JP2010119046A - System for recording data, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a system for recording data capable of efficiently recording and storing TSs received at a plurality of transmission points in a transmission path by a small-capacity recording device. <P>SOLUTION: Each error detector 30 receives TSs at each of transmission points P2-P6 of a transmission path La, detects a sequence error of an IP packet based on a sequence number attached to the IP packet constituting the TS, creates error data according to the detection result thereof, records and stores the error data in an RAM 43, and transmits the error data to a storage-reproduction device 31 via a bidirectional communication line Lb. The storage-reproduction device 31 receives the TS at a transmission point P1 for a transmitter 20 to transmit the TS via the transmission path La, records and stores all the IP packets constituting the TS in an HDD 55, receives the error data transmitted via the bidirectional communication line Lb by each error detector 30, and records and stores the error data in the HDD 55. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a data recording system, a program, and a recording medium. More specifically, the present invention realizes a data recording system for recording transmission data received and acquired at a plurality of transmission points in a data transmission path, and the data recording system. The present invention relates to a program for causing a computer system to function and a computer-readable recording medium on which the program is recorded.

  In recent years, broadcasting media such as satellite digital broadcasting such as BS (Broadcasting Satellite) digital broadcasting and CS (Communication Satellite) digital broadcasting, terrestrial digital broadcasting, CATV (CAble TeleVision), data distribution such as TV (TeleVision) broadcasting using the Internet, etc. In digital communication and communication media, digital broadcasting and digital communication services using compression coding technology based on MPEG (Moving Picture Experts Group) 2 are provided.

  In the MPEG2 system, which is a compression encoding system using MPEG2, an ES (Elementaly Stream) that is a bit stream of data obtained by compression encoding audio data (audio information) and video data (video information) is generated, and the audio data The ES (audio ES) and the video data ES (video ES) are multiplexed to generate a TS (Transport Stream).

Here, the ES packetized in meaningful units (frame unit for video data and block unit for audio data) is called a PES (Packetized Elementary Stream). The PES includes time information, and video data and audio data can be synchronized using this time information.
Since TS can constitute a plurality of programs in one bit stream, it is standardized assuming application to broadcasting media and communication media.

  One TS is composed of several to several hundred types of TS packets. The TS packet is a fixed-length packet such as 188 bytes or 204 bytes, and its length is considered to be consistent with ATM (Asynchronous Transfer Mode) cell length and applicability when performing error correction coding such as Reed-Solomon code. Has been determined.

  The TS packet includes a 4-byte fixed-length packet header, a variable-length adaptation field (adaptation field), and a payload. There are cases where only one of the adaptation field and the payload is present or both, and the presence or absence is indicated by a flag (adaptation field control) in the packet header.

The packet header includes various packet control data such as PID (Packet IDentification), a synchronization byte, and a continuity index, which are identifiers for identifying the type of TS packet.
The adaptation field includes reference time information (PCR: Program Clock Reference) for achieving synchronization between the transmission side and the reception side, and compression-coded video data or audio data.

The synchronization byte is data indicating the start of a TS packet.
The PID is data indicating the content of information included in the TS packet (channel number, which of video data and audio data of the channel is included, etc.).
Since the same video data and the same audio data have the same PID, the TS receiving system can return to the original PES using the PID.

A transmission system installed in a transmission station (broadcast station), a relay station, a CATV station, or the like is a data string of TS packets by time-division multiplexing the TS packets generated in this way for a plurality of channels. Since a TS is generated, a transmission signal is generated by modulating the TS with a predetermined modulation method, and the transmission signal is transmitted to the transmission means, television programs for a plurality of channels can be broadcast simultaneously.
The transmission means for transmitting signals is, for example, a broadcasting satellite in the case of satellite digital broadcasting, an antenna of a transmission / reception device in the case of terrestrial digital broadcasting, a dedicated communication line in the case of CATV, or an ISDN (Integrated Services Digital Network) in the case of the Internet. And public telephone lines including ADSL (Asymmetric Digital Subscriber Line), dedicated communication lines including optical communication lines, and the like.

In addition, a receiving system that receives digital broadcasting and digital communication receives a transmission signal transmitted from a transmission station (broadcasting station), a relay station, a CATV station, etc., and demodulates the received transmission signal using a predetermined demodulation method. By doing so, a TS is generated.
Then, the receiving system generates video data and audio data by selecting and decoding TS packets of a channel desired by the viewer (user) from among TS packets for a plurality of channels included in the TS, and these data are generated. Is output to a television receiver, personal computer, etc. for playback.

In such digital broadcasting and digital communication based on MPEG2, it is necessary to monitor the occurrence status (occurrence status) of plural types of individual TS packets generated by the transmission system or the reception system.
This is because, in order to realize normal broadcasting and communication, it is necessary to investigate the cause of the error based on the TS error occurrence state and take preventive measures so that the error does not occur from the next time.

  Incidentally, the causes of TS errors include, for example, malfunctions of various devices constituting the transmission system or reception system, malfunctions of power supplied to the various apparatuses, imperfect scheduling of television programs, malfunctions in pause timing of broadcasting, There are radio wave interference (rain attenuation, lightning interference, etc.) due to weather.

However, since one TS is composed of several to several hundred types of TS packets, when the occurrence status of a plurality of types of errors is monitored for each TS packet, the number of types of errors to be monitored is several tens to several tens of thousands. It is impossible to monitor the human system.
Therefore, the applicant (Traffic Sim Co., Ltd.) has developed and sold a TS packet monitoring device that monitors the occurrence of errors based on the reception interval time of TS packets identified by PID, interruption of continuity index, etc. (Product name “TS CaPID WA-1 / TSW-1000”). This TS packet monitoring apparatus has already been actually used in domestic major digital satellite broadcasting stations, and has contributed to improving the quality of broadcasting services.

In addition, as disclosed in Patent Document 1, the present applicant has an error detection unit that detects an error occurrence state included in data transferred in time series, and a predetermined period detected by the error detection unit. A data monitoring system having an error display means for displaying a list of error occurrences in time series is proposed.
According to the technique of this patent document 1, an operation manager (operator) of data transfer (data transmission) can confirm the occurrence status of errors in a predetermined period by simply looking at the list display of the error display means. It is also possible to reliably monitor errors that occur.

  By the way, in claim 1 of Patent Document 2, after storing the TS file fragment generated from the TS of the input digital broadcast signal in the temporary storage means for temporarily storing, the stored TS file fragment is stored in a large capacity. A digital broadcast broadcast program recording apparatus is described in which a continuous TS file for storage is obtained in the large-capacity recording means by intermittently transferring it to the recording means.

Further, claim 2 of Patent Document 2 includes means for generating a TS file in which the TS is filed in a unit of a plurality of frames from the TS of the input digital broadcast signal, and a TS file generated by the means. Means for adding a file header; first storage means for storing a TS file to which a file header has been added by the means; a TS processing unit comprising a system management interface; a CPU; The storage contents of the first storage means are transferred, and the second storage means, in which data from the present time to a predetermined time before is always stored, is connected to the TS processing unit via a LAN, and is controlled by the CPU. The third storage means is configured such that the stored contents of the second storage means are transferred periodically and stored as data for a certain period. The TS processing unit is connected to the LAN through the LAN, and the storage content of the second storage unit is transferred in response to a transfer request from the system management interface or the third storage is controlled by the CPU. The data stored by the means is supplied, the file header added in the TS processing unit is removed from the transferred or supplied data, and a signal corresponding to the TS of the input digital broadcast signal is restored. A broadcast program recording device for digital broadcasting, characterized by comprising a playback unit, is described.
JP 2006-13612 A (pages 1 to 29, FIGS. 1 to 14) Japanese Patent Laying-Open No. 2003-61022 (pages 1 to 7, FIGS. 3 and 4)

  Conventionally, in data transmission in MPEG2 digital broadcasting and digital communication, an error monitoring device for monitoring error occurrence is installed at each of a plurality of transmission points in a TS transmission path, and TS is acquired for each transmission point. By detecting the error, it is determined at which transmission point the TS error occurred, and the cause of the TS error is investigated based on the determination result. Hold the TS for a certain period in the past and use it as source data for subsequent error verification, return the TS acquired at each transmission point to the transmission point via a high-speed communication line equivalent to the transmission path, etc. Measures are taken.

