WO2025174049A1 - Method and device for transmitting and receiving wireless signals in wireless communication system - Google Patents

Abstract

Disclosed are a method performed by a UE and a device therefor in a wireless communication system according to various embodiments. Disclosed are a device and a method therefor, the device: receiving random access channel (RACH) resource configuration information for configuring a default random access channel occasion (RO) and additional ROs related to network energy saving (NES); and transmitting a physical random access channel (PRACH) on the basis of the RACH resource configuration information.

Description

Method and device for transmitting and receiving wireless signals in a wireless communication system

This specification relates to a wireless communication system, and more specifically, to a method and device for transmitting and receiving wireless signals.

Wireless communication systems are widely deployed to provide various types of communication services, such as voice and data. Typically, wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power). Examples of multiple access systems include 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).

As more and more communication devices demand ever-increasing communication traffic, the need for next-generation 5G systems, which offer enhanced wireless broadband communication capabilities over existing LTE systems, is growing. This next-generation 5G system, known as NewRAT, differentiates communication scenarios into Enhanced Mobile Broadband (eMBB), Ultra-reliability and low-latency communication (URLLC), and Massive Machine-Type Communications (mMTC).

Here, eMBB is a next-generation mobile communication scenario with characteristics such as High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate; URLLC is a next-generation mobile communication scenario with characteristics such as Ultra Reliable, Ultra Low Latency, and Ultra High Availability (e.g., V2X, Emergency Service, Remote Control); and mMTC is a next-generation mobile communication scenario with characteristics such as Low Cost, Low Energy, Short Packet, and Massive Connectivity (e.g., IoT).

The technical problem to be achieved by the present invention is to provide a more accurate and efficient signal transmission and reception method and a device therefor.

The technical challenges are not limited to the technical challenges mentioned above, and other technical challenges not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

A method by a UE (User Equipment) according to one aspect includes the steps of: receiving RACH (Random Access Channel) resource configuration information for configuring a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving); and transmitting a PRACH (Physical Random Access Channel) based on the RACH resource configuration information; wherein whether the additional RO is activated can be indicated through DCI (Downlink Control Information) of a specific format.

Alternatively, the DCI of the above specific format is characterized in that it is a DCI of group common DCI format 1_0 having a CRC (cyclic redundancy check) scrambled with a specific RNTI (Paging-Radio Network Temporary Identifier) related to an activation instruction of the above additional RO.

Alternatively, the additional RO is characterized in that whether it is activated is indicated through reserved bits included in the DCI format 1_0.

Alternatively, based on the overlap of the additional RO with the default RO, the beam direction of the additional RO is considered to be the same beam direction as the beam direction determined for the default RO.

Alternatively, the additional RO is characterized in that the additional RO is considered invalid based on the fact that the additional RO overlaps with the default RO.

Alternatively, the RACH resource configuration information is characterized in that it sets a plurality of default ROs including the default RO and a plurality of additional ROs including the additional RO, and the UE performs SSB mapping only for the remaining additional ROs excluding the additional RO overlapping with the default RO among the plurality of additional ROs.

Alternatively, the RACH resource configuration information is characterized in that it further includes information for setting priorities between the default RO and the additional RO.

Alternatively, the RACH resource configuration information is characterized in that it further includes information on a specific offset for configuring the additional RO based on the default RO.

Alternatively, the default RO is characterized in that it is always valid regardless of the indication of whether it is activated via the DCI.

A storage medium storing programs for performing the above-described method by the UE according to another aspect may be provided.

A UE may be provided that performs the above-described method according to another aspect.

A processing device may be provided for controlling a UE to perform the above-described method according to another aspect.

A method performed by a base station according to another aspect includes the steps of transmitting RACH (Random Access Channel) resource configuration information for configuring a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving); and receiving a PRACH (Physical Random Access Channel) based on the RACH resource configuration information; wherein whether the additional RO is activated can be indicated through DCI (Downlink Control Information) of a specific format.

According to various embodiments, signals can be transmitted or received more accurately and efficiently in a wireless communication system.

Alternatively, power usage of the network and/or terminals in a wireless communication system can be more efficiently controlled.

The effects that can be obtained in various embodiments are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

The drawings attached to this specification are intended to provide an understanding of the present invention, illustrate various embodiments of the present invention, and together with the description of the specification serve to explain the principles of the present invention.

Figure 1 is a drawing for explaining physical channels used in a 3GPP NR system and a general signal transmission method using them.

Figure 2 illustrates the structure of a radio frame.

Figure 3 illustrates a resource grid of slots.

Figure 4 illustrates an example of physical channels being mapped within a slot.

FIG. 5 and FIG. 6 are diagrams for explaining Idle Mode DRX (Discontinuous Reception) operation.

FIGS. 7 to 9 are diagrams for explaining DRX operation in RRC (Radio Resource Control) connected mode.

Figure 10 is a diagram for explaining a method of monitoring DCI format 2_6.

FIG. 11 is a diagram for explaining a method for performing communication based on cell DRX/DTX between a base station and a terminal.

Figure 12 is a diagram for explaining transmission of On-demand SIB1.

FIG. 13 is a diagram for explaining a method for a UE to transmit a signal based on RACH resource configuration information.

Figure 14 is a diagram for explaining a method for a base station to transmit RACH resource configuration information.

Figures 15 to 18 illustrate a communication system (1) and a wireless device applicable to the present invention.

The following technologies can be used in various wireless access systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with radio technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented with radio technologies such as GSM (Global System for Mobile communications)/GPRS (General Packet Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented with radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is a part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) 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.

As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing RAT (Radio Access Technology) is emerging. Furthermore, massive MTC (Machine Type Communications), which connects multiple devices and objects to provide various services anytime, anywhere, is also a key issue to be considered in next-generation communication. Furthermore, communication system design that considers reliability and latency-sensitive services/terminals is being discussed. Accordingly, the introduction of next-generation RATs that consider enhanced Mobile BroadBand Communication (eMBB), massive MTC, and Ultra-Reliable and Low Latency Communication (URLLC) is being discussed. In one embodiment of the present invention, for convenience, the corresponding technology is referred to as NR (New Radio or New RAT).

The term 'base station' used in this specification may be replaced with terms such as fixed station, Node B, gNode B (gNB), Access Point (AP), cell, or transmission and reception point (TRP). The term 'relay node' may be replaced with terms such as Relay Node (RN) or Relay Station. In addition, the term 'terminal' may be replaced with terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), or Subscriber Station (SS).

For clarity of explanation, the description will focus on 3GPP NR, but the technical idea of the present invention is not limited thereto.

The following documents may be referenced for background information, definitions of terms, abbreviations, etc. related to the present invention (Incorporated by Reference).

- 38.211: Physical channels and modulation

- 38.212: Multiplexing and channel coding

- 38.213: Physical layer procedures for control

- 38.214: Physical layer procedures for data

- 38.215: Physical layer measurements

- 38.300: NR and NG-RAN Overall Description

- 38.304: User Equipment (UE) procedures in idle mode and in RRC Inactive state

- 38.321Medium Access Control (MAC) protocol specification

- 38.331: Radio Resource Control (RRC) protocol specification

- 37.213: Introduction of channel access procedures to unlicensed spectrum for NR-based access

- 36.355: LTE Positioning Protocol

- 37.355: LTE Positioning Protocol

Terms and abbreviations

- 5GC: 5G Core Network

- 5GS: 5G System

- NES: network energy saving

- ES: energy saving

- SSB: synchronization signal/PBCH block

- FR: frequency range

- CC: component carrier

- NCGI: NR Cell Global Identifier

- SI: system information

- PCell: primary cell

- SCell: secondary cell

- PDCCH: Physical Downlink Control CHannel

- PDSCH: Physical Downlink Shared CHannel

- PUSCH: Physical Uplink Shared CHannel

- CSI: Channel state information

- RRM: Radio resource management

- SCS: Sub-carrier spacing

- RLM: Radio link monitoring

- DCI: Downlink Control Information

- CAP: Channel Access Procedure

- Ucell: Unlicensed cell

- TBS: Transport Block Size

- TDRA: Time Domain Resource Allocation

- SLIV: Starting and Length Indicator Value (This is an indicator value for the starting symbol index and number of symbols within the slot of the PDSCH and/or PUSCH, and can be set as a component of the entry that constitutes the TDRA field within the PDCCH that schedules the corresponding PDSCH and/or PUSCH.)

- BWP: BandWidth Part (can be composed of consecutive resource blocks (RBs) on the frequency axis and can correspond to one numerology (e.g., sub-carrier spacing, CP length, slot/mini-slot duration). In addition, multiple BWPs can be configured on one carrier (the number of BWPs per carrier can also be limited), but the number of activated BWPs can be limited to a part of it (e.g., 1) per carrier.)

- CORESET: COntrol REsourse SET (refers to the time-frequency resource area where PDCCH can be transmitted, and the number of CORESETs per BWP may be limited.)

- REG: Resource element group

- SFI: Slot Format Indicator (An indicator indicating the symbol level DL/UL direction within a specific slot(s), transmitted through the group common PDCCH.)

- COT: Channel occupancy time

- SPS: Semi-persistent scheduling

- QCL: Quasi-Co-Location (QCL relationship between two reference signals means that QCL parameters such as Doppler shift, Doppler spread, average delay, delay spread, and Spatial Rx parameter obtained from one reference signal can be applied to another reference signal (or antenna port(s) of the corresponding RS). In the NR system, four QCL types are defined as follows. 'typeA': {Doppler shift, Doppler spread, average delay, delay spread}, 'typeB': {Doppler shift, Doppler spread}, 'typeC': {Doppler shift, average delay}, 'typeD': {Spatial Rx parameter} For any DL RS antenna port(s), the first DL RS is set as a reference for QCL type X (X=A, B, C, or D), and additionally, the second DL RS is set as a reference for QCL type Y (Y=A, B, C, or D but X≠Y) ) can be set as a reference to

- TCI: Transmission Configuration Indication (A TCI state includes the QCL relationship between one or more DL RSs, such as DM-RS ports of the PDSCH, the DM-RS port of PDCCH, or the CSI-RS port(s) of a CSI-RS resource. For the 'Transmission Configuration Indication' field in the DCI that schedules the PDSCH, the TCI state index corresponding to each code point that constitutes the field is activated by the MAC CE, and the TCI state setting for each TCI state index is set through RRC signaling. In the Rel-16 NR system, the TCI state is set between DL RSs, but in future releases, setting between DL RS and UL RS or UL RS and UL RS may be allowed. Examples of UL RSs include SRS, PUSCH DM-RS, and PUCCH DM-RS.)

- SRI: SRS resource indicator (Indicates one of the SRS resource index values set in the 'SRS resource indicator' among the fields in the DCI that schedules the PUSCH. When transmitting a PUSCH, the UE can transmit the PUSCH using the same spatial domain transmission filter used for transmitting and receiving the reference signal linked to the corresponding SRS resource. At this time, the reference RS is set by RRC signaling through the SRS-SpatialRelationInfo parameter for each SRS resource, and SS/PBCH block, CSI-RS, or SRS can be set as the reference RS.)

- TRP: Transmission and Reception Point

In a wireless communication system, a terminal receives information from a base station via the downlink (DL) and transmits it to the base station via the uplink (UL). The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type and purpose of the information being transmitted and received.

Figure 1 is a drawing for explaining physical channels used in a 3GPP NR system and a general signal transmission method using them.

When a terminal is powered on again from a powered-off state or enters a new cell, it performs an initial cell search operation, such as synchronizing with the base station, in step S101. To this end, the terminal receives a Synchronization Signal Block (SSB) from the base station. The SSB includes a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). The terminal synchronizes with the base station based on the PSS/SSS and obtains information such as a cell ID (cell identity). In addition, the terminal can obtain broadcast information within the cell based on the PBCH. Meanwhile, the terminal can check the downlink channel status by receiving a Downlink Reference Signal (DL RS) during the initial cell search phase.

