KR102515542B1 - Method and apparatus for transmitting uplink signal in mobile communication system of unlicensed band - Google Patents

Abstract

Provided is a method for a terminal to transmit an uplink signal using a first cell type indicating a cell using a licensed band frequency and a second cell type indicating a cell using an unlicensed band frequency. The terminal configures at least one first radio bearer (RB) capable of using radio resources for the first cell type and radio resources for the second cell type for uplink transmission. The terminal configures at least one second RB that can use radio resources for the first cell type for uplink transmission. The terminal includes at least one first logical channel corresponding to the at least one first RB in a first logical channel group. And, the terminal includes at least one second logical channel corresponding to the at least one second RB in a second logical channel group.

Description

Method and apparatus for transmitting uplink signal in mobile communication system of unlicensed band

The present invention relates to a method and apparatus for transmitting an uplink signal in a mobile communication system (or cellular system) of an unlicensed band.

When CA (carrier aggregation) is provided to a terminal through a cell of a licensed band, since the frequency used for transmission belongs to an operator, there is no need for a wireless device to select a cell in consideration of traffic characteristics and transmit traffic therethrough. However, when CA is provided to a terminal through a licensed assisted access (LAA) cell using an unlicensed band, the delay required for transmission may increase due to listen before talk (LBT), so service traffic or protocols that are sensitive to delay The signaling message used in the procedure is preferably transmitted through a cell of a licensed band.

When a wireless device performs transmission in consideration of characteristics of data and characteristics of a cell, transmission must be divided into downlink transmission and uplink transmission according to a transmission direction. Specifically, since downlink transmission can be processed by a scheduler of the base station in consideration of characteristics of data to be transmitted and characteristics of a cell, this can be implemented by the base station. In contrast, since uplink transmission must be processed in consideration of the characteristics of data to be transmitted by the terminal and the characteristics of the cell, an operation method for this must be supported in terms of standards.

For uplink data transmission in long term evolution (LTE), after a logical connection such as radio bearer (RB) and logical channel (LC) configuration is established, uplink radio resource request and Uplink radio resource allocation procedure must be performed. However, in the LTE standard, buffer status reporting (BSR) for uplink (UL) radio resource allocation (UL grant) is performed in logical channel group (LCG) units, and uplink radio resources are allocated in units of terminals. The uplink radio resources allocated in units of terminals in this way generate medium access control (MAC) packet data units (PDUs) through a prioritization procedure of configured logical channels, which are transport channels ( It is transmitted in uplink through a transport channel).

When the above-described uplink transmission procedure is performed, in the existing Rel-12 CA, since all component carriers included in the CA use licensed band frequencies, the characteristics of the component carriers are the same. In contrast, in LAA, component carriers of an unlicensed band included in CA and component carriers of a licensed band have different characteristics. For example, since channel access and uplink transmission are performed through LBT in component carriers of unlicensed bands, transmission uncertainty is increased and transmission delay is highly likely to increase. Therefore, when an uplink signal is transmitted in consideration of the characteristics of the unlicensed band cell described above in the LAA, a method for guaranteeing traffic quality of service (QoS) is required.

An object to be solved by the present invention is to provide a method and apparatus for transmitting an uplink signal while guaranteeing QoS of traffic in LAA.

According to an embodiment of the present invention, a method for transmitting an uplink signal by a terminal using a first cell type indicating a cell using a licensed band frequency and a second cell type indicating a cell using an unlicensed band frequency is provided. The transmission method of the terminal may configure at least one first radio bearer (RB) capable of using radio resources for the first cell type and radio resources for the second cell type for uplink transmission. doing; setting at least one second RB capable of using radio resources for the first cell type for uplink transmission; including at least one first logical channel corresponding to the at least one first RB in a first logical channel group; and including, in a second logical channel group, at least one second logical channel corresponding to the at least one second RB.

Based on a frequency used by a secondary cell (SCell) operating through carrier aggregation (CA) among the licensed band frequency and the unlicensed band frequency, the SCell is set to one of the first cell type and the second cell type. can

The at least one second logical channel may use radio resources of a cell group of the first cell type for uplink transmission.

The at least one first logical channel may use radio resources of the cell group of the first cell type and radio resources of the cell group of the second cell type for uplink transmission.

The at least one second logical channel may use radio resources of a cell of the first cell type corresponding to the second logical channel group for uplink transmission.

The at least one first logical channel may use radio resources of a cell of the second cell type corresponding to the first logical channel group and a cell of the first cell type for uplink transmission.

The transmission method of the UE may include a medium MAC (medium MAC) based on at least one of the first logical channel group and the second logical channel group using a first uplink grant allocated to a cell of the second cell type. Attempting to transmit an access control (CE) control element; and when transmission of the MAC CE fails, attempting retransmission of the MAC CE using the second uplink grant assigned to the cell of the first cell type.

The attempting to transmit the MAC CE may include receiving a first period set for transmission of the MAC CE from a base station; and transmitting the MAC CE using the first uplink grant during the first period.

Attempting retransmission of the MAC CE may include performing retransmission of the MAC CE using the second uplink grant when the transmission of the MAC CE performed during the first period fails.

The transmission method of the terminal may include measuring congestion of a channel used in a cell of the second cell type; and when the channel congestion is less than the threshold, at least one of the first logical channel group and the second logical channel group using a first uplink grant allocated to a cell of the second cell type. Attempting transmission of a medium access control (MAC) control element (CE) based on the method may be further included.

The measuring of the channel congestion includes calculating the channel congestion, which is a ratio between the number of uplink grants assigned within an observation window for measuring the channel congestion and the number of successful uplink transmissions. can do.

The measuring of the channel congestion may include: calculating the channel congestion within a search window set for measuring the channel congestion; shifting the search window by a predetermined value smaller than the length of the search window; and calculating the channel congestion within the shifted search window.

The measuring of the channel congestion may include: calculating the channel congestion within a first search window set for measuring the channel congestion; and calculating the channel congestion within a second search window set not to overlap with the first search window.

The transmission method of the terminal may include receiving allocation of a first radio resource from a base station by using at least one of a cell of the first cell type and a cell of the second cell type; and a medium access control (MAC) control element (CE) based on at least one of the first channel group and the second channel group in order to report the status of a buffer for uplink transmission to the base station. It may further include transmitting to the base station through the resource.

The transmission method of the terminal may include radio of a cell of the first cell type for the second logical channel group when the second logical channel group includes a signaling radio bearer (SRB) or a logical channel for real-time traffic. Allocating resources; and allocating radio resources of a cell of the second cell type for the first logical channel group when the first logical channel group includes a logical channel for non-real time traffic.

