JP2001326647A - Communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication unit that effectively utilizes a communication resource so as to transmit control information, at transmission of video and audio signals. SOLUTION: A CPU 108 transmits video/audio data outputted from a VTR 101 via an ATM-I/F 110 and transmits control information from the ATM-I/F 110 by mapping the control information to a padding field of a User-PDU, which is a transmission unit of video and audio signal data and using the same virtual channel as that for the video audio data, when a user control request from the User-I/F 111 at the same time is detected. A CPU 113 judges that the control information is attached and detects the control information, when a data size included in the User-PDU received via an ATM-I/F 112 differs from a predetermined data size and outputs the detected control information to a VTR 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for transmitting real-time data such as video and audio data in real time using a network.

[0002]

2. Description of the Related Art ATM (Asynchronous Transfer Mode)
Technology is originally a broadband ISD that is responsible for multimedia communications
N was developed as a transmission and switching technology. ATM is not only high speed and wide band, but also has QoS (Quality of Service) specified by transmission bandwidth, delay, fluctuation, error rate, etc.
vice: quality of service), so it is suitable for multimedia communication.

In the ATM, audio data, video data, and other auxiliary data having different bit rates are assembled into fixed-length cells and can be asynchronously and unitarily handled. The configuration of the ATM cell includes a 5-byte header area and a 48-byte effective information area (payload), and is composed of 53-byte data in total.

The AAL (ATM Adaptation Layer) is a layer that performs mapping between data units of various upper-level applications and 48-byte user information that is uniformly handled in ATM cells. Among them, the AAL type 5 can realize efficient data transfer with less mounting overhead.

FIG. 11 shows AAL type 5 of the ATM communication system.
2 shows a protocol stack of the first embodiment. In FIG. 11, B is By
means te. As shown in FIG. 11, in AAL5, the variable length user information of the upper layer (User Inf in FIG. 11)
operation) with a header of 5 bytes and a payload of 48
It is mapped and transmitted to a fixed-length 53-byte ATM cell composed of bytes. In the upper layer, the size of the minimum transfer unit differs depending on the type of data.
The minimum transfer unit defined by the C (Digital Video Cassette) standard is a DIF (Digital Interface) block, and the size is 80 bytes. In the DVC standard, as shown in FIG. 11, a plurality of DIF blocks are combined to form a variable-length User-PDU (Protocol Data Unit), and the size of the User-PDU is a multiple of the payload size of the ATM cell. Padding (CP in FIG. 11)
The PAD in the CS-PDU is performed, and the CPCS trailer (4 bytes of UU, CPI, LENGTH in FIG. 11) is added, and the CPCS-PDU (Common Part Co.
nvergence Sublayer-Protocol Data Unit). Further, as shown in FIG.
It is divided into an 8-byte SAR Segment, mapped to an ATM cell with a 5B header added.

On the other hand, IEEE 1394 is a new general-purpose serial bus standard for personal computers (hereinafter, referred to as PCs) and digital AV equipment, and is becoming popular as a future standard digital interface. Especially in most of today's DV camcorders,
Various applications and systems can be built by integrating PCs and AV devices based on the IEEE 1394 technology, such as the emergence of standard-equipped PCs.

In IEEE 1394, not only AV signals but also device control commands can be sent.
An AV / C command set for transmitting a control command for an AV device includes a command C for controlling devices such as PLAY and STOP.
STA for ONTRO command and status inquiry
Four types of commands are defined: an INQUIRY command for inquiring whether a TUS command and a CONTROL command are supported, and a NOTIFY command for notifying a status change. Many specific commands are defined, but support levels such as mandatory / recommended / optional are defined for each command so that compatibility between products can be easily ensured. VT
Mandatory commands for R control basic mechanisms 9
Types of CONTROL commands and 7 types of STATUS
Command.

