Signal transfer system, wireless terminal, control device, and signal processing method

Abstract

Provided is a signal transfer system in which wireless communication is performed between a base station and a wireless terminal, said signal transfer system comprising: an information acquisition unit that acquires, for each traffic flow, traffic information pertaining to a traffic flow directed from the base station to the wireless terminal; a control determination unit that determines, on the basis of the traffic information acquired by the information acquisition unit for each traffic flow, a band control method for reducing frame jitter; and a communication control unit that performs an adjustment process for adjusting, on the basis of the band control method determined by the control determination unit, frame intervals between a plurality of frames constituting a downlink signal of a traffic flow.　

Description

Signal transfer system, wireless terminal, control device, and signal processing method

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

[0002] Conventionally, a signal forwarding system shown in Fig. 16 is known as a configuration for exchanging signals between a base station and a wireless terminal. Fig. 16 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. The wireless terminal 5 communicates with the server 1 via the base station 4 and the transfer device 2, and includes an application function unit 6 that receives signals transmitted from the server 1.

[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 signal transmission in conventional mobile communication systems, when signals are exchanged between a base station and a wireless terminal, TDD (Time Division Duplex) is used, which transmits downlink and uplink signals alternately in the time domain, and signals are transmitted and received in units of wireless transmission frames called Transport Blocks.

[0006] Even if each downlink traffic flow is transmitted to the base station 4 with the frame transmission intervals aligned in the upper network and with little jitter, there is a problem that the jitter increases due to the following factors. For example, jitter occurs due to the downlink transmission waiting time during uplink transmission in TDD, the waiting time for transport block formation when the transport block size is larger than the frame size received from the upper network, or the waiting time for retransmission data due to retransmission control, and as a result, the end-to-end jitter from the server 1 to the application function unit 6 of the wireless terminal 5 increases. Note that this problem is not limited to mobile communication systems, but is also a common problem in wireless communication systems other than mobile communication systems.

[0007] In view of the above circumstances, an object of the present invention is to provide a technique capable of suppressing an increase in jitter.

[0008] One aspect of the present invention is a signal transfer system in which wireless communication is performed between a base station and a wireless terminal, comprising: an information acquisition unit that acquires traffic information, which is information regarding the traffic flow from the base station to the wireless terminal, 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 an adjustment process to adjust the frame spacing of multiple frames that constitute the downlink signal of the traffic flow based on the bandwidth control method determined by the control decision unit.

[0009] One aspect of the present invention is a wireless terminal in a signal transfer system in which wireless communication is performed between a base station and a wireless terminal, the wireless terminal comprising: an application function unit that processes a downlink signal of a traffic flow from the base station to the wireless terminal; and a communication control unit that performs an adjustment process to adjust the frame spacing of multiple frames that constitute the downlink signal before the multiple frames are input to the application function unit, based on a bandwidth control method for reducing frame jitter determined based on traffic information that is information about the traffic flow.

[0010] One aspect of the present invention is a control device that controls a base station in a signal transfer system in which wireless communication is performed between the base station and a wireless terminal, and is equipped with a control decision unit that acquires traffic information, which is information about the traffic flow from the base station to the wireless terminal, for each traffic flow, determines a bandwidth control method for reducing frame jitter based on the acquired traffic information, and notifies the wireless terminal of the bandwidth control method via the base station.

[0011] One aspect of the present invention is a signal processing method performed by a signal transfer system in which wireless communication is performed between a base station and a wireless terminal, the signal processing method comprising: acquiring traffic information, which is information regarding the traffic flow from the base station to the wireless terminal, for each traffic flow; determining a bandwidth control method for reducing frame jitter based on the traffic information acquired for each traffic flow; and performing an adjustment process to adjust the frame spacing of multiple frames that constitute the downlink signal of the traffic flow based on the determined bandwidth control method.

[0012] According to the present invention, it is possible to suppress an increase in jitter.

[0013] 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 adjustment processing according to the first embodiment. FIG. 3 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the first embodiment. FIG. 4 is a diagram illustrating an example of a configuration of a signal transfer system according to a second embodiment. FIG. 5 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the second embodiment. FIG. 6 is a diagram illustrating an example of a configuration of a signal transfer system according to a third embodiment. FIG. 7 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the third embodiment. FIG. 8 is a diagram illustrating an example of a configuration of a signal transfer system according to a fourth embodiment. FIG. 9 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the fourth embodiment. FIG. 10 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the fifth embodiment. FIG. 11 is a diagram illustrating an example of a configuration of a signal transfer system according to a sixth embodiment. FIG. 12 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the sixth embodiment. FIG. 13 is a diagram illustrating an example of a configuration of a signal transfer system according to a seventh embodiment. FIG. 14 is a flowchart illustrating an example of a processing flow performed by the signal transfer system according to the seventh embodiment. FIG. 15 is a diagram illustrating an example of a configuration of a conventional signal transfer system.

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] (First embodiment) Fig. 1 is a diagram showing an example of the configuration of a signal transfer system 100 in the 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 wireless controller 30, and one or more base stations 40. Fig. 1 illustrates a case where the signal transfer system 100 includes two base stations 40-1 and 40-2.

[0016] 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 transmits a downlink signal addressed to the wireless terminal 50.

[0017] 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 a downlink signal transmitted from the server 10 to the base station 40 to which the destination wireless terminal 50 is connected. The transfer device 20 transfers an uplink signal transmitted from the wireless terminal 50 to the higher-level device.