In addition, according to another embodiment of the present invention, a method for transmitting an uplink signal by a terminal using a first cell type indicating a cell using a licensed band frequency and a second cell type indicating a cell using an unlicensed band frequency is provided. do. The transmission method of the terminal may include receiving a first uplink radio resource for uplink transmission from a base station; When receiving the first uplink grant from among the first uplink grant of the first cell type and the second uplink grant of the second cell type, at least one corresponding to the first cell type allocating as many radio resources as a priority bit rate (PBR) among the first uplink radio resources to each of the first logical channels in descending order of priority; And when the first uplink radio resources remain, allocating radio resources as many as PRBs among the remaining uplink radio resources to each of at least one second logical channel corresponding to the second cell type in descending order of priority. Include steps.

The step of allocating to each of the at least one second logical channel may include, when remaining radio resources excluding the radio resources allocated to the at least one second logical channel among the remaining uplink radio resources exist, the remaining radio resources present and further allocating radio resources to the at least one second logical channel in descending order of priority.

The transmission method of the terminal, when receiving the second uplink grant among the first uplink grant and the second uplink grant, the first uplink radio resource for each of the at least one second logical channel allocating radio resources as much as the PBR among them in descending order of priority; And if the first uplink radio resources remain, further allocating the remaining radio resources to the at least one second logical channel in descending order of priority.

The transmission method of the UE may, when receiving the first uplink grant and the second uplink grant, transmit the first uplink grant to the second medium access control (MAC) control element (CE) transmission. A step of prioritizing use prior to uplink grant may be further included.

In addition, according to another embodiment of the present invention, a method for transmitting an uplink signal by a terminal using a first cell type indicating a cell using a licensed band frequency and a second cell type indicating a cell using an unlicensed band frequency Provided. The transmission method of the terminal may include attempting uplink transmission using a cell of the second cell type; determining whether the uplink transmission is successful; and when the uplink transmission fails, at least one of a first HARQ parameter and a second HARQ parameter that are set independently for the first cell type and the second cell type and indicate the maximum number of hybrid automatic request (HARQ) retransmissions. Based on, attempting uplink retransmission using a cell of the second cell type.

The determining step includes recognizing failure of the uplink transmission through at least one of a physical HARQ indicator channel (PHICH) transmitted by the base station and scheduling information transmitted by the base station and indicating uplink retransmission can do.

The transmission method of the terminal may include allocating radio resources of the first cell type from a base station for radio link control (RLC) retransmission when the number of uplink retransmission attempts corresponds to the second HARQ parameter; and retransmission of the RLC PDU through radio resources for the RLC retransmission using at least one of a serial number of an RLC packet data unit (PDU) requiring RLC level retransmission and an HARQ process identifier used for retransmission of the RLC PDU. It may further include steps to do.

The transmission method of the terminal may include a first radio bearer (RB) capable of using radio resources of the first cell type and radio resources of the second cell type and the first cell type when the uplink transmission fails. Attempting RLC retransmission based on at least one of a first radio link control (RLC) parameter and a second RLC parameter that is independently set for a second RB capable of using radio resources of one cell type and indicates the maximum number of retransmissions Further steps may be included.

According to an embodiment of the present invention, in a LAA in which a cell of a licensed band frequency and a cell of an unlicensed band frequency operate through CA, QoS of service can be guaranteed and system performance can be improved when transmitting uplink traffic.

1 is a diagram illustrating an uplink transmission method of LAA according to an embodiment of the present invention.
2A and 2B are diagrams illustrating a method of limiting radio resources for uplink transmission when establishing a radio bearer according to an embodiment of the present invention.
3 is a diagram illustrating a method of transmitting a MAC control element (CE) according to an embodiment of the present invention.
4A and 4B are diagrams illustrating a method of using a search interval for measuring channel congestion according to an embodiment of the present invention.
5 is a diagram illustrating a method of setting an independent maximum number of HARQ transmissions for each of an off-loadable cell and a non-off-loadable cell according to an embodiment of the present invention.
6 is a diagram illustrating a wireless device according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

In this specification, redundant descriptions of the same components are omitted.

In addition, in this specification, when a component is referred to as being 'connected' or 'connected' to another component, it may be directly connected or connected to the other component, but another component in the middle It should be understood that may exist. On the other hand, in this specification, when a component is referred to as 'directly connected' or 'directly connected' to another component, it should be understood that no other component exists in the middle.

In addition, terms used in this specification are only used to describe specific embodiments and are not intended to limit the present invention.

Also, in this specification, a singular expression may include a plurality of expressions unless the context clearly indicates otherwise.

In addition, in this specification, terms such as 'include' or 'having' are only intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more It should be understood that the presence or addition of other features, numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Also in this specification, the term 'and/or' includes a combination of a plurality of listed items or any item among a plurality of listed items. In this specification, 'A or B' may include 'A', 'B', or 'both A and B'.

In addition, in the present specification, a terminal includes a mobile terminal, a mobile station, an advanced mobile station, a high reliability mobile station, a subscriber station, It may also refer to a portable subscriber station, access terminal, user equipment (UE), etc., and may refer to a terminal, mobile terminal, mobile station, advanced mobile station, high reliability mobile station, subscriber station, portable It may include all or part of the functions of subscriber stations, access terminals, user equipment, etc.

In addition, in the present specification, a base station (BS) includes an advanced base station, a high reliability base station, a node B (NB), an advanced node B (evolved node B, eNodeB, eNB), access point, radio access station, base transceiver station, mobile multihop relay (MMR)-BS, relay station serving as a base station, base station It may also refer to a high reliability relay station, repeater, macro base station, small base station, etc. It may include all or some functions of a transceiver base station, MMR-BS, repeater, high reliability repeater, repeater, macro base station, and small base station.

In 3rd generation partnership project (3GPP) RAN1 and RAN2, standardization of licensed assisted access (LAA), which is a cellular mobile communication technology of an unlicensed band, is in progress according to the following design goals.

One of the design goals is "A single global solution framework allowing compliance with any regional regulatory requirements". That is, one of the design goals is to derive a single solution that satisfies the various regional regulatory requirements.

Another of the design goals is "Effective and fair coexistence with Wi-Fi". That is, another one of the design goals is that the Wi-Fi service operating in the same unlicensed band should not be affected in terms of throughput and delay.

Another one of the design goals is "Effective and fair coexistence among LAA networks deployed by different operators". That is, another one of the design goals is for coexistence between LAA networks of different operators operating in unlicensed bands.

