Signal transmission / reception method for wireless communication and apparatus therefor

Abstract

According to one embodiment of the disclosure, a terminal can acquire a RACH configuration for at least one UL BWP among a plurality of UL BWPs, select an initial UL BWP from among the plurality of UL BWPs, and transmit a random access preamble on the selected initial UL BWP based on the RACH configuration, the plurality of UL BWPs can include a first UL BWP related to only a first type terminal whose capability is reduced to support a bandwidth smaller than a predetermined bandwidth, and a second UL BWP related to a second type terminal different from the first type terminal, and the terminal which is the first type terminal can be configured to select the first UL BWP or the second UL BWP as the initial UL BWP according to whether a predetermined condition is satisfied.

Description

TECHNICAL FIELD

[0001] The disclosure relates to wireless communications, and more specifically, to a method of transmitting or receiving an uplink / downlink signal in a wireless communication system and an apparatus therefor. BACKGROUND

[0002] Generally, wireless communication systems are developing toward different coverage of a wide range to provide communication services such as audio communication services, data communication services, etc. Wireless communication is a multiple access system that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). For example, the multiple access system can be any one of a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, and a single carrier frequency division multiple access (SC-FDMA) system. SUMMARY

[0003] TECHNICAL PROBLEM

[0004] An object of the disclosure is to provide a method of more efficiently transmitting and receiving a signal in a wireless communication system in which user equipments (UEs) of different types operate.

[0005] The object of the disclosure is not limited to what has been specifically described above, and other objects that can be achieved by the disclosure will be more clearly understood from the following detailed description.

[0006] TECHNICAL SOLUTION

[0007] In an aspect of the disclosure, a method of performing a random access procedure by a user equipment (UE) in a third generation partnership project (3GPP)-based wireless communication system is provided. The method can include obtaining a random access channel (RACH) configuration for at least one of a plurality of uplink (UL) bandwidth parts (BWPs), selecting an initial UL BWP from among the plurality of UL BWPs, and transmitting a random access preamble on the initial UL BWP selected from among the plurality of UL BWPs based on the RACH configuration. The plurality of UL BWPs can include a first UL BWP related to only a first type of UE having a reduced capability to support a smaller bandwidth than a predetermined bandwidth and a second UL BWP related to a second type of UE different from the first type of UE. The UE can be the first type of UE and be configured to select the first UL BWP or the second UL BWP as the initial UL BWP depending on whether a predetermined condition is satisfied.

[0008] Based on that the predetermined condition is not satisfied even though the UE is the first type of UE, the UE can be configured to select the second UL BWP as the initial UL BWP.

[0009] Based on that the capability of the UE does not support the second UL BWP, the UE can be configured to determine that the predetermined condition is satisfied and select the first UL BWP as the initial UL BWP.

[0010] Based on that the capability of the UE supports the second UL BWP even though the UE is the first type of UE, the UE can be configured to determine that the predetermined condition is not satisfied and select the second UL BWP as the initial UL BWP.

[0011] Based on that the first UL BWP is available for the UE, the UE can be configured to determine that the predetermined condition is satisfied and select the first UL BWP as the initial UL BWP.

[0012] Based on that the first UL BWP is not available for the UE even though the UE is the first type of UE, the UE can be configured to determine that the predetermined condition is not satisfied and select the second UL BWP as the initial BWP.

[0013] Based on that the first UL BWP is available for the UE, the UE can be configured to determine that the predetermined condition is satisfied regardless of the availability of the second UL BWP, and select the first UL BWP as the initial UL BWP.

[0014] The UE can be configured to determine the availability of the first UL BWP based on higher layer information obtained from a network.

[0015] In another aspect of the disclosure, a processor-readable storage medium having stored thereon a program for executing the above-described method is provided.

[0016] In another aspect of the disclosure, a device for 3GPP-based wireless communication is provided. The device can include a memory configured to store instructions and a processor configured to perform operations by executing the instructions. The operations performed by the processor can include obtaining a RACH configuration for at least one of a plurality of UL BWPs, selecting an initial UL BWP from among the plurality of UL BWPs, and transmitting a random access preamble on the initial UL BWP selected from among the plurality of UL BWPs based on the RACH configuration. The plurality of UL BWPs can include a first UL BWP related to only a first type of device having a reduced capability to support a smaller bandwidth than a predetermined bandwidth and a second UL BWP related to a second type of device different from the first type of device. The device can be the first type of device and configured to select the first UL BWP or the second UL BWP as the initial UL BWP depending on whether a predetermined condition is satisfied.

[0017] The device can further include a transceiver configured to transmit and receive radio signals under control of the processor.

[0018] The device can be a UE for the 3GPP-based wireless communication.

[0019] The device can be an application-specific integrated circuit (ASIC) or a digital signal processing device.

[0020] In another aspect of the disclosure, a method of performing a random access procedure with a UE by a base station in a 3GPP-based wireless communication system is provided. The method can include transmitting a RACH configuration for at least one of a plurality of UL BWPs and at least one condition for selecting an initial UL BWP, and detecting a random access preamble in the plurality of UL BWPs based on the RACH configuration. The plurality of UL BWPs can include a first UL BWP related to only a first type of UE having a reduced capability to support a smaller bandwidth than a predetermined bandwidth and a second UL BWP related to a second type of UE different from the first type of UE. The at least one condition for selecting the initial UL BWP can provide the first type of UE with a criterion for selecting one of the first UL BWP and the second UL BWP as the initial UL BWP.

[0021] In another aspect of the disclosure, a base station in a 3GPP-based wireless communication system is provided. The base station can include a memory configured to store instructions and a processor configured to perform operations by executing the instructions. The operations performed by the processor can include transmitting a RACH configuration for at least one of a plurality of UL BWPs and at least one condition for selecting an initial UL BWP, and detecting a random access preamble in the plurality of UL BWPs based on the RACH configuration. The plurality of UL BWPs can include a first UL BWP related to only a first type of UE having a reduced capability to support a smaller bandwidth than a predetermined bandwidth and a second UL BWP related to a second type of UE different from the first type of UE. The at least one condition for selecting the initial UL BWP can provide a criterion for the first type of UE to select one of the first UL BWP and the second UL BWP as the initial UL BWP.

[0022] Advantageous Effects

[0023] According to embodiments of the disclosure, a user equipment (UE) having a reduced bandwidth capability can more efficiently perform an initial uplink (UL) bandwidth part (BWP) operation and a random access procedure.

[0024] Effects of the disclosure are not limited to what has been particularly described hereinabove and other effects will be appreciated from combinations of the detailed description disclosed herein. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A physical channel used in a 3rd generation partnership project (3GPP) system as an exemplary wireless communication system is illustrated, and a general signal transmission method using the physical channel is illustrated.

[0026] Figure 2 A radio frame structure is illustrated.

[0027] Figure 3 A resource grid of a slot is illustrated.

[0028] Figure 4 A random access procedure is illustrated.

[0029] Figure 5 An example of physical channel mapping is illustrated.

[0030] Figure 6 An exemplary acknowledgement / negative-acknowledgement (ACK / NACK) transmission procedure is illustrated.

[0031] Figure 7 An exemplary physical uplink shared channel (PUSCH) transmission procedure is illustrated.

[0032] Figure 8 An example of multiplexing control information in a PUSCH is illustrated.

[0033] Figure 9 and Figure 10 A user equipment (UE) operation related to the proposals of the present disclosure is illustrated.

[0034] Figure 11 An example random access channel (RACH) configuration information in SIB1 / R-SIB1 is illustrated.

[0035] Figure 12 Signaling and reception related to the proposals of the present disclosure are illustrated.

[0036] Figure 13 and Figure 14 A communication system 1 and a wireless device to which the present disclosure is applied are illustrated.

[0037] Figure 15 A discontinuous reception (DRX) operation suitable for the present disclosure is illustrated. DETAILED DESCRIPTION

[0038] Embodiments of the present disclosure are applicable to various wireless access technologies such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). CDMA can be implemented as a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA can be implemented as a radio technology such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA can be implemented as a radio technology such as institute of electrical and electronics engineers (IEEE) 802.11 (wireless fidelity (Wi-Fi)), IEEE 802.16 (worldwide interoperability for microwave access (WiMAX)), IEEE 802.20, and evolved UTRA (E-UTRA). UTRA is a part of universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS) using E-UTRA, and LTE-advanced (A) is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A.

[0039] As more communication devices require greater communication capacity, enhanced mobile broadband communication relative to legacy radio access technologies (RATs) is required. In addition, massive machine-type communications (MTC), which is capable of providing various services at anytime anywhere by connecting a plurality of devices and objects, is another important issue to be considered in a next-generation communication. Also, communication system design considering services / UEs sensitive to reliability and latency is being discussed. Accordingly, introduction of a new radio access technology considering enhanced mobile broadband communication (eMBB), massive MTC, and ultra-reliable and low-latency communication (URLLC) is being discussed. In the present disclosure, for simplicity, this technology will be referred to as NR (New Radio or New RAT).

[0040] For clarity, 3GPP NR is mainly described, but the technical idea of the present disclosure is not limited thereto. LTE refers to technologies after 3GPP TS 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A Pro. 3GPP NR refers to technologies after TS 38.xxx Release 15. LTE / NR can be referred to as a 3GPP system. In this document, "xxx" indicates a detailed number of specifications. LTE / NR can be collectively referred to as a 3GPP system.

