Patent Application
20250203578
This disclosure relates to a wireless communication system.
Sidelink (SL) communication is a communication scheme in which a direct link is established between User Equipments (UEs) and the UEs exchange voice and data directly with each other without intervention of a base station. SL communication is under consideration as a solution to the overhead of a base station caused by rapidly increasing data traffic. Vehicle-to-everything (V2X) refers to a communication technology through which a vehicle exchanges information with another vehicle, a pedestrian, an object having an infrastructure (or infra) established therein, and so on. The V2X may be divided into 4 types, such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). The V2X communication may be provided via a PC5 interface and/or Uu interface.
Meanwhile, as a wider range of communication devices require larger communication capacities, the need for mobile broadband communication that is more enhanced than the existing Radio Access Technology (RAT) is rising. Accordingly, discussions are made on services and user equipment (UE) that are sensitive to reliability and latency. And, a next generation radio access technology that is based on the enhanced mobile broadband communication, massive Machine Type Communication (MTC), Ultra-Reliable and Low Latency Communication (URLLC), and so on, may be referred to as a new radio access technology (RAT) or new radio (NR).
In an embodiment, provided is a method for performing wireless communication by a first device. The method may comprise: obtaining information related to a first resource set in which a channel access procedure is performed in a shared spectrum; performing channel sensing for the first resource set; detecting a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold; and changing the first resource set to a second resource set based on the detection of the consistent LBT failure.
In an embodiment, provided is a first device adapted to perform wireless communication. The first device may comprise: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause the first device to perform operations comprising: obtaining information related to a first resource set in which a channel access procedure is performed in a shared spectrum; performing channel sensing for the first resource set; detecting a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold; and changing the first resource set to a second resource set based on the detection of the consistent LBT failure.
In an embodiment, provided is a processing device adapted to control a first device. The processing device may comprise: at least one processor; and at least one memory connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause the first device to perform operations comprising: obtaining information related to a first resource set in which a channel access procedure is performed in a shared spectrum; performing channel sensing for the first resource set; detecting a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold; and changing the first resource set to a second resource set based on the detection of the consistent LBT failure.
In an embodiment, provided is a non-transitory computer-readable storage medium storing instructions. The instructions, when executed, may cause a first device to perform operations comprising: obtaining information related to a first resource set in which a channel access procedure is performed in a shared spectrum; performing channel sensing for the first resource set; detecting a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold; and changing the first resource set to a second resource set based on the detection of the consistent LBT failure.
In the present disclosure, “A or B” may mean “only A”, “only B” or “both A and B.” In other words, in the present disclosure, “A or B” may be interpreted as “A and/or B”. For example, in the present disclosure, “A, B, or C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, C”.
A slash (/) or comma used in the present disclosure may mean “and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B, or C”.
In the present disclosure, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in the present disclosure, the expression “at least one of A or B” or “at least one of A and/or B” may be interpreted as “at least one of A and B”.
In addition, in the present disclosure, “at least one of A, B, and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, and C”. In addition, “at least one of A, B, or C” or “at least one of A, B, and/or C” may mean “at least one of A, B, and C”.
In addition, a parenthesis used in the present disclosure may mean “for example”. Specifically, when indicated as “control information (PDCCH)”, it may mean that “PDCCH” is proposed as an example of the “control information”. In other words, the “control information” of the present disclosure is not limited to “PDCCH”, and “PDCCH” may be proposed as an example of the “control information”. In addition, when indicated as “control information (i.e., PDCCH)”, it may also mean that “PDCCH” is proposed as an example of the “control information”.
In the following description, ‘when, if, or in case of’ may be replaced with ‘based on’.
A technical feature described individually in one figure in the present disclosure may be individually implemented, or may be simultaneously implemented.
In the present disclosure, a higher layer parameter may be a parameter which is configured, pre-configured or pre-defined for a UE. For example, a base station or a network may transmit the higher layer parameter to the UE. For example, the higher layer parameter may be transmitted through radio resource control (RRC) signaling or medium access control (MAC) signaling.
The technology described below may be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and so on. The CDMA may be implemented with a radio technology, such as universal terrestrial radio access (UTRA) or CDMA-2000. The TDMA may be implemented with a radio technology, such as global system for mobile communications (GSM)/general packet ratio service (GPRS)/enhanced data rate for GSM evolution (EDGE). The OFDMA may be implemented with a radio technology, such as institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WIMAX), IEEE 802.20, evolved UTRA (E-UTRA), and so on. IEEE 802.16m is an evolved version of IEEE 802.16e and provides backward compatibility with a system based on the IEEE 802.16e. The UTRA is part of a universal mobile telecommunication system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of an evolved UMTS (E-UMTS) using the E-UTRA. The 3GPP LTE uses the OFDMA in a downlink and uses the SC-FDMA in an uplink. LTE-advanced (LTE-A) is an evolution of the LTE.
5G NR is a successive technology of LTE-A corresponding to a new Clean-slate type mobile communication system having the characteristics of high performance, low latency, high availability, and so on. 5G NR may use resources of all spectrum available for usage including low frequency bands of less than 1 GHz, middle frequency bands ranging from 1 GHZ to 10 GHz, high frequency (millimeter waves) of 24 GHz or more, and so on.
A 6G (wireless communication) system has purposes such as (i) very high data rate per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) decrease in energy consumption of battery-free IoT devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capacity. The vision of the 6G system may include four aspects such as intelligent connectivity, deep connectivity, holographic connectivity and ubiquitous connectivity, and the 6G system may satisfy the requirements shown in Table 1 below. That is, Table 1 shows the requirements of the 6G system.
The 6G system may have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine type communications (mMTC), AI integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.
The 6G system will have 50 times higher simultaneous wireless communication connectivity than a 5G wireless communication system. URLLC, which is the key feature of 5G, will become more important technology by providing end-to-end latency less than 1 ms in 6G communication. The 6G system may have much better volumetric spectrum efficiency unlike frequently used domain spectrum efficiency. The 6G system may provide advanced battery technology for energy harvesting and very long battery life and thus mobile devices may not need to be separately charged in the 6G system. In 6G, new network characteristics may be as follows.
In the new network characteristics of 6G, several general requirements may be as follows.
Core implementation technology of 6G system is described below.
For clarity in the description, 5G NR is mainly described, but the technical idea according to an embodiment of the present disclosure is not limited thereto. Various embodiments of the present disclosure can also be applied to 6G communication systems.
Referring to
The embodiment of
Layers of a radio interface protocol between the UE and the network can be classified into a first layer (layer 1, L1), a second layer (layer 2, L2), and a third layer (layer 3, L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system. Among them, a physical (PHY) layer belonging to the first layer provides an information transfer service by using a physical channel, and a radio resource control (RRC) layer belonging to the third layer serves to control a radio resource between the UE and the network. For this, the RRC layer exchanges an RRC message between the UE and the BS.
Referring to
Between different physical layers, i.e., a physical layer of a transmitter and a physical layer of a receiver, data are transferred through the physical channel. The physical channel is modulated using an orthogonal frequency division multiplexing (OFDM) scheme, and utilizes time and frequency as a radio resource.
