JP6275519B2 - Wireless relay device, unmanned aircraft system, program, and wireless relay method - Google Patents

Description

  The present invention relates to a technique for relaying wireless communication using any one of a plurality of wireless communication interfaces.

  Recently, UAS (Unmanned Aircraft System: Unmanned Aircraft System) that can fly autonomously without pilots as a means to quickly establish a network with isolated areas where transportation and communication have been blocked due to the occurrence of natural disasters A wireless relay system using an aircraft system) has been proposed. FIG. 11 is a diagram showing a schematic configuration of such a wireless relay system. Here, a case where the communication method is Wi-Fi (Wireless Fidelity) will be described as an example. As shown in FIG. 11, the isolated area cannot pass between the non-isolated area. The unmanned aerial vehicle 100 includes a mobile router 102 having functions of an access point and a station. The unmanned aerial vehicle 100 flies over the isolated area, and performs real-time communication between the terminal 104 in the isolated area, the access point 106 and the Internet 108 in the non-isolated area.

  On the other hand, since the fuel (battery etc.) of the unmanned aircraft 100 is limited, the flight time is also limited. For this reason, a technique for accumulating data received in an isolated area in the unmanned aircraft 100 and releasing data accumulated in a non-isolated area has been proposed. Thereby, delay tolerance communication (DTN: Delay Tolerant Network) is realized.

RFC 4838 Delay-Tolerant Networking Architecture April 2007 http://tools.ietf.org/html/rfc4838

  However, as shown in FIG. 11, on the LAN side (Wi-Fi # 2) and WAN side (Wi-Fi # 1) of the mobile router 102, communication is performed depending on the wireless system used, the frequency, the wireless environment on the receiving side, and the like. Generally, the speed is different. As a result, waste of link capacity may occur. For example, consider wireless communication from an isolated area to a non-isolated area. When the communication speed is (Wi-Fi # 2)> (Wi-Fi # 1), high-speed communication is possible up to the mobile router 102, but the communication speed of Wi-Fi # 1 is relatively slow. . As a result, packet overflow or the like occurs in the mobile router 102, the speed of Wi-Fi # 2 decreases to Wi-Fi # 1, and high-speed communication is performed in Wi-Fi # 2, which should be originally capable of high-speed communication. Cannot be performed, and the capacity is wasted. In the example illustrated in FIG. 11, assuming that Wi-Fi # 2 has, for example, 100 link capacity, and Wi-Fi # 1 has, for example, 30 link capacity, Wi- In Fi # 2, although the link capacity of 100 can be used, the link capacity of Wi-Fi # 1 is restricted and only 30 link capacity can be used. As a result, 70 link capacities are wasted.

  The present invention has been made in view of such circumstances, and provides a wireless relay device, an unmanned aircraft system, a program, and a wireless relay method that can effectively utilize the surplus capacity of a high-speed wireless link. For the purpose.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the wireless relay device of the present invention is a wireless relay device that relays wireless communication using any one of a plurality of wireless communication interfaces, and has the link capacities of the first wireless link and the second wireless link. Based on the link capacity of the first wireless link and the second wireless link, a communication process for relaying the received wireless frame in real time or a storage process for storing the received wireless frame based on the link capacity of the first wireless link and the second wireless link When the data determination unit to be selected, the communication process is selected, the routing unit that routes the received radio frame to continue communication in real time, and when the storage process is selected, the received radio frame is stored in the database. And an accumulation processing unit for accumulating.

  As described above, based on the link capacities of the first radio link and the second radio link, the communication process for relaying the received radio frame in real time or the accumulation process for accumulating the received radio frame is selected, and the communication process is performed. When selected, the received radio frame is routed and communication is continued in real time. When the accumulation process is selected, the received radio frame is accumulated in the database, so depending on the capacity of the radio link, the communication process or It is possible to select an accumulation process. As a result, it is possible to perform control for optimizing the high-speed wireless link usage distribution.

  (2) Further, in the wireless relay device of the present invention, when the link capacity is different, the data determination unit performs the communication process with a smaller link capacity and corresponds to a capacity difference between the link capacities. The accumulation processing is performed with the link capacity to be performed.

