Terminal device and communication method

Abstract

To provide a terminal device that performs efficient communication and a communication method used in the terminal device, in a cellular communication system.SOLUTION: In a wireless communication system, a terminal device includes a medium access control layer processing unit and a physical layer processing unit. The medium access control layer processing unit determines whether a random access preamble group B is to be set for a PRACH resource group used for a random access procedure requesting to apply repeated transmission for a message 3 PUSCH, determines whether to request to apply repeated transmission for the message 3 based on the determination, and instructs the physical layer processing unit to transmit a PRACH.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a terminal device and a communication method. [Background technology]

[0002] The radio access method and radio network for cellular mobile communications (hereinafter referred to as "Long Term Evolution (LTE)" or "EUTRA: Evolved Universal Terrestrial Radio Access") is being developed by the Third Generation Partnership Project (3GPP). rd This is being studied in the LTE Generation Partnership Project. In LTE, base station devices are also called eNodeBs (evolved NodeBs) and terminal devices are also called UEs (User Equipment). LTE is a cellular communication system in which areas covered by base station devices are arranged in multiple cell-like configurations. A single base station device may manage multiple serving cells.

[0003] The 3GPP has been formulating a wireless communication standard (NR: New Radio), and is currently studying further extensions to the wireless communication standard (Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] “Release 17 package for RAN”, RP-193216, RAN chairman, RAN1 chairman, RAN2 chairman, RAN3 chairman, 3GPP TSG RAN Meeting #86, Sitges, Spain, 9th ― 12th December, 2019 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a terminal device that performs communication efficiently and a communication method used in the terminal device. [Means for solving the problem]

[0006] (1) A first aspect of the present invention is a terminal device comprising a media access control layer processing unit and a physical layer processing unit, wherein the media access control layer processing unit determines whether a random access preamble group B is configured for a PRACH resource group used for a random access procedure that requests the application of repetitive transmission for message 3 PUSCH, and the media access control layer processing unit determines whether to request the application of repetitive transmission for message 3 based on the determination, and instructs the physical layer processing unit to transmit PRACH.

[0007] (2) A second aspect of the present invention is a communication method used in a terminal device, comprising: The method includes the steps of: determining whether a random access preamble group B is configured for a PRACH resource group used for a random access procedure that requests the application of repeated transmission for a PUSCH; determining whether to request the application of repeated transmission for a message 3 based on the determination; and instructing the transmission of a PRACH. [Effects of the Invention]

[0008] According to the present invention, the terminal device can perform communication efficiently. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a conceptual diagram of a wireless communication system 9 according to an aspect of the present embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a resource grid according to an aspect of the present embodiment. [Figure 3]2 is a schematic block diagram illustrating an example of the configuration of a base station device 3 according to one aspect of the present embodiment. FIG. [Figure 4] 1 is a schematic block diagram showing an example of the configuration of a terminal device 1 according to an aspect of the present embodiment. [Figure 5] FIG. 10 is a diagram showing an example of a random access procedure performed in a medium access control layer processing unit 15 according to one aspect of this embodiment. [Figure 6] FIG. 5 is a diagram illustrating an example of a random access resource selection process 5002 performed by the medium access control layer processing unit 15 according to one aspect of the present embodiment. [Figure 7] FIG. 5 is a diagram showing an example of a random access resource selection process 5032X performed by the medium access control layer processing unit 15 according to one aspect of the present embodiment. [Figure 8] FIG. 10 is a diagram showing an example of a random access procedure performed in a medium access control layer processing unit 15 according to one aspect of this embodiment. [Figure 9] FIG. 10 is a diagram showing a procedure for selecting an "RA_TYPE" by a medium access control layer processing unit 15 according to one aspect of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described.

[0011] floor(C) may be a floor function for real number C. For example, floor(C) may be a function that outputs the largest integer not exceeding real number C. ceil(D) may be a ceiling function for real number D. For example, ceil(D) may be a function that outputs the smallest integer not below real number D. mod(E,F) may be a function that outputs the remainder when E is divided by F. mod(E,F) may be a function that outputs a value corresponding to the remainder when E is divided by F. exp(G) = e^G, where e is Napier's constant. H^I represents H to the Ith power. max(J,K) is a function that outputs the maximum value of J and K. Here, max(J,K) is a function that outputs J or K when J and K are equal. min(L,M) is a function that outputs the maximum value of L and M. Here, min(L,M) is a function that outputs L or M when L and M are equal. round(N) is a function that outputs the integer value closest to N. "·" indicates multiplication.

[0012] Fig. 1 is a conceptual diagram of a wireless communication system 9 according to one aspect of the present embodiment. In Fig. 1, the wireless communication system includes terminal devices 1A to 1C and a base station device 3 (BS#3: Base station#3). Hereinafter, the terminal devices 1A to 1C will be collectively referred to as terminal device 1 (UE#1: User Equipment#1), and the terminal device communicating with the base station device 3 will also be referred to as terminal device 1 (UE#1: User Equipment#1).

[0013] In the wireless communication system 9, the terminal device 1 and the base station device 3 may use one or more communication methods. For example, CP-OFDM (Cyclic Prefix - Orthogonal Frequency Division Multiplexing) may be used in the downlink of the wireless communication system 9. Furthermore, either CP-OFDM or DFT-s-OFDM (Discrete Fourier Transform - spread - Orthogonal Frequency Division Multiplexing) may be used in the uplink of the wireless communication system 9. Here, DFT-s-OFDM is a communication method in which modified precoding is applied prior to signal generation in CP-OFDM. Here, modified precoding is also referred to as DFT precoding.

[0014] As shown in Figure 1, the base station device 3 may be configured with one transceiver device (or transmission point, transmission device, reception point, reception device, transmission / reception point). Alternatively, in some cases, the base station device 3 may be configured to include multiple transceivers. When the base station device 3 is configured with multiple transceivers, each of the multiple transceivers may be located in a different geographical location.

[0015] The base station device 3 may provide one or more serving cells. A serving cell may be defined as a set of resources used in the wireless communication system 9. Here, a serving cell is also referred to as a cell.

[0016] A serving cell may be configured to include one downlink component carrier and / or one uplink component carrier. A serving cell may be configured to include two or more downlink component carriers and / or two or more uplink component carriers. Downlink component carriers and uplink component carriers are also collectively referred to as component carriers.

[0017] For a component carrier, one or more SCS-specific carriers One subcarrier-spacing configuration μ may be associated with one SCS-specific carrier.

[0018] The resources in the wireless communication system 9 may be managed by a resource grid using subcarrier indexes and OFDM symbol indexes.

[0019] The subcarrier spacing (SCS: SubCarrier Spacing) Δf for a certain subcarrier spacing setting μ is Δf=2 μ For example, the subcarrier spacing setting μ may represent any of 0, 1, 2, 3, or 4.

[0020] Time unit T c =1 / (Δf max N f ) may be used to represent the length in the time domain, where Δf max = 480 kHz. f = 4096. The constant κ may be expressed as κ = Δf max N f / (Δf ref N f,ref )=64. Also, Δf ref may be 15 kHz. f,refis 2048.

[0021] The downlink / uplink signal transmission is of length T f It may be organized into radio frames (system frames, frames) of T f =(Δf max N f / 100)·T s =10ms.

[0022] A radio frame may be configured to include 10 subframes, where the length of the subframe is T sf =(Δf max N f / 1000)·T s = 1 ms. The number of OFDM symbols per subframe may be N subframe,μ symb =N slot symb N subframe,μ slot may be.

[0023] An OFDM symbol is used as a time domain unit for the communication method used in the wireless communication system 9. For example, an OFDM symbol may be used as a time domain unit for CP-OFDM. Alternatively, an OFDM symbol may be used as a time domain unit for DFT-s-OFDM.

[0024] A slot may consist of multiple OFDM symbols, for example, N consecutive OFDM symbols. slot symb For example, in the normal CP setting, N OFDM symbols may constitute one slot. slot symb = 14. In addition, in the setting of the extended CP, N slot symb =12.

[0025] The slots may be indexed in the time domain, e.g., slot index n μs ranges from 0 to N in the subframe subframe,μ slot The slot index n may be given in ascending order as integer values ​​in the range -1. μ s,f ranges from 0 to N in the radio frame. frame,μ slot Integer values ​​in the range -1 to +1 may be given in ascending order.

[0026] 2 is a diagram showing an example of the configuration of a resource grid according to one aspect of this embodiment. In the resource grid of FIG. 2, the horizontal axis represents OFDM symbol index l sym and the vertical axis is the subcarrier index k sc The resource grid in Figure 2 is size,μ grid,x N RB sc contains N subcarriers, subframe,μ symb OFDM symbols, where N size,μ grid,x indicates the bandwidth of the SCS specific carrier. size,μ grid,x The value is in resource blocks.

[0027] Within the resource grid, subcarrier index k sc and OFDM symbol index l sym The resource identified by the resource element (RE: Resource It is also called Element.

[0028] Resource Block (RB) is N RB sc A resource block includes N consecutive subcarriers. A resource block is a collective term for a common resource block, a physical resource block (PRB), and a virtual resource block (VRB). For example, RB sc =12.

[0029] A BWP (BandWidth Part) may be configured as a subset of the resource grid. Here, a BWP configured for the downlink is also referred to as a downlink BWP. A BWP configured for the uplink is also referred to as an uplink BWP.

[0030] An antenna port may be defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. For example, a channel may correspond to a physical channel. Furthermore, a symbol may correspond to a modulation symbol arranged in a resource element. Here, "channel" may mean "propagation path." Furthermore, "channel" may mean "physical channel."

[0031] Two antenna ports are considered to be in a quasi-co-located (QCL) relationship when the large-scale properties of a channel through which symbols are transmitted at one antenna port can be estimated from the channel through which symbols are transmitted at the other antenna port. Here, the large-scale properties may include long-range channel properties. The large-scale properties may include some or all of delay spread, Doppler spread, Doppler shift, average gain, average delay, and beam parameters (spatial Rx parameters). The first and second antenna ports being QCL with respect to beam parameters may mean that the receive beam assumed by the receiver for the first antenna port is the same as (or corresponds to) the receive beam assumed by the receiver for the second antenna port. The first antenna port and the second antenna port being QCLs in terms of beam parameters may mean that a transmission beam assumed by the receiving side for the first antenna port and a transmission beam assumed by the receiving side for the second antenna port are the same (or correspond to each other). The terminal device 1 may assume that the two antenna ports are QCLs if the large-scale characteristics of a channel through which symbols are transmitted at one antenna port can be estimated from the channel through which symbols are transmitted at another antenna port. The two antenna ports being QCLs may mean that the two antenna ports are assumed to be QCLs.

[0032] Carrier aggregation may be performing communication using a plurality of aggregated serving cells. Also, carrier aggregation may be performing communication using a plurality of aggregated component carriers. Also, carrier aggregation may be performing communication using a plurality of aggregated downlink component carriers. Also, carrier aggregation may be performing communication using a plurality of aggregated uplink component carriers.

[0033] 3 is a schematic block diagram showing an example configuration of a base station device 3 according to one aspect of the present embodiment. As shown in FIG. 3, the base station device 3 includes a physical layer processing unit (radio transmission / reception unit) 30 and / or part or all of a higher layer processing unit 34. The physical layer processing unit 30 includes an antenna unit 31, an RF (Radio Frequency) processing unit 32, and part or all of a baseband processing unit 33. The higher layer processing unit 34 includes a medium access control layer (MAC layer) processing unit 35 and part or all of a radio resource control (RRC) layer processing unit 36.

[0034] The physical layer processing unit 30 performs physical layer processing. Here, the physical layer processing may include some or all of the following: generating a baseband signal of a physical channel; generating a baseband signal of a physical signal; detecting information transmitted by the physical channel; and detecting information transmitted by the physical signal. The physical layer processing may also include mapping a transport channel to a physical channel. Here, the baseband signal is also referred to as a time-continuous signal.

[0035] For example, the physical layer processing unit 30 may generate a baseband signal of a downlink physical channel, where a transport block delivered from a higher layer on the DL-SCH may be mapped to the downlink physical channel.

[0036] For example, the physical layer processing unit 30 may generate a baseband signal of a downlink physical signal.

[0037] For example, the physical layer processing unit 30 may attempt to detect information carried by an uplink physical channel, where a transport block of the information carried by the uplink physical channel may be delivered to higher layers on the UL-SCH.

[0038] For example, the physical layer processing unit 30 may attempt to detect information conveyed by an uplink physical signal.

[0039] The upper layer processing unit 34 performs some or all of the processing of the Medium Access Control (MAC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and RRC layer. Here, the MAC layer is also referred to as the MAC sublayer. The PDCP layer is also referred to as the PDCP sublayer. The RLC layer is also referred to as the RLC sublayer. The RRC layer is also referred to as the RRC sublayer.

[0040] The medium access control layer processing unit (MAC layer processing unit) 35 performs MAC layer processing. Here, the MAC layer processing includes mapping between logical channels and transport channels, is the multiplexing of multiple MAC SDUs (Service Data Units) into a transport block, and one or more MACs of the transport block delivered from the physical layer on the UL-SCH. This may include some or all of the following: decomposition into SDUs, application of Hybrid Automatic Repeat reQuest (HARQ) to transport blocks, and processing of scheduling requests.

