KR102023672B1 - Methods for configurationing a buffer status report for next-generation mobile communication And Apparatuses thereof - Google Patents

Abstract

The present disclosure relates to a technology for transmitting and receiving a buffer status report in a new radio access network (NR). More particularly, the present invention relates to a method and apparatus for efficiently transmitting a buffer status report for a plurality of logical channel groups to a base station. In one embodiment, a method for transmitting a buffer status report (BSR) by a terminal, the method comprising: receiving allocation information on an uplink resource from a base station and a padding bit according to data transmission using an uplink resource; Determining whether the number is greater than or equal to the first value of the size of the Short BSR plus the size of the Short BSR subheader, and determining whether the number of the padding bits is greater than or equal to the first value and the number of the padding bits is greater than or equal to the first value. Determining whether there is available data for uplink transmission in at least one logical channel group (LCG) when the second value is less than the second value, and the available data for uplink transmission in at least one logical channel group is present. If present, transmitting the short truncated BSR or the long truncated BSR to the base station according to a result of comparing the number of padding bits with the first value. Provide law and apparatus.

Description

Method for configuring a buffer status report for next-generation mobile communication And Apparatuses

The present disclosure relates to a technology for transmitting and receiving a buffer status report in a new radio access network (NR). More particularly, the present invention relates to a method and apparatus for efficiently transmitting a buffer status report for a plurality of logical channel groups to a base station.

3GPP recently approved a study item "Study on New Radio Access Technology" for the study of next generation / 5G radio access technology, and based on this, RAN WG1 has frame structure, channel coding and modulation for NR (New Radio) respectively. Discussions on waveforms and multiple access schemes are underway. NR is required to be designed to meet various requirements required for each segmented and detailed usage scenario as well as improved data rate in preparation for LTE / LTE-Advanced.

As representative usage scenarios of NR, enhancement Mobile BroadBand (eMBB), massive machine type communication (MMTC) and Ultra Reliable and Low Latency Communications (URLLC) have been raised, and LTE / LTE-Advanced preparation to meet the needs of each usage scenario. Flexible frame structure design is required.

In this way, NR needs to provide services such as eMBB, mMTC, which require high-speed, high-capacity data processing, and URLLC, which requires high-speed data processing, and requires efficient scheduling considering various traffic types.

However, in the prior art, only the information on the buffer status for the four logical channel groups can be transmitted in the buffer status report, which effectively limits scheduling. In order to solve this problem, when the buffer status report is transmitted by simply increasing the number of logical channel groups, the overhead of the entire system is increased, resulting in a waste of radio resources.

Therefore, for efficient scheduling, even if the number of logical channel groups increases, the development of a technique for transmitting a buffer status report with minimum overhead is required.

In the foregoing background, the present disclosure proposes a method and apparatus for transmitting a buffer status report when a logical channel group increases while minimizing an increase in radio resource overhead.

In order to solve the above-mentioned problems, an embodiment of the present invention provides a method for transmitting a buffer status report (BSR) by a terminal, the method comprising: receiving allocation information on uplink resources from a base station and uplink resources Determining whether the number of padding bits according to data transmission is greater than or equal to a first value of a size of a short BSR and a size of a short BSR subheader, and less than a second value of a size of a long BSR and a length of a long BSR subheader; Determining whether there is available data for uplink transmission in one or more logical channel groups (LCGs) when the number of padding bits is greater than or equal to the first value and less than the second value; If there is available data for uplink transmission, short or long truncated BSR is determined according to the result of comparing the number of padding bits and the first value. It provides a method comprising transmitting a station.

In addition, according to an embodiment of the present invention, a method of receiving a buffer status report (BSR) by a base station includes transmitting allocation information on uplink resources to a terminal and at least one logical channel group of the terminal. Receiving Short Truncated BSR or Long Truncated BSR determined based on the number of padding bits according to data transmission using uplink resources when there is available data for uplink transmission in LCG) and Short Truncated BSR Or identifying available data for uplink transmission of at least one logical channel group of the terminal according to a long truncated BSR.

In addition, according to an embodiment of the present invention, a terminal for transmitting a Buffer Status Report (BSR) includes: a receiver for receiving allocation information on uplink resources from a base station and the number of padding bits according to data transmission using uplink resources; It is determined whether the size of the short BSR and the size of the Short BSR subheader is equal to or greater than the first value, and the number of padding bits is equal to or greater than the first value, and the number of padding bits is equal to or greater than the first value. If less than 2, the controller determines whether there is available data for uplink transmission in at least one logical channel group (LCG) and the available data for uplink transmission exists in at least one logical channel group. In this case, a terminal including a transmitter for transmitting a short truncated BSR or a long truncated BSR to a base station according to a result of comparing the number of padding bits with a first value. Provide the device.

In addition, an embodiment is a base station receiving a Buffer Status Report (BSR), at least one logical channel group (LCG) of a transmitter and a terminal for transmitting allocation information for uplink resources to the terminal Receiving unit and Short Truncated BSR or Long for receiving Short Truncated BSR or Long Truncated BSR determined based on the number of padding bits according to data transmission using uplink resources when there is available data for uplink transmission According to Truncated BSR, there is provided a base station apparatus including a control unit for checking available data for uplink transmission of one or more logical channel groups of a terminal.

According to the present embodiments, even when the logical channel group is increased, the base station can efficiently perform uplink resource allocation by transmitting a buffer status report with minimal radio resource overhead.

1 is a diagram illustrating an example of a layer 2 structure for a new radio access technology (New RAT).
2 is a diagram illustrating a format of a short BSR and a Truncated BSR MAC control element according to the prior art.
3 is a diagram illustrating the format of a Long BSR MAC control element according to the prior art.
4 is a diagram illustrating an example of a Short BSR or Truncated BSR MAC control element.
5 is a diagram for describing an operation of a terminal, according to an exemplary embodiment.
6 is a diagram illustrating an example of a Short Truncated BSR format according to an embodiment.
7 is a diagram illustrating an example of a long truncated BSR format according to an embodiment.
8 illustrates a logical channel group included in a long truncated BSR according to an embodiment.
9 is a diagram for describing an operation of a base station according to an exemplary embodiment.
FIG. 10 is a diagram illustrating a table for generating index information included in a 5-bit buffer size field according to an embodiment.
FIG. 11 is a diagram illustrating a table for generating index information included in a 6-bit buffer size field according to an embodiment.
12 illustrates a MAC subheader when using a fixed size MAC control element according to an embodiment.
FIG. 13 illustrates a MAC subheader when using a 16-bit L field according to an embodiment. FIG.
14 is a diagram exemplarily illustrating a Long BSR format set to a designated size according to an embodiment.
FIG. 15 is a diagram illustrating a BSR format for designating a number of logical channel groups through a BSR according to an embodiment.
16 exemplarily illustrates a Long BSR format according to another embodiment.
17 is a diagram illustrating a Long BSR format according to another embodiment.
18 is a diagram illustrating a BSR format using an extension field according to an embodiment.
19 is a diagram illustrating a terminal configuration according to an embodiment.
20 is a diagram illustrating a configuration of a base station according to an embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present specification, the wireless communication system refers to a system for providing various communication services such as voice and packet data. The wireless communication system includes a user equipment (UE) and a base station (BS).

A user terminal is a comprehensive concept of a terminal in a wireless communication, and includes a user equipment (UE) in WCDMA, LTE, HSPA, and IMT-2020 (5G or New Radio), as well as a mobile station (MS) and a UT in GSM. It should be interpreted as a concept that includes a user terminal, a subscriber station (SS), and a wireless device.

A base station or cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, an eNB, a gNode-B, and a Low Power Node. ), Sector, site, various types of antennas, base transceiver system (BTS), access point, access point (for example, transmission point, reception point, transmission / reception point), relay node ( It is meant to encompass various coverage areas such as a relay node, a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, a remote radio head (RRH), a radio unit (RU), and a small cell.

Since the various cells listed above have a base station for controlling each cell, the base station may be interpreted in two meanings. 1) the device providing the mega cell, the macro cell, the micro cell, the pico cell, the femto cell, the small cell in relation to the wireless area, or 2) the wireless area itself. In 1) all devices that provide a given radio area are controlled by the same entity or interact with each other to cooperatively configure the radio area to the base station. According to the configuration of the wireless area, a point, a transmission point, a transmission point, a reception point, and the like become one embodiment of a base station. In 2), the base station may indicate the radio area itself that receives or transmits a signal from the viewpoint of the user terminal or the position of a neighboring base station.

In the present specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

In the present specification, the user terminal and the base station are used in a comprehensive sense as two entities (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by the terms or words specifically referred to. Do not.

Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, and use a frequency division duplex (FDD) scheme, a TDD scheme, and an FDD scheme, which are transmitted using different frequencies. Mixed mode may be used.

In addition, in a wireless communication system, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers.

