JP2011193046A - Wireless communication device, and priority control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a wireless communication device for efficiently suppressing a band of low priority traffic. <P>SOLUTION: The wireless communication device includes a traffic monitoring unit 81 for acquiring traffic information from a data packet received from a transmission terminal, a priority class determination unit 82 for determining a priority of a response packet, a control parameter determination unit 83 for determining a control parameter, an ACK discrimination unit 84 for discriminating the response packet received from a reception terminal according to the priority, an ACK delay processing unit 85 for performing delay processing to a low priority response packet discriminated to a low priority class, a window size change unit 86 for changing a receivable window size of the low priority response packet after delay processing, and a band correction processing unit 87 for further performing rewrite correction processing of the receivable window size to the low priority response packet after receivable window size change processing. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus that performs priority control in accordance with traffic priority.

  As for the conventional Internet / intranet, the best effort type service is mainly used. In a communication system using the Internet / intranet, TCP (Transmission Control Protocol) is frequently used as a protocol. TCP is a protocol that realizes reliable and efficient communication, and has a confirmation response function in order to realize reliable communication.

  Also, with the advent of various network applications, in a communication system using a single wireless communication line and connected to a plurality of receiving terminals, priority control is performed for each receiving terminal according to the priority of the application set by the user. Is going. As a result, it is possible to secure high priority traffic and improve user convenience. For example, in a conventional communication system, high-priority traffic is controlled by controlling the transmission interval and window size of an acknowledgment (ACK) to be notified according to the total bandwidth of a plurality of TCP sessions using the characteristics of TCP. Secured.

  However, since the communication band of wireless communication changes according to time and environment, priority control according to the band and priority control according to the traffic are required. As a method for solving such a problem, in Patent Document 1 below, a bandwidth transfer device connected to a receiving terminal calculates a communication bandwidth from a traffic amount of a packet received by a wireless interface, and according to the bandwidth, Delay processing is performed for ACK of TCP packets received with low priority traffic, or bandwidth control is performed by changing the window size according to the bandwidth, and the traffic bandwidth that the user wants to prioritize by either processing The technique of ensuring is disclosed.

  Further, in Patent Document 2 below, in a communication system that performs data communication between a plurality of terminals via a network, the target bandwidth is determined by dividing the line bandwidth by the number of assumed communication sessions, and the ACK transmission timing is changed. Accordingly, a technique has been disclosed in which band control is performed to enable high-speed communication by minimizing transfer delay.

International Publication No. 2005/006673 JP 2008-219605 A

  However, according to the technique disclosed in Patent Document 1, the bandwidth control device does not perform control that predicts a change in bandwidth of wireless communication depending on time or environment. For this reason, there is a problem in that efficient tracking control cannot be performed at the time of bandwidth fluctuation, and low-priority traffic is excessively suppressed. In addition, when band suppression is performed, it is not confirmed whether all the bands that can be actually used are used. For this reason, there is a problem that low-priority traffic is excessively suppressed even though there is a vacant bandwidth.

  Further, according to the technique of Patent Document 2, if suppression control is performed in a band that is simply divided by the number of sessions, if the total number of sessions is large, the suppression rate of low-priority traffic must be increased. There was a problem that the bandwidth of the priority traffic could not be secured. Further, when the number of low-priority traffic sessions is larger than the number of high-priority traffic sessions, there is a problem that a high-priority traffic band cannot be secured unless the low-priority traffic suppression rate is increased.

  The present invention has been made in view of the above, and an object of the present invention is to provide a radio communication apparatus capable of efficiently suppressing the bandwidth of low-priority traffic while securing the bandwidth of high-priority traffic. .

  In order to solve the above-described problems and achieve the object, the present invention relays communication between a transmission terminal and a reception terminal, and performs priority control on a response packet transmitted from the reception terminal to the transmission terminal. A wireless communication apparatus that performs traffic monitoring when the data packet received from the transmitting terminal is relayed to the receiving terminal, and that analyzes the data packet and obtains traffic information; and the traffic of the data packet is If there are multiple priority levels for each traffic, the priority of response packets for high-priority traffic data packets is set to high priority, and the priority of response packets for low-priority traffic data packets is set to low priority. Based on the priority information determining means, the traffic information and the priority for each traffic. Control parameter determining means for determining a control parameter for controlling transmission of data, and discriminating response packets received from the receiving terminal based on the priority determined by the priority class determining means, and discriminating as high priority A delay means for the low priority response packet discriminated as a low priority by the discrimination means based on the control parameter and a discrimination means for transmitting the high priority response packet to the transmitting terminal, and determined Delay processing means for transmitting a low priority response packet delayed by a delay time, window size changing means for changing the receivable window size of the low priority response packet after delay processing based on the control parameter, and the control parameter And the low-priority response path after the receivable window size change process based on the traffic information. Band correction processing means for further performing rewrite correction processing of the receivable window size on the network and transmitting the low priority response packet after the rewrite correction processing to the transmitting terminal. .

  According to the present invention, there is an effect that it is possible to efficiently suppress the bandwidth of low-priority traffic while securing the bandwidth of high-priority traffic.