The MAC layer provides services to a radio link control (RLC) layer, which is a higher layer of the MAC layer, via a logical channel. The MAC layer provides a function of mapping multiple logical channels to multiple transport channels. The MAC layer also provides a function of logical channel multiplexing by mapping multiple logical channels to a single transport channel. The MAC layer provides data transfer services over logical channels.
The RLC layer performs concatenation, segmentation, and reassembly of Radio Link Control Service Data Unit (RLC SDU). In order to ensure diverse quality of service (QoS) required by a radio bearer (RB), the RLC layer provides three types of operation modes, i.e., a transparent mode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM). An AM RLC provides error correction through an automatic repeat request (ARQ).
A radio resource control (RRC) layer is defined only in the control plane. The RRC layer serves to control the logical channel, the transport channel, and the physical channel in association with configuration, reconfiguration and release of RBs. The RB is a logical path provided by the first layer (i.e., the physical layer or the PHY layer) and the second layer (i.e., a MAC layer, an RLC layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer) for data delivery between the UE and the network.
Functions of a packet data convergence protocol (PDCP) layer in the user plane include user data delivery, header compression, and ciphering. Functions of a PDCP layer in the control plane include control-plane data delivery and ciphering/integrity protection.
A service data adaptation protocol (SDAP) layer is defined only in a user plane. The SDAP layer performs mapping between a Quality of Service (QOS) flow and a data radio bearer (DRB) and QoS flow ID (QFI) marking in both DL and UL packets.
The configuration of the RB implies a process for specifying a radio protocol layer and channel properties to provide a particular service and for determining respective detailed parameters and operations. The RB can be classified into two types, i.e., a signaling RB (SRB) and a data RB (DRB). The SRB is used as a path for transmitting an RRC message in the control plane. The DRB is used as a path for transmitting user data in the user plane.
When an RRC connection is established between an RRC layer of the UE and an RRC layer of the E-UTRAN, the UE is in an RRC_CONNECTED state, and, otherwise, the UE may be in an RRC_IDLE state. In case of the NR, an RRC_INACTIVE state is additionally defined, and a UE being in the RRC_INACTIVE state may maintain its connection with a core network whereas its connection with the BS is released.
Data is transmitted from the network to the UE through a downlink transport channel. Examples of the downlink transport channel include a broadcast channel (BCH) for transmitting system information and a downlink-shared channel (SCH) for transmitting user traffic or control messages. Traffic of downlink multicast or broadcast services or the control messages can be transmitted on the downlink-SCH or an additional downlink multicast channel (MCH). Data is transmitted from the UE to the network through an uplink transport channel. Examples of the uplink transport channel include a random access channel (RACH) for transmitting an initial control message and an uplink SCH for transmitting user traffic or control messages.
Examples of logical channels belonging to a higher channel of the transport channel and mapped onto the transport channels include a broadcast channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), a multicast traffic channel (MTCH), etc.
Referring to
In case of using a normal CP, each slot may include 14 symbols. In case of using an extended CP, each slot may include 12 symbols. Herein, a symbol may include an OFDM symbol (or CP-OFDM symbol) and a Single Carrier-FDMA (SC-FDMA) symbol (or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbol).
Table 2 shown below represents an example of a number of symbols per slot (Nslotsymb), a number slots per frame (Nframe,μslot), and a number of slots per subframe (Nsubframe,μslot) based on an SCS configuration (u), in a case where a normal CP or an extended CP is used.
In an NR system, OFDM (A) numerologies (e.g., SCS, CP length, and so on) between multiple cells being integrate to one UE may be differently configured. Accordingly, a (absolute time) duration (or section) of a time resource (e.g., subframe, slot or TTI) (collectively referred to as a time unit (TU) for simplicity) being configured of the same number of symbols may be differently configured in the integrated cells.
In the NR, multiple numerologies or SCSs for supporting diverse 5G services may be supported. For example, in case an SCS is 15 kHz, a wide area of the conventional cellular bands may be supported, and, in case an SCS is 30 kHz/60 kHz a dense-urban, lower latency, wider carrier bandwidth may be supported. In case the SCS is 60 kHz or higher, a bandwidth that is greater than 24.25 GHz may be used in order to overcome phase noise.
An NR frequency band may be defined as two different types of frequency ranges. The two different types of frequency ranges may be FR1 and FR2. The values of the frequency ranges may be changed (or varied), and, for example, the two different types of frequency ranges may be as shown below in Table 3. Among the frequency ranges that are used in an NR system, FR1 may mean a “sub 6 GHz range”, and FR2 may mean an “above 6 GHz range” and may also be referred to as a millimeter wave (mmW).
As described above, the values of the frequency ranges in the NR system may be changed (or varied). For example, as shown below in Table 4, FR1 may include a band within a range of 410 MHz to 7125 MHz. More specifically, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, and so on) and higher. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, and so on) and higher being included in FR1 mat include an unlicensed band. The unlicensed band may be used for diverse purposes, e.g., the unlicensed band for vehicle-specific communication (e.g., automated driving).
Referring to
A carrier includes a plurality of subcarriers in a frequency domain. A Resource Block (RB) may be defined as a plurality of consecutive subcarriers (e.g., 12 subcarriers) in the frequency domain. A Bandwidth Part (BWP) may be defined as a plurality of consecutive (Physical) Resource Blocks ((P) RBs) in the frequency domain, and the BWP may correspond to one numerology (e.g., SCS, CP length, and so on). A carrier may include a maximum of N number BWPs (e.g., 5 BWPs). Data communication may be performed via an activated BWP. Each element may be referred to as a Resource Element (RE) within a resource grid and one complex symbol may be mapped to each element.
Hereinafter, a bandwidth part (BWP) and a carrier will be described.
The BWP may be a set of consecutive physical resource blocks (PRBs) in a given numerology. The PRB may be selected from consecutive sub-sets of common resource blocks (CRBs) for the given numerology on a given carrier
For example, the BWP may be at least any one of an active BWP, an initial BWP, and/or a default BWP. For example, the UE may not monitor downlink radio link quality in a DL BWP other than an active DL BWP on a primary cell (PCell). For example, the UE may not receive PDCCH, physical downlink shared channel (PDSCH), or channel state information-reference signal (CSI-RS) (excluding RRM) outside the active DL BWP. For example, the UE may not trigger a channel state information (CSI) report for the inactive DL BWP. For example, the UE may not transmit physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH) outside an active UL BWP. For example, in a downlink case, the initial BWP may be given as a consecutive RB set for a remaining minimum system information (RMSI) control resource set (CORESET) (configured by physical broadcast channel (PBCH)). For example, in an uplink case, the initial BWP may be given by system information block (SIB) for a random access procedure. For example, the default BWP may be configured by a higher layer. For example, an initial value of the default BWP may be an initial DL BWP. For energy saving, if the UE fails to detect downlink control information (DCI) during a specific period, the UE may switch the active BWP of the UE to the default BWP.
