Method and apparatus for efficiently transmitting small-sized data in a next-generation mobile communication system

Abstract

This disclosure relates to a communication technology and system for combining a 5G communication system for supporting higher data transmission rates than 4G systems with IoT technology. Based on 5G communication technology and IoT-related technologies, this disclosure can be applied to intelligent services such as smart homes, smart buildings, smart cities, smart cars or connected vehicles, healthcare, digital education, retail businesses, and security and safety-related services. According to various embodiments of the present invention, a method and apparatus for effectively transmitting small-sized data in a next-generation mobile communication system can be provided.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for transmitting and receiving small-sized user data when a terminal in an idle mode (RRC_idle) or an inactive mode (RRC_inactive) in a mobile communication system performs a random access procedure with a base station without switching to a connected mode (RRC_connected). Background Art

[0002] To meet the increasing demand for wireless data traffic since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as beyond 4G networks or post-LTE systems. The 5G communication system is considered to be implemented in a higher frequency (millimeter wave) band (e.g., 60 GHz band) in order to achieve higher data rates. To reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies are discussed in the 5G communication system. In addition, in the 5G communication system, system network improvements are being developed based on advanced small cells, cloud radio access network (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), receiver interference cancellation, etc. In the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superimposed coding (SWSC) as advanced coding modulation (ACM), and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0003] The Internet is a human-centered connected network in which humans generate and consume information, and is now evolving towards the Internet of Things (IoT), in which distributed entities (such as things) exchange and process information without human intervention. The Internet of Everything (IoE), which combines IoT technology and big data processing technology, has emerged by connecting to a cloud server. Since IoT implementation requires technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, sensor networks, machine-to-machine (M2M) communication, machine type communication (MTC), etc. have been recently studied. Such an IoT environment can provide intelligent Internet technology services, creating new value for human life by collecting and analyzing data generated between interconnected things. Through the fusion and combination of existing information technology (IT) and various industrial applications, IoT can be applied to various fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0004] Accordingly, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M) communication, and machine type communication (MTC) can be implemented through beamforming, MIMO, and array antennas. Cloud radio access network (RAN), as an application of the above big data processing technology, can also be considered an example of the convergence between 5G technology and IoT technology. Summary of the Invention

[0005] Technical Problem

[0006] The present disclosure proposes a technique for transmitting and receiving small-sized user data when a terminal in an idle mode (RRC_idle) or an inactive mode (RRC_inactive) in a mobile communication system performs a random access procedure with a base station without switching to a connected mode (RRC_connected).

[0007] In addition, using the early data transmission (EDT) technique, the present disclosure proposes a method for a terminal to transmit user data to a base station in an uplink (mobile originated, MO) and a method for the base station to transmit user data to the terminal in a downlink (mobile terminated, MT).

[0008] Solution to the Problem

[0009] According to an embodiment of the present disclosure, a method performed by a terminal in a wireless communication system may include: receiving system information from a base station, the system information including configuration information related to early data transmission (EDT) of a normal uplink (NUL), configuration information related to EDT of a supplementary uplink (SUL), and reference signal received power (RSRP) threshold information for determining whether to apply the SUL; based on the system information, determining whether to trigger a random access for EDT and determining an uplink for performing the random access for EDT; and in a case where the random access for EDT is triggered, performing the random access for EDT through the determined uplink to the base station.

[0010] In addition, according to another embodiment of the present disclosure, a method performed by a base station in a wireless communication system may include sending system information to a terminal, the system information including configuration information related to early data transmission (EDT) of a normal uplink (NUL), configuration information related to EDT of a supplementary uplink (SUL), and reference signal received power (RSRP) threshold information for determining whether to apply the SUL; and receiving a random access preamble for EDT from the terminal via an uplink determined for performing random access for EDT, wherein the uplink determined for performing random access for EDT and whether to trigger random access for EDT are based on the system information.

[0011] In addition, according to yet another embodiment of the present disclosure, a terminal in a wireless communication system may include a transceiver; and a controller configured to receive system information from a base station, the system information including configuration information related to early data transmission (EDT) of a normal uplink (NUL), configuration information related to EDT of a supplementary uplink (SUL), and reference signal received power (RSRP) threshold information for determining whether to apply the SUL, determine whether to trigger random access for EDT and determine an uplink for performing random access for EDT based on the system information, and perform random access for EDT via the determined uplink to the base station when random access for EDT is triggered.

[0012] In addition, according to yet another embodiment of the present disclosure, a base station in a wireless communication system may include a transceiver; and a controller configured to send system information to a terminal, the system information including configuration information related to early data transmission (EDT) of a normal uplink (NUL), configuration information related to EDT of a supplementary uplink (SUL), and reference signal received power (RSRP) threshold information for determining whether to apply the SUL, and receive a random access preamble for EDT from the terminal via an uplink determined for performing random access for EDT, wherein the uplink determined for performing random access for EDT and whether to trigger random access for EDT are based on the system information.

[0013] Advantageous effects of the invention

[0014] According to an embodiment of the present disclosure, when a terminal needs to send small-sized data via an uplink, the control plane (CP) EDT can be used to effectively send the data.

[0015] In addition, according to another embodiment of the present disclosure, when a terminal needs to send small-sized data via an uplink, the user plane (UP) EDT can be used to effectively send the data.

[0016] In addition, according to another embodiment of the present disclosure, when the base station needs to transmit small-sized data via the downlink, CP EDT can be used to effectively transmit the data.

[0017] In addition, according to another embodiment of the present disclosure, when the base station needs to transmit small-sized data via the downlink, UP EDT can be used to effectively transmit the data. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a diagram showing the structure of a next-generation mobile communication system.

[0019] Figure 2 is a diagram showing the radio protocol structure in a mobile communication system according to an embodiment of the present disclosure.

[0020] Figure 3 is a diagram showing the operation sequence of a base station and a UE according to an embodiment of the present disclosure to explain the random access process.

[0021] Figure 4 is the operation sequence of a UE, an eNB, a mobility management entity (MME), and a serving gateway (S-GW) according to an embodiment of the present disclosure for explaining the uplink EDT operation in the four-step random access process.

[0022] Figure 5 is the operation sequence of a UE, an eNB, a mobility management entity (MME), and a serving gateway (S-GW) according to an embodiment of the present disclosure for explaining the uplink EDT operation in the four-step random access process.

[0023] Figure 6 is a diagram showing an example of applying an additional uplink frequency according to an embodiment of the present disclosure.

[0024] Figure 7 is a diagram showing a scenario of applying a bandwidth part in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0025] Figure 8 is a diagram showing the operation sequence of a UE and a gNB for performing EDT operation in the first embodiment of the present disclosure.

[0026] Figure 9 is a diagram showing the operation sequence of a UE and a gNB for performing EDT operation in the second embodiment of the present disclosure.

[0027] Figure 10 is a diagram showing the operation sequence of a UE and a gNB for performing EDT operation in the third embodiment of the present disclosure.

[0028] Figure 11It is a diagram showing the operation sequences of a UE and a gNB for performing EDT operations in the fourth embodiment of the present disclosure.

[0029] Figure 12 It is a diagram showing the operation sequence of a UE performing EDT in the second embodiment of the present disclosure.

[0030] Figure 13 It is a diagram showing the operation sequence of a gNB performing EDT in the second embodiment of the present disclosure.

[0031] Figure 14 It is a block diagram showing the internal structure of a UE according to an embodiment of the present disclosure.

[0032] Figure 15 It is a block diagram showing the internal structure of a base station according to an embodiment of the present disclosure. Detailed implementation manners

[0033] When describing the embodiments, descriptions of technical contents that are well-known in the technical field to which the present disclosure belongs and are not directly related to the present disclosure will be omitted. This is to more clearly convey the subject matter of the present disclosure without obscuring it due to the omission of unnecessary descriptions.

[0034] For the same reason, some elements are exaggerated, omitted, or schematically shown in the drawings. In addition, the illustrated sizes of each element do not exactly reflect the actual sizes. In the drawings, the same or corresponding elements are given the same reference numerals.

[0035] Through the embodiments described below with reference to the drawings, the advantages and features of the present disclosure and the ways to achieve them will become apparent. However, the present disclosure can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. The present disclosure is only defined by the scope of the appended claims. Throughout the specification, the same reference numerals represent the same constituent elements.

[0036] It will be understood that each block of the flowchart illustrations and combinations of blocks in the flowchart illustrations can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executed via the processor of the computer or other programmable data processing apparatus create means for implementing the functions specified in the (multiple) flowchart block(s). These computer program instructions may also be stored in a computer-usable or computer-readable memory, which can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instruction means for implementing the functions specified in the (multiple) flowchart block(s). The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in the (multiple) flowchart block(s).

[0037] In addition, each block of the flowchart may represent a module, a segment of code, or a portion of code that includes one or more executable instructions for implementing the (multiple) specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks may not occur in the order presented. For example, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

[0038] As used herein, the term "unit" refers to a software element or a hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the term "unit" does not always have a meaning limited to software or hardware. A "unit" may be configured to be stored in an addressable storage medium or to execute on one or more processors. Thus, a "unit" includes, for example, software elements, object-oriented software elements, class elements, or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided by the elements and units may be combined into the functions of a smaller number of elements and units or divided into the functions of a larger number of elements and units. In addition, the elements and units may be implemented as one or more central processing units (CPUs) within an operating device or a secure multimedia card.

[0039] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0040] Figure 1 is a diagram showing the structure of a next-generation mobile communication system.

[0041] Figure 1 The EN-DC architecture of the next-generation mobile communication system is shown.

