KR20220135406A - Method and apparatus for activating and deactivating uplink radio resource - Google Patents

Abstract

Disclosed is a grant-free radio resource allocation method in a communication system. An operation method of a terminal comprises: a step of receiving a radio resource control (RRC) message including configured grant (CG) configuration information from a base station; a step of transmitting a CG activation request to the base station when data corresponding to a data radio block (DRB), to which the CG configuration information is applied, is generated; a step of receiving CG activation downlink control information (DCI) from the base station in response to the CG activation request; a step of transmitting CG Confirm MAC CE to the base station in response to the CG activation DCI when the CG activation DCI is received; and a step of performing uplink communication through a resource activated by the CG activation DCI among radio resources according to the CG configuration information. Accordingly, the present invention can solve problems such as unnecessary waste of uplink radio resources and time delay of uplink data transmission.

Description

Method and apparatus for activation and deactivation of uplink radio resources {METHOD AND APPARATUS FOR ACTIVATING AND DEACTIVATING UPLINK RADIO RESOURCE}

The present invention relates to a grant-free radio resource allocation technique, and more particularly, to a technique for requesting activation and deactivation of a grant-free radio resource in a mobile communication system.

With the development of information and communication technology, various wireless communication technologies are being developed. Representative wireless communication technologies include long term evolution (LTE) and new radio (NR) defined in 3rd generation partnership project (3GPP) standards. LTE may be one of 4G (4th Generation) wireless communication technologies, and NR may be one of 5G (5th Generation) wireless communication technologies.

For the processing of wireless data rapidly increasing after the commercialization of a 4G communication system (eg, a communication system supporting LTE), a frequency band of a 4G communication system (eg, a frequency band of 6 GHz or less) as well as a 4G communication system A 5G communication system (eg, a communication system supporting NR) using a frequency band higher than the frequency band of (eg, a frequency band of 6 GHz or more) is being considered. The 5G communication system may support enhanced Mobile BroadBand (eMBB), Ultra-Reliable and Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC).

On the other hand, when the CG (Configured Grant) type 2 method among the grant-free methods which is one of the uplink resource allocation methods for the terminal of the base station in the existing mobile communication system is used, the resources set according to the CG type 2 are It is activated (Activation) or deactivated (Deactivation) by the base station. For this reason, the CG resource (ie, the resource set according to CG type 2) may be activated regardless of the time when data required for uplink transmission in the terminal is generated, and thus a waste of radio resources may occur. In addition, since uplink radio resources are shared and used by several terminals connected to one base station, waste of uplink radio resources may cause a problem in that terminals requiring uplink transmission cannot perform smooth data transmission. have.

An object of the present invention for solving the above problems is to provide a method and apparatus for a terminal to request CG activation or deactivation from a base station based on the characteristics of traffic generation of uplink data generated within the terminal.

A method of operating a terminal according to a first embodiment of the present invention for achieving the above object, the step of receiving a radio resource control (RRC) message including CG (configured grant) configuration information from the base station, the CG configuration information Transmitting a CG activation request to a base station when data corresponding to an applied data radio block (DRB) occurs, receiving CG activation downlink control information (DCI) from the base station in response to the CG activation request; When the CG activation DCI is received, transmitting a CG confirm MAC CE to the base station in response to the CG activation DCI and upstream through the resources activated by the CG activation DCI among radio resources according to the CG configuration information performing link communication.

According to the present invention, based on the characteristics of traffic generation of uplink data generated in the terminal, the terminal may request the base station to activate or deactivate the CG.

The UE may check whether or not periodic uplink traffic is generated, and may request activation of CG resource allocation from the base station only if necessary, and may request deactivation immediately if not required. Accordingly, problems caused by leading activation and deactivation of CG resource allocation in the existing base station, that is, unnecessary waste of uplink radio resources and delay of uplink data transmission time, can be solved.