In TR 36.889, the required functions for LAA are defined as follows based on the above design target.

One of the requested features is "listen-before-talk (clear channel assessment)". A listen-before-talk (LBT) procedure means that a wireless device (or communication node) performs clear channel assessment (CCA) and then accesses a shared channel in an unlicensed band. CCA is basically performed through energy detection, and a channel sensing function is required for fair operation between other wireless devices in an unlicensed band.

Another of the required functions is "discontinuous transmission on a carrier with limited maximum transmission duration". The length of the maximum transmission burst in the unlicensed band is defined as a regulation, and transmission considering this is required.

Another one of the requested features is "DFS (dynamic frequency selection) for radar avoidance in certain bands/regions". A radar system can be used in a specific frequency band, and DFS (eg, channel reselection, avoiding co-channel operation with radar system) considering this is required.

Another one of the requested features is "carrier selection". For minimization of interference and efficient co-existence, LAA nodes select a carrier and operate through inter-carrier movement.

Another one of the required functions is "transmit power control". LAA nodes operate in consideration of the maximum transmission power amount of unlicensed band wireless devices presented in the regulation requirements.

Another of the requested features is "RRM measurements including cell identification". In order to support mobility between secondary cells (SCells) and perform robust operation in an unlicensed band, radio resource management (RRM) measurement is required.

Also, the required functions include "AGC setting", "Coarse synchronization", "Fine frequency/time estimation at least for demodulation", and "CSI (channel state information) measurement including channel and interference". "ACG (automatic gain control) setting", "Coarse synchronization", "Fine frequency/time estimation at least for demodulation", and "CSI measurement including channel and interference" are required for RRM measurement and successful reception in unlicensed bands.

Hereinafter, traffic QoS characteristics are considered when a 3GPP LTE-based cellular mobile communication system is deployed and service is provided in an unlicensed band (e.g., 2 GHz band or 5 GHz band) where a number of wireless devices share and use channels. Thus, a method of transmitting an uplink signal will be described.

1 is a diagram illustrating an uplink transmission method of LAA according to an embodiment of the present invention.

A method of transmitting an uplink signal in consideration of characteristics of an unlicensed band in LAA is performed through a procedure illustrated in FIG. 1 . The overall operation procedure is similar to the uplink transmission proposed in Rel-12, but new functions are added to the detailed operation procedure to ensure traffic QoS.

Specifically, the terminal and the LAA base station perform radio bearer (RB) restriction setup (setup) (S10). The terminal transmits a scheduling request to the LAA base station (S11). The LAA base station performs scheduling (including UL grant) for the UE based on the scheduling request (S12). The terminal transmits the BSR to the LAA base station (S13). The LAA base station performs scheduling (including UL grant) for the UE based on the BSR (S14). The terminal performs prioritization of logical channels (S15) and transmits uplink data to the LAA base station (S16). When uplink transmission fails, the UE retransmits uplink data through fast radio link control (RLC) retransmission (S17). The fast RLC retransmission process (S17) includes an uplink data transmission process (S17-1).

Hereinafter, steps S10 to S17 will be described in detail.

First, a process of setting up a radio bearer (RB) restriction between a terminal and a base station (S10) will be described. Specifically, uplink RBs are configured by being divided into RBs that can be offloaded to the LAA cell (hereinafter referred to as 'off-loadable RBs') and RBs that are not (hereinafter referred to as 'non off-loadable RBs'). An off-loadable RB is a radio bearer capable of transmitting a signal using uplink radio resources of a licensed band cell and an unlicensed band cell. A non off-loadable RB is a radio bearer capable of transmitting signals using only uplink radio resources of a licensed band cell.

For example, a non off-loadable RB may be used for transmission of delay-sensitive traffic. For another example, for transmission of delay-insensitive traffic (eg, best effort traffic), off-loadable RBs and non off-loadable RBs may be used, and off-loadable RBs and non off-loadable RBs Uplink transmission is possible through In general, a radio bearer transmitting delay-sensitive traffic or a radio resource control (RRC) protocol message may be configured as a non off-loadable RB. In addition, a radio bearer transmitting delay-insensitive traffic (eg, best-effort traffic) or background traffic may be configured as an off-loadable RB. Control for these is set by RB restrictions.

The above-described RB restriction configuration may be performed through an uplink RB configuration procedure for data transmission, which is performed through an RRC procedure.

When configuring an RB for uplink transmission, the LAA base station sets a radio bearer identifier, a logical channel identifier, and a logical channel group identifier.

A radio bearer identifier configured during RB configuration corresponds (maps) 1:1 to a logical channel identifier, and one logical channel group (LCG) may include a plurality of logical channels. Therefore, a method of allocating a logical channel identifier and an LCG is to set different logical channel groups to which off-loadable RBs and non-off-loadable RBs belong. That is, since the LAA base station receives the radio resource allocation request for uplink transmission through the BSR for each logical channel group, by distinguishing the LCG to which the off-loadable RBs belong and the LCG to which the non-off-loadable RBs belong, It is possible to estimate the radio resource allocation request amount and the radio resource allocation request amount of the licensed band cell. The UE may configure an RB and a logical channel group based on the configuration by the LAA base station.

In LAA, cells may be classified into non off-loadable cells and off-loadable cells according to frequency resources used by cells included in (belonging to) CA. A non off-loadable cell is a cell using a licensed band frequency (eg, a cell using a licensed band frequency among PCell (primary cell) and SCell). An off-loadable cell is a cell (eg, LAA SCell) using an unlicensed band frequency.

Configuration information of the non off-loadable cell and the off-loadable cell may be described in an information element (IE) included in an RRC connection reconfiguration message. Here, the IE may be 'SCellToAddMod IE of SCellToAddModList in RRCConnectionReconfiguration'.

When configuring RBs, the following configuration methods (methods M100 and M110) may be considered for limiting radio resources of a cell used for uplink transmission.

Method M100 is a restriction method for each cell type. Specifically, when configuring RBs, a cell type capable of uplink transmission may be configured. Configuration information may include information on an off-loadable cell or a non-off-loadable cell. When setting a cell, the cell type is indicated. Since the PCell is a cell using a frequency of a licensed band, it is always set as a non off-loadable cell. SCell operating through CA is set to a non off-loadable cell when using a frequency of a licensed band, and set to an off-loadable cell when using a frequency of an unlicensed band.

Method M110 is a cell-by-cell restriction method. Specifically, when configuring RBs, cell identifiers capable of uplink transmission may be configured. Configuration information may include a list of cell identifiers. There are a setting method through a bitmap type and a setting method through a cell number.