[0041] Details of backgrounds, terms, abbreviations, etc. used herein can be found in documents published before the present disclosure. For example, the present disclosure can be supported by the following documents:

[0042] 3GPP LTE

[0043] - 36.211: Physical channels and modulation

[0044] - 36.212: Multiplexing and channel coding

[0045] - 36.213: Physical layer procedures

[0046] - 36.300: Overall description

[0047] - 36.321: Medium Access Control (MAC)

[0048] - 36.331: Radio Resource Control (RRC)

[0049] 3GPP NR

[0050] - 38.211: Physical channels and modulation

[0051] - 38.212: Multiplexing and channel coding

[0052] - 38.213: Physical layer procedures for control

[0053] - 38.214: Physical layer procedures for data

[0054] - 38.300: NR and NG-RAN overall description

[0055] - 38.321: Medium Access Control (MAC)

[0056] - 38.331: Radio Resource Control (RRC) protocol specification

[0057] Technical terms used in this document

[0058] - PDCCH: Physical Downlink Control Channel

[0059] - PDSCH: Physical Downlink Shared Channel

[0060] - PUSCH: Physical Uplink Shared Channel

[0061] - CSI: Channel State Information

[0062] - RRM: Radio Resource Management

[0063] - RLM: Radio Link Monitoring

[0064] - DCI: Downlink Control Information

[0065] - CAP: Channel Access Procedure

[0066] - Ucell: Unlicensed cell

[0067] - PCell: Primary cell

[0068] - PSCell: Primary SCG cell

[0069] - TBS: Transport Block Size

[0070] - SLIV: Start and Length Indicator Value (SLIV is a field that indicates a starting symbol index and a number of symbols in a slot for PDSCH and / or PUSCH, and SLIV is carried in a PDCCH that schedules the corresponding PDSCH and / or PUSCH.)

[0071] - BWP: Bandwidth Part (BWP can consist of contiguous resource blocks (RBs) in a frequency domain, which can correspond to one numerology (e.g., subcarrier spacing, cyclic prefix (CP) length, slot / min-slot duration, etc.). Also, multiple BWPs can be configured on one carrier (the number of BWPs per carrier can be limited), but the number of active BWPs in each carrier can be limited (e.g., one).

[0072] - CORESET: Control Resource Set (CORESET refers to a time-frequency resource region in which PDCCH can be transmitted, and the number of CORESETs per BWP can be limited.)

[0073] - REG: Resource Element Group

[0074] - SFI: Slot Format Indicator (SFI refers to an indicator indicating DL / UL direction at symbol level in a specific slot, and SFI is transmitted on group common PDCCH.)

[0075] - COT: Channel Occupancy Time

[0076] - SPS: Semi-Persistent Scheduling

[0077] - PLMN ID: Public Land Mobile Network Identifier

[0078] - RACH: Random Access Channel

[0079] - RAR: Random Access Response

[0080] - Msg3: A message transmitted on UL-SCH containing C-RNTI MAC CE or CCCH SDU submitted from upper layer and associated with UE contention resolution identity as part of random access procedure.

[0081] - Special Cell: For dual connectivity operation, the term special cell refers to the PCell of the MCG or the PSCell of the SCG, depending on whether the MAC entity is associated to the MCG or the SCG, respectively. Otherwise, the term special cell refers to the PCell. The special cell supports PUCCH transmission and contention-based random access, and is always activated.

[0082] - Serving Cell: PCell, PSCell or SCell

[0083] In this disclosure, the term "set" can be replaced with "configure" or "configuration," and the two are used interchangeably. Furthermore, conditional expressions (e.g., "if," "in this case," or "when") can be replaced with "based on" or "under what condition / state"). Additionally, the operation or software / hardware (SW / HW) configuration of the user equipment (UE) / base station (BS) can be derived / understood based on the satisfaction of corresponding conditions. When the process on the receiving (or transmitting) side can be derived / understood from the process on the transmitting (or receiving) side in signal transmission / reception between wireless communication devices (e.g., BS and UE), its description can be omitted. For example, signal determination / generation / encoding / transmission on the transmitting side can be understood as signal monitoring reception / decoding / determination on the receiving side. Furthermore, when referring to the UE performing (or not performing) a specific operation, this can also be interpreted as the BS expecting / assuming (or not expecting / assuming) the UE to perform a specific operation. Similarly, when referring to the BS performing (or not performing) a specific operation, this can also be interpreted as the UE expecting / assuming (or not expecting / assuming) the BS to perform a specific operation. In the following description, for ease of description, sections, embodiments, examples, options, methods, schemes, proposals, etc. are distinguished from each other and indexed. This does not mean that each of them necessarily constitutes an independent disclosure or that each of them can only be implemented alone. Unless explicitly contradictory, it can be deduced / understood that implementations can be combined or that at least some of sections, embodiments, examples, options, methods, schemes, proposals, etc., can be omitted.

[0084] In a wireless communication system, a user equipment (UE) receives information from a base station (BS) via a downlink (DL) and transmits information to the BS via an uplink (UL). The information transmitted and received by the BS and UE includes data and various control information, and involves various physical channels depending on the type / purpose of the information transmitted and received by the UE and BS.

[0085] Figure 1 The diagram illustrates the physical channels used in a 3GPP NR system and the general signal transmission methods employed therein.

[0086] When the UE is powered on again from a power-off state or enters a new cell, in step S101, the UE performs an initial cell search procedure (e.g., establishing synchronization with the BS). For this purpose, the UE receives a synchronization signal block (SSB) from the BS. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The UE establishes synchronization with the BS based on the PSS / SSS and obtains information such as the cell identifier (ID). The UE can obtain broadcast information within the cell based on the PBCH. During the initial cell search process, the UE can receive a DL reference signal (RS) to monitor the DL channel status.

[0087] An SSB consists of four consecutive OFDM symbols, each of which carries a PSS, a PBCH, a SSS / PBCH, or a PBCH. Each of the PSS and the SSS includes one OFDM symbol multiplied by 127 subcarriers, and the PBCH includes three OFDM symbols multiplied by 576 subcarriers. The PBCH is encoded / decoded based on a polar code and modulated / demodulated according to quadrature phase shift keying (QPSK). The PBCH in the OFDM symbol consists of data resource elements (REs) to which complex modulation values of the PBCH are mapped and demodulation reference signal (DMRS) REs to which DMRSs for the PBCH are mapped. Three DMRS REs are configured for each RB in the OFDM symbol, and three data REs are configured between the DMRS REs.

[0088] The PSS can be used in detecting a cell ID within a cell ID group, and the SSS can be used in detecting a cell ID group. The PBCH can be used in detecting an SSB (time) index and a half frame. There are 336 cell ID groups, and each cell ID group includes three cell IDs. Accordingly, there are a total of 1008 cell IDs.

[0089] An SSB is periodically transmitted with an SSB periodicity. A default SSB periodicity assumed by a UE in an initial cell search is defined as 20 ms. After cell access, the SSB periodicity can be set by a network (e.g., a BS) to one of {5 ms, 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms}. An SSB burst set can be configured at the start of the SSB periodicity. The SSB burst set can be set to a time window of 5 ms (i.e., a half frame), and an SSB can be repeatedly transmitted up to L times within the SSB burst set. The maximum number L of SSB transmissions can be given depending on a carrier frequency band as follows. One slot includes up to two SSBs.

[0090] - For a frequency range of up to 3 GHz, L = 4

[0091] - For a frequency range from 3 GHz to 6 GHz, L = 8

[0092] - For a frequency range from 6 GHz to 52.6 GHz, L = 64

[0093] The time domain positions of candidate SSBs in an SSB burst set can be defined depending on a subcarrier spacing. The time domain positions of the candidate SSBs are indexed in time order from (SSB index) 0 to L-1 within the SSB burst set (i.e., a half frame).

[0094] Multiple SSBs can be transmitted within a frequency span of a carrier. Each SSB can not need to have a unique physical layer cell identifier, but different SSBs can have different physical layer cell identifiers.

[0095] A UE can acquire DL synchronization by detecting an SSB. The UE can identify the structure of an SSB burst set based on a detected SSB (time) index, and thus the UE can detect symbol / slot / half frame boundaries. The frame / half frame number to which the detected SSB belongs can be identified based on system frame number (SFN) information and half frame indication information.

[0096] Specifically, the UE can obtain a 10-bit SFN of a frame to which a PBCH belongs from the PBCH. Then, the UE can obtain a 1-bit half frame indication information. For example, when the UE detects a PBCH in which the half frame indication bit is set to 0, the UE can determine that an SSB to which the PBCH belongs is included in the first half frame of the frame. When the UE detects a PBCH in which the half frame indication bit is set to 1, the UE can determine that an SSB to which the PBCH belongs is included in the second half frame of the frame. Finally, the UE can obtain an SSB index of an SSB to which the PBCH belongs based on a PBCH payload and a DMRS sequence carried by the PBCH.

[0097] After the initial cell search, the UE can acquire more specific system information by receiving a physical downlink control channel (PDCCH) and receiving a physical downlink shared channel (PDSCH) based on information of the PDCCH in step S102.

[0098] System information (SI) is divided into a master information block (MIB) and a plurality of system information blocks (SIBs). SI other than the MIB can be referred to as remaining minimum system information (RMSI). Details thereof will be described below.

[0099] - The MIB includes information / parameters for monitoring a PDCCH scheduling a PDSCH of a SIB1 (SystemInformationBlock1), and the MIB is transmitted by the BS on a PBCH of a SSB. For example, the UE can check whether there is a CORESET for a Type0-PDCCH common search space based on the MIB. The Type0-PDCCH common search space is a kind of PDCCH search space which is used for transmitting a PDCCH scheduling a SI message. If there is the Type0-PDCCH common search space, the UE can determine (i) a number of consecutive RBs and one or more consecutive symbols included in the CORESET, and (ii) a PDCCH occasion (e.g., a time domain location for PDCCH reception) based on information in the MIB (e.g., pdcch-ConfigSIB1). If the Type0-PDCCH common search space does not exist, the pdcch-ConfigSIB1 provides information about a frequency location where the SSB / SIB1 exists and information about a frequency range where the SSB / SIB1 does not exist.