The uplink and the downlink transmit control information through a control channel such as a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and the like. It is composed of the same data channel to transmit data.

Downlink (downlink) may mean a communication or communication path from the multiple transmission and reception points to the terminal, uplink (uplink) may mean a communication or communication path from the terminal to the multiple transmission and reception points. In this case, in the downlink, the transmitter may be part of multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The base station performs downlink transmission to the terminals. The base station transmits downlink control information such as scheduling required for reception of a downlink data channel, which is a main physical channel for unicast transmission, and a physical downlink for transmitting scheduling grant information for transmission on an uplink data channel. The control channel can be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

There is no limitation on the multiple access scheme applied in the wireless communication system. Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Non-Orthogonal Multiple Access (NOMA), OFDM-TDMA, OFDM-FDMA, Various multiple access techniques such as OFDM-CDMA can be used. Here, the NOMA includes a sparse code multiple access (SCMA) and a low density spreading (LDS).

One embodiment of the present invention is for asynchronous radio communication evolving to LTE / LTE-Advanced, IMT-2020 via GSM, WCDMA, HSPA, and synchronous radio communication evolving to CDMA, CDMA-2000 and UMB. Can be applied.

In the present specification, a MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. Alternatively, in the present specification, the MTC terminal may mean a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, in the present specification, the MTC terminal may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC related operations. Alternatively, in the present specification, the MTC terminal supports enhanced coverage compared to the existing LTE coverage, or UE category / type defined in the existing 3GPP Release-12 or lower, or newly defined Release-13 low cost (or supporting low power consumption). low complexity) can mean UE category / type. Or, it may mean a further Enhanced MTC terminal defined in Release-14.

In this specification, a NB-IoT (NarrowBand Internet of Things) terminal refers to a terminal that supports radio access for cellular IoT. The objectives of NB-IoT technology include improved Indoor coverage, support for large scale low speed terminals, low sensitivity, low cost terminal cost, low power consumption, and optimized network architecture.

As a typical usage scenario in New Radio (NR), which is recently discussed by 3GPP, enhanced Mobile BroadBand (eMBB), massive machine type communication (MMTC), and Ultra Reliable and Low Latency Communication (URLLC) are being raised.

In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, and various messages related to NR (New Radio). May be interpreted as meaning used in the past or present, or various meanings used in the future.

For example, in the present specification, LTE and NR mean different radio access technologies, and a new radio access technology discussed in Release-15 of 3GPP will be described using NR. NR may include various differences from LTE to other frame structures, channels, and core network technologies, and may add various functions for high-bandwidth wireless transmission, high speed, and large data transmission.

Hereinafter, for convenience of understanding, a conventional radio access technology will be described in LTE, and a new radio access technology discussed in 3GPP will be described in NR. In addition, the base station may be an eNB using the LTE technology, may be a gNB using the NR technology, and will be described separately as necessary.

In addition, a cell in the present specification is used as a term encompassing a radio path, a radio link, a carrier, and the like for transmitting data, and one base station can transmit and receive data through a plurality of cells. Alternatively, the terminal may transmit and receive data using a plurality of cells through a cell controlled by two base stations. As will be described below, the description will be made by describing carrier aggregation when one base station controls a plurality of cells, and described as dual connectivity when using a plurality of cells controlled by two or more base stations.

The present disclosure relates to a method and apparatus for configuring a buffer status report format in a next generation mobile communication network (NR).

NR (New Radio)

3GPP is working on a next generation / 5G radio access technology (hereinafter referred to as NR for convenience of explanation). NR provides a new AS sublayer on top of PDCP to provide flow-based QoS.

1 is a diagram illustrating an example of a layer 2 structure for a new radio access technology (New RAT).

As shown in FIG. 1, the main services and functions of the new AS sublayer are as follows.

Mapping between a QoS flow and a data radio bearer;

Marking QoS flow ID in both DL and UL packets.

In addition, the new user plane protocol layer can be applied to the connection to the next generation core. The new user plane protocol layer is applicable for connections to the NextGen Core.A single protocol entity of the new user plane protocol layer is configured for each individual PDU session.).

Buffer status reporting procedure

The buffer status reporting procedure is a procedure used to provide the serving base station with information about data available for transmission in uplink (UL) buffers associated with the MAC entity. The RRC entity configures three timers ( for example, periodicBSR-Timer , retxBSR-Timer and logicalChannelSR-ProhibitTimer ), and reports buffer status through signaling to assign logical channels to logical channel groups for each logical channel. Control Status Repot (BSR) transmission.

The buffer status report should be triggered when the following event occurs:

Uplink data is available for one logical channel belonging to one logical channel group (LCG) for transmission in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity. Lose. And the data belongs to a logical channel group belonging to any logical channel group and having a higher priority than the priority of the logical channels for the already available data, or among the logical channels belonging to one logical channel group. No data is available for anything. The buffer status report in this case is called "regular BSR".

-When uplink resources are allocated and the number of padding bits is equal to or larger than the size of the subheader added to the MAC control element, the buffer status report is called "padding BSR".

The buffer status report when the retransmission BSR timer (retxBSR-Timer) expires and the terminal has available data for transmission on any of the logical channels belonging to the LCG is also called a "regular BSR".

-The buffer status report when the periodic BSR-Timer expires is called "Periodic BSR".

In addition, the buffer status report together with the above-described classification according to the BSR trigger type may be divided into short BSR, Truncated BSR and Long BSR depending on the format.

2 is a diagram illustrating a short BSR format according to the prior art, and FIG. 3 is a diagram illustrating a long BSR format according to the prior art.

For Regular BSR and Periodic BSR, if more than one LCG has data available for transmission in the Transmission Time Interval (TTI) where the BSR is transmitted, send a Long BSR (if more than one LCG has data available for transmission). in the TTI where the BSR is transmitted: report Long BSR). Otherwise, send a short BSR.

For a Padding BSR, the number of padding bits is equal to or greater than the Short BSR plus its subheader, but less than the Long BSR plus its subheader, and if more than one LCG is sent for the TTI to which the BSR is sent, If there is available data, transmit the Truncated BSR of the LCG with the highest priority logical channel with the available data for transmission (if the number of padding bits is equal to or larger than the size of the Short BSR plus its subheader but smaller than the size of the Long BSR plus its subheader: if more than one LCG has data available for transmission in the TTI where the BSR is transmitted: report Truncated BSR of the LCG with the highest priority logical channel with data available for transmission;). Otherwise, send a short BSR.

Otherwise, if the number of padding bits is equal to or greater than the length of the long BSR plus the subheader, the long BSR is transmitted.

As shown in FIG. 2, the Short BSR and Truncated BSR include logical channel group ID information and buffer size information. As illustrated in FIG. 3, the Long BSR sequentially includes buffer size information for four LCGs.

The BSR is transmitted to the MAC Control Element (MAC CE), and one MAC Protocol Data Unit (PDU) may include at most one MAC BSR control element.

If one BSR is included in one MAC PDU for transmission, all triggered BSRs are cancelled.

The MAC entity should transmit at most one Regular / Periodic BSR within one Transmission Time Interval (TTI).

All BSRs sent in one TTI always indicate the buffer status after all MAC PDUs have been created for this TTI. Each logical channel group must transmit at most one buffer status value per TTI. This value must be transmitted in all BSRs that carry the buffer status for this logical channel group.

In this specification, the format of a BSR is divided into a short BSR and a long BSR. Meanwhile, the Short BSR and the Short Truncated BSR may be configured in the same format, and the Long BSR and Long Truncated BSR may be configured in the same format. Accordingly, the terms Short BSR and Short Truncated BSR may be used interchangeably in terms of format, and the terms Long BSR and Long Truncated BSR may be used in terms of format. Therefore, if necessary in terms of format, short BSR, short trunked BSR, long BSR, and long trunked BSR may be used as the same meaning.

Data available for transmission or data volume

For the purpose of reporting the buffer status of the MAC layer, the UE should consider the following as the amount of data available in the RLC layer.

RLC SDUs, or segments, not yet contained within the RLC data PDU

RLC data PDUs pending for retransmission (RLC AM)

RLC data PDUs pending for initial transmission

For the purpose of reporting the buffer status of the MAC layer, the UE shall consider PDCP control PDUs and the following as the amount of data available in the PDCP layer.

For SDUs with no PDUs submitted to lower layers,

If there is an SDU that has not yet been processed by PDCP, the SDU itself

PDU if there is an SDU processed by PDCP

Except for SDUs that indicate successful delivery by the PDCP status report, start with the first SDU for delivery of those PDUs not identified by the lower layer, and then submit those PDUs to the lower layer prior to PDCP reset. Regarding SDU,

If there is an SDU that has not yet been processed by PDCP, the SDU itself

PDU if there is an SDU processed by PDCP

As described above, two types of BSR formats (Short BSR and Long BSR) are supported in the conventional LTE technology. For long BSR, only 4 logical channel groups could be included. In addition to the eMBB service, NR can provide services such as massive MTC service or URLLC service, and efficient scheduling considering various traffic types can be considered. To support this, it is necessary to increase the number of LCGs currently limited to four. However, in this case, the overhead for transmitting the buffer status report for the increased LCG could be increased. In particular, in the current buffer status report format, the buffer size field includes 6 bits as shown in FIGS. 2 and 3.