[0042] EN-DC refers to the dual connection of the LTE system (EUTRAN) and the next-generation mobile communication system (NR), and is a scenario where a UE is simultaneously connected to two heterogeneous systems to receive services.

[0043] Reference Figure 1 , as shown in the figure, the radio access network of the next-generation mobile communication system may consist of a next-generation base station 110 (i.e., a new radio node B, hereinafter referred to as gNB) 110 and an AMF 105 (i.e., a new radio core network). A UE115 (i.e., a new radio user equipment, hereinafter referred to as NR UE or UE) may access an external network through the gNB 110 and the AMF 105.

[0044] In Figure 1 , the gNB 110 may correspond to an evolved node B (eNB) in a traditional LTE system. The gNB is connected to the NR UE 115 via a radio channel and can provide better services compared to a traditional nodeB. In the next-generation mobile communication system, since all user services are served via a shared channel, a device that may be required to collect UE state information (such as buffer state, available transmit power state, or channel state) and perform scheduling, and the gNB 110 may be responsible for this. Generally, one gNB may control multiple cells. To achieve high-speed data transmission compared to traditional LTE, the gNB 110 may have a larger bandwidth than the existing maximum bandwidth, and an additional beamforming technique using orthogonal frequency division multiplexing (hereinafter referred to as OFDM) may be used as a radio access technology. In addition, an adaptive modulation and coding (AMC) scheme that determines the modulation scheme and channel coding rate according to the UE's channel state may be applied. The AMF 105 may perform functions such as mobility support, bearer establishment, and quality of service (QoS) establishment. The AMF is a device responsible for various control functions and the mobility management function of the terminal, and may be connected to multiple base stations. In addition, the next-generation mobile communication system may be linked to a traditional LTE system, and the AMF is connected to the MME 125 through a network interface. The MME may be connected to a traditional base station, i.e., the eNB 130. In the EN-DC scenario, the gNB may be controlled by connecting to the eNB.

[0045] Figure 2 is a diagram showing the radio protocol structure in a mobile communication system according to an embodiment of the present disclosure.

[0046] The control plane (CP) radio protocol of a mobile communication system consists of Radio Resource Control (RRC) 202 or 245, Packet Data Convergence Protocol (PDCP) 205 or 240, Radio Link Control (RLC) 210 or 235, and Medium Access Control (MAC) 215 or 230 in each of the UE and the gNB. RRC 202 or 245 may be responsible for configurations related to RRC connection and mobility support. PDCP 205 or 240 may be responsible for operations such as IP header compression / restoration. RLC 210 or 235 may reconfigure the PDCP protocol data unit (PDCP PDU) to an appropriate size and perform operations such as automatic repeat request (ARQ). MAC 215 or 230 may be connected to several RLC layer devices configured in a UE and may perform operations such as multiplexing MAC PDUs into and demultiplexing MAC PDUs from MAC PDUs. The physical layer 220 or 225 may perform the following operations: channel coding and modulation of the upper layer data, generating OFDM symbols and transmitting them through the radio channel, or demodulating and channel decoding the OFDM symbols received through the radio channel and transmitting them to the upper layer.

[0047] Figure 3 is a diagram showing the operation sequence of a base station and a UE according to an embodiment of the present disclosure to explain the random access process.

[0048] The random access procedure can be performed when synchronizing the uplink or transmitting data over the network. Specifically, this operation can be performed when switching from the idle mode to the connected mode, when performing RRC reconstruction, when performing handover, when starting uplink data, or when starting downlink data. When receiving a dedicated preamble from the base station (eNB) 310, the UE 305 can apply the preamble and thus transmit the preamble. Otherwise, the UE can select one of two preamble groups and select a preamble belonging to the selected group. These groups can be referred to as group A and group B. If the channel quality state is better than a specific threshold and the size of msg3 is greater than a specific threshold, a preamble belonging to group B is selected; otherwise, a preamble belonging to group A can be selected. If a preamble is transmitted in the nth subframe (step 315), a random access response (RAR) window can be started from the (n + 3)th subframe, and it can be monitored whether the RAR is transmitted within the window time interval (step 320). The scheduling information of the RAR can be indicated by the random access radio network temporary identity (RA-RNTI) of the physical downlink control channel (PDCCH). The RA-RNTI can be derived using the radio resource position on the time axis and frequency axis for transmitting the preamble. The RAR message can include a timing advance command, uplink grant, and a temporary cell radio network temporary identity (C-RNTI). If the RAR is successfully received in the RAR window, msg3 can be transmitted using the UL grant information included in the RAR message (step 325). Depending on the purpose of the random access, different types of information can be included in msg3. The following table is an example of the information included in msg3.

[0049] [Table 1]

[0050]

[0051]

[0052] If a RAR is received in the nth subframe, msg3 can be sent in the n+6th subframe. From msg3 onwards, Hybrid Automatic Repeat reQuest (HARQ) can be applied. After sending msg3, the UE drives a specific timer and can monitor the Contention Resolution (CR) message until the timer expires (step 330). Depending on the purpose of the random access, in addition to the CR MAC CE, the CR message may also include an RRC connection establishment message or an RRC connection re-establishment message. The present disclosure proposes a technique for transmitting and receiving predetermined small-sized user data when a UE in the idle mode (RRC_idle) or the inactive mode (RRC_inactive) performs a random access procedure with a base station without switching to the connected mode (RRC_connected) in a mobile communication system. In the present disclosure, this technique may be referred to as Early Data Transmission (EDT). The present disclosure uses the EDT technique to propose a method for a UE to transmit user data to a base station in the uplink (Mobile Originated, MO) and a method for a base station to transmit user data to a UE in the downlink (Mobile Terminated, MT). In the present disclosure, the above uplink transmission may be referred to as Uplink Early Data Transmission (UL EDT), and the above downlink transmission may be referred to as Downlink Early Data Transmission (DL EDT). The present disclosure is characterized in that user data is transmitted in a four-step random access procedure. The details of the present disclosure may be described based on the NR system.

[0053] Figure 4 is an operation sequence of a UE, an eNB, a Mobility Management Entity (MME), and a Serving Gateway (S-GW) according to an embodiment of the present disclosure, for explaining the UL EDT operation in a four-step random access procedure.

[0054] Specifically, Figure 4 shows a flowchart of the UL EDT operation in the 4-step random access procedure in the LTE system.

[0055] A method for transmitting user data to a base station in a 4-step random access procedure may include Control Plane (CP) EDT and User Plane (UP) EDT.

[0056] Figure 4 is a flowchart of the CP EDT operation. The CP EDT may have the following characteristics.

[0057] - Uplink user data may be sent when it is included in the Non-Access Stratum (NAS) container of the RRCEarlyDataRequest message, which is an RRC message belonging to the Common Control Channel (CCCH).

[0058] - Optionally, the downlink user data can be sent when it is included in the NAS container of the RRCEarlyDataComplete message, which is an RRC message belonging to the CCCH.

[0059] - During the above process, there will be no handover to the RRC connected mode.

[0060] If there is a request for uplink user data transmission from the upper layer of the UE during the connection establishment request process, the UE 405 can initialize the EDT process according to predetermined conditions and select a configured random access preamble for the EDT process (step 425).

[0061] The eNB 410 can send a random access response message (RAR message) for the preamble to the UE (step 430).

[0062] The UE can include the NAS container (NAS message) containing the user data in the RRCEarlyDataRequest message, which is an RRC message belonging to the CCCH, and send it to the eNB (step 435).

[0063] The eNB can include the NAS container in the S1 application protocol (S1-AP) initial UE message and send it to the MME415 (or AMF) (step 440). At this time, the S1 connection can be established. During this process, the eNB can indicate to the MME that the connection is triggered by EDT.

[0064] The MME can request the S-GW 420 to reactivate the EPS bearer for the UE (step 445), and can send the user data to the S-GW (step 450). If the downlink user data of the UE is valid, the S-GW can send the downlink user data to the MME (step 455).

[0065] When receiving the downlink user data, the MME can send the data to the eNB through the DL NAS transmission process (step 460). Alternatively, the MME can trigger the S1-AP connection establishment indication process (step 465). The eNB can include the downlink user data in the NAS container of the RRCEarlyDataComplete message (which is an RRC message belonging to the CCCH) and send it to the UE (step 470). If the MME does not provide the downlink user data, the eNB can send the RRCEarlyDataComplete message to the UE without the downlink user data.

[0066] Thereafter, the S1 connection can be released (step 475), and the EPS bearer can be deactivated (step 480).

[0067] If additional data transmission / reception is required, the MME or eNB can switch the UE to the connected mode. If this switch is triggered, the eNB can send an RRCConnectionSetup message to the UE instead of an RRCEarlyDataComplete message. This means that the typical RRC connection establishment process is triggered.

[0068] Figure 5 is an operation sequence of a UE, an eNB, a mobility management entity (MME), and a serving gateway (S-GW) according to an embodiment of the present disclosure, for explaining uplink EDT operations in a four-step random access process.

[0069] In particular, Figure 5 is a flowchart of UP EDT operations. UP EDT has the following characteristics.

[0070] - To trigger UP EDT, the UE should previously receive an RRC connection release (RRCConnectionrelease or RRCRelease) message indicating a switch to the inactive mode and then be in the inactive mode. In this case, NextHopChainingCount information can be provided to the UE via an RRC message.

[0071] - Uplink user data is sent via a dedicated traffic channel (DTCH) and can be multiplexed into an RRCConnectionResumeRequest message which is an RRC message belonging to the CCCH. That is, this RRC message and the DTCH can be included together in msg3.