[0100] - The SIB1 includes information about availability and scheduling (e.g., transmission periodicity, SI window size, etc.) of remaining SIBs (hereinafter referred to as SIBx, where x is an integer greater than or equal to 2). For example, the SIB1 can indicate whether the SIBx is periodically broadcast or should be provided in an on-demand manner at the request of the UE. When the SIBx is provided in an on-demand manner, the SIB1 can include information necessary for the UE to transmit an SI request. The SIB1 is transmitted on a PDSCH, and a PDCCH scheduling the SIB1 is transmitted in a Type0-PDCCH common search space. That is, the SIB1 is transmitted on a PDSCH indicated by the PDCCH.

[0101] - The SIBx is included in an SI message and transmitted on a PDSCH. Each SI message is transmitted within a periodically occurring time window (i.e., SI window).

[0102] In steps S103 to S106, the UE can perform a random access procedure (e.g., a 4-step RA procedure) to access the BS. For the random access, the UE can transmit a preamble on a physical random access channel (PRACH) to the BS (S103), and receive a response message for the preamble on a PDCCH and a PDSCH corresponding to the PDCCH (S104). In the case of contention-based random access, the UE can perform a contention resolution procedure by further transmitting a PRACH (S105) and receiving a PDCCH and a PDSCH corresponding to the PDCCH (S106).

[0103] Hereinafter, a 2-step random access procedure will be briefly described. In the 2-step random access procedure, S103 / S105 (in which the UE performs transmission) can be performed in one step (message A), and S104 / S106 (in which the BS performs transmission) can be performed in one step (message B). Message A (MsgA) can include a preamble and a payload (PUSCH payload), and the preamble and the payload can be multiplexed based on time division multiplexing (TDM). In response to MsgA, message B (MsgB) can be transmitted for contention resolution, backoff indication(s), and / or backoff indication. The 2-step random access procedure can be subdivided into a contention-based random access (CBRA) procedure and a contention-free random access (CFRA) procedure. In the CFRA procedure, the BS can provide the UE with information on a preamble that the UE needs to transmit in MsgA and information on a PUSCH allocation before the UE transmits MsgA.

[0104] After the foregoing procedure, the UE can receive a PDCCH / PDSCH (S107) and transmit a physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) (S108) as a general downlink / uplink signal transmission procedure. Control information transmitted from the UE to the BS is referred to as uplink control information (UCI). The UCI includes a hybrid automatic repeat and request acknowledgement / negative determination (HARQ-ACK / NACK), a scheduling request (SR), channel state information (CSI), etc. The CSI includes a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), etc. Although the UCI is generally transmitted on the PUCCH, when control information and traffic data need to be simultaneously transmitted, the UCI can be transmitted on the PUSCH. In addition, the UCI can be transmitted aperiodically through the PUSCH according to a request / command of the network.

[0105] The NR system can support signal transmission / reception in an unlicensed band. According to regional regulations for the unlicensed band, a communication node in the unlicensed band needs to determine whether a channel is used by other communication node(s) before transmitting a signal. Specifically, the communication node can perform carrier sensing (CS) before transmitting a signal in order to check whether other communication node(s) performs signal transmission. When it is determined that other communication node(s) does not perform signal transmission, it can be said that a clear channel assessment (CCA) is confirmed. When a CCA threshold is predefined or configured by higher layer signaling (e.g., RRC signaling), the communication node can determine that a channel is busy if a detected channel energy is higher than the CCA threshold. Otherwise, the communication node can determine that the channel is idle. When it is determined that the channel is idle, the communication node can start signal transmission in the UCell. The above series of procedures can be referred to as listen before talk (LBT) or channel access procedure (CAP). LBT and CAP can be used interchangeably in this document.

[0106] Figure 2 A radio frame structure is illustrated. In NR, uplink and downlink transmissions are configured with a frame. Each radio frame has a length of 10 ms and is divided into two 5 ms half frames (HF). Each half frame is divided into five 1 ms subframes (SF). The subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). According to a cyclic prefix (CP), each slot includes 12 or 14 orthogonal frequency-division multiplexing (OFDM) symbols. When a normal CP is used, each slot includes 14 OFDM symbols. When an extended CP is used, each slot includes 12 OFDM symbols.

[0107] Table 1 exemplarily shows that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary according to the SCS when a normal CP is used.

[0108] [Table 1]

[0109] SCS (15*2^u) <![CDATA[N slot symb ]]> N frame,u slot ]] N subframe,u slot ]] 15 KHz (u=0) 14 10 1 30 KHz (u=1) 14 20 2 60 KHz (u=2) 14 40 4 120 KHz (u=3) 14 80 8 240 KHz (u=4) 14 160 16

[0110] *N slot symb : Number of symbols in a slot

[0111] *N frame,u slot : Number of slots in a frame

[0112] *N subframe,u slot : Number of slots in a subframe

[0113] Table 2 shows that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary according to the SCS when an extended CP is used.

[0114] [Table 2]

[0115] SCS (15*2^u) N slot symb ]]> N frame,u slot ]] N subframe,u slot ]] 60 KHz (u=2) 12 40 4

[0116] The structure of the frame is an example. The number of subframes, the number of slots, and the number of symbols in a frame can be varied.

[0117] In the NR system, OFDM numerology (e.g., SCS) can be configured differently for a plurality of cells aggregated for one UE. Accordingly, the (absolute time) duration of a time resource (e.g., SF, slot, or TTI) consisting of the same number of symbols (for simplicity, referred to as a time unit (TU)) can be configured differently among the aggregated cells. Here, a symbol can include an OFDM symbol (or CP-OFDM symbol) and an SC-FDMA symbol (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbol).

[0118] Figure 3 A resource grid is shown for a slot. A slot includes a plurality of symbols in the time domain. For example, a slot includes 14 symbols when a normal CP is used. However, a slot includes 12 symbols when an extended CP is used. A carrier includes a plurality of subcarriers in the frequency domain. A resource block (RB) is defined as a plurality of contiguous subcarriers (e.g., 12 contiguous subcarriers) in the frequency domain. A bandwidth part (BWP) can be defined as a plurality of contiguous physical RBs (PRBs) in the frequency domain and corresponds to a single numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., five) BWPs. Data communication can be performed through an enabled BWP, and only one BWP can be enabled for one UE. In the resource grid, each element is referred to as a resource element (RE), and one complex symbol can be mapped to each RE.

[0119] Bandwidth Part (BWP)

[0120] The NR system can support up to 400 MHz of frequency for each carrier. The network can instruct the UE to operate in only a partial bandwidth of such a wideband carrier, not the entire bandwidth. The partial bandwidth is referred to as a BWP. A BWP refers to a subset of contiguous common RBs defined for a numerology in the BWP of a carrier in the frequency domain, and one numerology (e.g., SCS, CP length, slot / min-slot duration, etc.) can be configured.

[0121] Activation / deactivation of DL / UL BWP or BWP switching can be performed according to network signaling and / or timer (e.g., L1 signaling corresponding to physical layer control signal, MAC control element corresponding to MAC layer control signal, RRC signaling, etc.). UE can not receive any DL / UL BWP configuration when performing initial access or before setting up RRC connection. The DL / UL BWP assumed by UE in this case is referred to as initial active DL / UL BWP.

[0122] In 3GPP NR specification, the following UE operation has been defined with respect to initial UL BWP.

[0123] * The UE determines the time resources and frequency resources for PUSCH occasions in the active UL BWP from msgA-PUSCH-config for the initial UL BWP. If the active UL BWP is not the initial UL BWP and no msgA-PUSCH-config is provided for the active UL BWP, the UE uses the msgA-PUSCH-config provided for the initial UL BWP.

[0124] * If the UE does not have a dedicated RRC configuration, or has the initial UL BWP as the active UL BWP, or is not provided startSymbolAndLengthMsgAPO, msgA-timeDomainAllocation provides the SLIV and PUSCH mapping type for PUSCH transmission by indicating:

[0125] - The first maxNrofUL-Allocations value from PUSCH-TimeDomainResourceAllocationList if PUSCH-TimeDomainResourceAllocationList is provided in PUSCH-ConfigCommon

[0126] - The entry if PUSCH-TimeDomainResourceAllocationList is not provided in PUSCH-ConfigCommon

[0127] Otherwise, the SLIV is provided by startSymbolAndLengthMsgAPO and the PUSCH mapping type is provided by mappingTypeMsgAPUSCH for PUSCH transmission.

[0128] * The active UL BWP for PUSCH transmission scheduled by a RAR UL grant is indicated by higher layers. The frequency domain resource allocation for PUSCH transmission within the active UL BWP is determined as follows - if the active UL BWP and the initial UL BWP have the same SCS and the same CP length, and the active UL BWP includes all RBs of the initial UL BWP, or the active UL BWP is the initial UL BWP, the initial UL BWP is used

[0129] - Otherwise, the RB numbering starts from the first RB of the active UL BWP and the maximum number of RBs used for frequency domain resource allocation is equal to the number of RBs in the initial UL BWP.

[0130] If the UE does not have a dedicated PUCCH resource configuration provided by PUCCH-ResourceSet in PUCCH-Config, the PUCCH resource set is provided by pucch-ResourceCommon with an index to a row of a pre-determined table for transmission of HARQ-ACK information on PUCCH in the initial UL BWP of N BWP size PRBs.