  Thus, when each link capacity is different, communication processing is performed with the smaller link capacity and storage processing is performed with the link capacity corresponding to the capacity difference between the link capacities. And a process of accumulating radio frames that cannot be transmitted through a low-speed radio link. This makes it possible to effectively utilize the surplus capacity of the high-speed wireless link.

  (3) In the wireless relay device of the present invention, when the link capacity is the same, the data determination unit performs the communication process with the link capacity.

  Thus, when the link capacities are the same, communication processing is performed with the link capacities, and so-called real-time communication can be performed up to the limit of the radio link capacity.

  (4) In the wireless relay device of the present invention, when the capacity difference between the link capacities is equal to or less than a predetermined threshold, the data determination unit performs the communication process, while the capacity difference is When the threshold value is exceeded, the accumulation process is performed with the excess link capacity.

  As described above, when the capacity difference between the link capacities is equal to or less than a predetermined threshold value, communication processing is performed. On the other hand, when the capacity difference exceeds the threshold value, accumulation processing is performed with the excess link capacity. Such a link can perform so-called real-time communication to the limit, and can perform processing for accumulating the amount that cannot be transmitted by a low-speed link. This makes it possible to effectively use the surplus capacity of the high-speed link.

  (5) In the wireless relay device of the present invention, the storage processing unit outputs the stored wireless frame when a predetermined condition is satisfied, and the routing unit routes the output wireless frame. And transmitting to the destination of the radio frame.

  As described above, when a predetermined condition is satisfied, the accumulated radio frame is output, and the output radio frame is routed and transmitted to the destination of the radio frame, so that it is possible to implement delay-tolerant communication. .

  (6) Further, in the wireless relay device of the present invention, the communication quality analysis unit includes data measured from measured throughput, throughput estimated from a TCP (Transmission Control Protocol) sequence number per unit time, congestion degree, and retransmission rate. The link capacity of the first radio link and the second radio link is analyzed using either the link layer throughput or the link capacity acquired in advance.

  Thus, since the link capacity of each radio link is analyzed, it is possible to select communication processing or storage processing according to the capacity of the radio link. As a result, it is possible to perform control for optimizing the high-speed wireless link usage distribution.

  (7) Further, in the wireless relay device of the present invention, when the data processing unit selects the storage process, the data processing unit notifies the transmission source of the radio frame that the storage process is selected. Features.

  As described above, when the storage process is selected, a notification indicating that the storage process is selected is sent to the wireless frame transmission source, so that the user who transmitted the wireless frame is stored instead of the real-time communication. Can be notified.

  (8) Moreover, the unmanned aerial vehicle system according to the present invention is characterized by using a flying body equipped with the wireless relay device according to any one of (1) to (7).

  With this configuration, communication processing or storage processing can be selected according to the capacity of the radio link. As a result, it is possible to perform control for optimizing the high-speed wireless link usage distribution.

  (9) A program of the present invention is a program of a radio relay apparatus that relays radio communication using any of a plurality of radio communication interfaces, and includes a first radio link and a second radio link. Processing for analyzing link capacity, communication processing for relaying received radio frames in real time based on link capacities of the first radio link and the second radio link, or storage processing for accumulating received radio frames When selecting the process, when the communication process is selected, when the received radio frame is routed to continue communication in real time, and when the accumulation process is selected, the process of storing the received radio frame in the database And causing a computer to execute a series of processes.

  As described above, based on the link capacities of the first radio link and the second radio link, the communication process for relaying the received radio frame in real time or the accumulation process for accumulating the received radio frame is selected, and the communication process is performed. When selected, the received radio frame is routed and communication is continued in real time. When the accumulation process is selected, the received radio frame is accumulated in the database, so depending on the capacity of the radio link, the communication process or It is possible to select an accumulation process. As a result, it is possible to perform control for optimizing the high-speed wireless link usage distribution.

  (10) The wireless relay method of the present invention is a wireless relay method that relays wireless communication using any of a plurality of wireless communication interfaces, and includes a first wireless link and a second wireless link. Analyzing the link capacity, and performing a communication process for relaying the received radio frame in real time or an accumulation process for accumulating the received radio frame based on the link capacity of the first radio link and the second radio link. Selecting, when the communication process is selected, routing the received radio frame to continue communication in real time, and when the storage process is selected, storing the received radio frame in a database And at least.

