JP2006050221A - System and device for observing data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent data to be stored from being affected by data loss in a network concerning a data observation system which monitors a large amount of observation data such as animation data in real-time and simultaneously performing recording and storing. <P>SOLUTION: A data packet with continuity information added thereto is transmitted by a datagram communication system or temporarily stored in an observation terminal, so as to inspect continuity in storage control. When data loss is performed, the lost data are re-transmitted by a virtual circuit communication system. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a remote data observation system, mainly for the purpose of crime prevention and disaster prevention, transmitting a moving image captured by a camera using a network such as a LAN, and monitoring and storing in real time at a remote location. The present invention relates to a monitoring system and devices constituting the monitoring system.

  Conventionally, in such a monitoring system, a dedicated cable is laid from the camera to the centralized monitoring device and a moving image is transmitted as an analog signal. However, with the development of a computer network and its peripheral technology, a moving image is displayed. Systems that transmit encoded digital data over a network have come to be used.

  As a communication method for moving image transmission using such a network, a datagram type communication method having an advantage that data processing at the time of transmission is simple and transmission processing time is short is the mainstream.

  However, in the datagram type communication system, it is difficult to guarantee the arrival order and to ensure reliability, and there is a disadvantage that data loss occurs on the network.

  Therefore, Patent Document 1 proposes a technique for preventing data loss in the network and reducing the processing at the time of image signal transmission in such a monitoring system.

  In this proposal, as shown in FIG. 11, the above-mentioned datagram type communication system and the virtual circuit type communication that can ensure the reliability of communication, although the data processing at the time of transmission is complicated and the transmission processing time is long. By providing a means for switching between different methods on the image transmission device side, it is possible to transmit in any communication method, so that important data can be transmitted to the network in a reliable manner while reducing the overall data processing. Is possible.

Also, as shown in FIG. 12, an image storage unit is provided to store an image, and when an abnormality such as data loss is detected in the network, the image is immediately read out from the image storage unit, Retransmission to the network is possible with a high communication method.
JP 2000-224569

  However, in recent years, there has been a demand for higher quality of surveillance video, and moving image data transmitted over the network is also using encoding technology such as MPEG2 (Moving Picture Experts Group 2). The amount of data has become large and uninterrupted.

  In this case, performing data transmission by virtual circuit communication causes a problem in real-time reproduction on the receiving side due to the disadvantage that the transmission processing time becomes long.

  In addition, it is difficult to detect data loss in an uninterrupted data stream using only the protocol of the datagram type communication method, and the configuration proposed in Patent Document 1 may not be able to cope with it.

  In addition, a datagram type communication method may be used for real-time monitoring, and a virtual circuit type communication method may be used for recording and storage. However, a large amount of the same data is transmitted repeatedly. There is a problem that the load on the network becomes very large.

  Therefore, the present invention provides a data observation system that monitors a large amount of observation data such as smooth moving image data with high image quality in real time at a display / storage terminal in a central monitoring station, and simultaneously records and stores the data. The purpose is to avoid being affected by data loss in the network.

  In order to achieve the above object, in the present invention, data from a remote data observation terminal is transmitted to a data display / storage terminal via a network to simultaneously display data and store data simultaneously. In the unit of transmitting data from the data input means, data from the data input means to the data observation terminal, encoding means for converting the data from the data input means into data that can be transmitted over a network, and data from the encoding means. Packetizing means for dividing, continuity information adding means for adding information capable of detecting continuity to the data from the packetizing means, transmission packet storing means for temporarily storing transmission data, and data display / storage A retransmission control means for reading data from the transmission packet accumulating means and resending data in accordance with a request from the means; Datagram type communication means and virtual circuit type communication means are provided as receiving means, and added to the data display / storage terminal at the data observation terminal, datagram type communication means and virtual circuit type communication means which are means for transmitting and receiving with the network Continuity information removing means for removing information that can be detected continuity, decoding means for decoding transmitted data into displayable data, and display output for immediately displaying data from the decoding means Data, a data storage means for storing the transmitted data, and a control for storing the transmitted data in the storage means, while checking the continuity of the data and detecting data loss, It is equipped with storage control means that has the function of requesting the observation terminal to retransmit lost data. Using signal scheme, the retransmission of the lost data was configured, which comprises using a virtual connection communication method.

  As described above, according to the present invention, in a system that simultaneously performs real-time monitoring and storage of a large amount of data captured at a remote location using a network, a packet of data to which information that can detect continuity is added. By using a datagram type communication system with a low data processing load, recording and storing data, the data loss is detected, and the lost data is retransmitted by a reliable virtual circuit type communication system. The real-time monitoring of large-capacity data and the reliability of storage are both achieved without imposing a heavy load on the system.

Example 1
Embodiments of the present invention will be described.

  FIG. 2 shows a configuration diagram of a system described in this embodiment.

  Reference numeral 200 denotes an imaging terminal, reference numeral 201 denotes a centralized monitoring station terminal, and reference numeral 202 denotes a network.

  The imaging terminal 200 is a terminal having a function of transmitting captured moving image data to the centralized monitoring station terminal 201 via the network 202.

