Information communication apparatus and information communication method

Abstract

To provide an information communication device and an information communication method that can appropriately adjust packet transfer speed in a shared section of communication flows of communication between a plurality of transmitting terminals and a plurality of receiving terminals.SOLUTION: A rated delay is stipulated as a delay upper limit reference of a communication flow F2 transferred with the highest priority among communication flows F1 and F2 for which a relay device 107 uses a link-sharing section 108. A measuring unit 115 measures a communication delay by communicating a measurement packet in the link-sharing section 108. Based on a comparison result between the rated delay and the communication delay in the link-sharing section 108, and priority of the communication flows F1 and F2, a limiting unit 122 limits transfer speed of packets other than the measurement packet in the link-sharing section 108 of the communication flows F1 and F2.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an information communication apparatus and an information communication method.

Background Art

[0002] For example, Patent Document 1 discloses a technique for a transmitting terminal to transmit data to a receiving terminal in real time. This document calculates a plurality of setting conditions for determining the bit rate of transmission data to be output from the transmitting terminal and the number of packets transmitted per unit time according to an index value indicating the data transmission state of the network, and evaluates the influence of each of the plurality of calculated setting conditions on the quality of the transmission data and the amount of data delay in the network, and performs transmission rate control according to the optimal setting conditions.

[0003] Non-Patent Document 1 also discloses a technique for monitoring an increase in delay and a saturation state of a communication bandwidth, and adjusting the input traffic per unit time so as to operate at an optimum operating point where the saturation of the bandwidth starts. The load on the network is periodically varied to update the round-trip time (RTT) and the estimated value of the bandwidth. At this time, the upper limit of the load is set as gain, and the aggressiveness of the control is adjusted by this gain.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the technology described in Patent Document 1, since the transmission rate is adjusted by an application executed by a transmission terminal, when a congestion state occurs in a part of the network due to the influence of a buffer blowout or the like caused by the communication load from nodes other than the transmission node, the delay cannot be suppressed.

[0007] An object of the present disclosure is to provide an information communication apparatus and an information communication method capable of appropriately adjusting the transfer speed of packets in a shared section of a communication flow that communicates between a plurality of transmission terminals and a plurality of reception terminals.

Means for Solving the Problems

[0008] According to the invention described in claim 1, a communication node communicates a link shared section shared by communication flows of packets that communicate between a plurality of transmission terminals and a plurality of reception terminals, and a rated delay is defined in the link shared section as a delay upper limit standard of the communication flow that is transferred with the highest priority among the communication flows that the communication node can use the link shared section. The measurement unit measures the communication delay by communicating a measurement packet in the link shared section. The restriction unit restricts the transfer speed of packets other than the measurement packet in the link shared section of the communication flow based on the comparison result between the rated delay and the communication delay of the link shared section, and the priority of the communication flow. The rated delay is set with the minimum delay time of the bottleneck link in the link sharing section as the lower limit. Thereby, the transfer speed of packets can be appropriately adjusted in the shared section of the communication flow that communicates between a plurality of transmission terminals and a plurality of reception terminals.

Brief Description of the Drawings

[0009]

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Mode for Carrying Out the Invention

[0010] Some embodiments will be described with reference to the drawings. For the embodiments described below, the same components may be denoted by the same reference numerals and the description thereof may be omitted.

[0011] (First Embodiment) FIG. 1 shows communication flows F1 and F2 between a plurality of transmission terminals 2 and 3 and a plurality of reception terminals 4 and 5 constituting an information communication system 1. In the following example, first, the form of the information communication system 1 that communicates through a network 6 will be conceptually described, and then an example applied to the system configuration related to the vehicle 100 will be described.

[0012] The information communication system 1 shown in FIG. 1 is configured by interconnecting a plurality of transmission terminals 2, 3, a transmission node 7, a link sharing section 8, a reception node 9, and a plurality of reception terminals 4, 5 via a network 6. The transmission node 7 has a configuration corresponding to a communication node according to the present application. The link sharing section 8 represents a section of a link shared by communication flows F1, F2 of packets that communicate between the plurality of transmission terminals 2, 3 and the plurality of reception terminals 4, 5, and shows a communication section including a communication link 8a such as LTE (registered trademark), W-CDMA, WiFi (registered trademark). In FIG. 1, a predetermined communication link 8a and the Internet 8b are illustrated in the link sharing section 8. In the following description, the communication link 8a shows a form in which it becomes the bottleneck link with the most significant communication delay among all the communication flows F1, F2.

[0013] The transmission node 7 is configured with a rated delay setting unit 20. The rated delay setting unit 20 sets a rated delay ta in the link sharing section 8 between the transmission node 7 and the reception node 9. The rated delay ta indicates a rated value of a so-called round trip time (RTT). The rated delay ta in this embodiment indicates the delay upper limit criterion of the communication flow (communication flow F2 in a specific embodiment described later) that transfers data with the highest priority among the plurality of communication flows F1, F2 in which the transmission node 7 uses the link sharing section 8.