FIG. 1 is a diagram illustrating a configuration example of a wireless communication system. FIG. 2 is a diagram illustrating transition of priority control processing. FIG. 3 is a diagram illustrating transition of priority control processing. FIG. 4 is a diagram illustrating a configuration example of the priority control apparatus. FIG. 5 is a sequence diagram showing the priority control process. FIG. 6A is a diagram illustrating a suppression table based on the total number of sessions. FIG. 6B is a diagram illustrating a suppression table based on the number of high priority sessions. FIG. 6C is a diagram illustrating a suppression table based on the number of low priority sessions. FIG. 7 is a diagram illustrating a suppression table based on the number of TCP sessions. FIG. 8 is a flowchart showing the band correction process. FIG. 9 is a flowchart showing the band correction process. FIG. 10 is a flowchart showing the band correction process. FIG. 11 is a flowchart showing the band correction process.

  Embodiments of a wireless communication apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of a wireless communication system including a wireless communication apparatus according to the present embodiment. The wireless communication system includes a transmitting terminal 1, an IP (Internet Protocol) network (IP network) 2, a GATEWAY 3, a wireless system 4, a wireless network 5, a wireless communication device 6, and receiving terminals 10 and 11. Prepare. The wireless communication device 6 includes a wireless interface 7, a priority control device 8, and an interface 9. The transmission terminal 1 uses TCP as a communication protocol, and transmits a TCP data packet to the wireless system 4 via the IP network 2 and GATEWAY 3. The wireless system 4 transmits the arrived TCP data packet to the receiving terminals 10 and 11 via the wireless network 5 and the wireless communication device 6. The receiving terminals 10 and 11 that have received the TCP data packet transmit the TCP-ACK packet to the wireless system 4 via the priority control device 6 and the wireless network 5. The wireless system 4 transmits the received TCP-ACK packet to the transmission terminal 1 via the GATEWAY 3 and the IP network 2.

  The wireless communication device 6 is a device that relays communication between the transmission terminal 1 and the reception terminals 10 and 11. The wireless interface 7 communicates with the transmission terminal 1 side, and the interface 9 communicates with the reception terminals 10 and 11 side. Communicate. Further, the priority control apparatus 8 performs priority control on the TCP-ACK packet transmitted from the receiving terminals 10 and 11 to the transmitting terminal 1. The interface 9 may be wired or wireless.

  Here, as an example, one transmission terminal 1 is used, but a plurality of transmission terminals 1 may exist. Moreover, although two receiving terminals 10 and 11 are provided, three or more receiving terminals may exist. In such a wireless communication system, a data packet is transmitted using a wireless network. However, the wireless network has a higher transmission loss rate than a wired network, frequent band fluctuations, and low transmission quality. Also, TCP works to limit the bandwidth of traffic that detects packet loss without distinguishing priority.

  Next, general priority control for a TCP-ACK packet in the wireless communication system shown in FIG. 1 will be described. FIG. 2 is a diagram illustrating transition of priority control processing. The wireless system 4 transmits a TCP data packet to the receiving terminals 10 and 11. In the priority control device 8 of the wireless communication device 6, the receiving terminal 10 can be given low priority and the receiving terminal 11 can be given high priority by the user setting or default setting. Here, in the priority control apparatus 8, there is a possibility that the high priority traffic is a packet loss or the like or a throughput that does not meet the user's intention (FIG. 2A). In such a case, the priority control device 8 can secure traffic to the receiving terminal 11 by reducing the low-priority bandwidth (changing the window size or performing ACK delay). However, in the priority control apparatus 8, if the bandwidth of the low priority traffic is reduced too much, the low priority traffic cannot be communicated and the user use may be affected (FIG. 2 (b)). In the present embodiment, the priority control device 8 can increase the bandwidth of the low-priority traffic that has been excessively reduced by performing bandwidth correction processing (FIG. 2C).

  Next, priority control different from FIG. 2 will be described. FIG. 3 is a diagram illustrating transition of priority control processing. As in FIG. 2, in the priority control device 8, there is a possibility that high priority traffic is a packet loss or the like or a throughput that does not conform to the user's intention (FIG. 3A). In such a case, the priority control device 8 can secure traffic to the receiving terminal 11 by reducing the low-priority bandwidth (changing the window size or performing ACK delay). However, in the priority control apparatus 8, due to insufficient reduction of the low-priority traffic band, the high-priority traffic band may be insufficient, which may affect user use (FIG. 3B). In the present embodiment, the priority control device 8 can further reduce the bandwidth of low-priority traffic that has been insufficiently reduced by performing processing for correcting the bandwidth (FIG. 3 (c)).

  Next, the configuration of the priority control device 8 will be described. FIG. 4 is a diagram illustrating a configuration example of the priority control device 8. The priority control device 8 includes a traffic monitoring unit 81, a priority class determining unit 82, a control parameter determining unit 83, an ACK discriminating unit 84, an ACK delay processing unit 85, a window size changing unit 86, and a band correction processing unit. 87.

