JP2019029688A - Communication system and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system and a communication method capable of preventing quality deterioration at an application level such as image distortion and control failure even when a plurality of communication paths are used at the same time. A communication node inspects a packet generated by itself or received from another transmitting node 400, selectively determines whether or not the packet needs to be duplicated based on the inspection result, and a packet that needs to be duplicated. Is characterized in that it is duplicated and transmitted to the receiving node 200 via a plurality of communication interfaces, and packets that do not need to be duplicated are transmitted to the receiving node 200 via any one communication interface. [Selection diagram] Fig. 2

Description

  In the present invention, two or more communication nodes that transmit and receive data including video, audio, control signals, feedback signals, etc., in which real-time properties are important, via a network via a network in which communication quality varies. The present invention relates to a communication system and a communication method for realizing improvement in communication bandwidth and reliability by providing different communication paths and using them simultaneously.

  In recent years, connection methods for connecting to a network for communication and using services have been diversified, and by using these multiple connection methods at the same time, compared to using only a single connection method. Therefore, a technique for expanding communication bandwidth, reducing network load, and improving resistance to communication interruption is used.

  As typical examples of such existing technology, MPTCP (Multipath TCP) (see Non-Patent Document 1), which is an extension of TCP (Transmission Control Protocol) suitable for applications that do not allow data loss and errors, video, There is MPRTP (Multipath RTP), which is an extension technology of RTP (Real-time Transport Protocol) often used for real-time voice communication (see Non-Patent Document 2 and Non-Patent Document 3).

  In these techniques, a packet to be transmitted is transmitted by selecting any one of available communication paths. By distributing the communication through multiple communication paths, the total bandwidth is increased by adding the communication bands of the multiple communication paths, or the bandwidth consumed by each path is distributed by distributing the communication that consumes a certain band to multiple paths. Reduce end-to-end resistance against communication path disruption by limiting packet loss and errors caused by deterioration in communication quality occurring in a communication path to only packets that flow through that communication path. Advantages such as being able to be improved are obtained.

  Of these, MPTCP can also duplicate and transmit all packets to all available communication paths by operating in redundant mode. This increases the probability of reducing the data communication delay while sacrificing the communication band.

A. Ford, 3 others, "TCP Extensions for Multipath Operation with Multiple Addresses", RFC6824, IETF, January 2013 V. Singh, 4 others, "Multipath RTP (MPRTP)", draft-ietf-avtcore-mprtp-03, AVT Core Working Group, Internet-Draft, IETF, July 8, 2016, [online], [Heisei Searched on June 22, 2017], Internet <URL: https: //tools.ietf.org/html/draft-ietf-avtcore-mprtp-03> V. Singh and two others, "MPRTP: Multipath Considerations for Real-time Media", ACM Multimedia Systems, MMSys, 2013

  However, the packets to be transmitted are not uniformly copied and transmitted to all available communication paths, but based on the size of the packet to be transmitted, the delay for each communication path, the bandwidth, and the packet loss rate. Then, any one of the communication paths is selected and transmitted. For example, in the case of a data packet having a large size, a communication path having the largest bandwidth ratio with respect to delay and a small loss rate is selected.

  When communication quality deteriorates in a certain route, packets flowing through that route may be lost or an error may occur, but with existing technologies, the magnitude of the effect of loss or error is considered. Therefore, if a problem occurs in the route through which such a packet flows, an important packet cannot be correctly received on the receiving side, which may cause a serious adverse effect.

  As shown in FIG. In the case of video data using a video codec that performs inter-frame compression such as H.264, when communication quality deteriorates in a communication path through which a packet including an IDR frame / I frame flows, it occurs in the other communication path. Compared to the case, the image is greatly disturbed.

  Further, even in an image codec that does not perform interframe compression, such as JPEG (Joint Photographic Experts Group), if a packet including a restart marker and a quantization table is lost, the decoding accuracy for data loss is reduced.

  In addition, as shown in FIG. 28, when metadata such as moving object detection, face recognition, and voice detection in a video is embedded in video data, or a time stamp that refers to video data is added and transmitted as separate data, If the communication quality deteriorates in the communication path through which the packet containing metadata etc. flows, the detection result is lost along with the video, or only the detection result remains and the video data indicating it is lost, or conversely, the video However, there is a problem that only the remaining detection results are lost. As a result, the operation of a system (such as a monitoring system) that operates according to the detection result may be defective.

