Method for user equipment, equipment and storage medium

Abstract

The UE may perform a first random access preamble transmission related to a preamble transmission counter set to a first value, and transmit an uplink channel based on a random access response for the first random access preamble transmission. A contention resolution timer may be started based on transmission of the uplink channel. The UE may perform a second random access preamble transmission for the random access procedure based on expiration of the contention resolution timer. The UE may start a cell DTX inactivity cycle while the contention resolution timer is running, and maintain a preamble transmission counter at a first value based on expiration of the contention resolution timer.

Description

Technical Field

[0001] This disclosure relates to a wireless communication system. Background Technology

[0002] Technologies such as machine-to-machine (M2M) communication, machine-type communication (MTC), and various devices requiring high data throughput (e.g., smartphones and tablet PCs) have emerged and become widespread. Consequently, the data throughput required to be processed in cellular networks is rapidly increasing. To meet this rapidly increasing data throughput, carrier aggregation or cognitive radio technologies have been developed for the efficient use of more frequency bands, as well as multiple-input multiple-output (MIMO) or multi-base station (BS) cooperation technologies to improve the data transmission capacity on limited frequency resources.

[0003] As more and more communication devices require greater communication capacity, there is a need for enhanced mobile broadband (eMBB) communication relative to traditional radio access technologies (RAT). Furthermore, massive machine-type communication (mMTC), which enables the provision of various services anytime, anywhere by connecting multiple devices and objects to each other, is a major issue to be considered in next-generation communications.

[0004] The design of communication systems for service / user equipment (UE) that are sensitive to reliability and latency is also under discussion. The introduction of next-generation RATs is being considered, taking into account eMBB communication, mMTC, and ultra-reliable low-latency communication (URLLC).

[0005] As the number of service / user equipment (UE) that the network needs to support increases rapidly, the demand for not only UE power saving but also network energy saving is gradually increasing. Summary of the Invention

[0006] Technical issues

[0007] One object of this disclosure is to provide methods and processes for network energy saving.

[0008] Another objective of this disclosure is to provide a random access procedure for network energy conservation.

[0009] The purposes that can be achieved by utilizing this disclosure are not limited to those specifically described above, and those skilled in the art will understand more clearly from the following detailed description other purposes not described herein.

[0010] Technical solution

[0011] In one aspect of this disclosure, a method performed by a user equipment (UE) is provided.

[0012] In another aspect of this disclosure, an apparatus is provided. The apparatus includes: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations for a UE.

[0013] In another aspect of this disclosure, a non-transitory computer-readable storage medium is provided. The storage medium stores at least one program code including instructions that, when executed, cause at least one processor to perform operations for a UE.

[0014] The method or operation may include: setting a preamble transmission counter for a random access procedure to a first value; transmitting a first random access preamble for the random access procedure on the cell; receiving a random access response to the transmitted first random access preamble; transmitting an uplink channel based on the random access response; initiating a contention resolution timer based on the transmission of the uplink channel; and transmitting a second random access preamble for the random access procedure upon the expiration of the contention resolution timer. The preamble transmission counter may be maintained at the first value based on the cell discontinuous transmission (DTX) inactivity period for the cell starting during the contention resolution timer's operation and the expiration of the contention resolution timer.

[0015] In another aspect of this disclosure, a method performed by a base station (BS) is provided.

[0016] In another aspect of this disclosure, a BS is provided. The BS includes: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations for the BS.

[0017] The method or operation may include: receiving from the UE a first random access preamble associated with a preamble transmission counter set to a first value for a random access procedure on the cell; sending a random access response to the first random access preamble to the UE; receiving an uplink channel based on the random access response; and attempting to send a downlink channel indicating successful contention resolution to the UE when a contention resolution timer started when the uplink channel is sent is running.

[0018] The method or operation may further include: receiving a second random access preamble for the random access procedure upon the expiration of the contention resolution timer. Based on the start of a cell discontinuous transmission (DTX) inactivity period for the cell during the contention resolution timer's operation and the expiration of the contention resolution timer, the preamble transmission counter may be maintained at a first value. Based on receiving a signal indicating successful contention resolution before the contention resolution timer expires, the UE may consider the contention resolution successful and the random access procedure successfully completed.

[0019] In each aspect of this disclosure, a method performed by the UE or an operation performed on the UE may include: monitoring the downlink channel for contention resolution based on a contention resolution timer running and the cell being in a cell DTX activity period.

[0020] In each aspect of this disclosure, the method performed by the UE or the operation performed on the UE may include: not monitoring the downlink channel used for contention resolution based on the cell being in a cell DTX inactive period.

[0021] In each aspect of this disclosure, a method performed by the BS or an operation performed on the BS may include: transmitting a downlink channel for contention resolution on the cell based on a contention resolution timer running and the cell being in a cell DTX activity period.

[0022] In each aspect of this disclosure, the method performed by the BS or the operation performed on the BS may include: not transmitting downlink channels for contention resolution based on the cell being in a cell DTX inactive period.

[0023] In each aspect of this disclosure, the preamble transmission counter can be incremented based on the fact that the cell DTX inactivity period has not started during the contention resolution timer operation and the contention resolution timer has expired.

[0024] The solutions described above are merely some examples of this disclosure, and those skilled in the art can deduce and understand various examples of the technical features incorporated herein from the following detailed description.

[0025] Beneficial effects

[0026] According to the implementation of this disclosure, energy-saving methods and processes for networks, base stations (BS), and / or user equipment (UE) can be provided.

[0027] According to the implementation of this disclosure, a random access procedure for network energy saving can be provided.

[0028] The effects of this disclosure are not limited to those specifically described above. Those skilled in the art will understand more clearly from the following detailed description other effects not described herein. Attached Figure Description

[0029] The accompanying drawings are included to provide a further understanding of this disclosure. The drawings illustrate examples of implementations of this disclosure and, together with the detailed description, serve to illustrate the implementations of this disclosure: Figure 1 An example of a communication system 1 to which the implementation of this disclosure is applied is shown; Figure 2 This is a block diagram illustrating an example of a communication device capable of performing the methods according to this disclosure; Figure 3 Another example of a wireless device capable of implementing the embodiments of this disclosure is shown; Figure 4 An example of a frame structure used in a wireless communication system based on the 3rd Generation Partnership Project (3GPP) is shown; Figure 5 The resource grid showing the time slots; Figure 6 The diagram illustrates the physical channels in a 3GPP-based communication system as an example wireless communication system, and the signal transmission / reception process using these physical channels. Figure 7 The random access procedure applicable to the implementation of this disclosure is illustrated; Figure 8 Discontinuous reception (DRX) operation is shown for implementations applicable to this disclosure; Figure 9 This shows the configurations for long and short DRX cycles; Figure 10 Examples of race-resolving timer operations according to some implementations of this disclosure are shown; Figure 11 This is a flowchart illustrating the operation of a user equipment (UE) according to some implementations of this disclosure; and Figure 12 This is a flowchart illustrating the operation of a base station (BS) according to some implementations of this disclosure. Detailed Implementation

[0030] In the following, implementations according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description given below with reference to the accompanying drawings is intended to illustrate exemplary implementations of the present disclosure, and not to show only implementations that can be implemented according to the present disclosure. The following detailed description includes specific details in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure can be practiced without these specific details.

[0031] In some cases, known structures and devices may be omitted or shown in block diagram form, thereby focusing on the essential features of the structures and devices so as not to obscure the concepts of this disclosure. The same reference numerals will be used throughout this disclosure to refer to the same or similar parts.

[0032] The following technologies, devices, and systems can be applied to various wireless multiple access systems. For example, multiple access systems may include Code Division Multiple Access (CDMA) systems, Frequency Division Multiple Access (FDMA) systems, Time Division Multiple Access (TDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single-Carrier Frequency Division Multiple Access (SC-FDMA) systems, Multi-Carrier Frequency Division Multiple Access (MC-FDMA) systems, etc. CDMA can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using radio technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), and Enhanced Data Rate GSM Evolution (EDGE) (i.e., GERAN). OFDMA can be specifically implemented using radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS), and the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of E-UMTS that uses E-UTRA. 3GPP LTE uses OFDMA on the downlink (DL) and SC-FDMA on the uplink (UL). LTE-Advanced (LTE-A) is an evolution of 3GPP LTE.

[0033] For ease of description, this disclosure will be given under the assumption that it applies to LTE and / or the new RAT (NR). However, the technical features of this disclosure are not limited thereto. For example, although the following detailed description is based on a mobile communication system corresponding to a 3GPP LTE / NR system, the mobile communication system is applicable to any other mobile communication system except for matters specific to the 3GPP LTE / NR system.

[0034] For any terms and techniques used in this disclosure that are not described in detail, reference may be made to 3GPP-based standard specifications (e.g., 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, 3GPP TS 36.300, 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.214, 3GPP TS 38.300, 3GPP TS 38.304, 3GPP TS 38.331, etc.).

[0035] In the examples of this disclosure described later, if the apparatus “assumes” something, this could mean that the channel transmitting entity transmits the channel in accordance with the corresponding “assumption.” This could also mean that the channel receiving entity receives or decodes the channel in a form consistent with that “assumption,” provided that the channel is transmitted in accordance with that “assumption.”

[0036] In this disclosure, a user equipment (UE) can be fixed or mobile. Each of various devices that transmit and / or receive user data and / or control information by communicating with a base station (BS) can be a UE. The term UE can be referred to as a terminal device, mobile station (MS), mobile terminal (MT), user terminal (UT), subscriber station (SS), radio device, personal digital assistant (PDA), wireless modem, handheld device, etc. In this disclosure, a BS refers to a fixed station that communicates with a UE and / or another BS and exchanges data and control information with the UE and another BS. The term BS can be referred to as an advanced base station (ABS), node B (NB), evolved node B (eNB), base transceiver system (BTS), access point (AP), processing server (PS), etc. Specifically, a BS for Universal Terrestrial Radio Access (UTRAN) is referred to as an NB, a BS for Evolved UTRAN (E-UTRAN) is referred to as an eNB, and a BS for New Radio Access Technology networks is referred to as a gNB. In the following, for ease of description, regardless of the type or version of the communication technology, NB, eNB, or gNB will be referred to as BS.

[0037] In this disclosure, a node refers to a fixed point capable of sending / receiving radio signals to / from a UE via communication with the UE. Various types of BSs can be used as nodes, regardless of their name. For example, BS, NB, eNB, picocell eNB (PeNB), home eNB (HeNB), repeater, transponder, etc., can be nodes. Alternatively, a node may not be a BS. For example, a Radio Remote Headend (RRH) or Radio Remote Unit (RRU) can be a node. Typically, RRHs and RRUs have a lower power level than the BS. Since RRHs or RRUs (hereinafter, RRH / RRU) are typically connected to the BS via dedicated lines such as fiber optic cables, cooperative communication between the RRH / RRU and the BS can be performed smoothly compared to cooperative communication between the BS connected via a radio link. Each node is equipped with at least one antenna. An antenna can refer to a physical antenna port or a virtual antenna or antenna array. A node can also be referred to as a point.

[0038] In this disclosure, a cell refers to a specific geographical area where one or more nodes provide communication services. Therefore, in this disclosure, communication with a specific cell can mean communication with a BS or node providing communication services to that specific cell. The DL / UL signal of a specific cell refers to the DL / UL signal from / to the BS or node providing communication services to that specific cell. A cell providing UL / DL communication services to a UE is specifically referred to as a serving cell. Furthermore, the channel state / quality of a specific cell refers to the channel state / quality of the channel or communication link generated between the BS or node providing communication services to the specific cell and the UE. In 3GPP-based communication systems, the UE can use the CRS transmitted on the Cell Specific Reference Signal (CRS) resource and / or the CSI-RS transmitted on the Channel State Information Reference Signal (CSI-RS) resource (assigned to the specific node by the antenna port of the specific node) to measure the DL channel state from the specific node.