[0072] - Optionally, downlink user data can be sent via the DTCH and can be multiplexed into an RRCConnectionRelease message which is an RRC message belonging to the DCCH. That is, this RRC message and the DTCH can be included together in msg 4.

[0073] - For the RRCConnectionResumeRequest message, the short resume MAC-I is reused as an authentication token and can be derived using the integrity key used in the previous connection.

[0074] - The above uplink and downlink user data can be encrypted. The security key to be applied can be derived using the NextHopChainingCount provided in the RRCConnectionRelease message in the previous connection.

[0075] - Using the newly exported security key, the RRCConnectionRelease message in msg 4 can be integrity protected and encrypted.

[0076] - During the above process, a handover to RRC connected mode does not occur.

[0077] If there is a request for uplink user data transmission from the upper layer of the UE during the connection establishment request procedure, the UE 505 may initialize the EDT procedure according to a predetermined condition and select a configured random access preamble for the EDT procedure (step 525).

[0078] The eNB 510 may send a random access response message (RAR message) for the preamble to the UE (step 530).

[0079] The UE may send an RRCConnectionResumeRequest message including a resume ID, a cause for establishment, and an authentication token to the eNB (step 535). The UE may restart all of the signaling radio bearer (SRB) and the data radio bearer (DRB), derive a new security key by using the NextHopChainingCount included in the RRCConnectionRelease message received in the previous connection, and re - establish the application security (AS). The uplink user data is encrypted and sent via the DTCH and may be multiplexed into the RRCConnectionResumeRequest message which is an RRC message belonging to the CCCH. The eNB may trigger an S1 - AP context recovery procedure (step 540) and restart the S1 connection. Then, the MME 515 may re - activate the S1 - U bearer.

[0080] The MME may request the S - GW 520 to re - activate the S1 - U bearer for the UE. The MME may respond to the eNB via a UE context recovery message (step 550).

[0081] The eNB that receives the uplink user data from the UE may send the uplink user data to the S - GW (step 565).

[0082] If the downlink user data of the UE is valid, the S - GW may send the downlink user data to the eNB (step 570).

[0083] If there is no additional data from the S - GW, the eNB may trigger the suspension of the S1 connection (step 575) and the de - activation of the S1 - U bearer (step 580).

[0084] To switch the UE back to the inactive (RRC_inactive) mode, the eNB may send an RRCConnectionRelease message to the UE, which includes a release cause indicated as 'rrc_Suspend', a resume ID, a NextHopChainingCount, and a drb-ContinueROHC (step 585). The listed information may be stored in the UE. If there is downlink user data, the data may be sent via the DTCH and multiplexed into the RRCConnectionRelease message, which is an RRC message belonging to the DCCH.

[0085] If additional data transmission / reception is required, the MME or the eNB may switch the UE to the connected mode. If this switch is triggered, the eNB may send an RRCConnectionResume message to the UE instead of an RRCConnectionRelease message. This means that the typical RRC connection establishment process is triggered. The data is sent via the DTCH and multiplexed into the RRCConnectionResume message, which is an RRC message.

[0086] Figure 6 FIG. is an example diagram showing the application of an additional uplink frequency according to an embodiment of the present disclosure.

[0087] In a mobile communication system, a phenomenon where the service areas in the uplink and downlink do not match may occur. This mismatch may occur due to different uplink and downlink channel characteristics, the maximum transmission power limit of the UE, or the structural limitations of the transmission antennas. Generally, the downlink service area may be wider than the uplink service area. For example, in a 3.5 GHz TDD system, the downlink service area 605 is wider than the uplink service area 610. In this case, the first UE 620 has no problem using the service in the uplink and downlink, but the second UE 625 may have a problem successfully sending data to the base station (gNB) 615 in the uplink. Therefore, to eliminate the problems caused by the mismatch, the effective downlink service area may be reduced to match the uplink. That is, although a wider service area may be provided in the downlink, it is limited by the uplink service area.

[0088] In the next-generation mobile communication system, to address the performance limitations caused by such mismatches, the UE is enabled to apply an uplink frequency with a wider service area. For example, an uplink of 1.8 GHz separate from the 3.5 GHz uplink can be additionally provided to the UE 630. The additional uplink frequency can be referred to as a supplementary uplink (SUL) frequency. In terms of frequency characteristics, the lower the frequency band, the longer the radio signal propagation distance. Therefore, 1.8 GHz, which is lower than 3.5 GHz, can achieve a wider service area. Thus, the second UE 650 can successfully transmit data to the base station (gNB) 640 by using the 1.8 GHz uplink 630. Additionally, although the first UE 645 is not related to the service area issue, since it can use both the 1.8 GHz uplink and the 3.5 GHz uplink, it can select and use one of 1.8 GHz and 3.5 GHz for the purpose of allocating uplink access congestion. The additional uplink frequency can be an LTE frequency.

[0089] An NR uplink frequency and an SUL frequency can be configured for a UE. In this case, the PUSCH, which is an uplink data channel, can be transmitted in only one uplink at a time. The PUCCH is also transmitted in only one uplink at a time and can be transmitted in the same or a different uplink as the uplink of the PUSCH.

[0090] Figure 7 FIG. is a diagram illustrating a scenario in which a bandwidth part is applied in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0091] The bandwidth part (BWP) technology means that a UE performs communication using only a part of the frequency bandwidth in the entire system frequency bandwidth used by a cell. The BWP can be used for the purpose of reducing UE manufacturing costs or saving power of the UE. The BWP can be configured by the base station only for the UE that supports it.

[0092] Reference Figure 7 , there may be three main BWP operation scenarios.

[0093] The first scenario is to apply the BWP to a UE that supports only a frequency bandwidth 710 narrower than the system frequency bandwidth 705 used by a cell. To reduce manufacturing costs, a specific UE can be developed to support a limited frequency bandwidth. The UE should report to the base station that it supports only a limited frequency bandwidth, and accordingly, the base station can configure a BWP with the maximum bandwidth supported by the UE or a smaller bandwidth.

[0094] The second scenario is to apply BWP for the purpose of UE power saving. For example, when a UE performs communication using the entire system frequency bandwidth 715 or a partial frequency bandwidth 720 used by a cell, the communication base station may configure a narrower frequency bandwidth 725 for power saving purposes.

[0095] The third scenario is to apply a single BWP corresponding to different parameter sets. A parameter set refers to diversifying the physical layer configuration in order to achieve optimal data transmission according to various service requirements. For example, in an OFDMA structure composed of multiple subcarriers, the interval between subcarriers can be variably adjusted according to a predetermined requirement. A UE can communicate by applying multiple parameter sets simultaneously. In this case, since the physical layer configurations corresponding to the respective parameter sets are different, it is preferable to apply each parameter set by separating individual BWPs 735 and 740.

[0096] Considering the main features in the next-generation mobile communication system, the present disclosure proposes EDT operation. Specifically, it is characterized in that, by reflecting the influence of SUL, BWP, etc., a normal uplink (NUL) or a supplementary uplink (SUL) is determined according to a predetermined condition, and random access is performed by applying the uplink. In the case where SUL is determined, a specific BWP is used during the random access process.

[0097] In the first embodiment, mobile-originated (MO) CP EDT considering SUL is described.

[0098] In the second embodiment, mobile-originated (MO) UP EDT considering SUL is described.

[0099] In the third embodiment, mobile-terminated (MT) CP EDT considering SUL is described.

[0100] In the fourth embodiment, mobile-terminated (MT) UP EDT considering SUL is described.

[0101] <First Embodiment>

[0102] Figure 8 It is a diagram showing the operation sequences of a UE and a gNB for performing EDT operation in the first embodiment of the present disclosure.

[0103] In the first embodiment, the process of the UE 805 using CP EDT in the case of needing to transmit small-sized data through the uplink will be described. In this case, the network can support MO EDT through SUL. When the UE is in the idle mode (RRC_IDLE), CP EDT can be performed.

[0104] The base station (gNB) 810 may broadcast the following relevant configuration information to support MO EDT in normal uplink (NUL) and SUL through system information (step 815).

[0105] - Separate indicators indicating whether the corresponding cell supports CP EDT and UP EDT for each of NUL and SUL. For example, a cp-EDT field and an up-EDT field indicating whether CP EDT and UP EDT are supported in NUL, and a cp-EDTforSUL field and an up-EDTforSUL field indicating whether CP EDT and UP EDT are supported in SUL may be defined. Alternatively, a cp-EDT field and an up-EDT field applicable to both NUL and SUL may be defined.

[0106] - rsrp-ThresholdSSB-SUL threshold for determining whether to apply SUL. When the measured downlink reference signal received power (RSRP) value is lower than the threshold, SUL may be selected to perform the random access operation. Otherwise, NUL may be selected. For EDT, a separate rsrp-ThresholdSSB-SULforEDT may be defined. When sending small-sized data through EDT operation, the UE may select NUL or SUL by applying ThresholdSSB-SULforEDT instead of rsrp-ThresholdSSB-SUL.

[0107] - edt-TBS field, the upper limit value of the data size (e.g., MAC PDU size) that can be sent through EDT operation. Since the data size may be different for NUL and SUL, an edt-TBS field and an edt-TBSforSUL field may be defined for NUL and SUL respectively.

[0108] - EDT-specific random access preamble information. May be provided for each of NUL and SUL.

[0109] - BWP information for performing the random access procedure for EDT in NUL and SUL. Although the present disclosure proposes the initial BWP as the BWP for performing the random access procedure for EDT, for flexibility, a separate BWP for performing the random access procedure for EDT may be configured. If a separate BWP is configured, this BWP is used; otherwise, if not configured, the initial BWP may be used.