Meanwhile, the BWP may be defined for SL. The same SL BWP may be used in transmission and reception. For example, a transmitting UE may transmit a SL channel or a SL signal on a specific BWP, and a receiving UE may receive the SL channel or the SL signal on the specific BWP. In a licensed carrier, the SL BWP may be defined separately from a Uu BWP, and the SL BWP may have configuration signaling separate from the Uu BWP. For example, the UE may receive a configuration for the SL BWP from the BS/network. For example, the UE may receive a configuration for the Uu BWP from the BS/network. The SL BWP may be (pre-) configured in a carrier with respect to an out-of-coverage NR V2X UE and an RRC_IDLE UE. For the UE in the RRC_CONNECTED mode, at least one SL BWP may be activated in the carrier.
Referring to
The BWP may be configured by a point A, an offset NstartBWP from the point A, and a bandwidth NsizeBWP. For example, the point A may be an external reference point of a PRB of a carrier in which a subcarrier 0 of all numerologies (e.g., all numerologies supported by a network on that carrier) is aligned. For example, the offset may be a PRB interval between a lowest subcarrier and the point A in a given numerology. For example, the bandwidth may be the number of PRBs in the given numerology.
Hereinafter, V2X or SL communication will be described.
A sidelink synchronization signal (SLSS) may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS), as a SL-specific sequence. The PSSS may be referred to as a sidelink primary synchronization signal (S-PSS), and the SSSS may be referred to as a sidelink secondary synchronization signal (S-SSS). For example, length-127 M-sequences may be used for the S-PSS, and length-127 gold sequences may be used for the S-SSS. For example, a UE may use the S-PSS for initial signal detection and for synchronization acquisition. For example, the UE may use the S-PSS and the S-SSS for acquisition of detailed synchronization and for detection of a synchronization signal ID.
A physical sidelink broadcast channel (PSBCH) may be a (broadcast) channel for transmitting default (system) information which must be first known by the UE before SL signal transmission/reception. For example, the default information may be information related to SLSS, a duplex mode (DM), a time division duplex (TDD) uplink/downlink (UL/DL) configuration, information related to a resource pool, a type of an application related to the SLSS, a subframe offset, broadcast information, or the like. For example, for evaluation of PSBCH performance, in NR V2X, a payload size of the PSBCH may be 56 bits including 24-bit cyclic redundancy check (CRC).
The S-PSS, the S-SSS, and the PSBCH may be included in a block format (e.g., SL synchronization signal (SS)/PSBCH block, hereinafter, sidelink-synchronization signal block (S-SSB)) supporting periodical transmission. The S-SSB may have the same numerology (i.e., SCS and CP length) as a physical sidelink control channel (PSCCH)/physical sidelink shared channel (PSSCH) in a carrier, and a transmission bandwidth may exist within a (pre-) configured sidelink (SL) BWP. For example, the S-SSB may have a bandwidth of 11 resource blocks (RBs). For example, the PSBCH may exist across 11 RBs. In addition, a frequency position of the S-SSB may be (pre-) configured. Accordingly, the UE does not have to perform hypothesis detection at frequency to discover the S-SSB in the carrier.
For example, (a) of
For example, (b) of
Referring to (a) of
For example, the first UE may receive information related to dynamic grant (DG) resource(s) and/or information related to configured grant (CG) resource(s) from the base station. For example, the CG resource(s) may include CG type 1 resource(s) or CG type 2 resource(s). In the present disclosure, the DG resource(s) may be resource(s) configured/allocated by the base station to the first UE through a downlink control information (DCI). In the present disclosure, the CG resource(s) may be (periodic) resource(s) configured/allocated by the base station to the first UE through a DCI and/or an RRC message. For example, in the case of the CG type 1 resource(s), the base station may transmit an RRC message including information related to CG resource(s) to the first UE. For example, in the case of the CG type 2 resource(s), the base station may transmit an RRC message including information related to CG resource(s) to the first UE, and the base station may transmit a DCI related to activation or release of the CG resource(s) to the first UE.
In step S810, the first UE may transmit a PSCCH (e.g., sidelink control information (SCI) or 1st-stage SCI) to a second UE based on the resource scheduling. In step S820, the first UE may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S830, the first UE may receive a PSFCH related to the PSCCH/PSSCH from the second UE. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second UE through the PSFCH. In step S840, the first UE may transmit/report HARQ feedback information to the base station through the PUCCH or the PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on the HARQ feedback information received from the second UE. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on a pre-configured rule. For example, the DCI may be a DCI for SL scheduling. For example, a format of the DCI may be a DCI format 3_0 or a DCI format 3_1.
Hereinafter, an example of DCI format 3_0 will be described.
DCI format 3_0 is used for scheduling of NR PSCCH and NR PSSCH in one cell.
The following information is transmitted by means of the DCI format 3_0 with CRC scrambled by SL-RNTI or SL-CS-RNTI:
Referring to (b) of
Referring to (a) or (b) of
Hereinafter, an example of SCI format 1-A will be described.
SCI format 1-A is used for the scheduling of PSSCH and 2nd-stage-SCI on PSSCH.
The following information is transmitted by means of the SCI format 1-A:
Hereinafter, an example of SCI format 2-A will be described.
SCI format 2-A is used for the decoding of PSSCH, with HARQ operation when HARQ-ACK information includes ACK or NACK, when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information.
The following information is transmitted by means of the SCI format 2-A:
Hereinafter, an example of SCI format 2-B will be described.
SCI format 2-B is used for the decoding of PSSCH, with HARQ operation when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information.
The following information is transmitted by means of the SCI format 2-B:
Referring to (a) or (b) of
Referring to (a) of
Hereinafter, a hybrid automatic repeat request (HARQ) procedure will be described.
For example, the SL HARQ feedback may be enabled for unicast. In this case, in a non-code block group (non-CBG) operation, if the receiving UE decodes a PSCCH of which a target is the receiving UE and if the receiving UE successfully decodes a transport block related to the PSCCH, the receiving UE may generate HARQ-ACK. In addition, the receiving UE may transmit the HARQ-ACK to the transmitting UE. Otherwise, if the receiving UE cannot successfully decode the transport block after decoding the PSCCH of which the target is the receiving UE, the receiving UE may generate the HARQ-NACK. In addition, the receiving UE may transmit HARQ-NACK to the transmitting UE.
For example, the SL HARQ feedback may be enabled for groupcast. For example, in the non-CBG operation, two HARQ feedback options may be supported for groupcast.
For example, if the groupcast option 1 is used in the SL HARQ feedback, all UEs performing groupcast communication may share a PSFCH resource. For example, UEs belonging to the same group may transmit HARQ feedback by using the same PSFCH resource.
For example, if the groupcast option 2 is used in the SL HARQ feedback, each UE performing groupcast communication may use a different PSFCH resource for HARQ feedback transmission. For example, UEs belonging to the same group may transmit HARQ feedback by using different PSFCH resources.
In the present disclosure, HARQ-ACK may be referred to as ACK, ACK information, or positive-ACK information, and HARQ-NACK may be referred to as NACK, NACK information, or negative-ACK information.