[0131] If the UE is not provided initialDownlinkBWP, the initial DL BWP is defined by the location and the number of consecutive PRBs starting from the PRB with the lowest index among the PRBs for the CORESET of the Type0-PDCCH CSS set and ending at the PRB with the highest index, and the SCS and cyclic prefix used for PDCCH reception in the CORESET of the Type0-PDCCH CSS set; otherwise, the initial DL BWP is provided by initialDownlinkBWP. For operation on a primary cell or a secondary cell, the UE is provided an initial UL BWP by initialUplinkBWP. If the UE is configured with a secondary UL carrier, the UE can be provided an initial UL BWP on the secondary UL carrier by initialUplinkBWP.

[0132] Figure 4 An exemplary normal random access procedure is illustrated. Specifically, Figure 4 A contention-based random access procedure for a UE is shown, which is performed in four steps.

[0133] First, the UE can transmit a message 1 (Msg1) including a random access preamble on PRACH (see 1701 of Figure 4

[0134] ​Random access preamble sequences with different lengths can be supported. The long sequence length of 839 can be applied for 1.25 and 5 kHz SCS, and the short sequence length of 139 can be applied for 15, 30, 60, and 120 kHz SCS.

[0135] A number of preamble formats can be defined by one or more RACH OFDM symbols and different CP (and / or guard time). The RACH configuration for a cell can be included in the SI about the cell and provided to the UE. The RACH configuration can include information about the SCS of PRACH, available preambles, preamble formats, etc. The RACH configuration can include information about the association between SSBs and RACH (time-frequency) resources. The UE transmits a random access preamble on the RACH time-frequency resource associated with the detected or selected SSB.

[0136] The threshold for SSB for RACH resource association can be configured by the network, and the RACH preamble can be transmitted or retransmitted based on the SSB measured reference signal received power (RSRP) satisfying the threshold. For example, the UE can select one SSB from among the SSBs satisfying the threshold, and transmit or retransmit the RACH preamble based on the RACH resource associated with the selected SSB.

[0137] Upon receiving the random access preamble from the UE, the BS can transmit a message 2 (Msg2) corresponding to a random access response (RAR) message to the UE (see Figure 4 of 1703). The PDCCH scheduling the PDSCH carrying the RAR can be CRC-masked with a random access (RA) radio network temporary identifier (RNTI) (RA-RNTI) and then transmitted. Upon detecting the PDCCH masked with the RA-RNTI, the UE can obtain the RAR from the PDSCH scheduled by the DCI carried by the PDCCH. The UE can check whether the RAR includes the RAR information in response to the preamble, i.e., Msg1, transmitted by the UE. The presence or absence of the RAR information in response to Msg1 transmitted by the UE can be determined depending on whether there is a random access preamble ID for the preamble transmitted by the UE. If there is no response to Msg1, the UE can retransmit the RACH preamble for a predetermined number of times while performing power ramping. The UE can calculate the PRACH transmission power for retransmitting the preamble based on the most recent path loss and a power ramping counter.

[0138] The RAR information transmitted on the PDSCH can include timing advance (TA) information for UL synchronization, an initial UL grant, and a temporary cell-RNTI (C-RNTI). The TA information can be used to control UL signal transmission timing. The UE can transmit an UL signal on an UL shared channel as a message 3 (Msg3) of the random access procedure based on the RAR information (see Figure 4 1705 of FIG. 17). The Msg3 can include an RRC connection request and a UE identifier. In response to the Msg3, the network can transmit a message 4 (Msg4), which can be considered as a contention resolution message on the DL (see Figure 4 1707 of FIG. 17). Upon receiving the Msg4, the UE can enter an RRC CONNECTED state.

[0139] On the other hand, when the UE is switched to another cell or BS or when it is requested by the BS, a contention-free random access procedure can be performed. In the contention-free random access procedure, a preamble to be used by the UE (hereinafter, referred to as a dedicated random access preamble) is allocated by the BS. Information about the dedicated random access preamble can be included in an RRC message (e.g., a handover command) or provided to the UE through a PDCCH order. When initiating the random access procedure, the UE can transmit the dedicated random access preamble to the BS. When the UE receives the RAR from the BS, the random access procedure is completed.

[0140] As described above, the UL grant in the RAR can schedule the PUSCH transmission to the UE. The PUSCH carrying the initial UL transmission based on the UL grant in the RAR is referred to as a Msg3 PUSCH. The content of the RAR UL grant can start at the MSB and end at the LSB, and the content can be given as shown in Table 3.

[0141] [Table 3]

[0142] RAR UL grant field Number of bits Frequency hopping flag 1 Msg3 PUCCH frequency resource allocation 12 Msg3 PUSCH time resource allocation 4 Modulation and coding scheme (MCS) 4 Transmit power control (TPC) for Msg3 PUSCH 3 CSI request 1

[0143] Figure 5 An example mapping of physical channels in a slot is illustrated. The PDCCH can be transmitted in a DL control region, and the PDSCH can be transmitted in a DL data region. The PUCCH can be transmitted in a UL control region, and the PUSCH can be transmitted in a UL data region. A guard period (GP) provides a time gap for transmission mode to reception mode switching or reception mode to transmission mode switching at the BS and the UE. Some symbols at the time of DL to UL switching in a subframe can be configured as a GP.

[0144] Each physical channel will be described in more detail below.

[0145] The PDCCH delivers DCI. For example, the PDCCH (i.e., DCI) can carry information on transport format and resource allocation of DL shared channel (DL-SCH), resource allocation information of uplink shared channel (UL-SCH), power control command, information about activation / deactivation of configured scheduling, etc. in addition to paging information on paging channel (PCH), system information on DL-SCH, information on resource allocation of higher layer control message, such as RAR transmitted on PDSCH, etc. The DCI includes cyclic redundancy check (CRC). The CRC is masked with various identifiers (IDs) (e.g., radio network temporary identifier (RNTI)) according to the owner or usage of the PDCCH. For example, if the PDCCH is for a specific UE, the CRC is masked with a UE ID (e.g., cell RNTI (C-RNTI)). If the PDCCH is for a paging message, the CRC is masked with a paging RNTI (P-RNTI). If the PDCCH is used for system information (e.g., system information block (SIB)), the CRC is masked with a system information RNTI (SI-RNTI). When the PDCCH is used for RAR, the CRC is masked with a random access-RNTI (RA-RNTI).

[0146] The PDCCH includes 1, 2, 4, 8, or 16 control channel elements (CCEs) according to its aggregation level (AL). The CCE is a logical allocation unit for providing a certain code rate for the PDCCH according to the state of a radio channel. The CCE includes 6 resource element groups (REGs), each of which is defined by one OFDM symbol×one (P) RB. The PDCCH is transmitted in a control resource set (CORESET). The CORESET is defined as a set of REGs having a given numerology (e.g., SCS, CP length, etc.). Multiple CORESETs for one UE can overlap with each other in the time / frequency domain. The CORESET can be configured by system information (e.g., master information block (MIB)) or UE-specific higher layer signaling (e.g., radio resource control (RRC) signaling). Specifically, the number of RBs and the number of symbols (up to 3) in the CORESET can be configured through higher layer signaling.

[0147] For PDCCH reception / detection, a UE monitors PDCCH candidates. A PDCCH candidate is a CCE that the UE should monitor to detect a PDCCH. Each PDCCH candidate is defined as 1, 2, 4, 8, or 16 CCEs according to an AL. Monitoring includes (blind) decoding of a PDCCH candidate. A set of PDCCH candidates decoded by a UE is defined as a PDCCH search space (SS). An SS can be a common search space (CSS) or a UE-specific search space (USS). A UE can obtain DCI by monitoring PDCCH candidates in one or more SSs configured by MIB or higher layer signaling. Each CORESET is associated with one or more SSs, and each SS is associated with one CORESET. An SS can be defined based on the following parameters.

[0148] - controlResourceSetld: CORESET related to the SS.

[0149] - monitoringSlotPeriodicityAndOffset: PDCCH monitoring periodicity (in units of slots) and PDCCH monitoring offset (in units of slots).

[0150] - monitoringSymbolsWithinSlot: PDCCH monitoring symbols in a slot (e.g., first symbol of a CORESET).

[0151] - nrofCandidates: Number of PDCCH candidates for each AL = {1, 2, 4, 8, 16} (one of 0, 1, 2, 3, 4, 5, 6, and 8).

[0152] * Where an occasion (e.g., time / frequency resource) in which a UE is to monitor a PDCCH candidate is defined as a PDCCH (monitoring) occasion. One or more PDCCH (monitoring) occasions can be configured in a slot.

[0153] Table 4 shows the characteristics of each SS.

[0154] [Table 4]

[0155]

[0156] Table 5 shows DCI formats transmitted on a PDCCH.

[0157] [Table 5]

[0158]

[0159] DCI format 0_0 can be used to schedule TB (or TB-level) based PUSCH, and DCI format 0_1 can be used to schedule TB (or TB-level) based PUSCH or code block group (CBG) (or CBG-level) based PUSCH. DCI format 1_0 can be used to schedule TB (or TB-level) based PDSCH, and DCI format 1_1 can be used to schedule TB (or TB-level) based PDSCH or CBG (or CBG-level) based PDSCH (DL grant DCI). DCI format 0_0 / 0_1 can be referred to as UL grant DCI or UL scheduling information, and DCI format 1_0 / 1_1 can be referred to as DL grant DCI or DL scheduling information. DCI format 2_0 is used to deliver dynamic slot format information (e.g., dynamic slot format indicator (SFI)) to UEs, and DCI format 2_1 is used to deliver DL pre-emption information to UEs. DCI format 2_0 and / or DCI format 2_1 can be delivered to a respective group of UEs on a group common PDCCH, which is a PDCCH for a group of UEs.