After completing the initial cell search, the terminal can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) based on the physical downlink control channel information in step S102.

Thereafter, the terminal may perform a random access procedure such as steps S103 to S106 to complete connection to the base station. To this end, the terminal may transmit a preamble through a physical random access channel (PRACH) (S103) and receive a response message to the preamble through a physical downlink control channel and a corresponding physical downlink shared channel (S104). In the case of contention-based random access, a contention resolution procedure such as transmission of an additional physical random access channel (S105) and reception of a physical downlink control channel and a corresponding physical downlink shared channel (S106) may be performed.

The terminal that has performed the procedure as described above can then perform the general uplink/downlink signal transmission procedure, such as receiving a physical downlink control channel/physical downlink shared channel (S107) and transmitting a physical uplink shared channel (PUSCH)/physical uplink control channel (PUCCH) (S108). The control information that the terminal transmits to the base station is collectively referred to as uplink control information (UCI). UCI includes HARQ ACK/NACK (Hybrid Automatic Repeat and request Acknowledgement/Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted through PUCCH, but can be transmitted through PUSCH when control information and traffic data must be transmitted simultaneously. Additionally, UCI can be transmitted aperiodically via PUSCH upon request/instruction from the network.

Figure 2 illustrates the structure of a radio frame. In NR, uplink and downlink transmissions are organized into frames. Each radio frame is 10 ms long and is divided into two 5 ms half-frames (HF). Each half-frame is divided into five 1 ms sub-frames (SF). A sub-frame is divided into one or more slots, and the number of slots within a sub-frame depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM (Orthogonal Frequency Division Multiplexing) symbols, depending on the cyclic prefix (CP). When a normal CP is used, each slot contains 14 OFDM symbols. When an extended CP is used, each slot contains 12 OFDM symbols.

Table 1 illustrates that when CP is normally used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

SCS (15*2 ^u ) N ^slot _symb N ^frame,u _slot N ^{subframes, u} _slots 15KHz (u=0) 14 10 1 30KHz (u=1) 14 20 2 60KHz (u=2) 14 40 4 120KHz (u=3) 14 80 8 240KHz (u=4) 14 160 16

* N ^slot _symb : Number of symbols in the slot

* N ^frame,u _slot : Number of slots in a frame

* N ^subframe,u _slot : number of slots in a subframe

Table 2 illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

SCS (15*2 ^u ) N ^slot _symb N ^frame,u _slot N ^{subframes, u} _slots 60KHz (u=2) 12 40 4

The structure of the frame is only an example, and the number of subframes, number of slots, and number of symbols in the frame can be varied.

In an NR system, OFDM numerology (e.g., SCS) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol), an SC-FDMA symbol (or Discrete Fourier Transform-spread-OFDM, DFT-s-OFDM symbol).

Figure 3 illustrates a resource grid of a slot. A slot includes multiple symbols in the time domain. For example, in the case of a regular CP, one slot includes 14 symbols, but in the case of an extended CP, one slot includes 12 symbols. A carrier includes multiple subcarriers in the frequency domain. A Resource Block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) is defined as multiple consecutive Physical RBs (PRBs) in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

Figure 4 illustrates an example of mapping physical channels within a slot. In an NR system, a frame is characterized by a self-contained structure in which a DL control channel, DL or UL data, and a UL control channel can all be included within a single slot. For example, the first N symbols within a slot can be used to transmit a DL control channel (e.g., PDCCH) (hereinafter, DL control region), and the last M symbols within a slot can be used to transmit a UL control channel (e.g., PUCCH) (hereinafter, UL control region). N and M are each integers greater than or equal to 0. The resource region (hereinafter, data region) between the DL control region and the UL control region can be used to transmit DL data (e.g., PDSCH) or UL data (e.g., PUSCH). GP provides a time gap when a base station and a terminal switch from a transmission mode to a reception mode or from a reception mode to a transmission mode. Some symbols at the time of switching from DL to UL within a subframe can be set as GP.

The PDCCH carries Downlink Control Information (DCI). For example, the PCCCH (i.e., DCI) carries the transmission format and resource allocation of the downlink shared channel (DL-SCH), resource allocation information for the uplink shared channel (UL-SCH), paging information for the paging channel (PCH), system information on the DL-SCH, resource allocation information for upper layer control messages such as random access responses transmitted on the PDSCH, transmission power control commands, activation/deactivation of Configured Scheduling (CS), etc. The DCI includes a cyclic redundancy check (CRC), which is masked/scrambled with various identifiers (e.g., Radio Network Temporary Identifier, RNTI) depending on the owner or usage of the PDCCH. For example, if the PDCCH is for a specific terminal, the CRC is masked with a terminal identifier (e.g., Cell-RNTI, C-RNTI). If the PDCCH is for paging, the CRC is masked with the Paging-RNTI (P-RNTI). If the PDCCH is for system information (e.g., a System Information Block, SIB), the CRC is masked with the System Information RNTI (SI-RNTI). If the PDCCH is for a random access response, the CRC is masked with the Random Access-RNTI (RA-RNTI).

For PDCCH reception, the UE may monitor (e.g., perform blind decoding) a set of PDCCH candidates in a CORESET. The PDCCH candidates represent the CCE(s) that the UE monitors for PDCCH reception/detection. PDCCH monitoring may be performed in one or more CORESETs on an active DL BWP on each activated cell in which PDCCH monitoring is configured. The set of PDCCH candidates that the UE monitors is defined as a PDCCH Search Space (SS) set. The SS set may be a Common Search Space (CSS) set or a UE-specific Search Space (USS) set.

Table 3 illustrates the PDCCH search space.

Search Space Type RNTI Use Case Type0-PDCCH Common SI-RNTI on a primary cell Broadcast of System Information Type0A-PDCCH Common SI-RNTI on a primary cell Broadcast of System Information Type1-PDCCH Common RA-RNTI or TC-RNTI on a primary cell Msg2, Msg4 in RACH Type2-PDCCH Common P-RNTI on a primary cell PagingSystem Information change notification Type3-PDCCH Common INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, C-RNTI, MCS-C-RNTI or CS-RNTI Group signaling UE Specific UE Specific C-RNTI, MCS-C-RNTI or CS-RNTI UE signaling (e.g., PDSCH/PUSCH)

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

- searchSpaceId: Indicates the ID of the SS set.

- controlResourceSetId: Indicates the CORESET associated with the SS set.

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

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

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

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

- DCI format: Indicates the DCI format of the PDCCH candidate.

Based on the CORESET/SS set configuration, a UE can monitor PDCCH candidates in one or more SS sets within a slot. An opportunity (e.g., time/frequency resources) for monitoring PDCCH candidates is defined as a PDCCH (monitoring) opportunity. One or more PDCCH (monitoring) opportunities can be configured within a slot.

PUCCH format Length in OFDM symbols Number of bits Usage Etc 0 1 - 2 ≤2 HARQ, SR Sequence selection 1 4 - 14 ≤2 HARQ, [SR] Sequence modulation 2 1 - 2 >2 HARQ, CSI, [SR] CP-OFDM 3 4 - 14 >2 HARQ, CSI, [SR] DFT-s-OFDM (no UE multiplexing) 4 4 - 14 >2 HARQ, CSI, [SR] DFT-s-OFDM (Pre DFT OCC)

1) PUCCH Format 0 (PF0)

- Supported UCI payload sizes: up to K bits (e.g., K = 2)

- Number of OFDM symbols constituting a single PUCCH: 1 to X symbols (e.g., X = 2)

- Transmission structure: Consists of only UCI signals without DM-RS, and transmits the UCI status by selecting and transmitting one of multiple sequences.

2) PUCCH Format 1 (PF1)

- Supported UCI payload sizes: up to K bits (e.g., K = 2)

- Number of OFDM symbols constituting a single PUCCH: Y to Z symbols (e.g., Y = 4, Z = 14)

Transmission Structure: DM-RS and UCI are configured in TDM format on different OFDM symbols, with UCI multiplying a specific sequence with modulation (e.g., QPSK) symbols. Cyclic Shift (CS)/Orthogonal Cover Code (OCC) is applied to both UCI and DM-RS to support CDM between multiple PUCCH resources (following PUCCH Format 1) (within the same RB).

3) PUCCH Format 2 (PF2)

- Supported UCI payload size: more than K bits (e.g., K = 2)

- Number of OFDM symbols constituting a single PUCCH: 1 to X symbols (e.g., X = 2)

- Transmission structure: DMRS and UCI are configured/mapped in FDM form within the same symbol, and are transmitted by applying only IFFT without DFT to the encoded UCI bits.

4) PUCCH Format 3 (PF3)

- Supported UCI payload size: more than K bits (e.g., K = 2)

- Number of OFDM symbols constituting a single PUCCH: Y to Z symbols (e.g., Y = 4, Z = 14)

Transmission structure: DMRS and UCI are configured/mapped to different symbols in TDM format, and transmitted by applying DFT to the corrupted UCI bits. OCC is applied to UCI at the DFT front end, and CS (or IFDM mapping) is applied to DMRS to support multiplexing to multiple terminals.

5) PUCCH Format 4 (PF4)

- Supported UCI payload size: more than K bits (e.g., K = 2)

- Number of OFDM symbols constituting a single PUCCH: Y to Z symbols (e.g., Y = 4, Z = 14)

- Transmission structure: DMRS and UCI are configured/mapped to different symbols in TDM format, and a structure that transmits without multiplexing between terminals by applying DFT to the encoded UCI bits.

DRX (Discontinuous Reception) Operation

The UE uses Discontinuous Reception (DRX) in the RRC_IDLE and RRC_INACTIVE states to reduce power consumption. When DRX is configured, the UE performs DRX operations according to DRX configuration information.

A UE operating based on DRX repeatedly turns ON/OFF its reception operation. For example, when DRX is configured, the UE attempts to receive/detect PDCCH (e.g., monitor PDCCH) only during a predetermined time interval (e.g., ON), and does not attempt PDCCH reception during the remaining time (e.g., OFF/Sleep).

At this time, the time that the terminal must attempt to receive the PDCCH is called On-duration, and On-duration is defined once per DRX cycle. The UE can receive DRX configuration information from a base station (e.g., gNB) through RRC signaling and perform DRX operation by receiving (Long) DRX command MAC CE.

Meanwhile, DRX configuration information can be included in MAC-CellGroupConfig. IE MAC-CellGroupConfig is used to configure MAC parameters for a cell group including DRX.

DRX (Discontinuous Reception) refers to an operation mode in which a UE (User Equipment) discontinuously receives/monitors a downlink channel to reduce battery consumption. In other words, a UE configured for DRX can reduce power consumption by discontinuously receiving downlink signals. DRX operation is performed in a DRX cycle, where On Duration represents a time interval that is periodically repeated. DRX includes On Duration and Sleep Duration (or Opportunity for DRX). On Duration represents the time interval during which the UE monitors the PDCCH to receive the PDCCH. DRX can be performed in the RRC (Radio Resource Control)_IDLE State (or mode), RRC_INACTIVE State (or mode), or RRC_CONNECTED State (or mode). In the RRC_IDLE State and RRC_INACTIVE State, DRX is used to discontinuously receive a paging signal.

- RRC_Idle State: A state in which a wireless connection (RRC connection) is not established between the base station and the terminal.

- RRC Inactive State: A wireless connection (RRC connection) is established between the base station and the terminal, but the wireless connection is inactive.

- RRC_Connected state: A wireless connection (RRC connection) is established between the base station and the terminal.