  If all data is simply duplicated and transmitted over all available communication paths, the risk of such problems can be reduced, but communication band consumption becomes inefficient.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent quality deterioration at the application level such as video disturbance and control failure even when a plurality of communication paths are used simultaneously. It is an object of the present invention to provide a communication system and a communication method.

  In order to achieve the above object, the applicant pays attention to the fact that there is a difference in the importance of the contents included in the packet in the packet sequence obtained by dividing one original data, and the highly important data. By using multiple routes redundantly for packets that contain packets, and for packets that are not so, select the communication route and transmit it, while suppressing the increase in network load and reaching the packets to the receiving node Invented a technique to improve the performance.

  The present invention is a communication system having a communication node having a plurality of communication interfaces and transmitting packets generated by itself or received from other transmission nodes to the reception node via the plurality of communication interfaces, The communication node inspects a packet generated by itself or received from another transmitting node, selectively determines whether or not to duplicate the packet based on the inspection result, and duplicates a plurality of packets that need to be duplicated. The packet is transmitted to the receiving node via the communication interface, and a packet that does not need to be duplicated is transmitted to the receiving node via any one of the communication interfaces.

  According to the present invention, in a communication system that uses a plurality of communication paths for data at the same time, even if communication quality deteriorates in some communication paths, a packet including important data has real-time characteristics. Since it is possible to be a receiving node without losing it, it is possible to suppress image disturbance and prevent control failure.

Overall configuration diagram of a communication system according to the present invention Operation | movement explanatory drawing of the communication system which concerns on 1st Embodiment Functional block diagram of a communication node according to the first embodiment Packet inspection unit operation flow Detailed operation flow of the packet inspection unit Operation flow of packet processor Operation sequence of communication system according to first embodiment Operation Flow of Packet Inspection Unit According to Embodiment 1 Example of inspection rule information according to the first embodiment Operation flow of packet inspection unit according to embodiment 2 Example of inspection rule information according to the second embodiment Operation Flow of Packet Inspection Unit According to Embodiment 3 Example of inspection rule information according to the third embodiment Example of transmission rule information according to the fourth embodiment Operation | movement explanatory drawing of the communication system which concerns on 2nd Embodiment Functional block diagram of a communication node according to the second embodiment Operation flow of pre-processing unit Operation flow of packet data holding unit Detailed operation flow of packet data holding unit Packet inspection unit operation flow Detailed operation flow of the packet inspection unit Operation sequence of communication system according to second embodiment Example of packet association information according to embodiment 5 Example of packet data holding rule according to embodiment 6 Example of packet data according to embodiment 7 Example of inspection rule information according to the eighth embodiment Diagram explaining problems in the prior art A diagram explaining other problems in the prior art

(First embodiment)
A communication system according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a communication system according to the present invention, and FIG. 2 is a diagram for explaining the operation of the communication system according to the first embodiment.

  In the present invention, a “packet” is a packet in the network layer, which is the third layer of the OSI (Open Systems Interconnection) reference model. That is, the present invention relates to a method for controlling packet transfer in the network layer, and relates to processing in the transport layer and higher of the OSI reference model.

  In FIG. 1, the communication node 100 operates the functions and programs of the present invention, holds a plurality of logical or physical communication interfaces connected to a plurality of networks 300, connects to the network, and connects to the receiving node 200. A device that generates and transmits a packet or forwards a packet received from another. That is, the communication node 100 functions as one or both of the transmission node and the relay node. The communication node 100 may be a physical device or a virtual device. The networks 300 to be connected may be physically the same or a combination of different ones.

  The receiving node 200 is an apparatus that is connected to the network 300 and receives a packet transmitted from a transmitting node (the communication node 100 or the transmitting node 400 in FIG. 1). The receiving node 200 may be a physical device or a virtual device.

  The transmission node 400 is an apparatus that is connected to the network 500 to generate and transmit a packet. The transmission node 400 may be a physical device or a virtual device.