  The traffic monitoring unit 81 analyzes the received TCP data packet. The priority class determination unit 82 determines high priority / low priority traffic according to a user instruction. That is, the priority of the TCP ACK packet corresponding to the TCP data packet is determined. The control parameter determination unit 83 determines a control parameter to be used for delay processing for a TCP-ACK packet with low priority. The ACK discriminating unit 84 discriminates TCP-ACK packets with high priority / low priority. The ACK delay processing unit 85 performs a delay process on the TCP-ACK packet that has been given low priority based on the control parameter. When there are a plurality of classes with low priority, it is assumed that the ACK delay processing unit 85 includes buffers as many as the number of classes. The window size changing unit 86 changes the window size based on the control parameter. The band correction processing unit 87 performs correction processing on the window size changed by the window size changing unit 86 based on the control parameter and the analysis result of the TCP data packet.

  In the priority control device 8, the TCP-ACK packet (hereinafter referred to as a high priority ACK packet) discriminated to the high priority class by the ACK discriminating unit 84 is transmitted to the radio interface 7 as it is, and the ACK discriminating unit 84 performs the low priority. A TCP-ACK packet (hereinafter referred to as a low-priority ACK packet) discriminated by class is transmitted to the wireless interface 7 after being delayed.

  Next, the priority control process of the priority control device 8 will be described. FIG. 5 is a sequence diagram showing the priority control process. First, the traffic monitoring unit 81 analyzes a TCP data packet received from the transmitting terminal 1 side (wireless interface 6), and acquires information on a reception rate, an RTT (Round Trip Time), and the number of TCP sessions. Then, the traffic monitoring unit 81 notifies the acquired information to the control parameter determination unit 83 (step S1). Further, the traffic monitoring unit 81 transmits the received TCP data packet to the interface 9 toward the receiving terminals 10 and 11. It is possible to obtain the amount of received traffic from the acquired reception rate.

  Next, the priority class determination unit 82 determines the correspondence between the priority class and traffic according to the default setting or the user's instruction, and notifies the determined priority class to the control parameter determination unit 83 and the ACK discrimination unit 84 (step S2). ). Here, each traffic is set to either high priority or low priority, TCP-ACK packets for high priority TCP data packets are set to high priority, and TCP-ACKs for low priority traffic TCP data packets are set. Decide to prioritize packets. In addition, although it is set as two classes of a high priority and a low priority, it is good also as three or more. Further, a plurality of priority classes may be provided in each of high priority and low priority. For example, according to a user instruction, a priority higher than a predetermined priority class is set as a high priority, and a priority lower than the predetermined priority class is set as a low priority.

  Further, the priority class determination unit 82 can determine whether or not priority control is performed. That is, it is possible to set whether to perform priority control for each configuration of the ACK delay processing unit 85, the window size changing unit 86, and the band correction processing unit 87. If set, the control parameter determination unit 83 is notified of this. Here, the determination and notification are performed after the reception of the TCP data packet, but may be performed before the reception of the TCP data packet.

  Next, the control parameter determination unit 83 determines the low rate based on the reception rate / RTT / TCP session number obtained from the traffic monitoring unit 81, the priority class obtained from the priority class determination unit 82, traffic correspondence, and whether or not priority control is performed. The control parameter used in the delay process for the priority ACK packet is determined, and the control parameter is notified to the ACK delay processing unit 85, the window size changing unit 86, and the band correction processing unit 87 (step S3).

  The ACK discriminating unit 84 discriminates the TCP-ACK packet received from the interface 9 into each priority class based on the priority class and traffic correspondence notification obtained from the priority class determining unit 82 (step S4). At this time, the ACK discriminating unit 84 transmits the packet (high priority ACK packet) discriminated to the high priority class to the radio interface 7 and the ACK delay for the packet discriminated to the low priority class (low priority ACK packet). Transfer to the processing unit 85.

  The ACK delay processing unit 85 determines a transmission delay time based on the control parameter for the low priority ACK packet discriminated into the low priority class, and performs a process of intentionally delaying the transmission (step S5). . Then, the ACK delay processing unit 85 delivers the delayed low priority ACK packet to the window size changing unit 86.

  The window size changing unit 86 analyzes the low priority ACK packet delayed by the ACK delay processing unit 85, and performs a process of changing the receivable window size in the low priority ACK packet based on the control parameter (step S6). Then, the window size changing unit 86 delivers the changed low priority ACK packet to the band correction processing unit 87.

  The bandwidth correction processing unit 87 includes the number of high-priority traffic TCP sessions and the low-priority traffic among the information acquired by the control parameter and the traffic monitoring unit 81 for the window size changed at a certain rate by the window size changing unit 86. The window size correction process is performed using the number of TCP sessions (step S7). Here, as the number of TCP sessions of high priority traffic and low priority traffic increases, the bandwidth of the priority traffic cannot be secured unless the low priority traffic is further suppressed. Further, when the number of TCP sessions for low priority traffic is larger than the number of TCP sessions for high priority traffic, there is a possibility that the bandwidth for high priority traffic cannot be secured unless the low priority traffic is further suppressed.