[0160] DCI format 0_0 and DCI format 1_0 can be referred to as fallback DCI formats, and DCI format 0_1 and DCI format 1_1 can be referred to as non-fallback DCI formats. In fallback DCI formats, DCI size / field configuration remains the same regardless of UE configuration. In contrast, DCI size / field configuration varies in non-fallback DCI formats depending on UE configuration.

[0161] PDSCH delivers DL data (e.g., DL shared channel transport block (DL-SCH TB)) and uses a modulation scheme such as quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation (16QAM), 64QAM, or 256QAM. A TB is encoded into a codeword. PDSCH can deliver up to two codewords. Scrambling and modulation mapping can be performed on a codeword basis, and modulation symbols generated from each codeword can be mapped to one or more layers. Each layer is mapped to a resource along with a demodulation reference signal (DMRS), and an OFDM symbol signal is generated from the mapped layers with DMRS and transmitted through a respective antenna port.

[0162] PUCCH delivers uplink control information (UCI). UCI includes the following information.

[0163] - SR (scheduling request): information for requesting UL-SCH resources.

[0164] - HARQ (Hybrid Automatic Repeat Request) - ACK (Acknowledgement): a response to a DL data packet (e.g., codeword) on PDSCH. The HARQ-ACK indicates whether the DL data packet has been successfully received. In response to a single codeword, a 1-bit HARQ-ACK can be transmitted. In response to two codewords, a 2-bit HARQ-ACK can be transmitted. The HARQ-ACK response includes a positive ACK (abbreviated as ACK), a negative ACK (NACK), a discontinuous transmission (DTX), or a NACK / DTX. The term HARQ-ACK is used interchangeably with HARQ ACK / NACK and ACK / NACK.

[0165] - CSI (Channel State Information): feedback information for a DL channel. The feedback information related to multiple-input multiple-output (MIMO) includes RI and PMI.

[0166] PUSCH delivers UL data (e.g., UL shared channel transport block (UL-SCH TB)) and / or UCI based on a CP-OFDM waveform or a DFT-s-OFDM waveform. When PUSCH is transmitted with a DFT-s-OFDM waveform, the UE transmits PUSCH with transform precoding. For example, when transform precoding is not possible (e.g., disabled), the UE can transmit PUSCH with a CP-OFDM waveform, and when transform precoding is possible (e.g., enabled), the UE can transmit PUSCH with a CP-OFDM waveform or a DFT-s-OFDM waveform. PUSCH transmission can be dynamically scheduled by an UL grant in DCI or semi-statically scheduled (configured scheduling or configured grant) by higher layer (e.g., RRC) signaling (and / or Layer 1 (L1) signaling such as PDCCH). PUSCH transmission can be performed in a codebook-based or non-codebook-based manner.

[0167] Initial UL BWP selection for cell access and initial access by a UE

[0168] Generally, a UE needs to support certain UE capabilities in order to access a cell. For example, in order to access an LTE cell, the UE needs to be able to receive the MIB and SIBs broadcast by the BS for the cell. Because there are several types of SIBs (e.g., SIB1, SIB2.., SIBx-y, etc.) and the SIBs are transmitted in multiple PRBs, a UE intending to access an LTE cell needs to have at least the capability to receive a 20 MHz bandwidth.

[0169] To access an NR cell, a UE needs to be able to receive MIB in SSB / PBCH transmitted in an initial DL BWP. Even if the UE is able to receive SSB / PBCH, based on cell access information contained in SIB1, the UE needs to check whether the UE is allowed to access the corresponding cell. For this, the UE can check whether there is a CORESET for Type0-PDCCH common search space (CSS) based on MIB. If there is Type0-PDCCH CSS, the UE can determine CORSET0 and PDCCH occasions based on information in MIB (e.g., pdcch-ConfigSIB1). Then, the UE can receive SIB1 through PDSCH indicated by PDCCH received on the corresponding PDCCH occasion.

[0170] Upon the UE receiving SIB, various information needs to be checked to determine whether the UE is allowed to access the cell. If the information does not satisfy some conditions, the UE can set the corresponding cell as a barred access cell. For example, the maximum UL channel bandwidth supported by the UE needs to be greater than or equal to the bandwidth of the initial UL BWP, and the maximum DL channel bandwidth supported by the UE needs to be greater than or equal to the bandwidth of the initial DL BWP. If this condition is not satisfied, the UE can set the corresponding cell as a barred access cell.

[0171] REL-17 NR aims to support a new type of UE with reduced capability. This type of UE is referred to as R-terminal or R-UE, which is different from a legacy REL-15 UE.

[0172] Because the UE capability of R-UE is limited compared to a legacy UE, problems can occur in a cell access procedure. For example, an R-UE can not be able to receive MIB in an initial DL BWP of a legacy NR cell. In addition, even if the R-UE is allowed to receive MIB, the R-UE can not be able to receive PDCCH scheduling CORSET#0 or SIB1. Alternatively, the maximum UL channel bandwidth or the maximum DL channel bandwidth of the R-UE can not be greater than or equal to the bandwidth of the initial BWP supported by a legacy NR cell. Alternatively, considering numerologies supported by the initial BWP of a legacy cell, the R-UE can not receive a paging message transmitted from a BS or can not be able to perform UL RACH transmission for initial access due to SCS. Due to these problems, a general NR cell can be frequently set as a barred access cell from the perspective of an R-UE.

[0173] The BS can need to provide a common channel transmission / reception method suitable for the R-UE at the beginning of the initial access procedure for the following reasons. First, a legacy UE can receive up to four transmissions based on frequency division multiplexing (FDM): paging, MIB, SIB1, and unicast, but the number of channels that the R-UE can simultaneously receive can be reduced due to the limited capability of the R-UE. Second, the numerology required for user service suitable for the R-UE can be different from the numerology accessible to the legacy UE, and thus the numerology of the initial BWP of the legacy cell can not be suitable for the R-UE. Third, the cell coverage of the R-UE can be reduced compared to that of the legacy UE due to the limited RF capability. Finally, the R-UE can require an improved power saving technique compared to the legacy UE.

[0174] Accordingly, the disclosure proposes a method in which, when an R-UE having a limited capability performs initial access to a wireless network system through a cell, a BS managing the corresponding cell provides an initial UL BWP available to the R-UE, and / or proposes a method in which the R-UE performs initial access based on the initial UL BWP. Specifically, the BS can provide two or more initial UL BWPs for a cell, and the UE can select one initial UL BWP from among the plurality of initial UL BWPs depending on a capability supported by the UE and / or at least some conditions, which will be described later. In addition, the UE can perform random access within the limited UE capability.

[0175] The UE can be provided with the following operations.

[0176] Figure 9 is a diagram for explaining UE operations in an initial UL BWP according to an embodiment of the disclosure.

[0177] Referring to Figure 9 The UE can detect a synchronization channel and receive master information for a cell (A05). The synchronization channel can correspond to an SSB. The master information can correspond to an MIB.

[0178] The UE can determine whether to configure a first initial UL BWP compatible with a first type of UE based on a capability of the UE (A10).

[0179] The first type of UE can have a reduced capability compared to a second type of UE corresponding to a Rel-15 NR UE.

[0180] The first initial UL BWP can be compatible with at least the first type of UE, and the second initial UL BWP can be compatible with at least the second type of UE.

[0181] The first initial UL BWP and the second initial UL BWP can provide different PRACH resources, and the configuration of the respective PRACH resources can be provided by SIB1 received in the first initial DL BWP mapped to the first initial UL BWP.

[0182] The UE can perform initial access to the cell based on the first initial UL BWP if one or more of the following conditions are met (A15). The UE can activate the first initial DL BWP to receive a response from the network and deactivate the second initial UL BWP used by the second type of UE during the initial access.

[0183] - when the capability of the UE cannot support the second initial UL BWP of the cell,

[0184] - when the first initial UL BWP is associated with at least the first type of UE, the association can be indicated by system information of the cell.

[0185] - for the UE, when the priority of the first initial UL BWP is higher than the priority of the second initial UL BWP,

[0186] - if quality of service (QoS) requirements are compatible with the first initial UL BWP, the QoS requirements can correspond to one or more of a delay, a priority, a data rate, a reliability, and a communication range mapped to a type of the UE, a service, a procedure, or a reason for triggering the initial access.

[0187] - when the UE is prohibited from using the second initial UL BWP or a DL BWP mapped to the second initial UL BWP,

[0188] - when a RSRP measurement result on an SSB for the cell is below (or above) a threshold value,

[0189] - when a congestion level (e.g., a number of LBT failures) of the second initial UL BWP is above a threshold value,

[0190] - when there is no RACH preamble associated with an SSB beam index having a RPRP measurement result above a threshold value, a set of RACH preambles configured for the first initial UL BWP is separated from a set of RACH preambles configured for the second initial UL BWP.

[0191] The UE transmits a RACH preamble or RACH MsgA (e.g., 2-step RACH MsgA) on the RACH resource configured by the network on the first initial UL BWP for initial access to the cell. Then, the UE receives a RAR or RACH MsgB on the initial DL BWP mapped to the first initial UL BWP for initial access to the cell. The initial DL BWP can also provide one or more of SSB, MIB, SIB1, other system information than SIB1, and paging at least for the first type of UE.

[0192] In the following, the first initial UL BWP is referred to as initial UL R-BWP, and the second initial UL BWP is referred to as initial UL BWP.

[0193] The transmission side (e.g., UE):

[0194] According to the proposal of the present disclosure, the R-UE can receive a (new) SIB1 configured for the R-UE if certain conditions are met. For example, the R-UE can receive a new SIB1 when the R-UE cannot receive the legacy SIB1 transmission, when the legacy SIB1 is not relevant for the R-UE (e.g., when the legacy SIB1 is not the SIB1 for the R-UE), and / or when the R-UE needs to receive additional R-UE specific information in addition to the legacy SIB1 information. For convenience, the SIB1 that can be received by the R-UE is referred to as R-SIB1. The R-SIB1 can include all or part of the configuration information included in the legacy SIB1, and the R-SIB1 can also include configuration information specific to the R-UE. The legacy UE does not receive the R-SIB1.

