Method performed by user equipment, user equipment, processing device and storage medium, and method performed by base station, and base station

Abstract

This equipment may: receive a first random access channel occasion (RO)-related configuration and a second RO-related configuration for a cell; receive a downlink control information (DCI) format for a random access process initiated by a physical downlink control channel (PDCCH) order; and perform PRACH transmission in an RO selected on the basis of the DCI format. The DCI format comprises an indication field regarding availability of an RACH resource configured by the second RO-related configuration, and on the basis that the indication field indicates that the RACH resource configured by the second RO-related configuration is available, the RO may be selected from among first ROs determined by the first RO-related configuration and second ROs determined by the second RO-related configuration.

Description

Method performed by a user device, user device, processing device and storage medium, and method performed by a base station and base station

[0001] This specification relates to wireless communication systems.

[0002] Various devices and technologies, such as machine-to-machine (M2M) communication, machine-type communication (MTC), and smartphones and tablet PCs (personal computers) that require high data transmission rates, are emerging and becoming widespread. Consequently, the amount of data required to be processed on cellular networks is rapidly increasing. To meet this rapidly increasing data processing demand, technologies such as carrier aggregation and cognitive radio are being developed to efficiently utilize more frequency bands, while multi-antenna technology and multi-BS cooperation technology are being developed to increase the data capacity transmitted within a limited frequency range.

[0003] As more and more communication devices demand greater capacity, the need for enhanced mobile broadband (eMBB) communications is emerging, surpassing legacy radio access technology (RAT). Furthermore, massive machine type communication (mMTC), which connects multiple devices and objects to provide diverse services anytime, anywhere, is a key issue to be considered in next-generation communications.

[0004] Additionally, discussions are underway on communication systems designed to accommodate reliability- and latency-sensitive services and user equipment (UE). The introduction of next-generation wireless access technologies is being discussed, including enhanced mobile broadband (eMBB), mMTC, and ultra-reliable and low latency communication (URLLC).

[0005] As the number of services / UEs that a network must support rapidly increases, the need for energy conservation in the network as well as power conservation in the UE is also gradually increasing.

[0006] One technical task of this specification is to provide methods and processes for network energy conservation.

[0007] Another technical challenge of this specification is to provide methods and processes for transmitting downlink signals so as to enable network energy conservation.

[0008] The technical tasks to be achieved by this specification are not limited to the technical tasks mentioned above, and other technical tasks not mentioned will be clearly understood by those of ordinary skill in the art related to this specification from the detailed description below.

[0009] In one aspect of the present disclosure, a method by a user device is provided. In another aspect of the present disclosure, the user device is provided, comprising: at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. In another aspect of the present disclosure, a processing device is provided, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. In another aspect of the present disclosure, a computer-readable, non-transitory storage medium is provided, storing at least one program code comprising instructions that, when executed, cause the at least one processor to perform operations. The method or the operations include: receiving a first random access channel occasion (RO)-related configuration and a second RO-related configuration for a cell; And receiving a downlink control information (DCI) format for a random access procedure initiated by a physical downlink control channel (PDCCH) order; selecting an RO for physical random access channel (PRACH) transmission based on the DCI format; and performing the PRACH transmission using the selected RO. In some implementations, the DCI format may include an indication field regarding the availability of RACH resources set by the second RO-related configuration.

[0010] In one aspect of the present disclosure, a method is provided by a base station. In another aspect of the present disclosure, a base station is provided, comprising: at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. The method or the operations may include: transmitting a first random access channel occasion (RO)-related configuration and a second RO-related configuration for a cell; and transmitting a downlink control information (DCI) format for a random access procedure initiated by a physical downlink control channel (PDCCH) order; and attempting to receive a physical random access channel (PRACH) based on the DCI format. In some implementations, the DCI format may include an indication field regarding the availability of RACH resources configured by the second RO-related configuration.

[0011] In the method in the user device, or in each aspect of the present specification relating to the user device, the processing device, or the storage medium, based on the indication field indicating that the RACH resource set by the second RO-related setting is available, the RO may be selected from among the first ROs determined by the first RO-related setting and the second ROs determined by the second RO-related setting, and based on the indication field indicating that the RACH resource set by the second RO-related setting is not available, the RO may be selected from among the first ROs determined by the first RO-related setting.

[0012] In the method in the user device, or in each aspect of the present specification relating to the user device, the processing device, or the storage medium, based on the indication field indicating that the RACH resource set by the second RO-related configuration is available, the PRACH reception may be attempted within the first ROs determined by the first RO-related configuration and the second ROs determined by the second RO-related configuration, and based on the indication field indicating that the RACH resource set by the second RO-related configuration is not available, the PRACH reception may be attempted within the first ROs determined by the first RO-related configuration.

[0013] In each aspect of this specification, the first RO-related settings and the second RO-related settings may be provided through system information block 1.

[0014] In each aspect of the present specification, the DCI format includes a PRACH mask index field, and based on the indication field indicating that the RACH resource set by the second RO-related configuration is not available, the value of the PRACH mask index field can be applied to the first ROs determined by the first RO-related configuration.

[0015] In each aspect of the present specification, the DCI format includes a PRACH mask index field, and based on the indication field indicating that RACH resources set by the second RO-related configuration are available, the value of the PRACH mask index field can be applied to the first ROs determined by the first RO-related configuration and the second ROs determined by the second RO-related configuration.

[0016] In each aspect of the present specification, the DCI format may include a synchronization signal / physical broadcast channel (SS / PBCH) block index field and a PRACH mask index field, and the selected RO may be related to an RO index indicated by the PRACH mask index field among ROs associated with the SS / PBCH indicated by the SS / PBCH block index field.

[0017] In the method in the user device, or in each aspect of the present specification relating to the user device, the processing device, or the storage medium, based on the indication field indicating that the RACH resource set by the second RO-related setting is not available, the selected RO may be one of at least one RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related setting.

[0018] In the method in the user device, or in each aspect of the present specification relating to the user device, the processing device, or the storage medium, based on the indication field indicating that the RACH resource set by the second RO-related setting is available, the selected RO may be one of i) at least one RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related setting, and ii) at least one RO obtained by applying the value of the PRACH mask index field to the second ROs determined by the second RO-related setting.

[0019] In the method at the base station, or in each aspect related to the base station, the DCI format includes a synchronization signal / physical broadcast channel (SS / PBCH) block index field and a PRACH mask index field, and the PRACH reception can be attempted in an RO and an RO index indicated by the PRACH mask index field among ROs associated with an SS / PBCH indicated by the SS / PBCH block index field.

[0020] In the above method at the base station, or in each aspect related to the base station, based on the indication field indicating that the RACH resource set by the second RO-related setting is not available, the PRACH reception may be attempted in an RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related setting.

[0021] In the method at the base station, or in each aspect related to the base station, based on the indication field indicating that the RACH resource set by the second RO-related configuration is available, the PRACH reception may be attempted in at least one RO obtained by i) applying the value of the PRACH mask index field to the first ROs determined by the first RO-related configuration, and ii) applying the value of the PRACH mask index field to the second ROs determined by the second RO-related configuration.

[0022] The above problem solving methods are only some of the examples of this specification, and various examples reflecting the technical features of this specification can be derived and understood by a person having ordinary knowledge in the relevant technical field based on the detailed description below.

[0023] According to some implementations of this specification, methods and procedures for energy saving of a network, BS and / or UE may be provided.

[0024] According to some implementations of this specification, methods and procedures for transmitting downlink signals to enable energy conservation of a network, a BS and / or a UE may be provided.

[0025] The effects according to this specification are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art related to this specification from the detailed description below.

[0026] To aid in understanding implementations of this specification, the accompanying drawings, which are included as part of the detailed description, provide examples of implementations of this specification and, together with the detailed description, illustrate implementations of this specification:

[0027] Figure 1 illustrates an example of a communication system 1 to which implementations of the present specification are applied;

[0028] FIG. 2 is a block diagram illustrating examples of communication devices capable of performing a method according to the present specification;

[0029] FIG. 3 illustrates another example of a wireless device capable of performing implementation(s) of the present specification;

[0030] FIG. 4 illustrates an example of a frame structure available in a 3rd generation partnership project (3GPP) based wireless communication system;

[0031] Figure 5 illustrates a resource grid of slots;

[0032] FIG. 6 illustrates physical channels used in a 3rd generation partnership project (3GPP)-based communication system, which is an example of a wireless communication system, and a signal transmission / reception process using the channels;

[0033] Figure 7 illustrates synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSBs) on a cell.

[0034] Figure 8 is a diagram illustrating the bitmaps used to indicate which SSBs are actually transmitted;

[0035] Figure 9 illustrates a process for acquiring system information (SI);

[0036] Figure 10 illustrates a random access process that may be applied to implementation(s) of this specification;

[0037] FIG. 11 illustrates an example of time domain resource allocation of a physical downlink shared channel (PDSCH) by a physical downlink control channel (PDCCH) and an example of time domain resource allocation of a physical uplink shared channel (PUSCH) by a PDCCH;

[0038] Figure 12 illustrates discontinuous reception (DRX) operation;

[0039] Figure 13 illustrates a case where a Long DRX cycle and a Short DRX cycle are set;

[0040] Figure 14 illustrates paging times according to several scenarios;

[0041] Figure 15 illustrates an operation procedure in a BS supporting network energy saving (NES) technology;

[0042] Figure 16 illustrates the mapping relationship between random access channel (RACH) periods and SSBs;

[0043] FIGS. 17 and 18 illustrate radio access control (RRC) settings that may be used or applied to some implementations of the present specification;

[0044] FIG. 19 illustrates RO adaptation through sparse and dense RACH occasions (ROs) according to some implementations of the present specification;

[0045] FIG. 20 is an example of random access channel (RACH) slots and RACH occasions (RO) according to physical random access channel (PRACH) settings;

[0046] Figure 21 illustrates an association interval according to the number of SSBs per RACH period;

[0047] Figure 22 illustrates an associated interval considering a valid RACH period;

[0048] Figure 23 illustrates an association pattern section and SSB-to-RO mapping considering a valid RACH occasion (RO);

[0049] FIG. 24 illustrates the flow of random access preamble transmission in a UE according to some implementations of the present specification;

[0050] Figure 25 illustrates the flow of random access preamble reception at BS according to some implementations of this specification.

[0051] Hereinafter, implementations according to this specification will be described in detail with reference to the attached drawings. The detailed description provided below, together with the attached drawings, is intended to describe exemplary implementations of this specification and is not intended to represent the only possible implementations of this specification. The detailed description below includes specific details to provide a thorough understanding of this specification. However, one of ordinary skill in the art will appreciate that this specification may be practiced without these specific details.

[0052] In some cases, to avoid ambiguity in the concepts of this specification, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device. Furthermore, identical components are described using the same drawing reference numerals throughout this specification.

[0053] In this specification, "A or B" can mean "only A", "only B", or "both A and B". In other words, in this specification, "A or B" can be interpreted as "A and / or B". For example, in this specification, "A, B or C" can mean "only A", "only B", "only C", or "any combination of A, B and C".

[0054] The slash ( / ) or comma used in this specification can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0055] In this specification, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted identically to "at least one of A and B".

[0056] Additionally, in this specification, “at least one of A, B and C” can mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C”.

[0057] Additionally, in this specification, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically limited. Accordingly, a first component in one embodiment of this specification may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0058] In the following explanation, ‘when ~, if ~, in case of ~’ can be replaced with ‘based on ~.’

[0059] In this specification, higher layer parameters can be configured, preset, or predefined for the UE. For example, the BS can transmit higher layer parameter(s) to the UE. For example, the UE can transmit parameters such as capabilities to the BS as higher layer parameters. For example, the higher layer parameters can be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0060] In this specification, "configured or pre-configured" information / state / parameters can be interpreted as information / state / parameters being provided / pre-provided to the UE through pre-defined signaling from the BS (e.g., system information block (SIB), medium access control (MAC), radio resource control (RRC)). In this specification, "defined or pre-defined" information / state / parameters can be interpreted as information that the BS and the UE know in advance or pre-store without signaling between the BS and the UE.

[0061] Technical features individually described within a single drawing in this specification may be implemented individually or simultaneously.

[0062] The techniques, devices, and systems described below can be applied to various wireless multiple access systems. Examples of multiple access systems 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, and multi-carrier frequency division multiple access (MC-FDMA) systems. CDMA can be implemented in wireless technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented in wireless technologies such as Global System for Mobile communication (GSM), General Packet Radio Service (GPRS), and Enhanced Data Rates for GSM Evolution (EDGE) (i.e., GERAN). OFDMA can be implemented in wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved-UTRA). UTRA is part of UMTS (Universal Mobile Telecommunication System), and 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of E-UMTS that uses E-UTRA.3GPP LTE adopts OFDMA for the downlink (DL) and SC-FDMA for the uplink (UL). LTE-A (LTE-advanced) is an evolved form of 3GPP LTE.

[0063] For convenience of explanation, the following description assumes that this specification applies to 3GPP-based communication systems, such as LTE and NR. However, the technical features of this specification are not limited to this. For example, although the detailed description below is based on a mobile communication system corresponding to a 3GPP LTE / NR system, it can also be applied to any other mobile communication system, except for features specific to 3GPP LTE / NR.

[0064] For terms and technologies used in this specification that are not specifically explained, reference may be made to 3GPP-based standard documents, such as 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, 3GPP TS 36.300 and 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.

[0065] In the examples of this specification described below, the expression "assumes" that a device "assumes" that the entity transmitting the channel transmits the channel in a manner consistent with the "assume." The entity receiving the channel may mean that, under the assumption that the channel was transmitted in a manner consistent with the "assume," the entity receiving the channel receives or decodes the channel in a manner consistent with the "assume."

[0066] In this specification, UE may be fixed or mobile, and includes various devices that communicate with a BS (base station) to transmit and / or receive user data and / or various control information. UE may be called (Terminal Equipment), MS (Mobile Station), MT (Mobile Terminal), UT (User Terminal), SS (Subscribe Station), wireless device, PDA (Personal Digital Assistant), wireless modem, handheld device, etc. In addition, in this specification, BS generally refers to a fixed station that communicates with UE and / or other BS, and exchanges various data and control information with UE and other BS. BS may be called by other terms such as ABS (Advanced Base Station), NB (Node-B), eNB (evolved-NodeB), BTS (Base Transceiver System), Access Point, PS (Processing Server), etc. In particular, the BS in UTRAN is called a Node-B, the BS in E-UTRAN is called an eNB, and the BS in a new radio access technology network is called a gNB. For convenience of explanation, BSs are collectively referred to as BSs below, regardless of the type or version of communication technology.

[0067] In this specification, a node refers to a fixed point that can transmit / receive radio signals by communicating with a UE. Various types of BSs can be used as nodes regardless of their names. For example, BSs, NBs, eNBs, pico-cell eNBs (PeNBs), home eNBs (HeNBs), relays, and repeaters can be nodes. Furthermore, a node may not be a BS. For example, it can be a radio remote head (RRH) or a radio remote unit (RRU). RRHs, RRUs, etc. generally have a lower power level than the BS. Since an RRH or RRU (hereinafter referred to as RRH / RRU) is generally connected to a BS via a dedicated line such as an optical cable, cooperative communication between an RRH / RRU and a BS can be performed more smoothly than cooperative communication between BSs that are generally connected via a wireless line. Each node is equipped with at least one antenna. The antenna may be a physical antenna, an antenna port, a virtual antenna, or an antenna group. A node is also called a point.

[0068] In this specification, a cell refers to a certain geographical area where one or more nodes provide communication services. Therefore, in this specification, communicating with a specific cell may mean communicating with a BS or node that provides communication services to the specific cell. In addition, the downlink / uplink signal of a specific cell refers to a downlink / uplink signal from / to a BS or node that provides communication services to the specific cell. A cell that provides uplink / downlink communication services to a UE is specifically referred to as a serving cell. In addition, the channel state / quality of a specific cell refers to the channel state / quality of a channel or communication link formed between a BS or node that provides communication services to the specific cell and the UE. In a 3GPP-based communication system, a UE can measure a downlink channel state from a specific node using CRS (Cell-specific Reference Signal) resources transmitted by antenna port(s) of the specific node on CRS resources allocated to the specific node and / or CSI-RS (Channel State Information Reference Signal) resources transmitted.

[0069] Meanwhile, 3GPP-based communication systems use the concept of cells to manage radio resources, and cells associated with radio resources are distinguished from cells in geographical areas.

[0070] A "cell" in a geographical area can be understood as the coverage over which a node can provide a service using a carrier, and a "cell" in a radio resource is associated with a bandwidth (BW), which is a frequency range configured by the carrier. Since downlink coverage, which is the range over which a node can transmit a valid signal, and uplink coverage, which is the range over which a node can receive a valid signal from a UE, depend on the carrier carrying the signal, the coverage of a node is also associated with the coverage of the "cell" of the radio resource used by the node. Therefore, the term "cell" can sometimes be used to mean the coverage of a service provided by a node, sometimes a radio resource, and sometimes the range over which a signal using the radio resource can reach with a valid intensity.

[0071] Meanwhile, the 3GPP communication standard uses the concept of a cell to manage radio resources. A "cell" associated with radio resources is defined as a combination of downlink resources (DL resources) and uplink resources (UL resources), i.e., a combination of a DL component carrier (CC) and an UL CC. A cell can be configured with DL resources alone or a combination of DL resources and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resources (or DL ​​CC) and the carrier frequency of the UL resources (or UL CC) can be indicated by system information. For example, the combination of DL resources and UL resources can be indicated by a System Information Block Type 2 (SIB2) linkage. Here, the carrier frequency can be the same as or different from the center frequency of each cell or CC. When carrier aggregation (CA) is established, the UE has only one radio resource control (RRC) connection with the network. One serving cell provides non-access stratum (NAS) mobility information during RRC connection establishment / re-establishment / handover, and one serving cell provides security input during RRC connection re-establishment / handover. Such a cell is called a primary cell (Pcell). A Pcell is a cell operating on the primary frequency where the UE performs initial connection establishment procedures or initiates connection re-establishment procedures.Depending on the UE capability, secondary cells (Scells) can be configured to form a set of serving cells together with Pcells. An Scell ​​can be configured after an RRC (Radio Resource Control) connection establishment has been made, and is a cell that provides additional radio resources in addition to the resources of a special cell (SpCell). The carrier corresponding to a Pcell in downlink is called a downlink primary CC (DL PCC), and the carrier corresponding to a Pcell in uplink is called an UL primary CC (UL PCC). The carrier corresponding to an Scell ​​in downlink is called a DL secondary CC (DL SCC), and the carrier corresponding to the Scell ​​in uplink is called an UL secondary CC (UL SCC).

[0072] For a UE for which CA is set and DC is not set, a Pcell PUCCH group (also referred to as a primary PUCCH group) consisting of a Pcell and zero or more Scells and a Scell ​​PUCCH group (also referred to as a secondary PUCCH group) consisting of only Scell(s) may be set. In the case of an Scell, an Scell ​​(hereinafter referred to as a PUCCH Scell) on which a PUCCH associated with the cell is transmitted may be set. An Scell ​​for which a PUCCH Scell ​​is indicated belongs to an Scell ​​PUCCH group (i.e., a secondary PUCCH group), and PUCCH transmission of the relevant UCI is performed on the PUCCH Scell, and an Scell ​​for which a PUCCH Scell ​​is not indicated or which is a Pcell and is indicated as a cell for PUCCH transmission belongs to a Pcell PUCCH group (i.e., a primary PUCCH group), and PUCCH transmission of the relevant UCI is performed on the Pcell. Hereinafter, if a UE is configured with an SCG and some implementations of this specification related to PUCCH are applied to the SCG, the primary cell may refer to a PSCell of the SCG. If a UE is configured with a PUCCH Scell ​​and some implementations of this specification related to PUCCH are applied to a secondary PUCCH group, the primary cell may refer to a PUCCH Scell ​​of the secondary PUCCH group.

[0073] In a wireless communication system, a UE receives information from a base station (BS) via the downlink (DL), and the UE transmits information to the base station via the uplink (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 and purpose of the information they transmit and / or receive.

[0074] 3GPP-based communication standards define downlink physical channels corresponding to resource elements that carry information originating from higher layers, and downlink physical signals corresponding to resource elements that are used by the physical layer but do not carry information originating from higher layers. For example, the physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), and physical downlink control channel (PDCCH) are defined as downlink physical channels, and reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, refers to a signal with a predefined, special waveform that is known to the BS and the UE. For example, the demodulation reference signal (DMRS), the channel state information RS (CSI-RS), and the positioning reference signal (PRS) are defined as downlink reference signals. 3GPP-based communication standards define uplink physical channels corresponding to resource elements that carry information originating from higher layers, and uplink physical signals corresponding to resource elements that are used by the physical layer but do not carry information originating from higher layers.For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are defined as uplink physical channels, and a demodulation reference signal (DMRS) for uplink control / data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

[0075] In this specification, PDCCH (Physical Downlink Control CHannel) refers to a set of time-frequency resources (e.g., resource elements (REs)) that carry DCI (Downlink Control Information), and PDSCH (Physical Downlink Shared CHannel) refers to a set of time-frequency resources that carry downlink data. In addition, PUCCH (Physical Uplink Control CHannel), PUSCH (Physical Uplink Shared CHannel), and PRACH (Physical Random Access CHannel) refer to sets of time-frequency resources that carry UCI (Uplink Control Information), uplink data, and random access signals, respectively (respectively). Hereinafter, the expression that a user equipment transmits / receives a PUCCH / PUSCH / PRACH is used with the same meaning as that uplink control information / uplink data / random access signals are transmitted / received on or through the PUCCH / PUSCH / PRACH, respectively. Additionally, the expression that BS transmits / receives PBCH / PDCCH / PDSCH is used with the same meaning as transmitting broadcast information / downlink control information / downlink data on or through PBCH / PDCCH / PDSCH, respectively.