[0014] The plurality of transmission terminals 2, 3 are each connected to the transmission node 7 through local networks 10, 11, and the transmission node 7 receives packets transmitted from the plurality of transmission terminals 2, 3. The transmission node 7 sequentially stores the packets from the plurality of transmission terminals 2, 3 in queues 16a, 16b. The transmission node 7 uses a scheduler 17a to sequentially transfer the packets to the reception node 9 through the link sharing section 8 based on the priority attached to the packets. When the reception node 9 receives a packet, it relays the packet to the reception terminal 4 or 5 with the destination address stored in the packet through the local network 13 or 14. Thereby, the reception terminal 4 or 5 can receive the packet.

[0015] The transmitting node 7 and the receiving node 9 of this form are configured with the function as the measurement unit 15. The measurement unit 15 measures the packet delay time by communicating measurement packets across the link sharing section 8.

[0016] The restriction unit 22 has a function of restricting the transfer speed of packets other than the measurement packets in the link sharing section 8 of each communication flow F1, F2 based on the comparison result between the rated delay ta and the communication delay of the link sharing section 8, and the priorities of the respective communication flows F1, F2.

[0017] <Specific embodiments> Next, an embodiment in which the information communication system 1 described above is applied to a vehicle system 101 will be described. Here, an embodiment in the case of transmitting data from the navigation ECU 102 that executes the car navigation function mounted on the vehicle 100 and the mobile terminal 103 held by the passenger of the vehicle 100 to the outside of the vehicle 100 will be described with reference to FIGS. 2 to 8. In FIGS. 2 to 6, the components shown in FIG. 1 are assigned reference numerals such that the tens and units digits of the corresponding component reference numerals are the same value while the hundreds digit is 1, and the description similar to that of the components of the information communication system 1 described above may be omitted.

[0018] FIG. 2 shows a configuration example when transmitting data from the navigation ECU 102 and the mobile terminal 103 to another mobile terminal 104 or the voice recognition server 105 outside the vehicle, and FIG. 3 shows a relay device 107 and an electrical configuration example around it.

[0019] This embodiment is applicable to services when a voice recognition request is sent from the navigation ECU 102 or the mobile terminal 103 mounted on the vehicle 100 to the voice recognition server 105. As shown in FIGS. 2 and 3, a navigation ECU 102 is installed in the vehicle 100. The navigation ECU 102 is connected to a locator 130. The locator 130 is composed of a GNSS receiver and an inertial sensor (both not shown). The navigation ECU 102 acquires current position information using the locator 130. The navigation ECU 102 can also perform data communication with other ECUs (not shown) through the in-vehicle LAN 110, and can be communicatively connected to the relay device 107 through the in-vehicle LAN 110.

[0020] In addition, a mobile terminal 103 is brought into the vehicle 100. The mobile terminal 103 can be connected to the in-vehicle WiFi router 111 by wireless communication, and is communicatively connected to the relay device 107 through the in-vehicle WiFi router 111. The relay device 107 is a control device called a TCU or DCM mainly including a microcomputer with a processor, a storage unit 116, and I / O. Functionally, the relay device 107 mainly operates with a communication control unit 107a and includes a communication unit 118 in addition to the storage unit 116. DCM is the abbreviation of Data Communication Module, and TCU is the abbreviation of Telematics Control Unit. The relay device 107 is configured as an information communication device according to this embodiment. The storage unit 21 can use a ROM, a RAM, a flash memory, etc., and also includes a configuration as a non-transitory tangible storage medium.

[0021] The communication control unit 107a includes a measurement unit 115, a storage unit 116 having a plurality of queues 116a, 116b, a communication management unit 117 that performs communication management using a scheduler 117a, a communication unit 118, a data acquisition unit 119, a fixed-delay setting unit 120, and a restriction unit 122. The measurement unit 115, the communication management unit 117, and the fixed-delay setting unit 120 are functions realized by a program stored in the storage unit 116 being executed by a microcontroller.

[0022] Data transmitted from the navigation ECU 102 and the mobile terminal 103 are respectively stored in the queues 116a and 116b. The communication management unit 117 includes a scheduler 117a that sets the communication order of the packets for transmission stored in the queues 116a and 116b based on their priorities. The communication management unit 117 also sets the communication resources and communication paths of the available lines by the communication unit 118. The communication unit 118 is hardware that communicates with a communication device outside the vehicle 100. The communication management unit 117 manages the relationship between the predicted arrival time and the transfer speed for each type of line.

[0023] The measurement unit 115 measures the communication delay of the link sharing section 108 by continuously transmitting and receiving measurement packets between the relay device 107 and the receiving node 109. The communication management unit 117 measures the communication delay by transmitting measurement packets with a higher priority than the actual packets transferred from the relay device 107 to the receiving node 109.

[0024] The rated delay setting unit 120 sets a rated delay ta in the link sharing section 108. The rated delay setting unit 120 sets the rated delay ta as the delay upper limit criterion of the communication flow F2 that is transferred with the highest priority among the communication flows F1 and F2 in which the relay device 107 and the receiving node 109 use the link sharing section 108. The link sharing section 108 mentioned here is composed of a wireless communication network 108a managed by a wireless communication carrier and the Internet 108b.

