Signal transfer device, relay device, control device, and signal processing method

Abstract

A relay device according to the present invention comprises: an information acquisition unit that, for every traffic flow from a wireless terminal to a higher-level device, acquires traffic information that is information about the traffic flow; and a communication control unit that, on the basis of a band control method for reducing the jitter of frames determined on the basis of the traffic information acquired by the information acquisition unit for each traffic flow, executes adjustment processing that controls transmission of a plurality of frames that constitute an uplink signal for the traffic flow.　

Description

Signal transfer device, relay device, control device, and signal processing method

[0001] The present invention relates to a signal transfer device, a relay device, a control device, and a signal processing method.

[0002] Conventionally, a signal forwarding system shown in Fig. 15 is known as a configuration for exchanging signals between a base station and a wireless terminal. Fig. 15 is a diagram showing an example configuration of a conventional signal forwarding system 1000. The signal forwarding system 1000 is a system that forwards signals from one communication device to another communication device in a mobile communication system. The signal forwarding system 1000 includes, for example, a server 1, one or more transfer devices 2, a transfer device controller 3, and one or more base stations 4.

[0003] The server 1 communicates with a wireless terminal 5 that is wirelessly connected to one or more base stations 4. The transfer device 2 transfers signals transmitted and received between the server 1 and the wireless terminal 5. The transfer device controller 3 controls each transfer device 2. The base station 4 communicates wirelessly with the wireless terminal 5, transmits signals transferred from the transfer device 2 to the wireless terminal 5, and transfers signals received from the wireless terminal 5 to the transfer device 2.

[0004] "3GPP TS 38.300 V17.5.0," 3GPP (registered trademark), 2023. "3GPP TS 38.214 V17.6.0," 3GPP, 2023. Kazuto Shimizu et al., "Core Network Technology Overview for Realizing 5G SA Voice Communications," NTT DOCOMO Technical Journal, Vol. 30, No. 4, 2023. "3GPP TS 23.501 V18.1.0," 3GPP, 2023.

[0005] In each traffic flow in uplink transmission of a mobile communication system, even if the frame intervals are uniform and jitter is low when the traffic flow is transmitted to the MAC (Medium Access Control) layer function in the wireless terminal 5 at the output of the application layer function in the wireless terminal 5, jitter can increase due to the following factors. For example, jitter occurs due to the uplink transmission wait time of TDD (Time Division Duplex) in wireless transmission between the base station 4 and the wireless terminal 5 (see, for example, Non-Patent Document 1), the wait time for forming a transport block (a wireless transmission frame) (see, for example, Non-Patent Document 2), or the wait time for retransmission data due to retransmission control, resulting in increased jitter when the traffic flow is received by the base station 4. This means that even if jitter is reduced in the upper network in uplink E2E transmission, jitter already occurs in the initial wireless transmission, resulting in increased end-to-end jitter. Note that this problem is not limited to mobile communication systems, but is also common to wireless communication systems other than mobile communication systems.

[0006] In view of the above circumstances, an object of the present invention is to provide a technique capable of suppressing an increase in jitter.

[0007] One aspect of the present invention is a signal transfer system comprising: an information acquisition unit that acquires traffic information, which is information regarding traffic flows from a wireless terminal to a higher-level device, for each traffic flow; a control decision unit that determines a bandwidth control method for reducing frame jitter based on the traffic information acquired by the information acquisition unit for each traffic flow; and a communication control unit that performs adjustment processing to control the transmission of multiple frames that constitute an uplink signal of the traffic flow based on the bandwidth control method determined by the control decision unit.

[0008] One aspect of the present invention is a relay device comprising: an information acquisition unit that acquires traffic information, which is information regarding traffic flows from a wireless terminal to a higher-level device, for each traffic flow; and a communication control unit that performs an adjustment process to control the transmission of multiple frames that constitute an uplink signal of the traffic flow based on a bandwidth control method for reducing frame jitter determined based on the traffic information acquired by the information acquisition unit for each traffic flow.

[0009] One aspect of the present invention is a control device that includes a control decision unit that acquires traffic information, which is information regarding traffic flows from a wireless terminal to a higher-level device, for each traffic flow, determines a bandwidth control method for reducing frame jitter based on the acquired traffic information, and notifies a relay device located between the wireless terminal and the higher-level device of the bandwidth control method.

[0010] One aspect of the present invention is a signal processing method that acquires traffic information, which is information regarding a traffic flow from a wireless terminal to a higher-level device, for each traffic flow, determines a bandwidth control method for reducing frame jitter based on the traffic information acquired for each traffic flow, and performs an adjustment process that controls the transmission of multiple frames that constitute an uplink signal of the traffic flow based on the determined bandwidth control method.

[0011] According to the present invention, it is possible to suppress an increase in jitter.

[0012] FIG. 1 is a diagram illustrating an example of a configuration of a signal transfer system according to a first embodiment. FIG. 2 is a diagram for explaining an overview of jitter generation in a conventional system. FIG. 3 is a diagram for explaining an overview of adjustment processing in the first embodiment. FIG. 4 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the first embodiment. FIG. 5 is a diagram illustrating an example of a configuration of a signal transfer system according to a second embodiment. FIG. 6 is a flowchart illustrating a processing flow performed by the signal transfer system according to the second embodiment. FIG. 7 is a diagram illustrating an example of a configuration of a signal transfer system according to a third embodiment. FIG. 8 is a flowchart illustrating a processing flow performed by the signal transfer system according to the third embodiment. FIG. 9 is a diagram illustrating an example of a configuration of a signal transfer system according to a fourth embodiment. FIG. 10 is a flowchart illustrating a processing flow performed by the signal transfer system according to the fourth embodiment. FIG. 11 is a diagram illustrating an example of a configuration of a signal transfer system according to a fifth embodiment. FIG. 12 is a flowchart illustrating a processing flow performed by the signal transfer system according to the fifth embodiment. FIG. 13 is a diagram illustrating an example of a configuration of a signal transfer system according to a sixth embodiment. FIG. 14 is a flowchart illustrating a processing flow performed by the signal transfer system according to the sixth embodiment. FIG. 15 is a diagram illustrating an example of a configuration of a conventional signal transfer system.