[0076] In this specification, radio resources (e.g., time-frequency resources) scheduled or configured by the BS to the UE for transmission or reception of PUCCH / PUSCH / PDSCH are also referred to as PUCCH / PUSCH / PDSCH resources.

[0077] Since the communication device receives a synchronization signal (SS), DMRS, CSI-RS, PRS, PBCH, PDCCH, PDSCH, PUSCH, and / or PUCCH in the form of radio signals on a cell, it cannot selectively receive through an RF receiver only radio signals including only a specific physical channel or only a specific physical signal, or selectively receive through an RF receiver only radio signals excluding only a specific physical channel or only a physical signal. In actual operation, the communication device first receives radio signals on a cell through an RF receiver, converts the radio signals, which are RF band signals, into baseband signals, and decodes a physical signal and / or a physical channel within the baseband signals using one or more processors. Thus, in some implementations of the present specification, not receiving a physical signal and / or a physical channel may not actually mean that the communication device does not receive wireless signals containing the physical signal and / or physical channel at all, but rather that it does not attempt to recover the physical signal and / or physical channel from the wireless signals, e.g., does not attempt to decode the physical signal and / or the physical channel.

[0078] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication over existing radio access technology (RAT) is emerging. Furthermore, massive MTC, which connects numerous devices and objects to provide diverse services anytime, anywhere, is also a key issue to be considered in next-generation communications. Furthermore, communication system design that considers reliability and latency-sensitive services / UEs is being discussed. The introduction of next-generation RATs that take advanced mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) into account is currently under discussion. 3GPP is currently conducting studies on next-generation mobile communication systems beyond EPC. For convenience, this technology is referred to as new RAT (NR) or 5G RAT, and a system that uses or supports NR is referred to as an NR system.

[0079] FIG. 1 illustrates an example of a communication system 1 to which implementations of the present specification are applied. Referring to FIG. 1, the communication system (1) applied to the present specification includes a wireless device, a BS, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (e.g., E-UTRA)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. Mobile devices may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. Home appliances may include a TV, a refrigerator, a washing machine, etc. IoT devices may include sensors, smart meters, etc. For example, a BS or network may also be implemented as a wireless device, and a specific wireless device may act as a BS / network node to other wireless devices.

[0080] Wireless devices (100a to 100f) can be connected to a network (300) via a BS (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via a network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the BS (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the BS / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0081] Wireless communication / connection (150a, 150b) can be performed between wireless devices (100a~100f) / BS (200) - BS (200) / wireless devices (100a~100f). Here, the wireless communication / connection can be performed through various wireless access technologies (e.g., 5G NR) for uplink / downlink communication (150a) and sidelink communication (150b) (or D2D communication). Through the wireless communication / connection (150a, 150b), the wireless device and the BS / wireless device can transmit / receive wireless signals to / from each other. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of this specification.

[0082] FIG. 2 is a block diagram illustrating examples of communication devices capable of performing a method according to the present specification. Referring to FIG. 2, a first wireless device (100) and a second wireless device (200) can transmit and / or receive wireless signals via various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the BS (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 1.

[0083] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement functions, procedures, and / or methods described / suggested below. For example, the processor (102) may process information in the memory (104) to generate first information / signals, and then transmit a wireless signal including the first information / signals via the transceivers (106). In addition, the processor (102) may receive a wireless signal including second information / signals via the transceivers (106), and then store information obtained from signal processing of the second information / signals in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the procedures and / or methods described / proposed below. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In this specification, a wireless device may also mean a communication modem / circuit / chip.

[0084] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the functions, procedures, and / or methods described / suggested below. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). In addition, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the procedures and / or methods described / proposed below. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In this specification, a wireless device may also mean a communication modem / circuit / chip.

[0085] The wireless communication technology implemented in the wireless device (100, 200) of the present specification may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PAN) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0086] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a service data adaptation protocol (SDAP) layer). One or more processors (102, 202) may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the functions, procedures, proposals, and / or methods disclosed in this specification. One or more processors (102, 202) may generate messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this specification. One or more processors (102, 202) may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this specification, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) may receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this specification.

[0087] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The functions, procedures, proposals, and / or methods disclosed in this specification may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the functions, procedures, suggestions and / or methods disclosed in this specification may be included in one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The functions, procedures, suggestions and / or methods disclosed in this specification may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0088] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0089] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as described in the methods and / or flowcharts of this specification, to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as described in the functions, procedures, proposals, methods and / or flowcharts of this specification, from one or more other devices. For example, one or more transceivers (106, 206) may be coupled to one or more processors (102, 202) and may transmit and / or receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and / or receive user data, control information, wireless signals / channels, or the like, as referred to in the functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this specification, via one or more antennas (108, 208). In this specification, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) may convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals for processing using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0090] FIG. 3 illustrates another example of a wireless device capable of performing implementation(s) of the present specification. Referring to FIG. 3, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 2 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 2. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 2. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0091] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output (I / O) unit, a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 1, 100a), a vehicle (Fig. 1, 100b-1, 100b-2), an XR device (Fig. 1, 100c), a portable device (Fig. 1, 100d), a home appliance (Fig. 1, 100e), an IoT device (Fig. 1, 100f), a UE for digital broadcasting, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 1, 400), a BS (Fig. 1, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0092] In FIG. 3, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of one or more processor sets. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, transitory memory, non-transitory memory, and / or a combination thereof.

[0093] In this specification, at least one memory (e.g., 104 or 204) can store instructions or programs that, when executed, cause at least one processor operably connected to the at least one memory to perform operations according to some embodiments or implementations of the present specification.

[0094] In this specification, a computer-readable (non-transitory) storage medium can store at least one instruction or computer program, which when executed by at least one processor causes the at least one processor to perform operations according to some embodiments or implementations of this specification.

[0095] In this specification, a processing device or apparatus may include at least one processor and at least one computer memory operatively connected to the at least one processor. The at least one computer memory may store instructions or programs, which, when executed, cause at least one processor operatively connected to the at least one memory to perform operations according to some embodiments or implementations of the present specification.

[0096] In this specification, a computer program may be stored in at least one computer-readable (non-transitory) storage medium and may include program code that, when executed, performs operations according to some implementations of the present specification or causes at least one processor to perform operations according to some implementations of the present specification. The computer program may be provided in the form of a computer program product. The computer program product may include at least one computer-readable (non-transitory) storage medium.

[0097] A communications device of the present specification comprises at least one processor; and at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations according to the example(s) of the present specification described below.

[0098] Figure 4 illustrates an example of a frame structure available in a 3GPP-based wireless communication system.

[0099] The structure of the frame in Fig. 4 is merely an example, and the number of subframes, the number of slots, and the number of symbols in the frame can be varied. In an NR system, OFDM numerology (e.g., subcarrier spacing (SCS)) may be set differently between multiple cells aggregated to a single UE. Accordingly, the (absolute time) duration of a time resource (e.g., a subframe, a slot, or a transmission time interval (TTI)) consisting of the same number of symbols may be set differently between the aggregated cells. Here, the symbol may include an OFDM symbol (or a cyclic prefix - orthogonal frequency division multiplexing (CP-OFDM) symbol), an SC-FDMA symbol (or a discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbol). In this specification, the terms symbol, OFDM-based symbol, OFDM symbol, CP-OFDM symbol, and DFT-s-OFDM symbols are interchangeable.

[0100] Referring to Figure 4, in the NR system, uplink and downlink transmissions are organized into frames. Each frame is T f = (△f max *N f / 100)*T c = 10 ms duration, divided into two half-frames of 5 ms each. Here, T is the basic time unit for NR. c = 1 / (△fmax *N f ) and △f max = 480*10 3 Hz, and N f =4096. For reference, T is the basic time unit for LTE. s = 1 / (△f ref *N f,ref ) and △f ref = 15*10 3 Hz, and N f,ref =2048. T s Wow T c is a constant κ = T s / T c = 64 relationship. Each half-frame consists of 5 subframes, and the duration of a single subframe is T. sf is 1ms. Subframes are further divided into slots, and the number of slots in a subframe depends on the subcarrier spacing. Each slot consists of 14 or 12 OFDM symbols based on the cyclic prefix. For a normal cyclic prefix (CP), each slot consists of 14 OFDM symbols, and for an extended CP, each slot consists of 12 OFDM symbols. The numerology is exponentially scalable with a subcarrier spacing △f = 2. u *Depends on 15 kHz. The following table shows the subcarrier spacing for regular CP △f = 2. u *Number of OFDM symbols per slot at 15 kHz (N) slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot ) is shown.

[0101]

[0102] The following table shows the subcarrier spacing for extended CP △f = 2. u*Indicates the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe at 15 kHz.

[0103]

[0104] For a subcarrier spacing setting u, slots are n in increasing order within a subframe. u s ∈ {0, ..., nsubframe,u slot - 1} and n in increasing order within the frame u s,f ∈ {0, ..., n frame,u slot - Numbered as 1}.

[0105] Figure 5 illustrates the resource grid of a slot. A slot contains multiple symbols (e.g., 14 or 12) in the time domain. For each numeral (e.g., subcarrier spacing) and carrier, a common resource block (CRB) N is indicated by higher layer signaling (e.g., radio resource control (RRC) signaling). start,u grid Starting from,N size,u grid,x *N RB sc Dog subcarriers and N subframe,u symb A resource grid of OFDM symbols is defined, where N size,u grid,x is the number of resource blocks (RBs) in the resource grid, and the subscript x is DL for downlink and UL for uplink. N RB sc is the number of subcarriers per RB, and in 3GPP-based wireless communication systems, N RB scis typically 12. For a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL), there is one resource grid. The carrier bandwidth N for subcarrier spacing configuration u size,u grid is given to the UE by higher layer parameters (e.g., RRC parameters) from the network. Each element in the resource grid for antenna port p and subcarrier spacing configuration u is called a resource element (RE), and one complex symbol can be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l indicating the symbol position relative to a reference point in the time domain. In an NR system, an RB is defined by 12 consecutive subcarriers in the frequency domain. In an NR system, RBs can be classified into common resource blocks (CRBs) and physical resource blocks (PRBs). CRBs are numbered upwards from 0 in the frequency domain for the subcarrier spacing configuration u. The center of subcarrier 0 of CRB 0 for the subcarrier spacing configuration u coincides with 'Point A', which is a common reference point for the resource block grids. PRBs for subcarrier spacing u are defined within the bandwidth part (BWP) and range from 0 to N. size,u BWP,i -1, where i is the number of the bandwidth part. Common resource block n u CRB and bandwidth part i within physical resource block n PRB The relationship between the two is as follows: n u PRB = n u CRB +N start,u BWP,i , here N start,u BWP,iis a common resource block (BRB) whose bandwidth part starts relative to CRB 0. A BWP comprises multiple consecutive RBs in the frequency domain. For example, a BWP may be a given numeral u within a BWP i on a given carrier. i A subset of contiguous CRBs defined for a carrier. 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 through the activated BWPs, and only a predetermined number (e.g., 1) of BWPs configured for the UE may be activated on the carrier.

[0106] For each serving cell in a set of DL BWPs or UL BWPs, the network configures at least an initial DL BWP and one (if the serving configuration is configured with uplink) or two (if supplementary uplink is used) initial UL BWPs. The network may also configure additional UL and DL BWPs for the serving cell. For each DL BWP or UL BWP, the UE is provided with the following parameters for the serving cell: i) subcarrier spacing, ii) cyclic prefix, and iii) N start BWP = Offset RB with the assumption of 275 set and length L RB CRBN provided by the RRC parameter locationAndBandwidth, which indicates the resource indicator value (RIV). start BWP =O carrier +RB start and the number of contiguous RBs N size BWP =L RB , and the subcarrier spacing is provided by the RRC parameter offsetToCarrierO carrier; an index within the set of DL BWPs or UL BWPs; a set of BWP-common parameters and a set of BWP-specific parameters.

[0107] Switching between configured BWPs can occur using RRC signaling, DCI, an inactivity timer, or upon initiation of a random access. If an inactivity timer is configured for a serving cell, expiration of the inactivity timer associated with the serving cell switches the active BWP to the default BWP configured by the network.

[0108] Virtual resource blocks (VRBs) are defined within the bandwidth part and are numbered from 0 to N. size,u BWP,i Numbered from -1, where i is the number of the bandwidth part. VRBs are mapped to physical resource blocks (PRBs) according to interleaved or non-interleaved mapping. In some implementations, for non-interleaved VRB-to-PRB mapping, VRB n may be mapped to PRB n.

[0109] NR frequency bands are defined by two types of frequency ranges, FR1 and FR2, with FR2 also referred to as millimeter wave (mmW). The following table lists the frequency ranges in which NR can operate.

[0110]

[0111] Figure 6 illustrates physical channels used in a 3GPP-based communication system, which is an example of a wireless communication system, and a signal transmission / reception process using the channels.

[0112] When a UE is powered on again after being powered off or has been disconnected from a wireless communication system, it first searches for a suitable cell to camp on (search cell) and performs an initial cell search process, such as synchronizing with the cell or the BS of the cell (S11). During the initial cell search process, the UE receives a synchronization signal block (SSB) (also called an SSB / PBCH block) from the BS. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The UE synchronizes with the BS based on the PSS / SSS and obtains information such as a cell identity (ID). In addition, the UE can obtain broadcast information within the cell based on the PBCH. Meanwhile, the UE can check the downlink channel status by receiving a downlink reference signal (DL RS) during the initial cell search process.

[0113] A UE that has completed initial cell search can camp on the cell. After camping on the cell, the UE monitors the PDCCH on the cell and receives the PDSCH based on the downlink control information (DCI) carried by the PDCCH to obtain more specific system information (S12).

[0114] Thereafter, the UE may perform a random access procedure to complete access to the BS (S13 to S16). For example, in the random access procedure, the UE may transmit a preamble through a physical random access channel (PRACH) (S13) and receive a random access response (RAR) to the preamble through a PDCCH and a corresponding PDSCH (S14). If reception of the RAR for the UE fails, the UE may retry transmitting the preamble. In the case of contention-based random access, a contention resolution procedure (S16) may be performed, including transmission of a PUSCH based on UL resource allocation included in the RAR (S15) and reception of a PDCCH and a corresponding PDSCH.

[0115] The UE, which has performed the procedure described above, can then perform reception of PDCCH / PDSCH (S17) and transmission of PUSCH / PUCCH (S18) as a general uplink / downlink signal transmission process. The control information that the UE transmits to the BS is collectively referred to as uplink control information (UCI). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK) (also referred to as HARQ-ACK), scheduling request (SR), channel state information (CSI), etc. CSI may include a channel quality indicator (CQI), a precoding matrix indicator (PMI), and / or a rank indicator. UCI is generally transmitted through PUCCH, but may be transmitted through PUSCH when control information and traffic data must be transmitted simultaneously. Additionally, based on a request / instruction from the network, the UE can transmit UCI aperiodically via PUSCH.

[0116] Figure 7 illustrates SS / PBCH blocks (SSBs) on a cell.

[0117] In 3GPP-based systems, each SSB is associated with a beam. For example, during a half-frame, different SSBs can be transmitted in different spatial directions (using different beams spanning the cell's coverage area). The possible temporal locations of SSBs within a half-frame are determined by the subcarriers, and the periodicity of the half-frames over which the SSBs are transmitted is set by the network. Multiple SSBs can be transmitted within the frequency span of a carrier. Different indices of SSBs transmitted / detected on a cell can correspond to different BS (wide) Tx beams. Multiple SSBs can be transmitted within the frequency span of a carrier. The physical (layer) cell identifiers (PCIs) of SSBs transmitted at different frequency locations need not be unique, and different SSBs in the frequency domain can have different PCIs. If an SSB is associated with a remaining minimum system information (RMSI), the SSB is referred to as a cell-defining SSB (CD-SSB), and the PCell is always associated with a CD-SSB located on the synchronization raster (sync raster). If an SSB is not associated with an RMSI, the SSB is referred to as a non-cell defining SSB (NCD-SSB), which can be used to perform RLM, BFD and RRM measurements, and measurements for random access resource selection within the active DL BWP if the active DL BWP does not include the CD-SSB.In 3GPP-based systems, multi-beam operation is based on beam switching / beam scanning, which transmits / receives signals while changing the beam direction over time. Beam sweeping means that a transmission and reception point (TRP) (e.g., a BS / cell) changes the beam (direction) of a wireless signal over time. In this specification, the terms beam and beam direction can be used interchangeably. SSBs can be transmitted periodically using beam sweeping. In this case, the SSB index is implicitly linked to the SSB beam. The SSB beam can be changed on an SSB (index) basis or on an SSB (index) group basis. In the latter case, the SSB beam remains the same within the SSB (index) group. For example, referring to Figure 7, the transmission beam direction of an SSB can be repeated for multiple consecutive SSBs. A set of SSBs is transmitted within a 5 ms half-frame. The set of bits transmitted within a 5 ms half-frame of an SSB transmission is called an SSB burst set. The maximum number of SSB transmissions within an SSB burst set is L. max has a value of 4, 8, or 64 depending on the frequency band to which the carrier belongs. For example, the maximum number of SSBs in an SSB burst set, L max can be given as follows.

[0118] - For frequency range up to 3 GHz, L max = 4

[0119] - For frequency range from 3GHz to 6 GHz, L max = 8

[0120] - For frequency range from 6 GHz to 52.6 GHz, L max = 64

[0121] The number of SSBs actually transmitted can be set, with a maximum number Lmax It can be smaller.

[0122] If multi-beam transmission is not applied, the number of SSB beams is 1.

[0123] Figure 8 is a diagram illustrating the bitmaps used to indicate which SSBs are actually transmitted.

[0124] Within an SSB burst set, up to L SSBs can be transmitted, and the number / positions of the SSBs actually transmitted may vary depending on the BS / cell. The number / positions of the SSBs actually transmitted are used for rate matching and measurement, and information about the SSBs actually transmitted (e.g., RRC configuration ssb-PositionsInBurst) can be indicated as follows.

[0125] - In case of rate-matching: It can be indicated via UE-specific RRC signaling or RMSI. The UE-specific RRC signaling includes a full (e.g., length L) bitmap in both the frequency ranges below 6 GHz and above 6 GHz. On the other hand, the remaining minimum system information (RMSI) (i.e., SIB1) includes a full bitmap below 6 GHz and a compressed bitmap above 6 GHz as illustrated. Specifically, information about actually transmitted SSB can be indicated using a group bitmap (8 bits) and an intra-group bitmap (8 bits). Here, resources (e.g., resource elements (REs)) indicated via the UE-specific RRC signaling or RMSI are reserved for SSB transmission, and PDSCH / PUSCH, etc. can be rate-matched considering SSB resources.

[0126] - For measurement purposes: When in RRC_CONNECTED mode, the network (e.g., BS) can indicate the set of SSBs to be measured within the measurement interval. The SSB set can be indicated per frequency layer. If there is no indication regarding the SSB set, the default SSB set is used. The default SSB set includes all SSBs within the measurement interval. The SSB set can be indicated using the full (e.g., length L) bitmap in RRC signaling. When in RRC_IDLE mode, the default SSB set is used.

[0127] Figure 9 illustrates a process for acquiring system information (SI). A UE can acquire AS / NAS information through the SI acquisition process. The SI acquisition process can be applied to UEs in the RRC_IDLE state, the RRC_INACTIVE state, and the RRC_CONNECTED state. RRC_CONNECTED is a state in which the UE has established an RRC connection with the network. RRC_IDLE is a state in which the UE is not registered in a specific cell and thus does not receive the access stratum (AS) context or other information received from the network. RRC_INACTIVE is a state in which the UE can move within an area established by the radio access network (RAN, e.g., BS(s)) without notifying the RAN while remaining in CM-CONNECTED, which is a state in which the UE has a signaling connection with the core network for connection management (CM). CM_CONNECTED is a state in which the UE has a non-access stratum (NAS) signaling connection with the core network, and CM_IDLE is a state in which the UE does not have any NAS signaling.

[0128] In a 3GPP-based system, SI can be divided into a master information block (MIB) and multiple system information blocks (SIBs). The MIB and multiple SIBs can be further divided into minimum SI and other SI. Here, the minimum SI can be composed of a MIB and a system information block 1 (SystemInformationBlock1, SIB1), and includes basic information required for initial connection and information for acquiring other SI. Here, SIB1 can be referred to as remaining minimum system information (RMSI). For more details, see the following.