[0110] -MT-EDT related configuration information, preambleInitialReceivedTargetPowerEDT, messagePowerOffsetEDT, otherOffset, etc. (Can be used for the following options 1 - 4.)

[0111] Depending on the state of the channel quality, the amount of data that can be sent with the same transmit power may vary. Therefore, even in EDT, the size of the EDT transport block size (edt-TBS) can vary according to the state of the channel quality experienced by the UE. To support this, multiple edt-TBSs (or edt-TBSforSUL) and corresponding multiple rsrp-ThresholdSSB-SUL (Reference Signal Receiving Power - Threshold Synchronization Signal Block - Supplementary Uplink or rsrp-TrheshodSSB-SULforEDT) can be configured.

[0112] The UE that receives the EDT configuration information can generate small-sized data to be transmitted. In this case, the UE can determine whether to send the data via EDT according to a predetermined rule, and if the data is to be sent via EDT, it can determine which uplink among NUL and SUL to use (step 820). The RRC layer of the UE that receives the system information containing the EDT configuration information mainly determines whether to trigger MO-EDT and requests the MAC layer to trigger EDT. The MAC layer can determine NUL or SUL for EDT operation, determine again whether data transmission via EDT is actually possible, and notify the RRC layer. For example, the RRC layer mainly uses the edt-TBS information contained in the received system information to determine whether EDT transmission is possible, but when the MAC layer actually configures the MAC PDU, due to the addition of MAC CE, etc., the amount of data to be sent may exceed the edt-TBS. In this case, the MAC layer can notify the RRC layer that the requested EDT cannot be performed.

[0113] When at least the following conditions are met, the RRC layer of the UE can request the lower MAC layer to trigger MO-EDT.

[0114] - In the case of CP-EDT, when the UE's NAS requests RRC establishment, when the UE itself supports CP-EDT in at least one uplink (NUL or SUL), and when the received system information contains an indicator indicating support for CP-EDT in at least one uplink (NUL or SUL)

[0115] - In the case of UP-EDT, when the NAS of the UE requests RRC resume, when the UE itself supports UP-EDT in at least one uplink (NUL or SUL), and when the received system information contains an indicator indicating the support of UP-EDT in at least one uplink (NUL or SUL)

[0116] - When the establishment cause value of the triggered access is mo-data

[0117] - When the access identifier mapped to the triggered access is access identifier 0 (general service), and when the access category is access category 1 (delay tolerant service) or access category 7 (mobile originated data, MO data)

[0118] - When the base station provides the configuration information required to perform the EDT operation

[0119] - When the expected amount of uplink data to be transmitted is less than or equal to the TBS indicated by at least one edt-TBS corresponding to the (multiple) uplinks supported by the UE provided in the system information

[0120] - When no EDT backoff indicator is received from the lower layer (the backoff indicator refers to the indicator reported by the lower layer to the RRC layer, which determines that the conditions for performing EDT are not met despite the RRC layer requesting EDT from the lower MAC layer.)

[0121] If the UE does not support SUL, the RRC layer does not consider SUL when evaluating the above conditions. Even if the UE supports SUL, it is the MAC layer rather than the RRC layer that can finally decide whether to use it in the EDT operation.

[0122] The MAC layer that receives the request to trigger the EDT operation can finally determine whether to perform EDT by considering one or a combination of the following multiple options, and determine whether it is the NUL or SUL to perform EDT.

[0123] Option 1-1: If both the UE and the base station support EDT operation in SUL and SUL, if the measured RSRP value of the downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) does not exceed the edt-TBSforSUL corresponding to SUL, then a random access for EDT can be triggered in SUL.

[0124] Otherwise, if both the UE and the base station support EDT operation in NUL, if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) does not exceed the edt-TBS corresponding to NUL, then random access for EDT can be triggered in NUL.

[0125] Otherwise, if both the UE and the base station support EDT operation in SUL, if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) exceeds the edt-TBS corresponding to NUL and does not exceed the edt-TBSforSUL corresponding to SUL, then random access for EDT can be triggered in SUL. In this case, even if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), EDT operation in SUL can be supported.

[0126] Otherwise, if the RSRP value of the measured downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL, then random access for RRC establishment can be triggered in SUL. Otherwise, random access for RRC establishment can be triggered in NUL.

[0127] Option 1-2: If the RSRP value of the measured downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) does not exceed the edt-TBSforSUL corresponding to SUL, then random access for EDT can be triggered in SUL. Otherwise, if the RSRP value of the measured downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) exceeds the edt-TBSforSUL corresponding to SUL, then random access for RRC establishment can be triggered in SUL.

[0128] If the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) does not exceed the edt-TBS corresponding to NUL, random access for EDT can be triggered in NUL. Otherwise, if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) exceeds the edt-TBS corresponding to NUL, random access for RRC establishment can be triggered in NUL.

[0129] Option 1-3: The edt-TBS may generally apply to both NUL and SUL. The EDT dedicated random access preamble can be configured separately for each of NUL and SUL. The network can configure the EDT dedicated random access preamble for NUL, SUL, or both.

[0130] If the edt-TBS and the EDT dedicated random access preamble for SUL are configured, and if the RSRP value of the measured downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) does not exceed the edt-TBSforSUL corresponding to SUL, random access for EDT can be triggered in SUL.

[0131] If the edt-TBS and the EDT dedicated random access preamble for NUL are configured, and if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), and if the amount of uplink data to be transmitted (MAC PDU) does not exceed the edt-TBS corresponding to NUL, random access for EDT can be triggered in NUL.

[0132] Otherwise, a general RRC establishment operation may be triggered.

[0133] Option 1 - 4: If both the UE and the base station support SUL and EDT operation in SUL, and if the RSRP value of the measured downlink path loss reference signal is less than rsrp - ThresholdSSB - SUL (or rsrp - ThresholdSSB - SULforEDT), then SUL can be selected. If the amount of uplink data to be transmitted (MAC PDU) (or the size of msg33) does not exceed edt - TBS and the following conditions are met,

[0134] RSRP of the DL path loss reference signal < PCMAX - preambleInitialReceivedTargetPowerEDT - messagePowerOffsetEDT(-otherOffset)

[0135] EDT can be triggered in SUL. Otherwise, random access for RRC establishment can be triggered in SUL.

[0136] preambleInitialReceivedTargetPowerEDT is the initial random access preamble transmission power in the random access procedure for EDT, messagePowerOffsetEDT is the transmission power offset value considering the amount of data to be transmitted (if multiple edt - TBS are provided, there can also be multiple such values), and otherOffset is any other offset value.

[0137] If both the UE and the base station support NUL and EDT operation in NUL, and if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp - ThresholdSSB - SUL (or rsrp - ThresholdSSB - SULforEDT), then NUL can be selected. If the amount of uplink data to be transmitted (MAC PDU) (or the size of msg33) does not exceed edt - TBS and the following conditions are met,

[0138] RSRP of the DL path loss reference signal < PCMAX - preambleInitialReceivedTargetPowerEDT - messagePowerOffsetEDT(-otherOffset)

[0139] EDT can be triggered in NUL. Otherwise, random access for RRC establishment can be triggered in NUL.

[0140] The base station can configure preambleInitialReceivedTargetPowerEDT, messagePowerOffsetEDT, and otherOffset in the system information and provide these parameters for each of NUL and SUL.

[0141] Option 1 - 5: If both the UE and the base station support EDT operations in SUL and SUL, and if the measured RSRP value of the downlink path loss reference signal is less than rsrp - ThresholdSSB - SUL (or rsrp - ThresholdSSB - SULforEDT), then SUL can be selected. If the amount of uplink data to be sent (MAC PDU) does not exceed the edt - TBSforSUL corresponding to SUL, then random access for EDT can be triggered in SUL. Otherwise, random access for RRC establishment can be triggered in SUL.

[0142] If both the UE and the base station support EDT operations in NUL and NUL, and if the measured RSRP value of the downlink path loss reference signal is greater than or equal to rsrp - ThresholdSSB - SUL (or rsrp - ThresholdSSB - SULforEDT), then NUL can be selected. If the amount of uplink data to be sent (MAC PDU) does not exceed the edt - TBS corresponding to NUL, then random access for EDT can be triggered in NUL. Otherwise, random access for RRC establishment can be triggered in NUL.

[0143] Even if the measured RSRP value of the downlink path loss reference signal is greater than or equal to rsrp - ThresholdSSB - SUL (or rsrp - ThresholdSSB - SULforEDT), the network can also be configured using an indicator (or configuration information) provided as system information to trigger EDT in SUL. In this case, when the UE meets the above conditions but cannot trigger EDT in NUL due to reasons such as the amount of uplink data to be sent (MAC PDU) exceeding the edt - TBS corresponding to NUL, EDT operations can be triggered in SUL. However, random access for EDT can only be triggered in SUL when the amount of uplink data to be sent (MACPDU) does not exceed the edt - TBSforSUL corresponding to SUL. Even in SUL, random access for EDT can be triggered in SUL. If the conditions for triggering EDT are not met even in SUL, the UE can trigger random access for RRC establishment in NUL.

[0144] Option 1-6: A base station supporting EDT operations in NUL and SUL may provide a UE with multiple RSRP thresholds, as well as a corresponding group of multiple edt-TBS information and EDT dedicated random access preambles. The edt-TBS information and the EDT dedicated random access preamble group corresponding to the RSRP threshold may be provided for each of NUL and SUL.