  Therefore, the bandwidth correction processing unit 87 has a suppression table as shown in FIGS. 6-1 to 6-3, and the low priority ACK is determined in the low priority traffic depending on the number of TCP sessions of the total / high priority / low priority traffic. A process for further correcting the window size of the packet is performed.

  FIG. 6A is a diagram illustrating a suppression table based on the total number of TCP sessions. When determining based on the number of TCP sessions of the total traffic, the bandwidth correction processing unit 87 sets threshold values A and B in advance, and determines whether or not to perform window size correction processing based on the result of comparison with the threshold values. For example, when the number of TCP sessions of the total traffic is A or less, it is determined that there is a sufficient bandwidth, and correction processing for increasing the low-priority traffic, that is, increasing the window size of the low-priority ACK packet is performed. If the number is greater than A and less than or equal to B, it is determined that there is no room in the bandwidth, and no change process is performed. If the number is more than B, it is determined that the bandwidth is insufficient, and correction processing is performed to reduce low-priority traffic, that is, to reduce the window size of the low-priority ACK packet.

  FIG. 6B is a diagram illustrating a suppression table based on the number of high priority TCP sessions. Similarly, when determining based on the number of high-priority traffic TCP sessions, the bandwidth correction processing unit 87 sets thresholds A1 and B1 in advance, and determines whether or not to perform window size correction processing based on the result of comparison with the thresholds. decide. For example, when the number of TCP sessions for high priority traffic is A1 or less, it is determined that there is a sufficient bandwidth, and correction processing for increasing the low priority traffic, that is, increasing the window size of the low priority ACK packet is performed. Further, when the number is more than A1 and less than or equal to B1, it is determined that there is no room in the band, and no change process is performed. If the number is greater than B1, it is determined that the bandwidth is insufficient, and correction processing is performed to reduce low-priority traffic, that is, to reduce the window size of the low-priority ACK packet.

  FIG. 6C is a diagram illustrating a suppression table based on the number of low-priority TCP sessions. Similarly, when determining based on the number of low-priority traffic TCP sessions, the bandwidth correction processing unit 87 sets thresholds A2 and B2 in advance, and determines whether to perform window size correction processing based on the result of comparison with the thresholds. decide. For example, when the number of TCP sessions of low priority traffic is A2 or less, it is determined that there is no room in bandwidth, and no change process is performed. If more than A2, it is determined that the bandwidth is insufficient, and correction processing is performed to reduce low-priority traffic, that is, to reduce the window size of low-priority ACK packets.

  Thereafter, the band correction processing unit 87 transmits the low-priority ACK packet after the correction process to the wireless interface 7.

  The priority control device 8 selects whether or not the ACK delay processing unit 85, the window size changing unit 86, and the band correction processing unit 87 are to be controlled based on the control presence / absence information from the priority class determination unit 82 set by the user. By making it possible, it is possible to respect the user's intention. Further, the tables of FIGS. 6-1 to 6-3 shown in the present embodiment are merely examples, and the thresholds and operations such as A and B in the table may be changeable according to user settings.

  As described above, in the present embodiment, in the priority control device 8, the band correction processing unit 87 performs correction processing on the low priority ACK packet that has been subjected to delay processing and window size change processing by priority control, The window size is adjusted according to the number of TCP sessions. That is, when the number of TCP sessions changes, the low-priority traffic band (because the bandwidth is determined by the window size / RTT) can be adjusted by rewriting the window size of the low-priority ACK packet of the low-priority traffic. Thereby, it is possible to appropriately suppress low-priority traffic according to the number of TCP sessions while securing a high-priority traffic band. Moreover, since the traffic of each priority is appropriately suppressed, the convenience for the user can be improved.

  In the present embodiment, two cases of high priority and low priority have been described. However, the present invention is not limited to this, and three or more priority classes can be used. In the case of using three or more, the priority control apparatus 8 sets each of the ACK delay processing unit 85, the window size changing unit 86, and the band correction processing unit 87 as one, and the ACK delay processing unit 85 responds to the number of priorities. In the priority control device 8, a plurality of ACK delay processing units 85, window size changing units 86, and band correction processing units 87 are provided according to the number of priorities. Also good.

Embodiment 2. FIG.
In the first embodiment, the bandwidth correction processing unit 87 determines the execution of the correction process based on the three suppression tables of the total number of TCP sessions, the number of high priority TCP sessions, and the number of low priority TCP sessions as the number of traffic TCP sessions. Was. In the present embodiment, the execution of the correction process is determined based on one suppression table. A different part from Embodiment 1 is demonstrated.

