JP2020053863A - Network node, control method, and program in system capable of communicating copied data between network and terminal device using multiple lines - Google Patents

Abstract

To effectively use radio resources in a radio communication system capable of copying data and transmitting the data through a plurality of lines.SOLUTION: A network node in a radio communication system that uses at least part of a plurality of lines and can perform radio communication between a terminal device and a network obtains line information including values relating to use situations of the respective lines, determines the number of lines used for radio communication between one terminal device and the network among the plurality of lines on the basis of the values and a threshold value relating to the use situation, and performs control to copy one piece of data and communicate between the one terminal device and the network using the determined number of lines.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a radio resource control technique in a system capable of executing communication of duplicated data between a network and a terminal device using a plurality of lines.

  The Third Generation Partnership Project (3GPP) stipulates that one terminal device and a network communicate by duplicating one data (see Non-Patent Document 1). The data here is a PDU (Protocol Data Unit) of Packet Data Convergence Protocol (PDCP), and a plurality of packets related to the copied PDCP PDU are transmitted by different carriers.

3GPP TS36.300, V15.0.0, July 2018

  As described above, the reliability of communication can be improved by copying and communicating one piece of data. On the other hand, despite the fact that sufficient wireless quality can be obtained, if communication is performed by duplication, a wireless line is unnecessarily established and communication is performed, and wireless resources may be wasted. was there.

  The present invention has been made in view of the above problems, and provides a technique for effectively utilizing wireless resources in a wireless communication system capable of copying data and transmitting the data over a plurality of lines. Aim.

  A base station device according to an aspect of the present invention is a network node in a wireless communication system capable of performing wireless communication between a terminal device and a network using at least a part of a plurality of lines, An obtaining unit configured to obtain line information including a value related to the use state of each of the plurality of lines, and one terminal of the plurality of lines based on the value and a threshold value related to the use state of the line; Determining means for determining the number of lines used for wireless communication between the device and the network, and using the number of lines determined by the determining means, between the one terminal device and the network And control means for performing control for copying and communicating one piece of data.

  ADVANTAGE OF THE INVENTION According to this invention, a radio | wireless resource can be utilized effectively in the radio | wireless communication system which can copy data and transmit the data by several lines.

FIG. 2 is a diagram illustrating a configuration example of a wireless communication system. FIG. 3 is a diagram illustrating a hardware configuration example of a network node. FIG. 3 is a diagram illustrating a functional configuration example of a network node. FIG. 9 is a diagram illustrating an example of a flow of processing executed by a network node.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(System configuration)
FIG. 1 is a diagram illustrating a configuration example of a wireless communication system according to the present embodiment. In one example, the wireless communication system may be a wireless communication system that complies with the NR (New Radio) standard, which is a fifth-generation cellular wireless communication system. However, the present invention is not limited to this, and any system capable of transmitting and receiving copied data between a terminal device and a base station device (two communication devices) by using at least a part of a plurality of configurable lines in parallel, The following discussion can be applied.

  In FIG. 1, a base station device and a terminal device communicate. Although FIG. 1 illustrates an example in which one base station device and one terminal device are provided, there may be many base station devices and many terminal devices as in a general cellular communication system. The base station device and the terminal device may be directly wirelessly connected, as shown in FIG. 1, or may perform wireless communication via a communication path via one or more relay devices. Here, the wireless communication means that a wireless link is established and communication is performed at least in a communication section between the base station device or the relay device and the terminal device. The base station device is equipment of a network operator and is treated as one of network nodes. In some cases, the relay device may be treated as a network node. In the following description, the “network node” is, for example, a base station device, but may be an arbitrary network node as a facility maintained and managed by another network operator. Further, the base station device is connected to a core network, but the core network is not shown here for the sake of simplicity.