[0041] The radio resource control layer processing unit 36 ​​performs processing for the RRC layer. The processing for the RRC layer may include some or all of management of broadcast signals, management of an RRC connection / RRC idle state, and RRC reconfiguration.

[0042] The radio resource control layer processing unit 36 ​​may manage RRC parameters used for various settings of the terminal device 1. For example, the radio resource control layer processing unit 36 ​​may include the RRC parameters in an RRC message on a certain logical channel and transmit the RRC message to the terminal device 1. Here, the RRC message may be mapped to any one of a BCCH (Broadcast Control CHannel), a CCCH (Common Control CHannel), and a DCCH (Dedicated Control CHannel).

[0043] The radio resource control layer processing unit 36 ​​may determine RRC parameters to be transmitted to the terminal device 1 based on the RRC parameters included in the RRC message transmitted from the terminal device 1. Here, the RRC message transmitted from the terminal device 1 may be related to a capability information report of the terminal device 1.

[0044] The physical layer processing unit 30 may perform some or all of modulation processing, encoding processing, and transmission processing. The physical layer processing unit 30 may generate a physical signal based on some or all of encoding processing, modulation processing, and baseband signal generation processing for the transport block. The physical layer processing unit 30 may map the physical signal to a BWP. The physical layer processing unit 30 may transmit the generated physical signal.

[0045] The physical layer processing unit 30 may perform one or both of demodulation and decoding processing. The physical layer processing unit 30 may deliver a transport block of information detected based on the demodulation and decoding processing of the received physical signal to a higher layer on the UL-SCH.

[0046] If carrier sensing is required in the band of the serving cell, the physical layer processing unit 30 may perform carrier sensing prior to transmitting a physical signal.

[0047] The RF unit 32 converts the signal received via the antenna unit 31 into a baseband signal. The RF unit 32 outputs the baseband signal to the baseband unit 33.

[0048] The baseband unit 33 may digitize the baseband signal input from the RF unit 32. The baseband unit 33 may remove a portion corresponding to a CP (Cyclic Prefix) from the digitized baseband signal. The baseband unit 33 may perform a Fast Fourier Transform (FFT) on the baseband signal from which the CP has been removed, to extract a signal in the frequency domain.

[0049] The baseband unit 33 may generate a baseband signal by performing an Inverse Fast Fourier Transform (IFFT) on the physical signal. The baseband unit 33 may add a CP to the generated baseband signal. The baseband unit 33 may convert the baseband signal to which the CP has been added into an analog signal. The baseband unit 33 may convert the analog signal into an analog signal. The multiplied baseband signal may be output to the RF unit 32 .

[0050] The RF unit 32 may remove unnecessary frequency components from the baseband signal input from the baseband unit 33. The RF unit 32 may up-convert the baseband signal to a carrier frequency to generate an RF signal. The RF unit 32 may transmit the RF signal via the antenna unit 31. The RF unit 32 may also have a function of controlling transmission power.

[0051] For the terminal device 1, one or more serving cells (or component carriers, downlink component carriers, uplink component carriers) may be configured.

[0052] Each of the serving cells configured for the terminal device 1 may be any of a PCell (Primary cell), a PSCell (Primary SCG cell), and an SCell (Secondary Cell).

[0053] The PCell is a serving cell included in an MCG (Master Cell Group). The PCell is a cell on which the terminal device 1 performs an initial connection establishment procedure or a connection re-establishment procedure (a cell on which the procedure has been performed).

[0054] The PSCell is a serving cell included in an SCG (Secondary Cell Group). The PSCell is a serving cell on which the terminal device 1 performs a random access procedure.

[0055] An SCell may be included in either an MCG or an SCG.

[0056] A serving cell group (cell group) is a general term for an MCG, an SCG, and a PUCCH cell group. A serving cell group may include one or more serving cells (or component carriers). One or more serving cells (or component carriers) included in a serving cell group may be operated by carrier aggregation.

[0057] One or more downlink BWPs may be configured for the terminal device 1. One or more uplink BWPs may be configured for the terminal device 1.

[0058] Of one or more downlink BWPs configured for the terminal device 1, one downlink BWP may be set as an active downlink BWP (or one downlink BWP may be activated). Of one or more uplink BWPs configured for the terminal device 1, one uplink BWP may be set as an active uplink BWP (or one uplink BWP may be activated).

[0059] The physical layer processing unit 30 may attempt to transmit the PDSCH, PDCCH, and CSI-RS on the active downlink BWP. The physical layer processing unit 10 may attempt to receive the PDSCH, PDCCH, and CSI-RS on the active downlink BWP. The physical layer processing unit 30 may attempt to receive the PUCCH and PUSCH on the active uplink BWP. The physical layer processing unit 10 may attempt to transmit the PUCCH and PUSCH on the active uplink BWP. Here, the active downlink BWP and the active uplink BWP are collectively referred to as the active BWP.

[0060] The physical layer processing unit 30 may not attempt to transmit the PDSCH, PDCCH, and CSI-RS on an inactive downlink BWP (a downlink BWP that is not an active downlink BWP). The physical layer processing unit 10 may not attempt to receive the PDSCH, PDCCH, and CSI-RS on an inactive downlink BWP. The physical layer processing unit 30 may not attempt to receive the PUCCH and PUSCH on an inactive uplink BWP (an uplink BWP that is not an active uplink BWP). The physical layer processing unit 10 may not attempt to transmit the PUCCH and PUSCH on an inactive uplink BWP. Here, the inactive downlink BWP and the inactive uplink BWP are collectively referred to as the inactive BWP.

[0061] A downlink BWP switch is a procedure for deactivating one active downlink BWP of a serving cell and activating one of the inactive downlink BWPs of the serving cell. The downlink BWP switch may be controlled by any of the physical layer, MAC layer, and RRC layer.

[0062] The uplink BWP switching is used to deactivate one active uplink BWP of a serving cell and activate one of the inactive uplink BWPs of the serving cell. The uplink BWP switching may be controlled by any of the physical layer, MAC layer, and RRC layer.

[0063] Two or more downlink BWPs may not be set as active downlink BWPs among one or more downlink BWPs configured for the terminal device 1. For a given component carrier, one downlink BWP may be active at a given time.

[0064] Of one or more uplink BWPs configured for the terminal device 1, two or more uplink BWPs may not be configured as active uplink BWPs. For a given component carrier, one uplink BWP may be active at a given time.

[0065] One downlink BWP may be set as an active downlink BWP for each downlink component carrier, i.e., two or more downlink BWPs may not be set as active downlink BWPs for a given downlink component carrier.

[0066] One uplink BWP may be set as an active uplink BWP for each uplink component carrier, i.e., two or more uplink BWPs may not be set as active uplink BWPs for a given uplink component carrier.

[0067] Fig. 4 is a schematic block diagram showing an example configuration of a terminal device 1 according to one aspect of the present embodiment. As shown in Fig. 4, the terminal device 1 includes a physical layer processing unit (radio transmitting / receiving unit) 10 and part or all of an upper layer processing unit 14. The radio transmitting / receiving unit 10 includes an antenna unit 11, an RF unit 12, and part or all of a baseband unit 13. The upper layer processing unit 14 includes a medium access control layer processing unit 15 and part or all of a radio resource control layer processing unit 16.

[0068] The physical layer processing unit 10 performs processing of the physical layer.

[0069] For example, the physical layer processing unit 10 generates a baseband signal of an uplink physical channel. Here, the transport block delivered from higher layers on the UL-SCH may be mapped to an uplink physical channel.

[0070] For example, the physical layer processing unit 10 may generate a baseband signal of an uplink physical signal.

[0071] For example, the physical layer processing unit 10 may attempt to detect information transmitted by a downlink physical channel, where a transport block of the information transmitted by the downlink physical channel may be delivered to a higher layer on the DL-SCH.

[0072] For example, the physical layer processing unit 10 may attempt to detect information carried by a downlink physical signal.

[0073] The upper layer processing unit 14 performs part or all of the processing of a Medium Access Control (MAC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and an RRC layer.

[0074] A medium access control layer processing unit (MAC layer processing unit) 15 performs MAC layer processing.

[0075] The radio resource control layer processing unit 16 performs processing of the RRC layer.

[0076] The radio resource control layer processing unit 16 may manage RRC parameters transmitted from the base station device 3. For example, the radio resource control layer processing unit 16 may acquire RRC parameters included in an RRC message on a certain logical channel and set the acquired RRC parameters in a storage area of ​​the terminal device 1. The RRC parameters set in the storage area of ​​the terminal device 1 may be provided to a lower layer.

[0077] The radio resource control layer processing unit 16 may include function information generated based on the functions of the terminal device 1 in an RRC message and transmit the RRC message to the base station device 3.

[0078] The physical layer processing unit 10 may perform some or all of modulation processing, encoding processing, and transmission processing. The physical layer processing unit 10 may generate a physical signal based on some or all of encoding processing, modulation processing, and baseband signal generation processing for the transport block. The physical layer processing unit 10 may map the physical signal to a certain BWP. The physical layer processing unit 10 may transmit the generated physical signal.

[0079] The physical layer processing unit 10 may perform one or both of demodulation and decoding processes. The physical layer processing unit 10 may deliver a transport block of information detected based on the demodulation and decoding processes on the received physical signal to a higher layer on the DL-SCH.

[0080] When carrier sensing is required in the band of the serving cell, the physical layer processing unit 10 may perform carrier sensing prior to transmitting a physical signal.

[0081] The RF unit 12 converts the signal received via the antenna unit 11 into a baseband signal. The RF unit 12 outputs the baseband signal to the baseband unit 13.

[0082] The baseband unit 13 may digitize the baseband signal input from the RF unit 12. The baseband unit 13 derives a CP (Cy The baseband unit 13 may perform a fast Fourier transform (FFT) on the baseband signal from which the CP has been removed, to extract a signal in the frequency domain.

[0083] The baseband unit 13 may generate a baseband signal by performing an Inverse Fast Fourier Transform (IFFT) on the physical signal. The baseband unit 13 may add a CP to the generated baseband signal. The baseband unit 13 may convert the baseband signal to which the CP has been added into an analog signal. The baseband unit 13 may output the analog baseband signal to the RF unit 12.

[0084] The RF unit 12 may remove unnecessary frequency components from the baseband signal input from the baseband unit 13. The RF unit 12 may up-convert the baseband signal to a carrier frequency to generate an RF signal. The RF unit 12 may transmit the RF signal via the antenna unit 31. The RF unit 12 may also have a function of controlling transmission power.

[0085] The physical signals will be explained below.

[0086] The physical signal is a general term for a downlink physical channel, a downlink physical signal, an uplink physical channel, and an uplink physical channel. The physical channel is a general term for a downlink physical channel and an uplink physical channel. The physical signal is a general term for a downlink physical signal and an uplink physical signal.

[0087] An uplink physical channel may correspond to a set of resource elements that convey information generated in a higher layer. The uplink physical channel may be a physical channel used in an uplink component carrier. The uplink physical channel may be transmitted by the physical layer processing unit 10. The uplink physical channel may be received by the physical layer processing unit 30. In the uplink of the wireless communication system according to one aspect of the present embodiment, some or all of the following uplink physical channels may be used. ·PUCCH (Physical Uplink Control CHannel) ·PUSCH (Physical Uplink Shared CHannel) ·PRACH(Physical Random Access CHannel)

[0088] The PUCCH may be transmitted to deliver (transmit, convey) uplink control information (UCI). The uplink control information may be mapped to the PUCCH. The physical layer processing unit 10 may transmit the PUCCH in which the uplink control information is mapped. The physical layer processing unit 30 may receive the PUCCH in which the uplink control information is mapped.

[0089] The uplink control information (uplink control information bits, uplink control information sequence, uplink control information type) includes some or all of channel state information (CSI), scheduling request (SR), and hybrid automatic repeat request ACKnowledgement (HARQ-ACK) information.

[0090] The channel state information is also referred to as a channel state information bit or a channel state information sequence. The scheduling request is also referred to as a scheduling request bit or a scheduling request sequence. The HARQ-ACK information is also referred to as a HARQ-ACK information bit or a HARQ-ACK information sequence.

[0091] The HARQ-ACK information corresponds to a transport block (TB). The HARQ-ACK information may be configured by HARQ-ACK bits. A HARQ-ACK bit may indicate an acknowledgement (ACK) or a negative acknowledgement (NACK) corresponding to a transport block. An ACK may indicate that the transport block has been decoded successfully. A NACK may indicate that the transport block has not been decoded successfully. The HARQ-ACK information may include one or more HARQ-ACK bits.

[0092] The HARQ-ACK for a transport block is also referred to as the HARQ-ACK for a PDSCH. Here, "HARQ-ACK for a PDSCH" refers to the HARQ-ACK for a transport block included in the PDSCH.