  The imaging terminal includes imaging means 203, encoding means 204, packetizing means 205, continuity information adding means 206, transmission packet storage means 207, retransmission control means 208, datagram type communication means 209, and virtual circuit type communication means 210. Composed.

  The centralized monitoring station terminal 201 has a function of displaying and recording and storing the moving image data from the imaging terminal sent through the network 202 in real time, and also has a function of reproducing the recorded and stored moving image data.

  Centralized monitoring station terminal includes datagram type communication means 211, virtual circuit type communication means 212, display reproduction control means 213, continuity information removal means 214, decoding means 215, video display means 216, storage control means 217, large capacity An image storage unit 220 and a user input / output unit 221 are included. The accumulation control means 217 includes a continuity inspection unit 218 and an accumulation control unit 219.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG.

  The imaging means 203 is a so-called camera, images a monitoring target, and inputs the moving image signal to the encoding means 204.

  The encoding unit 204 digitizes the moving image signal input from the imaging unit 203, further performs compression encoding, and inputs the signal to the packetizing unit 205 as a moving image data stream.

  The packetizing unit 205 divides the moving image data stream input from the encoding unit 204 into network transmission units, and inputs the divided data to the continuity information adding unit 106 as a moving image packet stream.

  The continuity information adding unit 206 adds information capable of detecting continuity to the packets of the moving image packet stream input from the packetizing unit 205. In this embodiment, a sequence number having a sufficiently large number of digits is added.

  The processing of the moving image data so far is shown in FIG.

  The moving image packet stream to which the continuity information is added by the continuity information adding unit 206 is passed to the datagram type communication unit 209 and the transmission packet storage unit 207.

  The moving image packet stream transferred to the datagram type communication means 209 is added with a datagram type communication system header and sent to the network 202 as a destination for the centralized monitoring station terminal. This process is shown in FIG.

  On the other hand, the moving image packet stream passed to the transmission packet accumulating unit 207 is accumulated in a state where individual packets can be identified and read from the sequence number which is continuity information. This process is shown in FIG.

  The moving image packet stream sent to the network 202 is received by the datagram type communication means 211 of the centralized monitoring station terminal 201.

  The moving image packet stream received by the datagram type communication means 211 is sent to the display reproduction control means 213 and the accumulation control means 217.

  The display reproduction control unit 213 has a function of switching between real-time monitoring and reproduction of the stored image in accordance with an instruction from the user by the user input / output unit 221.

  In this case, since real-time monitoring is considered, a moving image packet stream sent from the datagram type communication means is selected and sent to the continuity information removing means 214.

  The moving image packet stream sent to the continuity information removing means is removed from the continuity information and input to the decoding means 214.

  The moving image packet stream input to the decoding unit 214 is decoded by the decoding unit 214 and displayed on the video display unit 215 in real time. A series of these processes is shown in FIG.

  On the other hand, the moving image packet stream sent to the accumulation control means 217 is checked for continuity by referring to the sequence number which is continuity information in the continuity checking unit 218 in the accumulation control means 217. If there is no problem, the storage control unit 219 stores the packet in the large-capacity image storage unit 220 in a packetized state. This process is shown in FIG.

  The moving image data stored in the large-capacity image storage means 220 is read from the display reproduction control means 213 in accordance with a request from the user by the user input / output means 221 and the continuity information removing means 214 and the decoding means. Through 215, the image can be reproduced and displayed on the video display means 216.

  Next, processing when packet loss occurs in the network will be described.

If a packet of moving image data from the imaging terminal 200 by the datagram type communication method is lost in the network 202 for some reason, if the sequence number of the lost packet is n,
(1) A missing sequence number n is detected when the continuity check unit 218 of the accumulation control unit 217 of the centralized monitoring station terminal 201 checks the continuity.
(2) When a missing sequence number is detected in the received packet stream, the accumulation control unit 219 accumulates the packet stream in the large-capacity image accumulating unit 220 by leaving an area for the missing packet.
(3) At the same time, the continuity checking unit 218 sends a message requesting retransmission of the packet with the missing sequence number n to the imaging terminal 200 by the virtual circuit communication method using the virtual circuit communication unit 212. .
These processes ((1) to (3)) are shown in FIG.

In the imaging terminal 200,
(1) The retransmission control means 208 receives a reproduction request for the packet with the sequence number n via the virtual circuit type communication means 210.
(2) Upon receiving the retransmission request, the retransmission control unit 208 reads the packet with the corresponding sequence number n from the transmission packet storage unit 207.
(3) The read packet of sequence number n is sent to the centralized monitoring station terminal 201 by the virtual circuit communication method using the virtual circuit communication means 210.

  These processes ((1) to (3)) are shown in FIG.

  The retransmitted packet with the sequence number n is received by the virtual circuit type communication means 212 of the centralized monitoring station terminal 201, and passed to the accumulation control unit 219 of the accumulation control means 217.

  The accumulation control unit 219 stores the retransmitted packet in the corresponding accumulation area. These processes are shown in FIG.