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] 1 is a diagram showing an example of the configuration of a signal transfer system 100 according to a first embodiment. The signal transfer system 100 is a system that transfers signals from one communication device to another communication device. The signal transfer system 100 includes, for example, a server 10, one or more transfer devices 20, a transfer device controller 30, and one or more base stations 40.

[0015] The server 10 is a device that communicates with each of one or more wireless terminals 50 that are wirelessly connected to each base station 40. For example, the server 10 receives an uplink signal transmitted from the wireless terminal 50.

[0016] The transfer device 20 is a device that transfers signals exchanged between a higher-level device (e.g., the server 10) and one or more wireless terminals 50. For example, the transfer device 20 transfers an uplink signal transmitted from the wireless terminal 50 to the higher-level device. Furthermore, the transfer device 20 has a function of executing adjustment processing in response to instructions from the transfer device controller 30.

[0017] The adjustment process is a process of controlling the transmission intervals of multiple frames. The process of controlling the transmission intervals of multiple frames is a process, such as shaping, in which multiple frames with narrow frame intervals are buffered to widen the frame intervals and adjust the transmission intervals of multiple frames so that they are uniform. The transfer device 20 performs the adjustment process for each traffic flow transmitted by the wireless terminal 50.

[0018] Here, the above-mentioned frame refers to a frame that is propagated in the upstream direction and is transmitted to a destination such as a higher-level device. Therefore, when the destination is the server 10, the frame is transmitted from the wireless terminal 50 to the server 10.

[0019] The transfer device controller 30 is a device that controls one or more transfer devices 20 by transmitting control signals. Furthermore, the transfer device controller 30 acquires traffic information for each traffic flow currently flowing through the transfer device 20. Note that the traffic flow in the present invention refers to an upstream traffic flow transmitted from a wireless terminal 50. The transfer device controller 30 determines a bandwidth control method for reducing frame jitter based on the acquired traffic information for each traffic flow. The bandwidth control method is, for example, a shaping rate.

[0020] The traffic information includes information indicating the amount of data for each traffic flow and information indicating the priority of each traffic flow. The amount of data is, for example, a cumulative counter value of the amount of data that can be acquired using technologies such as Simple Network Management Protocol (SNMP) or telemetry, or a value of the amount of data per second expressed in bits per second (bps). The information indicating the priority of each traffic flow is, for example, Class of Service (CoS) information in a Virtual Local Area Network (VLAN) tag, Type of Service (ToS) information in an Internet Protocol (IP) header, or Network Slice Selection Assistance Information (NSSAI) that serves as a slice ID in a mobile communication system or a 5G QoS Indicator (5QI) defined for each Quality of Service Flow Indicator (QFI) (see, for example, Non-Patent Documents 3 and 4).

[0021] The base station 40 is a device that wirelessly communicates with one or more wireless terminals 50. The base station 40, for example, transmits signals transferred from the transfer device 20 to the wireless terminals 50, and transfers signals received from the wireless terminals 50 to the transfer device 20.

[0022] The wireless terminal 50 has one or more traffic flows, and transmits a signal for each traffic flow.

[0023] The one or more transfer devices 20 and the transfer device controller 30 included in the signal transfer system 100 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 20 and the transfer device controller 30 functions as a communication device equipped with a different control unit by the processor executing a program.

[0024] The control unit provides each function for causing the communication device to function as the transfer device 20 or the transfer device controller 30. Note that all or part of the functions 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).

[0025] 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 (Solid State Drives)), as well as storage devices such as hard disks and semiconductor storage devices built into computer systems. The above program may be transmitted via a telecommunications line.

[0026] The transfer device 20 may be installed between a central station and distributed stations that are obtained by dividing the functions of the base station 40. The central station and distributed stations are, for example, a CU (Central Unit) and a DU (Distributed Unit) in a mobile communication system. In this case, the transfer device 20 is installed in a section called an MMH (Mobile Midhaul). The central station and distributed stations may be regarded as a DU and a RU (Radio Unit), and the transfer device 20 may be installed in a section called an MFH (Mobile Front Haul). Furthermore, the application to a wireless communication system other than a mobile communication system may be considered, for example, by regarding the central station as a Wi-Fi controller and the distributed stations as Wi-Fi access points.

[0027] The base station 40 may be, for example, a Wi-Fi (registered trademark) access point. The signal transfer system 100 does not necessarily have to be applied to a mobile communication system, and may be applied to a wireless communication system other than a mobile communication system.

[0028] (Device Configuration) Next, the specific configuration of each device will be described. Each transfer device 20 includes an information acquisition unit 21 and a communication control unit 22. The information acquisition unit 21 acquires traffic information for each traffic flow currently flowing through the transfer device 20. The information acquisition unit 21 notifies the transfer device controller 30 of the acquired traffic information for each traffic flow.

[0029] The communication control unit 22 performs adjustment processing (for example, shaping) for each traffic flow in accordance with the shaping instruction sent from the transfer device controller 30 .