  The configuration of the priority control device 8 and the processing of the window size changing unit 86 in step S6 in the priority control processing sequence diagram of FIG. 5 are the same as those in the first embodiment. Next, the bandwidth correction processing unit 87 uses the control parameter and the number of TCP sessions of high-priority traffic among the information acquired by the traffic monitoring unit 81 for the window size changed by the window size changing unit 86 at a certain rate, A window size correction process is performed using the number of TCP sessions with low priority traffic (step S7). At this time, in the present embodiment, the bandwidth correction processing unit 87 has a table as shown in FIG. 7, and corrects low priority traffic according to the number of TCP sessions of total / high priority / low priority traffic. Then, a process of further correcting the window size of the low priority ACK packet is performed. FIG. 7 is a diagram illustrating a suppression table based on the number of traffic TCP sessions.

  Specifically, the bandwidth correction processing unit 87 sets a threshold value A3 in advance for the total number of TCP sessions for traffic, and the result of comparison with the threshold value, the number of TCP sessions for high priority traffic, and the number of TCP sessions for low priority traffic. Based on the comparison result, it is determined whether or not to change the low-priority traffic, that is, to perform the window size correction process for the low-priority ACK packet. For example, (1) if the total number of TCP sessions is less than A3 and the number of high-priority traffic TCP sessions is less than the number of low-priority traffic TCP sessions, the bandwidth correction processing unit 87 determines that the bandwidth is insufficient. Then, a correction process is performed to reduce the low priority traffic, that is, to reduce the window size of the low priority ACK packet.

  (2) When the total traffic TCP sessions is less than A3 and the number of high priority traffic TCP sessions is greater than the number of low priority traffic TCP sessions, the bandwidth correction processing unit 87 has a margin in bandwidth. It is determined that there is, and correction processing for increasing the low-priority traffic, that is, increasing the window size of the low-priority ACK packet is performed.

  (3) If the total traffic TCP sessions is greater than A3 and the number of high-priority traffic TCP sessions is less than the number of low-priority traffic TCP sessions, the bandwidth correction processing unit 87 determines that the bandwidth is insufficient. Then, a correction process is performed to reduce the low priority traffic, that is, to reduce the window size of the low priority ACK packet.

  (4) When the total traffic TCP sessions is greater than A3 and the number of high priority traffic TCP sessions is greater than the number of low priority traffic TCP sessions, the bandwidth correction processing unit 87 has a margin in bandwidth. It is determined that there is no change and no change process is performed.

  As in the first embodiment, the table in FIG. 7 is an example, and the threshold value A3 and each operation in the table may be changeable according to user settings.

  As described above, in the present embodiment, the band correction processing unit 87 uses a single suppression table used for determination when performing correction processing. Even in this case, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
In the present embodiment, the bandwidth correction processing unit 87 performs bandwidth correction processing based on a comparison between the number of high priority TCP sessions and the number of low priority TCP sessions. A different part from Embodiment 1 is demonstrated.

  Except for the processing of the band correction processing unit 87, it is the same as the first embodiment. FIG. 8 is a flowchart showing the band correction process of the present embodiment. First, the bandwidth correction processing unit 87 compares the number of high-priority TCP sessions and the number of low-priority TCP sessions in the information acquired by the traffic monitoring unit 81 (step S11). When the number of high-priority TCP sessions is equal to or less than the number of low-priority TCP sessions (step S11: No), the bandwidth correction processing unit 87 needs to suppress, so the window size of the low-priority ACK packet is multiplied by a constant B of 1 or less. Then, a correction process for reducing the window size is performed (step S12).

  On the other hand, when the number of high priority TCP sessions is greater than the number of low priority TCP sessions (step S11: Yes), the bandwidth correction processing unit 87 further multiplies the number of low priority TCP sessions by a constant A and the number of high priority TCP sessions. Are compared (step S13). If the number of high-priority TCP sessions is large (step S13: Yes), the bandwidth correction processing unit 87 corrects the suppression by multiplying the window size of the low-priority ACK packet by a constant C equal to or greater than 1 to increase the window size. Processing is performed (step S14).

  When the number of high-priority TCP sessions is small (step S13: No), the bandwidth correction processing unit 87 ends without performing correction processing for rewriting the window size of the low-priority ACK packet.

  In this way, the bandwidth correction processing unit 87 compares the current number of high-priority TCP sessions with the number of low-priority TCP sessions, and grasps the state of high-priority traffic and low-priority traffic to determine whether or not bandwidth suppression is necessary. Or determine if it can be mitigated.

  As described above, in this embodiment, the bandwidth correction processing unit 87 compares the number of high-priority TCP sessions with the number of low-priority TCP sessions, and based on the comparison result, the low-priority traffic low-priority ACK packet. Correction processing for changing the window size was performed. Even in this case, the same effect as in the first embodiment can be obtained.

Embodiment 4 FIG.
In the present embodiment, a case will be described in which a change in a wireless communication band is detected in advance and band correction processing is performed in advance. A different part from Embodiment 1 is demonstrated.