Therefore, if 3 bits are used as the Logical Channel Group Identifier (LCG ID) field, the Short BSR and Truncated BSR format of FIG. 2 may be provided as shown in FIG. 4.

4 is a diagram illustrating an example of a Short BSR or Truncated BSR MAC control element.

Referring to FIG. 4, seven reserved bits are used as the LCG ID occupies 3 bits and provides byte alignment for corresponding MAC control elements. This is an unnecessary overhead. Therefore, radio resources are wasted.

In order to solve this problem, the present disclosure provides a MAC PDU format (e.g., BSR format, BSR MAC CE format) that can provide an efficient buffer state transmission for increasing the number of LCGs currently limited to four. It is an object of the present invention to provide a method and apparatus.

Meanwhile, the present disclosure may be applied to any radio access (eg, LTE) network / terminal as well as next generation mobile communication (5G mobile / NR) terminal. For convenience of description, the base station may refer to an eNodeB and an LTE base station of the LTE / E-UTRAN, and a NR node, gNB, and gNB-CU in a 5G wireless network in which a central unit (CU) and a distribution unit (DU) are separated. , gNB-DU, or may represent a gNodeB, an NR base station in which a CU and a DU are implemented as one logical entity. Hereinafter, for convenience of description, the base station is represented, but all the aforementioned entities may be included in the scope of the term.

In addition, hereinafter, various BSR formats for transmitting buffer status reports for more than four logical channel groups in one BSR will be described with reference to each embodiment. For convenience of explanation, the case where there are eight logical channel groups will be described as an example. However, the number of logical channel groups is not limited thereto. For example, a method of providing a MAC PDU format for effectively transmitting a Short BSR, Truncated BSR, Long BSR format, or Truncated BSR will be described. In the present specification, a MAC PDU format including a BSR is described by using a BSR format or a BSR MAC CE format, and the like.

In addition, in the following embodiments, the BSR format for dividing the buffer size in logical channel group units is illustrated, but the BSR format for dividing the buffer size in logical channel units is included in the scope of the present disclosure.

In addition, although a subject for transmitting the buffer status report in the present specification is described as an example, at least one of trigger monitoring, BSR format determination, and transmission of the buffer status report may be performed in the MAC entity of the terminal. Therefore, the terminal below should be interpreted to include the MAC entity of the terminal, and may be interpreted as a MAC entity, a MAC layer, or the like.

Each embodiment described below may be applied individually or used in combination with each other.

5 is a diagram for describing an operation of a terminal, according to an exemplary embodiment.

Referring to FIG. 5, a terminal transmitting a buffer status report (BSR) may perform a step of receiving allocation information on an uplink resource from a base station (S510). For example, the terminal may receive allocation information on radio resources for transmitting uplink data according to scheduling of the base station. For example, the terminal may receive an uplink grant from the base station and receive information on radio resources for transmitting uplink data to the base station. As another example, the terminal may receive allocation information from the base station through the PDCCH.

If necessary, the terminal may transmit uplink data to the base station using allocation information. For this purpose, the terminal may transmit information for indicating that there is uplink data to be transmitted to the base station.

The terminal is whether the number of padding bits according to data transmission using an uplink resource is greater than or equal to a first value of a size of a short BSR and a size of a short BSR subheader, and is less than a second value of a length of a long BSR and a length of a long BSR subheader. The determining may be performed (S520). For example, in transmitting uplink data according to allocation information, the terminal may transmit by adding a padding bit to the uplink data according to the allocated radio resource. In this case, the terminal may add the buffer status report to the padding bits and transmit the report to the base station. Accordingly, the terminal can efficiently use the padding bits to deliver information about the amount of available data that the terminal intends to transmit to the base station.

For example, the terminal may compare the number of padding bits with the size of the MAC CE when transmitting the BSR to transmit the buffer status report by using the padding bits. For example, the terminal determines the first value by adding the short BSR subheader size to the size of the short BSR, and compares the first value with the number of padding bits. As another example, the terminal determines a second value obtained by adding the size of the long BSR and the size of the long BSR subheader, and compares the determined second value with the number of padding bits. As another example, the terminal determines whether the number of padding bits is greater than or equal to the first value and less than the second value. With reference to this result, the UE can determine whether to transmit the padding BSR.

When the number of padding bits is greater than or equal to the first value and less than the second value, the terminal may determine whether there is available data for uplink transmission in one or more logical channel groups (LCGs). (S530). If it is determined in step S520 that the number of padding bits is greater than or equal to the first value and less than the second value, the terminal may determine whether the amount of available data for uplink transmission exists in at least one logical channel group. That is, the terminal determines in step S520 whether there is enough space for the number of padding bits to transmit the padding BSR, and determines whether there is available data for BSR transmission in step S530. Based on this, the terminal may determine whether to transmit the padding BSR.

When there is available data for uplink transmission in at least one logical channel group, the terminal transmits a short truncated BSR or a long truncated BSR to the base station according to a result of comparing the number of padding bits with the first value. It may be (S540). For example, if the number of padding bits is large enough to transmit the padding BSR, and there is available data (available data) for uplink transmission in one or more logical channel groups, the terminal compares the information in step S520. The BSR is transmitted according to a result of comparing the number of one padding bits with the first value.

In this case, the transmitted BSR may be set in the format of a short trunked BSR or a long trunked BSR. The terminal may transmit the BSR to the base station using the short truncated BSR format when the number of padding bits is equal to the first value. In contrast, when the number of padding bits exceeds the first value, the terminal may transmit the BSR to the base station using the long truncated BSR format.

Hereinafter, a format of BSRs transmitted by the aforementioned terminal will be described with reference to the accompanying drawings. The format of the BSR is divided into short and long descriptions. If necessary, the short truncated BSR and the short BSR may be configured in the same format. Similarly, the Long Truncated BSR and the Long BSR may be configured in the same format. In other words, Truncated BSR is a classification according to the transmission type but not a format. Therefore, the description of the Short Truncated BSR and the Short BSR herein may be interchangeably applied as necessary, and the Long Truncated BSR and Long BSR may be interchangeably applied as necessary.

6 is a diagram illustrating an example of a Short Truncated BSR format according to an embodiment.

Referring to FIG. 6, a short truncated BSR may include a logical channel group identification field and a buffer size field. For example, the logical channel group identification field may consist of 3 bits, and the buffer size field may consist of 5 bits.

In this case, the logical channel group identification information indicates to which logical channel group the amount of available data included in the corresponding BSR is, and may include logical channel group ID information. The buffer size field includes information on the buffer size of the logical channel group indicated by the logical channel group identification field.

On the other hand, Short Truncated BSR may include only buffer size information for one logical channel group. Accordingly, the terminal should select a logical channel group to be included in the short truncated BSR. For example, the terminal may include buffer size information for one logical channel group including a logical channel having the highest priority among one or more logical channel groups. That is, priority information may be set for each logical channel, and the logical channel group refers to a group of one or more logical channels for which priority information is set. Accordingly, there exists a logical channel group to which the logical channel having the highest priority information belongs, and the short truncated BSR includes only buffer size information of one logical channel group including the logical channel having the highest priority.

7 is a diagram illustrating an example of a long truncated BSR format according to an embodiment.

Referring to FIG. 7, a long truncated BSR may include a logical channel group indication field 710 and buffer size fields 720 and 730. The logical channel group indication field 710 may indicate whether or not buffer size information for the logical channel group is included in the corresponding buffer status report (Long Truncated BSR). That is, the logical channel group indication field 710 includes information indicating whether a buffer size field exists for each logical channel group. For example, the logical channel group indication field 710 may consist of an 8-bit bitmap to indicate the presence or absence of buffer size fields 720 and 730 for each of the eight logical channel groups.

For example, the logical channel group indication field 710 and the buffer size fields 720 and 730 may be composed of 8 bits, respectively, and the logical channel group indication field 710 is available as 1 bit for each logical channel group. The case with and without uplink data may be set to 1 and 0 (or 0 and 1). For example, 1 indicates that buffer size information for the logical channel group is reported, and 0 indicates that buffer size information for the logical channel group is not reported. That is, when the value of the logical channel group indication field 710 is set to "01010100", it may indicate that buffer size information for logical channel groups 2, 4, and 6 is included in the corresponding buffer status report.

Through this, it is possible to inform the base station whether there are available uplink data for each of the eight logical channel groups through eight bits. In addition, the buffer size fields 720 and 730 are composed of 8 bits and may include buffer size information for up to eight logical channel groups.