[0093] The scheduling request may be used to request UL-SCH resources for an initial transmission. The scheduling request bit may be used to indicate either a positive SR or a negative SR. When the scheduling request bit indicates a positive SR, this is also referred to as "a positive SR is transmitted." A positive SR may indicate that UL-SCH resources are requested by the media access control layer processing unit 15 for the initial transmission. When the scheduling request bit indicates a negative SR, this is also referred to as "a negative SR is transmitted." A negative SR may indicate that UL-SCH resources are not requested by the media access control layer processing unit 15 for the initial transmission.

[0094] The channel state information may include some or all of a Channel Quality Indicator (CQI), a Precoder Matrix Indicator (PMI), and a Rank Indicator (RI). The CQI is an indicator related to the quality of a propagation path (e.g., propagation strength) or the quality of a physical channel, the PMI is an indicator related to a precoder, and the RI is an indicator related to a transmission rank (or the number of transmission layers).

[0095] The channel state information is an indicator related to the reception state of a physical signal (e.g., CSI-RS) used for channel measurement. The value of the channel state information may be determined by the terminal device 1 based on the reception state assumed by the physical signal used for channel measurement. The channel measurement may include interference measurement.

[0096] The PUCCH may be accompanied by a PUCCH format, where the PUCCH format may be a format of physical layer processing of the PUCCH, or a format of information conveyed using the PUCCH.

[0097] The PUSCH may be transmitted to convey one or both of uplink control information and a transport block. The PUSCH may be used to convey one or both of uplink control information and a transport block. The terminal device 1 may transmit a PUSCH in which one or both of uplink control information and a transport block are allocated. The base station device 3 may receive a PUSCH in which one or both of uplink control information and a transport block are allocated.

[0098] The PRACH may be transmitted to convey an index of the random access preamble. The terminal device 1 may transmit the PRACH. The base station device 3 may receive the PRACH. The terminal device 1 may transmit the random access preamble on the PRACH. The base station device 3 may receive the random access preamble on the PRACH.

[0099] An uplink physical signal may correspond to a set of resource elements. The uplink physical signal may not be used to transmit information generated in a higher layer. Note that the uplink physical signal may be used to transmit information generated in the physical layer. The uplink physical signal may be a physical signal used in an uplink component carrier. The physical layer processing unit 10 may transmit the uplink physical signal. The physical layer processing unit 30 may receive the uplink physical signal. In the uplink of the wireless communication system according to one aspect of the present embodiment, some or all of the following uplink physical signals may be used. ·UL DMRS(UpLink Demodulation Reference Signal) ·SRS(Sounding Reference Signal) ·UL PTRS(UpLink Phase Tracking Reference Signal)

[0100] UL DMRS is a general term for DMRS for PUSCH and DMRS for PUCCH.

[0101] The set of antenna ports for DMRSs for PUSCH (DMRSs related to PUSCH, DMRSs included in PUSCH, and DMRSs corresponding to PUSCH) may be determined based on the set of antenna ports for the PUSCH. For example, the set of antenna ports for DMRSs for PUSCH may be the same as the set of antenna ports for the PUSCH.

[0102] The propagation path of the PUSCH may be estimated from the DMRS for the PUSCH.

[0103] The set of antenna ports for DMRS for PUCCH (DMRS related to PUCCH, DMRS included in PUCCH, DMRS corresponding to PUCCH) may be the same as the set of antenna ports for PUCCH.

[0104] The propagation path of the PUCCH may be estimated from the DMRS for the PUCCH.

[0105] The downlink physical channel may correspond to a set of resource elements that convey information generated in a higher layer. The downlink physical channel may be a physical channel used in a downlink component carrier. The physical layer processing unit 30 may transmit the downlink physical channel. The physical layer processing unit 10 may receive the downlink physical channel. In the downlink of the wireless communication system according to one aspect of the present embodiment, some or all of the following downlink physical channels may be used. ·PBCH(Physical Broadcast Channel) ·PDCCH (Physical Downlink Control Channel) ·PDSCH(Physical Downlink Shared Channel)

[0106] The PBCH may be transmitted to carry one or both of a Master Information Block (MIB) and physical layer control information, where the physical layer control information is information generated in the physical layer. The MIB is an RRC message delivered from higher layers on the Broadcast Control Channel (BCCH).

[0107] The PDCCH may be transmitted to convey downlink control information (DCI). The downlink control information may be arranged in the PDCCH. The terminal device 1 may receive the PDCCH in which the downlink control information is arranged. The base station device 3 may transmit the PDCCH in which the downlink control information is arranged.

[0108] The downlink control information may be transmitted in a DCI format. The format may be interpreted as a form of downlink control information, and the DCI format may be interpreted as a set of downlink control information set in a certain downlink control information format.

[0109] The base station device 3 may notify the terminal device 1 of downlink control information using a PDCCH with a DCI format. Here, the terminal device 1 may monitor the PDCCH to acquire the downlink control information. Unless otherwise specified, the DCI format and the downlink control information may be described as equivalent. For example, the base station device 3 may include the downlink control information in a DCI format and transmit it to the terminal device 1. Furthermore, the terminal device 1 may control the physical layer processing unit 10 using the downlink control information included in the detected DCI format.

[0110] DCI format 0_0, DCI format 0_1, DCI format 1_0, and DCI format 1_1 are DCI formats. The uplink DCI format is a general term for DCI format 0_0 and DCI format 0_1. The downlink DCI format is a general term for DCI format 1_0 and DCI format 1_1.

[0111] DCI format 0_0 is used for scheduling a PUSCH allocated to a certain cell, and may include some or all of fields 1A to 1E. 1A) Identifier field for DCI formats 1B) Frequency domain resource assignment field field) 1C) Time domain resource assignment field 1D) Frequency hopping flag field 1E) MCS field (Modulation and Coding Scheme field)

[0112] The DCI format identification field may indicate whether the DCI format including the DCI format identification field is an uplink DCI format or a downlink DCI format. That is, the DCI format identification field may be included in both the uplink DCI format and the downlink DCI format. Here, the DCI format identification field included in DCI format 0_0 may indicate 0.

[0113] The frequency domain resource allocation field included in DCI format 0_0 may be used to indicate the allocation of frequency resources for the PUSCH scheduled by DCI format 0_0.

[0114] The time domain resource allocation field included in DCI format 0_0 may be used to indicate the allocation of time resources for the PUSCH scheduled by DCI format 0_0.

[0115] The frequency hopping flag field may be used to indicate whether frequency hopping is applied to the PUSCH scheduled by the DCI format 0_0.

[0116] The MCS field included in DCI format 0_0 indicates the modulation scheme for the PUSCH scheduled by the DCI format 0_0 and the The target coding rate may be used to indicate one or both of the target coding rates scheduled by the modulation scheme 0_1. The target coding rate may be a target coding rate for a transport block allocated to the PUSCH. The size of the transport block (TBS) allocated to the PUSCH may be determined based on the target coding rate and part or all of the modulation scheme for the PUSCH.

[0117] DCI format 0_0 may not include fields used for CSI requests.

[0118] DCI format 0_0 may not include a carrier indicator field. That is, the serving cell to which the uplink component carrier on which the PUSCH scheduled by DCI format 0_0 is allocated may be the same as the serving cell of the downlink component carrier on which the PDCCH including the DCI format 0_0 is allocated. By detecting DCI format 0_0 on a downlink component carrier of a serving cell, the terminal device 1 may recognize that the PUSCH scheduled by the DCI format 0_0 is allocated on the uplink component carrier of the serving cell.

[0119] DCI format 0_0 may not include a BWP field. Here, DCI format 0_0 may be a DCI format for scheduling a PUSCH without changing an active uplink BWP. Based on detecting DCI format 0_0 used for scheduling a PUSCH, the terminal device 1 may recognize that the PUSCH will be transmitted without switching the active uplink BWP.

[0120] DCI format 0_1 ​​is used for scheduling a PUSCH allocated to a certain cell. DCI format 0_1 ​​includes some or all of fields 2A to 2H. 2A) DCI format specific fields 2B) Frequency domain resource allocation field 2C) Uplink time domain resource allocation field 2D) Frequency hopping flag field 2E) MCS Field 2F) CSI request field 2G) BWP field 2H) Carrier indicator field

[0121] The DCI format specific field included in DCI format 0_1 ​​may indicate 0.

[0122] The frequency domain resource allocation field included in DCI format 0_1 ​​may be used to indicate the allocation of frequency resources for the PUSCH scheduled by DCI format 0_1.

[0123] The time domain resource allocation field included in DCI format 0_1 ​​may be used to indicate the allocation of time resources for the PUSCH scheduled by DCI format 0_1.

[0124] The MCS field included in the DCI format 0_1 ​​indicates the modulation scheme for the PUSCH scheduled by the DCI format 0_1 ​​and the This may be used to indicate one or both of the target coding rates for the PUSCH scheduled by the matrix 0_1.

[0125] The BWP field of DCI format 0_1 ​​may be used to indicate an uplink BWP in which a PUSCH scheduled by the DCI format 0_1 ​​is arranged. That is, the DCI format 0_1 ​​may or may not involve a change of the active uplink BWP. The terminal device 1 may recognize the uplink BWP in which the PUSCH is arranged based on detecting the DCI format 0_1 ​​used for scheduling the PUSCH.

[0126] The DCI format 0_1 ​​that does not include a BWP field may be a DCI format for scheduling a PUSCH without changing the active uplink BWP. The terminal device 1 may recognize that the PUSCH is to be transmitted without switching the active uplink BWP based on detecting the DCI format 0_1 ​​that is used for scheduling a PUSCH and does not include a BWP field.

[0127] If the DCI format 0_1 ​​includes a BWP field but the terminal device 1 does not support the BWP switching function using the DCI format 0_1, the BWP field may be ignored by the terminal device 1. That is, a terminal device 1 that does not support the BWP switching function may recognize that it will transmit the PUSCH without switching the active uplink BWP based on detecting the DCI format 0_1 ​​that is used for scheduling the PUSCH and includes the BWP field. Here, if the BWP switching function is supported, the radio resource control layer processing unit 16 may include, in the RRC message, capability information indicating that the BWP switching function is supported.

[0128] The CSI request field may be used to indicate the reporting of CSI.

[0129] When DCI format 0_1 ​​includes a carrier indicator field, the carrier indicator field may be used to indicate the serving cell of the uplink component carrier on which the PUSCH is arranged. Based on detecting DCI format 0_1 ​​in the downlink component carrier of a serving cell, the terminal device 1 may recognize that the PUSCH scheduled by the DCI format 0_1 ​​is arranged on the uplink component carrier of the serving cell indicated by the carrier indicator field included in the DCI format 0_1.

[0130] If DCI format 0_1 ​​does not include a carrier indicator field, the serving cell to which the uplink component carrier on which the PUSCH scheduled by DCI format 0_1 ​​is allocated may be the same as the serving cell of the downlink component carrier on which the PDCCH including the DCI format 0_1 ​​is allocated. Based on detecting DCI format 0_1 ​​on a downlink component carrier of a serving cell, the terminal device 1 may recognize that the PUSCH scheduled by the DCI format 0_1 ​​is allocated on the uplink component carrier of the serving cell.

[0131] DCI format 1_0 is used for scheduling a PDSCH allocated to a certain cell, and is configured by including some or all of 3A to 3F. 3A) DCI Format Specific Fields 3B) Frequency domain resource allocation field 3C) Time Domain Resource Allocation Field 3D) MCS field 3E) PDSCH_HARQ feedback timing indicator field 3F) PUCCH resource indicator field

[0132] The DCI format specific field included in DCI format 1_0 may indicate 1.

[0133] The frequency domain resource allocation field included in DCI format 1_0 may be used to indicate the allocation of frequency resources for the PDSCH scheduled by that DCI format.

[0134] The time domain resource allocation field included in DCI format 1_0 may be used to indicate the allocation of time resources for the PDSCH scheduled by that DCI format.

[0135] The MCS field included in DCI format 1_0 may be used to indicate one or both of a modulation scheme for a PDSCH scheduled by the DCI format and a target coding rate for a PDSCH scheduled by the DCI format. The target coding rate may be a target coding rate for a transport block allocated to the PDSCH. The size of the transport block (TBS) allocated to the PDSCH may be determined based on one or both of the target coding rate and the modulation scheme for the PDSCH.

[0136] The PDSCH_HARQ feedback timing indication field may be used to indicate the offset from the slot containing the last OFDM symbol of the PDSCH to the slot containing the first OFDM symbol of the PUCCH.

[0137] The PUCCH resource indication field may be used to indicate the resource of the PUCCH.

[0138] DCI format 1_0 may not include a carrier indicator field. That is, the downlink component carrier on which the PDSCH scheduled by DCI format 1_0 is arranged may be the same as the downlink component carrier on which the PDCCH including DCI format 1_0 is arranged. The terminal device 1 may recognize that the PDSCH scheduled by DCI format 1_0 is to be arranged on the downlink component carrier based on detecting DCI format 1_0 on the downlink component carrier.

[0139] DCI format 1_0 may not include a BWP field. Here, DCI format 1_0 may be a DCI format for scheduling a PDSCH without changing an active downlink BWP. The terminal device 1 may recognize that it will receive the PDSCH without switching the active downlink BWP based on detecting DCI format 1_0 used for scheduling the PDSCH.