  As described above, based on the link capacities of the first radio link and the second radio link, the communication process for relaying the received radio frame in real time or the accumulation process for accumulating the received radio frame is selected, and the communication process is performed. When selected, the received radio frame is routed and communication is continued in real time. When the accumulation process is selected, the received radio frame is accumulated in the database, so depending on the capacity of the radio link, the communication process or It is possible to select an accumulation process. As a result, it is possible to perform control for optimizing the high-speed wireless link usage distribution.

  According to the present invention, communication processing or storage processing can be selected according to the capacity of the radio link. As a result, it is possible to perform control for optimizing the high-speed wireless link usage distribution.

1 is a diagram illustrating a schematic configuration of an unmanned aerial vehicle system according to a first embodiment. It is a block diagram which shows schematic structure of the mobile router which concerns on 1st Embodiment. It is a flowchart which shows the operation | movement which a radio | wireless quality analysis part calculates actual measurement throughput. It is a flowchart which shows the operation | movement which a wireless quality analysis part outputs a TCP sequence number. It is a flowchart which shows the operation | movement which a wireless quality analysis part calculates the congestion degree of Wi-Fi. It is a flowchart which shows operation | movement in case a data judgment part makes a DHCP Discover response. 7 is a flowchart illustrating an operation of notifying the transmission source of a radio frame that storage processing has been performed when the data determination unit determines to perform storage processing. It is a flowchart which shows the operation | movement which the data judgment part 28 performs an accumulation | storage process, when the throughput in one link increases from the theoretical maximum value to the predetermined threshold value. It is a flowchart which shows the operation | movement which a data judgment part compares the throughput calculated from a congestion degree. It is a figure which shows schematic structure of the radio relay system which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the conventional UAS.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an unmanned aerial vehicle system according to the present embodiment. The UAS 1 includes a mobile router (MR) 3 having the function of the station 3a and the function of the access point 3b. Then, the radio frame received from the terminal 5 flies over an isolated area such as a disaster-stricken area, and it is determined whether to use real-time communication or storage-type communication. Further, it is also determined whether to use real-time communication or storage-type communication for a new user who has made a connection request.

  For example, in an isolated area such as a stricken area, there are many cases where the base station is broken and there are few terminals 5 that can communicate. For this reason, for a terminal capable of communication, the usable link capacity is large and high-speed communication is often possible. For example, in FIG. On the other hand, in a non-isolated area, since many user terminals are in a communicable state, the link capacity that can be used by each terminal is small. For example, in FIG.

  In the present embodiment, for each TCP session, it is controlled whether to use real-time communication or storage-type (anti-delay) communication. The high-speed link transmits to the limit, and the portion that cannot be transmitted by the low-speed link is temporarily stored in the MR. Thereafter, the accumulated amount is transmitted while determining the wireless quality of the low-speed link. In the example illustrated in FIG. 1, it is assumed that the link capacity of Wi-Fi # 2 is 100 and the link capacity of Wi-Fi # 1 is 30. In this case, 30 link capacities are used for real-time communication. On the other hand, the surplus 70 of the capacity 100 is regarded as accumulation type communication. Thereafter, when the link capacity of Wi-Fi # 1 increases or when the link capacity has a margin, the stored radio frames are transmitted to the access point 7 and the Internet 9. In this way, it is possible to effectively utilize the surplus capacity of a high-speed link using MR.

  FIG. 2 is a block diagram showing a schematic configuration of the mobile router according to the present embodiment. The mobile router 3 includes a wireless interface 20 on the LAN side and a wireless interface 22 on the WAN side. Further, a wireless quality analysis unit 24 on the LAN side and a wireless quality analysis unit 26 on the WAN side are provided. The radio quality analysis units 24 and 26 acquire radio frames from the radio interface on the LAN side or WAN side, and estimate the capacity of the radio link.