  Here, the terminal device duplicates one data (PDCP PDU) by using two or more lines selected and set from a plurality of lines that can be set with the base station device in parallel. Can be sent. Similarly, the base station apparatus can duplicate one piece of data and transmit it to the terminal apparatus using two or more such lines in parallel. For example, two or more lines can be set between one base station device and one terminal device using carrier frequency bands (carriers), as in carrier aggregation. The setting of two or more lines between one base station apparatus and one terminal apparatus is performed by two carriers of a direct link (a link obtained by directly wirelessly connecting the base station apparatus and the terminal apparatus). Or a direct link or a combination of two or more different relay links. Further, two or more lines may be set between two or more base stations (not relay devices) and one terminal device as in dual connectivity. However, in any case, the frequency band (carrier) used in each line can be set differently.

  Thus, by duplicating and transmitting one data using a plurality of lines, it is possible to improve communication reliability. That is, even if the communication fails with only one line, the communication can be successfully performed by performing the duplicate communication on another line. Also, by utilizing this characteristic, when communication can be successfully performed using only one line, the coding rate is reduced or the number of modulation levels is increased to the extent that communication is intentionally failed. Further, by transmitting the duplicate, the time length of one signal can be reduced. As a result, the time until the transmission of data to be transmitted by the signal is completed can be reduced, and communication with low delay can be realized.

  On the other hand, unnecessarily using a plurality of lines even when it is not necessary to use the plurality of lines leads to waste of radio resources. For this reason, in the present embodiment, a network node such as a base station device determines the number of lines used for wireless communication between the base station device and the terminal device based on information indicating various situations. . For example, for a plurality of lines that can be set up between one terminal device and the network (one or more base station devices), the network node acquires line information including values relating to the use status of each line. Then, the network node determines the number of lines to be used for wireless communication between the terminal device and the network, among the plurality of lines, based on the value indicated by the line information and the threshold value regarding the use state of the line, Control such as instructions to the terminal device and the base station device for performing communication according to the determination is performed. For example, the network node may decide not to use the line if the value related to the usage status of the line that is so high that the line is not congested does not exceed the threshold value corresponding to the line being not congested. Once determined, the number of lines used for communication can be determined.

  At this time, the network node can determine the number of lines to be used, for example, based on the allowable delay of communication between the network and the terminal device or the required reliability. For example, the network node may secure as many as possible two or more lines for a terminal device that requires low delay or has high required reliability. As an example, the network node may acquire information on a service provided to the terminal device, and determine the number of lines according to the service. For example, it is determined that a relatively large number of lines is used for a service requiring low delay (high real-time property) and a service requiring high reliability, and for other services, It may be decided to use a relatively small number of lines. In addition, the network node may secure as many as possible two or more lines for the terminal device expected to increase the communication delay. For example, the network node expects that the greater the number of relay devices and base station devices (the number of hops) included in the communication path between the terminal device and the network (the serving base station device of the terminal device), the greater the communication delay. To secure a relatively large number of lines. In addition, the network node determines a round trip time of communication between the terminal device and the network (the serving base station device of the terminal device) (or a time until a signal transmitted by the network or the terminal device reaches the other). Thus, the number of lines set for the terminal device may be determined. The round trip time may be measured by a network (base station device) or by a terminal device. When the terminal device performs the measurement, the measurement result is notified to the network node.

  The network node determines the number of lines to be used based on the permissible delay amount, the required reliability (type of service), and information on the delay amount in communication (hop count and round trip time). , A threshold value related to the line usage status can be used. For example, when it is necessary to secure two or more lines as much as possible, a relatively low threshold value is set, so that the network node secures many lines determined to be usable and reduces the number of lines. If it should be, a relatively high threshold is set, so that the number of lines determined to be usable can be reduced. Note that the network node may hold in advance correspondence information in which a threshold value to be used is associated with information such as the allowable delay amount, the required reliability, the service type, and information on the delay amount. In addition, the network node receives feedback as to whether or not the requested communication has been performed, for example, by performing communication on the determined number of lines, and satisfies the request in a predetermined ratio (for example, 95%) of communication according to the result. Correspondence information may be generated by specifying a threshold value that has been obtained.

