COMMUNICATION SYSTEM AND COMMUNICATION CONTROL METHOD

Abstract

Provided is a communication system comprising: at least one base station accommodating a wireless terminal; at least one transfer device which transfers, to a higher level, an uplink communication of the wireless terminal received via the base station; and a transfer device controller which controls the at least one transfer device, and the communication system further includes: an information acquisition unit for acquiring information regarding a wireless communication for each quality-of-service class between the base station and the wireless terminal; a rate determination unit for determining, for each of the quality-of-service classes, a shaping rate for traffic shaping such that a packet loss caused by congestion does not occur, on the basis of the information regarding the wireless communication for each quality-of-service class; and a communication control unit for executing, for each quality-of-service class, the traffic shaping at the higher level to the base station on the basis of the shaping rate determined by the rate determination unit.

Description

[Technical field]

[0001] The present invention relates to a communication system accommodating wireless terminals and a communication control method. [Background technology]

[0002] When multiple base stations are connected to a transfer device network, when multiple wireless terminals are connected to one base station, or when one wireless terminal has multiple traffic flows, data of multiple traffic flows may enter the transfer device network together. In such cases, a bandwidth guaranteed service is generally provided, which performs bandwidth control by applying traffic shaping with a bandwidth preset for each QoS (Quality of Service) class, or a best-effort service is provided without bandwidth guarantee.

[0003] For example, in the bandwidth control by CBQ (Class Based Queueing) described in Non-Patent Document 1, when a bandwidth increase occurs in a specific QoS class, the available bandwidth is allocated to other QoS classes as necessary. This makes it possible to temporarily communicate at a bandwidth higher than the shaping rate. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] “IEICE Knowledge Base”, 5th group, 4th issue, IECE, 2010. [Non-Patent Document 2] “3GPP TS 23.501 V17.0.0”, 3GPP, 2021. [Non-Patent Document 3] “3GPP TS 28.552 V17.3.1”, 3GPP, 2021. [Non-Patent Document 4] “3GPP TS 38.321 V16.4.0”, 3GPP, 2021. [Non-Patent Document 5] “3GPP TS 38.211 V16.5.0”, 3GPP, 2021. Summary of the Invention [Problem to be solved by the invention]

[0005] FIG. 8 is a diagram showing a configuration example of a mobile communication system 90a according to the prior art. The mobile communication system 90a includes, for example, a server 91a, one or more transfer devices 92a, a transfer device controller 93a, and a base station 94a. The server 91a is a device that communicates with each of one or more wireless terminals 95a. The one or more transfer devices 92a constitute a transfer device network 96a and are devices that transfer signals exchanged between the server 91a and each of the wireless terminals 95a. The transfer device controller 93a is a device that controls the one or more transfer devices 92a by transmitting a control signal. The base station 94a is a device that communicates with each of the one or more wireless terminals 95a, transmits a signal transferred from the transfer device 92a to each of the one or more wireless terminals 95a, and transfers a signal received from each of the one or more wireless terminals 95a to the transfer device 92a. The server 91a and the wireless terminal 95a have one or more traffic flows.

[0006] As in the above conventional technology, when multiple base stations 94a are connected to one transfer device 92a, when multiple wireless terminals 95a are connected to one base station 94a, or when one wireless terminal 95a has multiple traffic flows, these different types of traffic flows may enter the transfer device network 96a together. If a bandwidth increase of more than the shaping rate occurs in a specific QoS class, and there is available bandwidth, the available bandwidth may be assigned to other QoS classes as necessary, for example, as in the above conventional technology CBQ.

[0007] However, when a bandwidth increase occurs in a specific QoS class that exceeds the shaping rate, if there is no available bandwidth, the available bandwidth cannot be allocated to other QoS classes. In this case, there is a problem that packet loss may occur in the traffic flow of the QoS class in the transfer device network 96a.

[0008] In view of the above circumstances, an object of the present invention is to provide a technique capable of suppressing the occurrence of packet loss. [Means for solving the problem]

[0009] One aspect of the present invention is a communications system comprising one or more base stations accommodating wireless terminals, one or more forwarding devices that forward upstream communications of the wireless terminals received via the base stations to an upper side, and a forwarding device controller that controls the one or more forwarding devices, the communications system comprising: an information acquisition unit that acquires information regarding wireless communications for each service quality class between the base station and the wireless terminal; a rate determination unit that determines a shaping rate of traffic shaping for each service quality class based on the information regarding wireless communications for each service quality class so that packet loss due to congestion does not occur; and a communications control unit that performs traffic shaping for each service quality class on the upper side of the base station based on the shaping rate determined by the rate determination unit.

[0010] One aspect of the present invention is a communication control method in a communication system including one or more base stations accommodating wireless terminals, one or more forwarding devices that forward uplink communication of the wireless terminals received via the base stations to an upper side, and a forwarding device controller that controls the one or more forwarding devices, the method comprising: an information acquisition step of acquiring information regarding wireless communication for each service quality class between the base station and the wireless terminal; a rate determination step of determining a shaping rate of traffic shaping for each service quality class based on the information regarding wireless communication for each service quality class so that packet loss due to congestion does not occur; and a communication control step of performing traffic shaping for each service quality class on the upper side of the base station based on the shaping rate determined in the rate determination step. Effect of the Invention

[0011] According to the present invention, it is possible to suppress the occurrence of packet loss. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an example of a system configuration of a mobile communication system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a specific example of a functional configuration of the mobile communication system according to the first embodiment. [Diagram 3] FIG. 2 is a conceptual diagram showing that the effect of suppressing the occurrence of packet loss is obtained by shaping in a transfer device in the mobile communication system of the first embodiment. [Figure 4] FIG. 11 is a diagram showing a modified example of the mobile communication system of the first embodiment. [Diagram 5] FIG. 11 is a diagram illustrating an example of a system configuration of a mobile communication system according to a second embodiment. [Figure 6] FIG. 11 is a diagram illustrating an example of a system configuration of a mobile communication system according to a third embodiment. [Figure 7] FIG. 13 is a diagram illustrating an example of a system configuration of a mobile communication system according to a fourth embodiment. [Figure 8]FIG. 1 is a diagram showing an example of the configuration of a mobile communication system according to a conventional technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

[0014] First Embodiment [Mobile communication system configuration] 1 is a diagram showing an example of a system configuration of a mobile communication system 1A according to a first embodiment. The mobile communication system 1A includes, for example, one or more transfer devices 10, a transfer device controller 20, and one or more base stations 30. A server SV is a device that communicates with each of one or more wireless terminals CL.