Meanwhile, in the conventional unlicensed spectrum (NR-U), a communication method between a UE and a base station is supported in an unlicensed band. In addition, a mechanism for supporting communication in an unlicensed band between sidelink UEs is planned to be supported in Rel-18.
Meanwhile, a set of (equally spaced) non-contiguous RBs on a frequency may be allocated to a UE. This set of non-contiguous RBs may be referred to as interlaced RBs. This may be useful in spectrum (e.g., shared spectrum) that is subject to regulations such as occupied channel bandwidth (OCB), power spectral density (PSD), etc.
Referring to
A communication device (e.g., a device, a UE, a vehicle, a drone, etc. proposed in various embodiments of the present disclosure) may transmit a signal/channel by using one or more interlaced RBs.
In the present disclosure, a channel may refer to a set of frequency domain resources in which Listen-Before-Talk (LBT) is performed. In NR-U, the channel may refer to an LBT bandwidth with 20 MHz and may have the same meaning as an RB set. For example, the RB set may be defined in section 7 of 3GPP TS 38.214 V17.0.0.
In the present disclosure, channel occupancy (CO) may refer to time/frequency domain resources obtained by the base station or the UE after LBT success.
In the present disclosure, channel occupancy time (COT) may refer to time domain resources obtained by the base station or the UE after LBT success. It may be shared between the base station (or the UE) and the UE (or the base station) that obtained the CO, and this may be referred to as COT sharing. Depending on the initiating device, this may be referred to as gNB-initiated COT or UE-initiated COT.
Hereinafter, a wireless communication system supporting an unlicensed band/shared spectrum will be described.
In the following description, a cell operating in a licensed band (hereinafter, L-band) may be defined as an L-cell, and a carrier of the L-cell may be defined as a (DL/UL/SL) LCC. In addition, a cell operating in an unlicensed band (hereinafter, U-band) may be defined as a U-cell, and a carrier of the U-cell may be defined as a (DL/UL/SL) UCC. The carrier/carrier-frequency of a cell may refer to the operating frequency (e.g., center frequency) of the cell. A cell/carrier (e.g., CC) is commonly called a cell.
When the base station and the UE transmit and receive signals on carrier-aggregated LCC and UCC as shown in (a) of
In the embodiment of
Unless otherwise noted, the definitions below are applicable to the following terminologies used in the present disclosure.
Referring to
Table 9 shows an example of the channel access procedure (CAP) supported in NR-U.
Referring to Table 9, the LBT type or CAP for DL/UL/SL transmission may be defined. However, Table 9 is only an example, and a new type or CAP may be defined in a similar manner. For example, the type 1 (also referred to as Cat-4 LBT) may be a random back-off based channel access procedure. For example, in the case of Cat-4, the contention window may change. For example, the type 2 can be performed in case of COT sharing within COT acquired by the base station (gNB) or the UE.
Hereinafter, LBT-SubBand (SB) (or RB set) will be described.
In a wireless communication system supporting an unlicensed band, one cell (or carrier (e.g., CC)) or BWP configured for the UE may have a wideband having a larger bandwidth (BW) than in legacy LTE. However, a BW requiring CCA based on an independent LBT operation may be limited according to regulations. Let a subband (SB) in which LBT is individually performed be defined as an LBT-SB. Then, a plurality of LBT-SBs may be included in one wideband cell/BWP. A set of RBs included in an LBT-SB may be configured by higher-layer (e.g., RRC) signaling. Accordingly, one or more LBT-SBs may be included in one cell/BWP based on (i) the BW of the cell/BWP and (ii) RB set allocation information.
Referring to
Hereinafter, a channel access priority class (CAPC) will be described.
The CAPCs of MAC CEs and radio bearers may be fixed or configured to operate in FR1:
When selecting a CAPC of a DRB, the base station considers fairness between other traffic types and transmissions while considering 5QI of all QoS flows multiplexed to the corresponding DRB. Table 10 shows which CAPC should be used for standardized 5QI, that is, a CAPC to be used for a given QoS flow. For standardized 5QI, CAPCs are defined as shown in the table below, and for non-standardized 5QI, the CAPC with the best QoS characteristics should be used,
Hereinafter, a method of transmitting a downlink signal through an unlicensed band will be described. For example, a method of transmitting a downlink signal through an unlicensed band may be applied to a method of transmitting a sidelink signal through an unlicensed band.
The base station may perform one of the following channel access procedures (e.g., CAP) for downlink signal transmission in an unlicensed band.
In the type 1 DL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) may be random. The type 1 DL CAP may be applied to the following transmissions:
Referring to
Step 1) (S120) The base station sets N to Ninit (N=Ninit), where Ninit is a random number uniformly distributed between 0 and CWp. Then, step 4 proceeds.
Step 2) (S140) If N>0 and the base station determines to decrease the counter, the base station sets N to N−1 (N=N−1).
Step 3) (S150) The base station senses the channel for the additional sensing slot duration. If the additional sensing slot duration is idle (Y), step 4 proceeds. Otherwise (N), step 5 proceeds.
Step 4) (S130) If N=0 (Y), the base station terminates the CAP (S132). Otherwise (N), step 2 proceeds.
Step 5) (S160) The base station senses the channel until either a busy sensing slot is detected within an additional defer duration Ta or all the slots of the additional defer duration Ta are detected to be idle.
Step 6) (S170) If the channel is sensed to be idle for all the slot durations of the additional defer duration Td (Y), step 4 proceeds. Otherwise (N), step 5 proceeds.
Table 11 shows that mp, a minimum contention window (CW), a maximum CW, a maximum channel occupancy time (MCOT), and an allowed CW size, which are applied to the CAP, vary depending on channel access priority classes.
Referring to Table 11, a contention window size (CWS), a maximum COT value, etc. for each CAPC may be defined. For example, Ta may be equal to Tf+mp*Tsl (Td=Tf+mp*Tsl).
The defer duration Ta is configured in the following order: duration Tf (16 us)+mp consecutive sensing slot durations Tsl (9 us). Tf includes the sensing slot duration Tsl at the beginning of the 16 us duration.
The following relationship is satisfied: CWmin,p<=CWp<=CWmax,p. CWp may be configured by CWp=CWmin,p and updated before step 1 based on HARQ-ACK feedback (e.g., the ratio of ACK or NACK) for a previous DL burst (e.g., PDSCH) (CW size update). For example, CWp may be initialized to CWmin,p based on the HARQ-ACK feedback for the previous DL burst. Alternatively, CWp may be increased to the next higher allowed value or maintained as it is.
In the type 2 DL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) may be determined. The type 2 DL CAP is classified into type 2A/2B/2C DL CAPs.
The type 2A DL CAP may be applied to the following transmissions. In the type 2A DL CAP, the base station may perform transmission immediately after the channel is sensed to be idle at least for a sensing duration Tshort_dl=25 us. Herein, Tshot_dl includes the duration Tf (=16 us) and one sensing slot duration immediately after the duration Tf, where the duration Tf includes a sensing slot at the beginning thereof.