[0039] 3GPP-based communication systems use the concept of cells to manage radio resources and distinguish between cells associated with radio resources and cells representing geographical areas.

[0040] A "cell" of a geographic area can be understood as the coverage area within which a node can use a carrier to provide service, and a "cell" of radio resources is associated with the bandwidth (BW) of the frequency range configured by the carrier. Since DL coverage (the range within which a node can transmit a valid signal) and UL coverage (the range within which a node can receive a valid signal from a UE) depend on the carrier carrying the signal, a node's coverage area can also be associated with the coverage area of ​​the "cell" of the radio resources used by that node. Therefore, the term "cell" can be used to sometimes indicate the service coverage area of ​​a node, at other times to indicate a radio resource, or at other times to indicate the range within which a signal using a radio resource can reach with available effective strength.

[0041] In 3GPP communication standards, the concept of a cell is used to manage radio resources. A “cell” associated with radio resources is defined by a combination of DL resources and UL resources (i.e., a combination of DL component carriers (CCs) and UL CCs). A cell can be configured solely by DL resources or by a combination of DL and UL resources. If carrier aggregation is supported, the link between the carrier frequencies of the DL resources (or DL ​​CCs) and the UL resources (or UL CCs) can be indicated by system information. For example, a combination of DL and UL resources can be indicated by a System Information Block Type 2 (SIB2) link. In this case, the carrier frequencies can be equal to or different from the center frequencies of the individual cells or CCs. When carrier aggregation (CA) is configured, the UE has only one Radio Resource Control (RRC) connection with the network. During RRC connection establishment / re-establishment / handover, a serving cell provides Non-Access Plane (NAS) mobility information. During RRC connection re-establishment / handover, a serving cell provides security input. This cell is called the primary cell (Pcell). A Pcell refers to the cell operating on the primary frequency on which the UE performs the initial connection establishment procedure or initiates the connection re-establishment procedure. Depending on the UE's capabilities, a secondary cell (Scell) can be configured to form a set of serving cells together with a Pcell. An Scell ​​can be configured after RRC connection establishment and is used to provide additional radio resources beyond those of a specific cell (SpCell). The carrier corresponding to the Pcell on the DL is called the Downlink Primary CC (DL PCC), and the carrier corresponding to the Pcell on the UL is called the Uplink Primary CC (UL PCC). The carrier corresponding to the Scell ​​on the DL is called the Downlink Secondary CC (DLSCC), and the carrier corresponding to the Scell ​​on the UL is called the Uplink Secondary CC (UL SCC).

[0042] In dual connectivity (DC) operation, the term Special Cell (SpCell) refers to the Pcell of the Primary Cell Group (MCG) or the primary / secondary cell (Pcell) of the Secondary Cell Group (SCG). The SpCell supports PUCCH transmission and contention-based random access and is always enabled. The MCG is a set of serving cells associated with the primary node (e.g., BS) and includes the SpCell (Pcell) and optionally one or more Scells. For a UE configured with DC, the SCG is a subset of serving cells associated with the secondary node and includes the PSCell and zero or more Scells. The PSCell is the primary Scell ​​of the SCG. For a UE in the RRC_CONNECTED state without a CA or DC configured, only one serving cell exists, consisting only of the Pcell. For a UE in the RRC_CONNECTED state with a CA or DC configured, the term serving cell refers to the set of cells including the SpCell and all Scells. In DC, two Media Access Control (MAC) entities are configured for the UE: one MAC entity for the MCG and one MAC entity for the SCG.

[0043] For a UE configured with a CA but not a DC, a Pcell PUCCH group (also called a primary PUCCH group) including Pcells and 0 or more Scells can be configured, and an Scell ​​PUCCH group (also called a secondary PUCCH group) including only Scells can be configured. For an Scell, an Scell ​​(hereinafter, PUCCH Scell) can be configured to transmit PUCCHs associated with the corresponding cell. The Scell ​​indicating the PUCCH Scell ​​belongs to the Scell ​​PUCCH group (i.e., the secondary PUCCH group) and performs PUCCH transmission of the relevant uplink control information (UCI) on the PUCCH Scell. If no PUCCH Scell ​​is indicated for an Scell, or if the cell indicating the PUCCH transmission for the Scell ​​is a Pcell, then the Scell ​​belongs to the Pcell PUCCH group (i.e., the primary PUCCH group) and performs PUCCH transmission of the relevant UCI on the Pcell. In the following, if the UE is configured with an SCG and some implementations of this disclosure related to PUCCH are applied to the SCG, the primary cell can refer to the PSCell of the SCG. If the UE is configured with a PUCCH Scell ​​and some implementations of this disclosure related to PUCCH are applied to the secondary PUCCH group, then the primary cell may refer to the PUCCH Scell ​​of the secondary PUCCH group.

[0044] In addition to Pcell and PUCCH Scell, the UE can also be configured with PUCCH-sSCell, which is the Scell ​​used for PUCCH cell handover. For example, this can be achieved through RRC parameters. pucch-sSCell Provide PUCCH-sSCell to the UE. This can be done via RRC parameters. pucch-sSCellPattern Provide the UE with a periodic cell handover pattern for PUCCH transmission. pucch- sSCellPattern Each bit of the PUCCH cell handover can correspond to a time slot configured according to the reference subcarrier spacing (SCS), and indicates the PCell or PUCCH-sSCell as the cell used for PUCCH transmission during the time slot configured by the reference SCS. The UE transmits PUCCH on cells outside the PCell and PUCCH-sSCell that are not indicated for PUCCH transmission, without following the periodic cell handover pattern. When the UE is configured with dynamically indicated PUCCH cell handover based on the DCI format, the DCI format associated with the UE generating HARQ-ACK information may include a PUCCH cell indicator field indicating whether PUCCH transmissions from the UE with HARQ-ACK information are on the PCell or PUCCH-sSCell.

[0045] In this disclosure, the term PUCCH cell is used to refer to a cell configured with PUCCH resources. PCell, PUCCH Scell, or PUCCH-sSCell may correspond to a PUCCH cell.

[0046] In a wireless communication system, the UE receives information from the BS on the DL and transmits information to the BS on the UL. The information transmitted and / or received by the BS and UE includes data and various control information, and various physical channels exist depending on the type / purpose of the information transmitted and / or received by the UE and BS.

[0047] 3GPP-based communication standards define DL physical channels corresponding to resource elements carrying information originating from higher layers, and DL physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, the Physical Downlink Shared Channel (PDSCH), Physical Broadcast Channel (PBCH), Physical Multicast Channel (PMCH), Physical Control Format Indicator Channel (PCFICH), and Physical Downlink Control Channel (PDCCH) are defined as DL physical channels, and reference signals (RS) and synchronization signals are defined as DL physical signals. RS (also called pilot) represents a signal with a predefined special waveform known to both the BS and the UE. For example, demodulation reference signal (DMRS), channel state information RS (CSI-RS), and positioning reference signal (PRS) are defined as DL RS. 3GPP-based communication standards also define UL physical channels corresponding to resource elements carrying information originating from higher layers, and UL physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, the Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), and Physical Random Access Channel (PRACH) are defined as UL physical channels, and the DMRS for UL control / data signals and the SRS for UL channel measurements are defined, etc.

[0048] In this disclosure, PDCCH refers to the set of time-frequency resources (e.g., resource elements (REs)) carrying downlink control information (DCI), and PDSCH refers to the set of time-frequency resources carrying DL data. PUCCH, PUSCH, and PRACH refer to the set of time-frequency resources carrying UCI, the set of time-frequency resources carrying UL data, and the set of time-frequency resources carrying random access signals, respectively. In the following description, "UE transmits / receives PUCCH / PUSCH / PRACH" is used to mean the same as the UE transmitting / receiving UCI / UL data / random access signals on or through PUCCH / PUSCH / PRACH. Similarly, "BS transmits / receives PBCH / PDCCH / PDSCH" is used to mean the BS transmitting broadcast information / DCI / DL data on or through PBCH / PDCCH / PDSCH.

[0049] In this specification, radio resources (e.g., time-frequency resources) scheduled or configured by the BS for the UE to transmit or receive PUCCH / PUSCH / PDSCH may be referred to as PUCCH / PUSCH / PDSCH resources.

[0050] Because communication devices receive synchronization signals (SS), DMRS, CSI-RS, PRS, PBCH, PDCCH, PDSCH, PUSCH, and / or PUCCH in the form of radio signals on a cell, the communication device may not select and receive radio signals that only include specific physical channels or specific physical signals via a radio frequency (RF) receiver, or it may not select and receive radio signals without specific physical channels or specific physical signals via an RF receiver. In practice, the communication device receives radio signals on a cell via an RF receiver, converts the radio signals, which are RF band signals, into baseband signals, and then uses one or more processors to decode the physical signals and / or physical channels in the baseband signals. Therefore, in some implementations of this disclosure, not receiving physical signals and / or physical channels may mean that the communication device does not attempt to recover physical signals and / or physical channels from the radio signals, for example, it does not attempt to decode physical signals and / or physical channels, rather than that the communication device does not actually receive radio signals that include the corresponding physical signals and / or physical channels.

[0051] With an increasing number of communication devices requiring greater communication capacity, there is a need for eMBB communication relative to traditional radio access technologies (RATs). Furthermore, massive MTC (Medium-Terminal Communication) to provide various services anytime, anywhere by connecting multiple devices and objects to each other is a major issue to be considered in next-generation communications. In addition, communication system designs considering reliability and latency-sensitive services / UEs are also being discussed. The introduction of next-generation RATs is being discussed, taking into account eMBB communication, massive MTC, ultra-reliable low-latency communication (URLLC), etc. Currently, research on next-generation mobile communication systems after EPC is underway within 3GPP. In this disclosure, for convenience, the corresponding technology is referred to as New RAT (NR) or 5th Generation (5G) RAT, and systems using or supporting NR are referred to as NR systems.

[0052] Figure 1 An example of a communication system 1 to which the implementation of this disclosure is applied is shown. (Refer to...) Figure 1The communication system 1 applied to this disclosure includes wireless devices, a network, and a network. Here, a wireless device refers to a device that performs communication using RAT (e.g., 5G NR or LTE (e.g., E-UTRA)) and may be referred to as a communication / radio / 5G device. Wireless devices may include (but are not limited to) robots 100a, vehicles 100b-1 and 100b-2, extended reality (XR) devices 100c, handheld devices 100d, home appliances 100e, Internet of Things (IoT) devices 100f, and artificial intelligence (AI) devices / servers 400. For example, vehicles may include vehicles with wireless communication capabilities, autonomous vehicles, and vehicles capable of performing vehicle-to-vehicle communication. Here, vehicles may include unmanned aerial vehicles (UAVs) (e.g., drones). XR devices may include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices and may be implemented in the form of head-mounted displays (HMDs), head-up displays (HUDs) installed in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Handheld devices may include smartphones, smart tablets, wearable devices (e.g., smartwatches or smart glasses), and computers (e.g., laptops). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters. For example, the BS and network may also be implemented as wireless devices, and a particular wireless device may operate as a BS / network node relative to another wireless device.

[0053] Wireless devices 100a to 100f can connect to network 300 via BS 200. AI technology can be applied to wireless devices 100a to 100f, and wireless devices 100a to 100f can connect to AI server 400 via network 300. Network 300 can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although wireless devices 100a to 100f can communicate with each other via BS 200 / network 300, wireless devices 100a to 100f can perform direct communication with each other (e.g., sidelink communication) without going through the BS / network. For example, vehicles 100b-1 and 100b-2 can perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). IoT devices (e.g., sensors) can perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0054] Wireless communication / connections 150a and 150b can be established between wireless devices 100a to 100f and BS 200, as well as between wireless devices 100a to 100f. Here, wireless communication / connections such as UL / DL communication 150a and sidelink communication 150b (or device-to-device (D2D) communication) can be established via various RATs (e.g., 5G NR). The wireless devices and the BS / wireless devices can transmit / receive radio signals to / from each other via wireless communication / connections 150a and 150b. For this purpose, at least a portion of various configuration information configuration processes for transmitting / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and resource allocation processes can be performed based on various proposals of this disclosure.