  Except for the processing of the band correction processing unit 87, it is the same as the first embodiment. FIG. 9 is a flowchart showing the band correction processing according to the present embodiment. First, the band correction processing unit 87 uses the received traffic amount based on the reception rate among the information acquired by the traffic monitoring unit 81, and uses the latest received traffic amount T (a) and the received traffic amount T a predetermined time ago. A value obtained by multiplying (b) by a constant X is compared (step S21). As a result of the comparison, if T (a) is larger (step S21: Yes), the band correction processing unit 87 assumes that the band is in an increasing direction and widens the low-priority band in advance so as to alleviate the suppression. Then, correction processing is performed to make the window size of the low priority ACK packet C times (C is a constant of 1 or more) (step S22). On the other hand, if T (a) is equal to or smaller than T (b) × X as a result of comparison (step S21: No), the band correction processing unit 87 ends without performing correction processing for rewriting the window size of the low priority ACK packet. To do.

  As described above, in the present embodiment, the band correction processing unit 87 compares the current received traffic with a certain time ago and predicts that the band will increase in advance. In order to mitigate the suppression by widening, the correction processing for increasing the window size of the low-priority ACK packet is performed. Thereby, since throughput increases, reduction in suppression can be reduced, efficient communication can be realized, and user convenience can be improved.

  In the present embodiment, the constant C is used as an example. However, the present invention is not limited to this, and it is expected that C is variable according to the value of the received traffic amount T (a). The window size amount to be changed according to the bandwidth amount may be variable.

Embodiment 5 FIG.
In this embodiment, a case will be described in which past data is used to detect a change in a wireless communication band in advance and perform a band correction process in advance. A different part from Embodiment 4 is demonstrated.

  Except for the processing of the band correction processing unit 87, it is the same as the first embodiment. FIG. 10 is a flowchart showing the band correction processing of the present embodiment. First, the band correction processing unit 87 accumulates received traffic volume data among the information acquired by the traffic monitoring unit 81, and reads past received traffic data (step S31). Since there is no data to be read during past data accumulation, correction control is not performed.

  Next, the band correction processing unit 87 uses the latest received traffic volume T (a), the transition of the received traffic volume T (b) for a predetermined time, and the past received traffic volume data read in step S31. A comparison is made to see if there is a match (step S32). If there is matching data and the amount of received traffic after a predetermined time of data corresponding to the received traffic amount T (a) has increased in the past data (step S32: Yes), the band correction processing unit 87. Then, assuming that the band is increasing, correction processing is performed to increase the window size of the low-priority ACK packet by C times (C is a constant equal to or greater than 1) so that the low-priority band is expanded in advance and the suppression is eased ( Step S33). On the other hand, when the received traffic after a predetermined time of data corresponding to the received traffic T (a) has not increased in the past data (step S32: No), the band correction processing unit 87 is not in the direction of increasing the band. As described above, the correction process for rewriting the window size of the low priority ACK packet is not performed. Thereafter, the band correction processing unit 87 accumulates the latest received traffic volume T (a) and the received traffic volume T (b) for a predetermined time as past data (step S34).

  As described above, in the present embodiment, the band correction processing unit 87 compares the received traffic volume data accumulated in the past with the current received traffic volume data, and predicts that the band is likely to increase. In this case, correction processing for increasing the window size of the low-priority ACK packet is performed in advance so as to alleviate the suppression by widening the bandwidth of the low-priority traffic. Even in this case, the same effect as in the fourth embodiment can be obtained.

  As in the fourth embodiment, the constant C is used as an example. However, the present invention is not limited to this, and it is expected that C can be changed according to the value of the received traffic amount T (a). The window size amount to be changed according to the bandwidth amount may be variable.

Embodiment 6 FIG.
In the present embodiment, a case will be described in which a bandwidth correction process is performed by predicting a free bandwidth. A different part from Embodiment 4 is demonstrated.

  When performing the band correction process, the band correction processing unit 87 is predicted to suppress the low-priority traffic too much even though there is a vacant band. In order to avoid such a situation, the band correction processing unit 87 calculates empty traffic and relaxes priority control. In general, when there is no change in the RTT, there is a possibility that communication can be used stably, and there is a possibility that there is a vacant traffic band. In this embodiment, this principle is used, and an effect of appropriately suppressing low-priority traffic while securing high-priority traffic by performing predictive control is obtained.

  Note that the RTT used here is high-priority traffic data that is not subjected to suppression control. This is because in the case of low priority traffic, there is a possibility that the RTT has changed as a result of performing the traffic control.

  Except for the processing of the band correction processing unit 87, it is the same as the first embodiment. FIG. 11 is a flowchart showing the band correction process of the present embodiment. First, the band correction processing unit 87 compares the latest RTT: R0 with the RTTs R1, R2 of a predetermined time before using the RTT among the information acquired by the traffic monitoring unit 81 (step S41). As a result of the comparison, if it is determined that there is no change because it is within a certain range (step S41: Yes), the bandwidth correction processing unit 87 determines that there is a free bandwidth and increases the free bandwidth V, that is, the window of the low priority ACK packet Correction processing for increasing the size by a certain factor is performed (step S42). Thereafter, the band correction processing unit 87 waits for a certain period of time until a stable operation is performed (step S43).