[0030] The transfer device controller 30 includes a control decision unit 31. The control decision unit 31 calculates a shaping rate for each traffic flow that reduces jitter within a range that satisfies the delay requirement, taking into account the priority of each traffic flow, based on traffic information acquired from the transfer device 20. The control decision unit 31 transmits a shaping instruction to the transfer device 20 that includes at least the calculated shaping rate for each traffic flow and information indicating the traffic flow.

[0031] A method for calculating a shaping rate taking into account the priority of each traffic flow will be described. As an example, assume that the transfer capacity of the server 10-side port of the transfer device 20 is 1 Gbps, two traffic flows (e.g., a first traffic flow and a second traffic flow) are flowing through the transfer device 20, the first traffic flow has a higher priority, and the optimal shaping rates for both traffic flows are 600 Mbps. In this case, the control decision unit 31 determines 600 Mbps as the shaping rate for the high-priority traffic flow (first traffic flow). Then, for the low-priority traffic flow (second traffic flow), the control decision unit 31 determines 400 Mbps as the shaping rate, which is the value obtained by subtracting the shaping rate of the high-priority traffic flow (600 Mbps) from the transfer capacity of the server 10-side port of the transfer device 20. In this way, the control decision unit 31 uses a shaping rate that is smaller than the calculated shaping rate for a traffic flow with a low priority in order to prioritize a traffic flow with a high priority.

[0032] Here, the shaping rate may be calculated by, for example, calculating the amount of data per second based on the difference between a certain point in time and another point in time of a cumulative counter of the amount of data, averaging the acquired multiple amounts of data per second over a predetermined period of time (e.g., five minutes), or determining the future shaping rate by machine learning prediction using the cumulative counter or the amount of data per second. The shaping rate calculation and shaping instruction may be performed only once or multiple times. Furthermore, when traffic congestion occurs in a specific transfer device 20, the transfer device controller 30 may issue a route change instruction for a specific traffic flow in addition to a shaping instruction.

[0033] In the signal transfer system 100 according to the first embodiment, the information acquisition unit 21 and the communication control unit 22 are provided in the control unit of the transfer device 20 , and the control decision unit 31 is provided in the control unit of the transfer device controller 30 .

[0034] Next, an overview of the above-mentioned adjustment process will be described. Fig. 2 is a diagram for explaining an overview of jitter caused by the influence of TDD in a conventional system. Fig. 3 is a diagram for explaining an overview of the adjustment process in the first embodiment.

[0035] Image G101 in Fig. 2 shows the state of frames when the application layer function of the wireless terminal 50 is output. As shown in image G101, five frames, frames 1 to 5, are output at equal intervals when the application layer function of the wireless terminal 50 is output. Image G102 in Fig. 2 shows an example of the state of a signal transmitted from the wireless terminal 50 to the base station 40. In image G102, the period between frame 2 and frame 3 is the downlink transmission timing in TDD.

[0036] Uplink signals cannot be transmitted during the downlink transmission timing period. As a result, in the past, when base station 40 received a signal transmitted from wireless terminal 50, the time interval between frames 1 and 2 and the time interval between frames 2 and 3 were uneven, as shown in image G103. This unevenness in the intervals was a factor that increased jitter.

[0037] In contrast, in the adjustment process of the first embodiment, adjustment is performed so that the frame intervals between multiple frames become uniform, as shown below. Image G201 in Figure 3 shows the state of frames when the application layer function of the wireless terminal 50 is output. As shown in image G201, when the application layer function of the wireless terminal 50 is output, five frames, frames 1 to 5, are output at equal intervals.

[0038] Image G202 in Figure 3 shows an example of a signal transmitted from the wireless terminal 50 to the base station 40. In image G202, the period between frame 2 and frame 3 is the downlink transmission timing in TDD. Uplink signals cannot be transmitted during the downlink transmission timing. In the adjustment process in the first embodiment, as shown in image G203, the transfer device 20 buffers multiple frames with small frame intervals, adjusts the frame intervals of the multiple frames by shaping, and then transfers the frames to the server 10. This makes the frame intervals of the multiple frames uniform. Therefore, in the example of image G203, jitter is reduced. In this way, the adjustment process is performed to suppress an increase in jitter.

[0039] 4 is a flowchart showing an example of the flow of processing executed by the signal transfer system 100 according to the first embodiment. In the signal transfer system 100, the processing shown in FIG.

[0040] The transfer device 20 receives a signal for each traffic flow (step S101). The information acquisition unit 21 included in the transfer device 20 acquires traffic information for each traffic flow based on the received signal (step S102). The information acquisition unit 21 transmits the acquired traffic information for each traffic flow to the transfer device controller 30. Furthermore, the transfer device 20 transfers the received signal to the transfer device 20 or server 10 to which the transfer device 20 is connected.

[0041] The control decision unit 31 included in the transfer device controller 30 acquires traffic information for each traffic flow transmitted from the transfer device 20 (step S103). The control decision unit 31 determines a shaping rate for each traffic flow using the acquired traffic information for each traffic flow (step S104). Thereafter, the control decision unit 31 generates a shaping instruction including information on the determined shaping rate for each traffic flow. The control decision unit 31 transmits the generated shaping instruction to the transfer device 20 (step S105).