[0055] Figure 2 This is a block diagram illustrating an example of a communication device capable of performing the methods according to this disclosure. (Refer to...) Figure 2 The first wireless device 100 and the second wireless device 200 can transmit and / or receive radio signals via various RATs (e.g., LTE and NR). Here, {first wireless device 100 and second wireless device 200} can correspond to Figure 1 {Wireless Device 100x and BS 200} and / or {Wireless Device 100x and Wireless Device 100x}.

[0056] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and additionally include one or more transceivers 106 and / or one or more antennas 108. The processors 102 may control the memories 104 and / or the transceivers 106, and may be configured to implement the functions, processes, and / or methods described / presented below. For example, the processors 102 may process information in the memories 104 to generate first information / signals, and then transmit radio signals including the first information / signals via the transceivers 106. The processors 102 may receive radio signals including second information / signals via the transceivers 106, and then store the information obtained by processing the second information / signals in the memories 104. The memories 104 may be connected to the processors 102 and may store various information related to the operation of the processors 102. For example, the memories 104 may execute some or all of the processes controlled by the processors 102 or store software code including commands for executing the processes and / or methods described / presented below. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). Transceiver 106 may be connected to processor 102 and transmit and / or receive radio signals via one or more antennas 108. Each transceiver 106 may include a transmitter and / or a receiver. Transceiver 106 may be used interchangeably with radio frequency (RF) units. In this disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0057] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and additionally include one or more transceivers 206 and / or one or more antennas 208. The processors 202 may control the memories 204 and / or the transceivers 206, and may be configured to implement the functions, processes, and / or methods described / presented below. For example, the processors 202 may process information in the memories 204 to generate a third message / signal, and then transmit a radio signal including the third message / signal via the transceivers 206. The processors 202 may receive a radio signal including a fourth message / signal via the transceivers 206, and then store the information obtained by processing the fourth message / signal in the memories 204. The memories 204 may be connected to the processors 202 and may store various information related to the operation of the processors 202. For example, the memories 204 may execute some or all of the processes controlled by the processors 202 or store software code including commands for executing the processes and / or methods described / presented below. Here, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). Transceiver 206 may be connected to processor 202 and transmit and / or receive radio signals via one or more antennas 208. Each transceiver 206 may include a transmitter and / or a receiver. Transceiver 206 may be used interchangeably with an RF unit. In this disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0058] The wireless communication technologies implemented in the wireless devices 100 and 200 of this disclosure may include narrowband Internet of Things (IoT) for low-power communication, as well as LTE, NR, and 6G. For example, NB-IoT technology may be an example of low-power wide-area network (LPWAN) technology and implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2. However, NB-IoT technology is not limited to the above names. Alternatively or additionally, the wireless communication technologies implemented in the wireless devices XXX and YYY of this disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and is referred to by various names including enhanced machine-type communication (eMTC). For example, LTE-M technology may be implemented in at least one of the following standards: 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine-type communication, and / or 7) LTE M, etc., but LTE-M technology is not limited to the above names. Additionally or alternatively, considering low-power communication, the wireless communication technology implemented in the wireless devices XXX and YYY of this disclosure may include at least one of ZigBee, Bluetooth, and LPWAN, but the wireless communication technology is not limited to the above names. For example, ZigBee technology can be used to create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and ZigBee technology may be referred to by various names.

[0059] The hardware elements of wireless devices 100 and 200 will be described in more detail below. One or more protocol layers may be implemented by (but are not limited to) one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as the Physical (PHY) layer, Medium Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and Service Data Adaptation Protocol (SDAP) layer). One or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the functions, processes, proposals, and / or methods disclosed in this disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the functions, processes, proposals, and / or methods disclosed in this disclosure. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, proposals, and / or methods disclosed in this disclosure, and provide the generated signals to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive signals (e.g., baseband signals) and acquire PDUs, SDUs, messages, control information, data, or information from one or more transceivers 106 and 206 according to the functions, processes, proposals, and / or methods disclosed in this disclosure.

[0060] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field-programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. The functions, processes, proposals, and / or methods disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to perform the functions, processes, proposals, and / or methods disclosed in this disclosure may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204 to be driven by one or more processors 102 and 202. The functions, processes, proposals, and / or methods disclosed in this disclosure may be implemented using firmware or software in the form of code, commands, and / or sets of commands.

[0061] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, commands, and / or instructions. One or more memories 104 and 204 may be configured with read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard disk drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104 and 204 may be located internally and / or externally to one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 via various technologies such as wired or wireless connections.

[0062] One or more transceivers 106 and 206 may transmit user data, control information, and / or radio signals / channels mentioned in the methods and / or operation flowcharts of this disclosure to one or more other devices. One or more transceivers 106 and 206 may receive user data, control information, and / or radio signals / channels mentioned in the functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202 and transmit and receive radio signals. For example, one or more processors 102 and 202 may perform control to enable one or more transceivers 106 and 206 to transmit user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 may perform control to enable one or more transceivers 106 and 206 to receive user data, control information, or radio signals from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208. One or more transceivers 106 and 206 may be configured to transmit and receive user data, control information, and / or radio signals / channels mentioned in the functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure via one or more antennas 108 and 208. In this disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert received radio signals / channels, etc., from RF band signals to baseband signals for processing by one or more processors 102 and 202. One or more transceivers 106 and 206 may convert user data, control information, radio signals / channels, etc., processed by one or more processors 102 and 202 from baseband signals to RF band signals. For this purpose, one or more transceivers 106 and 206 may include (analog) oscillators and / or filters.

[0063] Figure 3 Another example of a wireless device capable of implementing the embodiments of this disclosure is shown. (Refer to...) Figure 3 Wireless devices 100 and 200 can correspond to Figure 2 The wireless devices 100 and 200 are configured with various elements, components, units / parts, and / or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and an additional component 140. The communication unit may include a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 may include... Figure 2One or more processors 102 and 202 and / or one or more memories 104 and 204. For example, transceiver 114 may include Figure 2 The device comprises one or more transceivers 106 and 206 and / or one or more antennas 108 and 208. Control unit 120 is electrically connected to communication unit 110, memory 130, and add-on components 140, and controls the overall operation of the wireless device. For example, control unit 120 may control the electrical / mechanical operation of the wireless device based on programs / code / commands / information stored in memory unit 130. Control unit 120 may transmit information stored in memory unit 130 to an external source (e.g., other communication devices) via communication unit 110 through a wireless / wired interface, or store information received from an external source (e.g., other communication devices) via communication unit 110 in memory unit 130 via a wireless / wired interface.

[0064] The additional component 140 can be configured differently depending on the type of wireless device. For example, the additional component 140 may include at least one of a power supply unit / battery, an input / output (I / O) unit, a drive unit, and a computing unit. The wireless device can be configured according to (but is not limited to) a robot ( Figure 1 100a), vehicles ( Figure 1 100b-1 and 100b-2), XR device ( Figure 1 100c), handheld device ( Figure 1 100d), home appliances ( Figure 1 100e), IoT devices ( Figure 1 100f), digital broadcast UE, holographic devices, public safety devices, MTC devices, medical devices, fintech devices (or financial devices), security devices, climate / environment devices, AI servers / devices ( Figure 1 400), BS ( Figure 1 This can be achieved through 200 network nodes, etc. Wireless devices can be used in mobile or fixed locations depending on usage / service.

[0065] exist Figure 3In wireless devices 100 and 200, all elements, components, units / parts, and / or modules may be interconnected via wired interfaces, or at least a portion thereof may be wirelessly connected via communication unit 110. For example, in each of wireless devices 100 and 200, control unit 120 and communication unit 110 may be wired connected, and control unit 120 and first units (e.g., 130 and 140) may be wirelessly connected via communication unit 110. The various elements, components, units / parts, and / or modules within wireless devices 100 and 200 may also include one or more elements. For example, control unit 120 may be configured as a collection of one or more processors. As an example, control unit 120 may be configured as a collection of communication control processors, application processors, electronic control units (ECUs), graphics processing units, and memory control processors. As another example, memory 130 may be configured as random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), flash memory, volatile memory, non-volatile memory, temporary memory, non-temporary memory, and / or combinations thereof.

[0066] In this disclosure, at least one memory (e.g., 104 or 204) may store instructions or programs, and when executed, these instructions or programs may cause at least one processor operatively connected to the at least one memory to perform operations according to some embodiments or implementations of this disclosure.

[0067] In this disclosure, a computer-readable (non-volatile or non-transitory) storage medium may store at least one instruction or program, and the at least one instruction or program, when executed by at least one processor, may cause the at least one processor to perform operations according to some embodiments or implementations of this disclosure.

[0068] In this disclosure, a processing apparatus or device may include at least one processor and at least one computer memory operatively connected to said at least one processor. The at least one computer memory may store instructions or programs, and when executed, these instructions or programs may cause the at least one processor operatively connected to the at least one memory to perform operations according to some embodiments or implementations of this disclosure.

[0069] In this disclosure, a computer program may include program code stored on at least one computer-readable (non-volatile) storage medium, and when executed, is configured to perform operations according to some implementation of this disclosure or to cause at least one processor to perform operations according to some implementation of this disclosure. The computer program may be provided in the form of a computer program product. A computer program product may include at least one computer-readable (non-volatile) storage medium.

[0070] The communication apparatus of this disclosure includes: at least one processor; and at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations according to examples of this disclosure described later.

[0071] Figure 4 An example of a frame structure used in a 3GPP-based wireless communication system is shown.

[0072] Figure 4 The frame structure described is merely exemplary, and the number of subframes, time slots, and symbols within a frame can vary. In an NR system, different sets of OFDM parameters (e.g., subcarrier spacing (SCS)) can be configured for multiple cells aggregated for a UE. Therefore, the (absolute time) duration of time resources comprising the same number of symbols (e.g., subframes, time slots, or transmission time intervals (TTI)) can be configured differently for the aggregated cells. Here, symbols may include OFDM symbols (or cyclic prefix-OFDM (CP-OFDM) symbols) and SC-FDMA symbols (or discrete Fourier transform-extended-OFDM (DFT-s-OFDM) symbols). In this disclosure, symbols, OFDM-based symbols, OFDM symbols, CP-OFDM symbols, and DFT-s-OFDM symbols are used interchangeably.

[0073] Reference Figure 4 In NR systems, UL and DL transmissions are organized into frames. Each frame has a T f =(△f max N f / 100) T c =10 ms duration and is divided into two half-frames, each 5 ms. The basic time unit of NR is T. c =1 / (△f max N f ), where △f max =480 10 3 Hz and N f =4096. For reference, the basic time unit for LTE is T. s =1 / (△f ref N f,ref ), where △f ref =15 10 3 Hz and N f,ref =2048. T s and T cHaving a constant κ=T s / T c =64. Each half-frame consists of 5 subframes, and the duration T of a single subframe is... sf The duration is 1 ms. Subframes are further divided into time slots, and the number of time slots within a subframe depends on the subcarrier spacing. Each time slot comprises either 14 or 12 OFDM symbols based on the cyclic prefix. In normal CP, each time slot comprises 14 OFDM symbols, while in extended CP, each time slot comprises 12 OFDM symbols. The parameter set depends on the exponentially scalable subcarrier spacing Δf = 2. u 15 kHz. The following shows the number of OFDM symbols per time slot ( N slot symb ), the number of time slots per frame ( N frame,u slot ) and the number of time slots per subframe ( N subframe,u slot ).

[0074] [Table 1]

[0075] The following table shows the subcarrier spacing Δf = 2 u 15 kHz, the number of OFDM symbols per time slot, the number of time slots per frame, and the number of time slots per subframe.

[0076] [Table 2]

[0077] For the subcarrier spacing configuration u, the time slots can be indexed in ascending order within the subframe as follows: n u s ∈{0, ..., n subframe ,u slot -1}, and indexed in ascending order within the frame as follows: n u s,f ∈{0, ..., n frame,u slot -1}.