The type 2B DL CAP is applicable to transmission(s) performed by the base station after a gap of 16 us from transmission(s) by the UE within a shared channel occupancy time. In the type 2B DL CAP, the base station may perform transmission immediately after the channel is sensed to be idle for Tf=16 us. Tf includes a sensing slot within 9 us from the end of the duration. The type 2C DL CAP is applicable to transmission(s) performed by the base station after a maximum of 16 us from transmission(s) by the UE within the shared channel occupancy time. In the type 2C DL CAP, the base station does not perform channel sensing before performing transmission.
Hereinafter, a method of transmitting an uplink signal through an unlicensed band will be described. For example, a method of transmitting an uplink signal through an unlicensed band may be applied to a method of transmitting a sidelink signal through an unlicensed band.
The UE may perform type 1 or type 2 CAP for UL signal transmission in an unlicensed band. In general, the UE may perform the CAP (e.g., type 1 or type 2) configured by the base station for UL signal transmission. For example, a UL grant scheduling PUSCH transmission (e.g., DCI formats 0_0 and 0_1) may include CAP type indication information for the UE.
In the type 1 UL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) is random. The type 1 UL CAP may be applied to the following transmissions.
Referring to
Step 1) (S220) The UE sets N to Ninit (N=Ninit), where Ninit is a random number uniformly distributed between 0 and CWp. Then, step 4 proceeds.
Step 2) (S240) If N>0 and the UE determines to decrease the counter, the UE sets N to N−1 (N=N−1).
Step 3) (S250) The UB senses the channel for the additional sensing slot duration. If the additional sensing slot duration is idle (Y), step 4 proceeds. Otherwise (N), step 5 proceeds.
Step 4) (S230) If N=0 (Y), the UE terminates the CAP (S232). Otherwise (N), step 2 proceeds.
Step 5) (S260) The UE senses the channel until either a busy sensing slot is detected within an additional defer duration Ta or all the slots of the additional defer duration Ta are detected to be idle.
Step 6) (S270) If the channel is sensed to be idle for all the slot durations of the additional defer duration Ta (Y), step 4 proceeds. Otherwise (N), step 5 proceeds.
Table 12 shows that mp, a minimum CW, a maximum CW, a maximum channel occupancy time (MCOT), and an allowed CW size, which are applied to the CAP, vary depending on channel access priority classes.
Referring to Table 12, a contention window size (CWS), a maximum COT value, etc. for each CAPC may be defined. For example, Ta may be equal to Tf+mp*Tsl (Td=Tf+mp*Tsl).
The defer duration Ta is configured in the following order: duration Tf (16 us)+mp consecutive sensing slot durations Tsl (9 us). Tf includes the sensing slot duration Tsl at the beginning of the 16 us duration.
The following relationship is satisfied: CWmin,p<=CWp<=CWmax,p. CWp may be configured by CWp=CWmin,p and updated before step 1 based on an explicit/implicit reception response for a previous UL burst (e.g., PUSCH) (CW size update). For example, CWp may be initialized to CWmin,p based on the explicit/implicit reception response for the previous UL burst. Alternatively, CWp may be increased to the next higher allowed value or maintained as it is.
In the type 2 UL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) may be determined. The type 2 UL CAP is classified into type 2A/2B/2C UL CAPs. In the type 2A UL CAP, the UE may perform transmission immediately after the channel is sensed to be idle at least for a sensing duration Tshort_dl=25 us. Herein, Tshort_dl includes the duration Tf (=16 us) and one sensing slot duration immediately after the duration Tr. In the type 2A UL CAP, Tf includes a sensing slot at the beginning thereof. In the type 2B UL CAP, the UE may perform transmission immediately after the channel is sensed to be idle for the sensing duration Tf=16 us. In the type 2B UL CAP, Tf includes a sensing slot within 9 us from the end of the duration. In the type 2C UL CAP, the UE does not perform channel sensing before performing transmission.
For example, according to the type 1 LBT-based NR-U operation, the UE having uplink data to be transmitted may select a CAPC mapped to 5QI of data, and the UE may perform the NR-U operation by applying parameters of the corresponding CACP (e.g., minimum contention window size, maximum contention window size, mp, etc.). For example, the UE may select a backoff counter (BC) after selecting a random value between the minimum CW and the maximum CW mapped to the CAPC. In this case, for example, the BC may be a positive integer less than or equal to the random value. The UE sensing a channel decreases the BC by 1 if the channel is idle. If the BC becomes zero and the UE detects that the channel is idle for the time Ta (Td=Tf+mp*Tsl), the UE may attempt to transmit data by occupying the channel. For example, Tsl (=9 usec) is a basic sensing unit or sensing slots, and may include a measurement duration for at least 4 usec. For example, the front 9 usec of Tf (=16 usec) may be configured to be Tsl.
For example, according to the type 2 LBT-based NR-U operation, the UE may transmit data by performing the type 2 LBT (e.g., type 2A LBT, type 2B LBT, or type 2C LBT) within COT.
For example, the type 2A (also referred to as Cat-2 LBT (one shot LBT) or one-shot LBT) may be 25 usec one-shot LBT. In this case, transmission may start immediately after idle sensing for at least a 25 usec gap. The type 2A may be used to initiate transmission of SSB and non-unicast DL information. That is, the UB may sense a channel for 25 usec within COT, and if the channel is idle, the UE may attempt to transmit data by occupying the channel.
For example, the type 2B may be 16 usec one-shot LBT. In this case, transmission may start immediately after idle sensing for a 16 usec gap. That is, the UE may sense a channel for 16 usec within COT, and if the channel is idle, the UE may attempt to transmit data by occupying the channel.
For example, in the case of the type 2C (also referred to as Cat-1 LBT or No LBT), LBT may not be performed. In this case, transmission may start immediately after a gap of up to 16 usec and a channel may not be sensed before the transmission. The duration of the transmission may be up to 584 usec. The UE may attempt transmission after 16 usec without sensing, and the UE may perform transmission for up to 584 usec.
In a sidelink unlicensed band, the UE may perform a channel access operation based on Listen Before Talk (LBT). Before the UE accesses a channel in an unlicensed band, the UE should check whether the channel to be accessed is idle (e.g., a state in which UEs do not occupy the channel, a state in which UEs can access the corresponding channel and transmit data) or busy (e.g., a state in which the channel is occupied and data transmission/reception is performed on the corresponding channel, and the UE attempting to access the channel cannot transmit data while the channel is busy). That is, the operation in which the UE checks whether the channel is idle or busy may be referred to as Clear Channel Assessment (CCA), and the UE may check whether the channel is idle or busy for the CCA duration.
Referring to
Meanwhile, if the UE performs channel sensing for a set of resources (e.g., a resource pool or an RB set), a consistent listen before talk (LBT) failure may be detected for a specific set of resources. Alternatively, if the UE performs channel sensing for a set of resources (e.g., a resource pool or an RB set), an LBT failure may be detected for a specific set of resources. In any of the above cases, UE operation needs to be clearly defined.
