JP6023655B2 - Relay communication device, relay communication method, and relay communication program - Google Patents

Description

  The present invention relates to a relay communication technique for transmitting received traffic through a wired communication path in a communication network in which two or more communication paths including a wired communication path are connected.

  In recent years, electronic products having a wireless LAN (Local Area Network) communication function compliant with the IEEE (The Institute of Electrical and Electronics Engineers, Inc.) 802.11 standard (for example, see Non-Patent Document 1) have become widespread. . For example, a notebook computer, a game machine, etc. (hereinafter referred to as “wireless terminal station”) can be connected to the Internet via an access point device using a wireless LAN communication function. The access point device communicates with a wireless terminal station through a wireless link in accordance with the IEEE 802.11 standard. The access point device communicates with the switch device via a wired link in accordance with the IEEE 802.3 standard (for example, see Non-Patent Document 2).

  FIG. 9 is a diagram illustrating an example of a network including a wireless terminal station, an access point device, and a switch device. In the access point device 90, the wireless LAN unit 901 exchanges wireless data frames with the wireless terminal stations 94 to 96 via the wireless link 93. The wireless data frame includes a PHY, a MAC header, and a payload necessary for transmitting the wireless link 93. The payload has a header and information for processing in an upper IP (Internet Protocol) layer. The wireless LAN unit 901 refers to the information of the PHY and MAC headers after receiving the wireless data frames from the wireless terminal stations 94 to 96 is completed. The wireless LAN unit 901 performs demodulation processing and error correction processing according to the procedure of the IEEE 802.11 standard. Thereby, PHY, MAC header, etc. are removed from the wireless data frame. The wireless LAN unit 901 transfers only the payload to the bridge unit 902.

  In the access point device 90, the bridge unit 902 is located between the wireless LAN unit 901 and the wired LAN unit 903. The bridge unit 902 processes the payload received from the wireless LAN unit 901 and the wired LAN unit 903 in the IP layer, and communicates bidirectionally in the IP layer. A buffer 904 is connected to the bridge unit 902. The buffer 904 temporarily stores a payload waiting for transfer. In the example of FIG. 9, the bridge unit 902 temporarily stores the payload received from the wireless LAN unit 901 in the buffer 904 and transfers it to the wired LAN unit 903. On the other hand, the bridge unit 902 temporarily stores the payload received from the wired LAN unit 903 in the buffer 904 and transfers it to the wireless LAN unit 901.

  The wired LAN unit 903 attaches PHY and MAC headers necessary for wired transmission to the IP layer information received from the bridge unit 902. The wired LAN unit 903 transmits a wired data frame to the switch 91 via the wired link 92. The switch 91 aggregates wired data frames from a plurality of access point devices and transfers them to the next router device. The wireless terminal stations 94 to 96 connect to the Internet through a series of wireless data frame processing, wired data frame processing, and transfer processing using the above-described function of the access point device 90.

  The access point device 90 is used in a wide variety of situations, such as the provision of a public wireless LAN developed by a communication carrier and the construction of a home network in the home. The access point device 90 consumes less power than a router or switch that processes or transfers a large amount of data frames. However, if the number of installed access point devices 90 increases in the future, the total power consumption increases. Amidst the importance of environmental energy problems, there is an increasing need for power saving in businesses and homes, and a reduction in power consumption of the access point device 90 is required.

  In order to reduce the power consumption of the access point device 90, a low power idling (LPI) that causes a low power operation when the traffic is not flowing in the wired link 92 connected between the wired LAN unit 903 and the switch 91. ) Method has been proposed (see, for example, Non-Patent Document 3). When traffic flows through the wired link 92, the power consumption of the wired LAN unit 903 decreases as the wired transmission rate used by the wired LAN unit 903 decreases (see, for example, Non-Patent Document 4).

IEEE Standard 802.11, Wireless LAN medium access control (MAC) and Physical layer (PHY) specification, 12 June, 2007. IEEE Standard 802.3, Local and metropolitan area networks specification, 26 December, 2008. IEEE Standard 802.3az, Local and metropolitan area networks specification, Amendment 5: Media access control parameters, physical layers and management parameters for energy-efficient Ethernet (registered trademark), 27 October, 2010. Dan Dove, “Energy efficient Ethernet: Switching perspective,” IEEE 802.3az Interim Meeting, Jan., 2008.