DRX is basically divided into Idle mode DRX, Connected DRX (C-DRX), and Extended DRX. DRX applied in the RRC IDLE state is called IDLE mode DRX, and DRX applied in the RRC CONNECTED state is called Connected mode DRX (C-DRX).

eDRX (Extended/enhanced DRX) is a mechanism that can extend the cycle of IDLE mode DRX and C-DRX. Whether eDRX is allowed in IDLE mode DRX can be set based on system information (e.g., SIB1).

SIB1 may include an eDRX-Allowed parameter. The eDRX-Allowed parameter is a parameter indicating whether IDLE mode extended DRX is allowed.

(1) IDLE mode DRX

In IDLE mode, the UE may use DRX to reduce power consumption. A paging opportunity (PO) may be a time interval (e.g., a slot or a subframe) during which a Paging-Radio Network Temporary Identifier (P-RNTI) based Physical Downlink Control Channel (PDCCH) may be transmitted. The P-RNTI based PDCCH may address/schedule paging messages. For P-RNTI based PDCCH transmission, the PO may indicate the starting subframe for PDCCH repetition.

A paging frame (PF) is a radio frame that may contain one or more paging opportunities. When DRX is used, the UE may be configured to monitor only one PO per DRX cycle. The PF and/or PO may be determined based on DRX parameters provided via network signaling (e.g., system information).

Hereinafter, 'PDCCH' may refer to MPDCCH, NPDCCH, and/or general PDCCH. Hereinafter, 'UE' may refer to MTC UE, BL (Bandwidth Reduced Low Complexity)/CE (Coverage Enhanced) UE, NB-IoT UE, RedCap (RedCap) UE, general UE, and/or IAB-MT (Mobile Termination).

FIG. 5 is a flowchart illustrating an example of a method for performing IDLE mode DRX operation.

The UE receives IDLE mode DRX configuration information from the base station through upper layer signaling (e.g., system information) (S110).

Additionally, the UE determines a Paging Frame (PF) and a Paging Occasion (PO) for monitoring the PDCCH in the paging DRX cycle based on the IDLE mode DRX configuration information (S120). In this case, the DRX cycle includes an On Duration and a Sleep Duration (or an Opportunity for DRX).

Additionally, the UE monitors the PDCCH in the PO of the determined PF (S130). Meanwhile, the UE monitors only one time interval (PO) per paging DRX cycle. For example, the time interval may be a slot or a subframe.

Additionally, if the UE receives a PDCCH (more precisely, a CRC of the PDCCH) scrambled by the P-RNTI during the On Duration (i.e., if paging is detected), the UE can transition to connected mode and transmit and receive data with the base station.

Figure 6 is a diagram showing an example of IDLE mode DRX operation.

Referring to Fig. 6, when there is traffic (data) directed to a UE in the RRC_Idle state (hereinafter referred to as 'Idle state'), paging occurs toward the UE.

Therefore, the UE wakes up every (paging) DRX cycle and monitors the PDCCH.

If paging is present, the UE transitions to the Connected state and receives data. Otherwise, the UE may enter sleep mode again.

(2) Connected mode DRX (C-DRX)

C-DRX is DRX applied in RRC Connected State. The DRX cycle of C-DRX can be configured as a short DRX cycle and/or a long DRX cycle. The short DRX cycle is optional.

When C-DRX is configured, the UE performs PDCCH monitoring during the On Duration. If a PDCCH is successfully detected during PDCCH monitoring, the UE operates (or runs) the Inactive Timer and remains in the Awake State. On the other hand, if no PDCCH is successfully detected during PDCCH monitoring, the UE enters the Sleep State after the On Duration ends.

When C-DRX is configured, PDCCH reception Occasions (e.g., slots with PDCCH search spaces/candidates) may be configured discontinuously based on the C-DRX configuration. On the other hand, when C-DRX is not configured, PDCCH reception Occasions (e.g., slots with PDCCH search spaces/candidates) may be configured continuously according to the PDCCH search space configuration. Meanwhile, PDCCH monitoring may be limited to a time interval set as a Measurement Gap regardless of the C-DRX configuration.

Figure 7 is a flowchart illustrating an example of a method for performing a C-DRX operation.

The UE receives RRC signaling (e.g., MAC-MainConfig IE) containing DRX configuration information from the base station (S310). The DRX configuration information may include the following information.

- on-duration: The period (duration) during which the UE waits to receive a PDCCH after waking up. If the UE successfully decodes the PDCCH, the UE stays awake and starts the drx-inactivity timer.

- onDurationTimer: The period (Duration) at which the DRX Cycle starts; for example, it can mean the time period that should be continuously monitored from the start of the DRX cycle, and can be expressed in ms.

- drx-InactivityTimer: Duration after the PDCCH Occasion corresponding to the PDCCH indicating a new UL or DL transmission for the MAC entity; for example, it may be a time period in milliseconds after the UE decodes a PDCCH with scheduling information. That is, the duration during which the UE waits to successfully decode another PDCCH after the last PDCCH decoded. If no other PDCCH is detected within this period, the UE transitions to Sleep mode.

The UE restarts the drx-inactivity timer after successful decoding of the PDCCH for initial transmission only, not for retransmission.

- drx-RetransmissionTimer: For DL, the maximum duration until a DL retransmission is received; For UL, the maximum duration until an acknowledgment for a UL retransmission is received. For example, for UL, it is the number of slots for the BWP (Bandwidth part) in which the TB (Transport Block) to be retransmitted is transmitted, and for DL, it is the number of slots for the BWP (Bandwidth part) in which the TB (Transport Block) to be retransmitted is received.

- longDRX-Cycle: On Duration occurrence cycle (Period)

- drxStartOffset: Subframe number where the DRX cycle starts

- drxShortCycleTimer: The period (Duration) during which the UE must follow the short DRX cycle;

- shortDRX-Cycle: DRX Cycle that runs for the number of drxShortCycleTimer when Drx-InactivityTimer ends

- drx-SlotOffset: Delay before drx-onDurationTimer starts; can be expressed in ms, or in multiples of 1/32ms.

- Active Time: The total period (Duration) that the UE monitors the PDCCH, including (a) the “On-duration” of the DRX cycle, (b) the time that the UE performs continuous reception while the drx-inactivity timer has not expired, and (c) the time that the UE performs continuous reception while waiting for a retransmission opportunity.

More specifically, when the DRX Cycle is configured, the Active Time for the serving cell of the DRX group includes the following times:

- (a) drx-onDurationTimer or (b) drx-InactivityTimer configured for the DRX group. or

- (c) drx-RetransmissionTimerDL or drx-RetransmissionTimerUL for all serving cells in the DRX group. or

- (d) ra-ContentionResolutionTimer or msgB-ResponseWindow. or

- (e) a section in which a Scheduling Request is transmitted via PUCCH and is pending, or

- (f) If a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity is not received after successfully receiving a Random Access Response (RAR) for a random access preamble not selected by the MAC entity during contention-based random access.

Additionally, when DRX 'ON' is set through the DRX command of MAC CE (command element) (S320), the UE monitors the PDCCH during the ON Duration of the DRX cycle based on the DRX setting (S330).

Figure 8 is a diagram showing an example of C-DRX operation.

Referring to FIG. 8, when the UE receives scheduling information (e.g., DL Assignment or UL Grant) in the RRC_Connected State (hereinafter referred to as Connected State), the UE executes the DRX Inactivity Timer and the RRC Inactivity Timer.

DRX mode starts after the DRX Inactivity Timer expires. The UE wakes up from the DRX Cycle and monitors the PDCCH for a predetermined period of time (on duration timer).

In this case, when Short DRX is set, when the UE starts DRX mode, the UE first starts a Short DRX Cycle, and after the Short DRX Cycle ends, the UE starts a Long DRX Cycle. At this time, the Long DRX Cycle is a multiple of the Short DRX Cycle. That is, the UE wakes up more frequently in the Short DRX Cycle. After the RRC Inactivity Timer expires, the UE transitions to the Idle state and performs Idle mode DRX operation.

Figure 9 illustrates a DRX Cycle. The C-DRX operation was introduced to save power for the UE. If the UE does not receive a PDCCH within the on-duration defined for each DRX cycle, it enters sleep mode and does not perform transmission/reception until the next DRX cycle.

On the other hand, if the UE receives a PDCCH in On-duration, the Active time may be maintained (or increased) based on the operation of the inactivity timer, retransmission timer, etc. If no additional data is received within the Active time, the UE may perform a sleep operation until the next DRX operation.

In NR, a wake up signal (WUS) is introduced to obtain additional power saving gains from the existing C-DRX operation. The WUS may be used to indicate whether the UE should perform PDCCH monitoring during the on-duration of each DRX cycle (or multiple DRX cycles). If the UE does not detect a WUS in a designated or indicated WUS occasion, the UE may remain in sleep mode without performing PDCCH monitoring for one or more DRX cycles associated with the WUS.

(3) Wake Up Signal (DCI Format 2_6)

Figure 10 is a diagram for explaining a method of monitoring DCI format 2_6.

In the power saving technology of the Rel-16 NR system, when a DRX operation is performed, whether or not each DRX cycle wakes up can be notified to the terminal through DCI format 2_6.

Referring to Figure 10, the monitoring occasion for DCI format 2_6 can be determined by the ps-Offset indicated by the network and the Time Gap reported by the terminal. In this case, the Time Gap reported by the terminal can be interpreted as a preparation period required for operation after the terminal wakes up.

Referring to FIG. 10, the network can instruct the terminal to configure a search space (SS) set capable of monitoring DCI format 2_6. The SS set configuration can instruct the terminal to monitor DCI format 2_6 through consecutive slots of a duration length at intervals of a monitoring periodicity.

In the DRX configuration, the monitoring window for monitoring DCI format 2_6 is determined by the start point of the DRX cycle (e.g., the point where the on-duration timer starts) and the ps-Offset configured by the network. In addition, PDCCH monitoring may not be required in the Time Gap section reported by the UE. Finally, the SS Set monitoring occasion where the UE performs actual monitoring can be determined as the first Full Duration (i.e., Actual Monitoring Occasions in FIG. 10) within the monitoring window.

By detecting DCI format 2_6 in the monitoring window set based on ps-Offset, the base station can instruct the terminal whether to wake up or not in the next DRX cycle.

NES (network energy saving)

Energy conservation at base stations is a key consideration in wireless communication systems, including 3GPP, as it can contribute to building eco-friendly networks by reducing carbon emissions and reducing the operational expenditure (OPEX) of telecommunications operators. In particular, the introduction of 5G communications will require higher transmission rates, necessitating base stations to be equipped with more antennas and provide services over wider bandwidths and frequency bands. Consequently, recent studies have shown that base station energy costs have reached up to 20% of total OPEX. This heightened interest in base station energy conservation has led to the approval of a new study item, "Study on Network Energy Savings," in certain scenarios (e.g., 3GPP NR Release 18).

Specifically, in order to improve the energy saving capability of the base station from the perspective of transmission and reception, the following enhancement techniques are being considered.

- A method for more fine-tuning transmission and/or reception dynamically and/or semi-statically in one or more of the network energy-saving techniques in the time, frequency, space and power domains, and for achieving more efficient operation through potential UE assistance/feedback and potential UE assistance information.

The base station identifies the NES solution(s) to be applied. The NES solution(s) may be related to control of signal transmission and reception (e.g., on/off), beam operation, handover procedures, channel measurement and reporting, etc. The NES solution(s) to be applied may be adaptively selected or predefined based on the current situation (e.g., cell load level, characteristics of connected terminals, etc.). The base station that identified the NES solution(s) performs signaling for the NES. The specific signaling procedure may vary depending on the identified NES solution(s). For example, the base station may transmit common information about the NES solution(s), transmit configuration information necessary for NES operation to at least one terminal, or transmit control information regarding the progress of the NES operation to at least one terminal. In addition, the base station may receive capability information related to the NES from at least one terminal. Thereafter, the base station performs operations for the NES. At this time, the base station may perform the operations for the NES based on the previously performed signaling. That is, based on the system information, configuration information, and control information transmitted through signaling, the base station can turn on/off transmission and reception of a specific signal, turn on/off elements in the spatial domain, or adjust resources for transmission and reception of a measurement signal.