Meanwhile, the buffer size fields 720 and 730 include index information set according to buffer size information of each logical channel group, and the index information may be mapped according to a range of buffer size information and determined according to a preset table. For example, a predetermined buffer size range may be mapped to one index, and 256 indexes may be previously stored in the terminal and the base station in the form of a table in order to correspond to 8-bit buffer size information. Accordingly, the buffer size field includes index information specified according to a table, and the base station receiving the buffer status report from the terminal checks the corresponding index information, checks the buffer size range on the table indicated by the index information, You can check the buffer size information for the logical channel group. For example, the table may be set in a form similar to that of FIG. 10 or 11. FIG. 10 illustrates an index table when the buffer size field is 5 bits, and FIG. 11 illustrates an index table when the buffer size field is 6 bits.

8 illustrates a logical channel group included in a long truncated BSR according to an embodiment.

In the case of Long Truncated BSR, the buffer status report is transmitted by using the padding bit. Therefore, buffer size information of all logical channel groups may not be transmitted. That is, buffer size information that can be transmitted compared to the Long BSR may be limited according to the number of padding bits. Therefore, the terminal should select some logical channel group and transmit Long Truncated BSR.

For example, the long truncated BSR may include buffer size information for one or more selected logical channel groups. In this case, the at least one selected logical channel group is selected based on the descending order of priority set for each logical channel, and when there are a plurality of logical channel groups including logical channels having the same priority, It may be selected based on ascending order. That is, the higher priority may be selected first, and if the priority is the same, the lower number of the logical channel group identification information (LCG ID) may be selected first.

Referring to FIG. 8, priority information may be set for each logical channel. For example, it is assumed that there are four logical channels and three logical channel groups. Logical channel 1 may be set to priority 5, logical channel 2 to priority 4, and logical channels 3 and 4 to priority 3. The priority may be set dynamically as needed, and one or more logical channels may be set to the same priority information. Priority in this description means that the higher the number, the higher the priority, but is not limited thereto. That is, priority 5 means higher priority than priority 4.

Meanwhile, the logical channel group 1 may be configured to include the logical channels 1 and 2, the logical channel group 2 to the logical channel 3, and the logical channel group 3 to include the logical channel 4.

In this case, the logical channel groups included in the above-mentioned long truncated BSR are selected from the highest priority to the lowest in the logical channels. Therefore, logical channel group 1 containing the two highest priorities is selected first. In addition, when the logical channel group may be additionally selected according to the number of padding bits, the logical channel group 2 or the logical channel group 3 including the logical channel 3 or the logical channel 4 having the next priority is selected.

However, in this case, since the logical channels have the same priority, the terminal selects the logical channel based on the ascending order of the logical channel group identification information. That is, since logical channel group 2 has lower identification information than logical channel group 3, the terminal preferentially selects logical channel group 2.

As such, the logical channel group included in the long truncated BSR is determined according to the priority of the logical channel and the identification information of the logical channel group.

9 is a diagram for describing an operation of a base station according to an exemplary embodiment.

Referring to FIG. 9, a base station receiving a buffer status report (BSR) may perform a step of transmitting allocation information on an uplink resource to a terminal (S910). For example, the base station may transmit to the terminal allocation information on radio resources that the terminal can use to transmit uplink data according to a scheduling request of the terminal. For example, the base station may receive a scheduling request from the terminal and transmit an uplink grant to the terminal. As another example, the base station may transmit allocation information through the PDCCH to the terminal. If necessary, the terminal may transmit uplink data to the base station using allocation information. For this purpose, the terminal may transmit information for indicating that there is uplink data to be transmitted to the base station.

The base station determines whether the available data for uplink transmission exists in at least one logical channel group (LCG) of the terminal based on the number of padding bits for data transmission using uplink resources. A step of receiving a BSR or a long truncated BSR may be performed (S920). For example, the base station can receive the buffer status report of the terminal through the padding bits of the uplink data transmitted by the terminal. As described above, in this case, the transmission of the buffer status report may be determined according to the comparison of the number of padding bits and the size of MAC CE of Short BSR or Long BSR.

For example, the Short Truncated BSR has a number of padding bits greater than or equal to a first value of the size of the Short BSR plus the Short BSR subheader size, and is less than a second value of the size of the Long BSR and the Long BSR subheader size. Can be received if the number is equal to the first value.

As another example, the Long Truncated BSR has a number of padding bits greater than or equal to the first value of the size of the Short BSR plus the Short BSR subheader size, and less than the second value of the size of the Long BSR and the Long BSR subheader size. May be received if the number exceeds the first value.

The base station may perform the step of identifying available data for uplink transmission of one or more logical channel groups of the terminal according to the short truncated BSR or the long truncated BSR (S930). For example, the base station may obtain information about the amount of available data that the logical channel group of the terminal intends to transmit to the base station through the padding bits of the received uplink data. However, as described above due to the limitation on the number of padding bits, each BSR includes buffer size information of the logical channel group selected by the terminal.

For example, the Short Truncated BSR includes buffer size information for one logical channel group including a logical channel having the highest priority among one or more logical channel groups, and includes a 3-bit logical channel group identification field and 5 bits. It may consist of a buffer size field of bits.

As another example, the Long Truncated BSR consists of a logical channel group indication field and a buffer size field, and the logical channel group indication field consists of an 8-bit bitmap to indicate the presence or absence of a buffer size field for each of the eight logical channel groups. have. Long Truncated BSRs contain buffer size information for one or more selected logical channel groups. The one or more selected logical channel groups are selected based on the descending order of priority set for each logical channel, and the ascending order of logical channel group identification information when a plurality of logical channel groups including logical channels having the same priority exist. Is selected.

As such, the base station may receive information about the available data for uplink transmission of the terminal by receiving the BSR from the terminal.

As described above, according to the present embodiment, even when the number of logical channel groups is increased, the terminal can transmit accurate buffer size information to the base station while minimizing system overhead.

Hereinafter, more various embodiments will be described in more detail, including the embodiment described with reference to FIGS. 1 to 9. Meanwhile, in the present specification, for convenience of understanding, the BSR format for dividing the buffer size in logical channel group units is illustrated, but the same may be applied to the BSR format for dividing the buffer size in logical channel units.

Each of the embodiments described below may be used independently, or some or all of the embodiments may be used in combination with each other.

First Embodiment: Logical Channel Group Identification Information Field (LCG  Information indicating whether to use 2-bit or 3-bit ID field) Signaling  How to configure the terminal through

As an example, if two bits are used for the LCG ID field, the above-described Short BSR and Truncated BSR MAC control element format of FIG. 2 may be used. Therefore, in this case, the short BSR or the truncated BSR can be transmitted without the overhead of 7 bits as shown in FIG. 4. Thus, unnecessary system overhead may not occur. Although NR can provide a variety of services or traffic types in addition to eMBB services, such as massive MTC services or URLLC services, in some cases logical channel / logical channel groups provided concurrently through the session in the case of NR (PDU / PDN) sessions. The number may consist of less than four. Thus, the format of FIG. 2 described above may be used.

However, in certain cases, up to eight logical channel / logical channel groups may be provided over one NR session. In this case, the aforementioned system overhead may occur.

Therefore, by dividing this case, the base station can control the use of the BSR format.

As an example, if the number of logical channel / logical channel groups simultaneously provided for one terminal is configured to be less than four (or if two channels are used for the logical channel group ID), the base station transmits the signaling to FIG. It can be indicated to use the Short BSR or Truncated BSR MAC control element format.

As another example, if it is desired to configure up to eight logical channel / logical channel group numbers simultaneously provided for one terminal (or use 3 bits for the logical channel group ID), the base station transmits signaling to the terminal. It can be instructed to use the Short BSR or Truncated BSR MAC control element format. Alternatively, the base station may instruct to use the format of FIGS. 6 to 8. That is, the base station may instruct the terminal to use a format capable of transmitting BSR for more than four logical channels or logical channel groups.

In detail, the terminal may receive information for indicating a bit of the LCG ID field to 2 bits or 3 bits from the base station through RRC signaling (or L2 signaling).

As such, the terminal may transmit the BSR using both formats, and in this case, the base station may indicate to the terminal the format to be used.

Second Embodiment: Method of Encoding Buffer Size Field to 5 Bits

For example, if the number of LCGs in NR is increased to eight (for example, three bits of the LCG ID field), the buffer size (BS) is used to provide a short BSR or Truncated BSR MAC control element through one byte. Field can be coded into 5 bits for transmission.

The buffer size level (BS level) is provided as a BS table having a coded value, and there may be two BS tables. Both BS tables can be coded with 6 bits. The UE may configure or use one table of two tables through the information indicated through RRC signaling. For example, the information indicated through the RRC signaling is transmitted through the extendedBSR-Sizes field, and when a value of the corresponding field is configured, the terminal may configure and use extended BSR size levels among two tables.