[0145] A UE supporting EDT operations in NUL and SUL may compare the measured RSRP value of the serving cell (the RSRP value of the measured downlink path loss reference signal) with multiple RSRP thresholds, and compare the amount of uplink data to be transmitted with the edt-TBS value corresponding to the maximum threshold among the RSRP thresholds less than or equal to the measured RSRP value. If the amount of uplink data to be transmitted does not exceed the edt-TBS, random access for EDT may be triggered. In the random access, one of the (multiple) EDT preambles corresponding to the selected threshold may be sent to the base station.

[0146] In the above options, any complementary combination of operations is also possible.

[0147] The UE may send an EDT dedicated random access preamble to the base station in the initial BWP of the selected uplink or the configured BWP (if configured by the base station) (step 825). If it is decided to perform EDT in the SUL, the UE may send an EDT dedicated random access preamble allocated to the SUL to the base station. The base station that receives the preamble may determine that the UE has requested EDT. The base station may send a random access response message (RAR message) to the UE (step 830). The RAR may include scheduling information for msg3. Although the UE has sent the preamble in the SUL, the base station may want to perform the remaining random access operations in the NUL rather than the SUL. For example, when evaluating the received signal strength of the preamble sent by the UE, in a case where there is no difficulty in performing the remaining random access operations in the NUL, or in a case where it is more preferable to perform the remaining random access operations in the NUL in terms of uplink load balancing, the base station may want to perform the remaining random access operations in the NUL rather than the SUL. That is, the base station may want to change the uplink. To this end, the base station may include an indicator indicating the uplink change in the DCI corresponding to the RA-RNTI, or include an indicator indicating the uplink change in the UL grant or a new field in the RAR. If there is no indicator, the UE may send msg3 in the uplink where the preamble was sent. It is also possible to change from the NUL to the SUL. The UE may include a specific RRC message (temporarily referred to as the RRCEarlyDataRequest message) in msg3 and send it to the base station (step 835). This message may include the ng-5G-S-TMSI as the ID of the UE, establishment cause information, and a NAS container storing the data to be sent. Once msg3 is received, the base station may send msg4 including a specific RRC message (temporarily referred to as the RRCEarlyDataComplete message) for the purpose of ACK to the UE (step 840). For the data included in msg3, there may be response data at the application layer. Therefore, in order to send the response data to the UE, the NAS container containing the response data may be included in msg4. In addition, the network may determine that it may be necessary to send / receive additional data that is difficult to deliver during the random access process. In this case, when it is determined that it is necessary to switch the UE to the connected mode because it is desired to switch the UE to the connected mode, the base station may send an RRCSetup message in msg4 instead of the RRCearlyDataComplete message. The RRC message includes information required for the UE to switch to the connected mode. If the received RRCSetup message is a response message to the sent RRCEarlyDataRequest message, the UE does not include the ng-5G-S-TMSI value field in the RRCSetupComplete message to be sent to the base station.Since the ng-5G-S-TMSI information is sent to the base station in the RRCEarlyDataRequest message, it is not necessary to send the ng-5G-S-TMSI or ng-5G-S-TMSI-Part2.

[0148] <Second Embodiment>

[0149] Figure 9 FIG. is a diagram showing an operation sequence of a UE and a gNB for performing an EDT operation in the second embodiment of the present disclosure.

[0150] In the second embodiment, a process of using UP EDT by the UE 905 when small-size data needs to be transmitted via the uplink will be described. In this case, the network can support MO EDT via SUL. When the UE is in the inactive mode (RRC_INACTIVE), UP EDT can be performed.

[0151] The base station (gNB) 910 can broadcast the following relevant configuration information to support MO EDT in NUL and SUL via system information (step 915).

[0152] - Separate indicators indicating whether the corresponding cell supports CP EDT and UP EDT for each of NUL and SUL. For example, a cp-EDT field and an up-EDT field indicating whether CP EDT and UP EDT are supported in NUL, and a cp-EDTforSUL field and an up-EDTforSUL field indicating whether CP EDT and UP EDT are supported in SUL can be defined. Alternatively, a cp-EDT field and an up-EDT field applicable to both NUL and SUL can be defined.

[0153] - rsrp-ThresholdSSB-SUL threshold for determining whether to apply SUL. When the measured downlink reference signal received power (RSRP) value is lower than the threshold, SUL can be selected to perform the random access operation. Otherwise, NUL can be selected. For EDT, a separate rsrp-ThresholdSSB-SULforEDT can be defined. When transmitting small-size data via an EDT operation, the UE can select NUL or SUL by applying ThresholdSSB-SULforEDT instead of rsrp-ThresholdSSB-SUL.

[0154] - edt - TBS field, which is the upper limit value of the data size (e.g., MAC PDU size) that can be sent through EDT operations. Since the data sizes of NUL and SUL may be different, the edt - TBS field and the edt - TBSforSUL field can be defined separately for NUL and SUL.

[0155] - EDT - specific random access preamble information. It can be provided for each of NUL and SUL.

[0156] - BWP information, which is used to perform the random access procedure for EDT in NUL and SUL. Although the present disclosure proposes the initial BWP as the BWP for performing the random access procedure for EDT, for flexibility, a separate BWP for performing the random access procedure for EDT can be configured. If a separate BWP is configured, this BWP is used; otherwise, if not configured, the initial BWP can be used.

[0157] - MT - EDT - related configuration information, such as preambleInitialReceivedTargetPowerEDT, messagePowerOffsetEDT, otherOffset, etc.

[0158] According to the state of the channel quality, the amount of data that can be sent with the same transmission power can be different. Therefore, even in EDT, the size of the EDT transport block size (edt - TBS) can vary according to the state of the channel quality experienced by the UE. To support this, multiple edt - TBS (or edt - TBSforSUL) and corresponding multiple rsrp - ThresholdSSB - SUL (or rsrp - TrheshodSSB - SULforEDT) can be configured.

[0159] A UE that receives EDT configuration information may generate small-sized data to be transmitted. In this case, the UE may determine whether to transmit data via EDT according to a predetermined rule, and if the data is to be transmitted via EDT, it may determine which uplink among NUL and SUL to use (step 920). The RRC layer of the UE that receives the system information containing the EDT configuration information mainly determines whether to trigger EDT and requests the MAC layer to trigger EDT. The MAC layer may determine NUL or SUL for EDT operation, determine again whether data transmission via EDT is actually possible, and notify the RRC layer of this. For example, the RRC layer mainly uses the edt-TBS information contained in the received system information to determine whether EDT transmission is possible, but when the MAC layer actually configures the MAC PDU, due to the addition of MAC CE, etc., the amount of data to be transmitted may exceed the edt-TBS. In this case, the MAC layer may notify the RRC layer that the requested EDT cannot be performed.

[0160] When at least the following conditions are satisfied, the RRC layer of the UE may request MO-EDT trigger from the lower MAC layer.

[0161] - In the case of CP-EDT, when the UE's NAS requests RRC establishment, when the UE itself supports CP-EDT in at least one uplink (NUL or SUL), and when the received system information contains an indicator indicating support for CP-EDT in at least one uplink (NUL or SUL)

[0162] - In the case of UP-EDT, when the UE's NAS requests RRC resume, when the UE itself supports UP-EDT in at least one uplink (NUL or SUL), and when the received system information contains an indicator indicating support for UP-EDT in at least one uplink (NUL or SUL)

[0163] - When the establishment cause value of the triggered access is mo-data

[0164] - When the access identifier mapped to the triggered access is access identifier 0 (general service), and when the access category is access category 1 (delay-tolerant service) or access category 7 (mobile-originated data, MO data)

[0165] - When the base station provides the configuration information required to perform EDT operation

[0166] - When the expected amount of uplink data to be transmitted is less than or equal to the TBS indicated by at least one edt-TBS corresponding to the (multiple) uplinks supported by the UE provided in the system information

[0167] - When no EDT backoff indicator is received from the lower layer (the backoff indicator means that although the RRC layer requests EDT from the lower MAC layer, the indicator reported by the lower layer to the RRC layer determines that the conditions for performing EDT are not met.)

[0168] If the UE does not support SUL, the RRC layer does not consider SUL when evaluating the above conditions. Even if the UE supports SUL, it is the MAC layer rather than the RRC layer that can ultimately decide whether to use it in EDT operations.

[0169] The MAC layer that receives a request to trigger an EDT operation can consider one or a combination of the options proposed in the first embodiment to ultimately determine whether to perform EDT and determine whether it is NUL or SUL that performs EDT.