[0025] The restriction unit 122 restricts the transfer speed of packets other than the measurement packets in the link sharing section 108 based on the comparison result between the communication delay of the link sharing section 108 measured by the measurement unit 115 and the rated delay ta, and the priorities of the respective communication flows F1 and F2 that communicate in the link sharing section 108.

[0026] By setting the rated delay ta in the link sharing section 108 by the rated delay setting unit 120, the restriction unit 122 restricts the transfer speed of the packets transferred from the queues 116a and 116b so as to satisfy this rated delay ta.

[0027] As illustrated in FIGS. 4 and 5, the wireless communication network 108a is configured as a bottleneck link that has the slowest data transfer speed among the paths of the end-to-end communication flows F1 and F2. The wireless communication network 108a is based on a core network such as LTE (registered trademark), W-CDMA, WiFi (registered trademark). The relay device 107 transfers data toward the receiving node 109 through the wireless communication network 108a and the Internet 108b.

[0028] The receiving node 109 transmits the packets transferred from the relay device 107 to the ISPs 113 and 114. ISP is the abbreviation of Internet Service Provider. The ISPs 113 and 114 transmit the packets to various terminals such as the mobile terminal 104 and the speech recognition server 105.

[0029] FIG. 6 shows the protocol stack of the system. Usually, the TCP / IP protocol is used when communicating with the network 6 through the Internet 108b. In its lower layer, LTE is used when the relay device 107 communicates with the wireless communication network 108a, and Ethernet (Eth) is used for other communications.

[0030] When the measurement unit 115 measures the transfer speed, for example, a ping command that transmits and receives an echo request message by ICMP (Internet Control Message Protocol) is generated by the measurement packet, and is transmitted from one to the other and from the other to one to the IP addresses pre-assigned to the transmitting node 7 and the receiving node 9 respectively, and the response speed is detected to measure the transfer speed of the data of the measurement packet. It is possible to measure one-way of the upstream or downstream line, or to measure the round trip of the upstream and downstream lines.

[0031] Next, the above operations will be described. In FIGS. 4 and 5, a communication flow F1 when a voice recognition request is transmitted from the navigation ECU 102 to the voice recognition server 105 and a communication flow F2 when a call is made from the mobile terminal 103 to the mobile terminal 104 using a phone application will be compared and described.

[0032] The voice data of the phone application transmitted through the communication flow F2 is required to have immediacy. Conversely, for data transfer other than a phone call, for example, the communication flow F1 of the voice recognition request from the navigation ECU 102 to the voice recognition server 105 by the navigation application executed by the navigation ECU 102 has lower immediacy compared to the communication flow F1.

[0033] Also, the amount of voice data requested to be transmitted in the communication flow F1 is smaller compared to the amount of voice recognition data requested to be transmitted in the communication flow F2. In such a case, the relay device 107 transfers the packet by regarding the communication flow F2 as having a lower load and a higher priority compared to the communication flow F1 by the scheduler 117a.

[0034] As described above, the measurement unit 115 always measures the communication delay of the link sharing section 108 between the relay device 107 and the receiving node 109 by transmitting and receiving measurement packets. When initially transferring data, the relay device 107 releases the restriction on the data transfer speed by the restriction unit 122, and as shown from time t0 to t1 in FIG. 7, transfers the data at the initial no-load delay tm without being affected by the input bandwidth restriction. The no-load delay tm indicates the original communication delay of the line of the wireless communication network 108a and is equivalent to RTprop described in Non-Patent Document 1.

[0035] As shown in the state of FIG. 5, when the communication delay measured by the measurement unit 115 is smaller than the threshold determined by the rated delay ta, the communication management unit 117 prevents the relay device 107 from performing bandwidth control. At this time, regardless of the types of applications executed by the navigation ECU 102 and the mobile terminal 103, the relay device 107 sequentially transfers the packets stored in the queues 116a and 116b.

[0036] When the amount of in - flight transfer data Inflight that is input to the wireless communication network 108a and for which reception completion has not been confirmed at the receiving node 109 increases with time, the increase in the bottleneck link bandwidth of the wireless communication network 108a stops at time t1. This is, for example, because the bottleneck link has reached the maximum bandwidth possible with the resources allocated within the wireless communication network 108a. However, as shown from time t1 to t2, the relay device 107 continues to load the wireless communication network 108a by increasing the amount of transfer data until the rated delay ta is reached, regardless of whether the increase in bandwidth continues or not.

[0037] In the wireless communication network 108a, a resource access mechanism considering fairness is typically implemented. When the wireless communication network 108a is, for example, a 4G / 5G cellular line, resource allocation is performed according to the amount of transfer - waiting data based on the BSR (Buffer Status Report). In the case of such a cellular line, the bottleneck link bandwidth depends on the buffer amount of the bottleneck IF, and resource allocation is performed according to this buffer amount.

[0038] Also, for example, even when WiFi (registered trademark) is applied as the wireless communication network 108a, WiFi adopts DCF (Distributed Coordination Function) and, according to the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) method, gives higher transfer priority to packets that arrive faster. For this reason, the relay device 107 can increase the probability of obtaining a data transfer opportunity by continuously maintaining a state where there is always data in the buffer of the WiFi interface.