Accordingly, when eight LCG IDs are used according to the present disclosure, the terminal may store a table capable of indicating a plurality of buffer size indices, and a table to be fixed and used according to an indication of the base station or for each BSR format may be determined. In this case, unlike the above, the bits of the table may be different from each other. For example, one table may be configured with 6 bits as in the past, and the other table may be configured with 5 bits.

FIG. 10 is a diagram illustrating a table for generating index information included in a 5-bit buffer size field according to an embodiment.

For example, referring to FIG. 10, a BS table indicating a buffer size level coded as 5 bits is defined, and a Short BSR or Truncated BSR MAC control element is defined as a 3-bit LCG ID field and a 5-bit buffer size field. It can be configured and used. That is, when the buffer size field is composed of 5 bits, an index indicating the level of the buffer size may be included using the table of FIG. 10. To this end, the base station may indicate the corresponding BSR size to the terminal through RRC signaling. Alternatively, the base station may instruct the use of the corresponding BSR format through RRC signaling. Alternatively, the base station may instruct the use of the corresponding BS table through RRC signaling. Alternatively, the BS table may be configured to be used fixedly.

FIG. 11 is a diagram illustrating a table for generating index information included in a 6-bit buffer size field according to an embodiment.

As another example, a short BSR or Truncated BSR MAC control element may be configured using a specific buffer size index available through 5 bits in a conventional 6 bit coded BS table.

If there are 32 specific buffer size indices, the general BSR size level may include BS = 0 with index = 0 to 967 <BS <= 1132 with index = 31 in the Short BSR or Truncated BSR MAC control element. .

If there are 32 specific buffer size indices, as shown in FIG. 11, in the extended BSR size level, from BS = 0 with index = 0 to 4017 <BS <= 4940 with index = 31 to the Short BSR or Truncated BSR MAC control element. It may include.

If there are 31 specific buffer size indices, the general BSR size level may include BS = 0 with index = 0 and 826 <BS <= 967 with index = 30 in the Short BSR or Truncated BSR MAC control element. Index = 31 may indicate that BS> 967.

If there are 31 specific buffer size indices, the extended BSR size level may include BS = 0 with index = 0 and 3267 <BS <= 4017 with index = 30 in the Short BSR or Truncated BSR MAC control element. Index = 31 may indicate the case where BS> 4017.

In this way, an additional 5-bit buffer size field may be added to be used by the control of the base station, or the buffer size field value of 5-bit may be determined using only a part of the existing buffer size field.

On the other hand, NR can increase the transmission rate significantly. In this case, a new BS table can be introduced. The use of the corresponding BS table may be configured in the terminal through RRC signaling. Alternatively, the BS table may be configured to be used fixedly. As another example, whether a new BS table is used may be included in the BSR format and transmitted. In this case, for example, a short BSR or Truncated BSR MAC control element can be configured up to a specific buffer size index available through 5 bits in a newly coded BS table of 6 bits or 6 bits or more.

Third Embodiment: MAC Subheader  1 bit together Logical channel ID  How to Direct Information

In MAC, a MAC PDU consists of a MAC header, zero or more MAC SDUs, zero or more MAC CEs, and optionally padding. ), zero, or more MAC control elements, and optionally padding). The MAC header consists of one or more MAC subheaders. Each MAC subheader corresponds to one MAC SDU, one MAC CE, or padding.The MAC header consists of one or more MAC sub-headers and each MAC sub-header is corresponding to either a MAC SDU, a MAC CE or padding).

In NR, the MAC subheader does not include an E field. In the NR, the MAC sub-header is located just before the corresponding MAC SDUs, MAC CEs or paddles, so there is no need for an E field such as LTE. In addition, NR does not include the F2 field used to determine the size of the L field to reduce overhead. However, variable length L and F fields with two values are included. F represents a format field and L represents a length field.

12 illustrates a MAC subheader when using a fixed size MAC control element according to an embodiment. FIG. 13 illustrates a MAC subheader when using a 16-bit L field according to an embodiment. FIG.

As illustrated in FIG. 12, the size of the LCID field in the NR is 6 bits. This has been increased to support more LCID values than LTE. The L field is not included for fixed size MAC CEs. In addition, as shown in FIG. 13, the L field is included for a variable size MAC CE. The L field is included for every MAC SDU.

If you increase the number of LCGs to eight in the NR (for example, three bits of the LCG ID field), you can utilize a certain number of bits on the MAC subheader to provide a Short BSR or Truncated BSR MAC control element through one byte. have. For convenience of description, a method of utilizing 1 bit on a MAC subheader is described as an embodiment, but utilizing one or more bits on a MAC subheader is also included in the scope of the present disclosure.

For example, a Short BSR or Truncated BSR MAC control element may be configured with a 2-bit LCG ID field and a 6-bit buffer size field.

In order to distinguish the LCG ID from the 3 bits, the LCG ID can be identified / divided / used by a 3-bit combination of 2 bits of the LCG ID of the Short BSR or Truncated BSR MAC control element and 1 bit of the MAC subheader. For example, this means that one bit on the MAC subheader can use one of the R bits on the MAC subheader. As another example, this may mean that one bit on the MAC subheader uses one of the F bits on the MAC subheader.

For convenience of description, the use of a 16-bit L field is illustrated as shown in FIG. 13, but the use of any number of bits as the L field is included in the scope of the present disclosure.

At this time, it is possible to combine the LCG ID 2 bits and any 1 bit order on the MAC subheader. Or, it may combine in any order of 1 bit on the MAC subheader, LCG ID 2 bits.

Fourth Embodiment: MAC Subheader  To Indicate Buffer Size Information with One Bit on the Table

For example, a Short BSR or Truncated BSR MAC control element can be configured with a 3-bit LCG ID field and a 5-bit buffer size field. However, the buffer size field may transmit buffer size information by using the above-described table of indexes 0 to 63. Therefore, 6-bit buffer size index information cannot be transmitted in a 5-bit buffer size field.

Therefore, in order to use 6 bits for different buffer size levels, 5 bits of the buffer size field of the Short BSR or Truncated BSR MAC control element and any 1 bit on the MAC subheader are combined, and 3 bits are used to identify the LCG ID. Can be. For convenience of description, an example of using a 6-bit BS table has been described, but this is only for convenience of description and the use of any number of bits as the buffer size level is included in the scope of the present disclosure.

For example, one bit on the MAC subheader used to indicate the buffer size field may be one of R bits on the MAC subheader. As another example, this may be that one bit on the MAC subheader is one of the F bits on the MAC subheader.

In this case, the buffer size field may be combined with 5 bits in any order of 1 bit on the MAC subheader. Or any 1 bit on the MAC subheader, 5 bits in the buffer size field.

Fifth Embodiment: LCID  through By logical channel group BSR  How to distinguish between formats

As another example, an LCID may be designated to indicate a short BSR or a truncated BSR MAC control element for a specific logical channel group. For example, the LCID may have a value different from that of the Short BSR or Truncated BSR MAC control element. As another example, each of the Short BSR control elements for a specific logical channel group may have a LCID.

As another example, each of the LCIDs of the Truncated BSR MAC control elements for a specific logical channel group may be provided.

As described above, in configuring the MAC BSR Control element format through the present embodiment, the bits included in the MAC BSR Control element field and the bits included in the MAC subheader associated with it (or any of the bits included in the associated MAC subheader). The bits included in the field of the B may be used together as a value of a field included in a MAC BSR control element (or used to distinguish a value of a field included in a MAC BSR control element). This may be applied to any MAC Control element as well as the MAC BSR Control element. For example, a corresponding MAC Control is used by using a bit included in an arbitrary MAC Control element field together with a bit included in an associated MAC subheader (or a bit included in any field included in an associated MAC subheader). It can be used as a value of a field included in an element (or used to distinguish a value of a field included in a corresponding MAC Control element).

In another example, a corresponding MAC sub using a bit included in an arbitrary MAC Control element field and a bit included in an associated MAC subheader (or a bit included in any field included in an associated MAC subheader) together. It can be used as a value of a field included in a header (or used to distinguish a value of a field included in a corresponding MAC subheader).

For example, combining / combining bits included in any Layer 2 header field with bits included in any L2 payload associated with it (or bits included in any field included in the associated L2 payload). It can be used as a value of a field included in a corresponding L2 payload (or used to distinguish a value of a field included in a corresponding L2 payload).

For example, combining / combining bits included in any Layer 2 header field with bits included in any L2 payload associated with it (or bits included in any field included in the associated L2 payload). It can be used as a value of a field included in a corresponding L2 header (or used to distinguish a value of a field included in a corresponding L2 header).

On the other hand, the following further describes an embodiment that effectively sends a BSR when increasing the number of LCG to eight.

How to Use Additional BSR Formats with Specified Sizes

14 is a diagram exemplarily illustrating a Long BSR format set to a designated size according to an embodiment.