  That is, the radio quality analysis units 24 and 26 input a radio frame such as Wi-Fi, and output the input radio frame and quality information of the radio frame. The wireless frame quality information is information indicating the name of the wireless interface, information indicating whether or not the wireless link is communicated, information indicating the wireless link capacity, source / destination IP address, and source / destination port number. Information and application layer protocol type.

  Whether or not the wireless link is in communication can be recognized by the number of received frames per unit time or a response to ping. The radio link capacity is measured throughput (for example, 54 Mbps for Wi-Fi), throughput estimated from a TCP SEQ number per unit time, Wi-Fi congestion degree, and data link layer throughput estimated from a retransmission rate. It can be recognized based on the link capacity broadcast from the ground AP / base station or the like. Also, the protocol type of the application layer is used to distinguish whether it is real-time communication such as voice call or storage type.

  The data determination unit 28 calculates a difference in the link capacity between the WAN side and the LAN side, and based on the difference in the link capacity, determines whether to perform communication processing for performing real-time communication on the radio frame or storage processing. Select. When communication processing is selected, a new DHCP Discover is distributed to the routing unit 30. On the other hand, when the accumulation process is selected, it is interrupted and a response is returned from the DHCP server in the MR. That is, the radio frame is stored in the DTN storage device 34 via the storage processing unit 32. It is also possible to make it known that all TCP sessions are accepted by communication processing, and if the capacity difference exceeds a threshold value, beacon or the like can accept only the protocol for the accumulation processing. Also, based on real-time type communication, a real-time type communication processing protocol disconnects a new TCP session depending on the difference in link capacity. On the other hand, it is determined whether or not to release the accumulated data.

  The data determination unit 28 inputs the output of the radio quality analysis units 24 and 265, for example, the radio frame and the quality information on the WAN side / LAN side, while the input radio frame and routing table update information (existing process) , Output the stored data output command. The update information of the routing table is added to the NAPT conversion table during communication processing and newly added during storage processing. Further, the output command of the accumulated data depends on the application of the accumulation process. That is, confirmation of establishment of a radio link on the receiving side, information for specifying a communication partner such as EID information acquired from Discovery in DTN, a command for writing a radio frame into a buffer, and the like are executed.

FIG. 3 is a flowchart illustrating an operation in which the wireless quality analysis unit calculates the actually measured throughput. First, the observation time γ _t is input (step S1), and “Timer Old = 0, Timer = 0, FLCounter = 0” is set (step S2). Next, a radio frame is received (step S3). Here, the reception time is T, and the received radio frame length is L. Next, “Timer = Timer + T” is set (step S4), and “FLCounter = FLCounter + L” is set (step S5). Next, it is determined whether or not “Timer-Timer Old> γ _t ” (step S6). If not “Timer-Timer Old> γ _t ”, the process proceeds to step S3. On the other hand, if “Timer-Timer Old> γ _t ” in step S6, the measured throughput is set to “TH = FLCounter / γ _t ” (step S7), and “Timer Old = Timer, FLCounter = 0” (step S7). S8), the actually measured throughput TH is output.

  Thus, since the actual measurement throughput is calculated, the actual measurement throughput can be obtained regardless of the protocol. Since the measurement is performed from the received radio frame, the link capacity can be measured with high accuracy.

FIG. 4 is a flowchart illustrating an operation in which the wireless quality analysis unit outputs a TCP sequence number. First, the observation time γ _t is input (step T1), and “Timer Old = 0, Timer = 0, SEQ Old.I = 0, SEQCnt.i = 0, N = 0” is set (step T2). Here, “.i” is a subscript representing an arbitrary TCP session. Next, a radio frame is received (step T3), and it is determined whether or not the received radio frame is a TCP frame (step T4). Here, T is the reception time. Next, “Timer = Timer + T” is set (step T5), and it is determined whether or not it is a new TCP session (step T6). Here, the TCP sequence number is Si.

If it is not a new TCP session, the process proceeds to step T8. If it is a new TCP session, “N = N + 1” is set (step T7), and “SEQCnt.i = SEQCnt.i + Si” is set (step T8). Next, it is determined whether or not “Timer-Timer Old> γ _t ” (step T9). If not “Timer-Timer Old> γ _t ”, the process proceeds to step T3. On the other hand, if “Timer-Timer Old> γ _t ” in step T9, “SEQ_inc” satisfying the following equation is calculated (step T10), and “Timer Old = Timer, SEQ Old.I = SEQCnt.i” is calculated. (Step T11), "SEQ_inc" is output.