[0195] When the legacy UE is in idle mode, the legacy UE can activate the initial DL BWP to receive system information or paging messages. However, the R-UE can not support the legacy initial DL BWP, or the legacy initial DL BWP can not be suitable for the operation of the R-UE. Therefore, the R-UE can operate (e.g., receive system information or paging messages) by activating the initial DL R-BWP specific to the R-UE.

[0196] Therefore, when the UE performs a RACH procedure for initial access, the UE can need to receive a DL transmission in the initial DL BWP or the initial DL R-BWP.

[0197] The R-UE can (i) perform a RACH procedure in the initial UL BWP or initial UL R-BWP based on the same RACH configuration information provided to legacy UEs, (ii) perform a RACH procedure in the initial UL BWP or initial UL R-BWP based on RACH configuration information dedicated for R-UEs, or (iii) perform a RACH procedure in the initial UL BWP or initial UL R-BWP based on both (at least part of) the RACH configuration information for legacy UEs and the RACH configuration information dedicated for R-UEs (e.g., based on configuration information obtained by combining / merging the RACH configuration information for legacy UEs and the RACH configuration information dedicated for R-UEs).

[0198] Similar to legacy UEs, the R-UE can also perform a RACH procedure: (i) when the UE requests or resumes an RRC connection; (ii) when the UE switches to a neighboring cell or performs a secondary cell group (SCG) addition; (iii) when the UE transmits a scheduling request to the BS; (iv) when the BS indicates the UE to perform random access with a PDCCH order; (v) when the UE requests system information; and / or (vi) when the UE detects a beam failure or an RRC connection failure.

[0199] When a UE in idle mode or connected mode performs a 4-step or 2-step RACH procedure, the R-UE can perform at least some of the following operations.

[0200] Operation 1) The R-UE can measure the SSB beam(s) or CSI-RS beam(s) in the initial DL BWP or initial DL R-BWP. The UE can select the RACH preamble and the PRACH resource linked / corresponding / mapped (e.g., logically mapped) to the index of the best SSB (i.e., the best beam) or the index of the CSI-RS. In this case, the DL BWP used by the UE to measure the beam(s) during the RACH procedure can be indicated by the RACH configuration information in the SIB1 or R-SIB1. Alternatively, the UE can select the RACH preamble and the PRACH resource corresponding to the best beam by measuring the SSB beam(s) or CSI-RS beam(s) based on the active DL BWP. For example, if the initial DL R-BWP is active, the UE can measure the SSB beam(s) or CSI-RS beam(s) in the initial DL R-BWP. On the other hand, if the initial DL R-BWP is not active, but if the legacy initial DL BWP is active, the UE can select the RACH preamble and the PRACH resource corresponding to the best beam by measuring the SSB beam(s) or CSI-RS beam(s) in the legacy initial DL BWP.

[0201] If the BS provides the RACH preamble set and the PRACH resource set specifically allocated to the UE in the SIB1 or R-SIB1, the R-UE can need to select the RACH preamble and the PRACH resource corresponding to the best beam from the RACH preamble set and the PRACH resource set specifically allocated to the R-UE. Thus, upon receiving the RACH preamble / resource specific to the R-UE, the BS can know that the UE is the R-UE, so that the BS can perform subsequent message transmission / reception suitable for the R-UE. If there is no RACH preamble set and / or PRACH resource set specifically allocated to the R-UE, the R-UE can select the RACH preamble and the PRACH resource corresponding to the best beam from the RACH preamble set and the PRACH resource set shared between the R-UE and the legacy UE.

[0202] In this case, the R-UE can select / configure the initial UL BWP or initial UL R-BWP in which the RACH preamble and the PRACH resource selected by the UE are located. The R-UE can select the initial UL BWP and / or the initial UL R-BWP according to one or more of the following conditions. Independently of or in addition to selecting the initial UL BWP / R-BWP, the R-UE can select the initial DL BWP and / or the initial DL R-BWP according to one or more of the following conditions (e.g., Figure 10 of B05).

[0203] - Condition 1: If the capability of the R-UE does not support the initial UL BWP, the R-UE can select the initial UL R-BWP. Otherwise, the R-UE can select the initial UL BWP.

[0204] - Condition 2: If the initial UL R-BWP is available for the R-UE, the R-UE can select the initial UL R-BWP. Otherwise, the R-UE can select the initial UL BWP. The availability of the R-BWP can be obtained / determined by system information (e.g., SIB1 or R-SIB1) transmitted by the cell or a UE-specific signal provided by the network.

[0205] - Condition 3: If the priority of the initial UL R-BWP is higher than the priority of the initial UL BWP, the R-UE can select the initial UL R-BWP. The priority information can be obtained from system information (e.g., SIB1 or R-SIB1) transmitted by the cell or a UE-specific signal provided by the network.

[0206] - Condition 4: If the initial UL R-BWP satisfies the QoS requirement (and if the initial UL BWP does not satisfy the QoS requirement), the R-UE can select the initial UL R-BWP. In this case, the QoS requirement can be mapped / correlated with latency, priority, transmission rate, transmission data volume, reliability, and / or communication range in meters (which can include one, some, or all of them). The QoS requirement can be determined / configured based on at least one of: a UE type (e.g., normal smartphone, smartwatch, IoT device, etc.); a UE category (e.g., Category 0, Category 1, etc.) (e.g., BWP determination / selection based on the UE category); a UE capability as specified in TS 38.331; a cause of the RACH transmission (e.g., high priority access, delay tolerant access, mobile originated signaling, mobile originated data, etc.); a procedure that triggers the RACH transmission (e.g., RRC connection establishment, RRC connection resume, RRC connection reset, system information request, RAN area update, tracking area update, etc.); and / or a service or application that triggers the RACH transmission (e.g., massive MTC, URLLC, short message, sensor information, CCTV video, factory automation command, image file, firmware upgrade, etc. as identified by an upper layer with a service ID or an application ID).

[0207] - Condition 5: When the R-UE is prohibited to perform the RACH transmission in the initial UL BWP or to perform the access on the initial UL BWP, the R-UE can select the initial UL R-BWP.

[0208] - Condition 6: When the cell quality measured on the SSB or CSI-RS is lower than or equal to a certain threshold (or higher than or equal to a certain threshold), the R-UE can select the initial UL R-BWP. Otherwise, the R-UE can select the initial UL BWP.

[0209] - Condition 7: If the congestion level of the initial UL BWP is higher than or equal to a certain level, the R-UE can select the initial UL R-BWP. Otherwise, the R-UE can select the initial UL BWP. For example, when LBT failure for RACH transmission in the initial UL BWP occurs a certain number of times or more (e.g., when the number of times that the channel is determined to be busy after LBT is greater than or equal to a threshold), the R-UE can switch to / select the initial UL R-BWP.

[0210] - Condition 8: When the RACH preamble and PRACH resource of the initial UL BWP are separated from the RACH preamble and PRACH resource of the initial UL R-BWP, the R-UE can select the initial UL BWP or the initial UL R-BWP in which the best beam is located. That is, if the best beam is not in the initial UL BWP, the R-UE can select the initial UL R-BWP. Alternatively, if the best beam is not in the initial UL R-BWP, the R-UE can select the initial UL BWP.

[0211] Operation 2) The R-UE can activate the selected BWP (e.g., Figure 10 ). For example, if the R-UE selects the initial UL R-BWP, the R-UE can activate the initial UL R-BWP and the initial DL BWP or the initial DL R-BWP mapped to the initial UL R-BWP. In this case, the R-UE can deactivate the initial DL BWP or can maintain the initial UL BWP in an active state. On the other hand, the R-UE can deactivate the initial DL BWP or the initial DL R-BWP mapped to the initial UL BWP, or can maintain the initial DL BWP or the initial DL R-BWP in an active state. The R-UE can receive configuration information about the initial DL R-BWP mapped to the initial UL R-BWP or the initial DL BWP in the SIB1, the R-SIB1, or the UE-specific signal.

[0212] Operation 3) The UE can transmit a RACH preamble or a RACH MsgA in the active BWP based on the previously selected RACH preamble and / or PRACH resource (e.g., Figure 10B15). If the UE does not receive the response from the BS, the UE can select the RACH preamble and / or PRACH resource in the same way as in the above procedure and then transmit the RACH preamble (Msg1) or RACH MsgA in the active BWP. In this case, the UE can reselect the BWP in the same way as in the above procedure. If the reselected BWP is different from the initially selected BWP, the UE can deactivate the initially selected UL BWP and the DL BWP mapped / associated with it.

[0213] Operation 4) After transmitting the RACH preamble (Msg1) or RACH MsgA, the UE can attempt to receive the response (e.g., RAR or MsgB) from the BS in the active initial DL BWP or initial DL R-BWP (e.g., Figure 10 B20). For example, if a Type1-PDCCH common search space (CSS) set is configured by PDCCH-ConfigCommon, the UE can monitor the PDCCH with CRC scrambled by RA-RNTI or temporary C-RNTI in the corresponding CSS.