[0078] Figure 5 The resource grid for the time slots is shown. A time slot comprises multiple (e.g., 14 or 12) symbols in the time domain. For each set of parameters (e.g., subcarrier spacing) and carrier, a Common Resource Block (CRB) is used, indicated by higher-layer signaling (e.g., RRC signaling). N start,u grid The definition has begun.N size,u grid,x N RB sc Subcarriers and N subframe,u symb A resource grid of OFDM symbols, wherein N size,u grid,x It represents the number of resource blocks (RBs) in the resource grid, and for downlinks, the subscript x is DL, and for uplinks, it is UL. N RB sc This refers to the number of subcarriers per RB. In 3GPP-based wireless communication systems, N RB sc Typically 12. For a given antenna port p Subcarrier spacing configuration u A resource grid exists between the transmission link (DL or UL). The subcarrier spacing configuration u is given to the UE via higher-layer parameters (e.g., RRC parameters). N size,u grid Used for antenna port p and subcarrier spacing configuration. u Each element in the resource grid is called a resource element (RE), and a complex symbol can be mapped to each RE. Each RE in the resource grid is indexed in the frequency domain. k and an index representing the sign position relative to a reference point in the time domain. l Uniquely identified. In NR systems, an RB is defined by 12 consecutive subcarriers in the frequency domain. In NR systems, RBs are classified as CRBs and Physical Resource Blocks (PRBs). For subcarrier spacing configuration... u CRBs are numbered from 0 upwards in the frequency domain. Subcarrier spacing configuration. u The center of subcarrier 0 of CRB 0 is equal to "point A", which serves as the common reference point for the RB grid. Subcarrier spacing configuration u The PRB is defined within the Bandwidth Part (BWP) and ranges from 0 to N size,u BWP,i -1 is the number, where i is the number of BWPs. PRB n in BWPi PRB With CRB n u CRB The relationship between n u PRB =n u CRB + Nsize,u BWP,i Given, among which N size BWP,i The BWP is the CRB that starts relative to CRB 0. A BWP comprises multiple consecutive RBs in the frequency domain. For example, a BWP can be a BWP i on a given carrier with a given set of parameters u. i A subset of adjacent CRBs is defined. A carrier may include up to N (e.g., 5) BWPs. A UE may be configured to have one or more BWPs on a given component carrier. Data communication is performed via enabled BWPs, and a predetermined number of BWPs (e.g., one BWP) may be active on the component carrier only among the BWPs configured for the UE.

[0079] For each serving cell in the set of DL BWPs or UL BWPs, the network can configure at least an initial DL BWP and one (if the serving cell has an uplink) or two (if supplementary uplinks are used) initial UL BWPs. The network can configure additional UL and DL BWPs. For each DL BWP or UL BWP, the following parameters can be provided to the UE for the serving cell: i) SCS; ii) CP; iii) parameters provided by the UE. N start BWP= The indicated offset is based on the assumption of 275. RB set and length L RB RRC parameter as Resource Indicator Value (RIV) locationAndBandwidth CRB provided N start BWP = O carrier + RB start and the number of adjacent RBs N size BWP = L RB and by RRC parameters offsetToCarrier For the value provided by SCS O carrier ; an index in the set of DL BWP or UL BWP; a set of BWP common parameters; and a set of BWP specific parameters.

[0080] Virtual Resource Blocks (VRBs) can be defined within a BWP and range from 0 to... N size,u BWP,i-1 index, where i represents the BWP number. VRBs can be mapped to PRBs based on interleaved or non-interleaved mappings. In some implementations, for non-interleaved VRB-to-PRB mappings, VRB n can be mapped to PRB n.

[0081] The NR band is defined as two types of frequency ranges, namely FR1 and FR2. FR2 is also known as millimeter wave (mmW). The following shows the frequency range that NR can operate in.

[0082] [Table 3]

[0083] Figure 6 This is a diagram illustrating the physical channels in a 3GPP-based communication system, which serves as an exemplary wireless communication system, and the signal transmission / reception process using these physical channels.

[0084] When the UE is powered on or disconnected from the wireless communication system, the UE searches for a cell to camp on and performs an initial cell search, involving synchronization with the BS in the cell (S11). For the initial cell search, the UE receives a synchronization signal block (SSB) (also known as an SS / PBCH block) from the BS. The SSB includes the primary synchronization signal (PSS), secondary synchronization signal (SSS), and physical broadcast channel (PBCH). The UE establishes synchronization with the BS and obtains information such as the cell identifier (ID) based on the PSS / SSS. The UE can obtain broadcast information in the cell based on the PBCH. The UE can receive a DL reference signal (RS) during the initial cell search to monitor the DL channel status.

[0085] After the initial cell search, the UE can camp on the cell. Subsequently, the UE can monitor the PDCCH in the cell and obtain more specific system information by receiving the PDSCH based on the DCI carried on the PDCCH (S12).

[0086] Subsequently, to establish a connection with the BS, the UE may perform a random access procedure (S13 to S16). During the random access procedure, for example, the UE may transmit a preamble on the PRACH (S13) and receive the PDCCH and a random access response (RAR) to the preamble on the PDSCH corresponding to the PDCCH (S14). If the UE fails to receive the RAR directed to the UE, the UE may attempt to retransmit the preamble. In the case of contention-based random access, the UE may transmit the PUSCH based on the UL resource allocation included in the RAR (S15) and perform a contention resolution procedure (S16) for receiving the PDCCH and the PDSCH corresponding to the PDCCH.

[0087] Following the above process, the UE can receive PDCCH / PDSCH from the BS (S17) and send PUSCH / PUCCH to the BS during normal UL / DL signal transmission (S18). The control information sent by the UE to the BS is usually referred to as uplink control information (UCI). UCI includes hybrid automatic repeat request acknowledgment / negative acknowledgment (HARQ ACK / NACK), scheduling request (SR), and channel state information (CSI). CSI includes channel quality indicator (CQI), precoding matrix indicator (PMI), and / or rank indicator (RI). Typically, UCI is sent on the PUCCH. However, when control information and data should be sent simultaneously, control information can be sent on the PUSCH. Additionally, the UE can send UCI aperiodically on the PUSCH when receiving a request / command from the network.

[0088] Figure 7 A random access procedure applicable to an implementation of this disclosure is shown. In particular, Figure 7 (a) shows the four-step random access procedure. Figure 7 (b) shows the two-step random access procedure.

[0089] Random access procedures can be used for various purposes, including initial access, UL synchronization adjustment, resource allocation, handover, radio link reconfiguration after radio link failure, and location. Random access procedures are classified into contention-based procedures and dedicated (i.e., non-contention-based) procedures. Contention-based random access procedures are typically involved in initial access, while dedicated random access procedures are used for UL synchronization reconfiguration in cases of handover, DL data arrival at the network, and location. In a contention-based random access procedure, the UE randomly selects a random access (RA) preamble. Therefore, multiple UEs can transmit the same RA preamble simultaneously, requiring a subsequent contention resolution process. In a dedicated random access procedure, the UE uses an RA preamble uniquely assigned to it by the BS. Therefore, the UE can perform the random access procedure without conflicting with other UEs.

[0090] Reference Figure 7 (a) The contention-based random access procedure comprises the following four steps. The messages sent in steps 1 to 4 may be referred to as message 1 (Msg1) to message 4 (Msg4), respectively.

[0091] - Step 1: The UE sends the RA preamble on the PRACH.

[0092] - Step 2: The UE receives the RAR from the BS on the PDSCH.

[0093] Step 3: The UE sends UL data to the BS on the PUSCH. The UL data includes Layer 2 (L2) / Layer 3 (L3) messages.

[0094] - Step 4: The UE receives the contention resolution message from the BS on the PDSCH.

[0095] The UE can receive random access information from the BS in the system information. For example, the system information can provide information about the timing of the RACH associated with an SSB on the cell. The UE can select an SSB among those received on the cell whose Reference Signal Received Power (RSRP) based on the SSB measurement exceeds a threshold. The UE can then transmit an RA preamble on the PRACH associated with the selected SSB. For example, when the UE needs random access, the UE transmits Msg1 (e.g., a preamble) to the BS on the PRACH. The BS can identify each RA preamble by the time / frequency resource (RA timing (RO)) carrying the RA preamble and the preamble index (PI). Upon receiving the RA preamble from the UE, the BS transmits a RAR message to the UE on the PDSCH. To receive the RAR message, the UE monitors the L1 / L2 control channel (PDCCH) with a Cyclic Redundancy Check (CRC) masked with a Random Access-RNTI (RA-RNTI) within a pre-configured time window (e.g., ra-ResponseWindow), including scheduling information for the RAR message. The length of the RAR window can be configured by higher-layer signaling, and the RAR window can begin at a specific time after the PRACH transmission (e.g., at the first symbol of the earliest control resource set (CORESET) in the Type 1 PDCCH common search space, starting at least one symbol after the PRACH timing corresponding to the PRACH transmission). When scheduling information is received on a PDCCH masked with RA-RNTI, the UE can receive the RAR message on the PDSCH indicated by the scheduling information. The UE then checks whether a RAR pointing to the UE exists in the RAR message. The existence of a RAR pointing to the UE can be determined by checking whether the random access preamble ID (RAPID) of the preamble sent by the UE exists. The index of the preamble sent by the UE can be the same as the RAPID. The RAR includes the index of the corresponding RA preamble, UL synchronization timing offset information (e.g., timing advance command (TAC)), UL scheduling information transmitted with Msg3 (e.g., UL permission), and UE temporary identification information (e.g., temporary-C-RNTI (TC-RNTI)). Upon receiving the RAR, the UE sends Msg3 on the PUSCH based on the UL scheduling information and timing offset value in the RAR. Msg3 may include the UE's ID (or global ID). Additionally, Msg3 may include RRC connection request information for initial network access (e.g., an RRCSetupRequest message). After receiving Msg3, the BS sends a contention resolution message (i.e., Msg4) to the UE. When the UE receives the contention resolution message and the contention is successfully resolved, the TC-RNTI changes to the C-RNTI. Msg4 may include the ID of UE / RRC connection-related information (e.g., an RRCSetup message).When the information sent in Msg3 does not match the information received in Msg4, or when the UE does not receive Msg4 within a predetermined time, the UE can determine that the contention resolution has failed and retransmit Msg3.

[0096] The Dedicated Random Access Procedure comprises the following three steps. The messages sent in steps 0 through 2 may be referred to as Msg0 through Msg2, respectively. The BS can trigger the Dedicated Random Access Procedure via a PDCCH (hereinafter referred to as the PDCCH command) serving the purpose of transmitting the command RA preamble.

[0097] - Step 0: The BS assigns the RA preamble to the UE via dedicated signaling.

[0098] - Step 1: The UE sends the RA preamble on the PRACH.

[0099] - Step 2: The UE receives the RAR from the BS on the PDSCH.

[0100] Steps 1 and 2 of the dedicated random access procedure can be the same as steps 1 and 2 of the contention-based random access procedure.

[0101] NR systems may require lower latency than traditional systems. In particular, for latency-sensitive services such as URLLC, a four-step random access procedure may not be preferred. Various scenarios within NR systems may require low-latency random access procedures. When the implementation of this disclosure is implemented together with the random access procedure, the implementation of this disclosure can be implemented together with the following two-step random access procedure to reduce the latency involved in the random access process.

[0102] Reference Figure 7 (b) The two-step random access procedure can be performed in two steps: a MsgA transmission from the UE to the BS and a MsgB transmission from the BS to the UE. The MsgA transmission may include the transmission of the RA preamble on the PRACH and the transmission of the UL payload on the PUSCH. In the MsgA transmission, the PRACH and PUSCH may be transmitted in time division multiplexing (TDM). Alternatively, in the MsgA transmission, the PRACH and PUSCH may be transmitted in frequency division multiplexing (FDM).