  In the case where the communication node 100 is an apparatus that exclusively transmits packets generated by itself, the network configuration is as shown in FIG. On the other hand, in the case where the communication node 100 is an apparatus that transfers a packet generated by another transmission node 400, the network configuration is as shown in FIG. In FIG. 1B, a node may be further configured in a multistage configuration between the transmission node 400 and the communication node 100.

  In the present embodiment, the communication node 100 transmits (transfers) a single type of packet. Here, a single type of packet refers to the data stream in the case where data communication in an upper layer (for example, application layer) between the transmission node and the reception node is performed by a single type of data stream (packet string). Means the packet. For example, H.264 using RTP (Real-time Transport Protocol). Examples include a packet related to H.264 codec video data transmission, a packet related to JPEG image data transmission using RTP, and a packet related to RTP data transmission including the motion detection result as metadata in the RTP header. The overall configuration of the communication system may be either of FIGS. 1 (a) and 1 (b). In the present embodiment, the configuration of FIG. 1A will be described as an example.

  As shown in FIG. 2, the communication system according to the present embodiment inspects the contents of the packet sequence to be generated (or received), determines whether or not the packet needs to be duplicated based on the inspection result, and requires duplication. The packet is duplicated and transmitted via a plurality of communication interfaces, and the packet which does not need to be duplicated is transmitted via any one of the plurality of communication interfaces.

  Next, the configuration of the communication node 100 will be described in detail with reference to FIG. FIG. 3 is a functional block diagram of the communication node according to the first embodiment. As shown in FIG. 3, the communication node 100 includes a packet generation unit 101, a packet reception unit 102, a packet inspection unit 103, an inspection rule management unit 104, a packet processing unit 105, a transmission rule management unit 106, A packet transmitting unit 107 and a plurality (three in the example of FIG. 3) of communication interfaces 190 are provided. Note that each unit constituting the communication node 100 may be implemented as hardware, installed by program installation in a physical device or virtual device, or a combination of these mounting technologies.

  The packet generation unit 101 is a functional block that packetizes original data such as video, that is, transmission target data. The packet generation unit 101 operates when the communication node 100 is used as a transmission node to generate a packet itself.

  The packet receiving unit 102 is a functional block that receives original data such as video, that is, transmission target data as a packet from the external transmission node 400. The packet receiving unit 102 operates when the technique of the present invention is used for a packet received as a forwarding node.

  The packet inspection unit 103 receives a packet from the packet generation unit 101 or the packet reception unit 102, inspects the contents of the packet based on the rule information acquired from the inspection rule management unit 104, and determines whether or not duplication transfer is necessary It is.

  The inspection rule management unit 104 is a functional block that holds the contents of inspection performed by the packet inspection unit 103 as rule information. The inspection rule management unit 104 may be configured to connect to an external database through a network and acquire rule information.

  The packet processing unit 105 is a functional block that performs packet duplication, identifier assignment processing, and determination of the communication interface 190 used for transmission of the packet based on the inspection result of the packet inspection unit 103. Here, the packet processing unit 105 determines the communication interface 190 used for packet transmission by referring to the state of the available communication interface 190 and the size of the packet to be transmitted based on transmission rule information described later. In addition, identifier assignment processing is a sequence of packets in subflow units in order to set different identifiers (subflow identifiers) for each communication interface that transmits packets and to measure packet loss for each subflow. In this process, a number is set and added to the packet header as additional information.

  The transmission rule management unit 106 is a functional block that stores rule information used when the packet processing unit 105 determines a communication interface 190 for copying and transmitting a packet. The transmission rule management unit 106 may be configured to connect to an external database through a network and acquire rule information.

  The packet transmission unit 107 is a functional block that transmits the packet processed by the packet processing unit 105 via the communication interface 190.

  The communication interface 190 is a connection interface with the network 300. Various standards can be used for the communication interface 190. Examples include Ethernet (registered trademark), wireless LAN (Local Area Network), GSM (Global System for Mobile communications), UMTS (Universal Mobile Telecommunications Service), LTE (Long Term Evolution), and the like. The communication interface 190 may be a physical interface or a logical communication interface.