[0015] One or more transfer devices 10 constitute a transfer device network TN, and are devices that transfer signals exchanged between the server SV and each of one or more wireless terminals CL. The transfer device controller 20 is a device that controls the one or more transfer devices 10 by transmitting a control signal. The base station 30 is a device that communicates with each of the one or more wireless terminals CL, transmits a signal transferred from the transfer device 10 to the wireless terminal CL, and transfers a signal received from the wireless terminal CL to the transfer device 10. The server SV and each of the one or more wireless terminals CL have one or more traffic flows. The transfer device controller 20 is communicably connected to each of the one or more transfer devices 10 and the base station 30.

[0016] The one or more transfer devices 10, the transfer device controller 20, and the base station 30 included in the mobile communication system 1A are configured using, for example, a processor such as a CPU (Central Processing Unit), a memory, and a communication interface. Each of the one or more transfer devices 10, the transfer device controller 20, and the base station 30 functions as a communication device having a control unit by the processor executing a program.

[0017] The control unit provides each function for causing the communication device to function as the transfer device 10, the transfer device controller 20, or the base station 30. Note that all or a part of each function of the control unit may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0018] The above program may be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include portable media such as flexible disks, optical magnetic disks, ROMs, CD-ROMs, and semiconductor storage devices (e.g., SSDs: Solid State Drives), and storage devices such as hard disks and semiconductor storage devices built into computer systems. The above program may be transmitted via an electric communication line.

[0019] [Specific example of functional configuration of a mobile communication system] 2 is a diagram showing a specific example of a functional configuration of a mobile communication system 1A according to the first embodiment. The mobile communication system 1A includes, for example, one or more information acquisition units 101A, a rate determination unit 102A, and one or more communication control units 103.

[0020] The information acquisition unit 101A acquires information on wireless communication between the base station 30 and the wireless terminal CL (hereinafter referred to as "wireless communication information"). The rate determination unit 102A collects the wireless communication information acquired by each of the one or more information acquisition units 101A, and determines a shaping rate of traffic shaping for each QoS class (quality of service class) based on the collected wireless communication information so as to prevent packet loss due to congestion in the transfer device network TN. The communication control unit 103 executes traffic shaping on the upstream side of the base station 30 based on the shaping rate determined by the rate determination unit 102A.

[0021] Specifically, in the mobile communication system 1A of the first embodiment, the information acquisition unit 101A is provided in a control unit of the base station 30, the rate determination unit 102A is provided in a control unit of the transfer device controller 20, and the communication control unit 103 is provided in a control unit of the transfer device 10.

[0022] In this case, the one or more information acquisition units 101A acquire information including control information related to the quality of wireless communication between the base station 30 and the wireless terminal CL (hereinafter referred to as "wireless quality information") as wireless communication information, and transmit the acquired wireless quality information to the transfer device controller 20. The wireless quality information includes information indicating the number of traffic flows and the traffic volume for each QoS class in the wireless communication between the base station 30 and the wireless terminal CL. Note that the wireless quality information may include information related to the communication quality for each traffic flow, and information indicating the priority for each traffic flow.

[0023] The rate determination unit 102A collects wireless quality information acquired by each of the one or more information acquisition units 101A, and determines a shaping rate for each QoS class based on the collected wireless quality information. Here, the rate determination unit 102A determines a shaping rate of traffic shaping for each QoS class, taking into consideration the priority and traffic volume of the traffic flow within a range that satisfies a predetermined delay requirement, so as to prevent packet loss due to congestion in the transfer device network TN. The rate determination unit 102A notifies the communication control unit 103 of the transfer device 10 of the determined shaping rate.

[0024] Then, in one or more transfer devices 10, the communication control unit 103 executes traffic shaping of the own device based on the shaping rate notified by the rate determination unit 102A of the transfer device controller 20.

[0025] Here, the wireless quality information acquired as the wireless communication information is, for example, a 5QI (5G QoS Indicator) (see, for example, Non-Patent Document 2) that is added to the header of an N3 interface signal in 5G (5th Generation) mobile communication, a PDCP SDU Data Volume for each 5QI, or a Number of QoS flow successfully established for each 5QI (see, for example, Non-Patent Document 3).

[0026] For example, the rate determination unit 102A of the transfer device controller 20 stores in advance a correspondence table (correspondence information) in which appropriate shaping rate candidates determined in advance according to a 5QI value are associated with the 5QI value, and determines in this correspondence table a shaping rate associated with a 5QI value (wireless quality information) acquired from the base station 30 as a shaping rate to be applied to the transfer device 10. Note that an appropriate shaping rate is a communication rate that is low enough to narrow the communication band so as to prevent packet loss due to congestion in the transfer device network TN while maintaining at least a minimum required communication rate.

[0027] Alternatively, examples of the wireless quality information acquired as wireless communication information include a buffer status report of a scheduling request, an uplink grant, and a buffer status report (see, for example, Non-Patent Document 4) that the base station 30 receives from the wireless terminal CL, and further, the wireless frame number, the subframe number, and the slot number (see, for example, Non-Patent Document 5) in which the base station receives the scheduling request, the uplink grant, and the buffer status report.

[0028] In general, a scheduling request is information that a wireless terminal transmits to a base station to notify the base station of the start of uplink communication. An uplink grant is information that a base station transmits in downlink communication to notify a wireless terminal of a wireless communication method and frequency resource allocation that permits uplink communication, and indirectly indicates the amount of data in uplink communication. A buffer status report is information that a wireless terminal transmits to notify a base station of how much data is stored in the buffer.