[0103] Upon receiving MsgA, the BS may send MsgB to the UE. MsgB may include a RAR for the UE. After sending MsgA, the UE monitors for a response from the network within a time window used to monitor the RAR in order to perform a two-step random access procedure. The length of this time window may be configured by higher-layer signaling, and the time window may begin at a specific timing after the transmission of MsgA (e.g., at least one symbol after the last symbol of the PUCCH timing corresponding to the transmission of MsgA, in the first symbol of the earliest CORESET in the Type 1 PDCCH common search space).

[0104] An RRC connection request message (e.g., an RRCSetupRequest message) requesting the establishment of a connection between the RRC layer of the BS and the RRC layer of the UE can be included in the payload of MsgA. In this case, MsgB can be used to send RRC connection-related information (e.g., an RRCSetup message). Alternatively, an RRC connection request message (e.g., an RRCSetupRequest message) can be sent on the PUSCH based on the UL permission in MsgB. In this case, the RRC connection-related information (e.g., an RRCSetup message) associated with the PUSCH transmission can be sent on the PDSCH after the PUSCH transmission based on MsgB.

[0105] Regarding contention resolution during random access, a contention resolution timer can be configured. For example, the BS can send an initial value for the contention resolution timer via higher-layer signaling for the cell. When a UE sends Msg3 with RACH configuration including parameters related to the contention resolution timer, it starts or restarts the contention resolution timer in the first symbol after the end of Msg3 transmission, or when Msg3 transmission is scheduled to repeat on PUSCH, it starts or restarts the contention resolution timer in the first symbol after the end of all repetitions of Msg3 transmission. While the contention resolution timer is running, the UE performs PDCCH monitoring. When the C-RNTI MAC control element (CE) is included in Msg3 and the PDCCH received by the UE while the contention resolution timer is running is addressed to the C-RNTI, the UE can consider the contention resolution successful, stop the contention resolution timer, discard the C-RNTI, and consider the random access procedure successfully completed. When the Common Control Channel (CCCH) SDU is included in Msg3, and the PDCCH received by the UE during the contention resolution timer is addressed to its TC-RNTI, and the MAC PDU carried by the PDSCH scheduled by the PDCCH is successfully decoded, the UE can stop the contention resolution timer. When the MAC PDU includes the UE Contention Resolution Identifier (MACCE) and the UE Contention Resolution Identifier in the MACCE matches the CCCH SDU sent in Msg''3, the UE can consider the contention resolution successful, discard the TC-RNTI, and consider the random access procedure successfully completed. When the contention resolution timer is running (i.e., until the contention resolution timer expires), if the UE fails to receive a PDCCH addressing the C-RNTI in the C-RNTIMAC CE sent via Msg3, if the UE fails to receive a PDCCH addressing its TC-RNTI, if the UE fails to successfully decode the MAC PDU in the PDSCH corresponding to the PDCCH addressing its TC-RNTI, or if the UE contention resolution identifier in the MAC PDU does not match the CCCH SDU sent via Msg3 (even if the MAC PDU is successfully decoded), the UE may consider the contention resolution unsuccessful. When contention resolution is considered unsuccessful, the UE refreshes the HARQ buffer used for the transmission of the MAC PDU in the Msg3 buffer and increments PREAMBLE_TRANSMISSION_COUNTER by 1. When PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax + 1, the UE's MAC layer may notify higher layers (e.g., the RRC layer) of the random access problem.When the random access procedure is not completed (e.g., when PREAMBLE_TRANSMISSION_COUNTER < preambleTransMax + 1), the UE can perform a random access resource selection procedure for the transmission of Msg1 (when the random access procedure is a 4-step random access procedure) or perform a random access resource selection procedure for the transmission of MsgA (when the random access procedure is a 2-step random access procedure).

[0106] During the random access procedure, PREAMBLE_TRANSMISSION_COUNTER is a UE variable for the random access procedure, and when the random access procedure is initiated, the UE sets PREAMBLE_TRANSMISSION_COUNTER to 1. preambleTransMax It is the maximum number of random access preamble transmissions (i.e., Msg1 transmissions) performed before the UE declares failure and can be provided by higher layer signaling (e.g., RRC signaling). In the case of a 2-step random access procedure, msgA-TransMax can be configured separately, which is the maximum number of MsgA transmissions performed before the UE switches to a 4-step random access. preambleTransMax When the MAC layer specifically notifies the UE's higher layer (e.g., RRC layer) from the MAC of the MCG about a random access problem, it can be considered that a radio link failure has been detected for the MCG, and actions are taken to enter RRC_IDLE, initiate a connection reconstruction procedure, or notify the network of the failure detected by the UE.

[0107] When the MAC layer specifically notifies the UE's higher layer (e.g., RRC layer) from the MAC of the MCG about a random access problem, it can be considered that a radio link failure has been detected for the MCG, and actions are taken to enter RRC_IDLE, initiate a connection reconstruction procedure, or notify the network of the failure detected by the UE.

[0108] Hereinafter, the physical channels available in a 3GPP-based wireless communication system will be described in detail.

[0109] The PDCCH carries the DCI. For example, the PDCCH (i.e., the DCI) carries information about the transmission format and resource allocation of the downlink shared channel (DL-SCH), information about the resource allocation of the uplink shared channel (UL-SCH), paging information about the paging channel (PCH), system information about the DL-SCH, resource allocation information about control messages (e.g., Random Access Response (RAR) sent on the PDSCH) of layers higher than the physical layer in the UE / BS protocol stack (hereinafter, higher layers), transmission power control commands, and information about enabling / disabling configuration scheduling (CS), etc. The DCI that includes resource allocation information about the DL-SCH is called the PDSCH scheduling DCI, and the DCI that includes resource allocation information about the UL-SCH is called the PUSCH scheduling DCI. The DCI includes Cyclic Redundancy Check (CRC). The CRC is masked / scrambled with various identifiers (e.g., Radio Network Temporary Identifier (RNTI)) according to the owner and purpose of the PDCCH. For example, if the PDCCH is used for a specific UE, the CRS is masked with the UE identifier (e.g., Cell-RNTI (C-RNTI)). If the PDCCH is used for paging messages, the CRC is masked with the Paging RNTI (P-RNTI). If the PDCCH is used for system information (e.g., System Information Block (SIB)), the CRC is masked with the System Information RNTI (SI-RNTI). If the PDCCH is used for random access responses, the CRC is masked with the Random Access-RNTI (RA-RNTI).

[0110] When a PDCCH on one serving cell schedules a PDSCH or PUSCH on another serving cell, it is called cross-carrier scheduling. Cross-carrier scheduling with a Carrier Indicator Field (CIF) allows the PDCCH on one serving cell to schedule resources on another serving cell. When a PDSCH on one serving cell schedules a PDSCH or PUSCH on another serving cell, it is called self-carrier scheduling. When cross-carrier scheduling is used in a cell, the BS can provide the UE with information about the scheduling cell. For example, the BS can inform the UE whether the serving cell is scheduled by a PDCCH on another (scheduling) cell or by the serving cell itself. If the serving cell is scheduled by another (scheduling) cell, the BS can inform the UE which cell signals the DL assignment and UL authorization of the serving cell. In this disclosure, the cell carrying the PDCCH is called the scheduling cell, and the cell whose PUSCH or PDSCH transmission is scheduled by the DCI included in the PDCCH (i.e., the cell carrying the PUSCH or PDSCH scheduled by the PDCCH) is called the scheduled cell.

[0111] PDSCH is the physical layer DL channel for DL ​​data transmission. PDSCH carries DL data (e.g., DL-SCH transport blocks) and is modulated using techniques such as Quadrature Phase Shift Keying (QPSK), 16-Quadrature Amplitude Modulation (QAM), 64 QAM, 256 QAM, etc. Codewords are generated by encoding the transport block (TB). PDSCH can carry up to two codewords. Scrambling and modulation mapping can be performed for each codeword, and modulation symbols generated from each codeword can be mapped to one or more layers. Each layer, along with DMRS, is mapped to radio resources and generated as OFDM symbol signals. The OFDM symbol signals are then transmitted through the corresponding antenna ports.

[0112] For UL-SCH data transmission, the UE needs UL resources available to it; for DL-SCH data reception, the UE needs DL resources available to it. The BS assigns UL and DL resources to the UE through resource allocation. Resource allocation may include time-domain resource allocation (TDRA) and frequency-domain resource allocation (FDRA). In this disclosure, UL resource allocation is also referred to as UL licensing, and DL resource allocation is also referred to as DL assignment. UL licensing can be dynamically received by the UE on the PDCCH or in the RAR, or UL licensing can be semi-persistently configured to the UE from the BS via RRC signaling. DL assignment can be dynamically received by the UE on the PDCCH, or semi-persistently configured to the UE from the BS via RRC signaling.

[0113] On the UL, the BS can dynamically allocate UL resources to the UE via the PDCCH addressed to the temporary identifier (Cell Radio Network Temporary Identifier, C-RNTI). The UE monitors the PDCCH to detect possible UL licenses for UL transmission. The BS can allocate UL resources to the UE using configuration licenses (CG). Two types of configuration licenses are available: Type 1 and Type 2. In Type 1, the BS directly provides the configured UL licenses (including periodicity) via RRC signaling. In Type 2, the BS configures the periodicity of RRC-configured UL licenses via RRC signaling and can signal and enable or disable the configured UL licenses via the PDCCH addressed to the configuration scheduling RNTI (CS-RNTI). For example, in Type 2, the PDCCH addressed to the CS-RNTI indicates deactivation, and the corresponding UL license can be implicitly reused based on the periodicity configured via RRC signaling.

[0114] On the DL (Deep Node) architecture, the BS (Base Station) can dynamically allocate DL resources to the UE via the PDCCH (Programmable Node Distributor) addressed to the C-RNTI (Central Receiver Instruction). The UE monitors the PDCCH to detect potential DL assignments. The BS can allocate DL resources to the UE using semi-persistent scheduling (SPS). The BS can configure the periodicity of the configured DL assignments via RRC (Regulatory Relationship Control) signaling and signal to enable or disable the configured DL assignments via the PDCCH addressed to the CS-RNTI. For example, indicating until deactivation via the PDCCH addressed to the CS-RNTI implicitly reuses the corresponding DL assignment based on the periodicity configured via RRC signaling.

[0115] A CORESET can be defined and / or configured as the set of time-frequency resources that the UE can monitor for PDCCH. A CORESET has a duration of one to three OFDM symbols and includes a set of PRBs. The PRBs included in the CORESET and the CORESET duration can be provided to the UE via higher-layer (e.g., RRC) signaling. The UE can monitor the set of PDCCH candidates in the configured CORESET according to the corresponding search space set. In this disclosure, monitoring means decoding (blind decoding) of each PDCCH candidate based on the monitored DCI format.

[0116] The set of PDCCH candidates monitored by the UE is defined according to the PDCCH search space set. The search space set can be a common search space (CSS) set or a UE-specific search space (USS) set. Each CORESET configuration is associated with one or more search space sets, and each search space set is associated with a CORESET configuration.

[0117] The UE monitors the PDCCH candidate set in one or more CORESETs on the active DLBWP of each enabled serving cell configured with PDCCH monitoring, based on the corresponding search space set. Monitoring means receiving each PDCCH candidate and decoding it according to the monitored DCI format.

[0118] The UE can monitor PDCCH candidates in one or more SS sets within a time slot, depending on the configuration of the CORESET / SS set. The timing of monitoring PDCCH candidates (e.g., time / frequency resources) is defined as the PDCCH (monitoring) timing. One or more PDCCH (monitoring) timings can be configured within a time slot.