[0129] - The MIB is always transmitted on the BCH with a periodicity of 80 ms and repetitions made within 80 ms. The MIB contains information / parameters related to the reception of SIB1 and is transmitted over the PBCH of SSB. During initial cell selection, the UE assumes that half-frames with SSB(s) repeat with a period of 20 ms. Based on the MIB, the UE can check whether a control resource set (CORESET) for the Type0-PDCCH common search space exists. The Type0-PDCCH common search space is a type of PDCCH search space and is used to transmit the PDCCH that schedules the SI message. If a Type0-PDCCH common search space exists, the UE can determine (i) multiple consecutive RBs and one or more consecutive symbols that constitute a CORESET and (ii) PDCCH occasions (i.e., time domain locations for PDCCH reception) based on information in the MIB (e.g., pdcch-ConfigSIB1). If a Type0-PDCCH common search space does not exist, pdcch-ConfigSIB1 provides information about frequency locations where SSB / SIB1 exists and frequency ranges where SSB / SIB1 does not exist.

[0130] - SIB1 is transmitted on the downlink shared channel (DL-SCH) with a periodicity of 160 ms and a variable transmission repetition period within 160 ms. The default transmission repetition period of SIB1 is 20 ms, but the actual transmission repetition period may vary depending on the network implementation. SIB1 contains information related to the availability and scheduling (e.g., transmission period, SI window size) of the remaining SIBs (hereinafter, SIBx, where x is an integer greater than or equal to 2). For example, SIB1 may indicate whether SIBx is broadcast periodically or provided on-demand upon request of the UE. If SIBx is provided on-demand, SIB1 may contain information necessary for the UE to perform an SI request. SIB1 is a cell-specific SIB. The PDCCH scheduling SIB1 is transmitted through the Type0-PDCCH common search space, and SIB1 is transmitted through the PDSCH indicated by the PDCCH.

[0131] - SIBx is included in SI messages and transmitted over the PDSCH. Each SI message is transmitted within a time window (i.e., SI window) that occurs periodically according to the SI scheduling information provided by SIB1.

[0132] A change in SI (other than for the earthquake and tsunami warning system (ETWS) and commercial mobile alert service (CMAS)) occurs only in a certain number of radio frames. This certain number of radio frames is called an SI modification period. SI can be transmitted multiple times with the same content within an SI modification period. SI modification period boundaries are defined by SFN values ​​satisfying: SFN mod m = 0, where m is the number of radio frames containing the SI modification period. The SI modification period can be configured by SIB1. When the network changes SI, the network can notify UEs of this change through an SI modification period, and then transmit the updated SI in the next SI modification period.

[0133] Figure 10 illustrates a random access process that may be applied to implementation(s) of the present specification. In particular, Figure 10(a) illustrates a four-step random access process, and Figure 10(b) illustrates a two-step random access process.

[0134] The random access procedure can be used for various purposes, such as initial access, uplink synchronization adjustment, resource allocation, handover, reconfiguration of radio links after radio link failure, and position measurement. The random access procedure is classified into a contention-based procedure and a dedicated (i.e., non-contention-based) procedure. The contention-based random access procedure is commonly used, including initial access, while the dedicated random access procedure is used for handovers, when downlink data arrives at the network, and to reestablish uplink synchronization in the case of position measurement. In the contention-based random access procedure, the UE randomly selects a random access (RA) preamble. Therefore, multiple UEs can transmit the same RA preamble simultaneously, necessitating subsequent contention resolution. In contrast, in the dedicated random access procedure, the UE uses an RA preamble uniquely assigned to the UE by the BS. Therefore, the UE can perform the random access procedure without collisions with other UEs.

[0135] Referring to Fig. 10(a), the contention-based random access process includes the following four steps. Hereinafter, the messages transmitted in steps 1 through 4 may be referred to as Msg1 through Msg4, respectively.

[0136] - Step 1: The UE transmits an RA preamble via PRACH.

[0137] - Step 2: The UE receives a random access response (RAR) from the BS via PDSCH.

[0138] - Step 3: The UE transmits UL data to the BS via PUSCH based on the RAR. Here, the UL data includes layer 2 and / or layer 3 messages.

[0139] - Step 4: The UE receives a contention resolution message from the BS via PDSCH.

[0140] A UE can receive information about random access from a BS through system information. For example, information about RACH occasions associated with SSBs on a cell can be provided through the system information. In this specification, a RACH occasion is also referred to as a PRACH occasion and may refer to a time-frequency resource for transmitting a random access preamble for Msg1. The UE can select an SSB among the SSBs received on the cell whose reference signal received power (RSRP) measured based on the SSB exceeds a threshold and transmit an RA preamble through the PRACH associated with the selected SSB. For example, if random access is required, the UE transmits Msg1 (e.g., a preamble) to the BS on the PRACH. The BS can distinguish each random access preamble through the time / frequency resource (RA Occasion, RO) in which the random access preamble is transmitted and the random access preamble index (Preamble Index, PI). When the BS receives the random access preamble from the UE, the BS transmits an RAR message to the UE on the PDSCH. To receive the RAR message, the UE monitors the L1 / L2 control channel (PDCCH) masked with a cyclic redundancy check (CRC) using a Random Access-RNTI (RA-RNTI), which contains scheduling information for the RAR message, within a preset time window (e.g., ra-ResponseWindow). When the UE receives scheduling information through the PDCCH masked with the RA-RNTI, the UE can receive the RAR message from the PDSCH indicated by the scheduling information. Thereafter, the UE determines whether the RAR message includes an RAR for itself.The presence of a RAR for oneself can be determined by checking whether there is a RAPID (Random Access Preamble ID) for the preamble transmitted by the UE. The index and RAPID of the preamble transmitted by the UE may be the same. The RAR includes a corresponding random access preamble index, timing offset information for UL synchronization (e.g., timing advance command (TAC), UL scheduling information for Msg3 transmission (e.g., UL grant), and UE temporary identification information (e.g., Temporary-C-RNTI, TC-RNTI). The UE receiving the RAR transmits Msg3 through the PUSCH according to the UL scheduling information and timing offset value in the RAR. Msg3 may include the ID of the UE (or the global ID of the UE). In addition, Msg3 may include information related to an RRC connection request for initial access to the network (e.g., an RRCSetupRequest message). After receiving Msg3, the BS transmits Msg4, which is a contention resolution message, to the UE. If the UE receives the contention resolution message and the contention is successfully resolved, the TC-RNTI is changed to the C-RNTI. Msg4 includes the ID of the UE. And / or RRC connection related information (e.g., RRCSetup message) may be included. If the information transmitted via Msg3 does not match the information received via Msg4, or if Msg4 is not received for a certain period of time, the UE may consider contention resolution to have failed and retransmit Msg3.

[0141] Meanwhile, the dedicated random access process includes the following three steps. Hereinafter, the messages transmitted in steps 0 to 2 may be referred to as Msg0 to Msg2, respectively. The dedicated random access process may be triggered in the UE by the BS using a PDCCH (hereinafter, PDCCH order) for commanding the transmission of an RA preamble.

[0142] - Step 0: BS allocates RA preamble to UE through dedicated signaling.

[0143] - Step 1: The UE transmits an RA preamble via PRACH.

[0144] - Step 2: The UE receives RAR via PDSCH from the BS.

[0145] The operation of steps 1 and 2 of the dedicated random access process may be identical to steps 1 and 2 of the contention-based random access process.

[0146] NR systems may require lower latency than traditional systems. Furthermore, a four-step random access process may be undesirable, especially for latency-sensitive services such as URLLC. A low-latency random access process may be required in various scenarios within NR systems. When implementing implementations of this specification in conjunction with a random access process, implementations of this specification may be implemented in conjunction with the following two-step random access process to reduce the latency of the random access process.

[0147] Referring to Fig. 10(b), the two-step random access process may be composed of two steps: transmission of MsgA from a UE to a BS and transmission of MsgB from the BS to the UE. The MsgA transmission may include transmission of an RA preamble via a PRACH and transmission of an UL payload via a PUSCH. In the MsgA transmission, the PRACH and PUSCH may be transmitted using time division multiplexing (TDM). Alternatively, in the MsgA transmission, the PRACH and PUSCH may be transmitted using frequency division multiplexing (FDM).

[0148] A BS that receives MsgA can transmit MsgB to the UE. MsgB can include an RAR for the UE.

[0149] An RRC connection request related message (e.g., an RRCSetupRequest message) requesting to establish a connection between the RRC layer of the BS and the RRC layer of the UE may be transmitted in the payload of MsgA. In this case, MsgB may be used to transmit RRC connection related information (e.g., an RRCSetup message). Alternatively, the RRC connection request related message (e.g., an RRCSetupRequest message) may be transmitted via a PUSCH transmitted based on a UL grant in MsgB. In this case, the RRC connection related information (e.g., an RRCSetup message) related to the RRC connection request may be transmitted via a PDSCH associated with the PUSCH transmission after the PUSCH transmission based on MsgB.

[0150] Below, the physical channels that can be used in 3GPP-based wireless communication systems are described in more detail.

[0151] The PDCCH carries DCI. For example, the PDCCH (i.e., DCI) carries the transmission format and resource allocation of the downlink shared channel (DL-SCH), resource allocation information for the uplink shared channel (UL-SCH), paging information for the paging channel (PCH), system information on the DL-SCH, resource allocation information for control messages of a layer (hereinafter, upper layer) located above the physical layer in the protocol stacks of the UE / BS, such as a random access response (RAR) transmitted on the PDSCH, transmission power control commands, activation / release of configured scheduling (CS), etc. The DCI that includes resource allocation information for the DL-SCH is also called PDSCH scheduling DCI, and the DCI that includes resource allocation information for the UL-SCH is also called PUSCH scheduling DCI. The DCI includes a cyclic redundancy check (CRC), and the CRC is masked / scrambled with various identifiers (e.g., radio network temporary identifier (RNTI)) depending on the owner or intended use of the PDCCH. For example, if the PDCCH is for a specific UE, the CRC is masked with the UE identifier (e.g., cell RNTI (C-RNTI)). If the PDCCH is for paging, the CRC is masked with the paging RNTI (P-RNTI). If the PDCCH is for system information (e.g., system information block (SIB)), the CRC is masked with the system information RNTI (SI-RNTI). If the PDCCH is for a random access response, the CRC is masked with the random access RNTI (RA-RATI).

[0152] When a PDCCH on one serving cell schedules a PDSCH or PUSCH on another serving cell, this is called cross-carrier scheduling. Cross-carrier scheduling using the carrier indicator field (CIF) can allow the PDCCH of a serving cell to schedule resources on another serving cell. On the other hand, when a PDSCH on a serving cell schedules a PDSCH or PUSCH on the serving cell, this is called self-carrier scheduling. When cross-carrier scheduling is used in a cell, the BS can provide the UE with information about the cell that schedules the cell. For example, the BS can provide the UE with information about whether the serving cell is scheduled by a PDCCH on another (scheduling) cell or by the serving cell, and if the serving cell is scheduled by another (scheduling) cell, which cell signals downlink assignments and uplink grants for the serving cell. In this specification, a cell that carries a PDCCH is called a scheduling cell, and a cell in which transmission of a PUSCH or PDSCH is scheduled by DCI included in the PDCCH, i.e., a cell that carries a PUSCH or PDSCH scheduled by the PDCCH, is called a scheduled cell.

[0153] The PDSCH is a physical layer DL channel for DL ​​data transport. PDSCH carries downlink data (e.g., DL-SCH transport blocks) and employs modulation methods such as Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64 QAM, and 256 QAM. Transport blocks (TBs) are encoded to generate codewords. A PDSCH can carry up to two codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword can be mapped to one or more layers. Each layer is mapped to radio resources along with the DMRS, generating an OFDM symbol signal and transmitting it through the corresponding antenna port.

[0154] A UE must have uplink resources available to it for UL-SCH data transmission, and downlink resources available to it for DL-SCH data reception. Uplink and downlink resources are assigned to the UE through resource allocation by the BS. Resource allocation may include time domain resource allocation (TDRA) and frequency domain resource allocation (FDRA). In this specification, uplink resource allocation is also referred to as uplink grant, and downlink resource allocation is also referred to as downlink assignment. An uplink grant is dynamically received by the UE on the PDCCH or within the RAR, or is semi-persistently configured to the UE by RRC signaling from the BS. A downlink assignment is dynamically received by the UE on the PDCCH, or is semi-persistently configured to the UE by RRC signaling from the BS.

[0155] In UL, the BS can dynamically allocate uplink resources to the UE via PDCCH(s) addressed to a cell radio network temporary identifier (C-RNTI). The UE monitors the PDCCH(s) to find possible uplink grant(s) for UL transmission. Furthermore, the BS can allocate uplink resources to the UE using the configured grant(s). Two types of configured grants can be used: Type 1 and Type 2. For Type 1, the BS directly provides the configured uplink grant (including the periodicity) via RRC signaling. For Type 2, the BS can configure the period of the RRC configured uplink grant via RRC signaling, and signal and activate or deactivate the configured uplink grant via a PDCCH addressed to a configured scheduling RNTI (CS-RNTI). For example, for Type 2, a PDCCH addressed to CS-RNTI implicitly indicates that the corresponding uplink grant can be reused according to a period set by RRC signaling until it is deactivated.

[0156] In DL, the BS can dynamically allocate downlink resources to the UE via PDCCH(s) addressed with the C-RNTI. The UE monitors the PDCCH(s) to discover possible downlink assignments. Additionally, the BS can allocate downlink resources to the UE using semi-persistent scheduling (SPS). The BS can configure the period of the configured downlink assignments via RRC signaling, and can signal and activate or deactivate the configured downlink assignments via the PDCCH addressed with the CS-RNTI. For example, a PDCCH addressed with the CS-RNTI implicitly indicates that the corresponding downlink assignment can be reused according to the period configured by the RRC signaling until it is deactivated.

[0157] Figure 11 illustrates an example of PDSCH time domain resource allocation by PDCCH and an example of PUSCH time domain resource allocation by PDCCH.

[0158] The DCI carried by the PDCCH for scheduling the PDSCH or PUSCH includes a time domain resource assignment (TDRA) field, which provides a value m for a row index m+1 of an allocation table for the PDSCH or PUSCH. A predefined default PDSCH time domain allocation is applied as the allocation table for the PDSCH, or a PDSCH time domain resource allocation table configured by the BS through RRC signaling pdsch-TimeDomainAllocationList is applied as the allocation table for the PDSCH. A predefined default PUSCH time domain allocation is applied as the allocation table for the PUSCH, or a PUSCH time domain resource allocation table configured by the BS through RRC signaling pushch-TimeDomainAllocationList is applied as the allocation table for the PUSCH. The PDSCH time domain resource allocation table to be applied and / or the PUSCH time domain resource allocation table to be applied may be determined according to fixed / predefined rules (e.g., see 3GPP TS 38.214).

[0159] In the PDSCH time domain resource configurations, each indexed row defines a DL allocation-to-PDSCH slot offset K0, a start and length indicator value SLIV (or directly a starting position (e.g., a starting symbol index S) and an allocation length (e.g., a number of symbols L) of a PDSCH within a slot), and a PDSCH mapping type. In the PUSCH time domain resource configurations, each indexed row defines a UL grant-to-PUSCH slot offset K2, a starting position (e.g., a starting symbol index S) and an allocation length (e.g., a number of symbols L) of a PUSCH within a slot, and a PUSCH mapping type. K0 for PDSCH or K2 for PUSCH indicates the difference between a slot with a PDCCH and a slot with a PDSCH or PUSCH corresponding to the PDCCH. SLIV is a joint indication of a starting symbol S relative to the start of a slot with a PDSCH or PUSCH and the number L of consecutive symbols counted from the symbol S. For PDSCH / PUSCH mapping type, there are two mapping types: one is mapping type A and the other is mapping type B. For PDSCH / PUSCH mapping type A, a demodulation reference signal (DMRS) is mapped to a PDSCH / PUSCH resource at the beginning of a slot, and one or two symbols of the PDSCH / PUSCH resource can be used as DMRS symbol(s) depending on other DMRS parameters. For example, for PDSCH / PUSCH mapping type A, the DMRS is located at the third symbol (symbol #2) or the fourth symbol (symbol #3) in a slot depending on RRC signaling. For PDSCH / PUSCH mapping type B, the DMRS is mapped based on the first OFDM symbol of the PDSCH / PUSCH resource, and one or two symbols from the first symbol of the PDSCH / PUSCH resource can be used as DMRS symbol(s) depending on other DMRS parameters.For example, in the case of PDSCH / PUSCH mapping type B, DMRS is located in the first symbol allocated for PDSCH / PUSCH. In this specification, PDSCH / PUSCH mapping type may be referred to as mapping type or DMRS mapping type. For example, in this specification, PUSCH mapping type A may be referred to as mapping type A or DMRS mapping type A, and PUSCH mapping type B may be referred to as mapping type B or DMRS mapping type B.

[0160] The above scheduling DCI includes a frequency domain resource assignment (FDRA) field that provides allocation information regarding resource blocks used for PDSCH or PUSCH. For example, the FDRA field provides the UE with information regarding the cell for PDSCH or PUSCH transmission, information regarding the BWP for PDSCH or PUSCH transmission, and information regarding resource blocks for PDSCH or PUSCH transmission.

[0161] A control resource set (CORESET), which is a set of time-frequency resources for which a UE can monitor PDCCH, may be defined and / or configured. A CORESET consists of a set of physical resource blocks (PRBs) with a duration of one to three OFDM symbols. The PRBs constituting the CORESET and the CORESET duration may be provided to the UE via higher layer (e.g., RRC) signaling. Within the configured CORESET(s), a set of PDCCH candidates is monitored according to the corresponding search space sets. In this specification, monitoring implies decoding (aka blind decoding) each PDCCH candidate according to the monitored DCI formats. A master information block (MIB) on the PBCH provides the UE with parameters (e.g., CORESET#0 configuration) for monitoring the PDCCH for scheduling a PDSCH carrying a system information block (SIB1). The PBCH may also indicate that there is no associated SIB1, in which case the UE may be instructed on other frequencies to search for SSBs associated with SIB1, as well as a frequency range in which it can assume that there are no SSBs associated with SSB1. At least CORESET#0, which is the CORESET for scheduling SIB1, may be configured via the MIB or dedicated RRC signaling.

[0162] More than one CORESET may be configured for a UE, and multiple CORESETs may overlap in the time / frequency domain.

[0163] The set of PDCCH candidates monitored by the UE is defined in terms of PDCCH search space sets. The search space set may 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 one CORESET configuration.

[0164] A set of PDCCH candidates can be monitored in one or more CORESETs on an active DL BWP on each activated serving cell for which PDCCH monitoring is configured, where monitoring implies receiving each PDCCH candidate and decoding it according to the monitored DCI formats. For example, the following DCI formats may be available:

[0165]

[0166] SS sets can be configured via system information (e.g., MIB) or UE-specific higher layer (e.g., RRC) signaling. Each DL BWP of a serving cell can have up to S (e.g., 10) SS sets configured. For example, the following parameters / information can be provided for each SS set. Each SS set is associated with one CORESET, and each CORESET configuration can be associated with one or more SS sets.

[0167] - searchSpaceId: Indicates the ID of the SS set.

[0168] - controlResourceSetId: Indicates the CORESET associated with the SS set.

[0169] - monitoringSlotPeriodicityAndOffset: Indicates the PDCCH monitoring period period (in slot units) and the PDCCH monitoring period offset (in slot units).

[0170] - monitoringSymbolsWithinSlot: Indicates the first OFDMA symbol(s) for PDCCH monitoring within the slot where PDCCH monitoring is configured. It is indicated through a bitmap, and each bit corresponds to each OFDMA symbol within the slot. The MSB of the bitmap corresponds to the first OFDM symbol within the slot. The OFDMA symbol(s) corresponding to the bit(s) with a bit value of 1 corresponds to the first symbol(s) of the CORESET within the slot.

[0171] - nrofCandidates: AL={1, 2, 4, 8, 16} indicates the number of PDCCH candidates (e.g., one of 0, 1, 2, 3, 4, 5, 6, 8).

[0172] - searchSpaceType: Indicates whether the SS type is CSS or USS.

[0173] - DCI format: Indicates the DCI format of the PDCCH candidate.

[0174] Based on the CORESET / SS set configuration, the UE can monitor PDCCH candidates in one or more SS sets within a slot. The occasions (e.g., time / frequency resources) during which PDCCH candidates should be monitored are defined as PDCCH (monitoring) occasions. One or more PDCCH (monitoring) occasions can be configured within a slot.

[0175] UE uses DRX to reduce power consumption. UE operating based on DRX repeats ON / OFF for reception operation. The features of DRX utilized for the purpose of reducing unnecessary power consumption of UE are as follows. DRX defines a structure for UE in RRC_IDLE state where RRC connection between UE and BS is not established (hereinafter referred to as I-DRX) and a structure for UE in RRC_CONNECTED state where RRC connection between UE and BS is established (hereinafter referred to as C-DRX). Both DRX structures are designed to reduce unnecessary power consumption in other periods by defining a period (e.g., active time period or on-duration period) in which UE can expect reception of DL signals to occur periodically. For reference, in the case of C-DRX, the start position of On-duration occurs periodically in the Rel-16 standard, and the size of the cycle that can be configured at this time (i.e., DRX cycle) can be determined / set through upper layer signaling, such as RRC signaling, provided by the BS to the UE.

[0176] Figure 12 illustrates a discontinuous reception (DRX) operation. In particular, Figure 12 illustrates a DRX cycle for a UE in RRC_CONNECTED state.