In the configuration method through the bitmap type, when n cells are configured through CA, bitmap information having a length of n bits is transmitted, and each bit indicates a cell identifier. For example, when 4 SCells operate through CA, a 5-bit bitmap (eg, 1 PCell + 4 SCells) may indicate configurable cells through the position of each bit. Here, the configurable cell means a cell usable for uplink transmission (or RB). For example, when a bit stream for setting an off-loadable cell in a 5-bit bitmap is 0110, second and third SCells among 4 SCells may be recognized as off-loadable cells.

In the setting method through the cell number, whether the corresponding cell is an off-loadable cell or a non-off-loadable cell is set when the SCell is set. For example, when 4 SCells operate through CA and 2 cells are available for the corresponding RB, the time at which the corresponding SCell is set (eg, DRB (data radio bearer) or SRB (signaling radio bearer) setting time ), an off-loadable cell flag for two independent cell identifiers is set.

Configuration information on the cell type or cell restriction for each RB may be described in the IE included in the RRC connection reconfiguration message. Here, the IE may be 'SRB-ToAddMod IE of SRB-ToAddModList in RadioResourceConfigDedicated' or 'DRB-ToAddMod IE of DRB-ToAddModList in RadioResourceConfigDedicated'.

2A and 2B are diagrams illustrating a method of limiting radio resources for uplink transmission when establishing a radio bearer according to an embodiment of the present invention. Method M100 is illustrated in FIG. 2A and method M110 is illustrated in FIG. 2B.

2A and 2B, LCG#1 includes logical channel #1 and logical channel #3 and corresponds to non off-loadable RBs, and LCG#2 includes logical channel #4 and corresponds to non off-loadable RBs. And, LCG #2 includes logical channel #5 and logical channel #6, and the case corresponding to off-loadable RBs is exemplified.

When radio resources are limited for each cell type, as illustrated in FIG. 2A, logical channels (logical channel #1, logical channel #3, and logical channel #4) included in LCG #1 and LCG #2 are non Uplink transmission is performed through radio resources of Cell#1 and Cell#2, which are off-loadable cells. And the logical channels (logical channel #5 and logical channel #6) included in LCG#3 are transmitted through the radio resources of Cell#3, an off-loadable cell, and the radio resources of Cell#1 and Cell#2, non-off-loadable cells. Performs uplink transmission.

On the other hand, when radio resources are limited for each cell identifier, as illustrated in FIG. 2B, the logical channels (logical channel #1 and logical channel #3) included in LCG #1 are non off-loadable cells such as Cell# Uplink transmission is performed using the radio resource of 1. In addition, the logical channel (logical channel #2) included in LCG #2 performs uplink transmission using radio resources of Cell#2, which is a non off-loadable cell. However, the logical channels (logical channel #5 and logical channel #6) included in LCG#3 are identical to the embodiment of FIG. Uplink transmission is performed using radio resources of Cell#1 and Cell#2.

Consequently, when radio resources are limited for each cell type, radio resource restrictions are made for each cell group having a cell type (non off-loadable cell type, off-loadable cell type). For example, in the embodiment of FIG. 2A, radio resources for each of the cell groups (Cell#1 and Cell#2) belonging to the non off-loadable cell type and the cell group (Cell#3) belonging to the off-loadable cell type restrictions are made

When radio resources are limited for each cell, radio resource restrictions are made for each cell. For example, in the embodiment of FIG. 2B , radio resource restrictions are made for each of Cell#1, which is a non off-loadable cell, Cell#2, which is a non off-loadable cell, and Cell#3, which is an off-loadable cell.

On the other hand, data transmission using the LAA SCell can obtain benefits in terms of radio resource usage efficiency in the unlicensed band, but there are cases where the service requirements (QoS) are not satisfied due to the delay caused by the uplink LBT. . Therefore, in the following, when there is no UL grant allocated to the non off-loadable cell but there is a UL grant allocated to the off-loadable cell, the MAC CE is restricted to the off-loadable cell. A method of transmitting in uplink using ? (method M200, method M210) will be described.

Method M200 is a method of performing retransmission using a non off-loadable cell after performing transmission using an off-loadable cell. Method M200 will be described in detail with reference to FIG. 3 .

3 is a diagram illustrating a method of transmitting a MAC control element (CE) according to an embodiment of the present invention. 3 illustrates an embodiment of a method (method M200) of performing transmission using an off-loadable cell and then performing retransmission using a non-off-loadable cell. MAC CE may be configured based on the above-described LCG (eg, LCG#1, LCG#2, LCG#3).

Specifically, in method M200, a wireless device (eg, terminal) attempts to transmit a MAC CE using an UL grant assigned to an off-loadable cell, and if the corresponding MAC CE is transmitted by an UL LBT If not, retransmission may be performed through an UL grant assigned to a non off-loadable cell.

To this end, the LAA base station, when configuring the RB for the UE, provides the UE with a period during which uplink transmission can be attempted through an UL grant allocated to an off-loadable cell (hereinafter referred to as an 'off-loadable period'). Set up.

The UE performs MAC CE transmission through an off-loadable cell (UL grant allocated to the off-loadable cell) during the set off-loadable period.

If MAC CE transmission through the off-loadable cell fails during the set off-loadable period (e.g., when the UE determines that the corresponding channel is busy through CCA for the channel), the UE then receives the licensed band cell The corresponding MAC CE is transmitted through an uplink grant (UL grant allocated to a non off-loadable cell). For example, when the terminal determines that the corresponding channel is in an idle state (or free state) through CCA for the channel, it can transmit a MAC CE through a non off-loadable cell.

When method M200 is used, the LAA base station needs to set an off-loadable period, which is a period during which the terminal performs a MAC CE transmission attempt through an off-loadable cell, through a signaling procedure.

Method M210 is a method of transmitting a MAC CE considering a channel congestion threshold.

In method M210, the terminal measures the congestion of a channel used in the off-loadable cell, and compares the congestion of the channel with a set threshold (threshold). The UE transmits the MAC CE using the UL grant assigned to the off-loadable cell only when the congestion of the channel is lower than the threshold. When the congestion of the channel is lower than the threshold value, the subsequent operation procedure of the terminal is the same as method M200. That is, the UE attempts MAC CE transmission for a certain period of time (eg, an off-loadable period) using an UL grant allocated to an off-loadable cell. If the corresponding MAC CE is not transmitted by the uplink LBT, the terminal attempts MAC CE retransmission through the UL grant of the non off-loadable cell received thereafter.