In an ATM network, a virtual channel (Virtual Channel, hereinafter referred to as VC) and a virtual path (Vir
Each cell is transferred to a target terminal using a tual path (hereinafter, VP). VC sets a virtual route between terminals for each communication. On the other hand, the VP is set by bundling the VCs. In ATM, the network route is V
Hierarchization into P and VC makes it possible to process communication from a plurality of different places such as data and control signals by physically providing a plurality of virtual lines on one line. However, when a data line and a control signal line are simultaneously used between the same terminals, a plurality of line settings are required, but this complicates the setting and wastes communication resources.

As a technique for efficiently transmitting data and control signals without wasting communication resources, Japanese Patent Laid-Open Publication No.
There is 1-441248 gazette. This is the CP shown in FIG.
By mapping significant information different from the main data to the 1U UU (User to User) field of the CS trailer, the utilization efficiency of the communication band is improved.

[0010]

However, in the above prior art, since significant information is mapped to the UU field in the AAL5 trailer different from the payload portion and transmitted, significant information is added in addition to a normal transmission data mapping and extraction circuit. Requires a mapping and extraction circuit,
The circuit scale increases.

Further, since the presence or absence of significant information cannot be determined from the outside, it is necessary to constantly detect information, and the processing load increases. In addition, significant information can only be mapped to one byte in one AAL type 5 frame. Further, there is a disadvantage that the transmission direction of the control signal is limited to the data transmission direction.

An object of the present invention is to provide a communication device which realizes efficient transmission of control information with a simple configuration without affecting the transmission of main real-time data.

[0013]

In order to solve the above-mentioned problem, a communication apparatus according to the present invention has a configuration in which a transmitting unit maps control information to a padding portion of data to be transmitted.

With this configuration, the communication device of the present invention can transmit control information without affecting the transmission of real-time data.

The receiving means transmits control information for controlling the data generating means on the same transmission path as that for transmitting real-time data, and the receiving means controls the data generating means based on the control information.

With this configuration, the communication device of the present invention
The control information can be transmitted in the direction opposite to the data transmission direction without affecting the transmission of real-time data.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A communication device according to the present invention is a communication device for digitizing real-time data at a fixed transmission rate and transmitting the data in a predetermined transmission unit, comprising: a data generating means for generating the real-time data; A transmission unit that generates transmission data serving as a data transmission unit, performs padding so that the data size of the transmission data is a multiple of the data size of the transmission unit, and transmits the transmission data in the transmission unit; Receiving means for restoring the real-time data from the received data, and data recording and reproducing means for recording and reproducing data output from the receiving means in real time, the transmitting means,
Control information for controlling the data recording / reproducing means is stored and transmitted in a padding portion added to the transmission data, and the receiving means detects the control information from the received data and controls the data recording / reproducing means. The transmission device is characterized in that the data length of each transmission data is predetermined, the transmission means transmits the transmission data by adding identification information capable of uniquely identifying the transmission data,
When the effective data length of the received transmission data exceeds the data length predetermined in the data, the receiving unit detects, as the control information, the effective data of a portion exceeding the data length from the discrimination information. With this configuration, the communication device of the present invention adds control information to a padding portion added to transmission data, so that control information can be transmitted without affecting transmission of real-time data.

Further, the transmitting means performs processing for each reproduction unit of the real-time data, and stores control information for controlling the data recording / reproducing means in a padding portion of the first transmission data constituting the reproduction unit, It is possible to control the reproduction unit for the remote data recording / reproducing means.

According to a second aspect of the present invention, in the first aspect, when receiving a control request from the data generating means, the receiving means transmits real-time data as control information for controlling the data generating means. The communication apparatus transmits data on the same transmission path as the transmission path, and the transmission unit controls the data generation unit based on the transmitted control information. Since the means transmits control information for controlling the data generating means on the same transmission path as the real-time data transmission path, the control information can be transmitted in a direction opposite to the data transmission direction without wasting communication resources. it can.