Examples of possible NES solutions include:

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

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

- SSB-less SCell solution: If SSB or SMTC (SSB-based RRM measurement timing configuration) configuration is not provided for the SCell, the UE can obtain timing reference and AGC source from another serving cell. In FR1 or FR2, the base station can configure intra-band CA or inter-band CA including the SCell without SSB transmission, in which case the SSB/SIB transmission can be triggered by the WUS (wake up signal) of the UE. Accordingly, since the period of common channels/signals such as SSB is increased, the base station can stay in the sleep state for a longer time.

- Cell DTX/DRX solution: In order to reduce the downlink transmission/uplink reception activity time of the base station, a periodic cell DTX/DRX pattern (e.g., active and inactive periods) can be commonly set for terminals within a cell having the corresponding feature. Here, the cell DTX pattern and the cell DRX pattern can be set and activated separately, and up to two cell DTX/DRX patterns can be set per MAC entity. When cell DTX is set and activated, at least one of monitoring for SPS opportunities or monitoring PDCCH can be stopped during the cell DTX inactivity period. When cell DRX is set and activated, at least one of transmission on CG resources or SR transmission can be stopped during the cell DRX inactivity period. Cell DTX/DRX can be activated/deactivated via RRC signaling or L1 group common signaling.

-- Parameters such as active duration and cycle can be configured for cell DTX/DRX. Active duration is the period during which the UE receives a PDCCH or SPS opportunity and waits to transmit SR or CG, and cycle specifies the periodic repetition of the active duration and inactive duration. When both cell DTX and cell DRX are configured, parameters such as active duration and cycle are common. If the base station recognizes an emergency call or a public safety-related service (e.g., MPS or MCS), the network can release or deactivate the cell DTX/DRX configuration so as not to affect the service. In addition, at least some overlap is required between the active duration of the connected mode DRX of the UE and the active duration of the cell DTX/DRX. For example, the connected mode DRX cycle of the UE may be a multiple of the cell DTX/DRX cycle, or vice versa.

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

- Spatial and power domain adaptation solution: To support the gNB for transceiver muting and/or transmit power adaptation, the UE may be configured to report multiple CSI entries in a CSI report based on multiple sub-configurations. Each sub-configuration corresponds to a spatial domain adaptation pattern (e.g., a subset of available spatial elements) and/or a power offset between a data channel (e.g., PDSCH) and CSI-RS. Depending on the application of the spatial and power domain adaptation solution, the CSI configuration, measurement, and/or reporting behavior may be affected.

FIG. 11 is a diagram for explaining a method for performing communication based on cell DRX/DTX between a base station and a terminal.

To enable base stations to operate in sleep mode for relatively long periods of time without frequent wake-ups, base station DTX/DRX has been proposed for NES purposes. The base station can reduce energy consumption by utilizing DTX transmission under low system load conditions by configuring cell DTX and setting the on-duration of C-DRX of terminals within the active period of the cell DTX.

Referring to FIG. 11, the base station transmits system information to the terminal (S111), and the terminal checks information related to cell DTX/DRX. For example, the system information may include MIB (master information block), SIB1 (System information block1), etc. In relation to the NES technology, as shown in Table 5 below, the MIB may include information related to cell barring (e.g., cellBarred), and the SIB1 may include information related to the cell barring status (e.g., cellBarredNES). Specifically, when cellBarred included in the MIB is set to a value indicating that it is not barred (e.g., notBarred), the terminal may determine that the cell is not barred, regardless of whether it supports NES cell DTX/DRX. Conversely, when cellBarred included in the received MIB is set to a value indicating that the cell is barred (e.g., barred), a terminal that does not support NES cell DTX/DRX may determine that the cell is barred. However, if the terminal has the capability to support NES cell DTX/DRX, the terminal checks SIB1 to determine the cell barring status. If cellBarred of MIB is set to barred and cellBarredNES is absent in SIB1, the terminal supporting NES cell DTX/DRX can treat the cell as barred and perform cell reselection to another cell. On the other hand, if cellBarred of MIB is set to barred and cellBarredNES is included in SIB1, the terminal supporting NES cell DTX/DRX can determine that the cell is not barred.

- SIB1
SIB1 message
SIB1-v1740-IEs ::= SEQUENCE {
si-SchedulingInfo-v1740 SI-SchedulingInfo-v1740 OPTIONAL, -- Need R
nonCriticalExtension SIB1-v1800-IEs OPTIONAL
}

SIB1-v1800-IEs ::= SEQUENCE {
cellBarredNES-r18 ENUMERATED {notBarred} OPTIONAL, -- Need R
nonCriticalExtension SEQUENCE {} OPTIONAL
}
SIB1 field descriptions
cellBarredNES
The presence of this field indicates that the cell is allowed for UEs supporting NES cell DTX/DRX.

The terminal has the capability to support NES cell DTX/DRX, and cellBarred in MIB is set to notBarred , or It is assumed that cellBarred of MIB is barred and cellBarredNES is included in SIB1. Accordingly, the terminal performs a random access procedure to access the base station (S112), and can perform communication thereafter. At this time, the base station performs a cell DTX/DRX operation and transmits configuration information related to the cell DTX/DRX operation to the terminal (S113). The configuration information related to the cell DTX/DRX operation (e.g., CellDTXDRX-Config ) includes at least one parameter related to the cell DTX/DRX, and may include, for example, at least one of an on-duration timer, a cycle start offset, a slot offset, a configuration type (e.g., DTX, DRX, or DTX-DRX), and an activation status of the DTX/DRX (e.g., active, inactive). Additionally, the configuration information may further include information for receiving and interpreting cell DRX/DRX related control information (e.g. DCI related information) (see TS 38.331 CellDTXDRX-Config ).

Thereafter, the base station transmits control information related to cell DTX/DRX to the terminal (S115). The control information related to cell DTX/DRX may include DCI having a designated format (e.g., format 2_9). If an operation for a serving cell according to at least one of the cell DTX operation and the cell DRX operation is configured by configuration information (e.g., cellDTXDRX -Config ), the terminal may check a set of search spaces (e.g., a Type3-PDCCH CSS set) for monitoring a PDCCH conveying control information of a designated format during an active time through a higher layer parameter (e.g., SearchSpace), and may obtain a location of information about the serving cell within the control information through a higher layer parameter (e.g., positionInDCI-cellDTRX ). Then, the terminal may obtain control information based on the identified set of search spaces and location.

Control information related to cell DTX/DRX may be used to indicate activation or deactivation of cell DTX and/or cell DRX, and/or to provide an NES-mode indicator, and may include, for example, at least one block including a cell DTX/DRX indicator and an NES-mode indicator. In this case, when the serving cell is configured as a SUL (supplementary uplink) carrier, the indication of activation or deactivation of cell DRX by the cell DTX/DRX indicator may be applied to both the UL carrier and the SUL carrier.

The DCI format 2_9 related to this can be defined as shown in Table 6 below.

- DCI Format 2_9
DCI format 2_9 is used for activating or de-activating the cell DTX and/or DRX configuration of one or multiple serving cells for one or more UEs, and/or for providing NES-mode indication of the primary cell for one or more UEs.
The following information is transmitted by means of the DCI format 2_9 with CRC scrambled by cellDTRX:
- block number 1, block number 2,..., block number N
where the starting position of a block associated with a serving cell is determined by the parameter positionInDCI-cellDTRX provided by higher layers for the UE.
If the UE is configured to monitor DCI 2_9 with CRC scrambled by cellDTRX-RNTI, one or more blocks are configured for the UE by higher layers, with the following fields defined for each block:
- Cell DTX/DRX indication - number of bits determined by the following:
- If higher layer parameter cellDTXDRX-L1activation is configured
- 2 bits as defined in Clause 11.5 of [5, TS38.213] if cellDTXDRXconfigType is configured to dtxdrx for the associated serving cell of the block, with the MSB corresponding to cell DTX configuration and the LSB corresponding to cell DRX configuration;
- 1 bit as defined in Clause 11.5 of [5, TS38.213] if cellDTXDRXconfigType is configured to either dtx or drx for the associated serving cell of the block;
- 0 bit otherwise.
- NES-mode indication - 1 bit indicating NES-specific CHO execution condition as defined in Clause 11.5 of [5, TS38.213], if the higher layer parameter nesEvent is configured and the associated serving cell of the block is primary cell; 0 bit otherwise.
The size of DCI format 2_9 is indicated by the higher layer parameter sizeDCI-2-9 .

Thereafter, the terminal and the base station can perform communication based on the cell DTX/DRX. Specifically, the base station can turn on/off the transmission and reception of signals according to the settings related to the cell DTX/DRX, and accordingly, the terminal can selectively monitor the signal from the base station. During the DTX-OFF, the base station enters a sleep mode to reduce energy consumption. At this time, the base station DTX cycle can be aligned with the cycle of the terminal DRX. The base station DTX-ON can completely cover the DRX-ON of the terminal. Furthermore, the base station can align the transmission of Xn/NG and the transmission of Uu for the purpose of NES. The DTX/DRX mechanism triggers the switching of reference signal resource set groups, and the base station can perform a dormancy-like behavior of sparsely transmitting or not transmitting SSB, SIB, and CSI-RS to reduce energy consumption. The terminal may sparsely receive or not receive a downlink signal/channel depending on the settings of the base station. Once the base station DTX/DRX operation is triggered, during the DTX/DRX OFF period, the terminal can discontinuously receive the corresponding CSI-RS, SSB, or PDCCH.

Enhancements of network energy savings for NR

A work item (WI) titled “Enhancements of network energy savings for NR” has been additionally approved for a given scenario (3GPP NR release 19). Specifically, the following enhancement techniques are being considered for the given scenario, as shown in Table 7.

Objective of SI or Core part WI or Testing part WI
The objectives of the work items are the following:
1. Specify procedures and signaling method(s) to support on-demand SSB SCell operation for UEs in connected mode configured with CA, for both intra-/inter-band CA. [RAN1/2/3/4]
- Specify triggering method(s) (select from UE uplink wake-up-signal using an existing signal/channel, cell on/off indication via backhaul, Scell activation/deactivation signaling)
- Note1: On-demand SSB transmission can be used by UE for at least SCell time/frequency synchronization, L1/L3 measurements and SCell activation, and is supported for FR1 and FR2 in non-shared spectrum.
2. Study procedures and signaling method(s) to support on-demand SIB1 for UEs in idle/inactive mode, including: [RAN1/2/3]
- Triggering method by uplink wake-up-signal using an existing signal/channel.
- Wake-up-signal configuration provisioning to UE
* Note: No modification of SSB will be discussed under this objective
- Information exchange between gNBs at least for the configuration of wake-up signal, if necessary.
- Checkpoint for normative work in RAN#105
3. Specify adaptation of common signal/channel transmissions . [RAN1/2/3/4]
- Adaptation of SSB in time domain, eg adapting periodicity
- Adaptation of PRACH in time domain
- Study adaptation of PRACH in spatial domain, eg non-uniform PRACH resources per SSB, and specify if found beneficial
--This study is to be done in 2Q'2024 only
- Adaptation of paging occasions including confining the paging occasions in the time domain
* Note: there shall be no paging latency increase
- Note: there shall be no negative impact to legacy UEs, unless significant benefits are shown
4. Specify the corresponding core requirements, for the above features [RAN4].

