KR102207499B1 - Method for determining transmission path of uplink signal transmitted from terminal and apparatus thereof - Google Patents

Abstract

Disclosed is a method of determining a transmission path of an uplink signal transmitted from a terminal. A method of operating a second base station in a communication system including a first base station, a second base station, and a terminal according to an embodiment includes the steps of: receiving the strength of a downlink signal transmitted from the second base station to the terminal; Measuring a signal-to-noise interference ratio of an uplink signal transmitted from a terminal to a second base station; Generating a control signal indicating a transmission path of an uplink signal of a terminal based on a first condition related to a strength of a downlink signal and a second condition related to a signal-to-noise interference ratio of an uplink signal; And transmitting the control signal to the first base station.

Description

A method and apparatus for determining a transmission path of an uplink signal transmitted from a terminal TECHNICAL FIELD [METHOD FOR DETERMINING TRANSMISSION PATH OF UPLINK SIGNAL TRANSMITTED FROM TERMINAL AND APPARATUS THEREOF}

The following embodiments relate to a method and apparatus for determining a transmission path of an uplink signal transmitted from a terminal, and, for example, to a technology related to a 5G communication service.

The official name of 5G communication is IMT-2020, which is a fifth generation communication standard defined by the International Telecommunication Union (ITU). 3GPP, an industry standard organization, aims to propose the content of standards completed in 2019 to ITU-R and obtain final approval by IMT-2020.

The ITU defines three main characteristics of 5G communication. The first major feature of 5G communication is'Enhanced Mobile Broadband (eMBB)'. For example, 5G communication can achieve speeds of up to 20 Gbps. The second major feature of 5G communication is'Ultra-reliable and Low Latency Communication (URLLC)'. For example, in 5G communication, the response speed can be reduced to 0.25ms. The third major characteristic of 5G communication is'Massive Machin Type Communication (M-MTC)'. For example, in 5G communication, a maximum of 1 million terminals/km ² can be connected.

In 3GPP, a non-standalone mode (NSA) was added as an intermediate step in progressing the IMT-2020 standard. The non-single mode is a network that connects 5G access network equipment to the 4G core network, and is characterized by using the 4G network together instead of using the 5G network alone. The non-standalone mode has the advantage of preventing data loss by using a 4G (LTE) network together when the network is not sufficiently established in the initial stage of 5G commercialization.

In a communication system including a first base station, a second base station, and a terminal according to an embodiment, a method of operating the second base station includes: receiving a strength of a downlink signal transmitted from the second base station to the terminal; Measuring a signal-to-noise interference ratio of an uplink signal transmitted from the terminal to the second base station; Generating a control signal indicating a transmission path of the uplink signal of the terminal based on a first condition related to the strength of the downlink signal and a second condition related to a signal-to-noise interference ratio of the uplink signal; And transmitting the control signal to the first base station.

According to an embodiment, the characteristics of the first base station and the characteristics of the second base station are different, and the characteristics of the first base station and the characteristics of the second base station are each of an uplink speed, a downlink speed, and a delay time. It may include at least one.

According to an embodiment, the first base station may include a base station that provides a communication service through a 4G network, and the second base station may include a base station that provides a communication service through a 5G network.

According to an embodiment, the transmission path includes a first section corresponding to uplink transmission using the first base station, a second section corresponding to uplink transmission using the second base station, and the first base station and the second base station. 2 It may include any one of the third period corresponding to the uplink transmission using the base station.

According to an embodiment, generating the control signal may include determining the first condition by comparing the intensity of the downlink signal with at least one predetermined reference value related to the intensity of the downlink signal. have.

According to an embodiment, generating the control signal comprises determining the second condition by comparing a signal-to-noise interference ratio of the uplink signal with a predetermined reference value related to the signal-to-noise interference ratio of the uplink signal. It may include steps.

According to an embodiment, in the generating of the control signal, when the strength of the downlink signal is less than a first reference value, a field corresponding to the transmission path in the control signal is used as first information indicating the first base station. Setting up; Setting the field in the control signal as second information indicating the first base station and the second base station when the strength of the downlink signal exceeds a second reference value; And when the strength of the downlink signal exceeds the first reference value and is less than the second reference value, and when the signal-to-noise interference ratio of the uplink signal exceeds a third reference value, the field in the control signal is used as the second information. Setting up; And setting the field in the control signal as the first information when the signal-to-noise interference ratio of the uplink signal is less than the third reference value.

According to an embodiment, the generating of the control signal includes: setting a first parameter related to the amount of transmission data of the terminal to a value corresponding to a maximum value; And setting a second parameter related to the transmission path of the terminal to a value indicating one of the first base station and the second base station, wherein the amount of transmission data of the terminal is smaller than the first parameter, The transmission path of the terminal may be determined by the value of the second parameter.

According to an embodiment, based on the control signal, the first base station controls the terminal to not transmit the uplink signal to the second base station, or transmits the uplink signal to the first base station and the second base station. The terminal can be controlled to transmit to the base station.

According to an embodiment, the receiving of the strength of the downlink signal includes: receiving the strength of the downlink signal transmitted periodically based on a predetermined time interval; And receiving the strength of the downlink signal transmitted aperiodically based on a trigger condition related to the strength of the downlink signal.

According to an embodiment, the receiving of the strength of the downlink signal comprises: receiving a report including the strength of the downlink signal from the terminal; And it may include at least one of receiving the report transmitted from the terminal from the first base station.

According to an embodiment, when the transmission path of the uplink signal includes the first base station and the second base station, the method of operating the second base station includes: receiving a second uplink signal from the terminal; And transmitting the second uplink signal to the EPC, wherein the second uplink signal and the first uplink signal transmitted to the EPC through the first base station are combined in the EPC and transmitted to a destination. Can be.

According to an embodiment, when the transmission path of the uplink signal includes the first base station and the second base station, the method of operating the second base station includes: receiving a second uplink signal from the terminal; Receiving a first uplink signal from the first base station; Combining the first uplink signal and the second uplink signal; And transmitting the combined signal to the EPC, wherein the combined signal transmitted to the EPC may be transmitted to a destination through the EPC.