However, in the above LPI method, when even a small amount of traffic flows through the wired link 92, the power consumption of the access point device 90 cannot be reduced because the low power operation cannot be performed. The traffic is a plurality of data frames.

  In the IEEE 802.3 standard, transmission rates of 10 Mbps, 100 Mbps, 1 Gbps, or 10 Gbps can be used as different wired transmission rates. The IEEE 802.3 standard also standardizes an auto-negotiation function for determining which wired transmission rate to use. Thereby, in the IEEE 802.3 standard, it is possible to switch the wired transmission rate suitable for communication by agreement between the wired LAN unit 903 and the switch 91.

As described above, the lower the wired transmission rate used by the wired LAN unit 903, the lower the power consumption of the wired LAN unit 903. Therefore, in order to reduce the power consumption of the access point device 90, the wired link 92 It is considered that the transmission rate should be lowered. Based on this idea, an ALR (Adaptive Link Rate) method has been proposed that reduces the wire transmission rate as the traffic volume decreases.
FIG. 10 is a diagram for explaining the ALR method and its problems. FIG. 10A is a graph showing the relationship between elapsed time and power consumption when the wired transmission rate is fixed at RATE (1). In FIG. 10A, after all traffic is transmitted during the traffic transmission period, a control signal transmission period in which only the control signal is transmitted is set. On the other hand, FIG. 10B shows the elapsed time and power consumption when the value of the wire transmission rate is lowered in order of RATE (1), RATE (2), and RATE (3) by the ALR method. It is a graph which shows the relationship. As shown in the graph of FIG. 10B, when the ALR method is adopted, the traffic transmission period becomes longer as compared with the case of FIG. 10A by lowering the wired transmission rate. It becomes possible to reduce electric power.

  However, when the amount of traffic to be transmitted is large and the wire transmission rate is lowered by the ALR method without special consideration, the time required to transmit all the traffic is prolonged as shown in FIG. Exceeds time requirements. FIG. 10C is a graph showing the relationship between the elapsed time and the power consumption when transmitting more traffic than in FIG. 10B by the ALR method. As described above, the ALR method has a disadvantage of increasing the traffic transmission time. As the traffic transmission time increases, the waiting time for newly input traffic also increases. Accordingly, the ALR method increases the transmission time of traffic, and as a result, increases the signal delay in the access point device 90.

  In view of the above circumstances, an object of the present invention is to provide a relay communication device, a relay communication method, and a relay communication program that suppress an increase in traffic transmission time during relay communication.

  One aspect of the present invention is a relay communication apparatus that includes two or more communication interfaces including a wired communication interface and transmits received traffic through the wired communication interface, and stores the received traffic within a predetermined update period. A buffer, a communication information storage unit that acquires a traffic amount and a transmission rate of the received traffic, and stores them as communication information, and received each of the traffics within the update period based on the communication information A transmission rate determining unit that determines a transmission rate for transmission through the wired communication interface within a range in which the total transmission time of all traffic is equal to or less than a predetermined threshold.

Further, in one aspect of the present invention, the transmission rate determination unit is a minimum larger than a transmission rate at the time of reception among a plurality of types of transmission rates that can be selected by the wired communication interface for each of the traffic. the transmission rate determined as a transmission rate for transmission over the wired communication interface.

Further, in one aspect of the present invention, the transmission rate determining unit is configured to all traffic received in the update period to calculate the power consumption when transmitting through the wired communication interface, the power consumption Gayori A transmission rate at the time of transmission through the wired communication interface is determined for each of the traffics so as to decrease.

  In one aspect of the present invention, the transmission rate determining unit determines a transmission priority indicating a priority when transmitting each of the traffic through the wired communication interface.

  One embodiment of the present invention is a relay communication method for transmitting received traffic through the wired communication path in a communication network in which two or more communication paths including a wired communication path are connected, and the relay communication method is within a predetermined update cycle. A traffic storage step for storing received traffic, a communication information storage step for obtaining a traffic amount and a transmission rate of the received traffic and storing them as communication information, and for each of the traffic, the communication information And determining a transmission rate for transmission through the wired communication path within a range in which the total transmission time of all traffic received within the update period is equal to or less than a predetermined threshold.