Further, the data generation means performs a process under the control of the reception control means, outputs an execution result of the process to the transmission control means, and the transmission means stores the execution result in a padding portion of the transmission data. The receiving means can detect the execution result from the received data, so that highly reliable remote control can be performed on a remote non-control device.

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

The real-time data in the present invention may be any digitized signal requiring real-time characteristics such as a video signal or an audio signal. In the present invention, DVC is used as real-time data unless otherwise specified.
DIF defined by standard NTSC (525/60)
Transmit the block. At this time, the transmission rate is about 28.8.
Mbps CBR (Constant Bit Rate: fixed rate).

As the interface for video and audio signals, any digital interface can be used as long as real-time characteristics are guaranteed. In the embodiment of the present invention, the isochronous (I
S for transmitting AV signals using sochronous) transmission
pecifications of Digital Interface for consumerEle
It is assumed that ctric Equipment (commonly called AV protocol) is used. As a control command interface between AV devices, any interface can be used as long as the device can be controlled. In the embodiment of the present invention, the IE is used.
AV / C c for sending control commands for AV devices using asynchronous transmission of EE1394
ommand transaction set shall be used.

The communication means may be any communication means capable of transmitting data in real time. In the embodiment of the present invention, an ATM is used.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a communication apparatus according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 101 denotes a VTR which is data generating means for reproducing and outputting video and audio data recorded on a built-in cassette tape;
A transmitting terminal for transmitting video and audio data input from the network to the network; 103, an ATM network;
Reference numeral 4 denotes a receiving terminal for receiving video and audio data from the ATM network 103; 105, a VTR which is a data recording / reproducing means for recording or decoding the video and audio data received by the receiving terminal 104;
A monitor device for displaying and outputting the video and audio data decoded at 05.

The component 107 of the transmitting apparatus 102 is an IEEE
An IEEE 1394-I / F 108 for extracting data to be transmitted from data in the E1394 format generates transmission data from the data stored in the memory 109 and adds a transmission header to the CPU. Reference numeral 110 denotes an ATM-I / F for transmitting transmission data as cells, and 111 denotes a User-I / F for inputting a control request from a user.

The component 112 of the receiving apparatus 104 receives an ATM cell from an ATM network.
I / F 113 is a CPU for restoring data stored in memory 114 to original data, 114 is a memory for temporarily storing received data, and 115 is a converter for converting data stored in memory 114 into IEEE 1394 format. IEEE 1394-I / F to output the data.

Further, in order to realize the QoS guarantee in this communication, CB is used for the ATM network to be used.
R (Peak Cell Ra) of transmission data in the direction of transmission of real-time data as an essential traffic parameter for R
te: maximum cell rate).

The operation of the communication device configured as described above will be described below. IEEE1394-I / F
107 extracts a video and audio data portion from the real-time data input from the VTR 101,
8 and stored in the memory 109. In addition, the CPU 10
8 stores the data stored in the memory 109 as an 80B DIF
The data is divided into block units, each divided data is arranged according to a predetermined format, and a transmission header is added.

FIG. 2 shows an example of User-PDU of DVC data. In the figure, Hn (hereinafter, n is an integer of 0 or more) is a header in the DIF sequence, SCn is a subcode in the DIF sequence, VAn is VAUX (Video Auxiliary information) in the DIF sequence, and An is D
The audio data in the IF sequence and Vn indicate each DIF block of the video data in the DIF sequence, and the DIF block is composed of 80B (Byte) data.

As shown in FIG. 2, User-PDU is 8
It is composed of a 0B DIF block, and a header is added at the beginning. Here, the video data in the User-PDU is arranged in units of 5DIF blocks, which are units of video segments. In FIG. 2, five DIF blocks of video data are arranged. Also, AAL type 5
In the transmission of real-time data, a sequence number is added to the beginning of the data to check the continuity of the data. In this case, the frame number and PD are included in the header.
A U number field is provided for each one byte. The data size in each User-PDU is determined in advance, and if the PDU number is known, the data size is associated so that the data size can be uniquely identified.