A second base station performing an operation in a communication system including a first base station, a second base station, and a terminal according to an embodiment includes a memory in which a program is recorded; And a processor that performs the program, wherein the program includes: receiving a strength of a downlink signal transmitted from the second base station to the terminal; Measuring a signal-to-noise interference ratio of an uplink signal transmitted from the terminal to the second base station; Generating a control signal indicating a transmission path of the uplink signal of the terminal based on a first condition related to the strength of the downlink signal and a second condition related to a signal-to-noise interference ratio of the uplink signal; And transmitting the control signal to the first base station.

1 is a diagram for explaining a communication system related to uplink transmission according to an embodiment.
2 is a diagram illustrating a transmission path of an uplink signal of a terminal according to a strength of a downlink signal transmitted from a second base station to a terminal and a signal-to-noise interference ratio of an uplink signal transmitted from a terminal to a second base station according to an embodiment. It is a drawing for explanation.
3 is a diagram for explaining a communication system related to generation of a control signal indicating a transmission path of an uplink signal according to an embodiment.
4 is an exemplary diagram of uplink transmission according to an embodiment.
5A to 5C are diagrams for explaining the operation of a split bearer according to an embodiment.
6 is a flowchart illustrating an operation method of a second base station for uplink transmission according to an embodiment.
7 is a flowchart illustrating an operation method of a second base station determining a transmission path of an uplink signal of a terminal by adjusting one or more parameter values according to an embodiment.
8 is a diagram for describing a method of registering a PDCP data PDU with a first RLC entity or a second RLC entity according to an embodiment.
9 is a diagram for describing a method of determining a transmission path of an uplink signal of a terminal based on a PDCP data amount of a terminal and a value of an ul-DataSplitThreshold parameter according to an embodiment.

Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only, and may be changed in various forms and implemented. Accordingly, the embodiments are not limited to a specific disclosure form, and the scope of the present specification includes changes, equivalents, or substitutes included in the technical idea.

Although terms such as first or second may be used to describe various components, these terms should be interpreted only for the purpose of distinguishing one component from other components. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

When a component is referred to as being "connected" to another component, it is to be understood that it may be directly connected or connected to the other component, but other components may exist in the middle.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate that the described feature, number, step, action, component, part, or combination thereof exists, but one or more other features or numbers, It is to be understood that the presence or addition of steps, actions, components, parts or combinations thereof does not preclude the possibility of preliminary exclusion.

Unless otherwise defined, all terms, including technical or scientific terms, used herein have the same meaning as commonly understood by one of ordinary skill in the relevant technical field. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this specification. Does not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The same reference numerals in each drawing indicate the same members.

1 is a diagram for explaining a communication system related to uplink transmission according to an embodiment.

Referring to FIG. 1, a communication system related to uplink transmission may include a terminal 110, a first base station 120, a second base station 130, and an evolved packet core (EPC) 140. The terminal 110 is a device capable of transmitting an uplink signal and receiving a downlink signal in a communication system, and may include various types, such as a tablet and a smart phone. The first base station 120 and the second base station 130 may be wireless communication facilities that connect a network and a terminal for a wireless communication service. The EPC 140 may be a core network structure that receives a signal from a base station and transmits a signal to an IP Multimedia Subsystem (IMS) or other network.

The characteristics of the first base station 120 and the characteristics of the second base station 130 may be different, and the characteristics of the first base station 120 and the characteristics of the second base station 130 are uplink speed, downlink speed, and It may include at least one of the delay times. For example, when the first base station 120 provides a communication service through a 4G network and the second base station 130 provides a communication service through a 5G network, the uplink speed of the second base station 130 and the /Or the downlink speed may be higher than the uplink speed and/or downlink speed of the first base station 120, and the delay time of the second base station 130 may be shorter than the delay time of the first base station 120 .

The terminal 110 may receive a downlink signal from a base station and transmit an uplink signal to the base station. According to an embodiment, the terminal 110 may determine a transmission path for transmitting an uplink signal. The transmission path is a path through which an uplink signal is transmitted, and may include, for example, at least one of the first base station 120 and the second base station 130. The transmission path may be a period in which an uplink signal is transmitted.

The terminal 110 may determine a transmission path for transmitting an uplink signal based on one or more parameter values. According to an embodiment, the transmission path of the uplink signal may be determined based on the ul-DataSplitThreshold parameter and the PrimaryPath parameter. The ul-DataSplitThreshold parameter may correspond to the first parameter of the claim, and the PrimaryPath parameter may correspond to the second parameter of the claim.

The ul-DataSplitThreshold parameter is a threshold specified in TS 36.323 [8], and a transmission path of an uplink signal may be determined based on a value of the ul-DataSplitThreshold parameter. The ul-DataSplitThreshold parameter value may be a value compared with the amount of data scheduled to be transmitted from the terminal. For example, when the value of the ul-DataSplitThreshold parameter is b100, the transmission path of the uplink signal may be determined based on whether the amount of data scheduled to be transmitted from the terminal exceeds 100 bytes. When the amount of data scheduled to be transmitted from the terminal is larger than the value of the ul-DataSplitThreshold parameter, the transmission path of the uplink signal may be determined by the first base station and the second base station. E-UTRAN can configure these fields only for split DRB (split DRB).

The PrimaryPath parameter may be a parameter that determines a transmission path of an uplink signal transmitted from the terminal when the amount of data scheduled to be transmitted from the terminal is less than the value of the ul-DataSplitThreshold parameter. According to an embodiment, when the amount of data scheduled to be transmitted from the terminal is less than the ul-DataSplitThreshold parameter value, if the PrimaryPath parameter value is set to 0, the transmission path of the uplink signal may be determined as the first base station. On the other hand, when the amount of data scheduled to be transmitted from the terminal is smaller than the ul-DataSplitThreshold parameter value, if the PrimaryPath parameter value is set to 1, the transmission path of the uplink signal may be determined as the second base station.