  Next, the band correction processing unit 87 compares the latest RTT: Ra with the RTT: Rb of a certain time before being within a certain range, and compares the latest RTT: Ra with the RTT: R0 and keeps constant. It is confirmed whether it is within the range (step S44). If both conditions are within a certain range (step S44: Yes), the band correction processing unit 87 determines that the free band prediction has been performed correctly, and does not perform any particular processing. On the other hand, if it is not within a certain range under any of the conditions (step S44: No), the band correction processing unit 87 determines that there is a predicted free band, assuming that a change has occurred in the RTT, and performed in step S42. Correction processing is performed to reduce the free bandwidth V, that is, to reduce the window size of the low-priority ACK packet by a certain factor (step S45).

  Returning to step S41, if it is determined that there is a change that is not within a certain range as a result of the comparison (step S41: No), the band correction processing unit 87 determines that there is no free band, and reduces the free band V. After that, correction processing is performed to reduce the window size of the low priority ACK packet by a certain factor (step S46). Thereafter, the band correction processing unit 87 waits for a certain period of time until a stable operation is performed (step S47).

  In the band correction processing unit 87, an upper limit value is set in advance for the vacant band V so as not to set a certain upper limit. The lower limit is 0.

  As described above, in the present embodiment, the bandwidth correction processing unit 87 uses the RTT to predict whether or not new traffic can be added to the current bandwidth at regular intervals, and the free bandwidth is determined. When it is determined that the packet exists, a correction process for increasing the window size of the low-priority ACK packet is performed so as to relax the suppression by widening the bandwidth of the low-priority traffic. Thereby, since throughput increases, reduction in suppression can be reduced, efficient communication can be realized, and user convenience can be improved.

  In this embodiment, the constant V is used as an example. However, the present invention is not limited to this, and the available bandwidth can be changed by making V variable according to the amount of traffic received from the control parameter determining unit 83. The window size amount to be changed according to the amount may be variable.

  As described above, the wireless communication apparatus according to the present invention is useful for an apparatus that relays communication between a wireless network and a receiving terminal, and is particularly suitable for performing priority control.

1 Sending terminal 2 IP network (IP network)
3 GATEWAY
4 wireless system 5 wireless network 6 wireless communication device 7 wireless interface 8 priority control device 9 interface 10, 11 receiving terminal 81 traffic monitoring unit 82 priority class determining unit 83 control parameter determining unit 84 ACK discriminating unit 85 ACK delay processing unit 86 window size Change unit 87 Bandwidth correction processing unit

Claims (18)