  The operation of the packet inspection unit 103 will be described with reference to FIG. When the packet inspection unit 103 is activated, it acquires the inspection rule from the inspection rule management unit 104 (step S1). When the packet inspection unit 103 receives the packet (step S2), the received packet is collated with the acquired inspection rule (step S3). If there is a match, the packet processing unit 105 is notified as a duplicate packet (step S4), and if there is no match, the packet processing unit 105 is notified as a non-replication packet (normal packet) (step S5).

  The detailed operation of the packet inspection unit 103 will be described with reference to FIG. In FIG. 5, the same operations as those in FIG. This detailed operation has the following inspection rules: “As the influence of packet loss is large, it is a delimited packet of the same group (eg, the end of a video frame) (step S3-1), decoding parameters (quantization table, encoding) Table (step S3-2), reference data (key frame in video codec, independent slice segment, etc.) packet (step S3-3), metadata (face recognition information, etc.) "What is determined as a replication target" (step S3-4) is applied. In addition, the reference | standard which determines as replication object may be said arbitrary arbitrary parts (FIG. 5 illustrates the case where all are used). The order of determination is not limited to the above example.

  The operation of the packet processing unit 105 will be described with reference to FIG. When started, the packet processing unit 105 acquires transmission rule information from the transmission rule management unit 106 (step S11), and receives a packet and an inspection result from the packet inspection unit 103 (step S12). Based on the acquired transmission rule information, the packet processing unit 105 selects an interface by the number of packet duplications among the available communication interfaces 190 when the inspection result of the packet is a duplication packet (steps S13 and S14). The packet is duplicated (step S15). Then, additional information is added to the packet (step S16), and the packet is passed to the communication interface 190 to be transmitted via the packet transmission unit 107 (step S17). Here, the processes of steps S16 and S17 are performed by the number of packet duplications. If the inspection result of the packet is not a duplicate packet, the packet processing unit 105 selects one interface to be used for transmission from the available communication interfaces 190 (steps S13 and S18), and transmits the transmission target via the packet transmission unit 107. The packet is transferred to the communication interface 190 (step S17).

  With such a configuration, the operation sequence of the communication system according to the present embodiment is as shown in FIG. In FIG. 7, only the case where the communication node 100 generates the original data is described for the sake of simplicity.

[Example 1]
As Example 1, the communication node 100 according to the present embodiment is an H.264 network using RTP. An example of an operation flow of the packet inspection unit 103 when operating on H.264 codec video data is shown in FIG. Moreover, the example of the inspection rule information in the present Example 1 is shown in FIG. In FIG. 8, the same operations as those in FIG.

  In the first embodiment, if there is a loss, a packet that has a large influence on the receiving side includes a packet including data at the end of the frame, a packet having data belonging to an SPS (Sequence Parameter Set) or PPS (Picture Parameter Set) or IDR picture, SEI In this example, a packet having (Supplemental Enhancement Information) data is determined as a duplicate packet. These are all set values defined by RFC6184.

  Specifically, as illustrated in FIGS. 8 and 9, the packet inspection unit 103 includes a packet having a marker bit of 1 (step S3-11), a packet having an NRI of 11 or 10 (step S3-12), and a NAL unit. A packet whose Type is 6 (step S3-13) is determined as a replication target.

  8 and 9, M is the value of the marker bit of the RTP header, and is set in the RTP header. NRI is a value of NAL Reference IDC, and is set in a NAL Unit header in the RTP payload. NALU_TYPE is a value of NAL Unit Type and is set in the NAL Unit header in the RTP payload.

[Example 2]
As Example 2, FIG. 10 shows an operation flow example of the packet inspection unit 103 when the communication node 100 according to the present embodiment operates on JPEG image data using RTP. Moreover, the example of the inspection rule information in the present Example 2 is shown in FIG. 10, the same operations as those in FIG. 4 are denoted by the same reference numerals.

  In the second embodiment, a packet including data at the end of a frame, a packet having a quantization table and a Huffman code table, and a packet having a restart marker are determined as duplicate packets as packets that have a large influence on the receiving side when lost. This is an example. These are all values defined by RFC2485.

  Specifically, as shown in FIGS. 10 and 11, the packet inspection unit 103 includes a packet with a marker bit of 1 (step S3-21), a packet with a type of 64 to 127 (step S3-22), Q The packet is 128 or more and 255 or less (step S3-23) and the Fragment Offset is 0 (step S3-24).