[0177] Referring to FIG. 12, a DRX cycle consists of an ON period and an Opportunity for DRX. A DRX cycle defines a time interval in which an ON period is periodically repeated, followed by a possible period of inactivity. The ON period represents a time interval during which the UE performs PDCCH monitoring to receive a PDCCH. When DRX is configured, the UE performs PDCCH monitoring during the ON period. If a PDCCH is successfully detected during PDCCH monitoring, the UE starts an inactivity timer and remains awake. On the other hand, if no PDCCH is successfully detected during PDCCH monitoring, the UE enters a sleep state after the ON period ends. Therefore, when DRX is configured, the UE may perform PDCCH monitoring / reception discontinuously in the time domain when performing a process and / or method according to the implementation(s) of this specification. For example, when DRX is configured, the PDCCH reception occasion (e.g., slot having PDCCH search space) in this specification may be configured discontinuously according to the DRX configuration. On the other hand, when DRX is not configured, the UE may perform PDCCH monitoring / reception continuously in the time domain. For example, when DRX is not configured, the PDCCH reception occasion (e.g., slot having PDCCH search space) may be configured continuously. On the other hand, regardless of whether DRX is configured, PDCCH monitoring may be restricted in the time period configured as the measurement gap. DRX configuration information is received via upper layer (e.g., RRC) signaling, and whether DRX is turned on / off is controlled by the DRX command of the MAC layer. When DRX is configured, the UE may perform PDCCH monitoring discontinuously, as illustrated in FIG. 12.

[0178] The following table illustrates the UE processes related to DRX. Referring to the following table, DRX configuration information is received via upper layer (e.g., RRC) signaling, and DRX ON / OFF is controlled by the DRX command of the MAC layer. When DRX is configured, the UE can perform PDCCH monitoring discontinuously, as illustrated in FIG. 12.

[0179]

[0180] Here, MAC-CellGroupConfig contains configuration information required to set MAC parameters for a cell group. MAC-CellGroupConfig may also contain configuration information related to DRX. For example, MAC-CellGroupConfig may contain DRX-related information as follows.

[0181] - Value of drx-onDurationTimer: Sets the duration at the start of the DRX cycle.

[0182] - Value of drx-SlotOffset: Sets the delay before starting drx-onDurationTimer.

[0183] - Value of drx-InactivityTimer: Sets the period after which a PDCCH epoch indicates a new UL or DL ​​transmission to the MAC entity.

[0184] - Value of drxRetransmissionTimerDL (per DL HARQ process except for the broadcast process): Sets the maximum duration until a DL retransmission is received.

[0185] - Value of drxRetransmissionTimerUL (per UL HARQ process): Sets the maximum duration until a grant for UL retransmission is received.

[0186] - Value of drx-HARQ-RTT-TimerDL (per DL HARQ process except for the broadcast process): Sets the maximum period of time after a DL initial transmission is received until a DL assignment for HARQ retransmission is received.

[0187] - Value of drx-HARQ-RTT-TimerUL (per UL HARQ process): Sets the maximum period from when a grant for UL initial transmission is received until a grant for UL retransmission is received.

[0188] - drx-LongCycleStartOffset: Sets the Long DRX cycle and drx-StartOffset, which defines the subframe where the Long and Short DRX cycles start.

[0189] - drx-ShortCycle (optional): Sets the short DRX cycle.

[0190] - drx-ShortCycleTimer (optional): Sets the duration for which the UE should follow the Short DRX cycle. For example, a value in multiples of the Short DRX cycle can be set by drx-CylceTimer. For example, the value of n can correspond to n*drx-ShortCycle.

[0191] A UE may perform PDCCH monitoring on serving cells within a DRX group when the DRX group is within its active time. Here, a DRX group is a group of serving cells configured by RRC and having the same DRX active time. Here, the active time is a total duration for which the UE monitors the PDCCH, and may include an ON period of a DRX cycle, a time for which the UE performs continuous reception while an inactivity timer has not expired, and a time for which the UE performs continuous reception while waiting for a retransmission opportunity. For example, when DRX is configured, the active time for serving cells within a DRX group is i) while drx-onDurationTimer or drx-InactivityTimer configured for the DRX group is running; or ii) while drx-RetransmissionTimerDL or drx-RetransmissionTimerUL is running on any serving cell within the DRX group; or ra-ContentionResoultionTimer or msgB-RsponseWindow is running; or a PDCCH indicating a new transmission addressed to a C-RNTI addressed to the MAC entity of the UE is not received after successful reception of a random access response to a random access preamble that is not selected by the MAC entity among the contention-based random access preambles.

[0192] A UE can be configured with one or more DRX groups via RRC signaling from a BS. For example, if two DRX groups are configured, each serving cell is uniquely assigned to one of the two DRX groups. The DRX parameters drx-onDurationTimer and drx-InactivityTimer are configured separately for each DRX group, and the 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 the DRX groups. Since each serving cell belongs to only one of the DRX groups, and the DRX parameters drx-onDurationTimer and drx-InactivityTimer are set for each DRX group, and the remaining DRX parameters are common to the DRX groups, it can be said that a serving cell is associated with only one set of DRX parameters.

[0193] Figure 13 illustrates a case where a Long DRX cycle and a Short DRX cycle are set. In particular, Figure 13 illustrates a case where drx-ShortCycleTimer is set to 2.

[0194] A BS can configure a Long DRX cycle and an additional Short DRX cycle that is shorter than the Long DRX cycle. If a Short DRX cycle is not configured, the UE follows the Long DRX cycle. When configuring a Short DRX cycle, the BS sets the duration of the Long DRX cycle to be a positive integer multiple of the Short DRX cycle. The same onDurationTimer value is configured for the Long DRX cycle and the Short DRX cycle. If there is no data activity during the ON period of the Long DRX cycle (e.g., no PDCCH reception), the UE follows the Long DRX cycle as if the Short DRX cycle is not configured. If there is data activity during the ON period of the Long DRX cycle, for example, while drx-onDurationTimer is running, the UE switches to the Short DRX cycle and follows the Short DRX cycle for a certain period of time (e.g., while drx-ShortCycleTimer is running). At this time, the start of the ON period in the Short DRX cycle is determined by drx-StartOffset and drx-SlotOffset, just like the Long DRX cycle. Referring to FIG. 13, if there is no data activity during the time following the Short DRX cycle, for example, if there is no data activity during the period defined by drx-ShortCycleTimer*drx-ShortCycle, the UE switches to the Long DRX cycle after drx-ShortCycleTimer Short DRX cycles.

[0195] Figure 14 illustrates paging times that can be monitored by a UE having a specific UE identifier.

[0196] If the UE has no ongoing data transmissions / receptions, the UE enters RRC_IDLE or RRC_INACTIVE to save power. When DL data for the UE arrives in the network, the network sends a paging message (e.g., paging DCI) at a paging occasion (PO) to trigger the RRC setup procedure, RRC connection resume procedure, etc. In multi-beam operations, the UE assumes that the same paging message is repeated on all transmitted beams. The paging message is the same for both radio access network (RAN) initiated paging and core network (CN) initiated paging.

[0197] In this specification, a PDCCH carrying a DCI format having a CRC scrambled with a P-RNTI is referred to as a paging PDCCH, and a PDSCH scheduled by the paging PDCCH is referred to as a paging PDSCH. A UE can decode the paging PDSCH based on scheduling information (e.g., frequency domain resource allocation, modulation and coding scheme, etc.) in the paging PDCCH. The paging PDSCH carries paging messages, which are used for notification to one or more UEs and may include one or more UE identifiers (IDs).

[0198] In each DRX cycle, the UE remains in sleep mode during the OFF period, but is expected to wake up during the paging period to monitor the PDCCH for paging. The UE monitors one PO per DRX cycle. Paging DRX (also called idle mode DRX) is defined, where a UE in RRC_IDLE or RRC_INACTIVE is only required to monitor the paging channels during one PO per DRX cycle. In each idle mode DRX (I-DRX) cycle, the UE monitors only one PO within a particular paging frame (PF). When a PDCCH for paging is received in a PO, the UE decodes the PDSCH to receive a paging message. If the paging is not for the UE, the UE falls back to sleep until the next PO.

[0199] A paging frame (PF) is a radio frame and may contain one or more POs or the starting point of a PO. The PF and PO for paging can be determined by predefined formulas. For example, in some implementations, the system frame number (SFN) for the PF may be determined by (SFN + PF_offset) mod T = (T div N)*(UE_ID mod N), and the index i_s indicating the index of the PO may be determined by i_s = floor(UE_ID) mod Ns, where T is the DRX cycle of the UE determined by the minimum of UE-specific DRX value(s) and / or default DRX value broadcast with system information, N is the total number of paging frames within T, Ns is the number of paging occasions for the PF, PF_offset is an offset used for PF determination, and UE_ID is a value determined based on 5G-S-TMSI. A parameter Ns relating to the number of paging occasions per paging frame, a parameter nAndPagingFrameOffset used to derive the total number of paging frames in T, a parameter nrofPDCCH-MonitoringOccasionsPerSSB-InPO relating to the number of PDCCH monitoring occasions corresponding to SSBs in a paging occasion, and a length of a default DRX cycle may be signaled by SIB1, and the values ​​of N and PF_offset are derived from the parameter nAndPagingFrameOffset.

[0200] A PO is a set of PDCCH monitoring occasions, which may consist of multiple time slots (e.g., subframes or OFDM symbols), and a DCI having a CRC scrambled with a P-RNTI may be transmitted in the PO. For example, a PO is a set of 'S*X' consecutive PDCCH monitoring occasions, where 'S' is the number of actual transmitted SSBs determined by the parameter ssb-PositionsInBurst in SIB1, and 'X' is nrofPDCCH-MonitoringOccasionPerSSB-InPO if set and equal to 1 otherwise. The parameter ssb-PositionsInBurst indicates time domain indications of SSBs transmitted within a half frame with SS / PBCH blocks, and the parameter nrofPDCCH-MonitoringOccasionPerSSB-InPO indicates the number of PDCCH monitoring occasions corresponding to SSBs within a paging occasion. The PDCCH monitoring occasions for paging can be determined based on the parameter firstPDCCH-MonitoringOccasionOfPO, which indicates the first PDCCH monitoring occasion for paging of each PO of the PF, and the parameter nrofPDCCH-MonitoringOccasionsPerSSB-InPO. The parameter firstPDCCH-MonitoringOccasionOfPO can be signaled by SIB1 for paging in the initial downlink BWP, and can be signaled with the corresponding BWP setting for paging in a DL BWP other than the initial downlink BWP.

[0201] Indicates the number of PDCCH monitoring periods corresponding to SSB within the paging period.

[0202] Energy conservation of base stations (BSs) is a key consideration in wireless communication systems, including 3GPP, as it can contribute to building eco-friendly networks by reducing carbon emissions and reducing the operational expenditure (OPEX) of telecommunications operators. In particular, the introduction of 5G communications will require higher transmission rates, necessitating BSs to be equipped with more antennas and provide services over wider bandwidths and frequency bands. Consequently, recent studies have shown that BS energy costs have reached up to 20% of total OPEX. This heightened interest in BS energy conservation led to the approval of a new study item, "Study on Network Energy Savings," in 3GPP NR Release 18. For example, to improve the energy saving capability of BS from the perspective of transmission and reception, the study investigates how to achieve dynamic and / or semi-static and finer granularity adaptation of transmission and / or reception to more efficient operation with one or more network energy saving techniques in time, frequency, space and power domains using potential assistance / feedback of UE and potential UE assistance information.

[0203] The following enhancement techniques may be considered:

[0204] > Specify SSB-less SCell operation for inter-band CA for FR1 and co-located cells, where a UE measures SSB transmitted on PCell or another SCell for an SCell's time / frequency synchronization (including downlink AGC), and L1 / L3 measurements, including potential enhancement on SCell activation procedures if necessary.

[0205] > Specify enhancement on cell DTX / DRX mechanism including the alignment of cell DTX / DRX and UE DRX in RRC_CONNECTED mode, and inter-node information exchange on cell DTX / DRX

[0206] > Specify the following techniques in spatial and power domains:

[0207] >> Specify necessary enhancements on CSI and beam management related procedures including measurement and report, and signaling to enable efficient adaptation of spatial elements (e.g., antenna ports, active transceiver chains).

[0208] >> Specify necessary enhancements on CSI-related procedures including measurement and report, and signaling to enable efficient adaptation of power offset values ​​between PDSCH and CSI-RS.

[0209] > Specify mechanism(s) to prevent legacy UEs camping on cells adopting the Rel-18 NES techniques, if necessary.

[0210] > Specify conditional handover (CHO) procedure enhancement(s) in case source / target cell is in NES mode.

[0211] > Specify inter-node beam activation and enhancements on restricting paging in a limited area.

[0212] > Specify the corresponding radio resource management / radio frequency (RRM / RF) core requirements, if necessary, for the above features.

[0213] A BS can apply technologies such as controlling the on / off duration in the time domain for NES purposes, controlling transmission / reception resources for UE-common or UE-specific signals / channels, changing the amount of frequency domain resources, controlling transmission power, or turning antenna port(s) or TRP(s) on / off in the spatial domain. A state in which such technologies (hereinafter, referred to as NES_tech for convenience) are applied is referred to as an NES mode or NES state.

[0214] Figure 15 illustrates an operating procedure in a BS that supports network energy saving (NES) technology.

[0215] Referring to FIG. 15, the BS identifies or determines the NES solution(s) to be applied (S1501). The NES solution(s) may be related to control of signal transmission / reception (e.g., on / off), beam operation, handover procedures, channel measurement and reporting, etc. The NES solution(s) to be applied may be adaptively selected or predefined depending on the current situation (e.g., cell load level, characteristics of connected UEs, etc.). The BS that has identified (or determined) the NES solution(s) may perform signaling for the NES (S1503). The specific signaling procedure may vary depending on the identified NES solution(s). For example, the BS may transmit common information about the NES solution(s), transmit configuration information necessary for NES operation to at least one UE, or transmit control information regarding the progress of the NES operation to at least one UE. Additionally, the BS may receive capability information related to the NES from at least one UE. Thereafter, the BS may perform operations for the NES (S1505). At this time, the BS may perform operations for the NES based on previously performed signaling. For example, based on system information, configuration information, and control information transmitted through signaling, the BS may turn on or off transmission / reception of a specific signal, turn on / off elements in the spatial domain, or adjust resources for transmission / reception of a measurement signal.

[0216] Through a procedure similar to that in Fig. 15, NES technology can be implemented. Examples of NES solutions that can be implemented through a procedure similar to that in Fig. 15 are as follows.

[0217] > Intra-system energy saving solution: A radio access network (RAN) node can request a neighboring RAN node to switch at least one SSB beam into its deactivated cell, or can perform paging using a limited set of beams to an inactive UE (e.g., a stationary UE).

[0218] > Inter-system energy saving solution: NG-RAN nodes that own capacity booster cells can autonomously transition those cells to inactive state.

[0219] > SSB-less SCell solution: If the SSB configuration for the SCell or the SSB-based RRM measurement timing configuration (SSB measurement timing configuration (SMTC)) is not provided, the UE can obtain the timing reference and automatic gain control (AGC) source from another serving cell. In FR1 or FR2, the BS can configure intra-band carrier aggregation (CA) or inter-band CA including the SCell without SSB transmission, in which case the SSB / SIB transmission can be triggered by the wake up signal (WUS) of the UE. Accordingly, the periodicity of common channels / signals such as SSB increases, so the BS can stay in the sleep state for a longer time.

[0220] > Cell DTX / DRX Solution: In order to reduce the downlink transmission / uplink reception active time of the BS, a common periodic cell DTX / DRX pattern (e.g., active and inactive periods) may be configured for UEs within a cell having the feature. Here, the cell DTX pattern and the cell DRX pattern may be configured and activated separately, and up to two cell DTX / DRX patterns may be configured per MAC entity. When cell DTX is configured and activated, at least one of monitoring for semi-persistent scheduling (SPS) occasions or PDCCH monitoring may be suspended during the cell DTX inactive period. When cell DRX is configured and activated, at least one of transmission on configured grant (CG) resources or scheduling request (SR) transmission may be suspended during the cell DRX inactive period. Cell DTX / DRX can be activated / deactivated via RRC signaling or L1 group common signaling (e.g., PDCCH on CSS). Parameters such as active duration and cycle can be configured for cell DTX / DRX. Active duration is the period during which the UE receives a PDCCH or SPS occasion and waits to transmit SR or CG, and cycle specifies the periodic repetition of active and inactive periods. When both cell DTX and cell DRX are configured, parameters such as active duration and cycle are common.If the BS recognizes an emergency call or a public safety related service (e.g., multimedia priority service (MPS) or mission critical service (MCS)), the network may release or deactivate the cell DTX / DRX configuration so as not to affect the service. In addition, at least some overlap is required between the active period of the connected mode DRX of the UE and the active period of the cell DTX / DRX. For example, the connected mode DRX periodicity of the UE may be a multiple of the cell DTX / DRX periodicity or vice versa.

[0221] > Conditional handover (CHO) solution: The CHO procedure, which is performed in a way that the execution of the handover is determined by the UE, is used while the NES technology is applied (e.g., when the cell activates or deactivates cell DTX / DRX). In this case, the UE can use NES-specific CHO events to initiate CHO for a candidate cell, and the reception of a DCI activating the CHO condition(s) set by the NES event indication can be applied as an additional triggering condition for this.

[0222] > Spatial and Power Domain Adaptation Solution: To support the BS for transmitter muting and / or transmit power adaptation, the UE may be configured to report multiple CSI entries in a CSI report based on multiple sub-configurations. Each sub-configuration may correspond to a spatial domain adaptation pattern (e.g., a subset of available spatial elements) and / or a power offset between a data channel (e.g., a PDSCH) and CSI-RSs. Depending on the application of the spatial and power domain adaptation solution, the CSI configuration, measurement, and / or reporting behavior may be affected.

[0223] The current standard document 3GPP TS 38.213 describes the random access process and PRACH configuration as follows. For a more detailed description of the RRC parameters mentioned below, please refer to 3GPP TS 38.331.

[0224] Prior to initiation of the physical random access process, layer 1 receives a set of SS / PBCH block indices from upper layers and provides a corresponding set of RSRP measurements to the upper layers.

[0225] Prior to initiating a physical random access process, layer 1 may receive an indication from upper layers to perform a type-1 random access process or a type-2 random access process.

[0226] Before initiating a physical random access process, Layer 1 receives the following information from higher layers:

[0227] - Physical random access channel (PRACH) transmission parameters (PRACH preamble format, time resources, and frequency resources for PRACH transmission).

[0228] - Parameters for determining root sequences and their cyclic shifts in the PRACH preamble sequence set (index to logical root sequence table, cyclic shift (N CS ), and set type (unrestricted, restricted set A, or restricted set B).

[0229] From a physical layer perspective, the type-1 L1 random access procedure includes transmission of a random access preamble (Msg1) in a PRACH, a random access response (RAR) with a PDCCH / PDSCH (Msg2), and, when applicable, transmission of a PUSCH scheduled by a RAR UL grant and a PDSCH for contention resolution.

[0230] From a physical layer perspective, the type-2 L1 random access process includes transmission of a random access preamble in a PRACH and of a PUSCH (MsgA), reception of a RAR message with PDCCH / PDSCH (MsgB), and transmission of a PDSCH for contention resolution with the PUSCH scheduled by the fallback RAR UL grant, if applicable.

[0231] When a random access procedure for a UE is initiated by a PDCCH order, the PRACH transmission has the same subcarrier spacing (SCS) as the PRACH transmission initiated by higher layers.

[0232] When a UE is configured with two UL carriers for a serving cell and the UE detects a PDCCH command, the UE uses the UL / supplementary UL (SUL) indicator field value from the detected PDCCH command to determine the UL carrier for the corresponding PRACH transmission.

[0233] The physical random access procedure for a UE is triggered upon a request for PRACH transmission by higher layers or via a PDCCH command for the cell. The higher layers' configuration for PRACH transmission includes:

[0234] - Settings for PRACH transmission on the above cell.

[0235] - Preamble index, preamble SCS, PRACH target reception power P PRACH,target , if applicable, the corresponding RA-RNTI, and the PRACH resources for the cell.

[0236] - If the UE would transmit the PRACH with repetitions, N for the PRACH transmission rep preamble >1 Number of preamble repetitions.

[0237] The UE may, on the indicated PRACH resources or N rep preamble For preamble repetitions, use the same spatial filter to obtain N rep preamble On a determined set of resources, the transmit power P as described in section 7.4 of 3GPP TS 38.214. PRACH,b,f,c(i) A UE transmits a PRACH on a cell using the selected PRACH format with transmission power P PRACH,b,f,c (i), as described in section 7.4 of 3GPP TS 38.214, on the indicated PRACH resource or on a determined set of N rep preamble resources using a same spatial filter in case of N rep preamble preamble repetitions.)