1 is a conceptual diagram illustrating a first embodiment of a communication system.
2 is a block diagram illustrating a first embodiment of communication nodes constituting a communication system.
3 is a flowchart illustrating a first embodiment of an uplink communication method according to a CG type 2 scheme in a communication system.
4 is a flowchart illustrating a CG deactivation request method using a CG inter-arrival timer in a terminal in a communication system.
5 is a flowchart illustrating a first embodiment of a method for requesting CG activation or deactivation using a CG inter-arrival timer when a CG activation MAC CE is used in a communication system.
6 is a flowchart illustrating a first embodiment of a method for requesting CG activation or deactivation using a CG inter-arrival timer when an RA preamble is used in a communication system.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that this does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate the overall understanding, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

A communication system to which embodiments according to the present invention are applied will be described. The communication system to which the embodiments according to the present invention are applied is not limited to the contents described below, and the embodiments according to the present invention can be applied to various communication systems. Here, a communication system may be used in the same meaning as a communication network (network).

1 is a conceptual diagram illustrating a first embodiment of a communication system.

1, the communication system 100 is a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). A plurality of communication nodes are 4G communication (eg, long term evolution (LTE), LTE-A (advanced)) defined in 3GPP (3rd generation partnership project) standard, 5G communication (eg, NR (new radio)) ) can be supported. 4G communication may be performed in a frequency band of 6 GHz or less, and 5G communication may be performed in a frequency band of 6 GHz or more as well as a frequency band of 6 GHz or less.

For example, a plurality of communication nodes for 4G communication and 5G communication is a CDMA (code division multiple access) based communication protocol, WCDMA (wideband CDMA) based communication protocol, TDMA (time division multiple access) based communication protocol, FDMA (frequency division multiple access) based communication protocol, OFDM (orthogonal frequency division multiplexing) based communication protocol, Filtered OFDM based communication protocol, CP (cyclic prefix)-OFDM based communication protocol, DFT-s-OFDM (discrete) Fourier transform-spread-OFDM) based communication protocol, OFDMA (orthogonal frequency division multiple access) based communication protocol, SC (single carrier)-FDMA based communication protocol, NOMA (Non-orthogonal multiple access), GFDM (generalized frequency) Division multiplexing)-based communication protocol, FBMC (filter bank multi-carrier)-based communication protocol, UFMC (universal filtered multi-carrier)-based communication protocol, SDMA (Space Division Multiple Access)-based communication protocol, etc. can be supported. .

Also, the communication system 100 may further include a core network. When the communication system 100 supports 4G communication, the core network may include a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), a mobility management entity (MME), and the like. have. When the communication system 100 supports 5G communication, the core network may include a user plane function (UPF), a session management function (SMF), an access and mobility management function (AMF), and the like.

On the other hand, a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-) constituting the communication system 100 4, 130-5, 130-6) may each have the following structure.

2 is a block diagram showing a first embodiment of a communication node constituting a communication system.

Referring to FIG. 2 , the communication node 200 may include at least one processor 210 , a memory 220 , and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240 , an output interface device 250 , a storage device 260 , and the like. Each of the components included in the communication node 200 may be connected by a bus 270 to communicate with each other.

However, each of the components included in the communication node 200 may not be connected to the common bus 270 but to the processor 210 through an individual interface or an individual bus. For example, the processor 210 may be connected to at least one of the memory 220 , the transceiver 230 , the input interface device 240 , the output interface device 250 , and the storage device 260 through a dedicated interface. .

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260 . The processor 210 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be configured as at least one of a read only memory (ROM) and a random access memory (RAM).