The ATM-I / F 110 has a data size of ATM for User-PDU generated by the CPU 108.
Padding is performed so as to be a multiple of the cell payload size, a CPCS trailer is added, the cell is converted into an ATM cell, and transmitted to a predetermined virtual channel of the ATM network.

FIG. 3 shows the C value corresponding to one frame of DVC data.
4 shows an example of a PCS-PDU format. Hn, SCn, VAn, Vn, An in FIG. 3 indicate the same data as in FIG. As shown in FIG. 3, the ATM-I / F 110
Performs padding so that the User-PDU shown in FIG. 2 is a multiple of the payload size of the ATM cell (PAD in FIG. 3), and adds a CPCS trailer to the CPCS-PD.
Generate U. In this case, the data of one frame is 140
CPCS-PDUs. As shown in FIG. 3, the size of each CPCS-PDU is predetermined. The size of the CPCS-PDU in this case is ATM
It is a multiple of the cell payload (48 bytes).
This is the size of the data contained in each CPCS-PDU,
In this case, it means that the number of DIF blocks is also determined.

As shown in FIG. 3, each CPCS-P
In the DU, video data is included in units of 5DIF blocks, which are units of video segments. For example,
5DIF block, CPC for CPCS-PDU000
The S-PDU001 includes 10 DIF blocks and 5D
It is a multiple of the IF block.

On the receiving side, the ATM-I / F 112
CPU 11 receives an ATM cell from the TM network,
3 and stored in the memory 114. IEEE 1394
-The I / F 115 converts the data stored in the memory into IEEE
The data is converted into 1394 format data and output to the VTR 105. The VTR 105 decodes the input video / audio data, and displays and outputs the same to the monitor device 106.

In the communication device of the present embodiment, the CPU
108 transmits the video / audio data and at the same time
Monitoring input of a user control request from the I / F 111,
When a control request from the user is detected, control information is added to the end of the User-PDU to which the video and audio signal data has been mapped, and the ATM-I / F 110 transmits the control information to the A-I / F 110.
Send it to the TM network 103.

FIG. 4 shows a format example of the control information.
Here, the control information includes IEEE1394 as shown in FIG.
4 bytes (command type, opcode, operand, etc.) corresponding to the command frame of the AV / C command set of the first embodiment are mapped. As shown in FIG. 4, the CPU 108 generates a User-PDU in which a header is mapped at the head of real-time data composed of a plurality of DIF blocks and control information is mapped at the end, and A
The TM-I / F 110 performs padding on the User-PDU so as to be a multiple of a predetermined ATM cell payload size, adds a CPCS trailer, generates a CPCS-PDU, and transmits the generated CPCS-PDU. By this processing, control information is mapped to the padding field of the User-PDU.

The ATM-I / F 112 receives ATM cells from the ATM network 103 and stores the data in the memory 114 via the CPU 113. The CPU 113 reconstructs the data from the header of the received data,
14. Further, the CPU 113 determines the data length of the User-PDU and the PD of the header from the header of the received data.
Whether or not the received data includes control information is identified from the correspondence between the U numbers. Since the data length included in the CPCS-PDU is uniquely determined from the PDU number, the CPU 113 determines that the data length of the data included in the received CPCS-PDU does not match the data length determined by the PDU number. , Control information is included, and control information added to the data is detected.

The control information detected by the CPU 113 is IE
AV / C supported through EE1394-I / F115
Converted to command. The VTR 105 performs processing such as recording and rewinding according to the received AV / C command.

As described above, in the present embodiment, the control information is mapped to the padding field on the same User-PDU as the transmission of the video and audio data, and the transmission is performed. VT in
Editing operations between R can be performed.

(Embodiment 2) In the present embodiment, a communication apparatus that maps control information to the PDU of the first frame of video and audio data will be described.

