Relay device, surveillance camera system, data relay method, and relay control program

Abstract

To provide a relay device capable of continuing transmission of video data even when a failure occurs between a video transmitting device and a relay device to which the video transmitting device is connected, and even when the video transmitting device fails.SOLUTION: A relay device 3 includes: a plurality of external interface units 13 each connected to an imaging device 1; a communication unit 12 connected to a communication network 5; and a relay control unit 11 that relays one piece of multicast data to the communication network when the plurality of external interface units is receiving the same multicast data. If reception of multicast data being relayed on one external interface unit stops, and another external interface unit is receiving other multicast data that has the same multicast address as the stopped multicast data, the relay control unit controls another external interface unit and the communication unit to relay other multicast data to the communication network.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a relay device that relays data packets, a surveillance camera system, a data relay method, and a relay control program. [Background technology]

[0002] Network cameras used for remote surveillance often transmit video packets to a video surveillance terminal via one or more network switches.

[0003] Therefore, when a transmission failure occurs on the network, the transmission of video packets to the video monitoring terminal becomes impossible.

[0004] To address this problem, the video relay device described in Patent Document 1 duplicates the paths along the way to prevent interruption of video data transmission when a failure occurs on one of the paths. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-188920 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology described in Patent Document 1 can handle cases where a failure occurs along the route, but cannot handle cases where a failure occurs between the device transmitting the video data and the relay device to which this device is connected, or where the device transmitting the video data breaks down, resulting in the problem of interrupted transmission of the video data.

[0007] The present disclosure has been made in consideration of the above, and aims to provide a relay device that can continue transmitting video data even when a failure occurs between a device that transmits video data and a relay device to which the device that transmits video data is connected, and even when the device that transmits video data breaks down. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, a relay device according to the present disclosure includes a plurality of external interface units each connected to an imaging device, a communication unit connected to a communication network, and a relay control unit that relays any one of the multicast data to the communication network when the plurality of external interface units are receiving multicast data having the same multicast address. When reception of one multicast data being relayed at one external interface unit stops and another external interface unit is receiving other multicast data having the same multicast address as the stopped one multicast data, the relay control unit controls the other external interface unit and the communication unit to relay the other multicast data to the communication network. [Effects of the Invention]

[0009] The relay device disclosed herein has the advantage of being able to continue transmitting video data even if a failure occurs between the device transmitting the video data and the relay device to which the device transmitting the video data is connected, or even if the device transmitting the video data breaks down. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a surveillance camera system realized by applying a relay device according to an embodiment; [Figure 2] FIG. 1 is a diagram illustrating an example of a hardware configuration and a functional block configuration of a relay device according to an embodiment. [Figure 3]10 is a flowchart showing an example of a data relay control process performed by a relay device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a relay device, a surveillance camera system, a data relay method, and a relay control program according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0012] Embodiment FIG. 1 is a diagram illustrating a configuration example of a monitoring camera system 100 realized by applying a relay device according to an embodiment.

[0013] The surveillance camera system 100 includes two imaging devices 1 that are network cameras, a video display terminal 2, and a relay device 3, and the video display terminal 2 and the relay device 3 are connected to a communication network 5.

[0014] The two imaging devices 1 are connected to a relay device 3. The two imaging devices 1 are installed in the same location, capture the same area, and transmit the video data to the relay device 3. In other words, the surveillance camera system 100 has a configuration in which the imaging devices 1 that transmit video data to the relay device 3 are duplicated.

[0015] The video display terminal 2 is a terminal for receiving video data obtained by imaging device 1 performing imaging via relay device 3 and communication network 5 and displaying the video data as video. For example, when the video display terminal 2 receives an operation to start video distribution from a user, it transmits a request to start video distribution to the imaging device 1 and receives video data distribution from the imaging device 1. Furthermore, when the video display terminal 2 receives an operation to stop video distribution from a user, it transmits a request to stop video distribution to the imaging device 1.