The transmission point includes a transmission point, a relay point, a reception point, and the like, and there may be a plurality of relay points and reception points.
For example, in digital communication (digital broadcasting), a transmission point is a location where a transmitter installed in a transmission station (broadcast station) outputs a TS via a transmission path, and a relay point is a transceiver installed in a relay station. Are points where TS is input via the transmission line, and the reception point is where the viewer terminal (receiver) held by the viewer inputs TS via the transmission line.

By the way, the aforementioned TS packet monitoring device detects that the continuity index that is cyclically incremented with a value of 0 to 15 described in the TS packet as one of the monitoring functions becomes discontinuous. For example, when 16 packets of a specific type are continuously lost, the continuity index remains continuous and it is difficult to detect an error.
In such a case, an inquiry about a failure may be received from the viewer after the fact, but the TS packet monitoring device described above does not detect and record an error, regardless of the error detection in the monitoring device, It is important to record the TS to be monitored for a certain period in the past.

Further, when an operation manager of data transmission investigates the cause of TS error occurrence, the error occurrence state over a long period (for example, several days to several months) may be examined.
For this purpose, it is necessary for the error monitoring device to record TS acquired at each transmission point at the same time as the long-term error occurrence situation, and to install an error monitoring device incorporating an expensive large-capacity recording device at each transmission point. Must be installed in.

  Therefore, data recording that can efficiently record and save TS acquired at multiple transmission points in the TS transmission path with a recording device with a small recording capacity, and easily determine between which transmission points the TS error occurred It is required to realize the system at a low cost.

By the way, the broadcast program recording device of Patent Document 2 is installed at a plurality of transmission points on the transmission path of the TS, and after the TS acquired at each transmission point is recorded on each broadcast program recording device, each broadcast program is recorded. It is conceivable to determine which transmission point has an error in the TS by analyzing the TS recorded by the recording device.
However, even in this case, when the broadcast program recording device is installed at a large number of transmission points, there is a problem that the installation cost increases as the number of broadcast program recording devices increases.

In general, in the case of a system for storing or recording a large amount of digital data, a means for dividing the acquired digital data into an appropriate size, storing it in a primary storage, and then transmitting it to a secondary storage is taken.
For example, in a CPU currently installed in a general personal computer, a memory for secondary access is stored in a primary memory excellent in random access installed in the CPU or the like for memory access from a program. Means for dividing the block into easy-to-handle blocks and transferring them to the secondary memory is taken, and this mechanism is incorporated in a CPU commercially available in the 1980s.
Also, with hard disk devices and control programs currently installed in general personal computers, data to be recorded on the hard disk is temporarily stored temporarily in the main memory of the personal computer, and then the hard disk is divided into easy-to-handle block units. Then, after being stored in the primary storage memory on the hard disk through the interface circuit with the hard disk, it is written in the recording part of the main body of the hard disk.

  The technique described in claim 1 of Patent Document 2 includes a temporary storage unit that temporarily stores a TS file fragment generated from a TS and a large-capacity recording unit that records a TS file in which the fragment is continuous. Therefore, the technique described in claim 1 of Patent Document 2 can be considered as an example of the primary recording and the secondary recording.

By the way, in the case of data distribution such as TV broadcasting using the Internet, a TS transmitted in time series is composed of a plurality of IP (Internet Protocol) packets.
The IP packet is composed of an IP header and a UDP (User Datagram Protocol) packet.
The UDP packet is composed of a UDP header and an RTP (Real-time Transport Protocol) packet.
The RTP packet is composed of an RTP header and a plurality of TS packets.
That is, an IP header, a UDP header, and an RTP header are provided in this order at the head of one IP packet, and a plurality of TS packets are provided following the RTP header.

The RTP header includes a sequence number that is information indicating the data order.
That is, the sequence number included in the RTP header is added to each IP packet.
The sequence number is composed of 16-bit fixed length data, and a number digit defined by the 16 bits is cyclically incremented.
For example, when the sequence number is composed of 1-byte data, the number from 0 to 255 is cyclically incremented, and after 255, it returns to 0 and the circulation (circulation) is repeated.

The reason why the sequence number is added to the IP packet is to detect a sequence error such as missing / duplicated / changed order of the IP packet.
The missing IP packet is a state in which the IP packet that must constitute the TS is missing and can be detected based on the missing sequence number.
IP packet duplication is a state in which a plurality of identical IP packets are duplicated in a TS, and duplication of IP packets can be detected based on duplication of sequence numbers.
The IP packet order change is a state in which the order of the IP packets constituting the TS is changed from the correct order, and the order change of the IP packets can be detected based on the change of the sequence number.

Therefore, in the case of data distribution such as TV broadcasting using the Internet, a sequence error monitoring device that detects and monitors a sequence error (missing / duplicate / order change of IP packets) is provided at a plurality of transmission points in the TS transmission path. It is conceivable to monitor the sequence error for each transmission point by installing it in the network.
However, even in such a case, it is necessary for the sequence error monitoring device to record TS acquired at each transmission point simultaneously with a long-term error occurrence situation, and a sequence incorporating an expensive large-capacity recording device. An error monitoring device must be installed at each transmission point.

The present invention has been made to satisfy the above requirements and has the following objects.
(1) To provide a data recording system capable of efficiently recording and storing data received at a plurality of transmission points in a data transmission path with a recording apparatus having a small recording capacity at a low cost.
(2) Provided is a data recording system capable of easily determining which transmission point a sequence error has occurred based on data recorded and stored by the data recording system of (1).
(3) A program for causing a computer system to function so as to realize the data recording system of (1) and (2) is provided.
(4) Provided is a computer-readable recording medium on which a program for causing a computer system to function is implemented so as to realize the data recording system of (1) and (2).

The invention described in claim 1
A transmission line (La) through which data (TS) is transmitted in time series;
The data is composed of divided data strings (IP packets), and each data string is appended with a sequence number that is information indicating the data order;
An error detection device (30) installed at each of a plurality of transmission points (P2 to P6) in the transmission line (La);
A first recording device (RAM 43) provided in each of the plurality of error detection devices (30);
A management device (31) installed at a transmission point (P1) at a starting point in the transmission path (La) and connected to the plurality of error detection devices (30) via a communication line (Lb);
A data recording system comprising a second recording device (HDD 55) provided in the management device (31),
Each of the plurality of error detection devices (30) receives the data (TS) for each transmission point (P2 to P6) in the transmission line (La), and forms the data (TS) The sequence number added to each IP packet) is checked and confirmed, and a sequence error of the data string (IP packet) is detected based on each sequence number, and error data is generated according to the detection result, Recording and storing the error data in the first recording device (RAM 43) and transmitting the error data to the management device (31) via the communication line (Lb);
As the types of sequence errors of the data string (IP packet), the data string (IP packet) that must be included in the data (TS) is missing and the data string is missing. TS) a plurality of the same data strings (IP packets) are included in duplicate, and the order of the data strings (IP packets) constituting the data (TS) should be correct. There is a change in the order of the data sequence being replaced, and the order
The management device (31) receives the data (TS) at the start transmission point (P1) in the transmission line (La), and records and saves the data (TS) in the second recording device (HDD 55). And a technique for receiving the error data transmitted from the plurality of error detection devices (30) via the communication line (Lb) and recording and storing the error data in a second recording device (HDD 55). Characteristic.