[0170] The UE may send an EDT dedicated random access preamble to the base station in the initial BWP of the selected uplink or the configured BWP (if configured by the base station) (step 925). If it is decided to perform EDT in the SUL, the UE may send an EDT dedicated random access preamble allocated to the SUL to the base station. The base station that receives the preamble may determine that the UE has requested EDT. The base station may send a random access response message (RAR message) to the UE (step 930). The RAR message may include scheduling information for msg3. Although the UE has sent the preamble in the SUL, the base station may want to perform the remaining random access operations in the NUL rather than the SUL. For example, when evaluating the received signal strength of the preamble sent by the UE, in a case where there is no difficulty in performing the remaining random access operations in the NUL, or in a case where it is more preferable to perform the remaining random access operations in the NUL in terms of uplink load balancing, the base station may want to perform the remaining random access operations in the NUL rather than the SUL. That is, the base station may want to change the uplink. To this end, the base station may include an indicator indicating the uplink change in the DCI corresponding to the RA-RNTI, or include an indicator indicating the uplink change in the UL grant or a new field in the RAR. If there is no indicator, the UE may send msg3 on the uplink where the preamble was sent. It is also possible to change from the NUL to the SUL. The UE may include a specific RRC message, the RRCResumeRequest message, in msg3 and send it to the base station (step 935). This message may include resumeIdentity as the ID of the UE, resume reason information, and resumeMAC-I. resumeIdentity is the UE ID information required for a base station to obtain the UE context from another base station having the UE context. resumeMAC-I is the token information for UE authentication in the base station. When switching from the connected mode to the inactive mode, the UE may receive an RRCRelease message containing the SuspendConfig IE from the base station. The SuspendConfig IE may include the fullI-RNTI (40 bits) and the shortI-RNTI (24 bits) that can be used as resumeIdentity. The base station indicates through the system information the ID that will be used as resumeIdentity to be included in the UE's RRCResumeRequest message, that is, the fullI-RNTI or the shortI-RNTI. Alternatively, in the EDT operation, the shortI-RNTI may always be used to optimize the size of msg3. The DTCH including the data to be sent may be multiplexed with the RRC message to configure msg3.Once msg3 is received, the base station may send msg4 including a specific RRC message (RRCRelease message) to the UE to switch the UE back to the inactive mode and for ACK purposes (step 940). In this case, the SuspendConfig IE may be included in the RRCRelease message. For the data included in msg3, there may be response data at the application layer. Thus, in order to send the response data to the UE, the DTCH including the response data may be multiplexed in msg4. Further, the network may determine that it may be necessary to send / receive additional data that is difficult to deliver during the random access procedure. In this case, when it is determined that it is necessary to switch the UE to the connected mode, since it is desired to switch the UE to the connected mode, the base station may send an RRCSetup message instead of an RRCRelease message in msg4. The RRC message includes the information required for the UE to switch to the connected mode.

[0171] <Third Embodiment>

[0172] Figure 10 FIG. is a diagram showing an operation sequence of a UE and a gNB for performing an EDT operation in the third embodiment of the present disclosure.

[0173] In the third embodiment, a process in which the UE 1005 uses CP EDT in a case where small-sized data needs to be transmitted through the downlink will be described. In this case, the network may support MT EDT through SUL. When the UE is in the idle mode (RRC_IDLE), CP EDT may be performed.

[0174] The base station (gNB) 1010 may broadcast the following related configuration information to support MT EDT in NUL and SUL through system information (step 1015).

[0175] - rsrp-ThresholdSSB-SUL threshold for determining whether to apply SUL. If the measured downlink RSRP value is lower than the threshold, SUL may be selected to perform the random access operation. Otherwise, NUL may be selected. For EDT, a separate rsrp-ThresholdSSB-SULforEDT may be defined. When transmitting small-sized data through an EDT operation, the UE may select NUL or SUL by applying ThresholdSSB-SULforEDT instead of rsrp-ThresholdSSB-SUL.

[0176] - EDT-specific random access preamble information. May be provided for each of NUL and SUL.

[0177] - BWP information for performing a random access procedure for EDT in NUL and SUL. Although the present disclosure proposes the initial BWP as the BWP for performing the random access procedure for EDT, for flexibility, a separate BWP for performing the random access procedure for EDT may be configured. If a separate BWP is configured, this BWP is used; otherwise, if not configured, the initial BWP may be used.

[0178] - MT-EDT related configuration information, such as preambleInitialReceivedTargetPowerEDT, messagePowerOffsetEDT, otherOffset, etc.

[0179] The base station may generate small-sized data to be sent to the UE that receives the EDT configuration information. In this case, the base station may determine whether to send the data via EDT according to a predetermined rule, and if the data is to be sent via EDT, the base station may send a paging message to the UE (step 1020). In this case, the paging message may include an indicator indicating the MT-EDT trigger in the PagingRecord IE containing the UE's ID. After receiving the paging message containing the indicator, the UE may determine which uplink will be used for the MT-EDT operation (step 1025). When at least the following conditions are met, the RRC layer of the UE may request an MT-EDT trigger from the lower MAC layer.

[0180] - In the case of CP-EDT, when the UE itself supports CP-EDT in at least one uplink (NUL or SUL)

[0181] - In the case of UP-EDT, when the UE itself supports UP-EDT in at least one uplink (NUL or SUL)

[0182] - When the establishment cause value of the triggered access is mt-access

[0183] - When the access identifier mapped to the triggered access is access identifier 0 (general service), and when the access category is access category 0

[0184] - When the base station provides the configuration information required to perform the EDT operation

[0185] - When no EDT backoff indicator is received from the lower layer (the backoff indicator refers to the indicator reported by the lower layer to the RRC layer, determining that the conditions for performing EDT are not met although the RRC layer requests EDT from the lower MAC layer).

[0186] If the UE does not support SUL, the RRC layer does not consider SUL when evaluating the above conditions. Even if the UE supports SUL, it is the MAC layer rather than the RRC layer that can finally decide whether to use it in EDT operation. For example, the MAC layer of the UE can determine whether to trigger MT-EDT by determining whether the following equation is satisfied.

[0187] The RSRP of the DL path loss reference signal < PCMAX - preambleInitialReceivedTargetPowerEDT - messagePowerOffsetEDT(-otherOffset)

[0188] Alternatively, different from MO-EDT, in MT-EDT, when receiving a paging message including an indicator, the UE can immediately trigger MT-EDT without determining MT-EDT triggering in the RRC layer and the MAC layer.

[0189] Considering one or a combination of the following options, the UE can determine whether to use NUL or SUL to perform MT-EDT.

[0190] Option 2-1: If both the UE and the base station support EDT operation in SUL and SUL, and if the RSRP value of the measured DL path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), random access for EDT can be triggered in SUL.

[0191] Otherwise, if both the UE and the base station support EDT operation in NUL and NUL, and if the RSRP value of the measured DL path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), random access for EDT can be triggered in NUL.

[0192] Otherwise, if information indicating that SUL does not support EDT is received in the paging message, random access for RRC establishment can be triggered in SUL.

[0193] Otherwise, if information indicating that NUL does not support EDT is received in the paging message, random access for RRC establishment can be triggered in NUL.

[0194] Option 2-2: If both the UE and the base station support SUL, and if the RSRP value of the measured downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), SUL can be selected. If the UE and the base station support the EDT operation in SUL, a random access for EDT can be triggered in SUL. If the EDT operation is not supported, a random access for RRC establishment can be triggered.

[0195] If the conditions for SUL are not met, if both the UE and the base station support NUL, and if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), NUL can be selected. If the UE and the base station support the EDT operation in NUL, a random access for EDT can be triggered in NUL. If the EDT operation is not supported, a random access for RRC establishment can be triggered.

[0196] The UE may send an EDT dedicated random access preamble to the base station in the initial BWP of the selected uplink or the configured BWP (if configured by the base station) (step 1030). If it is decided to perform EDT in the SUL, the UE may send an EDT dedicated random access preamble allocated to the SUL to the base station. The base station that receives the preamble may determine that the UE has requested EDT. The base station may send a random access response message (RAR message) to the UE (step 1035). The RAR message may include scheduling information for msg3. Although the UE has sent the preamble in the SUL, the base station may want to perform the remaining random access operations in the NUL instead of the SUL. For example, when evaluating the received signal strength of the preamble sent by the UE, in a case where there is no difficulty in performing the remaining random access operations in the NUL, or in a case where it is more preferable to perform the remaining random access operations in the NUL in terms of uplink load balancing, the base station may want to perform the remaining random access operations in the NUL instead of the SUL. That is, the base station may want to change the uplink. To this end, the base station may include an indicator indicating the uplink change in the DCI corresponding to the RA-RNTI, or include an indicator indicating the uplink change in the UL grant or a new field in the RAR message. It is also possible to change from the NUL to the SUL. The UE may include a specific RRC message (temporarily referred to as the RRCEarlyDataRequest message) in msg3 and send it to the base station (step 1040). This message may include the ng-5G-S-TMSI (or ng-5G-S-TMSI-Part1) as the ID of the UE and establishment cause information. Once msg3 is received, the base station may send msg4 including a specific RRC message (temporarily referred to as the RRCEarlyDataComplete message) to the UE (step 1045). In msg4, a NAS container containing downlink data may be included. In addition, the network may determine that it is necessary to send / receive additional data that is difficult to transfer during the EDT random access procedure. In this case, when it is determined that it is necessary to switch the UE to the connected mode because it is desired to switch the UE to the connected mode, the base station may send an RRCSetup message instead of the RRCearlyDataComplete message in msg4. The RRC message includes information required for the UE to switch to the connected mode.

[0197] <Fourth Embodiment>

[0198] Figure 11 is a diagram showing an operation sequence of a UE and a gNB for performing an EDT operation in the fourth embodiment of the present disclosure.

[0199] In the fourth embodiment, the process of the UE 1105 using UP EDT when small-sized data needs to be transmitted via the downlink will be described. In this case, the network can support MT EDT via SUL. When the UE is in the inactive mode (RRC_INACTIVE), UP EDT can be performed.

[0200] The base station (gNB) 1110 can broadcast the following relevant configuration information to support MT EDT in NUL and SUL via system information (step 1115).

[0201] - rsrp-ThresholdSSB-SUL threshold for determining whether to apply SUL. When the measured downlink RSRP value is lower than the threshold, SUL can be selected to perform the random access operation. Otherwise, NUL can be selected. For EDT, a separate rsrp-ThresholdSSB-SULforEDT can be defined. When transmitting small-sized data via EDT operation, the UE can select NUL or SUL by applying ThresholdSSB-SULforEDT instead of rsrp-ThresholdSSB-SUL.