[0018] The wireless controller 30 is a device that controls one or more base stations 40 by transmitting control signals. Furthermore, the wireless controller 30 acquires traffic information for each traffic flow currently flowing through the base station 40. Note that the traffic flow in the present invention refers to a downstream traffic flow transmitted from a higher-level device. Based on the acquired traffic information for each traffic flow, the wireless controller 30 determines a bandwidth control method that reduces frame jitter. The bandwidth control method is, for example, a shaping rate.

[0019] 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).

[0020] The base station 40 is a device that wirelessly communicates with one or more wireless terminals 50. For example, the base station 40 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. Furthermore, the base station 40 has a function to acquire traffic information for each traffic flow from the server 10 to the wireless terminals 50. Furthermore, the base station 40 has a function to notify the wireless terminals 50 of instructions transmitted from the wireless controller 30.

[0021] The wireless terminal 50 performs an adjustment process based on instructions notified from the base station 40. The adjustment process is a process of adjusting the frame intervals of multiple frames. The process of adjusting the frame intervals of multiple frames is a process of adjusting the frame intervals of multiple frames so that they are uniform, such as shaping. The wireless terminal 50 performs the above-mentioned adjustment process before the signal transmitted from the base station 40 is input to an application function within the terminal. This enables control so that jitter is minimized within the wireless terminal 50. The wireless terminal 50 performs the adjustment process for each traffic flow transmitted by the upper device.

[0022] Here, the above-mentioned frame means a frame that is propagated in the downstream direction and is transmitted to a destination such as the wireless terminal 50. Therefore, when the destination is the wireless terminal 50, the frame is a frame transmitted from the server 10 to the wireless terminal 50.

[0023] The wireless controller 30, one or more base stations 40, and wireless terminal 50 are configured using, for example, a processor such as a CPU (Central Processing Unit), memory, and a communication interface. Each of the wireless controller 30, one or more base stations 40, and wireless terminal 50 functions as a communication device equipped with different control units by the processor executing a program.

[0024] The control unit provides each function for causing the communication device to function as a wireless controller 30, a base station 40, or a wireless terminal 50. 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 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.

[0027] (Device Configuration) Next, the specific configuration of each device will be described. The wireless controller 30 includes a control decision unit 31. Based on traffic information acquired from the base station 40, 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 40, which includes at least the calculated shaping rate for each traffic flow and information indicating the traffic flow.

[0028] 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 between the base station 40 and the wireless terminal 50 is 1 Gbps, two traffic flows (e.g., a first traffic flow and a second traffic flow) are flowing through the base station 40, the first traffic flow has a higher priority, and the optimal shaping rate for each traffic flow is 600 Mbps. In this case, the control decision unit 31 determines the shaping rate for the high-priority traffic flow (first traffic flow) to be 600 Mbps. Then, for the low-priority traffic flow (second traffic flow), the control decision unit 31 determines the shaping rate to be 400 Mbps, which is the value obtained by subtracting the shaping rate of the high-priority traffic flow (600 Mbps) from the transfer capacity between the base station 40 and the wireless terminal 50 (1 Gbps). 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.

[0029] 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 in 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 wireless controller 30 may issue a route change instruction for a specific traffic flow in addition to a shaping instruction.

[0030] Base station 40-1 includes an information acquisition unit 41-1 and an information notification unit 42-1, and base station 40-2 includes an information acquisition unit 41-2 and an information notification unit 42-2. Note that the information acquisition unit 41-1 included in base station 40-1 and the information acquisition unit 41-2 included in base station 40-2 perform similar processing and will therefore be described as information acquisition unit 41. The information notification unit 42-1 included in base station 40-1 and the information notification unit 42-2 included in base station 40-2 perform similar processing and will therefore be described as information notification unit 42.

[0031] The information acquisition unit 41 acquires traffic information for each traffic flow currently flowing through the base station 40. The information acquisition unit 41 notifies the wireless controller 30 of the acquired traffic information for each traffic flow.

[0032] The information notification unit 42 transmits the shaping instruction received from the wireless controller 30 to the wireless terminal 50 corresponding to the traffic flow.

[0033] The wireless terminal 50 includes a communication control unit 51 and an application function unit 52. In accordance with a shaping instruction transmitted from the base station 40, the communication control unit 51 performs adjustment processing (e.g., shaping) for each traffic flow before the downlink signal of each traffic flow is input to the application function unit 52.

[0034] The application function unit 52 processes signals transmitted from the server 10 to the wireless terminal 50. The application function unit 52 processes downstream signals for each traffic flow after the communication control unit 51 has performed adjustment processing, for example.

[0035] In the signal transfer system 100, the control decision unit 31 is provided in the control unit of the wireless controller 30, the information acquisition unit 41 and the information notification unit 42 are provided in the control unit of the base station 40, and the communication control unit 51 and the application function unit 52 are provided in the control unit of the wireless terminal 50.

[0036] Next, an overview of the adjustment process described above will be explained. FIG. 2 is a diagram for explaining an overview of the adjustment process in the first embodiment. Image G101 in FIG. 2 shows an example of a signal transferred from the transfer device 20 and received by the base station 40. Image G101 shows five frames, frames "1" to "5", as the signal received by the base station 40. Image G102 in FIG. 2 shows an example of the state of a signal transmitted from the base station 40 to the wireless terminal 50. In image G102, the period between frame "2" and frame "3" is the uplink transmission timing in TDD.

[0037] Downlink signals cannot be transmitted during the uplink transmission timing. As a result, in the past, when wireless terminal 50 received a signal transmitted from base station 40, the time interval between frame "1" and frame "2" and the time interval between frame "2" and frame "3" were uneven, as shown in image G103. This uneven frame interval increases jitter.