  10 and 11, M is the value of the marker bit of the RTP header and is set in the RTP header. TYPE is set in the JPEG main header in the RTP payload and is a value representing the JPEG data type. Q is a value representing a quantization table number set in the JPEG main header in the RTP payload. Fragment Offset is an offset value from the first image data in the frame of the RTP packet in the same frame, which is set in the JPEG main header in the RTP payload.

[Example 3]
As Example 3, the operation of the packet inspection unit 103 when the communication node 100 according to the present embodiment operates on RTP data including a moving object detection (for example, face detection) result as metadata in the RTP header. An example of the flow is shown in FIG. Moreover, the example of the inspection rule information in the present Example 3 is shown in FIG. 12, the same operations as those in FIG. 4 are denoted by the same reference numerals.

  In the second embodiment, if the packet is lost, the detection result is lost, and the reception side has a large influence. A packet including data at the end of the frame and information indicating that the number of detections is 1 or more are set in the RTP extension header. This is an example when it is determined that a packet is a duplicate packet.

  Specifically, as illustrated in FIGS. 12 and 13, the packet inspection unit 103 performs packet inspection with a marker bit of 1 (step S3-31), X of 1 (step S3-32), and face detection ID (step S3-31). S3-33) and the number of detections> 0 (step S3-34) are determined as replication targets.

  In FIG. 12 and FIG. 13, M is the value of the marker bit of the RTP header and is set in the RTP header. X is the extension value of the RTP header and is set in the RTP header. The ID is an identifier indicating the detection type of the detection result set in the RTP extension header. In this example, the value is 0x000F, indicating that the face detection result is set. Further, detectedNum is a value indicating the number of detected faces. Note that the ID and detectedNum are one of the expression formats of the detection result, and do not depend on a specific specification or technology.

[Example 4]
FIG. 14 shows an example of transmission rule information managed by the transmission rule management unit 106 as the fourth embodiment. In FIG. 14, “Copied” indicates whether the packet is a duplicate packet (Yes) or a non-duplicate packet (No). Further, IF indicates the number of interfaces used for transmission of the packet from among the available communication interfaces. Criteria indicates a criterion for selecting an interface to be used for transmission of the packet from available communication interfaces. RR is the round robin method, Bandwidth (DESC) indicates the descending order of the bandwidth of the communication interface, non-duplicate packets are selected by round robin, and duplicate packets are selected N IFs in descending bandwidth order Indicates.

(Second Embodiment)
A communication system according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 15 is a diagram for explaining the operation of the communication system according to the second embodiment. Here, differences from the first embodiment will be described in detail. In the present embodiment, the same functions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  This embodiment is an embodiment in which the communication node 600 mixes and transmits (transfers) different types of packets. Here, when different types of packets are mixed, data communication in the upper layer (for example, application layer) between the transmission node and the reception node is performed by dividing it into a plurality of types of data streams (packet sequences). Means that the communication node 600 processes the packets related to each data stream in a mixed state. For example, there is a case where video data and metadata such as a moving object detection result in the video flow separately through the network as different types of packets instead of the same packet. The overall configuration of the communication system may be any of the above-described FIGS. 1 (a) and (b). In the present embodiment, the configuration of FIG. 1B will be described as an example.

  As shown in FIG. 15, the communication system according to the present embodiment generates or receives a plurality of different packet sequences, records the packet contents, checks the packet contents against the records, The necessity of packet duplication is determined based on the inspection result, and a packet that needs to be duplicated is duplicated and transmitted through a plurality of communication interfaces. A packet that does not need to be duplicated is one of the plurality of communication interfaces. To send through.

  Next, the configuration of the communication node 600 will be described in detail with reference to FIG. FIG. 16 is a functional block diagram of a communication node according to the second embodiment. As shown in FIG. 16, the communication node 600 includes a packet generation unit 101, a packet reception unit 102, a packet inspection unit 601, an inspection rule management unit 104, a packet processing unit 105, a transmission rule management unit 106, A packet transmission unit 107 and a plurality (three in the example of FIG. 16) of communication interfaces 190 are provided. The above configuration is the same as that of the first embodiment except for the operation of the packet inspection unit 601. Communication node 600 according to the present embodiment further includes a preprocessing unit 602, a packet data holding unit 603, a packet data holding rule management unit 604, and a packet association information management unit 605. Note that each unit constituting the communication node 600 may be implemented as hardware, installed by program installation in a physical device or virtual device, or a combination of these mounting technologies.