For example, the UE may transmit a Short BSR as shown in FIG. 4 if one LCG has available data for transmission in the TTI in which the BSR is transmitted.

For another example, the UE may transmit a Long BSR as shown in FIG. 14 if one or more LCGs have available data for transmission in the TTI in which the BSR is transmitted.

For another example, the UE may report the long BSR as shown in FIG. 14 if one or more LCGs have available data for transmission to the TTI in which the BSR is transmitted.

For another example, the UE may transmit a BSR having a specific size if the one or more LCGs have available data for transmission in the TTI in which the BSR is transmitted. The BSR may include one or more fields of a Logical Channel Group ID (LCG ID) field and a Buffer Size field. The above-described specific size may indicate the number of logical channel groups having available uplink data included in the BSR. This may be indicated to the terminal by the base station. For example, it may be indicated to the terminal through RRC signaling. For another example, the terminal may be instructed through the MAC CE, and an LCID (Logical Channel ID) for the MAC CE may be designated.

As another example, a BSR with a specified size can be defined and used as a Truncated BSR. Alternatively, a BSR with a specified size can be used as a new BSR that is distinguished from a Truncated BSR.

Here, the buffer size field indicates the total amount of available data through one logical channel group after all MAC PDUs are created in the corresponding TTI. The data amount is indicated by the number of bytes. This may include all data available for transmission at the RLC layer and PDCP layer (or RLC layer, PDCP layer, and New AS sublayer) (the Buffer Size field identifies the total amount of data available across all logical channels of a logical channel group after all MAC PDUs for the TTI have been built.The amount of data is indicated in number of bytes.It shall include all data that is available for transmission in the RLC layer and in the PDCP layer). As an example, the RLC and MAC headers are not taken into account in calculating the buffer size. As another example, the MAC header is not considered in the buffer size calculation, but the RLC header may be considered (included) in the buffer size calculation. This is because the RLC header can be made through preprocessing by removing the concatenation function from the RLC layer, so it may be desirable to include it in the calculation for accurate buffer size calculation. The above definition of the buffer size field may be applied to other embodiments. As another example, the MAC header and the RLC header may be considered (included) in calculating the buffer size. This is possible when considering new header processing different from LTE.

How to indicate the number of logical channel groups with available data for transmission via BSR

FIG. 15 is a diagram illustrating a BSR format for designating a number of logical channel groups through a BSR according to an embodiment.

For example, if one LCG has data available for transmission, the UE may transmit a BSR including the number of logical channel groups in the TTI in which the BSR is transmitted.

For another example, the UE may transmit the BSR including the number of logical channel groups if one or more LCGs have available data for transmission in the TTI in which the BSR is transmitted.

The BSR is the number of logical channel groups having available data for transmission (denoted by the length of FIG. 15, which is for convenience of explanation, other terms may be used), and the logical channel group ID (LCG ID) field. It can have a buffer size field. The above specific size indicates the number of logical channel groups included in the BSR.

If there are eight (all) LCGs having data available for transmission, the LCG ID field may be omitted and the buffer status report may be generated only with the buffer size field.

How to indicate the total buffer size of a logical channel group with data available for transmission

For example, the UE reports the BSR by adding the buffer sizes of the entire logical channel group having the available data for transmission to the TTI to which the BSR is transmitted, if one or more LCGs have available data for transmission. can do.

That is, the terminal may transmit the buffer status report to the base station by including information on all available data as one buffer size information, rather than dividing the buffer size information for each logical channel group.

How to indicate the buffer size sum of the available data for transmission of the remaining logical channel group

For example, if one or more LCGs have data available for transmission in the TTI to which the BSR is transmitted, the UE may include a logical channel group ID for the LCG having the highest priority and a buffer size for the LCG ID. The BSR may indicate the buffer size of the available data for the LCG ID with the available data for the rest of the transmission.

For another example, if the UE has one or more LCGs available for transmission in the TTI to which the BSR is transmitted, the UE transmits the logical channel group ID for the specific number of LCGs, the buffer size for the LCG ID, and the remaining transmissions. The BSR may indicate the buffer size of the available data for the LCG ID having the available data for the BSR. In this case, logical channel group IDs for a specific number of LCGs may be included in order of priority. The specific number may be preconfigured in the terminal or indicated by the base station. For example, a specific number may be indicated to the terminal through RRC signaling. As another example, a specific number may be indicated to the terminal via the MAC CE, and an LCID for the MAC CE may be designated. As another example, a specific number may be included in the BSR and transmitted.

How to indicate BSR by defining field indicating whether each logical channel group is included

For example, the NR may report a BSR by defining a field indicating whether each logical channel group is included in the TTI to which the BSR is transmitted, if one LCG has data available for transmission.

As another example, the NR may report a BSR by defining a field indicating whether each logical channel group is included in the TTI to which the BSR is transmitted, if one or more LCGs have data available for transmission.

The BSR may include a field indicating whether each logical channel group is included and a buffer size field. The field indicating whether each logical channel group is included in the above-described field can be indicated by setting 1 and 0 (or 0 and 1) with and without uplink data available in 1 bit for each logical channel group. have. Through this, eight bits (each bit may be designated as LI0 to LI7 or LI1 to LI8) may indicate whether there is available uplink data for each of the eight logical channel groups.

16 exemplarily illustrates a Long BSR format according to another embodiment.

The logical channel group index of the logical channel group indication field may be set to be included in ascending order as shown in FIG. 16 or 17.

Referring to FIG. 16, when the value of the logical channel group indication field is set to “01010100,” it may be indicated that buffer size information for logical channel groups 2, 4, and 6 is included in the corresponding buffer status report. The buffer size field may be configured with 6 bits as described above, or may be configured with 8 bits as shown in FIG. 17.

17 is a diagram illustrating a Long BSR format according to another embodiment.

Referring to FIG. 17, the aforementioned long BSR may include a logical channel group indication field and a buffer size (B / S) field indicating whether to include each logical channel group. The buffer size field may also be configured with 8 bits, and may include only buffer size information for the logical channel group indicated in the logical channel group indication field.

For example, the buffer size field may include only a buffer size of available uplink data of a logical channel group having available uplink data. For example, as shown in FIG. 6, when eight bits of the logical channel group indication field are "01010100" (when the second, fourth, and sixth logical channel groups have available uplink data), the second, Only the buffer size of each of the fourth and sixth logical channel groups may be included. In this case, the buffer size field may be included according to ascending priority. For example, as shown in FIG. 17, buffer size information for the second, fourth, and sixth logical channel groups may be sequentially included. Alternatively, the buffer size field may be included in the same order as the logical channel group indication field. For example, buffer size information for the sixth, fourth, and second logical channel groups may be sequentially included.

As another example, the buffer size field may include a buffer size of available uplink data of all logical channel groups.

As another example, the buffer size of the data included in the logical channel group may be included according to the priority.

To this end, the terminal may perform a step of monitoring the trigger of the regular buffer status report (Regular BSR) or periodic buffer status report (Periodic BSR). For example, the terminal may monitor whether the trigger status report triggers. The UE configures three timers (for example, periodicBSR-Timer, retxBSR-Timer and logicalChannelSR-ProhibitTimer) and monitors whether or not the trigger is performed using a periodic BSR timer and a retransmission BSR timer. In addition, by monitoring the occurrence of the above-described BSR event, it is possible to check whether the buffer status report is triggered and whether the buffer status report to be transmitted is a regular buffer status report or a periodic buffer status report. In addition, the UE may monitor the padding BSR as needed.

When there is available data for uplink transmission in one or more Logical Channel Groups (LCGs), the UE may perform the step of determining the buffer status report format as Long BSR. The terminal may determine the BSR format for the buffer status report. For example, when there is data available for uplink transmission in one or more logical channel groups in one transmission time unit (TTI), the terminal may determine a BSR format as a long BSR to transmit it. The above-described transmission time unit (TTI) may mean any physical layer transmission time unit defined in NR. For example, it may be one subframe, one slot, one minislot, n minislot, n slot, n symbol (where n is a natural number), which may be configured in the terminal through an RRC message by the base station. For another example, when the BSR is transmitted, the UE may determine the BSR format as Long BSR to transmit the available data for uplink transmission in one or more logical channel groups. For another example, when the BSR is triggered, when the available data for uplink transmission exists in at least one logical channel group, the terminal may determine the BSR format as a long BSR to transmit the same.

Thereafter, when the regular buffer status report or the periodic buffer status report is triggered, the terminal may perform a step of transmitting a buffer status report for all logical channel groups having data available for uplink transmission configured in a long BSR format to the base station. Can be. When there is data available for uplink transmission in one or more logical channel groups when a BSR is transmitted, the base station reports buffer status reports for all logical channel groups with data available for regular buffer status reporting or periodic buffer status reporting. To send.