[0214] In this case, according to the configuration information provided by the BS, the CSS for the RACH response can be located in the initial DL BWP or initial DL R-BWP. For example, the R-UE can transmit the RACH preamble or RACH MsgA in the initial UL R-BWP and monitor the DCI scrambled by the RA-RNTI in the CSS of the initial DL BWP. Alternatively, the R-UE can transmit the RACH preamble or RACH MsgA in the initial UL R-BWP and monitor the DCI scrambled by the RA-RNTI in the CSS of the initial DL R-BWP. In this case, the DCI can indicate the DL BWP in which the R-UE needs to receive the PDSCH. For example, the received DCI can indicate the initial DL BWP or initial DL R-BWP. Alternatively, the SIB1 or R-SIB1 can indicate the DL BWP in which the R-UE needs to receive the PDSCH. The R-UE can select and activate the indicated DL BWP and receive the PDSCH in the DL BWP.

[0215] For example, the UE can interpret / assume that the BWP in which Msg2 is received corresponds to the R-BWP. The BWP interpreted / assumed by the UE as the R-BWP can be the R-BWP different from the legacy UE BWP. However, the BWP can be the same as or at least partially overlap with the legacy UE BWP.

[0216] Operation 5) When the DCI received on PDCCH is based on C-RNTI (e.g., PDCCH scrambled with C-RNTI CRC), and when the corresponding C-RNTI is the same as the C-RNTI of the R-UE, or when the RAR MAC control element (CE) included in the PDSCH indicates the RACH preamble selected by the UE, the R-UE can determine that Msg2 is successfully received.

[0217] In this case, the RAR MAC CE (e.g., Msg2 PDSCH), PDCCH (e.g., Msg2 PDCCH), or MsgB can indicate the UE to switch to a specific UL BWP for Msg3 transmission or subsequent UL transmission. For example, the message can indicate the UE to switch to the initial UL BWP or the initial UL R-BWP. According to the instruction, the UE can activate the UL BWP to which the UE switches and deactivate the previous UL BWP.

[0218] 6) The R-UE can transmit an UL signal (e.g., PUSCH) on the UL resource allocated by the RAR MAC CE or PDCCH in the activated UL BWP (B25).

[0219] The receiving side (e.g., BS):

[0220] In the above example, from the perspective of the BS, one cell needs to operate two types of SIB1 simultaneously: SIB1 and R-SIB1. For example, one type of MIB can be mapped to both of the two types of SIB1. Alternatively, the MIB can be mapped to / associated with the legacy SIB1, and the legacy SIB1 can be mapped to / associated with the R-SIB1. In addition, the legacy SIB1 and / or the R-SIB1 can include scheduling information (e.g., SchedulingInfoList) informing whether other SIBs are broadcast and their transmission period. Furthermore, one cell can operate the legacy SIBx and the new SIBx simultaneously.

[0221] The new SIBx can include R-UE specific information or information irrelevant to the legacy UE, which is referred to as R-SIBx.

[0222] The BS can provide RACH configuration information available for R-UEs in SIB1 or R-SIB1 through one cell.

[0223] Figure 11 An example RACH configuration information in SIB1 or R-SIB1 is illustrated.

[0224] Referring to Figure 11All parameters of the RACH-ConfigCommon can be included in the SIB1, or all parameters can be included in the R-SIB1. Alternatively, some parameters can be included in the SIB1 and some parameters can be included in the R-SIB1. Accordingly, the R-UE can perform the RACH procedure by receiving only the SIB1, only the R-SIB1, or both the SIB1 and the R-SIB1. Here, the R-SIB1 can be replaced with SIBx. Specifically, the SIBx can represent that the R-SIB1 carries some or all of the RACH configuration information. For example, information on the BWP (e.g., the initial UL BWP, the initial UL R-BWP, the initial DL BWP, and / or the initial DL R-BWP) to which the RACH configuration information of Figure 11 is applicable can be additionally included in the corresponding RACH configuration information.

[0225] According to the disclosure, the UE with limited capability is allowed to appropriately configure the initial UL BWP dedicated thereto according to a certain condition, and thus, even in a cell in which the UE coexists with a legacy UE, the UE can appropriately perform the initial UL transmission.

[0226] Figure 12 An exemplary signal transmission / reception method based on the above proposal is illustrated. Figure 12 is one of examples to which the disclosure is applicable, and the disclosure is not limited to Figure 12 the example of Figure 12 .

[0227] The BS can transmit RACH configuration for at least one of a plurality of UL BWPs (D05), and the UE can obtain the RACH configuration for at least one of the plurality of UL BWPs. The plurality of UL BWPs can include a first UL BWP related only to a first type UE having a reduced capability to support a smaller bandwidth than a predetermined bandwidth and a second UL BWP related to a second type UE different from the first type UE.

[0228] The UE can select an initial UL BWP from among the plurality of UL BWPs (D10).

[0229] The UE can transmit a random access preamble on the initial UL BWP selected from among the plurality of UL BWPs based on the RACH configuration (D15). The BS can detect the random access preamble in the plurality of UL BWPs based on the RACH configuration (D20).

[0230] The UE can be the first type UE and be configured to select the first UL BWP or the second UL BWP as the initial UL BWP according to whether a predetermined condition is satisfied.

[0231] Based on the fact that the predetermined condition is not satisfied even if the UE is the first type UE, the UE can be configured to select the second UL BWP as the initial UL BWP.

[0232] Based on the fact that the capability of the UE does not support the second UL BWP, the UE can be configured to determine that the predetermined condition is satisfied and select the first UL BWP as the initial UL BWP.

[0233] Based on the fact that the capability of the UE supports the second UL BWP even if the UE is the first type UE, the UE can be configured to determine that the predetermined condition is not satisfied and select the second UL BWP as the initial UL BWP.

[0234] Based on the fact that the first UL BWP is available to the UE, the UE can be configured to determine that the predetermined condition is satisfied and select the first UL BWP as the initial UL BWP.

[0235] Based on the fact that the first UL BWP is not available to the UE even if the UE is the first type UE, the UE can be configured to determine that the predetermined condition is not satisfied and select the second UL BWP as the initial BWP.

[0236] Based on the fact that the first UL BWP is available to the UE, the UE can be configured to determine that the predetermined condition is satisfied regardless of the availability of the second UL BWP, and select the first UL BWP as the initial UL BWP.

[0237] The UE can be configured to determine the availability of the first UL BWP based on higher layer information obtained from the network.

[0238] The BS can provide the UE with information on the predetermined condition for the first type UE to select the initial UL BWP. The information on the predetermined condition (e.g., a condition for selecting the initial UL BWP) provided by the BS can be a criterion for the first type to select one of the first UL BWP and the second UL BWP as the initial UL BWP.

[0239] Figure 13 A communication system 1 to which the present disclosure is applied is illustrated.

[0240] Reference Figure 13, applied to the communication system 1 of the disclosure includes a wireless device, a base station (BS), and a network. Herein, a wireless device denotes a device performing communication using a radio access technology (RAT) (e.g., 5G new RAT (NR) or long term evolution (LTE)), and can be referred to as a communication / radio / 5G device. The wireless device can include, but is not limited to, a robot 100a, vehicles 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, the vehicles can include vehicles having a wireless communication function, self-driving vehicles, and vehicles capable of performing communication between vehicles. Herein, the vehicles can include unmanned aerial vehicles (UAVs) (e.g., drones). The XR device can include an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and can be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The handheld device can include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or smartglasses), and a computer (e.g., a notebook). The home appliance can include a TV, a refrigerator, and a washing machine. The IoT device can include a sensor and a smartmeter. For example, the BS and the network can be implemented as a wireless device, and a specific wireless device 200a can operate as a BS / network node with respect to other wireless devices.

[0241] The wireless devices 100a to 100f can be connected to the network 300 via the BS 200. The AI technology can be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f can be connected to the AI server 400 via the network 300. The network 300 can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f can communicate with each other through the BS 200 / network 300, the wireless devices 100a to 100f can perform direct communication (e.g., sidelink communication) with each other without going through the BS / network. For example, the vehicles 100b-1 and 100b-2 can perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) can perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0242] Wireless communication / connection 150a, 150b, or 150c can be established between the wireless devices 100a to 100f / BS 200 or the BS 200 / BS 200. Herein, the wireless communication / connection can be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication), or inter-BS communication (e.g., relay, integrated access backhaul (IAB)). The wireless devices and the BS / wireless devices can transmit / receive radio signals to / from each other through the wireless communication / connection 150a and 150b. For example, the wireless communication / connection 150a and 150b can transmit / receive signals through various physical channels. To this end, at least a part of various configuration information of procedures for transmitting / receiving radio signals, various signal processing procedures (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and resource allocation procedures can be performed based on various proposals of the disclosure.

[0243] Figure 14 A wireless device suitable for the disclosure is illustrated.

[0244] Referring to Figure 14 , the first wireless device 100 and the second wireless device 200 can transmit radio signals through various RATs (e.g., LTE and NR). Herein, the {first wireless device 100 and the second wireless device 200} can correspond to Figure 13 {wireless device 100x and BS 200} and / or {wireless device 100x and wireless device 100x} of the disclosure.

[0245] The first wireless device 100 can include one or more processors 102 and one or more memories 104, and additionally further include one or more transceivers 106 and / or one or more antennas 108. The processor(s) 102 can control the memory(s) 104 and / or the transceiver(s) 106, and can be configured to implement the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in the present document. For example, the processor(s) 102 can process information within the memory(s) 104 to generate first information / signals, and then transmit radio signals including the first information / signals through the transceiver(s) 106. The processor(s) 102 can receive radio signals including second information / signals through the transceiver(s) 106, and then store information obtained by processing the second information / signals in the memory(s) 104. The memory(s) 104 can be connected to the processor(s) 102, and can store a variety of information related to the operation of the processor(s) 102. For example, the memory(s) 104 can store software code including commands for executing some or all of the procedures controlled by the processor(s) 102 or for executing the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in the present document. Herein, the processor(s) 102 and the memory(s) 104 can be a part of a communication modem / circuitry / chip designed to implement a RAT (e.g., LTE or NR). The transceiver(s) 106 can be connected to the processor(s) 102 and transmit and / or receive radio signals through the one or more antennas 108. Each of the transceiver(s) 106 can include a transmitter and / or a receiver. The transceiver(s) 106 can be used interchangeably with radio frequency (RF) unit(s). In the present disclosure, a wireless device can represent a communication modem / circuitry / chip.