  One embodiment of the present invention is a relay communication program for causing a computer to function as the relay communication device.

  ADVANTAGE OF THE INVENTION According to this invention, the increase in the transmission time of the traffic at the time of relay communication can be suppressed.

It is a block diagram which shows the structure of the access point apparatus which concerns on one Embodiment of this invention. It is a figure which shows the structure of the PHY header of IEEE 802.11 standard. It is a figure which shows an example of a radio | wireless communication information table. It is a flowchart which shows the flow of a process of a wired transmission rate determination part. It is a figure which shows an example of the queue structure inside a buffer. It is a figure which shows an example of a wired transmission period. It is a figure which shows the other example of a radio | wireless communication information table. It is a figure which shows the effect of this invention. It is a block diagram which shows an example of the conventional network structure. It is a figure for demonstrating ALR method and its problem.

<1. Access point device>
FIG. 1 is a block diagram showing a configuration of an access point device 10 (relay communication device) according to an embodiment of the present invention. The access point device 10 includes a wireless LAN unit 101 (communication interface), a bridge unit 102, a wired LAN unit 103 (wired communication interface), a buffer 104, a wireless communication information storage unit 105 (communication information storage unit), A wired transmission rate determination unit 106 (transmission rate determination unit).

  The wireless LAN unit 101 enables communication between the access point device 10 and the wireless terminal stations 14 to 16 via the wireless link 13 (communication path). When receiving wireless traffic from the wireless terminal stations 14 to 16, the wireless LAN unit 101 performs necessary processing on the received wireless traffic. The wireless LAN unit 101 transfers the processed traffic to the bridge unit 102. When traffic is transferred, the bridge unit 102 refers to the transmission priority determined by the wired transmission rate determination unit 106 and stores the traffic in the transfer queue corresponding to the transmission priority of the buffer 104. The bridge unit 102 acquires the traffic stored in the buffer 104 and transfers it to the wired LAN unit 103. Conversely, when the bridge unit 102 receives traffic from the wired LAN unit 103, the bridge unit 102 transfers the traffic to the buffer 104. The wired LAN unit 103 is connected to the switch 11 by a wired link 12 (wired communication path). The wired LAN unit 103 processes the traffic transferred from the bridge unit 102 and transfers the traffic to the switch 11 as wired traffic.

  When the traffic is transferred to the bridge unit 102, the buffer 104 refers to the transmission priority determined by the wired transmission rate determination unit 106 and temporarily stores the traffic in a corresponding queue. The wireless communication information storage unit 105 acquires the traffic amount and transmission rate of traffic received from the wireless terminal stations 14 to 16 and stores them as communication information. Based on the communication information, the wired transmission rate determination unit 106 sets the wired link 12 within a range in which the total transmission time of all traffic received within a predetermined update period is equal to or less than a predetermined threshold. Determine the transmission rate when sending through. In addition, the wired transmission rate determination unit 106 determines a transmission priority indicating the priority at the time of transmission through the wired link 12 for each traffic.

  The bridge unit 102 acquires the traffic from the buffer 104 and transfers the traffic and its transmission priority to the wired LAN unit 103 in accordance with the wired transmission cycle in the wired LAN unit 103. The wired LAN unit 103 acquires the traffic and its transmission priority from the bridge unit 102 and transmits the traffic to the wired link 12 within a wired transmission period corresponding to the transmission priority. The wired LAN unit 103 dynamically changes the wired transmission rate in the wired link 12 by agreement with the switch 11.

<2. First relay method>
A first relay method for transmitting traffic received from the wireless terminal stations 14 to 16 through the wired link 12 in the access point device 10 will be described below. In the first relay method, the wired transmission rate determination unit 106 determines the transmission priority when transmitting the traffic received from the wireless terminal stations 14 to 16 based on the information collected from the wireless communication information storage unit 105. . Further, the wired transmission rate determination unit 106 sets the wired transmission rate in the wired link 12 based on the determined transmission priority.
The wireless LAN unit 101 receives wireless data frames standardized by the IEEE 802.11 standard from the wireless terminal stations 14 to 16 via the wireless link 13. The received wireless data frame includes a header related to communication. FIG. 2 is a diagram showing the configuration of the PHY header of the IEEE 802.11 standard. The wireless LAN unit 101 outputs the value of the RATE field in the PHY header to the wireless communication information storage unit 105 every time a wireless data frame is received from the wireless terminal stations 14 to 16. In the RATE field, information related to the wireless transmission rate used for transmitting the wireless data frame is described.