[0119] Discontinuous reception (DRX) of UE

[0120] To reduce power consumption, the UE uses DRX. A UE operating on DRX repeatedly turns its receive operation on and off. The characteristics of DRX for reducing unnecessary power consumption in the UE are as follows. For DRX, there are separately defined structures: one for UEs in the RRC_IDLE state where an RRC connection has not yet been established between the UE and the BS (hereinafter referred to as I-DRX), and one for UEs in the RRC_CONNECTED state where an RRC connection has been established between the UE and the BS (hereinafter referred to as C-DRX). Both DRX structures are designed to define periodic intervals (e.g., active time or on-duration period) at which the UE can expect to receive DL signals, thus reducing unnecessary power consumption in other periods. In particular, in the case of C-DRX, the start position of the on-duration period is periodically defined according to the NR Rel-16 specification. In this case, the size of the configured period (i.e., the DRX cycle) can be determined / configured by higher-level signaling such as RRC signaling provided by the BS to the UE.

[0121] Figure 8 This illustrates discontinuous reception (DRX) operation. Specifically, Figure 10 The DRX loop for a UE in the RRC_CONNECTED state is shown.

[0122] Reference Figure 8The DRX cycle includes an on-duration period and a DRX opportunity. The DRX cycle defines the time interval between periodic repetitions of the on-duration period, followed by a possible inactivity period. The on-duration period is the time period during which the UE monitors the PDCCH. When the UE is configured with DRX, it performs PDCCH monitoring during the on-duration period. When the UE successfully detects a PDCCH during the PDCCH monitoring period, it starts an inactivity timer and remains awake. Conversely, when the UE fails to detect any PDCCH during the PDCCH monitoring period, it transitions to a sleep state after the on-duration period. Therefore, when DRX is configured, the UE can perform PDCCH monitoring / reception discontinuously in the time domain within the procedures and / or methods according to the implementation of this disclosure. For example, when DRX is configured, the PDCCH reception timing (e.g., time slots with a PDCCH search space) can be configured discontinuously according to the DRX configuration in this disclosure. Conversely, when DRX is not configured, the UE can perform PDCCH monitoring / reception continuously in the time domain. For example, when DRX is not configured, the timing of PDCCH reception can be configured continuously in this disclosure (e.g., time slots with PDCCH search space). Regardless of whether DRX is configured, PDCCH monitoring can be restricted during the time period configured as a measurement interval. DRX configuration information is received via higher-layer (e.g., RRC) signaling, and DRX on / off is controlled via DRX commands from the MAC layer. Once DRX is configured, the UE can perform PDCCH monitoring discontinuously, such as... Figure 8 As shown.

[0123] The table below describes the UE's DRX operation. Referring to the table, DRX configuration information is received via higher-layer signaling (e.g., RRC signaling), and DRX is enabled / disabled via DRX commands from the MAC layer. Once DRX is configured, the UE can perform PDCCH monitoring discontinuously, such as... Figure 8 As shown.

[0124] [Table 4]

[0125] MAC-CellGroupConfig includes the configuration information required to configure MAC parameters for a cell group. MAC-CellGroupConfig may also include DRX configuration information. For example, when defining a DRX, MAC-CellGroupConfig may include the following information.

[0126] The value of -drx-OnDurationTimer: Configures the duration at which the DRX cycle begins.

[0127] The value of -drx-SlotOffset: Configures the delay before starting drx-onDurationTimer.

[0128] The value of -drx-InactivityTimer: PDCCH indicates the duration following the PDCCH timing of a new UL or DL ​​transmission by a MAC entity.

[0129] The value of -drxRetransmissionTimerDL (per DL HARQ processing, excluding broadcast processing): configures the maximum duration until a DL retransmission is received.

[0130] The value of -drxRetransmissionTimerUL (per UL HARQ process): Configures the maximum duration until a permission to retransmit to the UL is received.

[0131] The value of -drx-HARQ-RTT-TimerDL (per DL HARQ processing, excluding broadcast processing): configures the maximum duration from receiving the initial DL transmission to receiving the DL assignment for HARQ retransmission.

[0132] The value of -drx-HARQ-RTT-TimerUL (per UL HARQ process): Configures the maximum duration from receiving permission for the initial UL transmission to receiving permission for a UL retransmission.

[0133] -drx-LongCycleStartOffset: Configures the long DRX cycle and drx-StartOffset, which defines the subframes at the start of the long and short DRX cycles.

[0134] -drx-ShortCycle (optional): Configures a short DRX cycle.

[0135] -drx-ShortCycleTimer (optional): Configures the duration for which the UE should follow a short DRX cycle. For example, the value of a multiple of the short DRX cycle can be configured via drx-CycleTimer. For example, a value of n can correspond to n drx-ShortCycle.

[0136] If a DRX group is active, the UE can perform PDCCH monitoring on the serving cells within the DRX group. In this case, a DRX group refers to a group of serving cells configured by RRC and having the same DRX active time. Here, active time refers to the total duration for which the UE monitors the PDCCH. Active time may include the duration of the DRX cycle being active, the time during which the UE performs continuous reception while the inactivity timer has not expired, and the time during which the UE performs continuous reception while waiting for a retransmission opportunity. For example, when configuring DRX, the active time of a serving cell in a DRX group includes i) the time during which the drx-onDurationTimer or drx-InactivityTimer configured for the DRX group is running; or ii) the time during which the drx-RetransmissionTimerDL or drx-RetransmissionTimerUL is running on any serving cell in the DRX group; or the ra-ContentionResoultionTimer or msgB-RsponseWindow is running; or the time during which a new transmission of C-RNTI indicating to the MAC entity to be sent to the UE is not received after a successful reception of a random access response to a random access preamble not selected by the MAC entity in a contention-based random access preamble.

[0137] One or more DRX groups can be configured for the UE via RRC signaling from the BS. For example, if two DRX groups are configured, each serving cell is uniquely assigned to one of the two DRX groups. DRX parameters drx-onDurationTimer and drx-InactivityTimer are configured separately for each DRX group. DRX parameters drx-SlotOffset, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-LongCycleStartOffset, drx-ShortCycle (optional), drx-ShortCycleTimer (optional), drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerUL are common to all DRX groups. Since each serving cell belongs to only one DRX group, and the DRX parameters drx-onDurationTimer and drx-InactivityTimer are configured for each DRX group, while other DRX parameters are common to the DRX group, it can be considered that the serving cell is associated with only one set of DRX parameters.

[0138] Figure 9 This shows the configurations for long and short DRX cycles. Specifically, Figure 9This shows the case where drx-ShortCycleTimer is set to 2.

[0139] The BS can configure a long DRX cycle and an additional short DRX cycle shorter than the long DRX cycle. If no short DRX cycle is configured, the UE will follow the long DRX cycle. When a short DRX cycle is configured, the BS can set the duration of the long DRX cycle to a positive integer multiple of the short DRX cycle. The same settings can be configured for both long and short DRX cycles. onDurationTimer The value. If there is no data activity during the on-duration of the long DRX cycle (e.g., no PDCCH is received), the UE follows the long DRX cycle as if no short DRX cycle were configured. If there is data activity during the on-duration of the long DRX cycle, for example, while drx-onDurationTimer is running, the UE switches to a short DRX cycle and follows the short DRX cycle for a specific time period (e.g., while drx-ShortCycleTimer is running). In this case, the start of the on-duration in the short DRX cycle is determined by... drx-StartOffset and drx-SlotOffset Confirmed, just like in a long DRX loop. (See reference...) Figure 9 If there is no data activity during the time period when the UE follows the short DRX cycle, for example, if there is no data activity during the time period specified by drx-ShortCycleTimer If there is no data activity during the period defined by drx-ShortCycle, the UE switches from a short DRX cycle, which has a duration of drx-ShortCycleTimer, to a long DRX cycle.

[0140] Network energy saving and community DRX / DTX

[0141] Due to its potential contribution to building environmentally friendly networks by reducing carbon emissions and cutting communication operators' operating expenses (OPEX), network energy efficiency is being significantly considered in wireless communication systems, including those of 3GPP. In particular, with the increasing demand for high transmission rates following the advent of 5G communications, network base stations (BSs) need to be equipped with a greater number of antennas and provide services across wider bandwidths and frequency bands. According to recent research, the energy cost of BSs has reached up to 20% of total OPEX. Due to this increased focus on BS energy efficiency, 3GPP NR Release 18 approved a new research project called the "Network Energy Efficiency Study." For example, to enhance energy efficiency in BS transmission and reception, this study investigates how to use potential support / feedback from UEs and potential UE support information to achieve more efficient transmission and / or reception operations dynamically and / or semi-statically in the time, frequency, spatial, and power domains with finer adaptive granularity based on one or more network energy efficiency techniques.

[0142] When a BS operates in Network Energy Saving (NES) mode for energy saving (ES), it means that the BS has been pre-configured to disable the transmission of specific DL signals (e.g., the BS's Discontinuous Transmission (DTX) cycle) for multiple shutdown periods, and dynamically instructs one of these shutdown periods to indicate that no DL signals are transmitted during a predefined time period, thus reducing the power consumption of the BS and UE. NES mode can refer to an operating mode that reduces the power consumption of the BS and UE by performing operations in the frequency domain (e.g., BWP handover and dynamic resource block (RB) adaptation), the spatial domain (e.g., semi-statically or dynamically disabling a specific BS receive antenna port to stop transmission and / or reception through it), and the time domain.

[0143] As described above, when a UE is in connected mode after its initial connection to the BS, it should continuously perform PDCCH monitoring to identify whether scheduled transmissions for it exist in the search space of its various configurations. However, when such scheduling does not occur continuously, the UE's battery may be rapidly depleted due to unnecessary PDCCH monitoring each time. Therefore, the BS can configure the UE to have on periods (on duration) for PDCCH monitoring and off periods when monitoring is not required. That is, the BS can configure C-DRX for the UE to save UE power. The UE's C-DRX can also help the BS save power. For example, since the BS does not need to send PDCCH to a particular UE during the C-DRX off period of a particular UE, the BS can use resources (e.g., radio resources during the UE's C-DRX off period) for other purposes or to achieve ES gain from DTX / DRX. However, since the UE can perform transmissions without restriction in pre-configured resources (e.g., SR, PUCCH, CG PUSCH, etc.) when needed, the BS should remain ready to receive these unexpected UL transmissions from the UE even during the off period. Furthermore, because C-DRX is configured in a UE-specific manner, DRX cycles or on / off periods are not aligned among UEs within a cell (or BS). Therefore, when a UE's on period is configured in time-division multiplexing (TDM), the BS will not sleep, as it must remain awake during each on period of the UE within the cell (or BS) to transmit PDCCH, making it difficult for the BS to anticipate ES gain.

[0144] Therefore, in some implementations of this disclosure, similar to UE C-DRX, the BS can save energy by utilizing cell (specific) DTX / DRX configurations during recurring active and inactive periods to disable the transmission / reception of specific signals / channels during inactive periods. The following describes some implementations of this disclosure for the BS's cell (specific) DTX / DRX operation to save BS energy through restricted DTX / DRX, which either completely disables transmission / reception on the cell or allows transmission / reception of specific signals / channels during specific time periods. Furthermore, some implementations of this disclosure for UE operation during each time period of the combination of cell DTX / DRX with the UE's DRX operation in the cell are described. Although, for convenience, methods and corresponding operation methods for combining cell DTX / DRX with the UE's C-DRX operation are primarily described, some implementations of this disclosure can be similarly applied to and extended not only to C-DRX but also to and extended to other UE DRX operations (e.g., idle mode DRX).