[0246] The second wireless device 200 can include one or more processors 202 and one or more memories 204, and additionally further include one or more transceivers 206 and / or one or more antennas 208. The processor(s) 202 can control the memory(s) 204 and / or the transceiver(s) 206, and can be configured to implement the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in the present document. For example, the processor(s) 202 can process information within the memory(s) 204 to generate third information / signal, and then transmit a radio signal including the third information / signal through the transceiver(s) 206. The processor(s) 202 can receive a radio signal including fourth information / signal through the transceiver(s) 206, and then store information obtained by processing the fourth information / signal in the memory(s) 204. The memory(s) 204 can be connected to the processor(s) 202, and can store a variety of information related to operations of the processor(s) 202. For example, the memory(s) 204 can store software code including commands for executing some or all of the procedures controlled by the processor(s) 202 or for executing the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in the present document. Herein, the processor(s) 202 and the memory(s) 204 can be a part of a communication modem / circuitry / chip designed to implement a RAT (e.g., LTE or NR). The transceiver(s) 206 can be connected to the processor(s) 202 and transmit and / or receive a radio signal through the one or more antennas 208. Each of the transceiver(s) 206 can include a transmitter and / or a receiver. The transceiver(s) 206 can be used interchangeably with RF unit(s). In the present disclosure, a wireless device can represent a communication modem / circuitry / chip.

[0247] Hereinafter, the hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers can be implemented by, but not limited to, the one or more processors 102 and 202. For example, the one or more processors 102 and 202 can implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more processors 102 and 202 can generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document. The one or more processors 102 and 202 can generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document. The one or more processors 102 and 202 can generate signals (e.g., baseband signals) including the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document, and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 can receive signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document.

[0248] The one or more processors 102 and 202 can be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102 and 202 can be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) can be included in the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document can be implemented using firmware or software, and the firmware or software can be configured to include modules, procedures, or functions. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document can be included in the one or more processors 102 and 202 or stored in the one or more memories 104 and 204 to be driven by the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document can be implemented using firmware or software in the form of codes, commands, and / or command sets.

[0249] One or more memories 104 and 204 can be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories 104 and 204 can be configured by read-only memory (ROM), random-access memory (RAM), electrically programmable read-only memory (EPROM), flash memory, hard disk drive, register, cache memory, computer readable storage media, and / or a combination thereof. The one or more memories 104 and 204 can be located internal and / or external to the one or more processors 102 and 202. The one or more memories 104 and 204 can be connected to the one or more processors 102 and 202 through various technologies, such as wired or wireless connections.

[0250] The one or more transceivers 106 and 206 can transmit user data, control information, and / or radio signals / channels mentioned in the methods and / or operational flowcharts of the present document, to one or more other devices. The one or more transceivers 106 and 206 can receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document, from one or more other devices. For example, the one or more transceivers 106 and 206 can be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 can perform control so that the one or more transceivers 106 and 206 can transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 can perform control so that the one or more transceivers 106 and 206 can receive user data, control information, or radio signals from one or more other devices. The one or more transceivers 106 and 206 can be connected to the one or more antennas 108 and 208, and the one or more transceivers 106 and 206 can be configured to transmit and receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present document, through the one or more antennas 108 and 208. In the present document, the one or more antennas can be a plurality of physical antennas or a plurality of logical antennas (for example, antenna ports). The one or more transceivers 106 and 206 can convert received radio signals / channels, etc. from RF band signals to baseband signals in order to process received user data, control information, radio signals / channels, etc. using the one or more processors 102 and 202. The one or more transceivers 106 and 206 can convert user data, control information, radio signals / channels, etc. processed using the one or more processors 102 and 202 from baseband signals to RF band signals. To this end, the one or more transceivers 106 and 206 can include (analog) oscillators and / or filters.

[0251] Figure 15 FIG. 1 is a diagram illustrating a DRX operation of a UE according to an embodiment of the present disclosure.

[0252] A UE can perform DRX operation in the procedures and / or methods described / proposed above. A UE configured with DRX can reduce power consumption by discontinuously receiving DL signals. DRX can be performed in an RRC_IDLE state, an RRC_INACTIVE state, and an RRC_CONNECTED state. A UE performs DRX in an RRC_IDLE state and an RRC_INACTIVE state to discontinuously receive a paging signal. DRX in an RRC_CONNECTED state (RRC_CONNECTED DRX) will be described below.

[0253] A DRX cycle includes an ON duration and a DRX opportunity. The DRX cycle defines a time interval between periodic repetitions of the ON duration. The ON duration is a time period in which a UE monitors PDCCH. When a UE is configured with DRX, the UE performs PDCCH monitoring during the ON duration. When a UE successfully detects a PDCCH during PDCCH monitoring, the UE starts an inactivity timer and remains awake. In contrast, when a UE fails to detect any PDCCH during PDCCH monitoring, the UE transitions to a sleep state after the ON duration. Thus, when DRX is configured, PDCCH monitoring / reception can be performed discontinuously in time domain in the procedures and / or methods described / proposed above. For example, when DRX is configured, PDCCH reception occasions (e.g., slots with PDCCH SS) can be configured discontinuously according to DRX in the present disclosure. In contrast, when DRX is not configured, PDCCH monitoring / reception can be performed continuously in time domain. For example, when DRX is not configured, PDCCH reception occasions (e.g., slots with PDCCH SS) can be configured continuously in the present disclosure. Regardless of whether DRX is configured, PDCCH monitoring can be limited during a time period configured as a measurement gap.

[0254] The above-described embodiments are combinations of elements and features of the present disclosure in a specific form. Unless otherwise mentioned, these elements or features can be considered selective unless otherwise mentioned. Each element or feature can be implemented without being combined with other elements or features. Further, some elements and / or some features can be combined to configure an embodiment of the present disclosure. The order of the operations described in the embodiments of the present disclosure can be changed. Some constructions or features of any one embodiment can be included in another embodiment or can substitute for corresponding constructions or features of another embodiment. It is apparent that claims that are not explicitly mentioned in the appended claims can be presented as an embodiment of the present disclosure, or can be included in new claims after amendments after the application is submitted.

[0255] Those skilled in the art will appreciate that the disclosure herein is susceptible to variations in light of the above teachings, that the disclosure can be practiced or carried out in various ways, and that the disclosure can take a variety of embodiments. Accordingly, the disclosure is not limited by the foregoing description, and aspects of the disclosure that are within the scope of the appended claims along with their legal equivalents are covered whether now or in the future. The scope of the disclosure should be determined with reference to the appended claims, along with the full text of this disclosure, and legal equivalents in which the claims or their equivalents are implemented.

[0256] Industrial Applicability

[0257] The disclosure is applicable to a UE, a BS, or other apparatus in a wireless mobile communication system.

Claims

1. A method performed by a user equipment (UE), the method comprising: obtaining at least one random access channel (RACH) configuration; selecting an initial uplink (UL) bandwidth part (BWP) from among UL BWPs; and transmitting a random access preamble on the initial UL BWP selected from among the UL BWPs based on the at least one RACH configuration, and monitoring a physical downlink control channel (PDCCH), wherein the UL BWPs include a first UL BWP dedicated to a first type of UE having reduced capabilities compared to a second type of UE and a second UL BWP related to the second type of UE, wherein the UE is the first type of UE, wherein the first UL BWP is selected as the initial UL BWP for the UE based on a system information block 1 (SIB1), wherein the PDCCH is monitored in a first initial downlink (DL) BWP dedicated to the first type of UE, and wherein the random access preamble is determined based on a measurement of a synchronization signal block (SSB) associated with a second initial DL BWP related to the second type of UE. The at least one RACH configuration includes at least one of a first RACH configuration dedicated to the first type of UE and a second RACH configuration used by the second type of UE.

2. The method of claim 1, wherein, The at least one RACH configuration includes both the first RACH configuration and the second RACH configuration, and the UE transmits the random access preamble based on the first RACH configuration instead of the second RACH configuration.

3. The method of claim 2, wherein, The first type of UE supports a smaller maximum bandwidth than the second type of UE.

4. The method of claim 1, wherein, 5. A device comprising: a memory configured to store instructions; and a processor configured to perform operations by executing the instructions, wherein the operations performed by the processor include: obtaining at least one random access channel (RACH) configuration; selecting an initial uplink (UL) bandwidth part (BWP) from among UL BWPs; and transmitting a random access preamble on the initial UL BWP selected from among the UL BWPs based on the at least one RACH configuration, monitoring a physical downlink control channel (PDCCH), wherein the UL BWPs include a first UL BWP dedicated to a first type of device having reduced capabilities compared to a second type of device and a second UL BWP related to the second type of device, wherein the device is the first type of device, wherein the first UL BWP is selected as the initial UL BWP for the device based on a system information block 1 (SIB1), wherein the PDCCH is monitored in a first initial downlink (DL) BWP dedicated to the first type of device, and wherein the random access preamble is determined based on a measurement of a synchronization signal block (SSB) associated with a second initial DL BWP related to the second type of device. ​ ​ 6.The device of claim 5, further comprising a transceiver configured to transmit and receive radio signals under control of the processor, wherein the device is a user equipment (UE).

7. The apparatus of claim 5, wherein, The device is an application specific integrated circuit (ASIC) or a digital signal processing device.

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