  FIG. 3 is an example of the wireless communication information table TB1 held by the wireless communication information storage unit 105. In the wireless communication information table TB1, there are fields for describing information on each wireless communication performance time, wireless transmission rate, and traffic volume according to the connection IDs of the wireless terminal stations 14-16. Each time the access point device 10 communicates with the wireless terminal stations 14 to 16, the wireless communication information storage unit 105 stores the actual wireless communication time, the wireless transmission rate, and the traffic volume, and updates each field.

  The wired transmission rate determining unit 106 refers to the wireless transmission rates with the wireless terminal stations 14 to 16 and determines the planned wired transmission rate of the traffic received from the wireless terminal station. The wired LAN unit 103 can select 10 Gbps, 1 Gbps, and 100 Mbps as three types of wired transmission rates. The wired transmission rate determining unit 106 determines the planned wired transmission rate so that the traffic becomes a lower value for each of the traffics. The wired transmission rate determining unit 106 determines the planned wired transmission rate so that it is larger than the transmission rate at the time of reception for each traffic. Eventually, the wired transmission rate determination unit 106 determines, as the planned wired transmission rate, the smallest wired transmission rate that is larger than the wireless transmission rate of traffic among the three types of wired transmission rates. For example, if the wireless transmission rate of traffic is 54 Mbps, the planned wired transmission rate of the traffic is 100 Mbps. Further, if the wireless transmission rate of traffic is 150 Mbps, the planned wired transmission rate of the traffic is 1 Gbps. The wired transmission rate determination unit 106 writes the planned wired transmission rate in the wireless communication information table TB1 (see FIG. 3) of the wireless communication information storage unit 105.

次に、有線伝送レート決定部１０６は、算出した所要送信時間を所定の閾値αと比較する（Ｓ１０３）。閾値αは、更新周期より小さい数値である。有線伝送レート決定部１０６は、算出した所要送信時間が所定の閾値α以下の場合（Ｓ１０３−ＮＯ）、予定有線伝送レートに基づいてトラフィックの送信優先度を付与する（Ｓ１０６）。具体的には、有線伝送レート決定部１０６は、予定有線伝送レート１０Ｇｂｐｓを有するトラフィックに対して送信優先度１を与える。有線伝送レート決定部１０６は、予定有線伝送レート１Ｇｂｐｓを有するトラフィックに対して送信優先度２を与える。有線伝送レート決定部１０６は、予定有線伝送レート１００Ｍｂｐｓを有するトラフィックに対して送信優先度３を与える。 The wired transmission rate determination unit 106 considers traffic at a constant update cycle, and determines the transmission priority for outputting the traffic so as to satisfy the requirement for the transmission time in the wired link 12.
FIG. 4 is a flowchart showing a processing flow of the wired transmission rate determination unit 106. A procedure in which the wired transmission rate determining unit 106 assigns a transmission priority to each traffic will be described with reference to FIG.
First, the wired transmission rate determination unit 106 reads the traffic amount and the planned wired transmission rate of each traffic from the wireless communication information storage unit 105 (S101). For example, in FIG. 3, the traffic amounts of the traffic of connection ID 1 and connection ID 4 are 0.252 Mb and 0.27 Mb, respectively. The planned wired transmission rates for the traffic of connection ID 1 and connection ID 4 are both 100 Mbps. The traffic amount of the connection ID 2 is 0.3 Mb, and the planned wired transmission rate is 1 Gbps. The traffic volume of the connection ID 3 is 2 Mb, and the planned wired transmission rate is 10 Gbps.
Next, the wired transmission rate determination unit 106 calculates a required transmission time for transmitting all traffic on the wired link 12 from the following formula (1) based on the above information (S102).