The invention described in claim 2
The data recording system according to claim 1, wherein
The plurality of error detection devices (30) include:
A missing sequence number is confirmed by finding a place where the sequence number added to the data string (IP packet) is not normally incremented, and based on the lack of the sequence number, the data string (IP packet) Detecting the omission,
The sequence number immediately before the missing to the sequence number immediately after returning from the missing is extracted, the plurality of extracted sequence numbers, the date and time when the missing of the data string is detected, and the error detection device are installed A technical feature is that error data is generated by combining transmission point numbers (P2 to P6).

The invention according to claim 3
The data recording system according to claim 1, wherein
The plurality of error detection devices (30) include:
The duplication of the sequence number is confirmed by finding the part where the sequence number added to the data string (IP packet) is not normally incremented, and based on the duplication of the sequence number, the data string (IP packet) Detecting duplicates,
The sequence number immediately before the overlap is extracted from the sequence number immediately after returning from the overlap, the extracted plurality of sequence numbers, the date and time when the duplication of the data string is detected, and the error detection device are installed. A technical feature is that error data is generated by combining transmission point numbers (P2 to P6).

The invention according to claim 4
The data recording system according to claim 1, wherein
The plurality of error detection devices (30) include:
The sequence number added to the data string (IP packet) is checked for a change in order of the sequence number by finding a place where the sequence number is not normally incremented, and the data string (IP packet) is determined based on the change in order of the sequence number. )
The sequence number immediately before the forward change to the sequence number immediately after returning from the forward change are extracted, the extracted sequence numbers, the date and time when the forward change of the data string is detected, and the error detection device are installed. The technical feature is that error data is generated by combining the transmission point numbers (P2 to P6).

The invention described in claim 5
In the data recording system of any one of Claims 1-4,
The management device (31)
The plurality of errors based on all data strings (IP packets) constituting the data (TS) read from the second recording device (HDD 55) and the error data read from the second recording device (HDD 55). A technical feature is that the data string (IP packet) constituting the data (TS) received at the transmission points (P2 to P6) where the detection device (30) is installed is reproduced.

The invention described in claim 6
The data recording system according to claim 5, wherein
The management device (31)
When the data string is lost, the data string corresponding to the sequence number included in the error data is deleted and removed from all the data strings (IP packets) constituting the data (TS). Thus, it is technically characterized to reproduce the data string constituting the data received at the transmission points (P2 to P6) where the missing data string has occurred.

The invention described in claim 7
The data recording system according to claim 5, wherein
The management device (31)
When duplication of the data string occurs, the data corresponding to the duplicate sequence number among the sequence numbers included in the error data from all the data strings (IP packets) constituting the data (TS). A technical feature is that by duplicating the data string, the data string constituting the data received at the transmission points (P2 to P6) where the duplication of the data string occurs is reproduced.

The invention according to claim 8 provides:
The data recording system according to claim 5, wherein
The management device (31)
When the order of the data sequence is changed, it corresponds to the sequence number in which the order is changed among the sequence numbers included in the error data from all the data sequences (IP packets) constituting the data (TS). It is a technical feature that the data sequence constituting the data received at the transmission points (P2 to P6) where the order change of the data sequence occurs is changed by changing the order of the data sequence to be performed.

The invention according to claim 9 is:
In the data recording system according to any one of claims 1 to 8,
The management device (31), based on the error data recorded and stored in the second recording device (HDD 55), the data string (IP) at a plurality of transmission points (P2 to P6) in the transmission path (La). It is a technical feature that the occurrence of a sequence error of packet) is determined.

The invention according to claim 10 is:
The data recording system according to claim 9, wherein
Display that displays a list of the sequence errors of the data string (IP packet) at the plurality of transmission points (P2 to P6) determined by the management device (31) for a predetermined period for each of the plurality of transmission points. It is a technical feature that the apparatus (61) is provided.

The invention according to claim 11
The data recording system according to claim 9, wherein
Display device for displaying a list of occurrence status of sequence errors of the data string (IP packet) at least one of the plurality of transmission points (P2 to P6) determined by the management device (31) for a predetermined period. (61) is provided as a technical feature.

The invention according to claim 12
The data recording system according to any one of claims 1 to 11,
The data is technically characterized in that the data is TS (Transport Stream) in MPEG (Moving Picture Experts Group) 2.

The invention according to claim 13
The data recording system according to claim 12, wherein
The data string is an IP (Internet Protocol) packet, and the sequence number is included in an RTP (Real-time Transport Protocol) header as a technical feature.

The invention according to claim 14
A program for causing a computer system to function as the error detection device (30) and the management device (31) in the data recording system according to any one of claims 1 to 13 has a technical feature.

The invention according to claim 15 is:
A computer-readable record in which a program for causing a computer system to function as the error detection device (30) and the management device (31) in the data recording system according to any one of claims 1 to 13 is recorded. The medium is a technical feature.

<Explanation of terms>
Reference numerals in parentheses described in [Means for Solving the Problems] and [Effects of the Invention] described later are the components described in [Best Mode for Carrying Out the Invention] described later. This corresponds to the reference numerals of the constituent elements.
The correspondence between the constituent members and constituent elements described in [Means for Solving the Problems] and [Effects of the Invention] and the constituent members and constituent elements described in [Best Mode for Carrying Out the Invention] is as follows: It is as follows.

[Data] corresponds to TS in MPEG2.
The “data string” corresponds to an IP packet.
The “management device” corresponds to the storage / reproduction device 31.
The “first recording device” corresponds to the RAM 43.
The “second recording device” corresponds to the HDD 55.
“Communication line” corresponds to the bidirectional communication line Lb.

<Claim 1>
In claim 1, the same operation and effect as described in [1] of [Operation and effect of the present embodiment] described later can be obtained.
Therefore, according to the first aspect, the first recording device (RAM 43) having a small recording capacity for the data received and acquired at the plurality of transmission points (P2 to P6) in the transmission path (La) of the data (TS), and A data recording system (10) that can be efficiently recorded and stored by the second recording device (HDD 55) can be realized at low cost.

<Claim 2>
According to the second aspect, it is possible to obtain the same action and effect as described in [IP packet loss] in [Operation of error detection device 30] described later.

<Claim 3>
According to the third aspect, the same operation and effect as described in [IP packet duplication] in [Operation of error detection apparatus 30] can be obtained.

<Claim 4>
In the fourth aspect, the same operation and effect as described in [IP packet order change] in [Operation of error detection device 30] can be obtained.

<Claim 5>
According to the fifth aspect, the same operation and effect as described in [Operation of the storage / reproduction device 31] described later can be obtained.

<Claim 6>
According to the sixth aspect, it is possible to obtain the same operation and effect as described in [Missing IP packet] in [Operation of storage / reproduction device 31].

<Claim 7>
According to the seventh aspect, the same operation and effect as described in [IP packet duplication] in [Operation of storage / reproduction device 31] can be obtained.

<Claim 8>
According to the eighth aspect, the same operation and effect as described in [IP packet order change] in [Operation of storage / reproduction device 31] can be obtained.

<Claim 9>
In claim 9, the same operation and effect as described in [3] of [Operation and effect of the present embodiment] can be obtained.
Therefore, according to the ninth aspect, the management device (31) can determine the occurrence of a sequence error of the data string (IP packet) at the plurality of transmission points (P2 to P6). It is possible to easily determine whether or not a data string sequence error has occurred.