The channel congestion (CH _congestion ) of the off-loadable cell measured by the UE is the ratio of the number of uplink transmissions (the number of successful uplink transmissions) to the number of UL grants allocated within a specific observation window. It can be defined as a ratio and can be calculated as in Equation 1 below.

In Equation 1, the number of uplink grants (UL grants) may indicate the number of uplink grants (UL grants) allocated to an off-loadable cell within a specific discovery period, and the number of uplink transmissions (uplink transmission success number) may represent the number of uplink transmissions performed through an off-loadable cell within a specific search period.

Methods using an observation window include a sliding window method (method M211) or a specific observation window method (method M212). Referring to FIGS. 4A and 4B , the sliding window method (method M211) and the specific search interval method (method M212) will be described in detail.

4A and 4B are diagrams illustrating a method of using a search period for measuring channel congestion according to an embodiment of the present invention. Specifically, the sliding window method (method M211) is illustrated in FIG. 4A, and the specific search interval method (method M212) is illustrated in FIG. 4B.

The sliding window method (method M211) is a method of measuring channel congestion while shifting a search interval by an observation granularity. For example, as illustrated in FIG. 4A, when the discovery period is 4 ms and the measurement time unit is 1 ms, the terminal receives an uplink grant (UL grant) received every 1 ms until the initial 4 ms of the discovery period (observation window # 1). Calculate channel congestion, which is the ratio between ) and UL transmission. After the discovery period (observation window#1, 4 ms), the UE measures the channel congestion while moving the discovery period by 1 ms (eg, moving to the right). That is, the terminal measures the channel congestion within the observation window (observation window #2) in which the observation window (observation window #1) is shifted by 1 ms, and the observation window (observation window # 2) is shifted by 1 ms (observation window # 2). Measure channel congestion within window#3).

On the other hand, the search interval method (method M212) is a method of measuring channel congestion within a set search interval. For example, as illustrated in FIG. 4B, when the search period is 4 ms, the terminal newly sets the search period (observation window #1, observation window #2, observation window #3, ...) every 4 ms, , after initializing the previously measured channel congestion, the channel congestion is measured within each search interval. The search intervals (observation window#1, observation window#2, observation window#3, ...) are set so that they do not overlap each other. That is, the terminal initializes the channel congestion measured in the previous discovery period (eg, observation window #1), and measures the channel congestion in the next discovery period (eg, observation window #2).

When method M210 is used, the LAA base station, through the signaling procedure, the off-loadable period, which is the time for the UE to attempt MAC CE transmission through the off-loadable cell, the observation window, and the measurement time unit (observation granularity), and the congestion threshold of the channel.

Meanwhile, configuration information for transmitting the MAC CE through the above-described off-loadable cell may be described in the IE included in the RRC connection reconfiguration message. Here, the IE may be 'MAC-MainConfig IE in RadioResourceConfigDedicated'.

Next, a scheduling request (SR) process (S11) will be described.

SR is a signal requesting uplink radio resources for new transmission. This signal may be transmitted through PCell or physical uplink control channel (PUCCH) SCell.

Next, the scheduling (UL grant) process (S12) will be described.

The LAA base station allocates uplink radio resources to the SR of the UE transmitted in step S11. The BSR is transmitted through the uplink radio resource allocated in step S12. In step S12, the LAA base station may allocate radio resources of a licensed band cell or LAA SCell according to a MAC CE transmission method. Specifically, the following methods (method M300, method M310) may be considered.

Method M300 is a method of scheduling using a non off-loadable cell (licensed band cell). Method M310 is a method of scheduling using an off-loadable cell (LAA SCell). Method M300 may have a lower transmission delay than method M310, but has a disadvantage in that the use efficiency of unlicensed band radio resources is lowered. Method M310 has the advantage of increasing the efficiency of use of unlicensed band radio resources, but has the possibility of additional transmission delay according to LBT.

Considering the advantages and disadvantages of method M300 and method M310, the size of the MAC PDU required for BSR transmission is up to 5 Bytes (=MAC sub header + long BSR CE), which does not significantly affect radio resource use, so the LAA base station It is preferable to schedule using M300. However, the detailed scheduling method is determined by the scheduler of the LAA base station.

If uplink radio resources (e.g., radio resources for BSR) are allocated through method M310 and a method for transmitting MAC CE using limited off-loadable cells (e.g., method M200, method M210) is set , the MAC CE transmission procedure presented in the above-described process S10 may be used.

Next, the BSR transmission process (S13) will be described.

Step S13 is a procedure in which the UE reports uplink buffer information (eg, buffer status for uplink transmission) to the LAA base station. To this end, a MAC CE configured based on LCG may be used. BSR transmission uses the scheduling presented in step S12. For example, for BSR, the terminal may transmit the MAC CE configured based on at least one LCG to the LAA base station through radio resources allocated by step S12.

The size of the buffer included in the BSR refers to the amount of all data included in the RLC and packet data compression protocol (PDCP) buffers.

Next, the scheduling (UL grant) process (S14) will be described.

The LAA base station allocates uplink radio resources for data transmission based on the BSR received from the terminal. Specifically, the LAA base station may allocate uplink radio resources for non off-loadable cells and off-loadable cells through the BSR for each LCG received in step S13. For example, when the LCG (eg, LCG # 1) includes signaling radio bearer (SRB) or logical channels for real-time traffic, the base station uses a non off-loadable cell for the corresponding LCG (eg, LCG # 1) Uplink radio resources of can be allocated. For another example, when the LCG (eg, LCG #2) includes a logical channel for non-real-time traffic, the base station uses uplink radio resources of an off-loadable cell for the corresponding LCG (eg, LCG # 2) Priority (first) can be assigned. However, the detailed scheduling method is determined by the scheduler of the LAA base station.

Next, the prioritization process (S15) will be described.

In step S14, uplink radio resource allocation is performed in units of terminals based on the BSR received in step S13. The terminal allocated uplink radio resources performs a prioritization procedure for each logical channel, generates a MAC PDU for uplink transmission, and transmits the MAC PDU to the LAA base station through an uplink shared channel (UL-SCH). Prioritization in the LAA is performed through a logical channel prioritization (LCP) parameter received in step S10. That is, the UE sets the following prioritization procedure (first LCP method or second LCP method) for each logical channel for the uplink radio resource allocation information received in the UL grant of step S14. It is performed using the LCP parameter. Here, the first LCP method is a method of determining a cell type for a logical channel and performing an LCP procedure for each cell type. The second LCP method is a method of performing an LCP procedure for a logical channel.