In embodiment(s) of the present disclosure, in case that a UE that receives a COT from a UE that generated and shared the COT fails to successfully perform SL data transmission using the shared COT, a method for requesting a reconfiguration of the COT and a device supporting the same are proposed. In embodiment(s) of the present disclosure, UE operation for sharing a COT by reconfiguring the COT when the UE is requested to reconfigure the COT, and a device supporting the same, are proposed. In embodiment(s) of the present disclosure, in case that a COT failure (e.g. LBT failure) occurs, UE operation and a device supporting the same are proposed.
As shown in the embodiment of
For example, in order to attempt SL data transmission by performing short LBT (type 2 LBT) within the shared COT, the UE receiving the shared COT (the COT shared UE in the embodiment of
For example, the UE receiving the COT reconfiguration request message (or the message including the shared COT failure indication) may generate a new COT, and the UE may reshare the COT to the UE transmitting the COT reconfiguration request message. In this case, the UE reconfiguring the COT may perform type 1 LBT by applying a higher SL-CAPC (e.g., SL-CAPC 2, 3, 4) than a SL-CAPC (e.g., SL-CAPC 1) previously applied to generate and obtain the COT, and through this, the UE may reobtain the COT. In other words, applying a lower SL-CAPC (e.g., SL-CAPC 1) to generate the COT means that LBT was performed in less time, which can be interpreted as sensing the channel for less time. Therefore, to ensure a more reliable COT by allowing the UE to perform LBT for a longer period of time, the UE may apply a higher SL-CAPC (e.g., SL CAPC 2, 3, 4) than the previously applied SL-CAPC.
For example, the SL-channel access priority class (CAPC) may be defined as follows.
For example, the UE receiving the shared COT may declare a COT failure (e.g., CCA failure, LBT failure, etc.), and the UE may transmit a (shared) COT failure indication to the UE generating the COT. For example, the UE may declare a COT failure before the COT expires. For example, if all channels are determined to be busy, while the UE is performing CCA (e.g. LBT) N times (e.g., a threshold pre-defined or pre-configured from the base station or the UE (the UE generating the COT)), the UE may declare the COT failure (e.g., CCA failure, LBT failure, etc.) before the COT expires. For example, N may be a positive integer. For example, if the UE detects a consistent LBT failure in channels (e.g., a set of resources), while the UE is performing CCA (e.g., LBT) N times (e.g., a threshold pre-defined or pre-configured from the base station or the UE (the UE generating the COT)), the UE may declare the COT failure (e.g., CCA failure, LBT failure, etc.) before the COT expires.
In the above case, for example, the UE may release the shared COT. Alternatively, for example, in case that the COT failure occurs, the UE may reselect and use another SL resource pool from a SL resource pool it is using. Specifically, for example, if the UE detects a consistent LBT failure in channels (e.g., a set of resources), while the UE is performing CCA (e.g., LBT) N times (e.g., a threshold pre-defined or pre-configured from the base station or the UE (the UE generating the COT)), the UE may reselect a set of resources (e.g., a resource pool or an RB set). Herein, for example, if the UE changes a first set of resources to a second set of resources because it detects a consistent LBT failure for the first set of resources, the second set of resources may be a set of resources in which a consistent LBT failure was not detected. Or, for example, in case that the COT failure occurs, the UE may reselect resources by triggering a resource reselection procedure. Specifically, for example, if the UE detects an LBT failure (e.g., one LBT failure) for channels (e.g., a set of resources), the UE may trigger a resource reselection procedure and reselect resources.
Referring to
In the embodiment of
In the embodiment of
For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each SL-Channel Access Priority Class (CAPC). For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each SL-LBT type (e.g., Type 1 LBT, Type 2A LBT, Type 2B LBT, Type 2C LBT). For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured specifically (or differently or independently) depending on whether or not Frame Based LBT is applied. For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured specifically (or differently or independently) depending on whether or not Load Based LBT is applied.
For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each resource pool. For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each congestion level. For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each service priority. For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each service type. For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s) may be configured (differently or independently) for each QoS requirement (e.g., latency, reliability). For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each PQI (5G QoS identifier (5QI) for PC5). For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each traffic type (e.g., periodic generation or aperiodic generation). For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each SL transmission resource allocation mode (e.g., mode 1 or mode 2). For example, whether or not the (some) proposed method/rule of the present disclosure is applied and/or related parameter(s) (e.g., threshold value(s)) may be configured (differently or independently) for each Tx profile (e.g., a Tx profile indicating that a service supports sidelink DRX operation or a Tx profile indicating that a service does not need to support sidelink DRX operation).
For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) depending on whether a PUCCH configuration is supported (e.g., in case that a PUCCH resource is configured or in case that a PUCCH resource is not configured). For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each resource pool (e.g., a resource pool with a PSFCH or a resource pool without a PSFCH). For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each sidelink logical channel/logical channel group (or Uu logical channel or Uu logical channel group).
For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each resource pool. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each service/packet type. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each service/packet priority. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each QoS requirement (e.g., URLLC/EMBB traffic, reliability, latency). For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each PQI. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each PFI, For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each cast type (e.g., unicast, groupcast, broadcast). For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each (resource pool) congestion level (e.g., CBR). For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each SL HARQ feedback option (e.g., NACK-only feedback, ACK/NACK feedback). For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) for HARQ Feedback Enabled MAC PDU transmission. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) for HARQ Feedback Disabled MAC PDU transmission. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) according to whether a PUCCH-based SL HARQ feedback reporting operation is configured or not. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) for pre-emption or depending on whether or not pre-emption-based resource reselection is performed. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) for re-evaluation or depending on whether or not re-evaluation-based resource reselection is performed. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each (L2 or L1) (source and/or destination) identifier. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each (L2 or L1) (a combination of source ID and destination ID) identifier. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each (L2 or L1) (a combination of a pair of source ID and destination ID and a cast type) identifier. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each direction of a pair of source layer ID and destination layer ID. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each PC5 RRC connection/link. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) depending on whether or not SL DRX is performed. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) depending on whether or not SL DRX is supported. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured (differently or independently) for each SL mode type (e.g., resource allocation mode 1 or resource allocation mode 2). For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) for the case of performing (a) periodic resource reservation. For example, whether or not the proposed rule of the present disclosure is applied and/or related parameter configuration value(s) may be configured specifically (or differently or independently) for each Tx profile (e.g., a Tx profile indicating that a service supports sidelink DRX operation or a Tx profile indicating that a service does not need to support sidelink DRX operation).
The proposal and whether or not the proposal rule of the present disclosure is applied (and/or related parameter configuration value(s)) may also be applied to a mmWave SL operation.
Based on various embodiments of the present disclosure, if the UE performs channel sensing for a set of resources (e.g., a resource pool or an RB set), the UE may change a first set of resources to a second set of resources if a consistent listen before talk (LBT) failure is detected for the first set of resources. This can minimize the delay in SL communication caused by continuously performing channel sensing for the first set of resources. If the UE performs channel sensing for a set of resources (e.g., a resource pool or an RB set) and SL transmission fails to occur due to LBT failure for the first set of resources, the UE may trigger resource (re) selection. In this way, faster SL communication can be ensured.
Referring to
For example, the first resource set may be a first sidelink (SL) resource pool, and the second resource set is a second SL resource pool.