<Claim 10>
In claim 10, the same operation and effect as described in [First display method] in [3] of [Operation and effect of this embodiment] can be obtained.
Therefore, according to the tenth aspect, the occurrence status of the sequence error of the data string (IP packet) at the plurality of transmission points (P2 to P6) is displayed on the display device (61) as a list for a predetermined period for each transmission point. Therefore, the operation manager of the data recording system (10) can check the occurrence status of the sequence error of the data sequence by simply looking at the display screen (61a) of the display device, and the sequence error of the data sequence is large. Even if it occurs, it can be reliably monitored.

<Claim 11>
In claim 11, the same operation and effect as described in [Second display method] in [3] of [Operation and effect of this embodiment] can be obtained.
Therefore, according to the eleventh aspect, the occurrence status of the sequence error of the data string (IP packet) at at least one of the plurality of transmission points (P2 to P6) is listed on the display device (61) for a predetermined period. Therefore, the operation manager of the data recording system (10) can check the occurrence status of the sequence error of the data sequence by simply looking at the display screen (61a) of the display device. Even if it occurs in large quantities, it can be reliably monitored.

<Claim 12>
In the twelfth aspect, the operation and effect of the first to eleventh aspects can be obtained with respect to the TS by applying to a system for recording TS in MPEG2.

<Claim 13>
In Claim 13, the said effect | action and effect of Claims 1-11 can be acquired regarding an IP packet.

<Claim 14 and Claim 15>
According to the fourteenth aspect, it is possible to provide a program for causing a computer system to function so as to realize the data recording system according to any one of the first to thirteenth aspects.
According to claim 15, a computer-readable recording medium on which the program of claim 14 is recorded can be provided.

For example, the program can be recorded by using a ROM or backup RAM as a computer-readable recording medium, and the ROM or backup RAM can be incorporated into a computer system.
In addition, the program is recorded (stored) in an external recording device (external storage device) having a computer-readable recording medium, and the program is loaded from the external recording device to the computer system as necessary. May be used.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an overall schematic configuration of a data recording system 10 of the present embodiment.
The data recording system 10 is applied to data distribution such as MPEG2 TV broadcasting using the Internet, and includes an error detection device 30, a storage / reproduction device (management device) 31, a TS transmission path La, and a bidirectional communication line. Lb, transmission points P1 to P6, and the like.

  In the example shown in FIG. 1, the TS transmitted from the transmission station 11 via the transmission line La is transmitted from the relay station 12a to the viewer terminal 13a, and at the same time the viewer terminal from the relay station 12a via the relay station 12b. 13b and the relay station 12c, and transmitted from the relay station 12c to a viewer terminal or a relay station (not shown).

Each error detection device 30 is installed at each of the transmission points P2 to P6 in the transmission line La, and TS is received (input) and acquired at the transmission points P1 to P6.
The storage / reproduction device 31 is installed at the starting transmission point P1 in the transmission line La, and TS is received and acquired at the transmission points P1 to P6.

The transmission point P1 as a transmission point (transmission location) is a location where the transmitter 20 installed in the transmission station 11 transmits (outputs) the TS via the transmission path La.
Transmission points P2, P4, and P6 as relay points (relay locations) are locations where the transceiver 21 installed in the relay stations 12a, 12b, and 12c transmits the TS via the transmission line La.
Transmission points P3 and P5 as reception points (reception locations) are locations where the receiver 22 incorporated in the viewer terminals 13a and 13b of the viewer receives the TS via the transmission path La.
That is, each error detection device 30 is installed in the relay stations 12a, 12b, and 12c and is built in the viewer terminals 13a and 13b.

  Each error detection device 30 receives TS distributed by a distributor (not shown) connected in the transmission line La. Therefore, by providing each error detection device 30, the TS transmitted through the transmission line La is not affected in any way.

  The transceiver 21 is a device having a relay function for receiving and transmitting a TS. Specifically, the Ethernet Switch / Ethernet HUB (Ethernet is a registered trademark), ATM Switch, Network Routor, DVB- It consists of ASI Routor.

The storage / reproduction device 31 is connected to each error detection device 30 via the bidirectional communication line Lb.
The transmission line La is an Internet line composed of a public telephone line including ISDN and ADSL, a dedicated communication line including an optical communication line, and the like.
The bidirectional communication line Lb includes, for example, an Internet line using a public telephone line including ISDN and ADSL, a dedicated communication line such as CATV and LAN, an optical communication line, and a wireless line.

  FIG. 2 is a block diagram illustrating a schematic configuration of the error detection device 30 and the storage / reproduction device 31.

Each error detection device 30 is a known microcomputer system including a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, a RAM (Random Access Memory) 43, an input / output device (I / O) 44, and the like. (Hereinafter abbreviated as “microcomputer”) 40.
Each error detection device 30 performs the operation described later by loading a computer program of software stored (recorded) in the ROM 42 onto the CPU 41 and executing various arithmetic processes according to the computer program.

The storage / reproduction device 31 includes a computer main body 50, an input device 60, a display device 61, and the like.
The computer main body 50 is configured by a known microcomputer including a CPU 51, a ROM 52, a RAM 53, an input / output device 54, an HDD (Hard Disk Drive) 55, and the like.
The storage / reproduction device 31 loads the computer program of the software stored in the ROM 52 to the CPU 51, and performs various operations according to the computer program, thereby performing operations described later.

By the way, the computer program is stored in the microcomputer 40 or the computer main body 50, not in the ROMs 42 and 52 incorporated in the microcomputer 40 or the computer main body 50. The computer program may be recorded (stored) in a recording device (external storage device), and the computer program may be loaded from the backup RAM or the external recording device to the CPUs 41 and 51 as necessary.
Incidentally, computer-readable recording media include, for example, semiconductor memory, HD (Hard Disk), optical disc (CD-ROM, DVD, etc.), magneto-optical disc (MO, etc.), phase change disc, magnetic disc, magnetic tape. and so on. The names of specific examples of the recording medium include registered trademarks.

The input device 60 includes, for example, a keyboard and a pointing device, converts an instruction command from an operation manager of the data recording system 10 into a data signal, and converts the data signal to the input / output device 54 of the computer main body 50. To the CPU 51.
The display device 61 includes various types of displays such as an LCD (Liquid Crystal Display) and a CRT (Cathode Ray Tube), and the processing result of the CPU 51 transferred via the input / output device 54 of the computer main body 50 ( The stored result is displayed on the display screen (monitor screen) 61a to notify the operation manager.

A plurality of IP packets constituting the TS are input to the input / output device 44 of the microcomputer 40 of each error detection device 30 and the input / output device 54 of the computer main body 50 of the storage / reproduction device 31 via the transmission line La. Has been.
Further, the input / output device 44 of the microcomputer 40 of each error detection device 30 and the input / output device 54 of the computer main body 50 of the storage / reproduction device 31 are connected via a bidirectional communication line Lb.
A commercially available personal computer may be used for each error detection device 30 and storage / reproduction device 31.

[Operation of Error Detection Device 30]
Each error detection device 30 receives TS transmitted in time series for each of the transmission points P2 to P6 in the transmission line La, and inspects sequence numbers added to a plurality of IP packets constituting the TS. The IP packet sequence error is detected based on each sequence number, error data is generated according to the detection result, and the error data is recorded and stored in the RAM 43 and stored via the bidirectional communication line Lb. Send to reproduction device 31.

  Here, in the data recording system 10 of the present embodiment, the failure that occurs in the TS transmission path La is only when the IP packet sequence error (IP packet loss / duplication / order change) (data in each IP packet). Is applied to the case where a data error in which the content changes does not occur), and not applied when a data error occurs.