Specifically, the first LCP method is for a case where the cell type is set for each logical channel, and the terminal is included in the cell type (eg, non off-loadable cell type, off-loadable cell type) set for each logical channel ( It is to independently prioritize for UL grants). UL grants included in (belonging to) the list of non off-loadable cells or the list of off-loadable cells may be utilized individually or collectively. This is a terminal implementation issue.

The second LCP method is for a case where a cell identifier is set for each logical channel, and the UE has independent priority for an UL grant included in (belonging to) a list of cell identifiers set for each logical channel. to do the anger. UL grants included in (belonging to) the list of non off-loadable cells or the list of off-loadable cells may be utilized individually or collectively. This is a terminal implementation issue.

On the other hand, uplink radio resource allocation according to the BSR request may consider Cases (Case1, Case2, Case3) defined in Table 1 (example of UL grant in LAA) below.

UL grant for non off-loadable cells UL grant for off-loadable cells Remark Case1 X In case of receiving only UL grant of non off-loadable cell (licensed band cell) Case2 X When only the UL grant of the off-loadable cell (LAA cell) is received Case3 X X When receiving UL grant of non off-loadable cell (licensed band cell) and UL grant of off-loadable cell (LAA cell) at the same time

In Case 1, the terminal performs the LCP operation according to the following procedure. The UE performs the LCP operation for the UL grant allocated to all non off-loadable cells. Specifically, the terminal sequentially performs the following steps S20, S21, and S22 for a logical channel configured as a non off-loadable cell (cell type).

In step S20, the terminal allocates uplink radio resources corresponding to a priority bit rate (PBR) in descending order of priority for all logical channels j in which the value of B _j is greater than or equal to 0. Here, B _j represents a bucket variable (or current bucket content) for logical channel j.

In step S21, the UE reduces the MAC service data unit (SDU) size of logical channel j from B _j .

In step S22, if radio resources for uplink transmission remain after the terminal performs steps S20 and S21 in descending order of priority for all logical channels j, for the remaining uplink radio resources, the terminal performs the following steps. At least one of steps S22-1, S22-2, and S22-3 is performed.

In step S22-1, the terminal allocates the remaining uplink radio resources to logical channel j according to priority (descending priority).

In step S22-2, the terminal performs at least one of the following steps S22-2a, S22-2b, and S22-2c for a logical channel configured as an off-loadable cell (cell type).

In step S22-2a, the terminal allocates uplink radio resources equal to the PBR in descending order of priority for all logical channels j in which the value of B _j is greater than or equal to 0.

In step S22-2b, the UE reduces B _j by the MAC SDU size of logical channel j.

In step S22-2c, in the case where uplink radio resources remain after performing steps S22-2a and step S22-2b in descending order of priority for all logical channels j, for the remaining uplink radio resources, the UE proceeds to the next step. At least one of the steps S22-2c-1 and S22-2c-2 is performed.

In step S22-2c-1, the terminal allocates radio resources for uplink transmission to logical channel j according to priority (descending priority).

In step S22-2c-2, the terminal does not use the remaining uplink radio resources.

In step S22-3, the terminal does not use the remaining uplink radio resources.

Meanwhile, when the terminal performs the LCP procedure for Case 1 described above, the MAC of the terminal may transmit the MAC CE by giving priority to MAC CE transmission.

In Case 2, the terminal performs the LCP operation according to the following procedure.

The UE performs an LCP operation for UL grants allocated to all off-loadable cells. Specifically, the terminal may sequentially perform the following steps S30, S31, and S32 with respect to the logical channel configured as an off-loadable cell.

In step S30, the terminal performs step S20 of Case 1.

In step S31, the terminal performs step S21 of Case 1.

In step S32, if there are uplink radio resources remaining after the terminal performs steps S30 and step S31 in descending order of priority for all logical channels j, the terminal performs the next step S32-1 for the remaining uplink radio resources. At least one of process and process S32-2 is performed.

In step S32-1, the terminal performs step S22-1 of Case 1.

In step S32-2, the terminal performs step S22-3 of Case 1.

Meanwhile, when the terminal performs the LCP procedure for Case 2 described above, the MAC of the terminal transmits the MAC CE, which is the method presented in step S10, to the uplink using a limited off-loadable cell (eg, method M200 , Method M210), MAC CE transmission may be transmitted by prioritizing MAC CE transmission.

In Case 3, the terminal performs the LCP operation according to the following procedure.

The UE performs an LCP operation for UL grants allocated to all off-loadable cells. Specifically, the terminal may perform steps S30, S31, and S32 presented in Case 2 with respect to the logical channel configured as an off-loadable cell.

The UE performs an LCP operation for UL grants allocated to all non-off-loadable cells. Specifically, the UE may perform steps S20, S21, and S22 presented in Case 1 with respect to a logical channel configured as a non off-loadable cell.

Meanwhile, when the terminal performs the LCP procedure for Case 3 described above, the MAC of the terminal may prioritize and use the UL grant allocated for the non off-loadable cell for MAC CE transmission. . That is, the MAC of the UE may preferentially use the UL grant allocated to the non off-loadable cell over the UL grant allocated to the off-loadable cell for MAC CE transmission. .

If the UE has used all of the UL grants allocated to the non off-loadable cell, but there are more MAC CEs left to be transmitted by the UE, the UE's MAC restricts the MAC CE, which is the method presented in step S10, A method of uplink transmission using an off-loadable cell (eg, method M200 or method M210) may be considered, and MAC CE transmission may be transmitted by prioritizing MAC CE transmission.

Next, an uplink data transmission process (S16) will be described.

The MAC PDU generated by the prioritization process (S15) is transmitted to the physical layer, which is transmitted in uplink through the UL-SCH.

Next, the fast RLC retransmission process (S17) will be described.

The fast RLC retransmission process (S17) is an optional process performed when the UE performs the uplink data transmission process (S16) using an off-loadable cell, but the uplink transmission fails. If uplink transmission fails, the terminal can overcome the error through hybrid automatic request (HARQ) retransmission and RLC retransmission. However, when the UE performs the process S17, the characteristics of the off-loadable cell should be considered.

In general, RLC retransmission is performed when an RLC status report is received from the counterpart RLC, but in LAA where non-continuous transmission is performed by LBT, this type of retransmission method may cause a long delay. Therefore, a method capable of reducing the RLC retransmission delay of an off-loadable cell is required, and the following methods (method M400 and method M410) may be considered.

Method M400 is a method using HARQ parameters.