A wireless communication device that relays communication between a transmission terminal and a reception terminal and performs priority control on a response packet transmitted from the reception terminal to the transmission terminal,
Traffic monitoring means for analyzing the data packet and obtaining traffic information when relaying the data packet received from the transmitting terminal to the receiving terminal;
When there are a plurality of traffics of the data packet and the priority is specified for each traffic, the priority of the response packet to the data packet of high priority traffic is set to high priority, and the response packet to the data packet of low priority traffic is set. A priority class determining means for lowering the priority;
Control parameter determining means for determining a control parameter for controlling transmission of a low priority response packet based on the traffic information and the priority for each traffic;
Discriminating response packets received from the receiving terminal based on the priority determined by the priority class determining means, and discriminating means for transmitting the high priority response packet discriminated as high priority to the transmitting terminal;
Delay processing means for determining a delay time for the low priority response packet discriminated as low priority by the discrimination means based on the control parameter, and transmitting a low priority response packet delayed by the determined delay time;
Window size changing means for changing the receivable window size of the low-priority response packet after delay processing based on the control parameter;
Based on the control parameter and the traffic information, a rewrite correction process of the receivable window size is further performed on the low priority response packet after the receivable window size change process, and the low priority response packet after the rewrite correction process is Band correction processing means for transmitting to the transmitting terminal;
A wireless communication apparatus comprising: The traffic information is the number of sessions.
The wireless communication apparatus according to claim 1. The bandwidth correction processing means compares the current total number of sessions of all traffic with the threshold of the total number of sessions, or the number of traffic sessions for each current priority and the number of sessions set for each priority. The threshold value is compared with the corresponding priority unit, and the content of the rewrite correction process is determined based on one of the comparison results.
The wireless communication apparatus according to claim 2. The bandwidth correction processing means compares the current total number of sessions of all traffic with a threshold value of the total number of sessions, compares the number of high priority traffic sessions with the number of low priority traffic sessions, and compares them. Determine the content of the rewrite correction process based on the result,
The wireless communication apparatus according to claim 2. The bandwidth correction processing unit compares the number of high-priority traffic sessions with the number of low-priority traffic sessions and reduces the receivable window size of the low-priority response packet when the number of low-priority traffic sessions is larger. Make corrections,
If the number of high-priority traffic sessions is greater and the number of high-priority traffic sessions is greater than the value obtained by multiplying the number of low-priority traffic sessions by a constant A (A is a constant greater than 1), the number of sessions is low. Perform a correction process to increase the receivable window size of the priority response packet,
In other cases, the receivable window size of the low priority response packet is maintained.
The wireless communication apparatus according to claim 2. The traffic information is used as a received traffic amount,
The band correction processing means compares the current received traffic amount with a value obtained by multiplying the received traffic amount before a predetermined time by a constant B (B is a constant larger than 1), and the current received traffic amount is greater. When it is large, a correction process is performed to increase the receivable window size of the low priority response packet.
The wireless communication apparatus according to claim 1. When the traffic information is the received traffic volume and the data of the past received traffic volume is accumulated,
The band correction processing means reads data accumulated in a transition equivalent to the transition to the current received traffic volume from the past received traffic volume data, and more than an equivalent portion of the read received traffic volume data. When the data of the received traffic volume later tends to increase, a correction process is performed to increase the receivable window size of the low priority response packet.
The wireless communication apparatus according to claim 1. The traffic information is RTT,
The band correction processing means confirms a change from the RTT value before a predetermined time to the current RTT value, and increases the receivable window size of the low priority response packet when the change is within a predetermined range. Perform correction processing,
The wireless communication apparatus according to claim 1. The delay processing by the delay processing means, the receivable window size change processing by the window size changing means, and the rewrite correction processing of the receivable window size by the band correction processing means are executed by an external instruction.
The wireless communication device according to claim 1, wherein the wireless communication device is a wireless communication device. A wireless communication device that relays communication between a transmission terminal and a reception terminal is a priority control method when performing priority control on a response packet transmitted from the reception terminal to the transmission terminal,
A traffic monitoring step of analyzing the data packet and obtaining traffic information when relaying the data packet received from the transmitting terminal to the receiving terminal;
When there are a plurality of traffics of the data packet and the priority is specified for each traffic, the priority of the response packet to the data packet of high priority traffic is set to high priority, and the response packet to the data packet of low priority traffic is set. A priority class determining step in which priority is set to low priority;
A control parameter determining step for determining a control parameter for controlling transmission of a low priority response packet based on the traffic information and the priority for each traffic;
Based on the priority determined in the priority class determination step, a discrimination step for discriminating the response packet received from the receiving terminal according to the priority,
A high-priority response packet transmitting step for transmitting the high-priority response packet discriminated as high-priority in the discrimination step to the transmitting terminal;
A delay processing step of determining a delay time for the low priority response packet discriminated as low priority in the discrimination step based on the control parameter, and transmitting a low priority response packet delayed by the determined delay time; ,
A window size changing step for changing a receivable window size of the low-priority response packet after delay processing based on the control parameter;
Based on the control parameter and the traffic information, a correction processing step for performing a rewrite correction process of the receivable window size for the low priority response packet after the receivable window size change process,
A low-priority response packet transmission step for transmitting the low-priority response packet after the rewrite correction processing in the correction processing step to the transmitting terminal;
The priority control method characterized by including. The traffic information is the number of sessions.
The priority control method according to claim 10. In the correction processing step, the total number of sessions for all current traffic is compared with the threshold for the total number of sessions, or the number of traffic sessions for each current priority and the threshold for the number of sessions set for each priority. Are compared with the corresponding priority unit, and the content of the rewrite correction processing is determined based on one of the comparison results.
The priority control method according to claim 11. In the correction processing step, the current total number of sessions of all traffic is compared with the threshold of the total number of sessions, the number of high priority traffic sessions is compared with the number of low priority traffic sessions, and the comparison results Determine the content of the rewrite correction process based on
The priority control method according to claim 11. In the correction processing step, the number of high-priority traffic sessions and the number of low-priority traffic sessions are compared, and when the number of low-priority traffic sessions is larger, the correction that reduces the receivable window size of the low-priority response packet Process,
If the number of high-priority traffic sessions is greater and the number of high-priority traffic sessions is greater than the value obtained by multiplying the number of low-priority traffic sessions by a constant A (A is a constant greater than 1), the number of sessions is low. Perform a correction process to increase the receivable window size of the priority response packet,
In other cases, the receivable window size of the low priority response packet is maintained.
The priority control method according to claim 11. The traffic information is used as a received traffic amount,
In the correction processing step, the current received traffic amount is compared with a value obtained by multiplying the received traffic amount before a predetermined time by a constant B (B is a constant larger than 1), and the current received traffic amount is larger. In this case, a correction process is performed to increase the receivable window size of the low priority response packet.
The priority control method according to claim 10. When the traffic information is the received traffic volume and the data of the past received traffic volume is accumulated,
In the correction processing step, data accumulated with a transition equivalent to the current reception traffic amount is read from the past reception traffic amount data, and is later than the equivalent portion of the read reception traffic amount data. When the data of the received traffic volume is on an increasing trend, a correction process is performed to increase the receivable window size of the low priority response packet.
The priority control method according to claim 10. The traffic information is RTT,
In the correction processing step, a change from the RTT value before a predetermined time to the current RTT value is confirmed, and when the change is within a predetermined range, the receivable window size of the low priority response packet is increased. Perform correction processing,
The priority control method according to claim 10. The delay process in the delay process step, the receivable window size change process in the window size change step, and the rewrite correction process of the receivable window size in the correction process step are executed according to an instruction from the outside.
The priority control method according to any one of claims 10 to 17, characterized in that:

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