[Missing IP packet]
FIG. 3 is an explanatory diagram for explaining the operation of the error detection device 30 when an IP packet is lost as an IP packet sequence error.

As shown in FIG. 3A, it is assumed that sequence numbers [32] to [39] are added to the IP packets constituting the TS transmitted from the transmission station 11.
As shown in FIGS. 3B and 3C, the IP packets constituting the TS received at the transmission points P2 to P6 in which the arbitrary error detection device 30 is installed have sequence numbers [35] and [36]. ] Two IP packets are missing.

The error detection device 30 confirms the absence of the sequence number by finding a place where the sequence number added to the IP packet is not normally incremented (a place where the sequence number does not increase one by one in order) A missing IP packet is detected based on the missing sequence number.
Then, the error detection device 30 extracts the sequence number [34] immediately before the loss and the sequence number [37] immediately after the recovery from the loss.

  Further, as shown in FIG. 3D, the error detection device 30 includes the extracted two sequence numbers [34] and [37], the date and time (year / month / day / hour / minute / second) when the lack of the IP packet was detected, Error data is generated by combining the installed transmission point numbers (P2 to P6), and the error data is recorded and stored in the RAM 43 and transmitted to the storage / reproduction device 31 via the bidirectional communication line Lb.

[Duplicate IP packet]
FIG. 4 is an explanatory diagram for explaining the operation of the error detection apparatus 30 when IP packet duplication occurs as an IP packet sequence error.

As shown in FIG. 4A, it is assumed that sequence numbers [32] to [39] are added to the IP packets constituting the TS transmitted from the transmitting station 11.
As shown in FIGS. 4B and 4C, the IP packet constituting the TS received at the transmission points P2 to P6 in which the arbitrary error detection device 30 is installed includes the IP of the sequence number [35]. Assume that two packets overlap.

The error detection device 30 confirms duplication of the sequence number by finding a part where the sequence number added to the IP packet is not normally incremented, and detects duplication of the IP packet based on the duplication of the sequence number. .
Then, the error detection device 30 extracts from the sequence number [34] immediately before the overlap to the sequence number [36] immediately after the recovery from the overlap.

  Further, as shown in FIG. 4D, the error detection apparatus 30 detects the four extracted sequence numbers [34] [35] [35] [36] and the date and time (year / month) when the duplication of the IP packet is detected. Date / time / minute / second) and the number (P2 to P6) of the installed transmission point are generated, and the error data is recorded and stored in the RAM 43 and stored / reproduced via the bidirectional communication line Lb. Transmit to the device 31.

[IP packet order change]
FIG. 5 is an explanatory diagram for explaining the operation of the error detection device 30 when the IP packet sequence changes as an IP packet sequence error.

As shown in FIG. 5A, it is assumed that sequence numbers [32] to [39] are added to the IP packets constituting the TS transmitted from the transmission station 11.
As shown in FIGS. 5B and 5C, the IP packets constituting the TS received at the transmission points P2 to P6 in which the arbitrary error detection device 30 is installed have a sequence number [36] [35 ], The order of the two IP packets is changed.

The error detection device 30 confirms the sequence number sequence change by finding a place where the sequence number added to the IP packet is not normally incremented, and the IP packet sequence change based on the sequence number sequence change. Is detected.
Then, the error detection device 30 extracts from the sequence number [34] immediately before the forward change to the sequence number [37] immediately after the return from the forward change.

  Further, as shown in FIG. 5D, the error detection device 30 detects the four sequence numbers [34] [36] [35] [37] extracted and the date and time (year) when the IP packet order change is detected. Error data that combines the installed transmission point number (P2 to P6) and records and saves the error data in the RAM 43 and saves it via the bidirectional communication line Lb. Transmit to the reproduction device 31.

  By the way, each error detection device 30 adds a predetermined number Nx of IP packets when determining whether or not the IP packet sequence error (IP packet loss / duplication / order change) has returned to a normal state. When the sequence number that has been set is normally incremented, it is determined that the first IP packet of the predetermined number Nx of IP packets is a normal IP packet with no sequence error.

The value of the predetermined number Nx may be set by experimentally finding an optimum value by cut-and-try according to the property of the transmission line La and the number of IP packets transmitted per unit time. What is necessary is just to set to the appropriate number more than.
That is, when the transmission line La has such a property that it frequently occurs after a sequence error has occurred once, or when the number of IP packets transmitted per unit time is large, the predetermined number Nx is set to a larger value. That's fine.
Further, when the transmission line La has such a property that a sequence error rarely occurs or when the number of IP packets transmitted per unit time is small, the predetermined number Nx can be set to a small value. Good.

  Incidentally, in the examples shown in FIGS. 3 to 5, the sequence numbers [32] to [39] are represented by two-digit numbers for easy understanding, but in actual operation, they are included in the RTP header. Since the sequence number consists of 16-bit data, it is represented by a number between 0 and 65535.

[Operation of the storage / reproduction device 31]
The storage / reproduction device 31 receives the TS at the transmission point P1 where the transmitter 20 transmits the TS via the transmission line La, and records and stores the TS in the HDD 55. Therefore, all the IP packets constituting the TS transmitted by the transmitter 20 are recorded and stored in the HDD 55 of the storage / reproduction device 31.

  The storage / reproduction device 31 receives the error data transmitted from each error detection device 30 via the bidirectional communication line Lb, attaches a file name to the error data, and records and saves the data in the HDD 55.

As described above, the HDD 55 of the storage / reproduction device 31 records and stores all the IP packets constituting the TS transmitted by the transmitter 20 and the error data transmitted from each error detection device 30.
Therefore, the storage / reproduction device 31 uses the transmission points P <b> 2 to P <b> 6 where the error detection devices 30 are installed based on all the IP packets constituting the TS read from the HDD 55 and the error data read from the HDD 55. It is possible to reproduce (restore) the IP packets constituting the received TS.

[Missing IP packet]
As shown in FIG. 3, when an IP packet is lost, the sequence number [34 included in the error data is transmitted from the IP packet (FIG. 3A) constituting the TS transmitted from the transmitting station 11. [37] The TS received at the transmission points P2 to P6 where the IP packet is lost by removing and removing the IP packet (FIG. 3C) corresponding to (FIG. 3D). Can be reproduced (FIG. 3B).

[Duplicate IP packet]
As shown in FIG. 4, when duplication of IP packets occurs, the sequence number [34 included in the error data from the IP packet (FIG. 4A) constituting the TS transmitted from the transmitting station 11 is displayed. ] [35] [35] [36] (Fig. 4 (D)), duplicating the IP packet corresponding to the duplicate sequence number (Fig. 4 (C)), duplication of the IP packet occurs The IP packets constituting the TS received at the transmission points P2 to P6 can be reproduced (FIG. 4B).

[IP packet order change]
As shown in FIG. 5, when a change in the order of IP packets occurs, the sequence number [included in the error data from the IP packet (FIG. 5A) constituting the TS transmitted from the transmitting station 11 [ 34] [36] [35] [37] (FIG. 5 (D)), the order of the IP packet corresponding to the sequence number whose order has been changed (FIG. 5 (C)) is changed. The IP packets constituting the TS received at the transmission points P2 to P6 where the forward change has occurred can be reproduced (FIG. 5B).

[Operation and effect of this embodiment]
According to this embodiment, the following actions and effects can be obtained.

  [1] Each error detection device 30 installed at each of the transmission points P2 to P6 in the TS transmission path La detects a sequence error of the IP packet based on the sequence number added to the IP packet constituting the TS. Then, error data is generated according to the detection result, and the error data is recorded and stored in the RAM 43 and transmitted to the storage / reproduction device 31 via the bidirectional communication line Lb.