Referring back to FIG. 1 , the communication system 100 includes a plurality of base stations 110 - 1 , 110 - 2 , 110 - 3 , 120 - 1 and 120 - 2 , and a plurality of terminals 130 - 1, 130-2, 130-3, 130-4, 130-5, 130-6). base stations 110-1, 110-2, 110-3, 120-1, 120-2 and terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 The comprising communication system 100 may be referred to as an “access network”. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the cell coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the cell coverage of the third base station 110-3. have. The first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the cell coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, 120-2 is a NodeB (NodeB), an advanced NodeB (evolved NodeB), a base transceiver station (BTS), Radio base station (radio base station), radio transceiver (radio transceiver), access point (access point), access node (node), RSU (road side unit), RRH (radio remote head), TP (transmission point), TRP ( transmission and reception ooint), eNB, gNB, and the like.

Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 includes a user equipment (UE), a terminal, an access terminal, and a mobile terminal. Terminal (mobile terminal), station (station), subscriber station (subscriber station), mobile station (mobile station), portable subscriber station (portable subscriber station), node (node), device (device), Internet of Things (IoT) It may be referred to as a device, a mounted device (such as a mounted module/device/terminal or on board device/terminal).

Next, uplink communication methods according to a configured grant (CG) method will be described. Even when a method (eg, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding thereto is a method (eg, a method corresponding to the method performed in the first communication node) For example, reception or transmission of a signal) may be performed. That is, when the operation of the terminal is described, the corresponding base station may perform the operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the corresponding terminal may perform the operation corresponding to the operation of the base station.

In the CG method, configuration (Reconfiguration) and activation (Reconfiguration) and activation (Reconfiguration) by the base station RRC (Radio Resource Control) control data is performed by the CG type 1 and the base station RRC control data (Reconfiguration), and thereafter, DCI (Downlink Control Information) data There are two types of CG type 2 that are activated by

3 is a flowchart illustrating a first embodiment of an uplink communication method according to a CG type 2 scheme in a communication system.

Referring to FIG. 3 , a communication system may include a base station and a terminal. The base station may be the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 shown in FIG. 1, and the terminal is the terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the base station and the terminal may be configured the same or similar to the communication node 200 shown in FIG. 2 .

When the CG type 2 scheme is used, basic parameters necessary for CG may be set through an RRC message (eg, an RRC reconfiguration message) transmitted from the base station to the terminal. Additionally, major detailed parameters such as a configuration period for uplink resources, frequency and time resources, and Transport Block Size (TBS) may be configured by DCI transmitted from the base station to the terminal to activate the CG.

The base station may transmit an RRC message (eg, an RRC reconfiguration message) including CG configuration information to the terminal (S301). The terminal may receive an RRC message from the base station, and may set a data radio block (DRB) and a logical channel required for the CG based on information included in the RRC message, and It is possible to set basic parameters for (S302).

Example parameters for CG - frequencyHopping
- cg-DMRS-Configuration
- mcs-Table
- mcs-TableTransformPrecoder
- uci-OnPUsch, resourceAllocation
- rbg-Size
- powerControlLoopToUse
- p0-PUSCH-Alpha
- transformPrecoder
- nrofHARQ-Processes
- repK
- repK-RV
- periodicity
- configuredGrantTimer
- harq-ProcID-Offset
- configuredGrantConfigIndexMAC
- phy-PriorityIndex

In addition, the base station may allocate a CS-RNTI (Configured Scheduling - Radio Network Temporary Identifier) to the terminal instead of the existing RNTI to perform transmission and reception using CG.

When the RRC setting for the CG is completed, the base station may transmit a DCI for CG activation to the terminal to activate the CG (S303). At this time, the CG activation DCI (CG Activation DCI) may be set as follows.

DCI set value CRC (Cyclic Redundancy Check) in DCI format Scramble with CS-RNTI New Data Indicator (NDI) field 0 HARQ Process Number field 0 Redundancy Version field 0

Upon receiving the CG activation DCI, the UE may configure an uplink CG resource based on time and frequency resource information for a Physical Uplink Shared Channel (PUSCH) included in the DCI. That is, resources may be reserved in units of a period set through an RRC message based on time information (ie, slot index and symbol index) for PUSCH allocated by DCI, and frequency information for PUSCH allocated by DCI ( That is, the same frequency location and size may be periodically reserved based on a physical radio block (PRB) location and the number of PRBs). In addition, the UE may set the HARQ process ID based on the index of the slot in which the DCI is received and the number of HARQ (Hybrid Auto Repeat Request) processes set by RRC.