(1) On-demand SSB

A method to reduce energy consumption by having a base station transmit SSB on a specific cell through an on-demand SSB process and not transmit SSB on that cell when an on-demand SSB process is not available can be discussed. In the existing NR system, SSB must be transmitted periodically and always for purposes such as time/frequency synchronization or RRM (Radio Resource Management), making it difficult to reduce energy consumption even when the base station has no data to receive or send. Considering this, the base station can reduce base station energy consumption by not performing SSB transmission until the on-demand SSB process is involved and then performing SSB transmission. The on-demand SSB process can be triggered using one of the following methods:

1) The terminal requests SSB transmission from the base station by transmitting an uplink signal/channel (e.g., PRACH, PUCCH, PUSCH, SRS in the NR system).

2) Requesting SSB transmission from base station (or TRP) #1 to base station (or TRP) #2 through an interface between base stations (e.g., Xn interface in NR system) or backhaul signaling.

3) Signaling whether SSB transmission is possible for the corresponding Scell through Scell activation/deactivation signaling.

Considering coexistence with existing NR terminals, etc., the given scenario (3GPP NR release 19) is limited to on-demand SSB operation for connected mode terminals and SCells, but in future releases or next generation communication systems, on-demand SSB operation (for SSB transmission on PCell) considering inactive or idle mode terminals or initially connected terminals may be defined. In addition, CA (carrier aggregation) including the SCell can be applied to both intra-band CA and inter-band CA, and the SSB on the SCell transmitted through the on-demand SSB process can be utilized for at least functionality such as time/frequency synchronization, L1/L3 measurement, and SCell activation.

(2) On-demand SIB1 transmission

Figure 12 is a diagram for explaining transmission of On-demand SIB1.

In the existing NR system, SIB1, which contains system information, random access information, etc. for initial connection or idle mode terminals to access the cell, had to be provided periodically, so it was difficult to reduce energy consumption even when the base station had no data to receive or send. Considering this, a method was introduced in which the base station does not perform SIB1 transmission and only performs SIB1 transmission when an on-demand SIB1 process is involved, thereby reducing base station energy consumption. The on-demand SIB1 process can be triggered by the base station transmitting an uplink signal/channel (e.g., PRACH in the NR system). In this regard, the following scenarios can be considered.

(1) Scenario 1

Referring to Fig. 12 (a), the terminal may receive an SSB (and/or another downlink signal/channel) from cell#1 and recognize that SIB1 is not transmitted on the cell#1. In this case, the terminal may transmit a signal requesting SIB1 (hereinafter, for convenience of explanation, the signal is defined as a WUS, wake-up signal) based on information provided in the SSB (and/or another downlink signal/channel) and/or predetermined information, thereby triggering transmission of SIB1 related to the cell#1. The base station or cell#1 that receives the WUS may transmit a specific DL signal/channel on cell#1 in response to the WUS, and may transmit SIB1 on cell#1 (or without transmitting the corresponding DL signal/channel).

(2) Scenario 2

Referring to FIG. 12 (b), the terminal may receive an SSB (and/or another downlink signal/channel such as SIB1) from cell#1, recognize that SIB1 is not transmitted on cell#2, and attempt camp-on via cell#2. In this case, the terminal may transmit a signal (e.g., WUS) requesting SIB1 related to cell#2 on cell#1 based on information provided in the received SSB (and/or another downlink signal/channel such as SIB1) and/or predetermined information, thereby triggering transmission of SIB1 for cell#2. The base station receiving the WUS may transmit a specific DL signal/channel (on cell#1 or cell#2) in response to the WUS, and may transmit SIB1 for cell#2 on cell#1 or cell#2 (or without transmitting the DL signal/channel).

(3) Scenario 3

Referring to Fig. 12 (c), the terminal may receive an SSB (and/or other downlink signal/channel such as SIB1) from cell#1, recognize that SIB1 is not transmitted on cell#2, and attempt camp-on via cell#2. The terminal may trigger transmission of SIB1 for cell#2 by transmitting a WUS, which is a signal requesting SIB1, on cell#2 based on information provided in the received SSB (and/or other downlink signal/channel such as SIB1) and/or predetermined information. The base station may transmit a specific DL signal/channel on cell#2 in response to the WUS, and may transmit SIB1 for cell#2 on cell#2 (or without transmitting the corresponding DL signal/channel).

In this way, a method for reducing the energy consumption of the base station/cell by reducing the transmission frequency of common signals/channels such as SSB, PRACH, and paging by the base station can be discussed. As described above, completely turning off the transmission of SSB can significantly reduce the energy consumption of the base station. However, if there is no SSB, which performs functions such as time/frequency synchronization or RRM measurement from the perspective of the terminal, stable operation may not be guaranteed for cells that do not transmit SSB. Considering this, it may be more appropriate to save the energy of the base station/cell by changing the transmission pattern of SSB according to the situation rather than completely turning off the transmission of SSB. Here, the transmission pattern of SSB may be related to the transmission period, the period for each SSB candidate index, the SSB candidate index(es) transmitted within one transmission period, the transmission power, etc.

Alternatively, in the case of contention-based random access with respect to PRACH resources, the base station may not know when the terminal will transmit the PRACH. Therefore, the base station must always attempt to receive/monitor the configured PRACH resources, which may increase the energy consumption of the base station. Considering this, a method for controlling the amount of PRACH resources needs to be considered to save the energy of the base station. Here, controlling the amount of PRACH resources may be done by controlling the period of the PRACH resources, controlling the amount of resources by pre-configuring PRACH resource sets #1 and #2 and indicating whether to activate at least one of them, or providing the corresponding RACH (or PRACH) resource amount uniformly or non-uniformly for each SSB index.

Alternatively, in the case of paging, previously, paging frames (PFs) and/or paging occasions (POs) were distributed along the time axis within a DRX cycle (or paging cycle), and the terminal attempted to receive paging at a specific PF/PO derived from a formula based on its ID. From the base station's perspective, if paging was to be transmitted to multiple terminals simultaneously, the paging had to be transmitted frequently by waking up. As a method for reducing the base station energy consumption caused by this, a method of arranging PFs and/or POs for paging reception as close to the time axis as possible or arranging different frequency axis resources within the same time may be considered.

As higher data rates are demanded, base stations must be equipped with more antennas and provide services across wider bandwidths and frequency bands. Recent studies have shown that base station energy costs can account for up to 20% of total operational expenditures (OPEX). To build eco-friendly networks by reducing carbon emissions and lowering operating expenses (OPEX) for telecommunications operators, energy conservation at base stations is a key consideration in wireless communication systems, including 3GPP.

Due to this increased interest in base station energy savings, a new study item called “study on network energy savings” was approved for a given scenario (3GPP NR release 18), and the technologies specified in the subsequent work items included SSB-less SCell operation for inter-band CA of FR1 and co-located cells, improvements to the Cell DTX/DRX mechanism including alignment of Cell DTX/DRX and UE DRX in RRC_CONNECTED mode, and inter-node information exchange of Cell DTX/DRX. Additionally, it includes spatial and power domain techniques to enable efficient adaptation of spatial elements, efficient adaptation of power offset values between PDSCH and CSI-RS, mechanisms to prevent camping of legacy UEs in cells where NES techniques are adopted for a given scenario (Rel-18), improvements to CHO procedures, inter-node beam activation and improvements to limit paging in a limited area, and corresponding RRM/RF core requirements.

Meanwhile, since there are other technologies that have been found to be useful through study but are not yet specified in 3GPP Rel-18, 3GPP Rel-19 WI aims to adopt additional technologies that can achieve network energy saving benefits by targeting beneficial technologies that have been studied in 3GPP Rel-18 but not yet adopted (e.g., on-demand SSB and on-demand SIB1 transmission, adaptation of common signal/channel transmission, etc.).

Below, a method for dynamically controlling RO for energy saving of a base station, a method for directing/setting the same, and a method for determining the validity of RO when RO is dynamically controlled are described in detail.

Adaptation of PRACH for energy saving

The UE can receive the configuration information (e.g., time/frequency resources related to the PRACH) required to transmit the PRACH through the SIB1 of the base station or UE-specific RRC signaling, and can transmit the PRACH at RO (RACH occasions). In this case, the base station must wake up for each RO to monitor the PRACH of the UE in order to receive the PRACH that the UE may transmit. Therefore, if the RO period set for the UE is short, the energy consumption of the base station may be relatively greater than if the RO period is set long. However, if the ROs are set with an excessively long period to save the energy of the base station, there may be no RO resources near the time when the UE needs to transmit the PRACH for cell access. In this case, the UE may have to wait until the next RO resource becomes available before transmitting the PRACH, which may significantly increase the access delay of the UE to the cell. Delay in accessing such cells can lead to scheduling delays for the terminals, which can significantly degrade the performance of the terminals.

In addition, depending on the situation within the cell, the base station may have a small number of terminals in connected mode (or RRC connected mode), or there may be a time period when there is temporarily no data activity. In such a situation, the base station can save energy by switching to sleep mode, but it must wake up frequently and monitor the PRACH to check if there is a PRACH transmitted by the terminal in the periodically configured RO. In this case, it is difficult to expect a significant energy saving benefit because the base station cannot remain in sleep mode for a long time. Therefore, in such cases (e.g., when the number of terminals in the RRC connected state is below a certain threshold, or there is a time period when there is no data activity), setting a long RO period may be advantageous in terms of energy saving of the base station. However, since changing the settings such as the RO period is currently only possible through a semi-static method, it may take a relatively long time to change the RO period setting (e.g., SI modification), and the delay in performing such a change in the RO period setting may make it difficult for the base station to quickly respond in a situation where energy saving is possible.

Below, we propose specific methods to solve these problems.

1. Method #1: A method in which the terminal receives (separately) a default RO (relatively sparse RO) setting for legacy UEs (terminals that do not support the R19 NES feature) from the base station and an additional NES RO (e.g., additional RO) setting for NES UEs (terminals that support the R19 NES feature).

Method #1 may be a method that can expect a certain level of energy saving benefit for the base station without causing too long terminal connection delay. A method can be considered to configure a default RO (relatively sparse RO) for legacy UEs and an additional NES RO (i.e., additional RO) for NES UEs (terminals supporting the R19 NES feature). In this case, the NES_RO configuration may be included in the default RO configuration and configured together, or may be configured separately. Here, the RO for legacy UEs (RO configuration) may mean RO resources for Rel-15 4-step RACH, RO resources for Rel-16 2-step RACH, RO resources for Rel-17 Redcap UEs, or RO resources for Rel-18 CE (coverage enhancement). There may be at least one NES RO configuration, and the RO pattern/period, etc. may be configured differently for each NES RO configuration. Additionally, the NES RO configuration can be instructed to be activated in NES UEs via a pre-configured/defined index, or an already activated NES RO configuration can be instructed to be switched to another NES RO configuration. At least one NES RO configuration can be configured via SIB1, similar to the default RO configuration, or via RRC signaling.

An NES UE (or NES aware UE, a UE supporting Rel-19 NES) can be configured by the base station whether only the NES RO is available among the configured ROs, or whether both the default RO and the NES RO are available. If there is no such configuration, the NES UE can interpret/assume that both the default RO and the NES RO are available. For example, the NES UE can be provided with information about the default RO configuration and at least one NES RO configuration (or additional RO configuration), and can be instructed by the base station whether only the additional ROs (or NES ROs) according to the NES RO configuration are available among the two configurations, or whether all ROs according to the two configurations are available. If there is no such instruction, the NES UE can determine/determine that all ROs according to the default RO configuration and the NES RO configuration are available. Even if both the default RO and the NES RO are configured/instructed to be used, the NES RO may be normally deactivated. In this case, all terminals (e.g., both legacy UEs and NES UEs) can use only ROs according to the default RO setting, and NES RO can be activated dynamically by the base station (upon request of the terminal). Alternatively, when (de)activation of NES RO is indicated, (de)activation of default RO can be indicated together or separately.