For example, the first resource set may be a first resource block (RB) set, and the second resource set is a second RB set.
For example, the threshold may be configured for the first device.
For example, the second resource set may be a resource set in which the consistent LBT failure is not detected.
For example, based on that physical sidelink shared channel (PSSCH) transmission is not performed due to LBT failure, resource selection or resource reselection may be triggered by the first device.
Additionally, for example, the first device may receive, from a second device, information related to a first channel occupancy time (COT). For example, channel access based on channel sensing for a certain time duration may be performed within the first COT by the first device. Additionally, for example, the first device may transmit, to the second device, a COT reconfiguration request message based on failure of all LBT within the first COT. For example, the COT reconfiguration request message may include cause information representing failure of the first COT. For example, after transmitting the COT reconfiguration request message, channel access based on a random backoff may be performed by the first device before information related to a second COT is received. For example, a first SL-channel access priority class (CAPC) used for generating information related to the first COT may be smaller than a second SL-CAPC used for generating information related to the second COT. For example, a time for performing LBT for generating information related to the first COT may be shorter than a time for performing LBT for generating information related to the second COT.
The proposed method can be applied to devices based on various embodiments of the present disclosure. First, the processor 102 of the first device 100 may obtain information related to a first resource set in which a channel access procedure is performed in a shared spectrum. In addition, the processor 102 of the first device 100 may perform channel sensing for the first resource set. In addition, the processor 102 of the first device 100 may detect a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold. In addition, the processor 102 of the first device 100 may change the first resource set to a second resource set based on the detection of the consistent LBT failure.
Based on an embodiment of the present disclosure, a first device adapted to perform wireless communication may be provided. For example, the first device may comprise: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the first device to perform operations comprising: obtaining information related to a first resource set in which a channel access procedure is performed in a shared spectrum; performing channel sensing for the first resource set; detecting a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold; and changing the first resource set to a second resource set based on the detection of the consistent LBT failure.
Based on an embodiment of the present disclosure, a processing device adapted to control a first device may be provided. For example, the processing device may comprise: at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the first device to perform operations comprising: obtaining information related to a first resource set in which a channel access procedure is performed in a shared spectrum; performing channel sensing for the first resource set; detecting a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold; and changing the first resource set to a second resource set based on the detection of the consistent LBT failure.
Based on an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be provided. For example, the instructions, when executed, may cause a first device to perform operations comprising: obtaining information related to a first resource set in which a channel access procedure is performed in a shared spectrum; performing channel sensing for the first resource set; detecting a consistent listen before talk (LBT) failure based on that a number of times the channel sensing for the first resource set fails reaches a threshold; and changing the first resource set to a second resource set based on the detection of the consistent LBT failure.
Referring to
The proposed method can be applied to devices based on various embodiments of the present disclosure. First, the processor 202 of the second device 200 may control transceiver 206 to transmit, to a first device, information related to a first channel occupancy time (COT). In addition, the processor 202 of the second device 200 may control transceiver 206 to receive, from the first device, a COT reconfiguration request message based on failure of all listen before talk (LBT) within the first COT. In addition, the processor 202 of the second device 200 may generate information related to a second COT based on the COT reconfiguration request message. In addition, the processor 202 of the second device 200 may control transceiver 206 to transmit, to the first device, the information related to the second COT.
Based on an embodiment of the present disclosure, a second device adapted to perform wireless communication may be provided. For example, the second device may comprise: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the second device to perform operations comprising: transmitting, to a first device, information related to a first channel occupancy time (COT); receiving, from the first device, a COT reconfiguration request message based on failure of all listen before talk (LBT) within the first COT; generating information related to a second COT based on the COT reconfiguration request message; and transmitting, to the first device, the information related to the second COT.
Based on an embodiment of the present disclosure, a processing device adapted to control a second device may be provided. For example, the processing device may comprise: at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the second device to perform operations comprising: transmitting, to a first device, information related to a first channel occupancy time (COT); receiving, from the first device, a COT reconfiguration request message based on failure of all listen before talk (LBT) within the first COT; generating information related to a second COT based on the COT reconfiguration request message; and transmitting, to the first device, the information related to the second COT.
Based on an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be provided. For example, the instructions, when executed, may cause a second device to perform operations comprising: transmitting, to a first device, information related to a first channel occupancy time (COT); receiving, from the first device, a COT reconfiguration request message based on failure of all listen before talk (LBT) within the first COT; generating information related to a second COT based on the COT reconfiguration request message; and transmitting, to the first device, the information related to the second COT.
Various embodiments of the present disclosure may be combined with each other.
Hereinafter, device(s) to which various embodiments of the present disclosure can be applied will be described.
The various descriptions, functions, procedures, proposals, methods, and/or operational flowcharts of the present disclosure described in this document may be applied to, without being limited to, a variety of fields requiring wireless communication/connection (e.g., 5G) between devices.
Hereinafter, a description will be given in more detail with reference to the drawings. In the following drawings/description, the same reference symbols may denote the same or corresponding hardware blocks, software blocks, or functional blocks unless described otherwise.
Referring to
Here, wireless communication technology implemented in wireless devices 100a to 100f of the present disclosure may include Narrowband Internet of Things for low-power communication in addition to LTE, NR, and 6G. In this case, for example, NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology and may be implemented as standards such as LTE Cat NB1, and/or LTE Cat NB2, and is not limited to the name described above. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may perform communication based on LTE-M technology. In this case, as an example, the LTE-M technology may be an example of the LPWAN and may be called by various names including enhanced Machine Type Communication (eMTC), and the like. For example, the LTE-M technology may be implemented as at least any one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-Bandwidth Limited (non-BL), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and is not limited to the name described above. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may include at least one of Bluetooth, Low Power Wide Area Network (LPWAN), and ZigBee considering the low-power communication, and is not limited to the name described above. As an example, the ZigBee technology may generate personal area networks (PAN) related to small/low-power digital communication based on various standards including IEEE 802.15.4, and the like, and may be called by various names.
The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other through the BSs 200/network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs/network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g. Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.
Wireless communication/connections 150a, 150b, or 150c may be established between the wireless devices 100a to 100f/BS 200, or BS 200/BS 200. Herein, the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication 150a, sidelink communication 150b (or, D2D communication), or inter BS communication (e.g. relay, Integrated Access Backhaul (IAB)). The wireless devices and the BSs/the wireless devices may transmit/receive radio signals to/from each other through the wireless communication/connections 150a and 150b. For example, the wireless communication/connections 150a and 150b may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/demapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.
Referring to
The first wireless device 100 may include one or more processors 102 and one or more memories 104 and additionally further include one or more transceivers 106 and/or one or more antennas 108. The processor(s) 102 may control the memory(s) 104 and/or the transceiver(s) 106 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 102 may process information within the memory(s) 104 to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver(s) 106. The processor(s) 102 may receive radio signals including second information/signals through the transceiver 106 and then store information obtained by processing the second information/signals in the memory(s) 104. The memory(s) 104 may be connected to the processor(s) 102 and may store a variety of information related to operations of the processor(s) 102. For example, the memory(s) 104 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 102 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 102 and the memory(s) 104 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 106 may be connected to the processor(s) 102 and transmit and/or receive radio signals through one or more antennas 108. Each of the transceiver(s) 106 may include a transmitter and/or a receiver. The transceiver(s) 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.