[0202] - EDT-specific random access preamble information. It can be provided for each of NUL and SUL.

[0203] - BWP information for performing the random access procedure for EDT in NUL and SUL. Although the present disclosure proposes the initial BWP as the BWP for performing the random access procedure for EDT, for flexibility, a separate BWP for performing the random access procedure for EDT can be configured. If a separate BWP is configured, this BWP is used; otherwise, if not configured, the initial BWP may be used.

[0204] - MT-EDT-related configuration information, preambleInitialReceivedTargetPowerEDT, messagePowerOffsetEDT, otherOffset, etc.

[0205] The base station can generate small-sized data to be sent to a UE that receives EDT configuration information. In this case, the base station can determine whether to send the data via EDT according to a predetermined rule, and if the data is to be sent via EDT, the base station can send a paging message to the UE (step 1120). In this case, the paging message can include an indicator indicating MT-EDT triggering in a PagingRecord IE containing the UE's ID. After receiving the paging message containing the indicator, the UE can determine which uplink will be used for MT-EDT operation (step 1125). When at least the following conditions are met, the RRC layer of the UE can request MT-EDT triggering from the lower MAC layer.

[0206] - In the case of CP-EDT, when the UE itself supports CP-EDT in at least one uplink (NUL or SUL)

[0207] - In the case of UP-EDT, when the UE itself supports UP-EDT in at least one uplink (NUL or SUL)

[0208] - When the establishment cause value of the triggered access is mt-access

[0209] - When the access identifier mapped to the triggered access is access identifier 0 (general service), and when the access category is access category 0

[0210] - When the base station provides the configuration information required to perform EDT operation

[0211] - When no EDT fallback indicator is received from the lower layer (the fallback indicator refers to the indicator reported by the lower layer to the RRC layer, determining that the conditions for performing EDT are not met although the RRC layer requests EDT from the lower MAC layer.)

[0212] If the UE does not support SUL, the RRC layer does not consider SUL when evaluating the above conditions. Even if the UE supports SUL, it is the MAC layer rather than the RRC layer that can finally decide whether to use it in EDT operation. For example, the MAC layer of the UE can determine whether to trigger MT-EDT by determining whether the following equation is satisfied.

[0213] RSRP of the DL path loss reference signal < PCMAX - preambleInitialReceivedTargetPowerEDT - messagePowerOffsetEDT(-otherOffset)

[0214] Alternatively, different from MO-EDT, in MT-EDT, when receiving a paging message including an indicator, the UE can immediately trigger MT-EDT without determining the MT-EDT trigger in the RRC layer and the MAC layer. Considering one or a combination of the following options, the UE can determine NUL or SUL to perform MT-EDT.

[0215] Option 2-1: If both the UE and the base station support EDT operations in SUL and SUL, and if the RSRP value of the measured downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), random access for EDT can be triggered in SUL.

[0216] Otherwise, if both the UE and the base station support EDT operations in NUL and NUL, and if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), random access for EDT can be triggered in NUL.

[0217] Otherwise, if information indicating that SUL does not support EDT is received in the paging message, random access for RRC establishment can be triggered in SUL. Otherwise, if information indicating that NUL does not support EDT is received in the paging message, random access for RRC establishment can be triggered in NUL.

[0218] Option 2-2: If both the UE and the base station support SUL, and if the RSRP value of the measured downlink path loss reference signal is less than rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), SUL can be selected. If the UE and the base station support EDT operations in SUL, random access for EDT can be triggered in SUL. If EDT operations are not supported, random access for RRC establishment can be triggered.

[0219] If the conditions for SUL are not met, if both the UE and the base station support NUL, and if the RSRP value of the measured downlink path loss reference signal is greater than or equal to rsrp-ThresholdSSB-SUL (or rsrp-ThresholdSSB-SULforEDT), NUL can be selected. If the UE and the base station support EDT operations in NUL, random access for EDT can be triggered in NUL. If EDT operations are not supported, random access for RRC establishment can be triggered.

[0220] The UE may send an EDT dedicated random access preamble to the base station in the initial BWP of the selected uplink or the configured BWP (if configured by the base station) (step 1130). If it is decided to perform EDT in the SUL, the UE may send an EDT dedicated random access preamble allocated to the SUL to the base station. The base station that receives the preamble may determine that the UE has requested EDT. The base station may send a random access response message (RAR message) to the UE (step 1135). The RAR message may include scheduling information for msg3. Although the UE has sent the preamble in the SUL, the base station may want to perform the remaining random access operations in the NUL instead of the SUL. For example, when evaluating the received signal strength of the preamble sent by the UE, in a case where there is no difficulty in performing the remaining random access operations in the NUL, or in a case where it is more preferable to perform the remaining random access operations in the NUL in terms of uplink load balancing, the base station may want to perform the remaining random access operations in the NUL instead of the SUL. That is, the base station may want to change the uplink. To this end, the base station may include an indicator indicating the uplink change in the DCI corresponding to the RA-RNTI, or include an indicator indicating the uplink change in the UL grant or a new field in the RAR message. It is also possible to change from the NUL to the SUL. The UE may include a specific RRC message (RRCResumeRequest message) in msg3 and send it to the base station (step 1140). This message may include resumeIdentity and resumeMAC-1 as the UE's ID. resumeIdentity is the UE ID information required for the base station to obtain the UE context from other base stations having the UE context. resumeMAC-I is the token information for UE authentication in the base station. When switching from the connected mode to the inactive mode, the UE may receive an RRCRelease message containing the SuspendConfig IE from the base station. The SuspendConfig IE may include the fullI-RNTI (40 bits) and the shortI-RNTI (24 bits) that can be used as resumeIdentity. The base station indicates through the system information the ID that will be used as resumeIdentity to be included in the UE's RRCResumeRequest message, that is, the fullI-RNTI or the shortI-RNTI. Once msg3 is received, the base station may send msg4 including a specific RRC message (RRCRelease message) to the UE (step 1145). In this case, the SuspendConfig IE may be included in the RRCRelease message. The DTCH containing the downlink data to be sent may be multiplexed in msg4.In addition, the network may determine that it may be necessary to send / receive additional data that is difficult to deliver during the random access procedure. In this case, when it is determined that it is necessary to switch the UE to the connected mode, since it is desired to switch the UE to the connected mode, the base station may send an RRCSetup message instead of an RRCRelease message in msg4. The RRC message includes the information required for the UE to switch to the connected mode.

[0221] Figure 12 FIG. is a diagram showing an operation sequence of a UE that performs EDT in the second embodiment of the present disclosure.

[0222] In step S1205, EDT configuration information from the system information broadcast by the base station may be provided to the UE.

[0223] In step S1210, the UE may determine whether to perform EDT according to the method proposed in the present disclosure, and may select an uplink for performing EDT.

[0224] In step S1215, the UE may send an EDT dedicated random access preamble in the selected uplink.

[0225] In step S1220, the UE may receive a random access response message in the downlink of the base station.

[0226] In step S1225, the UE may send msg3 in the selected uplink, in which a DTCH including user data and an RRCResumeRequest message are multiplexed.

[0227] In step S1230, the UE may receive msg4 including an RRCRelease message from the base station, and may multiplex the DTCH including user data.

[0228] Figure 13 FIG. is a diagram showing an operation sequence of a gNB that performs EDT in the second embodiment of the present disclosure.

[0229] In step S1305, the base station (gNB) may broadcast EDT configuration information through system information.

[0230] In step S1310, the base station may receive an EDT dedicated random access preamble from one UE in one uplink.

[0231] In step S1315, the base station may send a random access response message to the UE.

[0232] In step S1320, the base station may receive msg3 from the UE in the uplink, in which the DTCH including user data and the RRC Resume Request message are multiplexed.

[0233] In step S1325, the base station may send msg4 including the RRC Release message to the UE. If there is user data to be sent, the base station may multiplex the DTCH including the user data into msg4 and send it to the UE.

[0234] Figure 14 is a block diagram showing the internal structure of a UE according to an embodiment of the present disclosure.

[0235] Referring to the above figure, the UE may include a radio frequency (RF) processor 1410, a baseband processor 1420, a storage 1430, and a controller 1440.

[0236] The RF processor 1410 may perform functions of transmitting and receiving signals through a wireless channel, such as frequency band conversion and amplification of signals. That is, the RF processor 1410 may up-convert the baseband signal provided by the baseband processor 1420 into an RF band signal and transmit it through an antenna, or down-convert the RF band signal received through the antenna into a baseband signal. For example, the RF processor 1410 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. In the above figure, only one antenna is shown, but the UE may include multiple antennas. In addition, the RF processor 1410 may include multiple RF chains. In addition, the RF processor 1410 may perform beamforming. For beamforming, the RF processor 1410 may adjust the phase and amplitude of each signal among the signals transmitted and received through multiple antennas or antenna elements. In addition, the RF processor may perform MIMO and may receive multiple layers when performing the MIMO operation.

[0237] The baseband processor 1420 can perform the conversion function between baseband signals and bitstreams according to the physical layer standard of the system. For example, when transmitting data, the baseband processor 1420 can generate complex symbols by encoding and modulating the bitstream to be transmitted. In addition, when receiving data, the baseband processor 1420 can recover the received bitstream by demodulating and decoding the baseband signal provided by the RF processor 1410. For example, in the case of conforming to the orthogonal frequency division multiplexing (OFDM) scheme, when transmitting data, the baseband processor 1420 can generate complex symbols by encoding and modulating the bitstream to be transmitted, map the complex symbols to subcarriers, and then form OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processor 1420 can divide the baseband signal provided by the RF processor 1410 into OFDM symbol units, recover the signals mapped to subcarriers through fast Fourier transform (FFT) operations, and then recover the received bitstream by demodulating and decoding.