The terminal may be configured with a NES RO using a time/frequency-offset by default RO/default RO group (or association period). For example, the terminal may be configured with corresponding NES ROs by default RO based on the time/frequency offset. Here, the association period may mean a time period in which an SSB is periodically mapped to an RO during SSB-to-RO mapping, such as {10, 20, 40, 80, 160ms}. If the time/frequency-offset for a specific default RO (group) or association period is set to 0 (or if the offset is not set), it may be determined/considered that an NES RO corresponding to the specific default RO or association period is not additionally configured. Meanwhile, the NES ROs configured for the NES UE may be adjusted by association pattern period (e.g., at least one association period) or by association period unit. For example, the base station may group multiple association pattern periods (or multiple association periods) into one group and configure/instruct the UE not to use all NES ROs within a specific group, or may configure/instruct the UE to always use NES ROs within some association periods within the group as default ROs for RACH transmission. When the NES UE needs NES ROs, the base station/NES cell may also indicate which NES ROs within the association period group or association pattern period are available ROs. For example, the base station may indicate to the UE whether NES ROs are activated or available for use in units of the association period or at least one association period.

The base station may configure the ROs in the NES RO configuration so that they do not overlap with the ROs in the default RO configuration in terms of time/frequency resources, or may intentionally configure the NES ROs so that specific NES ROs in the NES_RO configuration include all ROs in the default RO configuration. In this case, as one of the beam configuration methods between the overlapping default ROs and NES ROs, the UE may independently perform SSB-to-RO mapping for each of the default RO and the NES RO. In addition, the beam directions between the overlapping default RO and the NES RO may be configured to always be the same. Alternatively, when the beam directions between the overlapping default RO and the NES RO are different, the configuration of the default RO may be configured/defined to always be considered to have a higher priority than the NES RO. This may be a method (e.g., legacy SSB-to-RO mapping is prioritized) to ensure that the SSB index determined by the legacy SSB-to-RO mapping method is mapped to the NES ROs (e.g., NES ROs overlapping with the default RO). Alternatively, the UE may perform separate SSB-to-RO mapping only for NES ROs, but may perform SSB-to-RO mapping only for the remaining NES ROs, excluding NES ROs that are set to overlap with the default RO among the NES ROs.

Meanwhile, SSB-to-RO mapping for NES ROs may also be performed based on whether they overlap with a default RO. After SSB-to-RO mapping is performed on NES ROs that also include at least one NES RO that is configured to overlap with a default RO, the UE may be configured/instructed to use the beam direction of the overlapping default RO for the at least one overlapping RO (e.g., this has the effect of puncturing a specific beam direction in the NES ROs). Alternatively, SSB-to-RO mapping may be performed on the remaining NES ROs excluding the NES ROs that are configured to overlap with the default RO among the NES ROs according to the NES RO configuration. Here, the excluded NES ROs may be configured/instructed to use the beam direction of the default RO (e.g., this has the effect of postponing a specific beam direction in the NES ROs). In this case, the association period of the NES RO may be defined/configured to follow the association period of the default RO, or may be defined/configured to be less than or equal to the association period of the default RO.

Alternatively, overlapping between a default RO and a NES RO (e.g., an additional RO) may occur when both time and frequency resources overlap, or when frequency resources are different but only time resources overlap. Accordingly, the SSB-to-RO mapping method described above may be applied differently depending on the overlapping case/pattern between the ROs, as follows.

1) When the default RO and NES RO overlap in both time and frequency resources.

In this case, separate SSB-to-RO mapping can be performed only for NES ROs. Specifically, the terminal can perform SSB-to-RO mapping only for the remaining NES ROs, excluding the NES RO set to overlap with the default RO among the NES ROs. Alternatively, the terminal can determine that the NES RO set to overlap with the default RO is an invalid RO and perform SSB-to-RO mapping only for the remaining NES ROs, excluding the NES RO set to overlap with the default RO among the NES ROs.

2) If the default RO and NES RO overlap only in time resources (not in frequency).

In this case, the terminal may be instructed/configured to perform SSB-to-RO mapping for NES ROs that also include at least one NES RO that is set to overlap with a default RO, and to set the beam direction for said at least one RO to the beam direction of the overlapping default RO (in this case, this has the effect of puncturing a specific beam direction in the NES ROs).

Alternatively, the terminal may perform SSB-to-RO mapping for the remaining NES ROs, excluding at least one NES RO that overlaps with a default RO among the NES ROs. Here, the excluded at least one NES RO may be set/instructed to use the beam direction of the overlapping default RO (in this case, there is an effect that a specific beam direction is postponed in the NES ROs).

Alternatively, the terminal may determine that at least one NES RO among the NES ROs that is set to overlap with the default RO is an invalid RO, and perform SSB-to-RO mapping only for the remaining NES ROs excluding the NES RO.

Meanwhile, as in the case of "2)", when changing the beam direction of the NES RO to the beam direction of the default RO, there may be multiple SSB indices linked to the default RO corresponding to the (time) resource overlapping with the NES RO. In this case, the beam direction of the NES RO may be set/indicated as a specific SSB index among the SSB indices linked to the default RO (e.g., always the lowest/highest SSB index among the plurality of SSB indices). Alternatively, the beam direction of the NES RO may be defined in advance through a standard document, etc. as a specific SSB index among the SSB indices linked to the default RO, or SSB-to-(overlapping) NES RO mapping may be performed using the plurality of SSB indices linked to the default RO. Alternatively, if the NES RO overlapping with the default RO has a beam direction different from the beam direction of the default RO, the terminal may process the NES RO as an invalid RO.

In the above-described methods, the SSB-to-RO mapping method that takes into account the overlap with the default RO can also be applied to cases where only some SSB indices, not the entire SSB index, are mapped to the NES RO (e.g., an additional RO). Here, the entire SSB indices may refer to the SSB indices set via the ssb-PositionsInBurst parameter.

Alternatively, a time gap for beam switching may be defined when the beam directions between the default RO and the NES RO are different. For example, when the beam directions between the default RO and the NES RO are different and the beam direction of the NES RO needs to be changed to the beam direction of the default RO, a time gap for beam switching (e.g., beam switching between the beam direction of a specific NES RO that overlaps the default RO and the beam direction of a NES RO that does not overlap the default RO) may need to be additionally considered in relation to the beam direction settings of the overlapping default RO and NES RO. Therefore, when determining whether there is an overlap between the NES RO and the default RO in the time domain, the size of the pre-set/defined time gap also needs to be additionally considered. For example, when determining whether there is a time-domain overlap between the default RO and the NES RO, the size of the time gap may be compared with a time gap that is defined in advance (such as in a standard)/set/instructed by the base station. If the time gap between the default RO and the NES RO is less than the value of the configured time gap, the terminal may consider that there is an overlap between the default RO and the NES RO in the time domain and apply the above-described methods, or the NES RO may be processed/judged as an invalid RO. For example, even if the time resources between the default RO and the NES RO do not actually overlap, if the time gap between the time resources of the default RO and the time resources of the NES RO is less than the preset time gap, the default RO and the NES RO may be considered/processed as overlapping each other.

2. Method #2: How to dynamically receive an activation instruction for the NES RO (or NES RO settings) set by the base station.

A UE may receive a specific RNTI/CORESET/SS (search space) set for monitoring (GC-)DCI from a base station to indicate activation of a NES RO (or a NES RO configuration/parameter set). At this time, the DCI may be a group-common (GC) DCI of the DCI format 2_x series, or a UE-specific DCI. In addition, (group-common) MAC-CE may be used to indicate activation of the NES RO (or a NES RO configuration/parameter set). Alternatively, reserved bits of a specific DCI format (e.g., DCI format 1_0) may be utilized to indicate (de)activation of the NES RO. For example, a specific RNTI/CORESET/SS set may be set for the terminal to receive DCI (DCI format 1_0) that indicates activation/deactivation only for the NES RO setting among the default RO setting (or default RO parameter set) and the NES RO setting (or NES RO parameter set). For example, a Paging-Radio Network Temporary Identifier (P-RNTI) for indicating whether to activate the NES RO may be set as the specific RNTI, and the terminal may receive an indication of whether to activate the NES RO or the NES RO setting based on DCI format 1_0 having a CRC scrambled with the P-RNTI. Meanwhile, the default RO setting or the default RO parameter set is not activated/deactivated by the DCI, and if set, may be used for transmission of a PRACH or a PRACH preamble.

Alternatively, if (de)activation of a NES RO (or NES RO configuration/parameter set) is instructed via (GC-)DCI or MAC-CE, the terminal may receive a (de)activation instruction for at least one NES RO previously configured via a specific field/bit in the (GC-)DCI. Alternatively, the terminal may receive an instruction for switching from a (currently activated) first NES RO (or NES RO configuration/parameter set) to a second NES RO (or NES RO configuration/parameter set) via the DCI (e.g., DCI format 1_0) or MAC-CE. For example, the base station may be instructed to (de)activate a NES RO (or NES RO configuration/parameter set) using a field consisting of 1 bit in the GC-DCI. For example, if the value of the 1-bit field is 0, activation of the NES RO (or NES RO setting/parameter set) may be indicated, and if the value of the 1-bit field is 0, deactivation of the NES RO (or NES RO setting/parameter set) may be indicated. At this time, each of the NES RO settings may have a different RO cycle/pattern, etc., and it may also be possible to indicate switching between RO settings by deactivating the default RO and activating the NES RO. Alternatively, depending on the setting, an activation instruction of a specific state that may be indicated by (GC-DCI) may mean activation of the default RO + activation of the NES RO (or deactivation of the default RO + activation of the NES RO), and an instruction of deactivation may mean activation of the default RO + deactivation of the NES RO.

Meanwhile, the DCI indicating whether to activate the NES RO may be configured similarly to the DCI format 2_9 indicating (de)activation of the R18 NES cell DTX/DRX setting. For example, each bit of a bitmap (btmap) included in the DCI may be associated with a specific RO setting. For example, the bitmap may be set to indicate (de)activation of NES RO setting #1, NES RO setting #2, and NES RO setting #3 in order from the left bit. Alternatively, the bitmap may be set to indicate (de)activation of default RO, NES RO setting #1, and NES RO setting #2 in order from the left bit. Alternatively, considering multiple cells set for the terminal, the bit/field associated with cell #1 in the bitmap may be used to instruct (de)activation of NES RO setting #1 and NES RO setting #2 of cell #1, respectively, and the bit/field associated with cell #2 may be used to instruct (de)activation of NES RO setting #1 and NES RO setting #2 of cell #2, respectively. Alternatively, considering multiple cells set for the terminal, the bit/field associated with cell #1 in the bitmap may be used to instruct (de)activation of default RO and RO setting #1 of cell #1, respectively, and the bit/field associated with cell #2 may be used to instruct (de)activation of default RO and RO setting #1 of cell #2, respectively.

Meanwhile, in case of (de)activation of a specific NES RO setting through (GC-)DCI or MAC-CE, additional indication/setting of the point in time (or available point in time) at which the specific NES RO setting is applied and the valid time period, etc. may be required. In one method, considering the application delay of the terminal (e.g., processing time of the terminal, etc.), the indicated specific NES RO setting may be applied (or ROs according to the specific NES RO may be regarded as available or usable ROs) after a point in time/time (e.g., T symbol/slot) defined/set in advance (in a standard document, etc.) from the time of reception of (GC-)DCI or MAC-CE. In this case, the terminal may perform RACH or PRACH transmission using NES ROs according to the specific NES RO setting after the predefined time from the time of reception of the DCI. Specifically, in the case of deactivation, the specific NES RO setting may be considered as deactivated immediately upon reception/indication of (GC-)DCI or MAC-CE, without considering the application delay of the terminal, etc. Alternatively, the activation/deactivation time point of the specific NES RO setting indicated via (GC-)DCI or MAC-CE may be determined based on an index of one candidate indicated via (GC-)DCI or MAC-CE among pre-configured application time point/time candidates. Alternatively, the specific NES RO may be set/instructed to be applied (or activated) from the associated (pattern) period after the time point/time indicated by (GC-)DCI (or MAC-CE).