[0039] In a link where the amount of acquired resources can vary according to the buffer state, even if the communication delay increases from the no-load delay tm in response to an increase in the overall transfer data volume Inflight, the transfer speed continues to increase according to the buffer state as shown in the middle part of FIG. 8 without reaching a peak as shown in the comparative example in the lower part of FIG. 8. Refer to the region in FIG. 8 where the overall transfer data volume Inflight becomes equal to or greater than a predetermined value BDP. The predetermined value BDP shown here is a value estimated based on the technology described in Non-Patent Document 1 and is obtained by multiplying the maximum bandwidth (maxBW) by the minimum communication delay (minRTT).

[0040] Therefore, it is advisable to continue the transfer trial to increase the overall transfer data volume Inflight until the rated delay ta is reached regardless of the input limit bandwidth. By continuously increasing the transfer data volume and applying a communication load to the wireless communication network 108a, the relay device 107 can acquire more resource allocations as shown from time t2 to t3 in FIG. 7. In the example shown in FIG. 7, it shows the case where the bottleneck link is a line of the wireless communication network 108a where control is performed to allocate additional resources when the amount of data in the buffer exceeds a certain value, and the timing when the amount of data in the buffer reaches a certain value corresponds to t2. The relationship between the actual buffer state and the allocated resources generally varies depending on the network standard, and even for networks with the same standard, it varies depending on the implementation and settings of base station equipment, etc.

[0041] When the communication delay measured by the measurement unit 115 exceeds the rated delay ta, which is a delay upper limit standard determined in advance to be greater than RTprop at time t3, the relay device 107 adjusts the communication delay by adjusting the input bandwidth restriction by the restriction unit 122.

[0042] As shown in the state of FIG. 5, when the communication delay measured by the measurement unit 115 becomes larger than the rated delay ta, the communication management unit 117 performs bandwidth limitation on the communication flows F1 and F2, restricts the total number of packets input to the link sharing section 108 to a predetermined value or less, and restricts the packet transfer speed to a value equal to or less than the restriction target value. At this time, it is desirable to reflect the priorities of the communication flows F1 and F2 and perform packet bandwidth limitation on the lower-priority one first. During such input bandwidth limitation, the scheduler 117a of the communication management unit 117 sequentially holds the packets input from the navigation ECU 102 and the mobile terminal 103 in the queues 116a and 116b inside the relay device 107, respectively.

[0043] The restriction target value of the transfer speed is set, for example, to zero, that is, transfer stop, an arbitrary default value, or a value obtained by multiplying a predetermined ratio by the transfer speed immediately before it is confirmed that the transfer speed of the link sharing section 108 is in a congested state. In other words, it is set to a value obtained by multiplying a predetermined ratio by the transfer speed at the time when the communication delay was last confirmed to be lower than the rated delay ta.

[0044] The rule for determining the restriction target value of the transfer speed may be stored in a separate storage unit 116 and determined by referring to the rule by the restriction unit 122. Further, after falling below the rated delay ta, it is advisable to control the communication delay so as to increase it by a predetermined ratio of the bandwidth limitation value at the time when it was determined that the rated delay ta was fallen below immediately before.

[0045] When the restriction target value is set to a value other than zero, such as an arbitrary default value, even during input bandwidth limitation, the scheduler 117a preferentially transfers the accumulated packets in the queue 116b of the communication flow F2 to the link sharing section 108. For this reason, as shown by hatching the packets in the queues 116a and 116b in FIG. 5, the packet retention speed in the queue 116b becomes slower than that in the queue 116a.

[0046] As a result, the probability that the communication delay of the communication flow F2 with a low load and a high priority reaches the rated delay ta or more can be reduced regardless of the load situation of the other communication flow F1. Also, by performing control based on the rated delay ta, buffer blowout can be prevented. In the embodiment of this form, the immediacy of the telephone application can be maintained to the greatest extent possible.

[0047] In addition, the communication management unit 117 discards the transfer packets staying in the queues 116a and 116b when the established conditions are satisfied. The conditions for discarding the packets are, for example, when the data stay time in the queues 116a and 116b exceeds the specified timeout time, or when a packet is input after exceeding the specified upper limit data amount in the queues 116a and 116b. This condition may also be stored separately in the storage unit 116, and it is advisable for the communication management unit 117 to refer to this condition and discard the packets.

[0048] Next, the details of the method for setting the rated delay ta will be described with reference to FIG. 9. When the rated delay setting unit 120 sets the rated delay ta in the link sharing section 108, it is desirable to set the rated delay ta with the shortest required delay time, which is the shortest among the required delay times requested by the applications executed by the navigation ECU 102 and the mobile terminal 103, as the upper limit.

[0049] As described above, the transfer process of the voice data of the telephone application requires immediacy compared to the data transfer requested from, for example, a navigation application other than the telephone. Since the required delay time varies for each application that requests packet transfer, it is desirable to obtain the shortest required delay time among the delay times that all applications can request, and then set the rated delay ta with this shortest required delay time as the upper limit. At this time, it is not limited to the application with the shortest required delay among the currently used applications, but it is desirable to set the rated delay ta with the shortest required delay time, which is the shortest among the possible future occurrences including those not currently in use, as the upper limit.

