRX parameters, a default timer or DC. At least one of the first parameter or the second parameter may include information on a location of the wireless device. At least one of the first parameter or the second parameter may include information on Wi-Fi network to which the wireless device is connected. At least one of the first parameter or the second parameter may include inter-RAT measurement related parameters. At least one of the first parameter or the second parameter may include information on a power efficient mode. At least one of the first parameter or the second parameter may include information on rejection on configured carriers.

In step S2420, the wireless device applies the value of the first parameter.

In step S2430, the wireless device selects the value of the second parameter. The second parameter may be selected based on a power saving level of the wireless device or a traffic pattern of the wireless device.

In step S2440, the wireless device applies the value of the second parameter.

In step S2450, the wireless device reports the value of the second parameter to the network.

The present disclosure can have various advantageous effects.

For example, power efficient operation can be achieved.

In view of the exemplary systems described herein, methodologies that may be implemented in accordance with the disclosed subject matter have been described with reference to several flow diagrams. While for purposed of simplicity, the methodologies are shown and described as a series of steps or blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the order of the steps or blocks, as some steps may occur in different orders or concurrently with other steps from what is depicted and described herein. Moreover, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope of the present disclosure.

Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description 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.

Claims

A method for a wireless device in a wireless communication system, the method comprising:

receiving a first configuration of a first parameter from a network, wherein a value of the first parameter is selected by the network;

receiving a second configuration of a second parameter from the network, wherein the second parameter informs that the wireless device is allowed to select a value of the second parameter;

applying the value of the first parameter;

selecting the value of the second parameter;

applying the value of the second parameter; and

reporting the value of the second parameter to the network.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes multiple-input multiple-output (MIMO) or antenna related parameters.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on a number of component carriers (CCs) or a number of active CCs or a total bandwidth required for the wireless device.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on a total number of blind decodings or a maximum transport block size (TBS).
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on a numerology.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on discontinuous reception (DRX) parameters, a default timer or dual connectivity (DC).
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on a location of the wireless device.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on Wi-Fi network to which the wireless device is connected.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes inter-radio access technology (RAT) measurement related parameters.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on a power efficient mode.
The method of claim 1, wherein at least one of the first parameter or the second parameter includes information on rejection on configured carriers.
The method of claim 1, wherein the first parameter is selected by the network from multiple sets of the first parameter recommended by the wireless device.
The method of claim 1, wherein the second parameter is selected based on a power saving level of the wireless device or a traffic pattern of the wireless device.
The method of claim 1, wherein the wireless device is in communication with at least one of a mobile device, a network, and/or autonomous vehicles other than the wireless device.
A wireless device in a wireless communication system, the wireless device comprising:

a memory;

a transceiver; and

a processor, operably coupled to the memory and the transceiver, configured to:

receive a first configuration of a first parameter from a network, wherein a value of the first parameter is selected by the network;

receive a second configuration of a second parameter from the network, wherein the second parameter informs that the wireless device is allowed to select a value of the second parameter;

apply the value of the first parameter;

select the value of the second parameter;

apply the value of the second parameter; and

report the value of the second parameter to the network.