[0042] The communication control unit 22 included in the transfer device 20 acquires a shaping instruction transmitted from the transfer device controller 30. The communication control unit 22 performs an adjustment process on multiple frames in the traffic flow based on the acquired shaping instruction (step S106). As a result, the frame intervals of multiple frames are adjusted to be uniform, and jitter is reduced. Thereafter, the multiple frames after the adjustment process are transferred to the server 10. Note that the process of step S106 may be performed in all transfer devices 20, or may be performed in some of the transfer devices 20. When the adjustment process is performed in all transfer devices 20, the control decision unit 31 transmits a shaping instruction to all transfer devices 20.

[0043] The signal transfer system 100 configured as described above includes an information acquisition unit 21 that acquires traffic information, which is information regarding the traffic flow from the wireless terminal to the upper device, for each traffic flow, a control decision unit 31 that determines a bandwidth control method for reducing frame jitter based on the traffic information acquired by the information acquisition unit 21 for each traffic flow, and a communication control unit 22 that executes adjustment processing to control the transmission of multiple frames that constitute the upstream signal of the traffic flow based on the bandwidth control method determined by the control decision unit 31.

[0044] In this way, an adjustment process is performed to control the transmission of multiple frames that make up the uplink signal of a traffic flow based on the bandwidth control method, thereby making it possible to reduce jitter occurring in the uplink.

[0045] Furthermore, in the signal transfer system 100, the control decision unit 31 decides the bandwidth control method based on the traffic flow currently flowing through the transfer device 20. That is, in the signal transfer system 100, the bandwidth control method (e.g., shaping rate) is decided based on the characteristics of each traffic flow currently flowing through the transfer device 20. In contrast, in the shaping of the conventional technology, the rate is decided according to the limitations of predetermined service requirements, etc. In this way, the signal transfer system 100 makes it possible to control the bandwidth taking into account the current state.

[0046] Furthermore, in the signal transfer system 100, the control decision unit 31 decides the shaping rate based on the data volume and priority of each traffic flow currently flowing through the transfer device 20. In this way, in the signal transfer system 100, when there are multiple traffic flows, it is possible to suppress jitter in each traffic flow while ensuring the priority of the multiple flows.

[0047] Second Embodiment In a second embodiment, a configuration will be described in which a transfer device acquires traffic information, determines a shaping rate, and performs adjustment processing.

[0048] 5 is a diagram showing an example of the configuration of a signal transfer system 100a in the second embodiment. The signal transfer system 100a is a system that transfers signals from one communication device to another communication device. The signal transfer system 100a includes, for example, a server 10, one or more transfer devices 20a, and one or more base stations 40. The signal transfer system 100a differs in configuration from the signal transfer system 100 in that it does not include a transfer device controller 30 and includes a transfer device 20a instead of the transfer device 20. The following description will focus on the differences from the signal transfer system 100.

[0049] The transfer device 20a is a device that transfers signals exchanged between a higher-level device (e.g., the server 10) and one or more wireless terminals 50. For example, the transfer device 20a transfers uplink signals transmitted from the wireless terminals 50 to the higher-level device. Furthermore, the transfer device 20a has a function of determining a bandwidth control method and executing an adjustment process.

[0050] The one or more transfer devices 20a included in the signal transfer system 100a are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The transfer device 20a functions as a communication device equipped with a control unit when the processor executes a program. The control unit provides various functions for the communication device to function as the transfer device 20a.

[0051] The transfer device 20a may be installed between a central station and a distributed station, which are obtained by dividing the functions of the base station 40. If the central station and the distributed station are, for example, a CU and DU in a mobile communication system, the transfer device 20a is installed in a section called an MMH. The central station and the distributed station may be regarded as a DU and RU, and the transfer device 20a may be installed in a section called an MFH. Furthermore, the application to a wireless communication system other than a mobile communication system may be considered, for example, by regarding the central station as a Wi-Fi controller and the distributed station as a Wi-Fi access point.

[0052] (Device Configuration) Each transfer device 20a includes an information acquisition unit 21, a communication control unit 22, and a control decision unit 31. In this way, each transfer device 20a differs from the transfer device 20 in that it further includes the control decision unit 31. The control decision unit 31 included in the transfer device 20a calculates a shaping rate based on the traffic information acquired by the information acquisition unit 21, taking into account the priority of each traffic flow, such that jitter is reduced within a range that satisfies the delay requirements for each traffic flow.

[0053] In the signal transfer system 100a according to the second embodiment, the information acquisition unit 21, the communication control unit 22, and the control decision unit 31 are provided in the control unit of the transfer device 20a.

[0054] 6 is a flowchart showing the flow of processing performed by the signal transfer system 100a in the second embodiment. In the signal transfer system 100a, the processing shown in FIG. 6 is repeated.

[0055] The transfer device 20a receives a signal for each traffic flow (step S201). The information acquisition unit 21 included in the transfer device 20a acquires traffic information for each traffic flow based on the received signal (step S202). The information acquisition unit 21 outputs the acquired traffic information for each traffic flow to the control decision unit 31. Furthermore, the transfer device 20a transfers the received signal to the transfer device 20 or server 10 to which the transfer device 20a is connected.

[0056] The control decision unit 31 determines a shaping rate for each traffic flow using the traffic information for each traffic flow output from the information acquisition unit 21 (step S203). Then, the control decision unit 31 generates a shaping instruction including information on the determined shaping rate for each traffic flow. The control decision unit 31 outputs the generated shaping instruction to the communication control unit 22.

[0057] The communication control unit 22 performs an adjustment process on multiple frames in the traffic flow based on the shaping instruction output from the control determination unit 31 (step S204). As a result, the frame intervals of the multiple frames are adjusted to be uniform, and jitter is reduced. Thereafter, the multiple frames after the adjustment process are transferred to the server 10. Note that the process of step S204 may be performed by all transfer devices 20a or by some of the transfer devices 20a.