[0038] In contrast, in the adjustment process of the first embodiment, as described above, adjustment is performed so that the frame intervals between multiple frames are uniform before the wireless terminal 50 processes the downlink signal. As a result, as shown in image G104, the frame intervals between multiple frames are uniform. Therefore, in the example of image G104, jitter is reduced. In this way, the execution of the adjustment process suppresses an increase in jitter.

[0039] 3 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 base station 40 receives the signal for each traffic flow transmitted by the server 10 via the transfer device 20 (step S101). The information acquisition unit 41 included in the base station 40 acquires traffic information for each traffic flow based on the received signal (step S102). The information acquisition unit 41 transmits the acquired traffic information for each traffic flow to the wireless controller 30.

[0041] The control decision unit 31 included in the wireless controller 30 acquires traffic information for each traffic flow transmitted from the base station 40 (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). 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 40 (step S105).

[0042] In addition, when the control decision unit 31 generates a shaping instruction based on traffic information obtained from base station 40-1, it transmits the generated shaping instruction to base station 40-1, and when the control decision unit 31 generates a shaping instruction based on traffic information obtained from base station 40-2, it transmits the generated shaping instruction to base station 40-2.

[0043] The information notification unit 42 included in the base station 40 receives the shaping instruction transmitted from the wireless controller 30. The information notification unit 42 transmits the received shaping instruction to the wireless terminal 50 corresponding to the traffic flow (step S106). The communication control unit 51 of the wireless terminal 50 acquires the shaping instruction transmitted from the base station 40. The communication control unit 51 performs an adjustment process on multiple frames in the traffic flow based on the acquired shaping instruction (step S107). As a result, the frame intervals of the multiple frames are adjusted to be uniform, resulting in a state where jitter is reduced. Thereafter, the communication control unit 51 inputs the multiple frames after the adjustment process to the application function unit 52. The application function unit 52 processes the multiple input frames.

[0044] The signal transfer system 100 configured as described above includes an information acquisition unit 41 that acquires traffic information, which is information regarding the traffic flow from the base station 40 to the wireless terminal 50, 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 41 for each traffic flow; and a communication control unit 51 that performs an adjustment process to adjust the frame spacing of multiple frames that constitute the downlink signal of the traffic flow based on the bandwidth control method determined by the control decision unit 31.

[0045] In this way, an adjustment process is performed to adjust the frame spacing of the multiple frames based on the bandwidth control method for reducing frame jitter before the multiple frames are input to the application function unit 52 in the wireless terminal 50. This makes it possible to reduce jitter occurring in the downlink.

[0046] 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 base station 40. 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 base station 40. 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.

[0047] 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 base station 40. 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.

[0048] (Second embodiment) In the second embodiment, a configuration will be described in which a base station is provided with a central station and distributed stations that are distributed, the distributed stations acquire traffic information, a wireless controller that controls the base station determines a shaping rate, and a wireless terminal performs adjustment processing.

[0049] 4 is a diagram showing an example of the configuration of a signal transfer system 100a according to the second embodiment. The signal transfer system 100a is a system that transfers signals from one communication device to another. The signal transfer system 100a includes, for example, one or more transfer devices 20, a base station 40a, and a wireless controller 30. The base station 40a includes a central station 60 and one or more remote stations 70.

[0050] The signal transfer system 100a has a different configuration from the signal transfer system 100 in that it includes a base station 40a instead of the base station 40. The following will mainly describe the differences from the signal transfer system 100. In Fig. 4, a case will be described in which the signal transfer system 100a includes two remote stations 70-1 and 70-2.

[0051] The central station 60 is a device that transmits and receives signals to and from the wireless terminal 50. The central station 60 is one aspect of a higher-level device.

[0052] The remote station 70 is a device that wirelessly communicates with each of one or more wireless terminals 50. For example, the remote station 70 transmits signals transferred from the transfer device 20 to the wireless terminal 50, and transfers signals received from the wireless terminal 50 to the transfer device 20. Furthermore, the remote station 70 has a function to acquire traffic information for each traffic flow heading from the server 10 to the wireless terminal 50. Furthermore, the remote station 70 has a function to notify the wireless terminal 50 of instructions transmitted from the wireless controller 30.

[0053] The wireless controller 30, the wireless terminal 50, and the one or more distributed stations 70 are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The wireless controller 30, the wireless terminal 50, and the one or more distributed stations 70 function as communication devices equipped with different control units when the processor executes a program. The control units provide various functions that cause the communication device to function as the wireless controller 30, the wireless terminal 50, or the one or more distributed stations 70.

[0054] The central station 60 and one or more distributed stations 70 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 60 and one or more distributed stations 70 may also 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.

[0055] The central station 60 may be a Wi-Fi controller, and one or more remote stations 70 may be Wi-Fi access points. The signal transfer system 100a 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.

[0056] (Device Configuration) The distributed station 70-1 includes an information acquisition unit 41-1 and an information notification unit 42-1, and the distributed station 70-2 includes an information acquisition unit 41-2 and an information notification unit 42-2. The information acquisition unit 41-1 included in the distributed station 70-1 and the information acquisition unit 41-2 included in the distributed station 70-2 perform similar processing and will therefore be described as the information acquisition unit 41. The information notification unit 42-1 included in the distributed station 70-1 and the information notification unit 42-2 included in the distributed station 70-2 perform similar processing and will therefore be described as the information notification unit 42.

[0057] The information acquisition unit 41 acquires traffic information for each traffic flow currently flowing through the remote station 70. The information acquisition unit 41 notifies the wireless controller 30 of the acquired traffic information for each traffic flow.

[0058] The information notification unit 42 transmits the shaping instruction received from the wireless controller 30 to the wireless terminal 50 corresponding to the traffic flow.