Next, the wired transmission rate determination unit 106 compares the calculated required transmission time with a predetermined threshold value α (S103). The threshold value α is a numerical value smaller than the update cycle. If the calculated required transmission time is equal to or less than the predetermined threshold α (S103-NO), the wired transmission rate determination unit 106 assigns traffic transmission priority based on the planned wired transmission rate (S106). Specifically, the wired transmission rate determination unit 106 gives a transmission priority 1 to traffic having a planned wired transmission rate of 10 Gbps. The wired transmission rate determination unit 106 gives a transmission priority 2 to traffic having the planned wired transmission rate 1 Gbps. The wired transmission rate determination unit 106 gives a transmission priority 3 to traffic having a planned wired transmission rate of 100 Mbps.

  On the other hand, when the calculated required transmission time is greater than the predetermined threshold value α (S103-YES), the wired transmission rate determination unit 106 corrects the planned wired transmission rate (S104). Specifically, the wired transmission rate determination unit 106 increases the wired transmission rate of traffic having the lowest planned wired transmission rate. In the example of FIG. 3, the wired transmission rate determination unit 106 sets the wired transmission rate of the traffic of the connection ID 1 and the connection ID 4 whose planned wired transmission rate is 100 Mbps as the minimum to 1 Gbps (corrected wired transmission). (Transmission rate).

  Next, the wired transmission rate determination unit 106 determines whether or not the corrected wired transmission rate of all traffic is the maximum wired transmission rate (S105). In this example, when the wired transmission rate after correction of all traffic is not 10 Gbps (S105-NO), the process returns to the procedure of S102 again and is repeated. In the case of repetition, the planned wired transmission rate in the above description is read as the corrected wired transmission rate. On the other hand, when the planned wired transmission rate of all traffic becomes 10 Gbps (S105-YES), transmission priority 1 is assigned to all traffic (S106).

  As an example, the traffic amount and the scheduled wired transmission rate shown in FIG. 3 are applied to the flowchart of FIG. In S102, the required transmission time calculated by Equation (1) is 5.72 ms. In S103, when the threshold value α is set to 5 ms, the calculated required transmission time exceeds the threshold value. Therefore, in S104, the wired transmission rate determination unit 106 corrects the scheduled wired transmission rate. Specifically, the corrected wired transmission rate is increased to 1 Gbps for traffic with a planned wired transmission rate of 100 Mbps (connection ID is 1, connection ID is 4). As a result, the total traffic amount at the planned wired transmission rate of 1 Gbps is 0.822 Mb. In the determination in S105, since the planned wired transmission rate of all traffic is not the maximum 10 Gbps, the process returns to S102 and recalculates the required transmission time. The required transmission time recalculated in S102 is 1.022 ms, which is below the threshold value α. In S106, the wired transmission rate determination unit 106 gives a transmission priority 1 to traffic having the planned wired transmission rate 10Gbps. Further, the wired transmission rate determination unit 106 gives a transmission priority 2 to traffic having the planned wired transmission rate 1 Gbps.

  As described above, when the transmission priority is assigned, the wired transmission rate determination unit 106 outputs the transmission priority assigned to each traffic to the bridge unit 102. The bridge unit 102 transfers the traffic to the wired LAN unit 103. Specifically, the bridge unit 102 stores traffic in a corresponding queue in the buffer 104 when traffic is input from the wireless LAN unit 101. FIG. 5 is an example of the queue configuration inside the buffer 104. In the example shown in FIG. 5, three queues are prepared in order to cope with three types of wired transmission rates. Further, the bridge unit 102 acquires traffic from the queue corresponding to the buffer 104 and transfers the traffic to the wired LAN unit 103 according to the transmission period corresponding to each transmission priority in the wired transmission period of the wired LAN unit 103.

  When the traffic is transferred from the bridge unit 102, the wired LAN unit 103 transmits the traffic to the wired link 12 using a wired transmission rate corresponding to the traffic transmission priority in the wired transmission cycle. FIG. 6 is an example of a wired transmission cycle used by the wired LAN unit 103. In the wired transmission cycle shown in FIG. 6, transmission periods of three types of transmission priority are set. The transmission periods of the three types of transmission priority correspond to the three types of wired transmission rates that can be used in the wired LAN unit. For example, if three types of wired transmission rates 10 Gbps, 1 Gbps, and 100 Mbps can be used in the wired LAN unit 103, 10 Gbps corresponds to a transmission priority 1, 1 Gbps corresponds to a transmission priority 2, and 100 Mbps corresponds to a transmission period of a transmission priority 3. ing. During the transmission period with transmission priority 1 in the wired transmission period (A to B in FIG. 6), the wired LAN unit 103 acquires traffic with transmission priority 1 from the bridge unit 102 and transmits it to the wired link 12. Similarly, the wired LAN unit 103 sets each transmission priority within the transmission period of transmission priority 2 (B to C in FIG. 6) and within the transmission period of transmission priority 3 (C to D in FIG. 6). The corresponding traffic is acquired from the bridge unit 102 and transmitted to the wired link 12.