[0058] According to the signal transfer system 100a configured as described above, the same effects as those of the first embodiment can be obtained even in a configuration in which the transfer device 20a performs all of the processes of acquiring traffic information, determining the shaping rate, and adjusting the rate.

[0059] Third Embodiment In a third embodiment, a configuration will be described in which a base station acquires traffic information and performs adjustment processing, and a radio controller that controls the base station determines a shaping rate.

[0060] FIG. 7 is a diagram showing an example of the configuration of a signal transfer system 100b according to the third embodiment. The signal transfer system 100b is a system that transfers signals from one communication device to another. The signal transfer system 100b includes, for example, a server 10, one or more transfer devices 20b, one or more base stations 40b, and a wireless controller 60. The signal transfer system 100b differs in configuration from the signal transfer system 100 in that it does not include a transfer device controller 30, and includes a transfer device 20b and a base station 40b instead of the transfer device 20 and the base station 40, and in that it newly includes a wireless controller 60. The following will focus on the differences from the signal transfer system 100. FIG. 7 will explain the case where the signal transfer system 100b includes two base stations 40b-1 and 40b-2.

[0061] The transfer device 20b is a device that transfers signals exchanged between a higher-level device (e.g., the server 10) and one or more wireless terminals 50. For example, the transfer device 20b transfers uplink signals transmitted from the wireless terminals 50 to the higher-level device.

[0062] The base station 40b is a device that wirelessly communicates with one or more wireless terminals 50. For example, the base station 40b transmits signals transferred from the transfer device 20b to the wireless terminals 50, and transfers signals received from the wireless terminals 50 to the transfer device 20b. Furthermore, the base station 40b has a function of executing adjustment processing in response to instructions from the wireless controller 60.

[0063] The wireless controller 60 is a device that controls one or more base stations 40b by transmitting control signals. Furthermore, the wireless controller 60 acquires traffic information for each traffic flow currently flowing through the transfer device 20b. Based on the acquired traffic information for each traffic flow, the wireless controller 60 determines, for each base station 40b, a bandwidth control method that reduces frame jitter.

[0064] The one or more base stations 40b and the wireless controller 60 included in the signal transfer system 100b are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The base station 40b and the wireless controller 60 function as communication devices equipped with different control units when the processor executes a program. The control units provide various functions for causing the communication device to function as the base station 40b or the wireless controller 60.

[0065] The base station 40b may be, for example, a Wi-Fi (registered trademark) access point. The signal transfer system 100b does not necessarily have to be applied to a mobile communication system, and may be applied to a wireless communication system other than a mobile communication system.

[0066] (Device Configuration) The base station 40b-1 includes an information acquisition unit 21-1 and a communication control unit 22-1, and the base station 40b-2 includes an information acquisition unit 21-2 and a communication control unit 22-2. Note that the information acquisition unit 21-1 included in the base station 40b-1 and the information acquisition unit 21-2 included in the base station 40b-2 perform similar processing and will therefore be described as the information acquisition unit 21. The communication control unit 22-1 included in the base station 40b-1 and the communication control unit 22-2 included in the base station 40b-2 perform similar processing and will therefore be described as the communication control unit 22.

[0067] The information acquisition unit 21 acquires traffic information for each traffic flow currently flowing through the transfer device 20b, and notifies the wireless controller 60 of the acquired traffic information for each traffic flow.

[0068] The communication control unit 22 performs adjustment processing (for example, shaping) for each traffic flow in accordance with the shaping instruction transmitted from the wireless controller 60 .

[0069] The wireless controller 60 includes a control decision unit 31. Based on traffic information acquired from the base station 40b, the control decision unit 31 calculates a shaping rate for each traffic flow, taking into account the priority of each traffic flow, so that jitter is reduced within a range that satisfies the delay requirement. The control decision unit 31 transmits a shaping instruction to the base station 40b, which includes at least the calculated shaping rate for each traffic flow and information indicating the traffic flow.

[0070] In the signal transfer system 100 b according to the third embodiment, the information acquisition unit 21 and the communication control unit 22 are provided in the control unit of the base station 40 b , and the control decision unit 31 is provided in the control unit of the wireless controller 60 .

[0071] 8 is a flowchart showing the flow of processing performed by the signal transfer system 100b in the third embodiment. In the signal transfer system 100b, the processing shown in FIG. 8 is repeated.

[0072] The base station 40b receives a signal for each traffic flow (step S301). The information acquisition unit 21 included in the base station 40b acquires traffic information for each traffic flow currently flowing through the transfer device 20b based on the received signal (step S302). The information acquisition unit 21 transmits the acquired traffic information for each traffic flow to the wireless controller 60. Furthermore, the base station 40b transfers the received signal to the transfer device 20b to which the base station 40b is connected.

[0073] The control decision unit 31 included in the wireless controller 60 acquires traffic information for each traffic flow transmitted from the base station 40b (step S303). The control decision unit 31 determines a shaping rate for each traffic flow using the acquired traffic information for each traffic flow (step S304). The control decision unit 31 then generates a shaping instruction including information on the determined shaping rate for each traffic flow. The control decision unit 31 transmits the generated shaping instruction to the base station 40b (step S305). Note that if the control decision unit 31 generates a shaping instruction based on traffic information obtained from the base station 40b-1, it transmits the generated shaping instruction to the base station 40b-1. If the control decision unit 31 generates a shaping instruction based on traffic information obtained from the base station 40b-2, it transmits the generated shaping instruction to the base station 40b-2.