このように、ＴＣＰのシーケンス番号を算出するので、ＴＣＰの輻輳制御の影響を考慮したリンク容量を求めることが可能となる。プロトコルをＴＣＰに限定した場合に有効な手法である。

Thus, since the TCP sequence number is calculated, it is possible to obtain the link capacity in consideration of the influence of TCP congestion control. This is an effective technique when the protocol is limited to TCP.

FIG. 5 is a flowchart illustrating an operation in which the wireless quality analysis unit calculates the Wi-Fi congestion degree. First, the observation time γ _t is input (step P1), and “Timer Old = 0, Timer = 0, OccuSum = 0” is set (step P2). Next, a radio frame is received (step P3). Here, the reception time is T, the frame length is L, and the transmission rate is R. Next, “Timer = Timer + T” is set (step P4), and the congestion degree Octu is acquired (step P5). Note that a conventional technique can be used for the congestion degree calculation method itself. For example, "Measurement experiment of wireless LAN congestion and delay characteristics-Acquisition of basic data for heterogeneous radio-Tadayuki Fukuhara et al., IEICE Technical Report. SR, Software Radio 109 (442), 175- 182, 2010-02-24 ”.

Next, as “OccuSum = OccuSum + Occu” (step P6), it is determined whether or not “Timer-Timer Old> γ _t ” (step P7). If it is not “Timer-Timer Old> γ _t ”, the process proceeds to Step P3. On the other hand, if “Timer-Timer Old> γ _t ” in step P7, “OccuOut = OccuSum / γ _t ” is set (step P8), “Timer Old = Timer, OccuSum = 0” is set (step P9), Outputs “OccuOut”.

  Thus, since the degree of congestion of Wi-Fi is calculated, it becomes possible to consider the influence of retransmission and control packet resource consumption in the Wi-Fi section. This is an effective technique when the wireless interface is limited to Wi-Fi.

  FIG. 6 is a flowchart showing an operation in a case where the data determination unit 28 makes a DHCP Discover response. Here, communication processing or storage processing is performed for a user terminal that has newly made a connection request depending on which of the DHCP server of the mobile router 3 or the DHCP server in the non-isolated area allocates an IP address. Decide what to do. When a DHCP server in a non-isolated area allocates an IP address, communication processing is performed. On the other hand, when the DHCP server of the mobile router 3 allocates an IP address, the storage process is performed.

  In addition, it is determined whether to perform communication processing or storage processing for the already connected user terminal depending on whether or not the destination IP address of the received data frame is a mobile router. If the destination IP address of the received data frame is not a mobile router, communication processing is performed, whereas if the destination IP address of the received data frame is a mobile router, storage processing is performed.

  In FIG. 6, first, “DHCP Discover” is received (step Q1). Next, it is determined whether or not “determination frag = 1” (step Q2). If “determination frag = 1” is not established, communication processing is performed, and the process is distributed to the routing unit 30 (step Q3), and the process ends. On the other hand, if “determination frag = 1” in step Q2, accumulation processing is performed, “DHCP Offer” is returned to the transmission source (step Q4), and the process ends.

  FIG. 7 is a flowchart showing an operation of notifying the transmission source of the radio frame that the storage process has been performed when the data determination unit 28 determines to perform the storage process. If the criterion is satisfied, for example, the difference in link capacities exceeds a certain value, a bit is set at a predetermined position in the “vendor-specific field” of “Beacon” thereafter. The terminal that has received this “Beacon” recognizes whether or not the bit is set. If the bit is set, it is determined that the storage process is performed when a new connection is made.

  In FIG. 7, it is determined whether or not “determination frag = 1” (step R1). If “judgment frag = 1” is not satisfied, the process ends. If “judgment frag = 1”, a bit is set at a predetermined position of “vendor-specific field” of “Beacon” (step R2). finish.