Table 1 below defines an operation in which a terminal transmits an uplink signal according to an embodiment.

Here, PDCP is an abbreviation of Packet Data Convergence Protocol, PDU is an abbreviation of Protocol Data Unit, and RLC is an abbreviation of Radio Link Control. Referring to Table 1, PDCP pending for initial transmission in two related RLC entities When the total amount of the data volume and the RLC data volume is less than the value of the ul-DataSplitThreshold parameter, the PDCP data PDU may be registered with the first RLC entity. On the other hand, when the total amount of the PDCP data volume and the RLC data volume is greater than the ul-DataSplitThreshold parameter, the PDCP data PDU may be registered with the first RLC entity or the second RLC entity.

More details related to determining the transmission path of the uplink signal of the terminal based on the ul-DataSplitThreshold parameter and the PrimaryPath parameter will be described later with reference to FIG. 7.

More details related to registering the PDCP data PDU to the first RLC entity or the second RLC entity will be described later with reference to FIG. 8.

Further details related to comparing the total amount of the PDCP data volume and the RLC data volume with the ul-DataSplitThreshold parameter will be described later with reference to FIG. 9.

The terminal 110 may transmit an uplink signal to at least one of the first base station 120 and the second base station 130 according to the determined transmission path. For example, the terminal 110 may transmit an uplink signal only to the first base station 120 or may transmit an uplink signal to the first base station 120 and the second base station 130. When a transmission path including a plurality of base stations is determined, the uplink signal may be divided and transmitted through a plurality of base stations, thereby improving the transmission speed of the uplink signal. Alternatively, transmission diversity may be improved by overlapping the same uplink signal and transmitting it through a plurality of base stations.

Hereinafter, for convenience of description, the transmission path is i) a first transmission path for transmitting an uplink signal using only the first base station 120, and ii) the first base station 120 and the second base station 130 together. Embodiments in which any one of the second transmission paths for transmitting the uplink signal is selected will be described. However, these embodiments are only exemplary, and the embodiments are substantially applicable to scenarios in which an uplink signal is transmitted using only the second base station 130 or an uplink signal is transmitted using three or more base stations. It can be applied in the same way.

According to an embodiment, the transmission path is based on the strength of the downlink signal transmitted from the second base station 130 to the terminal, and the signal-to-noise interference ratio of the uplink signal transmitted from the terminal to the second base station 130. Can be determined. The transmission path may be determined by the second base station 130. The transmission path is i) a first transmission path that transmits an uplink signal using only the first base station 120, and ii) an uplink signal is transmitted using both the first base station 120 and the second base station 130 In the case of including a second transmission path, whether or not the terminal 110 transmits an uplink signal to the second base station 130 may be determined according to the transmission path.

The terminal 110 may receive a downlink signal from the second base station 130. The terminal 110 may measure the strength of the downlink signal received from the second base station 130. The terminal 110 may transmit the measured strength of the downlink signal to the first base station 120 or the second base station 130. For example, the terminal 110 may transmit a measurement report (MR) including the strength of a downlink signal received from the second base station 130.

The second base station 130 may receive the strength of the downlink signal from the terminal 110. Depending on the design of the communication system, the second base station 130 may directly receive the strength of the downlink signal from the terminal 110 or may receive the strength of the downlink signal through the first base station 120. The strength of the downlink signal may be transmitted periodically based on a predetermined time interval, or may be transmitted aperiodically based on a trigger condition related to the strength of the downlink signal. For example, the strength of the downlink signal may be periodically transmitted every 0.1 seconds, or may be transmitted aperiodically whenever the strength of the downlink signal changes by 1 dBm or more. Alternatively, the strength of the downlink signal may be transmitted aperiodically through a trigger condition based on comparison with a predetermined threshold value.

The second base station 130 may receive an uplink signal from the terminal 110. The second base station 130 may measure a signal-to-noise interference ratio of the uplink signal received by the terminal 110.

Based on the signal-to-noise interference ratio of the uplink signal received from the terminal 110 and the strength of the downlink signal transmitted from the second base station 130 to the terminal 110, the second base station 130 It is possible to generate a control signal indicating the transmission path of. More details related to the operation of generating the control signal in the second base station 130 will be described later with reference to FIGS. 2 and 7.

The first base station 120 and the second base station 130 may transmit the uplink signal received from the terminal 110 to the EPC 140. According to an embodiment, when the first base station 120 and the second base station 130 receive an uplink signal from the terminal 110, the first base station 120 transmits the received uplink signal to the second base station ( 130), and the second base station 130 may combine a plurality of uplink signals and transmit them to the EPC 140. In this case, the EPC 140 may receive the combined signal and transmit it to the destination. According to an embodiment, when the first base station 120 and the second base station 130 receive an uplink signal from the terminal 110, the first base station 120 transmits the received uplink signal to the EPC 140. And the second base station 130 may transmit the received uplink signal to the EPC 140. In this case, the EPC 140 may combine the received uplink signals and transmit them to the destination. When the EPC 140 receives an uplink signal from one base station, the uplink signal may be transmitted from the EPC 140 to a destination. The destination may include IMS, and may include other networks such as the Internet.

2 is a diagram illustrating a transmission path of an uplink signal of a terminal according to a strength of a downlink signal transmitted from a second base station to a terminal and a signal-to-noise interference ratio of an uplink signal transmitted from a terminal to a second base station according to an embodiment It is a drawing for explanation.

2, a second base station indicates a transmission path of an uplink signal based on a signal-to-noise interference ratio of an uplink signal received from a terminal and a strength of a downlink signal transmitted from the second base station to the terminal. It can generate control signals. The terminal may correspond to the terminal 110 of FIG. 1, and the second base station may correspond to the second base station 130 of FIG. 1. According to an embodiment, the strength of the downlink signal transmitted from the second base station to the terminal may be included in an MR that the second base station receives from the terminal.