[0029] The radio frame number, subframe number, and slot number are three-level data unit numbers transmitted via wireless communication. A radio frame is defined as 10 ms, a subframe as 1 ms, and a slot as a length that can be selected from multiple values, such as 1 ms or 0.5 ms. The transmission and reception timing of wireless communication can be calculated from these numbers.

[0030] The scheduling request, uplink grant, and buffer status report are transmitted in association with the radio frame number, subframe number, and slot number that indicate the transmission timing of the uplink communication. In this case, the rate determination unit 102A collects radio quality information acquired by each of the one or more information acquisition units 101A, and determines an appropriate shaping rate for each QoS class by calculation based on the collected radio quality information.

[0031] Specifically, the rate determining unit 102A recognizes the amount of data (hereinafter referred to as "buffer data") buffered in the wireless terminal CL from a buffer status report received from the wireless terminal CL. The rate determining unit 102A calculates, as an appropriate shaping rate, a communication rate that is low enough to narrow the communication band so as not to cause packet loss due to congestion in the transfer device network TN, while at least maintaining a minimum communication rate required for transmitting the recognized amount of buffer data.

[0032] More specifically, for example, when the rate determining unit 102A obtains a scheduling request from the information obtaining unit 101A, the shaping rate is initialized and the radio frame number, subframe number, and slot number associated with the obtained scheduling request are held. After that, the rate determining unit 102A updates the shaping rate every time the rate determining unit 102A obtains a buffer status report from the information obtaining unit 101A.

[0033] The shaping rate is updated, for example, by adding a cumulative value of the data volume of uplink communication calculated from one or more uplink grants acquired by rate determination unit 102A from information acquisition unit 101A between the radio frame number, subframe number, and slot number associated with the scheduling request and the radio frame number, subframe number, and slot number associated with the buffer status report, to the data volume held by the wireless terminal notified in the buffer status report, and dividing the result by a time interval calculated from the radio frame number, subframe number, and slot number associated with the scheduling request and the radio frame number, subframe number, and slot number associated with the buffer status report, thereby determining the shaping rate.

[0034] The rate determination unit 102A may be configured to collect information on the state of the transfer device network TN (hereinafter referred to as "state information") from the transfer device 10, and calculate a shaping rate to be applied to the transfer device 10 based on this state information and wireless quality information acquired from the base station 30. For example, the rate determination unit 102A may calculate the shaping rate by taking into account the congestion state of the transfer device network TN recognized based on the state information.

[0035] According to the mobile communication system 1A of the first embodiment configured as described above, the transfer device 10 performs shaping at a shaping rate determined for each QoS class based on wireless quality information regarding wireless communication between the wireless terminal CL and the base station 30, thereby making it possible to suppress the occurrence of packet loss due to congestion that may have occurred in the transfer device network TN.

[0036] [Effect of suppressing packet loss occurrence] Fig. 3 is an image diagram showing the effect of suppressing the occurrence of packet loss by shaping of the transfer device 10 in the mobile communication system 1A of the first embodiment. In Fig. 3, the upper diagram shows a situation in which packet loss occurs by the conventional technology, and the lower diagram shows a situation in which the occurrence of packet loss is suppressed by the mobile communication system 1A of the present embodiment.

[0037] As an example, assume that a first traffic flow (hereinafter referred to as "traffic flow 1") with a bandwidth limit of 100 [Mbps], a second traffic flow (hereinafter referred to as "traffic flow 2") with a bandwidth limit of 300 [Mbps], and a third traffic flow (hereinafter referred to as "traffic flow 3") that provides the remaining bandwidth of 600 [Mbps] on a best-effort basis are set for a total bandwidth of 1 [Gbps]. Consider a case in which the state of traffic flow 2 changes to a traffic state in which a bandwidth of 400 [Mbps] may be required against the bandwidth limit of 300 [Mbps] due to an increase in bandwidth.

[0038] The flow from the initial state until the state of traffic flow 2 changes due to an increase in bandwidth (steps S1 to S2) is the same in the conventional technology and this embodiment. Hereinafter, the flow from steps S1 to S2, which is the same in the conventional technology and this embodiment, will be first described.

[0039] 3, step S1 represents an initial state, which represents a situation in which no packet loss due to congestion occurs. Specifically, in step S1, the bandwidth required for traffic flow 1 is within the range of the bandwidth limit (100 [Mbps]) preset for traffic flow 1, the bandwidth required for traffic flow 2 is within the range of the bandwidth limit (300 [Mbps]) preset for traffic flow 2, and the bandwidth required for traffic flow 3 is within the remaining bandwidth (600 [Mbps]).

[0040] 3, step S2 represents a situation in which the traffic state of traffic flow 2 changes and packet loss due to congestion may occur. Specifically, in step S2, the bandwidth required for traffic flow 2 increases to 400 [Mbps], exceeding the range of the bandwidth limit (300 [Mbps]) previously set for traffic flow 2.

[0041] After that, in the conventional communication system, packet loss occurs if the buffer cannot withstand a change in traffic state that occurs in traffic flow 2, in which the required bandwidth exceeds the bandwidth limit range. Specifically, when a bandwidth of 400 [Mbps] is actually required in traffic flow 2, packet loss of 100 [Mbps] occurs (step S31).

[0042] In contrast to the above-mentioned conventional technology, the mobile communication system 1A of the present embodiment changes the shaping rate in advance based on the wireless quality information acquired by the information acquisition unit 101A in advance. Specifically, as shown in FIG. 3, the mobile communication system 1A of the present embodiment predicts that the bandwidth of the traffic flow 2 will be insufficient by 100 [Mbps] by calculation based on the wireless quality information acquired in advance, and increases (expands) the bandwidth limit of the traffic flow 3 from 300 [Mbps] to 400 [Mbps] in advance (step S32). That is, in the mobile communication system 1A of the present embodiment, the rate determination unit 102A acquires wireless quality information from the information acquisition unit 101A and appropriately sets the shaping rate for each QoS class in advance before the traffic actually arrives at the transfer device network TN. At this time, the bandwidth of the best-effort type traffic flow 3 is automatically reduced from 600 [Mbps] to 500 [Mbps].