[0145] During the periodic on duration, the UE performs PDCCH monitoring to identify any UL or DL ​​transmission / reception to be performed. Upon receiving the PDCCH, the UE performs DL reception or UL transmission according to the PDCCH's indication. For UL, if data to be transmitted exists in the UL buffer, the UE can wake up and send a scheduling request (SR) regardless of C-DRX, even if it is in sleep mode. UEs in idle mode periodically perform paging monitoring. When the UE is not a paging target, it can re-enter sleep mode and operate in idle mode (idle mode DRX (i.e., I-DRX)). When it is said that the UE operates in sleep mode, this can mean that the UE performs SR transmissions "regardless of the active time determined by C-DRX" or "even during periods outside the active time determined by C-DRX". In C-DRX operation, a DRX cycle is a recurring time period that includes an on duration and an off duration. The length of the DRX cycle can be defined from the beginning of the on duration until the next on duration. DRX cycles can be classified as long DRX cycles and short DRX cycles. As the DRX cycle length increases, latency can increase because when the BS has a PDSCH to send to the UE immediately after the end of a specific on-time duration, the BS must wait until the UE's next on-time duration. From the BS's perspective, since the UE does not send periodic CSI (P-CSI) or sounding reference signals (SRS) during the off-time period, the BS can allocate these resources (i.e., resources used for P-CSI or SRS transmission) to other UEs, thereby increasing resource utilization. The BS can also switch to power-saving mode during the UE's off-time period to conserve energy.

[0146] Regarding C-DRX, the BS can instruct the UE to immediately enter DRX sleep mode and not operate in active mode until the on-time duration ends via the DRX command MAC control element (CE). For example, the BS can instruct the UE to end its current active time and immediately enter a DRX cycle. When the UE is only configured with a long DRX cycle, it can operate in a long DRX cycle (based on the DRX command MAC CE). When both long and short DRX cycles are configured for the UE, the UE immediately enters a short DRX cycle after receiving the DRX command MAC CE. Furthermore, when the BS provides a long DRX command MAC CE, the UE can operate in a long DRX cycle even if a short DRX cycle is configured. The BS can also configure the long DRX cycle via RRC parameters. drx-LongCycleStartOffset and the subframes that define the start of long and short DRX cycles. drx-SlotOffset Adjust / change the starting point of a long DRX cycle. RRC parameters drx- LongCycleStartOffset The value is defined in milliseconds to allow long DRX cycles to begin at slot boundaries. Additionally, another RRC parameter... drx-SlotOffset This can be used to configure the start point of the on-time duration with slot-level granularity. In this case, by ( drx-SlotOffset The time slot offset indicated is applied to drx-LongCycleStartOffset The indicated reference point is used to define the relative position of the on duration. Although the BS can use the alignment between the on and off durations of multiple UEs within the cell, for ES based on the BS's dynamic transmit / receive off time pattern by adjusting the start of the DRX cycle and the start of the on duration, a more dynamic offset value indication may be required.

[0147] Compared to continuous monitoring of the PDCCH (e.g., in every time slot), the UE can save energy by waking up only during the active duration to monitor the PDCCH sent to it according to the C-DRX configuration. Furthermore, when the BS has no data to send to the UE during the upcoming active duration, the BS can save even more battery power by sending a Wake-Up Signal (WUS) before the start of the UE's active duration, thus indicating that waking up is not required during the active duration (i.e., no need to initiate the onDurationTimer). In this case, when the BS has no data to send to / receive from a UE with C-DRX configuration during the upcoming active duration, the BS can instruct the UE not to wake up during that active duration by sending a WUS that can be transmitted in DCI format 2_6 (used to notify one or more UEs of power-saving information outside of DRX active time) at a WUS timing configured before the active duration. Upon receiving the WUS (e.g., a wake-up indication via DCI format 2_6), the UE can remain in sleep mode without transitioning to active mode, thus saving even more energy.

[0148] In the following description, UE DRX or C-DRX and I-DRX refer to discontinuous reception from the UE's perspective. Cell DRX refers to discontinuous reception from the BS's perspective, while cell DTX refers to discontinuous transmission from the BS's perspective. From the UE's perspective, cell DRX can mean disabling UL transmission, and cell DTX can mean disabling DL reception.

[0149] Based on cell DTX / DRX operation, similar to the structure of UE C-DRX, active and inactive periods (periods outside the active period) can be configured. During an active period, all signals and channels can be transmitted / received without restriction. During an inactive period, transmission / reception of all signals and channels is disabled, or only specific signals and channels can be transmitted / received with restrictions (e.g., only channels / signals such as PDCCH transmission or RACH / SR PUCCH reception are allowed to be transmitted / received). Cell DTX / DRX configuration can be configured and activated solely by RRC (i.e., solely via RRC signaling), or some parameters for cell DTX / DRX can be configured by RRC, while the remaining parameters are configured / indicated and activated by L1 and / or L2 signaling (e.g., (group common) DCI and / or MAC CE). Information regarding the location and duration (in the time domain) of the cell DTX / DRX active and inactive periods can be pre-configured via specific RRC parameters. For example, the start of an active period can be configured by offset from a specific subframe boundary or a specific system frame number (SFN) value, and the duration can be configured by duration-related parameters or timers. In some implementations, the BS can pre-configure multiple parameter or timer candidates and indicate one of the candidates when activated via L1 and / or L2 signaling. During a cell DTX / DRX active period, the transmission / reception of all signals and channels may not be subject to special restrictions, as is the case during normal BS operation. Time periods outside of active periods are generally considered inactive periods, during which transmission / reception is restricted except for pre-configured signals and channels, and the BS can achieve ES gain by performing only such minimal transmission / reception operations. Therefore, operations performed when NES state / mode is enabled can be considered for use in time periods outside of active periods.

[0150] For example, to reduce the activity time of DL transmission / UL reception by the BS, the UE can be configured with periodic cell DTX / DRX patterns (i.e., active and inactive periods). The cell DTX / DRX pattern can be shared by all UEs within the cell. Periodic cell DTX patterns can be configured for individual serving cells via RRC. The BS can configure cell-only DTX, cell-only DRX, or both for a cell. Cell DTX and cell DRX patterns can be configured and enabled individually. Up to N cell DTX / DRX patterns can be configured per MAC entity for different serving cells, where N is a predefined value. Cell DTX / DRX can be enabled / disabled via RRC signaling or L1 group common signaling (e.g., signaling via group common PDCCH). The BS can control cell DTX and cell DRX operations by providing cell DTX / DRX configuration via RRC signaling. For example, through cell DTX / DRX configuration, the BS can provide timers (e.g., cell DTX / DRX enable duration timers) related to the active period at the start of a cell DTX / DRX cycle, the subframe at the start of the cycle, the delay before the start of the active period, and the RRC parameters for the cell DTX / DRX cycle period (i.e., cell DTX / DRX periodicity). The active period in cell DTX / DRX can be the period during which the UE waits to receive a PDCCH or SPS and transmits an SR or CG. Cell DTX / DRX cycling specifies that the active period repeats periodically following the inactive period. The active period and cycle parameters can be common to both cell DTX and cell DRX. The BS can configure C-DRX and cell DTX / DRX to at least partially overlap between the UE's C-DRX enable period and the cell DTX / DRX active period. For example, the BS can configure the UE's C-DRX periodicity to be an integer multiple of the cell DTX / DRX periodicity, and vice versa.

[0151] In some implementations, cell DTX operation may affect the UE's monitoring activity of PDCCH and configured DL assignments under RRC_CONNECTED. For a serving cell with cell DTX configured and enabled, the UE (e.g., the UE's MAC entity) monitors the PDCCH on the serving cell when the serving cell is in a cell DTX activity period. The serving cell's cell DTX activity period may include the time period for running a cell DTX / DRX enable duration timer for the serving cell. For example, for a serving cell with cell DTX configured and enabled, when the serving cell is not in a cell DTX activity period, the UE (e.g., the UE's MAC entity) will not monitor the PDCCH on the serving cell and will not receive transport blocks on the serving cell according to the SPS configured DL assignment (i.e., SPS PDSCH reception is not performed), regardless of whether the UE is in a UE C-DRX activity period.

[0152] In some implementations, cell DRX operation can control the SR (Send Transfer) and configure UL (Ultimate Required Transfer) activities of a UE in RRC_CONNECTED state. In some cases, when cell DRX is configured and enabled for a serving cell, the UE (e.g., the UE's MAC entity) can, in principle, only perform CG PUSCH and PUCCH transmissions on the serving cell during cell DRX active periods (if the serving cell is a PUCCH cell). For example, when the serving cell with cell DRX configured and enabled is in a cell DRX inactive period, the UE (e.g., the UE's MAC entity) does not send SRs in the PUCCH resources used for SRs (even if the serving cell is a PUCCH cell), does not report periodic CSIs on the PUCCH (even if the serving cell is a PUCCH cell), and does not report semi-persistent CSIs configured on the serving cell's PUSCH. In other words, when cell DRX is configured and enabled for a serving cell, the UE will not perform transmissions in the serving cell's CG resources or send SRs on the serving cell during DRX inactive periods.

[0153] [Method #1] Locating / existing cell DTX inactivity cycles after Msg3 transmission time and handling UE operations and timers.

[0154] (1-1) A method to maintain the contention resolution (CR) timer and then restore the CR timer after the cell DTX inactive period.

[0155] (1-2) A method to maintain the RACH TX counter value even if the CR timer expires without maintaining the CR timer.

[0156] Figure 10 Examples of CR timer operation according to some implementations of this disclosure are shown. Figure 10 In this context, cell A can be a cell configured with a CR timer.

[0157] As described above, when the UE successfully receives RAR clearance within the RAR window after sending Msg1, the UE can send Msg3 PUSCH based on the corresponding information (e.g., RAR clearance). The UE starts the CR timer (e.g., ra- ContentionResolutionTimer(Or restart the CR timer in case of Msg3 retransmission) and monitor the PDCCH. When the UE already has a C-RNTI, the BS can send a PDCCH (bearing UL clearance or DL ​​assignment) through the UE's C-RNTI to notify the UE that the random access procedure has succeeded. If the UE does not receive a PDCCH scrambled with the UE's C-RNTI (i.e., a PDCCH carrying a DCI with a CRC scrambled with the C-RNTI) before the CR timer expires, the UE can consider the contention resolution to have failed. When the UE does not have a C-RNTI, the BS can send Msg4 including the UE contention resolution identifier MAC CE to notify the UE that the random access procedure has succeeded. Upon receiving Msg4 including the UE contention resolution identifier MAC CE, if the UE recognizes that the UE contention resolution identifier MAC CE is the same as the UE contention resolution identifier MAC CE sent by the UE, the UE can consider the random access procedure to have succeeded. If the UE does not receive Msg4 including the same UE contention resolution identifier as the UE contention resolution identifier sent by the UE before the CR timer expires, the UE can consider the contention resolution to have failed. In both cases (i.e., when the UE already has a C-RNTI and when the UE does not have a C-RNTI), the UE that fails to resolve the contention returns to the random access resource selection procedure to retry the random access procedure and increments the RACH Tx counter value of the random access procedure (see the aforementioned PREAMBLE_TRANSMISSION_COUNTER).

[0158] However, when the cell in which the UE performs a random access procedure is configured and operates in cell DTX / DRX mode, the transmission / reception of specific DL / UL signals / channels (pre-configured and / or defined in the standard) can be turned off during inactive periods. For example, if the UE transmits Msg3 during an ongoing random access procedure and the BS needs to transmit PDCCH / PDSCH to the UE for contention resolution, when the cell enters a cell DTX inactive period, even if the BS successfully receives the Msg3 transmitted by the UE, the BS may be unable to transmit the PDCCH (scrambled with C-RNTI or TC-RNTI) or the PDSCH (scheduled by the PDCCH and carrying a MAC PDU with a contention resolution identifier MAC CE or CCCH SDU) until the CR timer expires.

[0159] In this scenario (e.g., when a cell DTX inactivity period begins after the UE has sent Msg3 and is waiting for the reception of the contention resolution-related PDCCH and corresponding PDSCH), the UE fails to resolve the contention, not because the BS failed to receive Msg3. With this in mind, in some implementations of this disclosure, the UE and BS can operate as follows.

[0160] Reference Figure 10 In some implementations of this disclosure, according to method (1-1), the BS and UE can maintain the CR timer during the cell DTX inactivity period and resume the CR timer when the cell DTX inactivity period ends. According to some implementations of this disclosure, even if the cell DTX inactivity period begins when the CR timer is running, the CR timer will run for the configured duration, thereby guaranteeing the duration for which contention resolution messages may be sent.