That is, each error detection device 30 records and saves only error data in the RAM 43, and does not record and save the IP packets constituting the TS.
Here, the error data is a combination of the sequence number, the date and time when the sequence error was detected, and the transmission point numbers (P2 to P6), and its data size is small.
Therefore, since the recording capacity of the RAM 43 built in each error detection device 30 can be reduced, each error detection device 30 can be provided at low cost.

  On the other hand, in the method in which each error detection device 30 records and saves all IP packets constituting the TS transmitted by the transmitter 20, the large capacity and cost for recording and saving all IP packets constituting the TS. It is necessary to incorporate a recording device (for example, HDD) in each error detection device 30, and the cost of each error detection device 30 increases significantly.

  According to the present embodiment, as the number of transmission points on which the error detection device 30 is installed increases as compared with the conventional technique in which a sequence error monitoring device is installed for each transmission point P2 to P6 of the transmission line La of TS, data recording The installation cost of the entire system 10 can be kept low.

  By the way, a method for setting the timing for deleting (erasing) error data recorded and stored in the RAM 43 of each error detection device 30 includes, for example, the following.

  [A] The storage / reproduction device 31 receives the error data transmitted from the error detection device 30 via the two-way communication line Lb. When the error data is normally received, the storage / reproduction device 31 confirms reception of the error data. A message is generated, and the reception confirmation message is transmitted to the error detection device 30 via the bidirectional communication line Lb.

  Each error detection device 30 deletes the error data recorded and stored in the RAM 43 when receiving the reception confirmation message transmitted from the storage / reproduction device 31 via the bidirectional communication line Lb.

  Each error detection device 30 transmits error data to the storage / reproduction device 31 via the bidirectional communication line Lb, and then a predetermined time Ta set by the operation manager of the data recording system 10 in advance. If the reception confirmation message cannot be received before the elapse of time, a retransmission process for transmitting error data to the storage / reproduction device 31 via the bidirectional communication line Lb is performed again.

  When each error detection device 30 cannot receive the reception confirmation message even if the retransmission processing is repeated until the predetermined number of retransmission times Nr set in advance by the operation manager of the data recording system 10 is reached, The error data recorded and saved in the RAM 43 is deleted.

  [B] Each error detection device 30 records and saves the data in the RAM 43 when a predetermined time Tb preset by the operation manager of the data recording system 10 has elapsed after transmitting the error data to the storage / reproduction device 31. Delete the error data.

  [C] Each error detection device 30 deletes the error data recorded and stored in the RAM 43 when an instruction to delete the error data is given from the operation manager of the data recording system 10.

  [D] Each error detection device 30 continuously transmits error data to the storage / reproduction device 31 for a predetermined number of times Ny preset by the operation manager of the data recording system 10, and transmits the predetermined number of times Ny. When finished, the error data recorded and saved in the RAM 43 is deleted.

  In the methods [b] to [d], error data is only transmitted from each error detection device 30 to the storage / reproduction device 31, so that the bidirectional communication line Lb can be replaced with a one-way communication line.

The values of the predetermined times Ta and Tb, the predetermined number of times Ny, and the predetermined number of retransmissions Nr are respectively the time required for the storage / reproduction device 31 to receive the error data transmitted from each error detection device 30, and the error data. Considering the reliability and line speed of the bidirectional communication line Lb to be transmitted, the frequency of error data transmission, and the time required for recovery when the storage / reproduction device 31 fails or when the bidirectional communication line Lb fails Then, the optimum value may be found and set experimentally by cut-and-try.
If an error correction code is added to the error data, the predetermined times Ta and Tb, the predetermined number of times Ny, and the predetermined number of retransmissions Nr can be set to small values.

  Therefore, even when the operation manager of the data recording system 10 investigates the sequence error of the IP packet, even when monitoring and examining the occurrence status of the sequence error over a long period (for example, several days to several weeks) In this embodiment, since it is not necessary to record and store the long-term error data in the RAM 43 of each error detection device 30, an inexpensive RAM 43 with a small recording capacity can be used.

  As a result, according to the present embodiment, when a sequence error occurrence state of an IP packet over a long period of time is monitored and studied, an expensive large-capacity recording medium must be provided in the sequence error monitoring apparatus. Compared to, the installation cost of the entire system can be kept low.

By the way, it is conceivable that the broadcast program recording device of Patent Document 2 is installed for each transmission point P2 to P6, and the TS received at each transmission point P2 to P6 is recorded in each broadcast program recording device. .
Here, the technique described in claim 1 of Patent Document 2 includes a temporary storage unit and a large-capacity storage unit.
Further, in the technique described in claim 2 of Patent Document 2, the first storage means, the second storage means, and the third storage means are provided, and the first embodiment of Patent Document 2 includes the first storage means. The primary storage device as the storage means is embodied by RAM, the secondary storage device as the second storage means is embodied by HD, the tertiary storage device as the third storage means is embodied by magnetic tape, It is described that an autochanger for replacing the magnetic tape is provided.

Therefore, the broadcast program recording apparatus of Patent Document 2 is very expensive as compared with each error detection apparatus 30 having only one RAM 43.
Therefore, according to the present embodiment, the installation cost of the entire data recording system 10 increases as the number of transmission points where the error detection device 30 is installed increases as compared with the technique of installing the broadcast program recording device of Patent Document 2 at the transmission point. Can be kept low.

As described above, in this embodiment, only the HDD 55 built in the storage / reproduction device 31 records and stores all the IP packets constituting the TS transmitted by the transmitter 20.
Error data transmitted from each error detection device 30 is also recorded and stored in the HDD 55 of the storage / reproduction device 31, but the data size of the error data is small, so that the error data is recorded and stored in the HDD 55. There is no need to greatly increase the recording capacity.
Therefore, according to the present embodiment, the data recording system 10 that can efficiently record and store TS obtained by receiving and obtaining TS at a plurality of transmission points in the transmission line La with a recording device (RAM 43, HDD 55) having a small recording capacity is reduced. Can be realized at cost.

  [2] When the storage / reproduction device 31 records and saves the error data transmitted from each error detection device 30 in the HDD 55, the storage / reproduction device 31 includes a transmission point where the error detection device 30 that has transmitted the error data is installed. The date and time when the error detection device 30 detects the sequence error of the IP packet and the range of the sequence number included in the error data must be recorded and stored in a format that can be easily retrieved from the HDD 55 and read out.

  Therefore, the file name given when the storage / reproduction device 31 records and saves the error data in the HDD 55 is the number of the transmission point (P2 to P6) where the error detection device 30 that has transmitted the error data is installed, and The date and time (year / month / day / hour / minute / second) when the error detection device 30 detected the sequence error of the IP packet may be combined with the first sequence number and the last sequence number among the sequence numbers included in the error data.

  For example, the transmission point number is “P2”, the date and time when the sequence error was detected is “November 19, 2008 3: 24: 8”, and four sequence numbers [34] as shown in FIG. When [36] [35] [37] are included in the error data, the following file names are given.

    File name: P2-20081119-032408-34-37

Here, the date and time when the error detection device 30 detected the sequence error of the IP packet is described in the file name in order to distinguish error data having the same transmission point number and sequence number.
That is, the sequence number is made up of 16-bit fixed length data, and the number defined by the 16 bits is cyclically incremented.
Therefore, when error data over a long period is recorded and stored in the HDD 55 of the storage / reproduction device 31, a plurality of error data having the same transmission point number and sequence number may appear.
Therefore, if the date and time when the error detection device 30 detects a sequence error of the IP packet is described in the file name, it can be distinguished even if error data having the same transmission point number and sequence number appears.