In the case where the valid time of the NES RO configuration for which activation is indicated is the same (or, the valid time between NES RO configurations is the same, or, the activation of the NES RO configuration is indicated in the same cycle), the valid time of the specific NES RO configuration for which activation is indicated may be until the next (GC-)DCI or MAC-CE indication is received. Alternatively, a timer (or valid duration) defined/set in advance (in a standard document, etc.) may be applied. In this case, the activation indication for the specific NES RO configuration may be considered valid while the timer is running (or within the valid duration). The value of the timer (or valid duration) may be directly indicated via the (GC-)DCI or MAC-CE among multiple timer (or valid duration) candidate values that are set in advance. Alternatively, when the timer expires (or the valid duration has elapsed), it may automatically fallback to the previous NES RO configuration that was activated before the (GC-)DCI or MAC-CE indication was received. Alternatively, if one of the multiple pre-configured NES RO settings is promised/set as the default NES setting, when the timer expires, the specific NES RO setting whose activation was instructed may always be switched (or activated/deactivated) to the default NES RO setting. Alternatively, the validity time of the specific NES RO setting whose activation was instructed may be set/instructed in units of an associated (pattern) period.

Alternatively, the terminal may be configured to divide a specific time interval (defined/set) in advance into N, and dynamically be instructed on the availability of NES RO (or NES RO setting) for each divided time interval. For example, if the default RO setting and NES RO setting #1 are set, the 160ms time interval may be divided into 20ms units, and the activation or availability of NES RO setting for each 20ms time interval may be instructed through a bitmap consisting of 8 bits in (GC-)DCI.

The NES RO or NES RO configuration may be indicated as available when retransmission of RACH (PRACH, MSG A, MSG 1) is required. For example, the UE may be dynamically indicated whether the NES RO is available and its valid duration/timer via the DCI scheduling the retransmission of RACH (PRACH, MSG A, MSG 1). For example, the UE may be indicated as to whether the NES RO/NES RO configuration is available for retransmission of RACH (PRACH, MSG A, MSG 1) and information about the valid duration of the NES RO via the DCI scheduling the retransmission of RACH (PRACH, MSG A, MSG 1). Alternatively, if the UE transmits RACH on a NES RO and fails and tries to retransmit the RACH (or PRACH) when the NES RO is no longer valid, the UE may be configured/instructed to perform retransmission of the RACH (or PRACH) via a default RO. Alternatively, if the NES RO is deactivated during retransmission of the RACH (or PRACH), the UE may consider it as a failure of the RACH (or PRACH) transmission (e.g., the maximum number of retransmissions (max counter) has been reached). Additionally, an NES RO may suddenly become available at the time of retransmission of the RACH (or PRACH) after a failed transmission of the RACH via the default RO (e.g., a situation in which the NES RO becomes available due to an instruction to activate the NES RO configuration via DCI after a failed transmission of the RACH). In this case, the UE may be configured/instructed to use the NES RO with priority for retransmission of the RACH (or PRACH), or to use the default RO with priority for retransmission of the RACH (or PRACH) even if the NES RO exists. Alternatively, the UE may be configured in advance by the base station which RO between the default RO and the NES RO to use with priority (for retransmission of the RACH (or PRACH)). If transmission of the RACH (or PRACH) fails a certain number of times (a pre-arranged/configured number of times/max counter) in the default RO, the UE may be configured/instructed to attempt (re)transmission of the RACH (or PRACH) by switching to the NES RO (or vice versa). Alternatively, the UE may be configured/instructed to perform initial transmission of the PRACH using only the default RO, and to use the NES RO together from the retransmission of the PRACH. The availability and validity time (or timer) of the above-mentioned NES RO may be indicated by CFRA scheduling DCI (PDCCH ordered RACH procedure). The terminal may receive an instruction for dynamic adaptation of the period of an SSB burst/SSB index/SSB index group through (GC-)DCI or MAC-CE, and the availability of the NES RO may also be dynamically indicated in the instruction for adaptation of the transmission period of SSB.

Meanwhile, the base station can determine whether to activate/deactivate the NES RO based on the communication environment within the coverage. For example, the base station can instruct the activation of the NES RO if it is determined that the failure of RACH transmission from the terminal has become frequent based on the report of the transmission power (or power ramping counter) of the PRACH of the terminal. For example, the base station can determine that the failure of RACH transmission has become frequent if the number of UEs retransmitting the PRACH or the number of collisions between the terminals transmitting the RACH (e.g., the number of PRACHs having the same RAPID among the received PRACHs) is greater than a certain threshold based on the transmission power of the PRACH of the terminal. Alternatively, the base station can determine whether to activate the NES RO based on the degree of RACH congestion periodically reported through a specific UL signal/channel. Alternatively, the base station may receive information/signal requesting activation of NES RO from the terminal through a specific UL signal/channel configured in advance, and may indicate availability/activation of NES RO according to the request. For example, the NES terminal may request NES RO when retransmission of RACH is required, or may also perform a request for NES RO when transmitting RACH (or PRACH) for CBRA (contention based random access) or CFRA (contention free random access). For example, the request for NES RO for retransmission of RACH may be transmitted through RO/RAPID (Random Access Preamble ID) configured separately in advance, or a specific UL signal/channel (e.g., (SR) PUCCH, CG-PUSCH, P/SP-PUCCH/PUSCH). Alternatively, the base station may configure/indicate whether the on-demand RO procedure can be performed and the resources related thereto (e.g., resources for the request of the NES RO) when instructing the activation of the SCell through SIB1, SCell configuration (addition/modification/release) or MAC-CE.

The above-described proposed methods can also be applied to the PUSCH occasion of MSG A of the 2-step RACH procedure.

3. Method #3: How to set the default state (or initial state) when an additional RO (or NES RO) is set

Meanwhile, as described above, an additional RO for NES (e.g., NES RO) may be configured for the terminal via a higher layer signal such as RRC. In this case, the terminal may be explicitly instructed/configured to activate/deactivate the additional RO (NES RO) configuration via a separate parameter. Alternatively, if the additional RO does not have a separate configuration/instruction for a default state in the configuration, the default state of the additional RO may be agreed/defined between the terminal and the base station to be activated (or deactivated). Alternatively, if the default state for the additional RO is set to be deactivated, the activation state of the additional RO/additional RO configuration may be indicated via DCI or MAC-CE. Alternatively, if the default state for the additional RO is set to be activated, the deactivation state of the additional RO/additional RO configuration may be indicated via an additional DCI.

In addition, when multiple additional RO settings are set in the terminal, the terminal may be explicitly instructed which additional RO among the multiple additional RO settings is initially activated. For example, the terminal may determine the additional RO setting with the highest or lowest index among the multiple additional RO settings as the initially activated additional RO setting, or may determine an additional RO explicitly indicated through a separate parameter as the initially activated additional RO. Alternatively, when all additional RO settings are set to the disabled state in the initial setting and a default additional RO setting is subsequently set/defined, the default additional RO setting may be (always) determined/considered to be in the enabled state by default even if there is no separate instruction/setting for the default state. Alternatively, when there is no separate setting/instruction for the default state for the default additional RO setting, the default state of the default additional RO setting may be considered/defined to be in the enabled state, and the default additional RO/additional RO setting may be deactivated through a separate DCI.

4. Method #4: How to set up msg A PUSCH resources when additional RO (NES RO) is supported in 2-step RACH

A terminal (or NES-capable UE) may be configured with a priority order among ROs configured by a base station (e.g., default RO (configuration) and NES RO (configuration)) as to whether only NES RO is available, whether both default RO and NES RO are available, and/or which one between default RO and NES RO is available with priority. In this way, if the priority order between ROs (default RO and NES RO) is configured in advance, the base station can predict in which RO the UE will transmit PRACH. In addition, if the NES RO also supports 2-step RACH (e.g., if the NES RO can transmit msgA PRACH/PUSCH for 2-step RACH procedure), a separate MsgA PUSCH resource for the NES RO may not be configured separately. For example, the NES RO configuration can be set by indicating a specific time/frequency offset (default RO configuration + time/frequency offset) in relation to the default RO configuration, and msgA PUSCH resources for/related to the NES RO can be set based on the specific time/frequency offset. For example, similar to a parameter introduced in IAB (Integrated Access and Backhaul) (e.g., PRACH-ConfigurationPeriodScaling-IAB ), the UE can determine/configure NES ROs by applying a specific time/frequency offset (e.g., an offset separately indicated for configuring NES RO) to the default RO configuration set by rach-ConfigCommon, and the UE can also determine msgA PUSCH resources for the NES RO by applying the specific time/frequency offset value to the msgA PUSCH resources set in the default RO. Alternatively, the time/frequency offset for setting/determining msgA PRACH/PUSCH to be used in performing the 2-step RACH procedure via NES RO may be indicated separately from the time/frequency offset applied to the default RO for setting NES RO.

In this way, the proposed invention can expect a certain level of energy saving benefit for the base station without causing excessively long access delays for the terminals by additionally setting an additional NES RO (e.g., an additional RO) for the NES UE (a terminal supporting the R19 NES feature) in addition to setting a default RO (a relatively sparse RO) for the legacy UEs.

FIG. 13 is a diagram for explaining a method for a UE to transmit a signal based on RACH resource configuration information.

A UE may be an NES aware UE capable of supporting the operation of a base station/cell performing NES operations. As described above, the UE may be configured with both a default RO previously configured in relation to PRACH (e.g., an RO configured for a legacy UE that is not an NES aware UE) and an additional RO (or PRACH configuration) related to NES from a NES base station/NES cell (hereinafter, NES cell) performing NES operations. The method described below is a method for the "Adaptation of PRACH for energy saving" described above, and even if some of the methods described in FIG. 13 are not explicitly described below, the methods described in "Adaptation of PRACH for energy saving" can be naturally applied.

Specifically, referring to FIG. 13, a UE may receive RACH (Random Access Channel) resource configuration information that configures a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving) (S131). For example, as described above, the RACH resource configuration information may configure at least one default RO and at least one additional RO. The additional RO is an RO additionally configured for the UE, which is an NES aware UE, in relation to the NES operation/management of the base station, and may be defined as a NES RO. Alternatively, the RACH resource configuration information may include a first parameter set that configures the default RO and a second parameter set that configures the additional RO, and a period of the NES RO may be shorter than a period of the default RO.

In addition, whether the additional RO is activated or not can be indicated through a DCI (Downlink Control Information) of a specific format. For example, whether the additional RO is activated/deactivated can be indicated through the DCI of the group common DCI format 1_0 as described above. For example, the UE can be indicated whether to activate or not through the reserved bits included in the DCI of the DCI format 1_0. Alternatively, a Paging-Radio Network Temporary Identifier (P-RNTI) for indicating whether to activate the additional RO can be set as the specific RNTI, and the UE can be indicated whether to activate the additional RO only through the DCI of the DCI format 1_0 having a CRC scrambled with the P-RNTI. Meanwhile, the default RO, unlike the additional RO, can always be used regardless of the DCI. In other words, the default RO can always be determined as a valid RO regardless of the indication of whether to activate or not through the DCI when set by the RACH resource configuration information.

Alternatively, the RACH resource configuration information may further include specific offset information (e.g., time and/or frequency offset) for configuring the additional RO based on the default RO. For example, the UE may determine a default RO based on the RACH resource configuration information, and determine the additional RO by applying a specific offset included in the specific offset information to the determined default RO. Alternatively, the RACH resource configuration information may further include priority information for setting a priority between the default RO and the additional RO, and the UE may determine an RO to be used for transmission of the PRACH among the default RO and the additional RO based on the priority information.