  FIG. 8 is a flowchart showing an operation in which the data determination unit 28 performs an accumulation process when the throughput in one link increases from the theoretical maximum value to a predetermined threshold value. In FIG. 8, “determination frag = 0” is set, and the input is a margin γ (step U1). Next, the wireless quality information is received (step U2), and it is determined whether (one maximum theoretical throughput) − (the other actually measured throughput) is equal to or greater than a threshold value γ (step U3). If (one maximum theoretical throughput)-(the other actual measured throughput) is not equal to or greater than the threshold γ, the process ends, and (one maximum theoretical throughput)-(the other actual measured throughput) is equal to or greater than the threshold γ. Ends with “determination frag = 1” (step U4). When the threshold value γ is 0 or less, “when one is equal to or greater than the other theoretical value” is obtained.

  Instead of the actually measured throughput, it is also possible to use the throughput calculated from the increase in the TCP sequence number shown in FIG. 4 or the Wi-Fi congestion degree shown in FIG. That is, regarding the increase in the TCP sequence number shown in FIG. 4, “the throughput conversion of the increase in the TCP SEQ is throughput = Seq_inc * 8 [bps]”. For the Wi-Fi congestion degree shown in FIG. 5, “Wi-Fi congestion degree throughput conversion is defined as throughput = FLOOR ((1−OccuOut) / (transmission time per data packet + each packet). "FLOOR ()" represents rounding down after the decimal point. However, the calculation of (transmission time per data packet) requires a radio frame length [bps] and MCS, and here, it is calculated assuming that the maximum MTU size and transmission rate can be obtained.

  By calculating in this way, communication processing can be performed up to the limit of the link capacity. Since it is easier to select the communication process than the accumulation process, the communication efficiency can be enhanced most if the wireless communication environment is good. If the wireless communication environment is inferior, it may be an effective method when the wireless communication environment is good, because unsuccessful communication processing may be repeated to reduce efficiency.

  FIG. 9 is a flowchart illustrating an operation in which the data determination unit 28 compares the throughputs calculated from the congestion degree. In FIG. 9, first, “determination frag = 0” is set, and the input is a margin γ (step W1). Next, the wireless quality information is received (step W2), and it is determined whether (one Wi-Fi congestion degree throughput) − (the other Wi-Fi congestion degree throughput) is equal to or greater than a threshold γ (step W3). If (one Wi-Fi congestion degree throughput)-(the other Wi-Fi congestion degree throughput) is not equal to or greater than the threshold value γ, the process is terminated, and (one Wi-Fi congestion degree throughput)-(the other Wi-Fi congestion degree throughput) If -Fi congestion degree throughput) is equal to or greater than the threshold value γ, “determination frag = 1” is set (step W4), and the process ends.

  As described above, the throughput conversion of the degree of Wi-Fi congestion is: throughput = FLOOR ((1−OccuOut) / (transmission time per data packet + waiting time defined for each packet)). FLOOR () represents truncation after the decimal point, but the radio frame length [bps] and MCS are used for the calculation of (transmission time per data packet).

  By calculating in this way, it is possible to compensate for the amount by the accumulation processing in consideration of a case where the wireless communication environment is bad, such as a wireless section being congested on one link.

  As described above, according to the first embodiment, it is possible to switch between the communication process and the accumulation process in accordance with the difference in link capacity. As a result, more data can be acquired within a limited battery of the UAS (Unmanned Aircraft System), that is, within the flight time. Further, when the UAS moves and comes over the isolated area, only the accumulation process can be performed.

(Second Embodiment)
FIG. 10 is a diagram illustrating a schematic configuration of a wireless relay system according to the second embodiment. In this embodiment, it is composed only of an AP operated by a WDS (Wireless Distribution System) and a storage device. In FIG. 10, the relay device 3-1 includes an access point 3-1a and a DTN storage device 3c. That is, this relay device 3-1 operates with WDS, and UAS becomes an access point. With this configuration, the station function can be deleted, so that the device configuration is simplified.

  As described above, according to the present embodiment, communication processing or storage processing can be selected according to the capacity of the radio link. As a result, it is possible to perform control for optimizing the high-speed wireless link usage distribution.