[0043] According to the mobile communication system 1A of the first embodiment configured in this manner, the transfer device 10 performs shaping for each QoS class with a shaping rate determined for each QoS class based on wireless quality information related to wireless communication between one or more wireless terminals CL and one or more base stations 30. The mobile communication system 1A of the first embodiment can increase (extend) the shaping rate in advance before a state in which packet loss due to congestion in the transfer device network TN may occur in a specific traffic flow. This allows the mobile communication system 1A of the first embodiment to suppress the occurrence of packet loss due to congestion that may occur in the transfer device network TN.

[0044] As described above, in the example of Fig. 3, the mobile communication system 1A of the present embodiment is configured to prevent packet loss by temporarily shifting a part of the bandwidth of the best-effort traffic flow 3 to the traffic flow 2. However, the present invention is not limited to this configuration. For example, the mobile communication system 1A may be configured such that a part of the bandwidth of a traffic flow having a bandwidth limit such as the traffic flow 1 shown in Fig. 3 is temporarily shifted to another traffic flow as necessary.

[0045] In the mobile communication system 1A of the first embodiment, the configuration in which the transfer device controller 20 determines the shaping rate of the transfer device 10 for each QoS class based on wireless quality information is also applicable to communication systems other than mobile communication systems. For example, if the base station 30 is replaced with a wireless LAN (Local Area Network) access point (hereinafter referred to as a "wireless AP"), the occurrence of packet loss due to congestion in the wireless LAN system can be suppressed by acquiring wireless quality information about wireless communication between the wireless AP and a wireless terminal CL connected to the wireless AP.

[0046] (Modification) Fig. 4 is a diagram showing a modified example of the mobile communication system 1A of the first embodiment. In the first embodiment, the case where the base station 30 directly supplies wireless quality information to the transfer device controller 20 has been described, but the wireless quality information may be supplied to the transfer device controller 20 via a device other than the base station 30 as shown in Fig. 4.

[0047] For example, in a modified mobile communication system 1A', if there are multiple base stations 30 and there is also a radio controller 40 that controls the multiple base stations 30, the radio controller 40 may be configured to collect radio quality information from the multiple base stations 30 and supply the collected radio quality information of the multiple base stations 30 to the transfer device controller 20.

[0048] The example of FIG. 4 shows a case where the wireless terminal CL before the movement is accommodated in a base station 30 different from the base station before the movement after the movement. Specifically, in the example of FIG. 4, the wireless terminal CL is accommodated in the base station 30-1 at the position before the movement, and is accommodated in the base station 30-2 at the position after the movement. In this case, the transfer device controller 20 instructs the transfer devices 10-1 and 10-2 accommodating the base stations 30-1 and 30-2, and the transfer device 10-3 located above them, to switch the path accompanying the movement of the wireless terminal CL. This allows the wireless terminal CL to continue communication with the server SV even if the base station 30 accommodating itself is changed.

[0049] In this case, in addition to controlling the base stations 30-1 and 30-2, the wireless controller 40 collects wireless quality information from the base stations 30-1 and 30-2, respectively, and supplies the collected wireless quality information to the transfer device controller 20. In this case, for example, the transfer device controller 20 determines a shaping rate to be applied to the transfer device 10 (e.g., the transfer devices 10-1 and 10-3) of the communication path before the wireless terminal CL moves based on the wireless quality information acquired from the base station 30-1, and determines a shaping rate to be applied to the transfer device 10 (e.g., the transfer devices 10-2 and 10-3) of the communication path after the wireless terminal CL moves for each QoS class based on the wireless quality information acquired from the base station 30-2. With such a configuration, the mobile communication system 1A' of this modified example can appropriately update the shaping rate for each QoS class for the multiple transfer devices 10 constituting the transfer device network TN adaptively to the movement of the wireless terminal CL.

[0050] In the mobile communication system 1A' of this modified example, the configuration in which the transfer device controller 20 determines the shaping rate of the transfer device 10 for each QoS class based on the wireless quality information is also applicable to communication systems other than the mobile communication system. For example, if the base station 30 is replaced with a wireless AP, the occurrence of packet loss due to congestion in the wireless LAN system can be suppressed by acquiring wireless quality information about wireless communication between the wireless AP and the wireless terminal CL connected to the wireless AP.

[0051] <Second embodiment> 5 is a diagram showing an example of a system configuration of a mobile communication system 1B of the second embodiment. The mobile communication system 1B is different from the mobile communication system 1A of the first embodiment in that a base station 30 includes one or more remote stations 31A and a central station 32, and one or more transfer devices 10 transfer communication between one or more remote stations 31A and the central station 32. The other configurations of the mobile communication system 1B are the same as those of the mobile communication system 1A of the first embodiment. Therefore, the same reference numerals as those in FIG. 2 are used to denote the same configurations as those in the mobile communication system 1A of the first embodiment, and the description thereof will be omitted.

[0052] The one or more remote stations 31A and the central station 32 are configured using, for example, a processor such as a CPU, a memory, and a communication interface, similar to the one or more transfer devices 10 and the transfer device controller 20 included in the mobile communication system 1B. Each of the one or more remote stations 31A and the central station 32 functions as a communication device equipped with a control unit by the processor executing a program.

[0053] The control unit provides each function for making the communication device function as the remote station 31A or the central station 32. All or part of each function of the control unit may be realized using hardware such as ASIC, PLD, or FPGA. The above program may be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and semiconductor storage devices (e.g., SSDs), and storage devices such as hard disks and semiconductor storage devices built into a computer system. The above program may be transmitted via a telecommunications line.