[0016] The relay device 3 is, for example, a network switch. When the relay device 3 receives video data from both of the two imaging devices 1, it sets one of the received video data as relay target data and relays it to the communication network 5, and sets the other as relay stop data and discards it. Furthermore, when the relay device 3 is unable to receive the video data set as relay target data, it starts relaying the video data that it set as relay stop data. Note that in addition to the imaging device 1, a device different from the imaging device 1, for example, a device similar to the video display terminal 2, may be connected to the relay device 3.

[0017] 1 is used to monitor, for example, rivers, roads, train stations, etc. For example, two imaging devices 1 are installed near a river, and a video display terminal 2 is installed at a monitoring station, and one of the video data output by the two imaging devices 1 is relayed to a communication network 5 by a relay device 3. The video data relayed to the communication network 5 is received by the video display terminal 2 and displayed as a video, allowing a monitor at the monitoring station to check the condition of the river.

[0018] FIG. 2 illustrates an example of a hardware configuration and a functional block configuration of the relay device 3 according to the embodiment.

[0019] As shown in FIG. 2, the relay device 3 is configured with hardware including a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only Memory) 103, a first interface circuit 104, and multiple second interface circuits 105. The first interface circuit 104 is an electronic circuit for connecting the relay device 3 to the communication network 5, and the second interface circuit 105 is an electronic circuit for connecting the relay device 3 to the imaging device 1. While FIG. 2 shows an example configuration including two second interface circuits 105, three or more second interface circuits 105 may be provided. Another device, for example, a communication module for performing data communication via the communication network 5, may be connected to the second interface circuit 105 to which the imaging device 1 is not connected. The first interface circuit 104 may be an electronic circuit having the same configuration as the second interface circuit 105, or may be an electronic circuit having a different configuration. Furthermore, two or more first interface circuits 104 may be provided.

[0020] The CPU 101, RAM 102, and ROM 103 constitute the relay control unit 11. A relay control program, which is a program describing each process to be executed by the relay control unit 11, is written in the ROM 103. The CPU 101 operates as the relay control unit 11 by reading and executing the relay control program written in the ROM 103. Note that, although the relay control unit 11 is constituted by the CPU 101, RAM 102, and ROM 103 in the example shown in Fig. 2, the relay control unit 11 may also be constituted by a processing circuit such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these.

[0021] The first interface circuit 104 constitutes the communication unit 12. The second interface circuit 105 constitutes the external interface unit 13.

[0022] The relay control unit 11 controls the relay operation of the video data by the external interface unit 13 and the communication unit 12. In detail, the relay control unit 11 analyzes packets received from the imaging device 1 by each of the multiple external interface units 13, and determines whether two second interface circuits 105 are receiving packets containing the same video data. If two second interface circuits 105 are receiving packets containing the same video data, the relay control unit 11 controls the communication unit 12 to transmit one of the packets containing the same video data to the communication network 5 and discard the other.

[0023] The communication unit 12 is connected to the communication network 5 and transmits and receives signals to and from other devices via the communication network 5 .

[0024] The external interface unit 13 acquires the video data output by the imaging device 1 .

[0025] Next, an example of the operation of the relay device 3, specifically, an example of the operation of relaying video data received from the imaging device 1 to the video display terminal 2, will be described with reference to Fig. 3. Fig. 3 is a flowchart showing an example of a processing procedure for data relay control by the relay device 3. Each process included in the processing procedure described below may be modified as much as possible. Furthermore, steps in the processing procedure described below may be omitted, replaced, or added as appropriate depending on the embodiment.

[0026] First, the relay device 3 checks whether or not it has started receiving multicast data (step S1). Specifically, the relay control unit 11 checks whether or not the external interface unit 13 has started receiving video packets transmitted from the imaging device 1. Note that the video packets are packets that store video data, and a multicast address is set as the destination.

[0027] If the reception of multicast data has not started (step S1: No), the relay device 3 repeats the checking operation of step S1.