[0059] In the signal transfer system 100a of the second embodiment, the information acquisition unit 41 and the information notification unit 42 are provided in the control unit of the remote station 70, the control decision unit 31 is provided in the control unit of the wireless controller 30, and the communication control unit 51 and the application function unit 52 are provided in the control unit of the wireless terminal 50.

[0060] 5 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. 5 is repeated.

[0061] The remote station 70 receives the signal for each traffic flow transmitted from the central station 60 via the transfer device 20 (step S201). The information acquisition unit 41 included in the remote station 70 acquires traffic information for each traffic flow based on the received signal (step S202). The information acquisition unit 41 transmits the acquired traffic information for each traffic flow to the wireless controller 30.

[0062] The control decision unit 31 included in the wireless controller 30 acquires traffic information for each traffic flow transmitted from the remote station 70 (step S203). The control decision unit 31 determines a shaping rate for each traffic flow using the acquired traffic information for each traffic flow (step S204). 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 70 (step S205).

[0063] In addition, when the control decision unit 31 generates a shaping instruction based on traffic information obtained from the distributed station 70-1, it transmits the generated shaping instruction to the distributed station 70-1, and when the control decision unit 31 generates a shaping instruction based on traffic information obtained from the distributed station 70-2, it transmits the generated shaping instruction to the distributed station 70-2.

[0064] The information notification unit 42 included in the remote station 70 receives the shaping instruction transmitted from the wireless controller 30. The information notification unit 42 transmits the received shaping instruction to the wireless terminal 50 corresponding to the traffic flow (step S206). The communication control unit 51 of the wireless terminal 50 acquires the shaping instruction transmitted from the remote station 70. The communication control unit 51 performs an adjustment process on multiple frames in the traffic flow based on the acquired shaping instruction (step S207). As a result, the frame intervals of the multiple frames are adjusted to be uniform, thereby reducing jitter. Thereafter, the communication control unit 51 inputs the multiple frames after the adjustment process to the application function unit 52. The application function unit 52 processes the multiple input frames.

[0065] According to the signal transfer system 100a configured as above, even in a configuration in which the base stations 40a are distributed between the central station 60 and the remote stations 70, it is possible to obtain the same effects as in the first embodiment.

[0066] (Third embodiment) In the third embodiment, a configuration will be described in which a central station and distributed stations are provided as base stations, the central station acquires traffic information, a wireless controller that controls the base stations determines the shaping rate, and wireless terminals perform adjustment processing.

[0067] 6 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, one or more transfer devices 20, a base station 40b, and a wireless controller 30. The base station 40b includes a central station 60b and one or more remote stations 70b.

[0068] The signal transfer system 100b differs in configuration from the signal transfer system 100a in that it includes a base station 40b instead of the base station 40a. The following will focus on the differences from the signal transfer system 100a. In Fig. 6, the signal transfer system 100b will be described as including two remote stations 70b-1 and 70b-2.

[0069] The central station 60b is a device that transmits and receives signals to and from the wireless terminal 50. Furthermore, the central station 60b has a function of acquiring traffic information about each traffic flow directed to the wireless terminal 50. The central station 60b is one aspect of a higher-level device.

[0070] The remote station 70b is a device that wirelessly communicates with each of one or more wireless terminals 50. The remote station 70b, 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. Furthermore, the remote station 70b has a function of notifying the wireless terminals 50 of instructions transmitted from the wireless controller 30.

[0071] The wireless controller 30, the wireless terminal 50, the central station 60b, and the one or more remote stations 70b are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The wireless controller 30, the wireless terminal 50, the central station 60b, and the one or more remote stations 70b function as communication devices equipped with different control units when the processor executes a program. The control units provide various functions that cause the communication device to function as the wireless controller 30, the wireless terminal 50, the central station 60b, or the one or more remote stations 70b.

[0072] The central station 60b and one or more distributed stations 70b are a CU and one or more DUs in the mobile communication system. In this case, the forwarding device 20 is installed in a mobile midhaul section. Note that the central station 60b and one or more distributed stations 70b may also be a DU and one or more RUs in the mobile communication system. In this case, the forwarding device 20 is installed in a mobile fronthaul.

[0073] The central station 60b may be a Wi-Fi controller, and one or more remote stations 70b may be Wi-Fi access points. 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.

[0074] (Device Configuration) Next, the specific configuration of each device will be described. The central station 60b includes an information acquisition unit 41. The information acquisition unit 41 acquires traffic information for each traffic flow currently flowing through all remote stations 70. The information acquisition unit 41 notifies the wireless controller 30 of the acquired traffic information for each traffic flow. Note that the information acquisition unit 41 adds identification information for identifying the remote station 70 to the traffic information, so that it is possible to identify which remote station 70 the traffic information was acquired from, and notifies the wireless controller 30 of the traffic information.

[0075] The distributed station 70b-1 includes an information notification unit 42-1, and the distributed station 70b-2 includes an information notification unit 42-2. Note that the information notification unit 42-1 included in the distributed station 70b-1 and the information notification unit 42-2 included in the distributed station 70b-2 perform similar processing, and therefore will be described as the information notification unit 42.

[0076] The information notification unit 42 transmits the shaping instruction received from the wireless controller 30 to the wireless terminal 50 corresponding to the traffic flow.

[0077] In the signal transfer system 100b of the third embodiment, the information acquisition unit 41 is provided in the control unit of the central station 60b, the information notification unit 42 is provided in the control unit of the remote station 70b, the control decision unit 31 is provided in the control unit of the wireless controller 30, and the communication control unit 51 and the application function unit 52 are provided in the control unit of the wireless terminal 50.