[0054] For example, the one or more distributed stations 31 and the central station 32 in the second embodiment are one or more DUs (Distributed Units) and CUs (Central Units) in a mobile communication system. In this case, the section between the CU and DU in which the transfer device 10 is installed is called an MMH (Mobile Midhaul). Also, for example, the one or more distributed stations 31 and the central station 32 in the second embodiment may be one or more RUs (Radio Units) and DU in a mobile communication system. In this case, the section between the DU and RU in which the transfer device 10 is installed is called an MFH (Mobile Fronthaul).

[0055] Specifically, in the mobile communication system 1B of the second embodiment, the information acquisition unit 101A is provided in a control unit of the remote station 31A, the rate determination unit 102A is provided in a control unit of the transfer device controller 20, and the communication control unit 103 is provided in a control unit of the transfer device 10.

[0056] In this case, the information acquisition unit 101A acquires wireless quality information related to wireless communication between one or more remote stations 31A and one or more wireless terminals CL as wireless communication information, and transmits the acquired wireless quality information to the transfer device controller 20. The wireless quality information includes information indicating the number of traffic flows for each QoS class and the traffic volume for each QoS class in the wireless communication between the base station 30 and the wireless terminals CL.

[0057] The rate determining unit 102A collects wireless quality information acquired by one or more information acquiring units 101A, and determines a shaping rate for each QoS class based on the collected wireless quality information. Here, the rate determining unit 102A determines a shaping rate for each QoS class while taking into consideration the priority and traffic volume of the traffic flow and within a range that satisfies a predetermined delay requirement, so that no packet loss occurs due to congestion. The rate determining unit 102A notifies the communication control unit 103 of the transfer device 10 of the determined shaping rate.

[0058] Then, in one or more transfer devices 10, the communication control unit 103 executes traffic shaping of the transfer device based on the shaping rate notified by the rate determination unit 102A of the transfer device controller 20.

[0059] According to the mobile communication system 1B of the second embodiment configured in this way, the transfer device 10 performs shaping for each QoS class with a shaping rate determined for each QoS class based on wireless quality information related to wireless communication between one or more wireless terminals CL and one or more remote stations 31A. The mobile communication system 1B of the second embodiment can increase the shaping rate in advance before a state in which packet loss due to congestion in the transfer device network TN may occur in a specific traffic flow. This allows the mobile communication system 1B of the second embodiment to suppress the occurrence of packet loss due to congestion that may occur in the transfer device network TN.

[0060] In the above embodiment, the case where the base station 30 directly supplies the wireless quality information to the transfer device controller 20 has been described, but the wireless quality information may be supplied to the transfer device controller 20 via a device other than the base station 30. For example, in the mobile communication system 1B, when there are multiple base stations 30 and a wireless controller that controls the multiple base stations 30 is further present, the wireless controller may be configured to collect wireless quality information from the multiple base stations 30 and supply the collected wireless quality information of the multiple base stations 30 to the transfer device controller 20.

[0061] In the mobile communication system 1B of the second embodiment, the configuration in which the transfer device controller 20 determines the shaping rate of the transfer device 10 for each QoS class based on the wireless quality information is also applicable to communication systems other than the mobile communication system. For example, if one or more remote stations 31A and the central station 32 in the second embodiment are replaced with a wireless AP and a wireless LAN controller in a wireless LAN system, the occurrence of packet loss due to congestion in the wireless LAN system can be suppressed by acquiring wireless quality information about wireless communication between the wireless AP and the wireless terminal CL connected to the wireless AP.

[0062] <Third embodiment> FIG. 6 is a diagram showing an example of a system configuration of a mobile communication system 1C of the third embodiment. The mobile communication system 1C is different from the mobile communication system 1A of the first embodiment in that the base station 30 includes one or more remote stations 31 and a central station 32A, and one or more transfer devices 10 transfer communication between one or more remote stations 31 and the central station 32A. The mobile communication system 1C is also different from the mobile communication system 1B of the second embodiment in that the central station 32A includes an information acquisition unit 101B, and the remote station 31 does not include an information acquisition unit. The other configurations of the mobile communication system 1C are the same as those of the mobile communication system 1A of the first embodiment. Therefore, the same reference numerals as those in FIG. 2 are used to denote the same configurations as those in the mobile communication system 1A of the first embodiment, and the description thereof will be omitted.

[0063] The one or more remote stations 31 and the central station 32A are configured using, for example, a processor such as a CPU, a memory, and a communication interface, similar to the one or more transfer devices 10 and the transfer device controller 20 included in the mobile communication system 1C. Each of the one or more remote stations 31 and the central station 32A functions as a communication device equipped with a control unit by the processor executing a program.

[0064] The control unit provides each function for making the communication device function as the remote station 31 or the central station 32A. All or part of each function of the control unit may be realized using hardware such as ASIC, PLD, or FPGA. The above program may be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and semiconductor storage devices (e.g., SSDs), and storage devices such as hard disks and semiconductor storage devices built into a computer system. The above program may be transmitted via an electric communication line.

[0065] For example, the one or more remote stations 31 and the central station 32A in the third embodiment are one or more DUs and CUs in a mobile communication system. In this case, the section between the CU and DU in which the transfer device 10 is installed is called an MMH. Also, for example, the one or more remote stations 31 and the central station 32A in the second embodiment may be one or more RUs and DUs in a mobile communication system. In this case, the section between the DU and RU in which the transfer device 10 is installed is called an MFH (Mobile Fronthaul).

[0066] Specifically, in the mobile communication system 1C of the third embodiment, the information acquisition unit 101B is provided in a control unit of the central station 32A, the rate determination unit 102B is provided in a control unit of the transfer device controller 20, and the communication control unit 103 is provided in a control unit of the transfer device 10.

[0067] In this case, the information acquisition unit 101B acquires wireless quality information related to wireless communication between one or more remote stations 31 and one or more wireless terminals CL as wireless communication information, and transmits the acquired wireless quality information to the transfer device controller 20. The wireless quality information includes information indicating the number of traffic flows for each QoS class and the traffic volume for each QoS class in the wireless communication between the base station 30 and the wireless terminals CL.