The second wireless device 200 may include one or more processors 202 and one or more memories 204 and additionally further include one or more transceivers 206 and/or one or more antennas 208. The processor(s) 202 may control the memory(s) 204 and/or the transceiver(s) 206 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 202 may process information within the memory(s) 204 to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver(s) 206. The processor(s) 202 may receive radio signals including fourth information/signals through the transceiver(s) 106 and then store information obtained by processing the fourth information/signals in the memory(s) 204. The memory(s) 204 may be connected to the processor(s) 202 and may store a variety of information related to operations of the processor(s) 202. For example, the memory(s) 204 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 202 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 202 and the memory(s) 204 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 206 may be connected to the processor(s) 202 and transmit and/or receive radio signals through one or more antennas 208. Each of the transceiver(s) 206 may include a transmitter and/or a receiver. The transceiver(s) 206 may be interchangeably used with RF unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.
Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Unit (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document.
The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software and the firmware or software may be configured to include the modules, procedures, or functions. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be included in the one or more processors 102 and 202 or stored in the one or more memories 104 and 204 so as to be driven by the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of code, commands, and/or a set of commands.
The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and/or commands. The one or more memories 104 and 204 may be configured by Read-Only Memories (ROMs), Random Access Memories (RAMs), Electrically Erasable Programmable Read-Only Memories (EPROMs), flash memories, hard drives, registers, cash memories, computer-readable storage media, and/or combinations thereof. The one or more memories 104 and 204 may be located at the interior and/or exterior of the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.
The one or more transceivers 106 and 206 may transmit user data, control information, and/or radio signals/channels, mentioned in the methods and/or operational flowcharts of this document, to one or more other devices. The one or more transceivers 106 and 206 may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, from one or more other devices. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices. The one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208 and the one or more transceivers 106 and 206 may be configured to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, through the one or more antennas 108 and 208. In this document, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or more transceivers 106 and 206 may convert received radio signals/channels etc. from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc. using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals/channels, etc. processed using the one or more processors 102 and 202 from the base band signals into the RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and/or filters.
Referring to
Codewords may be converted into radio signals via the signal processing circuit 1000 of
Specifically, the codewords may be converted into scrambled bit sequences by the scramblers 1010. Scramble sequences used for scrambling may be generated based on an initialization value, and the initialization value may include ID information of a wireless device. The scrambled bit sequences may be modulated to modulation symbol sequences by the modulators 1020. A modulation scheme may include pi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying (m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complex modulation symbol sequences may be mapped to one or more transport layers by the layer mapper 1030. Modulation symbols of each transport layer may be mapped (precoded) to corresponding antenna port(s) by the precoder 1040. Outputs z of the precoder 1040 may be obtained by multiplying outputs y of the layer mapper 1030 by an N*M precoding matrix W. Herein, N is the number of antenna ports and M is the number of transport layers. The precoder 1040 may perform precoding after performing transform precoding (e.g., DFT) for complex modulation symbols. Alternatively, the precoder 1040 may perform precoding without performing transform precoding.
The resource mappers 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMA symbols) in the time domain and a plurality of subcarriers in the frequency domain. The signal generators 1060 may generate radio signals from the mapped modulation symbols and the generated radio signals may be transmitted to other devices through each antenna. For this purpose, the signal generators 1060 may include Inverse Fast Fourier Transform (IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-Analog Converters (DACs), and frequency up-converters.
Signal processing procedures for a signal received in the wireless device may be configured in a reverse manner of the signal processing procedures 1010 to 1060 of
Referring to
The additional components 140 may be variously configured according to types of wireless devices. For example, the additional components 140 may include at least one of a power unit/battery, input/output (I/O) unit, a driving unit, and a computing unit. The wireless device may be implemented in the form of, without being limited to, the robot (100a of
In
Hereinafter, an example of implementing
Referring to
The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from other wireless devices or BSs. The control unit 120 may perform various operations by controlling constituent elements of the hand-held device 100. The control unit 120 may include an Application Processor (AP). The memory unit 130 may store data/parameters/programs/code/commands needed to drive the hand-held device 100. The memory unit 130 may store input/output data/information. The power supply unit 140a may supply power to the hand-held device 100 and include a wired/wireless charging circuit, a battery, etc. The interface unit 140b may support connection of the hand-held device 100 to other external devices. The interface unit 140b may include various ports (e.g., an audio I/O port and a video I/O port) for connection with external devices. The I/O unit 140c may input or output video information/signals, audio information/signals, data, and/or information input by a user. The I/O unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker, and/or a haptic module.
As an example, in the case of data communication, the I/O unit 140c may acquire information/signals (e.g., touch, text, voice, images, or video) input by a user and the acquired information/signals may be stored in the memory unit 130. The communication unit 110 may convert the information/signals stored in the memory into radio signals and transmit the converted radio signals to other wireless devices directly or to a BS. The communication unit 110 may receive radio signals from other wireless devices or the BS and then restore the received radio signals into original information/signals. The restored information/signals may be stored in the memory unit 130 and may be output as various types (e.g., text, voice, images, video, or haptic) through the I/O unit 140c.
Referring to
The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and road side units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 100. The control unit 120 may include an Electronic Control Unit (ECU). The driving unit 140a may cause the vehicle or the autonomous vehicle 100 to drive on a road. The driving unit 140a may include an engine, a motor, a powertrain, a wheel, a brake, a steering device, etc. The power supply unit 140b may supply power to the vehicle or the autonomous vehicle 100 and include a wired/wireless charging circuit, a battery, etc. The sensor unit 140c may acquire a vehicle state, ambient environment information, user information, etc. The sensor unit 140c may include an Inertial Measurement Unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward/backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illumination sensor, a pedal position sensor, etc. The autonomous driving unit 140d may implement technology for maintaining a lane on which a vehicle is driving, technology for automatically adjusting speed, such as adaptive cruise control, technology for autonomously driving along a determined path, technology for driving by automatically setting a path if a destination is set, and the like.
For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving path and a driving plan from the obtained data. The control unit 120 may control the driving unit 140a such that the vehicle or the autonomous vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed/direction control). In the middle of autonomous driving, the communication unit 110 may aperiodically/periodically acquire recent traffic information data from the external server and acquire surrounding traffic information data from neighboring vehicles. In the middle of autonomous driving, the sensor unit 140c may obtain a vehicle state and/or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving path and the driving plan based on the newly obtained data/information. The communication unit 110 may transfer information about a vehicle position, the autonomous driving path, and/or the driving plan to the external server. The external server may predict traffic information data using AI technology, etc., based on the information collected from vehicles or autonomous vehicles and provide the predicted traffic information data to the vehicles or the autonomous vehicles.
Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0045104 | Apr 2022 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/004908 | 4/12/2023 | WO |