When the strength of the downlink signal is less than a first predetermined reference value in relation to the generation of the control signal, a field corresponding to the transmission path in the control signal may be set as first information indicating the first base station (210, 240). . The first base station may correspond to the first base station 120 of FIG. 1. When the strength of the downlink signal exceeds a second predetermined reference value in relation to the generation of the control signal (the second reference value may be characterized by exceeding the first reference value), a field corresponding to a transmission path in the control signal May be set as second information indicating the first base station and the second base station (230, 260).

When the strength of the downlink signal exceeds the first reference value and is less than the second reference value, the second base station is also uplinked by comparing the signal-to-noise interference ratio of the uplink signal with a third reference value predetermined in relation to the generation of the control signal. It is possible to determine whether a signal is to be transmitted. Specifically, when the signal-to-noise interference ratio of the uplink signal exceeds the third reference value, a field corresponding to the transmission path in the control signal may be set as second information indicating the first base station and the second base station (220). . On the other hand, when the signal-to-noise interference ratio of the uplink signal is smaller than the third reference value, a field corresponding to a transmission path in the control signal may be set as first information indicating the first base station (250).

When the strength of the downlink signal matches the first reference value, the field corresponding to the transmission path in the control signal may be set as first information indicating the first base station (210, 240), and the signal-to-noise of the uplink signal It may be determined whether or not an uplink signal is to be transmitted to the second base station by comparing the interference ratio with a predetermined third reference value (220 and 250). When the strength of the downlink signal matches the second reference value, it may be determined whether or not the uplink signal is to be transmitted to the second base station by comparing the signal-to-noise interference ratio of the uplink signal with a predetermined third reference value (220, 250), a field corresponding to a transmission path in the control signal may be set as second information indicating the first base station and the second base station (230, 260).

In the case where it is determined whether or not the uplink signal is transmitted to the second base station by comparing the signal-to-noise interference ratio of the uplink signal with the third reference value, when the signal-to-noise interference ratio of the uplink signal coincides with the third reference value , The field corresponding to the transmission path in the control signal may be set as second information indicating the first base station and the second base station (220), and the field corresponding to the transmission path in the control signal is a first base station indicating the first base station. It may be set as information (250).

According to an embodiment, the first base station may be a base station that provides a communication service through a 4G network, and the second base station may be a base station that provides a communication service through a 5G network. According to an embodiment, the first reference value may be -110dBm, the second reference value may be -95dBm, and the third reference value may be 4dB. When the strength of the downlink signal is less than -110dBm, a field corresponding to a transmission path in the control signal may be set to indicate a base station providing a communication service through a 4G network (210, 240). When the strength of the downlink signal exceeds a predetermined -95dBm, the field corresponding to the transmission path in the control signal indicates the base station providing communication service through the 4G network and the indicator station providing communication service through the 5G network. Can be set (230, 260). When the downlink signal strength has a value between -110dBm and -95dBm and the signal-to-noise interference ratio of the uplink signal exceeds 4dB, the field corresponding to the transmission path in the control signal provides communication service through the 4G network. It can be set to indicate a base station and an indication station that provides a communication service through a 5G network (220). When the downlink signal strength is between -110dBm and -95dBm and the signal-to-noise interference ratio of the uplink signal is less than 4dB, the field corresponding to the transmission path in the control signal provides communication service through the 4G network. It can be set to indicate the base station (250).

3 is a diagram for explaining a communication system related to generation of a control signal indicating a transmission path of an uplink signal according to an embodiment.

Referring to FIG. 3, a communication system related to generating a control signal indicating a transmission path of an uplink signal may include a terminal 301, a first base station 302, and a second base station 303. The terminal 301 may correspond to the terminal 110 of FIG. 1, the first base station 302 may correspond to the first base station 120 of FIG. 1, and the second base station 303 may correspond to the terminal 110 of FIG. 1. It may correspond to the second base station 130.

According to an embodiment, the second base station 303 may be added to a communication system for performing uplink transmission in the terminal 301 using the first base station 302. In order to add the second base station 303 to the communication system, the first base station 302 may transmit a signal including an additional request to the second base station 303 (304). When the second base station 303 normally receives the signal including the additional request, the second base station 303 may transmit a response signal to the first base station 302 (305). The response signal may include information indicating that a signal including an additional request has been normally received and information indicating whether the second base station 303 can be added to the communication system.

The first base station 302 may receive a response signal from the second base station 303 and check the information. When the response signal includes information indicating that the second base station 303 cannot be added to the communication system, the second base station 303 may not be added to the communication system. When the response signal includes information informing that the second base station 303 can be added to the communication system, the first base station 302 includes a request to change the structure of a radio resource control (RRC) connection to the terminal 301 It is possible to transmit a signal (306). The signal including the request to change the structure of the RRC connection corresponding to step 306 may include a request to set the ul-DataSplitThreshold parameter value as a default value. According to an embodiment, the signal including the request to change the structure of the RRC connection corresponding to step 306 may also include a request to set the PrimaryPath parameter value as a default value. The ul-DataSplitThreshold parameter may correspond to the ul-DataSplitThreshold parameter of FIG. 1, and the PrimaryPath parameter may correspond to the PrimaryPath parameter of FIG. 1.

Upon receiving the signal including the request for changing the structure of the RRC connection, the terminal 301 may transmit a signal including information indicating that the structure of the RRC connection has changed to the first base station 302 (307). Upon receiving a signal including information indicating that the structure of the RRC connection has been changed, the first base station 302 transmits a signal including information indicating that the second base station 303 has been added to the communication system to the second base station 303. Can transmit (308).

Through steps 306 and 307, the terminal 301 and the second base station 303 may exchange setting values necessary for transmitting downlink and uplink data. The terminal 301 may perform a RACH procedure for uplink synchronization with the second base station 303 (RACH) 309.

While the terminal 301 receives the signal corresponding to step 306 and performs the RACH procedure, the first base station 302 fails to transmit to the terminal 301 and stores downlink data in the buffer and/or the terminal 301 Uplink data received from the EPC but not delivered to the EPC and accumulated in the buffer may be transferred to the second base station 303. (Data Forwading) (309).