[0028] When the relay device 3 starts receiving multicast data (step S1: Yes), the relay device 3 checks whether it is currently receiving the same multicast data (step S2). Specifically, the relay control unit 11 checks whether other external interface units 13 are receiving the same multicast data as the multicast data that the relay device 3 has started receiving. The "other external interface units 13" refers to external interface units 13 other than the external interface unit 13 that has started receiving the multicast data. In other words, in step S2, the relay control unit 11 checks whether multiple external interface units 13 are receiving the same multicast data. The same multicast data refers to a video packet with the same multicast address set. In other words, the relay control unit 11 analyzes the video packet that the external interface unit 13 has started receiving and checks whether the other external interface units 13 are currently receiving a video packet with the same multicast address set as the video packet that the relay device 3 has started receiving. Note that the two imaging devices 1 shown in FIGS. 1 and 2 are pre-configured so that the destination addresses of the video packets output to the relay device 3 are the same multicast address.

[0029] If the same multicast data is not being received (step S2: No), the relay control unit 11 sets the multicast data that has started to be received as data to be relayed to the video display terminal 2 (step S6). For example, the relay control unit 11 instructs the external interface unit 13, which has started to receive the multicast data, to output the multicast data to the communication unit 12. Upon receiving this instruction, the external interface unit 13 starts the process of transferring the received multicast data to the communication unit 12. The communication unit 12 transmits the multicast data received from the external interface unit 13 to the communication network 5. Note that if there is no video display terminal 2 requesting video distribution, the communication unit 12 does not transmit the multicast data received from the external interface unit 13 to the communication network 5. In other words, if there is no video display terminal 2 requesting video distribution, the multicast data set as data to be relayed is transferred from the external interface unit 13 to the communication unit 12, but the relay control unit 11 controls the external interface unit 13 and the communication unit 12 so that the data is discarded by the communication unit 12. If there is no video display terminal 2 requesting video distribution, the relay control unit 11 may control the external interface unit 13 to discard the multicast data set as the data to be relayed without passing it on to the communication unit 12. After executing step S6, the process returns to step S1.

[0030] Furthermore, if the same multicast data is being received (step S2: Yes), the relay control unit 11 sets the multicast data that has started to be received as relay stop data, which is data that will not be relayed to the video display terminal 2 (step S3). For example, the relay control unit 11 instructs the external interface unit 13 that has started to receive the multicast data not to output the multicast data to the communication unit 12. Upon receiving this instruction, the external interface unit 13 starts processing to discard the received multicast data without passing it on to the communication unit 12.

[0031] After executing step S3, the relay device 3 receives the same multicast data from the two imaging devices 1 and relays one of the multicast data to the communication network 5. Thereafter, the relay device 3 checks whether the reception of the multicast data being relayed has stopped (step S4). If the reception of the multicast data being relayed has not stopped (step S4: No), the relay device 3 repeats the checking operation of step S4.

[0032] On the other hand, if reception of the multicast data being relayed stops (step S4: Yes), the relay device 3 changes the setting of the data for which relaying is being stopped to data to be relayed (step S5). Specifically, the relay control unit 11 sets the multicast data that had previously been set as data to be stopped from relaying to data to be relayed. For example, the relay control unit 11 instructs the external interface unit 13, which is executing processing to discard the received multicast data without passing it on to the communication unit 12, to output the received multicast data to the communication unit 12. Upon receiving this instruction, the external interface unit 13 starts processing to pass the received multicast data to the communication unit 12. After executing step S5, the process returns to step S1.

[0033] In this embodiment, whether the multicast data is the same or not is determined based on the multicast address, but other methods may be used for the determination. For example, each imaging device 1 may insert information indicating that the data is the same (same information) at a predetermined position in the video packet before transmitting it, and the relay control unit 11 may determine whether the data is the same multicast data or not based on this information. As another determination method, the relay device 3 may acquire and store in advance setting information of the imaging devices 1 connected to each external interface unit 13, and determine whether the same multicast data has been received based on the stored setting information. The setting information of the imaging device 1 includes information that can determine whether the data is the same multicast data or not, such as a multicast address to be set in the video packet. The setting information of the imaging device 1 may be manually registered in the relay device 3 by the user, or the external interface unit 13 may acquire the setting information from the imaging device 1 when it detects that the imaging device 1 has been connected.