[0050] At timing t10 in FIG. 9, when the power switch of vehicle 100 is turned on and power is supplied, the navigation ECU 102 is activated and the navigation application is executed. When the user voices a destination using the navigation system, the navigation ECU 102 accesses the voice recognition server 105 through the relay device 107 and utilizes the cloud voice recognition service provided by the voice recognition server 105. When the link sharing section 108 is in use or is scheduled to be used, a request delay time is set from the navigation application.

[0051] For example, when the request delay time for voice recognition communication from the navigation application is set to 500 ms, the relay device 107 sets the request delay time of the corresponding communication flow F1 to 500 ms. If this is the shortest among the request delays from all applications, for example, when no other applications are running and the navigation application itself is not performing communication other than voice recognition, this 500 ms is set as the shortest request delay time. Note that the request delay time for each communication flow may be set from the application as described above, or may be set in advance for each flow attribute. The flow attribute is defined by, for example, the address and port number of the access destination server, the protocol type, and the value of the field that defines the quality on the protocol header.

[0052] Thereafter, at time t15 in FIG. 9, when the phone application pre-installed in the mobile terminal 103 is activated based on the operation of the vehicle occupant of vehicle 100, the phone application of the mobile terminal 103 starts a call with another mobile terminal 104 through the relay device 107.

[0053] When the request delay time from the phone application is set to 50 ms, the relay device 107 determines that the request delay time of the communication flow F2 used by this phone application for communication is shorter than that of the communication flow F1, and updates 50 ms as the shortest request delay time. The rated delay setting unit 120 can satisfy the request delay times from the navigation application and the phone application by setting the rated delay ta with the shortest request delay time as the upper limit. In particular, since the request from the phone application with the shortest request delay time can also be satisfied, the vehicle occupant of vehicle 100 can comfortably use the phone application without response delay.

[0054] Also, it is desirable that the rated delay ta be set with the minimum delay time of the wireless communication network 108a that becomes the bottleneck link in the link sharing section 108 as the lower limit. The minimum delay time of the wireless communication network 108a is a time corresponding to the delay time tm when there is no load (hereinafter referred to as the no-load delay tm). The no-load delay tm is the delay time during which the wireless communication network 108a can communicate without applying a communication load from the relay device 107. This no-load delay tm is a value equivalent to RTprop, which is the original communication delay of the line in the technology described in Non-Patent Document 1.

[0055] For example, it is good to set the no-load delay tm for each type of the wireless communication network 108a such as LTE (registered trademark), W-CDMA, WiFi (registered trademark), and set the rated delay ta with this no-load delay tm as the lower limit.

[0056] When determining the no-load delay tm, it is good to specifically determine by referring to the table stored in advance in the storage unit 116 for each attribute of the link. For example, it may be set to a fixed value specified in advance such as 5 ms for LTE, 20 ms for W-CDMA, and 1 ms for WiFi. Also, based on the delay samples measured by the measurement unit 115, for example, the no-load delay tm estimated by applying statistical processing such as taking the minimum value among a large number of samples may be used.

[0057] Also, the attributes of the link are, for example, due to connection systems such as LTE / W-CDMA / WiFi, and its network connection state, and the no-load delay tm and the rated delay ta assumed based on the attributes of this link may be changed. The attributes of the link also vary depending on the country or region. For example, even for the same LTE, the delay varies depending on the country. Also, within Japan, for example, in the case of remote islands in Tokyo, due to delays in the core network of the wireless communication network 108a, etc., the delay becomes larger than that in Tokyo. Therefore, it is good to set different values based on the network connection area.

[0058] The no-load delay tm may be determined based on the standard information and design information of the wireless system itself. For example, in LTE, the communication delay in the wireless communication network 108a is specified to be within a predetermined value, for example, 5 ms. Therefore, even when there is no load, a delay of 5 ms will occur. Thus, it is advisable to set this 5 ms as the no-load delay tm. Also, when other no-load delays tm are known within the link sharing section 8, it is advisable to set the no-load delay tm as the time obtained by adding this known value to 5 ms.

[0059] Also, even while the relay device 107 is connected to the same type of wireless communication network 108a, it is advisable to change the assumed no-load delay tm based on the network connection state and, if necessary, change the rated delay ta.

[0060] For example, at times t12, t14, and t16 in FIG. 9, it is advisable to change the setting of the no-load delay tm assumed when the connection is sequentially changed from the connected cell C1 to the connected cells C2, C3, and C4. When changing the connected cells C1 to C4, the communication frequency band, bandwidth, base station transmission power, etc. may change. In such a case, the setting of the no-load delay tm should be changed accordingly, and the rated delay setting unit 120 should set the rated delay ta within an appropriate range with the no-load delay tm as the lower limit.

[0061] Also, the no-load delay tm varies based on the wireless link state. Also, when the amount of allocated resources, etc. changes dynamically, the no-load delay tm also changes accordingly. Therefore, it is advisable to change the setting of the no-load delay tm to match this variation and set the rated delay ta within an appropriate range.