[0140] DCI format 1_1 is used for scheduling PDSCHs allocated to a cell. DCI format 1_1 is composed of some or all of 4A to 4I. 4A) DCI Format Specific Fields 4B) Frequency domain resource allocation field 4C) Time Domain Resource Allocation Field 4E) MCS Field 4F) PDSCH_HARQ feedback timing indication field 4G) PUCCH resource indication field 4H) BWP Field 4I) Career Indicator Field

[0141] The DCI format specific field included in DCI format 1_1 may indicate 1.

[0142] The frequency domain resource allocation field included in DCI format 1_1 may be used to indicate the allocation of frequency resources for the PDSCH scheduled by DCI format 1_1.

[0143] The time domain resource allocation field included in DCI format 1_1 may be used to indicate the allocation of time resources for the PDSCH scheduled by DCI format 1_1.

[0144] The MCS field included in DCI format 1_1 may be used to indicate one or both of the modulation scheme for the PDSCH scheduled by DCI format 1_1 and the target coding rate for the PDSCH scheduled by DCI format 1_1.

[0145] If DCI format 1_1 includes a PDSCH_HARQ feedback timing indication field, the PDSCH_HARQ feedback timing indication field may be used to indicate an offset from the slot including the last OFDM symbol of the PDSCH to the slot including the first OFDM symbol of the PUCCH. If DCI format 1_1 does not include a PDSCH_HARQ feedback timing indication field, a parameter indicating the offset from the slot including the last OFDM symbol of the PDSCH to the slot including the first OFDM symbol of the PUCCH may be provided by the RRC layer.

[0146] The PUCCH resource indication field may be used to indicate the resource of the PUCCH.

[0147] The BWP field of DCI format 1_1 may be used to indicate the downlink BWP in which the PDSCH scheduled by the DCI format 1_1 is arranged. That is, the DCI format 1_1 may or may not involve a change of the active downlink BWP. The terminal device 1 may recognize the downlink BWP in which the PDSCH is arranged based on detecting the DCI format 1_1 used for scheduling the PDSCH.

[0148] The DCI format 1_1 that does not include a BWP field may be a DCI format for scheduling a PDSCH without changing the active downlink BWP. The terminal device 1 detects the DCI format 1_1 that is used for scheduling a PDSCH and does not include a BWP field. Based on this, it may be recognized that the PDSCH is received without switching the active downlink BWP.

[0149] If the DCI format 1_1 includes a BWP field but the terminal device 1 does not support the BWP switching function by the DCI format 1_1, the BWP field may be ignored by the terminal device 1. In other words, a terminal device 1 that does not support the BWP switching function may recognize that it will receive the PDSCH without switching the active downlink BWP based on detecting DCI format 1_1 that is used for scheduling the PDSCH and includes a BWP field. Here, if the BWP switching function is supported, the radio resource control layer processing unit 16 may include, in the RRC message, capability information indicating that the BWP switching function is supported.

[0150] When DCI format 1_1 includes a carrier indicator field, the carrier indicator field may be used to indicate the serving cell of the downlink component carrier on which the PDSCH scheduled by DCI format 1_1 is arranged. Based on detecting DCI format 1_1 on the downlink component carrier of a serving cell, the terminal device 1 may recognize that the PDSCH scheduled by DCI format 1_1 is arranged on the downlink component carrier of the serving cell indicated by the carrier indicator field included in DCI format 1_1.

[0151] If DCI format 1_1 does not include a carrier indicator field, the downlink component carrier on which the PDSCH scheduled by DCI format 1_1 is arranged may be the same as the downlink component carrier on which the PDCCH including DCI format 1_1 is arranged. Based on detecting DCI format 1_1 in a certain downlink component carrier, the terminal device 1 may recognize that the PDSCH scheduled by DCI format 1_1 is to be arranged on the downlink component carrier.

[0152] The PDSCH may be transmitted to transmit a transport block. The PDSCH may be used to transmit a transport block. The transport block may be arranged in the PDSCH. The base station device 3 may transmit the PDSCH in which the transport block is arranged. The terminal device 1 may receive the PDSCH in which the transport block is arranged.

[0153] The downlink physical signal may correspond to a set of resource elements. The downlink physical signal does not have to be used to transmit information generated in a higher layer. The downlink physical signal may be used to transmit information generated in the physical layer. The downlink physical signal may be a physical signal used in a downlink component carrier. The physical layer processing unit 10 may transmit the downlink physical signal. The physical layer processing unit 30 may receive the downlink physical signal. In the downlink of the wireless communication system according to one aspect of the present embodiment, at least some or all of the following downlink physical signals may be used. ·Synchronization signal (SS) ·DL DMRS(DownLink DeModulation Reference Signal) ·CSI-RS(Channel State Information-Reference Signal) ·DL PTRS(DownLink Phase Tracking Reference Signal)

[0154] The synchronization signal is transmitted to the terminal device 1 in one or both of the frequency domain and the time domain of the downlink. The synchronization signal is a general term for a PSS (Primary Synchronization Signal) and an SSS (Secondary Synchronization Signal).

[0155] The antenna ports for the PSS, SSS, PBCH, and DMRS for the PBCH may be the same.

[0156] The PBCH on which the PBCH symbol is transmitted at a certain antenna port may be estimated by the DMRS for the PBCH that is placed in the slot to which the PBCH is mapped and is included in the SS / PBCH block to which the PBCH belongs.

[0157] DL DMRS is a general term for DMRS for PBCH, DMRS for PDSCH, and DMRS for PDCCH.

[0158] The set of antenna ports for DMRSs for a PDSCH (DMRSs associated with a PDSCH, DMRSs included in a PDSCH, and DMRSs corresponding to a PDSCH) may be determined based on the set of antenna ports for the PDSCH. For example, the set of antenna ports for DMRSs for a PDSCH may be the same as the set of antenna ports for the PDSCH.

[0159] A propagation path of a PDSCH may be estimated from a DMRS for the PDSCH. If a set of resource elements carrying a certain PDSCH symbol and a set of resource elements carrying a DMRS symbol for the PDSCH are included in the same precoding resource group (PRG), the PDSCH carrying the PDSCH symbol for a certain antenna port may be estimated by the DMRS for the PDSCH.

[0160] The antenna port of the DMRS for the PDCCH (DMRS related to the PDCCH, DMRS included in the PDCCH, DMRS corresponding to the PDCCH) may be the same as the antenna port for the PDCCH.

[0161] The propagation path of a PDCCH may be estimated from the DMRS for the PDCCH. If the same precoder is applied (or assumed to be applied) to a set of resource elements on which a PDCCH symbol is transmitted and a set of resource elements on which a DMRS symbol for the PDCCH is transmitted, the PDCCH on which a PDCCH symbol for a certain antenna port is transmitted may be estimated by the DMRS for the PDCCH.

[0162] The BCH (Broadcast CHannel), the UL-SCH (Uplink-Shared CHannel), and the DL-SCH (Downlink-Shared CHannel) are transport channels.

[0163] The BCH of the transport layer may be mapped to the PBCH of the physical layer. That is, a transport block delivered from an upper layer on the BCH of the transport layer may be placed on the PBCH of the physical layer. Also, the UL-SCH of the transport layer may be mapped to the PUSCH of the physical layer. That is, a transport block delivered from an upper layer on the UL-SCH of the transport layer may be placed on the PUSCH of the physical layer. Also, the DL-SCH of the transport layer may be mapped to the PDSCH of the physical layer. That is, a transport block delivered from an upper layer on the DL-SCH of the transport layer may be placed on the PDSCH of the physical layer.

[0164] The transport layer may apply Hybrid Automatic Repeat reQuest (HARQ) to the transport block.

[0165] The BCCH (Broadcast Control CHannel), CCCH (Common Control CHannel), and DCCH (Dedicated Control CHannel) are logical channels. For example, the BCCH may be used to deliver an RRC message including an MIB or an RRC message including system information. The CCCH may also be used to transmit an RRC message including RRC parameters common to multiple terminal devices 1. Here, the CCCH may be used, for example, for terminal devices 1 that are not RRC connected. The DCCH may also be used to transmit an RRC message dedicated to a certain terminal device 1. Here, the DCCH may be used, for example, for terminal devices 1 that are RRC connected.

[0166] The BCCH may be mapped to the BCH or DL-SCH. That is, an RRC message containing MIB information may be delivered on the BCH. An RRC message containing system information other than MIB information may be delivered on the DL-SCH. The CCCH may be mapped to the DL-SCH or UL-SCH. That is, an RRC message mapped to the CCCH may be delivered on the DL-SCH or UL-SCH. The DCCH may be mapped to the DL-SCH or UL-SCH. That is, an RRC message mapped to the DCCH may be delivered on the DL-SCH or UL-SCH.

[0167] The medium access control layer processing unit 15 may implement a random access procedure.

[0168] 5 is a diagram showing an example of a random access procedure performed in the medium access control layer processing unit 15 according to one aspect of this embodiment. In the random access procedure shown in FIG. 5, the medium access control layer processing unit 15 may first perform decision 5001. Here, in decision 5001, the type of random access procedure may be determined. Furthermore, the type of random access procedure may be either a four-step random access procedure or a two-step random access procedure. In other words, in decision 5001, either the four-step random access procedure or the two-step random access procedure may be selected.

[0169] Here, "RA_TYPE" is a variable in which a value corresponding to the random access procedure selected in decision 5001 is stored. For example, the value corresponding to the four-step random access procedure may be "4STEP_RA", and the value corresponding to the two-step random access procedure may be "2STEP_RA". For example, if the media access control layer processing unit 15 selects the two-step random access procedure in decision 5001, "2STEP_RA" may be input to the variable "RA_TYPE".

[0170] In decision 5001, a determination regarding the strength of a downlink signal may be made. Here, the determination regarding the strength of the downlink signal in decision 5001 may be made based at least on comparing the RSRP value of a downlink pathloss reference (DPL) with a predetermined threshold #5001. For example, if the RSRP value of the downlink pathloss reference is greater than the predetermined threshold #5001, the media access control layer processing unit 15 may select a two-step random access procedure. Alternatively, if the RSRP value of the downlink pathloss reference is less than the predetermined threshold #5001, the media access control layer processing unit 15 may select a four-step random access procedure. Alternatively, if the RSRP value of the downlink pathloss reference is equal to the predetermined threshold #5001, the media access control layer processing unit 15 may select either the two-step random access procedure or the four-step random access procedure. For example, the downlink pathloss reference may be a physical signal used to determine a pathloss estimation value used in uplink power control. Alternatively, the downlink pathloss reference may be an SS / PBCH block selected in the random access procedure.

[0171] If the media access control layer processing unit 15 selects the four-step random access procedure in decision 5001, the media access control layer processing unit 15 may perform a random access resource selection process 5002. Here, in the random access resource selection process 5002, one or both of a random access preamble group selection and a PRACH resource group selection may be performed.

[0172] FIG. 6 is a diagram illustrating an example of the random access resource selection process 5002 performed by the media access control layer processing unit 15 according to one aspect of this embodiment. First, the media access control layer processing unit 15 may perform decision 6001. Here, in decision 6001, the media access control layer processing unit 15 may make a decision regarding the strength of the downlink signal. For example, the decision regarding the strength of the downlink signal in decision 6001 may be made based on comparing the value of the RSRP of the downlink path loss reference with a predetermined threshold #6001. For example, if the value of the RSRP of the downlink path loss reference is smaller than the predetermined threshold #6001, the media access control layer processing unit 15 may proceed to decision 6005. Alternatively, if the value of the RSRP of the downlink path loss reference is greater than the predetermined threshold #6001, the media access control layer processing unit 15 may select decision 6002. If the RSRP value of the downlink path loss reference is equal to the predetermined threshold #6001, the media access control layer processing unit 15 may proceed to either decision 6002 or decision 6005. Here, the downlink path loss reference may be a physical signal used to determine a path loss estimation value used in uplink power control. Alternatively, the downlink path loss reference may be an SS / PBCH block selected in the random access procedure.

[0173] If the media access control layer processing unit 15 proceeds to decision 6002, the media access control layer processing unit 15 may perform decision 6002. Here, in decision 6002, the media access control layer processing unit 15 may perform one or both of a decision regarding the strength of a downlink signal and a decision regarding the size of uplink data. For example, the decision regarding the downlink signal strength in decision 6002 may be made based on comparing a path loss value measured based on a certain physical signal with threshold value #6002a. Here, threshold value #6002a may be a threshold determined based on one or more parameters. For example, the one or more parameters in decision 6002 may be parameters used for uplink transmission power control. For example, threshold value #6002a may be determined based on the serving cell configured maximum transmit power PCMAX in which the random access procedure is performed, the target received power of the random access preamble preambleReceivedTargetPower, the offset value msg3-DeltaPreamble between the target received power of the message 3 PUSCH and the target received power of the random access preamble, and the offset value messagePowerOffsetGroupB for decision 6002. For example, threshold value #6002a may be determined by calculating PCMAX-preambleReceivedTargetPower-msg3-DeltaPreamble-messagePowerOffsetGroupB.