In addition, the terminal receiving the CG activation DCI may transmit a CG Confirm MAC (Medium Access Control) CE (Control Element) (CG Confirm MAC CE) to the base station to inform the base station that the CG activation DCI has been successfully received (S304). ). Step S304 may be omitted.

In this way, after CG is activated (S305), when data (eg, packet) corresponding to the DRB set as CG is generated, the terminal transmits the data using the CG resource set in advance through the previous steps. It can be transmitted to the base station (S306). Whenever data to be transmitted to the DRB configured as CG is issued, the UE may repeatedly perform this operation.

The base station periodically performs a DMRS (Demodulation Reference Signal) detection operation for each CG resource, detects the presence or absence of CG data transmission from the terminal based on this, and if there is transmitted data, the corresponding PUSCH can be decoded. In this case, if a decoding error of transmitted data occurs, a retransmission DCI may be generated, transmitted to the terminal, and request for retransmission. At this time, the CRC of the transmitted retransmission DCI format is scrambled with CS-RNTI and the NDI is set to '1', and the UE receiving the retransmission DCI may retransmit a TB (Transport Block) associated with the corresponding HARQ Process ID. have.

Meanwhile, in order to deactivate the CG in the base station, a CG deactivation DCI (CG deactivation DCI) may be set according to the following conditions and transmitted to the terminal (S307).

DCI set value CRC (Cyclic Redundancy Check) in DCI format Scramble with CS-RNTI NDI field 0 HARQ Process Number field 0 Redundancy Version field 0 All bits in the Modulation and Coding Scheme field One FDRA (Frequency Domain Resource Assignment) field (when FDRA Type 0) 0 FDRA (Frequency Domain Resource Assignment) field (when FDRA Type 1) One

Upon receiving the CG deactivation DCI, the terminal may transmit a CG confirm MAC CE to the base station to inform the base station that the CG deactivation DCI has been successfully received (S308). Step S308 may be omitted. In addition, the UE receiving the CG deactivation DCI may stop data transmission through the CG resource.

4 is a flowchart illustrating a CG deactivation request method using a CG inter-arrival timer in a terminal in a communication system.

Referring to FIG. 4 , in order for the terminal to determine the CG deactivation time, it may set a CG inter-arrival timer through an RRC message (eg, an RRC reconfiguration message) (S401). The CG inter-arrival timer may be included in an RRC setup or RRC reconfiguration message. When the CG is activated by the request of the base station, the UE starts driving the CG inter-arrival timer (S402), and may restart the CG inter-arrival timer whenever a packet is generated in the DRB corresponding to the CG (S403). If the started CG inter-arrival timer expires, the UE determines that packets no longer occur in the DRB corresponding to the CG, and may request the base station to deactivate the CG (S404).

[CG activation method using CG activation MAC CE]

5 is a flowchart illustrating a first embodiment of a method for requesting CG activation or deactivation using a CG inter-arrival timer when a CG activation MAC CE is used in a communication system.

Referring to FIG. 5 , the base station may transmit an RRC message (eg, an RRC reconfiguration message) including CG configuration information to the terminal (S501). The terminal may receive the RRC message from the base station, and may set the CG based on the information included in the RRC message (S502).

When data corresponding to the DRB set to the CG is generated (eg, when data corresponding to the DRB is first generated), the terminal may generate a CG activation MAC CE to the base station and transmit it to the base station (S503). Upon receiving the CG activation MAC CE, the base station may transmit a CG activation DCI for CG radio resource allocation (eg, activation of the allocated radio resource) to the corresponding terminal in response to the CG activation request (S504). Upon receiving the CG activation DCI, the terminal may transmit a CG confirm MAC CE to the base station in response thereto (S505). Step S505 may be omitted. Radio resources according to the CG configuration information may be activated by the CG activation DCI (S506).