[0062] In addition, in a wireless link, the retransmission factor due to packet discard and the delay fluctuation due to the change in the propagation environment are large. For the same amount of in-flight transfer data, there is an error range in the delay measurement result, and it is difficult to accurately obtain a predetermined value BDP with a small number of samples. Therefore, it is desirable to set the rated delay ta to a value higher than the margin of the fluctuation by more than the known no-load delay tm. By setting the rated delay ta to a value higher than the known no-load delay tm by a predetermined margin or more, it is possible to prevent a decrease in bandwidth utilization efficiency or an excessive delay caused by the delay fluctuation.

[0063] Also, for example, the measurement unit 115 may determine that the link quality is good if the CQI, which is a parameter representing the propagation path quality, is equal to or greater than a predetermined value, and the link quality is bad if it is less than the predetermined value, and accordingly change the setting of the no-load delay tm. When the relay device 107 is connected to the connection cell C1 of the wireless communication network 108a, as shown at times t10 to t11 in FIG. 9, within the same connection cell C1, when the link quality is good, that is, when the quality is high, the delay time tends to be short. Therefore, it is advisable to estimate and set the no-load delay tm to be short.

[0064] Conversely, when the link quality is bad, that is, when the quality is low, the delay time tends to be long. Therefore, as shown at times t11 to t12 in FIG. 9, it is advisable to estimate and set the no-load delay tm to be long. While changing the setting of the no-load delay tm based on these factors, it is advisable to change the rated delay ta within an appropriate range.

[0065] For example, when roaming or the like is executed during movement, the no-load delay tm also fluctuates as the communication operator, that is, the carrier, changes. Thus, in accordance with the fluctuations based on various factors, it is advisable to change the setting of the no-load delay tm and change the rated delay ta within an appropriate range. Thereby, when changing the connection cells C1 to C4, the wireless link state, or the communication operator, by changing the setting of the no-load delay tm and changing the rated delay ta, the scheduler 117a can always keep the rated delay ta within an appropriate predetermined range when applying a load to the link sharing section 108.

[0066] According to this embodiment, the rated delay ta is defined in the link sharing section 108 as the upper limit criterion for the delay of the communication flow F2 that the relay device 107 transfers with the highest priority. Based on the comparison result between the communication delay of the link sharing section 108 and the rated delay ta, and the priorities of the communication flows F1 and F2, the transfer speeds of the packets other than the measurement packets in the link sharing section 108 of the communication flows F1 and F2 are restricted. Thereby, the transfer speed of the packets in the link sharing section 108 can be appropriately adjusted. In particular, the rated delay ta is set with the minimum delay time of the wireless communication network 108a, which becomes the bottleneck link in the link sharing section 108, as the lower limit, and the shortest required delay time requested from the application through the relay device 107 as the upper limit. Thereby, a more appropriate rated delay ta can be set.

[0067] Next, a comparative example when applying the prior art is described, and the effects of this embodiment on the comparative example are described. Regarding the components of the comparative example corresponding to the components of this embodiment, they will be described with the symbol obtained by setting the hundreds digit of the symbol of the components of the above-described embodiment to 2. <Comparative Example> The comparative example will be described based on the technique described in Non-Patent Document 1, whose processing content is closer to this example. As illustrated in FIG. 10, a configuration in which a tunnel gateway 50 for performing IPIP tunneling is arranged at the transmitting node 207 and the receiving node 209 located at both ends of the link common section 208 is considered as a comparative example. In this technique, the tunnel gateway 50 is arranged at the transmitting node 207 and the receiving node 209, and tunneling is performed using an arbitrary tunneling protocol such as existing IPIP. Further, as shown in FIG. 10, it is conceivable to introduce the BBR session described in Non-Patent Document 1 into the IPIP tunnel. In the tunnel gateway 50, the extraction of the queues 16a and 16b for each priority is implemented, and the flow control is performed within the BBR session.

[0068] However, the technology described in Non-Patent Document 1 is based on TCP, and the protocol header and processing overhead are large. Also, for a line where an increase in communication delay does not necessarily occur in conjunction with a saturated bandwidth situation such as a cellular line, it does not operate optimally. In the description of Non-Patent Document 1, it is reported that by increasing the gain up to 1.25, it can follow the fluctuations of the cellular line. However, since this gain varies depending on the control situation of the cellular line, it is difficult to find the optimal value for tuning.

[0069] The maximum communication delay based on the execution of the applications in the transmitting terminals 2 and 3 becomes larger by a margin than the original communication delay of the line, which is RTTprop. Also, due to the existence of this peak, when there is a two-way load, the error in the bandwidth measurement expands.

[0070] As described above, the bottleneck link bandwidth in a cellular line depends on the buffer amount of the interface of the bottleneck line. In session control using BBR, the bottleneck speed is obtained as the point saturated with respect to the load, but only the minimum bottleneck bandwidth is secured. Note that the lower part of FIG. 7 shows the changes when the comparative example is applied. When the communication delay reaches the bottleneck bandwidth, the communication delay is reduced, and thus it is controlled to the original communication delay of the line, which is RTTprop.