  When the accumulation process is performed, it may be notified that the accumulation process has been performed, not the communication process for performing real-time communication from the application layer to the transmission source. It is also possible to adopt a configuration in which communication processing or storage processing is switched according to the remaining amount of the UAS battery or the remaining amount of the mobile router battery.

3 Mobile router 3-1 Relay device 3-1a Access point 3a Station 3b Access point 3c DTN storage device 5 Terminal 7 Access point 9 Internet 20 Wireless interface (LAN side)
20 Routing unit 22 Wireless interface (WAN side)
24 Wireless quality analysis unit (LAN side)
26 Radio Quality Analysis Department (WAN side)
28 Data judgment unit 30 Routing unit

Claims (9)

An unmanned aerial vehicle system comprising a mobile router having the functions of an access point and a station, and an unmanned aircraft equipped with the mobile router ,
A wireless quality analysis unit that estimates the link capacity of the wireless link on the LAN side and the WAN side for each TCP session ;
A data determination unit that selects, for each TCP session , a communication process for relaying a received radio frame in real time or a storage process for accumulating the received radio frame based on the link capacity of the LAN side and WAN side radio links When,
When the communication processing is selected, a routing unit that continues the communication in real time by routing the received radio frame;
A storage processing unit for storing the received radio frame in a database when the storage processing is selected ,
An unmanned aerial vehicle system that performs real-time communication according to the link capacity of the radio link and accumulation according to the link capacity of the radio link for each TCP session . The unmanned aerial vehicle system according to claim 1, wherein when the data determination unit selects the accumulation process, the wireless frame transmission source is notified that the accumulation process is selected. The data determination unit, when the link capacities are different, performs the communication process with a smaller link capacity and performs the accumulation process with a link capacity corresponding to a capacity difference between the link capacities. The unmanned aerial vehicle system according to claim 1 or 2 . 4. The unmanned aerial vehicle system according to claim 1 , wherein, when the link capacities are the same, the data determination unit performs the communication processing with the link capacities. 5. The data determination unit performs the communication process when the capacity difference between the link capacities is equal to or less than a predetermined threshold, and when the capacity difference exceeds the threshold, The unmanned aerial vehicle system according to claim 1 or 2, wherein accumulation processing is performed. The accumulation processing unit outputs the accumulated radio frame when a predetermined condition is satisfied,
The unmanned aircraft system according to any one of claims 1 to 5 , wherein the routing unit routes the output radio frame to transmit to the destination of the radio frame. The radio quality analysis unit uses either measured throughput, throughput estimated from a TCP (Transmission Control Protocol) sequence number per unit time, data link layer throughput estimated from the degree of congestion, or link capacity acquired in advance. The unmanned aerial vehicle system according to any one of claims 1 to 6 , wherein a link capacity of the wireless link on the LAN side and the WAN side is analyzed. A mobile router program installed on an unmanned aerial vehicle and having access point and station functions,
Link capacity estimation processing for estimating the link capacity of the wireless link on the LAN side and WAN side for each TCP session;
A selection process for selecting a communication process for relaying a received radio frame in real time or an accumulation process for accumulating the received radio frame based on link capacity of the LAN side and WAN side radio links for each TCP session;
When the communication process is selected, a routing process that continues the communication in real time by routing the received radio frame;
When the accumulation process is selected, a series of processes of accumulating received radio frames in a database is executed, and for each TCP session, real-time communication according to the link capacity of the radio link and the radio A program that performs accumulation according to the link capacity of a link. A relay method using a mobile router having functions of an access point and a station, and an unmanned aircraft system composed of an unmanned aircraft equipped with the mobile router,
In the mobile router,
Estimating the link capacity of the LAN side and WAN side radio links for each TCP session;
Selecting a communication process for relaying the received radio frame in real time or an accumulation process for accumulating the received radio frame based on the link capacity of the LAN side and WAN side radio links for each TCP session;
If the communication process is selected, routing the received radio frame to continue communication in real time;
If the storage process is selected, storing the received radio frame in a database;
Including
A relay method characterized by performing real-time communication according to the link capacity of the radio link and accumulation according to the link capacity of the radio link for each TCP session.

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