  The wired LAN unit 103 determines the transmission priority of traffic in the buffer 104 acquired from the bridge unit 102 and the wired transmission rate used by the wired link 12 in order to determine the transmission period of each transmission priority in the wired transmission cycle. Use. For example, in the example illustrated in FIG. 3, the total traffic amount of the transmission priority 1 and the transmission priority 2 is 2 Mb and 0.822 Mb. Since the wired transmission rates are 10 Gbps and 1 Gbps, respectively, the transmission period of transmission priority 1 is set to 0.2 ms, and the transmission period of transmission priority 2 is set to 0.822 ms. Further, within the wired transmission cycle, the transmission period with the transmission priority 3 is set except for the transmission period with the transmission priority 1 and the transmission priority 2.

  The wired LAN unit 103 dynamically sets a wired transmission rate according to the transmission priority of the traffic output from the bridge unit 102 to save power. In addition, since the wired LAN unit 103 sets the wired transmission rate so that the traffic transmission time is within the wired transmission period (update period), an increase in the transmission time in the wired link 12 can be avoided. The wired LAN unit 103 switches the wired transmission rate to be used according to the transmission period of each transmission priority. The wired LAN unit 103 may use the IEEE 802.3 standard auto-negotiation function when switching the wired transmission rate with the switch 11, or the wired transmission rate may be agreed by other methods. If possible, that method may be used.

<3. Second relay method>
Next, a second relay method for transmitting traffic received from the wireless terminal stations 14 to 16 through the wired link 12 in the access point device 10 will be described below. In the second relay method, the wired transmission rate is determined in consideration of the power consumption of the wired LAN unit 103 in addition to the received traffic information.

  The wireless communication information storage unit 105 stores the wireless transmission rate and traffic amount of traffic received by the wireless LAN unit 101. FIG. 7 shows an example of the wireless communication information table TB2 stored in the wireless communication information storage unit 105. The wireless communication information table TB2 includes fields that describe the actual wireless communication time, the wireless transmission rate, and the traffic amount according to the connection IDs of the wireless terminal stations 14 to 16. Each time the wireless communication information storage unit 105 communicates with the wireless terminal stations 14 to 16, the wireless communication information storage unit 105 stores the wireless communication performance time, the wireless transmission rate, and the traffic amount, and updates each field. The wireless communication information storage unit 105 obtains the total amount of traffic received within a predetermined update period. For example, in the wireless communication information table TB2 shown in FIG. 7, the total traffic volume of the received traffic is 2.822 Mb. Based on the total traffic volume, the wired transmission rate is determined so as to satisfy the transmission time requirement in the wired link 12.

In the wired LAN unit 103, it is assumed that there are three types of wire transmission rates that can be used: 10 Gbps, 1 Gbps, and 100 Mbps. When the threshold β as a requirement for transmission time in the wired link 12 is set to 5 ms, the transmission time required to transmit 2.822 Mb of the total traffic amount at each wired transmission rate is 0.2822 ms, 2 .822 ms and 28.22 ms. There are only two types of wired transmission rates for which the required transmission time is equal to or less than the threshold value β, 10 Gbps and 1 Gbps.
The wireless communication information storage unit 105 transmits all traffic by substituting the value of power consumption at each wired transmission rate into the following formula (2) for the wired transmission rate at which the required transmission time is equal to or less than the threshold value β. determine the total power consumption for.