FIG. 5 is a block diagram showing a configuration of a communication device according to the second embodiment of the present invention. In FIG. 5, 60
Reference numeral 1 denotes a hard disk (HDD) that records video and audio data of the DVC standard. Note that components having the same reference numerals as those in the first embodiment are assumed to have the same components and operate in the same manner, and descriptions thereof will be omitted. Further, the difference between the present embodiment and the first embodiment is the HDD 601 and the control information mapping method.

The operation of the communication device configured as described above will be described below.

First, a user issues a control request associated with video and audio data recorded on the HDD 601.
The data is input to the CPU 108 through the ser-I / F 111. The CPU 108 to which the control request has been input reads out the video and audio data recorded in the HDD 601 according to the input control request, and stores it in the memory 109. Also,
The CPU 108 stores the data stored in the memory 109 as 80
The data is divided into B DIF blocks, the divided data are arranged according to a predetermined format, and a transmission header is added. The ATM-I / F 110 performs padding so that the data size is a multiple of the ATM cell payload size, adds a CPCS trailer, and
The data is converted into a TM cell and transmitted to a predetermined virtual channel of the ATM network 103.

On the receiving side, ATM-I / F 112
When an ATM cell is received from the TM network 103, the
U <b> 113 reconstructs the data from the header of the received data and stores the data in the memory 114.

The IEEE 1394-I / F 115 converts the data stored in the memory into data in the IEEE 1394 format and outputs the data to the VTR 105. And VTR105
Then, the input video / audio data is decoded, displayed on the monitor device 106, and output.

At the same time as transmitting the video and audio data, the CPU 108 maps the control information to the same PDU as the video and audio data and transmits it in response to a control request from the user.

FIG. 6 shows a CPC to which control information is mapped.
It is a figure which shows S-PDU. Figure 6 shows a 2-byte header,
4 bytes of control information, 1008 bytes of CPCS-PD with padding and 42 bytes of CPCS trailer added
Indicates U. In this case, one frame of data is composed of 140 CPCS-PDUs (CPCS-PDU0000 to CPCS-PDU0000).
CS-PDU 139). For example, when the user designates recording of an arbitrary frame section, the first PDU of the start frame (CPCS-PDU00
0), the recording command information is mapped to the control information, and the first PDU (CPCS-PDU 13)
The recording pause command information is mapped to the control information of 9).

The ATM-I / F 112 receives an ATM cell from the ATM network, and the CPU 113 detects control information from the received data and outputs the control information to the IEEE 1394-I / F.
It is converted into the corresponding AV / C command through F115. The VTR 105 performs recording from the frame to which the recording command information is mapped according to the received AV / C command, and operates to pause the recording operation in the frame to which the recording pause command information is mapped.

As described above, in the present embodiment, control information is mapped to the padding field of the PDU of the first frame of the video / audio data, so that communication resources are not wasted and a remote VTR can be used. Accurate editing operations in frame units are possible.

In this embodiment, the recording command information and the recording pause command information are transmitted as the control information, but the present invention is not limited to this.

(Embodiment 3) In this embodiment, a communication apparatus that transmits control information on the same virtual channel as the transmission of video and audio data and performs remote control of a VTR remote from the receiving side will be described.

FIG. 7 is a block diagram showing a configuration of a communication device according to the third embodiment of the present invention. In FIG. 7, 8
01 is a user-input terminal for inputting a control request from the receiving user.
I / F. Note that components having the same reference numerals as those of the communication device according to the first embodiment indicate the same components, and a description thereof will be omitted.

To realize the QoS guarantee in the communication of the present embodiment, the ATM network used
PCR (Peak Cel) of transmission data in the direction of real-time data transmission as an essential traffic parameter for CBR
l Rate: Maximum cell rate). Also, the PCR in the direction opposite to the transmission data is not 0,
Need to be set. However, the control information may be an extremely small amount in both the transmission data and its data amount and transmission frequency.