  The preprocessing unit 602 is a functional block that passes a packet received from the packet generation unit 101 or the packet reception unit 102 to the packet data holding unit 603 and the packet inspection unit 601.

  The packet data holding unit 603 is a functional block that reads the packet received from the preprocessing unit 602 and records and holds packet data used by the packet inspection unit 601 for packet inspection.

  The packet data holding rule management unit 604 is a functional block that holds as a rule what the packet data holding unit 603 should hold in the received packet information. The configuration may be such that rule information is acquired by connecting to an external database through a network.

  The packet inspection unit 601 is a functional block that reads the packet received from the preprocessing unit 602 and determines whether or not packet duplication is necessary using the inspection rule and the packet data held by the packet data holding unit 603.

  The packet association information management unit 605 is a functional block that holds association information between different types of packets received by the packet inspection unit 601. The configuration may be such that rule information is acquired by connecting to an external database through a network.

  The operation of the preprocessing unit 602 will be described with reference to FIG. When the preprocessing unit 602 is activated and receives a packet (step S21), it passes the packet to the packet inspection unit 601 and the packet data holding unit 603 in parallel (steps S22 and S23).

  The operation of the packet data holding unit 603 will be described with reference to FIG. When activated, the packet data holding unit 603 acquires a holding rule from the packet data holding rule management unit 604 (step S31), receives a packet from the preprocessing unit 602 (step S32), and holds packet data that matches the holding rule. (Step S33).

  The detailed operation of the packet data holding unit 603 will be described with reference to FIG. 19, the same operations as those in FIG. 18 are denoted by the same reference numerals. In this detailed operation, as a packet data retention rule managed by the packet data retention rule management unit 604, a retention condition is defined for each packet type, and for the packet that matches the retention condition, time information and sequence number that the packet has The necessity of holding information, flag information, and measured quantity information and the holding format for holding are defined. Here, the time information means a value that is set in the header or payload of the packet and represents the generation time, transmission time, or transfer time of the packet. For example, in the RTP packet, the RTP timestamp value set in the header corresponds. The sequence number information means a value indicating the order between a plurality of packets set in the header or payload of the packet. For example, in the RTP packet, the value of the RTP sequence number set in the header corresponds. The flag information means a value that is set in the header or payload of the packet and indicates two values, such as presence / absence of a function, success / failure of a processing result, and good / bad state. For example, in the RTP packet, the value of the RTP marker bit set in the header corresponds. The measured amount information means a value indicating a physical quantity such as speed, acceleration, temperature, humidity, and luminous intensity, an industrial quantity, and other quantities set in a packet header or payload. For example, the probability (likelihood) of the result of analyzing the type of an object present in a captured image, which is set in the payload of an RTP packet transmitted by a camera having an object detection function, is expressed by a real value from 0 to 1 Applicable value.

  If the packet received from the preprocessing unit 602 matches the holding condition (step S33-1), the packet data holding unit 603 determines that the time information, sequence number information, flag information, and measurement amount information need to be held. These are held as packet data according to the holding format (steps S33-2,..., S33-9).

  The operation of the packet inspection unit 601 will be described with reference to FIG. When activated, the packet inspection unit 601 acquires the inspection rule from the inspection rule management unit 104 (step S41), and acquires the packet association information from the packet association information management unit 605 (step S42). Next, when the packet inspection unit 601 receives a packet from the preprocessing unit 602 (step S43), if the received packet alone matches the inspection rule, the packet inspection unit 601 notifies the packet processing unit 105 that the copy is necessary (steps S44 and S48). ).

  If there is no match, the packet inspection unit 601 determines the retained packet data of a packet of a type different from the received packet based on the packet association information as an acquisition target (step S45), and acquires the packet data from the packet data storage unit 603. (Step S46). Then, the packet inspection unit 601 checks whether or not the corresponding information of the packet data and the received packet matches (step S47), and if they match, notifies the packet processing unit 105 that copying is necessary (step S48). On the other hand, if there is no match, the packet processor 105 is notified as a non-replicated packet (normal packet) (step S49).