Next, the UE can transmit a PRACH (Physical Random Access Channel) based on the RACH resource configuration information (S133). For example, if the additional RO is activated (e.g., if activation is indicated through a DCI related to paging), the UE can transmit the PRACH or PRACH preamble (a preamble for a determined RAPID for the UE) in an RO randomly selected (or instructed by the base station) from among the default RO and the additional RO. Alternatively, the UE can determine an RO to transmit the PRACH or PRACH preamble based on the SSB-to-RO mapping result for the default RO and the additional RO. For example, if the reception quality of an SSB with an SSB index 1 among a plurality of SSBs is the best, the UE can transmit the PRACH or PRACH preamble in an RO mapped to the SSB index 1 among the default RO and the additional RO.

Alternatively, the UE may determine a beam direction for the additional RO through at least one of the SSB-to-RO mapping methods for the additional RO proposed in the above-described “Method #1” when the additional RO overlaps with the default RO. For example, the UE may determine/configure a plurality of default ROs including the default RO and a plurality of additional ROs including the additional RO based on the RACH resource configuration information. At this time, if a specific additional RO among the plurality of additional ROs overlaps with the default RO, the UE may consider the specific additional RO to be invalid and perform SSB-to-RO mapping for the remaining additional ROs. Alternatively, the UE may perform SSB-to-RO mapping only for the remaining additional ROs excluding the specific additional RO among the plurality of additional ROs when the additional RO overlaps with the default RO. In this case, the beam direction of the specific additional RO may be determined/considered to have the same beam direction as the beam direction for the default RO.

Figure 14 is a diagram for explaining a method for a base station to transmit RACH resource configuration information.

Referring to FIG. 14, a base station/cell capable of performing an NES operation may transmit RACH resource configuration information to a UE that configures a default RO (e.g., a RO configured for a legacy UE that is not an NES aware UE) configured in relation to an existing PRACH and an additional RO (or, PRACH configuration) for an NES aware UE (S141). For example, as described above, the RACH resource configuration information may configure at least one default RO and at least one additional RO. The additional RO may be defined as an NES RO as an RO additionally configured for the UE that is an NES aware UE in relation to the NES operation/management of the base station. Alternatively, the RACH resource configuration information may include a first parameter set that configures the default RO and a second parameter set that configures the additional RO, and a period of the NES RO may be shorter than a period of the default RO.

Next, the base station can indicate whether to activate the additional RO through DCI (Downlink Control Information) of a specific format (S143). For example, the base station can indicate to the UE whether to activate the additional RO through reserved bits included in the DCI of the DCI format 1_0. Alternatively, a Paging-Radio Network Temporary Identifier (P-RNTI) for indicating whether to activate the additional RO can be set as the specific RNTI, and the base station can indicate whether to activate the additional RO through DCI of the DCI format 1_0 having a CRC scrambled with the P-RNTI.

Alternatively, the RACH resource configuration information may further include specific offset information (e.g., time and/or frequency offset) for configuring the additional RO based on the default RO. Alternatively, the RACH resource configuration information may further include priority information for configuring a priority between the default RO and the additional RO.

Next, the base station can receive a PRACH (Physical Random Access Channel) based on the RACH resource configuration information (S145). For example, if the additional RO is activated (e.g., activation is indicated through a DCI related to paging), the base station can monitor the PRACH or PRACH preamble in the default RO and the additional RO.

Alternatively, the base station may expect to determine the beam direction for the additional RO through at least one of the SSB-to-RO mapping methods for the additional RO proposed in “Method #1” described above when the additional RO overlaps with the default RO.

In this way, the proposed invention can quickly adjust the RO cycle according to the base station's situation by additionally setting an additional RO that is dynamically controlled in relation to the NES. Alternatively, the proposed invention can effectively indicate whether to activate the additional RO through an existing DCI of a specific format, without defining a separate DCI. Alternatively, the proposed invention can increase the energy saving benefit of the base station by setting a long default RO cycle, and can also effectively resolve the UE's connection delay problem due to the increase in the default RO cycle by dynamically adjusting the additional RO with a relatively short cycle according to the base station's situation.

Examples of communication systems to which the invention applies

Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and/or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication/connection (e.g., 5G) between devices.

Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings/descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

Figure 15 illustrates a communication system applied to the present invention.

Referring to FIG. 15, a communication system (1) applied to the present invention includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication/wireless/5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device/server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality)/VR (Virtual Reality)/MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station/network node to other wireless devices.

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

Wireless communication/connection (150a, 150b, 150c) can be established between wireless devices (100a~100f)/base stations (200), and base stations (200)/base stations (200). Here, wireless communication/connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink/downlink communication (150a), sidelink communication (150b) (or D2D communication), and base station-to-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication/connection (150a, 150b, 150c), wireless devices and base stations/wireless devices, and base stations and base stations can transmit/receive wireless signals to each other. For example, wireless communication/connection (150a, 150b, 150c) can transmit/receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting/receiving wireless signals, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, resource mapping/demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

Examples of wireless devices to which the present invention is applied

Figure 16 illustrates a wireless device applicable to the present invention.

Referring to FIG. 16, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and/or {the wireless device (100x), the wireless device (100x)} of FIG. 15.

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

Specifically, the first wireless device or terminal (100) may include a processor (102) and a memory (104) connected to a transceiver (106). The memory (104) may include at least one program capable of performing operations related to the embodiments described in FIGS. 11 to 14.

A processor (102) controls a transceiver (106) to receive RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving), and transmits a PRACH (Physical Random Access Channel) based on the RACH resource configuration information. Here, whether the additional RO is activated can be indicated through DCI (Downlink Control Information) of a specific format.

Alternatively, a processing device may be configured, including a processor (102) controlling a terminal and a memory (104). In this case, at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions, based on being executed by the at least one processor, cause the terminal to: receive RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving), and transmit a PRACH (Physical Random Access Channel) based on the RACH resource configuration information. Here, whether the additional RO is activated can be indicated through DCI (Downlink Control Information) of a specific format.

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

Specifically, the second wireless device or base station (200) may include a processor (202) and a memory (204) connected to a transceiver or RF transceiver (206). The memory (204) may include at least one program capable of performing operations related to the embodiments described in FIGS. 11 to 14.

The processor (202) controls the transceiver (206) to transmit RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving), and can receive a PRACH (Physical Random Access Channel) based on the RACH resource configuration information. Here, whether the additional RO is activated can be indicated through DCI (Downlink Control Information) of a specific format.

Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and/or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein.

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

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

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

Examples of wireless devices to which the present invention is applied

Figure 17 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case/service (see Figure 15).

Referring to FIG. 17, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 16 and may be composed of various elements, components, units/units, and/or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and/or one or more memories (104, 204) of FIG. 17. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and/or one or more antennas (108, 208) of FIG. 16. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical/mechanical operation of the wireless device based on the program/code/command/information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless/wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless/wired interface in the memory unit (130).

The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit/battery, an input/output unit (I/O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 15, 100a), a vehicle (Fig. 15, 100b-1, 100b-2), an XR device (Fig. 15, 100c), a portable device (Fig. 15, 100d), a home appliance (Fig. 15, 100e), an IoT device (Fig. 15, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate/environmental device, an AI server/device (Fig. 15, 400), a base station (Fig. 15, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use/service.

In FIG. 17, various elements, components, units/parts, and/or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit/part, and/or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of a set of one or more processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and/or a combination thereof.

Examples of vehicles or autonomous vehicles to which the present invention is applied

Figure 18 illustrates a vehicle or autonomous vehicle applicable to the present invention. The vehicle or autonomous vehicle may be implemented as a mobile robot, a car, a train, a manned or unmanned aerial vehicle (AV), a ship, or the like.

Referring to FIG. 18, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110/130/140a to 140d correspond to blocks 110/130/140 of FIG. 17, respectively.

The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired/wireless charging circuit, a battery, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward/backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed/direction control). During autonomous driving, the communication unit (110) can irregularly/periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on newly acquired data/information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

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

The embodiments described above are combinations of components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment of the present invention by combining some components and/or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or incorporated as a new claim through a post-application amendment.

In this document, embodiments of the present invention have been described primarily focusing on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is equally/similarly extended to signal transmission and reception between a terminal and a relay or a base station and a relay. Certain operations described as being performed by a base station in this document may, in some cases, be performed by its upper node. That is, it is obvious that various operations performed for communication with a terminal in a network composed of multiple network nodes including a base station may be performed by the base station or network nodes other than the base station. The base station may be replaced by terms such as fixed station, Node B, eNode B (eNB), and access point. In addition, the terminal may be replaced by terms such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station).

Embodiments of the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

When implemented via firmware or software, an embodiment of the present invention may be implemented in the form of modules, procedures, functions, etc. that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor via various known means.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims (15)

In a method using UE (User Equipment), A step of receiving RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving); and A step of transmitting a PRACH (Physical Random Access Channel) based on the above RACH resource configuration information; A method in which the above additional RO is indicated to be activated via DCI (Downlink Control Information) of a specific format. In the first paragraph, A method, characterized in that the DCI of the above specific format is a DCI of a group common DCI format 1_0 having a CRC (cyclic redundancy check) scrambled with a specific RNTI (Paging-Radio Network Temporary Identifier) related to an activation instruction of the additional RO. In the second paragraph, A method characterized in that the above additional RO is indicated as to whether or not to be activated through reserved bits included in the DCI of the DCI format 1_0. In the first paragraph, A method characterized in that, based on the overlap of the additional RO and the default RO, the beam direction of the additional RO is considered to be the same beam direction as the beam direction determined for the default RO. In the first paragraph, A method characterized in that the additional RO is considered invalid based on the fact that the additional RO overlaps with the default RO. In the first paragraph, The above RACH resource configuration information sets a plurality of default ROs including the default RO and a plurality of additional ROs including the additional RO, A method characterized in that the UE performs SSB mapping only for the additional ROs excluding the additional ROs that overlap with the default RO among the plurality of additional ROs. In the first paragraph, A method characterized in that the RACH resource configuration information further includes information for setting priorities between the default RO and the additional RO. In the first paragraph, A method characterized in that the RACH resource configuration information further includes information on a specific offset for configuring the additional RO based on the default RO. In the first paragraph, A method characterized in that the above default RO is always valid regardless of the indication as to whether or not to activate it via the DCI. A computer-readable recording medium having recorded thereon a program for performing the method described in paragraph 1. In UE (User Equipment), RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to receive RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving), and transmits a PRACH (Physical Random Access Channel) based on the RACH resource configuration information. The above additional RO is indicated to be activated via a specific format of DCI (Downlink Control Information) to the UE. In Article 11, A UE characterized in that the DCI of the above specific format is a DCI of group common DCI format 1_0 having a CRC (cyclic redundancy check) scrambled with a specific RNTI (Paging-Radio Network Temporary Identifier) associated with an activation instruction of the additional RO. In a processing device that controls UE (User Equipment), at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said UE: Receive RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving), and transmit a PRACH (Physical Random Access Channel) based on the RACH resource configuration information, The above additional RO is a processing device whose activation is indicated through a DCI (Downlink Control Information) of a specific format. In the method by the base station, A step of transmitting RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving); and A step of receiving a PRACH (Physical Random Access Channel) based on the above RACH resource configuration information; A method in which the above additional RO is indicated to be activated via DCI (Downlink Control Information) of a specific format. At the base station, RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to transmit RACH (Random Access Channel) resource configuration information that sets a default RO (Random Access Channel Occasion) and an additional RO related to NES (network energy saving), and receives a PRACH (Physical Random Access Channel) based on the RACH resource configuration information. The above additional RO is a base station whose activation is indicated through a DCI (Downlink Control Information) of a specific format.