[0068] The rate determining unit 102B determines a shaping rate for each QoS class based on the wireless quality information acquired by the information acquiring unit 101B. Here, the rate determining unit 102B determines a shaping rate for each QoS class while taking into consideration the priority and traffic volume of the traffic flow and within a range that satisfies a predetermined delay requirement, so as not to cause packet loss due to congestion. The rate determining unit 102B notifies the communication control unit 103 of the transfer device 10 of the determined shaping rate.

[0069] Then, the communication control unit 103 in one or more transfer devices 10 executes traffic shaping of the own device based on the shaping rate notified by the rate determination unit 102B of the transfer device controller 20.

[0070] According to the mobile communication system 1C of the third embodiment configured in this way, the transfer device 10 performs shaping for each QoS class with a shaping rate determined for each QoS class based on wireless quality information related to wireless communication between one or more wireless terminals CL and one or more remote stations 31. The mobile communication system 1C of the third embodiment can increase the shaping rate in advance before a state in which packet loss due to congestion in the transfer device network TN may occur in a specific traffic flow. This allows the mobile communication system 1C of the third embodiment to suppress the occurrence of packet loss due to congestion that may occur in the transfer device network TN.

[0071] In the above embodiment, the case where the base station 30 directly supplies the wireless quality information to the transfer device controller 20 has been described, but the wireless quality information may be supplied to the transfer device controller 20 via a device other than the base station 30. For example, in a mobile communication system 1C, when a plurality of base stations 30 exists and a wireless controller that controls the plurality of base stations 30 also exists, the wireless controller may be configured to collect wireless quality information from the plurality of base stations 30 and supply the collected wireless quality information of the plurality of base stations 30 to the transfer device controller 20.

[0072] In the mobile communication system 1C of the third embodiment, the configuration in which the transfer device controller 20 determines the shaping rate of the transfer device 10 for each QoS class based on the wireless quality information is also applicable to communication systems other than the mobile communication system. For example, if one or more remote stations 31 and the central station 32A in the third embodiment are replaced with a wireless AP and a wireless LAN controller in a wireless LAN system, the occurrence of packet loss due to congestion in the wireless LAN system can be suppressed by acquiring wireless quality information about wireless communication between the wireless AP and the wireless terminal CL connected to the wireless AP.

[0073] <Fourth embodiment> FIG. 7 is a diagram showing an example of a system configuration of a mobile communication system 1D of the fourth embodiment. The mobile communication system 1D is different from the mobile communication system 1A of the first embodiment in that the base station 30 includes one or more remote stations 31A and a central station 32A, and one or more transfer devices 10 transfer communication between one or more remote stations 31A and the central station 32A. The mobile communication system 1D is also different from the mobile communication system 1B of the second embodiment in that not only the remote station 31A includes an information acquisition unit 101A, but also the central station 32A includes an information acquisition unit 101B. The other configurations of the mobile communication system 1D are the same as those of the mobile communication system 1A of the first embodiment. Therefore, the same reference numerals as those in FIG. 2 are used to denote the same configurations as those in the mobile communication system 1A of the first embodiment, and the description thereof will be omitted.

[0074] The one or more remote stations 31A and the central station 32A are configured using, for example, a processor such as a CPU, a memory, and a communication interface, similar to the one or more transfer devices 10 and the transfer device controller 20 included in the mobile communication system 1D. Each of the one or more remote stations 31A and the central station 32A functions as a communication device equipped with a control unit by the processor executing a program.

[0075] The control unit provides each function for making the communication device function as the remote station 31A or the central station 32A. All or part of each function of the control unit may be realized using hardware such as ASIC, PLD, or FPGA. The above program may be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and semiconductor storage devices (e.g., SSDs), and storage devices such as hard disks and semiconductor storage devices built into a computer system. The above program may be transmitted via an electric communication line.

[0076] For example, the one or more remote stations 31A and the central station 32A in the fourth embodiment are one or more DUs and CUs in a mobile communication system. In this case, the section between the CU and DU in which the transfer device 10 is installed is called an MMH. Also, for example, the one or more remote stations 31A and the central station 32A in the fourth embodiment may be one or more RUs and DUs in a mobile communication system. In this case, the section between the DU and RU in which the transfer device 10 is installed is called an MFH (Mobile Fronthaul).

[0077] Specifically, in the mobile communication system 1D of the fourth embodiment, the information acquisition unit 101A is provided in a control unit of the remote station 31A, the information acquisition unit 101B is provided in a control unit of the central station 32A, the rate determination unit 102C is provided in a control unit of the transfer device controller 20, and the communication control unit 103 is provided in a control unit of the transfer device 10.

[0078] In this case, the information acquiring unit 101A and the information acquiring unit 101B acquire wireless quality information related to wireless communication between one or more remote stations 31 and one or more wireless terminals CL as wireless communication information, and transmit the acquired wireless quality information to the transfer device controller 20. The wireless quality information includes information indicating the number of traffic flows for each QoS class and the traffic volume for each QoS class in the wireless communication between the base station 30 and the wireless terminals CL.

[0079] The rate determination unit 102C collects wireless quality information acquired by one or more information acquisition units 101A and 101B, and determines a shaping rate for each QoS class based on the collected wireless quality information. Here, the rate determination unit 102C determines a shaping rate for each QoS class while taking into consideration the priority and traffic volume of the traffic flow within a range that satisfies a predetermined delay requirement, so as not to cause packet loss due to congestion. The rate determination unit 102C notifies the communication control unit 103 of the transfer device 10 of the determined shaping rate.

[0080] Then, the communication control unit 103 in one or more transfer devices 10 executes traffic shaping of the own device based on the shaping rate notified by the rate determination unit 102C of the transfer device controller 20.