The power consumption of the wired LAN unit 103 varies depending on the medium of the wired link 12 even at the same wired transmission rate (see Non-Patent Document 4). For example, when the medium of the wired link 12 is a metal cable, the power consumption when transmitting at a wired transmission rate of 10 Gbps is 10 W, and the power consumption when transmitting at a wired transmission rate of 1 Gbps is 0.65 W. On the other hand, when the medium of the wired link 12 is an optical fiber, the power consumption when transmitting at a wired transmission rate of 10 Gbps is 2 W, and the power consumption when transmitting at a wired transmission rate of 1 Gbps is 1 W.
Therefore, if the medium of the wired link 12 is a metal cable, power consumption when transmitting all traffic (2.822Mb) using wired transmission rate 10Gbps is as Equation (3). Further, power consumption when transmitting all traffic (2.822Mb) using wired transmission rate 1Gbps is as Equation (4).

数式（３）〜数式（４）の計算結果から、有線リンク１２の媒体がメタルケーブルの場合には、１Ｇｂｐｓの有線伝送レートを選択する方が有線ＬＡＮ部１０３の消費電力量は小さい。他方、数式（５）〜数式（６）の計算結果から、有線リンク１２の媒体が光ファイバの場合には、１０Ｇｂｐｓの有線伝送レートを選択する方が有線ＬＡＮ部１０３の消費電力量は小さい。有線伝送レート決定部１０６は、有線リンク１２の媒体の種類に基づいて、トラフィックを送信する際の有線ＬＡＮ部１０３の消費電力を見込み、より省電力となる有線伝送レートを各トラフィックの有線伝送レートとして決定する。また、有線伝送レート決定部１０６は、決定した有線伝送レートをブリッジ部１０２に通知する。ブリッジ部１０２は、有線伝送レート決定部１０６から通知された有線伝送レートを有線ＬＡＮ部１０３に通知する。有線ＬＡＮ部１０３は、有線伝送周期において通知された有線伝送レートに切り替えて、バッファ１０４から取得したトラフィックを有線リンク１２に送信する。なお、トラフィックの転送が終了して次の有線伝送周期までのトラフィックの転送をしない期間には、有線ＬＡＮ部１０３は最も低い有線伝送レートに切り替えて、省電力化を図る。
On the other hand, if the medium of the wired link 12 of the optical fiber, the power consumption when transmitting all traffic (2.822Mb) using wired transmission rate 10Gbps is as Equation (5). Further, power consumption when transmitting all traffic (2.822Mb) using wired transmission rate 1Gbps is as equation (6).

From the calculation result of the formula (3) to Equation (4), when the medium wired link 12 of the metal cable is better to choose a wired transmission rate of 1Gbps is the power consumption of the wired LAN unit 103 is small. On the other hand, from the calculation result of the formula (5) to Equation (6), when the medium of the wired link 12 of the optical fiber is better to choose a wired transmission rate of 10Gbps is the power consumption of the wired LAN unit 103 is small. The wired transmission rate determination unit 106 expects the power consumption of the wired LAN unit 103 when transmitting traffic based on the medium type of the wired link 12, and sets the wired transmission rate that saves more power to the wired transmission rate of each traffic. Determine as. Further, the wired transmission rate determination unit 106 notifies the bridge unit 102 of the determined wired transmission rate. The bridge unit 102 notifies the wired LAN unit 103 of the wired transmission rate notified from the wired transmission rate determination unit 106. The wired LAN unit 103 switches to the wired transmission rate notified in the wired transmission cycle, and transmits the traffic acquired from the buffer 104 to the wired link 12. Note that, during the period when traffic transfer is completed and traffic is not transferred until the next wired transmission cycle, the wired LAN unit 103 switches to the lowest wired transmission rate to save power.

  According to the access point device 10 described above, it is possible to suppress an increase in traffic transmission time even when power consumption during relay communication is reduced. FIG. 8 is a diagram showing the effect of the present invention. In FIG. 8, RATE (1) and RATE (2) indicate values of wired transmission rates. RATE (1) has a larger value than RATE (2). Compared with FIG. 10 (c) showing the prior art, the wire transmission rate of traffic corresponding to the wire transmission rate of RATE (3) in FIG. 10 (c) is increased in FIG. Wired transmission rate. As a result, in FIG. 8, the transmission time of all traffic (traffic transmission period) is kept within a predetermined requirement, and the remaining time is set as a control signal transmission period. In FIG. 8, the present invention realizes a reduction in power consumption as compared with the case where a fixed wired transmission rate is used.