[3] Based on the error data recorded and stored in the HDD 55, the storage / reproduction device 31 can easily determine at which transmission point at each transmission point P2 to P6 at which date and time an IP packet sequence error has occurred. It can be determined (detected).
Then, the storage / reproduction device 31 displays a determination result (detection result) of the occurrence of an IP packet sequence error on the display screen 61a of the display device 61. Examples of the display method include the following.

[First display method]
FIG. 6 is a front view showing a first display method of the determination result of the occurrence of sequence error in the IP packet displayed on the display screen 61a of the display device 61. FIG.
On the display screen 61a, a table in which four cells in the vertical direction and 24 cells in the horizontal direction are arranged in a matrix is displayed. In the vertical heading, codes indicating the transmission points P2 to P6 are displayed. In the heading, the time of dividing the day every hour is displayed.
Then, a cell representing the occurrence of an IP packet sequence error is made visible by being distinguished from other cells by changing its display color from that of other cells or by blinking the display.

In the example shown in FIG. 6, on the display screen 61a, the display colors of the four cells indicating the transmission points P3 to P6 at 14:00 are changed.
By the way, in the example shown in FIG. 6, 24 hours of a specific date (November 19, 2008) is displayed, but the setting selection button labeled “Display previous day” is input to the input device 60. 24 hours of the previous day (November 18, 2008) is displayed by operating using, and the next day (by displaying the next day by using the input device 60 with the setting selection button marked “Display next day”. November 20, 2008) is displayed for 24 hours.

In addition to the example shown in FIG. 6, 60 cells may be arranged in the horizontal direction, and a specific hour may be displayed in the horizontal heading every minute.
In addition, seven cells may be arranged in the horizontal direction, and a date (day of the week) obtained by dividing a specific week by day may be displayed in the horizontal heading.
Further, 31 cells may be arranged in the horizontal direction, and a date in which a specific month is divided every day may be displayed in the horizontal heading.
Then, by designating an arbitrary cell displayed on the display screen 61a using the input device 60, these displays may be switched.

[Second display method]
FIG. 7 is a front view showing a second display method of the determination result of the occurrence of the sequence error of the IP packet displayed on the display screen 61a of the display device 61. FIG.
On the display screen 61a, a table in which 24 cells in the vertical direction and 31 cells in the horizontal direction are arranged in a matrix is displayed, and in the vertical heading, the time divided into one hour is displayed. In the horizontal heading, a date in which one month is divided every day is displayed.
Then, a cell representing the occurrence of an IP packet sequence error is made visible by being distinguished from other cells by changing its display color from that of other cells or by blinking the display.

  In this second display method, when a sequence error is determined at any one of the transmission points P2 to P6, the display color of the cell corresponding to the date and time when the sequence error occurred is displayed. It can be changed.

  By the way, in the example shown in FIG. 7, one month of a specific year (November 2008) is displayed. A setting selection button labeled “Display previous month” is used by using the input device 60. One month of the previous month (October 2008) is displayed by operating, and the next month (December 2008) is operated by operating the setting selection button marked “Display next month” using the input device 60. Is displayed for one month.

In addition to the example shown in FIG. 7, 60 cells are arranged in a matrix in the vertical and horizontal directions, and the time divided by 1 second is displayed in the vertical heading, and the horizontal heading is displayed. You may make it display the time which divided specific 1 hour for every minute.
In addition, 24 cells in the vertical direction and 7 cells in the horizontal direction are arranged in a matrix, and the vertical heading displays the time divided by 1 hour, and the horizontal heading displays a specific week. May be displayed on a date (day of the week) divided by day.
Then, by designating an arbitrary cell displayed on the display screen 61a using the input device 60, these displays may be switched.

By the way, in the first display method and the second display method, an error is detected at transmission points P2 to P6 corresponding to the designated cell by designating the cell displayed on the display screen 61a using the input device 60. The IP packet constituting the TS received by the device 30 may be output from the storage / reproduction device 31.
In other words, the cell displayed on the display screen 61a may be specified using the input device 60 in order to specify the time range to be reproduced and the transmission points P2 to P6.
For example, in FIG. 6, when the cell CL displayed on the display screen 61a is designated, it is designated to reproduce the IP packet that constitutes the TS of the 14:00 November 19, 2008 transmission point P6.

Only the presence / absence of a sequence error of a specific type (missing / duplicate / change in order of IP packets) may be displayed on the display screen 61a.
Further, by changing the display color of the cell and the blinking interval for each type of sequence error, the type of sequence error may be distinguished and visually recognized.
Then, the storage / reproduction device 31 may record and save the determination result of the IP packet sequence error in the HDD 55.

  As described above, by using the first display method and the second display method, the operation manager of the data recording system 10 can perform the IP in a predetermined period only by looking at the display screen 61a of the display device 61 of the storage / reproduction device 31. The occurrence status of packet sequence errors can be confirmed, and even if a large number of IP packet sequence errors occur, it can be reliably monitored.

<Another embodiment>
The present invention is not limited to the above-described embodiment, and may be embodied as follows. Even in this case, the same operation or effect as that of the above-described embodiment can be obtained.

<1> In the above embodiment, the transceiver 21 is a device having a relay function for receiving and transmitting a TS, and each error detection device 30 is connected to a distributor (not shown) connected in the transmission line La. The distributed TS is input.
However, the transceiver 21 may be omitted and only the distributor may be provided.
Further, the distributor 21 may be omitted by providing the transceiver 21 with the function of the error detection device 30.
Further, the receiver 22 may be provided with the function of the error detection device 30.

<2> In the above embodiment, the operation of each error detection device 30 is realized by software processing by the microcomputer 40, and the operation of the storage / reproduction device 31 is realized by software processing by the computer main body 50. Yes.
However, the microcomputer 40 may be replaced with a dedicated circuit provided with a dedicated circuit having a function of realizing the operation of each error detection device 30 as hardware.
Moreover, the computer main body 50 may be replaced with a dedicated circuit provided as a hardware with a dedicated circuit having a function of realizing the operation of the storage / reproduction device 31.

  <3> In the above embodiment, the RAM 43 and the HDD 55 are used as recording media. However, if the operations of the error detection device 30 and the storage / reproduction device 31 can be performed reliably, the RAM 43 and the HDD 55 can be used in any manner. It may be replaced with a new recording medium.

<4> The above embodiment is applied to data distribution such as TV broadcast by MPEG2 using the Internet.
However, the present invention may be applied to MPEG2 digital broadcasting. In this case, the transmission line La may be a one-way communication line. For example, the transmission line La may be embodied by a broadcast wave, a dedicated communication line, an optical communication line, or the like. Good.
Further, the present invention may be applied to data communication based on MPEG2, and in this case, the transmission line La may be a bidirectional communication line.

  In the above embodiment, when the transmission line La is a bidirectional communication line, the functions of the bidirectional communication line Lb can be included using the transmission line La. The function equivalent to that of the above embodiment can be realized by eliminating the line Lb and using only the transmission line La.

<5> In the above embodiment, the sequence number added to the IP packet constituting the TS is used.
However, the TS may be divided by an appropriate dividing method, and a sequence number may be added in advance for each packet group (data string packet) composed of the divided TS.
In this case, the transmitter 20 transmits a TS to which a sequence number is added for each packet group.
Here, TS division methods (division rules) include, for example, the following, but not limited to the following examples, any division method may be used.

[A] The TS is divided for each TOT (Time Offset Table) packet included in the TS, and a packet group is generated by collecting a plurality of TS packets constituting the TS every time the TOT packet appears.
When dividing the TS, only one of the audio ES and video ES multiplexed in the TS may be extracted, and the extracted ES may be divided.

  [A] A method of dividing a TS based on DTS (Decoding Time Stamp) or PTS (Presentation Time Stamp) in PCR or PES.