[0074] The communication control unit 22 included in the base station 40b receives the shaping instruction transmitted from the wireless controller 60. Based on the received shaping instruction, the communication control unit 22 performs an adjustment process on multiple frames in the traffic flow (step S306). As a result, the frame intervals of the multiple frames are adjusted to be uniform, and jitter is reduced. The multiple frames after the adjustment process are then transferred to the server 10.

[0075] According to the signal transfer system 100b configured as above, even in a configuration in which the base station 40b performs adjustment processing, it is possible to obtain the same effects as those of the first embodiment.

[0076] (Fourth embodiment) In the fourth embodiment, a configuration will be described in which a central station and distributed stations are provided as base stations, the distributed stations acquire traffic information and perform adjustment processing, and a wireless controller that controls the base stations determines the shaping rate.

[0077] 9 is a diagram showing an example of the configuration of a signal transfer system 100c according to the fourth embodiment. The signal transfer system 100c is a system for transferring signals from one communication device to another. The signal transfer system 100c includes, for example, one or more transfer devices 20b, a base station 40c, and a wireless controller 60. The base station 40c includes a central station 70 and one or more remote stations 80.

[0078] The signal transfer system 100c differs in configuration from the signal transfer system 100b in that it includes a base station 40c instead of the base station 40b. The following will focus on the differences from the signal transfer system 100b. In Fig. 9, the signal transfer system 100c will be described as including two remote stations 80-1 and 80-2.

[0079] The central station 70 is a device that transmits and receives signals to and from the wireless terminal 50. The central station 70 is one aspect of a higher-level device.

[0080] The remote station 80 is a device that wirelessly communicates with each of one or more wireless terminals 50. For example, the remote station 80 transmits a signal transferred from the transfer device 20b to the wireless terminal 50, and transfers a signal received from the wireless terminal 50 to the transfer device 20b. Furthermore, the remote station 80 has a function of executing adjustment processing in response to an instruction from the wireless controller 60.

[0081] The one or more distributed stations 80 and the wireless controller 60 included in the signal transfer system 100c are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The one or more distributed stations 80 and the wireless controller 60 function as communication devices equipped with different control units when the processor executes a program. The control units provide various functions for causing the communication device to function as one or more distributed stations 80 or wireless controller 60.

[0082] The central station 70 and one or more distributed stations 80 are a CU and one or more DUs in a mobile communication system. In this case, the forwarding device 20 is installed in a mobile midhaul section. Note that the central station 70 and one or more distributed stations 80 may be a DU and one or more RUs in a mobile communication system. In this case, the forwarding device 20 is installed in a mobile fronthaul.

[0083] The central station 70 may be a Wi-Fi controller, and one or more remote stations 80 may be Wi-Fi access points. The signal transfer system 100c does not necessarily have to be applied to a mobile communication system, and may be applied to a wireless communication system other than a mobile communication system.

[0084] (Device Configuration) The distributed station 80-1 includes an information acquisition unit 21-1 and a communication control unit 22-1, and the distributed station 80-2 includes an information acquisition unit 21-2 and a communication control unit 22-2. The information acquisition unit 21-1 included in the distributed station 80-1 and the information acquisition unit 21-2 included in the distributed station 80-2 perform similar processing and will therefore be described as the information acquisition unit 21. The communication control unit 22-1 included in the distributed station 80-1 and the communication control unit 22-2 included in the distributed station 80-2 perform similar processing and will therefore be described as the communication control unit 22.

[0085] The information acquisition unit 21 acquires traffic information for each traffic flow currently flowing through the transfer device 20b, and notifies the wireless controller 60 of the acquired traffic information for each traffic flow.

[0086] The communication control unit 22 performs adjustment processing (for example, shaping) for each traffic flow in accordance with the shaping instruction transmitted from the wireless controller 60 .

[0087] In the signal transfer system 100 c of the fourth embodiment, the information acquisition unit 21 and the communication control unit 22 are provided in the control unit of the remote station 80 , and the control decision unit 31 is provided in the control unit of the wireless controller 60 .

[0088] 10 is a flowchart showing the flow of processing performed by the signal transfer system 100c in the fourth embodiment. In the signal transfer system 100c, the processing shown in FIG.

[0089] The remote station 80 receives a signal for each traffic flow (step S401). The information acquisition unit 21 included in the remote station 80 acquires traffic information for each traffic flow currently flowing through the transfer device 20b based on the received signal (step S402). The information acquisition unit 21 transmits the acquired traffic information for each traffic flow to the wireless controller 60. Furthermore, the remote station 80 transfers the received signal to the transfer device 20 to which it is connected.

[0090] The control decision unit 31 included in the wireless controller 60 acquires traffic information for each traffic flow transmitted from the remote station 80 (step S403). The control decision unit 31 determines a shaping rate for each traffic flow using the acquired traffic information for each traffic flow (step S404). The control decision unit 31 then generates a shaping instruction including information on the determined shaping rate for each traffic flow. The control decision unit 31 transmits the generated shaping instruction to the remote station 80 (step S405). Note that if the control decision unit 31 generates a shaping instruction based on traffic information obtained from the remote station 80-1, it transmits the generated shaping instruction to the remote station 80-1. If the control decision unit 31 generates a shaping instruction based on traffic information obtained from the remote station 80-2, it transmits the generated shaping instruction to the remote station 80-2.

[0091] The communication control unit 22 included in the remote station 80 receives the shaping instruction transmitted from the wireless controller 60. Based on the received shaping instruction, the communication control unit 22 performs an adjustment process on the multiple frames in the traffic flow (step S406). As a result, the frame intervals of the multiple frames are adjusted to be uniform, and jitter is reduced. The multiple frames after the adjustment process are then transferred to the server 10.