The operation of the communication device configured as described above will be described below. IEEE1394-I / F10
Reference numeral 7 extracts the video and audio data portions from the input data and stores the extracted data in the memory 109 via the CPU 108. Further, the CPU 108 generates transmission data from the data stored in the memory 109 and adds a transmission header. ATM-I / F110 uses CPCS for the data to be transmitted.
A trailer is added, converted to an ATM cell, and transmitted to a predetermined virtual channel of the ATM network.

On the receiving side, ATM-I / F 111
CPU 11 receives an ATM cell from the TM network,
2 restores the original data from the received data and stores it in memory 1
13 is stored. The IEEE 1394-I / F 114 converts data stored in the memory into IEEE 1394 format data and outputs the data to the VTR 105. And VTR1
In step 05, the input video / audio data is decoded, and displayed and output to the monitor device 106.

The CPU 112 monitors the user input from the User-I / F 801 simultaneously with the video / audio data, and when detecting a control request from the user, transmits the corresponding control information from the ATM-I / F 111 to the video and audio data. The voice signal is transmitted to the ATM network 103 through the same virtual channel.

FIG. 8 shows a format example of the control information.
Here, it is assumed that 4 bytes (command type, operation code, operand, etc.) of information corresponding to the command frame of the IEEE 1394 AV / C command set are transmitted as the control information.

The ATM-I / F 110 receives control information from the ATM network, the CPU 108 sends the received control information to the VTR 101 via the IEEE 1394-I / F 107, and the VTR 101 reproduces the received control information according to the received control command. And processing such as rewind reproduction.

As described above, in the present embodiment, the control information is transmitted on the same virtual channel as the transmission of the video and audio data, so that the communication resources are not wasted and the VTR remote from the receiving side is not lost. Remote control becomes possible.

(Embodiment 4) In the present embodiment, a communication apparatus capable of transmitting control information on the same virtual channel as the transmission of video and audio data and obtaining a response from a controlled device will be described.

The communication device according to the present embodiment has the same configuration as that of the third embodiment. The difference between the present embodiment and the third embodiment is that the transmitting device transmits response information in response to a control request from the receiving device. In the present embodiment,
The following description focuses on the processing of the transmitting device in response to a control request from the receiving device.

FIG. 9 is a time chart showing an example of a control command transaction according to the fourth embodiment of the present invention.

As shown in FIGS. 9A to 9G, the transmission terminal 102
Transmits real-time data to the receiving terminal 104. The CPU 112 monitors a user input from the User-I / F 801. When the transmitting terminal 102 is transmitting real-time data to the receiving terminal 104 at the timing shown in FIG. 9C, the CPU 112 sets the User-I / F 8
01 when a control request is detected from the user via
As shown in FIG. 9D, the CPU 112 sends the corresponding control information from the ATM-I / F 111 to the ATM network 103 on the same virtual channel as the video and audio signals.

Upon receiving the control information from the ATM-I / F 110, the CPU 108 sends a corresponding control command to the VTR 101 through the IEEE 1394-I / F 107,
The TR 101 executes processing such as reproduction and rewind reproduction according to the received control command. Further, the CPU 108 maps the contents of the response frame returned from the VTR 101 to the padding field of the User-PDU as response information to the control information, and sends it to the ATM network 103, as shown in FIG.

FIG. 10 shows a format example of the response information. As shown in FIG. 10, the response information is User-PDU
And the response information is mapped to 4-byte information corresponding to the response frame of the IEEE 1394 AV / C command set. Upon receiving this response, the CPU 108 acquires the execution result of the controlled device with respect to the transmitted control information.

The CPU 108 notifies the user of response information obtained through the User-I / F 801. However,
If a response cannot be obtained within a predetermined time, the CPU 108 determines that an error has occurred on the network, and sends out the control information again. If the acquired information is INTERIM indicating that a response could not be made within the time, the process waits until a resultant response is obtained.

As described above, in the present embodiment, the control information is transmitted on the same virtual channel as the transmission of the video and audio data, and the response of the non-control device is obtained so that the communication resources are not wasted. It is possible to perform highly reliable remote control on a remote VTR.