  When determining the number of lines, the network node may determine whether or not each of the plurality of configurable lines can be used by using the same threshold, or may use different thresholds to determine whether or not the line can be used. The availability may be determined. For example, when the capacity such as the frequency bandwidth for each line is constant, the same threshold is used, and when the capacity for each line is not constant, a threshold suitable for each line can be used. In one example, the value related to the line utilization status may be a value that increases as the vacancy rate of the line increases, but the vacancy rate is 50% when the frequency bandwidth is 5 MHz and the vacancy rate when the frequency bandwidth is 20 MHz. At 20%, since the capacity actually available for communication is larger in the latter, different thresholds can be set for each frequency bandwidth without using a uniform threshold. It should be noted that the value relating to the line usage status may be a value that increases as the free space (unit: Mbps, for example) of the line increases. In addition, the value related to the line usage status increases as the number of terminal devices connected to the line (for example, directly connected to the base station device) decreases (for example, the number of connected terminal devices). (Reciprocal number). In addition, the network node may determine whether the line is used as a value related to the line use status, such as an arbitrary value regarding the line vacancy rate, an arbitrary value regarding the line free capacity, or an arbitrary value regarding the number of terminal devices connected to the line. Any value that can determine whether or not there is congestion can be obtained. In addition, these examples of the value regarding the use state of the line may be used alone or in combination of two or more. Still another value having a value that is so high that the line is not used may be used as a value related to the use state of the line. If the line is a multi-hop line including a relay device, the network node obtains a plurality of values for each of the communication links included in the communication path, and among the plurality of values, the line is A value indicating that the line is used most may be used as a value related to the line use status of the line. For example, it is assumed that a line of a base station device → relay device → terminal device exists. At this time, when the vacancy rate of the resource of the communication link between the base station apparatus and the relay apparatus is 40%, and the vacancy rate of the resource of the communication link between the relay apparatus and the terminal apparatus is 50%. The network node determines the number of lines assuming that the vacancy rate of the line is 40%. Similarly, if the free space on the communication link between the base station device and the relay device is 20 Mbps and the free space on the communication link between the relay device and the terminal device is 8 Mbps, , The number of lines is determined on the assumption that the free space is 8 Mbps. Similarly, for the number of connected terminal devices, the value with the larger number of connections is used. Thus, for example, it is possible to determine the number of lines appropriately after roughly estimating the amount of radio resources that can be secured in each line.

  The above-described determination of the number of lines can be performed separately for the uplink in the direction from the terminal device to the network and for the downlink in the direction from the network to the terminal device. This is because, for example, when different frequency bands are used for the uplink and the downlink, the congestion degrees of these are considered to be independent.

(Device configuration)
Next, an example of a hardware configuration of a network node that executes the above-described processing will be described with reference to FIG. The network node includes, for example, a processor 201, a ROM 202, a RAM 203, a storage device 204, and a communication circuit 205. The processor 201 is a computer including one or more processing circuits such as a general-purpose CPU (central processing unit) and an ASIC (application-specific integrated circuit), and is stored in the ROM 202 or the storage device 204. By reading and executing the program, the entire process of the network node and the above-described processes are executed. The ROM 202 is a read-only memory that stores a program related to processing executed by each device and information such as various parameters. The RAM 203 functions as a workspace when the processor 201 executes a program, and is a random access memory that stores temporary information. The storage device 204 includes, for example, a removable external storage device. The communication circuit 205 includes, for example, a circuit for wired communication or wireless communication. When the network node is a base station device, the network node includes, for example, an NR baseband circuit, an RF circuit, and the like, and an antenna as a communication circuit 205 for communication with the terminal device 103. Further, the communication circuit 205 of the network node may include, for example, a circuit for performing (wired or wireless) communication with another base station device or a network node. Although one communication circuit 205 is illustrated in FIG. 2, a network node may include a plurality of communication circuits.