For example, the terminal may inform the base station of the buffer status information of the terminal by transmitting a buffer status report of the Long BSR format to the base station in a regular or periodic BSR.

For example, a buffer status report configured in a long BSR format may include a logical channel group indication field and a buffer size field. In this case, the logical channel group indication field includes information indicating whether a buffer size field exists for each logical channel group in the buffer status report. In addition, the logical channel group indication field is composed of an 8-bit bitmap to indicate whether a buffer size field exists for each logical channel group.

In addition, the logical channel group indication field indicates whether a buffer size field exists for each logical channel group for eight logical channel groups, but the buffer size field indicates only the buffer size information for the logical channel group having available data in ascending order. Can be included according to.

The buffer size field is composed of 8 bits for each logical channel group, and includes index information set according to buffer size information of each logical channel group. The index information is mapped according to a range of buffer size information and determined according to a preset table. Can be.

As such, in order to minimize the overhead when the UE sets the long BSR format to transmit a buffer status report including buffer status information of all logical channel groups in which data is available, the logical channel group indication field and The Long BSR format may be configured by including a buffer size field in which buffer status information exists.

Of course, as described above, when the BSR is transmitted through the padding bit, the format of FIG. 16 or 17 described above may be applied.

How to define an extension field to indicate whether there is a logical channel added to the BSR

For example, if a single LCG has data available for transmission in a TTI in which the BSR is transmitted, the UE may transmit an BSR by defining an extension field.

For another example, the UE may transmit an BSR by defining an extended field if one or more LCGs have available data for transmission in a TTI in which the BSR is transmitted.

The BSR may include a buffer size for each logical channel group according to the priority of the logical channel group having the available data for transmission. The BSR may include information of one or more of an LCG ID field, a buffer size field, and an extension field.

The extended field is a flag (1 and 0 (or 0 and 1) to indicate whether there is an additional logical channel group with available data after that logical channel group (if more LCG (s) is / are present). Indicates the field).

For convenience of description, the corresponding field is indicated as an extension field (E in FIG. 18). This is merely for convenience of description and may use any other name.

18 is a diagram illustrating a BSR format using an extension field according to an embodiment.

Referring to FIG. 18, when the highest priority LCG ID is LCG ID 1, LCG ID 1 is included first. In the case where there is data available for LCG ID 1 and LCG ID 2, the extended field indicates 1 that there is an additional logical channel group with available data. In FIG. 13, the first E is 1 and the second E is 1 third. E is set to zero.

How to Instruct Multiple LCGs in Truncated BSR

For a Padding BSR, the number of padding bits is equal to or greater than the Short BSR plus its subheader, but less than the Long BSR plus its subheader, and if more than one LCG is sent for the TTI to which the BSR is sent, If there is data available, it transmits the Truncated BSR of the LCG with the highest priority logical channel with the data available for transmission. In the conventional LTE technology, the Padding BSR or Truncated BSR only transmits a buffer size for one logical channel having the highest priority. In NR, one or more LCG buffer sizes may be transmitted to the Padding BSR or the Truncated BSR. For example, the above-described methods may be used individually or in combination. As another example, buffer sizes may be transmitted in order of priority for as many logical channel groups as possible within the number of padding bits.

How to use the integrated BSR format

For example, one of the aforementioned methods may be used to perform buffer status transfer using one unified BSR format.

For another example, buffer status transmission may be performed using an integrated BSR format for a triggered BSR or a triggered logical channel group after defining a specific trigger criterion or according to an existing trigger criterion.

As described above, according to the present disclosure, the terminal may transmit buffer state information for the logical channel group of more than the number of logical channel groups transmitted in the related art to the base station while minimizing radio resource overhead.

The configuration of a terminal and a base station capable of performing some or all of the above-described embodiments will be described once again with reference to the drawings.

19 is a diagram illustrating a terminal configuration according to an embodiment.

Referring to FIG. 19, a terminal 1900 that transmits a buffer status report (BSR) may be configured to include a receiver 1930 for receiving allocation information on uplink resources from a base station and data transmission using uplink resources. It is determined whether the number of padding bits is greater than or equal to the first value of the size of the Short BSR and the size of the Short BSR subheader, and is less than the second value of the length of the Long BSR and the length of the Long BSR subheader. If the above value is less than the second value, the control unit 1910 determines whether there is available data for uplink transmission in at least one logical channel group (LCG) and uplink transmission to at least one logical channel group. And a transmitter 1920 for transmitting a short truncated BSR or a long truncated BSR to a base station according to a result of comparing the number of padding bits with a first value when there is available data for the base station. Can.

For example, the receiver 1930 may receive allocation information on radio resources for transmitting uplink data according to scheduling of the base station. As an example, the receiver 1930 may receive an uplink grant from a base station, and may receive information about a radio resource for transmitting uplink data to the base station. As another example, the terminal may receive allocation information from the base station through the PDCCH.

If necessary, the transmitter 1920 may transmit uplink data to the base station using allocation information. For this purpose, the transmitter 1920 may transmit information for indicating that there is uplink data to be transmitted to the base station. .

Meanwhile, in transmitting the uplink data according to the allocation information, the transmitter 1920 may add a padding bit to the uplink data according to the allocated radio resource and transmit the uplink data. In this case, the transmitter 1920 may add the buffer status report to the padding bit and transmit the report to the base station. Accordingly, the terminal 1900 may efficiently use the padding bits to transmit information about the amount of available data that the terminal intends to transmit to the base station.

For example, the controller 1910 may compare the number of padding bits and the size of the MAC CE when transmitting the BSR to transmit the buffer status report by using the padding bits. For example, the controller 1910 determines a first value by adding a short BSR subheader size to a size of a short BSR, and compares the first value with the number of padding bits. As another example, the controller 1910 determines a second value obtained by adding the size of the long BSR and the size of the long BSR subheader, and compares the determined second value with the number of padding bits. As another example, the controller 1910 determines whether the number of padding bits is greater than or equal to the first value and less than the second value. Referring to this result, the controller 1910 may determine whether to transmit the padding BSR.

If the number of padding bits is greater than or equal to the first value and less than the second value, the controller 1910 may determine whether there is an amount of available data for uplink transmission in one or more logical channel groups. That is, the controller 1910 determines whether there is enough space for the number of padding bits to transmit the padding BSR, and determines whether there is available data for BSR transmission. Based on this, the controller 1910 may determine whether to transmit the padding BSR.

If the number of padding bits is large enough to transmit the padding BSR, and the available data (available data) for uplink transmission exists in one or more logical channel groups, the controller 1910 The BSR format is determined according to the comparison result of the first value. In this case, the BSR may be set in the format of a short trunked BSR or a long trunked BSR and transmitted. In addition, the controller 1910 may control to transmit the BSR to the base station using the short truncated BSR format when the number of padding bits is equal to the first value. In contrast, when the number of padding bits exceeds the first value, the controller 1910 may control to transmit the BSR to the base station using the long truncated BSR format.

In addition, the controller 1910 independently or mutually combines various embodiments for efficiently transmitting the BSR for the logical channel group when the number of logical channel groups required to perform all the embodiments increases. To control the overall operation of the terminal to perform. The transmitter 1920 and the receiver 1930 are used to transmit and receive signals, messages, and data necessary for carrying out the above-described disclosure with the base station.

20 is a diagram illustrating a configuration of a base station according to an embodiment.

Referring to FIG. 20, a base station 2000 that receives a buffer status report (BSR) may include a transmitter 2020 for transmitting allocation information on uplink resources to a terminal and one or more logical channel groups of the terminal. Receiving unit 2030 for receiving a Short Truncated BSR or Long Truncated BSR determined based on the number of padding bits according to data transmission using uplink resources when there is available data for uplink transmission in a channel group (LCG) And a controller 2010 for checking available data for uplink transmission of one or more logical channel groups of the terminal according to the short truncated BSR or the long truncated BSR.

The transmitter 2020 may transmit, to the terminal, allocation information on radio resources that the terminal can use to transmit uplink data according to a scheduling request of the terminal. For example, the receiver 2030 may receive a scheduling request from the terminal, and the transmitter 2020 may transmit an uplink grant to the terminal. As another example, the transmitter 2020 may transmit allocation information through the PDCCH to the terminal. If necessary, the terminal may transmit uplink data to the base station 2000 using allocation information. For this purpose, the terminal may transmit information for indicating that there is uplink data to be transmitted to the base station 2000. .

Meanwhile, the receiver 2030 may receive a buffer status report of the terminal through the padding bit of the uplink data transmitted by the terminal. As described above, in this case, the transmission of the buffer status report may be determined according to the comparison of the number of padding bits and the size of MAC CE of Short BSR or Long BSR.

For example, the Short Truncated BSR has a number of padding bits greater than or equal to a first value of the size of the Short BSR plus the Short BSR subheader size, and is less than a second value of the size of the Long BSR and the Long BSR subheader size. Can be received if the number is equal to the first value.