[0081] According to the mobile communication system 1D of the fourth embodiment configured in this way, the transfer device 10 performs shaping for each QoS class with a shaping rate determined for each QoS class based on wireless quality information related to wireless communication between one or more wireless terminals CL and one or more remote stations 31A. The mobile communication system 1D of the fourth embodiment can increase the shaping rate in advance before a state in which packet loss due to congestion in the transfer device network TN may occur in a specific traffic flow. As a result, the mobile communication system 1D of the fourth embodiment can suppress the occurrence of packet loss due to congestion that may occur in the transfer device network TN.

[0082] In the above embodiment, the case where the base station 30 directly supplies the wireless quality information to the transfer device controller 20 has been described, but the wireless quality information may be supplied to the transfer device controller 20 via a device other than the base station 30. For example, in the mobile communication system 1D, when a plurality of base stations 30 exists and a wireless controller that controls the plurality of base stations 30 also exists, the wireless controller may be configured to collect wireless quality information from the plurality of base stations 30 and supply the collected wireless quality information of the plurality of base stations 30 to the transfer device controller 20.

[0083] In the mobile communication system 1D of the fourth embodiment, the configuration in which the transfer device controller 20 determines the shaping rate of the transfer device 10 for each QoS class based on the wireless quality information is also applicable to communication systems other than the mobile communication system. For example, if one or more remote stations 31A and the central station 32A in the fourth embodiment are replaced with a wireless AP and a wireless LAN controller in a wireless LAN system, the occurrence of packet loss due to congestion in the wireless LAN system can be suppressed by acquiring wireless quality information about wireless communication between the wireless AP and the wireless terminal CL connected to the wireless AP.

[0084] According to the above-mentioned embodiment, the communication system includes one or more base stations that accommodate wireless terminals, one or more transfer devices that transfer the upstream communication of the wireless terminals received via the base stations to the upper side, and a transfer device controller that controls the one or more transfer devices. For example, the communication system is the mobile communication systems 1A, 1A', 1B, 1C, and 1D in the embodiment, the wireless terminal is the wireless terminal CL in the embodiment, the base station is the base station 30, 30-1, and 30-2 in the embodiment, and the transfer device controller is the transfer device controller 20 in the embodiment.

[0085] The above communication system includes an information acquisition unit, a rate determination unit, and a communication control unit. For example, the information acquisition unit is the information acquisition units 101A and 101B in the embodiment, the rate determination unit is the rate determination units 102A and 102B in the embodiment, and the communication control unit is the communication control unit 103 in the embodiment.

[0086] The information acquisition unit acquires information related to wireless communication for each service quality class. The rate determination unit determines a shaping rate of traffic shaping for each service quality class based on the information related to wireless communication for each service quality class so as not to cause packet loss due to congestion. The communication control unit executes traffic shaping for each service quality class on the upper side of the base station based on the shaping rate determined by the rate determination unit. For example, the service quality class is a QoS class in the embodiment, and the information related to wireless communication is wireless quality information and wireless communication information in the embodiment.

[0087] In addition, the information acquisition unit may acquire wireless quality information regarding wireless communication between the base station and the wireless terminal for each service quality class, and the rate determination unit may determine a shaping rate to be applied to one or more forwarding devices for each service quality class based on correspondence information indicating the correspondence between the wireless quality information and the shaping rate and the wireless quality information acquired from the base station, and the communication control unit may perform traffic shaping in the one or more forwarding devices at the shaping rate determined for each service quality class by the rate determination unit.

[0088] The base station may have a remote station and a central station, the information acquisition unit acquires wireless quality information related to wireless communication between the remote station and the wireless terminal for each service quality class, the rate determination unit determines a shaping rate to be applied to one or more transfer devices for each service quality class based on the correspondence information indicating the correspondence between the wireless quality information and the shaping rate and the wireless quality information acquired from the remote station, and the communication control unit may execute traffic shaping at the shaping rate determined for each service quality class by the rate determination unit in one or more transfer devices. For example, the remote station is the remote station 31, 31A in the embodiment, the central station is the central station 32, 32A in the embodiment, and the correspondence information is a correspondence table in which suitable shaping rate candidates determined in advance according to the value of 5QI in the embodiment are associated with the value of the 5QI.

[0089] In addition, the base station may have a remote station and a central station, an information acquisition unit may acquire wireless quality information regarding wireless communication between the remote station and the wireless terminal for each service quality class, a rate determination unit may determine a shaping rate to be applied to one or more forwarding devices for each service quality class based on correspondence information indicating the correspondence between the wireless quality information and the shaping rate and the wireless quality information acquired from the central station, and a communication control unit may perform traffic shaping in one or more forwarding devices at the shaping rate determined for each service quality class by the rate determination unit.

[0090] In addition, the base station may have a remote station and a central station, an information acquisition unit may acquire wireless quality information regarding wireless communication between the remote station and the wireless terminal for each service quality class, a rate determination unit may determine a shaping rate to be applied to one or more forwarding devices for each service quality class based on correspondence information indicating the correspondence between the wireless quality information and the shaping rate and the wireless quality information acquired from the remote station and the central station, and a communication control unit may perform traffic shaping in the one or more forwarding devices at the shaping rate determined for each service quality class by the rate determination unit.

[0091] In addition, the wireless quality information may include at least one of information indicating the number of traffic flows for each service quality class and information indicating the traffic volume for each service quality class, and the rate determination unit may determine a shaping rate for each service quality class based on the number of traffic flows and the traffic volume.