When the second base station 303 is added to the communication system, the terminal 301 may perform uplink transmission using the first base station 302 and the second base station 303 (310). Also, although not shown in the drawing, the second base station 303 may perform downlink transmission to the terminal 301. The terminal 301 may measure the strength of the downlink signal received from the second base station 303 and transmit the measured strength of the downlink signal to the first base station 302 or the second base station 303. (311). The strength of the downlink signal may be transmitted periodically based on a predetermined time interval, or may be transmitted aperiodically based on a trigger condition related to the strength of the downlink signal. When the strength of the downlink signal measured by the terminal 301 is transmitted to the first base station 302, the first base station 302 may transmit the strength of the downlink signal to the second base station 303.

The second base station 303 may measure a signal-to-noise interference ratio of the uplink signal received from the terminal 301. The second base station 303 indicates the transmission path of the uplink signal based on the strength of the downlink signal received from the terminal 301 or the first base station 302 and the measured signal-to-noise interference ratio of the uplink signal. It is possible to generate a control signal (312). The second base station may transmit the generated control signal to the first base station (312). For example, when a field corresponding to the transmission path in the control signal is set as information indicating the first base station 302, the first base station 302 transmits a signal including a request to change the structure of the RRC connection to the terminal 301 It can be transmitted to (313). The signal including the request to change the structure of the RRC connection corresponding to step 313 may include a request for setting the ul-DataSplitThreshold parameter value to a value corresponding to the maximum value. According to an embodiment, the signal including the request to change the structure of the RRC connection corresponding to step 313 may also include a request to set the PrimaryPath parameter value as a default value. The terminal 301 receiving the RRC connection structure change request may perform uplink transmission using the first base station 302 without using the second base station 303 (314). According to an embodiment, the first base station 302 may determine whether a current transmission path and an updated transmission path are different, and may generate a control signal based on the determination result.

4 is an exemplary diagram of uplink transmission according to an embodiment.

Referring to FIG. 4, the NSA terminal 401 is an example of the terminal 110 of FIG. 1, and is a non-standalone (NSA) network that connects 5G access network equipment to an LTE (4G) core network. It may be a terminal using. The LTE base station 402 is an example of the first base station 120 of FIG. 1, and may be a base station that provides a communication service through an LTE network. The 5G base station 403 is an example of the second base station 130 of FIG. 1 and may be a base station that provides a communication service through a 5G network. The EPC 404 may correspond to the EPC 140 of FIG. 1.

The transmission path of the uplink signal of the NSA terminal 401 may correspond to uplink transmission using the LTE base station 402 and the 5G base station 403 (a, b). When both the LTE base station 402 and the 5G base station 403 are used for uplink transmission, the LTE base station 402 according to an embodiment may transmit the received first uplink signal to the 5G base station 403. In this case, the 5G base station 403 may combine the first uplink signal received from the LTE base station 402 and the second uplink signal received from the terminal 401 and transmit it to the EPC 404. The uplink signal transmitted to the EPC 404 may be transmitted to the destination IMS or another network 405 (a).

When both the LTE base station 402 and the 5G base station 403 are used for uplink transmission, the LTE base station 402 and the 5G base station 403 according to an embodiment transmit the received uplink signal to the EPC 404 I can. In this case, the first uplink signal transmitted to the EPC 404 through the LTE base station 402 and the second uplink signal transmitted to the EPC 404 through the 5G base station 403 are combined in the EPC 404 It may be transmitted to the destination IMS or other network 405 (b).

The transmission path of the uplink signal of the NSA terminal 401 may correspond to uplink transmission using the LTE base station 402. The LTE base station 402 may transmit the received uplink signal to the EPC 404. The uplink signal transmitted to the EPC 404 through the LTE base station 402 may be transmitted from the EPC 404 to the destination IMS or another network 405 (c).

5A is a diagram illustrating an operation of a split bearer according to an embodiment.

Referring to FIG. 5A, a split bearer 510 may be located between a first base station and a second base station. The split bearer 510 may be a bearer that transmits data to a terminal by using both 4G (Master eNB) and 5G (Secondary gNB) resources. When the split bearer 510 performs 5G Addition, the split bearer 510 may switch from an existing MCG bearer to an SCG split bearer. When the split bearer 510 performs 5G Release, the split bearer 510 may switch from an SCG split bearer to an MCG bearer. Through these processes, the split bearer 510 may support a function of simultaneously transmitting an uplink signal to the first base station and the second base station.

5B is a diagram for describing an operation of a split bearer according to an embodiment.

Referring to FIG. 5B, a radio protocol architecture used by a bearer may be determined according to the type of bearer. The radio protocol architecture used by the MCG bearer, the SCG bearer, and the split bearer 510 may be determined as shown in the figure. Features according to the radio protocol architecture can be shown in Table 2 below.

MCG Bearer SCG Bearer Split Bearer Use MeNB resources only Use SeNB resources only Use MeNB and SeNB resources Similar to legacy bearer supporting both data and signaling Data only Data only RRC is located at the MeNB → signaling radio bearers use MCG bearer and MeNB resources S1-U interface terminates at SeNB S1-U interface terminates at MeNB Bearer level split at SGW Bearer level split at SGW DL data aggregation at PDCP layer NO UL data aggregation at UE VoLTE, IMS signaling Data Data

Figure 5c is a diagram for explaining the operation of the split bearer according to an embodiment. Referring to Figure 5c, using a split bearer 510, using both 4G (Master eNB) and 5G (Secondary gNB) resources Data can be transmitted to the terminal. According to an embodiment, data may be transmitted to the terminal using an MCG split bearer (Option 3). According to an embodiment, data may be transmitted to the terminal using the SCG split bearer (Option 3x).

6 is a flowchart illustrating an operation method of a second base station for uplink transmission according to an embodiment.