[0092] According to the signal transfer system 100c configured as above, even in a configuration in which the base stations 40c are distributed between the central station 70 and the remote stations 80, it is possible to obtain the same effects as in the first embodiment.

[0093] Fifth Embodiment In the fifth embodiment, a configuration will be described in which a base station acquires traffic information, determines a shaping rate, and performs adjustment processing.

[0094] 11 is a diagram showing an example of the configuration of a signal transfer system 100d according to the fifth embodiment. This diagram shows an example of the configuration of the signal transfer system 100d according to the fifth embodiment. The signal transfer system 100d is a system that transfers a signal from one communication device to another communication device. The signal transfer system 100d includes, for example, a server 10, one or more transfer devices 20b, and one or more base stations 40d.

[0095] The signal transfer system 100d differs in configuration from the signal transfer system 100b in that it includes a base station 40d instead of the base station 40b. The following will focus on the differences from the signal transfer system 100b. In Figure 11, a case will be described in which the signal transfer system 100d includes two base stations 40d-1 and 40d-2.

[0096] The base station 40d is a device that wirelessly communicates with one or more wireless terminals 50. For example, the base station 40d transmits signals transferred from the transfer device 20b to the wireless terminals 50, and transfers signals received from the wireless terminals 50 to the transfer device 20b. Furthermore, the transfer device 20d has a function of determining a bandwidth control method and executing adjustment processing.

[0097] One or more base stations 40d included in the signal transfer system 100d are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The base station 40d functions as a communication device equipped with a control unit when the processor executes a program. The control unit provides various functions for the communication device to function as the base station 40d.

[0098] The base station 40d may be, for example, a Wi-Fi access point. The signal transfer system 100d does not necessarily have to be applied to a mobile communication system, and may be applied to a wireless communication system other than a mobile communication system.

[0099] (Device Configuration) Each base station 40d includes an information acquisition unit 21, a communication control unit 22, and a control decision unit 31. As described above, each base station 40d differs from base station 40b in that it further includes a control decision unit 31. Based on the traffic information acquired by the information acquisition unit 21, the control decision unit 31 included in base station 40d calculates a shaping rate for each traffic flow that reduces jitter within a range that satisfies the delay requirement, taking into account the priority of each traffic flow.

[0100] In a signal transfer system 100d according to the fifth embodiment, the information acquisition unit 21, the communication control unit 22, and the control decision unit 31 are provided in the control unit of a base station 40d.

[0101] 12 is a flowchart showing the flow of processing performed by the signal transfer system 100d in the fifth embodiment. In the signal transfer system 100d, the processing shown in FIG.

[0102] The base station 40d receives a signal for each traffic flow (step S501). The information acquisition unit 21 included in the base station 40d acquires traffic information for each traffic flow currently flowing through the transfer device 20b based on the received signal (step S502). The information acquisition unit 21 outputs the acquired traffic information for each traffic flow to the control decision unit 31. Furthermore, the base station 40d transfers the received signal to the transfer device 20b to which the base station 40d is connected.

[0103] The control decision unit 31 determines a shaping rate for each traffic flow using the traffic information for each traffic flow output from the information acquisition unit 21 (step S503). Then, the control decision unit 31 generates a shaping instruction including information on the determined shaping rate for each traffic flow. The control decision unit 31 outputs the generated shaping instruction to the communication control unit 22.

[0104] The communication control unit 22 performs an adjustment process on the multiple frames in the traffic flow based on the shaping instruction output from the control determination unit 31 (step S504). As a result, the frame intervals of the multiple frames are adjusted to be uniform, and jitter is reduced. Thereafter, the multiple frames after the adjustment process are transferred to the server 10.

[0105] According to the signal transfer system 100d configured as above, even in a configuration in which the base station 40d performs all of the processes of acquiring traffic information, determining a shaping rate, and adjusting the same, effects as those of the first embodiment can be obtained.

[0106] Sixth Embodiment In the sixth embodiment, a configuration will be described in which a central station and remote stations are provided as base stations, and the remote stations acquire traffic information, determine a shaping rate, and perform adjustment processing.

[0107] 13 is a diagram showing an example of the configuration of a signal transfer system 100e according to the sixth embodiment. This diagram shows an example of the configuration of the signal transfer system 100e according to the sixth embodiment. The signal transfer system 100e is a system that transfers a signal from one communication device to another communication device. The signal transfer system 100e includes, for example, a server 10, one or more transfer devices 20b, and one or more base stations 40e. The base station 40e is configured from a central station 70 and one or more remote stations 80e.

[0108] The signal transfer system 100e differs in configuration from the signal transfer system 100c in that it includes a base station 40e instead of the base station 40c. The differences from the signal transfer system 100c will be mainly described below. In Fig. 13, a case will be described in which the signal transfer system 100e includes two remote stations 80e-1 and 80e-2.

[0109] The distributed station 80e is a device that wirelessly communicates with one or more wireless terminals 50. For example, the distributed station 80e transmits signals transferred from the transfer device 20b to the wireless terminals 50, and transfers signals received from the wireless terminals 50 to the transfer device 20b. Furthermore, the distributed station 80e has a function of determining a bandwidth control method and executing adjustment processing.

[0110] The one or more distributed stations 80e included in the signal transfer system 100e are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The one or more distributed stations 80e function as communication devices equipped with different control units when the processor executes a program. The control units provide various functions for causing the communication device to function as one or more distributed stations 80e.