In Rel-12 MAC, the number of HARQ retransmissions is defined through maxHARQ-Tx included in MAC-Main Config IE, and this parameter is commonly applied to all cells included in (belonging to) CA. However, as described above, since characteristics of off-loadable cells and non-off-loadable cells are different, it is necessary to set corresponding parameters independently for each cell in consideration of this. 5 is a diagram illustrating a method of setting an independent maximum number of HARQ transmissions for each of an off-loadable cell and a non-off-loadable cell according to an embodiment of the present invention. For example, as illustrated in FIG. 5, the parameter for the maximum number of HARQ retransmissions for a non off-loadable cell (cell type) may be set to maxHARQ-Tx, and the maximum HARQ for an off-loadable cell (cell type) The retransmission count parameter may be set to maxHARQ-Tx-LAA.

After the terminal performs uplink transmission, a method of determining whether the uplink transmission is successful includes a method using explicit signaling and a method using delivery of scheduling information for uplink retransmission.

A method using explicit signaling is a method in which a base station transmits a physical layer channel, a physical HARQ indicator channel (PHICH) through downlink, and informs the user equipment of whether or not the uplink transmission is successful.

A method of using the transmission of scheduling information for uplink retransmission is a method in which a base station transmits scheduling information indicating (indicating) a corresponding uplink retransmission to a terminal when an uplink transmission error occurs.

The terminal recognizes an uplink transmission error through two methods (a method using explicit signaling and a method using delivery of scheduling information for uplink retransmission), and the above parameters (e.g., maxHARQ-Tx, maxHARQ-Tx -LAA) may be considered to perform retransmission.

A method of reducing the RLC retransmission delay of an off-loadable cell using an HARQ parameter (method M400) may be performed through the following steps S40, S41, and S42.

In step S40, the terminal performs HARQ retransmission. Specifically, when an error occurs after uplink transmission, the terminal may perform uplink retransmission using an off-loadable cell as many as the set maximum number of HARQ retransmissions (maxHARQ-Tx-LAA).

In step S41, the terminal requests and receives uplink radio resources of a non off-loadable cell (cell type). Specifically, when the number of uplink retransmission attempts reaches the set maximum number of HARQ retransmissions (eg, maxHARQ-Tx-LAA), the UE uses the SR procedure and the BSR procedure to obtain uplink radio resources of a non off-loadable cell. Uplink radio resources of a non off-loadable cell may be allocated according to the allocation or recognition and determination of the base station. Through this, the terminal can secure radio resources for RLC retransmission.

In step S42, the UE retransmits the RLC PDU according to the MAC indication. Specifically, the terminal may perform RLC retransmission through the uplink (uplink radio resource) of the non off-loadable cell configured in step S41. Process S42 may be performed based on the following two methods (method M401 and method M402).

Method M401 is a method in which the RLC of the UE and the MAC of the UE share an RLC PDU sequence number. Specifically, when the RLC transmits the RLC PDU for uplink transmission to the MAC, it may transmit the sequence number of the corresponding RLC PDU to the MAC. Then, when the number of uplink retransmission attempts reaches the HARQ maximum number of retransmissions (e.g. maxHARQ-Tx-LAA) and RLC-level retransmission is required, the MAC sends the RLC to the corresponding serial number (RLD PDU serial number that requires retransmission). It can request and receive the corresponding RLC PDU and retransmit it.

Method M402 is a method in which the RLC of the terminal and the MAC of the terminal share an HARQ process identifier. Specifically, when requesting an RLC PDU from RLC, the MAC may deliver an HARQ process identifier to be used for transmission to RLC. Then, when the number of uplink retransmission attempts reaches the HARQ maximum number of retransmissions (eg, maxHARQ-Tx-LAA) and RLC-level retransmission is required, the MAC transmits the corresponding HARQ process identifier (HARQ process identifier to be used for retransmission) to the RLC and RLC may retransmit the RLC PDU corresponding to the received HARQ process identifier.

Method M410 is a method using RLC parameters. Specifically, method M410 is a method of independently setting maxRetxThreshold, a parameter for the maximum number of retransmissions used for retransmission in RLC, to non off-loadable RBs and off-loadable RBs. Through this, fast RLC retransmission can be performed. The UE may perform RLC retransmission based on an RLC parameter (maxRetxThreshold) independently set for each of the non off-loadable RB and the off-loadable RB.

For example, the RLC parameter (maxRetxThreshold) for an off-loadable RB may be set to a value smaller than the RLC parameter (maxRetxThreshold) for a non off-loadable RB, and through transmission and reception of an RLC status report accordingly, Retransmission to a non off-loadable cell may be performed. In this case, the MAC scheduler may allocate radio resources for uplink transmission of a non off-loadable cell or an off-loadable cell through scheduling according to an RLC transmission type (eg, initial transmission or retransmission).

6 is a diagram illustrating a wireless device according to an embodiment of the present invention. The wireless device TN100 may be a base station or a terminal described in this specification.

In the embodiment of FIG. 6 , the wireless device TN100 may include at least one processor TN110, a transmitting/receiving device TN120 connected to a network to perform communication, and a memory TN130. In addition, the wireless device TN100 may further include a storage device TN140, an input interface device TN150, and an output interface device TN160. Components included in the wireless device TN100 may communicate with each other by being connected by a bus TN170.

The processor TN110 may execute program commands stored in at least one of the memory TN130 and the storage device TN140. The processor TN110 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Processor TN110 may be configured to implement procedures, functions, and methods described in connection with embodiments of the present invention. The processor TN110 may control each component of the wireless device TN100.

Each of the memory TN130 and the storage device TN140 may store various information related to the operation of the processor TN110. Each of the memory TN130 and the storage device TN140 may include at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory TN130 may include at least one of read only memory (ROM) and random access memory (RAM).

The transmitting/receiving device TN120 may transmit or receive a wired signal or a wireless signal. Also, the wireless device TN100 may have a single antenna or multiple antennas.

Meanwhile, the embodiments of the present invention are not implemented only through the devices and/or methods described so far, and may be implemented through a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium in which the program is recorded. And, such an implementation can be easily implemented by those skilled in the art from the description of the above-described embodiment.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also included in the scope of the present invention. that fall within the scope of the right.