[0071] <Configuration and Effects of the Present Embodiment Compared to the Comparative Example> When adopting the method of the present embodiment, by controlling to maintain a rated delay ta, which is a value larger than the known no-load delay tm, for the communication delay, a load is constantly applied to the wireless communication network 108a, and resource allocation can be obtained from the wireless communication network 108a that becomes the bottleneck link. In other words, according to the present embodiment, by setting a large rated delay ta, a larger bandwidth can be obtained. As a result, the end-to-end throughput of both communication flows F1 and F2 can be improved. The present embodiment is also advantageous in that both the processing and communication overheads can be configured to be small.

[0072] (Second Embodiment) The second embodiment will be described with reference to FIG. 11. As shown in FIG. 11, the measurement unit 115 may be configured without passing through the relay device 107.

[0073] In this case, the measurement unit 115 can directly measure the transfer speeds of the in-vehicle LAN 110 and the link sharing section 108 without passing through the relay device 107, and can measure while excluding the transfer delay of the relay device 107 as much as possible. The measurement unit 115 transmits the measurement results measured by the measurement packets to the scheduler 117a of the communication management unit 117 through the in-vehicle LAN 110, and the scheduler 117a manages the packet transfer process based on this measurement result. Also in this case, the same operational effects as those of the foregoing embodiment are achieved.

[0074] (Third Embodiment) The third embodiment will be described with reference to FIG. 12. As shown in FIG. 12, the measurement unit 115 may be configured for a vehicle device in the vehicle 100 connected via the relay device 107. The measurement unit 115 transmits measurement packets to the relay device 107.

[0075] The scheduler 117a of the relay device 107 transfers the measurement packets from the measurement unit 115 to the outside of the vehicle 100 with the highest priority. Also in this case, the measurement unit 115 can measure the transfer speeds among the in-vehicle LAN 110, the relay device 107, the wireless communication network 108a, and the Internet 108b. Thereby, the same operational effects as those of the foregoing embodiment are achieved.

[0076] (Other Embodiments) The present invention is not limited to the foregoing embodiments, and can be implemented with various modifications, and is applicable to various embodiments without departing from the gist thereof. For example, the following modifications or expansions are possible.

[0077] The memory unit 116 may have a configuration including a non-volatile memory medium. Various programs executed by each processor are stored in the memory medium. For example, the memory unit 116 is not limited to a configuration provided on a circuit board, and may be configured by a memory card or the like, or may be configured to be electrically connected to the processing circuit of the relay device 107 by being inserted into a slot unit.

[0078] The method of the transmission node 7 and the relay device 107 described in the present disclosure may be implemented by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the transmission node 7, the relay device 107, and the method thereof described in the present disclosure may be implemented by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0079] Alternatively, the transmission node 7, the relay device 107, and the method thereof described in the present disclosure may be implemented by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured by one or more hardware logic circuits. Further, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0080] The present invention has been described in accordance with the foregoing embodiments, but it is understood that the present invention is not limited to such embodiments or structures. The present invention includes various modifications and modifications within the equivalent scope. In addition, various combinations and forms, and further other combinations and forms including one element, more, or less thereof, are within the scope and spirit of the present invention.

Explanation of Reference Numerals

[0081] In the drawings, 7 is a transmission node (communication node), 107 is a relay device (information communication device), 8 and 108 are link sharing sections, 108a is a wireless communication network (bottleneck link), 9 is a receiving node (communication node), 15 and 115 are measurement units, and 22 and 122 are restriction units.

Claims

1. A communication node (7, 107) that communicates a link sharing section (8, 108) shared by communication flows of packets respectively communicated between a plurality of transmission terminals and a plurality of reception terminals, configured to measure a communication delay by communicating a measurement packet in the link sharing section by a measurement unit (15, 115), and a rated delay is defined in the link sharing section as a delay upper limit standard for the communication flow that is transferred with the highest priority among the communication flows in which the communication node can use the link sharing section, a limiting unit (22, 122) that limits the transfer speed of the packets other than the measurement packet based on a comparison result between the communication delay in the link sharing section and the rated delay, and the priority of the communication flow, The information communication device in which the rated delay is set with the shortest delay time of a bottleneck link (8a, 108a) in the link sharing section as a lower limit.

2. A communication node (7, 107) that communicates a link sharing section (8, 108) shared by communication flows of packets respectively communicated between a plurality of transmission terminals and a plurality of reception terminals, configured to measure a communication delay by communicating a measurement packet in the link sharing section by a measurement unit (15, 115), and a rated delay is defined in the link sharing section as a delay upper limit standard for the communication flow that is transferred with the highest priority among the communication flows in which the communication node can use the link sharing section, a limiting unit (22, 122) that limits the transfer speed of the packets other than the measurement packet based on a comparison result between the communication delay in the link sharing section and the rated delay, and the priority of the communication flow, The information communication device in which the rated delay is set with the shortest required delay time requested from an application through the communication node as an upper limit.