[0078] 7 is a flowchart showing an example of the flow of processing executed by the signal transfer system 100b in the third embodiment. In the signal transfer system 100b, the processing shown in FIG.

[0079] The information acquisition unit 41 included in the central station 60b acquires traffic information about the traffic flow currently flowing through each remote station 70b for each traffic flow (step S301). The information acquisition unit 41 associates the acquired identification information of each remote station 70b with the traffic information, and transmits the traffic information for each traffic flow to the wireless controller 30 (step S302).

[0080] The control decision unit 31 included in the wireless controller 30 acquires, for each remote station 70b, traffic information for each traffic flow transmitted from the central station 60b. Here, the description will be made assuming that the control decision unit 31 acquires traffic information for each traffic flow of one remote station 70b (e.g., remote station 70b-1). The control decision unit 31 determines a shaping rate for each traffic flow using the acquired traffic information for each traffic flow (step S303). 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 70b-1 (step S304).

[0081] In addition, when the control decision unit 31 generates a shaping instruction based on traffic information obtained from the distributed station 70b-1, it transmits the generated shaping instruction to the distributed station 70b-1, and when the control decision unit 31 generates a shaping instruction based on traffic information obtained from the distributed station 70b-2, it transmits the generated shaping instruction to the distributed station 70b-2.

[0082] The information notification unit 42-1 included in the remote station 70b-1 receives the shaping instruction transmitted from the wireless controller 30. The information notification unit 42-1 transmits the received shaping instruction to the wireless terminal 50 corresponding to the traffic flow (step S305). The communication control unit 51 of the wireless terminal 50 acquires the shaping instruction transmitted from the remote station 70b-1. The communication control unit 51 performs an adjustment process on multiple frames in the traffic flow based on the acquired shaping instruction (step S306). As a result, the frame intervals of the multiple frames are adjusted to be uniform, resulting in a state where jitter is reduced. Thereafter, the communication control unit 51 inputs the multiple frames after the adjustment process to the application function unit 52. The application function unit 52 processes the multiple input frames.

[0083] According to the signal transfer system 100b configured as described above, the base station 40b is distributed to the central station 60b and the remote station 70b, and the central station 60b is equipped with an information acquisition unit 41, so that the same effects as those of the first embodiment can be obtained.

[0084] Fourth Embodiment In a fourth embodiment, a configuration will be described in which a base station acquires traffic information and determines a shaping rate, and a wireless terminal performs adjustment processing.

[0085] FIG. 8 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 that transfers signals from one communication device to another communication device. The signal transfer system 100c includes, for example, a server 10, one or more transfer devices 20, and one or more base stations 40c. The signal transfer system 100c differs in configuration from the signal transfer system 100 in that it does not include a wireless controller 30 and includes a base station 40c instead of the base station 40. The following description will focus on the differences from the signal transfer system 100. FIG. 8 describes a case in which the signal transfer system 100c includes two base stations 40c-1 and 40c-2.

[0086] The base station 40c is a device that wirelessly communicates with one or more wireless terminals 50. For example, the base station 40c transmits signals transferred from the transfer device 20 to the wireless terminal 50, and transfers signals received from the wireless terminal 50 to the transfer device 20. Furthermore, the base station 40c has a function to acquire traffic information for each traffic flow from the server 10 to the wireless terminal 50. Furthermore, the base station 40c has a function to determine a bandwidth control method. Furthermore, the base station 40c has a function to notify the wireless terminal 50 of an instruction determined by the bandwidth control method.

[0087] The base station 40c and the wireless terminal 50 are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The base station 40c and the wireless terminal 50 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 40c or the wireless terminal 50.

[0088] The base station 40c may be, for example, a Wi-Fi access point. 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.

[0089] (Device Configuration) Next, the specific configuration of each device will be described. The base station 40c-1 includes an information acquisition unit 41-1, an information notification unit 42-1, and a control decision unit 31-1, and the base station 40-2 includes an information acquisition unit 41-2, an information notification unit 42-2, and a control decision unit 31-2. Note that the information acquisition unit 41-1 included in the base station 40c-1 and the information acquisition unit 41-2 included in the base station 40c-2 perform similar processing and will therefore be described as the information acquisition unit 41. The information notification unit 42-1 included in the base station 40c-1 and the information notification unit 42-2 included in the base station 40c-2 perform similar processing and will therefore be described as the information notification unit 42. The control decision unit 31-1 included in the base station 40c-1 and the control decision unit 31-2 included in the base station 40c-2 perform similar processing and will therefore be described as the control decision unit 31.

[0090] Based on the traffic information acquired by the information acquisition unit 41, 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.

[0091] In the signal transfer system 100c, the control decision unit 31, information acquisition unit 41 and information notification unit 42 are provided in the control unit of the base station 40c, and the communication control unit 51 and application function unit 52 are provided in the control unit of the wireless terminal 50.

[0092] 9 is a flowchart showing an example of the flow of processing executed by the signal transfer system 100c in the fourth embodiment. In the signal transfer system 100c, the processing shown in FIG.

[0093] The base station 40c receives the signal for each traffic flow transmitted by the server 10 via the transfer device 20 (step S401). The information acquisition unit 41 included in the base station 40 acquires traffic information for each traffic flow based on the received signal (step S402). The information acquisition unit 41 outputs the acquired traffic information for each traffic flow to the control decision unit 31.

[0094] 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 41 (step S403). 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 information notification unit 42.