6, the second base station may receive a report including the strength of a downlink signal transmitted from the second base station to the terminal from the terminal or the first base station (610). The terminal may correspond to the terminal 110 of FIG. 1, the first base station may correspond to the first base station 120 of FIG. 1, and the second base station may correspond to the second base station 130 of FIG. I can. The strength of the downlink signal may be transmitted periodically based on a predetermined time interval, or may be transmitted aperiodically based on a trigger condition related to the strength of the downlink signal.

The second base station may receive an uplink signal from the terminal. The second base station may measure a signal-to-noise interference ratio of an uplink signal transmitted from the terminal to the second base station (620). The second base station may transmit the uplink signal received from the terminal to the EPC.

The second base station may generate a control signal indicating a transmission path of the uplink signal of the terminal (630). The control signal may be generated based on a first condition related to the strength of the downlink signal in step 610 and a second condition related to a signal-to-noise interference ratio of the uplink signal in step 620.

The second base station may transmit the generated control signal to the first base station (640). When the field corresponding to the transmission path in the control signal is set to information indicating the first base station, the first base station may transmit a signal including a request for changing the structure of the RRC connection to the terminal. The terminal receiving the request for changing the structure of the RRC connection may perform uplink transmission using the first base station without using the second base station.

7 is a flowchart illustrating an operation method of a second base station determining a transmission path of an uplink signal of a terminal by adjusting one or more parameter values according to an embodiment.

Referring to FIG. 7, in order to allow the transmission path of an uplink signal to include the first base station and the second base station, a split bearer may be set to be located between the first base station and the second base station (701). The split bearer can operate as described in Figures 5A-5C.

The second base station may set the ul-DataSplitThreshold parameter value and the PrimaryPath parameter value as default values (702). The ul-DataSplitThreshold parameter may correspond to the ul-DataSplitThreshold parameter of FIG. 1, and the PrimaryPath parameter may correspond to the PrimaryPath parameter of FIG. 1. According to an embodiment, the default value of the ul-DataSplitThreshold parameter may be b100, and the default value of the PrimaryPath parameter may be 0. In this case, when the amount of data scheduled to be transmitted from the terminal is less than 100 bytes, the transmission path of the uplink signal may be determined to the first base station. On the other hand, when the amount of data scheduled to be transmitted from the terminal exceeds 100 bytes, the transmission path of the uplink signal may be determined by the first base station and the second base station. If the ul-DataSplitThreshold value is sufficiently small, it may be determined that the transmission path of the uplink signal is determined as the first base station and the second base station.

In step 702, the second base station may transmit a signal including a request to change the structure of the RRC connection to the terminal through the first base station, and the signal including the request to change the structure of the RRC connection sets the ul-DataSplitThreshold parameter as a default value. It can also include a request and a request that sets the PrimaryPath parameter to the default value. The signal including the request to change the structure of the RRC connection may correspond to step 306 of FIG. 3.

Hereinafter, for convenience of description, embodiments in which the default value of the PrimaryPath parameter is 0 will be described. However, these embodiments are only exemplary, and the embodiments may be applied in substantially the same manner to a scenario in which the default value of the PrimaryPath parameter is 1, and the like.

The second base station may monitor the wireless environment based on the MR transmitted by the terminal and the signal-to-noise interference ratio measured by the second base station (703). The MR transmitted by the terminal may include the strength of a downlink signal transmitted from the second base station to the terminal. The signal-to-noise interference ratio measured by the second base station may correspond to a signal-to-noise interference ratio of an uplink signal transmitted from the terminal to the second base station.

Based on the result of monitoring the radio environment, the second base station determines whether the strength of the downlink signal included in the MR is less than the RSRP _min value, or the strength of the downlink signal included in the MR is greater than the RSRP _min value and the RSRP _max value. It may be determined whether the signal-to-noise interference ratio measured by the second base station while being smaller than is smaller than the SINR _a value (704). RSRP _min , RSRP _max , and SINR _a values are predetermined values in relation to the generation of a control signal transmitted from the second base station to the first base station, and the RSRP _min value may correspond to the first reference value of FIG. 2, and RSRP _{The max} value may correspond to the second reference value of FIG. 2, and the SINR _a value may correspond to the third reference value of FIG. 2.

If it is determined that the condition of step 704 is not satisfied, the second base station may monitor the wireless environment based on the MR transmitted by the terminal and the signal-to-noise interference ratio measured by the second base station (703). Monitoring does not have to be continuous and can be done at some time interval. For example, monitoring may be performed whenever a new MR transmitted by the terminal is received. Alternatively, monitoring may be performed repeatedly at a predetermined period.

When it is determined that the condition of step 704 is satisfied, the second base station may set the ul-DataSplitThreshold parameter value to a value corresponding to the maximum value and set the PrimaryPath parameter value to 0 (705 ). According to an embodiment, the ul-DataSplitThreshold parameter value may be set to the largest value that can be implemented. When the ul-DataSplitThreshold value is a value corresponding to the maximum value and the PrimaryPath parameter value is set to 0, it may be determined that the transmission path of the uplink signal is determined as the first base station.

In step 705, the second base station may transmit a signal including a request to change the structure of the RRC connection to the terminal through the first base station, and the signal including the request to change the structure of the RRC connection corresponds to the ul-DataSplitThreshold parameter to the maximum value. A request to set as a value and a request to set the PrimaryPath parameter to 0 may also be included. The signal including the request to change the structure of the RRC connection may correspond to step 313 of FIG. 3.

The second base station may monitor the wireless environment based on the MR transmitted by the terminal and the signal-to-noise interference ratio measured by the second base station (706). Based on the result of monitoring the radio environment, the second base station determines whether the strength of the downlink signal included in the MR is less than the RSRP _min value, or the strength of the downlink signal included in the MR is greater than the RSRP _min value and the RSRP _max value. It may be determined whether the signal-to-noise interference ratio measured by the second base station while being smaller than is smaller than the SINR _a value (707).

If it is determined that the condition of step 707 is satisfied, the second base station may monitor the wireless environment based on the MR transmitted by the terminal and the signal-to-noise interference ratio measured by the second base station (706). Monitoring does not have to be continuous and can be done at some time interval. For example, monitoring may be performed every time a new MR transmitted by the terminal is received. Alternatively, monitoring may be performed repeatedly at a predetermined period.