  FIG. 3 shows a functional configuration example of the network node. The network node includes, for example, a communication unit 301, an information acquisition unit 302, a line number determination unit 303, and a communication control unit 304. The communication unit 301 is a functional unit that communicates with another device to acquire and provide information and to input and output instruction and control information. For example, when the network node is a device that controls a plurality of base station devices, the communication unit 301 is configured to establish a wired or wireless communication link with the plurality of base station devices to perform communication. . Further, for example, when the network node is a base station device, the communication unit 301 is configured to perform wireless communication with a terminal device in addition to communication with another network node / base station device.

  The information acquiring unit 302 acquires, for example, for each of a plurality of available lines, information including a value related to the use state of the line that takes a higher value so that the line is not congested. This information is, for example, as described above, a value that increases as the vacancy rate of the line bandwidth increases, a value that increases as the vacant capacity of the line increases, and a value that increases as the number of terminal devices connected to the line decreases. At least one of the following values: When the line is a multi-hop line based on a communication path including a relay device, the above information may be obtained for each of the plurality of communication links included in the communication path, or the plurality of communication links may be obtained. Of the information on each of the above, only the information of the value indicating the most used (most congested) may be acquired. That is, the network node may collect information on all communication links included in one line, and may select information used to determine the number of lines to be used, or may be selected by another node. Information may be acquired to determine the number of lines. Further, when the line is a multi-hop line including a relay device, the number of terminal devices connected to the line may include the number of terminal devices connected via the relay device. The information acquisition unit 302 also provides information on services provided to the terminal device, the allowable delay and required reliability of the terminal device, the number of hops between the terminal device and its serving base station, the round trip time, and the like. Any information that can be used to determine the number can be obtained.

  The line number determining unit 303 determines the number of lines used for communication between one terminal device and the network based on the information acquired by the information acquiring unit 302. The number-of-lines determining unit 303 decides not to use a line that is estimated to be highly congested because the value indicated by the acquired information does not exceed the threshold, and uses the line for communication of the terminal device. Determine the number of lines. That is, when all available lines are congested, the number-of-lines determining unit 303 can determine to reduce the number of lines, for example, setting the number of lines to one. Note that the line number determination unit 303 can use different thresholds for a plurality of configurable lines, for example, based on the characteristics of each line. For example, for a line corresponding to a communication path having a large number of hops, a high threshold may be set so that the line is not used. Further, the number-of-lines determining unit 303 can determine the number of lines further based on, for example, the current situation of the terminal device. For example, the number-of-lines determining unit 303 determines the service provided to the terminal device, the allowable delay and required reliability of the terminal device, the number of hops in the communication path between the terminal device and the serving base station, the round trip time of communication, and the like. , The number of lines can be determined. In other words, for a terminal device having a short allowable delay or a high required reliability of a service or device to be provided or a terminal device considered to have a large delay, the number of lines is relatively reduced so that the delay time is reduced. Make a decision to be more. Note that the line number determination unit 303 can set the above-described threshold value low, for example, so that a line with a high congestion degree can be selected. Note that the number-of-lines determining unit 303 sets an upper limit of the number of lines in advance, and can determine the number of lines to be used as the upper limit even when a line exceeding the upper limit can be set. The upper limit is 2 in one example. As described above, by appropriately setting the above-described threshold value, the line number determination unit 303 can determine the number of lines in consideration of information such as the request and status of the terminal device in addition to the degree of congestion of the lines. it can. Thus, for example, when a line is congested, a plurality of lines are set only for necessary terminal devices, and when the lines are open, a plurality of lines are set for many terminal devices. For example, the number of lines to be set can be flexibly determined according to the degree of congestion and the status of the terminal device.