[0174] For example, the serving cell configured maximum transmit power PCMAX for performing the random access procedure may be a value that is set according to the frequency band (frequency position, band, frequency band) to which the serving cell belongs. Furthermore, the target received power preamble preambleReceivedTargetPower may be provided by the RRC layer. Furthermore, the offset value msg3-DeltaPreamble between the target received power of message 3 PUSCH and the target received power of the random access preamble may be provided by the RRC layer. Furthermore, the offset value messagePowerOffsetGroupB may be provided by the RRC layer.

[0175] For example, the determination regarding the size of the uplink data in decision 6002 may be made based on comparing the size of the uplink data with threshold #6002b. For example, in decision 6002, the uplink data may be the payload of a potential Message 3 PUSCH. Here, the payload of the potential Message 3 PUSCH may be a transport block assigned to a Message 3 PUSCH expected to be transmitted in the random access procedure. Furthermore, the payload of the potential Message 3 PUSCH may be one or both of a MAC SDU and a MAC subheader multiplexed onto a transport block assigned to a Message 3 PUSCH expected to be transmitted in the random access procedure. Here, the MAC SDU may be a MAC SDU delivered from a higher layer on the CCCH, or may be a MAC SDU delivered from a higher layer on a logical channel other than the CCCH. A MAC SDU delivered from a higher layer on the CCCH is also referred to as a CCCH SDU. Note that when media access control layer processing unit 15 makes decision 6002, the transmission of the Message 3 PUSCH may not have been performed yet, so the determination is made based on the payload of the “potential” Message 3 PUSCH.

[0176] For example, decision 6002 may be a decision based on one or both of the truth or falsity of proposition 6002a and the truth or falsity of proposition 6002b. For example, the media access control layer processing unit 15 may proceed to operation 6004 based on the determination that proposition 6002a is true. Alternatively, the media access control layer processing unit 15 may proceed to operation 6004 based on the determination that proposition 6002b is true. Alternatively, the media access control layer processing unit 15 may proceed to operation 6003 based on the determination that proposition 6002a is false and the determination that proposition 6002b is false.

[0177] For example, proposition 6002a may be that the size of uplink data is greater than threshold value #6002b and the path loss value is less than threshold value #6002a. Alternatively, proposition 6002a may be that the size of uplink data is not less than threshold value #6002b and the path loss value is less than threshold value #6002a. Alternatively, proposition 6002a may be that the size of uplink data is greater than threshold value #6002b and the path loss value is not greater than threshold value #6002a. Alternatively, proposition 6002a may be that the size of uplink data is not less than threshold value #6002b and the path loss value is not greater than threshold value #6002a.

[0178] The physical signal used in determining the downlink physical signal strength in process 6002 may be one SS / PBCH block selected from multiple SS / PBCH blocks. Here, the multiple SS / PBCH blocks may be multiple SS / PBCH blocks configured for the serving cell. The media access control layer processing unit 15 may select one SS / PBCH block from the multiple SS / PBCH blocks based on a comparison between the RSRP value for at least one SS / PBCH block and threshold value #6002x. For example, if the RSRP value for at least one SS / PBCH block is greater than threshold value #6002x, the media access control layer processing unit 15 may select one SS / PBCH block from among the SS / PBCH blocks whose RSRP values ​​are greater than threshold value #6002x. Alternatively, if the RSRP values ​​for all SS / PBCH blocks are less than threshold value #6002x, the media access control layer processing unit 15 may select one SS / PBCH block from the multiple SS / PBCH blocks.

[0179] For example, threshold #6002x may be provided by a higher layer.

[0180] For example, proposition 6002b may be that a random access procedure is initiated for CCCH and the size of uplink data is greater than threshold #6002b, or that a random access procedure is initiated for CCCH and the size of uplink data is not less than threshold #6002b.

[0181] In process 6003, the media access control layer processing unit 15 may select random access preamble group A. Also, in process 6003, the media access control layer processing unit 15 may determine not to request application of repeated transmission to the message 3 PUSCH.

[0182] In process 6004, the media access control layer processing unit 15 may select random access preamble group B. Also, in process 6004, the media access control layer processing unit 15 may determine not to request application of repeated transmission to the message 3 PUSCH.

[0183] The terminal device 1 may notify the base station device 3 of information indicating whether to request application of repeat transmission to the message 3 PUSCH, using the PRACH transmitted during the random access procedure. For example, transmission of the PRACH based on the first PRACH resource group may correspond to requesting application of repeat transmission to the message 3 PUSCH. Furthermore, transmission of the PRACH based on the second PRACH resource group may correspond to not requesting application of repeat transmission to the message 3 PUSCH.

[0184] That is, when the media access control layer processing unit 15 requests the application of repeat transmission to the message 3 PUSCH, it may be that the media access control layer processing unit 15 selects the first PRACH resource group. Also, when the media access control layer processing unit 15 does not request the application of repeat transmission to the message 3 PUSCH, it may be that the media access control layer processing unit 15 selects the second PRACH resource group.

[0185] A PRACH resource group may include one or more PRACH resources, where a PRACH resource may be identified by one or both of a time-frequency resource (e.g., a PRACH opportunity) and a random access preamble index.

[0186] Here, it may be determined whether to configure the random access preamble group B for each PRACH resource group. For example, the random access preamble group B may not be configured for the first PRACH resource group. Also, a parameter indicating whether to configure the random access preamble group B for the first PRACH resource group may be provided by the RRC layer.

[0187] For example, a parameter indicating whether or not to configure random access preamble group B for each PRACH resource group may be provided by the RRC layer.

[0188] In decision 6005, the media access control layer processing unit 15 may make a decision regarding the size of the uplink data. For example, the decision regarding the size of the uplink data in decision 6005 may be made by comparing the size of the uplink data with a threshold value #6002b. It may be given based on.

[0189] For example, the media access control layer processing unit 15 may proceed to decision 6007 when the random access procedure is initiated for the CCCH and the size of the uplink data is greater than threshold value #6002b. Alternatively, the media access control layer processing unit 15 may proceed to decision 6006 when the random access procedure is initiated for the CCCH and the size of the uplink data is smaller than threshold value #6002b. Alternatively, the media access control layer processing unit 15 may proceed to either step 6006 or step 6007 when the random access procedure is initiated for the CCCH and the size of the uplink data is equal to threshold value #6002b. Alternatively, the media access control layer processing unit 15 may proceed to step 6006 when the random access procedure is not initiated for the CCCH. In another example, the media access control layer processing unit 15 may proceed to decision 6002 when the random access procedure is not initiated for the CCCH.

[0190] In process 6006, the media access control layer processing unit 15 may select random access preamble group A. Also, in process 6006, the media access control layer processing unit 15 may determine to request application of repeated transmission to the message 3 PUSCH.

[0191] In decision 6007, the media access control layer processing unit 6007 may determine whether or not random access preamble group B is configured for the first PRACH resource group. For example, if random access preamble group B is configured for the first PRACH resource group, the media access control layer processing unit 15 may proceed to operation 6009. Alternatively, if random access preamble group B is not configured for the first PRACH resource group, the media access control layer processing unit 15 may proceed to operation 6008.

[0192] In process 6008, the media access control layer processing unit 15 may select random access preamble group B. Also, in process 6008, the media access control layer processing unit 15 may determine not to request application of repeated transmission to the message 3 PUSCH.

[0193] In process 6009, the media access control layer processing unit 15 may select random access preamble group B. Also, in process 6009, the media access control layer processing unit 15 may determine to request application of repeated transmission to the message 3 PUSCH.

[0194] As described above, in the random access procedure, whether or not the media access control layer processing unit 15 requests the application of repeated transmission to the message 3 PUSCH may be determined based on one or both of the value of the RSRP of the downlink path loss reference and whether or not the random access preamble group B is configured for the first PRACH resource group.

[0195] For example, the media access control layer processing unit 15 may not request the application of repeat transmission to the message 3 PUSCH based on the RSRP value of the downlink path loss reference being greater than threshold value #6001. Also, the media access control layer processing unit 15 may not request the application of repeat transmission to the message 3 PUSCH based on the RSRP value of the downlink path loss reference being not less than threshold value #6001.

[0196] For example, the media access control layer processing unit 15 may request the application of repeat transmission to the message 3 PUSCH based on the fact that the RSRP value of the downlink path loss reference is smaller than threshold #6001 and that random access preamble group B is configured for the first PRACH resource group. Alternatively, the media access control layer processing unit 15 may request the application of repeat transmission to the message 3 PUSCH based on the fact that the RSRP value of the downlink path loss reference is not greater than threshold #6001 and that random access preamble group B is configured for the first PRACH resource group.

[0197] For example, the media access control layer processing unit 15 may not request the application of repeat transmission to the message 3 PUSCH based on the fact that the RSRP value of the downlink path loss reference is smaller than threshold #6001 and that random access preamble group B is not configured for the first PRACH resource group. Also, the media access control layer processing unit 15 may not request the application of repeat transmission to the message 3 PUSCH based on the fact that the RSRP value of the downlink path loss reference is not larger than threshold #6001 and that random access preamble group B is not configured for the first PRACH resource group.

[0198] Here, the base station apparatus 3 may set information included in the message 2 PDSCH (random access response grant) based on the presence or absence of a request transmitted from the terminal apparatus 1.

[0199] For example, the media access control layer processing unit 15 may select one PRACH opportunity in the random access resource selection process 5002. Here, the media access control layer processing unit 15 may select one PRACH opportunity from among the PRACH opportunities associated with the PRACH resource group.

[0200] For example, the media access control layer processing unit 15 may select one random access preamble based on the selected PRACH resource group and the selected random access preamble group.

[0201] After performing operation 5002, the media access control layer processing unit 15 may perform operation 5003. Here, operation 5003 may include a process for transmitting a random access preamble and a process for receiving a random access response.

[0202] Here, the process of transmitting the random access preamble may be a process of instructing the physical layer processing unit 10 to transmit the selected random access preamble in the selected PRACH opportunity selected by the medium access control layer processing unit 15. In other words, the medium access control layer processing unit 15 may instruct the physical layer processing unit 10 to transmit the selected random access preamble in the selected PRACH opportunity.

[0203] Furthermore, the random access response reception process may be a process in which the media access control layer processing unit 15 monitors the PDCCH for a predetermined period of time. Here, the predetermined period is also referred to as a random access response window. Here, even if the PDCCH monitoring is actually performed by the physical layer processing unit 10, the monitoring may be considered to have been performed by the media access control layer processing unit 15.

[0204] For example, the media access control layer processing unit 15 may start the random access response window at the first PDCCH monitoring occasion from the end of the transmission of the random access preamble. A parameter (ra-ResponseWindow) that determines the duration of the response window may be provided by the RRC layer.

[0205] For example, different parameters may be used to determine the duration of the random access response window depending on whether or not application of repeat transmission to the message 3 PUSCH is requested. For example, a first parameter and a second parameter may be provided by the RRC layer. Here, if application of repeat transmission to the message 3 PUSCH is requested, the media access control layer processing unit 15 may determine the duration of the random access response window based on the value indicated by the first parameter. Also, if application of repeat transmission to the message 3 PUSCH is not requested, the media access control layer processing unit 15 may determine the duration of the random access response window based on the value indicated by the second parameter.

[0206] For example, if a random access response including a field indicating the index of the selected random access preamble is received within the duration of the random access response window, the media access control layer processing unit 15 may consider the reception of the random access response to be successful. On the other hand, if the random access response window has expired and a random access response including a field indicating the index of the selected random access preamble is not received, the media access control layer processing unit 15 may consider the reception of the random access response to be unsuccessful.

[0207] If the random access response is not successfully received, the media access control layer processing unit 15 may increment a preamble transmission counter. If the value of the preamble transmission counter reaches a predetermined value #5003, the media access control layer processing unit 15 may notify the upper layer that a problem has occurred in the implementation of the random access procedure (random access problem).

[0208] Here, the predetermined value #5003 may be determined by a parameter provided by the RRC layer. For example, different parameters may be used to determine the predetermined value #5003 depending on whether or not the application of repetitive transmission to the message 3 PUSCH is requested. For example, a third parameter and a fourth parameter may be provided by the RRC layer. Here, when the application of repetitive transmission to the message 3 PUSCH is requested, the medium access control layer processing unit 15 may determine the predetermined value #5003 based on the value indicated by the third parameter. Furthermore, when the application of repetitive transmission to the message 3 PUSCH is not requested, the medium access control layer processing unit 15 may determine the predetermined value #5003 based on the value indicated by the fourth parameter.

[0209] If the random access response has been successfully received, the media access control layer processing unit 15 may process an uplink grant (random access response grant) included in the random access response. In processing the uplink grant, the media access control layer processing unit 15 may instruct the physical layer processing unit 10 to transmit a message 3 PUSCH.

[0210] For example, if the random access response has been successfully received, the media access control layer processing unit 15 may proceed to process 5004. Here, process 5004 may include contention resolution processing.

[0211] For example, in the collision resolution process, a contention window may be initiated each time a message 3 PUSCH transmission occurs. During the duration of the contention window, the medium access control layer processing unit 15 may monitor the PDCCH.