[0161] Alternatively, refer to Figure 10 In some implementations of this disclosure, according to method (1-2), the BS and UE do not maintain the CR timer even during the cell DTX inactive period, but instead maintain the RACHTX counter value even after the timer expires. According to some implementations of this disclosure, even if the BS does not send the PDCCH / PDSCH to notify of successful contention resolution before the CR timer expires due to entering the cell DTX inactive period (although Msg3 sent by the UE is successfully received), the failure probability of the entire random access procedure can be reduced because the UE maintains the preamble transmission counter instead of incrementing it. Therefore, an increase in initial access delay can be prevented.

[0162] [Method #2] Signaling method for cell blocking for UEs with Rel-18 NES capability and UEs with Rel-19 NES capability

[0163] When a particular cell aims to gain ES (Elastic Opportunity) by disabling the transmission / reception of DL / UL signals / channels pre-configured / defined with specific active / inactive cycle modes (such as cell DTX / DRX configurations introduced in NR Release 18), legacy UEs that do not support cell DTX / DRX operation (e.g., only support features prior to Release 17) and UEs that do support cell DTX / DRX operation can coexist within that cell. In this case, when the BS disables CSI-RS transmission for CSI reporting during a pre-agreed cell DTX inactive cycle, UEs with Rel-18 NES capability will not expect CSI-RS reception during that cycle and will not perform CSI reporting. However, even without CSI-RS transmission, it is possible that legacy UEs that do not support the aforementioned feature may calculate CSI and send unnecessary CSI reports. Therefore, even considering legacy UEs, the BS may not be able to utilize ES opportunities through CSI-RS by continuing to perform CSI-RS transmissions during cell DTX inactive cycles.

[0164] Therefore, in some implementations of this disclosure, when the BS wants to implement ES using NES technology introduced in a specific version, it can allow only UEs with NES capability that support this feature to access the cell and induce them to perform cell reselection by prohibiting traditional UEs that do not support this feature from accessing the cell. Cell prohibition can be signaled by adding specific bits to SIB1. For example, two bits can be introduced into SIB1, and it can be defined that if both bits are "00", only UEs with Rel-18 NES capability can access the cell; if they are "01", only UEs with Rel-19 NES capability can access the cell; if they are "10", any UE supporting NES technology introduced after Rel-18 can access the cell; and if they are "11", only UEs with Rel-19 NES capability can access the cell. The BS can indicate to UEs wishing to access the cell whether or not they are allowed to access the cell by setting two bits in SIB1 to specific values. In another approach, whether to prohibit a UE with Rel-18 NES capability from accessing a cell can be signaled by 1 bit in SIB1, and whether to prohibit a UE with Rel-19 NES capability from accessing a cell can be signaled by another 1 bit.

[0165] UEs with Rel-18 NES capability and UEs with Rel-19 NES capability can refer to UEs supporting the NES technology introduced in version 18 and the NES technology introduced in version 19, respectively. When the cell prohibition indication field / bit is not present in SIB1, the UE can determine whether to access the cell based on the traditional cell prohibition indication.

[0166] According to method #2, the BS can prevent UEs that do not support cell DTX / DRX from accessing a cell with cell DTX / DRX configuration by using specific fields / bits in the cell's SIB1. Based on these specific fields / bits, UEs that support cell DTX / DRX can attempt to access the cell by performing a random access procedure, while UEs that do not support cell DTX / DRX can perform a cell search to detect the cell to access without attempting a random access procedure for that cell. Therefore, according to method #2, energy can be saved for both the BS and the UE.

[0167] Methods #1 and #2 described above can be applied individually or together. When methods #1 and #2 are applied together, for example, when the UE acquires the SIB1 of a cell during a cell search process, and when the cell prohibition information based on the SIB1 of the cell according to method #2 does not prohibit access to the cell, the UE can perform a random access procedure according to some implementations of method #1 of this disclosure.

[0168] According to some implementation methods of this disclosure, energy can be saved for the BS and / or UE.

[0169] Figure 11 This is a flowchart illustrating UE operation according to some implementations of this disclosure.

[0170] The UE can perform operations according to some implementations of this disclosure. The UE may include: at least one transceiver; at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of this disclosure. A processing apparatus for the UE may include: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of this disclosure. A computer-readable (non-volatile or non-transitory) storage medium may store at least one computer program including instructions that, when executed by the at least one processor, cause the at least one processor to perform operations according to some implementations of this disclosure. A computer program or computer program product may include instructions recorded on at least one computer-readable (non-volatile or non-transitory) storage medium and, when executed, cause (at least one processor) to perform operations according to some implementations of this disclosure.

[0171] The method performed by the UE, or the operation in the UE, processing apparatus, (non-transitory) computer-readable storage medium, and / or computer program product, may include: setting a preamble transmission counter for a random access procedure to a first value; transmitting a first random access preamble for the random access procedure on the cell (S1101); receiving a random access response for the transmitted first random access preamble; transmitting a UL channel based on the random access response; and initiating a CR timer based on the transmission of the UL channel (S1103). The method or operation may include: determining whether contention resolution was successful based on whether a DL channel (e.g., PDCCH and corresponding PDSCH) indicating successful contention resolution was received before the contention resolution timer expires (S1105). The method or operation may include: transmitting a second random access preamble for the random access procedure based on the expiration of the contention resolution timer. The method or operation may include: maintaining the preamble transmission counter to a first value based on the start of a cell DTX inactivity period for the cell during the contention resolution timer's operation and the expiration of the CR timer (S1107a). The method or operation may include: considering the contention resolution successful and the random access procedure successfully completed based on receiving a DL channel indicating successful contention resolution before the CR timer expires (S1107b).

[0172] In some implementations, the method or operation may include: monitoring the DL channel used for contention resolution based on CR timer operation and the cell being in the cell DTX activity period.

[0173] In some implementations, the method or operation may include: not monitoring the DL channel used for contention resolution based on the cell being in a cell DTX inactive period.

[0174] In some implementations, the method or operation may include: incrementing the preamble transmission counter based on the fact that the cell DTX inactivity period has not started during the CR timer's operation and the CR timer has expired.

[0175] Figure 12 This is a flowchart illustrating some implementations of BS operations according to this disclosure.

[0176] The BS can perform operations according to some implementations of this disclosure. The BS may include: at least one transceiver; at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of this disclosure. A processing apparatus for the BS may include: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of this disclosure. A computer-readable (non-volatile or non-transitory) storage medium may store at least one computer program including instructions that, when executed by the at least one processor, cause the at least one processor to perform operations according to some implementations of this disclosure. A computer program or computer program product may include instructions recorded on at least one computer-readable (non-volatile or non-transitory) storage medium and, when executed, cause (at least one processor) to perform operations according to some implementations of this disclosure.

[0177] The method performed by the BS, or the operation in the BS, processing apparatus, (non-transitory) computer-readable storage medium, and / or computer program product, may include: receiving from the UE a first random access preamble associated with a preamble transmission counter set to a first value for a random access procedure on the cell (S1201); sending a RAR for the first random access preamble to the UE (S1203); receiving a UL channel based on the RAR (S1205); and attempting to send signals indicating successful contention resolution (e.g., PDCCH and corresponding PDSCH) when a CR timer started when the UL channel is sent (S1207). The method or operation may further include: receiving a second random access preamble for the random access procedure upon the expiration of the CR timer. Based on the start of a cell DTX inactivity period for the cell during the CR timer's operation and the expiration of the CR timer, the preamble transmission counter may be maintained at the first value. Based on receiving a DL channel indicating successful contention resolution before the expiration of the CR timer, the UE may consider the contention resolution successful and the random access procedure successfully completed.

[0178] In some implementations, the method or operation may include: transmitting a DL channel for contention resolution on the cell based on CR timer operation and the cell being in a cell DTX activity period.

[0179] In some implementations, the method or operation may include: not transmitting DL channels for contention resolution based on the cell being in a cell DTX inactive period.

[0180] In some implementations, the preamble transmission counter may not be incremented if the cell DTX inactivity period has not started during the CR timer's operation and the CR timer expires.

[0181] Examples of this disclosure as described above have been presented to enable those skilled in the art to implement and practice this disclosure. Although the disclosure is described with reference to examples, various modifications and variations can be made to the examples of this disclosure by those skilled in the art. Therefore, this disclosure is not intended to be limited to the examples set forth herein, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

[0182] Implementations of this disclosure can be used in BS, UE, or other devices in wireless communication systems.

Claims

1. A method performed by a user equipment (UE), the method comprising the following steps: Set the preamble transmission counter for the random access procedure to the first value; Send a first random access preamble for the random access procedure on the cell; Receive a random access response in response to the first random access preamble sent; The uplink channel is sent based on the random access response; The transmit start contention resolution timer based on the uplink channel; as well as Upon the expiration of the contention resolution timer, a second random access preamble for the random access procedure is sent. Specifically, based on the cell discontinuous transmission DTX inactivity period for the cell starting when the contention resolution timer runs and when the contention resolution timer expires, the preamble transmission counter is maintained at the first value.

2. The method according to claim 1, wherein the method comprises the following steps: Based on the operation of the contention resolution timer and the cell being within the cell DTX activity period, the downlink channel used for contention resolution is monitored.

3. The method according to claim 1, wherein the method comprises the following steps: Since the cell is in a DTX inactive period, the downlink channel used for contention resolution is not monitored.

4. The method according to claim 1, wherein the method comprises the following steps: The preamble transmission counter is incremented based on the fact that the cell DTX inactivity period has not started while the contention resolution timer is running and the contention resolution timer has expired.

5. An apparatus, said apparatus comprising: At least one processor; as well as At least one computer memory, operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations for a user equipment (UE), the operations including: Set the preamble transmission counter for the random access procedure to the first value; Send a first random access preamble for the random access procedure on the cell; Receive a random access response in response to the first random access preamble sent; The uplink channel is sent based on the random access response; The transmit start contention resolution timer based on the uplink channel; and Upon the expiration of the contention resolution timer, a second random access preamble for the random access procedure is sent, and Specifically, based on the cell discontinuous transmission DTX inactivity period for the cell starting when the contention resolution timer runs and when the contention resolution timer expires, the preamble transmission counter is maintained at the first value.

6. The device according to claim 5, wherein, The operation includes: Based on the operation of the contention resolution timer and the cell being within the cell DTX activity period, the downlink channel used for contention resolution is monitored.

7. The device according to claim 5, wherein, The operation includes: Since the cell is in a DTX inactive period, the downlink channel used for contention resolution is not monitored.

8. The device according to claim 5, wherein, The operation includes: The preamble transmission counter is incremented based on the fact that the cell DTX inactivity period has not started while the contention resolution timer is running and the contention resolution timer has expired.

9. A non-transitory computer-readable storage medium storing at least one program code including instructions that, when executed, cause at least one processor to perform operations for a user equipment (UE), the operations including: Set the preamble transmission counter for the random access procedure to the first value; Send a first random access preamble for the random access procedure on the cell; Receive a random access response in response to the first random access preamble sent; The uplink channel is sent based on the random access response; The transmit start contention resolution timer based on the uplink channel; as well as Upon the expiration of the contention resolution timer, a second random access preamble for the random access procedure is sent, and Specifically, based on the cell discontinuous transmission DTX inactivity period for the cell starting when the contention resolution timer runs and when the contention resolution timer expires, the preamble transmission counter is maintained at the first value.

10. The non-transitory computer-readable storage medium according to claim 9, wherein, The operation includes: Based on the operation of the contention resolution timer and the cell being within the cell DTX activity period, the downlink channel used for contention resolution is monitored.

11. The non-transitory computer-readable storage medium according to claim 9, wherein, The operation includes: Since the cell is in a DTX inactive period, the downlink channel used for contention resolution is not monitored.

12. The non-transitory computer-readable storage medium according to claim 9, wherein, The operation includes: The preamble transmission counter is incremented based on the fact that the cell DTX inactivity period has not started while the contention resolution timer is running and the contention resolution timer has expired.

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