In the present invention, a VTR and an HDD are used as means for generating real-time data. However, the present invention is not limited to this, and any device or medium capable of transmitting or recording data in real time may be used.

[0071]

As is clear from the above description, according to the present invention, by storing control information in the padding field of transmission data and transmitting it, transmission of video and audio data is not affected and communication resources are not affected. Editing between remote VTRs without wasting time.

Also, by transmitting control information on the same virtual channel as the transmission of the video and audio data and obtaining the response of the controlled device, communication resources are not wasted, and the remote VTR can be reliably used. It is possible to perform highly reliable remote control.

[Brief description of the drawings]

FIG. 1 is a block diagram of a communication device according to a first embodiment of the present invention;

FIG. 2 User-PD of DVC by AAL type 5
Diagram showing U format example

FIG. 3 is a diagram showing an example of a transmission format of DVC data according to AAL type 5;

FIG. 4 is a CPCS-PDU format diagram including control information according to Embodiment 1 of the present invention.

FIG. 5 is a block diagram of a communication device according to a second embodiment of the present invention.

FIG. 6 is a CPCS-PDU format diagram including control information according to Embodiment 2 of the present invention.

FIG. 7 is a block diagram of a communication device according to a third embodiment of the present invention.

FIG. 8 is a control information format diagram in Embodiment 3 of the present invention.

FIG. 9 is a time chart illustrating an example of a control command transaction according to the fourth embodiment of the present invention.

FIG. 10 is a CPCS-PDU format diagram including response information according to Embodiment 4 of the present invention.

FIG. 11 is a diagram showing an AAL type 5 protocol stack.

[Explanation of symbols]

 101, 105 VTR 102 Sending terminal 103 ATM network 104 Receiving terminal 106 Monitor device 107, 115 IEEE1394-I / F 108, 113 CPU 109, 114 Memory 110, 112 ATM-I / F 111, 801 User-I / F 601 HDD

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/14 H04N 5/782 Z 5K030 5/91 N (72) Inventor Yoshihiro Morioka Kazuma, Kadoma, Osaka 1006 Matsushita Electric Industrial Co., Ltd. F-term (reference) 5K030 HA10 HB02 JA01 JA05 LE06 MB11

Claims (5)

[Claims] 1. A communication device for digitizing real-time data at a fixed transmission rate and transmitting the data in a predetermined transmission unit, comprising: a data generating means for generating the real-time data; A transmitting unit that generates transmission data, performs padding so that a data size of the transmission data is a multiple of a data size of the transmission unit, and transmits the transmission unit; and the real-time data from the data transmitted by the transmission unit. Receiving means for restoring the data, and data recording / reproducing means for recording / reproducing data output from the receiving means, wherein the transmitting means controls the data recording / reproducing means in a padding portion added to the transmission data. Storing and transmitting information, the receiving means detecting control information from the received data, A communication device for controlling the data recording / reproducing means. 2. The data length of each transmission data is predetermined, and the transmission means transmits the transmission data by adding discrimination information capable of uniquely discriminating the transmission data, and the receiving means transmits the discrimination information. The method according to claim 1, wherein when the effective data length of the received transmission data exceeds a data length predetermined for the data, the effective data of a portion exceeding the data length is detected as control information. The communication device as described. 3. The transmission unit performs processing for each unit of reproduction of real-time data, and stores control information for controlling the data recording / reproduction unit in a padding portion of the first transmission data constituting the reproduction unit. Claim 1
The communication device as described. 4. When receiving a control request from the data generating means, the receiving means transmits control information for controlling the data generating means on the same transmission path as that for transmitting real-time data. 2. The communication device according to claim 1, wherein the communication device controls the data generating means based on the transmitted control information. 5. The data generating means performs a process under the control of the transmission control means, outputs an execution result of the processing to the transmission control means, and the transmission means stores the execution result in a padding portion of the transmission data. The communication device according to claim 4, wherein the receiving unit detects an execution result from the received data.