  Note that the wired transmission rate determination unit 106 may use a fixed value for the update period, or may dynamically change it according to the traffic situation. In the example of FIG. 3, three types of transmission priorities are determined for three types of wired transmission rates. However, the number of transmission priorities may be increased or decreased according to the number of available wire transmission rates. The threshold value α may be set according to the wired transmission cycle of the wired LAN unit 103. The wired transmission cycle and the threshold value α of the wired LAN unit 103 may be set to a fixed value or may be dynamically changed according to a request for transmission time in the wired link 12. In the example of FIG. 5, three queues are prepared to support three types of wired transmission rates. However, the bridge unit 102 may dynamically increase or decrease the number of queues according to the number of wired transmission rates to be used and traffic conditions.

  <3. In the second relay method> column, a common wired transmission rate is set as the wired transmission rate of each traffic. Similar to the first relay method> column, a different wired transmission rate may be set for each traffic. <2. When correcting the planned wired transmission rate of each traffic in the first relay method> column, <3. You may correct | amend based on actual power consumption like 2nd relay method> column.

  1 is recorded in a computer-readable recording medium, and the program recorded in the recording medium is read into a computer system and executed to perform relay communication processing. May be. The “computer system” here includes an OS (Operating System) and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible disk, a magneto-optical disk, a portable medium such as a ROM (Read Only Memory) and a CD-ROM, and a hard disk incorporated in a computer system. Say. Furthermore, “computer-readable recording medium” refers to a fixed volatile memory such as a volatile memory inside a computer system serving as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Including those holding time programs.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes a design that does not depart from the gist of the present invention. Needless to say, the above-described embodiment and a plurality of modifications can be combined within a range in which the contents do not conflict with each other. Further, in the above-described embodiments and modifications, the structure of each part has been specifically described, but the structure and the like can be changed in various ways within a range that satisfies the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Access point apparatus (relay communication apparatus), 11 ... Switch, 12 ... Wired link (wired communication path), 13 ... Wireless link (communication path), 14-16 ... Wireless terminal station, 101 ... Wireless LAN part (communication interface) , 102 ... Bridge unit, 103 ... Wired LAN unit (wired communication interface), 104 ... Buffer, 105 ... Wireless communication information storage unit (communication information storage unit), 106 ... Wired transmission rate determination unit (transmission rate determination unit)

Claims (6)

A relay communication device comprising two or more communication interfaces including a wired communication interface, and transmitting received traffic through the wired communication interface,
A buffer for storing traffic received within a predetermined update period;
A communication information storage unit that acquires the traffic volume and transmission rate of the received traffic and stores the traffic as communication information;
For each of the traffics, transmission when transmitting through the wired communication interface within a range in which the total transmission time of all traffic received within the update period is equal to or less than a predetermined threshold based on the communication information A relay communication apparatus comprising: a transmission rate determining unit that determines a rate. The transmission rate determination unit transmits, for each of the traffic, a minimum transmission rate larger than the transmission rate at the time of reception through the wired communication interface among a plurality of types of transmission rates selectable by the wired communication interface. The relay communication device according to claim 1, wherein the relay communication device is determined as a transmission rate for the transmission. The transmission rate determining unit is configured to all traffic received in the update period to calculate the power consumption when transmitting through the wired communication interface, so that the power consumption amount becomes smaller, each of the traffic On the other hand, the relay communication device according to claim 1, wherein a transmission rate at the time of transmission through the wired communication interface is determined.   4. The relay communication apparatus according to claim 1, wherein the transmission rate determining unit determines a transmission priority indicating a priority when transmitting the traffic through the wired communication interface. 5. . In a communication network in which two or more communication paths including a wired communication path are connected, a relay communication method for transmitting received traffic through the wired communication path,
A traffic storage stage for storing traffic received within a predetermined update period;
A communication information storage step of acquiring the traffic volume and transmission rate of the received traffic and storing it as communication information;
For each of the traffic, transmission when transmitting through the wired communication path within a range in which the total transmission time of all traffic received within the update period is equal to or less than a predetermined threshold based on the communication information A relay communication method comprising: a determination step of determining a rate; The relay communication program for functioning a computer as a relay communication apparatus of any one of Claims 1-4 .

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