[C] A method of dividing a TS based on a continuity index in a TS packet such as a PAT (Program Association Table) that is known to be inserted into a TS at a specific period.
Here, since the PAT cycle is around 100 ms and the continuity index ranges from 0 to 15, for example, if only TS packets with continuity index = 0 are picked up, the TS can be divided in units of about 1.6 seconds. If the time error between the transmission points P2 to P6 is sufficiently small with respect to the 1.6 seconds, it can be used as a dividing method.

  [D] A method of dividing a TS based on an identification code generated from a variety of data included in the TS by a hash function and a set of approximate times.

  [E] A method of dividing a TS into packet groups composed of the predetermined number of TS packets by grouping a predetermined number of TS packets into one packet group.

<6> The present invention is not limited to the TS (MPEG2 TS) in MPEG2, but may be applied to any data as long as it is data transmitted in time series.
In this case, the data division method corresponding to the above <5> may be set as appropriate in accordance with the characteristics of the data. For example, if data does not cause data loss, the data is divided for each predetermined amount of data. Thus, the data may be divided.

1 is a block diagram showing an overall schematic configuration of a data recording system 10 according to an embodiment embodying the present invention. 1 is a block diagram showing a schematic configuration of an error detection device 30 and a storage / reproduction device 31 in a data recording system 10. FIG. Explanatory drawing for demonstrating operation | movement of the error detection apparatus 30 when the loss of an IP packet generate | occur | produces as a sequence error of an IP packet. Explanatory drawing for demonstrating operation | movement of the error detection apparatus 30 when duplication of IP packet generate | occur | produces as a sequence error of IP packet. Explanatory drawing for demonstrating operation | movement of the error detection apparatus 30 when the order change of an IP packet generate | occur | produces as a sequence error of an IP packet. The front view which shows the 1st display method of the determination result of the sequence error generation | occurrence | production of IP packet displayed on the display screen 61a of the display apparatus 61. FIG. The front view which shows the 2nd display method of the determination result of the sequence error generation | occurrence | production of IP packet displayed on the display screen 61a of the display apparatus 61. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Data recording system 11 ... Transmitting station 12a, 12b, 12c ... Relay station 13a, 13b ... Viewer terminal 20 ... Transmitter 21 ... Transmitter / receiver 22 ... Receiver 30 ... Error detection apparatus 31 ... Storage / reproduction apparatus (management apparatus) )
40 ... Microcomputer system 43 ... RAM
50 ... Computer body 55 ... HDD
60 ... Input device 61 ... Display device 61a ... Display screen P1 to P6 ... Transmission point La ... Transmission path Lb ... Bidirectional communication line

Claims (15)

A transmission path through which data is transmitted in time series;
The data is composed of divided data strings, and each data string is appended with a sequence number that is information representing the data order;
An error detection device installed at each of a plurality of transmission points in the transmission path;
A first recording device provided in each of the plurality of error detection devices;
A management device installed at a transmission point at a starting point in the transmission path and connected to the plurality of error detection devices via a communication line;
A data recording system comprising a second recording device provided in the management device,
Each of the plurality of error detection devices receives the data for each transmission point in the transmission path, and checks and confirms the sequence numbers added to the data strings constituting the data, respectively. A sequence error in the data string is detected based on the sequence number, error data is generated according to the detection result, the error data is recorded and stored in the first recording device, and transmitted to the management device via the communication line. And
The type of sequence error of the data string includes a missing data string that is missing the data string that must constitute the data, and a duplicate of the same data string in the data. There is a duplication of included data strings, and a change in the order of the data strings in which the order of the data strings constituting the data is replaced with the correct order,
The management device receives the data at the transmission point at the starting point in the transmission path, records and stores the data in the second recording device, and the plurality of error detection devices transmit the data via the communication line. A data recording apparatus comprising: receiving the error data; and recording and storing the error data in a second recording apparatus. The data recording system according to claim 1, wherein
The plurality of error detection devices include:
Confirming a missing sequence number by finding a place where the sequence number added to the data string is not normally incremented, and detecting the missing data string based on the missing sequence number;
The sequence number immediately before the missing to the sequence number immediately after returning from the missing is extracted, the plurality of extracted sequence numbers, the date and time when the missing of the data string is detected, and the error detection device are installed A data recording apparatus characterized by generating error data by combining with a transmission point number. The data recording system according to claim 1, wherein
The plurality of error detection devices include:
Confirming duplication of the sequence number by finding a place where the sequence number added to the data string is not normally incremented, and detecting duplication of the data string based on the duplication of the sequence number;
The sequence number immediately before the duplication is extracted from the sequence number immediately after returning from the duplication, the extracted sequence numbers, the date and time when the duplication of the data string is detected, and the error detection device are installed. A data recording apparatus characterized by generating error data by combining with a transmission point number. The data recording system according to claim 1, wherein
The plurality of error detection devices include:
Confirming a change in the order of the sequence number by finding a place where the sequence number added to the data string is not normally incremented, and detecting a change in the order of the data string based on the change in the order of the sequence number When,
The sequence number immediately before the forward change to the sequence number immediately after returning from the forward change are extracted, the extracted sequence numbers, the date and time when the forward change of the data string is detected, and the error detection device are installed. A data recording apparatus, characterized in that error data is generated by combining a transmission point number. In the data recording system of any one of Claims 1-4,
The management device
Received at the transmission point where the plurality of error detection devices are installed based on all the data strings constituting the data read from the second recording device and the error data read from the second recording device A data recording apparatus for reproducing the data string that constitutes the recorded data. The data recording system according to claim 5, wherein
The management device
If the data string is missing, the missing data string is removed by removing the data string corresponding to the sequence number included in the error data from all the data strings constituting the data. A data recording apparatus, which reproduces a data string constituting the data received at a transmission point at which occurrence occurs. The data recording system according to claim 5, wherein
The management device
When duplication of the data string occurs, by duplicating the data string corresponding to the duplicate sequence number among the sequence numbers included in the error data from all the data strings constituting the data A data recording apparatus for reproducing a data string constituting the data received at a transmission point where the duplication of the data string has occurred. The data recording system according to claim 5, wherein
The management device
When a change in the order of the data strings occurs, the order of the data strings corresponding to the sequence numbers in which the order is changed among the sequence numbers included in the error data is switched from all the data strings constituting the data. Thus, a data recording apparatus that reproduces the data sequence that constitutes the data received at the transmission point where the order of the data sequence has changed. In the data recording system according to any one of claims 1 to 8,
The data management system, wherein the management device determines occurrence of a sequence error of the data string at a plurality of transmission points in the transmission path based on the error data recorded and stored in a second recording device . The data recording system according to claim 9, wherein
A data recording system comprising: a display device that displays a list for a predetermined period for each of the plurality of transmission points with respect to the occurrence status of the sequence error of the data string at the plurality of transmission points determined by the management device . The data recording system according to claim 9, wherein
A data recording system, comprising: a display device that displays a list of a sequence error occurrence state of the data string at at least one of the plurality of transmission points determined by the management device for a predetermined period. The data recording system according to any one of claims 1 to 11,
The data recording system is characterized in that the data is TS (Transport Stream) in MPEG (Moving Picture Experts Group) 2. The data recording system according to claim 12, wherein
The data recording system, wherein the data string is an IP (Internet Protocol) packet, and the sequence number is included in an RTP (Real-time Transport Protocol) header.   The program for functioning a computer system as the said error detection apparatus and the said management apparatus in the data recording system of any one of Claims 1-13.   14. A computer-readable recording medium in which a program for causing a computer system to function as the error detection device and the management device in the data recording system according to claim 1 is recorded.

Images