If it is determined that the condition of step 707 is not satisfied, the second base station may set the ul-DataSplitThreshold parameter value and the PrimaryPath parameter value as default values (702).

8 is a diagram for describing a method of registering a PDCP data PDU with a first RLC entity or a second RLC entity according to an embodiment.

Referring to FIG. 8, since the PDCP data PDU may be transmitted to the LTE RLC 820 or NR RLC 830 in standard 36.323, the PDCP data PDU may be expressed as a first RLC entity or a second RLC entity. For example, PDCP Packet #1 may be transmitted to either LTE RLC or NR RLC instead of being transmitted to both the LTE RLC 820 and the NR RLC 830, which has one NSA structure and one PDCP and RLC This is because is a structure with two or more.

Accordingly, when the amount of data accumulated in the terminal PDCP buffer is greater than the ul-DataSplitThreshold value set by the base station, data can be simultaneously transmitted to the 4G base station and the 5G base station.

9 is a diagram for describing a method of determining a transmission path of an uplink signal of a terminal based on a PDCP data amount of a terminal and a value of an ul-DataSplitThreshold parameter according to an embodiment.

Referring to FIG. 9, a first base station may transmit a signal including a request to change a structure of a radio resource control (RRC) connection to a terminal. The terminal may set the transmission path of the uplink signal of the terminal to the first base station or the first base station and the second base station by changing the structure of the RRC connection based on the received signal. In this case, the first base station may include a base station that provides a communication service through a 4G network, and the second base station may include a base station that provides a communication service through a 5G network.

The PDCP data volume and the RLC data volume pending for initial transmission in two related RLC entities may be accumulated in the terminal PDCP buffer. By comparing the data amount of the terminal PDCP buffer and the ul-DataSplitThreshold parameter value, a transmission path of the uplink signal may be determined (910). The signal including the request to change the structure of the RRC connection transmitted from the first base station to the terminal may include an ul-DataSplitThreshold parameter value. According to an embodiment, the setting range of the ul-DataSplitThreshold parameter value may include values of 0 bits or more and 6553600 bits (2 ¹⁸ Х 5 ² ) or less, and 6553600 bits may be a value corresponding to the maximum value.

When the data amount of the terminal PDCP buffer is smaller than the ul-DataSplitThreshold parameter and the PrimaryPath parameter value is set to 0, the transmission path of the uplink signal may be determined as the first base station (LTE) (a) 920. When the data amount of the terminal PDCP buffer is greater than the ul-DataSplitThreshold parameter, the transmission path of the uplink signal may be determined by the first base station (LTE) and the second base station (5G) (b) 920.

The embodiments described above may be implemented as a hardware component, a software component, and/or a combination of a hardware component and a software component. For example, the devices, methods, and components described in the embodiments include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate (FPGA). array), programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions, such as one or more general purpose computers or special purpose computers. The processing device may execute an operating system (OS) and one or more software applications executed on the operating system. In addition, the processing device may access, store, manipulate, process, and generate data in response to the execution of software. For the convenience of understanding, although it is sometimes described that one processing device is used, one of ordinary skill in the art, the processing device is a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that it may include. For example, the processing device may include a plurality of processors or one processor and one controller. In addition, other processing configurations are possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of these, configuring the processing unit to behave as desired or processed independently or collectively. You can command the device. Software and/or data may be interpreted by a processing device or to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. , Or may be permanently or temporarily embodyed in a transmitted signal wave. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of the program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

As described above, although the embodiments have been described by the limited drawings, a person of ordinary skill in the art can apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order from the described method, and/or components such as a system, structure, device, circuit, etc. described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved.

Therefore, other implementations, other embodiments, and claims and equivalents fall within the scope of the claims to be described later.

Claims (21)