[0092] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included. [Industrial Applicability]

[0093] The present invention is applicable to a communication system accommodating wireless terminals and a communication control method. [Explanation of symbols]

[0094] 1A, 1A', 1B, 1C, 1D... mobile communication system, 10, 10-1, 10-2, 10-3... transfer device, 20... transfer device controller, 30, 30-1, 30-2... base station, 31, 31A... remote station, 32, 32A... central station, 40... wireless controller, 90, 90a... mobile communication system, 91, 91a... server, 92, 92a... transfer device, 93, 93a... transfer device controller, 94, 94a... base station, 95, 95a... wireless terminal, 96, 96a... transfer device network, 101A, 101B... information acquisition unit, 102A, 102B... rate determination unit, 103... communication control unit

Claims

1. One or more base stations accommodating wireless terminals; one or more forwarding devices for forwarding upstream communication of the wireless terminal received via the base station to an upper side; A transfer device controller that controls the one or more transfer devices; A communication system comprising: an information acquisition unit that acquires information regarding wireless communication for each service quality class between the base station and the wireless terminal; a rate determination unit that determines, for each of the quality of service classes, a communication rate that is low enough to narrow a communication band so as not to cause packet loss due to congestion while at least maintaining a communication rate necessary for transmitting the amount of buffer data of the wireless terminal, based on information regarding wireless communication for each of the quality of service classes, including a value of a data amount of buffer data of the wireless terminal; and a communication control unit that performs traffic shaping for each of the service quality classes on an upper side of the base station based on the shaping rate determined by the rate determination unit; A communication system comprising:

2. the information acquisition unit acquires wireless quality information regarding wireless communication between the base station and the wireless terminal for each of the service quality classes; the rate determination unit determines a shaping rate to be applied to the one or more transfer devices for each of the service quality classes based on correspondence information indicating a correspondence between wireless quality information and a shaping rate and the wireless quality information acquired from the base station; the communication control unit executes traffic shaping in the one or more transfer devices at a shaping rate determined for each of the quality of service classes by the rate determination unit. The communication system according to claim 1 .

3. The base station includes a distributed station and a central station, the information acquisition unit acquires wireless quality information regarding wireless communication between the remote station and the wireless terminal for each of the service quality classes; the rate determination unit determines a shaping rate to be applied to the one or more transfer devices for each of the service quality classes based on correspondence information indicating a correspondence between wireless quality information and a shaping rate and the wireless quality information acquired from the remote station; the communication control unit executes traffic shaping in the one or more transfer devices at a shaping rate determined for each of the quality of service classes by the rate determination unit. The communication system according to claim 1 .

4. One or more base stations accommodating wireless terminals; one or more forwarding devices for forwarding upstream communication of the wireless terminal received via the base station to an upper side; A transfer device controller that controls the one or more transfer devices; A communication system comprising: an information acquisition unit that acquires information regarding wireless communication for each service quality class between the base station and the wireless terminal; a rate determination unit that determines a shaping rate of traffic shaping for each of the quality of service classes based on information about wireless communication for each of the quality of service classes so that packet loss due to congestion does not occur; a communication control unit that performs traffic shaping for each of the service quality classes on an upper side of the base station based on the shaping rate determined by the rate determination unit; Equipped with The base station includes a distributed station and a central station, the information acquisition unit acquires wireless quality information regarding wireless communication between the remote station and the wireless terminal for each of the service quality classes; the rate determination unit determines a shaping rate to be applied to the one or more transfer devices for each of the service quality classes based on correspondence information indicating a correspondence between wireless quality information and a shaping rate and the wireless quality information acquired from the central station; The communication control unit performs traffic shaping in the one or more transfer devices at a shaping rate determined for each of the quality of service classes by the rate determination unit. Communication systems.

5. One or more base stations accommodating wireless terminals; one or more forwarding devices for forwarding upstream communication of the wireless terminal received via the base station to an upper side; A transfer device controller that controls the one or more transfer devices; A communication system comprising: an information acquisition unit that acquires information regarding wireless communication for each service quality class between the base station and the wireless terminal; a rate determination unit that determines a shaping rate of traffic shaping for each of the quality of service classes based on information about wireless communication for each of the quality of service classes so that packet loss due to congestion does not occur; a communication control unit that performs traffic shaping for each of the service quality classes on an upper side of the base station based on the shaping rate determined by the rate determination unit; Equipped with The base station includes a distributed station and a central station, the information acquisition unit acquires wireless quality information regarding wireless communication between the remote station and the wireless terminal for each of the service quality classes; the rate determination unit determines a shaping rate to be applied to the one or more transfer devices for each of the service quality classes based on correspondence information indicating a correspondence between wireless quality information and a shaping rate and the wireless quality information acquired from the remote station and the central station; The communication control unit performs traffic shaping in the one or more transfer devices at a shaping rate determined for each of the quality of service classes by the rate determination unit. Communication systems.

6. the wireless quality information includes at least one of information indicating a number of traffic flows for each of the service quality classes and information indicating a traffic volume for each of the service quality classes; the rate determination unit determines the shaping rate for each quality of service class based on the number of traffic flows and the traffic volume. A communication system according to any one of claims 2 to 5.

7. One or more base stations accommodating wireless terminals; one or more forwarding devices for forwarding upstream communication of the wireless terminal received via the base station to an upper side; A transfer device controller that controls the one or more transfer devices; In a communication system comprising: an information acquisition step of acquiring information regarding wireless communication for each service quality class between the base station and the wireless terminal; a rate determination step of determining, for each quality of service class, a communication rate that is low enough to narrow a communication band so as not to cause packet loss due to congestion while at least maintaining a communication rate necessary for transmitting the amount of buffer data of the wireless terminal based on information related to wireless communication for each quality of service class, including a value of the amount of buffer data of the wireless terminal; and a communication control step of executing traffic shaping for each of the quality of service classes at an upper side of the base station based on the shaping rate determined in the rate determination step; A communication control method comprising the steps of:

8. A transfer device controller controls one or more transfer devices that transfer upstream communication of a wireless terminal received via one or more base stations accommodating the wireless terminal to an upper side, a rate determination unit that determines, for each quality of service class, a communication rate that is low enough to narrow a communication band so as not to cause packet loss due to congestion while at least maintaining a communication rate necessary for transmitting the amount of buffer data of the wireless terminal, based on information regarding wireless communication between the base station and the wireless terminal for each quality of service class, including a value of a data amount of buffer data of the wireless terminal; and a transmission unit that transmits the shaping rate determined by the rate determination unit to the transfer device that performs traffic shaping for each of the service quality classes on an upper side of the base station; A transfer device controller comprising:

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