[0212] For example, if a PDCCH detected during the duration of the contention window and the collision resolution identifier contained in a transport block contained in a PDSCH scheduled by that PDCCH is equal to the value of the collision resolution identifier transmitted in the message 3 PUSCH, the medium access control layer processing unit 15 may consider the collision resolution to be successfully completed.

[0213] For example, if the media access control layer processing unit 15 fails to detect a PDSCH containing a collision resolution identifier that indicates a value equal to the value of the collision resolution identifier transmitted in the message 3 PUSCH during the duration of the contention window, the media access control layer processing unit 15 may consider that the collision resolution has not been completed successfully. For example, if the contention window has expired, the media access control layer processing unit 15 may consider that the collision resolution has not been completed successfully.

[0214] For example, if collision resolution is not completed successfully, the media access control layer processing unit 15 may increment a preamble transmission counter.

[0215] If the media access control layer processing unit 15 selects the two-step random access procedure in decision 5001, the media access control layer processing unit 15 may perform a random access resource selection process 5005. Here, in the random access resource selection process 5005, a random access preamble group may be selected.

[0216] In the random access resource selection process 5005, the media access control layer processing unit 15 may perform a decision 5005. Here, in the decision 5005, the media access control layer processing unit 15 may perform one or both of a decision regarding the strength of the downlink signal and a decision regarding the size of the uplink signal.

[0217] For example, the determination of downlink signal strength in decision 5005 may be made based on comparing a path loss value measured based on a certain physical signal with threshold value #5005a. Here, threshold value #5005a may be a threshold determined based on one or more parameters. For example, the one or more parameters in decision 5005 may be parameters used for uplink transmit power control. For example, threshold value #5005a may be determined based on a serving cell configured maximum transmit power PCMAX for which the random access procedure is performed, a target received power of the random access preamble msgA-preambleReceivedTargetPower, an offset value msgA-DeltaPreamble between the target received power of the message A PUSCH and the target received power of the random access preamble, and an offset value messagePowerOffsetGroupB for decision 5005. For example, threshold value #5005a may be determined by calculating PCMAX - msgA-preambleReceivedTargetPower - msgA-DeltaPreamble - messagePowerOffsetGroupB.

[0218] For example, the target received power of the random access preamble msgA-preambleReceivedTargetPower may be provided by the RRC layer, and the offset value msgA-DeltaPreamble between the target received power of the message A PUSCH and the target received power of the random access preamble may be provided by the RRC layer.

[0219] For example, the determination regarding the size of the uplink data in decision 5005 may be made based on comparing the size of the uplink data with a threshold #5005b. For example, the uplink data in decision 5005 may be the payload of a potential Message A PUSCH. For example, the payload of a potential Message A PUSCH may be a transport block placed in a Message A PUSCH expected to be transmitted in a random access procedure. Also, the payload of a potential Message A PUSCH may be a transport block placed in a Message A PUSCH expected to be transmitted in a random access procedure. The payload of the USCH may be one or both of a MAC SDU and a MAC subheader multiplexed into a transport block placed in a message A PUSCH expected to be transmitted in the random access procedure. Note that, at the time when the medium access control layer processing unit 15 performs decision 5005, the message A PUSCH may not yet be transmitted, so the decision is made based on the payload of the “potential” message A PUSCH.

[0220] For example, the determination 5005 may be based on one or both of the truth or falsity of the proposition 5005a and the truth or falsity of the proposition 5005b. For example, the medium access control layer processing unit 15 may select the random access preamble group A based on the determination that the proposition 5005a is true. Alternatively, the medium access control layer processing unit 15 may select the random access preamble group A based on the determination that the proposition 5005b is true. Alternatively, the medium access control layer processing unit 15 may select the random access preamble group B based on the determination that the proposition 5005a is false and the determination that the proposition 5005b is false.

[0221] For example, proposition 5005a may be that the size of uplink data is greater than threshold value #5005b and the path loss value is less than threshold value #5005a. Alternatively, proposition 5005a may be that the size of uplink data is not less than threshold value #5005b and the path loss value is less than threshold value #5005a. Alternatively, proposition 5005a may be that the size of uplink data is greater than threshold value #5005b and the path loss value is not greater than threshold value #5005a. Alternatively, proposition 5005a may be that the size of uplink data is not less than threshold value #5005b and the path loss value is not greater than threshold value #5005a.

[0222] For example, proposition 5005b may be that a random access procedure is initiated for CCCH and the size of uplink data is greater than threshold #5005b, or that a random access procedure is initiated for CCCH and the size of uplink data is not less than threshold #5005b.

[0223] In contention-based two-step random access, the media access control layer processing unit 15 may perform decision 5005. On the other hand, in non-contention-based two-step random access, the media access control layer processing unit 15 may not perform decision 5005. Here, in non-contention-based two-step random access, if decision 5005 is not performed, the media access control layer processing unit 15 may proceed to step 5006 after performing decision 5001.

[0224] After performing step 5005, the media access control layer processing unit 15 may perform step 5006. Here, step 5006 may include a process for transmitting message A and a process for receiving message B.

[0225] Here, message A is a name that includes the random access preamble and the message A PUSCH. That is, the transmission process of message A may include the transmission process of the random access preamble and the transmission process of the message A PUSCH.

[0226] Furthermore, the reception process of message B may be a process in which the media access control layer processing unit 15 monitors the PDCCH for a predetermined period of time. Here, the predetermined period of time is also called a message B window.

[0227] For example, the media access control layer processing unit 15 may start the message B window at the first PDCCH monitoring occasion after the end of the transmission of the random access preamble, where a parameter (msgB-ResponseWindow) determining the duration of the message B window may be provided by the RRC layer.

[0228] For example, if a message B including a first data unit is received during the duration of the message B window and a random access response including a field indicating the index of the selected random access preamble is received, the media access control layer processing unit 15 may consider that reception of the random access response has been successfully completed. If reception of the random access response has been successfully completed, the media access control layer processing unit 15 may proceed to operation 5004.

[0229] Here, the data unit may be in a format or form of data that is recognized by the MAC layer.

[0230] For example, if message B including a second data unit different from the first data unit is received during the duration of the message B window and the collision resolution identifier included in the second data unit is equal to the value of the collision resolution identifier transmitted in the message A PUSCH, the media access control layer processing unit 15 may determine that reception of message B has been successfully completed. If reception of message B has been successfully completed, the media access control layer processing unit 15 may determine that reception of the random access response has been successfully completed. Also, if reception of message B has been successfully completed, the media access control layer processing unit 15 may determine that the random access procedure has been successfully completed.

[0231] If the message B window expires and the reception of the random access response is not completed successfully, the media access control layer processing unit 15 may increment the preamble transmission counter. If the value of the preamble transmission counter reaches a predetermined value #5006, the media access control layer processing unit 15 may change "RA_TYPE" to "4STEP_RA". Also, if the value of the preamble transmission counter reaches the predetermined value #5006, the media access control layer processing unit 15 may proceed to process 5002.

[0232] When "RA_TYPE" is changed from "2STEP_RA" to "4STEP_RA" in the random access procedure, the medium access control layer processing unit 15 may perform a random access resource selection process 5002X instead of the random access resource selection process 5002. Here, the random access resource selection process 5002X may select one or both of a random access preamble group and a PRACH resource group.

[0233] In the random access resource selection process 5002X, the media access control layer processing unit 15 may perform decision 5002X. Here, in decision 5002X, the media access control layer processing unit 15 may perform one or both of a decision regarding downlink signal strength and a decision regarding selection of a random access preamble group. For example, the decision regarding downlink signal strength in decision 5002X may be made based on comparing the RSRP value of a downlink path loss reference with a predetermined threshold #5002X. Here, the downlink path loss reference may be a physical signal used to determine a path loss estimation value used in uplink power control. Alternatively, the downlink path loss reference may be an SS / PBCH block selected in the random access procedure.

[0234] For example, regarding the selection of the random access preamble group in decision 5002X, In this determination, the media access control layer processing unit 15 may determine whether a random access preamble group has already been selected. For example, in determination 5002X, it may be determined whether a random access preamble group has already been selected in a two-step random access performed prior to determination 5002X.

[0235] For example, if the RSRP value of the downlink path loss reference is greater than a predetermined threshold #5002X and a random access preamble group has not yet been selected, the media access control layer processing unit 15 may perform process 5012X. Alternatively, if the RSRP value of the downlink path loss reference is not less than the predetermined threshold #5002X and a random access preamble group has not yet been selected, the media access control layer processing unit 15 may perform process 5012X. Alternatively, if the RSRP value of the downlink path loss reference is greater than the predetermined threshold #5002X and a random access preamble group has already been selected, the media access control layer processing unit 15 may perform process 5022X. Alternatively, if the RSRP value of the downlink path loss reference is not less than the predetermined threshold #5002X and a random access preamble group has already been selected, the media access control layer processing unit 15 may perform process 5022X. Furthermore, if the RSRP value of the downlink path loss reference is smaller than the predetermined threshold #5002X and a random access preamble group has not yet been selected, the media access control layer processing unit 15 may perform processing 5032X. If the RSRP value of the downlink path loss reference is not greater than the predetermined threshold #5002X and a random access preamble group has not yet been selected, the media access control layer processing unit 15 may perform processing 5032X. If the RSRP value of the downlink path loss reference is smaller than the predetermined threshold #5002X and a random access preamble group has already been selected, the media access control layer processing unit 15 may perform processing 5042X. If the RSRP value of the downlink path loss reference is not greater than the predetermined threshold #5002X and a random access preamble group has already been selected, the media access control layer processing unit 15 may perform processing 5042X.

[0236] For example, in the random access resource selection process 5012X, one or both of a determination regarding random access preamble group B configuration and a determination regarding the size of the payload of message A may be performed. Here, in the determination regarding random access preamble group B configuration in the random access resource selection process 5012X, the medium access control layer processing unit 15 may determine whether or not random access preamble group B is configured for the second PRACH resource group. Furthermore, the determination regarding the size of the payload of message A in the random access resource selection process 5012X may be made based on a comparison between the size of the payload of message A and a threshold value 5012X. For example, the size of the payload may be the size of the transport block of the payload.

[0237] For example, in random access resource selection process X, the medium access control layer processing unit 15 may select random access preamble group B based on the fact that proposition 5012Xa is true and proposition 5012Xb is true. Also, in random access resource selection process 5012X, the medium access control layer processing unit 15 may select random access preamble group A based on the fact that proposition 5012Xa is false. Also, in random access resource selection process 5012X, the medium access control layer processing unit 15 may select random access preamble group A based on the fact that proposition 5012Xb is false.

[0238] For example, proposition 5012Xa may be that random access preamble group B is configured for the second PRACH resource group.

[0239] Proposition 5012Xb may also be that the size of the transport block of the payload of message A corresponds to the size of the transport block of the payload of message A related to random access preamble group B. Here, the fact that the size of the transport block of the payload of message A corresponds to the size of the transport block of the payload of message A related to random access preamble group B may mean that the size of the transport block of the payload of message A is larger than threshold value #5005b. The fact that the size of the transport block of the payload of message A corresponds to the size of the transport block of the payload of message A related to random access preamble group B may mean that the size of the transport block of the payload of message A is not smaller than threshold value #5005b. The fact that the size of the transport block of the payload of message A corresponds to the size of the transport block of the payload of message A related to random access preamble group B may mean that the size of the transport block of the payload of message A is larger than threshold value #6002b. Furthermore, the size of the transport block of the payload of message A corresponding to the size of the transport block of the payload of message A for random access preamble group B may be such that the size of the transport block of the payload of message A is not smaller than threshold #6002b.

[0240] For example, in the random access resource selection process 5022X, the media access control layer processing unit 15 may select the same random access preamble group as the already selected random access preamble group.

[0241] 7 is a diagram illustrating an example of a random access resource selection process 5032X performed by the media access control layer processing unit 15 according to one aspect of the present embodiment. First, in the random access resource selection process 5032X, the media access control layer processing unit 15 may perform decision 7001. Here, decision 7001 may be a decision regarding random access preamble group B configuration. For example, in decision 7001, the media access control layer processing unit 15 may proceed to decision 7005 based on the fact that random access preamble group B is not configured for the first PRACH resource group. Alternatively, in decision 7001, the media access control layer processing unit 15 may proceed to decision 7002 based on the fact that random access preamble group B is configured for the first PRACH resource group.

[0242] For example, the media access control layer processing unit 15 may determine whether the proposition 5012Xb is true or false in decision 7002. For example, the media access control layer processing unit 15 may proceed to operation 7004 based on the fact that the proposition 5012Xb is true in decision 7002. Alternatively, the media access control layer processing unit 15 may proceed to operation 7003 based on the fact that the proposition 5012Xb is false in decision 7002.

[0243] In process 7003, the media access control layer processing unit 15 may select random access preamble group A. Also, in process 7003, the media access control layer processing unit 15 may determine not to request application of repeated transmission to the message 3 PUSCH.

[0244] In process 7004, the media access control layer processing unit 15 may select random access preamble group B. Also, in process 7004, the media access control layer processing unit 15 may determine not to request application of repeated transmission to the message 3 PUSCH.