[0095] The information notification unit 42 transmits the shaping instruction output from the control decision unit 31 to the wireless terminal 50 corresponding to the traffic flow (step S404). The communication control unit 51 of the wireless terminal 50 acquires the shaping instruction transmitted from the base station 40c. The communication control unit 51 performs an adjustment process on multiple frames in the traffic flow based on the acquired shaping instruction (step S405). As a result, the frame intervals of the multiple frames are adjusted to be uniform, resulting in a state where jitter is reduced. Thereafter, the communication control unit 51 inputs the multiple frames after the adjustment process to the application function unit 52. The application function unit 52 processes the multiple input frames.

[0096] According to the signal transfer system 100c configured as above, even if the wireless controller 30 is not provided and the base station 40c is provided with the control decision unit 31, it is possible to obtain the same effects as those of the first embodiment.

[0097] (Fifth embodiment) In the fifth 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 determine shaping rates, and wireless terminals perform adjustment processing.

[0098] 10 is a diagram showing an example of the configuration of a signal transfer system 100d according to the fifth embodiment. The signal transfer system 100d is a system for transferring signals from one communication device to another. The signal transfer system 100d includes, for example, one or more transfer devices 20 and a base station 40d. The base station 40d includes a central station 60 and one or more remote stations 70d.

[0099] The signal transfer system 100d differs in configuration from the signal transfer system 100c in that it includes a base station 40d instead of the base station 40c. The differences from the signal transfer system 100c will be mainly described below. In Fig. 10, a case will be described in which the signal transfer system 100d includes two remote stations 70d-1 and 70d-2.

[0100] The remote station 70d is a device that wirelessly communicates with one or more wireless terminals 50. The remote station 70d, 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. The remote station 70d also has a function to acquire traffic information for each traffic flow from the server 10 to the wireless terminals 50. The remote station 70d also has a function to determine a bandwidth control method. The remote station 70d also has a function to notify the wireless terminals 50 of instructions determined by the bandwidth control method.

[0101] The wireless terminal 50 and the distributed station 70d are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The wireless terminal 50 and the distributed station 70d 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 wireless terminal 50 or the distributed station 70d.

[0102] The central station 60 and one or more distributed stations 70d are a CU and one or more DUs in the mobile communication system. In this case, the forwarding device 20 is installed in a mobile midhaul section. Note that the central station 60 and one or more distributed stations 70d may also be a DU and one or more RUs in the mobile communication system. In this case, the forwarding device 20 is installed in a mobile fronthaul.

[0103] The central station 60 may be a Wi-Fi controller, and one or more remote stations 70d may be Wi-Fi access points. 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.

[0104] (Device Configuration) Next, the specific configuration of each device will be described. The distributed station 70d-1 has an information acquisition unit 41-1, an information notification unit 42-1, and a control decision unit 31-1, while the distributed station 70d-2 has an information acquisition unit 41-2, an information notification unit 42-2, and a control decision unit 31-2. The information acquisition unit 41-1 of the distributed station 70d-1 and the information acquisition unit 41-2 of the distributed station 70d-2 perform similar processing and will therefore be described as the information acquisition unit 41. The information notification unit 42-1 of the distributed station 70d-1 and the information notification unit 42-2 of the distributed station 70d-2 perform similar processing and will therefore be described as the information notification unit 42. The control decision unit 31-1 of the distributed station 70d-1 and the control decision unit 31-2 of the distributed station 70d-2 perform similar processing and will therefore be described as the control decision unit 31.

[0105] Based on the traffic information acquired by the information acquisition unit 41, 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.

[0106] In the signal transfer system 100d, the control decision unit 31, information acquisition unit 41 and information notification unit 42 are provided in the control unit of the remote station 70d, and the communication control unit 51 and application function unit 52 are provided in the control unit of the wireless terminal 50.

[0107] 11 is a flowchart showing an example of the flow of processing executed by the signal transfer system 100d according to the fifth embodiment. In the signal transfer system 100d, the processing shown in FIG.

[0108] The remote station 70d receives the signal for each traffic flow transmitted by the server 10 via the transfer device 20 (step S501). The information acquisition unit 41 included in the remote station 70d acquires traffic information for each traffic flow based on the received signal (step S502). The information acquisition unit 41 outputs the acquired traffic information for each traffic flow to the control decision unit 31.

[0109] 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 41 (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 information notification unit 42.

[0110] The information notification unit 42 transmits the shaping instruction output from the control decision unit 31 to the wireless terminal 50 corresponding to the traffic flow (step S504). The communication control unit 51 of the wireless terminal 50 acquires the shaping instruction transmitted from the remote station 70d. The communication control unit 51 performs an adjustment process on multiple frames in the traffic flow based on the acquired shaping instruction (step S505). As a result, the frame intervals of the multiple frames are adjusted to be uniform, resulting in a state where jitter is reduced. Thereafter, the communication control unit 51 inputs the multiple frames after the adjustment process to the application function unit 52. The application function unit 52 processes the multiple input frames.

[0111] According to the signal transfer system 100d configured as described above, the system does not include a wireless controller 30, and the base station 40d is distributed between the central station 60 and the remote station 70d, and the remote station 70d is equipped with a control decision unit 31. This configuration also achieves the same effects as the first embodiment.

[0112] (Sixth embodiment) In the sixth embodiment, a configuration will be described in which a base station is provided with a central station and distributed stations that are distributed, the central station acquires traffic information, the distributed stations determine shaping rates, and wireless terminals perform adjustment processing.

[0113] 12 is a diagram showing an example of the configuration of a signal transfer system 100e according to the sixth embodiment. The signal transfer system 100e is a system for transferring signals from one communication device to another. The signal transfer system 100e includes, for example, one or more transfer devices 20 and a base station 40e. The base station 40e includes a central station 60e and one or more remote stations 70e.