[0238] For a Type-1 random access procedure, the UE is provided with a number N of SS / PBCH block indexes associated with a PRACH occasion and a number R of contention based preambles per SS / PBCH block index per valid PRACH occasion by the RRC parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0239] For a type-1 random access procedure with a common configuration of PRACH occasions, the UE is provided with the number N of SS / PBCH block indices associated with a PRACH occasion by the RRC parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB and the number Q of contention-based preambles per SS / PBCH block index per valid PRACH occasion by the RRC parameter msgA-CB-PreamblesPerSSB-PerSharedRO. A PRACH transmission may occur on a subset of PRACH occasions associated with the same SS / PBCH block index within a SSB-RO mapping cycle for the UE provided with the PRACH mask index by the RRC parameter msgA-SSB-SharedRO-MaskIndex according to 3GPP TS 38.321.

[0240] For a Type-2 random access procedure with a separate configuration of PRACH occasions with a Type-1 random access procedure, the UE receives the number N of SS / PBCH block indices associated with a PRACH occasion and the number R of contention-based preambles per SS / PBCH block index per valid PRACH occasion, when provided, by an RRC parameter msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, otherwise, ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0241] For a random access procedure associated with a feature combination indicated by the RRC information element FeatureCombinationPreambles, which associates a feature combination with a set of preambles, the UE is provided with the number N of SS / PBCH block indices associated with one PRACH occasion by the RRC parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB or, if provided, msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, and with the number S of contention-based preambles per SS / PBCH block index per valid PRACH occasion by the RRC parameter startPreambleForThisPartition and the RRC parameter numberOfPreamblesPerSSB-ForThisPartition. A PRACH transmission is performed on a PRACH mask index associated with the same SS / PBCH block index within a SSB-RO mapping cycle for a UE provided with a PRACH mask index by ssb-SharedRO-MaskIndex according to 3GPP TS 38.321. It can be done on subsets of PRACH periods.

[0242] Figure 16 illustrates the mapping relationship between RACH occasions and SSBs. In Figure 16, msg1-FDM is the number of ROs multiplexed in the frequency domain, and ssb-perRACH-Occasion is the number of SSBs mapped to one RO.

[0243] For a Type-1 random access procedure, or for a Type-2 random access procedure having a separate set of PRACH occasions from the Type-1 random access procedure, if N < 1, one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH occasions, and R contention-based preambles having consecutive indices associated with the SS / PBCH block index per valid PRACH occasion are mapped starting from preamble index 0. If N ≥ 1, R contention-based preambles having consecutive indices associated with the SS / PBCH block index n per valid PRACH occasion are mapped to preamble index n*N. total preamble Starting from / N, 0 ≤ n ≤ N-1, and N total preamble is provided by totalNumberOfRA-Preambles for a type-1 random access process, or by msgA-TotalNumberOfRA-Preambles for a type-2 random access process that has a separate set of PRACH occasions from a type-1 random access process, and is an integer multiple of N.

[0244] For a type-2 random access process having a common set of PRACH epochs with a type-1 random access process, if N < 1, one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH epochs, and Q contention-based preambles having consecutive indices associated with the SS / PBCH block index per valid PRACH epoch start from preamble index R. If N ≥ 1, Q contention-based preambles having consecutive indices associated with SS / PBCH block index n per valid PRACH epoch are mapped to preamble index n*N. total preamble Starting from / N + R, where 0 ≤ n ≤ N-1, and N total preambleis provided by totalNumberOfRA-Preambles for type-1 random access processes.

[0245] In case of link recovery, the UE is provided with N SS / PBCH block indices associated with one PRACH occasion by the RRC parameter ssb-perRACH-Occasion in the RRC configuration BeamFailureRecoveryConfig. In case of dedicated RACH configuration provided by the RRC configuration RACH-ConfigDedicated, if parameters cfra for contention free random access to a given target cell are provided, the UE is provided with N SS / PBCH block indices associated with one PRACH occasion by the parameter ssb-perRACH-Occasion in the parameter occasions for random access occasions for contention free random access. If N < 1, then one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH occasions. If N ≥ 1, then all N consecutive SS / PBCH block indices are associated with one PRACH occasion.

[0246] The SS / PBCH block indices provided by ssb-PositionsInBurst in SIB1 or RRC configuration ServingCellConfigCommon are mapped to valid PRACH occasions in the following order, with parameters as described in 3GPP TS 38.211.

[0247] > First, in increasing order of preamble indices within a single PRACH period.

[0248] > Second, in increasing order of frequency resource indices for frequency multiplexed PRACH periods.

[0249] > Third, in increasing order of time resource indices for time-multiplexed PRACH periods within a PRACH slot.

[0250] > Fourth, in increasing order of indexes for PRACH slots

[0251] The association period, starting from frame 0, for mapping SS / PBCH block indices to PRACH periods is N SSB Tx An association period, starting from frame 0, for mapping SS / PBCH block indexes to PRACH occasions is the smallest integer number in the set determined by the PRACH configuration period according to the following table such that N SSB Tx SS / PBCH block indexes are mapped at least once to the PRACH occasions within the association period), where the UE determines N from the value of ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon. SSB Tx Get .

[0252] The following table illustrates the mapping between the PRACH configuration period and the SS / PBCH block to PRACH occasion association period.

[0253]

[0254] For a PRACH transmission by a UE triggered by a PDCCH command, if the value of the random access preamble index field is not 0, the PRACH mask index field indicates a PRACH occasion for the PRACH transmission, where the PRACH occasions are associated with the SS / PBCH block index indicated by the SS / PBCH block index field of the PDCCH command, and the cell indicator field, if any, indicates a cell for the PRACH transmission (see 3GPP TS 38.212). The UE may indicate K by the RRC parameter cellSpecificKoffset. cell,offset If provided, the PRACH period is slot n + 2 u ·K cell,offset After that, n is T TA = 0, is a slot of a UL BWP for a PRACH transmission overlapping the end of a PDCCH command reception, and u is an SCS configuration for the PRACH transmission. If a PDCCH reception for a PDCCH command includes two PDCCH candidates from two linked search space sets based on the RRC parameter searchSpaceLinkingId used to link two search spaces of the same type within the same BWP, then the last symbol of the PDCCH reception is the last symbol of the later-ending PDCCH candidate, as described in section 10.1 of 3GPP TS 38.213. The PDCCH reception includes the two PDCCH candidates even when the UE is not required to monitor one of the two PDCCH candidates as described in sections 10 (except section 10.4), 11.1, 11.1.1 and 17.2 of 3GPP 38.213.

[0255] For PRACH transmissions triggered by upper layers, if the RRC parameter ssb-ResourceList is provided, the PRACH mask index is indicated by the RRC parameter ra-ssb-OccasionMaskIndex, which indicates the PRACH occasion for the PRACH transmission.

[0256] PRACH epochs are mapped consequently for each SS / PBCH block index. The indexing of the PRACH epoch indicated by the mask index value is reset per mapping cycle of consecutive PRACH epochs for each SS / PBCH block index. The UE selects the PRACH epoch indicated by the PRACH mask index value for the indicated SS / PBCH block index for PRACH transmission within the first available mapping cycle.

[0257] For the above indicated preamble index, the ordering of PRACH epochs is

[0258] > First, for frequency multiplexed PRACH periods, in increasing order of frequency resource indices

[0259] > Second, for the time-multiplexed PRACH periods within the PRACH slot, in increasing order of time resource indices.

[0260] > Third, in increasing order of indexes for PRACH slots

[0261] N rep preamble For PRACH transmissions with multiple preamble repetitions, the set is N, which are consecutive in time and use the same frequency resources and are associated with the same one or more SS / PBCH block index(es). rep preambleIt consists of a set of valid PRACH epochs, and each SS / PBCH block index is associated with the same preamble index within all valid PRACH epochs within the set.

[0262] For PRACH transmission with preamble repetitions, the time interval starting from frame 0 is N SSB Tx For a PRACH transmission with preamble repetitions, a time period, starting from frame 0, is the smallest integer number of association pattern periods such that at least one set of valid PRACH occasions for each of the N SS / PBCH block indices can be determined within the time period for all the configured number of preamble repetitions. SSB Tx SS / PBCH block indexes can be determined within the time period for all configured preamble repetitions. The set(s) of valid PRACH occasions for each configured number of preamble repetitions repeats every time period.

[0263] Within a time interval, N rep preamble N for PRACH transmission with dog preamble repetitions rep preamble For a set(s) of valid preamble repetitions

[0264] > The first valid PRACH epoch of the first set is the first valid PRACH epoch

[0265] > The first valid PRACH epoch of subsequent sets (if any) is determined by the ordering of the valid PRACH epochs.

[0266] >> First, in increasing order of frequency resource indices for frequency multiplexed PRACH periods.

[0267] >> Second, in increasing order of time resource indexes of time multiplexing PRACH periods

[0268] Here, for each frequency resource index for frequency multiplexed PRACH periods,

[0269] > The first valid PRACH epoch of the first set is the first valid PRACH epoch

[0270] > If any, the first valid PRACH period of the subsequent sets is

[0271] >> If the RRC parameter msg1-RepetitionTimeOffsetROGroup is provided, it is msg1-RepetitionTimeOffsetROGroup consecutive valid PRACH occasions in time from the first valid PRACH occassion of the previous set, where each PRACH occassion is associated with the same SS / PBCH block index(es) and each SS / PBCH block index is associated with the same preambles.

[0272] >> If the RRC parameter msg1-RepetitionTimeOffsetROGroup is not provided, it is after the PRACH time of the previous set.

[0273] For PRACH transmissions triggered upon request by upper layers, if the RRC parameter csi-ResourceList is provided, the value of the RRC parameter ra-OccasionList indicates a list of PRACH occasions for the PRACH transmission, where the PRACH occasions are associated with a selected CSI-RS index indicated by the RRC parameter csi-RS. The indexing of the PRACH occasions indicated by ra-OccasionList is reset for each associated pattern interval.

[0274] For paired spectrum (e.g., frequency division duplex (FDD)) or supplementary uplink bands, all PRACH occasions are valid.

[0275] For unpaired spectrum (e.g. time division duplex (TDD) cases),

[0276] > If the UE is not provided with RRC configuration tdd-UL-DL-ConfigurationCommon, the PRACH timing within the PRACH slot shall not precede the SS / PBCH block within the PRACH slot and shall be at least N symbols after the last SS / PBCH block received. gap If it starts after the dog symbols, it is valid, where N gap is provided in the following table and does not overlap with the set of consecutive symbols before the start of the next channel occupancy time (see 3GPP TS 37.213) that the UE does not transmit if the RRC parameter channelAccessMode="semiStatic" is provided.

[0277] >> The candidate SS / PBCH block index of an SS / PBCH block corresponds to the SS / PBCH block index provided by ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon as described in section 4.1 of 3GPP TS 38.213.

[0278] > When the UE is provided with tdd-UL-DL-ConfigurationCommon, the PRACH time within the PRACH slot is valid when:

[0279] >> If it is within the UL symbol, or

[0280] >> It does not precede the SS / PBCH block within the above PRACH slot and is at least N blocks after the last downlink symbol. gap After the dog symbols and after the last SS / PBCH block symbol, at least N gap Starting after the dog symbols, here N gap is provided in the following table, and if channelAccessMode = "semiStatic" is provided, it does not overlap with the set of consecutive symbols before the start of the next channel occupancy time during which there shall be no transmissions (it does not precede a SS / PBCH block in the PRACH slot and starts at least N gap symbols after a last downlink symbol and at least N gap symbols after a last SS / PBCH block symbol, where N gapis provided in the following table, and ifchannelAccessMode= "semiStatic" is provided, does not overlap with a set of consecutive symbols before the start of a next channel occupancy time where there shall not be any transmissions, as described in 3GPP TS 37.213.

[0281] >>> The candidate SS / PBCH block index of the above SS / PBCH block corresponds to the SS / PBCH block index provided by ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon as described in section 4.1 of 3GPP TS 38.213.

[0282] The following table shows N for different preamble SCS u gap Here are some examples of values.

[0283]

[0284] For preamble format B4 described in 3GPP TS 38.211, N gap = 0.

[0285] When a random access procedure is initiated by a PDCCH command, the UE transmits a PRACH within the selected PRACH period as described in 3GPP TS 38.321, if requested by upper layers, wherein the time between the last symbol of PDCCH command reception and the first symbol of the PRACH transmission is N T,2 + T BWPswitchDelay + △ Delay + T switch + T SSB + △RF / BB preparationmsec is greater than or equal to, where

[0286] > N T,2is a time duration of N2 symbols corresponding to the PUSCH preparation time for UE processing capability 1 (see 3GPP TS 38.214), assuming u corresponds to the smallest SCS setting among the SCS setting of the PDCCH command and the SCS setting of the corresponding PRACH transmission.

[0287] > If the active UL BWP does not change or the cell indicator field in the PDCCH command indicates a non-serving cell, T BWPswitchDelay = 0, otherwise T BWPswitchDelay is defined in 3GPP TS 38.133

[0288] > About FR1 △ Delay = 0.5 msec and △ for FR2 Delay = 0.25 msec

[0289] > T switch is the switching gap duration as defined in 3GPP TS 38.214

[0290] > The cell indicator field in the above PDCCH command indicates the serving cell or T if the cell indicator field does not exist. SSB = 0, otherwise T SSB is defined in 3GPP TS 38.133

[0291] > If the cell indicator field in the above PDCCH command indicates a serving cell or the cell indicator field does not exist, △RF / BB preparation = 0, otherwise △RF / BB preparation is defined in 3GPP TS 38.133.

[0292] For PRACH transmission using 1.25 kHz or 5 kHz SCS, the UE determines N2 assuming SCS setting u = 0.

[0293] For single cell operation or operation with contiguous carrier aggregation in the same frequency band or operation with non-continuous carrier aggregation in the same frequency band if the UE is not provided with intraBandNC-PRACH-simulTx-r17, the UE shall:

[0294] > Does not transmit PRACH and PUSCH / PUCCH / SRS in a same slot with respect to the smallest SCS configuration between the SCS configuration for the UL BWP with the PRACH and the SCS configuration for the UL BWP with the PUSCH / PUCCH / SRS transmissions.

[0295] > If the first or last symbol of a PRACH transmission in the first slot is separated by less than N symbols from the last or first symbol of a PUSCH / PUCCH / SRS transmission in the second slot, respectively, the PRACH and PUSCH / PUCCH / SRS are not transmitted.

[0296] > N rep preambleFor a PRACH transmission with >1 preamble repetitions, if the UE does not indicate prach-repetition, the UE does not transmit the first repetition of the PRACH and the second repetition of the PRACH if the first or the last symbol of the first repetition of the PRACH in the first slot is separated by less than N symbols from the last or the first symbol of the second repetition of the PRACH in the second slot, respectively; otherwise, the UE transmits the first repetition of the PRACH and the second repetition of the PRACH.

[0297] Here, N=2 for u=0 or u=1, N=4 for u=2 or u=3, N=16 for u=5, and N=32 for u=6, where u is the smallest SCS setting among the SCS settings for UL BWP with PRACH and the SCS settings for UL BWP with PUSCH / PUCCH / SRS transmissions. For PUSCH transmissions with repetition type B, this applies to each actual repetition for the PUSCH transmission.

[0298] A UE may receive (e.g., via the RACH-related configuration) a parameter ra-ssb-OccasionMaskIndex that sets a PRACH mask index when receiving RACH-related configuration for CFRA, system information (SI) request, and / or beam failure recovery (BFR). Referring to section 8.1 of 3GPP TS 38.213, for a PRACH transmission triggered by higher layer(s), if ssb-ResourceList is provided, a PRACH mask index is indicated in ra-ssb-OccasionMaskIndex that indicates PRACH occasions for said PRACH transmission, where said PRACH occasions are associated with SS / PBCH block indices selected (by the UE). As described in section 8.1 of 3GPP TS 38.213, the parameter ra-ssb-OccasionMaskIndex is a parameter that sets a PRACH mask index for a RACH occasion (RO) and is used by the UE to select a resource for random access (RA). It can be applied to all SSB beams (e.g., all SSB resources) used in the cell through ssb-ResourceList and can be set by including in at least one of the following information elements (IEs). Here, ssb-ResourceList is a list of SSB resource indices used in the cell.

[0299] >BeamFailureRecoveryConfig. IEBeamFailureRecoveryConfig is used to configure the UE with RACH resources and candidate beams for beam failure recovery in case of beam failure detection.

[0300] >RACH-ConfigDedicated. IERACH-ConfigDedicated is used to specify the dedicated random access parameters.

[0301] >SI-RequestConfig. IESI-RequestConfig contains configuration for Msg1 based SI request without Msg1 repetition. For any access parameters not set in SI-RequestConfig (e.g., prach-RootSequenceIndex, msg1-SubcarrierSpacing, etc.), unless otherwise specified, the UE applies the parameters set in the RRC configurationrach-ConfigCommon corresponding to the RACH resource set selected during RACH initialization of the initial uplink BWP.

[0302] >SI-RequestConfigRepetition. IESI-RequestConfigRepetition contains configuration for Msg1 based SI request with Msg1 repetition. For any access parameters not configured in SI-RequestConfigRepetition (e.g., msg1-RootSequenceIndex, msg1-SubcarrierSpacing, msg1-RepetitionTimeOffsetROGroup, etc.), unless otherwise specified, the UE applies the parameters configured in rach-ConfigCommon corresponding to the RACH resource set selected during RACH initialization of the initial uplink BWP.

[0303] If the RACH configuration for the 2-step random access process is referred to as the 2-step RACH configuration, in the case of the 2-step random access process, a parameter msgA-SSB-SharedRO-MaskIndex for configuring the PRACH mask index of RO may be provided within the 2-step RACH configuration. The 2-step RACH configuration may be, for example, RACH-ConfigCommonTwoStepRA, where IERACH-ConfigCommonTwoStepRA is a configuration of cell-specific random access parameters that the UE uses for contention-based and contention-free 2-step random access type processes.

[0304] The UE may be provided with a parameter ssb-SharedRO-MaskIndex that indicates a subset of the 4-phase random access type ROs that are shared with the 2-phase random access type ROs for each SSB. The parameter ssb-SharedRO-MaskIndex is set only when more than one RO is allocated per SSB, and if this field is absent, all ROs are interpreted as shared. The parameter ssb-SharedRO-MaskIndex may be set by being included in at least one of the following IEs.

[0305] >FeatureCombinationPreambles. IEFeatureCombinationPreambles indicates a feature or a combination of features to be associated with a set of random access resources.

[0306] >RACH-ConfigCommonTwoStepRA.

[0307] In some implementations, the UE may be dynamically indicated one of the PRACH mask indices in Table 7.4-1 of 3GPP TS 38.321 via a 4-bit field in DCI format 1_0, where this parameter (e.g., PRACH mask index) is an integer value from 0 to 15 indicating one of the indices in Table 7.4-1 of 3GPP TS 38.321, where the PRACH occassion index is determined by SSB-to-RO mapping. Referring to 3GPP TS 38.213, for example, PRACH occassions are mapped consecutively by their corresponding SS / PBCH block indices (also called SSB indices). The indexing of the PRACH occasion indicated by the mask index value is reset per mapping cycle of consecutive PRACH occasions per SS / PBCH block index. The UE selects for a PRACH transmission the PRACH occasion indicated by the PRACH mask index value for the SS / PBCH block index indicated by the PDCCH order in the first available mapping cycle.

[0308] For example, the PRACH occasion index is indexed as described in 3GPP TS 38.213, and is determined by the parameter ssb-perRACH-Occasion value N, which relates to the number of SSBs mapped per RO. If the value of N is greater than 1, the PRACH occasion index of all ROs is the same, and if the value of N is less than 1, the N PRACH occasions mapped to the same SSB index in the frequency domain can be sequentially indexed starting from the lowest frequency RO.

[0309] The following table is Table 7.4-1 of 3GPP TS 38.321, and illustrates PRACH mask index values. Referring to the following table, an example of how the PRACH mask index is set / indicated is that when the PRACH mask index value (PIV) = 0, it indicates that all ROs of PRACH occasion indices (POIs) are available ROs, and when PIV = 1 to PIV = 8, it means that one RO among POI 1 to POI 8 is available depending on the PIV value, and when PIV = 9, it means that ROs of even POIs are available ROs, and when PIV = 10, it may mean that ROs of odd POIs are available ROs, and the UE may perform RA by selecting an available RO within the first (available) mapping cycle after receiving the PIV.

[0310]

[0311] Figures 17 and 18 illustrate radio access control (RRC) settings that may be used or applied to some implementations of the present specification. In particular, Figure 17 illustrates the CFRA field and the CFRA-SSB-Resource field among the fields in IErach-ConfigDedicated as described in 3GPP TS 38.331, and Figure 18 illustrates a portion of IERACH-ConfigGeneric as described in 3GPP TS 38.331. IErach-ConfigDedicated may be used to specify dedicated random access parameters, and IERACH-ConfigGeneric may be used to specify random access parameters for both regular random access as well as beam failure recovery.

[0312] PRACH masking can also be utilized in contention-free random access (CFRA). CFRA includes CFRA for reconfiguration with sync (e.g., handover) and CFRA based on a PDCCH order (hereinafter, PDCCH order CFRA). In the case of reconfiguration with sync (e.g., handover), the UE is provided with a separate RACH configuration, including a PRACH configuration index for CFRA, via IErach-ConfigDedicated as described in 3GPP TS 38.331. In addition, the UE can be provided with parameters such as an SSB index, a preamble index, and a PRACH mask index.