[0245] For example, the media access control layer processing unit 15 may determine whether the proposition 5012Xb is true or false in decision 7005. For example, the media access control layer processing unit 15 may proceed to operation 7006 based on the fact that the proposition 5012Xb is true in decision 7005. Alternatively, the media access control layer processing unit 15 may proceed to operation 7007 based on the fact that the proposition 5012Xb is false in decision 7005.

[0246] In process 7006, the media access control layer processing unit 15 may select random access preamble group A. Also, in process 7006, the media access control layer processing unit 15 may determine to request application of repeated transmission to the message 3 PUSCH.

[0247] In process 7007, the media access control layer processing unit 15 may select random access preamble group B. Also, in process 7007, the media access control layer processing unit 15 may determine not to request application of repeated transmission to the message 3 PUSCH.

[0248] For example, whether or not repetition is requested for the message 3 PUSCH may be determined based on one or both of the size of the transport block of the payload of message A and whether or not random access preamble group B is configured for the first PRACH resource group.

[0249] For example, in process 5042X, a determination regarding configuration of random access preamble group B may be performed. For example, in process 5042X, the medium access control layer processing unit 15 may determine not to request application of repeat transmission to the message 3 PUSCH based on the fact that random access preamble group B is not configured for the first PRACH resource group. Furthermore, in process 5042X, the medium access control layer processing unit 15 may determine to request application of repeat transmission to the message 3 PUSCH based on the fact that random access preamble group B is configured for the first PRACH resource group.

[0250] 8 is a diagram illustrating an example of a random access procedure performed in the media access control layer processing unit 15 according to one aspect of the present embodiment. In the random access procedure illustrated in FIG. 8, the media access control layer processing unit 15 may first perform decision 8001. Here, in decision 8001, a type of random access procedure may be determined. Furthermore, the type of random access procedure may be any of a four-step random access procedure without requesting application of repetitive transmission to the message 3 PUSCH, a four-step random access procedure with requesting application of repetitive transmission to the message 3 PUSCH, and a two-step random access procedure. That is, in decision 8001, any of a four-step random access procedure without requesting application of repetitive transmission to the message 3 PUSCH, a four-step random access procedure with requesting application of repetitive transmission to the message 3 PUSCH, and a two-step random access procedure may be selected.

[0251] Here, "RA_TYPE" is a variable in which a value corresponding to the random access procedure selected in decision 8001 is stored. For example, the value corresponding to a 4-step random access procedure that does not involve a request for applying repetitive transmission to the message 3 PUSCH may be "4STEP_RA", and the value corresponding to a 2-step random access procedure may be "2STEP_RA". A value corresponding to the four-step random access procedure with a request to apply repeat transmission may be "4STEP_RAreq." For example, if in decision 8001 the media access control layer processing unit 15 selects the four-step random access procedure with a request to apply repeat transmission for message 3 PUSCH, "4STEP_RAreq" may be input to the variable "RA_TYPE."

[0252] In decision 8001, a determination regarding the strength of the uplink signal may be made. Here, the determination regarding the strength of the downlink signal in decision 8001 may be made based on one or both of comparing the RSRP value of the downlink path loss reference with a predetermined threshold #5001 and comparing the RSRP value of the downlink path loss reference with a predetermined threshold #8001. For example, if the RSRP value of the downlink path loss reference is greater than the predetermined threshold #5001, the media access control layer processing unit 15 may select a two-step random access procedure. Alternatively, if the RSRP value of the downlink path loss reference is less than the predetermined threshold #8001, the media access control layer processing unit 15 may select a four-step random access procedure involving requesting the application of repeated transmission for message 3 PUSCH. Furthermore, if the RSRP value of the downlink path loss reference is smaller than predetermined threshold #5001 and greater than predetermined threshold #8001, the media access control layer processing unit 15 may select a 4-step random access procedure that does not involve a request for repeat transmission for the message 3 PUSCH. Furthermore, if the RSRP value of the downlink path loss reference is equal to predetermined threshold #5001, the media access control layer processing unit 15 may select a 2-step random access procedure or a 4-step random access procedure that does not involve a request for repeat transmission for the message 3 PUSCH. Furthermore, if the RSRP value of the downlink path loss reference is equal to predetermined threshold #8001, the media access control layer processing unit 15 may select either a 4-step random access procedure that does not involve a request for repeat transmission for the message 3 PUSCH or a 4-step random access procedure that involves a request for repeat transmission for the message 3 PUSCH.

[0253] If the media access control layer processing unit 15 selects the four-step random access procedure without requesting the application of repetitive transmission for the message 3 PUSCH in decision 8001, the media access control layer processing unit 15 may proceed to process 8002. Here, the media access control layer processing unit 15 may proceed to process 8002 and select a second PRACH resource group.

[0254] In process 8002, the media access control layer processing unit 15 may select a random access preamble group. For example, in process 8002, the media access control layer processing unit 15 may select random access preamble group B based on a determination that proposition 6002a is true. Also, in process 8002, the media access control layer processing unit 15 may select random access preamble group B based on a determination that proposition 6002b is true. Also, in process 8002, the media access control layer processing unit 15 may select random access preamble group A based on a determination that proposition 6002a is false and a determination that proposition 6002b is false.

[0255] Since process 8003 is the same as process 5003, a detailed description thereof will be omitted.

[0256] For example, if the random access response is successfully received in step 8003, the media access control layer processing unit 15 may proceed to step 8004. Here, step 8004 may include a collision resolution process.

[0257] For example, in the collision resolution process, a contention window may be initiated each time a message 3 PUSCH transmission occurs. During the duration of the contention window, the medium access control layer processing unit 15 may monitor the PDCCH.

[0258] For example, if a PDCCH detected during the duration of the contention window and the collision resolution identifier contained in a transport block contained in a PDSCH scheduled by that PDCCH is equal to the value of the collision resolution identifier transmitted in the message 3 PUSCH, the medium access control layer processing unit 15 may consider the collision resolution to be successfully completed.

[0259] For example, if the media access control layer processing unit 15 fails to detect a PDSCH containing a collision resolution identifier that indicates a value equal to the value of the collision resolution identifier transmitted in the message 3 PUSCH during the duration of the contention window, the media access control layer processing unit 15 may consider that the collision resolution has not been completed successfully. For example, if the contention window has expired, the media access control layer processing unit 15 may consider that the collision resolution has not been completed successfully.

[0260] For example, if collision resolution is not completed successfully, the media access control layer processing unit 15 may increment a preamble transmission counter.

[0261] For example, if collision resolution is not completed successfully, the media access control layer processing unit 15 may increment a request counter. If the request counter reaches a predetermined value #8004, the media access control layer processing unit 15 may recognize that the four-step random access procedure without requesting the application of repeat transmission for message 3 PUSCH has failed.

[0262] For example, if the media access control layer processing unit 15 recognizes that a four-step random access procedure without requesting the application of repeat transmission for message 3 PUSCH has failed, the media access control layer processing unit 15 may proceed to process 8005.

[0263] For example, whether the media access control layer processing unit 15 proceeds to step 8005 depends on message 3 The determination may be based on some or all of the following: whether it has been recognized that the 4-step random access procedure without requesting the application of repetitive transmission to the PUSCH has failed; whether the random access preamble group B has been configured for the first PRACH resource group; and whether the random access preamble group B has already been selected. Here, the media access control layer processing unit 15 may proceed to process 8005 and change “RA_TYPE” from “4STEP_RA” to “4STEP_RAreq”.

[0264] For example, when the media access control layer processing unit 15 recognizes that the four-step random access procedure without requesting the application of repetitive transmission for the message 3 PUSCH has failed, the random access preamble group B has been configured for the first PRACH resource group, and the random access preamble group B has been selected in process 8002, the media access control layer processing unit 15 may proceed to process 8005. Also, when the media access control layer processing unit 15 recognizes that the four-step random access procedure without requesting the application of repetitive transmission for the message 3 PUSCH has failed, the random access preamble group B has been configured for the first PRACH resource group, and the random access preamble group A ... If the media access control layer processing unit 15 recognizes that the four-step random access procedure without a request for the application of repetitive transmission has failed, the random access preamble group B has not been configured for the first PRACH resource group, and the random access preamble group B has been selected in process 8002, the media access control layer processing unit 15 does not need to proceed to process 8005. Alternatively, if the media access control layer processing unit 15 recognizes that the four-step random access procedure without a request for the application of repetitive transmission for the message 3 PUSCH has failed, the random access preamble group B has not been configured for the first PRACH resource group, and the random access preamble group A has been selected in process 8002, the media access control layer processing unit 15 may proceed to process 8005.

[0265] Here, the predetermined value #8004 may be determined based on parameters provided by the RRC layer.

[0266] If the media access control layer processing unit 15 selects the four-step random access procedure involving requesting application of repetitive transmission to the message 3 PUSCH in decision 8001, the media access control layer processing unit 15 may proceed to operation 8005. Here, selection of a random access preamble group may be performed in operation 8005. Here, the media access control layer processing unit 15 may proceed to operation 8005 and select a first PRACH resource group.

[0267] In operation 8005, the media access control layer processing unit 15 may select a random access preamble group. For example, if random access preamble group B is configured for the first PRACH resource group, in operation 8005, the random access preamble group may be selected based on a determination regarding the size of uplink data. Here, in operation 8005, the determination regarding the size of uplink data may be based on comparing the size of the uplink data with threshold value #8005a. For example, in operation 8005, the uplink data may be the payload of a potential message 3 PUSCH.

[0268] For example, in process 8005, it may be determined whether proposition 8005 is true or false. For example, proposition 8005 may be that a random access procedure is initiated for CCCH and the size of uplink data is greater than threshold value #8005. Alternatively, proposition 8005 may be that a random access procedure is initiated for CCCH and the size of uplink data is not smaller than threshold value #8005.

[0269] For example, if proposition 8005 is determined to be true, the media access control layer processing unit 15 may select random access preamble group B. Alternatively, if proposition 8005 is determined to be false, the media access control layer processing unit 15 may select random access preamble group A.

[0270] For example, if random access preamble group B is configured for the first PRACH resource group, in operation 8005, the random access preamble group may be selected based on one or both of a determination of downlink signal strength and a determination regarding the size of uplink data. For example, the determination of downlink signal strength in operation 8005 may be based on comparing a path loss value measured based on a certain physical signal with threshold value #8005a. Here, threshold value #8005a may be a threshold determined based on one or more parameters. For example, the one or more parameters in operation 8005 may be parameters used for uplink transmission power control. For example, threshold value #8005a may be a value determined based on the random access preamble group B when the random access preamble group B is configured for the first PRACH resource group. The threshold value #8005a may be determined based on the maximum transmit power PCMAX configured by the serving cell in which the access procedure is performed, the target received power of the random access preamble preambleReceivedTargetPowerReq, the offset value msg3-DeltaPreambleReq between the target received power of the message 3 PUSCH and the target received power of the random access preamble, and the offset value messagePowerOffsetGroupBReq for decision 8005. For example, threshold value #8005a may be determined by calculating PCMAX-preambleReceivedTargetPowerReq-msg3-DeltaPreambleReq-messagePowerOffsetGroupBReq.

[0271] For example, the target received power of the random access preamble, preambleReceivedTargetPowerReq, may be provided by the RRC layer. Also, the offset value msg3-DeltaPreambleReq between the target received power of the message 3 PUSCH and the target received power of the random access preamble may be provided by the RRC layer. Also, the offset value messagePowerOffsetGroupBReq may be provided by the RRC layer.

[0272] For example, determination 8005 may be a determination based on one or both of the truth or falsity of proposition 8005 and the truth or falsity of proposition 8005a. For example, the medium access control layer processing unit 15 may select random access preamble group B based on the determination that proposition 8005 is true. Alternatively, the medium access control layer processing unit 15 may select random access preamble group B based on the determination that proposition 8005a is true. Alternatively, the medium access control layer processing unit 15 may select random access preamble group A based on the determination that proposition 8005 is false and the determination that proposition 8005a is false.

[0273] For example, proposition 8005a may be that the size of uplink data is greater than threshold value #8005 and the path loss value is less than threshold value #8005a. Alternatively, proposition 8005a may be that the size of uplink data is not less than threshold value #8005 and the path loss value is less than threshold value #8005a. Alternatively, proposition 8005a may be that the size of uplink data is greater than threshold value #8005 and the path loss value is not greater than threshold value #8005a. Alternatively, proposition 8005a may be that the size of uplink data is not less than threshold value #8005 and the path loss value is not greater than threshold value #8005a.

[0274] The physical signal used in determining the downlink physical signal strength in process 8005 may be one SS / PBCH block selected from multiple SS / PBCH blocks. Here, the multiple SS / PBCH blocks may be multiple SS / PBCH blocks configured for the serving cell. The media access control layer processing unit 15 may select one SS / PBCH block from the multiple SS / PBCH blocks based on a comparison between the RSRP value for at least one SS / PBCH block and threshold value #8005x. For example, if the RSRP value for at least one SS / PBCH block is greater than threshold value #8005x, the media access control layer processing unit 15 may select one SS / PBCH block from among the SS / PBCH blocks whose RSRP values ​​are greater than threshold value #8005x. Alternatively, if the RSRP values ​​for all SS / PBCH blocks are less than threshold value #8005x, the media access control layer processing unit 15 may select one SS / PBCH block from the multiple SS / PBCH blocks.