  As described above, in a system that simultaneously performs real-time monitoring and recording / storage of moving images, a packet of moving image data to which a sequence number is added is transmitted using a datagram type communication method, and data is lost for recording / accumulating data. By detecting the data and retransmitting the missing data using the virtual circuit communication method, both real-time monitoring of large-capacity moving image data and ensuring the reliability of recording and storage were made possible.

(Example 2)
An embodiment that can be implemented in the case of a system in which the packet transmission interval from the data observation terminal is constant will be described. However, the basic operation conforms to the first embodiment.
Hereinafter, a description will be given with reference to FIG.

  Assume that the transmission interval of data packets is Δt.

  The continuity information adding means 106 has a timer means that can acquire the absolute time, and adds the absolute time when the data packet was transmitted as continuity information.

  The continuity checking unit 117 of the storage control unit 116 refers to the transmission absolute time of the received packet stream, determines that the interval is not Δt, data loss, and requests the data observation terminal 100 to retransmit.

  In this case, the retransmission request message includes absolute transmission times of previous and subsequent packets in order to identify lost packets.

  The retransmission control means 108 of the data observation terminal 100 refers to the absolute transmission times of the packets before and after the retransmission request message, and reads and retransmits the packets sent from the transmission packet storage means 107 during that time.

  If the transmission interval is constant as assumed in this embodiment, data loss cannot be detected by checking the reception interval on the receiving side without adding continuity information, but transmission fluctuations in the network are not detected. The risk of being erroneously determined by

  Thus, by adopting the configuration of the present invention as described above, it is possible to reliably detect data loss.

It is a figure showing the structure of this invention. It is a figure showing the structure of the Example of this invention. It is a figure showing data processing of the example of the present invention. It is a figure showing data processing of the example of the present invention. It is a figure showing data processing of the example of the present invention. It is a figure showing data processing of the example of the present invention. It is a figure showing data processing of the example of the present invention. It is a figure showing data processing of the example of the present invention. It is a figure showing data processing of the example of the present invention. It is a figure showing data processing of the example of the present invention. It is a figure showing the structure of the system proposed conventionally. It is a figure showing the structure of the system proposed conventionally.

Explanation of symbols

100 data observation terminal
200 Imaging terminal
101 Data display / storage terminal
201 Central monitoring station terminal
102,202 network
103 Data input means
203 Imaging means
104,204 encoding means
105,205 Packetization means
106,206 Continuous information adding means
107,207 Transmission packet storage means
108,208 Retransmission control means
109,111,209,211 Datagram type communication means
110,112,210,212 Virtual circuit type communication means
113,214 Continuity information removal means
213 Display reproduction control means
114,215 Decryption means
115 Display output means
216 Video display means
116,217 Accumulation control means
117,218 Continuity inspection department
118,219 Accumulation controller
119 Data storage means
220 Large-capacity image storage means
221 User input / output means
301 Image capture means
302 A / D converter
303 Image signal compression means
304 Virtual circuit type communication means
305 Datagram type communication means
306 Data switching means
307 Protocol arbitration means
308 network
309 Image signal receiving means
310 Data reception error detection means
311 Transmission image switching means
312 Transmission image storage means
313 Transmission image storage control means
314 Transmission image switching control means

Claims (6)

A device that constitutes a system that transmits data from a remote data observation terminal to a data display / storage terminal via a network, and simultaneously displays the data and stores the data at the same time. , Data input means,
Encoding means for converting data from the data input means into data that can be transmitted over a network;
Packetizing means for dividing the data from the encoding means into transmission units;
In accordance with a request from a continuity information adding means for adding information capable of detecting continuity to the data from the packetizing means, a transmission packet storing means for temporarily storing transmission data, and a request from the data display / accumulating means, A retransmission control unit that reads data from a transmission packet storage unit and retransmits the data, and a datagram type communication unit and a virtual circuit type communication unit as a transmission / reception unit to and from the network. The data display / storage terminal is connected to the network. Datagram type communication means and virtual circuit type communication means as transmission / reception means, continuity information removal means for removing information added to the data observation terminal that can detect continuity, and transmitted data can be displayed Decryption means for decrypting the data;
Data output means for immediately displaying the data from the decoding means, data storage means for storing the transmitted data, and control for storing the transmitted data in the storage means, while performing data continuity And a storage control unit having a function of requesting the data observation terminal to retransmit lost data when data loss is detected and an apparatus constituting the data observation system.   2. The data observation system according to claim 1, wherein a datagram type communication system is used for normal data transmission and a virtual circuit type communication system is used for retransmission of lost data, and an apparatus constituting the data observation system. .   The data observation system according to claim 1 or 2, wherein a sequence number is used as the information capable of detecting the continuity, and an apparatus constituting the data observation system.   3. The data observation system according to claim 1, wherein a data transmission time is used as the information capable of detecting the continuity, and an apparatus constituting the data observation system.   5. A data observation system according to claim 1, wherein the data input means is an imaging device, and the observation data is an image, and constitutes the data observation system. apparatus.   6. The data observation system according to claim 5, wherein MPEG2 (Moving Picture Experts Group 2) is used for encoding used by the encoding means, and an apparatus constituting the data observation system.

Images