[0034] As described above, the surveillance camera system 100 according to the present embodiment includes a video display terminal 2 and a relay device 3 connected to a communication network 5, and multiple imaging devices 1 connected to the relay device 3, which capture the same area and output the same multicast data. When the relay device 3 receives the same multicast data from multiple imaging devices 1, it relays one of the received multicast data to the video display terminal 2 via the communication network 5 and discards the remaining multicast data without relaying it. Furthermore, when the reception of the multicast data being relayed stops, the relay device 3 changes its settings to start relaying the multicast data that it had been discarding without relaying, and starts relaying it to the video display terminal 2. The surveillance camera system 100 enables the transmission of multicast data to the video display terminal 2 to continue even if a failure occurs between the imaging device 1 that transmits multicast data of a video to be displayed by the video display terminal 2 and the relay device 3 to which the imaging device 1 is connected, or even if the imaging device 1 that transmits the multicast data breaks down, thereby improving the reliability of the system.

[0035] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, and parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0036] 1 imaging device, 2 video display terminal, 3 relay device, 5 communication network, 11 relay control unit, 12 communication unit, 13 external interface unit, 100 surveillance camera system, 101 CPU, 102 RAM, 103 ROM, 104 first interface circuit, 105 second interface circuit.

Claims

1. a plurality of external interface units each connected to the imaging device; a communication unit connected to a communication network; a relay control unit that relays any one of the multicast data to the communication network when the plurality of external interface units are receiving multicast data having the same multicast address; Equipped with The relay control unit When reception of one multicast data item being relayed at one external interface unit is stopped and another external interface unit is receiving another multicast data item having the same multicast address as the stopped one multicast data item, the other external interface unit and the communication unit are controlled to relay the other multicast data item to the communication network. A relay device characterized by:

2. The relay control unit When the external interface unit starts receiving multicast data and multicast data having the same multicast address as the multicast data that has started to be received is being relayed to the communication network, the external interface unit and the communication unit are controlled so as not to relay the multicast data that has started to be received to the communication network.

2. The relay device according to claim 1, wherein:

3. The relay control unit When the external interface unit starts receiving multicast data and multicast data having the same multicast address as the multicast data that has started to be received is not being relayed to the communication network, the external interface unit and the communication unit are controlled to relay the multicast data that has started to be received to the communication network.

3. The relay device according to claim 1 or 2.

4. An imaging device; a relay device that receives multicast data including video data from the imaging device and relays the multicast data to a communication network; a video display terminal connected to the communication network, for receiving the multicast data and displaying the video data; Equipped with the imaging device captures an image of the same range as a target and outputs the image data; The relay device a plurality of external interface units each connected to the imaging device; a communication unit connected to the communication network; a relay control unit that relays any one of the multicast data to the communication network when the plurality of external interface units are receiving multicast data having the same multicast address; Equipped with The relay control unit When reception of one multicast data item being relayed at one external interface unit is stopped and another external interface unit is receiving another multicast data item having the same multicast address as the stopped one multicast data item, the other external interface unit and the communication unit are controlled to relay the other multicast data item to the communication network. A surveillance camera system characterized by:

5. When a plurality of external interface units respectively connected to the imaging device receive multicast data having the same multicast address, relaying any one of the multicast data to a communication network; a step of relaying the other multicast data to the communication network when reception of the one multicast data being relayed at one external interface unit is stopped and another external interface unit is receiving the other multicast data having the same multicast address as the one multicast data that has been stopped; A data relay method comprising:

6. When a plurality of external interface units respectively connected to the imaging device receive multicast data having the same multicast address, relaying any one of the multicast data to a communication network; a step of relaying the other multicast data to the communication network when reception of the one multicast data being relayed at one external interface unit is stopped and another external interface unit is receiving the other multicast data having the same multicast address as the one multicast data that has been stopped; A relay control program that causes a computer to execute the above.

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