  The communication control unit 304 controls the base station device and the terminal device to establish communication with the target terminal device with the number of lines determined by the line number determining unit 303 and perform communication. For example, the communication control unit 304 selects the determined number of lines from a plurality of settable lines, and executes control for connecting the terminal device to the selected lines. In addition, the communication control unit 304, for example, from the remaining lines except for the line determined not to be used by the line number determination unit 303, for example, the line with the lowest delay or the delay amount is equal to or less than a predetermined value, Select a line that meets the predetermined criteria. When the network node is a base station device, it can control its own device and the terminal device. For example, when a line between another base station device and a terminal device is used, the Can be controlled. If the network node is different from the base station device, the communication control unit 304 sends an instruction signal to all base station devices (or relay devices as necessary) and a terminal device for which a line is set up with the terminal device. , Etc., to control communication. When the number of lines is plural, the communication control unit 304 controls communication such that a signal obtained by duplicating one data is transmitted in each of the plural lines. Note that the term “copy” here suffices if there is one original data, and it is not necessary that the signals actually transmitted be the same, for example, different redundant components are added thereto. When such copy communication is performed in the uplink, the communication control unit 304 instructs the terminal device to use a plurality of lines (a destination base station device or a relay device and a used carrier) to be used. At the same time, it instructs each of the plurality of lines to transmit a plurality of signals obtained by duplicating data. When performing copy communication on the downlink, the communication control unit 304 transmits, for example, a signal obtained by copying one piece of data to a base station apparatus that transmits a signal to a terminal apparatus, and transmits the signal. May be transmitted to the base station apparatus including information specifying a carrier or the like for transmitting the information. The communication control unit 304 transmits an instruction to the serving base station of the terminal device to transfer one data to be transmitted to another base station device that establishes a line with the terminal device. May be. In this case, there is no need to transfer data (signal) from the communication control unit 304. Another base station apparatus may transmit a signal including one piece of acquired data using the carrier specified by the instruction signal from communication control section 304. The method of copying and transmitting data may be executed by any other method.

(Processing flow)
Finally, an outline of the flow of the above-described processing executed by the network node will be described with reference to FIG. The present method is realized, for example, by the processor 201 executing a program stored in the ROM 202 or the storage device 204. The processing executed in each processing step is as described above, and thus will not be described in detail here, but will be described only in outline.

  The network node first determines the status of one terminal device that is the subject of this processing (for example, the service to be provided, the allowable delay amount and required reliability, the number of hops and round trip time of the communication line with the serving base station). ) Is obtained (S401). Then, based on the information, the network node sets, for each of the plurality of configurable lines, a threshold value related to the line use status (S402). Note that the threshold value for a plurality of lines can be adjusted by, for example, adding an addition value or subtracting a subtraction value based on the information acquired in S401 to a threshold value obtained based on the characteristics of those lines. Note that the processes of S401 and S402 only need to be executed as needed, and do not necessarily have to be executed.

  After that, the network node acquires information including a value relating to the line utilization status at the present time (or based on an average from a predetermined time in the past to the present) for each of the plurality of lines (S403). This value relates to the degree of congestion of the line, for example, as described above, a value that increases as the vacancy rate of the line increases, a value that increases as the vacant capacity of the line increases, and The value may be higher so that it is not crowded, such as at least one of the higher values. Thereafter, the network node determines the number of lines to be used for one terminal device to be subjected to this processing based on the information acquired in S403 and the threshold set in S402 (S404). Then, the network node sets up the number of lines determined in S404 between one terminal device and the network, and uses the terminal device so that communication between the terminal device and the network is performed. And the base station device included in the line to be controlled (S405). In S404, not only the number of lines but also the line to be used may be determined, or the line to be used may be determined in S405. In addition, for example, a line having a sufficiently small delay (a line having a minimum delay or a predetermined delay amount in an example) is selected from lines not determined to be used in the determination of the number of lines in S404. The line is selected based on a predetermined criterion, such as a line with a smaller size or a line with sufficiently high radio quality (in one example, a line with the best radio quality or a line with a radio quality exceeding a predetermined value).