As another example, the Long Truncated BSR has a number of padding bits greater than or equal to the first value of the size of the Short BSR plus the Short BSR subheader size, and less than the second value of the size of the Long BSR and the Long BSR subheader size. May be received if the number exceeds the first value.

The controller 2010 may obtain information on the amount of available data that the logical channel group of the terminal intends to transmit to the base station through the received padding bits of the uplink data. However, as described above due to the limitation on the number of padding bits, each BSR includes buffer size information of the logical channel group selected by the terminal.

For example, the Short Truncated BSR includes buffer size information for one logical channel group including a logical channel having the highest priority among one or more logical channel groups, and includes a 3-bit logical channel group identification field and 5 bits. It may consist of a buffer size field of bits.

As another example, the Long Truncated BSR consists of a logical channel group indication field and a buffer size field, and the logical channel group indication field consists of an 8-bit bitmap to indicate the presence or absence of a buffer size field for each of the eight logical channel groups. have. Long Truncated BSRs contain buffer size information for one or more selected logical channel groups. The one or more selected logical channel groups are selected based on the descending order of priority set for each logical channel, and the ascending order of logical channel group identification information when a plurality of logical channel groups including logical channels having the same priority exist. Is selected.

As such, the controller 2010 may receive information about the data available for uplink transmission of the terminal by receiving the BSR from the terminal.

In addition, the controller 2010 independently or mutually combines various embodiments for efficiently transmitting the BSR for the logical channel group when the number of logical channel groups required to perform all the embodiments increases. To control the overall operation of the base station to perform. The transmitter 2020 and the receiver 2030 are used to transmit and receive a signal, a message, and data necessary for carrying out the present disclosure.

The standard contents or standard documents mentioned in the above embodiments are omitted to simplify the description of the specification and form a part of the present specification. Therefore, the addition of the contents of the standard and part of the standard documents to the specification or the description in the claims should be construed as falling within the scope of the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (24)

In the method for the terminal to transmit a buffer status report (Buffer Status Report, BSR),
Receiving allocation information on an uplink resource from a base station;
The number of padding bits according to data transmission using the uplink resource is greater than or equal to a first value of the size of the short BSR and the size of the short BSR subheader, and less than a second value of the length of the long BSR and the length of the long BSR subheader. Determining cognition;
Determining whether there is available data for uplink transmission in at least one logical channel group (LCG) when the number of padding bits is greater than or equal to the first value and less than the second value; And
When there is available data for uplink transmission in the at least one logical channel group, transmitting a short truncated BSR or a long truncated BSR to the base station according to a result of comparing the number of padding bits with the first value; Including,
The transmitting step,
If the number of padding bits is equal to the first value, transmitting the Short Truncated BSR,
And when the number of padding bits exceeds the first value, transmitting the long truncated BSR. delete The method of claim 1,
The Short Truncated BSR is,
Buffer size information for one logical channel group including a logical channel having the highest priority among the one or more logical channel groups,
And a 3-bit logical channel group identification field and a 5-bit buffer size field. The method of claim 1,
The Long Truncated BSR is,
It consists of logical channel group indication field and buffer size field.
The logical channel group indication field indicates whether a buffer size field exists for each logical channel group. The method of claim 4, wherein
The logical channel group indication field is
And an 8-bit bitmap to indicate the presence of the buffer size field for each of the eight logical channel groups. The method of claim 4, wherein
The buffer size field is
Each of the logical channel group is composed of 8 bits, and includes index information set according to the buffer size information of each logical channel group,
And the index information is mapped according to a range of buffer size information and determined according to a preset table. The method of claim 4, wherein
The Long Truncated BSR is,
Contains buffer size information for one or more selected logical channel groups,
The at least one selected logical channel group is
The method is selected based on the descending order of priority set for each logical channel, and is selected based on the ascending order of logical channel group identification information when a plurality of logical channel groups including the same logical channel exist. How to. In the method of receiving a buffer status report (Buffer Status Report, BSR),
Transmitting allocation information on an uplink resource to a terminal;
Short Truncated determined based on the number of padding bits according to data transmission using the uplink resource when available data for uplink transmission exists in at least one logical channel group (LCG) of the terminal. Receiving a BSR or Long Truncated BSR; And
Identifying available data for uplink transmission of at least one logical channel group of the terminal according to the short truncated BSR or long truncated BSR,
The Short Truncated BSR is,
The number of padding bits is equal to or greater than a first value obtained by adding a size of a short BSR and a size of the short BSR subheader, and less than a second value by adding a size of a long BSR and a size of the long BSR subheader.
And received if the number of padding bits is equal to the first value. delete The method of claim 8,
The Long Truncated BSR is,
The number of padding bits is equal to or greater than a first value obtained by adding the size of the Short BSR and the size of the Short BSR subheader, and is less than a second value obtained by adding the size of the Long BSR and the size of the Long BSR subheader.
Received when the number of padding bits exceeds the first value. The method of claim 8,
The Short Truncated BSR is,
Buffer size information for one logical channel group including a logical channel having the highest priority among the one or more logical channel groups,
And a 3-bit logical channel group identification field and a 5-bit buffer size field. The method of claim 8,
The Long Truncated BSR is,
It consists of logical channel group indication field and buffer size field.
The logical channel group indication field is
And an 8-bit bitmap to indicate the presence of the buffer size field for each of the eight logical channel groups. In the terminal for transmitting a Buffer Status Report (BSR),
A receiving unit for receiving allocation information on uplink resources from the base station;
The number of padding bits according to data transmission using the uplink resource is greater than or equal to a first value of the size of the short BSR and the size of the short BSR subheader, and less than a second value of the length of the long BSR and the length of the long BSR subheader. To determine whether
A controller for determining whether there is available data for uplink transmission in at least one logical channel group (LCG) when the number of padding bits is greater than or equal to the first value and less than the second value; And
Transmitter for transmitting a Short Truncated BSR or Long Truncated BSR to the base station according to the comparison result of the number of padding bits and the first value when there is available data for uplink transmission in the at least one logical channel group Including,
The transmitting unit,
If the number of padding bits is equal to the first value, transmitting the Short Truncated BSR,
And when the number of the padding bits exceeds the first value, transmitting the long truncated BSR. delete The method of claim 13,
The Short Truncated BSR is,
Buffer size information for one logical channel group including a logical channel having the highest priority among the one or more logical channel groups,
And a 3-bit logical channel group identification field and a 5-bit buffer size field. The method of claim 13,
The Long Truncated BSR is,
It consists of logical channel group indication field and buffer size field.
The logical channel group indication field indicates whether a buffer size field exists for each logical channel group. The method of claim 16,
The logical channel group indication field is
A terminal comprising an 8-bit bitmap to indicate the presence of the buffer size field for each of the eight logical channel groups. The method of claim 16,
The buffer size field is
Each of the logical channel group is composed of 8 bits, and includes index information set according to the buffer size information of each logical channel group,
And the index information is mapped according to a range of buffer size information and determined according to a preset table. The method of claim 16,
The Long Truncated BSR is,
Contains buffer size information for one or more selected logical channel groups,
The at least one selected logical channel group is
The method is selected based on the descending order of priority set for each logical channel, and is selected based on the ascending order of logical channel group identification information when a plurality of logical channel groups including the same logical channel exist. Terminal. In the base station receiving the Buffer Status Report (BSR),
A transmitter for transmitting allocation information on an uplink resource to a terminal;
Short Truncated determined based on the number of padding bits according to data transmission using the uplink resource when available data for uplink transmission exists in at least one logical channel group (LCG) of the terminal. Receiving unit for receiving the BSR or Long Truncated BSR; And
And a controller for checking available data for uplink transmission of at least one logical channel group of the terminal according to the short truncated BSR or long truncated BSR.
The Short Truncated BSR is,
The number of padding bits is equal to or greater than a first value obtained by adding a size of a short BSR and a size of the short BSR subheader, and less than a second value by adding a size of a long BSR and a size of the long BSR subheader.
And is received when the number of padding bits is equal to the first value. delete The method of claim 20,
The Long Truncated BSR is,
The number of padding bits is equal to or greater than a first value obtained by adding the size of the Short BSR and the size of the Short BSR subheader, and is less than a second value obtained by adding the size of the Long BSR and the size of the Long BSR subheader.
And is received if the number of padding bits exceeds the first value. The method of claim 20,
The Short Truncated BSR is,
Buffer size information for one logical channel group including a logical channel having the highest priority among the one or more logical channel groups,
And a logical field group identification field of three bits and a buffer size field of five bits. The method of claim 20,
The Long Truncated BSR is,
It consists of logical channel group indication field and buffer size field.
The logical channel group indication field is
A base station comprising an 8-bit bitmap to indicate the presence of the buffer size field for each of the eight logical channel groups.

Images