[0114] The signal transfer system 100e differs in configuration from the signal transfer system 100d in that it includes a base station 40e instead of the base station 40d. The differences from the signal transfer system 100d will be mainly described below. In Fig. 12, a case will be described in which the signal transfer system 100e includes two remote stations 70e-1 and 70e-2.

[0115] The central station 60e is a device that transmits and receives signals to and from the wireless terminal 50. Furthermore, the central station 60e has a function of acquiring traffic information about each traffic flow directed to the wireless terminal 50. The central station 60e is one aspect of a higher-level device.

[0116] The distributed station 70e is a device that wirelessly communicates with one or more wireless terminals 50. For example, the distributed station 70e 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. Furthermore, the distributed station 70e has a function of determining a bandwidth control method. Furthermore, the distributed station 70e has a function of notifying the wireless terminals 50 of instructions determined by the bandwidth control method.

[0117] The wireless terminal 50, the central station 60e, and one or more distributed stations 70e are configured using, for example, a processor such as a CPU, a memory, and a communication interface. The wireless terminal 50, the central station 60e, and one or more distributed stations 70e function as communication devices equipped with different control units when the processor executes a program. The control units provide various functions that cause the communication device to function as the wireless terminal 50, the central station 60e, or one or more distributed stations 70e.

[0118] The central station 60e and one or more distributed stations 70e are a CU and one or more DUs in the mobile communication system. In this case, the forwarding device 20 is installed in a mobile midhaul section. Note that the central station 60e and one or more distributed stations 70e may be a DU and one or more RUs in the mobile communication system. In this case, the forwarding device 20 is installed in a mobile fronthaul.

[0119] The central station 60e may be a Wi-Fi controller, and one or more remote stations 70e 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.

[0120] (Device Configuration) Next, the specific configuration of each device will be described. The central station 60e includes an information acquisition unit 41. The information acquisition unit 41 acquires traffic information for each traffic flow currently flowing through all remote stations 70e. The information acquisition unit 41 notifies the remote station 70e of the acquired traffic information for each traffic flow. The information acquisition unit 41 notifies each traffic information to the remote station 70e from which it was acquired.

[0121] The distributed station 70e-1 has an information notification unit 42-1 and a control decision unit 31-1, and the distributed station 70e-2 has an information notification unit 42-2 and a control decision unit 31-2. Note that the information notification unit 42-1 provided in the distributed station 70e-1 and the information notification unit 42-2 provided in the distributed station 70e-2 perform similar processing and will be described as the information notification unit 42. The control decision unit 31-1 provided in the distributed station 70e-1 and the control decision unit 31-2 provided in the distributed station 70e-2 perform similar processing and will be described as the control decision unit 31.

[0122] Based on the traffic information notified from the central station 60e, the control decision unit 31 calculates a shaping rate for each traffic flow that minimizes jitter within a range that satisfies the delay requirement, taking into account the priority of each traffic flow.

[0123] In the signal transfer system 100e, the information acquisition unit 41 is provided in the control unit of the central station 60e, the control decision unit 31 and the information notification unit 42 are provided in the control unit of the remote station 70e, and the communication control unit 51 and the application function unit 52 are provided in the control unit of the wireless terminal 50.

[0124] 13 is a flowchart showing an example of the flow of processing executed by the signal transfer system 100e in the sixth embodiment. In the signal transfer system 100e, the processing shown in FIG.

[0125] The information acquisition unit 41 included in the central station 60e acquires traffic information about the traffic flow currently flowing through each of the remote stations 70e for each traffic flow (step S601). The information acquisition unit 41 notifies the corresponding remote station 70b of the acquired traffic information about each of the remote stations 70b (step S602). For example, when the information acquisition unit 41 acquires traffic information about the traffic flow of the remote station 70b-1, the information acquisition unit 41 notifies the remote station 70b-1 of the traffic information.

[0126] The control decision unit 31 included in the remote station 70b acquires traffic information for each traffic flow transmitted from the central station 60e. The control decision unit 31 determines a shaping rate for each traffic flow using the acquired traffic information for each traffic flow (step S603). 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 outputs the generated shaping instruction to the information notification unit 42.

[0127] The information notification unit 42 transmits the shaping instruction output from the control decision unit 31 to the wireless terminal 50 corresponding to the traffic flow (step S604). The communication control unit 51 of the wireless terminal 50 acquires the shaping instruction transmitted from the remote station 70e. The communication control unit 51 performs an adjustment process on multiple frames in the traffic flow based on the acquired shaping instruction (step S605). As a result, the frame intervals of the multiple frames are adjusted to be uniform, resulting in a state where jitter is reduced. Thereafter, the communication control unit 51 inputs the multiple frames after the adjustment process to the application function unit 52. The application function unit 52 processes the multiple input frames.

[0128] According to the signal transfer system 100e configured as described above, the system does not include a wireless controller 30, and the base station 40e is distributed to the central station 60e and the remote station 70e, and the central station 60e is equipped with an information acquisition unit 41 and the remote station 70d is equipped with a control decision unit 31. This configuration also achieves the same effects as the first embodiment.

[0129] Seventh Embodiment In the seventh embodiment, a configuration will be described in which a wireless terminal acquires traffic information, determines a shaping rate, and performs adjustment processing.

[0130] Fig. 14 is a diagram showing an example of the configuration of a signal transfer system 100f according to the seventh embodiment. The signal transfer system 100f is a system that transfers signals from one communication device to another communication device. The signal transfer system 100f includes, for example, a server 10, one or more transfer devices 20, and one or more base stations 40f. Fig. 14 illustrates a case where the signal transfer system 100f includes two base stations 40f-1 and 40f-2.