[0313] For example, referring to FIG. 17, msg1-RepetitionNum in the CFRA field indicates the Msg1 repetition number used for contention free 4-phase random access type, and if the msg1-RepetitionNum field is absent, the UE performs contention free 4-phase random access without Msg1 repetition. Occasions in the CFRA field is used to set RA occasions for contention free random access. ra-ssb-OccasionMaskIndex in the CFRA field is a PRACH mask index explicitly signaled for RA resource selection, and the mask is valid for all SSB resources signaled in ssb-ResourceList. rach-ConfigGeneric in the CFRA field is a setting of contention free random access occasions for CFRA. A part of IERACH-ConfigGeneric given by rach-ConfigGeneric in the CFRA field is illustrated in FIG. 18. CFRA field The ssb-perRACH-Occasion field indicates the number of SSBs per RACH occasion. The TotalNumberOfRA-Preambles field in the CFRA field indicates the total number of preambles used for contention free random access on the RACH resources defined in the CFRA, excluding preambles used for other purposes (e.g., SI requests). The ssb in the CFRA-SSB-Resource field indicates the ID of the SSB transmitted by the corresponding serving cell. The ra-PreambleIndex in the CFRA-SSB-Resource field is the preamble index used by the UE when performing the CFRA to select candidate beams identified by the corresponding SSB. The msgA-PUSCH-Resource-Index in the CFRA-SSB-Resource field identifies the index of the PUSCH resource used for the MsgA CFRA.The PUCCH resource index indicates a valid PUSCH occasion and the associated DMRS resources corresponding to a PRACH slot.

[0314] The UE can be provided with RACH configuration including PRACH configuration index through IERACH-ConfigGeneric, and can be instructed to designate 1:1 preamble index for each SSB beam index used in the cell through ssb-ResourceList.

[0315] For example, referring to FIG. 18, msg1-FDM is the number of PRACH occasions (also called PRACH transmission occasions) that are frequency division multiplexed (FDM) within a time instance, msg1-FrequencyStart is the lowest PRACH transmission occasion in the frequency domain relative to PRB 0, PowerRampingStep indicates the power ramping steps for the PRACH, prach-ConfigurationIndex is the PRACH configuration index, PreambleReceivedTargetPower is the target power level at the network receiver side, PreambleTransMax is the maximum number of RA preamble transmissions performed before the UE (or its MAC entity) declares a failure, ra-ResponseWindow is the Msg2 (RAR) window length in number of slots, and zeroCorrelationZoneConfig is the N used for preamble generation. CS It's a setting.

[0316] Referring to 3GPP TS 38.212, Figures 17 and 18, DCI format 1_0 is used for scheduling PDSCH within a DL cell. The following information can be transmitted via DCI format 1_0 with a CRC scrambled by C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0317] > Identifier for DCI formats - 1 bit

[0318] >> The value of this bit field is always set to 1, indicating the DL DCI format.

[0319] > Frequency domain resource assignment - Ceil{log2(N DL,BWP RB (N DL,BWP RB + 1) / 2)} bits, where N DLBWP RB is given by the size of CORESET 0 if CORESET 0 is set for the cell, and is the size of the initial DL bandwidth part if CORESET 0 is not set for the cell.

[0320] If the CRC of the DCI format 1_0 is scrambled by the C-RNTI and the "Frequency domain resource assignment" field is of all ones, the DCI format 1_0 is for a random access process initiated by a PDCCH order, and all remaining fields are set as follows.

[0321] > Random Access Preamble Index - 6 bits according to ra-PreambleIndex in 3GPP TS 38.321

[0322] > UL / SUL Indicator - 1 bit. If the value of the "Random Access Preamble index" is not all zeros and if the UE is configured with supplementaryUplink in ServingCellConfig in the cell, this field indicates which UL carrier in the cell to transmit the PRACH according to Table 9; otherwise, this field is reserved. IEServingCellConfig is used to configure (add or modify) a UE with a serving cell, which may be a SpCell or an SCell of an MCG or SCG, and the supplementaryUplink field in IEServingCellConfig may contain an IEUplinkConfig providing common uplink parameters of the cell.

[0323] > SS / PBCH index - 6 bits. If the value of the "Random Access Preamble Index" above is not all zeros, this field indicates the SS / PBCH used to determine the PRACH timing for PRACH transmission; otherwise, this field is reserved.

[0324] > PRACH Mask Index - 4 bits. If the value of the "Random Access Preamble Index" is not all zeros, this field indicates the RACH time associated with the SS / PBCH indicated by the "SS / PBCH Index" for the PRACH transmission; otherwise, this field is reserved.

[0325] > Cell indicator - Ceil{log2(C + 1)} bits indicating the cell for the corresponding PRACH transmission, if the UE is configured with the higher layer parameter EarlyUlSyncConfig, where C is the number of candidate cells configured with the higher layer parameter EarlyUlSyncConfig; otherwise 0 bit. The bit field index 0 of the cell indicator field is mapped to the serving cell, and other bit field indexes are mapped to the candidate cells configured with a higher layer parameter EarlyUlSyncConfig according to an ascending order of a candidate identity configured by ltm-CandidateId, with the bit field index 1 mapped to the candidate cell with the smallest candidate identity. IEEarlyUlSyncConfig is used to configure random access resources for early UL synchronization process, and parameter ltm-CandidateId is used to identify L1 / L2 triggered mobility (LTM) candidate configuration.

[0326] > PRACH association indicator - 0 or 1 bit

[0327] >> If the UE is provided with tag2-Id indicating the second timing advance group (TAG) information for the serving cell, and the UE is not provided with coresetPoolIndex, which is the index of the CORESET pool for the CORESET, or is provided with coresetPoolIndex with value 0 for the first CORESETs and coresetPoolIndex with value 1 for the second CORESETs, then 1 bit

[0328] >>> If the UE is provided with SSB-MTC-AddtionalPCI, which is used to configure an additional SSB with a different physical cell identity (PCI) than the serving cell's PCI, this field indicates the PCI associated with the PRACH transmission. Bit field index 0 of this field is mapped to the PCI of the serving cell, and bit field index 1 of this field is mapped to the additional PCI associated with active transmission configuration indicator (TCI) states.

[0329] >>> If the UE is not provided with SSB-MTC-AddtionalPCI, this field indicates a pathloss reference signal (PL-RS) for PRACH transmission. Bit field index 0 of this field is mapped to the DL RS that the DM-RS of the PDCCH order is quasi-collocated with, and bit field index 1 of this field is mapped to the SS / PBCH indicated by the SS / PBCH index field in this DCI format.

[0330] >>> 0 bit otherwise

[0331] > PRACH retransmission indicator - 0 or 1 bit

[0332] >> 1 bit if the UE is configured with the upper layer parameter EarlyUlSyncConfig. If the cell indicated by the Cell Indicator field is a candidate cell, this field indicates initial transmission or retransmission of the PRACH according to Table 10. If the cell indicated by the Cell Indicator field is a serving cell and not a candidate cell, this field is reserved.

[0333] >> Otherwise 0 bits.

[0334] > Reserved bits - the number of bits as determined by:

[0335] >> (12 - Y1- Y2) bits for operation in a cell with shared spectrum channel access in frequency range 1 or when the DCI format is monitored in common search space for operation in a cell in frequency range 2-2; otherwise (10 - Y1- Y2) bits;

[0336] >>> If the UE is not configured with the upper layer parameter EarlyUlSyncConfig, then Y1 = 0; otherwise, Y1 = Ceil{log2(C + 1)}

[0337] >>> If the above "PRACH Association Indicator" field does not exist in this DCI format, Y2 = 0; otherwise, Y2 = 1.

[0338]

[0339]

[0340] For the PDCCH order CFRA, as defined in DCI format 1_0 of 3GPP TS 38.212 described above, the random access preamble index indicates the preamble index, the SS / PBCH index indicates the SSB index, and the PRACH mask index is used to indicate which RO is valid. When CFRA is indicated via the PDCCH order, the UE and the BS use the PRACH configuration provided via the system information block (SIB) rather than rach-ConfigDedicated, and the RACH resource(s) allocated via rach-ConfigDedicated can be configured separately from the RACH resource(s) allocated via SIB1.

[0341] The UE is configured with the information required to transmit a PRACH (e.g., information about time / frequency resources) through the BS's SIB1 or UE-specific RRC signaling, and can transmit the PRACH at RACH occasions (ROs) determined / configured based on the information, and the BS must wake up for each RO and wait for PRACH reception to receive the PRACH that the UE may transmit. Therefore, if the period of the ROs configured for the UE is short, the energy consumption of the BS may be relatively greater than when the period of the ROs is set to be long. However, if the ROs are configured with an excessively long period for the purpose of saving the BS's energy, if there is no RO resource near the time when the UE needs to transmit a PRACH for cell access, the UE may have to wait until the next RO resource becomes available before transmitting, which may increase the access delay, and this may lead to a scheduling delay, which may cause a degradation in the performance of the UE. In addition, the BS can save energy by switching to sleep mode when the number of connected mode UEs is small or there is a time period with no data activity temporarily depending on the situation in the cell. However, since the BS must wake up frequently to check for PRACH transmitted by UEs in the RO set in the cell periodically and receive, it cannot stay in sleep mode for a long time and it is difficult to expect a large energy saving benefit. Therefore, in such cases, setting the RO periodicity to a long time may be advantageous in terms of BS energy saving. However, according to the current standard, only semi-static methods (such as SI modification) are possible to change the settings such as the cell RO periodicity, which takes a relatively long time and may make it difficult to quickly respond to opportunities for energy saving.

[0342] Taking this into account, some implementations of this specification may perform common channel adaptation to adjust the density and / or periodicity of PRACH epochs at the request of the BS or UE.

[0343] Figure 19 illustrates RO adaptation through sparse and dense RACH occasions (ROs) according to some implementations of the present specification.

[0344] Referring to FIG. 19, the BS sets (in the time domain) sparse ROs and dense ROs that can be dynamically activated or deactivated (for a cell or BWP), and normally operates only according to the sparse ROs for energy saving, but when certain conditions are satisfied, such as when the initial access delay of a UE increases or when the number of UEs transmitting RACH in one RO increases and causes congestion, the BS can activate the dense ROs (in the time domain) based on a request from the UE(s) or a dynamic indication by the BS (e.g., via a group common DCI and / or MAC control element (CE)), thereby providing an opportunity to save energy for the BS while minimizing performance degradation. FIG. 19 illustrates a case where sparse ROs may correspond to legacy PRACH resources and dense ROs correspond to additional PRACH resources that are turned ON / OFF by activation / deactivation instructions, but it is also possible that the additional PRACH resources are configured as sparse (in the time domain) more than the legacy PRACH resources and that the additional PRACH resources are activated / deactivated.

[0345] In some implementations, for adaptation of PRACH in the time domain, additional PRACH resources may be configured based on at least a PRACH configuration index. The PRACH configuration index may be the same as or different from the PRACH configuration index for legacy PRACH resources. If the PRACH configuration index for the additional PRACH resources is the same as the PRACH resource configuration for the legacy resource, additional parameters for determining the additional PRACH resources may be provided. In some implementations, the additional parameters may include, for example, a scaled / adjusted PRACH configuration period, an additional timing offset, adjusting parameters of the PRACH configuration (e.g., (x, y) values ​​and slot numbers), and / or muting / masking ROs. If the PRACH configuration index for the additional PRACH resources is different from the PRACH configuration index for the legacy resource, an additional mechanism for determining the PRACH resources may be used. In some implementations, muting / masking ROs may be used as an additional mechanism (e.g., when the PRACH configuration index for additional PRACH resources includes legacy resources). In some implementations, additional parameters may be used to facilitate condensed / clustered RACH resources in the time domain.

[0346] In some implementations, methods for configuring and adapting additional ROs through PRACH masking / muting may be considered. These may include configuring additional PRACH resources (hereinafter, A-ROs) using a legacy PRACH configuration index and additional parameters (e.g., subframe-level or slot-level offsets) and then configuring actual effective ROs through muting / masking, or configuring a PRACH configuration index for additional PRACH resources separately from the legacy PRACH configuration index and then configuring actual effective ROs through muting / masking.

[0347] Since the UE can assume that only the ROs indicated by the PRACH mask index among the configured ROs are available and select and use them during a random access process, the BS can perform RO adaptation through PRACH masking when it wants to use only specific ROs to save energy.

[0348] Below, some implementations of this specification are described, such as how to set up additional PRACH resources for energy conservation of the BS, and / or how to adapt RACH timing for contention-free random access (CFRA) (e.g., via PRACH masking or muting).

[0349] <Method #A> PRACH masking / muting method using the reserved state of the PRACH mask index value table or using a new table

[0350] In order to achieve frequency / time domain RO adaptation in terms of energy saving of BS, a more flexible RO adjustment method may be required. Accordingly, among the PRACH mask indices defined in Table 8, the PRACH mask indices for the reserved states that are not in use can be configured / defined to be utilized for additional PRACH epoch index (group) indications, or to be utilized for new PRACH epoch index indications by overriding the allowed PRACH epochs that can be indicated by the existing PRACH mask index values. Accordingly, the mapping relationship between the existing PRACH mask index values ​​defined in Table 8 and the PRACH epoch indices can be newly defined or established. Alternatively, a table of PRACH mask index values ​​for RO (e.g., A-RO) for NES may be separately defined in a standard document or configured by BS to UE(s), and it is also possible that the PRACH mask index values ​​may be reinterpreted as a separate PRACH mask index value table / state according to the SSB-to-RO mapping ratio (e.g., ssb-perRACH-Occasion(N)). For example, the allowed PRACH occasion index corresponding to the PRACH mask index value may be different for each N value, or a separate PRACH mask index value table may be defined / configured for each N value.

[0351] The UE can be configured with a PRACH occassion index (group) that can be indicated by a PRACH mask index value via higher layer signaling such as SIB / RRC (or in a standard document, etc.). For example, the UE can be configured with additional allowed PRACH occassion indices for the existing reserved state via SIB / RRC, such as PRACH mask index value 11 = PRACH occassion indices 1, 2, 3, 4, PRACH mask index value 12 = PRACH occassion indices 5, 6, 7, 8. In this case, if the PRACH mask index value 11 is configured / indicated via RRC or DCI format 1_0, the UE and BS can assume that only PRACH occassions 1, 2, 3, 4 are configured / indicated as available ROs. This means that when ssb-perRACH-Occasion(N) = 1 / 4 and FDMed RO = 4, and the number of SSB indices used in the cell is 2, the ROs can be regulated through a masking operation that allows only one RO group among the four FDMed PRACH occasions 1, 2, 3 and 4 or PRACH occasions 5, 6, 7 and 8 for a particular symbol as RA resources. Alternatively, depending on the configuration (e.g. for A-RO), instead of considering a PRACH occassion index indicated by a particular PRACH mask index value as an allowed RO, it can be set / indicated as an unused muted RO that is muted.

[0352] <Method #B> A method of masking / muting the PRACH occasion index by reinterpreting the PRACH occasion index as an SSB index (with SSB index) according to the ssb-perRACH-Occasion(N) value set for the UE.

[0353] As explained above, the number of ROs mapped per SSB index varies depending on the ssb-perRACH-Occasion (N) value set for the UE, and when N is greater than 1, the PRACH occasion indices of all ROs are the same, so only some ROs cannot be set / designated as allowed ROs by using the method of masking a specific RO (group) by indicating the current PRACH mask index value.

[0354] Therefore, when the ssb-perRACH-Occasion(N) value is less than 1, a method of setting / instructing masking for a specific PRACH occasion index in the same way as before or in the same way as Method #A can be considered, and when the ssb-perRACH-Occasion(N) value is greater than 1, a method of reinterpreting the PRACH occasion index in Table 8 as an SSB index can be considered to mask only a specific PRACH occasion index as an allowed RO. For example, if the PRACH mask index value (PIV) = 0, it may be interpreted that ROs associated with all SSB indices are indicated as available ROs, and for PIV = 1 to PIV = 8, only ROs associated with each SSB index are reinterpreted as available ROs depending on the PIV value, for PIV = 9, only ROs associated with even SSB indices are reinterpreted as available ROs, and for PIV = 10, only ROs associated with odd SSB indices are reinterpreted as available ROs. Alternatively, a table of PRACH mask index values ​​for ROs for NES (e.g., A-RO) may be defined separately in a standard document or configured by the BS to UE(s), and the PRACH mask index values ​​may be reinterpreted as a separate PRACH mask index value table / state depending on the SSB-to-RO mapping ratio (e.g., ssb-perRACH-Occasion(N)). For example, the allowed PRACH timing index corresponding to the PRACH mask index value may be different for each N value, or a PRACH mask index value table may be defined / set separately for each N value.

[0355] <Method #C> A method of muting / masking RO through a time domain index or starting OFDM symbol index in a RACH slot.

[0356] Since the RO masking operation through setting / indication of the PRACH mask index value is performed based on the PRACH epoch index, it can be set / indicated only after the SSB to RO mapping is performed. In addition, the current PRACH epoch index is assigned in a frequency first, time second manner. For example, depending on whether there is an FDM RO set for the symbol, the FDM ROs are sequentially indexed starting from the lowest index for the lowest FDM RO in the frequency axis, and then indexed in the order of the lowest FDM RO of the RO set for the next symbol. Therefore, although there is a frequency domain index for PRACM masking, the time domain index is not separately defined. Therefore, if the time domain index is defined and the BS sets the time domain index to the UE, in addition to the RO masking of specific PRACH epoch indices through the PRACH mask index, RO adaptation can also be performed through the setting / indication of the time domain index.

[0357] For example, a method of masking allowed ROs by defining a starting OFDM symbol index or a time domain index may be considered. Since the starting OFDM symbol index is determined for each RO, if one of them is indicated, the entire RO and FDMed ROs allocated to the corresponding symbol may be regarded as allowed ROs or unavailable, or all ROs located in symbols after the indicated RO within the slot may be set / indicated to be interpreted as available or unavailable.

[0358] <Method #1> How to set up / adjust additional PRACH resources (e.g., A-RO) through PRACH masking / muting

[0359] In order to ensure that the UE's connection delay is not too long while still achieving some energy saving benefits for the BS, some implementations of this specification consider providing a default RO configuration (relatively sparse ROs) for legacy UEs and configuring additional ROs for NES UEs (e.g., UEs supporting the NES feature). Hereinafter, ROs for UEs supporting the NES feature or UEs requiring additional ROs for other reasons are referred to as additional ROs (A-ROs), and a configuration for at least one additional RO is referred to as an A-RO configuration. Additional ROs configured according to some implementations of this specification are not limited to NES technologies.

[0360] In some implementations of this specification, the A-RO configuration may be provided together with the default RO (D-RO) configuration or may be provided separately. In some implementations, RO for legacy UEs may mean RO resources for the 4-phase random access procedure of 3GPP Release-15, RO resources for the 2-phase random access procedure of 3GPP Release-16, RO resources for reduced capability (Redcap) UEs of 3GPP Release-17, or RO resources for coverage enhancement (CE) of 3GPP Release-18. There may be one or more A-RO configurations. Different RO patterns / periodicity, etc. may be configured for each A-RO configuration, and switching between A-RO configurations may be indicated for NES-capable UEs through a pre-configured / defined index, either activated or already activated. One or more A-RO configurations may be provided via SIB1, similar to D-RO configurations, or may be configured via other RRC signaling.

[0361] An NES-capable UE can be configured by the BS to use only A-RO or to use both D-RO and A-RO among the ROs configured. If there is no separate configuration for this, an NES-capable UE can be interpreted as being configured to use both D-RO and A-RO. Even when an NES-capable UE is configured to use both D-RO and A-RO, normally A-RO is deactivated and all UEs (e.g., both legacy UEs and NES-capable UEs) can use only D-RO, and A-RO can be activated by dynamic indication from the BS (upon the request of the UE). Alternatively, when the activation (deactivation) of A-RO is indicated, the activation (deactivation) of D-RO may be indicated together or separately.

[0362] To aid in understanding some implementations of this specification, the PRACH settings according to the current standard document are first described with reference to the following table and Figure 20.

[0363] The following table illustrates random access configurations. In particular, the table is part of Table 6.3.3.2-4, which defines random access configurations for FR2 and unpaired spectrum, as described in 3GPP TS 38.211.

[0364]

[0365] The table above is a mother table for indicating the PRACH configuration index in 3GPP TS 38.211. The UE determines an appropriate table from SIB1 based on the frequency range and whether it is frequency division duplex (FDD) or time division duplex (TDD), and is instructed to configure RACH slots and ROs by receiving an index of one row in the determined table. Based on the PRACH configuration index (also referred to as the RACH configuration index), the UE can know an available set of PRACH occasions for transmitting a random access preamble for Msg1.

[0366] Figure 20 illustrates examples of random access channel (RACH) slots and RACH occasions (ROs) according to physical random access channel (PRACH) configurations. In particular, Figure 20 illustrates RACH slots and ROs when PRACH configuration index 9 is provided through RACH configuration for cells on FR2 and unpaired spectrum.

[0367] Referring to Table 11 and Figure 19, if PRACH setting index = 9 based on Table 11 is provided, first n f The periodicity of the RO in the SFN unit in the time domain is determined through mod x = y. Since (x, y) = (2, 1), there can be an RO for every odd SFN with a period of 20 ms, and the RACH slot within the frame of the corresponding SFN is set / determined through the slot number.