3. A communication node (7, 107) that communicates a link sharing section (8, 108) shared by communication flows of packets respectively communicated between a plurality of transmission terminals and a plurality of reception terminals, The measurement unit (15, 115) is configured to measure the communication delay by communicating the measurement packet in the link sharing section, and the rated delay is defined in the link sharing section as the delay upper limit criterion for the communication flow that is transferred with the highest priority among the communication flows that the communication node can use the link sharing section. A limiting unit (22, 122) is provided to limit the transfer speed of the packets other than the measurement packet based on the comparison result between the communication delay in the link sharing section and the rated delay, and the priority of the communication flow. An information communication device in which the limiting target value when the limiting unit limits the transfer speed is set to zero, an arbitrary default value, or a value obtained by multiplying a predetermined ratio by the transfer speed immediately before it is confirmed that the transfer speed in the link sharing section is in a congested state.

4. A communication node (7, 107) that communicates with a link sharing section (8, 108) shared by communication flows of packets that communicate between a plurality of transmission terminals and a plurality of reception terminals respectively. The measurement unit (15, 115) is configured to measure the communication delay by communicating the measurement packet in the link sharing section, and the rated delay is defined in the link sharing section as the delay upper limit criterion for the communication flow that is transferred with the highest priority among the communication flows that the communication node can use the link sharing section. A limiting unit (22, 122) is provided to limit the transfer speed of the packets other than the measurement packet based on the comparison result between the communication delay in the link sharing section and the rated delay, and the priority of the communication flow. The rated delay is set in advance to be greater than the known no-load delay (tm). An information communication device comprising a scheduler (117) that always controls the communication delay so as to keep the rated delay within a predetermined range when a load is applied to the link sharing section.

5. A communication node (7, 107) communicates a link sharing section (8, 108) shared by communication flows of packets that communicate between a plurality of transmission terminals (2, 102, 3, 103) and a plurality of reception terminals (4, 104, 5, 105), and when a rated delay is defined in the link sharing section as a delay upper limit criterion for the communication flow that is transferred with the highest priority among the communication flows that the communication node can use the link sharing section, a measurement unit (15, 115) measures a communication delay by communicating a measurement packet in the link sharing section; a restriction unit (22, 122) restricts a transfer speed of the packets other than the measurement packet in the link sharing section of the communication flow based on a comparison result between the rated delay and the communication delay of the link sharing section and on the priority of the communication flow; and includes wherein the rated delay is set with a minimum delay time of a bottleneck link (8a, 108a) in the link sharing section as a lower limit. **Claim 6** A communication node (7, 107) communicates a link sharing section (8, 108) shared by communication flows of packets that communicate between a plurality of transmission terminals (2, 102, 3, 103) and a plurality of reception terminals (4, 104, 5, 105), and when a rated delay is defined in the link sharing section as a delay upper limit criterion for the communication flow that is transferred with the highest priority among the communication flows that the communication node can use the link sharing section, a measurement unit (15, 115) measures a communication delay by communicating a measurement packet in the link sharing section; a restriction unit (22, 122) restricts a transfer speed of the packets other than the measurement packet in the link sharing section of the communication flow based on a comparison result between the rated delay and the communication delay of the link sharing section and on the priority of the communication flow; and includes wherein the rated delay is set with a shortest required delay time requested from an application through the communication node as an upper limit.

7. A communication node (7, 107) communicates a link sharing section (8, 108) shared by communication flows of packets that communicate between a plurality of transmission terminals (2, 102, 3, 103) and a plurality of reception terminals (4, 104, 5, 105), respectively. When a rated delay is defined in the link sharing section as a delay upper limit criterion of the communication flow that is transferred with the highest priority among the communication flows in which the communication node can use the link sharing section, a measurement unit (15, 115) measures a communication delay by communicating a measurement packet in the link sharing section; and a restriction unit (22, 122) restricts a transfer speed of packets other than the measurement packet in the link sharing section of the communication flow based on a comparison result between the rated delay and the communication delay of the link sharing section and a priority of the communication flow; and It comprises: An information communication method in which a restriction target value when the restriction unit restricts the transfer speed is set to zero, an arbitrary default value, or a value obtained by multiplying a transfer speed immediately before it is confirmed that the transfer speed of the link sharing section is in a congested state by a predetermined ratio.

8. A communication node (7, 107) communicates a link sharing section (8, 108) shared by communication flows of packets that communicate between a plurality of transmission terminals (2, 102, 3, 103) and a plurality of reception terminals (4, 104, 5, 105), respectively. When a rated delay is defined in the link sharing section as a delay upper limit criterion of the communication flow that is transferred with the highest priority among the communication flows in which the communication node can use the link sharing section, a measurement unit (15, 115) measures a communication delay by communicating a measurement packet in the link sharing section; and a restriction unit (22, 122) restricts a transfer speed of packets other than the measurement packet in the link sharing section of the communication flow based on a comparison result between the rated delay and the communication delay of the link sharing section and a priority of the communication flow; and It comprises: The rated delay is preset to be greater than a known no-load delay (tm), and a process of always controlling the communication delay by a scheduler (117) so as to keep the rated delay within a predetermined range when applying a load to the link sharing section. An information communication method comprising the above is provided.

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