[0131] The base station 40 f is a device that wirelessly communicates with one or more wireless terminals 50 f. For example, the base station 40 f transmits signals transferred from the transfer device 20 to the wireless terminals 50 f, and transfers signals received from the wireless terminals 50 f to the transfer device 20.

[0132] The wireless terminal 50f executes the adjustment process. Furthermore, the wireless terminal 50f has a function of acquiring traffic information for each traffic flow from the server 10 to the wireless terminal 50. Furthermore, the wireless terminal 50f has a function of determining a bandwidth control method.

[0133] The wireless terminal 50f is configured using, for example, a processor such as a CPU, a memory, and a communication interface. The processor executes a program, causing the wireless terminal 50f to function as a communication device equipped with different control units. The control units provide various functions that cause the communication device to function as the wireless terminal 50f.

[0134] The base station 40f may be, for example, a Wi-Fi access point. The signal transfer system 100f 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.

[0135] (Device Configuration) Next, a specific configuration of the device will be described. The wireless terminal 50f includes an information acquisition unit 41, an information notification unit 42, a control decision unit 31, a communication control unit 51, and an application function unit 52.

[0136] In the signal transfer system 100f, the control decision unit 31, the information acquisition unit 41, the information notification unit 42, the communication control unit 51, and the application function unit 52 are provided in the control unit of the wireless terminal 50f.

[0137] Fig. 15 is a flowchart showing an example of the flow of processing executed by the signal transfer system 100f in the seventh embodiment. In the signal transfer system 100f, the processing shown in Fig. 15 is repeated.

[0138] The wireless terminal 50f receives the signal for each traffic flow transmitted by the server 10 via the transfer device 20 and the base station 40f (step S701). The information acquisition unit 41 included in the wireless terminal 50f acquires traffic information for each traffic flow based on the received signal (step S702). The information acquisition unit 41 outputs the acquired traffic information for each traffic flow to the control decision unit 31.

[0139] 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 41 (step S703). 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 information notification unit 42.

[0140] The information notification unit 42 outputs the shaping instruction output from the control determination unit 31 to the communication control unit 51. The communication control unit 51 performs adjustment processing on multiple frames in the traffic flow based on the shaping instruction output from the information notification unit 42 (step S704). As a result, the frame intervals of the multiple frames are adjusted to be uniform, resulting in a state where jitter is reduced. Thereafter, the communication control unit 51 inputs the multiple frames after the adjustment processing to the application function unit 52. The application function unit 52 processes the multiple input frames.

[0141] According to the signal transfer system 100f configured as above, the same effects as those of the first embodiment can be obtained even in a configuration in which the wireless terminal 50f performs all of the processes of acquiring traffic information, determining the shaping rate, and adjusting the rate.

[0142] 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.

[0143] The present invention can be applied to a communication system that accommodates wireless terminals and a communication control method.

[0144] REFERENCE SIGNS LIST 10... server, 20... transfer device, 30... wireless controller, 31... control decision unit, 40, 40-1 to 40-2, 40a, 40b, 40c, 40c-1 to 40c-2, 40d, 40e, 40f, 40f-1 to 40f-2... base stations, 41, 41-1 to 41-2... information acquisition unit, 42, 42-1 to 42-2... information notification unit, 50, 50f... wireless terminal, 51... communication control unit, 52... application function unit, 60, 60b, 60e... central station, 70, 70-1 to 70-2, 70b, 70b-1 to 70b-2, 70d, 70d-1 to 70d-2, 70e, 70e-1 to 70e-2... remote stations, 100, 100a, 100b, 100c, 100d, 100e, 100f... signal transmission system

Claims

1. A signal transfer system in which wireless communication is performed between a base station and a wireless terminal, comprising: an information acquisition unit that acquires traffic information for each traffic flow, which is information about the traffic flow from the base station to the wireless terminal; 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 an adjustment process to adjust the frame spacing of multiple frames that constitute the downstream 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 the base station.

3. The signal transfer system according to claim 1 or 2, wherein the control decision unit decides the shaping rate based on the data volume and priority of each traffic flow currently flowing through the base station.

4. A signal transfer system according to claim 1 or 2, wherein the control decision unit is provided in any of the base station, the wireless terminal, and a wireless control device that wirelessly controls the base station.

5. A wireless terminal in a signal transfer system in which wireless communication is performed between a base station and a wireless terminal, comprising: an application function unit that processes a downstream signal of a traffic flow from the base station to the wireless terminal; and a communication control unit that executes an adjustment process that adjusts the frame spacing of multiple frames that make up the downstream signal before the multiple frames are input to the application function unit, based on a bandwidth control method for reducing frame jitter determined based on traffic information that is information about the traffic flow.

6. The wireless terminal according to claim 5, further comprising: an information acquisition unit that acquires the traffic information for each traffic flow; and a control decision unit that decides the bandwidth control method based on the traffic information acquired by the information acquisition unit for each traffic flow.

7. A control device that controls a base station in a signal transfer system in which wireless communication is performed between the base station and a wireless terminal, comprising: a control decision unit that acquires traffic information, which is information about the traffic flow from the base station to the wireless terminal, for each traffic flow, determines a bandwidth control method for reducing frame jitter based on the acquired traffic information, and notifies the wireless terminal of the bandwidth control method via the base station.

8. A signal processing method performed by a signal transfer system in which wireless communication is performed between a base station and a wireless terminal, comprising: acquiring traffic information for each traffic flow, which is information relating to the traffic flow from the base station to the wireless terminal; determining a bandwidth control method for reducing frame jitter based on the traffic information acquired for each traffic flow; and performing an adjustment process to adjust the frame spacing of multiple frames constituting the downstream signal of the traffic flow based on the determined bandwidth control method.

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