[0368] In some implementations of this specification, a UE may be configured for D-RO and A-RO via multiple PRACH configuration indices within a single PRACH configuration, or via separate PRACH configurations that may have different PRACH configuration indices. For example, a BS may provide a first PRACH configuration index for D-RO and a second PRACH configuration index for A-RO in a single RACH configuration, or may provide a RACH configuration for D-RO that includes a first PRACH configuration index for D-RO and a PRACH configuration for A-RO that includes a second PRACH configuration index for A-RO. A UE provided with a first PRACH configuration index and a second PRACH configuration index may determine ROs based on which PRACH configuration index(es) among the first PRACH configuration index and the second PRACH configuration index are activated.

[0369] For example, A-RO is n of D-RO f It can be set by adding or subtracting an offset to the x value and / or y value used in the calculation for mod x = y, or by setting an index value other than PRACH configuration index 9 to the UE.

[0370] In summary, the BS can 1) configure additional PRACH resources (e.g., A-RO) via a legacy PRACH configuration index and additional parameters (e.g., subframe-level or slot / symbol-level offset, x and / or y values, etc.) and set actual effective ROs via muting / masking and dynamically adapt the ROs, or 2) configure a PRACH configuration index for additional PRACH resources separately from the legacy PRACH configuration index, set actual effective ROs via muting / masking, and dynamically adjust the corresponding effective ROs via (group-common) DCI or MAC CE.

[0371] First, the UE needs to select an actual valid RO among the configured A-ROs through PRACH masking / muting. Parameters for masking / muting (e.g., ra-ssb-OccasionMaskIndex-R19) can be configured together with additional parameters for the aforementioned A-RO configuration (e.g., subframe-level or slot / symbol-level offset, x and / or y values, etc.) or separate additional PRACH configuration, and the UE can be provided with allowed PRACH occasions or muted PRACH occasions through the configured masking / muting parameters among all configured A-ROs.

[0372] For example, referring to Table 11, if ra-ssb-OccasionMaskIndex-R19 = 1, only the RO corresponding to the PRACH occassion index 1 among the A-ROs is considered a valid RO or only that RO can be muted. Additionally, in the case of A-ROs, the RO corresponding to the PRACH occassion index 1 and the FDMed ROs may be considered as valid ROs together or all FDMed ROs may be muted. Alternatively, the BS and the UE may reinterpret the PRACH occassion index as an SSB index (with SSB index) and consider or mute only the RO corresponding to the SSB index or the RO and all FDMed ROs as allowed ROs. Additionally, the UE may be instructed to dynamically perform PRACH masking / muting for the valid ROs configured in this way through (group-common) DCI or MAC CE. For example, if a PRACH mask index value = 2 is indicated through a 4-bit field in DCI format 1_0, the RO corresponding to PRACH period index 2 and the FDMed ROs can be dynamically deactivated.

[0373] Alternatively, the BS and the UE may reinterpret the allowed PRACH occasions indicated by the PRACH mask index value by the index value set by SIB / RRC by applying the aforementioned Method #A, Method #B, or Method #C (e.g., if the PRACH mask index value is indicated, use the PRACH index value set by SIB / RRC for the PRACH mask index value instead of using the PRACH index value defined in the standard (e.g., see Table 8)), or perform masking / muting through a separately set / defined PRACH mask index table, or mute / mask A-RO through a time domain index or a start OFDM symbol index in the RACH slot.

[0374] <Method #2> How to set / adjust additional PRACH resources (hereinafter, A-RO) for CFRA through PRACH masking / muting

[0375] When A-RO, which can be dynamically activated (deactivated) with D-RO, is configured for energy saving of BS, it is necessary to configure / indicate whether A-RO is also configured / used for CFRA, and in that case, whether the UE applies PRACH masking / muting only to D-RO or applies masking / muting to both A-RO and D-RO to select RO for CFRA.

[0376] The UE may receive the following configuration / instruction from the BS, for example, for cases where A-RO can also be used for CFRA:

[0377] 1) How to set PRACH masking / muting to apply only to D-RO

[0378] 2) How to set PRACH masking / muting to apply only to A-RO

[0379] 3) How to set PRACH masking / muting to apply to the entire D-RO and A-RO

[0380] 4) How to set one of the above options to be applied depending on whether A-RO is valid (or activated)

[0381] 5) How to receive instructions on which of the above options to apply through the PDCCH command DCI

[0382] When PRACH masking / muting is configured to be applied only to D-ROs, the UE may select allowed PRACH occasions by applying a pre-configured (handover command) masking parameter (e.g., ra-ssb-OccasionMaskIndex) to the D-ROs as before or by applying a PRACH mask index value dynamically indicated via a PDCCH command (e.g., DCI format 1_0) to select an RO for CFRA among the allowed PRACH occasions. In some implementations, the UE may interpret the masked allowed PRACH occasions as muted PRACH occasions for the purpose of R19 NES and may consider the ROs invalid and select an RO for CFRA among the remaining ROs. Furthermore, in some implementations, the BS and the UE may configure both the ROs with masking configured / indicated and the FDMed ROs to be allowed ROs or mute them all, depending on the configuration.

[0383] When PRACH masking / muting is configured to be applied only to A-RO or to both D-RO and A-RO, the UE may apply the masking / muting method for D-RO described above to A-RO or to the entire RO including D-RO and A-RO. In this case, if A-RO is deactivated and thus invalid, masking / muting for A-RO may be omitted.

[0384] Alternatively, the BS can preset which method to apply depending on the validity (or activation) of A-RO. For example, the UE can be configured to apply PRACH masking / muting to both D-RO and A-RO when A-RO is activated, and to apply PRACH masking / muting only to D-RO when A-RO is deactivated. In this case, if A-RO is valid when the UE receives the PDCCH command, the UE can perform CFRA on the resources indicated by the DCI while considering both D-RO and A-RO. If A-RO is invalid, the UE can perform CFRA on the resources indicated by the DCI while considering only D-RO, similar to the legacy CFRA PRACH masking. Alternatively, the option to be applied can be dynamically indicated through a specific field in the PDCCH command DCI for CFRA. Alternatively, one of the two preset options can be indicated in the form of a 1-bit flag. For example, a 1-bit flag in the DCI for the PDCCH command may indicate whether A-RO as well as D-RO is available when the UE selects resources for a CFRA. The UE may select an RO for a PRACH transmission triggered by the PRACH indication from among the available ROs. In some implementations, if A-RO is indicated to be available, the UE may determine both D-RO and A-RO to be available ROs and perform RO selection after applying PRACH masking / muting to both D-RO and A-RO, and if A-RO is indicated to be unavailable, the UE may determine only D-RO to be available RO and apply PRACH masking / muting only to D-RO and perform RO selection.

[0385] At this time, as a masking / muting method of D-RO / A-RO for CFRA, the BS and UE may apply Method #A, Method #B, or Method #C to reinterpret the allowed PRACH timing indicated by the PRACH mask index value with the index value set by SIB / RRC (for example, if the PRACH mask index value is indicated, use the PRACH index value set by SIB / RRC for the PRACH mask index value instead of using the PRACH index value defined in the standard (e.g., see Table 8)), or perform masking / muting through a separately set / defined PRACH mask index table, or mute / mask A-RO through a time domain index or a start OFDM symbol index in the RACH slot.

[0386] Meanwhile, in the case of CFRA for handover (HO) in the current NR, parameters such as PRACH configuration index, PRACH configuration, SSB index, preamble index, and PRACH mask index are configured by rach-ConfigDedicated, and masking / muting cannot be applied to A-RO configuration for CBRA. Therefore, a method of including masking parameters (e.g., ra-ssb-OccasionMaskIndex-R19) for masking / muting together with parameters for A-RO configuration (e.g., time offset or scaling value) in RACH-ConfigCommon configured by SIB1 may be considered.

[0387] In method #2 of this specification, when PRACH is triggered via DCI format 1_0 with C-RNTI for PRACH adaptation for a connected mode UE (i.e., when PRACH transmission is triggered by a PDCCH command), the availability of additional PRACH resources (i.e., A-RO) may be indicated via a 1-bit field in the DCI, and when the 1-bit field indicates that A-RO is available, the A-RO may be considered valid for a duration / timer set by a higher layer signal from a pre-configured or standard-defined reference point. When a value '1' of the 1-bit field indicates that A-RO is available, the UE may apply a PRACH mask index indicated via a 4-bit PRACH mask index field in the DCI to D-RO and A-RO, respectively. After applying the PRACH mask, it may be necessary to define / configure which of the allowed D-ROs and A-ROs the UE will select to transmit the PRACH.

[0388] In some implementations, A-ROs can be obtained by 1) applying a separately configured frequency offset value to ROs configured by the same PRACH configuration index as the PRACH configuration index for D-ROs, and the remaining ROs can be configured as valid A-ROs after excluding ROs that overlap with the D-ROs in the frequency / time domain (e.g., time and frequency domains), or 2) applying a separately configured frequency offset value to ROs configured by a different PRACH configuration index from the PRACH configuration index for D-ROs, and similarly, among ROs determined to be A-ROs, the remaining ROs can be configured as valid A-ROs after excluding ROs that overlap with the D-ROs in the frequency / time domains. In addition, after performing SSB-to-RO mapping on the valid A-ROs configured by method 1) or 2), a semi-statically configured PRACH association (pattern) section or a SFN-based PRACH mask can be selectively applied.

[0389] If a PRACH is triggered by a PDCCH command without a separate priority being set between D-RO and A-RO for the UE in advance, and both D-RO and A-RO are available, in some implementations, the UE may perform RO selection differently depending on whether the PRACH configuration index of the A-RO configuration is the same as or different from the PRACH configuration index of the D-RO configuration. For example, if the PRACH configuration index of the A-RO is the same as the PRACH configuration index of the D-RO, the UE may select the earliest available RO after the processing time from the time of receiving the DCI and transmit the PRACH regardless of the RO type. Otherwise, the UE may prioritize the A-RO and select the A-RO located at the earliest time after the processing time from the time of receiving the DCI and transmit the PRACH. Alternatively, the UE may prioritize the D-RO and select the D-RO located at the earliest time to transmit the PRACH. As another example, if the PRACH configuration index of A-RO is the same as the PRACH configuration index of D-RO, the A-RO located at the earliest point in time after the processing time from the time of receiving DCI is selected to transmit the PRACH, or conversely, the D-RO is given priority and the D-RO at the earliest point in time is selected to transmit the PRACH, and if they are different, the PRACH can be transmitted by selecting the available RO at the earliest point in time regardless of the RO type.

[0390] Meanwhile, in some implementations, when RO adaptation is indicated via a specific (group-common) DCI (e.g., DCI format 1_0 with P-RNTI / C-RNTI / SI-RNTI or DCI format 2_7 / DCI format 2_9, etc.) (i.e., when there is an A-RO availability indication via (group-common) DCI), a reference point needs to be defined for when the UE can actually assume A-RO is available after receiving said (group-common) DCI. The following Options can be considered as reference points:

[0391] * Option 1: SFN of the first PF from the next I-DRX cycle

[0392] * Option 2: SFN of the first PF from the current I-DRX cycle

[0393] * Option 3: From the first frame of the first PRACH association period after the UE receives the DCI

[0394] * Option 4: From the first frame of the current SI modification period

[0395] * Option 5: From the first frame of the next SI modification period

[0396] However, for example, if the RO adaptation indication is indicated via DCI format 1_0 with P-RNTI (also called paging DCI), the timing of receiving the RO adaptation indication may vary among IDLE or INACTIVE mode UEs since the locations of the POs that they need to monitor within the paging frame (PF) may be different. In IDLE or INACTIVE state, a UE performs paging monitoring on every PO for itself, whereas in CONNECTED mode, a UE only needs to monitor any PO within the SI modification interval, so the timing of receiving the RO adaptation indication may vary significantly among UEs. Therefore, a method may be considered in which the endpoints of the A-RO valid or available time intervals (or the timer expiration times) are aligned to be the same for all UEs, regardless of whether the reference point is determined by one of the above Options. For example, if a specific (group-common) DCI indicating RO adaptation is received at a different monitoring occasion (MO) for each UE, a pre-configured A-RO availability timer / period is started for each UE from a reference point (which may be pre-configured by the BS as one of the above Options or defined in a standard document), and the UE can assume that A-RO is available until the end of the specific SI modification interval in which the RO adaptation indication was received. Consequently, even if the start points of the timers / periods are different because the points in time when RO adaptation is instructed are different for each UE, the end points of the timers / periods can be identically set for all (RRC state) UEs.

[0397] Alternatively, the RO adaptation may be maintained (e.g., assuming A-RO is available) until the end of the SI modification interval, which includes the time when the A-RO availability timer expires or the end of the period from the reference point. Alternatively, the UE may be configured with different A-RO availability / validity timer / duration values ​​depending on the PO / PF (group) to which it belongs. For example, the timers / durations configured by the BS for each PO / PF (group) may all have the same expiration or ending time.

[0398] <Method #3> In case there are multiple ROs / RO groups / SSB-to-RO mapping cycles / associated sections within an SSB-to-RO mapping cycle / associated (pattern) section, a method of indexing by specific unit (e.g., RO / RO group unit or mapping cycle unit) and masking / muting the cycle corresponding to the index set / indicated by MAC CE / DCI.

[0399] The RRC parameters and related standards related to the association period are as follows.

[0400] >MSG1-FDM(msg1-FDMinRACH-ConfigGeneric) within RACH-ConfigGeneric: The number of ROs FDM'd in a single time instance. One of {1, 2, 4, 8} is set as the msg1-FDM value.

[0401] >occasionsinssb-perRACH-Occasion(ssb-perRACH-Occasioninoccasions): If N < 1, one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH occasions. If N ≥ 1, all consecutive N SS / PBCH block indexes are associated with one PRACH occasion.

[0402] > If there are any PRACH epochs that are not associated with SS / PBCH block indices after an integer multiple of the associated intervals, they are not used for PRACH transmissions.

[0403] Figure 21 illustrates an association interval according to the number of SSBs per RACH period. The association interval is N given by ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon. SSB TX is the minimum interval (e.g., minimum number of PRACH configuration periods) required to map the SSB indices to valid PRACH occasions at least once. In the example of Fig. 21, it is assumed that the number of time domain ROs within 10 ms = 1, the number of frequency domain ROs = 4, and the number of actually transmitted SSBs = 6. In this case, referring to Fig. 21(a), the association interval for ssb-perRACH-Occasion = 1 is 20 ms, and referring to Fig. 21(b), the association interval for ssb-perRACH-Occasion = 2 is 10 ms.

[0404] Figure 22 illustrates an association interval considering a valid RACH period. Referring to Figure 22, for example, if the PRACH configuration interval = 10 ms, the number of time domain ROs within 10 ms = 3, the number of frequency domain ROs = 1, and the number of actually transmitted SSBs = 4, the first RO becomes invalid due to SSB, so the association interval is 20 ms, and since the SSB to RO mapping cycle cannot be satisfied with one remaining RO within the association interval, the remaining RO is not used for PRACH transmission.

[0405] Figure 23 illustrates the association pattern interval and SSB-to-RO mapping considering the valid RACH period.

[0406] An association pattern period includes one or more association periods and is determined so that a pattern between PRACH occasions (i.e., RO occasions) and SS / PBCH blocks repeats at most every 160 msec. An association pattern period may be N due to a TDD pattern or from the SSB or the last DL symbol in a PRACH slot. gap This was introduced to reduce the computational complexity for SSB-to-RO mapping, since the number of ROs within the association interval may not be constant when an invalid RO occurs due to the condition that there will be a number of ROs after the dog symbols. For example, if the UE performs RO validation or SSB-to-RO mapping every time, the complexity of the UE would be too large. Therefore, an association pattern interval can be used to repeatedly apply the mapping relationship to reduce the complexity of the UE.

[0407] Referring to FIG. 23, for example, if the number of time domain ROs within 10 ms = 4, the number of frequency domain ROs = 1, and the number of actually transmitted SSBs = 3, then in SFN #0 the association interval = 10 ms, but since the number of valid ROs in SFN #1 is only 2, a 20 ms annual interval is required for 3 SSBs to be mapped at least once to valid ROs within the association interval. Therefore, in the example of FIG. 23, in order for the mapping pattern between RACH epochs and SSB indices to repeat, the annual interval pattern must include an annual interval of 10 ms and an association interval of 20 ms, and thus the annual interval pattern is 30 ms.

[0408] Referring to Fig. 23, when the association interval is 10 ms, the SSB-to-RO mapping is performed once within the 10 ms association interval, but when the number of available ROs is sufficient, such as in SFN #1 and SFN #2 where the association interval is 20 ms, all SSB indices #0, #1, and #2 for the number of actually transmitted SSBs = 3 can be mapped twice within the association intervals of SFN #1 and SFN #2.

[0409] In this way, when an SSB-to-RO mapping cycle / association (pattern) interval is defined for an RO set to a UE, and there are multiple ROs or RO groups within an SSB-to-RO mapping cycle, or multiple SSB-to-RO mapping cycles within an association interval, or multiple association intervals within an association pattern interval, the UE and BS can index the ROs by each unit (e.g., mapping cycle) and mask / mute the ROs corresponding to the index set / indicated by MAC CE / DCI.

[0410] A bitmap may be configured within the MAC CE / DCI, and each 1 bit of the bitmap may be one of 1) an RO or a group of ROs (e.g., time-division multiplexed (TDM) ROs), 2) an SSB-to-RO mapping cycle, or 3) an associated (pattern) interval, and which of these may be defined in advance (e.g., in a standard) or set by the BS to the UE(s). If an N-bit bitmap is used, the starting reference point of a unit (e.g., an SSB-to-RO mapping cycle) indicated by the bitmap may be, for example, the first RO or RO group from SFN 0, and the first RO or RO group corresponds to the first bit of the bitmap, the N-th RO or RO group corresponds to the N-th bit of the bitmap, and so on, and the bitmap may be applied cyclically thereafter. As another example, if the bitmap indicates one of multiple mapping cycles within the associated section, the SSB-to-RO mapping cycle that will arrive earliest based on the time point at which MAC CE / DCI is received may be set to correspond to the first bitmap of the bitmap. In this case, the value N, which is the size of the bitmap, may also be separately defined (in a standard, etc.), set (by the BS), or determined by a rule. For example, if the number of SSB-to-RO mapping cycles within the associated section is 4, it may be determined that N=4 when each bit of the bitmap corresponds to one SSB-to-RO mapping cycle.

[0411] As another example, when there are multiple associated sections within a single associated pattern section, the bits in the bitmap may be assigned / mapped one-to-one for each associated section (or associated section group), so that ON / OFF of ROs within each associated (pattern) section may be indicated on an associated section basis. If the number of SSB-to-RO mapping cycles within the associated section is greater than the size of the bitmap, for example, when N=4 and the number of mapping cycles within the associated section is 8 (or more), the BS may group and associate the SSB-to-RO mapping cycles, or may map the SSB-to-RO mapping cycles to each state that can be indicated by the PRACH mask index value, and indicate ON / OFF of ROs within each associated (pattern) section using all 16 states. Alternatively, the BS and UE can apply the bitmap information as is to the SSB-to-RO mapping cycle located in the first half (front) of the associated section, and also apply the bitmap information as is to the SSB-to-RO mapping cycle located in the second half (back) of the associated section.

[0412] Meanwhile, when masking / muting is indicated in the form of a bitmap, if each 1-bit in the bitmap corresponds / maps to one RO (group) or mapping cycle, the reference point below can be the starting point of each associated (pattern) section. For example, assuming that the bitmap size is set to 4 bits, each 1-bit corresponds to one mapping cycle, and there are a total of 10 mapping cycles in one associated (pattern) section, the 4-bit bitmap can be applied twice repeatedly for the first 8 cycles, and only the first 2 bitmaps in the bitmap are applied for the remaining 2 cycles, and then the bitmap can be applied again for the next associated (pattern) section in the same manner as above, where 4 bits + 4 bits + first 2 bits of the bitmap are applied. When this method is used, there is an advantage that the original associated (pattern) section (determined according to the RO mapping pattern) is maintained even if the bitmap is applied.

[0413] <Method #4> A method of setting a masking / muting pattern of a specific unit in the existing PRACH mask index value table or defining / setting a new table through a higher layer signal such as RRC / SIB to instruct the UE to perform A-RO masking / muting.

[0414] According to method #1 of this specification, the existing PRACH mask index value table may be reinterpreted or a table consisting of new PRACH epoch indices may be established for R19 NES capable UEs. In addition, according to method #3, in case there are multiple ROs / RO groups / SSB-to-RO mapping cycles / association (pattern) intervals within an SSB-to-RO mapping cycle / association (pattern) interval, ROs may be indexed and masked / muted via DCI in specific units (e.g., RO / RO group units or mapping cycle units).

[0415] By combining the above two methods according to Method #1 and Method #3, each index of the existing PRACH mask index value table can be reinterpreted in a specific unit (RO unit / RO group unit or mapping cycle unit) for the R19 NES capable UE, or a separate table (for NES) in which PRACH mask indices are defined in a specific unit can be defined in a standard document, etc., or can be set to the UE by the BS.