[0238] The baseband processor 1420 and the RF processor 1410 can transmit and receive signals as described above. Therefore, the baseband processor 1420 and the RF processor 1410 can be referred to as transmitters, receivers, transceivers, or communication units. In addition, at least one of the baseband processor 1420 and the RF processor 1410 can include multiple communication modules to support multiple different radio access technologies. In addition, at least one of the baseband processor 1420 and the RF processor 1410 can include different communication modules to process signals in different frequency bands. For example, different radio access technologies can include wireless LAN (e.g., IEEE 802.11), cellular networks (e.g., LTE), etc. In addition, different frequency bands can include super high frequency (SHF) (e.g., 2.NRHz, NRHz) bands and millimeter wave (e.g., 60 GHz) bands.

[0239] The storage 1430 can store default programs, application programs, and data such as configuration information for UE operations. Specifically, the storage 1430 can store information related to a second access node that performs wireless communication using a second radio access technology. In addition, the storage 1430 can provide the stored data in response to a request from the controller 1440.

[0240] The controller 1440 may control the overall operation of the UE. For example, the controller 1440 may transmit and receive signals through the baseband processor 1420 and the RF processor 1410. In addition, the controller 1440 writes data to and reads data from the storage 1430. To this end, the controller 1440 may include at least one processor. For example, the controller 1440 may include a communication processor (CP) that controls communication, and an application processor (AP) that controls an upper layer such as an application program.

[0241] Figure 15 is a block diagram showing the internal structure of a base station according to an embodiment of the present disclosure.

[0242] Referring to the above figure, the base station is configured to include an RF processor 1510, a baseband processor 1520, a backhaul communication unit 1530, a storage 1540, and a controller 1550.

[0243] The RF processor 1510 may perform functions of transmitting and receiving signals through a wireless channel, such as frequency band conversion and amplification of signals. That is, the RF processor 1510 may up-convert a baseband signal provided by the baseband processor 1520 into an RF band signal and transmit it through an antenna, or down-convert an RF band signal received through the antenna into a baseband signal. For example, the RF processor 1510 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. In the above figure, only one antenna is shown, but the first node may include multiple antennas. In addition, the RF processor 1510 may include multiple RF chains. In addition, the RF processor 1510 may perform beamforming. For beamforming, the RF processor 1510 may adjust the phase and amplitude of each signal among signals transmitted and received through multiple antennas or antenna elements. In addition, the RF processor may perform a downlink MIMO operation by transmitting at least one layer.

[0244] The baseband processor 1520 may perform the conversion function between baseband signals and bitstreams according to the physical layer standard of the first radio access technology. For example, when transmitting data, the baseband processor 1520 may generate complex symbols by encoding and modulating the bitstream to be transmitted. In addition, when receiving data, the baseband processor 1520 may recover the received bitstream by demodulating and decoding the baseband signal provided by the RF processor 1410. For example, in the case of conforming to the OFDM scheme, when transmitting data, the baseband processor 1520 may generate complex symbols by encoding and modulating the bitstream to be transmitted, map the complex symbols to subcarriers, and then form OFDM symbols through IFFT operations and CP insertion. In addition, when receiving data, the baseband processor 1520 may divide the baseband signal provided by the RF processor 1510 into OFDM symbol units, recover the signals mapped to subcarriers through FFT operations, and then recover the received bitstream by demodulating and decoding. The baseband processor 1520 and the RF processor 1510 may transmit and receive signals as described above. Therefore, the baseband processor 1520 and the RF processor 1510 may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0245] The backhaul communication unit 1530 may provide an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 1530 may convert the bitstream sent from the master base station to another node (e.g., a secondary base station, a core network, etc.) into a physical signal, and convert the physical signal received from another node into a bitstream.

[0246] The storage 1540 may store default programs, application programs, and data such as configuration information for the operation of the master base station. Specifically, the storage 1540 may store information about the bearers allocated to the accessing UEs, measurement results reported by the accessing UEs, etc. In addition, the storage 1540 may store information used as a criterion for determining whether to provide or stop multiple connections to the UEs. In addition, the storage 1540 may provide the stored data in response to a request from the controller 1550.

[0247] The controller 1550 may control the overall operation of the master base station. For example, the controller 1550 may send and receive signals through the baseband processor 1520 and the RF processor 1510 or through the backhaul communication unit 1530. In addition, the controller 1550 writes data to and reads data from the storage 1540. To this end, the controller 1550 may include at least one processor.

[0248] The embodiments of the present disclosure are merely examples presented for the ease of explaining the technical content and facilitating the understanding of the present disclosure, and are not intended to limit the technical scope of the present disclosure. Therefore, in addition to the embodiments disclosed herein, the technical scope of the present disclosure should be construed to include all changes or modifications of the technical ideas derived from various embodiments of the present disclosure.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: Receiving system information SI from a base station, the SI including a first threshold and a second threshold, wherein the first threshold is associated with small data transmission SDT, and the second threshold is associated with supplementary uplink SUL; Identifying a data size and a reference signal received power RSRP for path loss reference; Determining the SUL for the SDT based on the first threshold, the second threshold, the data size, and the RSRP of the path loss reference; and Performing the SDT on the SUL in a radio resource control RRC inactive state.

2. The method according to claim 1, Among them, The first threshold is associated with the data size, and wherein the second threshold is associated with the reference signal received power RSRP.

3. The method according to claim 1, wherein the determining comprises: Identifying whether the data size is less than or equal to the first threshold; In the case where the data size is less than or equal to the first threshold, identifying whether the RSRP of the path loss reference is less than the second threshold; And In the case where the RSRP of the path loss reference is less than the second threshold, determining the SUL for the SDT.

4. The method according to claim 1, Among them, The SDT is performed on an initial bandwidth part BWP.

5. The method according to claim 1, wherein the performing comprises: Sending a random access preamble to the base station; Receiving a random access response message from the base station in response to the random access preamble; And Sending an RRC resume request message and SDT data to the base station.

6. A method performed by a base station in a wireless communication system, the method comprising: Generating system information SI, the SI including a first threshold and a second threshold, wherein the first threshold is associated with small data transmission SDT, and the second threshold is associated with supplementary uplink SUL; and Sending the SI including the first threshold and the second threshold to a terminal; Wherein the SUL for the SDT is based on the first threshold, the second threshold, the identified data size, and the reference signal received power RSRP of the identified path loss reference; and Wherein the SDT is performed on the SUL.

7. The method according to claim 6, Among them, The first threshold is associated with the data size, and wherein the second threshold is associated with the reference signal received power RSRP.

8. The method according to claim 6, In the case where the data size is less than or equal to the first threshold and the RSRP of the path loss reference is less than the second threshold, the SUL for the SDT is determined.

9. The method according to claim 6, Among them, The SDT is performed on an initial bandwidth part BWP.

10. The method according to claim 6, the method further comprising: Receiving a random access preamble from the terminal; Send a random access response message in response to the random access preamble to the terminal; and Receive a radio resource control (RRC) resume request message and SDT data from the terminal.

11. A terminal in a wireless communication system, the terminal comprising: A transceiver; and A controller configured to: Receive system information (SI) from a base station, the SI including a first threshold and a second threshold, wherein the first threshold is associated with small data transmission (SDT), and the second threshold is associated with supplementary uplink (SUL); Identify the data size and the reference signal received power (RSRP) of the path loss reference; Determine the SUL for the SDT based on the first threshold, the second threshold, the data size, and the RSRP of the path loss reference; and Perform the SDT on the SUL in a radio resource control (RRC) inactive state.

12. The terminal according to claim 11, Among them, The first threshold is associated with the data size, and wherein the second threshold is associated with the reference signal received power (RSRP).

13. The terminal according to claim 11, the controller is further configured to: Identify whether the data size is less than or equal to the first threshold; In the case where the data size is less than or equal to the first threshold, identify whether the RSRP of the path loss reference is less than the second threshold; and In the case where the RSRP of the path loss reference is less than the second threshold, determine the SUL for the SDT.

14. The terminal according to claim 11, Among them, The SDT is performed on an initial bandwidth part (BWP).

15. The terminal according to claim 11, wherein the controller is further configured to: Send a random access preamble to the base station, Receive a random access response message in response to the random access preamble from the base station, and Send an RRC resume request message and SDT data to the base station.

16. A base station in a wireless communication system, the base station comprising: A transceiver; and A controller configured to: Generate system information (SI), the SI including a first threshold and a second threshold, wherein the first threshold is associated with small data transmission (SDT), and the second threshold is associated with supplementary uplink (SUL); and Send the SI including the first threshold and the second threshold to a terminal; wherein the SUL for the SDT is based on the first threshold, the second threshold, the identified data size, and the identified reference signal received power (RSRP) of the path loss reference; and wherein the SDT is performed on the SUL.

17. The base station according to claim 16, Among them, The first threshold is associated with the data size, and wherein the second threshold is associated with the reference signal received power (RSRP).

18. The base station according to claim 16, The SUL for the SDT is determined when the data size is less than or equal to the first threshold and the RSRP of the path loss reference is less than the second threshold.

19. The base station according to claim 16, Among them, The SDT is performed on an initial bandwidth part BWP.

20. The base station according to claim 16, the controller is further configured to: Receive a random access preamble from the terminal; Send a random access response message in response to the random access preamble to the terminal; and Receive a radio resource control RRC resume request message and SDT data from the terminal.

Images