[0275] For example, threshold #8005x may be provided by the RRC layer.

[0276] Since process 8006 is the same as process 5003, a detailed description thereof will be omitted.

[0277] For example, the media access control layer processing unit 15 performs the random access level control in step 8006. If the response has been successfully received, the process may proceed to operation 8007, which may include a collision resolution process.

[0278] For example, in the collision resolution process, a contention window may be initiated each time a message 3 PUSCH transmission occurs. During the duration of the contention window, the medium access control layer processing unit 15 may monitor the PDCCH.

[0279] For example, when repeated transmission is applied to the message 3 PUSCH, a contention window may be started for each repeated transmission of the message 3 PUSCH. Alternatively, when repeated transmission is applied to the message 3 PUSCH, a contention window may be started for the first repeated transmission of the message 3 PUSCH, and a contention window may not be started for repeated transmissions of the message 3 PUSCH other than the first.

[0280] For example, if a PDCCH detected during the duration of the contention window and the collision resolution identifier contained in a transport block contained in a PDSCH scheduled by that PDCCH is equal to the value of the collision resolution identifier transmitted in the message 3 PUSCH, the medium access control layer processing unit 15 may consider the collision resolution to be successfully completed.

[0281] For example, if the media access control layer processing unit 15 fails to detect a PDSCH containing a collision resolution identifier that indicates a value equal to the value of the collision resolution identifier transmitted in the message 3 PUSCH during the duration of the contention window, the media access control layer processing unit 15 may consider that the collision resolution has not been completed successfully. For example, if the contention window has expired, the media access control layer processing unit 15 may consider that the collision resolution has not been completed successfully.

[0282] For example, if collision resolution is not completed successfully, the media access control layer processing unit 15 may increment a preamble transmission counter.

[0283] For example, if collision resolution is not completed successfully, the media access control layer processing unit 15 may increment a request counter. If the request counter reaches a predetermined value #8007, the media access control layer processing unit 15 may recognize that the four-step random access procedure involving a request to apply repeat transmission to the message 3 PUSCH has failed. For example, if the media access control layer processing unit 15 recognizes that the four-step random access procedure involving a request to apply repeat transmission to the message 3 PUSCH has failed, the media access control layer processing unit 15 may notify a higher layer of the random access problem.

[0284] Here, the predetermined value #8007 may be determined based on parameters provided by the RRC layer.

[0285] Since process 8008 is the same as process 5005, a detailed description thereof will be omitted.

[0286] After performing step 8008, the media access control layer processing unit 15 may perform step 8009. Here, step 8009 may include a process for transmitting message A and a process for receiving message B.

[0287] Furthermore, the reception process of message B may be a process in which the media access control layer processing unit 15 monitors the PDCCH for a predetermined period of time. Here, the predetermined period of time is also called a message B window.

[0288] For example, the media access control layer processing unit 15 may start the message B window at the first PDCCH monitoring opportunity after the end of the transmission of the random access preamble.

[0289] For example, if message B including a first data unit is received during the duration of the message B window and a random access response including a field indicating the index of the selected random access preamble is received, the media access control layer processing unit 15 may consider that reception of the random access response has been successfully completed. If reception of the random access response has been successfully completed, the media access control layer processing unit 15 may proceed to operation 8004 or operation 8007. Here, the random access response may include information instructing the media access control layer processing unit 15 whether to proceed to operation 8004 or operation 8007. The media access control layer processing unit 15 may select either operation 8004 or operation 8007 based on the information included in the random access response.

[0290] Here, the data unit may be in a format or form of data that is recognized by the MAC layer.

[0291] For example, if message B including a second data unit different from the first data unit is received during the duration of the message B window and the collision resolution identifier included in the second data unit is equal to the value of the collision resolution identifier transmitted in the message A PUSCH, the media access control layer processing unit 15 may determine that reception of message B has been successfully completed. If reception of message B has been successfully completed, the media access control layer processing unit 15 may determine that reception of the random access response has been successfully completed. Also, if reception of message B has been successfully completed, the media access control layer processing unit 15 may determine that the random access procedure has been successfully completed.

[0292] If the message B window expires and the reception of the random access response is not completed successfully, the media access control layer processing unit 15 may increment the preamble transmission counter. If the value of the preamble transmission counter reaches a predetermined value #5006, the media access control layer processing unit 15 may change "RA_TYPE" to "4STEP_RA" or "4STEP_RAreq". Also, if the value of the preamble transmission counter reaches the predetermined value #5006, the media access control layer processing unit 15 may proceed to process 8002 or process 8005.

[0293] Whether the media access control layer processing unit 15 changes "RA_TYPE" to "4STEP_RA" or "4STEP_RAreq" when the value of the preamble transmission counter reaches a predetermined value #5006 may be determined based on some or all of the following: whether the value of the preamble transmission counter has reached the predetermined value #5006; whether random access preamble group B has been set for the first PRACH resource group; whether random access preamble group B has already been selected; and the determination of the uplink signal strength.

[0294] FIG. 9 is a diagram showing an example of an “RA_TYPE” selection procedure performed by the media access control layer processing unit 15 according to one aspect of this embodiment. First, the media access control layer processing unit 15 may proceed to decision 9001. In decision 9001, a determination regarding the strength of the downlink signal may be made. Here, the determination regarding the strength of the downlink signal in decision 9001 may be made based at least on comparing the RSRP value of the downlink path loss reference with a predetermined threshold #8001. For example, if the RSRP value of the downlink path loss reference is smaller than the predetermined threshold #8001, the media access control layer processing unit 15 may proceed to decision 9002. Alternatively, if the RSRP value of the downlink path loss reference is greater than the predetermined threshold #8001, the media access control layer processing unit 15 may proceed to process 8002. Alternatively, if the RSRP value of the downlink path loss reference is equal to the predetermined threshold #8001, the media access control layer processing unit 15 may proceed to process 8002 or decision 9002.

[0295] In decision 9002, the media access control layer processing unit 15 may determine whether or not random access preamble group B is configured for the first PRACH resource group. For example, if random access preamble group B is not configured for the first PRACH resource group, the media access control layer processing unit 15 may proceed to decision 9003. Alternatively, if random access preamble group B is configured for the first PRACH resource group, the media access control layer processing unit 15 may proceed to process 8005.

[0296] In decision 9003, the media access control layer processing unit 15 may determine whether a random access preamble group has already been selected. If random access preamble group A has already been selected, the media access control layer processing unit 15 may proceed to operation 8005. If random access preamble group B has already been selected, the media access control layer processing unit 15 may proceed to operation 8002. If a random access preamble group has not yet been selected and the size of the transport block of the payload of message A does not correspond to the size of the transport block of the payload of message A for random access preamble group B, the media access control layer processing unit 15 may proceed to operation 8005. If a random access preamble group has not yet been selected and the size of the transport block of the payload of message A corresponds to the size of the transport block of the payload of message A for random access preamble group B, the media access control layer processing unit 15 may proceed to operation 8002.

[0297] Various aspects of the device according to one aspect of this embodiment will be described below.

[0298] (1) To achieve the above object, aspects of the present invention provide the following measures: That is, a first aspect of the present invention is a terminal device including a medium access control layer processing unit and a physical layer processing unit, wherein the medium access control layer processing unit determines whether a random access preamble group B is configured for a PRACH resource group used for a random access procedure that requests application of repetitive transmission for a message 3 PUSCH, and the medium access control layer processing unit determines whether to request application of repetitive transmission for message 3 based on the determination, and instructs the physical layer processing unit to transmit a PRACH.

[0299] The programs operating in the base station device 3 and terminal device 1 according to the present invention may be programs (programs that cause a computer to function) that control a CPU (Central Processing Unit) or the like so as to realize the functions of the above-described embodiments according to the present invention. Information handled by these devices is temporarily stored in RAM (Random Access Memory) during processing, and then stored in various ROMs such as Flash ROM (Read Only Memory) or HDD (Hard Disk Drive), and is read, modified, and written by the CPU as necessary.

[0300] Note that the terminal device 1 and part of the base station device 3 in the above-described embodiment may be realized by a computer. In this case, a program for realizing this control function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to realize the function.

[0301] The "computer system" referred to here is a computer system built into the terminal device 1 or the base station device 3. It refers to a computer system that is installed on a computer system, including hardware such as the OS and peripheral devices. Also, "computer-readable recording media" refers to portable media such as flexible disks, optical magnetic disks, ROMs, CD-ROMs, and storage devices such as hard disks built into computer systems.

[0302] Furthermore, the term "computer-readable recording medium" may include a medium that dynamically stores a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, or a medium that stores a program for a fixed period of time, such as volatile memory within a computer system that serves as a server or client in such a case. The program may also be one that realizes part of the above-mentioned functions, or one that can realize the above-mentioned functions in combination with a program already stored in the computer system.

[0303] Furthermore, the base station device 3 in the above-described embodiment can also be realized as a collection (device group) consisting of multiple devices. Each of the devices constituting the device group may have some or all of the functions or functional blocks of the base station device 3 according to the above-described embodiment. It is sufficient for the device group to have all of the functions or functional blocks of the base station device 3. Furthermore, the terminal device 1 according to the above-described embodiment can also communicate with the base station device as a collection.

[0304] Furthermore, the base station device 3 in the above-described embodiments may be an EUTRAN (Evolved Universal Terrestrial Radio Access Network) and / or an NG-RAN (NextGen RAN, NR RAN). Furthermore, the base station device 3 in the above-described embodiments may have some or all of the functions of an upper node for an eNodeB and / or a gNB.

[0305] Furthermore, some or all of the terminal device 1 and base station device 3 in the above-described embodiments may be realized as an LSI, which is typically an integrated circuit, or as a chipset. Each functional block of the terminal device 1 and base station device 3 may be individually formed into a chip, or some or all of them may be integrated into a chip. Furthermore, the integrated circuit method is not limited to LSI, and may be realized using a dedicated circuit or a general-purpose processor. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology, it is also possible to use an integrated circuit based on that technology.

[0306] Furthermore, in the above-described embodiment, a terminal device is described as an example of a communication device, but the present invention is not limited to this and can also be applied to terminal devices or communication devices such as stationary or non-movable electronic devices installed indoors or outdoors, for example, AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0307] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the invention. Furthermore, the present invention is susceptible to various modifications within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted with elements that achieve the same effect are also included. [Explanation of symbols]

[0308] 1(1A, 1B, 1C) Terminal equipment 3 Base station equipment 9. Wireless Communication Systems 10, 30 Physical layer control unit 10a, 30a Radio transmitter 10b, 30b Wireless receiver 11, 31 Antenna section 12, 32 RF section 13, 33 Baseband section 14, 34 Upper layer processing unit 15, 35 Medium access control layer processing unit 16, 36 Radio resource control layer processing unit 5001, 6001, 6002, 6005, 6007, 7001, 7002, 7005, 8001, 9001, 9002, 9003 Judgment 5002, 5003, 5004, 5005, 5006, 6003, 6004, 6006, 6008, 6009, 7003, 7004, 7006, 7007, 8002, 8003, 8004, 8005, 8006, 8007, 8008, 8009 Processing

Claims

1. a medium access control layer processing unit; a physical layer processing unit; Equipped with The medium access control layer processing unit configures a first PRACH resource group used for a random access procedure requesting application of repetitive transmission for a PUSCH in a message 3 and a second PRACH resource group used for not requesting application of the repetitive transmission to the PUSCH; selecting one of the first process and the second process based on comparing the RSRP value of the downlink path loss reference with a predetermined threshold; In the first process, the second PRACH resource group is selected; In the second process, a first determination is made as to whether a random access preamble group B is configured for the first PRACH resource group; selecting either a third process or a fourth process based on the first determination; In the third process, the first PRACH resource group is selected; In the fourth process, a second determination is made as to whether the random access preamble group B is selected; selecting either the first PRACH resource group or the second PRACH resource group based on the second determination; determining whether to request to apply the repeated transmission for the message 3 PUSCH based on the selected PRACH resource group; Instructing the physical layer processing unit to transmit a PRACH; Terminal device.

2. A communication method used in a terminal device, comprising: Message 3: Configure a first PRACH resource group to be used for a random access procedure requesting application of repetitive transmission for a PUSCH and a second PRACH resource group to be used for not requesting application of the repetitive transmission to the PUSCH; selecting one of the first process and the second process based on comparing the RSRP value of the downlink path loss reference with a predetermined threshold; In the first process, the second PRACH resource group is selected; In the second process, a first determination is made as to whether a random access preamble group B is configured for the first PRACH resource group; selecting either a third process or a fourth process based on the first determination; In the third process, the first PRACH resource group is selected; In the fourth process, a second determination is made as to whether the random access preamble group B is selected; selecting either the first PRACH resource group or the second PRACH resource group based on the second determination; determining whether to request repeated transmission for the message 3 based on the selected PRACH resource group; Instructing the transmission of PRACH; Communication method.

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