In this way, after CG is activated, when a data packet corresponding to the DRB set to the CG is generated, the terminal may transmit the corresponding data to the base station using the allocated CG resource (S507). Whenever data to be transmitted to the DRB configured as CG is issued, the UE may repeatedly perform this operation.

[CG Deactivation Method of CG Deactivation Using MAC CE]

When the time comes to request CG deactivation, the UE may generate a CG deactivation MAC CE and transmit it to the base station (S508). Upon receiving the CG deactivation MAC CE, the base station may transmit a CG activation DCI to the corresponding UE in response to the CG deactivation request (S509). Upon receiving the CG deactivation DCI, the UE may transmit a CG confirm MAC CE to the base station in response thereto (S510). Step S510 may be omitted. And the corresponding terminal may deactivate the configured CG resource.

[How to activate CG using random access preamble]

6 is a flowchart illustrating a first embodiment of a method for requesting CG activation or deactivation using a CG inter-arrival timer when an RA preamble is used in a communication system.

Referring to FIG. 6 , an RA preamble for CG activation among Contention-Free RA (Random Access) preambles through an RRC message (eg, RRC reset message) between the base station and the terminal is set in advance to UE-dedicated. can

When the time comes to request CG activation, the terminal may transmit the RA preamble previously set for CG activation to the base station (S601). When the base station receives the RA preamble for CG activation, it may generate a random access response (RAR) message by deriving a timing advanced (TA), uplink transmission power, UL grant, and RA-RNTI. Here, a CG activation flag may be included in the RAR message (in this case, the value of the CG activation flag is set to TRUE) (S602). The terminal may configure CG resources based on information included in the RRC message received from the base station.

When the UE receives the RAR in which the CG activation flag is TRUE, Msg 3 may be transmitted based on the UL grant information in the RAR, and the CG confirm MAC CE may be included in Msg 3 (S603). Step S603 may be omitted. A CG resource may be periodically set based on the PUSCH transmitting Msg 3 (S605). And, the terminal may activate the configured CG resource (S604).

[How to deactivate CG using random access preamble]

An RA preamble for CG deactivation among Contention-Free RA preambles may be preset as UE-dedicated through an RRC message (eg, an RRC reconfiguration message) between the base station and the UE.

When the time comes to request CG deactivation, the UE may transmit the RA preamble previously set for CG deactivation to the base station (S606). The base station may generate a RAR message including a UL grant and a CG deactivation flag (in this case, a value of the CG deactivation flag is set to TRUE) (S607).

When the terminal receives the RAR in which the CG deactivation flag is TRUE, the terminal may transmit a CG confirm MAC CE message to the base station through the uplink resource allocated through the RAR (S608). Step S608 may be omitted. And, the corresponding terminal may deactivate the configured CG resource.

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer readable medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software.

Examples of computer-readable media include hardware devices specially configured to store and carry out program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a setting computer using an interpreter or the like. The hardware device described above may be configured to operate as at least one software module to perform the operations of the present invention, and vice versa.

Although it has been described with reference to the above embodiments, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. will be able

Claims (1)

A method of operating a terminal in a communication system, comprising:
Receiving a radio resource control (RRC) message including configured grant (CG) configuration information from the base station;
transmitting a CG activation request to the base station when data corresponding to a data radio block (DRB) to which the CG configuration information is applied is generated;
receiving CG activation downlink control information (DCI) from the base station in response to the CG activation request;
transmitting a CG confirm MAC CE to the base station in response to the CG activation DCI when the CG activation DCI is received; and
and performing uplink communication through a resource activated by the CG activated DCI among radio resources according to the CG configuration information.

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