Claims (20)

A method in which a terminal transmits an uplink signal using a first cell type indicating a cell using a licensed band frequency and a second cell type indicating a cell using an unlicensed band frequency,
establishing at least one first radio bearer (RB) in which radio resources of the first cell type and radio resources of the second cell type are used for uplink transmission;
setting at least one second RB in which radio resources of the first cell type are used for uplink transmission;
including at least one first logical channel corresponding to the at least one first RB in a first logical channel group; and
including at least one second logical channel corresponding to the at least one second RB in a second logical channel group;
A transmission method of a terminal including a. According to claim 1,
Based on a frequency used by a secondary cell (SCell) operating through carrier aggregation (CA) among the licensed band frequency and the unlicensed band frequency, the SCell is set to one of the first cell type and the second cell type
Terminal transmission method. According to claim 1,
The at least one second logical channel uses radio resources of a cell group of the first cell type for uplink transmission,
The at least one first logical channel uses radio resources of a cell group of the first cell type and radio resources of a cell group of the second cell type for uplink transmission.
Terminal transmission method. According to claim 1,
The at least one second logical channel uses radio resources of a cell of the first cell type corresponding to the second logical channel group for uplink transmission,
The at least one first logical channel uses radio resources of a cell of the second cell type and a cell of the first cell type corresponding to the first logical channel group for uplink transmission.
Terminal transmission method. According to claim 1,
MAC (medium access control) CE (control element) based on at least one of the first logical channel group and the second logical channel group using a first uplink grant allocated to a cell of the second cell type. ) attempting to transmit; and
If transmission of the MAC CE fails, attempting to retransmit the MAC CE using a second uplink grant assigned to a cell of the first cell type.
A transmission method of a terminal further comprising a. According to claim 5,
The step of attempting transmission of the MAC CE,
Receiving settings for a first period for transmission of the MAC CE from a base station; and
performing transmission of the MAC CE using the first uplink grant during the first period;
Attempting retransmission of the MAC CE,
When the MAC CE transmission performed during the first period fails, performing retransmission of the MAC CE using the second uplink grant
Terminal transmission method. According to claim 1,
measuring a degree of congestion of a channel used in a cell of the second cell type; and
When the channel congestion is less than the threshold, using a first uplink grant allocated to a cell of the second cell type, based on at least one of the first logical channel group and the second logical channel group Attempting transmission of a medium access control (MAC) control element (CE)
A transmission method of a terminal further comprising a. According to claim 7,
The step of measuring the channel congestion,
Calculating the channel congestion, which is a ratio between the number of uplink grants allocated within an observation window for measuring the channel congestion and the number of successful uplink transmissions
Terminal transmission method. According to claim 7,
The step of measuring the channel congestion,
calculating the channel congestion within a search window set for measuring the channel congestion;
shifting the search window by a predetermined value smaller than the length of the search window; and
Comprising the step of calculating the channel congestion within the shifted search window
Terminal transmission method. According to claim 7,
The step of measuring the channel congestion,
calculating the channel congestion within a first search window set for measuring the channel congestion; and
Comprising the step of calculating the channel congestion within a second search window set not to overlap with the first search window
Terminal transmission method. According to claim 1,
allocating a first radio resource from a base station using at least one of a cell of the first cell type and a cell of the second cell type; and
In order to report the status of the buffer for uplink transmission to the base station, a medium access control (MAC) control element (CE) based on at least one of the first logical channel group and the second logical channel group is assigned to the first logical channel group. Transmitting to the base station through radio resources
A transmission method of a terminal further comprising a. According to claim 1,
If the second logical channel group includes a signaling radio bearer (SRB) or a logical channel for real-time traffic, allocating radio resources of a cell of the first cell type for the second logical channel group; and
When the first logical channel group includes a logical channel for non-real-time traffic, allocating radio resources of a cell of the second cell type for the first logical channel group;
A transmission method of a terminal further comprising a. A method in which a terminal transmits an uplink signal using a first cell type indicating a cell using a licensed band frequency and a second cell type indicating a cell using an unlicensed band frequency,
Allocating a first uplink radio resource for uplink transmission from a base station;
When receiving the first uplink grant from among the first uplink grant of the first cell type and the second uplink grant of the second cell type, at least one corresponding to the first cell type allocating as many radio resources as a priority bit rate (PBR) among the first uplink radio resources to each of the first logical channels in descending order of priority; and
If the first uplink radio resources remain, allocating radio resources as much as the PBR among the remaining uplink radio resources to each of at least one second logical channel corresponding to the second cell type in descending order of priority.
A transmission method of a terminal including a. According to claim 13,
The step of allocating to each of the at least one second logical channel,
When there are remaining radio resources other than the radio resources allocated to the at least one second logical channel among the remaining uplink radio resources, the remaining radio resources are selected from the at least one second logical channel in descending order of priority. further allocating to logical channels.
Terminal transmission method. According to claim 13,
When the second uplink grant is received among the first uplink grant and the second uplink grant, radio resources as much as the PBR among the first uplink radio resources are assigned to each of the at least one second logical channel. Allocating in descending order of priority; and
If the first uplink radio resources remain, additionally allocating the remaining radio resources to the at least one second logical channel in descending order of priority.
A transmission method of a terminal further comprising a. According to claim 13,
When the first uplink grant and the second uplink grant are received, the first uplink grant takes precedence over the second uplink grant for medium access control (MAC) control element (CE) transmission. step to do
A transmission method of a terminal further comprising a. A method in which a terminal transmits an uplink signal using a first cell type indicating a cell using a licensed band frequency and a second cell type indicating a cell using an unlicensed band frequency,
attempting uplink transmission using a cell of the second cell type;
determining whether the uplink transmission is successful; and
When the uplink transmission fails, at least one of a first HARQ parameter and a second HARQ parameter that is set independently for the first cell type and the second cell type and indicates the maximum number of hybrid automatic request (HARQ) retransmissions. Based on this, attempting uplink retransmission using a cell of the second cell type
A transmission method of a terminal including a. According to claim 17,
The determining step is
Recognizing failure of the uplink transmission through at least one of a physical HARQ indicator channel (PHICH) transmitted by the base station and scheduling information transmitted by the base station and indicating uplink retransmission
Terminal transmission method. According to claim 17,
allocating radio resources of the first cell type from a base station for radio link control (RLC) retransmission when the number of uplink retransmission attempts corresponds to the second HARQ parameter; and
Retransmitting the RLC PDU through radio resources for the RLC retransmission using at least one of a serial number of an RLC packet data unit (PDU) requiring retransmission at the RLC level and an HARQ process identifier used for retransmission of the RLC PDU step
A transmission method of a terminal further comprising a. According to claim 17,
If the uplink transmission fails, a first radio bearer (RB) capable of using radio resources of the first cell type and radio resources of the second cell type and radio resources of the first cell type Attempting RLC retransmission based on at least one of a first radio link control (RLC) parameter and a second RLC parameter that is set independently for an available second RB and indicates the maximum number of retransmissions
A transmission method of a terminal further comprising a.

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