  The detailed operation of the packet inspection unit 601 will be described with reference to FIG. In FIG. 21, the same operations as those in FIG. In this detailed operation, any one of time information, sequence number information, flag information, measurement amount information, or a combination thereof is held as an inspection rule between a packet to be inspected and packet data acquired based on the packet association information. It is determined whether or not the specified condition to be met is satisfied, and if it matches, the copy is required (steps S47-1,... S47-4).

  In the example of FIG. 21, an example is described in which all of the time information, sequence number information, flag information, and measurement amount information are used for determination, but may be a part, and the order of determination is not limited. . In addition, in the example of FIG. 21, an example is described in which whether or not the matching with each specified condition is determined based on the AND condition determines whether or not the final duplication is necessary. Decision logic may be used and is not limited to specific decision logic.

  With such a configuration, the operation sequence of the communication system according to the present embodiment is as shown in FIG. In FIG. 22, for the sake of simplicity of explanation, a part of the same parts as those in the first embodiment is omitted.

[Example 5]
FIG. 23 shows an example of packet association information managed by the packet association information management unit 605 as the fifth embodiment. FIG. 23 is an example of a case where the packet type A and the packet type B are related to each other. With such packet association information, when packet type A is received, it is necessary to acquire packet type B packet data and use it for inspection, or vice versa, when packet type B is received, packet type It can be seen that the packet data of A needs to be acquired and used for inspection.

[Example 6]
FIG. 24 shows an example of a packet data holding rule managed by the packet data holding rule management unit 604 as the sixth embodiment. In FIG. 24, for packet type A (H.264 / RTP video packet), M = 1 is set as flag information for a packet with an RTP marker bit of 1, and the RRI marker bit is 0 but NRI is 10 or 11. For each packet, M = 0 is held as flag information, RTP time stamp values are used as time information, RTP sequence number values are used as sequence number information, and measurement quantity information is used. This is an example of a case where an NRI value is held.

  On the other hand, for packet type B (object detection metadata in XML format), time information and XML tt: Frame only for packets indicating that some object has been detected (the XML tt: Object element exists). The value of the element's UtcTime attribute is retained as much as the measured value information for the tt: Type element value (generic name of the detected object) and the tt: Likelihood value (detection likelihood) of XML. This is an example in which the number information and flag information are not held.

[Example 7]
FIG. 25 shows an example of packet data held by the packet data holding unit 603 as the seventh embodiment. FIG. 25 shows an example of packet data held based on the packet data holding rule exemplified in the sixth embodiment. For packet type B (object detection metadata), for example, a metadata packet having time information equal to (or close to) an important video packet including a key frame or a decoding parameter (NRI is 10 or more) It is possible to judge that deemed duplication is necessary.

  Similarly, for packet type A (video), for example, a video packet having time information equal to (or close to) metadata indicating that a human is detected with a certain likelihood or more is regarded as relevant and duplicated. It becomes possible to judge that it is necessary.

[Example 8]
FIG. 26 shows an example of inspection rule information in the case of the detailed operation of the packet inspection unit 601 described above with reference to FIG. The inspection rule information has the same inspection rule as that of the third embodiment described above with reference to FIG. 13 as a single packet inspection rule. As an inspection rule by matching with packet data of the packet type B (object detection metadata) that is executed when the inspection rule of the single packet is not matched, a person (Human) has a likelihood (Likelihood) of 0.8. This is an example in which it is determined that a type A packet having type B metadata indicating that it has been detected and time information within an error E is required to be copied.

  Based on such inspection rule information, a packet of a video frame that matches or is close to a video frame in which a person is detected with a certain likelihood or more can be determined to be important and copied and transferred.

  As mentioned above, although embodiment and the Example of this invention were explained in full detail, this invention is not limited to this. For example, the data communication protocol and application in the upper layer between the transmission node and the reception node are merely examples, and the present invention can be applied to other protocols and applications. Further, the inspection rule information, the transmission rule information, the packet data holding rule, the data structure and parameters of the packet association information, etc., described in detail in the above embodiments and examples are merely examples, and the upper level between the transmission node and the reception node It can be appropriately selected according to the data communication protocol and application in the layer.