In a method of operating the second base station in a communication system including a first base station, a second base station, and a terminal,
Receiving a strength of a downlink signal transmitted from the second base station to the terminal;
Measuring a signal-to-noise interference ratio of an uplink signal transmitted from the terminal to the second base station;
Generating a control signal indicating a transmission path of the uplink signal of the terminal based on a first condition related to the strength of the downlink signal and a second condition related to a signal-to-noise interference ratio of the uplink signal; And
Transmitting the control signal to the first base station
Including,
Generating the control signal comprises:
Setting a first parameter value related to an amount of transmitted data of the terminal based on the first condition and the second condition;
Setting a second parameter related to the transmission path of the terminal to a value indicating one of the first base station and the second base station;
When the first parameter value is compared with the transmission data amount of the terminal, and when the transmission data amount of the terminal is smaller than the first parameter, the transmission of the terminal to a base station indicated by a second parameter value related to the transmission path of the terminal Determining a path, and when the amount of transmission data of the terminal is greater than the first parameter, determining a transmission path of the terminal to the first base station and the second base station; And
Generating a control signal indicating the determined transmission path
Including
Method of operation of the second base station.
The method of claim 1,
The characteristics of the first base station and the characteristics of the second base station are different,
The characteristic of the first base station and the characteristic of the second base station each include at least one of an uplink speed, a downlink speed, and a delay time.
The method of claim 1,
The first base station includes a base station that provides a communication service through a 4G network, and the second base station includes a base station that provides a communication service through a 5G network.
The method of claim 1,
The transmission path is
A first section corresponding to uplink transmission using the first base station,
A second interval corresponding to uplink transmission using the second base station, and
A third section corresponding to uplink transmission using the first base station and the second base station
Including any one of, the operation method of the second base station.
The method of claim 1,
Generating the control signal comprises:
Determining the first condition by comparing the strength of the downlink signal with at least one predetermined reference value related to the strength of the downlink signal
Including, the operation method of the second base station.
The method of claim 1,
Generating the control signal comprises:
Determining the second condition by comparing a signal-to-noise interference ratio of the uplink signal with a predetermined reference value related to the signal-to-noise interference ratio of the uplink signal
Including, the operation method of the second base station.
The method of claim 1,
Generating the control signal comprises:
Setting a field corresponding to the transmission path in the control signal as first information indicating the first base station when the strength of the downlink signal is less than a first reference value;
Setting the field in the control signal as second information indicating the first base station and the second base station when the strength of the downlink signal exceeds a second reference value; And
When the strength of the downlink signal exceeds the first reference value and is less than the second reference value,
Setting the field in the control signal as the second information when the signal-to-noise interference ratio of the uplink signal exceeds a third reference value; And
When the signal-to-noise interference ratio of the uplink signal is less than the third reference value, setting the field in the control signal as the first information
Including, the operation method of the second base station.
The method of claim 1,
Generating the control signal comprises:
Setting a second parameter related to the transmission path of the terminal to a value indicating one of the first base station and the second base station;
Setting a first parameter related to the amount of transmission data of the terminal to a predetermined default value;
Setting the first parameter to a value corresponding to a maximum value when the strength of the downlink signal is less than a first reference value; And
When the strength of the downlink signal is greater than the first reference value and less than the second reference value, and the signal-to-noise interference ratio of the uplink signal is less than a third reference value, setting the first parameter to a value corresponding to the maximum value.
Including more,
When the amount of transmission data of the terminal is less than the first parameter, the transmission path of the terminal is determined as a base station indicated by the value of the second parameter,
When the transmission data amount of the terminal is greater than the first parameter, the transmission path of the terminal is determined by the first base station and the second base station.
Method of operation of the second base station.
The method of claim 1,
Based on the control signal, the first base station
Controlling the terminal so as not to transmit the uplink signal to the second base station, or controlling the terminal to transmit the uplink signal to the first base station and the second base station,
Method of operation of the second base station.
The method of claim 1,
Receiving the strength of the downlink signal comprises:
Receiving a strength of the downlink signal transmitted periodically based on a predetermined time interval; And
Receiving a strength of the downlink signal transmitted aperiodically based on a trigger condition related to the strength of the downlink signal
Including at least one of, the operation method of the second base station.
The method of claim 1,
Receiving the strength of the downlink signal comprises:
Receiving a report including the strength of the downlink signal from the terminal; And
Receiving the report transmitted from the terminal from the first base station
Including at least one of, the operation method of the second base station.
The method of claim 1,
When the transmission path of the uplink signal includes the first base station and the second base station,
Receiving a second uplink signal from the terminal; And
Transmitting the second uplink signal to an EPC
Including more,
The second uplink signal and the first uplink signal transmitted to the EPC through the first base station are combined in the EPC and transmitted to a destination,
Method of operation of the second base station.
The method of claim 1,
When the transmission path of the uplink signal includes the first base station and the second base station,
Receiving a second uplink signal from the terminal;
Receiving a first uplink signal from the first base station;
Combining the first uplink signal and the second uplink signal; And
Transmitting the combined signal to an EPC
Including more,
The combined signal transmitted to the EPC is transmitted to a destination through the EPC,
Method of operation of the second base station.
A computer-readable recording medium containing a program for performing the method of any one of claims 1 to 13.
In a second base station performing an operation in a communication system including a first base station, a second base station, and a terminal,
A memory in which a program is recorded; And
Processor that executes the above program
Including,
The above program,
Receiving a strength of a downlink signal transmitted from the second base station to the terminal;
Measuring a signal-to-noise interference ratio of an uplink signal transmitted from the terminal to the second base station;
Setting a first parameter value related to an amount of transmitted data of the terminal based on a first condition related to the strength of the downlink signal and a second condition related to a signal-to-noise interference ratio of the uplink signal;
Setting a second parameter related to the transmission path of the terminal to a value indicating one of the first base station and the second base station;
When the first parameter value is compared with the transmission data amount of the terminal, and when the transmission data amount of the terminal is smaller than the first parameter, the transmission of the terminal to a base station indicated by a second parameter value related to the transmission path of the terminal Determining a path, and when the amount of transmission data of the terminal is greater than the first parameter, determining a transmission path of the terminal to the first base station and the second base station;
Generating a control signal indicating the determined transmission path; And
Transmitting the control signal to the first base station
The second base station to perform.
The method of claim 15,
The characteristics of the first base station and the characteristics of the second base station are different,
The second base station, wherein the characteristics of the first base station and the characteristics of the second base station each include at least one of an uplink speed, a downlink speed, and a delay time.
The method of claim 15,
The second base station, wherein the first base station includes a base station that provides a communication service through a 4G network, and the second base station includes a base station that provides a communication service through a 5G network.
The method of claim 15,
The transmission path is
A first section corresponding to uplink transmission using the first base station,
A second interval corresponding to uplink transmission using the second base station, and
A third section corresponding to uplink transmission using the first base station and the second base station
Including any one of, the second base station.
The method of claim 15,
Generating the control signal comprises:
Determining the first condition by comparing the strength of the downlink signal with at least one predetermined reference value related to the strength of the downlink signal
Including, the second base station.
The method of claim 15,
Generating the control signal comprises:
Determining the second condition by comparing a signal-to-noise interference ratio of the uplink signal with a predetermined reference value related to the signal-to-noise interference ratio of the uplink signal
Including, the second base station.
The method of claim 15,
Generating the control signal comprises:
Setting a second parameter related to the transmission path of the terminal to a value indicating one of the first base station and the second base station;
Setting a first parameter related to the amount of transmission data of the terminal to a predetermined default value;
Setting the first parameter to a value corresponding to a maximum value when the strength of the downlink signal is less than a first reference value; And
When the strength of the downlink signal is greater than the first reference value and less than the second reference value, and the signal-to-noise interference ratio of the uplink signal is less than a third reference value, setting the first parameter to a value corresponding to the maximum value.
Including more,
When the amount of transmission data of the terminal is less than the first parameter, the transmission path of the terminal is determined as a base station indicated by the value of the second parameter,
When the transmission data amount of the terminal is greater than the first parameter, the transmission path of the terminal is determined by the first base station and the second base station.
The second base station.

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