  As described above, in the present embodiment, the network node determines the number of lines used by the terminal device based on the value relating to the line use status of each of the plurality of lines. Thus, in a situation where the lines are congested, by suppressing the number of lines to be used, communication opportunities are provided to many terminal devices, and in a situation where the lines are not congested, the number of lines to be used is increased. Thereby, it is possible to improve communication reliability and reduce delay. In addition, by changing the threshold value in consideration of the status of the terminal device, it is possible to increase the number of lines to be used for the necessary terminal device even in a situation where the lines are congested. For a terminal device that does not need to be used, the number of lines used can be reduced. As described above, the network node according to the present embodiment can determine whether or not to perform the copy communication and flexibly control the number of lines to be used in consideration of various situations.

Claims (12)

A network node in a wireless communication system capable of performing wireless communication between a terminal device and a network using at least a part of a plurality of lines,
Acquisition means for acquiring line information including a value relating to the use status of each line for the plurality of lines,
Determining means for determining the number of lines to be used for wireless communication between one terminal device and the network among the plurality of lines,
Control means for performing control for copying and communicating one data between the one terminal device and the network by using the number of lines determined by the determination means;
A network node comprising: The determining means determines the number of lines using different thresholds for two or more of the plurality of lines,
The network node according to claim 1, wherein: The value relating to the line usage status includes information on the vacancy rate of the line bandwidth, the vacant capacity of the line, and at least one of the number of terminal devices connected to the line
The network node according to claim 1 or 2, wherein: The value related to the line utilization status is a value that increases as the vacancy rate of the line bandwidth increases, a value that increases as the vacant capacity of the line increases, and increases as the number of terminal devices connected to the line decreases. And at least one of
The determining means determines not to use a line whose value does not exceed the threshold, and determines the number of lines.
The network node according to any one of claims 1 to 3, characterized in that: When the communication path between the network and the one terminal device includes a plurality of wireless links formed by one or more relay devices, the determining unit corresponds to the line information about the plurality of wireless links. Using the value for the link indicating that the value to be used most is used as the value relating to the use status of the line, and determining the number of lines,
The network node according to any one of claims 1 to 4, characterized in that: The determining means determines the number of lines based further on the number of relay devices included in a communication path between the network and the one terminal device,
The network node according to any one of claims 1 to 5, characterized in that: The determining means further determines the number of lines based on a round trip time of communication between the network and the one terminal device,
The network node according to any one of claims 1 to 5, characterized in that: The determining means determines the number of lines by using the different threshold value for each service provided to the one terminal device,
The network node according to any one of claims 1 to 7, characterized in that: The determination means determines the number of lines separately for uplink and downlink,
The network node according to any one of claims 1 to 8, characterized in that: The network node is a base station device,
The network node according to any one of claims 1 to 9, characterized in that: A control method executed by a network node in a wireless communication system capable of performing wireless communication between a terminal device and a network using at least a part of a plurality of lines,
For the plurality of lines, an acquisition step of acquiring line information including a value related to the use status of each line,
A determination step of determining the number of lines to be used for wireless communication between one terminal device and the network among the plurality of lines,
Control means for performing control for copying and communicating one data between the one terminal device and the network using the number of lines determined in the determining step,
A control method comprising: Using at least a part of the plurality of lines, a computer provided in a network node in a wireless communication system capable of performing wireless communication between the terminal device and the network,
For the plurality of lines, let the line information including a value relating to the use status of each line be obtained,
Based on the value and the threshold value regarding the use status of the line, the number of lines used for wireless communication between one terminal device and the network among the plurality of lines is determined.
Using the determined number of lines, control for copying and communicating one data between the one terminal device and the network is performed.
Program for.

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