[0111] The central station 70 and one or more distributed stations 80e are a CU and one or more DUs in the mobile communication system. In this case, the transfer device 20b is installed in the mobile midhaul section. Note that the central station 70 and one or more distributed stations 80e may also be a DU and one or more RUs in the mobile communication system. In this case, the transfer device 20b is installed in the mobile fronthaul.

[0112] The central station 70 may be a Wi-Fi controller, and one or more remote stations 80e may be Wi-Fi access points. The signal transfer system 100e does not necessarily have to be applied to a mobile communication system, and may be applied to a wireless communication system other than a mobile communication system.

[0113] (Device Configuration) Each distributed station 80e includes an information acquisition unit 21, a communication control unit 22, and a control decision unit 31. In this way, each distributed station 80e differs from the distributed station 80 in that it further includes a control decision unit 31. The control decision unit 31 included in the distributed station 80e calculates a shaping rate based on the traffic information acquired by the information acquisition unit 21, taking into account the priority of each traffic flow, such that jitter is reduced within a range that satisfies the delay requirement for each traffic flow.

[0114] In the signal transfer system 100e of the sixth embodiment, the information acquisition unit 21, the communication control unit 22, and the control decision unit 31 are provided in the control unit of the remote station 80e.

[0115] 14 is a flowchart showing the flow of processing performed by the signal transfer system 100e in the sixth embodiment. In the signal transfer system 100e, the processing shown in FIG.

[0116] The remote station 80e receives a signal for each traffic flow (step S601). The information acquisition unit 21 included in the remote station 80e acquires traffic information for each traffic flow currently flowing through the transfer device 20b based on the received signal (step S602). The information acquisition unit 21 outputs the acquired traffic information for each traffic flow to the control decision unit 31. Furthermore, the remote station 80e transfers the received signal to the transfer device 20b to which it is connected.

[0117] The control decision unit 31 determines a shaping rate for each traffic flow using the traffic information for each traffic flow output from the information acquisition unit 21 (step S603). Then, the control decision unit 31 generates a shaping instruction including information on the determined shaping rate for each traffic flow. The control decision unit 31 outputs the generated shaping instruction to the communication control unit 22.

[0118] The communication control unit 22 performs an adjustment process on the multiple frames in the traffic flow based on the shaping instruction output from the control determination unit 31 (step S604). As a result, the frame intervals of the multiple frames are adjusted to be uniform, and jitter is reduced. Thereafter, the multiple frames after the adjustment process are transferred to the server 10.

[0119] According to the signal transfer system 100e configured as described above, the base station 40e is distributed to the central station 70 and the remote station 80e, and the remote station 80e performs all of the processes of acquiring traffic information, determining the shaping rate, and adjusting the traffic information, and the same effects as in the first embodiment can be obtained.

[0120] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0121] The present invention can be applied to a communication system that accommodates wireless terminals and a communication control method.

[0122] 10...server, 20, 20a, 20b...transfer device, 21...information acquisition unit, 22...communication control unit, 30...transfer device controller, 31...control decision unit, 40, 40b, 40b-1 to 40b-2, 40c, 40d, 40d-1 to 40d-2, 40e...base station, 50...wireless terminal, 60...wireless controller, 70...central station, 80, 80-1 to 80-2, 80e, 80e-1 to 80e-2...remote station, 100, 100a, 100b, 100c, 100d, 100e...signal transfer system

Claims

1. A signal transfer system comprising: an information acquisition unit that acquires traffic information, which is information regarding traffic flows from a wireless terminal to a higher-level device, for each traffic flow; a control decision unit that determines a bandwidth control method for reducing frame jitter based on the traffic information acquired by the information acquisition unit for each traffic flow; and a communication control unit that executes adjustment processing to control the transmission of multiple frames that constitute an upstream signal of the traffic flow based on the bandwidth control method determined by the control decision unit.

2. The signal transfer system according to claim 1, wherein the control decision unit decides the bandwidth control method based on a traffic flow currently flowing through a relay device located between the wireless terminal and the higher-level device.

3. A signal transfer system as described in claim 1 or 2, wherein the control decision unit determines a shaping rate based on the data volume and priority of each traffic flow currently flowing through a relay device located between the wireless terminal and the higher-level device.

4. A signal transfer system according to claim 1 or 2, wherein the control decision unit is provided in either a relay device located between the wireless terminal and the higher-level device, or a control device that controls the relay device.

5. A relay device comprising: an information acquisition unit that acquires traffic information, which is information regarding the traffic flow from a wireless terminal to a higher-level device, for each traffic flow; and a communication control unit that executes an adjustment process to control the transmission of multiple frames that constitute the upstream signal of the traffic flow based on a bandwidth control method for reducing frame jitter determined based on the traffic information acquired by the information acquisition unit for each traffic flow.

6. The relay device according to claim 5, further comprising a control determination unit that determines the bandwidth control method based on the traffic information acquired by the information acquisition unit for each traffic flow.

7. A control device comprising: a control decision unit that acquires traffic information, which is information regarding traffic flows from a wireless terminal to a higher-level device, for each traffic flow; determines a bandwidth control method for reducing frame jitter based on the acquired traffic information; and notifies a relay device located between the wireless terminal and the higher-level device of the bandwidth control method.

8. A signal processing method comprising: acquiring traffic information for each traffic flow, which is information relating to a traffic flow from a wireless terminal to a higher-level device; determining a bandwidth control method for reducing frame jitter based on the traffic information acquired for each traffic flow; and performing an adjustment process for controlling the transmission of multiple frames constituting an uplink signal of the traffic flow based on the determined bandwidth control method.

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