DESCRIPTION OF SYMBOLS 100,600 ... Communication node 101 ... Packet receiving part 102 ... Packet receiving part 103,601 ... Packet inspection part 104 ... Inspection rule management part 105 ... Packet processing part 106 ... Transmission rule management part 107 ... Packet transmission part 190 ... Communication interface 200 ... Receiving node 300, 500 ... Network 400 ... Sending node 602 ... Pre-processing unit 603 ... Packet data holding unit 604 ... Packet data holding rule management unit 605 ... Packet association information management unit

Claims (8)

A communication system comprising a plurality of communication interfaces and a communication node that transmits a packet generated by itself or received from another transmission node to the reception node via the plurality of communication interfaces,
The communication node inspects a packet generated by itself or received from another transmitting node, selectively determines whether or not to duplicate the packet based on the inspection result, and duplicates a plurality of packets that need to be duplicated. A communication system that transmits to a receiving node via a communication interface, and transmits a packet that does not require duplication to the receiving node via any one communication interface. An inspection rule management unit that manages inspection rules for packets generated by itself or received from other transmission nodes;
A packet inspection unit that inspects a packet based on the inspection rule acquired from the inspection rule management unit and determines whether the packet needs to be copied;
Based on the necessity of duplication of the packet notified from the packet inspection unit, the packet that needs to be duplicated is duplicated and transmitted to the receiving node via a plurality of communication interfaces, and the packet that does not need to be duplicated is any one communication. The communication system according to claim 1, further comprising: a packet processing unit that transmits to the receiving node via the interface. The packet inspection unit determines whether the packet corresponds to any one or any combination of a delimited packet, a packet including a parameter set, a packet including a key frame, a packet including metadata, based on the content of the packet. The communication system according to claim 2, wherein the necessity of duplication of the packet is determined. A communication system in which a plurality of different types of packets are generated by itself or received from other transmission nodes and transmitted to a reception node,
When the communication node inspects the packet, the information of the packet to be inspected is recorded, and the packet is selectively selected based on the result of obtaining and comparing the recorded packet information regarding the packet of a type different from the packet to be inspected. The packet that needs to be copied is duplicated and sent to the receiving node via a plurality of communication interfaces, and the packet that does not need to be duplicated is sent to the receiving node via any one communication interface. The communication system according to claim 1. An inspection rule management unit for managing inspection rules for packets generated by itself or received from others;
A packet inspection unit that inspects a packet based on an inspection rule acquired from the inspection rule management unit and determines whether or not a packet needs to be copied;
A packet data holding rule management unit for managing packet information to be recorded as packet data holding rules;
A packet data holding unit that records packet information based on a packet data holding rule acquired from the packet data holding rule management unit;
A preprocessing unit for notifying the packet inspection unit and the packet data holding unit of the packet to be inspected;
A packet processing unit that duplicates a packet that needs to be duplicated and transmits the packet to a receiving node via a plurality of communication interfaces, and a packet processing unit that sends a packet that does not need to be duplicated to a receiving node via any one communication interface ,
The communication system according to claim 4. The packet data holding unit holds, as packet data, any one or any combination of time information, sequence number information, flag information, and measurement amount information that the packet has,
The communication system according to claim 5, wherein the packet inspection unit determines whether the packet needs to be copied based on a result of collating the packet with packet data held in the packet data holding unit. When duplicating a packet that needs to be duplicated, refer to the state of an available communication interface and the size of the packet to be transmitted, determine one or more communication interfaces to be used for transmitting the packet, and determine the determined communication The communication system according to any one of claims 1 to 6, further comprising: a packet processing unit that transmits the packet via an interface. A communication node comprising a plurality of communication interfaces is a communication method for transmitting a packet generated by itself or received from another transmission node to a reception node via the plurality of communication interfaces,
The communication node inspects a packet generated by itself or received from another transmitting node, selectively determines whether or not to duplicate the packet based on the inspection result, and duplicates a plurality of packets that need to be duplicated. A communication method characterized by transmitting packets to a receiving node via any communication interface, and transmitting a packet that does not require duplication to any receiving node via any one communication interface.

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