[0416] For example, if UE(s) are configured via RRC / SIB to reinterpret the existing table (e.g., see Table 8) on a per SSB-to-RO mapping cycle basis for A-RO, and PRACH mask index #1 is configured to mask / mute the first SSB-to-RO mapping cycle (e.g., SSB-to-RO mapping cycle index 1) within the associated interval, the UE instructed with that index can consider all ROs within the first SSB-to-RO mapping cycle for each associated interval as allowed A-ROs or all muted ROs.

[0417] As another example, if a new table is defined in the standard document or set by the BS for A-RO per association interval, and PRACH mask index #1 is set to mask / mute the first association interval (e.g., the association interval of association interval index #1) within the association pattern interval, the UE indicated by that index can consider all ROs within the first association interval for each association pattern interval as allowed A-ROs or all muted ROs.

[0418] More specifically, in some implementations, a legacy PRACH mask index table #1 (see Table 8) and a new PRACH mask index table #2 (for PRACH mask index for NES) can be generated, and for each index (code-point) of the new table #2, various types can be configured by mixing multiple unit masking / muting patterns, such as SSB-to-RO mapping cycles and / or associated (pattern) sections. For example, PRACH mask index #0 in new Table #2 may be configured to indicate that all ROs are allowed A-ROs or all ROs are muted ROs, mask indices #1, #2, #3, and #4 may be configured to correspond respectively to SSB-to-RO mapping cycles #1, #2, #3, and #4, mask index #5 may be configured to correspond to SSB-to-RO mapping cycles #1 and #2, mask index #6 may be configured to correspond to SSB-to-RO mapping cycles #3 and #4, mask index #7 may be configured to correspond to SSB-to-RO mapping cycles #1, #2, and #3, mask index #8 may be configured to correspond to SSB-to-RO mapping cycles #2, #3, and #4, and mask indices #9 and #10 may be configured to correspond respectivly to associated intervals #1 and #2, respectively.

[0419] The BS can configure in advance via RRC or configure / instruct the UE via PDCCH command DCI which of these tables to utilize for A-RO masking / muting. In some implementations, more than one new table can be configured, and multiple tables can be defined in configuration or standard documents, for example, new table #2 mainly utilizing SSB-to-RO mapping cycle, new table #3 mainly utilizing association (pattern) interval. The BS can configure / instruct the UE via RRC or PDCCH command DCI which of the three table candidates to utilize.

[0420] In this way, the PRACH mask index table set in a specific unit through a higher layer signal such as SIB / RRC can also be applied to the method of setting / adjusting additional PRACH resources (e.g., A-RO) for CFRA through PRACH masking / muting described in the aforementioned method #2. For example, when the BS indicates CFRA through PDCCH and indicates PRACH mask index #1 of the table set in units of SSB-to-RO mapping cycles, it can be stipulated or assumed that the A-ROs included in the first SSB-to-RO mapping cycle within the associated interval are indicated for CFRA.

[0421] <Method #5> A method of identifying a subset of additional PRACH resources through a PRACH mask of a PRACH association interval unit among the additional PRACH resources set for NES.

[0422] The UE may be configured with an additional PRACH configuration index for A-ROs, and before SSB-to-RO mapping, only A-ROs configured through the PRACH configuration index that do not overlap with the time / frequency resources (e.g., time and frequency resources) of valid D-ROs may be configured or defined as valid ROs. In addition, the UE may additionally be configured with a PRACH mask index per PRACH association interval to extract a subset of A-ROs.

[0423] For example, the PRACH mask index can be semi-statically set to one of the entries in the following table defined in 3GPP TS 38.213, and the A-ROs within the first 1 / 2, 1 / 4, 1 / 8, 1 / 16 APs among multiple association periods (APs) within K association pattern periods (APPs) can be considered as actual valid A-ROs. The following table shows K mask Mapping of mask index to association periods per K association pattern intervals mask (assocation pattern periods) are exemplified.

[0424]

[0425] However, according to the current 3GPP TS 38.213, an association pattern period includes one or more association periods and is determined so that a pattern between PRACH occasions and SS / PBCH block indexes repeats at most every 160 msec. Therefore, according to the current standard, 3 or 5 APs (which are not multiples of 2, 4, 8, or 16) may be included in an APP. In this case, when a specific mask index is indicated so that the UE wants to identify or select the first 1 / 2, 1 / 4, 1 / 8, or 1 / 16 APs, the total number of APs divided by 2, 4, 8, or 16 may not be an integer. Therefore, when applying PRACH masking per AP within an APP using the set mask index, one of the following Options formulas can be applied to ensure that an integer number of APs are always masked. For example, each enumeration in the table above can be replaced with one of the following formulas.

[0426] > Option 1: Max(1, floor(1st half or quarter or eighth or sixteenth of the APs in K APPs))

[0427] > Option 3: Max(1, Round(1st half or quarter or eighth or sixteenth of the APs in K APPs))

[0428] > Option 2: Max(1, ceil(1st half or quarter or eighth or sixteenth of the APs in K APPs))

[0429] For example, if each entry in Table 12 is updated with the formula of Option 1, it can be expressed as follows.

[0430]

[0431] <Method #6> RRC connected mode UE's RO selection and PRACH transmission method when the availability of additional PRACH resources (A-RO) is indicated to the UE through DCI format 1_0 with C-RNTI (e.g., PDCCH command).

[0432] A-RO for NES can be configured by RACH-ConfigCommon together with D-RO, and if the availability of A-RO is indicated and valid (within the validity duration) via DCI format 1_0 with C-RNTI, the UE can use A-RO for PRACH transmission. The UE can use RO resources for CBRA configured in RACH-ConfigCommon when CFRA is indicated by PDCCH command and there is no PRACH configuration in separately configured RACH-ConfigDedicated (or when the reference signal received power (RSRP) is below a certain threshold).

[0433] Therefore, if there is no separate additional PRACH resource configuration in the dedicated RACH configuration (e.g., RACH-ConfigDedicated) and the availability of additional PRACH resources is indicated by the DCI format 1_0 with C-RNTI (e.g., PDCCH command), the UE can transmit PRACH by selecting the additional PRACH resources configured in RACH-ConfigCommon only when the preamble index field in the DCI format 1_0 with C-RNTI points to a CBRA (e.g., all '0').

[0434] Alternatively, when the UE is provided with RACH-ConfigDedicated and the availability of A-RO can be indicated by a 1-bit in the PDCCH command DCI (e.g., PRACH Resource Indicator field), if the random access preamble index indicated by the DCI indicates CBRA (e.g., all zeros), the availability of A-RO can be indicated by that 1-bit, whereas if the random access preamble index indicates CFRA (e.g., not all zeros), the PRACH Resource Indicator 1-bit can be ignored or considered as a reserved bit by the UE. When RACH-ConfigDedicated is set, if the random access preamble index indicates CFRA (e.g., all zeros), the UE determines that A-RO is not available if the corresponding 1-bit in the PRACH Resource Indicator field indicates '0', and the UE determines that A-RO is available if the corresponding 1-bit indicates '1'. may. Additionally, when RACH-ConfigDedicated is set, if the random access preamble index indicates CFRA (e.g., is not all zeros), the UE may determine that A-RO is not available (regardless of what the PRACH resource indicator bit 1 indicates).

[0435] In some implementations, the UE may be pre-configured or standardized to always prefer A-RO when available, or to always use A-RO when its availability is indicated via a PDCCH command. Alternatively, the UE may select the closest RO (e.g., D-RO or A-RO) from the time it intends to transmit the PRACH.

[0436] Some implementations of the present specification described above may be applied not only to RO for 4-stage RACH but also to MsgA PRACH / PUSCH for 2-stage RACH. For example, if additional RO for NES (also called NES RO) is also supported for 2-stage RACH, the UE may mask / mute by applying the PRACH occassion index indicated by the PRACH mask index value to MsgA PRACH / PUSCH for 2-stage RACH.

[0437] The methods or implementations of the present specification described above may be applied independently, but may also be applied in the form of a combination (or merge) of some proposed methods. Information regarding whether the methods / implementations of the present specification described above are applied (or information regarding the rules of the methods / implementations of the present specification described above) may be specified for the BS to inform the UE through a predefined signal (e.g., a physical layer signal or a higher layer signal). In the present specification, the higher layer may include one or more of functional layers such as MAC, RLC, PDCP, RRC, and SDAP, for example.

[0438] According to some implementations of this specification, unlike legacy PRACH resources (see D-RO described above) that are always configured and never turned off on a cell for a random access procedure, additional PRACH resource(s) (see A-RO described above) may or may not be configured on a cell, and the additional PRACH resource(s) configured for a cell may be activated or deactivated depending on network or cell conditions. According to some implementations of this specification, the availability of additional PRACH resources is indicated to the UE through the DCI format for the PDCCH command, so that the BS can dynamically activate (deactivate) the additional PRACH resources for the cell, and the UE can quickly determine the availability of the additional PRACH resources.

[0439] When the availability of additional PRACH resources is notified based on the P-RNTI, the UE in RRC connected mode is not forced to monitor the paging PDCCH on the PO associated with its UE identifier among the POs within the SI modification interval, and can monitor any PO within the SI modification interval. Therefore, even if the BS activates or deactivates A-RO, the UE does not know when it will determine the availability of A-RO, and it is difficult for the UE to determine whether A-RO can be used for CFRA until it determines the availability of A-RO on the PO based on the P-RNTI. In contrast, according to some implementations of the present specification, the availability of A-RO can be indicated through the DCI for the PDCCH command that triggers CFRA, so that the UE can immediately determine whether A-RO as well as D-RO can be used when selecting an RO for CFRA.

[0440] According to some implementations of this specification, when a BS triggers a random access procedure to a UE via a PDCCH command (e.g., DCI format 1_0 with C-RNT), the BS can quickly resolve the intra-cell RO congestion problem and increase the energy saving opportunity of the BS by indicating the availability of additional PRACH resources via the DCI for the PDCCH command without waiting for the next PO for the UE.

[0441] Figure 24 illustrates the flow of random access preamble transmission in a UE according to some implementations of this specification.

[0442] A UE may perform operations according to some implementations of the present disclosure in connection with transmitting a random access preamble. The UE may include at least one transceiver; at least one processor; and at least one computer memory operably 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 the present disclosure. A processing device for the UE may include at least one processor; and at least one computer memory operably 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 the present disclosure. A computer-readable (non-transitory) storage medium may store at least one computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer program or computer program product may be recorded on at least one computer-readable (non-transitory) storage medium and may contain instructions that, when executed, cause (at least one processor) to perform operations according to some implementations of the present specification.

[0443] A method performed by the UE, or in the UE, the processing device, the computer-readable (non-transitory) storage medium, and / or the computer program product, the operations may include: receiving a first random access channel occasion (RO) related configuration and a second RO related configuration for a cell (S2401); and receiving a downlink control information (DCI) format for a random access procedure initiated by a physical downlink control channel (PDCCH) order (S2403); selecting an RO for physical random access channel (PRACH) transmission based on the DCI format; and performing the PRACH transmission using the selected RO (S2405). In some implementations, the DCI format may include an indication field regarding the availability of RACH resources configured by the second RO related configuration.

[0444] Figure 25 illustrates the flow of random access preamble reception at BS according to some implementations of this specification.

[0445] A BS may perform operations according to some implementations of the present disclosure in connection with receiving a random access preamble. The BS may include at least one transceiver; at least one processor; and at least one computer memory operably 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 the present disclosure. A processing device for the BS may include at least one processor; and at least one computer memory operably 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 the present disclosure. A computer-readable (non-transitory) storage medium may store at least one computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer program or computer program product may be recorded on at least one computer-readable (non-transitory) storage medium and may contain instructions that, when executed, cause (at least one processor) to perform operations according to some implementations of the present specification.

[0446] A method performed by the BS, or in the BS, the processing device, the computer-readable (non-transitory) storage medium, and / or the computer program product, the operations may include: transmitting (S2501) a first random access channel occasion (RO) related configuration and a second RO related configuration for a cell; and transmitting (S2503) a downlink control information (DCI) format for a random access procedure initiated by a physical downlink control channel (PDCCH) order; and attempting to receive a physical random access channel (PRACH) based on the DCI format (S2505). In some implementations, the DCI format may include an indication field regarding the availability of RACH resources configured by the second RO related configuration.

[0447] In some implementations related to FIG. 24, based on the indication field indicating that RACH resources configured by the second RO-related configuration are available, the RO may be selected from among first ROs determined by the first RO-related configuration and second ROs determined by the second RO-related configuration, and based on the indication field indicating that RACH resources configured by the second RO-related configuration are not available, the RO may be selected from among first ROs determined by the first RO-related configuration.

[0448] In some implementations related to FIG. 25, based on the indication field indicating that RACH resources configured by the second RO-related configuration are available, the PRACH reception may be attempted within first ROs determined by the first RO-related configuration and second ROs determined by the second RO-related configuration, and based on the indication field indicating that RACH resources configured by the second RO-related configuration are not available, the PRACH reception may be attempted within the first ROs determined by the first RO-related configuration.

[0449] In some implementations related to FIGS. 24 and 25, the first RO-related settings and the second RO-related settings may be provided via system information block 1.

[0450] In some implementations related to FIGS. 24 and 25, the DCI format includes a PRACH mask index field, and based on the indication field indicating that RACH resources configured by the second RO-related configuration are not available, a value of the PRACH mask index field can be applied to the first ROs determined by the first RO-related configuration.

[0451] In some implementations related to FIGS. 24 and 25, the DCI format includes a PRACH mask index field, and based on the indication field indicating that RACH resources configured by the second RO-related configuration are available, a value of the PRACH mask index field can be applied to the first ROs determined by the first RO-related configuration and the second ROs determined by the second RO-related configuration.

[0452] In some implementations related to FIGS. 24 and 25, the DCI format may include a synchronization signal / physical broadcast channel (SS / PBCH) block index field and a PRACH mask index field, and the selected RO may be one associated with an RO index indicated by the PRACH mask index field among ROs associated with the SS / PBCH indicated by the SS / PBCH block index field.

[0453] In some implementations related to FIG. 24, based on the indication field indicating that the RACH resource set by the second RO-related configuration is not available, the selected RO may be one of at least one RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related configuration.

[0454] In some implementations related to FIG. 24, based on the indication field indicating that RACH resources configured by the second RO-related configuration are available, the selected RO may be one of i) at least one RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related configuration, and ii) at least one RO obtained by applying the value of the PRACH mask index field to the second ROs determined by the second RO-related configuration.

[0455] In some implementations related to FIG. 25, the DCI format includes a synchronization signal / physical broadcast channel (SS / PBCH) block index field and a PRACH mask index field, and the PRACH reception may be attempted in an RO with an RO index indicated by the PRACH mask index field among ROs associated with the SS / PBCH indicated by the SS / PBCH block index field.

[0456] In some implementations related to FIG. 25, based on the indication field indicating that the RACH resource set by the second RO-related configuration is not available, the PRACH reception may be attempted in an RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related configuration.

[0457] In some implementations related to FIG. 25, based on the indication field indicating that RACH resources configured by the second RO-related configuration are available, the PRACH reception may be attempted in at least one RO obtained by i) applying the value of the PRACH mask index field to the first ROs determined by the first RO-related configuration, and ii) applying the value of the PRACH mask index field to the second ROs determined by the second RO-related configuration.

[0458] As described above, the examples disclosed herein are provided to enable those skilled in the art to implement and practice the present disclosure. While the examples have been described above with reference to the examples of the present disclosure, those skilled in the art will appreciate that various modifications and variations may be made to the examples of the present disclosure. Accordingly, the present disclosure is not intended to be limited to the examples described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0459] Implementations of this specification can be used in wireless communication systems, BSs, user equipment, and other equipment.

Claims

1. In a method performed by a user device, Receiving a first random access channel occasion (RO) related setting and a second RO related setting for the cell; and Receive a downlink control information (DCI) format for a random access process initiated by a physical downlink control channel (PDCCH) order; Selecting an RO for physical random access channel (PRACH) transmission based on the above DCI format; and comprising performing the PRACH transmission using the selected RO; The above DCI format includes an indication field regarding the availability of RACH resources set by the second RO related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the RO is selected from among the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the RO is selected from among the first ROs determined by the first RO-related settings. method.

2. In paragraph 1, The above first RO related settings and the above second RO related settings are received through system information block 1. method.

3. In paragraph 1, The above DCI format includes a PRACH mask index field, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the value of the PRACH mask index field is applied to the first ROs determined by the first RO-related settings. method.

4. In paragraph 1, The above DCI format includes a PRACH mask index field, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the value of the PRACH mask index field is applied to the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings. method.

5. In paragraph 1, The above DCI format includes a synchronization signal / physical broadcast channel (SS / PBCH) block index field and a PRACH mask index field, The selected RO is related to the RO index indicated by the PRACH mask index field among the ROs associated with the SS / PBCH indicated by the SS / PBCH block index field. method.

6. In paragraph 5, Based on the indication field indicating that the RACH resource set by the second RO-related setting is not available, the selected RO is one of at least one RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related setting. method.

7. In paragraph 5, Based on the indication field indicating that the RACH resource set by the second RO-related setting is available, the selected RO is one of i) at least one RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related setting and ii) at least one RO obtained by applying the value of the PRACH mask index field to the second ROs determined by the second RO-related setting. method.

8. At least one transmitter / receiver; at least one processor; and At least one computer memory operably connectable to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations comprising: Receiving a first random access channel occasion (RO) related setting and a second RO related setting for the cell; and Receive a downlink control information (DCI) format for a random access process initiated by a physical downlink control channel (PDCCH) order; Selecting an RO for physical random access channel (PRACH) transmission based on the above DCI format; and comprising performing the PRACH transmission using the selected RO; The above DCI format includes an indication field regarding the availability of RACH resources set by the second RO related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the RO is selected from among the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the RO is selected from among the first ROs determined by the first RO-related settings. User device.

9. At least one processor; and At least one computer memory operably connectable to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations comprising: Receiving a first random access channel occasion (RO) related setting and a second RO related setting for the cell; and Receive a downlink control information (DCI) format for a random access process initiated by a physical downlink control channel (PDCCH) order; Selecting an RO for physical random access channel (PRACH) transmission based on the above DCI format; and comprising performing the PRACH transmission using the selected RO; The above DCI format includes an indication field regarding the availability of RACH resources set by the second RO related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the RO is selected from among the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the RO is selected from among the first ROs determined by the first RO-related settings. Processing unit.

10. In a computer-readable non-transitory storage medium, The storage medium stores at least one program code comprising instructions that, when executed, cause at least one processor to perform operations, the operations comprising: Receiving a first random access channel occasion (RO) related setting and a second RO related setting for the cell; and Receive a downlink control information (DCI) format for a random access process initiated by a physical downlink control channel (PDCCH) order; Selecting an RO for physical random access channel (PRACH) transmission based on the above DCI format; and comprising performing the PRACH transmission using the selected RO; The above DCI format includes an indication field regarding the availability of RACH resources set by the second RO related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the RO is selected from among the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the RO is selected from among the first ROs determined by the first RO-related settings. Storage media.

11. In a method performed by a base station, Transmitting the first random access channel occasion (RO) related settings and the second RO related settings for the cell; and Transmits downlink control information (DCI) format for a random access process initiated by a physical downlink control channel (PDCCH) order; Including attempting to receive a physical random access channel (PRACH) based on the above DCI format, The above DCI format includes an indication field regarding the availability of RACH resources set by the second RO related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the PRACH reception is attempted within the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the PRACH reception is attempted within the first ROs determined by the first RO-related settings. method.

12. In paragraph 11, The above first RO related settings and the above second RO related settings are transmitted through system information block 1. method.

13. In paragraph 11, The above DCI format includes a PRACH mask index field, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the value of the PRACH mask index field is applied to the first ROs determined by the first RO-related settings. method.

14. In paragraph 11, The above DCI format includes a PRACH mask index field, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the value of the PRACH mask index field is applied to the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings. method.

15. In paragraph 11, The above DCI format includes a synchronization signal / physical broadcast channel (SS / PBCH) block index field and a PRACH mask index field, The above PRACH reception is attempted in an RO with an RO index indicated by the PRACH mask index field among the ROs associated with the SS / PBCH indicated by the SS / PBCH block index field. method.

16. In paragraph 15, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the PRACH reception is attempted in the RO obtained by applying the value of the PRACH mask index field to the first ROs determined by the first RO-related settings. method.

17. In paragraph 15, Based on the indication field indicating that the RACH resources set by the second RO-related configuration are available, the PRACH reception is attempted in at least one RO obtained by i) applying the value of the PRACH mask index field to the first ROs determined by the first RO-related configuration and ii) applying the value of the PRACH mask index field to the second ROs determined by the second RO-related configuration. method.

18. At least one transmitter / receiver; at least one processor; and At least one computer memory operably connectable to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations comprising: Transmitting the first random access channel occasion (RO) related settings and the second RO related settings for the cell; and Transmits downlink control information (DCI) format for a random access process initiated by a physical downlink control channel (PDCCH) order; Including attempting to receive a physical random access channel (PRACH) based on the above DCI format, The above DCI format includes an indication field regarding the availability of RACH resources set by the second RO related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are available, the PRACH reception is attempted within the first ROs determined by the first RO-related settings and the second ROs determined by the second RO-related settings, Based on the indication field indicating that the RACH resources set by the second RO-related settings are not available, the PRACH reception is attempted within the first ROs determined by the first RO-related settings. Base station.

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